(2005)Status Evolution and Competition Theory and Evidence
STATUS EVOLUTION AND COMPETITION:THEORY AND EVIDENCEMARVIN WASHINGTON Texas Tech University EDWARD J.ZAJAC Northwestern UniversityIn this study,we (1)clarify and distinguish the concept of status,(2)identify and analyze the institutional and organizational factors that can lead to differences in organizational status over time,and (3)empirically assess the privileges implied by such ing extensive longitudinal data on competitive intercollegiate athletics,we found that status was a significant predictor of whether a college was invited to participate in the NCAA postseason basketball tournament,independently of performance considerations.While management scholars have long applied the concepts and tools of economists to study com-petition among organizations,more recent research has benefited from also considering the social foun-dations of competitive or market relations.In par-ticular,understanding of competing and transact-ing organizations has been enriched by the inclusion of concepts such as social embedded-ness,network ties,trust,and institutional environ-ments (Baker,1990;Granovetter,1985;Orru,Big-gart,&Hamilton,1992).Similarly,employing the essential and venerable sociological concept of sta-tus offers promise in enabling researchers to gain greater insight into both the antecedents and the consequences of interorganizational competition.The concept of status can be traced back to We-ber,who viewed it as “an effective claim to social esteem in terms of positive or negative privileges”(1978:305).Weber included status (staendische Lage,which translates approximately to “class po-sition”)as a positional or relational element of so-cial structure that can exist independently of eco-nomic antecedents and whose consequences can at best be described as privileges (rather than as merit-or achievement-based rewards).The implication of this for management researchers interested in com-petitive and/or market relations is that status dif-ferences (and changes in such differences over time)can affect competitive organizational behav-iors and outcomes in ways that are not based on traditional performance considerations.In this study,we contribute to the literature on organizational status and competition in several ways.We first decided that for the concept of status to have maximal usefulness in management and organizational research,it needed to be more clearly delineated from other related but distinct concepts,such as reputation and legitimacy.Spe-cifically,we analyzed why the notion of reputation refers more closely to economists’notion of per-ceived quality (useful for economic analyses of competitive outcomes),but status refers more to the unearned ascription of social rank (useful for un-derstanding the sociological foundation of compet-itive behaviors and outcomes).We suggest that this important difference be-tween economists’notion of reputation and sociol-ogists’notion of status has been underemphasized and/or conflated in prior research because it is much easier when discussing competition to view organizations as purely economic entities rather than also as social entities.We do not deny that organizations (or individuals)in competitive situ-ations are achievement-oriented in the pursuit of specific competitive outcomes (e.g.,gain market share,win the race).Rather,we suggest these com-petitive contests are also socially situated,and that an important implication of the social embedded-ness of competitive contests is that the quality (real or perceived)of competitors’achievements is not the only factor determining the competitive out-comes.We propose that social status,as the un-earned ascription of social rank,can also play a meaningful role in competition—irrespective of performance.Both authors contributed equally.We would like to thank Cameron Anderson,Tina Dacin,Rodney Lacey,Michael Lounsbury,Mark Mizruchi,Willie Ocasio,Huggy Rao,Marshall Schminke,Art Stinchcombe,and three anonymous AMJ reviewers for their helpful comments.Academy of Management Journal 2005,Vol.48,No.2,282–296.282A related challenge in the study of organizational status and competition is an empirical one:It is typically difficult to identify differences in compet-itive organizational outcomes that can be confi-dently attributed to socially based differences in status,rather than quality-or merit-based differ-ences that correspond to reputation.For example, research attempting to explain the variance in the Fortune reputation index has found that it funda-mentally mirrors differences in financial perfor-mance(Fryxell&Wang,1994).Studies of organiza-tional status typically do not control for real or perceived differences in quality or merit,which in turn makes it impossible to determine whether one is capturing differences in social status or simply reputational differences based on an organization’s ability to generate higher versus lower product quality.In fact,some prior research has actually defined status in terms of differences in perceived product quality;an example is Podolny’s definition of organizational status as“the perceived quality of that producer’s products in relation to the per-ceived quality of that producer’s competitor’s prod-ucts”(1993:830).What is needed,then,in efforts to assess whether organizational status matters,is empirical research that can control for merit-or quality-based explanations for competitive market stly,there exists a need for more research attempts to explicitly identify the institu-tional and organizational factors that can maintain, grow,or erode the status of an organization over time.In this article,we seek to address each of these issues.First,we theoretically and empirically an-alyze the concept of status and its potential rele-vance for understanding interorganizational com-petition.We propose three specific mechanisms—historical legacy,accumulation of positive association,and accumulation of negative associ-ation—that can affect the evolution of status for organizational actors.We then examine how these mechanisms can result in privileges(i.e., non-merit-based rewards)for higher-status actors in competitive contests.We develop and report tests of our hypotheses using a desirable empiri-cal context that allowed us to examine the effects of status after controlling thoroughly for merit-based performance.Specifically,we used exten-sive longitudinal data on intercollegiate athletics to test our status-based model by predicting which colleges a tournament selection committee would invite to participate in major yearly post-season basketball tournaments,independently of their performance and their competitors’performance.THEORYDefining StatusAs suggested above,for status to contribute max-imally to researchers’understanding of competi-tion,it must first be differentiated from other re-lated but distinct concepts used in the study of competitive processes.Prior research has shown sur-prisingly little interest in such an endeavor;in fact, prior research has confused status with reputation. To define organizational status as a summary indica-tor of perceived(that is,intersubjectively agreed-upon)or historical,performance-based differences in quality between(or among)two(or more)organiza-tions,given imperect information,is simply to use a definition that is more appropriately equated with “reputation.”Fombrun(1996:190)saw reputation as an indicator of“overall quality,”for example.We suggest that there are subtle but important differences between the two concepts:status is fundamentally a sociological concept that captures differences in so-cial rank that generate privilege or discrimination (not performance-based awards),while reputation is fundamentally an economic concept that captures differences in perceived or actual quality or merit that generate earned,performance-based rewards.1It is not surprising that economists have em-braced the concept of reputation and have linked it to the extensive literature on market signaling (Spence,1974;Weigelt&Camerer,1988).Organi-zations that are of high quality can develop repu-tations for quality over time,which can then serve a useful signaling function when other forms of direct and credible information on quality are lack-ing.Note that no reference to privilege is needed here,nor would it be appropriate,since reputation reflects either the underlying reality or the inter-subjectively agreed-upon reality of quality differ-ences among organizations.Again,reputation is an 1Social psychological research on intraorganizational institutions has sometimes invoked the concept of status; studies by of Sutton and Hargadon(1996)and Elsbach and Kramer(1996)are examples.However,these studies, while valuable,have typically used the term“status”without either defining it or distinguishing it from repu-tation or quality.For example,Sutton and Hargadon used “status”to refer to reputational gains or losses in techni-cal skills(they even labeled their context a“peer-ori-ented meritocracy”).Thus,their notion of status actually captures a rank-ordering of reputation that is based on performance-based evidence of actual and/or perceived quality.Similarly,Elsbach and Kramer,in their study of organizational identity,used“status”and“reputation”interchangeably when referring to the BusinessWeek rankings of top business schools.2005283Washington and Zajaceconomics-based concept:overall quality earns merit-based rewards and benefits,as does overall quality over time,embodied in reputation.In the case of organizations,it refers to an organization’s abilities(applied to the achievement of its funda-mental objectives).From this perspective,while some intersubjec-tive agreement is required when referring to an organization’s reputation,no assumption of full in-tersubjective agreement is required,since differ-ences in available information could lead to differ-ences in opinions(which may even be actively shaped by self-interest,as Fombrun[1996]sug-gested).Such differences can essentially be ex-plained away by“information asymmetries,”in keeping with an economic orientation.Status dif-ferences,on the other hand,reflect fundamental, social characteristics that can be unrelated to—and exist independently of—the product/service qual-ity differences(real or perceived)of primary inter-est to economists interested in competition.As noted earlier,we believe that this important difference has not received much attention in re-search on organizational status because it is much easier to conceive of an organization as an eco-nomic entity than as a social entity.To make our distinction between status and reputation more vivid,we would therefore like to use the example of individuals or products,rather than organiza-tions.For example,the Jaguar automobile has long suffered from a reputation for poor quality,while at the same time benefiting from the privilege of high social status.In the last decade,the Jaguar’s repu-tation has improved,owing to increases in per-ceived and actual quality,while its status has re-mained unchanged(or perhaps even decreased under new ownership by Ford Motor Company,a U.S.firm).Consider also the case of the Ford Motor Company(FMC)itself,which has often had descen-dants of Henry Ford at or near its top.Is the con-tinuing effort to have a Ford family member visible in the upper echelon of FMC contributing to the company’s reputation or to its status?Or consider another example of competition at the individual level:were votes for George W.Bush in the2000 presidential elections based more on his reputation (that is,an assessment of his accumulated experi-ences and actions in public office)or his status (that is,a social rank held by virtue of sharing a name and genetic relationship with a former pres-ident)?While one can and should debate these questions,and the question of how the two con-structs relate to each other,the key point is that reputation(based on perceived or actual quality) and status(based on agreed-upon social rank)are clearly two analytically distinct constructs.Stated more precisely,the concept of reputation, when applied to organizations,refers to a summary categorization of real or perceived historical differ-ences in product or service quality among organi-zations,given imperfect information.In contrast, our definition of status,which we see as consistent with Weber’s initial conceptualization,refers to a socially constructed,intersubjectively agreed-upon and accepted ordering or ranking of individuals, groups,organizations,or activities in a social sys-tem.Status generates social esteem and special, unearned(i.e.,non-merit-based)benefits known as privileges,which are granted to and enjoyed by high-status actors in a social system.Privilege can be understood very clearly by considering its op-posite,which is discrimination—an unearned det-riment for an individual,group,or organization (this equates with Weber’s notion of“negative priv-ilege”).Just as discrimination cannot be explained by perceived quality,privilege cannot be explained by perceived quality.Both come from social beliefs that have little to do with assessments of quality and have much more to do with social or cultural categorization schemata or stereotypes(e.g.,class, family,ethnicity,etc).Just as there are economic barriers to mobility or entry for organizations(with implications for the monopolization of profits),there are also social bar-riers to mobility or entry(with implications for the monopolization of privilege),which can be repre-sented as status differences.Note that we do not deny that economic considerations may have influ-enced the genesis of status differences(for instance, merit could have mattered at some point in his-tory),but we would add that the reverse may also be true(status differences may have influenced the genesis of economic differences).Our position is simply that the evolution of status over time in competitive situations can ultimately be ex-plained—at least in part—without reference to eco-nomic or merit-based logics.2Although the discussion above highlights how status can be confused with a fundamentally eco-nomic concept such as reputation,we also suggest that status can be confused with other sociological concepts,such as legitimacy.Legitimacy refers to the level of social acceptability bestowed upon a set of activities or actors(Dowling&Pfeffer,1975;2An alternative terminological choice would be to differentiate the concepts of reputation and status by contrasting“earned reputation”with“unearned reputa-tion,”or“merit-based status”with“class-based status.”Such constructions,however,seem awkward and less consistent with Weber’s initial conceptualization of status.284AprilAcademy of Management JournalSuchman,1995).Legitimacy may correlate posi-tively with status,but it may also be largely uncor-related or even negatively correlated with status. For example,although gambling activities have grown more socially acceptable in the United States,they have not seen an equal growth in sta-tus.Polo and bowling are both socially legitimate, but polo is the higher-status sport,in that people associated with it will be presumed to also have other,more socially valued attributes.Similarly,a high number of actors pursuing a particular activity is often viewed as reflecting the activity’s greater social legitimacy(Haveman,1993;Washington& Ventresca,2004),but popularity or pervasiveness may be uncorrelated,or even negatively corre-lated,with the social status of that activity.If one compared bowling to curling in the United States,the latter would emerge as the higher-status activity,despite the greater popularity of the former.In other words,an activity or an or-ganization can be highly socially legitimate(i.e., have achieved wide acceptance),but also have low social status.While our concern is with how the concept of status differs from the concepts of reputation and legitimacy,it is interesting to remember that Rao’s (1994)careful distinction between reputation and legitimacy.Rao noted that reputation is associated with an economic logic(we agree)and that legiti-macy is more social(we agree again).However,Rao did not devote similar attention to the differences between legitimacy and status,and his empirical study of competitive contests did not separate mer-it-based from class-based outcomes.Before proceeding,we would like to emphasize that neither our attempt to be true to Weber’s con-ceptualization of status nor our view of status as an organization-level property is idiosyncratic.For ex-ample,Simmel(1950),in his discussion of status, shared Weber’s emphasis on the privileges of social position,drawing a distinction between the actions of actors and the actors’places in a social hierar-chy,and arguing that hierarchical position deter-mines rewards.In addition,Stinchcombe followed Weber’s emphasis on the privileges of status and called for a general theory of status that was spe-cific to organizations,writing that“what is needed then,is a general measure of the predominant method of organizing social life into units which are evaluated relative to each other,and which reap the benefits of high rank or the disadvantages of low rank”(Stinchcombe,1965:71).The Evolution of StatusAnswering Stinchcombe’s call for the identifica-tion of organization-specific mechanisms of status, we propose three mechanisms governing three dif-ferent trajectories in the evolution of organizational status and privilege over time in a set of competing organizations.The first is historical legacy.Once status differences form,they tend to be perpetu-ated.Status evolves in a privilege-perpetuating di-rection by means of historical legacy.The second mechanism is the accumulation of positive anizations can positively influence their status over time.Status thus evolves in a privilege-enhancing direction through the accumulation of positive association.The third mechanism is the accumulation of negative association.Status can diminish over time,evolving in a privilege-reduc-ing direction through the accumulation of negative association.The first of the three mechanisms(historical leg-acy)is more cultural,and the latter two(accumu-lation of positive or negative associations)are more structural(Biggart&Delbridge,2004).Since all three mechanisms can coexist at any time,we ex-pect that their combined effect will predict the evolution of organizational status differences.Note that these mechanisms are neither mutually exclu-sive nor exhaustive;rather,we see them as a subset of potentially specific important explanations of how and why status can endure,but also may change over time as the strengths of various mech-anisms change.Status and Historical LegacyThe first evolutionary mechanism,historical leg-acy,operates through the perpetuating effect of dif-fering prior conditions.Merton(1968)termed this “the Matthew effect,”referring to a verse in the first book of the New Testament:“For unto everyone that hath shall be given,and he shall have abun-dance;but from he that hath not shall be taken away even what he hath.”In other words,once a system of social stratification has been established, it is likely to be perpetuated independently of merit.Prior research on the advantages of reputa-tion for perceived quality(Podolny,1993)has noted how prior conditions tend to be perpetuated, but it is important to note that Merton(1968:59) saw this process as a“double injustice”whose outcomes imply“enhancing rank”for high-status actors and“suppressing recognition”for low-status actors.Merton also wrote that the Matthew effect among scientists he studied“violates the norm of universalism embodied in the institution of science2005285Washington and Zajacand curbs the advancement of knowledge”(1968: 59).Perpetuation of a class system that exists apart from a merit-based system implies that organiza-tions of high status will continue to enjoy positive privileges and those of low status will continue to experience negative privileges(Weber’s term),or discrimination.If benefits had a meritocratic basis (either real or perceived quality),one would not expect the Matthew effect to persist over time. Merton’s(1968)research and his discussion of the Matthew effect are quite consistent with We-ber’s and Stinchcombe’s view of status,in that it proposes how an emphasis on tradition or status conventions(again,Weber’s term)can perpetuate differences in status and privilege that are not earned(i.e.,merit-based).The perpetuation of sta-tus differences is thus a form of social monopoliza-tion.This discussion of historical legacy suggests the first proposition regarding status in competitive environments:Proposition1.An organization with a histori-cal legacy of high status is likely to enjoy the privileges of high status in subsequent periods, independently of its competitive performance in those periods.Status and the Accumulation of Positive AssociationsThe first mechanism proposed as important for understanding the evolution of status tends to per-petuate the status quo,but other mechanisms pro-vide the potential for changing the evolutionary direction of an organization’s status.Given that status is fundamentally a relational concept,one mechanism for understanding changes in status differences among competing organizations over time is the accumulation of positive associations. More specifically,we suggest that status contagion processes can provide privileges for organizations that interact with other organizations that have high status.3Note that although our argument for status en-hancement focuses on contagion by association,it differs in significant ways from the typical network contagion argument used to assess the reputational benefits of collaborative affiliations,such as inter-firm alliances.First,our argument is original in that we propose that status contagion processes apply not just in cooperative relationships,but also in competitive relationships.We posit that the sheer act of electing to compete with high-status organi-zations becomes a positive association for a focal organization.Consistently with our emphasis on a privilege-based conceptualization of status,we ar-gue that the accumulation of such positive associ-ations enhances that organization’s status,inde-pendently of how well the organization fares in competition with those high-status organizations. Given these differences between network conta-gion and contagion by association,we believe it is both possible and desirable to conceptually and empirically separate two related notions:reputa-tion benefits and status benefits.Reputation bene-fits,the more economic notion,signal quality asso-ciated with earned rewards.Such benefits derive from cooperative associations.Status benefits,the more social notion,are an effective claim to social esteem associated with privileges,and they derive from either cooperative or competitive associa-tions.Status benefits,from our perspective,can accrue from an organization’s accumulation of ex-change relationships with high-status organiza-tions,even if these relationships are directly com-petitive,and even if the focal organization fares poorly in the competition.In other words,an orga-nization choosing high-status competitors can suf-fer a reputational loss through poor performance but a status gain through the social identification of being in the same group with higher-status compet-itors.Proposition2.An organization having associ-ations with high-status organizations is likely to enjoy the privileges of high status in subse-quent periods,independently of its competi-tive performance in those periods.Status and the Accumulation of Negative AssociationsThe contagion arguments made above clearly suggest that associating with high-status others is a3An accumulation of positive associations is likely to be particularly significant in well-established organiza-tional fields,where differing status positions are more clearly defined and visible(cf.Elsbach&Kramer,1996). Although our focus is on organizational status and com-petition,the notion of status and positive associations has a parallel in individual-level research.For instance,the study by Cialdini,Borden,Thorne,Walker,Freeman, and Sloan(1976)on“basking in reflected glory”showed that students were more likely to wear clothing with a school’s name on it when the school’s football team won its games than when it lost.Just as individuals seek association with successful organizations to increase their individual status,so do organizations,and we sug-gest further that organizations are willing to compete with high-status organizations(and even lose)to realize the benefits of associating with high-status actors.286AprilAcademy of Management Journalmechanism for status attainment.To the extent that the arguments are symmetric,they suggest a related mechanism;namely,that avoiding the accumula-tion of associations with low-status organizations will enhance a focal organization’s status.Note that the mechanism is again performance-independent: A focal organization’s status loss attributable to competing with low-status organizations will be significant and will be independent of that organi-zation’s competitive success vis-a`-vis the lower-status organizations.In short,we argue that status can be enhanced through the accumulation of pos-itive associations and depleted through the accu-mulation of negative associations.Thus, Proposition3.An organization having associ-ations with low-status organizations is less likely to enjoy the privileges of high status in subsequent periods,independently of its com-petitive performance in those periods.Note also that Propositions2and3are not re-dundant with each other,since the effect of associ-ation may not be symmetric;in addition,some organizations may simply have no associations with high-or low-status organizations.We now move to discussing our empirical context for exam-ining the three mechanisms discussed above and their predicted effects.EMPIRICAL SETTING:THE NCAATOURNAMENTEach year more than300college basketball teams in the United States compete for the opportunity to participate the NCAA(National Collegiate Athletic Association)postseason basketball tournament.Of the64teams that get invited each year to partici-pate in the NCAA tournament,about30receive automatic bids that are based on their win/lose performance records in their conferences for the year.An automatic,performance-based bid also goes to each champion(the team with the best win/lose record in its conference,or the winner of the conference tournament)of certain regional con-ferences.These conferences represent sets of col-leges such as the Big Ten,Ivy League,and the Pacific Ten.However,many other teams receive invitations to participate in the tournament that are based on the outcome of a private meeting of the NCAA Selection Committee.About35of the re-maining269to272members of basketball confer-ences are invited to the NCAA.The tournament selection committee is asked to pick the best teams in the current year.While the selection committee uses many“objective”criteria, such as a team’s win/lose record and their oppo-nents’win/lose record,it considers more clearly subjective criteria.In fact,contrary to popular opin-ion,the committee does not use a computer or an algorithm to determine which teams to invite to the tournament.A formal document,“NCAA Division I Men’s Basketball Championship Principles and Procedures for Establishing the64-Team Bracket,”describes how the committee selects,seeds,and creates the tournament bracket.There are two prin-ciples:“Select the best available teams to fill the at-large berths,regardless of conference affiliation, and“There is no limit on the number of teams the basketball committee may select from one confer-ence.”While it takes only two members of the nine-member committee to nominate a school for a potential at-large bid,it takes seven members to eliminate a“potential school”from receiving a bid. Lastly,the principles and procedures document states that“at any time during the process,the chair may designate a quiet period,generally15minutes in length,to permit members to individually reflect on the way they will vote.”This setting provided a desirable empirical con-text for examining status and privileges for at least two reasons.First,the subjective and secretive na-ture of the selection committee deliberations gen-erates controversy almost every year,as interested constituents attempt to divine why one school was invited when other schools with apparently supe-rior performance records were not.Clearly,the dis-cretion given to the committee provides a context in which the privileges of high status can operate, either consciously or unconsciously for committee members.Second,an invitation to participate in the NCAA postseason tournament provides substantial finan-cial rewards for the invited schools.During its early history,the NCAA tournament did not financially benefit its participants,but in the last ten years this has dramatically changed.Revenue for the1970 NCAA tournament was only$1.4million dollars (Raiborn,1986);for the1989NCAA tournament,it was$70million dollars;and for1995,it was more than$184million dollars(NCAA,1995).For the 1996NCAA tournament,television revenue alone was more than$178million dollars(NCAA,1997). This revenue is distributed to the teams that par-ticipate in the tournament.Each round of the NCAA postseason tournament that a school played in1990,the last year for which data are available, was worth about$294,000to the school(NCAA, 1997).Selection for the NCAA tournament also produces indirect financial gain as it increases at-tendance at regular season games,television cover-age,and alumni contributions.Padilla and Baumer (1994)found that while a regular season victory in2005287Washington and Zajac。
竞争进化与协同进化_王德利
生态学杂志 Chinese Journal of Ecology 2005, 24( 10) : 1182~ 1186
/ 协同0并 非是生物学或生 态学的一个专 门术 语。协同的词义是协调、适应、和谐的意思。在生物 学中将协同理解为生物之间相互选择、相互协调的 现象或过程。自然生物群落中, 生物之间不仅有体 现为负相互作用的竞争, 同样有反映出互利互惠的 协同。近年来, 在描述生物之间相互关系、特别是生 物进化时, 越来越多的研究者更愿意接受、并且频繁 地使用 这一术语, 从而 产生了协 同适应 ( coadapt a2 t ion) 、协同进化( coevolut ion) 等概念[ 38] 。协 同进化 一般是指两个相互作用的物种在进化过程中发展的 相互适应的共同进化。从广义的概念来理解, 协同 进化又可以指生物与生物、生物与环境之间在长期 相互适应过程中的共同进化或演化。
竞争导致物种改变其形态、生理及生活史特征, 以提高自身的综合竞争能力。这些特化的特征长期 固定下来, 成为该物种的适应性进化特征。动物群 落中捕食者与被捕食者之间进行的/ 军备竞赛0式的 竞争结果是, 捕食者的攻击器官更发达, 而被捕食者 的防卫器官越来越有效[ 33] 。竞争是影响植物形态 可塑性的重要 因子之一, 可塑 性或形状 差异 ( t rait differences) 可能体现在扎根类型和深度、植株大小、 生长率、高度、截留光的能力等。对不同的扎根深度 对植物适合度( fitness) 的重要性研究结果 显示, 具 有不同扎根类型的两种个体对不同土壤层的利用可 以促进其共存, 维持种群的遗传多样性。植物改变 其匍匐茎的分枝频率、节间长度和生长方向以适应 不同的光或营养水平[14, 15, 16, 28, 29] 。竞争可以影响 植物某一性状的可塑性, 增加其自身的平均适合度, 使得这个物种在群落中对环境条件有更好的适应能 力[ 10] 。Grime[20] 提出的最大生长率理论( maximum growth rate t heory) 是建立在植物生活史特征基础 之上, 侧重于建成植物性状和竞争影响, 认为具有最 大营养组织生长率( 即最大资源捕获潜力) 的物种将 是竞争的优胜者, 使得种群在竞争中得以延续, 体现 了最适生活史对成功地生存和繁殖造成的相对进化 优势。
全球化与不平等
全球化與不平等Globalization and Inequality東海大學社會學系4631九十六學年度第二學期(Spring 2008)課程教學綱要授課時間: Wednesday 14:10-17:10授課教室: SS 306授課教師(合授): 陳正慧(Cheng-hui Lucy Chen) & 蔡瑞明(Ruey-ming Tsay)授課教師: 陳正慧(Cheng-hui Lucy Chen)辦公室: SS 536 電話: 04-2359-0121, ext 36310E-Mail: slgcchen@.tw約談時間: Tuesday 13:00~14:00, Thursday 16:20~17:20, or by appointment授課教師: 蔡瑞明(Ruey-ming Tsay)辦公室: SS 540 電話: 04-2359-0121, ext 36314E-Mail: rmtsay@.tw約談時間: Tuesday 10:00~12:00, or by appointment課程介紹：對大部分人們而言，「全球化」已經不是一陌生的名詞，在我們日常生活之中，吃的、穿的、用的、戴的，已無一不被「全球化」了。
全球化的影響更是深入每個社會與地區，在環境、自然資源、教育、財富分配、經濟發展等各方面產生極不平等的分配。
這門課即試圖以宏觀的角度來討論全球化下有關不平等的一些議題。
依兩位授課老師的研究興趣，這門課的兩大核心焦點為農業全球化及全球化與社會階層，簡介如下：這學期第一部分的焦點是探討全球化對不平等的影響。
全球化的影響與日俱增，深入每個社會與地區，產生不平等的資源分配。
過去以一個社會為對象的社會學分析，已經漸感不足，有需要以宏觀的角度來審視全球化下的社會階層化現象。
第一部份的內容主要是以討論全球化的研究如何來解釋這個現象與不平等的關連。
這學期第二部分上課的內容主要是探討農業全球化的相關議題。
竞争的名言英语
竞争的名言英语导读：本文是关于竞争的名言英语，如果觉得很不错，欢迎点评和分享！1、有竞争才有活力。
There is competition is dynamic.2、没有斗争就没有进步。
No struggle, no progress.3、逆境增才干不增财富。
Adversity makes a man wise, not increase wealth.4、竞争者，进化之母也。
Competitors and also the mother of evolution.5、物竞天择，适者生存。
Natural selection, survival of the fittest.6、谁笑在最后，谁笑得最好。
He who laughs last laughs best.7、不景气淘汰了不争气之人。
Bad eliminated unwillingly.8、一定要比你竞争对手更努力。
Must be harder than your competitors.9、一定要不断的研究竞争对手！Must constantly study the competition!10、正当的竞争能带来共同的进步。
Proper competition can bring the common progress.11、生活就是行动，行动就是竞争。
Life is action, action is the competition.12、弱智坐待时机，强者创造时机。
Retarded sit and opportunity, the strong creates opportunity.13、没有竞争的地方表示没有市场。
No said there was no market competition.14、天才只总味着终身不懈的努力。
Genius only total our hard-working all one's life.15、敢于梦想，一切都将成为可能。
我国大学生体育锻炼投入:测量、前因与后效
我国大学生体育锻炼投入：测量、前因与后效董宝林【摘要】以积极心理学为框架,运用文献资料法、半结构式访谈、质性研究的开放性问卷、心理测量法和数理统计法等方法,探讨我国大学生体育锻炼投入的测量、前因与后效等问题.结果显示:体育锻炼投入是大学生对体育锻炼持有一种自主、积极、持久、沉浸的心理情境和快乐体验,体现了个体对锻炼行为的合理认知和角色认同,其内涵应包含个体既有的锻炼认知、角色认同、目标导向,锻炼践行的精力、活力、兴趣水平、自主性,以及勇于挑战并沉浸其中的参与状态;编制的大学生体育锻炼投入自评量表包括了活力坚持度、专注满足感、价值观认知和参与自主性共4个维度20个题项,量表具有较好的信度和效度,符合心理测量学的要求,可以作为研究大学生体育锻炼投入状态的自评测量工具;自我效能感和社会支持是大学生体育锻炼投入的两个前因变量,其中,社会支持在自我效能感影响大学生体育锻炼投入时具备了调节效应;锻炼效果和积极情感是大学生体育锻炼投入的两个后效变量,其中,锻炼效果在体育锻炼投入一下大学生积极情感时具备了部分中介效应.【期刊名称】《天津体育学院学报》【年(卷),期】2017(032)002【总页数】9页(P176-184)【关键词】大学生;体育锻炼投入;积极心理学;体育锻炼投入量表【作者】董宝林【作者单位】上海杉达学院体育教研室,上海201209【正文语种】中文【中图分类】G804.85;G806大学生对体育锻炼的积极态度和沉浸体验对其身心健康发展、幸福指数提升皆具举足轻重的作用。
20世纪末，积极心理学领域形成了一个全新研究主题——投入（Involvement），用以考察个体从事社会行为时在认知、情感和体验上的卷入状态。
学者对投入的思辨源于日常生活与生产实践，其概念界定始于工作投入的探讨，而在体育领域有关投入的探讨尚属概念引入阶段，至今对体育锻炼投入的定义莫衷一是，对其内涵、测量、前因与后效等问题的探讨相对薄弱，导致锻炼投入研究深化发展受阻。
熊彼特竞争、专有资产与人力资本的互补性与创新激励
业，需要的财务投入越多，也就越可能受到融资约束［25］，更高原创性需要更多专有资产，专有资产投入是
创新原创性的一个良好测度①。在专有资产一定的前提下，专有资产独特性 α 越大（例如 ROMER［26］所考
虑的 AK 模型中对专有资产技术含量的识别），创新原创性也就越高。本文定义创新原创性 δ 如下。
性知识在多样性团队中互补的结果，投入与创新能力流无须满足通常假设的边际报酬递减规律，因而认
为 β ∈ (0，1)。定义专有资产指数 α 与人力资本指数 β 的和(α + β)为两类资本间的互补性，与通常的 C-D
生产函数相同，表示投入变化对产出影响的规应对行为，并且企业通过对环境的适应来获取发展机会［24］。企业投入
特竞争对创新原创性、创新复杂性与创新团队剩余索取权分配的影响。研究表明：熊彼特竞争与创新复杂性和
剩余索取权分配比例负相关；熊彼特竞争对创新原创性与创新团队努力程度的影响取决于两类资本的互补性，
其中创新团队能力独特性发挥了调节作用；创新原创性和团队努力程度两者在委托代理关系存在与否时的相
对水平取决于两类资本的互补性，而创新复杂性在委托代理关系存在与否时的相对水平则依赖于熊彼特竞争。
研究结论凸显了熊彼特竞争和两类资本互补性对创新项目选择和创新激励的影响，提高了企业响应外部竞争
和管理创新团队的可操作性。
关键词：原创性；复杂性；互补性；创新激励
中图分类号：F273. 1；G301
文献标识码：A
创新原创性和创新复杂性对创新企业至关重要。理论与实践证实了原创性与创新收益之间的关系， 1985 年 DAVID［1］指出转换成本是高原创性产品赢利能力低于中等原创性产品的关键。随后，KLEIN⁃ SCHMIDT 和 COOPER［2］发现创新原创性与创新收益之间的 U 型关系，而 CALNTONE 等［3］进一步证实他 们的观点，认为创新原创性的提高会降低客户熟悉度，部分抵消对创新收益的正面影响。STOCK 和 TATIKONDA［4］则说明高原创性所具有的不确定性足以抹杀其为客户带来的新价值。近年来，多数学者 坚持原创性与创新收益的正向关系，如：LYNCH 等［5］认为企业可以获得必要的技能、知识和能力，利用市 场机会在竞争中领先，通过高原创性获得更多收益；TEPIC 等［6］证实原创性是产品潜能的决定因素，而产品潜 能又决定了创新收益。与此同时，创新复杂性也会对创新收益产生重大影响，ALMIRALL 和 CASADESUSMASANELL［7］认为复杂性更高的创新会得到更高创新收益，但与之不同，张慧颖和王辉［8］表明创新复杂性 与创新绩效负相关。此外，创新复杂性对技术学习［9］、知识域之间的耦合点［10］等相关因素与创新绩效之 间的关系也会产生影响。因而，创新原创性与创新复杂性面临着高收益与高风险的权衡，是企业创新的 重要挑战。
新教材2024高考英语二轮专题复习专题四语法填空第二讲名形副教师用书
第二讲名、形、副三管齐下巧化词形转换词形转换是高考语法填空的一个重点。
在解答语法填空中词形转换的相关题目时，一要根据空处在句中所作的成分确定词性：名词在句中常作主语、宾语、表语或定语等，动词作谓语与非谓语，形容词作表语、定语、补足语，副词作状语修饰动词、形容词、副词或整个句子；二要根据标志词及语境确定比较级；三要根据名词前的数词、量词、冠词等修饰语以及主谓一致原则来确定名词的单复数。
如何判断是否考查词形转换[答案] __originally__ 换形式。
技法1 提示词为动词的词形转换提示词为动词，如果既不是谓语动词，也不是非谓语动词，则考虑动词词形转换。
动词1．名词变复数的规则(1)大部分单数可数名词变为复数一般直接加s；如果是以ch, sh, s, x等结尾的单词，则一般加es：trees, bikes, books, buses, watches, boxes, bushes；(2)辅音字母＋y结尾的单词，变y为i再加es；但元音字母＋y结尾的单词，则直接加s：babies, families; boys, plays；(3)以o结尾的单词除了两人(negro, hero)、两菜(tomato, potato)加es外，其余一般加s：radios, photos；(4)以f或fe结尾的单词，通常变f, fe为v再加es：wives, knives, wolves。
2．名词变复数的不规则变化(1)man→men, woman→women, tooth→teeth, foot→feet, child→children, mouse→mice；(2)单复数同形：Chinese, Japanese, people, sheep, deer, fish。
随堂落实·创新应用体验[2023·辽宁省沈阳市二模]In China, there are 44 nationallevel intangible cultural heritage items related 1.________ tea, including the art of making Biluochun, 2.________ type of green tea. With a history of about 1，000 years,Biluochun, 3.________ translates as “green spiral spring (碧螺春)”， is made from tender tea shoots. It is known for its spirallike 4.________ (appear).To make this tea, the tea trees and fruit trees 5.________ (plant) together. The practice, passed down from ancestors, guarantees the 6.________ (tea) fruity and sweet taste.Traditionally，Biluochun is produced 7.________ (entire) by hand. About 1 kilogram of leaves 8.________ (pick) from a big tea tree produce only 0.1 kilogram of tea after processing.Biluochun must be processed soon after. Tender tea shoots are placed in a heated iron pan and stirred (搅拌) quickly. A person needs to be particularly attentive 9.________ (adjust) the level of heat to judge the condition of the tea by smell. Next 10.________ (come) the shaping process. By stirring, shaking and rubbing the tea leaves in the pan at 100℃， they begin to dry and develop a spiral form. The entire process usually takes about 40 minutes. Every minute matters, or the tea will not taste good.1．____________ 2.__________ 3.__________4．____________ 5.__________ 6.__________7．____________ 8.__________ 9.__________10．__________第二讲名、形、副三管齐下巧化词形转换命题专家授策略技法11．答案与解析：participation 句意：在烤串端上餐桌之前，已经七八分熟了，食客可以在自己的炉子上烤至完全熟，这给人一种参与的感觉。
(高级管理学讨论资料)Evolution and revolution as organizations grow
Mainiero, L. and Tromley, C. Developing Managerial Skills in Organizational Behavior: Exercises, Cases, and Readings (Englewood Cliffs, NJ: Prentice Hall) (2d ed. 1994), pp. 322-329.Evolution and Revolution as Organizations GrowLarry E. GreinerA small research company chooses too complicated and formalized an organization structure for its young age and limited size. It flounders in rigidity and bureaucracy for several years and is finally acquired by a larger company.Key executives of a retail store chain hold on to an organization structure long after it has served its purpose, because their power is derived from this structure. The company eventually goes into bankruptcy.A large bank disciplines a "rebellious" manager who is blamed for current control problems, when the underlying cause is centralized procedures that are holding back expansion into new markets. Many younger managers subsequently leave the bank, competition moves in, and profits are still declining.The problems of these companies, like those of many others, are rooted more in past decisions than in present events or outside market dynamics. Historical forces do indeed shape the future growth of organizations. Yet management, in its haste to grow, often overlooks such critical developmental questions as: Where has our organization been? Where is it now? And what do the answers to these questions mean for where we are going? Instead, its gaze is fixed outward toward the environment and the future--as if more precise market projections will provide a new organizational identity.Companies fail to see that many clues to their future success lie within their own organizations and their evolving states of development. Moreover, the inability of management to understand its organization development problems can result in a company becoming "frozen" in its present stage of evolution or, ultimately, in failure, regardless of market opportunities.My position in this article is that the future of an organization may be less determined by outside forces than it is by the organization's history. In stressing the force of history on an organization, I have drawn from the legacies of European psychologists (their thesis being that individual behavior is determined primarily by previous events and experiences, not by what lies ahead). Extending this analogy of individual development to the problems of organization development, I shall discuss a series of developmental phases through which growing companies tend to pass. But, first, let me provide two definitions:1. The term evolution is used to describeprolonged periods of growth where nomajor upheaval occurs in organizationpractices.2. The term revolution is used to describethose periods of substantial turmoil inorganization life.As a company progresses through developmental phases, each evolutionary period creates its own revolution. For instance, centralized practices eventually lead to demands for decentralization. Moreover, the nature of management's solution to each revolutionary period determines whether a company will move forward into its next stage of evolutionary growth. As I shall show later, there are at least five phases of organizationdevelopment, each characterized by both an evolution and a revolution.KEY FORCES IN DEVELOPMENTDuring the past few years a small amount of research knowledge about the phases of organization development has been building. Some of this research is very quantitative, such as time-series analyses that reveal patterns of economic performance over time.1 The majority of studies, however, are case-oriented and use company records and interviews to reconstruct a rich picture of corporate development.2 Yet both types of research tend to be heavily empirical without attempting more generalized statements about the overall process of development.A notable exception is the historical work of Alfred D. Chandler, Jr., in his book Strategy and Structure.3 This study depicts four very broad and general phases in the lives of four large U.S. companies. It proposes that outside market opportunities determine a company's strategy, which in turn determines the company's organization structure. This thesis has a valid ring for the four companies examined by Chandler, largely because they developed in a time of explosive markets and technological advances. But more recent evidence suggests that organization structure may be less malleable than Chandler assumed; in fact, structure can play a critical role in 1 See, for example, William H. Starbuck, "Organizational Metamorphosis," in Promising Research Directions, edited by R. W. Millman and M. P. Hottenstein (Tempe, Arizona, Academy of Management, 1968), p. 113.2 See, for example, the Grangesberg case series, prepared by C. Roland Christensen and Bruce R. Scott, Case Clearing House, Harvard Business School.3Strategy and Structure: Chapters in the History of the American Industrial Enterprise (Cambridge, Massachusetts, The M.I.T. Press, 1962).influencing corporate strategy. It is this reverse emphasis on how organization structure affects future growth which is highlighted in the model presented in this article.From an analysis of recent studies,4five key dimensions emerge as essential for building a model of organization development:1. Age of the organization.2. Size of the organization.3. Stages of evolution.4. Stages of revolution.5. Growth rate of the industry.I shall describe each of these elements separately, but first note their combined effect as illustrated in Exhibit I.Note especially how each dimension influences the other over time; when all five elements begin to interact, a more complete and dynamic picture of organizational growth emerges.After describing these dimensions and their interconnections, I shall discuss each evolutionary/revolutionary phase of development and show (a) how each stage of evolution breeds its own revolution, and (b) how management solutions to each revolution determine the next state of evolution.Age of the OrganizationThe most obvious and essential dimension for any model of development is 4 I have drawn on many sources for evidence: (a) numerous cases collected at the Harvard Business School; (b) Organization Growth and Development, edited by William H. Starbuck (Middlesex, England, Penguin Books, Ltd., 1971), where several studies are cited; and (c) articles published in journals, such as Lawrence E. Fouraker and John M. Stopford, "Organization Structure and the Multinational Strategy," Administrative Science Quarterly, Vol. 13, No. 1, 1968, p. 47; and Malcolm S. Salter, "Management Appraisal and Reward Systems," Journal of Business Policy, Vol. 1, No. 4, 1971.the life span of an organization (represented as the horizontal axis in Exhibit I).All historical studies gather data from various points in time and then make comparisons. From these observations, it is evident that the same organization practices are not maintained throughout a long time span. This makes a most basic point management problems and principles are rooted in time. The concept of decentralization, for example, can have meaning for describing corporate practices at one time period but loses its descriptive power at another.The passage of time also contributes to the institutionalization of managerial attitudes. As a result, employee behavior becomes not only more predictable but also more difficult to change when attitudes are outdated.Size of the OrganizationThis dimension is depicted as the vertical axis in Exhibit I. A company's problems and solutions tend to change markedly as the number of employees and sales volume increase. Thus time is not the only determinant of structure; in fact, organizations that do not grow in size can retain many of the same management issues and practices over lengthy periods. In addition to increased size, however, problems of coordination and communication magnify, new functions emerge, levels in the management hierarchy multiply, and jobs become more interrelated.Stages of EvolutionAs both age and size increase, another phenomenon becomes evident: the prolonged growth that I have termed the evolutionary period. Most growing organizations do not expand for two years and then retreat for one year; rather, those that survive a crisis usually enjoy four to eight years of continuous growth without a major economic setback or severe internal disruption. The term evolution seems appropriate for describing these quieter periods because only modest adjustments appear necessary for maintaining growth under the same overall pattern of management.Stages of RevolutionSmooth evolution is not inevitable; it cannot be assumed that organization growth is linear. Fortune's "500"list, for example, has had significant turnover during the last 50 years. Thus we find evidence from numerous case histories which reveals periods of substantial turbulence spaced between smoother periods of evolution.I have termed these turbulent times the periods of revolution because they typically exhibit a serious upheaval of management practices. Traditional management practices, which were appropriate for a smaller size and earlier time, are brought under scrutiny by frustrated top managers and disillusioned lower-level managers. During such periods of crisis, a number of companies fail--those unable to abandon past practices and effect major organization changes are likely either to fold or to level off in their growth rates.The critical task for management in each revolutionary period is to find a new set of organization practices that will become the basis for managing the next period of evolutionary growth. Interestingly enough, these new practices eventually sow their own seeds of decay and lead to another period of revolution. Companies therefore experience the irony of seeing a major solution in one time period become a major problem at a later date.Growth Rate of the IndustryThe speed at which an organization experiences phases of evolution and revolution is closely related to the market environment of its industry. For example, a company in a rapidly expanding market will have to add employees rapidly; hence, the need for new organization structures to accommodate large staff increases is accelerated. While evolutionary periods tend to be relatively short in fast-growing industries, much longer evolutionary periods occur in mature or slowly growing industries.Evolution can also be prolonged, and revolutions delayed when profits come easily. For instance, companies that make grievous errors in a rewarding industry can still look good on their profit and loss statements; thus they can avoid a change in management practices for a longer period. The aerospace industry in its infancy is an example. Yet revolutionary periods still occur, as one did in aerospace when profit opportunities began to dry up. Revolutions seem to be much more severe and difficult to resolve when the market environment is poor.PHASES OF GROWTHWith the foregoing framework in mind, let us now examine in depth the five specific phases of evolution and revolution. As shown in Exhibit II, each evolutionary period is characterized by the dominant management style used to achieve growth, while each revolutionary period is characterized by the dominant management problem that must be solved before growth can continue. The patterns presented in Exhibit II seem to be typical for companies in industries with moderate growth over a long time period: companies in faster growing industries tend to experience all five phases more rapidly, while those in slower growing industries encounter only two or three phases over many years.It is important to note that each phase is both an effect of the previous phase and a cause for the next phase. For example, the evolutionary management style in Phase 3 of the exhibit is "delegation," which grows out of, and becomes the solution to, demands for greater "autonomy" in the preceding Phase 2 revolution. The style of delegation used in Phase 3, however, eventually provokes a major revolutionary crisis that is characterized by attempts to regain control over the diversity created through increased delegation.The principal implication of each phase is that management actions are narrowly prescribed if growth is to occur. For example, a company experiencing an autonomy crisis in Phase 2 cannot return to directive management for a solution--it must adopt a new style of delegation in order to move ahead.Phase 1: Creativity . . .In the birth stage of an organization, the emphasis is on creating both a product and a market. Here are the characteristics of the period of creative evolution:• The company's founders are usually technically or entrepreneuriallyoriented, and they disdain managementactivities; their physical and mentalenergies are absorbed entirely inmaking and selling a new product.• Communication among employees is frequent and informal.• Long hours of work are rewarded by modest salaries and the promise ofownership benefits.• Control of activities comes from immediate marketplace feedback: themanagement acts as the customersreact.. . . & the leadership crisis: All of the foregoing individualistic and creative activities are essential for the company to get off the ground. But therein lies the problem. As the company grows, larger production runs require knowledge about the efficiencies of manufacturing. Increased numbers of employees cannot be managed exclusively through informal communication; new employees are not motivated by an intense dedication to the product or organization. Additional capital must be secured, and new accounting procedures are needed for financial control.Thus the founders find themselves burdened with unwanted management responsibilities. So they long for the "good old days"' still trying to act as they did in the past. And conflicts between the harried leaders grow more intense.At this point a crisis of leadership occurs, which is the onset of the first revolution. Who is to lead the company out of confusion and solve the managerial problems confronting it? Quite obviously, a strong manager is needed who has the necessary knowledge and skill to introduce new business techniques. But this is easier said than done. The founders often hate to step aside even though they are probably temperamentally unsuited to be managers. So here is the first critical development choice--to locate and install a strong business manager who is acceptable to the founders and who can pull the organization together.Phase 2: Direction . . .Those companies that survive the first phase by installing a capable business manager usually embark on a period of sustained growth under able and directive leadership. Here are the characteristics of this evolutionary period:• A functional organization structure is introduced to separate manufacturingfrom marketing activities, and jobassignments become more specialized.• Accounting systems for inventory and purchasing, are introduced.• Incentives, budgets, and workstandards are adopted.• Communication becomes more formal and impersonal as a hierarchy of titlesand positions builds• The new manager and his keysupervisors take most of theresponsibility for instituting direction,while lower-level supervisors aretreated more as functional specialiststhan as autonomous decision-makingmanagers,. . . & the autonomy crisis. Although the new directive techniques channel employee energy more efficiently into growth, they eventually become inappropriate for controlling a larger, more diverse and complex organization. Lower-level employees find themselves restricted by a cumbersome and centralized hierarchy. They have come to possess more direct knowledge about markets and machinery than do the leaders at the top; consequently, they feel torn between following procedures and taking initiative on their own.Thus the second revolution is imminent as a crisis develops from demands for greater autonomy on the part of lower-level managers. The solution adopted by most companies is to move toward greater delegation. Yet it is difficult for managers who were previously successful at being directive to give upresponsibility. Moreover, lower-level managers are not accustomed to making decisions for themselves. As a result, numerous companies flounder during this revolutionary period, adhering to centralized methods while lower-level employees grow more disenchanted and leave the organization.Phase 3: Delegation . . .The next era of growth evolves from the successful application of a decentralized organization structure. It exhibits these characteristics:• Much greater responsibility is given to the managers of plants and marketterritories.• Profit centers and bonuses are used to stimulate motivation.• The top executives at headquarters restrain themselves to managing byexception, based on periodic reportsfrom the field.• Management often concentrates on making new acquisitions which can belined up beside other decentralizedunits.• Communication from the top is infrequent, usually by correspondence,telephone, or brief visits to fieldlocations.The delegation stage proves useful for gaining expansion through heightened motivation at lower levels. Decentralized managers with greater authority and incentive are able to penetrate larger markets, respond faster to customers, and develop new products.. . . & the control crisis: A serious problem eventually evolves. however, as top executives sense that they are losing control over a highly diversified field operation. Autonomous field managers prefer to run their own shows without coordinating plans, money. technology, and manpower with the rest of the organization. Freedom breeds a parochial attitude.Hence, the Phase 3 revolution is under way when top management seeks to regain control over the total company. Some top managements attempt a return to centralized management, which usually fails because of the vast scope of operations. Those companies that move ahead find a new solution in the use of special coordination techniques.Phase 4: Coordination . . .During this phase, the evolutionary period is characterized by the rise of formal systems for achieving greater coordination and by top executives taking responsibility for the initiation and administration of these new systems. For example:• Decentralized units are merged into product groups.• Formal planning, procedures are established and intensively reviewed.• Numerous staff personnel are hired and located at headquarters to initiatecompanywide programs of control andreview for line managers.• Capital expenditures are carefully weighed and parceled out across theorganization.• Each product group is treated as an investment center where return oninvested capital is an importantcriterion used in allocating funds.• Certain technical functions, such as data processing, are centralized atheadquarters, while daily operatingdecisions remain decentralized.• Stock options and company-wide profit sharing are used to encourage identitywith the firm as a whole.All of these new coordination systems prove useful for achieving growth through more efficient allocation of a company's limited resources. They prompt field managers to look beyond the needs of their local units. While these managers still have much decisionmaking responsibility, they learn to justify their actions more carefully to a "watchdog" audience at headquarters.. . . & the red tape crisis: But a lack of confidence gradually builds between line and staff, and between headquarters and the field. The proliferation of systems and programs begins to exceed its utility; a red-tape crisis is created. Line managers, for example, increasingly resent heavy staff direction from those who are not familiar with local conditions. Staff people, on the other hand, complain about uncooperative and uninformed line managers. Together both groups criticize the bureaucratic paper system that has evolved. Procedures take precedence over problem solving, and innovation is dampened. In short, the organization has become too large and complex to be managed through formal programs and rigid systems. The Phase 4 revolution is underway.Phase 5: Collaboration . . .The last observable phase in previous studies emphasizes strong interpersonal collaboration in an attempt to overcome the red-tape crisis. Where Phase 4 was managed more through formal systems and procedures, Phase 5 emphasizes greater spontaneity in management action through teams and the skillful confrontation of interpersonal differences. Social control and self-discipline take over from formal control. This transition is especially difficult for those experts who created the old systems as well as for those line managers who relied on formal methods for answers.The Phase 5 evolution, then, builds around a more flexible and behavioral approach to management. Here are its characteristics:• The focus is on solving problemsquickly through team action.• Teams are combined across functions for task-group activity.• Headquarters staff experts are reduced in number, reassigned, and combinedin interdisciplinary teams to consultwith, not to direct, field units.• A matrix-type structure is frequently used to assemble the right teams for theappropriate problems.• Previous formal systems are simplified and combined into single multipurposesystems.• Conferences of key managers are held frequently to focus on major problemissues.• Educational programs are utilized to train managers in behavioral skills forachieving better teamwork and conflictresolution.• Real-time information systems are integrated into daily decision making.• Economic rewards are geared more to team performance than to individualachievement.• Experiments in new practices are encouraged throughout theorganization.. . . & the ? crisis: What will be the revolution in response to this stage of evolution? Many large U.S. companies are now in the Phase 5 evolutionary stage, so the answers are critical. While there is little clear evidence, I imagine the revolution will center around the "psychological saturation" of employees who grow emotionally and physically exhausted by the intensity of teamwork and the heavy pressure for innovative solutions.My hunch is that the Phase 5 revolution will be solved through new structure and programs that allow employees to periodically rest, reflect, and revitalize themselves. We may even see companies with dual organization structures: a "habit " structure for getting the daily work done, and a "reflective" structure for stimulating perspective and personal enrichment. Employees could then move back and forth between the two structures as their energies are dissipated and refueled.One European organization has implemented just such a structure. Five reflective groups have been established outside the regular structure for the purpose of continuously evaluating five task activities basic to the organization. They report directly to the managing director, although their reports are made public throughout the organization. Membership in each group includes all levels and functions, and employees are rotated through these groups on a six-month basis.Other concrete examples now in practice include providing sabbaticals for employees, moving managers in and out of "hot spot " jobs, establishing a four-day workweek, assuring job security, building physical facilities for relaxation during the working day, making jobs more interchangeable, creating an extra team on the assembly line so that one team is always off for reeducation, and switching into longer vacations and more flexible working hours.The Chinese practice of requiring executives to spend time periodically on lower-level jobs may also be worth a nonideological evaluation. For too long U.S. management has assumed that career progress should be equated with an upward path toward title, salary, and power. Could it be that some vice presidents of marketing might just long for, and even benefit from, temporary duty in the field sales organization? IMPLICATIONS OF HISTORYLet me now summarize some important implications for practicing managers. First, the main features of this discussion are depicted in Exhibit III,which shows the specific management actions that characterize each growth phase. These actions are also the solutions which ended each preceding revolutionary period.In one sense, I hope that many readers will react to my model by calling it obvious and natural for depicting the growth of an organization. To me this type of reaction is a useful test of the model's validity.But at a more reflective level I imagine some of these reactions are more hindsight than foresight. Those experienced managers who have been through a developmental sequence can empathize with it now, but how did they react when in the middle of a stage ofevolution or revolution? They can probably recall the limits of their own developmental understanding at that time. Perhaps they resisted desirable changes or were even swept emotionally into a revolution without being able to propose constructive solutions. So let me offer some explicit guidelines for managers of growing organizations to keep in mind.Know where you are in the developmental sequence.Every organization and its component parts are at different stages of development. The task of top management is to be aware of these stages; otherwise. it may not recognize when the time for change has come, or it may act to impose the wrong solution.Top leaders should be ready to work with the flow of the tide rather than against it; yet they should be cautious, since it is tempting to skip phases out of impatience. Each phase results in certain strengths and learning experiences in the organization that will be essential for success in subsequent phases. A child prodigy, for example, may be able to read like a teenager, but he cannot behave like one until he ages through a sequence of experiences.I also doubt that managers can or should act to avoid revolutions. Rather, these periods of tension provide the pressure, ideas, and awareness that afford a platform for change and the introduction of new practices.Recognize the limited range of solutions.In each revolutionary stage it becomes evident that this stage can be ended only by certain specific solutions; moreover, these solutions are different from those which were applied to the problems of the preceding revolution. Too often it is tempting to choose solutions that were tried before, which makes it impossible for a new phase of growth to evolve.Management must be prepared to dismantle current structures before the revolutionary stage becomes too turbulent. Top managers, realizing that their own managerial styles are no longer appropriate, may even have to take themselves out of leadership positions. A good Phase 2 manager facing Phase 3 might be wise to find another Phase 2 organization that better fits his talents, either outside the company or with one of its newer subsidiaries.Finally, evolution is not an automatic affair; it is a contest for survival. To move ahead, companies must consciously introduce planned structure that not only are solutions to a current crisis but also are fitted to the next phase of growth. This requires considerable self-awareness on the part of top management, as well as great interpersonal skill in persuading other managers that change is needed.Realize that solutions breed new problems.Managers often fail to realize that organizational solutions create problems for the future (i.e., a decision to delegate eventually causes a problem of control). Historical actions are very much determinants of what happens to the company at a much later date.An awareness of this effect should help managers to evaluate company problems with greater historical understanding instead of "pinning the blame" on a current development. Better yet, managers should be in a position to predict future problems, and thereby to prepare solutions and coping strategies before a revolution gets out of hand.。
人民币汇率与日元汇率规章制度演变历程及启示(英文版)
RMB Exchange Rate SystemA Case Study of RMB And Yen Exchange RateTed (Student No:201130451377)ABSTRACTAs we all know ,the influence of exchange rate movements on a country's economy is important. On the domestic economy, on the one hand, Exchange rate movements affect the price rise or fall, After the exchange rate changes, affect on the price of imported goods happen immediately. First is the changes in prices of consumer goods and raw materials import, and then to import raw material processing or similar domestic goods and imported goods prices have also changed After exchange rate changes, the domestic prices of export commodities are also changed. On the other hand, the exchange rate changes affect export commodities production department. Foreign currency appreciation, will make imports more expensive, so to export commodity producers, mainly imported raw materials, production costs rise, weaken its competition ability in the international market, and to give priority to with domestic raw materials exports producer favourable. Foreign currency devaluation, would make imports cheaper, so that the export commodity producers specializing in importing raw materials of lower production costs, export products also enhance its capability of international competition in the market, while at the same time is given priority to with domestic raw materials of export commodity producers can not get the benefits due to exchange rate changes. exchange rate changes also affect a country's foreign economic. The fall in the value of the currency expand their exports, to inhibit the action of the domestic import, which is likely to reverse the trade deficit, also can promote local tourism and related trade income increase. In addition, exchange rate changes affect a country's gold reserves .Reserve currencyexchange rate movements affect the real value of a country's foreign exchange reserves, reserve currency appreciation, is the real value of a country's foreign exchange reserves increase, reduce conversely. In a word, exchange rate changes has the important influence to the national economy. However, Who influence exchange rates? Of course is the exchange rate system. Since 1949, official RMB exchange rate has experienced a rate to the market, from a fixed exchange rate guide the evolution of the management of the floating exchange rate. There are three periods , they are the planned economy period, economic transition period, the socialist market economy period . We can get the experience and inspiration from the study of the yen exchange rate and exchange rate system changes.KEYWORDSThe exchange rate system , RMB exchange rate, Yen exchange rate, economy.BACKGROUND OF RMB EXCHANGE RATERMB appreciation pressure status analysis and mitigation countermeasures on July 21, 2005, the people's bank of China issued announcement: China since that day, practice on the basis of market supply and demand, "a basket of currencies, managed floating exchange rate system. This suggests that the Chinese return to management of the floating way, officially launched the reform of RMB exchange rate regime . After the international community have great expectations, revaluation of the renminbi in 2005, however, small amplitude of appreciation of the yuan far cannot satisfy the need of relevant countries, these countries to continue to put pressure on our government, still require further renminbi appreciation.EVOLUTION OF RMB EXCHANG RATE SYETEMSThe Planned Economy Period （1949-1978）On January 8, 1949, the people's bank of China began to currency exchange rates published in the sky. Under the unified management of the central, Shanghai and guangzhou used tianjin exchange rate as the standard, according to the local price situation, published their own exchange rate. RMB exchange rate of planned economy period in a longer historical period of a fixed exchange rate arrangement, has been pegged to a basket of currencies.Figure1Economic Transition Period (1979-1993)1.The imposition of trade internal settlement price and dual exchange rate system of foreign currency. In 1981-1984, official RMB exchange rate has a trade internal settlement price and non-trade dual exchange rate system of open quotation. On January 1, 1985 to cancel internal settlement price, to execute a single exchange rate, the exchange rate of 1 dollar to2.8 yuan. This is the first time that the RMB exchange rate system.2.According to the price changes inside and outside the government adjusted the official exchange rate . During 1985-1990, according to the change of domestic prices in our country, the government adjusted the exchange rate to 6 yuan for one dollar.3.The official exchange rate and currency swap market exchange rate ofRMB exchange rate regime. Since 1980, the country started to implement system of foreign exchange swap, set up a foreign exchange swap center, opened foreign exchange swap open market operations, formed the official exchange rate and regulate the market exchange rate occurring together. Since April 9, 1991, our country executed a managed floating exchange rate, at the end of 1993 to $1 to 5.8 yuan.Figure2The Socialist Market Economy Period (1994-?)1. Since January 1, 1994, official RMB exchange rate and market exchange rates get in touch, the bank written guarantee system, established a nationwide unified inter-bank foreign exchange market, based on market supply and demand will be implemented for a single exchange rates. This is the second time of connection between the RMB exchange rate system and .market rate of exchange.2. Southeast Asia financial turmoil in 1997, China made China's exchange rate form a fixed exchange rate peg to the dollar in order to maintain regional economic and financial stability, keep the RMB exchange rate strength with a attitude of powers responsible.Then the RMB exchange rate was to $1 to 8.7 yuan.On July 21, 2005, the central bank announce improving reform of the RMB exchange rate formation mechanism . Approved by the state council, since July 21, 2005, China began to implement managed floating exchange rate system that be based on market supply and demand, referencing to a basket of currencies, . The RMB exchange rate is a more flexible RMB exchangerate mechanism no longer pegged to the dollar. The RMB exchange rate is rising in 2013, and reached a new higher level with $1 to 6.10 yuan in 2013. Figure3EVOLUTION OF YEN EXCHANG RATE SYETEMSBefore 1971The yen at the fixed exchange rate stage, during this period against the yen, the dollar exchange rate to yen has remained at the fixed level of 1:360.After 1971A sudden rise in the yen, which mainly stems from Nixon crisis in August 1971 (August 15, 1971, President Nixon spoke, its purpose is to terminate the dollar with gold convertibility, end the standard of the price of $35 per ounce of gold dollar commitment. It has broken the original countries to perform for dollar to gold, currencies binding international exchange rate system, began to implement floating exchange rate system. And in December Bretton woods agreement and Smith agreement established。
汶川地震前的b值变化
汶川地震前的b值变化史海霞;孟令媛;张雪梅;常莹;杨振涛;谢蔚云;服部克巳;韩鹏【摘要】Gutenberg-Richter定理给出了地震频度随震级的分布特征.大量研究表明频度-震级关系的斜率(b值)在大地震孕育的过程中会出现减小.为了考察b值在汶川地震孕育过程中的时间演化特征,本文尝试基于破裂断层选取研究区域,考察了2000年1月至2008年4月间,汶川地震(Ms8.0)破裂区的地震活动性,并对该区域b值的变化进行了探讨.结果表明,在2005年中至2006年底,地震月频度及季度频度有一个较明显的下降.b值从2002年始至地震前呈现出一个长期趋势性减小;在地震前约半年,出现快速、显著的下降.b值的这一时间变化特征与其他研究者报道的日本东北Mw9.0级地震前的b值变化特征具有很高相似性,可能反映了大地震准备过程中的应力变化.以上结果有益于认识和理解大地震孕育演化过程,同时也表明b值在中长期地震灾害评估中具有潜在价值.【期刊名称】《地球物理学报》【年(卷),期】2018(061)005【总页数】9页(P1874-1882)【关键词】汶川地震;b值;地震活动性;孕震区【作者】史海霞;孟令媛;张雪梅;常莹;杨振涛;谢蔚云;服部克巳;韩鹏【作者单位】中国地震台网中心,北京 100045;中国地震台网中心,北京 100045;中国地震台网中心,北京 100045;南方科技大学地球与空间科学系,广东深圳 518055;南方科技大学地球与空间科学系,广东深圳 518055;Chiba University, Chiba,Japan;Chiba University, Chiba, Japan;南方科技大学地球与空间科学系,广东深圳518055【正文语种】中文【中图分类】P3150 引言古登堡和里克特(Gutenberg and Richter, 1944)提出了有关地震频度(N)与频度震级(M)的统计关系logN=a-bM，称为古登堡—里克特定理.其中常量a反映了区域的地震活动性，b值反映了区域内大小地震的相对比例.研究表明b值的变化可反应地下介质的应力状态(Narteau et al., 2009; Mousavi et al., 2017).地震学家试图利用b值寻找俯冲带的闭锁区域，以此来识别大地震的潜在震源位置(Sobiesiak et al., 2007; Ghosh et al., 2008).同时，一些室内试验也表明在岩石最终破裂前，b值会出现一个系统性的下降(Lei, 2003).特别是大震前的低b值特征，被多次震例检验：如1976年唐山MS7.8地震(李全林等，1979)；2004年印尼苏门答腊MW9.1级地震和2011年日本东北MW9.0级地震(Nanjo et al.，2012).因而，利用统计地震学分析复杂构造区域的地震活动，监测b值的动态变化，以此寻找潜在大震孕震区的相关研究一直备受关注(Smith, 1981).2008年汶川8.0级大地震为检验和改进现有的地震预测知识和理论模型提供了宝贵资料和震例.本文以汶川地震的主破裂区龙门山断裂带为研究区域，采用2000年1月—2008年4月间的地震目录(中国地震台网中心提供，全国地震编目系统(新)http:∥10.5.160.18/console/index.action),统计分析地震频度和b值的时间变化.尝试从b值动态变化中获取中长期与中短期的孕震信息, 进而探求利用b值估计孕震状态的方法，为大震风险评估提供有益参考.1 研究资料的选取汶川地震(31.01°N，103.42°E) 发生于北京时间2008年5月12日，面波震级8.0，震源深度19 km.该地震发生在青藏块体东缘龙门山断裂上，为西南向东北传播的单侧破裂，余震区长约330 km(田勤俭，2009).龙门山断裂带位于青藏高原与扬子地块挤压拼接的交汇部位，龙门山构造系及其相邻断裂带是新生代以来强烈的褶皱隆起区，呈现推覆逆掩断裂构造特征.包括3条近似平行的主要断裂，即都江堰—江油断裂(前山断裂)，映秀—北川—青川断裂(中央断裂)，茂县—汶川断裂(后山断裂).这3条断裂带均显示由北西向南东的逆冲运动，并兼有右旋走滑分量(朱介寿，2008)，其中中央断裂被认为是汶川地震的主破裂断层(贺鹏超和沈正康，2014).马瑾等(2013)提出汶川地震孕震范围的认识，认为汶川地震的孕育部位主要分布在汶川段映秀—北川断裂和后山断裂之间，解释为有限断层段上孕育的地震快速失稳过程.Nanjo等(2012)对日本东北9.0级地震的研究也表明，主破裂区的地震活动性参数(b值)在震前变化最明显，具有很好的前兆特征.因而，为了更加有效地考察汶川地震前地震活动性的变化，本研究选取龙门山断裂带附近(中央主破裂断层两侧60 km区域)作为研究区域.图1给出了汶川地震的震源及本研究的考察区域(蓝色矩形框内).其中绿色实线表示中央断裂(断层数据源于邓启东等，2002).本文使用中国地震台网中心提供的地震目录.在2000年，中国数字台网进行了更新，检测能力得到了大幅提升(Liu et al., 2003).因而，本文选用2000年1月至2008年4月的地震目录.图2展示了在此其间研究区域内的地震震级-频度分布图.从中可以发现完备震级为MC=ML1.5 .这一结果与Huang使用RTL方法研究汶川地震前的地震平静所用最小震级一致(Huang，2008).以往研究表明，余震序列可能具有与主震及背景地震不同的统计特征(Molchan and Dmitrieva，1992).因而在分析地震活动性变化时，需要考察余震序列的影响.图3展示了2000年1月至2008年4月研究区域内的地震在时间域的分布特征.最大震级为ML4.2级.图3a反映了累计地震数目的变化，图3b为震级-时间图.从中可以看出并无显著的余震序列.为了最大程度保持资料的原始性和完整性，本研究未进行去余震处理，而是使用所有大于等于下限震级的地震资料.图1 龙门山断裂带2000年1月—2008年4月(红色空心圈)ML≥ 1.5地震分布图及研究区范围图中蓝色实心框为研究区域，绿色曲线为汶川8.0级地震主破裂带，黑色细线为断层.Fig.1 Locations of earthquakes (red open circle) withML≥1.5 during January, 2000—April, 2008 surrounding the Longmenshan Fault The blue box indicates the study area, the green line represents the main rupture fault, and black lines show active faults.图2 研究区域2000年1月—2008年4月震级-频度图Fig.2 The frequency-magnitude distribution of earthquakes in the study area during January, 2000—April, 20082 震前地震活动性的变化2.1 地震频度变化地震活动在时间上的分布特征可以反映出研究区域应力场所处的状态.研究表明大地震发生之前可能会出现“地震平静”现象(Wyss and Habermann， 1988).这种现象通常直观的表现是地震活动性减弱，即地震频度相对于背景值减小(Huang，2004，2006；Huang and Nagao，2002).为了考察汶川地震的孕育演化过程，我们分析了图1中所选取的研究区域内的地震频度变化.图4a展示了地震月频度的变化，图4b展示了地震季度频度的变化.在两幅图中均可以发现，从2005年中至2006年底，地震频度相对于平均背景值(水平虚线)有一个较明显的减弱.Huang(2008)使用RTL方法研究汶川地震前的地震活动性，发现在2006年至2007年震源区附近有一个明显的地震平静(RTL值减小).考虑到在他的结果中所用的时间窗是1年，因而实际地震平静期应为2005—2006年，与本文图4所示结果一致.类似的地震平静及地震频度减小也被发现于神户地震(Huang et al., 2001)及玉树地震之前(陈学忠和李艳娥，2012).图3 研究区域地震时间分布特征 (a) 累计地震数目随时间的变化; (b) 震级-时间图.Fig.3 The temporal distribution of earthquakes in the study area (a) The temporal variation of cumulative number of earthquakes; (b) The temporal variation of magnitude.图4 研究区地震月累计频度(a)和季度累计频度(b). 各子图中水平虚线代表相应的(月频度或季度频度)均值Fig.4 Monthly frequency (a) and quarterly frequency (b) of earthquakes in the study area The dashed line in each subplot shows the corresponding average value2.2 b值变化目前最常用的b值计算方法有线性最小二乘拟合和最大似然估计，考虑到后者计算简便，不易受个别较大地震影响，且计算结果较为稳定，本研究采用最大似然估计法求取b值.研究采用Aki和Utsu 1965年提出最大似然法求解(Aki，1965; Utsu, 1965)，具体计算公式如下：(1)其中，为研究区域时间窗内的平均震级，MC为下限震级.在本研究中，基于第二节的讨论，MC取1.5. b值计算误差可用以下公式评估(Aki，1965)：(2)其中σb为b值的标准差，其值越大，表明b值的不确定性(误差)越大.N为时间窗内地震样本的个数.从公式(2)可以发现，较大的样本数N可以降低b值估算的不确定性，减小误差.同时为了保证在每一个窗内具有相同的地震样本数，本文选用500个地震样本为一个时间窗，计算b值.为了考察b值在时间域的变化，我们采用步长为50个地震，向后逐步滑动样本窗，计算每一个窗口内的b值.这种基于样本数选取窗口和步长的方法在统计意义上具有一定优势，但每一个窗口和步长的时间尺度可能存在差别.图5展示了研究区域内b值随时间的变化.其中蓝色圆圈给出了每一个窗口的b值，对应的横坐标为该窗口内最后一个地震的发生时间.这样标注的好处是各时刻对应的b值完全由该时刻之前已发生的地震事件决定，在实际应用中更具可操作性.灰色误差棒给出了b值一倍标准差区间.从图中可以看出，b值呈现一个长期的趋势性下降，并大致可分为如下三个阶段：从2002年初至2005年初有一个快速明显的下降；在2005年至2007年中b值相对稳定并略有上升趋势；自2007年中至发震前b值出现连续的的下降，且下降幅度越来越快，尤其是2008年初b值出现大幅度的显著下降.上述结果与日本东北9.0级地震前b值变化形态非常相似(Nanjo et al.,2012图3B)，但绝对b值有明显差异.相较而言，汶川地区b值水平较高，这与汶川地区的构造环境、岩性特征以及应力状态有关.图5 b值时间曲线 (震级下限Mc=1.5，统计样本数为500个地震)Fig.5 The temporal variation of b value (Mc=1.5, the sample size is 500)为了更详细直观地反映b值变化特征，我们在图5中每个阶段各选取一个窗口，考察各窗内地震的震级-频度分布.图6给出对应W1, W2, W3窗内具体的b值计算拟合线，其中W1对应绿色实线，b=1.48±0.07，W2对应蓝色实线，b=1.16±0.05，W3对应红色实线，b=1.08±0.05.从中可以看出，随着窗口时间越来越靠近汶川地震，窗口内较大地震的占比越来越大，对应b值越来越小.图6 各选取窗内地震样本的震级-频度分布Fig.6 The frequency-magnitude distribution in each selected window虽然图6可以直观地反映b值的变化特征，但并不能给出这些变化是否具有统计显著性.为了定量识别b值的变化，我们基于赤池信息量准则(AIC)(Akaike，1974)对两个样本窗内的b值进行P-检验.假设1：两个样本窗内的b值无差异；假设2：两个样本窗内的b值有差异，分别为b1，b2.假设1与假设2的AIC之差ΔAIC为(Utsu, 1992)：ΔAIC=-2(N1+N2)ln(N1+N2)(3)其中，N1，N2为两个样本窗内的地震数目，b1，b2为两个样本窗内的b值.Pb表示两个样本窗内的地震来自于同一个总体即b值无差异的概率, 当样本数较大时，Pb可近似表示为(Utsu, 1999)(4)在图6中，三个窗的地震数目均为500，基于公式(3)和(4)，我们分别计算了W2，W3相对于W1的ΔAIC 及他们之间b值无差异的概率. 其中，W2与W1之间ΔAIC12 = 12.80，Pb=2.247×10-4; W3与W1之间ΔAIC13=22.7170，Pb=1.58×10-6. 上述结果表明，两个窗中b值无差异的概率很低，如果取常用的95%置信区间，则可以判定图6中W2，W3中b值相对于W1中b值的变化是显著的.3 讨论地震活动性反映的是一定区域内地震的统计特征，因而不同选取研究区域的方法可能带来不同的结果.以往的研究更多的是把地震近似为点源，以震源为中心选取一定范围内的区域作为孕震区域进而考察震前地震活动性变化.对于较大震级的地震，孕震范围通常也较大.如果不考虑可能的实际孕震区域而简单地以震源为中心选取研究资料，可能会包含大量与地震准备过程无关的地震样本.这些无关的地震样本很可能影响总体的统计特征，使得包含在地震活动性中的孕震信息无法被识别.Nanjo等(2012)对日本东北9.0级地震的研究中，选用了考虑实际断层走向的研究区域，所得b值变化特征较好地反映了孕震过程.考虑到汶川地震是一个较为特殊的单侧破裂，本文选取了主破裂断层两侧的研究区域，考察了b值在汶川地震前的时间演化特征.这种基于实际断层模型选取研究区域的方法，可能具有一定的潜在优势，值得在今后的地震活动性研究中进一步试验和讨论.在2.2节中可以发现b值在汶川地震前呈现趋势性的衰减特征.根据公式(1)和(2)，b值的计算结果及可信度受地震样本数N和下限震级Mc的影响.因而，为了确认b值的衰减特征是真实客观存在的而非参数选择造成的，我们考察了不同N及Mc 对计算结果的影响.图7给出了应用不同地震样本数N选取窗口(地震数目分别50，100，200，400，500，600)计算所得的b值曲线.从图中可以看出，所有的曲线均呈现一个长期的下降趋势，地震样本数小于200的结果波动较大，绝对b值存在明显差异；自样本数400起至600的b值曲线基本一致，相似度较高，即地震样本数400及以上的b值计算结果具有很好的稳定性.因而图5中所反映的b值减小趋势不太可能是地震样本数选取造成的.理论上讲，样本数越多，b值计算结果可信度越高.然而，较小的窗口可以提供较高的时间解析度.因此，基于两者之间的平衡，本文选取500个地震样本作为窗长.图8给出了Mc=1.5，Mc=1.6，Mc=1.7的b值动态变化曲线.其中窗口长度均为500个地震样本，步长为50个地震样本.从图中可以发现，选用不同的下限震级，b值的计算结果存在差异.这一方面是因为最大似然法本身所存在的计算误差，对不同的震级下限较为敏感(Lombardi，2003)，另外一方面也因为选取不同震级下限时，包含相同地震数目的窗口在时间跨度上存在较大的不一致性，而不同时间的b值可能存在差异.从趋势上看，三条曲线特征具有很好的相似性. 因此，图5所展示的b值长期趋势性减小是客观真实的.值得注意的是，虽然选用更大Mc在理论上可使得地震目录的完备性更可靠，但会造成地震样本数大幅减小，使得b值计算结果的时间分辨率(固定窗口样本数目)或稳定性(固定窗口时间尺度)变差.实际上，我们也尝试计算了Mc大于1.7时的b值，仍可发现b值减小的整体趋势，但趋势变得越来越平缓.在图4中可以发现，2005—2006地震频度出现了下降，这与Huang(2008)基于RTL研究所得的汶川地震前的“地震平静”较为一致.b值在该段时间对应为相对稳定，两者之间可能具有某种内在联系.一种可能的解释是在该时间段应力达到了某种临界状态. 紧接着这一阶段，地震频度出现反弹，同时b值表现为连续性减小，且减小速率越来越大.这可能反映了临界状态被打破，进入了失稳阶段(Main et al., 1989).图7 不同样本窗的b值时间曲线 (震级下限Mc=1.5，步长为50个地震)Fig.7 b value variations of different window length (sample size) (Mc=1.5, step length=50)图8 不同震级下限Mc的b值时间曲线 (窗长为500个地震，步长为50个地震)Fig.8 b value variations of different Mc (The ample size is 500, and the step length is 50)4 结论与展望本文根据汶川地震的破裂特征及可能的孕震区，选取了主破裂断层两侧作为研究区域，考察了地震活动性在汶川地震前的时间演化特征，得到如下结论：(1) 从2005年中至2006年底，地震频度有一个较明显的减弱.这一结果与其他研究者报道的汶川地震的震前“平静”在时间上具有很好的一致性.(2) b值总体呈现一个长期的趋势性下降.这一下降趋势与地震样本窗口大小和下限震级的选取无关，是一个客观存在的事实，且在统计上具有显著性.(3) b值的具体变化特征可分为三个阶段：从2002年初至2005年初有一个快速明显的下降；在2005年至2007年中b值相对稳定并略有上升趋势；自2007年中至发震前b值出现连续的的下降，且下降幅度越来越快，尤其是2008年初b 值出现大幅度的显著下降.上述结果与Nanjo等(2012)报道的日本东北9.0级地震前b变化特征非常相似.b值的这一演化特征是否具有普适性及可能的内在物理含义需要进一步的研究.以上结论表明b值在中长期地震灾害评估中具有潜在价值，有益于认识和理解大地震孕育演化过程，尤其是b值变化显著性水平的定量分析，可在一定程度上为大地震的概率预测及震情会商提供量化信息.然而在现阶段，单纯依靠b值或其他地震活动性参数来预报地震仍面临很大困难(Zhao and Wu, 2008).其中一个关键的原因是，这些参数均是基于统计所得，反应的是一种整体趋势的变化，它们在中长期时间尺度上可能具有较好的参考价值(易桂喜等，2013；闻学泽等，2013；Zhang and Zhou, 2016)，对于最关键的短临预报，目前似乎很难给出有意义的信息.一种可能的解决方法是综合其他直接的地球物理观测结果，比如电磁场(Hattori et al., 2013; 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赤点石斑鱼两种芳香化酶cDNA的克隆及其表达的组织特异性(1)
动物学报 50(5):791-799,2004A cta Zoologica S i nica 赤点石斑鱼两种芳香化酶cD NA的克隆及其表达的组织特异性3李广丽1,2 刘晓春1 张 勇1 贝锦新1 林浩然1331.中山大学水生经济动物研究所暨广东省水生经济动物良种繁育重点实验室,广州51027522.湛江海洋大学水产学院,广东 湛江524025摘 要 以赤点石斑鱼(Epinephelus akaara)脑垂体中提取的RNA为模板,根据芳香化酶的保守序列设计引物,利用G eneRacer TM技术,克隆出两种芳香化酶即脑芳香化酶(P450aromB)和性腺芳香化酶(P450aromA)的cDNA,其全长分别为1901bp(编码509aa)和1833bp(编码518aa)。
序列分析结果表明,赤点石斑鱼两种芳香化酶cDNA序列的同源性为5116%,氨基酸序列之间同源性为6215%,与斜带石斑鱼两种芳香化酶氨基酸同源性分别为9417%和9719%。
对8个科的10种鱼进行了分子系统进化树分析,结果与根据传统的形态学和生化特征分类进化地位基本一致。
以特异性引物扩增雌、雄赤点石斑鱼各种组织(垂体、嗅球、端脑、下丘脑、中脑、后脑、延脑、心脏、肾脏、肝脏、脾脏、性腺、鳃、胃、肠、皮肤、脂肪、肌肉、头肾、胸腺、鳔),以β2actin作内标比较各组织芳香化酶基因表达量的差异,结果表明,赤点石斑鱼脑芳香化酶(P450aromB)有广泛的组织分布,脑和垂体的表达量很高,各组织表达量有明显的雌、雄差异;而性腺芳香化酶(P450aromA)表达主要集中于垂体和性腺,且不论雌雄,其性腺表达量均高于脑垂体,和P450aromB的表达模式明显不同,表现为在脑部,P450aromB表达量高于P450aromA,而在性腺,P450aromA表达量高于P450aromB,两种芳香化酶在脑垂体和性腺出现重叠表达[动物学报50(5):791-799,2004]。