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J.Nanopart.Res.,2009,11,1513–Rheological behaviour of ethylene glycol-titanate nanotube nano

BRIEF COMMUNICATIONRheological behaviour of ethylene glycol-titanate nanotube nanoﬂuidsHaisheng Chen ÆYulong Ding ÆAlexei Lapkin ÆXiaolei FanReceived:11July 2008/Accepted:4February 2009/Published online:26February 2009ÓSpringer Science+Business Media B.V.2009Abstract Experimental work has been performed on the rheological behaviour of ethylene glycol based nanoﬂuids containing titanate nanotubes over 20–60°C and a particle mass concentration of 0–8%.It is found that the nanoﬂuids show shear-thinning behaviour particularly at particle concentrations in excess of *2%.Temperature imposes a very strong effect on the rheological behaviour of the nanoﬂuids with higher temperatures giving stronger shear thinning.For a given particle concentration,there exists a certain shear rate below which the viscosity increases with increasing temperature,whereas the reverse occurs above such a shear rate.The normalised high-shear viscosity with respect to the base liquid viscosity,however,is independent of temperature.Further analyses suggest that the temperature effects are due to the shear-dependence of the relative contributions to the viscosity of the Brownian diffusion and convection.The analyses also suggest that a combination of particle aggregation and particle shape effects is the mechanism for the observed high-shear rheological behaviour,which is also supported by the thermal conductivity measure-ments and analyses.Keywords Rheological behaviour ÁEthylene glycol ÁTitanate nanotube ÁNanoﬂuid ÁThermal conductivityNanoﬂuids are dilute suspensions of particles with at least one dimension smaller than about 100nm (Choi 1995).Such a type of materials can be regarded as functionalized colloids with special requirements of a low-particle loading,a high-thermal performance,favourable ﬂow/rheolgocial behaviour,and a great physical and chemical stability over a wide range of process and solution chemistry conditions.Nano-ﬂuids have been shown to be able to enhance heat transfer (Choi 1995;Wang and Mujumdar.2007),mass transfer (Krishnamurthy et al.2006),and wetting and spreading (Wasan and Nikolov 2003),and have been a hot topic of research over the past decade (Wang and Mujumdar 2007;Keblinski et al.2005).Most published studies have focused on the heat transfer behaviour including thermal conduction (Choi 1995;Wang et al.1999;Wang and Mujumdar 2007;Keblinski et al.2005;Eastman et al.2001;He et al.2007;Ding et al.2006),phase change (boiling)heat transfer (Das et al.2003;Pak and Cho 1998),and convective heat transfer (Wang and Mujumdar 2007;Keblinski et al.2005;He et al.2007;Ding et al.2006,Chen et al.2008;Prasher et al.2006a and Yang et al.2005).Only few studies have been devoted to the rheological behaviour ofH.Chen ÁY.Ding (&)Institute of Particle Science and Engineering,University of Leeds,Leeds,UK e-mail:y.ding@pkin ÁX.FanDepartment of Chemical Engineering,University of Bath,Bath,UKJ Nanopart Res (2009)11:1513–1520DOI 10.1007/s11051-009-9599-9nanoﬂuids(He et al.2007;Chen et al.2008;Prasher et al.2006a,b;Kwak and Kim2005;Lee et al.2006), although there is a large body of literature on suspensions rheology;see for example,Russel et al. (1991);Chow(1993);Petrie(1999),Larson(1999); Goodwin et al.(2000)l;Mohraz et al.(2004);Larson (2005);Egres and Wagner(2005);Abdulagatov and Azizov(2006).Particularly,there is little in the literature on the effect of temperature on the rheo-logical behaviour of nanoﬂuids.Clearly,there is a gap in the current rheological literature for this type ofﬂuids.Furthermore,recent work has shown that the thermal behaviour of nanoﬂuids correlates well with their rheological behaviour(Prasher et al.2006a, b;Chen et al.2007a;Abdulagatov and Azizov2006). In a recent study,we investigated systemically the rheological behaviour of ethylene glycol(EG)based spherical TiO2nanoﬂuids(Chen et al.2007b).The results show that the nanoﬂuids are Newtonian over a shear rate range of0.5–104s-1and the shear viscosity is a strong function of temperature,particle concentration and aggregation microstructure.This work is concerned about the rheological behaviour of EG based nanoﬂuids containing titanate nanotubes (TNT).The speciﬁc objectives of the work are to investigate the effects of particle shape,particle concentration and temperature on nanoﬂuids viscosity, and to understand the relationship between the rheo-logical behaviour and the effective thermal conductivity of nanoﬂuids.It is for theﬁrst time that the rheological behaviour of a highly viscous EG based TNT nanoﬂuids is investigated in a systematic manner.As will be seen later,the results of this work provide further evidence that the rheological measure-ments could provide information of particle structuring for predicting the effective thermal conductivity of nanoﬂuids.The EG-TNT nanoﬂuids used in this work were formulated by using the so-called two-step method with EG purchased from Alfa Aesar and TNT synthesized in our labs using a method described elsewhere(Bavykin et al.2004).The details of nanoﬂuids formulation can be found elsewhere(Wen and Ding2005;He et al.2007;Chen et al.2007b). The TNT particles have a diameter(b)of*10nm and a length(L)of*100nm,giving an aspect ratio of(r=L/b)of*10.To avoid complications in interpreting the experimental results,no dispersants/ surfactants were used in the formulation.The nanoﬂuids formulated were found stable for over 2months.The rheological behaviour of the nano-ﬂuids was measured by using a Bolin CVO rheometer (Malvern Instruments,UK)over a shear rate range of 0.03–3,000s-1,a nanoparticle mass concentration of w=0–8%,and a temperature range of20–60°C (293–333K).The nanoﬂuids were characterised for their size by using a Malvern Nanosizer(Malvern Instruments,UK)and a scanning electron microscope (SEM).The average effective particle diameter was found to be*260nm for all nanoﬂuids formulated. This size is much larger than the equivalent diameter of the primary nanoparticles due to aggregation;see later for more discussion.Note that the particle size characterisation was performed both before and after the rheological measurements and no detectable changes to particle size were found.Figure1shows the viscosity of pure EG and EG-TNT nanoﬂuids as a function of shear rate at 40°C.The results at other temperatures are similar.It can be seen that the EG-TNT nanoﬂuids exhibit highly shear-thinning behaviour particularly when the TNT concentration exceeds*2%.Such behaviour is different from the observed Newtonian behaviour of EG-TiO2nanoﬂuids containing spherical nanoparti-cles over similar shear rate range(Chen et al.2007b) where the base liquid,EG,is the same as that used in the current wok.The behaviour is similar to the observations of carbon nanotube nanoﬂuids(Ding et al.2006)and CuO nanorod nanoﬂuids(Kwak and Kim2005),although there are important differencesbetween them such as temperature dependence as will be discussed later.The shear-thinning behaviour of well-dispersed suspensions can be interpreted by the structuring of interacting particles(Doi and Edwards1978a,b and Larson1999).In a quiescent state,a rod-like particle has three types of motion due to Brownian diffusion: rotational(end-over-end)motion around the mid-point and translational motion in parallel or perpendicular to the long axis.For dilute suspensions with a number density,c,ranging between0and1/L3or volume fraction,u,ranging between0and1/r2),the average spacing between the particles is larger than the longest dimension of the rod,and zero shear viscosity can be approximated by gð0Þ%g0ð1þAÁcL3Þwith g0the base liquid viscosity and A,a numerical constant(Doi and Edwards1978a).For suspensions with 1/L3\c\1/bL2or1/r2\f/\1/r,the rod-like particles start to interact.The rotational motion is severely restricted,as well as the translational motion perpendicular to the long axis,and the zero shear viscosity can be estimated by gð0Þ%g0ð1þðBcL3Þ3Þ; with B a numerical constant(Doi and Edwards1978b). As a consequence,the zero shear viscosity can be much greater than the base liquid viscosity.The large viscosity is due to the rod-like shape effect and the viscosity is very sensitive to shear,which tends to align particles and hence the shear-thinning behaviour as shown in Fig.1.Note that the above mechanism can give a qualitative explanation for the experimental observations at low-shear rates and the shear-thinning behaviour as shown in Fig.1,it does not explain the high-shear viscosity of the nanoﬂuids,which will be discussed later.It should also be noted that the criteria for classifying nanoﬂuids given above need to be modiﬁed due to the presence of aggregates;see later for more discussion.Figure2shows the shear viscosity of4.0%EG-TNT nanoﬂuids as a function of shear rate at different temperatures.The results under other concentrations are similar.It can be seen that the temperature has a very strong effect on the rheological behaviour of nanoﬂuids with higher temperatures giving stronger shear thinning.For shear rates below*10s-1,the shear viscosity increases with increasing temperature, whereas the trend is reversed when the shear rate is above*10s-1.As mentioned above,this behaviour was not observed for carbon nanotube(Ding et al. 2006)and CuO nanorod(Kwak and Kim2005)nanoﬂuids and we have not seen reports on such behaviour for nanoﬂuids in the literature;see later for more discussion on the underlying mechanisms. Figure2also shows that the strongest shear thinning occurs at40–60°C,whereas very weak-shear thinning takes places at20–30°C.It is also noted that the shear viscosity of nanoﬂuids at all temperatures investigated approaches a constant at high-shear rates.If the high-shear viscosity is plotted against temperature,Fig.3is obtained where the shear rate corresponding to the high-shear viscosity is taken as *2,000s-1.An inspection of all the data indicates that theyﬁt the following equation very well:ln g¼AþBÂ1000=TþCðÞð1Þwhere g is the shear viscosity(mPaÁs),T is the absolute temperature(K),and A,B and C areconstants given in Table1.Equation(1)takes a similar format as that widely used for liquid viscosity (Bird et al.2002)and for EG based nanoﬂuids containing spherical particles(Chen et al.2007b).If the measured high-shear viscosity is normalized with respect to the shear viscosity of the base liquid, the relative increaseðg i¼ðgÀg0Þ=g0Þof the high-shear viscosity is found to be only a function of concentration but independent of temperature over the temperature range investigated in this work.The relative increments in the shear viscosities of nano-ﬂuids containing0.5%,1.0%,2.0%,4.0%and8.0% particles are 3.30%,7.00%,16.22%,26.34%and 70.96%,respectively.Similar temperature indepen-dence of the shear viscosity was also observed for EG-TiO2and water-TiO2nanoﬂuids containing spherical nanoparticles(Chen et al.2007b).The experimentally observed temperature depen-dence can be interpreted as follows.Given the base liquid and nanoparticles,the functional dependence of viscosity on shear rate is determined by the relative importance of the Brownian diffusion and convection effects.At temperatures below*30°C,the contribu-tion from the Brownian diffusion is weak due to high-base liquid viscosity.As a consequence,the shear dependence of the suspension is weak(Fig.2).The contribution from the Brownian diffusion becomes increasingly important with increasing temperature particularly above40°C due to the exponential dependence of the base liquid viscosity on temperature (Fig.3).At very high-shear rates,the Brownian diffusion plays a negligible role in comparison with the convective contribution and hence independent of the high-shear viscosity on the temperature.We now start to examine if the classical theories for the high-shear viscosity predict the experimental measurements(note that there is a lack of adequate theories for predicting the low shear viscosity).Figure4shows the shear viscosity increment as a function of nanoparticle volume concentration together with the predictions by the following Brenner &Condiff Equation for dilute suspensions containing large aspect ratio rod-like particles(Brenner and Condiff1974):g¼g01þg½ uþO u2ÀÁÀÁð2Þwhere the intrinsic viscosity,½g ;for high-shear rates has the following form(Goodwin and Hughes2000):½g ¼0:312rln2rÀ1:5þ2À0:5ln2rÀ1:5À1:872rð3ÞAlso included in Fig.4are the data for EG-TiO2 nanoﬂuids with spherical nanoparticles(Chen et al. 2007b)and predictions by the Einstein Equation (Einstein1906,1911)for dilute non-interacting suspensions of spherical particles,g¼g01þ2:5uðÞ: It can be seen that both the Einstein and Brenner& Condiff equations greatly underpredict the measured data for the EG-TNT nanoﬂuids.The high-shear viscosity of EG-TNT nanoﬂuids is much higher than that of the EG-TiO2nanoﬂuids containing spherical nanoparticles,indicating a strong particle shape effect on the shear viscosity of nanoﬂuids.Although the shear-thinning behaviour of the nanoﬂuids could be partially attributed to the structuring of interacting rod-like particles,the large deviation between the measured high-shear viscosity and the predicted ones by the Brenner&Condiff equation cannot fully be interpreted.In the following,an attempt is made to explain the experimental observations from the viewpoint of aggregation of nanaoparticles,which have been shown to play a key role in thermal behaviour of nanoﬂuids in recent studies(Wang et al. 2003;Xuan et al.2003;Nan et al.1997;Prasher et al. 2006a,b;Keblinski et al.2005).Such an approach is also supported by the SEM and dynamic lightTable1Empirical constants for Eq.(1)a Maximum discrepancies;b Minimum discrepancies Concentration(wt%)A B C MaxD a(%)MinD b(%)0.0-3.21140.86973-154.570.62-1.440.5-3.42790.94425-148.490.93-0.471.0-2.94780.81435-159.14 1.11-0.692.0-2.2930.65293-174.57 1.64-0.694.0-2.63750.7574-165.820.99-0.948.0-2.73140.93156-145.010.88-1.57scattering analyses,which,as mentioned before, show clear evidence of particle aggregation.According to the modiﬁed Krieger-Dougherty equation(Goodwin and Hughes2000;Wang et al. 2003;Xuan et al.2003;Nan et al.1997),the relative viscosity of nanoﬂuids,g r,is given as:g r¼1Àu a=u mðÞÀ½g u mð4Þwhere u m is the maximum concentration at which the ﬂow can occur and u a is the effective volume fraction of aggregates given by u a¼u=u ma with u ma the maximum packing fraction of aggregates.As aggre-gates do not have constant packing throughout the structure,the packing density is assumed to change with radial position according to the power law with a constant index(D).As a result,u a is given as u a¼uða a=aÞ3ÀD;with a a and a,the effective radii of aggregates and primary nanoparticles,respectively. The term D is also referred as the fractal index meaning the extent of changes in the packing fraction from the centre to the edge of the aggregates.Typical values of D are given in normal textbook as D= 1.8–2.5for diffusion limited aggregation(DLA)and D=2.0–2.2for reaction limited aggregation(RLA); see for example Goodwin and Hughes(2000).For nanoﬂuids containing spherical nanoparticles,the value of D has been shown experimentally and numerically to be between1.6and1.8(Wang et al. 2003,Xuan et al.2003)and between1.8and2.3, respectively(Waite et al.2001).A typical value of 1.8is suggested for nanoﬂuids made of spherical nanoparticles(Prasher et al.2006a,b).However,little research has been found on the fractal index for nanoﬂuids containing rod-like nanoparticles.The colloid science literature suggests a fractal index of 1.5–2.45for colloidal suspensions depending on the type of aggregation,chemistry environment,particle size and shape and shearﬂow conditions(Haas et al. 1993;Mohraz et al.2004;Hobbie and Fry2006; Micali et al.2006;Lin et al.2007).In a recent study, Mohraz et al.(2004)investigated the effect of monomer geometry on the fractal structure of colloi-dal rod aggregates.They found that the fractal index is a non-linear function of the monomer aspect ratio with the D increasing from*1.80to*2.3when the aspect ratio of the rod-like nanoparticles increases from1.0to30.6.Based on the above,a value of D=2.1is taken for nanoﬂuids used in this work (Mohraz et al.2004,Lin et al.2007).Although the fractal model may appear to simplify the complexity of microstructures in aggregating systems containing rod-like particles,excellent agreement between the model prediction and experimental measurements exists when a a/a=9.46;see Fig.4.Here the aggregates are assumed to formﬂow units of an ellipsoidal shape with an effective aspect ratio of r a¼L a=b a;where L a and b a are the effective length and diameter,respectively.In the calculation,a typical value of u m of0.3is taken(Barnes et al.1989),and the intrinsic viscosity[g]is calculated by Eq.(3).It is to be noted that the aggregate size thatﬁts well to the rheological data(Fig.4)is consistent with the particle size analyses using both the SEM and the Malvern Nanosizer.A comparison between the EG-TNT data (a a/a=9.46,D=2.1,u m=0.30)and the EG-TiO2 data(a a/a=3.34,D=1.8,u m=0.605)(Chen et al. 2007b)in Fig.4suggests that the larger aggregate size in TNT nanoﬂuids be an important factor responsible for the stronger shear-thinning behaviour and higher shear viscosity of TNT nanoﬂuids.An inspection of Eq.(4)indicates that the effec-tive volume fraction u a u a¼u a a=aðÞ3ÀDis much higher than the actual volume fraction(u).This leads to the experimentally observed high-shear viscosity even for very dilute nanoﬂuids,according to the classiﬁcation discussed before.As a consequence,the demarcations deﬁning the dilute and semi-concen-trated dispersions should be changed by using the effective volume fraction.The model discussed above can also provide a macroscopic explanation for the temperature indepen-dence of the high-shear viscosity.From Eq.(4),one can see that the relative high-shear viscosity depends on three parameters,the maximum volume fraction, u m,the effective volume fraction,u a and the intrinsic viscosity,[g].For a given nanoﬂuid at a temperature not far from the ambient temperature,the three parameters are independent of temperature and hence the little temperature dependence of the relative shear viscosity.Microscopically,as explained before,the temperature-independent behaviour is due to negligi-ble Brownian diffusion compared with convection in high-shearﬂows.To further illustrate if the proposed aggregation mechanism is adequate,it is used to predict the effective thermal conductivity of the nanoﬂuids by using the following conventional Hamilton–Crosser model(H–C model)(Hamilton and Crosser1962):k=k0¼k pþðnÀ1Þk0ÀðnÀ1Þuðk0Àk pÞk pþðnÀ1Þk0þuðk0Àk pÞð5Þwhere k and k0are,respectively,the thermal conductivities of nanoﬂuids and base liquid,n is the shape factor given by n=3/w with w the surface area based sphericity.For TNT used in this work,the sphericity w is estimated as0.6(Hamilton and Crosser1962).For suspensions of aggregates,the above equation takes the following form:k=k0¼k aþðnÀ1Þk0ÀðnÀ1Þu aðk0Àk aÞa0a0að6Þwhere k a is the thermal conductivity of aggregates.To calculate k a,Eq.(6)is combined with the following Nan’s model(Nan et al.2003)for randomly dispersed nanotube-based composites:k a=k0¼3þu in½2b xð1ÀL xÞþb zð1ÀL zÞ3Àu in½2b x L xþb z L zð7Þwhere/in is the solid volume fraction of aggregates, b x¼ðk xÀk0Þ=½k mþL xðk tÀk mÞ and b z¼ðk zÀk0Þ=½k mþL zðk tÀk mÞ with k x,k m and k t being the thermal conductivities of nanotubes along trans-verse and longitudinal directions and isotropic thermal conductivity of the nanotube,respectively. In this work,k x,k m and k t are taken the same value as k p for aﬁrst order of approximation due to lack of experimental data,and L x and L z are geometrical factors dependent on the nanotube aspect ratio given by L x¼0:5r2=ðr2À1ÞÀ0:5r coshÀ1r=ðr2À1Þ3=2 and L z¼1À2L x:Figure5shows the experimental results together with predictions by the original H–C model(Eq.5) and revised H–C model(Eq.6).Here the experiment data were obtained using a KD2thermal property meter(Labcell,UK)(Murshed et al.2005;Chen et al. 2008).One can see that the measured thermal conductivity is much higher than the prediction by the conventional H–C model(Eq.5),whereas the modiﬁed H–C model taking into account the effect of aggregation(Eq.6)agrees very well with the exper-imental data.The above results suggest that nanoparticle aggregates play a key role in the enhancement of thermal conductivity of nanoﬂuids. The results also suggest that one could use the rheology data,which contain information of particle structuring in suspensions,for the effective thermal conductivity prediction.In summary,we have shown that EG-TNT nano-ﬂuids are non-Newtonian exhibiting shear-thinning behaviour over20–60°C and a particle mass concen-tration range of0–8%,in contrast to the Newtonian behaviour for EG-TiO2nanoﬂuids containing spher-ical particles.The non-Newtonian shear-thinning behaviour becomes stronger at higher temperatures or higher concentrations.For a given particle concen-tration,there exists a certain shear rate(e.g.*10s-1 for4wt%)below which the viscosity increases with increasing temperature,whereas the reverse occurs above such a shear rate.The normalised high-shearviscosity with respect to the base liquid viscosity, however,is found to be independent of temperature. These observations have not been reported in the literature for nanoﬂuids.Further analyses suggest that the temperature effects are due to the shear-depen-dence of the relative contributions to the viscosity of the Brownian diffusion and convection.The analyses also suggest that a combination of particle aggregation and particle shape effects is the mechanism for the observed high-shear rheological behaviour,which is supported not only by the particle size measurements but also by the thermal conductivity measurements and analyses using a combination of the H–C and Nan’s models.The results of this work also indicate that one could use the information of aggregation from the rheological experiments for predicting the effec-tive thermal conductivity of nanoﬂuids. 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我们人类的探索何尝不是如此。

无论遇到什么困难，我们都要不断探索。

中国的进步浩浩荡荡，势不可挡，在五千年的历史长河中，中国人民以自己的聪明智慧，凭自己的顽强不屈的精神，为人类做出了不可磨灭的贡献。

每次浩劫前，我们的英雄从未止步，如中华人民共和国的主要缔造者毛主席；解决中国几亿人吃饭困难的院士袁隆平；研制出埃博拉病毒疫苗的院士陈薇在困难面前，在未知领域面前，他们不断探索，从未止步。

我们要勇敢的接过这根光荣而又沉重的接力棒，继续奋斗，永不止步。

无论遇到什么困难，我们都会奔向家的港湾。

“秋风起兮白云飞，草木黄落兮雁南归。

”大雁排成美丽的十四行，在湛蓝的天空翱翔，南来北往，它们在干什么？是什么力量让它们不惧困难，飞越一座座高峰，穿过人类精心设计的一个个捕猎点，那是对家乡的执念，那是对亲朋的无限挂牵。

大雁如此，我们更是不能割舍对家的爱恋。

“每逢佳节倍思亲。

”归心似箭的游子，从未停止回家团圆的`脚步。

每年春季，中国人都有一次浩浩荡荡的大规模迁徙活动，由南到北，由北到南，抛到一边劳累与烦恼，此刻，归途成了风景，因为家才是心中的港湾。

无论遇到什么困难，我都要奔向终点。

一场大雨突然而至，一只小蝴蝶未及时躲闪，翅膀被雨水打湿了，惊魂未定的它，拼尽全力，扇动翅膀，终于可以停落在窗的边沿。

雨过天晴，它又在花丛中翩翩起舞，陶醉于五彩斑斓的美景中。

试想，如果它不与暴雨搏击，又怎能看到雨后这美丽的彩虹。

学习中，生活中，我们会遇到许多的困难，如一道难解的数学题，一篇无法下笔的作文，大量需要完成的作业如果我们被这些小困难吓到，那心中的梦想怎能实现？“心若在，梦就在。

”只要你步履坚定，一切困难就是毫不起眼的小泥丸。

从未止步，不要止步。

初中作文篇2这桃花开了，落了，一年复着一年，一天复着一天。

花开啦，花落啦。

花开啦，花又落啦。

郎咸平谈理念：四两何以拨千斤

郎咸平谈理念：四两何以拨千斤大卫：大家知道你是敢说真话的经济学家，你说的话大家都感兴趣，大家对你个人更充满兴趣。

能否谈谈你个人呢？郎咸平：我很喜欢跟我们的读者朋友谈我个人的问题。

我从来就不是一个品学兼优的好学生，小时候跟人家打架，而且还打不过别人……大卫：是不是屡败屡战啊？(笑)郎咸平：我想是屡战屡败更贴切一些，我没有那么伟大，没有屡败屡战的胸怀，只是小孩子喜欢跟人家吵架。

大卫：有些朋友特想问你，当年的理想是什么？郎咸平：当年没有理想。

只想考上大学，让爸爸妈妈高兴一下。

大卫：没有想过成为经济学家？郎咸平：从来不想的，当初大学毕业以后，当了两年记者，挺高兴的，正想大干一场的时候，遇上了服兵役，服完兵役后找不到工作，我是没有办法才出国的，实话告诉你，我根本就不想出国。

大卫：你现在是八面威风，当然也四面树敌，有人说你是纸上谈兵，有人说你是外星人，根本不了解中国国情，你怎么看呢？郎咸平：在2004年很多人说过我外星人不了解中国国情，可是现在没有人说了。

因为大概在两年之前，我就把2008年的中国说得非常清楚，从2008年之后没有人说这个话了，因为事实说明了一切，就像我前面所说的，股市泡沫、楼市泡沫的本质就是制造业的回光返照。

因此今年按照我的理论推导下来，那一定是股市跌，楼市跌，而下一步将是制造业大量倒闭，这是我2007年初讲的话，现在，又得到了验证。

大卫：想问一个小问题，你曾做过主持人，在主持人与经济学教授之间，你更喜欢哪一种？郎咸平：我没当过真正意义上的主持人，我是自弹自唱，我这样讲好了，经济学是基础，基础是不会让我激动的，真正让我激动的是做自弹自唱的主持人，可以这么说吧，上电视我都会激动的。

大卫：满足了你的虚荣心是不是。

郎咸平：(大笑)因为做主持人很过瘾，如果上电视的时候，又能把学术传播出去，那更有意思了。

不过，我觉得我还是更喜欢主持人这个角色。

大卫：那你想做哪个节目主持人？郎咸平：超女，哈哈哈。

大卫：有没有跟湖南卫视联系过？郎咸平：哈哈，没有。

【2018最新】团课新闻稿-推荐word版 (5页)

本文部分内容来自网络整理，本司不为其真实性负责，如有异议或侵权请及时联系，本司将立即删除！== 本文为word格式，下载后可方便编辑和修改！ ==团课新闻稿篇一：团课新闻稿能动12423“学习十八大”主题团课圆满结束11月25号晚7点201X级能动（3）班于九教三楼职工之家举行了“学习十八大”主题团课，同学们齐聚一堂，热情活泼的场面开启了能动三班新的一章。

参加本次团课的，除了全班同学外，还有班主任陈老师。

为了让大一更好的开展本班团课，陈老师特意为我们接到了职工之家。

本次团课由刘博和王欣主持，韩冠宇场控，刘博首先说：“十八大以一次胜利的大会顺利闭幕，当前大家都在学习十八大精神，我们适时召开专门团课学习十八大精神，希望大家认真学习，积极讨论，领悟十八大精神内涵，学习党的精神，做合格新时代大学生。

我宣布，团课正式开始。

”然后进入到本次团课的第一个环节。

第一环节是观看十八大胡主席报告视频，由于时间关系，我们重点观看了领导人入场介绍和办人民满意的教育，以及增加社会就业等与大学生密切相关的部分，为团课学习奠定了一个好的气氛。

接下来是第二个环节，班主任结合十八大报告详细地为大家解读，陈老师讲的很认真，很详细，设涉及了十八大报告的12个大方面，每个大点下面，老师又结合实际，结合我们的生活做了详细地解读，娓娓道来，语重心长。

经过老师的解读，十八大报告不再那样生硬陌生，相反切实联系着我们大学生生活，激起了同学们的兴趣。

紧接着到了第三个环节，这一环节是材料学习和问题抢答的环节。

刘博首先给大家读了一段材料，接着就材料向大家同学们提了许多问题，答对同学奖励给棒棒糖，整个场面充满了和谐，同学们积极参与活动，温暖和友好。

接着，李明辉汇报班级情景剧的比赛情况，雷阳祥通知了下周工作。

最后，一起观看了当时回顾党史纪录片主持人刘博宣布团课结束，班主任陈老师对本次团课做出了很高的评价，并激励我们今后认真办好每次团会，班会。

通过这次“学习十八大”的主题团课，同学们都感领悟到了十八大的精神内涵。

课程设计的范式与方法

课程设计的范式与方法2023-11-12目录CATALOGUE•课程设计概述•课程设计的范式•课程设计的方法•课程设计的实施步骤•课程设计的评估与改进•课程设计的实践案例01CATALOGUE课程设计概述课程设计是一个规划和实施教学计划、课程内容和教学方法的过程，旨在满足学生的学习需求和实现教育目标。

定义课程设计的目标是提高教学质量，促进学生学习效果，培养学生的知识、技能和态度，以满足个人和社会发展的需求。

目标定义与目标有效的课程设计能够适应不同学生的需求和能力，确保每个学生都能从教学中获益。

课程设计的重要性适应学生差异合理的课程设计有助于提高教学质量，通过精心规划和实施教学方法，确保学生能够掌握所需的知识和技能。

提高教学质量良好的课程设计能够培养学生的创新思维和解决问题的能力，通过提供具有挑战性的学习经验，鼓励学生主动探索和思考。

培养创新能力原则课程设计应遵循系统性、目的性、可行性和创新性等原则，以确保教学计划的全面性、目的性、实施性和发展性。

指导思想课程设计应以学生的学习需求和教学目标为导向，以培养学生的综合素质和实践能力为目标，注重学生的主体性和参与性，以及教师的专业性和指导性。

课程设计的原则与指导思想02CATALOGUE课程设计的范式总结词以经验为依据，强调实践和经验的重要性。

详细描述经验范式认为课程设计应该基于过去的经验和成果，通过实践和反复尝试来不断完善和优化。

这种范式强调实践的重要性，认为只有在实践中才能真正理解和掌握知识。

经验范式总结词以理性思维为指导，强调逻辑和规律的重要性。

详细描述理性主义范式认为课程设计应该基于理性的分析和思考，通过逻辑推理和规律总结来推导出最佳的课程方案。

这种范式强调规律和逻辑的重要性，认为只有这样才能设计出具有科学性和系统性的课程。

总结词以学生为中心，强调学生的主动性和建构性。

详细描述建构主义范式认为课程设计应该以学生为中心，充分发挥学生的主动性和建构性，让学生在学习过程中自主探索、自我完善。

【推荐】郎咸平秘密演讲-精选word文档 (11页)

本文部分内容来自网络整理，本司不为其真实性负责，如有异议或侵权请及时联系，本司将立即删除！== 本文为word格式，下载后可方便编辑和修改！ ==郎咸平秘密演讲篇一：(转)郎咸平沈阳激愤演讲原文地址：（转）郎咸平沈阳激愤演讲作者：黄海岸边一棵树（转）郎咸平沈阳激愤演讲作者：虎啸《郎咸平沈阳激愤演讲》中国从上说谎说到下，所有的数据他们全部造假。

任何新闻，只要有一点负面的全部都不能曝光。

不要以为现在天下太平了，其实什么都不能报导。

中国三十年经济改革的成果，中国老百姓基本上没有享受到，但是经济萧条所带来的恶果却要他们来背负，这是一个什么样的国家，什么样的执政者？摘自：宇天龙_副博《郎咸平沈阳激愤演讲》 (201X-11-13 15:11:37)篇二：郎咸平演讲今天这个题目叫做"中国楼市的疯狂急涨"，大家知道今天已经不是楼市问题了，随着楼市涨的还是股市，还有汽车，还有奢侈品，我们就以股市为例，中国的股市差不多是领先全世界达4 到5个月之久，就开始回暖了。

中国楼市在你们这儿跟上海差不多2、 3月就开始回暖。

美国的楼市到现在都没有回暖，我们2、3月就开始回暖，你看我们牛不牛。

奢侈品市场，全世界奢侈品狂跌14％，今年第一季度奢侈品平均跌幅10％，但是广东经济受挫最大的丽白广场狂涨20％，价值十几万几十万的名表狂涨90％以上。

汽车美国除了7月份除了旧车换新车拉动以外其他时间都是跌幅20、30％，就这几个市场而论，我们的股市、楼市、奢侈品市场，你应该觉得我们的经济回暖了，而是我在这儿，私底下告诉各位来宾一句话，如果我们的经济要比别人早这么长时间回暖，和别人这么不一样，请你千万相信，肯定是我们那里不正常了，而不是全世界其他国家都不正常了。

你比别人都早复苏，肯定你出了什么问题，那是可能的。

你就挖几条高速公路、印几张钞票就复苏了?你觉的可能吗？而且你们不要把股价和楼市当成经济回暖的指标，根本不是，因为当做经济危机的指标才正确一点。

设备检修安全措施及应急预案

案2023-11-05CATALOGUE目录•设备检修安全措施•设备检修应急预案•设备故障诊断与预防措施•设备维护与安全管理•典型案例分析•总结与展望01设备检修安全措施确保检修人员配备合适的个人防护装备，如防护眼镜、防护手套、防护鞋等，以防止在检修过程中受伤。

安全防护措施个人防护装备对需要检修的设备进行隔离，确保电源已经切断，避免在检修过程中发生意外启动或其他危险。

设备隔离在检修现场设置警示标识，提醒其他人员注意安全，避免干扰检修过程。

警示标识安全操作要求针对不同的检修任务，制定相应的安全操作要求，包括操作前的准备、操作过程中的注意事项等，确保检修过程安全可靠。

操作步骤明确检修设备的操作步骤，包括设备的关闭、拆卸、检查、维修等，确保检修人员按照规定的步骤进行操作。

操作记录记录检修过程中的操作步骤和相关数据，以便后续查阅和总结经验教训。

安全操作规程安全检查与监督安全监督安排专门的安全监督人员，对检修过程进行监督，发现不安全因素及时采取措施予以纠正。

安全培训定期对检修人员进行安全培训，提高他们的安全意识和操作技能，确保他们在工作中始终遵循安全规定。

安全检查在检修前对设备进行检查，确保设备处于安全状态，避免因设备故障导致的意外事故。

02设备检修应急预案应急响应流程事后处理事故处理完毕后，进行事后处理，包括原因调查、责任追究等。

应急处置在预案启动后，相关人员应按照预案要求进行应急处置，包括设备隔离、紧急抢修等。

启动应急预案根据事故的性质和影响范围，决定是否启动应急预案。

事故发现当发生设备故障或事故时，相关人员应立即报告给现场负责人。

现场初步评估现场负责人对事故进行初步评估，确定事故的性质和影响范围。

在设备故障导致电力中断时，应急发电机组可以提供电力支持。

应急发电机组在事故现场光线不足时，应急照明设备可以提供照明。

应急照明设备在设备故障时，应急工具和材料可以用于紧急抢修。

应急工具和材料在事故现场存在火灾或有害气体泄漏时，消防器材和安全帽可以用于紧急救援。

郎咸平沈阳演讲

中国和谐已经破产---记郎咸平10月22日沈阳演讲全文===============================================================香港中文大学教授、经济学家郎咸平于两周之前，即10月22日在沈阳发表了一个针对国有企业的演讲。

他说自己这次要讲的都是实话，并要求在座学员不要录像、录音，更不要发表微博评论，以避免难堪。

但是他的讲课录音还是被有心网友上传到了网上。

因演讲内容非常敏感，涉及许多中国目前的经济内幕与现状，如郎咸平称“中国和谐已经破产”等，现其演讲录音已被中国当局全面封杀。

鉴于4个多小时的录音，下载不易。

看中国编辑整理了其演讲内容，以飨读者。

文章中保留了其演讲时的粗口，以尽量保持原汁原味。

并加注小标题以方便阅读。

其演讲中有几处难以辨认，错漏在所难免。

其中谈到的“美国阴谋论”等内容，并不代表看中国网站的观点，请读者自行鉴别。

中国和谐已经破产既然听我讲课，我们人啊就上道一点，你不要把我讲的事情，拿到网站上去讨论，搞得大家都很难堪，为什么？因为我今天讲到的都是实话，在今天这个体制下啊，他妈实话是不能讲的，他妈从上说谎说到下，所有的数据，他妈全部造假，任何，任何新闻，只要有一点负面的啊，全部都不准报，建党90周年啊，对于媒体的打压啊，都从来没有今天这么严重，什么都不准报道，每个礼拜啊，一叠禁止令，什么负面都不可以报道，所以各位现在，你不要以为现在天下太平，其实是什么都不能报道，就这么简单，我们做这个电视节目啊痛苦不堪，什么题目都不准做，只要讲到跟整治有关，跟现实今天有关的，什么都不准做，因此呢，你们看到四个地方和谐批准发债，你们可能觉得是好消息，我告诉各位，完了，两个字，你还想让他发债呀！我今天的开场白，我们和谐已经破产了，你知不知道，各位同学，听到下午啊，听到你毛骨悚然，因此呢，我今天在开始讲课之前呢，必须跟你做个协议，四个要求，大家一定要切实遵行。

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