CUMCM-2019-Problem-C-Chinese2019高教社杯全国大学生数学建模竞赛题目
2019年高教社杯全国大学生数学建模竞赛题目大全(共5题)
2019高教社杯全国大学生数学建模竞赛题目（请先阅读“全国大学生数学建模竞赛论文格式规范”）A题高压油管的压力控制燃油进入和喷出高压油管是许多燃油发动机工作的基础，图1给出了某高压燃油系统的工作原理，燃油经过高压油泵从A处进入高压油管，再由喷口B喷出。
燃油进入和喷出的间歇性工作过程会导致高压油管内压力的变化，使得所喷出的燃油量出现偏差，从而影响发动机的工作效率。
图1 高压油管示意图问题1. 某型号高压油管的内腔长度为500mm，内直径为10mm，供油入口A 处小孔的直径为1.4mm，通过单向阀开关控制供油时间的长短，单向阀每打开一次后就要关闭10ms。
喷油器每秒工作10次，每次工作时喷油时间为2.4ms，喷油器工作时从喷油嘴B处向外喷油的速率如图2所示。
高压油泵在入口A处提供的压力恒为160 MPa，高压油管内的初始压力为100 MPa。
如果要将高压油管内的压力尽可能稳定在100 MPa左右，如何设置单向阀每次开启的时长？如果要将高压油管内的压力从100 MPa增加到150 MPa，且分别经过约2 s、5 s和10 s 的调整过程后稳定在150 MPa，单向阀开启的时长应如何调整？图2 喷油速率示意图问题2. 在实际工作过程中，高压油管A处的燃油来自高压油泵的柱塞腔出口，喷油由喷油嘴的针阀控制。
高压油泵柱塞的压油过程如图3所示，凸轮驱动柱塞上下运动，凸轮边缘曲线与角度的关系见附件1。
柱塞向上运动时压缩柱塞腔内的燃油，当柱塞腔内的压力大于高压油管内的压力时，柱塞腔与高压油管连接的单向阀开启，燃油进入高压油管内。
柱塞腔内直径为5mm，柱塞运动到上止点位置时，柱塞腔残余容积为20mm3。
柱塞运动到下止点时，低压燃油会充满柱塞腔（包括残余容积），低压燃油的压力为0.5 MPa。
喷油器喷嘴结构如图4所示，针阀直径为2.5mm、密封座是半角为9°的圆锥，最下端喷孔的直径为1.4mm。
针阀升程为0时，针阀关闭；针阀升程大于0时，针阀开启，燃油向喷孔流动，通过喷孔喷出。
2019-2019全国大学生英语竞赛(c类)试题及答案汇总-36页word资料
2019Part I Listening Comprehension (25 minutes, 30 marks)Part II Vocabulary and Structures ( 15 marks )There are 15 incomplete sentences in this part. For each blank there are four choices, marked A, B C and D. Choose the one that best completes the sentence, then mark the corresponding letter on the Answer Sheet with a single line through the center.31. When Ian was injured, Harry was chosen as last-minute for the rugby team.A. preferenceB. diversificationC. alternativeD. replacement32.—Hello, Mr. Brown, I’m ringing about our component delivery. It’s not arrived yet and it’s already three o’clock inthe afternoon.—Let’s see...it’s reach you on Tuesday afternoon.A. owing toB. likely toC. due toD. subject to33. Among the last groups of people to accept the new model were religious groups, who still the idea that the earth was the center of the universe.A. clung toB. applied toC. adapted toD. contributed to34. Although apparently rigid, bones exhibit a degree of elasticity that enables the skeleton to considerable impact.A. escapeB. overwhelmC. withstandD. suppress35.—Would you like me to go to the dentist with you?—No, you with me.A. need not to goB. need not goC. do not need goD. not need go36. Lance returned to cycling and training only five months after he was diagnosed with cancer.A. aggressivelyB. drasticallyC. exactlyD. initially37. Great minds generally look at life in a way to themselves.A. peculiarB. confinedC. similarD. unusual38. They called in an electrician he could put a finger on the cause of the short circuit.A. to hopeB. to be hopingC. hopingD. to have hoped39. The resistance experienced when one body moves over another, it is in contact, is called frictional force.A. to whichB. whereC. with whichD. while40. Above all, they want to study a question: Are humans actually aware of the world they live in?A. contraryB. fundamentalC. solemnD. progressive41.—Tina, I hear you had a good journey to the Maldives last week, How was it?—I enjoyed the beautiful scenery, but the hotel was satisfactory.A. not anythingB. nothing fromC. nothing butD. anything but42.At the beginning of the 20th century, people made coffee a cloth bag full of coffee grounds into boiling water.A. by dumpingB. to dumpC. for dumpingD. that dumped43. If you Sus an recently, you’d think the photograph on the right was strange.A. shouldn’t contactB. hadn’t contactC. weren’t to contactD. didn’t contact44. Beata: I’ve put the job advertisement in the newspaper, Mr. Trim.Trim: Good.Beata: Well, it was a bit more than the ＄10 that they quoted us.Trim: As long as it wasn’t ＄10 a day.A. How to schedule it?B. How much was it?C. How often was it put there?D. How about the newspaper?45. Woman: Who is Jackie Tow? I have a parcel here for him.Jackie: That’s me.Woman: Yes, put your name here.Jackie: Thank you. It must be the new pair of shoes I bought online.A. This is the receipt for it.B. Do you have the sender’s address?C. I have to check the packageD. Do I have to sign for it?Part III Cloze (10 marks)R ead the following passage and fill in each blank with one word. Choose the word in one of the following three ways: according to the context, by using the correct form of the given word, or by using the given letters of the word. Remember to write the answers on the answer sheet.Where The Wild Thing Are“I didn’t set out to make a children’s movie,” says Being john Malkovich director Spike Jonze , “I set out to make a movie about childhood.” Indeed, like the recent alternative children’s book (46) adapt , Fantastic Mr Fox, thisis more like an adult film (47) children’s clothing －or rather in Jim Henson monster suits. When rambunctious (无法无天) nine-year-old Max feels (48) ig by his busy single mum and her new boyfriend, and runs away (49) home , he finds himself on an island populated by huge, hairy, scary Wild Things. Here, he gets himself crowned king, and he and the monsters fight and play, and throw mud at each other (which the younger viewers will love). They return home. That’s it .And that’s your problem. As a film , I can’t (50) de it’s disappointing. Despite whimsical (异想天开) imaginative and heart-tugging moments, Jonze and co-writer Dave Eggers inevitably lose the wonderful subtlety (精妙之处) of Maurice sendak’s well-loved 338-word picture book just by (51) (spin) it out into a full-length feature. Enough already! We get this dysfunctional group of neurotic Wild Things (52) rep Max’s child’s eye view of grown-ups as comprehensible giants, both terrifying and loving.(53) , even the repetitive action and non-subtleties (54) ,make this feel more like family therapy than a fairy (55)t can’t destroy the film’s haunting magic.Part IV Reading Comprehension (40marks)Read the following passages carefully and answer the questions given. Remember to write the answers on the answer sheet.Section A (10 marks)HOLDA YS IN WALES1. Rhos –Ddu Country CottagesYnys, Criccieth LL532 OPBDelightful hideaway cottages with private fishing. Comfortably furnished with antiques, old oak beams, log fires, giving the aura and grace of a bygone age, but with all the essentials of the 20th century –sauna, jacuzzi , four poster bed ,snooker table… A holiday venue one rarely finds –but often dreams of.For Enquiries contact:Mrs A JonesRhandir, Boduan, Pwllheli Gwynedd, LL53 8UA2. Five Star CottageTalhenbont hall, Talhenbont, Criccieth, GwyneddEnq: Roger & Gillian GoodLovingly restored stone cottage and hunting lodge in 70 acre wooded country estate with river. A luxurious and carefree holiday for the discerning. Available throughout the year.Woodland walks and wildlife.Free tennis, riding and fishing .One mile from coast, five miles Snowdonia . Under the personal supervision of the owners.3.Windsor Flats12 Marine Terrace, Criccieth,Gwynedd,LL52 OEFOn sea front close to Criccieth Castlefortable, clean,fully equipped,completely private flats,in picturesque village central for Snowdonia and the Llyn Peninula. Climbing, sailing, fishing, walking, tennis and golf closeby. Colour TV,payphone.Bed linen supplied. Short breaks available out of season.Write or phone for brochure.4.Dwyach CottagesCticciech, GwyneddEnquiries: Mrs S Edwards Pen-y-Bryn,Chwilog, Pwllheli, Gwyhedd,LL53 6SXEnjoy a peaceful holiday in beautifully situated farmhouse or single storey cottage. This is an area of unrivalled natural beauty, the haunt of buzzards and woodpeckers. Cottages are superbly equipped to make your holiday relaxed and memorable. Dishwasher , washer/dryer, microwave, linen, children’s play area, barbecue and farm trail.5.Bron Afon Self CateringBorth-y-Gest, Phorthmadog, Gwynedd, LL49 9TUSituated only minutes from the beach with fabulous views of garden, sea and mountains. The accommodation is quiet and private. An ideal base for touring , walking, climbing, fishing, the slate mines, castles, Portmeirion, Porthmadog leisure centre or just relaxing on the beach.Bed & Breakfast also available.Question 56 to 58: Decide whether the following statements are true(T) or false(F) according to the advertisements.56.To have a holiday in a delightful hideaway cottage ,you should contact Mrs S Edwards.57.In the Cticcieth Five Star Hotel , free tennis ,game fishing, riding and golf are available.58.Short breaks are available out of season in the Llyn Peninsula.Question 59 to 60:Answer the following questions briefly according to the advertisements.59. If you plan to have a holiday with your children, what is the best place?60.What will you enjoy most in Bron Afon Self Catering?Section B(10 marks)The giant panda,the creature that has become a symbol of conservation ,is facing extinction. The major reason is loss of habitat, which has contitued despite the establishment of 14 panda reserves . Deforestation , mainly carried out by farmers clearing land to make way for fields as they move higher into the mountains,has drastically contracted the mamm al’s range. The panda has disappeared from much of central and eastern China, and is now restricted to the eastern flank of the Himalayas.Satellite imagery has shown the seriousness of the situation ; almost half of the panda’s habitat has been cut down or degraded since 1975.Worse ,the surviving panda population has also become fragmented; a combination of satellite imagery and ground surveys reveals panda “islands” in patches of forest separated by cleared land. The population of these islands has become isolated because the animals are loath to cross open areas .Just putting aroad through panda habitat may be enough to split a population in two.The minuscule size of the panda populations worries conservationists. The smallest groups have too few animals to be viable, and will inevitably die out .The larger populations may be viable in the short term, but will be susceptible to genetic defects as a result of inbreeding.In these circumstances, a more traditional threat to pandas – the cycle of flowering and subsequent withering of the bamboo that is their staple food – can become literally species-threatening. The flowering prompts pandas to move from one area to another, thus preventing inbreeding in otherwise sedentary populations. In pandas, however, bamboo flowering could prove catastrophic（灾难性的）because the pandas are unable emigrate.The latest conservation management plan for the panda, prepared by China’s Ministry of Forestry and the World Wide Fund for Nature, aims primarily at maintaining panda habitats and ensuring that populations are linked wherever possible. This plan will change some existing reserve boundaries, establish 14 new reserves and protect or replant corridors-of forest between panda islands. Other measures include better control of poaching, reducing the degradation of habitats outside reserves, and reforestation.The plan is ambitious. Implementation will be expensive and will require participation by individuals ranging from villagers to government officials.Question 61 to 65: Complete the summary with words from the passage, changing the form where necessary, only one word for each blank.The survival of the giant panda is being seriously (61) .This is largely because the overall size of their habitat has been reduced. As a result, pandas are more prone to problems and are unable to (62) around freely, following the growth cycles of (63) plant. A new plan aims to protect existing panda (64) and to join some of them together. This plan also involves reforestation and the creation of new reserves. To succeed, everyone, (65) both the government and individuals, will have to cooperate.Section C (10 marks)Honda has developed a way to read patterns of electric currents on a person’s scalp as well as changes in cerebral blood flow when a person thinks about four simple movements-moving the right hand, moving the left hand, running and eating.67 In a video shown at Tokyo headquarters, a person wearing a helmet sat still but thought about moving his right hand – a thought that was picked up by electrodes attached to his head inside the helmet.68 Honda said the technology wasn’t quite ready for a live demonstration because of possible distractions in the person’s thinking.Another problem is that brain patterns differ greatly among individuals, and so about two to three hours of studying them in advance are needed for the technology to work. The company, a leader in robotics, acknowledged the technology was still at a basic research stage, with no immediate practical applications in the works.69 Japan boasts one of the leading robotics industries in the world, and the government is pushing to develop the industry as a road to growth. Research on the brain is being tackled around the world, but Honda said its research was among the most advanced in figuring out ways to read brain patterns without having to hurt theperson, such as embedding (植入) sensors into the skin . Honda has made robotics a centerpiece of its image, sending Asimo to events and starring the walking, talking robot in TV ads.70 “Our products are for people to use. It is important for us to understand human behavior, ” he said.“We think this is the ultimate in making a machine move.”Question 66:Choose the best answer according to the passage.66. What does Honda say about its robot Asimo?A. It can detect a person’s way of thinking.B. It can imitate complex human movements.C. It is still in its experimental stage.D. It is ready for market distribution.Question 67 to 70: Choose the most appropriate of the following paragraphs that fit into questions 67 to 70 in the passage.A. “I’m talking about dreams today,” said Yasuhisa Arai, executive at the Honda Research Institute in Japan, the company’s research unit. “Practical uses are still way into the future.”B. Among the challenges for this brain technology is making the reading-device smaller so it can be portable, according to Honda.C. After several seconds, Asimo, programmed to respond to these brain signals, lifted its right arm.D. Honda succeeded in analysing these thought patterns, and then relayed them as wireless commands to Asimo, its human-shaped robot.Section D (10marks)Being an introvert is a bad thing, right? Well, a lot of people seem to think so, judging by the number of articles I’ve read about how to “cure” introversion. In response to these articles, I wrote The Introverts Strike Back, in which I argued that introverts can’t become extraverts, and they shouldn’t particularly want to.However, I’m not here to debate whether it’s better to be an introvert to an extravert. The fact is, we all have to interact with both types of people every day. Regardless of which type you are, you can greatly improve your relationships by learning to get along better with people of the other type. Here are some tips for getting started.For Introverts:*Indicate to others when you’re busy.When an extravert sees you reading, writing, or maybe just thinking, he might assume that the only reason you are doing t his is because you don’t have someone to talk to. So he thinks he’s doing you a favor by striking up a conversation, when he’s actually interrupting.To prevent this, be sure to give an indication that you’re in the middle of something and don’t want to socialiseright now. This can be a visual sign or verbal.I know one person who tended to get a lot of visitors at work, and while he was actually an extravert, the frequent visits were slowing him down too much. He put a sign on his door saying “If I don’t make eye contact or respond to you, I apologize. I’m not trying to be rude, I just have a lot of work to do. Thank you for understanding.” While I don’t think many people need to go that far, it certainly worked!*Realise that extraverts often need to talk.Because extraverts are more in touch with the external world, for them talking is something as necessary as breathing. They might think out loud by bouncing their thoughts off other people, and they might need to chat in order to boost their energy.For an introvert, this can be the most difficult part of dealing with an extravert. The same conversation that energises the extravert also drains the introvert. However, keeping in mind that the extravert is not being intentionally malicious, the introvert has at least two options for handling this in a polite way. They can patiently participate in the conversation, and then, when it’s over, recharge by being alone. Or they can cut off the conversation early by mentioning something else they need to be doing, or even by saying, “I’d like to help, but I’m not sure that I’m the right person for you to be talking to.”Of course, sometimes a conversation can be very enjoyable for an introvert, in which case this isn’t a problem.For Extraverts:*Ask if someone is busy before spending time with them.If someone appears to be lonely, they might not be. Even if they’re just sitting there and don’t seem to be doing anything, they could be deep in thought and not want to be interrupted.If you need something, try to ask for it up front. Otherwise, look for clues that they might not feel like talking right now, such as lack of eye contact.If they seem uninterested, don’t take it personally. You just don’t know what you’re interrupting.*Understand what a draining effect a conversation can have on someone.No matter how fabulous a person you are, keep in mind that introverts simply prefer their internal world to the external world. They might start off with a fully changed battery, but while they’re engaged in conversation, that battery is steadily draining. How long it lasts depends on various factors, but be sure to keep an eye out for when they’re starting to lose interest. Be more to the point with introverts, and save most of your chatting for extraverts who will appreciate it more.Questions 71 to 74: Complete each of the following sentences with NO MORE THAN FIVE WORDS according to the passage.71. Introverts are advised to to prevent interrupting when they are in the middle of something.72. For extraverts, having a conversation with people can be as important as73. An important clue that someone might not feel like talking with you right now is74. It is necessary to remember that introverts tend to focus more onQuestion 75: Choose the best answer according to the passage.75. What is the passage mainly about?A. Whether it is better to be an introvert or an extravert.B. How to get along with both introverts and extraverts.C. How to avoid embarrassment in conversations.D. One should be neither an introvert nor an extravert.Part V Translation (20marks)Section A (10 marks)Translate the underlined sentences in the following passage into Chinese. Remember to write the answers on the answer sheet.A soaring dropout rate is causing the United Stated to lose ground educationally to rivals abroad and is trapping millions of young American at the very margins of the economy. (76)The Obama administration acknowledges the problems in its new budget, which includes a ＄50 million prevention programme, but solving this problem will require a lot more money and a comprehensive national strategy.The alarming scope of the dropout crisis is laid out by the Center for Labor Market Studies at Northeastern University in Boston and the Alternative Schools Network in Chicago. (77)Their study, which examines data from the 12 largest states, finds that 16 percent of people from the ages of 16 to 24 have dropped out.(78) The problem is especially pronounced among men, who make up more than 60 percent of those who change school nationally. The dropout problem hits minorities really hard.(79) Many of this country’s large urban high schools are rightly called “dropout factories” because more students leave school than graduate. According to the study, state dropout rates are highest in the South, where Gerorgia (22.1 percent), Florida (20.1 percent) and Texas (18.5 percent) lead the way.(80) The dropout crisis presents a clear danger to national prosperity, but at the moment, states and localities are struggling to contain it with little help or guidance from the federal government. Congress, which is just waking up to this issue, can improve the situation by the putting its money and muscle behind proven programmes that have been shown to re-engage young people who have dropped out, and that keep at-risk children on track to complete their educations.Section B (10 marks)Translate the following sentences into English, using the words given in brackets. Remember to write the answers on the answer sheet.81.石油价格的飞速上涨对世界经济产生了很大的影响。
2019年数学建模国赛A题
2019高教社杯全国大学生数学建模竞赛题目（请先阅读“全国大学生数学建模竞赛论文格式规范”）A题高压油管的压力控制燃油进入和喷出高压油管是许多燃油发动机工作的基础，图1给出了某高压燃油系统的工作原理，燃油经过高压油泵从A处进入高压油管，再由喷口B喷出。
燃油进入和喷出的间歇性工作过程会导致高压油管内压力的变化，使得所喷出的燃油量出现偏差，从而影响发动机的工作效率。
图1 高压油管示意图问题1. 某型号高压油管的内腔长度为500mm，内直径为10mm，供油入口A处小孔的直径为1.4mm，通过单向阀开关控制供油时间的长短，单向阀每打开一次后就要关闭10ms。
喷油器每秒工作10次，每次工作时喷油时间为2.4ms，喷油器工作时从喷油嘴B处向外喷油的速率如图2所示。
高压油泵在入口A处提供的压力恒为160 MPa，高压油管内的初始压力为100 MPa。
如果要将高压油管内的压力尽可能稳定在100 MPa左右，如何设置单向阀每次开启的时长？如果要将高压油管内的压力从100 MPa增加到150 MPa，且分别经过约2 s、5 s和10 s的调整过程后稳定在150 MPa，单向阀开启的时长应如何调整？图2 喷油速率示意图问题2. 在实际工作过程中，高压油管A处的燃油来自高压油泵的柱塞腔出口，喷油由喷油嘴的针阀控制。
高压油泵柱塞的压油过程如图3所示，凸轮驱动柱塞上下运动，凸轮边缘曲线与角度的关系见附件1。
柱塞向上运动时压缩柱塞腔内的燃油，当柱塞腔内的压力大于高压油管内的压力时，柱塞腔与高压油管连接的单向阀开启，燃油进入高压油管内。
柱塞腔内直径为5mm，柱塞运动到上止点位置时，柱塞腔残余容积为20mm3。
柱塞运动到下止点时，低压燃油会充满柱塞腔（包括残余容积），低压燃油的压力为0.5 MPa。
喷油器喷嘴结构如图4所示，针阀直径为2.5mm、密封座是半角为9°的圆锥，最下端喷孔的直径为1.4mm。
针阀升程为0时，针阀关闭；针阀升程大于0时，针阀开启，燃油向喷孔流动，通过喷孔喷出。
2019全国大学生英语竞赛决赛c类试题
2019全国大学生英语竞赛决赛c类试题2019年全国大学生英语竞赛（C类）决赛试题涵盖了多个方面，包括听力、阅读、写作、翻译等部分。
以下是该试题的模拟内容：听力部分：1. 短对话理解：包含10个短对话，每个对话后有1个问题，考生需根据对话内容选择正确答案。
2. 长对话理解：2个长对话，每个对话后有3-5个问题，考生需理解对话的主旨和细节信息。
3. 短文理解：3篇短文，每篇短文后有3-5个问题，考生需理解短文的主旨大意和具体信息。
4. 听力填空：1篇短文，考生需根据听到的内容填写空缺的单词或短语。
阅读部分：1. 快速阅读：1篇文章，包含5个问题，考生需快速浏览文章并找到相关信息。
2. 阅读理解：3篇文章，每篇文章后有5个问题，考生需深入理解文章内容并回答相关问题。
3. 完形填空：1篇文章，包含10个空，考生需根据上下文选择合适的词汇填空。
写作部分：1. 图表作文：考生需根据所给图表信息，写一篇不少于150词的短文，描述图表所展示的趋势或特点。
2. 议论文写作：考生需就某一话题发表自己的观点，写一篇不少于200词的议论文。
翻译部分：1. 英译汉：1段英文材料，考生需将其翻译成中文。
2. 汉译英：1段中文材料，考生需将其翻译成英文。
词汇和语法部分：1. 词汇题：10个问题，涉及词汇的用法和意义。
2. 语法题：10个问题，涉及英语语法的各个方面。
智力测试部分：1. 逻辑推理题：5个问题，考生需通过逻辑推理解决相关问题。
2. 数学问题：5个问题，涉及基本的数学运算和推理。
注意：以上内容仅为模拟试题，实际的2019年全国大学生英语竞赛C 类决赛试题可能有所不同。
考生应以官方发布的试题为准。
数学建模大赛2019年c题
数学建模大赛2019年c题2019年高教社杯全国大学生数学建模竞赛C题"太阳灶加热"问题太阳灶是利用太阳能辐射加热的设备。
请你们建立一个数学模型来描述太阳灶加热过程，以便预测在给定时间和给定天气条件下，太阳灶的加热效果。
问题分析====首先，我们需要理解太阳灶的工作原理。
太阳灶是通过聚焦太阳光来加热物体的设备。
在这个过程中，太阳光首先被反射并集中到一个焦点上，然后通过这个焦点处的热量来加热物体。
因此，我们需要考虑两个主要因素：太阳光的能量和焦点处的温度。
其次，我们需要考虑如何将这些因素转化为数学模型。
由于太阳光的能量是随着时间变化的，因此我们需要一个时间函数来表示这个变化。
同时，我们需要一个函数来表示太阳灶的效率，即它如何将太阳光的能量转化为焦点处的热量。
最后，我们需要将这些函数结合起来，以预测在给定时间和天气条件下，太阳灶的加热效果。
这可以通过建立一个微分方程来实现，该方程描述了焦点处温度随时间的变化。
数学模型====1. 时间函数：我们使用一个时间函数 \(t(t)\) 来表示太阳光能量随时间的变化。
这个函数可以是任何描述太阳光强度随时间变化的函数。
例如，我们可以使用一个简单的线性函数：\(t(t) = a + bt\)，其中 \(a\) 和 \(b\) 是常数。
2. 效率函数：我们使用一个效率函数 \(e(T)\) 来表示太阳灶将太阳光能量转化为热量的效率。
这个函数可以是任何描述效率随温度变化的函数。
例如，我们可以使用一个简单的线性函数：\(e(T) = c + dT\)，其中 \(c\) 和 \(d\) 是常数。
3. 微分方程：我们将时间函数和效率函数结合起来，建立一个微分方程来描述焦点处温度随时间的变化：\(\frac{dT}{dt} = e(T) \cdot t(t)\)。
4. 初始条件和边界条件：我们需要为微分方程指定初始条件和边界条件。
例如，我们可以假设初始时焦点处的温度为0：\(T(0) = 0\)。
L215-中国大学生数学建模竞赛2019Problems-CUMCM-2019-Problem-E
2019年高教社杯全国大学生数学建模竞赛题目
（请先阅读“全国大学生数学建模竞赛论文格式规范”）
E题“薄利多销”分析
“薄利多销”是通过降低单位商品的利润来增加销售数量，从而使商家获得更多盈利的一种扩大销售的策略。
对于需求富有弹性的商品来说，当该商品的价格下降时，如果需求量（从而销售量）增加的幅度大于价格下降的幅度，将导致总收益增加。
在实际经营管理中，“薄利多销”原则被广泛应用。
(https:///item/薄利多销)
附件1和附件2是某商场自2016年11月30日起至2019年1月2日的销售流水记录，附件3是折扣信息表，附件4是商品信息表，附件5是数据说明表。
请根据这批数据，建立数学模型解决下列问题：
1.计算该商场从2016年11月30日到2019年1月2日每天的营业额和利润率
（注意：由于未知原因，数据中非打折商品的成本价缺失。
一般情况下，零售商的利润率在20%-40%之间)。
2.建立适当的指标衡量商场每天的打折力度，并计算该商场从2016年11月30
日到2019年1月2日每天的打折力度。
3.分析打折力度与商品销售额以及利润率的关系。
4.如果进一步考虑商品的大类区分，打折力度与商品销售额以及利润率的关系
有何变化？
附件1、附件2：销售流水记录
附件3：折扣信息表
附件4：商品信息表
附件5：数据说明表。
高教社杯全国大学生数学建模竞赛题目
高教社杯全国大学生数学建模竞赛题目高教社杯全国大学生数学建模竞赛已经成为了我国大学生数学建模领域一项极具影响力的赛事之一。
作为一项旨在提高大学生数学建模能力和创新能力的比赛，其题目的设计非常关键。
从2009年开始，高教社杯全国大学生数学建模竞赛就引入了“数学、建模和计算机”三个方面相结合来设置竞赛题目，旨在充分体现创新性、实际性和时代性。
每年的竞赛题目独具特色，既注重基础，又注重应用，给参赛选手提供了一个广泛展示科技创新成果的舞台，极大地推动了我国大学生数学建模水平的提升。
以下是近几年高教社杯全国大学生数学建模竞赛的题目：2019年：多元时空数据的融合与应用该题目要求选手用数据分析和模型建模技术进行多元时空数据融合，制作出能应用于数据分析、可视化和预测等领域的模型。
该题目考验选手的计算机应用能力和数据处理能力。
2018年：海洋环境与生态建设该题目需要选手从海洋生态、环境污染、资源利用、气候变化等方面出发，结合数学模型和计算机技术，探究关键问题。
选手要能积极运用大数据技术，分析丰富的海洋数据，并针对不同海洋问题给出行之有效的数学和计算模型。
2017年：共享单车智能管理与优化该题目以共享单车为研究对象，要求选手分析共享单车智能管理的效能，探究如何在现有的单车停放、调度、维修等方面研究出更优的管理模式，实现精准的数量分配和智能的管理系统。
以上三个题目从不同的角度出发，分别涉及了数据分析、海洋环境、共享单车等多个领域。
它们都融合了计算机技术和数学建模思想，是一道技术与创新相结合的精彩之作。
总体而言，高教社杯全国大学生数学建模竞赛的题目设计体现了需求实际、具有挑战性和创新性等特点，能够有效地提高大学生的数学建模和创新能力。
同时，它也为推进我国大学生数学建模水平的提升做出了重大贡献。
相信未来会有更多具有前瞻性和实践性的竞赛题目出现，让更多大学生通过数学建模实现梦想。
2019年全国大学生英语竞赛c类决赛试题
2019年全国大学生英语竞赛c类决赛试题2019年全国大学生英语竞赛C类决赛试题涵盖了听力、阅读、写作、翻译和综合知识等多个部分，旨在全面考察参赛学生的英语应用能力。
以下是试题的大致内容：听力部分1. 短对话理解：包含10个短对话，每个对话后有一个问题，要求学生根据对话内容选择正确答案。
2. 长对话理解：包括2个长对话，每个对话后有3-4个问题，学生需根据对话内容回答相关问题。
3. 短文理解：播放2篇短文，每篇后有3-4个问题，测试学生对短文主旨大意和细节信息的理解。
阅读部分1. 快速阅读：提供1篇文章，学生需要在限定时间内快速阅读并回答相关问题。
2. 阅读理解：包含3篇文章，每篇文章后有若干问题，要求学生仔细阅读并理解文章内容，然后选择或回答相关问题。
写作部分1. 应用文写作：如写一封邀请信、建议信或投诉信等，要求学生根据给定情景写出合适的应用文。
2. 议论文写作：提供话题，要求学生写出自己的观点，并给出支持观点的理由和例证。
翻译部分1. 英译汉：提供一段英文材料，要求学生翻译成中文。
2. 汉译英：提供一段中文材料，要求学生翻译成英文。
综合知识部分1. 词汇和语法：包含若干选择题，测试学生对英语词汇和语法知识的掌握。
2. 完形填空：提供一篇文章，其中部分词汇被删除，学生需要从选项中选择最合适的词汇填入空白处。
附加题1. 智力题：可能包括逻辑推理、数学问题等，旨在测试学生的逻辑思维和解决问题的能力。
请注意，以上内容仅为示例，具体的试题内容和题型可能会有所不同。
实际的试题应以官方发布的为准。
- 1、下载文档前请自行甄别文档内容的完整性，平台不提供额外的编辑、内容补充、找答案等附加服务。
- 2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
- 3、如文档侵犯您的权益，请联系客服反馈,我们会尽快为您处理(人工客服工作时间：9:00-18:30)。
2019高教社杯全国大学生数学建模竞赛题目（请先阅读“全国大学生数学建模竞赛论文格式规范”）
问题C 机场的出租车问题
大多数乘客下飞机后要去市区（或周边）的目的地，出租车是主要的交通工具之一。
国内多数机场都是将送客（出发）与接客（到达）通道分开的。
送客到机场的出租车司机都将会面临两个选择：
(A) 前往到达区排队等待载客返回市区。
出租车必须到指定的“蓄车池”排队等候，依“先来后到”排队进场载客，等待时间长短取决于排队出租车和乘客的数量多少，需要付出一定的时间成本。
(B) 直接放空返回市区拉客。
出租车司机会付出空载费用和可能损失潜在的载客收益。
在某时间段抵达的航班数量和“蓄车池”里已有的车辆数是司机可观测到的确定信息。
通常司机的决策与其个人的经验判断有关，比如在某个季节与某时间段抵达航班的多少和可能乘客数量的多寡等。
如果乘客在下飞机后想“打车”，就要到指定的“乘车区”排队，按先后顺序乘车。
机场出租车管理人员负责“分批定量”放行出租车进入“乘车区”，同时安排一定数量的乘客上车。
在实际中，还有很多影响出租车司机决策的确定和不确定因素，其关联关系各异，影响效果也不尽相同。
请你们团队结合实际情况，建立数学模型研究下列问题：
(1) 分析研究与出租车司机决策相关因素的影响机理，综合考虑机场乘客数量的变化规律和出租车司机的收益，建立出租车司机选择决策模型，并给出司机的选择策略。
(2) 收集国内某一机场及其所在城市出租车的相关数据，给出该机场出租车司机的选择方案，并分析模型的合理性和对相关因素的依赖性。
(3) 在某些时候，经常会出现出租车排队载客和乘客排队乘车的情况。
某机场“乘车区”现有两条并行车道，管理部门应如何设置“上车点”，并合理安排出租车和乘客，在保证车辆和乘客安全的条件下，使得总的乘车效率最高。
(4) 机场的出租车载客收益与载客的行驶里程有关，乘客的目的地有远有近，出租车司机不能选择乘客和拒载，但允许出租车多次往返载客。
管理部门拟对某些短途载客再次返回的出租车给予一定的“优先权”，使得这些出租车的收益尽量均衡，试给出一个可行的“优先”安排方案。