Chapter 15 Dynamically Driven Recurrent Networks 《神经网络与机器学习》教学课件

合集下载

英语学术写作智慧树知到课后章节答案2023年下重庆大学

英语学术写作智慧树知到课后章节答案2023年下重庆大学重庆大学第一章测试1.The English college students use to study their specialization is （）.答案:English for Specific Academic Purposes2.Which of the following is one of the features of academic English？（）答案:Technical terms3.Most of the research articles published on academic periodicals are of （）.答案:written expert genres4.Which type of report follows IMRD structure? （）答案:Genre-based report5.In IMRD structure, “D” stands for （）.答案:discussion第二章测试1.Please choose the best way to make the given sentence written by studentcorrect, more concise and formal: People tried to develop economy andignore the restraints of the natural environment. （）答案:People tried to develop economy and ignored the restraints of thenatural environment.2.Please choose the best way to make the given sentence written by studentcorrect, more concise and formal: It is apparently that ignorance of humanscause their own afflictions. （）答案:It is apparent that ignorance of humans has caused their own afflictions.3.Please choose the best way to make the given sentence written by studentcorrect, more concise and formal: There are many problems wait for peopleto solve and theses problems are tough. （）答案:Many tough problems are waiting for people to solve.4.Please choose the best way to make the given sentence written by studentcorrect, more concise and formal: The Internet has instead of teachers inmany classrooms. （）答案:The Internet has replaced teachers in many classrooms.5.Please choose the best way to make the given sentence written by studentcorrect, more concise and formal: Computer is conveniently, save us time, bring about entertainment, we can play games and watch movies, andconnect people in the distance. （）答案:Computer is convenient, saving us time, entertaining us with movies and games, and connecting us with people in the distance.第三章测试1.One of the characteristics of a good title is （）.答案:Researchable2.We can find In-depth information in （）.答案:research articles3.When you evaluate the sources, you need to take（） into consideration.答案:All of the above4.In a decimal outline, ideas are organized by （）.答案:Arabic number5.When drawing an outline，you need to make the main idea in each bodyparagraph （） the thesis statement.答案:logically connected with第四章测试1.In exposition, the writer often focuses on （）.答案:giving information2.In the process exposition, writers do not have to give a thesis statement. （）答案:对3.Feasibility report belongs to（） essay.答案:problem and solution4.Which of the following is true of a good argument? （）答案:A good argument is a claim that is justified.5.Academic writing tends to avoid words like “all”, “every”, “always”and neverbecause （）.答案:These words suggest absolutes第五章测试1.How does a good thesis statement help?（）答案:It gives the reader an idea what to expect.;It establishes a boundaryaround the subject;It charts an orderly course from the paper.;Itprevents the author from wandering aimlessly.2.What can be used as evidence to support the topic sentence? （）答案:Factual information;Statistics;tables;Words from authorities3.Evidence can speak for itself. （）答案:错4.Which of the following word do academic writers tend to avoid using （）.答案:In any case5.What can a writer do in conclusion?（）答案:To summarize the main points.第六章测试1.To guarantee unity, a writer needs make sure the supporting details in abody paragraph should relate back to the main idea presented by the （）.答案:topic sentence2.Coherence means “sticking （）”.答案:together3. A writer needs to repeat the key nouns to maintain coherence when （）.答案:the meaning of key nouns are diminishing.4.Overusing transitional words and phrases could make your writing （）.答案:redundant5.Theme is the（） element of a clause and it establishes what you are talkingabout.答案:first第七章测试1.Which of the following documentation styles is not usually used in the UnitedStates? （）答案:Harvard2.In the APA, all lines after the first line of each entry must be indented one-half inch from the left margin. This is called a(n) （） indentation.答案:Hanging3.In the MLA, when must we use block quotations? （）答案:Four lines of prose or three lines of verse4.For a direct quotation in the APA, they must always require a(n) （）_.答案:Page number5._____ is usually used cite sources in the humanities, including the fields ofliterature and foreign languages; _____ is usually used to cite sources in thesocial sciences. （）答案:MLA; APA第八章测试1.Plagiarism could occur in which of the following types of sources and media?（）答案:All of the above2.（） involves putting the main idea(s) into your own words, including onlythe main point(s), and are significantly shorter than the original and take abroad overview of the source material.答案:Summarizing3.（） involves putting a passage from source material into your own words,and takes a somewhat broader segment of the source and condensing itslightly.答案:Paraphrasing4.Which of the following is NOT a stated reason for why we shouldparaphrase/summarize from sources? （）答案:To show that you deserve a good grade for your work5.In （）, the author of the source referred to is only acknowledged throughthe reference not in the running text.答案:Non-integral第九章测试1.Choose the best answer to make the following sentence accurate andacademic: Some people believe teamwork is efficient, but the professor （）it is not always true.答案:argues2.Which of the following sentence is more academic? （）答案:It is of importance to improve the environmental awareness.3.Which of the following multi-word phrases indicates the stance of the writer?（）答案:As far as I am concerned4.Which of the following words sounds more academic? （）答案:Much5.Which of the following sounds more like a technical term? （）答案:Currency第十章测试cation is a soft-pure discipline. （）答案:错2.Register is about the social context in which a discourse appears. （）答案:对3.Contractions should be avoided in any writing but acceptable in spokenEnglish. （）答案:错4.Nominalization is one of the characteristics of the academic writing, but itmay cause （）答案:对5.Hedging indicates that we should be cautious in speaking and writingespecially when we propose something new or draws a conclusion. （）答案:对第十一章测试1.An abstract is a broad and comprehensive summary of the contents of thearticle. （）答案:错2. A well-prepared abstract can be the most important single paragraph in anarticle. （）答案:对3.The abstract needs to be loose with information. （）答案:错4.Abstract should include （）答案:The main points of the research;Key discoveries;Backgroundinformation or main problem;Conclusion or suggestion for future action5. A well-prepared abstract can be （）答案:coherent and readable;accurate;non-evaluative;concise。

通向实在之路英文版

通向实在之路英文版The Path to Reality (通向实在之路) is a book written by British physicist Sir Roger Penrose. The book explores various aspects of mathematics, physics, and philosophy, providing a comprehensive and multidimensional perspective on the nature of reality.In "The Path to Reality," Penrose delves into the fundamental principles of mathematics and theirrelationship to the physical world. He discusses topics such as geometry, algebra, calculus, and their applications in physics. Penrose also explores the concept of space and time, discussing theories like relativity and quantum mechanics.Furthermore, Penrose delves into the philosophical implications of these scientific theories. He examines the nature of consciousness, the role of mathematics in understanding reality, and the potential limitations of scientific knowledge. Penrose's exploration goes beyondtraditional scientific boundaries, addressing profound questions about the nature of existence itself."The Path to Reality" offers a comprehensive and in-depth analysis of the interconnectedness between mathematics, physics, and philosophy. Penrose's approach provides readers with a holistic understanding of reality, emphasizing the importance of both scientific and philosophical perspectives in unraveling the mysteries of the universe.Overall, "The Path to Reality" serves as a thought-provoking and enlightening guide for those interested in gaining a deeper understanding of the fundamental nature of reality from various angles, combining rigorous scientific analysis with philosophical contemplation.。

(完整版)Chapter14,15

十四章土壤及其应用Soil and land are not the same. Land is the part of the world not covered by the oceans. Soil is a thin covering over the land consisting of a mixture of minerals, organic material, living organisms, air, and water that together support the growth of plant life.土壤和陆地是不同的。

陆地是地球上未被海洋覆盖的部分。

土壤是陆地上一层薄的覆盖层，由矿物质、有机质、活的生物体、空气和水组成的混合物，这些物质一起支持植物的生长。

A combination of physical, chemical, and biological events acting over time is responsible for the formation of soil.土壤的形成涉及一系列物理、化学和生物过程。

The organic material resulting from the decay of plant and animal remains is known as humus.植物和动物残骸分解产生的有机物质称为腐殖质。

Soil properties include soil texture, structure, atmosphere, moisture, biotic content and chemical composition. Soil texture is determined by the size of the mineral particles within the soil.土壤的性质包括土壤的质地、结构、含气量、水分、生物和化学组分等。

英语考研2024真题答案

英语考研2024真题答案### English Postgraduate Entrance Examination 2024: Sample Answers#### Part I: Reading Comprehension (40 points)Passage 1: The Impact of Technology on EducationThe article discusses the profound influence of technology on modern education. It highlights how digital tools have revolutionized teaching methods, making learning more interactive and personalized. The integration of AI in classrooms has allowed for the creation of adaptive learning environments that cater to the needs of individual students. Moreover, the use of online platforms has expanded access to education, breaking down geographical barriers and providing opportunities for lifelong learning.Questions:1. What is the primary focus of the article?- The primary focus is the impact of technology on the field of education.2. How has AI been utilized in classrooms?- AI has been used to create adaptive learning environments tailored to individual students' needs.3. What benefits does online education offer?- Online education offers expanded access, overcoming geographical limitations and promoting lifelong learningopportunities.Passage 2: Climate Change and Its Effects on BiodiversityThis passage examines the alarming effects of climate change on global biodiversity. It underscores the rapid loss of species due to habitat destruction and altered ecosystems. The text also discusses the potential for climate change to exacerbate existing threats to biodiversity, such as overfishing and deforestation. The urgency for global action to mitigate these effects is emphasized, with the need for sustainable practices and conservation efforts.Questions:1. What is the main concern of the passage?- The main concern is the impact of climate change on biodiversity and the rapid loss of species.2. Which factors contribute to the threats to biodiversity mentioned in the passage?- Factors include habitat destruction, altered ecosystems, overfishing, and deforestation.3. What solutions does the passage suggest?- The passage suggests global action, sustainable practices, and conservation efforts as solutions.#### Part II: Cloze Test (20 points)In the cloze test section, candidates are required to fill in the blanks with the most appropriate word from the given options to ensure the passage makes sense both contextually and grammatically. This section tests the ability tounderstand context and the correct usage of vocabulary.#### Part III: Translation (20 points)English to Chinese:Translate the following sentence into Chinese, ensuring accuracy and fluency.- "The rapid development of urbanization has led to a series of environmental issues."Chinese to English:Translate the following sentence into English, maintaining the original meaning and ensuring natural language flow.- "随着科技的不断进步，我们的生活变得越来越便利。

新发展研究生英语2翻译

UNIT 1五十年前父母大都会问男孩子们长大后想不想当总统，问这话时一本正经，并非开玩笑。

许多穷得跟乞丐似的父母也仍然相信他们的孩子能当上总统。

亚伯拉罕•林肯就做到了。

我们与林肯那个时代仅仅差年。

依然健在的许多爷爷辈的人还能记得林肯时代。

就是他们最喜欢问你长大后想不想当总统。

回答说想当的小男孩数量多得惊人，而且他们是当真的。

我就曾经被问过多次。

我会回答说不，我长大后不想当总统。

有一个年纪大的叔叔，当着母亲的面向我提出这个问烂了的问题，发现了我对当总统不感兴趣，他就接着又问：“那你长大了想干什么呢？我那时喜欢到垃圾堆上去拣东西，收集空瓶子、有漂亮标签的罐子和废弃的杂志。

世界上最吸引我的工作立刻浮现在我的脑子里。

“我想当一个垃圾工。

”我说道。

叔叔听后笑了，而母亲却觉察到了我那呆头呆脑的苗头，不免伤心。

“有点上进心吧，拉塞尔。

”她说道。

她叫我“拉塞尔”表明她不高兴，因为她夸我的时候总是叫我“小家伙”。

转眼间我长到了八岁，她觉得我得找个工作，开始踏上那条让我自己成就点什么的道路，而不能再四平八稳地坐失良机了。

“巴迪”，有一天她跟我说，“今天放学后马上回家。

有人要来，我要你见见他。

”那天下午我冲进家门的时候，她正在客厅里跟柯蒂斯出版公司的一个负责人谈话。

他把我介绍给他。

他弯下腰和我握了握手，问我是不是像母亲说的那样渴望获得进入商界的机会。

母亲在一旁忙说我决意要使自己成为一个有所成就的人。

“是的。

”我低声说。

“那么，你是否具备在商业上获得成功所需要的刚强、勇气和绝不放弃的精神呢？”母亲回答说我当然具备。

“是的。

”我说。

他盯着我好一会儿，默不作声，似乎在掂量着我是否值得他的信任，然后和我坦率地谈了起来。

他说，在走出关键性的一步之前，他得提醒我，年轻人为柯蒂斯出版公司工作要承担巨大的责任。

它是美国最了不起的公司之一，也许是世界上最了不起的出版公司。

毫无疑问，我肯定听说过《星期六晚邮报》吧？岂止听说过母亲说全家人可是都知道《星期六邮报》的，而且说我实际上是它的忠实读者。

2025新航道考研英语阅读

2025新航道考研英语阅读In the year 2025, the landscape of postgraduate entrance examinations has evolved, with a new emphasis on English proficiency. The reading section has become a pivotal part of the test, reflecting the globalized nature of academia.This new paradigm demands a deeper understanding ofdiverse topics, from scientific breakthroughs to cultural studies. Students are expected to not only comprehend complex texts but also to analyze and synthesize information in a nuanced manner.The inclusion of contemporary issues in the reading materials ensures that candidates stay informed about global events and their implications. This approach prepares themfor the challenges of a rapidly changing world, where cross-cultural communication is key.Moreover, the test format has been designed to assess critical thinking skills. Questions often require inferential reasoning, where students must draw conclusions based on the information presented in the texts.The diversity of the reading materials also extends tothe styles of writing. Students are exposed to various genres, including academic papers, editorials, and narratives, which helps them develop a versatile reading repertoire.Another notable feature of the 2025 English reading section is the integration of multimedia elements. Articles may be accompanied by graphs, charts, and images, requiring students to interpret visual data alongside textual content.The preparation for this section involves extensive reading practice, with a focus on speed and comprehension. Strategies such as skimming, scanning, and summarization are essential for managing the time constraints of the exam.Lastly, the 2025 English reading section underscores the importance of adaptability. Students must be ready to engage with unfamiliar content and demonstrate their ability to learn and adapt quickly, a skill highly valued in the professional world.。

基于自适应多尺度注意力机制的CNN-GRU矿用电动机健康状态评估

基于自适应多尺度注意力机制的CNN−GRU矿用电动机健康状态评估谭东贵，袁逸萍，樊盼盼（新疆大学智能制造现代产业学院，新疆乌鲁木齐　830017）摘要：利用多传感器信息融合技术进行电动机健康状态评估时，矿用电动机监测数据中存在异常值和缺失值，而卷积神经网络和循环神经网络等深度学习模型在数据质量下降严重的情况下难以有效提取数据特征和更新网络权重，导致梯度消失或爆炸等问题。

针对上述问题，提出了一种基于自适应多尺度注意力机制的CNN−GRU （CNN−GRU−AMSA ）模型，用于评估矿用电动机健康状态。

首先，对传感器采集的电动机运行数据进行填补、剔除和标准化处理，并以环境温度变化作为依据对矿用电动机运行数据进行工况划分。

然后，根据马氏距离计算出电动机电流、电动机三相绕组温度、电动机前端轴承温度和电动机后端轴承温度等健康评估指标的健康指数（HI ），采用Savitzky–Golay 滤波器对指标HI 进行降噪、平滑、归一化处理，并结合主成分分析法计算的不同指标对矿用电动机的贡献度，对指标HI 进行加权融合得到矿用电动机HI 。

最后，将矿用电动机HI 输入CNN−GRU−AMSA 模型中，该模型通过动态调整注意力权重，实现对不同尺度特征的信息融合，从而准确输出电动机健康状态评估结果。

实验结果表明，与其他常见的深度学习模型CNN ，CNN−GRU ，CNN−LSTM ，CNN−LSTM−Attention 相比，CNN−GRU−AMSA 模型在均方根误差、平均绝对误差、准确率、Macro F1及Micro F1等评价指标上更优，且预测残差的波动范围更小，稳定性更优。

关键词：电动机健康状态评估；自适应多尺度注意力机制；CNN−GRU ；多传感器信息融合；主成分分析中图分类号：TD614 文献标志码：AHealth status evaluation of CNN-GRU mine motor based on adaptive multi-scale attention mechanismTAN Donggui, YUAN Yiping, FAN Panpan(Intelligent Manufacturing Modern Industry College, Xinjiang University, Urumqi 830017, China)Abstract : When using multi-sensor information fusion technology to evaluate the health status of motors,there are outliers and missing values in the monitoring data of mine motors. However, deep learning models such as convolutional neural networks and recurrent neural networks find it difficult to effectively extract data features and update network weights when the data quality is severely degraded, resulting in problems such as vanishing or exploding gradients. In order to solve the above problems, A CNN-GRU (CNN-GRU-AMSA) model based on adaptive multi-scale attention mechanism is proposed to evaluate the health status of mine motors. Firstly, the model fills in, removes, and standardizes the motor operation data collected by sensors, and classifies the operating conditions of mine motors based on environmental temperature changes. Secondly, based on the Mahalanobis distance, the health index (HI) of health evaluation indicators such as motor current, three-phase收稿日期：2023-11-08；修回日期：2024-02-25；责任编辑：盛男。

122急性胰腺炎患者血清降钙素原测定及其临床意义

文章编号:1007-4287(2004)06-0633-02急性胰腺炎患者血清降钙素原测定及其临床意义宋秀琴1,时　兢2,俞娅芬1,穆会君2(11苏州大学附属无锡市第四人民医院IC U,江苏无锡214062;21南京医科大学附属无锡市第一人民医院IC U)摘要:目的　探讨急性胰腺炎(AP)患者血清降钙素原(PCT)水平变化及其意义。

方法　根据AP的临床诊断标准,入选的45例AP患者分为水肿型20例和出血坏死型25例。

采用免疫发光法测定其入院第1、4、7、10天血清PCT,并与正常对照组15例进行比较。

结果　AP患者血清PCT水平明显高于正常对照组,出血坏死型患者血清PCT水平明显高于水肿型,且持续较长时间(>7天)。

结论　PCT可以作为AP的早期诊断和判断预后的指标。

关键词:降钙素原;急性胰腺炎;鉴别诊断;指标中图分类号:R65715+1文献标识码:AThe Measurement and It’s Clinical Significance of Serum Procalcitonin(PCT)in P atients with Acute P ancreatitis SH ONG Xiu2qin,SHI Jing,YU Ya2fen,et al.(The Fourth Hospital o f Wuxi City,Wuxi214062,China)Abstract:Objective　T o probe into the changes and clinical significance of serum procalcitonin(PCT)levels in patients with acute pancreatitis.Methods　According to the clinical diagnostic criteria of acute pancreatitis,forty2five patients were divided into tw o groups:simple edematous panceratitis(n=20)and haem orrhagic necrotic pancreatitis(n=25).Blood samples were collected on the day of admission(day1)in intensive care unit and on days4,7and10.C ompared with the normal control group(n=15),PCT plasma levels were determined dynamically,using a specific immunoluminometric assay.R esults　Serum PCT levels of acute pancre2 atitis were much m ore higher than of control group,s o as do the group of haem orrhagic necrotic pancreatitis than group of simple edematous pancreatitis,and the serum PCT levels of haem orrhagic necrotic pancreatitis group continues much m ore longer(>7day).Conclusion　PCT routinely measurements can be useful in the early diagnosis and prognosis of acute pancreatits.K ey w ords:procalcitonin;acute pancreatits;differential diagnosi;marker(Chin J Lab Diagn,2004,8:633) 血清降钙素原(procalctionin,PCT)是最近应用于临床的重症感染监测指标,对全身炎症反应(sys2 tenic in flammatory response syndrome,SIRS)和全身性感染(sepsis)具有较高的诊断价值[1,2]。

机器学习PPT(15)

Figure 15.12 Illustration of the vanishing-gradient problem: (a) State xn resides in the basin of attraction, β, but outside the reduced attraction set . (b) State xn resides inside the reduced attraction set .
Copyright ©2009 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved.
Table 15.2
Neural Networks and Learning Machines, Third Edition Simon Haykin
Copyright ©2009 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved.
Figure 15.14 Closed-loop feedback system embodying the RMLP and the EKF: (a) The RMLP, with weight vector ˆwn|n - 1, operates on the input vector un to produce the output vector yn. (b) The EKF, supplied with the prediction ˆdn|n - 1 = yn, operates on the desired response dn to produce the filtered weight vector ˆwn|n = ˆwn+1|n, thereby preparing the closed-loop feedback system for the next iteration.

Glider Flying Handbook说明书

Glider Flying Handbook2013U.S. Department of TransportationFEDERAL AVIATION ADMINISTRATIONFlight Standards Servicei iPrefaceThe Glider Flying Handbook is designed as a technical manual for applicants who are preparing for glider category rating and for currently certificated glider pilots who wish to improve their knowledge. Certificated flight instructors will find this handbook a valuable training aid, since detailed coverage of aeronautical decision-making, components and systems, aerodynamics, flight instruments, performance limitations, ground operations, flight maneuvers, traffic patterns, emergencies, soaring weather, soaring techniques, and cross-country flight is included. Topics such as radio navigation and communication, use of flight information publications, and regulations are available in other Federal Aviation Administration (FAA) publications.The discussion and explanations reflect the most commonly used practices and principles. Occasionally, the word “must” or similar language is used where the desired action is deemed critical. The use of such language is not intended to add to, interpret, or relieve a duty imposed by Title 14 of the Code of Federal Regulations (14 CFR). Persons working towards a glider rating are advised to review the references from the applicable practical test standards (FAA-G-8082-4, Sport Pilot and Flight Instructor with a Sport Pilot Rating Knowledge Test Guide, FAA-G-8082-5, Commercial Pilot Knowledge Test Guide, and FAA-G-8082-17, Recreational Pilot and Private Pilot Knowledge Test Guide). Resources for study include FAA-H-8083-25, Pilot’s Handbook of Aeronautical Knowledge, FAA-H-8083-2, Risk Management Handbook, and Advisory Circular (AC) 00-6, Aviation Weather For Pilots and Flight Operations Personnel, AC 00-45, Aviation Weather Services, as these documents contain basic material not duplicated herein. All beginning applicants should refer to FAA-H-8083-25, Pilot’s Handbook of Aeronautical Knowledge, for study and basic library reference.It is essential for persons using this handbook to become familiar with and apply the pertinent parts of 14 CFR and the Aeronautical Information Manual (AIM). The AIM is available online at . The current Flight Standards Service airman training and testing material and learning statements for all airman certificates and ratings can be obtained from .This handbook supersedes FAA-H-8083-13, Glider Flying Handbook, dated 2003. Always select the latest edition of any publication and check the website for errata pages and listing of changes to FAA educational publications developed by the FAA’s Airman Testing Standards Branch, AFS-630.This handbook is available for download, in PDF format, from .This handbook is published by the United States Department of Transportation, Federal Aviation Administration, Airman Testing Standards Branch, AFS-630, P.O. Box 25082, Oklahoma City, OK 73125.Comments regarding this publication should be sent, in email form, to the following address:********************************************John M. AllenDirector, Flight Standards Serviceiiii vAcknowledgmentsThe Glider Flying Handbook was produced by the Federal Aviation Administration (FAA) with the assistance of Safety Research Corporation of America (SRCA). The FAA wishes to acknowledge the following contributors: Sue Telford of Telford Fishing & Hunting Services for images used in Chapter 1JerryZieba () for images used in Chapter 2Tim Mara () for images used in Chapters 2 and 12Uli Kremer of Alexander Schleicher GmbH & Co for images used in Chapter 2Richard Lancaster () for images and content used in Chapter 3Dave Nadler of Nadler & Associates for images used in Chapter 6Dave McConeghey for images used in Chapter 6John Brandon (www.raa.asn.au) for images and content used in Chapter 7Patrick Panzera () for images used in Chapter 8Jeff Haby (www.theweatherprediction) for images used in Chapter 8National Soaring Museum () for content used in Chapter 9Bill Elliot () for images used in Chapter 12.Tiffany Fidler for images used in Chapter 12.Additional appreciation is extended to the Soaring Society of America, Inc. (), the Soaring Safety Foundation, and Mr. Brad Temeyer and Mr. Bill Martin from the National Oceanic and Atmospheric Administration (NOAA) for their technical support and input.vv iPreface (iii)Acknowledgments (v)Table of Contents (vii)Chapter 1Gliders and Sailplanes ........................................1-1 Introduction....................................................................1-1 Gliders—The Early Years ..............................................1-2 Glider or Sailplane? .......................................................1-3 Glider Pilot Schools ......................................................1-4 14 CFR Part 141 Pilot Schools ...................................1-5 14 CFR Part 61 Instruction ........................................1-5 Glider Certificate Eligibility Requirements ...................1-5 Common Glider Concepts ..............................................1-6 Terminology...............................................................1-6 Converting Metric Distance to Feet ...........................1-6 Chapter 2Components and Systems .................................2-1 Introduction....................................................................2-1 Glider Design .................................................................2-2 The Fuselage ..................................................................2-4 Wings and Components .............................................2-4 Lift/Drag Devices ...........................................................2-5 Empennage .....................................................................2-6 Towhook Devices .......................................................2-7 Powerplant .....................................................................2-7 Self-Launching Gliders .............................................2-7 Sustainer Engines .......................................................2-8 Landing Gear .................................................................2-8 Wheel Brakes .............................................................2-8 Chapter 3Aerodynamics of Flight .......................................3-1 Introduction....................................................................3-1 Forces of Flight..............................................................3-2 Newton’s Third Law of Motion .................................3-2 Lift ..............................................................................3-2The Effects of Drag on a Glider .....................................3-3 Parasite Drag ..............................................................3-3 Form Drag ...............................................................3-3 Skin Friction Drag ..................................................3-3 Interference Drag ....................................................3-5 Total Drag...................................................................3-6 Wing Planform ...........................................................3-6 Elliptical Wing ........................................................3-6 Rectangular Wing ...................................................3-7 Tapered Wing .........................................................3-7 Swept-Forward Wing ..............................................3-7 Washout ..................................................................3-7 Glide Ratio .................................................................3-8 Aspect Ratio ............................................................3-9 Weight ........................................................................3-9 Thrust .........................................................................3-9 Three Axes of Rotation ..................................................3-9 Stability ........................................................................3-10 Flutter .......................................................................3-11 Lateral Stability ........................................................3-12 Turning Flight ..............................................................3-13 Load Factors .................................................................3-13 Radius of Turn ..........................................................3-14 Turn Coordination ....................................................3-15 Slips ..........................................................................3-15 Forward Slip .........................................................3-16 Sideslip .................................................................3-17 Spins .........................................................................3-17 Ground Effect ...............................................................3-19 Chapter 4Flight Instruments ...............................................4-1 Introduction....................................................................4-1 Pitot-Static Instruments ..................................................4-2 Impact and Static Pressure Lines................................4-2 Airspeed Indicator ......................................................4-2 The Effects of Altitude on the AirspeedIndicator..................................................................4-3 Types of Airspeed ...................................................4-3Table of ContentsviiAirspeed Indicator Markings ......................................4-5 Other Airspeed Limitations ........................................4-6 Altimeter .....................................................................4-6 Principles of Operation ...........................................4-6 Effect of Nonstandard Pressure andTemperature............................................................4-7 Setting the Altimeter (Kollsman Window) .............4-9 Types of Altitude ......................................................4-10 Variometer................................................................4-11 Total Energy System .............................................4-14 Netto .....................................................................4-14 Electronic Flight Computers ....................................4-15 Magnetic Compass .......................................................4-16 Yaw String ................................................................4-16 Inclinometer..............................................................4-16 Gyroscopic Instruments ...............................................4-17 G-Meter ........................................................................4-17 FLARM Collision Avoidance System .........................4-18 Chapter 5Glider Performance .............................................5-1 Introduction....................................................................5-1 Factors Affecting Performance ......................................5-2 High and Low Density Altitude Conditions ...........5-2 Atmospheric Pressure .............................................5-2 Altitude ...................................................................5-3 Temperature............................................................5-3 Wind ...........................................................................5-3 Weight ........................................................................5-5 Rate of Climb .................................................................5-7 Flight Manuals and Placards ..........................................5-8 Placards ......................................................................5-8 Performance Information ...........................................5-8 Glider Polars ...............................................................5-8 Weight and Balance Information .............................5-10 Limitations ...............................................................5-10 Weight and Balance .....................................................5-12 Center of Gravity ......................................................5-12 Problems Associated With CG Forward ofForward Limit .......................................................5-12 Problems Associated With CG Aft of Aft Limit ..5-13 Sample Weight and Balance Problems ....................5-13 Ballast ..........................................................................5-14 Chapter 6Preflight and Ground Operations .......................6-1 Introduction....................................................................6-1 Assembly and Storage Techniques ................................6-2 Trailering....................................................................6-3 Tiedown and Securing ................................................6-4Water Ballast ..............................................................6-4 Ground Handling........................................................6-4 Launch Equipment Inspection ....................................6-5 Glider Preflight Inspection .........................................6-6 Prelaunch Checklist ....................................................6-7 Glider Care .....................................................................6-7 Preventive Maintenance .............................................6-8 Chapter 7Launch and Recovery Procedures and Flight Maneuvers ............................................................7-1 Introduction....................................................................7-1 Aerotow Takeoff Procedures .........................................7-2 Signals ........................................................................7-2 Prelaunch Signals ....................................................7-2 Inflight Signals ........................................................7-3 Takeoff Procedures and Techniques ..........................7-3 Normal Assisted Takeoff............................................7-4 Unassisted Takeoff.....................................................7-5 Crosswind Takeoff .....................................................7-5 Assisted ...................................................................7-5 Unassisted...............................................................7-6 Aerotow Climb-Out ....................................................7-6 Aerotow Release.........................................................7-8 Slack Line ...................................................................7-9 Boxing the Wake ......................................................7-10 Ground Launch Takeoff Procedures ............................7-11 CG Hooks .................................................................7-11 Signals ......................................................................7-11 Prelaunch Signals (Winch/Automobile) ...............7-11 Inflight Signals ......................................................7-12 Tow Speeds ..............................................................7-12 Automobile Launch ..................................................7-14 Crosswind Takeoff and Climb .................................7-14 Normal Into-the-Wind Launch .................................7-15 Climb-Out and Release Procedures ..........................7-16 Self-Launch Takeoff Procedures ..............................7-17 Preparation and Engine Start ....................................7-17 Taxiing .....................................................................7-18 Pretakeoff Check ......................................................7-18 Normal Takeoff ........................................................7-19 Crosswind Takeoff ...................................................7-19 Climb-Out and Shutdown Procedures ......................7-19 Landing .....................................................................7-21 Gliderport/Airport Traffic Patterns and Operations .....7-22 Normal Approach and Landing ................................7-22 Crosswind Landing ..................................................7-25 Slips ..........................................................................7-25 Downwind Landing ..................................................7-27 After Landing and Securing .....................................7-27viiiPerformance Maneuvers ..............................................7-27 Straight Glides ..........................................................7-27 Turns.........................................................................7-28 Roll-In ...................................................................7-29 Roll-Out ................................................................7-30 Steep Turns ...........................................................7-31 Maneuvering at Minimum Controllable Airspeed ...7-31 Stall Recognition and Recovery ...............................7-32 Secondary Stalls ....................................................7-34 Accelerated Stalls .................................................7-34 Crossed-Control Stalls ..........................................7-35 Operating Airspeeds .....................................................7-36 Minimum Sink Airspeed ..........................................7-36 Best Glide Airspeed..................................................7-37 Speed to Fly ..............................................................7-37 Chapter 8Abnormal and Emergency Procedures .............8-1 Introduction....................................................................8-1 Porpoising ......................................................................8-2 Pilot-Induced Oscillations (PIOs) ..............................8-2 PIOs During Launch ...................................................8-2 Factors Influencing PIOs ........................................8-2 Improper Elevator Trim Setting ..............................8-3 Improper Wing Flaps Setting ..................................8-3 Pilot-Induced Roll Oscillations During Launch .........8-3 Pilot-Induced Yaw Oscillations During Launch ........8-4 Gust-Induced Oscillations ..............................................8-5 Vertical Gusts During High-Speed Cruise .................8-5 Pilot-Induced Pitch Oscillations During Landing ......8-6 Glider-Induced Oscillations ...........................................8-6 Pitch Influence of the Glider Towhook Position ........8-6 Self-Launching Glider Oscillations During Powered Flight ...........................................................8-7 Nosewheel Glider Oscillations During Launchesand Landings ..............................................................8-7 Tailwheel/Tailskid Equipped Glider Oscillations During Launches and Landings ..................................8-8 Aerotow Abnormal and Emergency Procedures ............8-8 Abnormal Procedures .................................................8-8 Towing Failures........................................................8-10 Tow Failure With Runway To Land and Stop ......8-11 Tow Failure Without Runway To Land BelowReturning Altitude ................................................8-11 Tow Failure Above Return to Runway Altitude ...8-11 Tow Failure Above 800' AGL ..............................8-12 Tow Failure Above Traffic Pattern Altitude .........8-13 Slack Line .................................................................8-13 Ground Launch Abnormal and Emergency Procedures ....................................................................8-14 Abnormal Procedures ...............................................8-14 Emergency Procedures .............................................8-14 Self-Launch Takeoff Emergency Procedures ..............8-15 Emergency Procedures .............................................8-15 Spiral Dives ..................................................................8-15 Spins .............................................................................8-15 Entry Phase ...............................................................8-17 Incipient Phase .........................................................8-17 Developed Phase ......................................................8-17 Recovery Phase ........................................................8-17 Off-Field Landing Procedures .....................................8-18 Afterlanding Off Field .............................................8-20 Off-Field Landing Without Injury ........................8-20 Off-Field Landing With Injury .............................8-20 System and Equipment Malfunctions ..........................8-20 Flight Instrument Malfunctions ................................8-20 Airspeed Indicator Malfunctions ..........................8-21 Altimeter Malfunctions .........................................8-21 Variometer Malfunctions ......................................8-21 Compass Malfunctions .........................................8-21 Glider Canopy Malfunctions ....................................8-21 Broken Glider Canopy ..........................................8-22 Frosted Glider Canopy ..........................................8-22 Water Ballast Malfunctions ......................................8-22 Retractable Landing Gear Malfunctions ..................8-22 Primary Flight Control Systems ...............................8-22 Elevator Malfunctions ..........................................8-22 Aileron Malfunctions ............................................8-23 Rudder Malfunctions ............................................8-24 Secondary Flight Controls Systems .........................8-24 Elevator Trim Malfunctions .................................8-24 Spoiler/Dive Brake Malfunctions .........................8-24 Miscellaneous Flight System Malfunctions .................8-25 Towhook Malfunctions ............................................8-25 Oxygen System Malfunctions ..................................8-25 Drogue Chute Malfunctions .....................................8-25 Self-Launching Gliders ................................................8-26 Self-Launching/Sustainer Glider Engine Failure During Takeoff or Climb ..........................................8-26 Inability to Restart a Self-Launching/SustainerGlider Engine While Airborne .................................8-27 Self-Launching Glider Propeller Malfunctions ........8-27 Self-Launching Glider Electrical System Malfunctions .............................................................8-27 In-flight Fire .............................................................8-28 Emergency Equipment and Survival Gear ...................8-28 Survival Gear Checklists ..........................................8-28 Food and Water ........................................................8-28ixClothing ....................................................................8-28 Communication ........................................................8-29 Navigation Equipment ..............................................8-29 Medical Equipment ..................................................8-29 Stowage ....................................................................8-30 Parachute ..................................................................8-30 Oxygen System Malfunctions ..................................8-30 Accident Prevention .....................................................8-30 Chapter 9Soaring Weather ..................................................9-1 Introduction....................................................................9-1 The Atmosphere .............................................................9-2 Composition ...............................................................9-2 Properties ....................................................................9-2 Temperature............................................................9-2 Density ....................................................................9-2 Pressure ...................................................................9-2 Standard Atmosphere .................................................9-3 Layers of the Atmosphere ..........................................9-4 Scale of Weather Events ................................................9-4 Thermal Soaring Weather ..............................................9-6 Thermal Shape and Structure .....................................9-6 Atmospheric Stability .................................................9-7 Air Masses Conducive to Thermal Soaring ...................9-9 Cloud Streets ..............................................................9-9 Thermal Waves...........................................................9-9 Thunderstorms..........................................................9-10 Lifted Index ..........................................................9-12 K-Index .................................................................9-12 Weather for Slope Soaring .......................................9-14 Mechanism for Wave Formation ..............................9-16 Lift Due to Convergence ..........................................9-19 Obtaining Weather Information ...................................9-21 Preflight Weather Briefing........................................9-21 Weather-ReIated Information ..................................9-21 Interpreting Weather Charts, Reports, andForecasts ......................................................................9-23 Graphic Weather Charts ...........................................9-23 Winds and Temperatures Aloft Forecast ..............9-23 Composite Moisture Stability Chart .....................9-24 Chapter 10Soaring Techniques ..........................................10-1 Introduction..................................................................10-1 Thermal Soaring ...........................................................10-2 Locating Thermals ....................................................10-2 Cumulus Clouds ...................................................10-2 Other Indicators of Thermals ................................10-3 Wind .....................................................................10-4 The Big Picture .....................................................10-5Entering a Thermal ..............................................10-5 Inside a Thermal.......................................................10-6 Bank Angle ...........................................................10-6 Speed .....................................................................10-6 Centering ...............................................................10-7 Collision Avoidance ................................................10-9 Exiting a Thermal .....................................................10-9 Atypical Thermals ..................................................10-10 Ridge/Slope Soaring ..................................................10-10 Traps ......................................................................10-10 Procedures for Safe Flying .....................................10-12 Bowls and Spurs .....................................................10-13 Slope Lift ................................................................10-13 Obstructions ...........................................................10-14 Tips and Techniques ...............................................10-15 Wave Soaring .............................................................10-16 Preflight Preparation ...............................................10-17 Getting Into the Wave ............................................10-18 Flying in the Wave .................................................10-20 Soaring Convergence Zones ...................................10-23 Combined Sources of Updrafts ..............................10-24 Chapter 11Cross-Country Soaring .....................................11-1 Introduction..................................................................11-1 Flight Preparation and Planning ...................................11-2 Personal and Special Equipment ..................................11-3 Navigation ....................................................................11-5 Using the Plotter .......................................................11-5 A Sample Cross-Country Flight ...............................11-5 Navigation Using GPS .............................................11-8 Cross-Country Techniques ...........................................11-9 Soaring Faster and Farther .........................................11-11 Height Bands ..........................................................11-11 Tips and Techniques ...............................................11-12 Special Situations .......................................................11-14 Course Deviations ..................................................11-14 Lost Procedures ......................................................11-14 Cross-Country Flight in a Self-Launching Glider .....11-15 High-Performance Glider Operations and Considerations ............................................................11-16 Glider Complexity ..................................................11-16 Water Ballast ..........................................................11-17 Cross-Country Flight Using Other Lift Sources ........11-17 Chapter 12Towing ................................................................12-1 Introduction..................................................................12-1 Equipment Inspections and Operational Checks .........12-2 Tow Hook ................................................................12-2 Schweizer Tow Hook ...........................................12-2x。

永恒的边缘英语原著

永恒的边缘：探索未知领域的深度思考The Eternal Edge: Delving into the Depths of Unknown TerritoriesIn the realm of literature, few works have captured the essence of human exploration and the quest for knowledge quite like "The Eternal Edge". This profound novel, written by a master of the craft, takes us on a journey through the vast unknown, challenging our understanding of reality and pushing the boundaries of our imagination.The narrative unfolds in a world where the edge of knowledge is constantly shifting, and the line between what is known and unknown is blurred. The protagonist, a seeker of truth and understanding, embarks on a perilous journey to the fringes of existence, seeking answers to theultimate questions of life and the universe.As the story progresses, the reader is treated to arich tapestry of characters, each with their own unique perspectives and beliefs about the world. Theirinteractions and conflicts not only add depth to the plotbut also reflect the complexities of human thought and understanding.One of the most captivating aspects of "The Eternal Edge" is its exploration of the nature of knowledge itself. The novel questions whether knowledge is a finite resource that can be fully grasped or an infinite ocean that can never be fully explored. This philosophical inquiry challenges our assumptions about what it means to know something and how we can truly understand the world.Moreover, the novel delves into the psychology of exploration and the drive that propels individuals to pursue knowledge, even in the face of danger and uncertainty. The protagonist's journey is not just a physical one; it is also a deeply personal and emotional one that explores the costs and rewards of seeking truth. The writing style of "The Eternal Edge" is both elegant and powerful, conveying the depth and complexity of the narrative with clarity and precision. The author's use of language is masterful, creating a vivid and immersive world that draws the reader in and holds them captive.The themes and ideas explored in this novel are timely and relevant, resonating with the current zeitgeist of curiosity and exploration. As we navigate the complexitiesof the 21st century, "The Eternal Edge" offers valuable insights into the human drive to understand and make senseof the world.In conclusion, "The Eternal Edge" is a remarkableliterary achievement that challenges our understanding of knowledge and exploration. It is a must-read for anyone interested in delving into the depths of unknownterritories and seeking answers to life's ultimate questions.**永恒的边缘：探索未知领域的深度思考**在文学的世界里，很少有作品能像《永恒的边缘》这样，捕捉到人类探索和追求知识的精髓。

临界反应英语

临界反应英语全文共6篇示例，供读者参考篇1Title: Critical ReactionHey guys! Today I want to talk to you about something super cool – critical reactions! Have you ever heard of them? Basically, a critical reaction is when something happens that sets off a chain reaction of events. It's like a chain of dominoes falling down, one after the other.Let me give you an example. Imagine you have a piece of uranium. When a neutron hits the uranium, it can split the uranium atom in two, releasing more neutrons. These new neutrons can then hit other uranium atoms, causing them to split as well. This creates a chain reaction, with more and more atoms splitting and releasing energy.This process is called nuclear fission, and it's what powers things like nuclear reactors and atomic bombs. But here's the thing – fission reactions need to be controlled. If too many atoms split at once, it can create a huge explosion, like in a nuclear bomb. This is called a critical reaction.Scientists have to carefully control fission reactions in nuclear reactors to make sure they don't get out of hand. They use things like control rods to absorb excess neutrons and stop the chain reaction from speeding up too much.So, next time you hear about critical reactions, remember that it's all about controlling the energy released by splitting atoms. It's like a super cool science experiment, but withreal-world implications. Pretty awesome, right? Let me know if you have any questions about critical reactions – I'd love to chat more about it with you!篇2Title: The Critical ReactionHey guys! Today I'm gonna tell you all about this really cool thing called critical reaction. It's like when things get super intense and reach a tipping point, you know? Let's dive right in!So, imagine you have a bunch of chemicals in a test tube. They're just chilling there, minding their own business. But then, you add a little extra something-something, like heat or a catalyst, and bam! Those chemicals start reacting like crazy. This is what we call a critical reaction.It's like the chemicals are having a party in that test tube, dancing and bouncing around. And when they reach a certain point, the reaction goes into overdrive. It's like they can't stop themselves!But here's the thing - critical reactions can be a bit dangerous. If you're not careful, things can get out of control real quick. That's why scientists always wear safety goggles and gloves when they're working with chemicals. Safety first, guys!But critical reactions aren't just for scientists. They can happen in all sorts of situations. Like when you and your friends are having a heated debate about which is better, pizza or ice cream. Things can escalate pretty quickly, right?So next time you see a critical reaction happening, remember to stay safe and keep a cool head. And who knows, maybe you'll discover something amazing in the process! Stay curious, my friends.篇3Once upon a time, there was a super important scientific thing called nuclear fission. It's like when a big atom breaks into smaller atoms and releases a bunch of energy. This is what happens in a nuclear power plant to make electricity.But sometimes, things can get a little crazy. If the atoms are breaking too fast and releasing too much energy, it's called a critical reaction. It's like when you're playing with a toy and it's going so fast that it starts to overheat and smoke. That's not good!In a nuclear reactor, if there's a critical reaction, it can be dangerous. The heat and energy can get out of control, and that's called a meltdown. Just like when your ice cream cone melts in the sun, except way scarier!That's why scientists and engineers have to be super careful when they're working with nuclear reactors. They have to make sure everything is just right so that there's no critical reaction. They use special controls and safety measures to keep everything under control.So remember, nuclear fission is cool and all, but we have to be really careful with it. We don't want anything to go boom!篇4Title: The Critical ReactionHey guys, today I want to talk to you about something super cool and important called the critical reaction. Have you everheard of it before? Well, don't worry if you haven't because I'm here to explain it to you!So, the critical reaction is basically a super important process in science where things change really quickly and can even create a big explosion! It happens when a certain amount of stuff, like chemicals or atoms, come together and react in a big way. It's kind of like when you mix vinegar and baking soda and it fizzes up everywhere!But the thing about the critical reaction is that it can be really dangerous if it's not controlled properly. That's why scientists have to be really careful when they're working with things that could cause a critical reaction. They have to follow all the rules and wear special gear to keep themselves safe.One famous example of a critical reaction is when atomic bombs were dropped on Japan during World War II. The reaction was so powerful that it caused immense destruction and loss of life. That's why it's super important for us to understand the critical reaction and be careful with it.So, remember guys, the critical reaction is a really cool but also really serious thing. Make sure to always be safe and follow the rules when you're doing any experiments or science projects. Stay curious and keep learning! Bye for now!篇5Title: The Exciting Adventure of Critical Reaction!Once upon a time, I learned about something super cool called a critical reaction in science class. It's like when a bunch of atoms get super excited and start bouncing around like crazy. It's kind of like when my little brother has too much sugar and can't sit still!So, the other day in class, my teacher showed us this experiment where she mixed two liquids together and BAM! they started fizzing and bubbling like a volcano! It was so awesome!She explained that in a critical reaction, the atoms in the liquids get so hyped up that they start smashing into each other and creating new substances. It's like a big party inside the beaker!I asked my teacher why critical reactions happen, and she said it's because the atoms in the liquids don't like being alone. They want to be with their friends, so they get all jittery and jump around until they find a buddy to hang out with. It's like a big game of tag, but with atoms!I also learned that critical reactions can be dangerous if you're not careful. My teacher told us to always wear safety goggles and follow the instructions carefully. Safety first, always!I can't wait to do more experiments with critical reactions. It's like being a scientist in a super cool lab, mixing things together and watching the magic happen. Who knew science could be so fun?篇6Title: The Critical ReactionHey guys, today I want to talk about something super cool and important - it's called a critical reaction! It's like when you mix two things together and they make a big BOOM! But don't worry, it's all safe and controlled in science labs.So, a critical reaction is when you have just the right amount of stuff mixed together to make a big reaction happen. If you have too little or too much of something, then nothing cool will happen. It's all about finding that perfect balance.One example of a critical reaction is in nuclear power plants. They use uranium to make energy, but if you have too much uranium in one place, it can be really dangerous. So scientistsmake sure to keep everything in just the right amounts to keep things safe and working properly.Another example is in chemistry labs when you mix chemicals together. If you have just the right amount of each chemical, then they can react and make new substances. It's like magic happening right before your eyes!So, remember, a critical reaction is all about finding that perfect balance. Too little or too much of something won't work, but just the right amount can create some amazing reactions. Keep exploring and experimenting, and who knows what cool things you might discover!。

高二英语气候变迁阅读理解25题

高二英语气候变迁阅读理解25题1<背景文章>Climate change is one of the most significant challenges facing our planet today. The Earth's climate has been changing for millions of years, but in recent decades, the rate of change has accelerated dramatically. Global temperatures are rising, causing a wide range of impacts. One of the most visible effects is the melting of glaciers and ice caps, which is leading to a rise in sea levels. This poses a serious threat to coastal communities and low-lying islands.The increase in temperature is also affecting weather patterns. We are seeing more extreme weather events such as hurricanes, floods, droughts, and wildfires. These events can cause significant damage to infrastructure, agriculture, and human lives.Another consequence of climate change is the disruption of ecosystems. Many species are struggling to adapt to the changing climate, and some may even face extinction. This can have a domino effect on the entire food chain.Scientists are working hard to understand the causes and consequences of climate change. They are also looking for solutions to mitigate its effects. One of the key strategies is to reduce greenhouse gasemissions. This can be achieved by increasing the use of renewable energy sources such as solar and wind power, improving energy efficiency, and reducing deforestation.In conclusion, climate change is a complex and urgent problem that requires immediate action. We all have a role to play in protecting our planet for future generations.1. What is one of the most visible effects of climate change?A. Increase in population.B. Melting of glaciers and ice caps.C. Decrease in temperature.D. Increase in deforestation.答案：B。

新SAT官方指南阅读第十五篇全解析

新SAT官⽅指南阅读第⼗五篇全解析新SAT官⽅指南阅读第⼗五篇全解析This passage is adapted from Richard J.Sharpe and Lisa Heyden,“Honey Bee Colony Collapse Disorder is Possibly Caused by a Dietary Pyrethrum Deficiency.”?2009by Elsevier Ltd.Colony collapse disorder is characterized by the disappearance of adult worker bees from hives.Honey bees are hosts to the pathogenic large ectoparasitic mite Varroa destructor(Varroa mites).These mites feed on bee hemolymph(blood)and can kill bees directly or by increasingtheir susceptibility to secondary infection with fungi,bacteria or viruses.Little is known about the natural defenses that keep the mite infections under control.Pyrethrums are a group of flowering plants which include Chrysanthemum coccineum,5Chrysanthemum cinerariifolium,Chrysanthemum marschalli,and related species.These plantsproduce potent insecticides with anti-mite activity.The naturally occurring insecticides are known as pyrethrums.A synonym for the naturally occurring pyrethrums is pyrethrin and syntheticanalogues of pyrethrums are known as pyrethroids.In fact,the human mite infestation known as scabies(Sarcoptes scabiei)is treated with a topical pyrethrum cream.10We suspect that the bees of commercial bee colonies which are fed mono-crops are nutritionally deficient.In particular,we postulate that the problem is a diet deficient in anti-mite toxins:pyrethrums,and possibly other nutrients which are inherent in such plants.Without,atleast,intermittent feeding on the pyrethrum producing plants,bee colonies are susceptible to mite 15infestations which can become fatal either directly or due to a secondary infection ofimmunocompromised or nutritionally deficient bees This secondary infection can be viral,bacterial or fungal and may be due to one or more pathogens.In addition,immunocompromised or nutritionally deficient bees may be further weakened when commercially produced insecticidesare introduced into their hives by bee keepers in an effort to fight mite infestation.We furtherpostulate that the proper dosage necessary to prevent mite infestation may be better left to the bees, 20who may seek out or avoid pyrethrum containing plants depending on the amount necessary todefend against mites and the amount already consumed by the bees,which in higher doses could be potentially toxic to them. This hypothesis can best be tested by a trial wherein a small number of commercial honey25bee colonies are offered a number of pyrethrum producing plants,as well as a typical bee foodsource such as clover,while controls are offered only the clover.Mites could then be introduced to each hive with note made as to the choice of the bees,and the effects of the mite parasites on the experimental colonies versus control colonies.It might be beneficial to test wild-type honey bee colonies in this manner as well,in case there could be some genetic difference between them that affects the bees’preferences for30pyrethrum producing flowers.42、How do the words“can,”“may,”and“could”in the third paragraph(lines11-23) help establish the tone of the paragraph?A)They create an optimistic tone that makes clear the authors are hopeful about the effects of their research on colony collapse disorder.B)They create a dubious tone that makes clear the authors do not have confidence in the usefulness of the research described.C)They create a tentative tone that makes clear the authors suspect but do not know that their hypothesis is correct.D)They create a critical tone that makes clear the authors are skeptical of claims that pyrethrums are inherent in mono-crops.正确答案：C分析：⽂章当中，作者讨论蜂群问题时，使⽤了“我们猜想”（we suspect）和“我们推测”（we postulate）这样的句式，还采⽤了“can””may”和“could”这样表⽰可能的情态动词，是为了强调作者是猜测但是不确定的语⽓。

经皮肾镜碎石取石术手术流程

经皮肾镜碎石取石术手术流程1.患者躺在手术台上，接受全身麻醉。

The patient lies on the operating table and receives general anesthesia.2.医生进行消毒，准备手术部位。

The doctor sterilizes and prepares the surgical site.3.医生在患者的腰部做小切口。

The doctor makes a small incision in the patient's lower back.4.医生插入肾镜到患者的肾脏。

The doctor inserts a nephroscope into the patient's kidney.5.医生观察肾脏内部的情况。

The doctor observes the inside of the kidney.6.医生使用超声波或激光技术找到肾结石。

The doctor uses ultrasound or laser technology to locate the kidney stones.7.医生使用碎石器具粉碎肾结石。

The doctor uses a lithotripter to crush the kidney stones.8.医生用特殊夹子取出小块碎石。

The doctor removes small pieces of crushed stones with special forceps.9.医生反复冲洗肾脏，清除碎石碎片。

The doctor flushes the kidney repeatedly to remove stone fragments.10.医生确保肾脏内没有残留的结石。

The doctor ensures there are no remaining stones in the kidney.11.医生清洗手术部位并缝合切口。

学术英语(理工)翻译text16

Text16转基因大豆对生育的影响幼鼠体重与生存率摘要研究了转基因大豆对大白鼠后代的出生率和存活率的影响。

一组雌性白鼠在交配和怀孕之前用转基因大豆粉喂养。

对照组用传统大豆喂养，第三组阳性对照组不喂养大豆粉。

对新生幼崽的体重和死亡率进行分析。

研究表明，相比于对照组和阳性对照组(分别为 9%和 6.8%)，转基因大豆组有很高的幼崽死亡率( 55.6%) 。

而且，第一组在哺乳期间继续死亡，幸存下来的体重也低于其他两组。

实验结果表明，转基因大豆对大白鼠的后代有消极影响。

介绍转基因生物是为了产生某些新的特性 (例如抗害虫和除草剂) 而从其他生物转移基因并通过重组 DNA 技术生产出来的植物、微生物和动物。

世界各国科学家谈论了转基因生物的危害的四个主要来源： 1)由新基因产生的危害和引入的基因产品； 2) 技术固有的非预期效果； 3)外源基因和宿主基因的相互作用； 4)普通异花授粉和水平基因转移引起的引种基因传播。

(世界科学家声明 2000)转基因作物包含自然条件下不存在的物质，它们成为我们日常饮食的一部分。

为了了解转基因植物对我们和动物有什么影响，研究这些转基因植物对不同物种中几代人的影响是至关重要的。

目前这些研究缺乏科学文献的支持。

此外，转基因作物对动物的代谢也有些有害的影响。

许多调查显示，转基因生物对动物和环境的危害。

早些时候的研究表明，动物食用转基因食物会导致其生物体发生负面改变。

普斯陶伊的试验显示，被植入的雪花莲凝集素基因 ( 一种杀虫蛋白) 修饰的土豆阻碍了白鼠的生长，显著地影响了它们的一些重要器官，包括，肾脏，胸腺，胃线虫肌肉等 (1998)，并且损害了它们的肠道和免疫系统。

(埃文和普斯陶伊1999) .俄罗斯营养所得到转基因土豆对白鼠的类似影响(埃尔恩 2005) 。

风险评估文件中提出，转基因植物的转基因成分在人类和动物的消化道中被完全破坏，以及在其中发现的其他遗传物质。

可是，外源 DNA 质粒的抗消化比原先认为的要稳定。

新托福TPO15阅读原文及译文(二)

新托福TPO15阅读原文(二)：Mass ExtinctionsTPO15-2：Mass ExtinctionsCases in which many species become extinct within a geologically short interval of time are called mass extinctions. There was one such event at the end of the Cretaceous period (around 70 million years ago). There was another, even larger, mass extinction at the end of the Permian period (around 250 million years ago). The Permian event has attracted much less attention than other mass extinctions because mostly unfamiliar species perished at that time.The fossil record shows at least five mass extinctions in which many families of marine organisms died out. The rates of extinction happening today are as great as the rates during these mass extinctions. Many scientists have therefore concluded that a sixth great mass extinction is currently in progress.What could cause such high rates of extinction? There are several hypotheses, including warming or cooling of Earth, changes in seasonal fluctuations or ocean currents, and changing positions of the continents. Biological hypotheses include ecological changes brought about by the evolution of cooperation between insects and flowering plants or of bottom-feeding predators in the oceans. Some of the proposed mechanisms required a very brief period during which all extinctions suddenly took place; other mechanisms would be more likely to have taken place more gradually, over an extended period, or at different times on different continents. Some hypotheses fail to account for simultaneous extinctions on land and in the seas. Each mass extinction may have had a different cause. Evidence points to hunting by humans and habitat destruction as the likely causes for the current mass extinction.American paleontologists David Raup and John Sepkoski, who have studied extinction rates in a number of fossil groups, suggest that episodes of increased extinction have recurred periodically, approximately every 26 million years since the mid-Cretaceous period. The late Cretaceous extinction of the dinosaurs and ammonoids was just one of the more drastic in a whole series of such recurrentextinction episodes. The possibility that mass extinctions may recur periodically has given rise to such hypotheses as that of a companion star with a long-period orbit deflecting other bodies from their normal orbits, making some of them fall to Earth as meteors and causing widespread devastation upon impact.Of the various hypotheses attempting to account for the late Cretaceous extinctions, the one that has attracted the most attention in recent years is the asteroid-impact hypothesis first suggested by Luis and Walter Alvarez. According to this hypothesis, Earth collided with an asteroid with an estimated diameter of 10 kilometers, or with several asteroids, the combined mass of which was comparable. The force of collision spewed large amounts of debris into the atmosphere, darkening the skies for several years before the finer particles settled. The reduced level of photosynthesis led to a massive decline in plant life of all kinds, and this caused massive starvation first of herbivores and subsequently of carnivores. The mass extinction would have occurred very suddenly under this hypothesis.One interesting test of the Alvarez hypothesis is based on the presence of the rare-earth element iridium (Ir). Earth’s crust contains very little of this element, but most asteroids contain a lot more. Debris thrown into the atmosphere by an asteroid collision would presumably contain large amounts of iridium, and atmospheric currents would carry this material all over the globe. A search of sedimentary deposits that span the boundary between theCretaceous and Tertiary periods shows that there is a dramatic increase in the abundance of iridium briefly and precisely at this boundary. This iridium anomaly offers strong support for the Alvarez hypothesis even though no asteroid itself has ever been recovered.An asteroid of this size would be expected to leave an immense crater, even if the asteroid itself was disintegrated by the impact. The intense heat of the impact would produce heat-shocked quartz in many types of rock. Also, large blocks thrown aside by the impact would form secondary craters surrounding the main crater. To date, several such secondary craters have been found along Mexico’s Yucatan Peninsula, and heat-shocked quartz has been found both in Mexico and in Haiti. Alocation called Chicxulub, along the Yucatan coast, has been suggested as the primary impact site.TPO15-2译文：大规模物种灭绝地质年代中，在一个短期的时间间隔有大量物种灭绝的现象就被称为大规模物种灭绝。

stephen_Crane

Crane‟s fictional world is a naturalistic one in which man is deprived of free will and expects no help from any quarter whatever. It is a world in which “God is cold.”

Upon his return to New York, Crane‟s health was already broken by the hardships he had endured, and possibly owing to his early treatment of squalor in Maggie and rumors about the immorality of his common-law 事实婚姻 wife, a myth now arose

In this sense, the captain is at once a majestic and tragic figure.
The Oiler (Billie)

The only refugee from the ship to die in the final attempt at reaching land. Before the ship sank, the oiler worked a double watch in the engine room, and he is most likely to be exhausted in the dinghy.

Further, the oiler is portrayed as the most overworked among them: "Previously to the foundering, by the way, the oiler had worked double-watch in the engine-room of the ship".