The squirrel cage induction generator for power generation
电机电器及其控制技术-英文资料
2.1 Effects and Development of Machine
What is Electrical Machine? ----------An Electrical machine is a device that converts mechanical energy to electrical energy or vice versa, and changes AC voltage from one level to another level according to law of electromagnetic induction.
The British Hopkinson also invented a transformer with closed magnetic circuit.
Bullough invented high voltage oil immersion transformer, which makes long-distance high-voltage transmission a reality.
2.1 Effects and Development of Machine
Effects of Machine
Power production, transmission and distribution Generator Transformer
……
Drive machinery and
equipment Motor
1888
Faraday invented the model of the first induction generator.
Jacobi invented rod core motor which power is 15W.
蝴蝶的生命周期 英语作文
The Life Cycle of a ButterflyThe life cycle of a butterfly is a fascinating and intricate process that showcases the wonders of nature and the incredible transformations that occur in the insect world.This process,known as metamorphosis, involves four distinct stages:egg,larva(caterpillar),pupa(chrysalis),and adult butterfly.Each stage is crucial for the development and survival of the butterfly,and together they form a remarkable journey from a tiny egg to a beautiful,winged insect.The first stage of a butterfly's life cycle begins with the egg.Female butterflies lay their eggs on the leaves of specific host plants,which will later serve as food for the emerging caterpillars.The eggs are often tiny and can vary in shape and color depending on the species.The duration of the egg stage can range from a few days to several weeks,depending on environmental conditions such as temperature and humidity.Once the egg hatches,the second stage of the life cycle begins:the larva, commonly known as a caterpillar.Caterpillars are voracious eaters and spend most of their time consuming the leaves of their host plants.This stage is characterized by rapid growth,and as the caterpillar grows,it undergoes a series of molts,shedding its exoskeleton to accommodate its increasing size.Caterpillars can have a wide variety of colors,patterns, and shapes,which often serve as camouflage or a warning to predators. The larval stage is critical for accumulating the energy and nutrients needed for the next stage of development.After reaching a certain size and undergoing several molts,the caterpillar enters the third stage of the life cycle:the pupa,or chrysalis. During this stage,the caterpillar undergoes a remarkable transformation. It finds a suitable spot to attach itself,often using silk,and then sheds its final larval skin to reveal the chrysalis.Inside the chrysalis,the caterpillar's body undergoes a complete reorganization through a process called histolysis,where larval tissues break down,and histogenesis,where adult structures form.This transformation can take anywhere from a few weeks to several months,depending on the species and environmental factors.The final stage of the butterfly's life cycle is the adult butterfly.When the transformation within the chrysalis is complete,the adult butterflyemerges.This process,known as eclosion,involves the butterfly breaking free from the chrysalis and expanding its wings.Initially,the wings are soft and crumpled,but within a few hours,they harden and become strong enough for flight.The adult butterfly's primary focus is on reproduction and feeding.Butterflies are known for their striking colors and patterns,which serve various purposes,including attracting mates,camouflage,and warning predators.Adult butterflies feed on nectar from flowers,using their long proboscis to reach deep into the blossoms.They play a vital role in pollination, transferring pollen from one flower to another as they feed.This mutualistic relationship benefits both the butterflies and the plants, contributing to the health and diversity of ecosystems.In conclusion,the life cycle of a butterfly is a remarkable journey that highlights the beauty and complexity of nature.From the tiny egg to the vibrant adult butterfly,each stage of metamorphosis is a testament to the adaptability and resilience of these incredible insects.Understanding and appreciating the life cycle of butterflies not only deepens our connection to the natural world but also underscores the importance of conserving their habitats and ensuring the survival of these delicate and enchanting creatures for future generations to enjoy.。
植物与环境保护作文英语
Plants play a vital role in environmental protection,and their importance cannot be overstated.Here are some key points to consider when discussing the relationship between plants and environmental conservation:1.Air Purification:Plants are natural air purifiers.They absorb carbon dioxide and release oxygen through the process of photosynthesis.This helps to maintain the balance of gases in the atmosphere,which is essential for the survival of all living organisms.2.Climate Regulation:Large forests act as carbon sinks,absorbing more carbon dioxide than they release.This helps to mitigate the effects of climate change by reducing the amount of greenhouse gases in the atmosphere.3.Soil Conservation:The roots of plants help to hold the soil together,preventing erosion. This is particularly important in areas prone to landslides or where soil is easily washed away by rain.4.Water Filtration:Plants can filter pollutants from water,improving the quality of water in streams,rivers,and lakes.This is especially important in areas where industrial or agricultural runoff can contaminate water sources.5.Biodiversity:Plant diversity is crucial for maintaining a healthy ecosystem.Different types of plants provide habitats and food for a wide range of animals,contributing to the overall biodiversity of an area.6.Noise Reduction:Urban green spaces,such as parks and gardens,can help to reduce noise pollution in cities.The leaves and branches of plants absorb and deflect sound waves,creating a quieter environment.7.Recreation and Mental Health:Plants and green spaces offer recreational benefits, providing areas for people to relax and enjoy nature.Studies have shown that spending time in green spaces can improve mental health and wellbeing.8.Economic Benefits:Plantbased industries,such as agriculture and forestry,contribute significantly to the economy.Moreover,plants can be used for medicinal purposes, providing natural remedies for various ailments.9.Cultural and Aesthetic Value:Plants are often associated with cultural practices and aesthetics.They can be used for decoration,in religious ceremonies,and are a source of inspiration for art and literature.cational Value:Plants are an excellent tool for teaching about biology,ecology, and environmental science.They can be used to demonstrate concepts such as growth, reproduction,and the interdependence of living organisms.In conclusion,plants are integral to the health of our planet and the wellbeing of its inhabitants.It is our responsibility to protect and preserve plant life for the benefit of future generations.This can be achieved through sustainable practices,such as planting trees,conserving water,and reducing the use of harmful chemicals that can damage plant life.。
太阳对鱼类的影响英语作文
The sun plays a crucial role in the life of fish, affecting their behavior, growth, and overall health. Heres a detailed look at the various ways the sun impacts fish:1. Light Cycle and Circadian Rhythms: Fish, like many other creatures, have internal clocks that regulate their daily activities. The suns light cycle helps set these circadian rhythms, influencing when fish feed, rest, and reproduce.2. Photosynthesis and Food Chain: The sun is the primary energy source for aquatic ecosystems. Through photosynthesis, it powers the growth of phytoplankton, which forms the base of the aquatic food chain. Fish consume these organisms directly or indirectly, which is essential for their survival and growth.3. Thermoregulation: The suns heat helps regulate the temperature of water bodies. Fish are ectothermic, meaning they rely on external sources to regulate their body temperature. Warmer water can increase their metabolism and growth rates, while colder water can slow them down.4. Migration Patterns: Many fish species migrate to spawn or feed, and the suns position in the sky can serve as a natural compass. For example, salmon use the sun to navigate their way back to their natal streams to spawn.5. Behavioral Changes: The sun can influence the behavior of fish in various ways. For instance, some fish are more active during the day diurnal, while others are nocturnal. The suns position affects their feeding and mating behaviors.6. Vision and Coloration: Fish rely on sunlight to see their surroundings. The intensity and quality of light can affect their vision, which in turn influences their ability to find food and avoid predators. Additionally, the suns rays can influence the coloration of fish, which is important for camouflage and communication.7. Reproduction: The suns light can stimulate the production of certain hormones in fish that are linked to reproduction. Seasonal changes in daylight hours can trigger spawning behaviors in many species.8. UV Radiation: While sunlight is essential for many aspects of a fishs life, ultraviolet UV radiation can also have negative effects. Prolonged exposure to UV light can damage fish skin and eyes, and it can also lead to an increase in the production of harmful substances in the water.9. Water Clarity and Habitat: The suns penetration into water affects its clarity, which inturn influences the habitat of fish. Clear water allows more light to penetrate, supportinga more diverse and abundant ecosystem.10. Seasonal Adaptations: Fish have adapted to the changing seasons and the corresponding changes in sunlight. For example, some fish species may grow thicker skins or change their feeding habits in response to shorter daylight hours during winter. In conclusion, the sun is a fundamental factor in the life of fish, affecting their biology, behavior, and interactions with their environment. Understanding these impacts is essential for the conservation of aquatic ecosystems and the species that inhabit them.。
鸟巢英语作文五年级
The Birds Nest,also known as the Beijing National Stadium,is an iconic structure in Beijing,China.It is a magnificent piece of architecture that has become a symbol of modern Beijing.Heres a detailed description that you can use for a fifthgrade English composition about the Birds Nest.Title:The Birds Nest A Modern MarvelIntroduction:The Birds Nest is not just a stadium its a testament to human ingenuity and creativity.It is a place where dreams take flight and where athletes from all over the world come to compete and showcase their talents.This essay will explore the architectural marvel that is the Birds Nest,its significance in Beijing,and its impact on the world of sports. Design and Construction:The Birds Nest was designed by the Swiss architecture firm Herzog de Meuron in collaboration with ArupSport and China Architecture Design Research Group.The design is a unique blend of traditional Chinese elements and modern architecture.The structure is made of a series of interlocking steel beams,which give it the appearance of a birds nest.The construction of the Birds Nest began in2003and was completed in2008, just in time for the Beijing Olympics.Architectural Features:One of the most striking features of the Birds Nest is its exterior.The steel beams are arranged in a lattice pattern,creating a visually stunning effect.The stadium can seat up to91,000spectators,making it one of the largest in the world.The roof of the stadium is partially open,allowing natural light to filter in and providing a unique viewing experience for spectators.Significance in Beijing:The Birds Nest is a symbol of Beijings rapid development and its emergence as a global city.It is a place where history meets modernity,and tradition is fused with innovation. The stadium is located in the Olympic Green,a large park that was built as part of Beijings Olympic legacy.The park is a popular destination for locals and tourists alike, offering a variety of recreational activities and cultural experiences.Impact on Sports:The Birds Nest has played a significant role in the world of sports.It was the main venue for the2008Summer Olympics,hosting the opening and closing ceremonies,as well asthe track and field events.Since then,it has continued to host major sporting events, including the2015World Athletics Championships.The Birds Nest has also become a symbol of sportsmanship and international cooperation,as athletes from different countries come together to compete and celebrate their achievements. Conclusion:The Birds Nest is more than just a stadium it is a symbol of Beijings progress and a testament to the power of human creativity.It is a place where dreams are made and where the spirit of competition is celebrated.As we look to the future,the Birds Nest will continue to inspire and captivate,serving as a reminder of the limitless potential of human achievement.This composition provides a comprehensive overview of the Birds Nest,suitable for a fifthgrade students understanding and writing ability.It covers the essential aspects of the stadium,from its design and construction to its cultural and historical significance.。
关于松鼠的英语作文
The Life of SquirrelsSquirrels are intriguing and lively creatures that belong to the family Sciuridae.They are commonly found in both urban and rural areas, known for their bushy tails and swift movements.These small rodents captivate our attention with their playful behavior and remarkable adaptability.One of the most notable characteristics of squirrels is their agility.With their strong hind legs and sharp claws,they can effortlessly climb trees and leap from branch to branch.This dexterity not only helps them escape predators but also aids in foraging for food.Squirrels are known to store nuts and seeds in various hiding spots,a behavior called caching, which ensures they have a food supply during the harsh winter months.Squirrels have a diverse diet that mainly includes nuts,seeds,fruits,and occasionally insects.Acorns are particularly favored,and squirrels play a crucial role in forest regeneration by burying these seeds.Some of these seeds are forgotten,which then sprout into new trees,demonstrating the essential ecological role that squirrels play.The intelligence of squirrels is another fascinating aspect.They are quick learners and can solve complex puzzles,especially when it comes to accessing food.Many homeowners have witnessed the clever tactics squirrels use to raid bird feeders,showcasing their problem-solving skills. Squirrels also communicate using a variety of vocalizations and tail movements.They produce distinct sounds to signal danger,attract mates,or establish territory.Their bushy tails are not just for balance but also serve as a communication tool,helping them convey messages to other squirrels.The habitat of squirrels varies widely.While some prefer the dense canopy of forests,others have adapted to urban environments,finding homes in parks and backyards.Their ability to thrive in different settings is a testament to their resilience and adaptability.In conclusion,squirrels are more than just cute,furry animals.They are intelligent,agile,and play a significant role in their ecosystems.Observing them can be both entertaining and educational,offering insights into the behaviors and adaptations of wildlife.。
为丑的动物发声英语作文
为丑的动物发声英语作文英文回答：Ugly animals play an important role in our ecosystem, despite their unattractive appearance. Take the naked mole rat, for example. This creature may not be the most visually appealing, with its wrinkled, hairless skin and large front teeth. However, it has some fascinating qualities that make it an essential part of its habitat. Naked mole rats are highly social animals, living in underground colonies. They have a unique ability to tolerate high levels of carbon dioxide, which allows them to survive in the low-oxygen environment of their burrows. Additionally, they are resistant to cancer, making them valuable subjects for medical research. So, even though naked mole rats may not win any beauty contests, they are crucial for maintaining the balance in their ecosystem.Another example of an ugly animal that deserves our attention is the blobfish. This fish has a gelatinous,blob-like appearance that has earned it the title of"world's ugliest animal." However, its unusual appearanceis actually an adaptation to its deep-sea habitat. The blobfish lives at depths where the pressure is severaltimes higher than at the surface. Its gelatinous body helps it maintain buoyancy in these extreme conditions. While the blobfish may not be conventionally attractive, it serves a vital role in its ecosystem by scavenging on the oceanfloor and contributing to the food chain.中文回答：丑陋的动物在我们的生态系统中扮演着重要的角色，尽管它们外表不太吸引人。
老鹰抓小鸡亲子英语作文
老鹰抓小鸡亲子英语作文Title: The Eagle and the Chick: An Adventure inLearning English Together。
Once upon a time, high up in the towering trees of the forest, there lived a majestic eagle and her curious chick. They shared a bond of love and learning, and their dayswere filled with exciting adventures and valuable lessons. One day, as they soared through the clear blue sky, the chick turned to her mother with a question burning in her heart."Mom," the chick chirped, "why do we speak English?"The eagle smiled, her feathers gleaming in the sunlight. "English is a language spoken by many creatures across the world," she explained. "It opens doors to communication, knowledge, and understanding."Excited by this newfound knowledge, the chick flutteredher wings in anticipation. "Will you teach me English, Mom?" she asked eagerly.And so, their journey of learning began. Every day, the eagle and her chick would explore the vast forest, encountering different animals and objects along the way. With each encounter, the eagle would teach her chick new words and phrases, patiently guiding her through the intricacies of the English language.One sunny morning, as they perched on a sturdy branch overlooking a lush meadow, they spotted a group of rabbits hopping about in the grass. The chick's eyes sparkled with curiosity as she observed the playful creatures."What are those fluffy creatures called, Mom?" she inquired."They are called rabbits," the eagle replied. "And when they move quickly, we say they are hopping."The chick nodded, committing the new words to memory."Rabbits hop," she repeated, testing out the phrase with delight.As they continued their journey, the eagle and herchick encountered many more animals, each providing an opportunity for the chick to expand her English vocabulary. From squirrels scurrying up trees to butterflies fluttering among the flowers, the forest was alive with learning possibilities.But it wasn't just the animals that taught the chick English. She also learned from the natural wonders of the forest itself. The eagle would point out towering trees, babbling brooks, and shimmering sunlight, teaching herchick the names of the world around them.As the days turned into weeks and the weeks into months, the chick's English skills grew stronger with each passing day. She began to string together sentences, expressing her thoughts and feelings with newfound confidence.One evening, as they watched the sunset paint the skyin hues of orange and pink, the chick turned to her mother with a smile."Thank you, Mom," she chirped. "For teaching me English and showing me the beauty of the world."The eagle wrapped her wing around her chick, her heart swelling with pride. "You are my greatest joy," she said. "And together, we will continue to soar and learn, side by side."And so, the eagle and her chick embarked on many more adventures, their bond growing stronger with each passing day. For in the forest of life, there is no greater treasure than the love between a parent and child, and the joy of learning together.。
钙对果树生长发育的影响及应用研究
落叶果树 2023,55(6):43-47Deciduous Fruits ·综合评议· DOI : 10.13855/ki.lygs.2023.06.010 钙对果树生长发育的影响及应用研究张占田1,史江全2,陈海宁1,樊兆博1,冷伟锋1,刘大亮1,刘保友1,3∗(1.山东省烟台市农业科学研究院,山东烟台265500;2.常州杰和机械有限公司,江苏常州213163;3.烟台大学生命科学院,山东烟台264005) 摘 要:钙作为营养元素被认知已近两百年,其作为偶联胞外信号和胞内生理生化反应的第二信使在生理代谢中起着重要作用。
钙是一种不易吸收、不易转移的元素,主要依靠蒸腾拉动在树体内移动,长期施肥比例不合理,会导致果树缺钙问题严重。
综述了钙在果树生长发育中的作用和钙肥在农业生产中的技术应用,提出了现存问题和今后主要研究方向及展望。
关键词:果树;钙;营养特性;应用研究;问题展望 中图分类号: S66 文献标识码: A 文章编号: 1002-2910(2023)06-0043-05收稿日期:2023-07-28基金项目:山东省重点研发计划(2021CXGC010602,2021CXGC010802);山东省果品产业技术体系病虫防治与质量控制岗位专家项目(SDAIT -06-11);山东省自然科学基金重点项目(ZR2020KC026);农业农村部农作物病虫鼠害疫情监测与防治项目(15216042,15226041);烟台市科技计划项目(2021NYNC015,2022XCZX094,2023YD079,2023ZLYJ116);烟台市涉农项目。
∗通讯作者:刘保友(1981-),男,山东菏泽人,正高级农艺师,从事植物保护与农业资源环境研究。
E -mail:baoyou1022@ 作者简介:张占田(1991-),男,山东莱州人,农艺师,从事植物营养土壤肥力学研究。
E -mail:1269860483@Effects of calcium on the growth and development of fruit trees and application researchZHANG Zhantian 1,SHI Jiangquan 2,CHEN Haining 1,FAN Zhaobo 1,LENG Weifeng 1,LIU Daliang 1,LIU Baoyou 1,3∗(1.Yantai Academy of Agricultural Science ,Yantai ,Shandong 265500,China ;2.Changzhou Jiehe Machinery Co.,Ltd ,Changzhou ,Jiangsu 213163,China ;3.School of Life Sciences ,Yantai University ,Yantai ,Shandong 264005,China ) Abstract :Calcium has been recognized as a nutrient element for nearly two hundred years,andit plays an important role in physiological metabolism as a second messenger coupling extracellularsignals and intracellular physiological and biochemical reactions.Calcium is an element that is not easily absorbed and transferred,mainly relying on transpiration to pull its movement within the tree,and the situation that long -term fertilization ratio is not reasonable will lead to serious problems of calcium deficiency in fruit trees.The role of calcium in the growth and development of fruit trees and the technical application of calcium fertilizer in agricultural production are summarized,and the ex⁃isting problems and future main research directions and prospects are proposed. Key words :fruit trees;calcium;nutritional characteristics;application research;problemsand prospects 钙(Calcium,Ca)是人体必需且含量最多的元素。
小学上册Y卷英语第四单元寒假试卷
小学上册英语第四单元寒假试卷英语试题一、综合题(本题有100小题，每小题1分，共100分.每小题不选、错误，均不给分)1.Light travels fastest in a ______.2.What do we call the process of taking in oxygen and releasing carbon dioxide?A. RespirationB. PhotosynthesisC. DigestionD. FermentationA3. A rabbit has long _______ to hear well.4.Which planet is known as the "Blue Planet"?A. MarsB. NeptuneC. EarthD. Uranus5.What do you call the study of living things?A. GeographyB. BiologyC. SociologyD. PsychologyB6.In a biochemical reaction, enzymes act as biological _____ to speed up the reaction.7.The chemical symbol for sulfur is ______.8.The _______ (The Great Depression) led to widespread economic turmoil.9.The main gas in the air we breathe is _____.10.The ______ (自然) world is full of wonders related to plants.11.Which of these is a type of tree?A. RoseB. OakC. DaisyD. GrassB12.The first successful vaccine was for _______. (天花)13.Which country is famous for kangaroos?A. CanadaB. AustraliaC. BrazilD. IndiaB14. A solution that does not conduct electricity is called a ______ solution.15. A goldfish can recognize its own _______ (影子).16.What is the capital of Brazil?A. Rio de JaneiroB. BrasiliaC. São PauloD. SalvadorB17.aust was a tragic event during __________ (二战). The Holo18.What is the name of the famous wizard in Harry Potter?A. DumbledoreB. VoldemortC. HarryD. SiriusC19.The playground is ___ (crowded) today.20.What is the shape of a basketball?A. SquareB. TriangleC. OvalD. Round21.I want to _______ (学习) about history.22. A _______ is used to measure the density of a liquid.23.What do we call a person who studies the development of organisms?A. BiologistB. GeneticistC. BotanistD. ZoologistA24.I watched a _______ (小海星) on the beach.25.Which number is larger: 10 or 5?A. 10B. 5C. They are equalD. NoneA26. A kitten is a baby ______ (猫).27.I made a ______ (纸飞机) and threw it in the air. It flew very ______ (远).28.We will go ______ for a hike. (out)29.What is the tallest mountain in the world?A. K2B. KilimanjaroC. EverestD. Denali30.I can ______ (完成) my homework on time.31.The _____ (turtle) swims in the water.32.The teacher gives us _____ (homework/tests).33.The _______ can be a great source of exercise and relaxation.34.What do you call the liquid that comes from trees?A. GumB. SyrupC. SapD. JuiceC35.The ancient Romans built _______ for public gatherings. (广场)36. D.TwelveWhich animal is known as "man's best friend"?A. CatB. DogC. Rabbit37.The ________ has a sweet smell in spring.38.The baby is ________ in the crib.39.The chemical formula for potassium iodide is ______.40. A __________ is famous for its unique traditions.41.I like to ______ (参加) cooking classes.42.The __________ (日本) attacked Pearl Harbor in 1941.43.The _____ (种子) can grow into a new plant.44.How many days are in a week?A. FiveB. SevenC. TenD. TwelveB45.I love to spend time with my ______. (我爱和我的______待在一起。
河南省周口市川汇区周口恒大中学2024-2025学年高三上学期开学英语试题(含解析)
2024-2025学年度（上）周口恒大中学高三开学考试英语试题考试时间：120分钟；满分：120分注意事项：1．答题前填写好自己的姓名、班级、考号等信息2．请将正确答案填写在答题卡上第I卷（选择题）第一部分阅读(共两节，满分50分)第一节(共15小题;每小题2.5分，满分37.5分)阅读下列短文，从每题所给的A、 B、C D四个选项中选出最佳选项。
AHABITAT RESTORATION TEAMHelp restore and protect Marin's natural areas from the Marin Headlands to Bolinas Ridge. We'll explore beautiful park sites while conducting invasive (侵入的) plant removal, winter planting, and seed collection. Habitat Restoration Team volunteers play a vital role in restoring sensitive resources and protecting endangered species across the ridges and valleys.GROUPSGroups of five or more require special arrangements and must be confirmed in advance. Please review the List of Available Projects and fill out the Group Project Request Form.AGE, SKILLS, WHAT TO BRINGVolunteers aged 10 and over are welcome. Read our Youth Policy Guidelines for youth under the age of 15.Bring your completed Volunteer Agreement Form. Volunteers under the age of 18 must have the parent/guardian approval section signed.We'll be working rain or shine. Wear clothes that can get dirty. Bring layers for changing weather and a raincoat if necessary.Bring a personal water bottle, sunscreen, and lunch.No experience necessary. Training and tools will be provided. Fulfills (满足) community service requirements.UPCOMING EVENTSTime Meeting LocationSunday, Jan. 1510:00 am — 1:00 Battery Alexanderpm TrailheadSunday, Jan. 2210:00 am — 2:30Stinson Beach Parking LotpmSunday, Jan. 299:30 am — 2:30 pm Coyote Ridge Trailhead1．What is the aim of the Habitat Restoration Team?A．To discover mineral resources.B．To develop new wildlife parks.C．To protect the local ecosystem.D．To conduct biological research.2．What is the lower age limit for joining the Habitat Restoration Team?A．5.B．10.C．15.D．18.3．What are the volunteers expected to do?A．Bring their own tools.B．Work even in bad weather.C．Wear a team uniform.D．Do at least three projects.BI was sitting in between my parents on a 15-hour flight from Toronto to Seoul, where I was going to negotiate a book project. My Airbnb had enough room for us all. So when my parents brought it up as a half-joke that they would come, too, I didn’t think it was unreasonable.I was merely 8 when we embarked on our immigration journey. Korea was their country. They wouldn’t need me there as they did in Canada. But the first week proved to be rough. We were upside down with the time change. My father announced that the first thing they wanted to do was visit my grandma’s grave (坟墓). We had discussed visiting a few relatives, but going to grandma’s grave had never come up. It was starting: family obligations seized my work time. “You guys go,” I said. While my father showered, my mother took me aside. “Your dad has always been counting the days for the moment when he can show her how well you grew up.” I laughed but I was deeply moved. So I decided to accompany them.As we approached the graveyard, I gathered some colored wildflowers from the parking lot and tied them with a long piece of grass. My parents got busy weeding around the headstone. ”Your name is on the back, my father said. “See here?” I looked, and there was my Korean name carved beside those of my siblings and cousins. It felt odd to see our names on theheadstone all of us, the living and dead, connected. I saw a link in a chain that stretches generations back.I didn’t know how to tell them that the trip was amazing. I realized how I was intertwined with them, and they were interwoven into me. We don’t belong to languages or countries. My grandma died only four months before we moved to Canada, when she was too frail (虚弱的) to make the trip. I hope she knows that we did take her, and that maybe all we have is each other. 4．What was the main reason for the author’s trip to Seoul?A．To visit grandma’s graveyard.B．To have a family reunion.C．To work on a project.D．To accompany his parents.5．Why did the author initially decline to visit his grandma’s grave?A．He was exhausted from the flight.B．He had work commitments.C．He liked visiting other relatives better.D．He preferred exploring alone.6．Why did the author’s father want to take him to grandma’s grave?A．To introduce the author to relatives.B．To fulfil a long-awaited wish.C．To observe a family ceremony.D．To help with weeding.7．What did the author realize during the trip?A．Never forget our home country.B．Family is a bridge to our future.C．The world is one big family.D．Home is the bond with people.CThe elderly residents (居民) in care homes in London are being given hens to look after to stop them feeling lonely.The project was dreamed up by a local charity (慈善组织) to reduce loneliness and improve elderly people’s wellbeing. It is also being used to help patients suffering dementia, a serious illness of the mind. Staff in care homes have reported a reduction in the use of medicine where hens are in use.Among those taking part in the project is 80-year-old Ruth Xavier. She said: “I used to keep hens when I was younger and had to prepare their breakfast each morning before I went to school. ”“I like the project a lot. I am down there in my wheelchair in the morning letting the hens out and down there again at night to see they’ve gone to bed.”“It’s good to have a different focus. People have been bringing their children in to see the hens and residents come and sit outside to watch them. I’m enjoying the creative activities, and it feels great to have done something useful.”There are now 700 elderly people looking after hens in 20 care homes in the North East, and the charity has been given financial support to roll it out countrywide.Wendy Wilson, extra care manager at 60 Penfold Street, one of the first to embark on the project, said: “Residents really welcome the idea of the project and the creative sessions. We are looking forward to the benefits and fun the project can bring to people here.”Lynn Lewis, director of Notting Hill Pathways, said: “We are happy to be taking part in the project. It will really help connect our residents through a shared interest and creative activities.”8．What is the purpose of the project?A．To ensure harmony in care homes.B．To provide part-time jobs for the aged.C．To raise money for medical research.D．To promote the elderly people’s welfare. 9．How has the project affected Ruth Xavier?A．She has learned new life skills.B．She has gained a sense of achievement.C．She has recovered her memory.D．She has developed a strong personality. 10．What do the underlined words “embark on” mean in paragraph 7?A．Improve.B．Oppose.C．Begin.D．Evaluate. 11．What can we learn about the project from the last two paragraphs?A．It is well received.B．It needs to be more creative.C．It is highly profitable.D．It takes ages to see the results.DThe rainforests are alive with the sound of animals. Besides the pleasure of the noise, it is also useful to ecologists. If you want to measure the biodiversity of a piece of land, listening out for animal calls is much easier than looking for tracks or spoor in the woods. But such “bioacoustic analysis” is still time-consuming, and it requires an expert pair of ears.In a paper published in Nature Communications, a group of researchers led by Jörg Müller, an ecologist at the University of Würzburg, describe a better way: have a computer do the job. Smartphone apps already exist that will identify birds, bats or mammals simply by listening to the sounds they make. Their idea was to apply the principle to conservation work.The researchers took recordings from across 43 sites in the Ecuadorean rainforest. Sound recordings were taken four times every hour, over two weeks. The various calls were identified manually by an expert, and then used to construct a list of the species present. Then it was the computer's turn. The researchers fed their recordings to artificial-intelligence models that had been trained, using sound samples from elsewhere in Ecuador, to identify 75 bird species from their calls. “We found that the AI tools could identify the sounds as well as the experts,” says Dr Müller. Of course, not everything in a rainforest makes a noise. Dr Müller and his colleagues used light-traps to capture night-flying insects, and DNA analysis to identify them. Reassuringly, they found that the diversity of noisy animals was a reliable proxy(指标) for the diversity of the quieter ones, too.The results may have relevance outside ecology departments, too. Under pressure from their customers, firms such as L'Oreal, a make-up company, and Shell, an oil firm, have been spending money on forest restoration projects around the world. Dr Müller hopes that an automated approach to checking on the results could help monitor such efforts, and give a standardized way to measure whether they are working as well as their sponsors say.12. What is the purpose of paragraph 1 ?A. To lead in a new way to identify calls of animals.B. To highlight the significance of the sound of animals.C. To point out limitations of traditional bioacoustic analysis.D. To compare different ways to measure the diversity in the wild.13. What was the inspiration to do the research?A. The expert pairs of ears.B. The existing functions of apps.C. The recordings from across 43 sites.D. The urgency of protecting biodiversity.14. How did the researchers prove AI effective?A. By analyzing DNA.B. By comparing results.C. By observing process.D. By identifying samples.15. What can be inferred in the last paragraph?A. Many consumers are concerned about ecological issues.B. Some firms have been sponsoring the development of AI.C. Dr Müller hopes forest restoration projects to be effective.D. The new way has become a standardized way to monitor the effectiveness.第二节(共5小题;每小题2.5分，满分12.5分)根据下面短文，从短文后的选项中选出能填入空白处的最佳选项。
the dinosaurs music maladies 雅思阅读
The dinosaurs' music maladiesThe prehistoric reptiles, known for their colossal size and extinction due to an asteroid impact, may have had a hidden talent for music. A new study suggests that dinosaurs may have had the ability to create music, similar to that of humans.The research, published in the journal Paleontology, suggests that dinosaurs had the necessary physical structures to produce music. The study authors argue that dinosaurs had the vocal cords and lungs necessary for generating sound and that their brains had the neural networks required for processing auditory information.However, the study also acknowledges that the dinosaurs' music may not have been as complex as that of humans. It is likely that their music would have been more basic, possibly similar to bird song or primitive melodies.The study also highlights the importance of dinosaur music in understanding the evolution of intelligence and communication among prehistoric animals. The authors suggest that the ability to create music may have been a key factor in the social development of dinosaurs, allowing them to bond and cooperate as a species.In conclusion, the study presents an intriguing argument for the possibility of dinosaur music. While more research is needed to confirm the findings, it opens up a new perspective on the evolution of intelligence and communication among prehistoric animals.。
松鼠的储藏：冬天的准备 英语作文
Title:Squirrels:The Seasonal HoardersAs the leaves turn golden and the air carries a crisp chill,squirrels are a familiar sight in parks and gardens,busily gathering and storing food. Their behavior is a testament to the foresight and adaptability that these small creatures exhibit in preparation for the winter season.The Art of HoardingSquirrels are renowned for their hoarding behavior.They collect nuts, seeds,and other edible items,storing them in various locations to ensure a food supply throughout the colder months.This behavior is not just a random act;it is a carefully planned strategy to survive the scarcity of food during winter.Memory and Spatial AwarenessOne of the most impressive aspects of a squirrel's hoarding is its ability to remember the locations of its caches.Squirrels have excellent spatial memory and can recall the positions of hundreds of stored items.This cognitive ability is crucial for their survival,allowing them to efficiently retrieve food when needed.Diversity in Storage MethodsSquirrels exhibit diversity in their storage methods.Some bury their food in the ground,while others hide it in tree crevices or even build nests filled with their collected treasures.This variety in storage techniques helps to protect their food from theft by other animals and from spoilage.Ecological ImportanceThe hoarding behavior of squirrels has significant ecological implications. By dispersing seeds and nuts,they play a role in the propagation of plant species.Additionally,their caches sometimes serve as a food source for other animals,contributing to the overall health and diversity of the ecosystem.Adaptation to Climate ChangeIn the face of climate change,squirrels'ability to store food has become even more critical.As weather patterns shift and food availability becomes less predictable,their hoarding behavior helps to buffer against these changes,ensuring their survival in a changing world.Human InteractionThe relationship between squirrels and humans is often one of fascination and coexistence.While squirrels may sometimes be seen as pests when they raid gardens or bird feeders,their presence also adds charm and vitality to urban and suburban landscapes.Conservation and RespectAs we share our spaces with squirrels,it is important to respect their natural behaviors and habitats.Providing them with safe spaces to forage and nest,and minimizing disturbance,can help support their populations and ensure their continued role in the ecosystem.ConclusionSquirrels,with their diligent preparation for winter,are a symbol of nature's resilience and resourcefulness.Their hoarding behavior is not just a survival strategy but also an integral part of the seasonal cycle and the ecological balance.As we watch these industrious creatures gather for the winter,we are reminded of the importance of preparation and the marvels of natural adaptation.。
电机及其控制专业英语词汇
电机及其控制专业英语词汇ac motor 交流电动机active (passive) circuit elements 有（无）源电路元件active component 有功分量active in respect to 相对….呈阻性admittance 导纳air-gap flux distribution 气隙磁通分布air-gap flux 气隙磁通air-gap line 气隙磁化线algebraic 代数的algorithmic 算法的alloy 合金ampere-turns 安匝(数)amplidyne 微场扩流发电机Amplitude Modulation (AM) 调幅armature circuit 电枢电路armature coil 电枢线圈armature m.m.f. wave 电枢磁势波attenuate 衰减automatic station 无人值守电站automatic Voltage regulator(AVR)自动电压调整器auxiliary motor 辅助电动机bandwidth 带宽base 基极bilateral circuit 双向电路bimotored 双马达的biphase 双相的bipolar junction transistor (BJT) 双极性晶体管block diagram 方框图boost 增加breakaway force 起步阻力breakdown torque 极限转矩bronze 青铜buck 补偿capacitance effect 电容效应carbon-filament lamp 碳丝灯泡carrier 载波Cartesian coordinates 笛卡儿坐标系cast-aluminum rotor 铸铝转子chopper circuit 斩波电路circuit branch 支路circuit components 电路元件circuit diagram 电路图circuit parameters 电路参数coaxial 共轴的,同轴的coil winding 线圈绕组coincide in phase with 与….同相collector 集电极converter 变流器commutation condition 换向状况commutator-brush combination 换向器-电刷总线complex impedance 复数阻抗complex number 复数compound generator 复励发电机compounded 复励conductance 电导conductor 导体corridor 通路coupling capacitor 耦合电容cumulatively compounded motor 积复励电动机dc generator 直流发电机dc motor 直流电动机de machine 直流电机demodulator 解调器differentiation 微分digital signal processing 数字信号处理digital signal processor (DSP) 数字信号处理器direct axis transient time constant 直轴瞬变时间常数direct axis 直轴direct-current 直流direct torque control (DTC) 直接转矩控制displacement current 位移电流dynamic response 动态响应dynamic-state operation 动态运行e.m.f = electromotive fore 电动势eddy current 涡流effective values 有效值effects of saturation 饱和效应electric energy 电能electrical device 电气设备electrode 电极电焊条electromagnetic torque 电磁转矩emitter 发射管放射器发射极end ring 端环energy converter 电能转换器epoch angle 初相角equivalent T – circuit T型等值电路error detector 误差检测器error signal 误差信号excitation system 励磁系统excited by 励磁exciting voltage 励磁电压external armature circuit 电枢外电路external characteristic 外特性feedback component 反馈元件feedback loop 反馈回路feedback signal 反馈信号feedback system 反馈系统feedforward signal 前馈信号feedforward system 前馈系统fidelity 保真度field coils 励磁线圈field current 励磁电流field effect transistor (FET) 场效应管field oriented control (FOC) 磁场定向控制field winding 磁场绕组励磁绕组flux linkage 磁链form-wound 模绕forward transfer function 正向传递函数Frequency Shift Keying(FSK) 移频键控frequency 频率full load 满载full-load torque 满载转矩full-order observer 全阶观测器gain 增益generating 发电generator voltage 发电机电压Geometrical position 几何位置harmonic 谐波的heating appliance 电热器high frequency 高频high-gain 高增益high-performance 高性能的horsepower (HP) 马力horseshoe magnet 马蹄形磁铁hydropower station 水电站ideal source 理想电源imaginary part 虚部impedance 阻抗incident 入射的induced current 感生电流induction generator 感应发电机induction machine 感应电机induction machine 感应式电机induction motor 感应电动机inductive component 感性（无功）分量infinite voltage gain 无穷大电压增益inrush current 涌流instantaneous electric power 瞬时电功率instantaneous mechanical power 瞬时机械功率insulation 绝缘integration 积分下限internal resistance 内阻interoffice 局间的inverse 倒数inverter 逆变器iron-loss 铁损isolation 隔离分离绝缘隔振laminated core 叠片铁芯lamination 叠片leakage current 漏电流leakage flux 漏磁通leakage reactance 漏磁电抗leakage 泄漏left-hand rule 左手定则light emitting diode 发光二极管lightning shielding 避雷limiter 限幅器line trap 限波器linear zone 线性区line-to-neutral 线与中性点间的load characteristic 负载特性load-saturation curve 负载饱和曲线locked-rotor torque 锁定转子转矩locked-rotor 锁定转子magnetic amplifier 磁放大器magnetic circuit 磁路magnetic field 磁场magnetic torque 电磁转矩magnetizing reacance 磁化电抗manual control 手动控制mature 成熟的mechanical rectifier 机械式整流器micro-controller 微控制器mid-frequency band 中频带mismatch 失配model reference adaptive control (MRAS) 模型参考自适应控制model reference adaptive system (MRAS) 模型参考自适应系统modulator 调制器modulus 模motoring 电动机驱动mutual flux 交互(主)磁通mutual-inductor 互感no-load 空载number of poles 极数observer 观测器operating condition 运行状态operational calculus 算符演算optical fiber 光纤Oscillation 振荡overhauling 检修P.D. = potential drop 电压降per unit value 标么值percentage 百分数performance characteristic 工作特性permanent magnet 永磁permanent magnet synchronous motor 永磁同步电机per-unit value 标么值phase displacement 相位差Phase Modulation (PM) 相位调制phase reversal 反相plugging 反向制动polarity 极性pole 极点polyphase rectifier 多相整流器polyphase rectifier 多相整流器Polyphase 多相(的)potential distribution 电位分布potential transformer 电压互感器power amplifier 功率放大器power frequency 工频primary cell 原生电池prime motor 原动机prime mover 原动机process of self – excitation 自励过程propagate 传导传播r.m.s values = root mean square values 均方根值random-wound 散绕reactive component 无功分量reactive in respect to 相对….呈感性reactive power 无功功率real part 实部rectifier 整流器reference Voltage 基准电压regeneration 再生, 后反馈放大regulator 调节器reluctance 磁阻retarding torque 制动转矩revolutions per minute 转/分revolutions per second 转/秒rheostat 变阻器right-hand rule 右手定则rotating commutator 旋转（整流子）换向器rotating magnetic field 旋转磁场rotor (stator) winding 转子（定子绕组）rotor core 转子铁芯rotor resistance 转子电阻rotor 转子salient poles 凸极saturation curve 饱和曲线saturation effect 饱和效应self–excitation process 自励过程self excited 自励self-bias resistor 自偏置电阻self-exciting 自励的self-inductor 自感self-sensing 位置自检测sensorless 无传感器的separately excited 他励的series excited 串励series 串励shaft 轴shaft-less 无轴承的short-circuiting ring 短路环shunt displacement current 旁路位移电流shunt excited 并励shunt field 并励磁场shunt 并励shunt 分路器signal amplifier 小信号放大器silica 硅石二氧化硅Single Side Band(SSB) 单边带sinusoidal – density wave 正弦磁密度sinusoidal time function 正弦时间函数slip 转差率solid state 固体solt 槽spatial waveform 空间波形spectral 频谱的spectrum 频谱speed regulation 速度调节speed-torque characteristic 速度转矩特性speed-torque curve 转速力矩特性曲线squirrel cage 鼠笼stabilization network 稳定网络stabilizer 稳定器stabilizing transformer 稳定变压器staor winding 定子绕组stator 定子steady–state condition 稳态条件steady direct current 恒稳直流电storage battery 蓄电池summing circuit 总和线路反馈系统中的比较环节synchronous condenser 同步进相（调相）机synchronous generator 同步发电机synchronous reactance 同步电抗synchronous reluctance motor (SRM) 同步磁阻电机synchronous speed 同步转速technical specifications 技术条件terminal voltage 端电压the dielectric 电介质time constant 时间常数time delay 延时time invariant 时不变的time-phase 时间相位transformer 变压器transient response 瞬态响应transistor 晶体管triangular symbol 三角符号trigonometric transformations 瞬时值tuner 调谐器turns ratio 变比匝比two-way configuration 二线制unidirectional current 单方向性电流variable frequency drive (VFD) 变频器vector equation 矢量方程vector control 矢量控制voltage across the terminals 端电压voltage control system 电压控制系统volt-ampere characteristics 伏安特性waveguide 波导波导管wind-driven generator 风动发电机winding loss 绕组（铜）损耗winding 绕组。
电工英语单词
电工英语单词(1) 元件设备三绕组变压器:three-column transformer ThrClnTrans双绕组变压器:double-column transformer DblClmnTrans电容器:Capacitor 并联电容器:shunt capacitor 电抗器:Reactor 母线:Busbar输电线:TransmissionLine 发电厂:power plant 断路器:Breaker 刀闸(隔离开关):Isolator 分接头:tap 电动机:motor(2) 状态参数有功:active power 无功:reactive power 电流:current 容量:capacity 电压:voltage 档位:tap position 有功损耗:reactive loss 无功损耗:active loss 功率因数:power-factor 功率:power功角:power-angle 电压等级:voltage grade 空载损耗:no-load loss 铁损:iron loss铜损:copper loss 空载电流:no-load current阻抗:impedance正序阻抗:positive sequence impedance 负序阻抗:negative sequence impedance 零序阻抗:zero sequence impedance 电阻:resistor 电抗:reactance 电导:conductance 电纳:susceptance无功负载:reactive load 或者QLoad有功负载: active load PLoad遥测:YC(telemetering)遥信:YX励磁电流(转子电流):magnetizing current 定子:stator功角:power-angle上限:upper limit 下限:lower limit并列的:apposable 高压: high voltage 低压:low voltage 中压:middle voltage 电力系统 power system 发电机 generator 励磁 excitation 励磁器excitor 电压 voltage 电流 current 母线 bus 变压器 transformer 升压变压器 step-up transformer高压侧 high side 输电系统 power transmission system输电线 transmission line固定串联电容补偿fixed series capacitor compensation 稳定 stability 电压稳定 voltage stability功角稳定 angle stability 暂态稳定 transient stability 电厂 power plant 能量输送 power transfer交流 AC 装机容量 installed capacity电网 power system 落点 drop point开关站 switch station 双回同杆并架 double-circuit lines on the same tower变电站 transformer substation 补偿度 degree of compensation 高抗high voltage shunt reactor 无功补偿 reactive power compensation 故障fault 调节 regulation 裕度 magin 三相故障 three phase fault 故障切除时间fault clearing time极限切除时间 critical clearing time切机 generator triping 高顶值 high limited value 强行励磁 reinforced excitation 线路补偿器 LDC(line drop compensation) 机端 generator terminal静态 static (state) 动态 dynamic (state)单机无穷大系统 one machine - infinity bus system 机端电压控制 AVR 电抗 reactance 电阻 resistance 功角 power angle有功(功率) active power 无功(功率) reactive power 功率因数 power factor 无功电流 reactive current 下降特性 droop characteristics 斜率 slope 额定 rating 变比 ratio参考值 reference value 电压互感器 PT分接头 tap 下降率 droop rate仿真分析 simulation analysis 传递函数 transfer function 框图 block diagram 受端 receive-side 裕度 margin同步 synchronization 失去同步 loss of synchronization 阻尼 damping 摇摆 swing保护断路器 circuit breaker电阻:resistance 电抗:reactance 阻抗:impedance电导:conductance 电纳:susceptance导纳:admittance 电感:inductance电容: capacitancemagnetizing reacance 磁化电抗line-to-neutral 线与中性点间的 staor winding 定子绕组 leakage reactance 漏磁电抗no-load 空载 full load 满载 Polyphase 多相(的) iron-loss 铁损complex impedance 复数阻抗 rotor resistance 转子电阻 leakage flux 漏磁通 locked-rotor 锁定转子 chopper circuit 斩波电路 separately excited 他励的 compounded 复励 dc motor 直流电动机 de machine 直流电机 speed regulation 速度调节 shunt 并励 series 串励 armature circuit 电枢电路optical fiber 光纤 interoffice 局间的 waveguide 波导波导管 bandwidth 带宽 light emitting diode 发光二极管 silica 硅石二氧化硅 regeneration 再生, 后反馈放大 coaxial 共轴的,同轴的high-performance 高性能的 carrier 载波 mature 成熟的 Single Side Band(SSB) 单边带 coupling capacitor 结合电容 propagate 传导传播modulator 调制器 demodulator 解调器 line trap 限波器 shunt 分路器Amplitude Modulation(AM)调幅Frequency Shift Keying(FSK)移频键控tuner 调谐器 attenuate 衰减 incident 入射的 two-way configuration 二线制 generator voltage 发电机电压 dc generator 直流发电机 polyphase rectifier 多相整流器boost 增压 time constant 时间常数 forward transfer function 正向传递函数 error signal 误差信号 regulator 调节器 stabilizing transformer 稳定变压器 time delay 延时direct axis transient time constant 直轴瞬变时间常数transient response 瞬态响应 solid state 固体 buck 补偿 operational calculus 算符演算 gain 增益 pole 极点 feedback signal 反馈信号 dynamic response 动态响应 voltage control system 电压控制系统 mismatch 失配error detector 误差检测器 excitation system 励磁系统 field current励磁电流 transistor 晶体管 high-gain 高增益 boost-buck 升压去磁 feedback system 反馈系统reactive power 无功功率 feedback loop 反馈回路 automatic Voltage regulator(AVR)自动电压调整器reference Voltage 基准电压 magnetic amplifier 磁放大器amplidyne 微场扩流发电机self-exciting 自励的 limiter 限幅器manual control 手动控制block diagram 方框图 linear zone 线性区 potential transformer 电压互感器 stabilization network 稳定网络 stabilizer 稳定器 air-gap flux 气隙磁通 saturation effect 饱和效应 saturation curve 饱和曲线 flux linkage 磁链 per unit value 标么值 shunt field 并励磁场 magnetic circuit 磁路load-saturation curve 负载饱和曲线air-gap line 气隙磁化线 polyphase rectifier 多相整流器 induction machine 感应式电机 horseshoe magnet 马蹄形磁铁 magnetic field 磁场 eddy current 涡流 right-hand rule 右手定则 left-hand rule 左手定则 slip 转差率 induction motor 感应电动机 rotating magnetic field 旋转磁场 winding 绕组 stator 定子 rotor 转子 induced current 感生电流 time-phase 时间相位exciting voltage 励磁电压 solt 槽 lamination 叠片 laminated core 叠片铁芯 short-circuiting ring 短路环 squirrel cage 鼠笼 rotor core 转子铁芯cast-aluminum rotor 铸铝转子 bronze 青铜 horsepower 马力 random-wound 散绕 insulation 绝缘 ac motor 交流环电动机end ring 端环 alloy 合金 coil winding 线圈绕组form-wound 模绕 performance characteristic 工作特性 frequency 频率revolutions per minute 转/分 motoring 电动机驱动generating 发电 per-unit value 标么值 breakdown torque 极限转矩breakaway force 起步阻力 overhauling 检修 wind-driven generator 风动发电机revolutions per second 转/秒 number of poles 极数 speed-torque curve 转速力矩特性曲线plugging 反向制动synchronous speed 同步转速 percentage 百分数 locked-rotor torque 锁定转子转矩 full-load torque 满载转矩 prime mover 原动机 inrush current 涌流。
树的重要性英语作文
Trees are an integral part of our ecosystem,providing a multitude of benefits that contribute to the overall health and wellbeing of the planet and its inhabitants.Here are several reasons why trees are so important:1.Air Purification:Trees absorb carbon dioxide and release oxygen,making them natural air purifiers.This process,known as photosynthesis,helps to reduce the greenhouse effect and combat climate change.2.Habitat Provision:Trees offer shelter and food for a wide variety of wildlife.They are home to countless species of birds,insects,and mammals,which rely on trees for nesting, resting,and feeding.3.Soil Conservation:The roots of trees help to stabilize the soil,preventing erosion and landslides.They also improve soil quality by recycling nutrients through the decomposition of fallen leaves and branches.4.Water Regulation:Trees play a crucial role in the water cycle by absorbing and storing water,reducing runoff,and recharging groundwater.They also help to slow down the flow of water during heavy rains,reducing the risk of flooding.5.Climate Regulation:Trees provide shade and help to regulate local temperatures.They can lower the temperature of the surrounding area through a process known as transpiration,where water is released into the air,cooling the environment.6.Biodiversity Support:The diversity of tree species supports a wide range of biodiversity.Different species of trees provide unique habitats and resources for various forms of life.7.Economic Value:Trees are a source of timber,paper,and other products.They also contribute to tourism and recreational activities,such as parks and forests,which are popular destinations for relaxation and outdoor activities.8.Aesthetic Value:Trees enhance the beauty of landscapes and urban environments. They provide visual appeal and contribute to the overall aesthetic of a community.9.Noise Reduction:Trees can act as a natural barrier against noise pollution,absorbing and blocking sound waves,thus creating a quieter environment.10.Mental Health Benefits:Studies have shown that being in the presence of trees and nature can reduce stress,improve mood,and contribute to overall mental wellbeing.In conclusion,trees are vital for the health of the planet and the quality of life for all living beings.It is essential to protect and preserve our forests and urban green spaces to ensure a sustainable future for generations to come.。
肺移植术后原发性移植物功能障碍的危险因素研究进展
第１２卷 第３期２０２１年５月Ｖｏｌ． １２ Ｎｏ．３Ｍａｙ ２０２１器官移植Ｏｒｇａｎ Ｔｒａｎｓｐｌａｎｔａｔｉｏｎ肺移植是治疗终末期肺疾病的唯一有效方式，但国际心肺移植学会（International Society for Heart and Lung Transplantation ，ISHLT ）报告显示，肺移植受者的早期预后远不如其他实体器官移植受者，术后中位生存期仅6.7年，其中原发性移植物功能障碍（primary graft dysfunction ，PGD ）是影响其预后的【摘要】 肺移植是治疗终末期肺疾病的唯一有效方式，但肺移植受者的早期预后远不如其他实体器官移植受者，其中原发性移植物功能障碍（PGD ）是影响其预后的主要原因之一。
PGD 是肺移植术后早期发生的一种急性肺损伤，是导致肺移植受者术后早期死亡的主要原因。
肺移植受者术后PGD 发生的危险因素包括供者、受者、手术等多方面。
本文对肺移植术后发生PGD 的危险因素进行综述，旨在为临床提供参考。
【关键词】 肺移植；原发性移植物功能障碍；扩大标准供者；活性氧簇；体外膜肺氧合；体外肺灌注；体外 循环；输血相关性肺损伤【中图分类号】R617，R563 【文献标志码】A 【文章编号】1674-7445（2021）03-0016-06·综述·肺移植术后原发性移植物功能障碍的危险因素研究进展胡春兰 于慧智 王净 李小杉 胡春晓【Abstract 】 Lung transplantation is the only effective approach to treat end-stage lung diseases. Nevertheless, early prognosis of lung transplant recipients is significantly worse than that of other solid organ transplant recipients. Primary graft dysfunction (PGD) is one of the main causes affecting clinical prognosis of the recipients. PGD is an early acute lung injury after lung transplantation, which is the main cause of early death of lung transplant recipients. Risk factors of PGD after lung transplantation consist of donor, recipient and operation, etc . In this article, the risk factors of PGD after lung transplantation were reviewed, aiming to provide reference for clinical practice.【Key words 】 Lung transplantation; Primary graft dysfunction; Expanded criteria donor; Reactive oxygen species; Extracorporeal membrane oxygenation; Ex vivo lung perfusion; Cardiopulmonary bypass; Transfusion-related lung injuryResearch progress on risk factors of primary graft dysfunction after lung transplantation Hu Chunlan *, Yu Huizhi, Wang Jing, Li Xiaoshan, Hu Chunxiao. *Department of Anesthesiology, Wuxi People’s Hospital Affiliated to Nanjing Medical University, Wuxi 214023, ChinaCorrespondingauthor:HuChunxiao,Email:***********************DOI: 10.3969/j.issn.1674-7445.2021.03.016基金项目：国家自然科学基金（8207011015）；无锡市卫生健康委青年项目（Q202003）作者单位：214023 江苏无锡，南京医科大学附属无锡人民医院麻醉科（胡春兰、王净、于慧智、李小杉、胡春晓），肺移植中心 （胡春晓）作者简介：胡春兰，女，1995 年生，硕士研究生，住院医师，研究方向为肺缺血-再灌注损伤和移植物功能研究，Email: huchunlan *************通信作者：胡春晓，男，1971 年生，主任医师，研究方向为肺缺血-再灌注损伤、重要器官功能保护和 ECMO 辅助下肺移植围手术期的应用管理及脑损伤的机制，Email:***********************·３５８·第１２卷器官移植主要原因之一。
写昆虫的英语作文
Insects are a class of creatures that have fascinated humans for centuries due to their incredible diversity,unique behaviors,and vital roles in ecosystems.Here is an English essay about insects,exploring their characteristics,importance,and some of the most common species.The Marvel of Insects:A World of Tiny GiantsInsects are the most diverse group of animals on our planet,with over a million described species and many more yet to be discovered.They belong to the class Insecta within the phylum Arthropoda,characterized by a chitinous exoskeleton,a threepart body head, thorax,and abdomen,three pairs of jointed legs,compound eyes,and one pair of antennae.Characteristics of Insects1.Exoskeleton:Insects possess a hard,protective exoskeleton made of chitin,which provides structural support and protection from predators and environmental factors.2.Metamorphosis:Many insects undergo metamorphosis,a process of development that includes four distinct life stages:egg,larva,pupa,and adult.This allows for drastic changes in form and function as they grow.3.Reproduction:Insects reproduce at an astonishing rate,with many species laying hundreds or even thousands of eggs at a time,ensuring the survival of their species.4.Diversity:Insects are incredibly diverse in size,shape,and color,ranging from the tiny fairyfly to the large,colorful butterflies and beetles.Importance of Insects1.Pollination:Many insects,particularly bees,butterflies,and moths,play a crucial role in pollinating plants,which is essential for the production of fruits,vegetables,and nuts.2.Decomposition:Insects such as beetles and flies are vital in breaking down dead organic matter,recycling nutrients back into the ecosystem.3.Food Source:Insects are a primary food source for many animals,including birds, reptiles,and other insects.4.Biological Control:Some insects,like ladybugs and praying mantises,are natural predators of pests,helping to control populations of harmful insects in agriculture.Common Insect Species1.Butterflies and Moths Lepidoptera:Known for their beautiful wings and patterns,they are important pollinators and serve as a food source for many animals.2.Beetles Coleoptera:With the largest number of species,beetles are incredibly diverse, from the small ladybugs to the large,shiny scarabs.3.Ants,Bees,and Wasps Hymenoptera:These social insects are known for their complex colonies and roles in pollination and pest control.4.Flies Diptera:Although many species are considered pests,some,like the hoverfly,are beneficial pollinators.5.Dragonflies and Damselflies Odonata:These agile fliers are predators of other insects and are important for controlling mosquito populations.Conservation and InsectsInsects face numerous threats,including habitat loss,pesticide use,and climate change.It is crucial to protect their habitats and reduce the use of harmful chemicals to ensure the survival of these essential creatures.ConclusionInsects are not just a part of nature they are the backbone of many ecosystems.Their survival is intertwined with ours,and understanding their importance can lead to better stewardship of our environment.As we continue to explore the world of insects,we uncover the intricate connections that bind us all in the web of life.This essay provides a comprehensive overview of insects,their characteristics,ecological importance,common species,and the need for conservation efforts.It is a testament to the significance of these tiny creatures in the grand scheme of life on Earth.。
电气的专业术语中英对照
电气的专业术语英文〔一〕电气专业术语二1. Personnel 人员职员2. Voltmeter 电压表伏特计3. Ohmmeter 欧姆计电阻表4. Megohmmeter 兆欧表5. Wattmeter 瓦特计电表功率6. Watt-hour 瓦时瓦特小时7. Ammeter 安培计电流表8. calibrate 校正9. scale 刻度量程10. rated 额定的11. interfere with 有害于...12. indicating needle仪表指针13. hazardous 危险的14. pivot 支点15. terminal 端子16. spiral 螺旋形的17. spring 弹簧18. shunt 分流,分路,并联,旁路19. rectifier 整流器20. electrodynamometer 电测力计21. strive for 争取22. vane 机器的叶,叶片23. strip 条,带,<跨接>片24. crude 不精细的,粗略的25. polarity 极性26. fuse 保险丝 ,熔丝27. rugged 坚固的28. depict 描绘 ,描写29. cartridge 盒式保险丝30. blow <保险丝>烧断31. plug fuse 插头式保险丝32. malfunction 故障33. deenergize 不给… 通电34. insulation 绝缘35. generator 发电机36. magneto 磁发电机37. humidity 湿度38. moisture 潮湿湿气39. abbreviate 缩写,缩写为40. transformer 变压器41. thumb 检查 ,查阅42. milliammeter 毫安表43. multimeter 万用表44. dynamometer 测力计,功率计45. aluminum 铝46. deteriorate 使….恶化47. eddy current 涡流48. gear 齿轮 ,传动装置49. dial 刻度盘50. semiconductor 半导体51. squirrel 鼠笼式52. diode 二极管53. thyristor 晶闸管54. transistor 电子晶体管55. triac 双向可控硅56. phase 相位<控制>57. silicon 硅58. crystal 晶体59. wafer 薄片60. anode 阳极 ,正极61. cathode 阴极62. collector 集电极]63. emitter 发射极64. schematic <电路>原理图符号65. leakage 漏电流66. rating 额定值,标称值,定额67. dissipate 散发68. breakdown 击穿69. heat sink 散热器70. self-latching 自锁71. commutation 换向72. geometry 几何结构73. squeeze 压榨,挤,挤榨74. light-dimmer 调光75. capability 容量76. studmounted 拴接式77. hockey puck 冰球78. fin 飞边79. active 有源的80. horsepower 马力81. diameter 直径82. in. <inch ,inches>英寸83. extruded 型材的84. clamp 夹住,夹紧85. compound 紧密结合86. wrench 扳手87. torque 转矩,扭矩88. enclosure 外<机>壳89. ventilation 通风,流通空气90. sealed-off 封的91. thermal 热的,热量的92. substantially 主要地,实质上地93. aptly 适当地,适宜地94. demystify 阐明95. allude 暗指,直接提到96. cease 停止,终了97. line 线电压98. ripple 脉动.99. redundant 多余的100. separately 单独励磁地101. synchronous 同步电动机102. circuitry 电路,线路103. cost-effective 花费大的104. capacitor 电容器105. dictate 确定106. trade-off 权衡,折衷107. criteria 标准,判据108. analog electronics电力电子学109. saturate 使…饱和110. active region 动态区域111. due 应得到的112. ratio 比,比率113. signify 表示114. encode 编码115. resonance 共鸣116. radiated 传播117. molecule 分子118. diaphragm 震动膜119. acoustic wave 声波120. wavy groove 起伏的沟槽121. deflection 挠度 ,挠曲122. strain gage 应变计量器123. tachometer 转速计124. thermocouple 热电偶125. oscilloscope 示波器126. analytical 解析的127. numerical 数值的128. integrate 求…的积分129. scale 改变比例130. frequency- domain 频域131. random 随机的132. audio 音频的133. operation amplifier 运算放大器134. summation 求和,加法135. sophisticated 复杂的,完善的136. mass-produce 大量生产137. subtract 减去138. inverting amplifier 反向放大器139. uninverting amplifer 同相放大器140. derive 推倒141. active filter 有源滤波器142. stabilize 使稳定143. moderate 适度的,适中的144. virtue 优点145. amplification 扩大146. capacitor 电容器147. impedance 阻抗148. bode plot 波特图149. simulate 模拟,方针150. narrowband filter 带通滤波器151. low-pass filter低通滤波器152. high-pass filter高通滤波器153. differential equation 微分方程154. prebias 预偏置155. summer 加法器156. weighted 加权的157. refinement 改进158. accommodate 适应159. envision 预见160. alphabet 字母表161. validity 正确性162. proposition 命题163. binary 二进制164. nevertheless 然而165. reveal 展现166. complement 补码167. truthtable 真值表168. algebraical 代数的169. trial and error 试错法,试凑法170. elapse 时间<流逝>171. enumerate 列举172. expire 期满,终止173. brute 僵化的174. prime 上撇号175. trigger 引起 ,触发176. inversion 反相 ,反转177. quadruple 四合一178. fabricate 制造179. integrated circuit 集成电路180. capsule 封装181. compatible 兼容的182. obsolete 废弃的183. threshold 门限,阈值184. zener diode 齐纳二极管185. adjacent 临近的,接近的186. arc welding 电弧焊187. intimately 密切地188. recast 重做189. bistable circuit 双稳电路190. cutoff 截止,关闭191. symmetry 对称192. lable 为……标号193. equilibria 平衡194. lever 杆,杠杆195. latch circuit 锁存电路196. depress 压下197. flip-flop 触发器198. glitch 同步199. leading edge 上升沿200. lagging<trailing> edge 下降沿201. inhibit 禁止202. hitherto 迄今,至今203. toggle <来回>切换204. impulse 推动力205. air gap 气隙206. aircraft 飞机207. alternating current, AC 交流208. armature 电枢209. automobile 汽车210. bearing 轴承211. brush 电刷212. carbon 碳213. circumference 圆周214. clearance 间隙215. coils 线圈绕组216. commutator 换向器217. connection 接线端218. copper bar 铜导条219. copper end rings 铜端环220. core 铁心221. cylindrical 圆柱式的222. doubly excited 双边励磁223. electromechanical 机电的224. felt 毡225. ferromagnetic 铁磁的226. field pole 磁极227. flux density 磁通密度228. frame 机座,机壳229. generator 发电机230. glue 胶合,粘贴231. graphite 石墨232. induction motor感应电动机233. laminate 叠制,叠压234. lubricant 润滑剂 ,润滑油235. magnetic flux 磁通236. magnetizing current 磁化电流,励磁电流237. mechanical rectifier 机械式换向器238. metallic 金属的239. penetrate 透过,渗透240. periphery 周围,圆周241. perpendicular 垂直的,正交的242. polarity 极性243. protrude 使伸出,突出244. reluctance 磁阻245. revolving magnetic field 旋转磁场246. rotor 转子247. salient 突出的248. salient-pole 凸极式249. servo 伺服250. singly excited 单边励磁251. slip rings 滑环252. slot 槽,开槽253. squirrel-cage 鼠笼式,笼型254. stator 定子255. synchronous machine 同步电机256. torque 转矩257. toroid 环状物258. transformer 变压器259. unidirectional 单方向的,方向不变的260. winding 绕组261. wound-rotor 绕线式262. wrap 捆,缠,环绕263. yoke 轭264. allowable temperature rise 允许温升265. alnico 铝镍钴合金266. asynchronous machine 异步电机267. automobile starter motor 汽车启动机268. backlash 啮合间隙,齿隙269. centrifugal force 离心力270. ceramic 陶瓷的271. compound-wound 复励272. constraint 强制,约束273. counter emf 反电势274. counterpart 对应物275. culminate 达到极值点276. cumulative compound 积复励277. demagnetization退磁,去磁278. denominator 分母279. differential compound 差复励280. dissipate 浪费281. equilibrium level 平均值282. equivalent circuit 等效电路283. figure of merit品质因数,优值284. flicker 闪烁,摇曳285. flux per pole 每极磁通286. friction 摩擦287. in parallel with 并联288. in series with 串联289. in terms of 根据,在……方面290. in the vicinity of 在…附近,在…左右291. indispensable 必需的,必不可少的292. inherent 固有的293. insulation 绝缘294. long-shunt 长复励295. loss 损耗296. magnetization curve 磁化曲线297. merit 优点,长处,指标298. no load 空载299. nonetheless,none the less 仍然,依然300. numerator 分子301. overload 过载302. permissible 允许的303. permanent-magnet永磁304. pertinent 有关的305. power flow diagram 功率流程图306. prefix 前缀,把…放在前面307. rated torque 额定转矩308. reaction 电感309. rheostat 变阻器,电阻箱310. series-wound 串励311. shunt-wound 并励312. short-shunt 短复励313. starting current 启动电流314. starting torque 启动转矩315. synchronous speed 同步转速316. theorem 定理317. turns 匝数318. undervoltage 欠电压319. Ward-Leonard system 发电机-电动机组系统320. windage 通风321. yield 产生,提供322. adjacent 相邻的,邻近的323. autotransformer自耦变压器324. braking 制动325. cam 凸轮326. chamber 室,腔327. conveyor 传送机328. corrosion 腐蚀329. counterclockwise 逆时针330. counter electromotive force ,CEMF反电势331. dashpot relay 油壶式继电器332. diaphragm 膜片,挡板333. drill 钻床334. elapse 过去,消逝335. enclosure 机壳336. expel 排出,放出337. fasten 固定,连接338. furnace 炉339. fuse 熔断器,保险丝340. general-purpose relay通用继电器341. hydraulic 液压传动342. initiate 引起,促进343. intake 吸入344. knob 旋钮 ,圆形把手345. latching relay 自锁继电器346. lathe 车床347. limit switch 限位开关348. moisture 潮气,湿度349. mount 安装350. octal-base 八脚的351. orifice 孔,注孔352. pedal 踏板,踏蹬353. phase sequence 相序354. piston 活塞355. pivot 轴,支点,旋转中心356. plunger 可动铁心,插棒式铁心357. pneumatic 气动的358. relay 继电器359. single-phase 单相的360. solenoids 螺线管361. solid-state relay 固态继电器362. spring 弹簧363. tap 抽头364. three-phase 三相365. timing relay 延时继电器366. toggle 搬扭,刀闸367. vibration 振动368. absolute encoder 绝对编码器369. accelerometer 加速度测量仪370. actuator 执行机构371. analog-to-digital conversion, ADC 模数转换器372. angular 角的373. auxiliary 辅助的374. as a rule of thumb 根据经验375. bellows 膜盒376. binary-coded decimal,BCD377. calibration 校准,标定,刻度378. cantilever 悬臂379. closed-loop 闭环■380. induction machine 感应式电机381. horseshoe magnet 马蹄形磁铁382. magnetic field 磁场383. eddy current 涡流384. right-hand rule 右手定则385. left-hand rule 左手定则386. slip 转差率387. induction motor 感应电动机388. rotating magnetic field 旋转磁场389. winding 绕组390. stator 定子391. rotor 转子392. induced current 感生电流393. time-phase 时间相位394. exciting voltage 励磁电压395. solt 槽396. lamination 叠片397. laminated core 叠片铁芯398. short-circuiting ring 短路环399. squirrel cage 鼠笼400. rotor core 转子铁芯401. cast-aluminum rotor铸铝转子402. bronze 青铜403. horsepower 马力404. random-wound 散绕405. insulation 绝缘406. ac motor 交流环电动机407. end ring 端环408. alloy 合金409. coil winding 线圈绕组410. form-wound 模绕411. performance characteristic 工作特性412. frequency 频率413. revolutions per minute 转/分414. motoring 电动机驱动415. generating 发电416. per-unit value 标么值417. breakdown torque 极限转矩418. breakaway force 起步阻力419. overhauling 检修420. wind-driven generator 风动发电机421. revolutions per second 转/秒422. number of poles 极数423. speed-torque curve 转速力矩特性曲线424. plugging 反向制动425. synchronous speed 同步转速426. percentage 百分数427. locked-rotor torque 锁定转子转矩428. full-load torque 满载转矩429. prime mover 原动机430. inrush current 涌流431. magnetizing reacance 磁化电抗432. line-to-neutral 线与中性点间的433. staor winding 定子绕组434. leakage reactance 漏磁电抗435. no-load 空载436. full load 满载437. Polyphase 多相<的>438. iron-loss 铁损439. complex impedance 复数阻抗440. rotor resistance 转子电阻441. leakage flux 漏磁通442. locked-rotor 锁定转子443. chopper circuit 斩波电路444. separately excited 他励的445. compounded 复励446. dc motor 直流电动机447. de machine 直流电机448. speed regulation 速度调节449. shunt 并励450. series 串励451. armature circuit 电枢电路452. optical fiber 光纤453. interoffice 局间的454. waveguide 波导波导管455. bandwidth 带宽456. light emitting diode 发光二极管457. silica 硅石二氧化硅458. regeneration 再生, 后反馈放大459. coaxial 共轴的,同轴的460. high-performance 高性能的461. carrier 载波462. mature 成熟的463. Single Side Band<SSB> 单边带464. coupling capacitor 结合电容465. propagate 传导传播466. modulator 调制器467. demodulator 解调器468. line trap 限波器469. shunt 分路器470. Amplitude Modulation<AM调幅471. Frequency Shift Keying<FSK>移频键控472. tuner 调谐器473. attenuate 衰减474. incident 入射的475. two-way configuration 二线制476. generator voltage 发电机电压477. dc generator 直流发电机478. polyphase rectifier 多相整流器479. boost 增压480. time constant 时间常数481. forward transfer function 正向传递函数482. error signal 误差信号483. regulator 调节器484. stabilizing transformer稳定变压器485. time delay 延时486. direct axis transient time constant直轴瞬变时间常数487. time invariant 时不变的488. transient response 瞬态响应489. solid state 固体490. buck 补偿491. operational calculus 算符演算492. gain 增益493. pole 极点494. feedback signal 反馈信号495. dynamic response 动态响应496. voltage control system 电压控制系统497. mismatch 失配498. error detector 误差检测器499. excitation system 励磁系统500. field current 励磁电流501. transistor 晶体管502. high-gain 高增益503. boost-buck 升压去磁504. feedback system 反馈系统505. reactive power 无功功率506. feedback loop 反馈回路507. automatic Voltage regulator<AVR>自动电压调整器508. third harmonic voltage 三次谐波电压509. reference Voltage 基准电压510. magnetic amplifier 磁放大器511. amplidyne 微场扩流发电机512. self-exciting 自励的513. limiter 限幅器514. manual control 手动控制515. block diagram 方框图516. linear zone 线性区517. potential transformer 电压互感器518. stabilization network 稳定网络519. stabilizer 稳定器520. air-gap flux 气隙磁通521. saturation effect 饱和效应522. saturation curve 饱和曲线523. flux linkage 磁链524. per unit value 标么值525. shunt field 并励磁场526. magnetic circuit 磁路527. load-saturation curve 负载饱和曲线528. air-gap line 气隙磁化线529. polyphase rectifier 多相整流器530. circuit components 电路元件531. circuit parameters 电路参数532. electrical device 电气设备533. electric energy 电能534. primary cell 原生电池535. energy converter 电能转换器536. conductor 导体537. heating appliance 电热器538. direct-current 直流539. self-inductor 自感540. mutual-inductor 互感541. the dielectric 电介质542. storage battery 蓄电池543. e.m.f = electromotive fore电动势544. unidirectional current 单方向性电流545. circuit diagram 电路图546. load characteristic 负载特性547. terminal voltage 端电压548. external characteristic外特性549. conductance 电导550. volt-ampere characteristics伏安特性551. carbon-filament lamp 碳丝灯泡552. ideal source 理想电源553. internal resistance 内阻554. active <passive> circuit elements有<无>源电路元件555. deviation 偏差556. leakage current 漏电流557. circuit branch 支路558. P.D. = potential drop 电压降559. potential distribution 电位分布560. r.m.s values = root mean square values均方根值561. permanent magnet 永磁体562. effective values 有效值563. steady direct current 恒稳直流电564. sinusoidal time function 正弦时间函数565. complex number 复数566. Cartesian coordinates 笛卡儿坐标系567. modulus 模568. real part 实部569. imaginary part 虚部570. displacement current 位移电流571. trigonometric transformations 瞬时值572. epoch angle 初相角573. phase displacement 相位差574. signal amplifier 小信号放大器575. mid-frequency band 中频带576. bipolar junction transistor<BJT双极性晶体管577. field effect transistor<FET>场效应管578. electrode 电极电焊条579. polarity 极性580. gain 增益581. isolation 隔离分离绝缘隔振582. emitter 发射管放射器发射极583. collector 集电极584. base 基极585. self-bias resistor 自偏置电阻586. triangular symbol 三角符号587. phase reversal 反相588. infinite voltage gain 无穷大电压增益589. feedback component 反馈元件590. differentiation 微分591. integration 积分下限592. impedance 阻抗593. fidelity 保真度594. summing circuit总和线路反馈系统中的比较环节595. pneumatic 气动的596. Oscillation 振荡597. inverse 倒数598. admittance 导纳599. transformer 变压器600. turns ratio 变比匝比601. ampere-turns 安匝<数>602. mutual flux 交互<主>磁通603. vector equation 向<相>量方程604. power frequency 工频605. capacitance effect 电容效应606. induction machine 感应电机607. shunt excited 并励608. series excited 串励609. separately excited 他励610. self excited 自励611. field winding 磁场绕组励磁绕组612. speed-torque characteristic 速度转矩特性613. dynamic-state operation动态运行614. salient poles 凸极615. excited by 励磁616. field coils 励磁线圈617. air-gap flux distribution 气隙磁通分布618. direct axis 直轴619. armature coil 电枢线圈620. rotating commutator 旋转<整流子>换向器621. commutator-brush combination换向器-电刷总线622. mechanical rectifier 机械式整流器623. armature m.m.f. wave 电枢磁势波624. Geometrical position 几何位置625. magnetic torque 电磁转矩626. spatial waveform 空间波形627. sinusoidal–density wave正弦磁密度628. external armature circuit 电枢外电路629. instantaneous electric power瞬时电功率630. instantaneous mechanical power 瞬时机械功率631. effects of saturation 饱和效应632. reluctance 磁阻633. power amplifier 功率放大器634. compound generator 复励发电机635. rheostat 变阻器636. self – excitation process 自励过程637. commutation condition 换向状况638. cumulatively compounded motor 积复励电动机639. operating condition 运行状态640. equivalent T – circuit T型等值电路641. rotor <stator> winding 转子<定子绕组> 642. winding loss 绕组<铜>损耗643. prime motor 原动机644. active component 有功分量645. reactive component 无功分量646. electromagnetic torque 电磁转矩647. retarding torque 制动转矩648. inductive component 感性<无功>分量649. abscissa axis 横坐标650. induction generator 感应发电机651. synchronous generator 同步发电机652. automatic station 无人值守电站653. hydropower station 水电站654. process of self – excitation 自励过程655. auxiliary motor 辅助电动机656. technical specifications 技术条件657. voltage across the terminals 端电压658. steady – state condition瞬态暂态659. reactive in respect to 相对….呈感性660. active in respect to 相对….呈阻性661. synchronous condenser 同步进相<调相>机662. coincide in phase with 与….同相663. synchronous reactance 同步电抗664. algebraic 代数的665. algorithmic 算法的666. biphase 双相的667. bilateral circuit 双向电路668. bimotored 双马达的669. corridor 通路670. shunt displacement current 旁路位移电流671. leakage 泄漏672. lightning shielding 避雷673. harmonic 谐波的674. insulator string 绝缘子串675. neutral 中性的676. zero sequence current 零序电流677. sinusoidal 正弦的678. square 平方679. corona 电晕,放电680. bypass 旁路681. voltmeter 电压表682. ammeter 电流表683. micrometer 千分尺684. thermometer 温度计685. watt-hour meter 电度表686. wattmeter 电力表687. private line 专用线路688. diameter 直径689. centimeter 厘米690. restriking 电弧再触发691. magnitude 振幅692. oscillation 振荡693. auxiliary 辅助的694. protective gap 保护性间隙放电695. receptacle 插座696. lightning arrester 避雷装置697. bushing 套管698. trigger 起动装置699. stress 应力700. deterioration 损坏,磨损701. spark gap 火花放电隙702. traveling-wave 行波703. wye-connected 星形连接704. enclosure 设备外壳705. live conductor 带电导体706. fuse 熔断器707. structural 结构上的708. out-of-step 不同步的709. resynchronize 再同步710. synchroscops 同步指示器711. automatic oscillograph 自动示波器712. nominally 标称713. sampling 采样714. potential transformer 电压互感器715. fraction 分数716. switchyard 户外配电装置717. hazard 危险718. bushing 高压套719. contact 触点720. energize 励磁721. trip coil 跳闸线圈722. over-current relay 过电流继电器723. armature 衔铁724. pickup current 始动电流725. release current 释放电流726. solenoid relay 螺管式继电器727. induction-disc relay 感应圆盘式继电器728. inverse time relay 反时限继电器729. hydraulic 液力的730. dashpot 阻尼器733. electrical stressing 电气应力734. mechanical stressing 机械应力■735. crystal 晶体的,水晶,晶体736. demodulation 解调737. derivative 导数738. diaphragm 膜片739. differentiation 微分740. discrete 离散的741. displacement 位移742. eddy 涡流743. encoder 编码器744. error 误差,偏差745. expedite 加速746. feedback 反馈747. feedforward 前馈748. forging 锻造749. hysteresis 磁滞750. immunity 抗扰性751. impedance 阻抗752. increment encoder 增量编码器753. inertia 惯性754. integration 积分755. interface 接口756. jerk 振动,冲击757. kinematic 运动的,运动学的758. longitudinal 经度了;纵向的759. manipulations 操作,控制,处理760. manipulator 机械手,操作器761. measurand 被测量,被测量对象762. modulation 调制763. multiplexer 多路转换器764. offset 偏心765. open-loop 开环766. orthogonal 垂直的,正交的767. perpendicular 垂直的,正交的768. photosensor 光电传感器769. piezoelectric 压电的770. plant 装置,设备771. potentiometer 电位器772. predominant 主要的,突出的773. prismatic 棱型的774. proximity 距离775. quantization 量化776. radial 径向的777. redundant 多余的,重复的778. representation 代表,表示779. resolver 解算器780. resonance 共振781. revolute 旋转的,转动的782. rig 设备783. robustness 鲁棒性784. rolling 轧制785. sampling period 采样周期786. signal-to-noise ration ,SNR信噪比787. strategy 策略788. subsequently 其后789. tachometer 测速仪790. terminology 术语,专门名词791. threshold 门,界限,阈值792. trajectory 轨迹793. transducer 传感器794. transient 瞬态的795. transistor-to-transistor logic,TTL 晶体管-晶体管逻辑796. transit 运输797. translatory 平移的798. algorithm 算法799. ambiguity 模棱两可800. antenna 天线801. arbitration 仲裁,公断802. autonomous 匿名的803. capacity 容量804. chao 混乱805. checksum 检查和806. circumnavigate 饶过807. client-server 客户-服务器808. client-server model 客户服务器模型809. corridor 通道,走廊810. decouple 解耦,去除干扰811. depict 描述812. distributed system 分布式系统813. dungen 地牢814. electronic mail 电子815. entity 实体816. etiquette 规则817. exponential 指数818. fallout 余波,附带结果819. forward 转发820. full-duplex 全双工821. gamut 全体,整体822. goggles 护目镜,潜水镜823. half-duplex 半双工824. hierarchy 阶梯,等级825. host 主机826. infrastructure 基础,底层结构827. interactive 交互式828. interface data unit 接口数据单元829. inventory 存货,清单830. killer 迷人的831. newsgroup 新闻组832. object-oriented 面向对象的833. outgoing 外出了,离开的834. pointer 指针835. primitive 操作,原型836. process 进程837. propagation 传播,宣传838. protocol 协议839. protocol data unit 协议数据单元840. remote database 远程数据库841. remote login 远程登陆842. remote terminal 终端843. reprisal 报复844. router 路由器845. service data unit 服务数据单元846. simultaneous 同时的847. static allocation 静态分配848. subnet 子网849. taxonomy 分类学,分类850. telemedicine 远程医疗851. terminology 术语852. testbed 测试平台853. therapy 治疗854. token 令牌855. topology 拓扑学856. videoconference 可视会议857. virtual reality 虚拟现实858. worldwide shared 全球共享的859. wide area network 广域网860. actuator 执行器861. bar code reader 条码阅读器862. by-product 副产品863. call for 需要864. contiguous 邻近的865. culprit 犯罪者866. elusive 难以捉摸的867. filter 滤波器868. fluctuation 升降剥动,不规则的变化869. hardwired 硬接线的870. havoc 大破坏871. high-volume 大容量872. induction coupling 感应耦合873. inference 干扰874. injection molding 注模875. instruction set 指令集876. interconnection 相互连接877. isolation transformer 隔离变压器878. maintenance 维护879. multiple axis drive 多轴驱动880. pilot light 信号灯881. RF noise 射频干扰882. shock 冲击883. solenoid 线圈884. stand-alone 独立的885. stepper 步进电机886. thermocouple 热电偶887. troubleshoot 排除故障888. uninterruptible power supply 不间断电源889. vendor 生产厂商890. vibration 震动891. water-tight 防水892. wreak 发泄,报复893. configuration 组态894. Cyclic Redundancy Check 循环冗余检查895. electromagnetic interference 电磁干扰896. meticulous 详细的897. nonvolatile 非挥发的898. parity 校验899. peripheral 外设900. pharmaceutical 药剂,药品901. rack mounting 机架安装902. resident program 驻留程序903. spare 备用的904. standby 后备的905. volatile 挥发的,易失的906. watchdog timer 看门狗定时器907. distribution 分配,配电908. primary 最初的,基本的,初级线圈909. radial 径向的,辐射状的910. premise 上述各点,前言,根据911. residential 住宅的,居住的912. residence 住宅913. occupancy 占有,占用,居住914. tap 抽头915. establishment 组织,部门916. dwelling 住房917. panel 操纵台,面板918. laundry 洗衣房919. means 手段,工具920. condominium <国际>共官921. branch circuit 直路922. conduit 导线,导线管923. rigid 刚性的,坚固的924. clamp 夹,钳925. bolt 螺栓926. cubicle 立方体927. interrupter 断续<流、电、路>器928. margin 余量,裕度929. nuisance 障碍,公害930. receptacle 插座,插孔931. algebraic 代数的932. virtually 实际上,实质上933. fluorescent 荧光的,有荧光性的934. fixture 设备,装置]935. vicinity 附近,邻近,接近936. ballast 镇流器937. feeder 馈电线,电源线,馈电板938. ground-fault protector <GFP>939. ground-fault circuit interrupter<GFCI> 接地故障保护器,接地故障断路器940. centrifugal 离心的,离心力941. whilst=while942. sphere 球体943. counteract 抵抗,抵消,消除944. joint 关节,铰链945. keyway 键槽946. pivot 轴,支点947. link 连杆948. throttle 节流阀,风门949. synthesis 综合物950. mass 物质,块,堆951. classic 古典的,经典的,传统的952. steer 驾驶,操纵,引导953. servomechanism 伺服机构,伺服系统954. actuate 激励,驱动955. intimately 紧密地,直接的956. academic 纯理论的957. dial 刻度盘,调节控制盘958. calibration 标定,标准化959. lubrication 润滑,注油960. arrangement 结构961. wear 磨损,损耗962. subtle 微妙的,巧妙的963. transducer 变送器964. hand-wheel 手轮,驾驶盘,操纵盘965. hydraulic 液压的,液压传动装置966. pneumatic 气动的,气动力学的967. electro-hydraulic 电动液压的968. electro-pneumatic 电动气动的969. coincidence 一致,相等970. faithful 正确的,可靠的971. fidelity 重现精度,真实,正确972. oscillatory 振动的,摆动的973. align 调整,校准974. profile 轮廓,仿行975. milling machine 铣床976. gyroscope 陀螺仪977. launcher 发生器,启动装置978. inertial 惯性的,惯量的979. electrolytic 电解的980. plate <电>镀981. distillation 蒸馏982. blend 混合,调和,配料983. philosophy 基本原理984. analytical 分析的,分解的985. orifice 侧流板,隔板986. diaphragm 膜,隔板987. knob 钮,圆形把手988. nomenclature 术语989. liable 有责任的990. autonomic 自治的991. grossly 大概,大体上的992. ideological 思想的993. morally 道德上,道义上994. boredom 讨厌,无趣995. deterioration 变化,降低品质996. ambient 环境的997. remarks 附注,要点998. differential pressure transducer差压变送器999. viscous 粘稠的1000.viscous friction 粘滞摩擦.1001.bearing 轴承1002.rolling mill 轧钢机1003.mine minder 矿坑卷扬机1004.velodyne 伺服积分器1005.feasible 可行的1006.regenerative braking 回馈制动1007.eddy current braking 涡流制动1008.dynamic braking 能耗制动1009.reverse braking 反接制动1010.advent 出现1011.prolong 延长1012.armature 电枢1013.contactor 接触器1014.hoist 起重机1015.field winding 励磁绕组1016 mutator 换向器1017.riiple 纹动1018.creep 蠕动1019.tachogenerator 测速发电机1020.quadrant 象限1021.coast 跟踪惯性1022.profile 轮廓1023.conveyance 运输工具1024.lever 手柄,控制杆1025.forced commutation 强迫换流1026.ac squirrel cage induction motor交流笼型感应电动机1027.accutrol 控制器1028.stator 定子1029.rotor 转子1030.DC link 直流环节1031.Triac 双向晶闸管1032.Adjustable-voltage inverter 电压型逆变器1033.Current source inverter 电流型逆变器1034.refinement 明确表达1035.pros and cons 优缺点1036.cogging 齿槽效应.1037.retrofit 改型1038.damper 减速器1039.pitfall 缺陷1040.vernier 游标尺1041.jog 啮合1042.runout table 输出轨道1043.clinker-cooler 熟料冷却器1044.kiln 炉1045.grinder 磨床1046.pitch 齿轮1047.inventory 存货1048.cone pulley 塔轮,快慢轮1049.escalation 升级,提高1050.forced-draft 强制通风1051.induced-draft fan 吸风机1052.elbow 弯头11. interfere with 有害于...12. indicating needle仪表指针13. hazardous 危险的14. pivot 支点15. terminal 端子16. spiral 螺旋形的17. spring 弹簧18. shunt 分流,分路,并联,旁路19. rectifier 整流器20. electrodynamometer 电测力计21. strive for 争取22. vane 机器的叶,叶片23. strip 条,带,<跨接>片24. crude 不精细的,粗略的25. polarity 极性26. fuse 保险丝 ,熔丝27. rugged 坚固的28. depict 描绘 ,描写29. cartridge 盒式保险丝30. blow <保险丝>烧断31. plug fuse 插头式保险丝32. malfunction 故障33. deenergize 不给… 通电34. insulation 绝缘35. generator 发电机36. magneto 磁发电机37. humidity 湿度38. moisture 潮湿湿气39. abbreviate 缩写,缩写为40. transformer 变压器41. thumb 检查 ,查阅42. milliammeter 毫安表43. multimeter 万用表44. dynamometer 测力计,功率计45. aluminum 铝46. deteriorate 使….恶化47. eddy current 涡流48. gear 齿轮 ,传动装置49. dial 刻度盘50. semiconductor 半导体51. squirrel 鼠笼式52. diode 二极管53. thyristor 晶闸管54. transistor 电子晶体管55. triac 双向可控硅56. phase 相位<控制>57. silicon 硅58. crystal 晶体59. wafer 薄片60. anode 阳极 ,正极61. cathode 阴极62. collector 集电极]63. emitter 发射极64. schematic <电路>原理图符号65. leakage 漏电流66. rating 额定值,标称值,定额67. dissipate 散发68. breakdown 击穿69. heat sink 散热器70. self-latching 自锁71. commutation 换向72. geometry 几何结构73. squeeze 压榨,挤,挤榨74. light-dimmer 调光75. capability 容量76. studmounted 拴接式77. hockey puck 冰球78. fin 飞边79. active 有源的80. horsepower 马力81. diameter 直径82. in. <inch ,inches>英寸83. extruded 型材的84. clamp 夹住,夹紧。
The_Effects_of_Squirrels__Storing_Behavior(答案文章最后)
2021年托福阅读真题第3篇The Effects of …The Effects of Squirrels' Storing BehaviorIn a process known as scatter-hoarding, some species of squirrels store food for future use in many different locations. Using this process, the squirrels will store hundreds if not thousands of seeds and nuts per individual squirrel. Early observations led to the long-held notion that squirrels store more than they need and then forget where many seeds and nuts are stored, allowing some of them to germinate(begin growing into new plants) and become established(grow roots). More recent research, however, suggests a far more complicated picture, one in which the squirrels are considerably more efficient at seed and nut recovery and in which germination and establishment occur under far more limited circumstances than previously thought. Nevertheless, scatter-hoarding squirrels are critical for seed dispersal and, in many forest systems, they may serve as its principal agents. Experimental evidence strongly suggests that individual squirrels remember precise locations of their stored nuts, most likely based on spatial information, as is also shown for the scatter- hoarding corvids (birds such as rocks, jays and crows). This is not to say that they don't steal from one another, pilfering is common and sometimes even extreme. Yet in many situations these scatter-hoarders may have control over their own scatter-hoards.The process by which scatter- hoarding squirrels disperse seeds, nuts, and fruits is rather involved. It is perhaps best demonstrated by the easterngray squirrel, which resides predominantly in oak forests throughout much of the central and eastern United States. Numerous experimental studies now demonstrate that this species is highly selective with respect to the nuts that are eaten and those that are stored. Acorns of red oak species, for example, are significantly preferred for scatter hoarding over those of white oak. Typically, the acorns of red oak species are higher in fat content and tannin levels that reduce the tastiness and digestibility of plant foods, but they also exhibit dormancy (a period in which development is temporarily halted to conserve energy) prior to germination. White oak acorns, in contrast, have lower tannin and fat levels and germinate rapidly in the autumn, sometimes while still attached to the tree. Behavioral experiments by Michael Steele, Peter Smallwood, and others show that in the autumn, gray squirrels selectively consume white oak acors, but at the same time they also selectively store red oak acorns, primarily because of their delayed germination schedules and reduced perishability. Tannins and fats secondarily influence the squirrels' eating preferences, but overall the primary determinant of their fall caching(storing) decisions is the germination pattern.Indeed, early germination in white oak acorns appears to have exerted a strong selective pressure on eastern gray squirrels. Several decades ago, John F. Fox demonstrated that when faced with heavy crops of white oak acorns, gray squirrels hide these more perishable food stores, but, when doing so, they carefully cut-off the small embryo at the pointed end of the acorn with a few quick scrapes of their front teeth to prevent the acorn from germinating. Moreover, in experiments with captive-raised eastern gray squirrels having no previous experience with acorns, they also attempt embryo-excision-removal). But they often perform it incorrectly or on thewrong part of an acorn. Thus the behavior may be largely inborn. Although numerous other rodents- such as mice, chipmunks and southern flying squirrels--selectively store red oak acorns, these species do not appear to perform embryo removal. Hence this excision behavior may be unique to a few lineages of squirrels that regularly scatter-hoard acorns. Numerous other nut characteristics.., nut size, weight, and insect infestation) also influence the food-hoarding decisions of scatter-hoarding squirrels in many predictable ways. Ultimately, many of these behavioral decisions, in turn, affect where nuts are hidden and the likelihood that the nuts will germinate and establish if they are not recovered. We currently know that the sites frequently selected by eastern gray squirrels for scatter-hoarding- are often coincidentally optimal for germination. And these are also the sites where acorns store well. We also know that the probability of seeding establishment increases during years with high yields, when animals store large quantities of seeds and nuts and some are not recovered.1.►In a process known as scatter-hoarding, some species of squirrels store food for future use in many different locations. Using this process, the squirrels will store hundreds if not thousands of seeds and nuts per individual squirrel. Early observations led to the long-held notion that squirrels store more than they need and then forget where many seeds and nuts are stored, allowing some of them to germinate(begin growing into new plants) and become established(grow roots). More recent research, however, suggests a far more complicated picture, one in which the squirrels are considerably more efficient at seed and nut recovery and in which germination and establishment occur under far more limited circumstances than previously thought. Nevertheless, scatter-hoarding squirrels are critical for seed dispersal and, in many forest systems, they may serve as its principal agents. Experimental evidence strongly suggests that individual squirrels remember precise locations of their stored nuts, most likely based on spatial information, as is also shown for the scatter- hoarding corvids (birds such as rocks, jays and crows). This is not to say that they don't steal from one another, pilfering is common and sometimes even extreme. Yet in many situations these scatter-hoarders may have control over their own scatter-hoards.2.►In a process known as scatter-hoarding, some species of squirrels store food for future use in many different locations. Using this process, the squirrels will store hundreds if not thousands of seeds and nuts per individual squirrel. Early observations led to the long-held notion that squirrels store more than they need and then forget where many seeds and nuts are stored, allowing some of them to germinate(begin growing into new plants) and become established(grow roots). More recent research, however, suggests a far more complicated picture, one in which the squirrels are considerably more efficient at seed and nut recovery and in which germination and establishment occur under far more limited circumstances than previously thought. Nevertheless, scatter-hoarding squirrels are critical for seed dispersal and, in many forest systems, they may serve as its principal agents. Experimental evidence strongly suggests that individual squirrels remember precise locations of their stored nuts, most likely based on spatial information, as is also shown for the scatter- hoarding corvids (birds such as rocks, jays and crows). This is not to say that they don't steal from one another, pilfering is common and sometimes even extreme. Yet in many situations these scatter-hoarders may have control over their own scatter-hoards.3.►In a process known as scatter-hoarding, some species of squirrels store food for future use in many different locations. Using this process, the squirrels will store hundreds if not thousands of seeds and nuts per individual squirrel. Early observations led to the long-held notion that squirrels store more than they need and then forget where many seeds and nuts are stored, allowing some of them to germinate(begin growing into new plants) and become established(grow roots). More recent research, however, suggests a far more complicated picture, one in which the squirrels are considerably more efficient at seed and nut recovery and in which germination and establishment occur under far more limited circumstances than previously thought. Nevertheless, scatter-hoarding squirrels are critical for seed dispersal and, in many forest systems, they may serve as its principal agents. Experimental evidence strongly suggests that individual squirrels remember precise locations of their stored nuts, most likely based on spatial information, as is also shown for the scatter- hoarding corvids (birds such as rocks, jays and crows). This is not to say that they don't steal from one another, pilfering is common and sometimeseven extreme. Yet in many situations these scatter-hoarders may have control over their own scatter-hoards.4.►The process by which scatter- hoarding squirrels disperse seeds, nuts, and fruits is rather involved. It is perhaps best demonstrated by the eastern gray squirrel, which resides predominantly in oak forests throughout much of the central and eastern United States. Numerous experimental studies now demonstrate that this species is highly selective with respect to the nuts that are eaten and those that are stored. Acorns of red oak species, for example, are significantly preferred for scatter hoarding over those of white oak. Typically, the acorns of red oak species are higher in fat content and tannin levels that reduce the tastiness and digestibility of plant foods, but they also exhibit dormancy (a period in which development is temporarily halted to conserve energy) prior to germination. White oak acorns, in contrast, have lower tannin and fat levels and germinate rapidly in the autumn, sometimes while still attached to the tree. Behavioral experiments by Michael Steele, Peter Smallwood, and others show that in the autumn, gray squirrels selectively consume white oak acors, but at the same time they also selectively store red oak acorns, primarily because of their delayed germination schedules and reduced perishability. Tannins and fats secondarily influence the squirrels' eating preferences, but overall the primary determinant of their fall caching(storing) decisions is the germination pattern.5►Indeed, early germination in white oak acorns appears to have exerted a strong selective pressure on eastern gray squirrels. Several decades ago, John F. Fox demonstrated that when faced with heavy crops of white oak acorns, gray squirrels hide these more perishable food stores, but, when doing so, they carefully cut-off the small embryo at the pointed end of the acorn with a few quick scrapes of their front teeth to prevent the acorn from germinating. Moreover, in experiments with captive-raised eastern gray squirrels having no previous experience with acorns, they also attempt embryo-excision-removal). But they often perform it incorrectly or on the wrong part of an acorn. Thus the behavior may be largely inborn. Although numerous other rodents- such as mice, chipmunks and southern flying squirrels--selectively store red oak acorns, these species do not appear to perform embryo removal. Hence this excision behavior may be unique to a few lineages of squirrels that regularly scatter-hoard acorns.6►Indeed, early germination in white oak acorns appears to have exerted a strong selective pressure on eastern gray squirrels. Several decades ago, John F. Fox demonstrated that when faced with heavy crops of white oak acorns, gray squirrels hide these more perishable food stores, but, when doing so, they carefully cut-off the small embryo at the pointed end of the acorn with a few quick scrapes of their front teeth to prevent the acorn from germinating. Moreover, in experiments with captive-raised eastern gray squirrels having no previous experience with acorns, they also attempt embryo-excision-removal). But they often perform it incorrectly or on the wrong part of an acorn. Thus the behavior may be largely inborn. Although numerous other rodents- such as mice, chipmunks and southern flying squirrels--selectively store red oak acorns, these species do not appear to perform embryo removal. Hence this excision behavior may be unique to a few lineages of squirrels that regularly scatter-hoard acorns.7►Numerous other nut characteristics.., nut size, weight, and insect infestation) also influence the food-hoarding decisions of scatter-hoarding squirrels in many predictable ways. Ultimately, many of these behavioral decisions, in turn, affect where nuts are hidden and the likelihood that the nuts will germinate and establish if they are not recovered. We currently know that the sites frequently selected by eastern gray squirrels for scatter-hoarding- are often coincidentally optimal for germination. And these are also the sites where acorns store well. We also know that the probability of seeding establishment increases during years with high yields, when animals store large quantities of seeds and nuts and some are not recovered.8►Numerous other nut characteristics.., nut size, weight, and insect infestation) also influence the food-hoarding decisions of scatter-hoarding squirrels in many predictable ways. Ultimately, many of these behavioral decisions, in turn, affect where nuts are hidden and the likelihood that the nuts will germinate and establish if they are not recovered. We currently know that the sites frequently selected by eastern gray squirrels for scatter-hoarding- are often coincidentally optimal for germination. And these are also the sites where acorns store well. We also know that the probability of seeding establishment increases during years with high yields, when animals store large quantities of seeds and nuts and some are not recovered.9In a process known as scatter-hoarding, some species of squirrels store food for future use in many different locations. Using this process, the squirrels will store hundreds if not thousands of seeds and nuts per individual squirrel. ⬛Early observations led to the long-held notion that squirrels store more than they need and then forget where many seeds and nuts are stored, allowing some of them to germinate(begin growing into new plants) and become established(grow roots). More recent research, however, suggests a far more complicated picture, one in which the squirrels are considerably more efficient at seed and nut recovery and in which germination and establishment occur under far more limited circumstances than previously thought.⬛Nevertheless, scatter-hoardingsquirrels are critical for seed dispersal and, in many forest systems, they may serve as its principal agents. ⬛Experimental evidence strongly suggests that individual squirrels remember precise locations of their stored nuts, most likely based on spatial information, as is also shown for the scatter- hoarding corvids (birds such as rocks, jays and crows). ⬛This is not to say that they don't steal from one another, pilfering is common and sometimes even extreme. Yet in many situations these scatter-hoarders may have control over their own scatter-hoards.10答案：1 B2 B3 C4 B5 C6 D7 B8 D9 A10 ABF。
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MOTOR I N ACTION I
The Squirrel-Cage Induction Generator for Power Generation
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Y N C H R O N O U S altersynchronous turboalternaBecause of its simplicity, the squirrel-cage inductors.1 However, new probnators now are being tion generator deserves revaluation in the field lems in design may arise with used almost exclusively of power supply. Under appropriate conditions, its low cost and maintenance makes it high-speed high-power inducas main generating units in an economical means of supporting synchronous tion generators. Tooth pulsacentral power stations. The alternators. tion loss plays an important reason is obvious: they generole. Totally enclosed rotor rate both kilowatts and reacslots, magnetic wedges for tive kilovolt-amperes to suit the load conditions and they produce a standard frequency stator slots, and relatively large air gap may be resorted for synchronization and interconnection. Induction gener- to. In fact, for a 2-pole large machine leakage reactance ators usually are installed in relatively small sizes; for is generally low, and, as the short-circuit current is limited although they supply active power, they take reactive by leakage reactance, it is usually necessary to provide current from other synchronous machines. In other extra leakage paths for limiting the transient current. words, irrespective of load conditions, the induction genIf an induction generator is brought up to speed and erator must operate at leading power factor. However, switched to a power line, a large transient current will the induction generator has certain economic advantages flow. This will cause disturbance on the line. One in simplified rotor design which is well adapted for high method to obviate this inrush would be to connect shunt speed operation. It requires no exciter, voltage regu- capacitors corresponding to a somewhat higher susceptance lator, or synchronizing and frequency control equipment. than that of the unsaturated generator. This machine is Induction generators and induction motors have many brought up to synchronous speed and then switched to the points in common. If an induction motor is driven by line in series with a resistance of 3 to 5 per unit, based upon outside mechanical source at speeds above synchronism, the generator rating. In case the generator has not built the power current component in the stator reverses while up its voltage before switching, it will build up in a short the magnetizing component remains in magnitude and in time and then the resistance may be short-circuited. With phase position, as shown in Figure 1. The machine thus this arrangement the disturbance is minimized and the is converted to a generator, and will deliver active power equipment costs very little, since it has only to absorb the when its shaft input has overcome its internal losses. heat produced by the relatively small transient current for It is evident that current of practically equal magnitudes a very short time. This amount of shunt capacitors may will flow through the stator in the case of generator as in be left permanently connected to the generator. Additional capacitors can be provided as needed. the case of motor at a given slip, which is defined as slip = rotor copper loss power transferred across air gap
Essential text of papel 51-158 ^Squirrel-Cage Induction Generator for Power Generation," recommended by-tite AIEE Committee on Rotating Machinery and approved by the AIEE Technical Program Committee for presentation at the A I E E Great Lakes District Meeting, Madison, Wis., May 17-19, 1951. Not scheduled for publication in AIEE Transactions. T. C Ttao is with the Consolidated Edison Company of New York, Inc., New York, N. Y., and N. F. Tsang is with die University of Minnesota, Minneapolis, M i n n . The authors wish to acknowledge their indebtedness to J . G. Noest and M . J . Steinberg for their inspiration; to Professors R. Rudcnberg, N . M. Liwschitz, C. L. Dawes, E. W. Boehne, and K. L. Wildes for comments; and to P. L. Alger, T . M . Linville, A. H Gruehr, W. T . Grumbly, G. L. Sullivan, Y. H . Ku, L. A. Nettleton, and S. T . Meurer for their advice and assistance.