位置的英语怎么读

geological location

地理位置可分为：经纬位置和海陆位置和交通位置

geographic location of China

In general, directions of the east is at right, and the west at left while the north is up and the south down on a map.

以中国为例 China The People"s Republic of China is a socialism country with its own characteristics. It is one of the developing countries. China lies in the east of Asia. It has a number of neighboring countries. To the north, northeast and northwest are the Mongolia, Russia and Korea. To the south are Vietnam, Laos, Thailand and the Philippine. To the west and southwest are India, Burma, Bhutan, Nepal and Pakistan. To the east is Japan, which faces China across the East China Sea. China is a country with a vast territory. It has an area of over 9,600,000 square kilometers. It consists of 34 provinces, autonomous regions, and municipalities directly under the Central Covernment. Beijing, which is situated in the North China, is its capital. The People"s Republic of China is one of the largest countries in the world. Now it has a population of more than 1.2 billion, making up a quarter of the world population. 以下是汉字部分哈: ①中华人民共和国是一个有中国特色的社会主义国家。它是一个发展中国家。 ②中国位于亚洲的东部，有许多邻国。北面和东北面有蒙古，俄罗斯和朝鲜；南面有越南、老挝、泰国和菲律宾；西面和西南面有缅甸、印度、尼泊尔、不丹和巴基斯坦；东面有日本，与中国隔海相望。 ③中国幅员辽阔，有九百六十万平方千米。 ④它有34个省、直辖市和自治区。首都是北京，位于华北。 ⑤中国是世界上最大的国家之一。现在，它有12多亿人口，占世界人口的四分之一。

Compared to the United Kingdom, the United States, China"s geographical location is different

The United States of America locates in central and northwest North America with coastlines on the Atlantic and Pacific oceans.It includes the noncontiguous states of Alaska and Hawaii and various island territories in the Caribbean Sea and Pacific Ocean. 美国位于北美洲中部和西北,海岸线延及太平洋和大西洋.它包括非邻接的阿拉斯加州、夏威夷洲和在加勒比海、太平洋中的许多岛屿领土.

Located in the east of the Asia-Europe Continent, on the western shore of the Pacific Ocean, China has a land boundary of some 20,000 km, with 15 neighboring countries.　　China"s mainland coastline extends from the Yalu River on the border with North Korea in the north to the Beilun River on the border of China and Vietnam in the south, measuring approximately 18,000 km. The Chinese mainland is flanked to the east and south by the Bohai, Yellow, East China and South China seas. A total of over 5,000 islands dot China"s territorial waters. The largest of these is Taiwan. The island coastline measures approximately 14,000 km.　　China is bordered by Korea to the east; Mongolia to the north; Russia to the northeast; Kazakhstan, Kyrgyzstan and Tajikistan to the northwest; Afghanistan, Pakistan, India, Nepal, Sikkim and Bhutan to the west and southwest; and Vietnam, Laos and Myanmar to the south.　　Across the seas to the east and southeast of China are Japan, the Republic of Korea, the Philippines, Malaysia, Indonesia and Brunei.

Australia country in the Southern Hemisphere comprising the mainland of the Australian continent (the world"s smallest), the island of Tasmania and numerous smaller islands in the Indian and Pacific Oceans. Neighbouring countries include Indonesia, East Timor and Papua New Guinea to the north, the Solomon Islands.

Great Britain (Scottish Gaelic: Breatainn Mhòr, Welsh: Prydain Fawr) is the largest island of the British Isles, the largest island in Europe and the eighth-largest island in the world. It lies to the northwest of Continental Europe, with Ireland to the west, and makes up the largest part of the territory of the state known as the United Kingdom of Great Britain and Northern Ireland. It is surrounded by over 1,000[citation needed] smaller islands and islets.The historic nations of England, Scotland and the principality of Wales are mostly situated on the island, along with their capital cities, London, Edinburgh and Cardiff respectively.

美国位于北美洲南部，东临大西洋，西濒太平洋，北接加拿大，南靠墨西哥及墨西哥湾。美国国土面积占世界总面积的7％，居世界第四位。美国面积9372610平方公里（其中陆地面积915.8960万平方公里，内陆水域面积约20万平方公里），如果加上五大湖中美国主权部分约17万平方公里，河口、港湾、内海等沿海水域面积约10万平方公里，面积为963万平方公里，如果只计陆地面积，美国排名第三，仅次于俄罗斯、中国，在加拿大之前。扩展资料美国国土地形变化多端，地势西高东低。东海岸沿海地区有着海岸平原，南宽北窄，一直延伸到新泽西州，在长岛等地也有一些冰川沉积平原。在海岸平原后方的是地形起伏的山麓地带，延伸到位于北卡罗来纳州和新罕布什尔州、高1830米的阿巴拉契亚山脉为止。美国大部分地区属于大陆性气候，南部属亚热带气候。中北部平原温差很大，芝加哥1月平均气温-3℃，7月24℃；墨西哥湾沿岸1月平均气温11℃，7月28℃。

用in the southeast of China in表示"在……范围内”,还表示“在…之中”. 比如：Haikou lies in the south of China on表示“与……毗邻,接壤”,还有表示“在……之上”强调和表面接触, 比如：Canada lies on the north of America to表示方位,不接壤. 比如:Haikou lies to the south of Guangzhou 另外： at,in和on表示地点时的区别 1.at表示地点： （1）用于指较小的地方.如： I shall wait for you at the station. （2）用于门牌号码前.如： He lives at 115 Zhongshan Road. 2.in表示地点： （1）用于指较大的地方.如： He lives in Shanghai. （2）虽然是很小的地方,如果说话人住在那里,也可用in.商店、学校、机关等,若看作一个地点（point）用at,若看作一个场所（place）用in.如： I met him at the post-office. I"m now working in the post-office. 3.on表示地点,一般指与面或线接触,意为“在……上；在……旁”.如： The picture was hanging on the wall. New York is on the Hudson River.

Xi"an lies on the Guanzhong Plain in central China, on a flood plain created by the eight surrounding rivers and streams, most of which are too polluted to be used as sources of fresh water.The city has an average elevation of 400 metres (1,312 ft) above sea level and an annual precipitation of 550 millimetres (22 in). The urban area of Xi"an is located at 34°16′N 108°56′E / 34.267°N 108.933°E / 34.267; 108.933 The Wei River provides potable water to the city.The city borders the northern foot of the Qinling Mountains to the south, and the banks of the Wei River to the north. Hua Shan, one of the five sacred Taoist mountains, is located 100 km away to the east of the city.At the beginning of Han Dynasty, Prime Minister Zhang Liang advised the emperor Liu Bang to choose Guanzhong as the capital of the Han Dynasty: "Guanzhong Plain, which is located behind Xiao Pass and Hangu Pass, connects Long Plain and Shu Plain. Land of thousands miles and rich in harvest can be found here, as if this place is belongs to the nation of the heaven." ("关中左崤函, 右陇蜀, 沃野千里, 此所谓金城千里, 天府之国也" 《史记·留侯世家》) Since then, Guanzhong is also known as "Nation of the Heaven".

oriental pearl 东方明珠

AF] AFRICA 非洲 [EU] EUROPE 欧洲 [AS] ASIA 亚洲 [OA] OCEANIA 大洋洲 [NA] NORTH AMERICA 北美洲 [SA] SOUTH AMERICA 南美洲 [AN] ANTARCTICA 南极洲

France is located in the Western Europe and lies between latitudes 48° 50" N, and longitudes 2° 20" E.

地理位置 United Kingdom, island country located off the northwestern coast of mainland Europe. The United Kingdom comprises the whole of the island of Great Britain—which contains England, Wales, and Scotland—as well as the northern portion of the island of Ireland.面积 The total area of the United Kingdom is approximately 244500 square kilometres.

the location of WuHan city in the map

ChinaThe People"s Republic of China is a socialism country with its own characteristics. It is one of the developing countries.China lies in the east of Asia. It has a number of neighboring countries. To the north, northeast and northwest are the Mongolia, Russia and Korea. To the south are Vietnam, Laos, Thailand and the Philippine. To the west and southwest are India, Burma, Bhutan, Nepal and Pakistan. To the east is Japan, which faces China across the East China Sea.China is a country with a vast territory. It has an area of over 9,600,000 square kilometers. It consists of 34 provinces, autonomous regions, and municipalities directly under the Central Covernment. Beijing, which is situated in the North China, is its capital.The People"s Republic of China is one of the largest countries in the world. Now it has a population of more than 1.2 billion, making up a quarter of the world population.以下是汉字部分哈:①中华人民共和国是一个有中国特色的社会主义国家。它是一个发展中国家。②中国位于亚洲的东部，有许多邻国。北面和东北面有蒙古，俄罗斯和朝鲜；南面有越南、老挝、泰国和菲律宾；西面和西南面有缅甸、印度、尼泊尔、不丹和巴基斯坦；东面有日本，与中国隔海相望。③中国幅员辽阔，有九百六十万平方千米。④它有34个省、直辖市和自治区。首都是北京，位于华北。⑤中国是世界上最大的国家之一。现在，它有12多亿人口，占世界人口的四分之一。

Australia is a country in the Southern Hemisphere comprising the mainland of the Australian continent (the world"s smallest),the island of Tasmania and numerous smaller islands in the Indian and Pacific Oceans.Neighbouring countries include Indonesia,East Timor and Papua New Guinea to the north,the Solomon Islands,Vanuatu and New Caledonia to the northeast and New Zealand to the southeast.

British mainland western Europe from Great Britain and Ireland, north-east and many nearby islands. The full name of the United Kingdom of Great Britain and Northern Ireland. She east by the North Sea, the Atlantic Ocean to the west, up to the North Atlantic off Iceland, Yugoslavia and the European continent, separated only by a strip of water, the English Channel. British total area of about 243,000 square kilometers. The main island is a British territory of Great Britain from northern Scotland. southwest of the southern and central parts of England and Wales, three regional groupings. England area of 130,000 square kilometers which, accounting for most of the island of Great Britain; Wales area of 20,000 square kilometers, territory is mountainous and rugged; Scottish area of 78,000 square kilometers. Northern Ireland area of 14,000 square kilometers. Britain is about 1,000 km from south to north and 50 ° north latitude and 61 ° C; Most things is not more than 500 km wide, east longitude 1 ° 45 "W 8 ° 10" between. Zero meridian through the southeast London GMT (Greenich). British coastline of about 11,500 km. Although the British high latitudes, but due to a single Atlantic, not the cold winter. British maritime climate temperate broadleaf forests. In normal years, the hottest (July), the average temperature of 19-25 degrees Celsius. the coldest (January), the average temperature of 4-7 degrees Celsius. British uneven rainfall throughout England low-lying, with an average rainfall of 830 mm, west, Mountain precipitation in the northern part of a larger, up to 4,000 mm. Britain is the main mineral resources of coal, iron, oil and gas. Hard coal reserves of 170 billion tons. Rail reserves of about 3.8 billion tons. In the United Kingdom North Sea continental shelf oil reserves of about 10-40 million tons. 8600-25,850 billion cubic meters of natural gas reserves in between. Britain"s total population of about 59 million, of which 50 million in England, Scotland, five million, three million in Wales. Northern Ireland 2 million. In the British capital of London, England.

以中国为例 China The People"s Republic of China is a socialism country with its own characteristics.It is one of the developing countries. China lies in the east of Asia.It has a number of neighboring countries.To the north,northeast and northwest are the Mongolia,Russia and Korea.To the south are Vietnam,Laos,Thailand and the Philippine.To the west and southwest are India,Burma,Bhutan,Nepal and Pakistan.To the east is Japan,which faces China across the East China Sea. China is a country with a vast territory.It has an area of over 9,600,000 square kilometers.It consists of 34 provinces,autonomous regions,and municipalities directly under the Central Covernment.Beijing,which is situated in the North China,is its capital. The People"s Republic of China is one of the largest countries in the world.Now it has a population of more than 1.2 billion,making up a quarter of the world population. 以下是汉字部分哈: ①中华人民共和国是一个有中国特色的社会主义国家.它是一个发展中国家. ②中国位于亚洲的东部,有许多邻国.北面和东北面有蒙古,俄罗斯和朝鲜；南面有越南、老挝、泰国和菲律宾；西面和西南面有缅甸、印度、尼泊尔、不丹和巴基斯坦；东面有日本,与中国隔海相望. ③中国幅员辽阔,有九百六十万平方千米. ④它有34个省、直辖市和自治区.首都是北京,位于华北. ⑤中国是世界上最大的国家之一.现在,它有12多亿人口,占世界人口的四分之一.

澳大利亚是大洋洲最大的国家,首都是堪培拉,但是主要城市还是悉尼,与新西兰隔海相望 Australia is the largest country in Oceania, the capital of Canberra, major cities of Sydney and New Zealand across the sea

搜一下：课题：大武汉。武汉的地理位置，要用英文写，越多越好，谢谢各位姐姐，哥哥。。

南京，地处我国东部沿海、长江下游地区。南京有很多古称，如金陵、建康、建业、江宁等，是我国八大古都之一，有近500年的建都史，东吴、东晋、南朝宋、齐、梁、陈先后在南京建都。南京之所以被戏称为“徽京”，有地理位置、历史、文化、经济等几个方面的原因。南京是国家重要的科教中心，自古以来就是一座崇文重教的城市，有“天下文枢”“东南第一学”之称，明清中国一半以上的状元均出自南京江南贡院。截至2020年，南京有各类高等院校68所，其中双一流高校13所、111计划高校10所，211高校8所、两院院士81人，均仅次于北京上海；全球科研城市20强排名，南京位列全球第8、中国第3。

Qingshen County is affiliated with Emei City, Sichuan Province. It is located in the southwest of Chengdu Plain of South west China, having a perfect location with Dongpo District in the north, Leshan City in the south,Emei Moutain in the west andten towns are under the jurisdiction.Qingshen County covers 385 square kilometre with the population of 197,029.

Most of Harvard University is located in and near Cambridge,Boston,and Allston,Massachusetts,on the east coast of the United States of America.Harvard College and some graduate schools are located in Cambridge.The Harvard Business School and many athletic facilities are across the Charles River in Allston.The Harvard Medical School,the Harvard School of Public Health,the Harvard School of Dental Medicine,and many affiliated medical institutions are in an area of Boston known as the Longwood Medical Area or Longwood Medical Campus.

1、优越的地理位置predominant geographical position2、丰富独特的旅游资源plentiful unique tourist resources/ plentiful unique sightseeing resource3、催人奋进的奋斗目标inspiring striving goal4、多元化的立体交通网络 a wide range of steric traffic network5、强大的能源支撑 powerful support for energy6、必要性和可行性 necessity and feasibility7、建设规模及内容 construction scale and content 8、建设条件 condition construction9、市场预测 market forecasting10、项目效益分析 project-benefit analysis11、市场预测和效益分析 market forecasting and benefit analysis12、项目前期工作进展情况 the progress of the project of preliminary work

Tongjiang county belongs to the northeast of sichuan bazhong, MiCangShan eastern, south dabashan mountain gaps in 31 ° north latitude 39 "~ 32 ° 33", longitude 106 ° between "~ 107 ° 46" 59. Pingchang county wanyuan county east, south, west by bazhou, nanjiang county, shaanxi province in the north to south, xixiang, zheng town three counties. Tongjiang county 150 kilometers south from dazhou, 420 km away from chongqing. 89 kilometers west of bazhong, 580 km from provincial capital chengdu, 270 km away from in guangyuan city; East 180 kilometers away from wanyuan; The north is 158 km from zhenba county of shaanxi province. 131 kilometers northwest of nanjiang.

　　Guizhou Province is in the southwest part of the People"s Republice of China.The origin of the Zhujiang River is in the Mut Wumeng.There"re millions of mountains and people there arekind of poor but honest and hard-working. Guizhou Province is hot and rains a lot in the summur.But it is not cold and dry in the winter.

Guangzhou Travel Guide Guangzhou, the South Gate of China, is the capital city of Guangdong.It"s the center of its political, economic, scientific, educational and cultural life. The kapok is the city flower and the kapok tree is the city tree of Guangzhou. Guangzhou is located in the middle south of Guangdong Province, north of the Pearl River Delta. It lies close to the South China Sea, Hong Kong, and Macau. Zhujiang (The Pearl River), the third largest river of China, runs through Guangzhou and is navigable to the South China Sea. Situated in such an excellent geographical region, Guangzhou is called China"s South Gate. Covering an area of 7434.4 square kilometers,Guangzhou is home to more than 11 million people.(不好意思，字数我也不知对不对，看着删减吧）

1.south 2.north3.east4.north-westnorth-east

France is to the south of England.France is on the west of Switzerland.

Certainly one of the best spots in the Mediterranean , Barcelona is the capital city of Catalunya and is one of the 17 Autonomous Communities that make up Spain . It is strategically located in a very privileged position on the northeastern coast of the Iberian peninsula, along the Mediterranean coast, around 41 and 2 Its being located at the Mediterranean sea in the very north of the Spanish coast also contributes to making it certainly the most cosmopolitan and most economically active city in the country of Spain . Barcelona is 160 km (100 mi) south of the Pyrenees mountain range and is nestled in between the mouths of the rivers Llobregat and Bes , and the shores of the Mediterranean . It has an altitude of 4 m above sea level and has the following distances from: Tarragona (98 km), Girona (100 km), Lleida (156 km), Huesca (274 km), Castellon (284 km), Zaragoza (296 km) and Madrid (621 km).Located in the comarca of Barcelon , Barcelona is also the second largest city in Spain in both size and population. The city has a population of 1,510,000, but this number escalates to more than 4,000,000 if the outlying areas are also included in the count. As estimated as of year 2005, the population of the city proper is at 1,593,075, while the population of the metropolitan area is at 4,686,701. On the other hand, population of the province of Barcelona is 5,226,354 although this population only covers 7,733 km (3,000 mi around the city.

Jiangsu is a province of the People"s Republic of China, located along the east coast of the country.Jiangsu borders Shandong in the north, Anhui to the west, and Zhejiang and Shanghai to the south. Jiangsu has a coastline of over one thousand kilometers along the Yellow Sea, and the Yangtze River passes through its southern parts. Since the inception of economic reforms in 1978, Jiangsu has been a hot spot for economic development, and is now one of China"s most prosperous provinces.

音质好。雅马哈YSTSW011是雅马哈公司生产的重低音音箱，频率响应30200Hz，最大输出功率100W，频率响应30200Hz，该音箱音质好，价格便宜。

两台电动机顺启逆停电路图设计：原理解析：顺序启动、逆序停止控制电路是在一个设备启动之后另一个设备才能启动运行的一种。控制方法，常用于主辅设备之间的控制，如图当辅助设备的接触器KM1启动之后，主要设备的接触器KM2才能启动，主设备KM2不停止，辅助设备KM1也不能停止。分类形式：一、按电动机结构尺寸分类①大型电动机指电动机机座中心高度大于630mm，或者16号机座及以上.或定子铁芯外径大于990mm者.称为大型电动机。②中型电动机指电动机机座中心高度在355一630mm之间.或者11-15号机座.或定子铁芯外径在560~990mm之间者.称为中型电动机。③小型电动机指电动机机座中心高度在80-315mm.或者10号及以下机座，或定子铁芯外径在125-560mm之间者.称为小型电动机。二、按电动机转速分类①恒转速电动机有普通笼型、特殊笼型(深槽式、双笼式、高启动转矩式)和绕线型。②调速电机就是配有有换向器的电动机。一般采用三相并励式的绕线转子电动机(转子控制电阻、转子控制励磁)。③变速电动机有变极电动机、单绕组多速电动机、特殊笼型电动机和转差电动机等。

伺服液压机比普通液压机箱就是多了一个位置检测机构以及反馈执行机构，伺服液压机通过伺服电机带动液压泵改变流量，或者是通过伺服阀来控制压力大小，流量大小等等，然后通过位置传感器检测位置信息进行反馈控制。

调压阀型号规格是有很多种的，但使用调压阀的主要是为了节能，空气或水流经过调压阀时，通过对空气和水的压力控制，使其系统流量分布合理，有效的改善了系统布局与工况，大大降低了资源的浪费。在日常我们经常会见到的调压阀有先导活塞式调压阀,薄膜式调压阀和比例式调压阀以及背压调节阀等等，这些调压阀除了工作环境和使用场景以及各自的工作原理与有所区别外，但这些调压阀的主要功能都是差不多的，为了保持压力的稳定，通过启闭件将进口压力降至我们需要的出口压力，大多数情况下，减压阀的进出口之间的压力差需要大于等于0.2兆帕。因为在出口压力不够的情况下，主阀体会全开，长期使用会出现一定的问题，为了保证安全性，减压阀的进出口之间的压力差必需要大于等于0.2兆帕。总的来说，DPC调压阀主要适用于水，蒸汽以及空气介质的管路上，都是通过把进口压力值降到我们需要的出口压力值，如果进口压力值和流量发生了改变，调压阀会根据介质的能量会把出口压力确定在一定的范围之内。

XTT（Xin Time Token）是基于以太坊 ERC20 平台，是去中心化、基于区块链作为支付技术的数字货币载体。以太坊是一个开源的有智能合约功能的公共区块链平台，通过其专用加密货币以太币（Ether，简称“ETH”）提供去中心化的以太虚拟机来处理点对点合约。以太坊的概念首次在2013至2014年间由程序员Vitalik Buterin受比特币启发后提出，大意为“下一代加密货币与去中心化应用平台”，在2014年通过ICO众筹开始得以发展。扩展资料：产生背景比特币开创了去中心化密码货币的先河，五年多的时间充分检验了区块链技术的可行性和安全性。比特币的区块链事实上是一套分布式的数据库，如果再在其中加进一个符号——比特币，并规定一套协议使得这个符号可以在数据库上安全地转移，并且无需信任第三方，这些特征的组合完美地构造了一个货币传输体系——比特币网络。然而比特币并不完美，其中协议的扩展性是一项不足，例如比特币网络里只有一种符号——比特币，用户无法自定义另外的符号，这些符号可以是代表公司的股票，或者是债务凭证等，这就损失了一些功能。另外，比特币协议里使用了一套基于堆栈的脚本语言，这语言虽然具有一定灵活性，使得像多重签名这样的功能得以实现，然而却不足以构建更高级的应用，例如去中心化交易所等。以太坊从设计上就是为了解决比特币扩展性不足的问题。参考资料来源：百度百科-以太坊

a．放电时，lani5h6中h元素被氧化，为电池的负极，故a错误；b．放电时，lani5h6被氧化生成h2o，电极反应式为lani5h6+6oh--6e-=lani5+6h2o，故b正确；c．充电时，阳极发生反应6ni（oh）2+6oh-=6nio（oh）+6e-+6h2o，c（oh-）减小，故c错误；d．充电时，应发生lani5+6h2o+6e-=lani5h6+6oh-，储氢合金作阴极，故d正确．故选bd．

1.多用电表的原理(1)多用电表的用途：在直流电源电路中，测量电路某两点的电压用，测量电路中的电流用，多用电表又叫万用表，是一种集测量与电压、和电阻等功能于一体的测量仪器.(2)多用电表的原理：如图是多用电表电路图.①多用电表的核心是一只直流灵敏电流计G(即表头)、电阻与拨动转换开关等部分组成.②将选择开关拨至触点1或2为直流测量端.③将选择开关拨至触点3或4为直流测量端.④将选择开关拨至触点5为测量端.(3)多用电表的电压挡、电流挡和欧姆挡①多用电表测直流电流和电压，同电流表和电压表的原理相同，实质就是采用并联电阻分流和串联电阻分压的原理.注意读数时要读取跟选择开关挡位相对应的刻度值.②多用电表电阻挡(欧姆档)测电阻的设计原理是闭合电路欧姆定律.如图所示，R6为可变电阻，(R5+R6)=R，为调零电阻.当待测电阻Rx接入公共端和测量端5后，形成闭合电路，可以根据Rx与电路电流I的关系将刻度盘上的电流值改为电阻值，即可得到待测电阻Rx的阻值.I当未接入电阻时(断路状态，Rx)电流I=0，指针不偏转，表盘最左端指示电阻为处.II当两表笔直接相连时(短路状态，Rx=0)电流I为满偏电流，指针指到最大值，表盘最右端指示电阻为0处.2.多用电表的表面结构:(1)上半部分为表盘，共有三条刻度线.①最上面的刻度线的左端标有，右端标有0，是用于测电阻的.②中间的刻度线是用于测直流电流和直流电压的,其刻度是分布均匀的.③最下面一条刻度线左侧标有是用于测交流电压的，其刻度是不均匀的.(2)下半部分为选择开关，周围标有测量功能的区域和量程.将多用电表的选择开关旋转到电流挡，多用电表就测量电流;当选择开关旋转到其他功能区域时，就可测量电压或电阻.(3)多用电表表面还有一对正、负插孔.红表笔插+插孔，黑表笔插-插孔,插孔上面的旋钮叫欧姆调零，用它可进行电阻调零，另外，在表盘和选择开关之间还有一个机械调零,用它可以进行机械调零，即旋转该调零螺丝，可使指针(在不接入电路中时)指在左端0刻线.

1.伺服主要靠脉冲来定位，基本上可以这样理解，伺服电机接收到1个脉冲，就会旋转1个脉冲对应的角度，从而实现位移，因为，伺服电机本身具备发出脉冲的功能，所以伺服电机每旋转一个角度，都会发出对应数量的脉冲，这样，和伺服电机接受的脉冲形成了呼应，或者叫闭环，如此一来，系统就会知道发了多少脉冲给伺服电机，同时又收了多少脉冲回来，这样，就能够很精确的控制电机的转动，从而实现精确的定位，可以达到0.001mm。直流伺服电机分为有刷和无刷电机。有刷电机成本低，结构简单，启动转矩大，调速范围宽，控制容易，需要维护，但维护不方便（换碳刷），产生电磁干扰，对环境有要求。因此它可以用于对成本敏感的普通工业和民用场合。 　　无刷电机体积小，重量轻，出力大，响应快，速度高，惯量小，转动平滑，力矩稳定。控制复杂，容易实现智能化，其电子换相方式灵活，可以方波换相或正弦波换相。电机免维护，效率很高，运行温度低，电磁辐射很小，长寿命，可用于各种环境。 　　2.交流伺服电机也是无刷电机，分为同步和异步电机，目前运动控制中一般都用同步电机，它的功率范围大，可以做到很大的功率。大惯量，最高转动速度低，且随着功率增大而快速降低。因而适合做低速平稳运行的应用。 　　3.伺服电机内部的转子是永磁铁，驱动器控制的U/V/W三相电形成电磁场，转子在此磁场的作用下转动，同时电机自带的编码器反馈信号给驱动器，驱动器根据反馈值与目标值进行比较，调整转子转动的角度。伺服电机的精度决定于编码器的精度（线数）。

储氢合金形成的金属氢化物稳定。根据相关资料查询，对于储氢合金形成的金属氢化物而言，稳定性可以由其原子尺寸、原子量以及溶液中的氢的浓度等因素来控制，这些条件得到合理控制，这些金属氢化物就会变得非常稳定。

先搞懂磁场才能理解电磁感应!这是所有电动或动电转换的前提!磁场,是一种物理能量!磁场无处不在!只是强度不同!地球本身就是一个大磁体!它的两个磁极在南北两极!S/N!因我们所有的磁场都在地球上!因此所有的磁体场都具有南北两个磁极!我门常见到的吸铁石(天然磁铁矿(Fe3O4,和人造铁,镍,钴磁钢等),磁场的特性是异极相吸!同极相斥!这个特性很重要!因为所有的电磁动力转换都源于此!迈克尔·法拉第(Michael Faraday，公元1791～公元1867)英国物理学家,由他发现的电磁感应现像和定律几乎改变了整个世界!从此这个世界认识并开发使用了电磁感应衍生的一系列可能!电生磁!磁生电!导体切割磁力线!有电流就有磁场!有磁场就有就有极性!有极性就有相互的力!这就是一切电动设备的原理!(包括电动机)磁场说完了!说说电机!交流异步电机!先说为何称异步电机!我国的工频交流电其频率是每秒50周(50NZ/S)!三相电机的三组绕组是按相差120度均布在本360度的圆周磁铁芯(磁场)里的!按最少的相组每相需要对应两组绕组!也就是说有一对磁极!以频率50周,每分钟60秒来算三相交变磁场的旋转速度最高也就是3000转/分钟!而一般的异步交流电机其转子磁电枢都是错角闭合鼠笼式的!在定子铁芯的旋转磁场里它要获得转距就必需和磁场形成错角差步!也就是说它的转速永远都落后于定子旋转磁场的速度!这就是异步的由来!(同步电机有其独特的构造),当然根据需要电机会有2极,4极,8极设计!极数越多转速越慢!但转距增大!因此拖动电机以低速具多!常用电机多为4极!其实交流异步电机的工作原理已经大致清楚了!每秒50周的三相交变电流在120度差角等分的三相绕组里产生出旋转的交变磁场!(转速取决于定子一周内所分布的三相磁极数!)铁芯所嵌有差角闭合鼠笼导体的转子在强大的旋转磁场里会产生强大的感应电流!这同频与定子电流的交变电流同样也能产生强力的交变旋转磁场!它只要和定子的旋转磁场保持有差角(异步转距)它就会不停地转下去!

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卸载调压阀也叫气压调节阀，和装在气泵缸盖上的松压阀。组成气压调压装置。作用是使储气筒维持在规定气压范围以内，当超过规定范围使空压机卸载，从而减小发动机动力损失。和安全阀的作用相比，在减小发动机动力损失方面，是安全阀不能达到的。规定气压是由气压调节阀的弹簧预紧度和调节螺栓设定的。其实就是一个单向阀。当储气筒气压升到8公斤平方厘米时，气压推动调节阀的膜片并带动芯杆向上升，使芯杆与阀门脱开，同时回位弹簧把阀门顶起，封闭与大气相同的气孔。这时压缩空气通过芯杆进入压缩机缸盖上的松压阀，使松压阀阀杆下行，把压缩机的进气阀片顶开，使其不能关闭。这样空压机与大气相同。空压机开始空转，不再产生压缩空气。当储气筒气压低于8公斤平方厘米时，弹簧推动膜片下行，使芯杆与阀门接触，关闭储气筒与松压阀之间的通道，同时芯杆下行把阀门顶离阀座，将排气通道打开，这样松压阀上方管路的压缩空气便由气压调节阀的排气口排除，松压阀杆在弹簧的作用下回位，进气阀开始起密封作用。空压机正常工作。接空气滤清器的管子是空压机的进气管和发动机共用一个滤清器。装了干燥器后还是这样工作。

储氢材料hydrogen storage material20世纪70年代以后，由于对氢能源的研究和开发日趋重要，首先要解决氢气的安全贮存和运输问题，储氢材料范围日益扩展至过渡金属的合金。如镧镍金属间化合物就具有可逆吸收和释放氢气的性质：每克镧镍合金能贮存0.157升氢气，略为加热，就可以使氢气重新释放出来。LaNi5是镍基合金，铁基合金可用作储氢材料的有TiFe，每克TiFe能吸收贮存0.18升氢气。其他还有镁基合金，如Mg2Cu、Mg2Ni等，都较便宜。

设矩阵X=(xij)，矩阵Y=(yst)则dY/dX为一个超矩阵，即矩阵dY/dX的每一个元素都是矩阵dY/dX = ( dyst/dX ) = ( (Pyst/Pxij) ) 其中P为偏导符号即超矩阵dY/dX中的每个元素为矩阵Y中的每个元素yst对X求导dyst/dX而矩阵dyst/dX中的每个元素为yst对矩阵X中的每个元素xij求偏导Pyst/Pxij复合函数求导法则仍然适用