首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
GENERAL SYSTEMS THEORY 1 The Greek word "systema" means union, and scientists use the word "system" to describe
GENERAL SYSTEMS THEORY 1 The Greek word "systema" means union, and scientists use the word "system" to describe
admin
2012-01-14
25
问题
GENERAL SYSTEMS THEORY
1 The Greek word "systema" means union, and scientists use the word "system" to describe a collection of several components that are linked to one another by functional relationships. Everything outside the system is known as the surroundings. Most scientific literature is a description of the components of a system, their relationships with one another, and their relationships with other systems. Although each science has its own systems with their own subject matter and networks of relationships, the formal characteristics of systems are similar for all sciences. The scientific discipline called general systems theory formulates principles that are valid for systems in general, no matter the elements involved and the relations or forces among them.
2 Systems can be divided into two types: closed systems and open systems. A closed system receives no supply of energy from outside and transfers no energy outwards. An open system receives energy from its surroundings and transfers it out again.
3 A closed system is isolated fiom its surroundings. The energy supply of a closed system is limited and is progressively used up by the processes operating within the system. The ability of the system to function decreases as the available energy is exhausted. Without any additional energy supplied from the outside, the system’s processes stop altogether and no further change is possible in the system. A mill wheel supplied with water from a non-refillable container is a closed system. Once the container of water is empty, the wheel no longer turns because there is no water to turn it. In a truly closed system, the water would have to be collected below the mill wheel in a second container to ensure that the system did not supply any energy to the outside.
4 Some scientists argue that there are few truly closed systems in nature, and many define closed systems more broadly as those allowing energy but not mass to cross the system boundary. By this definition, the Earth system as a whole is a closed system. The boundary of the Earth system is the outer edge of the atmosphere, and except for the occasional meteorite, virtually no mass is exchanged between the Earth system and the rest of the universe. However, energy in the form of solar radiation passes from the sun, through the atmosphere to the Earth’s surface, which in turn radiates energy back out to space across the system boundary. Hence, energy passes across the Earth’s system boundary, but mass does not, making it a closed system.
5 In an open system, energy and mass can be transferred between the system and its surroundings. Living organisms are open systems. They absorb light energy or chemical energy in the form of organic molecules and release heat and metabolic waste products, such as carbon dioxide, to the surroundings. Generally, relationships exist between the components of a system and its surroundings, that is, other systems. Each open system is part of a larger system that receives and gives off energy. In an open system, the energy is continually resupplied from sources outside the system. In the example of the mill wheel, if the non-refillable water container is replaced by a reservoir fed continuously by a stream, it becomes an open system because the energy supply is renewed from the outside.
6 The natural environment is made up of open systems. These can behave as closed systems temporarily if the energy supply is halted for a period. If, for example, the stream to the reservoir supplying the mill dries up for a long period, the energy consumption of the mill wheel cannot be balanced by new energy supply. The water in the reservoir is used up, and if the dry period is long enough, the mill wheel stops turning. Eventually, the stream may flow again, filling the reservoir and turning the mill wheel again. This occurs because the stream-reservoir-mill system is itself a part of the Earth’s much larger systems of water circulation and water budget, which include condensation, precipitation, run-off, and evaporation. The water systems receive their energy supply from the Earth’s heat budget, which in turn receives its energy supply from the sun’s radiation.
In paragraph 3, the author discusses the example of a mill wheel to illustrate what point about closed systems?
选项
A、The energy supply of a closed system is limited.
B、Closed systems are rare in the natural environment.
C、The Earth system as a whole is a closed system.
D、Closed systems get energy from their surroundings.
答案
A
解析
The example of a mill wheel illustrates the point that the energy supply of a closed system is limited. Clues: The energy supply of a closed system is limited and is progressively used up by the processes operating within the system; Without any additional energy supplied from the outside, the system’s processes stop altogether...; Once the container of water is empty, the wheel no longer turns because there is no water to turn it. (1.1)
转载请注明原文地址:https://kaotiyun.com/show/fwyO777K
0
托福(TOEFL)
相关试题推荐
Lookatthefollowingdescriptionsandthelistofcompaniesbelow.Matcheachdescriptionwiththecorrectcompany,A-F.
Completethenotesbelow.ChooseONEWORDONLYfromthepassageforeachanswer.Writeyouranswersinboxesonyourans
Completeeachsentencewiththecorrectending,A-E,below.Writethecorrectletter,A-E,inboxesonyouranswersheet.A.
Completethesentencesbelow.ChooseNOMORETHANTWOWORDSfromthepassageforeachanswer.Writeyouranswersinboxesonyou
Gestures—especially______ones.Students______outwordsandothersguessthem.
Betweenwhattimesistheroadtrafficlightest?Whichisthecorrectconstructionforacousticdoubleglazing?
TheConstructionEducationCentrehasexistedfor______.【16】
Theprofessorsaysthatsuperhighways______.【26】
AYourpassport.BYourchildren’spassports.CYourPoliceRegistrationCertificate.DAletterfromyourcollege
Whataretheparkingregulationsoncampus?
随机试题
社区照顾的过程目标是要建立一个()的社区。
______PacificOceanis______verylargeseatothewestofNorthandSouthAmerica,andtotheeastofAsiaandAustralia.
用九分法计算成人烧伤面积,下列错误的是
建设工程项目工程款的支付担保是指( )提拱的担保。
商业银行贷款的流动性与效益性成正比。()
A会计师事务所的注册会计师王某正在为拟设定的W公司(筹)进行验资。下面的诸事项中正确的是( )。注册会计师在盈利预测审核报告中对盈利预测所依据的基本假设发表意见时,以下说法是不正确的( )。
心理学家戴维斯在实验中,将被试者分为两组学习射箭。甲组受到详细指导:演示如何站立、握弓、放箭;乙组自行尝试,未受严格指导。经18次练习,甲组射中率为65%,乙组射中率为45%。这一实验结果表明,在动作技能的学习过程中()因素很重要。
一国为了扩充本国大型机器设备或成套设备出口,指定商业银行或进出口银行向外国进口商或进口商所在地银行提供的贷款,称为()。
1911年的武昌起义掀起了辛亥革命的高潮,打开了清王朝的缺口。在一个月内,就有13个省以及上海和许多州县宣布起义,脱离清政府的统治。腐朽的清王朝迅速土崩瓦解。武昌起义具体组织者和发动者是
以下涉及字符串数组、字符指针的程序段,不会产生编译错误的是
最新回复
(
0
)