【正文】 aid of optical interferometry this can be done extremely accurately . These socalled ThompsonLampard cylinder capacitors can achieve an inaccuracy of less than 10^8. 它可以構(gòu)建電容器的從四個(gè)同軸鋼瓶,電容僅憑長度的汽缸。 A disadvantage ,however ,is the fact that the capacitance is small (approximately per metre ). For lowerorder standards other configurations of electrodes are used ,which provide larger capacitance values (10~1000pF),but also e larger uncertainties .然而,一個(gè)不利條件的人來說,(大約每米)。Frequency 頻率 The standard of frequency is based on quantum mechanical effect that electrons in an atom can only occupy one of a limited number of energy levels .If an electron jumps to a higher or a lower energy level ,the difference in energy E of the photon that is absorbed or a emitted , respectively ,is related to the frequency of the photon by the expression E=h atoms are irradiated with electromagnetic energy of frequency f0,many electrons will pass to higher energy levels .標(biāo)準(zhǔn)的頻率是基于量子力學(xué)效應(yīng)原子電子之一只能占據(jù)數(shù)量有限的能量水平,如果一個(gè)電子的價(jià)格漲到一個(gè)更高的或較低的能量水平,不同的能源E被吸收的光,分別或發(fā)出有關(guān)光子的頻率的表情E = h f0 . 當(dāng)原子電磁能量下的頻率f0,許多電子將通過更高能量水平。other factors are also being ,、,這些依賴這些寄生蟲數(shù)量,影響了測量結(jié)果,在測量過程不是固定不變,讓人很難矯正錯(cuò)誤的測量。It is , for example, not very practicable to isolate a section of the population from the rest of the world , for the sake of an economic measurement conducted to verify the relationship between the scarcity and the price of consumer goods .The object of the measurement continues to interact with its surroundings, to an extent and in a manner that remains ,不太可行的隔離人群的一部分從世界的其他地方,為了進(jìn)行經(jīng)濟(jì)測量,驗(yàn)證的缺乏和之間的關(guān)系的消費(fèi)品的價(jià)格,測量對象繼續(xù)相互作用,它周圍的環(huán)境中,在某種程度上,而在某種程度上,但仍是未知的。As opposed to a physical measurement ,the object of a nonphysical measurement is often conscious of being measured .The mere fact that we measure influences the subject .The subject will behave differently in a laboratory than in daily life . An example for an often used (and abused ) test animal :the rat .A measurement can even cause irrevocable processes in the object .我們反對一種物理測量、非物質(zhì)的對象測量被測經(jīng)常意識到,單單是我們測量的影響,這個(gè)問題行為不同學(xué)科將在一個(gè)實(shí)驗(yàn)室比的日常生活中。數(shù)據(jù)可以一種事實(shí)的陳述的物理現(xiàn)象。信息或強(qiáng)度大小物理現(xiàn)象。在處理、數(shù)據(jù)的實(shí)證分析常被引用為原料,或未加工的數(shù)據(jù),而數(shù)據(jù)被稱為加工的數(shù)據(jù)進(jìn)行了分析。 sometimes statistical processing is applied to indicate the nature of experimental precision..數(shù)據(jù)收集后,它可能需可以被處理和利用數(shù)學(xué)計(jì)算通過把一些富有意義的方式。作為整個(gè)過程的一部分,減少,明顯的錯(cuò)誤發(fā)生的數(shù)據(jù)或矛盾之處,應(yīng)該找。一個(gè)精心制作的控制系統(tǒng)集中在下丘腦的大腦維持體溫孕37攝氏度(℃)盡管改變身體的活動(dòng)和外部的氣氛。*許多復(fù)雜的還包括控制系統(tǒng)的功能的人體。Threading a needle and driving an automobile are two ways in which the human body functions as a plex controller. The eyes are sensor that detects the position of the needle and thread, or of the automobile and the center of the road. A plex controller, the brain, pares the two positions and determines which actions must be performed to acplish the desired result. The body implements the control action by moving the thread or turning the steering wheel。實(shí)施控制作用的身體可以通過移動(dòng)的螺紋或把方向盤,一個(gè)有經(jīng)驗(yàn)的車手能夠預(yù)見到所有類型的干擾的系統(tǒng),例如粗糙的一段路面或一個(gè)緩慢移動(dòng)車輛前進(jìn)。污水和垃圾處理也需要使用自動(dòng)控制系統(tǒng)的無意識A control system is any group of ponents that maintains a desired result or value. From the previous examples it is clear that a great variety of ponents may be 。他們也影響產(chǎn)品和服務(wù)的生產(chǎn),使產(chǎn)品的純度和保證我們所吃的食物的均勻性維護(hù)質(zhì)量的產(chǎn)品,從造紙廠、鋼廠、化工廠、煉油廠以及其他類型的制造工廠。眼睛是傳感器檢測位置的針和線,或汽車和中心的路。在一個(gè)控制系統(tǒng)對學(xué)生eyethe直徑自動(dòng)調(diào)節(jié)控制光的總量達(dá)到視網(wǎng)膜上。另一個(gè)控制系統(tǒng)保持水平的鈉離子液體濃度包圍在單個(gè)細(xì)胞。Unit6 1. An Overview for Control System在控制系統(tǒng)的概述Control systems are everywhere around us and within us. *Many plex control systems are included among the functions of the human body. An elaborate control systems centered in the hypothalamus of the brain maintains body temperature at 37 degrees Celsius (℃) despite changes in physical activity and external 。數(shù)據(jù)可以進(jìn)入降低計(jì)算機(jī),或者,在某些情況下,檢測儀表可以進(jìn)行天文數(shù)據(jù)歸算在儀器。通常情況下,比較理論數(shù)據(jù)測或處理過的數(shù)據(jù)作為測試的理論。它可以是孤立的價(jià)值或可以依賴于時(shí)間和地點(diǎn)。當(dāng)數(shù)據(jù)純粹是描述性的,據(jù)說是定性的數(shù)據(jù)。 psychological experiments ,for example ,can cause catatonic states in certain patients ,resulting in disorders or even chronic schizophrenia .The effects measurement above will generally make it different to reproduce measurements in the fields of human and social studies accurately ,assuming that these measurements can actually be made reasonably selectively and objectively . 某些心理學(xué)實(shí)驗(yàn),例如,會(huì)造成的緊張性精神分裂癥在某些病人,分別導(dǎo)致疾病甚至慢性精神分裂癥患者影響以上,測量不同,通常也使復(fù)制測量結(jié)果和人類社會(huì)的研究領(lǐng)域準(zhǔn)確、假設(shè)這些測量了可以有選擇地、合理的基礎(chǔ)性工作。Also ,the repetition of experiment is often not possible when dealing with such plex measurement objects .With physical measurements we often repeat a measurement to see how reproducible it is and to determine the magnitude of random errors .With nonphysical measurements ,however ,the object often behaves differently the second time ,because it no longer motivated to cooperate ,has bee tired ,etc .Think ,for example ,of taking the same examination twice .同時(shí),重復(fù)實(shí)驗(yàn)通常是不可能在處理復(fù)雜的測量各種物理測量物體我們經(jīng)常重復(fù)測量重復(fù)性看到并決定隨機(jī)誤差的大小以非物理性的測量,但對象第二次常常表現(xiàn)出不同,因?yàn)樗辉儆袆?dòng)力去合作,已成為累了,例如建立相同的檢查兩次。