coordinated-60

与逆变器相关的英文文章

歌曲名:time zones

歌手:negativland

专辑:escape from noise。

The Autonomous Commie Republic, which is part of the Russian。

Federation, is situated in the far northwest of Europe, and spreads up to。

the Arctic part of the Ural Mountains. It's crossed by 9 northern。

parallels. Ten fair-sized European states could be placed on its。

territory. Besides indigenous residents (that is, the Commie people), there。

are also Russians, Ukranians, Nenetzes, Tchubashis, and Tartars.。

And now, let's go back into history a little bit. (CLICK)。

A boil lying on skins behind our backs was turning the knobs of a。

small transistor radio.。

(".....making efforts to use radios as vehicles of the。

psychological warfare. A subversive....")。

And the tent was suddenly filled with an announcer's voice speaking Commie.。

(Jane Jane Jane....)。

Then, with music from Moscow, followed by English and French speech.。

("The recording was made at the Moscow Theatre of Musical Miniatures.")。

Now, back to modern times.。

YOUR ATTENTION PLEASE. AT THE RECOMMENDATION OF THE INTERNATIONAL。

TIME BUREAU, COMMENCING AT TWENTY-THREE (23) HOURS, FIFTY-NINE (59)。

MINUTES, SIXTY (60) SECONDS UTC, AN EXTRA SECOND WILL BE INSERTED INTO THE。

NBS TIME SCALE. THIS ADJUSTMENT IS REQUIRED TO MAINTAIN INTERNATIONALLY。

COORDINATED UNIVERSAL TIME AS BROADCAST FROM THESE STATIONS, IN CLOSE。

AGGREEMENT WITH UT1, OR ASTRONOMICAL TIME.。

("WA6ODB....with...a question....")。

"and, uh ..."

"Do you know how many time zones there are in the Soviet Union?"。

"and about power ..."。

"d'you kn--"

"we got so much power now ..."。

"Do you know how many time zones there are in the Soviet Union?"。

"we got so much power now, that's ridiculous."。

"d'you kn-- do you know how many time zones there are in the Soviet Union?"。

"power, and all that, that's power, we got so much power, that's。

ridiculous."

"We have--"

Negativland

"power, power, power, power, power, power now, it's ridiculous. We。

got so much power now ..."。

"Do you know how many time zones there are in the Soviet Union?"。

"It's not even funny."。

"D'you--"

"That's ridiculous."。

"Do you know how many--"。

"It's not even funny."。

"D'you kn--"

"That's ridiculous."。

"Do you know how many--"。

"That's, that's ridiculous."。

"Do you know how many time--"。

"That's ridiculous. It's not even funny."。

"D'you--"

"It's not even funny."。

"D--"

"It's not even funny."。

"Do you know how many time zones there are in the Soviet Union?"。

"It's not even funny.。

http://music.baidu.com/song/14111024。

关于C++时间函数和随机函数

Inverter may refer to。

Inverter (electrical), a device that converts direct current to alternating current 。

Inverter (air conditioning), an air conditioner that can continuously regulate its output by altering the compressor speed in response to cooling demand 。

Uninterruptible power supply, which often are based on an electrical inverter 。

Inverter (logic gate), a logic gate also called a NOT gate 。

Inverter (electrical)。

An inverter is an electrical device that converts direct current (DC) to alternating current (AC); the converted AC can be at any required voltage and frequency with the use of appropriate transformers, switching, and control circuits.。

Static inverters have no moving parts and are used in a wide range of applications, from small switching power supplies in computers, to large electric utility high-voltage direct current applications that transport bulk power. Inverters are commonly used to supply AC power from DC sources such as solar panels or batteries.。

The electrical inverter is a high-power electronic oscillator. It is so named because early mechanical AC to DC converters were made to work in reverse, and thus were "inverted", to convert DC to AC.。

The inverter performs the opposite function of a rectifier.。

Applications

DC power source utilization。

An inverter converts the DC electricity from sources such as batteries, solar panels, or fuel cells to AC electricity. The electricity can be at any required voltage; in particular it can operate AC equipment designed for mains operation, or rectified to produce DC at any desired voltage.。

Grid tie inverters can feed energy back into the distribution network because they produce alternating current with the same wave shape and frequency as supplied by the distribution system. They can also switch off automatically in the event of a blackout.。

Micro-inverters convert direct current from individual solar panels into alternating current for the electric grid.。

Uninterruptible power supplies。

An uninterruptible power supply (UPS) uses batteries and an inverter to supply AC power when main power is not available. When main power is restored, a rectifier is used to supply DC power to recharge the batteries.。

Induction heating。

Inverters convert low frequency main AC power to a higher frequency for use in induction heating. To do this, AC power is first rectified to provide DC power. The inverter then changes the DC power to high frequency AC power.。

[edit] HVDC power transmission。

With HVDC power transmission, AC power is rectified and high voltage DC power is transmitted to another location. At the receiving location, an inverter in a static inverter plant converts the power back to AC.。

[edit] Variable-frequency drives。

Main article: variable-frequency drive。

A variable-frequency drive controls the operating speed of an AC motor by controlling the frequency and voltage of the power supplied to the motor. An inverter provides the controlled power. In most cases, the variable-frequency drive includes a rectifier so that DC power for the inverter can be provided from main AC power. Since an inverter is the key component, variable-frequency drives are sometimes called inverter drives or just inverters.。

[edit] Electric vehicle drives。

Adjustable speed motor control inverters are currently used to power the traction motors in some electric and diesel-electric rail vehicles as well as some battery electric vehicles and hybrid electric highway vehicles such as the Toyota Prius. Various improvements in inverter technology are being developed specifically for electric vehicle applications.[2] In vehicles with regenerative braking, the inverter also takes power from the motor (now acting as a generator) and stores it in the batteries.。

[edit] Air conditioning。

Main article: Inverter (air conditioning)。

An air conditioner bearing the inverter tag uses a variable-frequency drive to control the speed of the motor and thus the compressor.。

[edit] The general case。

A transformer allows AC power to be converted to any desired voltage, but at the same frequency. Inverters, plus rectifiers for DC, can be designed to convert from any voltage, AC or DC, to any other voltage, also AC or DC, at any desired frequency. The output power can never exceed the input power, but efficiencies can be high, with a small proportion of the power dissipated as waste heat.。

Warnings

Some low power inverters have a warning not to use conventional fluorescent lighting. This is due to the power correction capacitor connected in parallel with the lamp. Removing the capacitor will fix the problem. What may not be known is that in dual lamp fittings the capacitor may be connected in series with the second lamp, thus removing the problem as well as the stroboscopic effect caused by the mains frequency.。

Basic designs

In one simple inverter circuit, DC power is connected to a transformer through the centre tap of the primary winding. A switch is rapidly switched back and forth to allow current to flow back to the DC source following two alternate paths through one end of the primary winding and then the other. The alternation of the direction of current in the primary winding of the transformer produces alternating current (AC) in the secondary circuit.。

The electromechanical version of the switching device includes two stationary contacts and a spring supported moving contact. The spring holds the movable contact against one of the stationary contacts and an electromagnet pulls the movable contact to the opposite stationary contact. The current in the electromagnet is interrupted by the action of the switch so that the switch continually switches rapidly back and forth. This type of electromechanical inverter switch, called a vibrator or buzzer, was once used in vacuum tube automobile radios. A similar mechanism has been used in door bells, buzzers and tattoo guns.。

As they became available with adequate power ratings, transistors and various other types of semiconductor switches have been incorporated into inverter circuit designs.。

[edit] Output waveforms。

The switch in the simple inverter described above, when not coupled to an output transformer, produces a square voltage waveform due to its simple off and on nature as opposed to the sinusoidal waveform that is the usual waveform of an AC power supply. Using Fourier analysis, periodic waveforms are represented as the sum of an infinite series of sine waves. The sine wave that has the same frequency as the original waveform is called the fundamental component. The other sine waves, called harmonics, that are included in the series have frequencies that are integral multiples of the fundamental frequency.。

The quality of the inverter output waveform can be expressed by using the Fourier analysis data to calculate the total harmonic distortion (THD). The total harmonic distortion is the square root of the sum of the squares of the harmonic voltages divided by the fundamental voltage:。

The quality of output waveform that is needed from an inverter depends on the characteristics of the connected load. Some loads need a nearly perfect sine wave voltage supply in order to work properly. Other loads may work quite well with a square wave voltage.。

[edit] Advanced designs。

H-bridge inverter circuit with transistor switches and antiparallel diodesThere are many different power circuit topologies and control strategies used in inverter designs. Different design approaches address various issues that may be more or less important depending on the way that the inverter is intended to be used.。

The issue of waveform quality can be addressed in many ways. Capacitors and inductors can be used to filter the waveform. If the design includes a transformer, filtering can be applied to the primary or the secondary side of the transformer or to both sides. Low-pass filters are applied to allow the fundamental component of the waveform to pass to the output while limiting the passage of the harmonic components. If the inverter is designed to provide power at a fixed frequency, a resonant filter can be used. For an adjustable frequency inverter, the filter must be tuned to a frequency that is above the maximum fundamental frequency.。

Since most loads contain inductance, feedback rectifiers or antiparallel diodes are often connected across each semiconductor switch to provide a path for the peak inductive load current when the switch is turned off. The antiparallel diodes are somewhat similar to the freewheeling diodes used in AC/DC converter circuits.。

Fourier analysis reveals that a waveform, like a square wave, that is antisymmetrical about the 180 degree point contains only odd harmonics, the 3rd, 5th, 7th etc. Waveforms that have steps of certain widths and heights eliminate or “cancel” additional harmonics. For example, by inserting a zero-voltage step between the positive and negative sections of the square-wave, all of the harmonics that are divisible by three can be eliminated. That leaves only the 5th, 7th, 11th, 13th etc. The required width of the steps is one third of the period for each of the positive and negative steps and one sixth of the period for each of the zero-voltage steps.。

Changing the square wave as described above is an example of pulse-width modulation (PWM). Modulating, or regulating the width of a square-wave pulse is often used as a method of regulating or adjusting an inverter's output voltage. When voltage control is not required, a fixed pulse width can be selected to reduce or eliminate selected harmonics. Harmonic elimination techniques are generally applied to the lowest harmonics because filtering is more effective at high frequencies than at low frequencies. Multiple pulse-width or carrier based PWM control schemes produce waveforms that are composed of many narrow pulses. The frequency represented by the number of narrow pulses per second is called the switching frequency or carrier frequency. These control schemes are often used in variable-frequency motor control inverters because they allow a wide range of output voltage and frequency adjustment while also improving the quality of the waveform.。

Multilevel inverters provide another approach to harmonic cancellation. Multilevel inverters provide an output waveform that exhibits multiple steps at several voltage levels. For example, it is possible to produce a more sinusoidal wave by having split-rail direct current inputs at two voltages, or positive and negative inputs with a central ground. By connecting the inverter output terminals in sequence between the positive rail and ground, the positive rail and the negative rail, the ground rail and the negative rail, then both to the ground rail, a stepped waveform is generated at the inverter output. This is an example of a three level inverter: the two voltages and ground.[3]。

[edit] Three phase inverters。

3-phase inverter with wye connected loadThree-phase inverters are used for variable-frequency drive applications and for high power applications such as HVDC power transmission. A basic three-phase inverter consists of three single-phase inverter switches each connected to one of the three load terminals. For the most basic control scheme, the operation of the three switches is coordinated so that one switch operates at each 60 degree point of the fundamental output waveform. This creates a line-to-line output waveform that has six steps. The six-step waveform has a zero-voltage step between the positive and negative sections of the square-wave such that the harmonics that are multiples of three are eliminated as described above. When carrier-based PWM techniques are applied to six-step waveforms, the basic overall shape, or envelope, of the waveform is retained so that the 3rd harmonic and its multiples are cancelled.。

3-phase inverter switching circuit showing 6-step switching sequence and waveform of voltage between terminals A and CTo construct inverters with higher power ratings, two six-step three-phase inverters can be connected in parallel for a higher current rating or in series for a higher voltage rating. In either case, the output waveforms are phase shifted to obtain a 12-step waveform. If additional inverters are combined, an 18-step inverter is obtained with three inverters etc. Although inverters are usually combined for the purpose of achieving increased voltage or current ratings, the quality of the waveform is improved as well.。

翻译成英语~！谢谢！

void main()

time_t nowtime;。

nowtime=time(NULL);//获取时间1970年1月1日00:00:00到当前时刻的秒数。

struct tm *local;//注意类型是tm struct 只是表示是结构体，tm才是结构体名称。

local=localtime(&nowtime);//将秒数转化成本地时间，并转成struct tm类型，该类型的各数据成员分别表示年月日时分秒。

dsptime(local);//显示时间。

srand(time(NULL));//产生时间种子。

int n;

n=rand()%20;//产生随机数。

cout<<n<<endl;。

[英语翻译]关于水和人口 谁帮我翻一下啊

既然不要机器翻译的，想必是学校布置的作业或者是现实中需要手工翻译的吧，那只能是你自己翻译噢!!别人可帮不了你了!。

以下翻译来自雅虎:

From the 1950s, Western translator the theory basically is and the linguistics synchronization development. Translates the theoretician to favor in regards the translation from the linguistics angle. Is in vogue what in 60-70 ages is Eugene•nai reaches (Eugene A.Nida) coordinated theory. in 1964 nai reached proposed the translation process three stage patterns: Analysis, transformation and reorganization. He also exhaustively elaborated himself to put forward “dynamic coordinated” the concept which coordinated opposed with the form, pointed out: “dynamic coordinated is the information receiver who refers to the translation to the translation response should with the original text receiver to the original text information reflection basic same.”Although nai reached in the 80s revises “dynamic coordinated” has discussed and proposed “the function was coordinated” the concept, achieved the content and the form proper attention to both, but nai reached in time the explanation translation nature said: “the translation is in translates into the language with most to be close to, the most natural coordinated language reappearance primitive information, first is in the semantic coordination, next is in the style coordination. Obviously, although nai reaches the position content first, the form second, and this kind of translator the method named social linguistics method, actually is still selects the translation in the language hierarchy scope, but had not realized that to the translation essence is not only the pure language aspect transformation, but is the establishment in the language different culture exchange during formally. However, the 1960s-1970s's linguistics theory monopolized, European translator the theorists has not taken the above question fully the solution. Practices the development which along with the translation and studies, the language school of thought also gradually realizes its intrinsic weakness. Stemming from to this pure linguistics translation theory's disaffection, the West already appeared in the 70s face has translated the language culture the translation research trend, has broken free from the translation research tradition which the beforehand text center discusses, causes the translator more to pay attention to the translation and the translation reader, more pays attention to the translation the social effect and the phatic function. Carefully examined the translation activity by the new angle of view, the German function sends translator the theory to get rid of the coordinated translation theory fetter which at that time was in vogue, has expanded the translation fundamental research domain, entrusted with has translated more implications.。

希望能帮到你：

This is the March 16, 2006, Bangladesh Women's water supply sector in Dhaka hands outside the water to protest the shortage of water and air. This is January 11, 2006, near Garissa in Kenya, a mother and son in the road where the puddles of water. At present, the world is facing a water crisis.。

Let us now look at the world's population growth。

This is a map of world population growth from the 1850s the world's population reached 1 billion run in the 20th century, the world's population is accelerating the growth of the total number of 150 years to 6000 million。

Because of the substantial increase in population caused by the increased population density and urbanization increased. If the situation continues to worsen, According to UN research, 20% of the world's population - 1.1 billion people - cannot drink clean water by 2050 at least 2 billion people in 48countries, and at most 7 billion people in 60 countries, will have serious trouble obtaining enough water. Now let us facie South Korea and China's water shortage。

Let us look at the per capita water resources of internationally recognized standards。

<3000cubic meter mild dry。

<2000cubic meter water at moderate level。

<1000cubic meter for the severe water shortage。

<500 cubic meter water to extreme。

South Korea's per capita is only 1488 cubic meters of water in the world among 153 countries in the first 130.。

Although the total water resources in China total 2.8 trillion cubic meters, in Brazil, the former Soviet Union, Canada, after the United States and Indonesia is the sixth in the world. China's large population, there is also a serious water shortage in the country, per capita is only 2400 cubic meters of water, some of the world's average is only about 1 / 4 of section 109 in the world.。

With China now the economic and social development, population increase and climate change and other reasons, a very serious situation of water resources, not only resources, water quality and increasing water scarcity, and the lakes, rivers, wetlands sharply reduced water pollution control and other ecological functions weakened. Forest Lawn-sik, the destruction of a reduced ability to conserve water. Wastewater emissions year-on-year rise, increasing the damage the water environment. As soon as possible if they do not take rigid measures, China will face catastrophic water crisis. China has taken measures to continuously enhance the sense of urgency, efforts to explore the potential of water resources, solid and effective in promoting water conservation, water management, water from the work of water resources and promote economic and social comprehensive, coordinated and sustainable development.。

原文地址：http://www.qianchusai.com/coordinated-60.html