提高功率因素的意義是什麼

滿意答案孤帆5級2009-02-12無功功率：也就是沒有做功就損耗掉的功率（不管以什麼管道，簡單的說，你可以理解為不能轉化為機械能的功，如電感裏震盪消耗的功）.我的用電，通常（又比如電機啦），為的就是要電流做功（比如機械功）.如果該電網功率因素小（有功功率/總功率），就代表做同樣的功（比如電機轉同樣的轉數），其消耗的能量（瓦為組織的量）會更多，無功功就是浪費掉了的能量（電）.所以無功功被叫做“電網污染”.各大電網對功率因素都有嚴格的要求來避免浪費.因為無功功率都由感性負載帶來，所以用容性負載就可以改善.中應該都有介紹.最好找來看看.我好久沒碰電機了，可能解釋不够精確，嚴密.ミKaづKaミ的感言：總體而言提高功率因數，可以充分利用輸電與發電設備.

輸送功率kw

就是輸送的功率，kW是功率的組織，即千瓦.1kW=1000W.

功率譜密度是啥意思

對於具有連續頻譜和有限平均功率的訊號或雜訊，表示其頻譜分量的組織頻寬功率的頻率函數.注：1通常訊號或雜訊的暫態功率等於其暫態值的平方，如該特徵量為一場量，則此平方與物理功率成比例.2功率譜密度是該訊號或雜訊…

正功率與負功率的含義

功率正，負主要與電流流向有關.分兩種情况說明：1.對於出線電路母排輸出的功率是正的；流向母排供電的功率是負的.2.對於進線電路向母排供電的功率是正的；母排輸出的功率是負的.

W有功率的意思，W還代表什麼？

表示功率組織瓦特，還有做功

平均功率的概念問題
若發動機在2秒內做功6J，2秒後關閉，求4秒內發動機的功率？這時的t應取2秒還是4秒？
如果還是上面的條件，就說求發動機的平均功率，那這時t又該怎麼取？

第一個t=4秒，第二個t=2；

電流做功和消耗多少電能是啥意思？

從問題可以看出，你對控制變數法的應用有問題，由於我們的認知所限，國中通常只研究一個變數和另一個變數之間的關係，不同時研究幾個變數的關係.1.錯.用做功來比較組織時間內消耗的電能（即：電功率），就必須控制時間，使時…

高中所有有關三角形的公式和定理，什麼內接外切圓與三角型的公式之類的.
還有一堆心的定理…

內切圓的圓心在三角形的三條中線的交點
外切圓的圓心在三角形的三條高線的延長線的交點
在直角三角形中一個角等於30°那麼這個角所對的邊是斜邊的一半
在直角三角形中斜邊上的中線是斜邊的一半
在等腰三角形中底邊上的高線也是頂角的角平分線也是底邊的中線，3條線重合也叫3線和一
這些先用吧，給我點分吧

《面對突發事件》高中900字作文什麼題材都行（當然除詩歌）哪位高手能幫幫忙，Thank you very much~~~~~

急求一篇高中英語課說課稿，人教版的.Thank you very much！

no problem！
高中英語閱讀課說課稿
人教版必修三Unit 5 Canada-The True North
Good afternoon everyone，
It is my great honor to be here to share my teaching ideas with you！The content I chose is the reading part of Unit 5.Now let me introduce it in detail.
The teaching goal of this period is to enable Ss to catch the main idea by fastreading.Thento find out the detailed information through carefulreading.Thethird is to express themselves with the language learned in class.
The goal of learning ability is to develop Ss basicskills:Listening，Speaking，Reading andWriting.Ofcourse，the centre of this lesson is to practice reading，including predicting，skimming，scanning anddigesting.MeanwhileI will encourage Ss to practice，participate and cooperate in the classroom activities，and provide the students with the situations where they can acquire knowledge naturally.
As for the teaching method，I will adopt communication method，task-based method and cooperation studymethod.Withthe help of the computer，I believe the efficiency of our class will be greatly improved.
The teaching steps are as follows:
Step 1 is Warming-up
In this step，I will ask Ss to talk about something about Canada and do the quiz on their books to arouse their interests in learning English.
Step2.Pre-reading
Ask Ss to think about the question“What is the longest trip you have ever taken？”Then let the Ss to look at the map of Canada and discuss the question“If you take a trip to Canada，what do you think you might see there？”inpairs.Andthen look at the picture to predict the main idea of the passage.
Step3 Fast-reading
In this step，I will ask Ss to read the text as quickly as possible to catch the main idea of the passage and get a brief impression ofCanada.Bydong so，I will train Ss skimming skills.
Step 4 Careful-reading
In this step，I will let Ss read the passage carefully and answer the following questions according to thepassage.Thepurpose is to train Ss to get some important facts and some detailed information and improve the ability of scanning skills.
Step 5 Post-reading
For the Ss to understand the text better，I will get the students to analyze several difficult sentences to smooth away the difficulties of understanding thetext.Andthen I will give Ss 5 minutes to retell the passage.
Step 6 Discussion
In this step，the Ss will be asked to have a discussion in groups about the question，“If someday you go to Canada，where will you go？Why？”Then I will invite several groups to report their work to the whole class in public to overcome their shyness.I think to use the language is the most important，so while teaching them，I always provide more opportunities for Ss to practice and cooperate in our class.
Step 7 Summary
In this step，what the Ss will do is to appreciate the beautiful scenery of Canada as well as listening to the tape so that they can revise what they have learned in the class.
Step 8 Homework
Write a composition about the summary of the passage.
This is about my teaching，and during my teaching，I will try my best to make my class alive and encourage them to practice more and act more.I believe I can arouse their interests in learning English.
That’sall.Thankyou.
你可以借鑒下！我還有很多，給我郵箱地址，

提高功率因素的意義是什麼