【正文】 圖32此波形有如下特點： 1．振動周期大于無阻尼自由振動周期T，即。學(xué)會根據(jù)自由衰減振動波形確定系統(tǒng)的固有頻率和阻尼比。計算靈敏度L=ΔU/ΔW和非線性誤差δf ，并求出未知的重物的重量。重復(fù)5步驟，直到精確為止，把電壓量綱V改為重量量綱Kg即可以稱重。圖22加托盤后電橋調(diào)零。15V電源，檢查無誤后，合上主控臺電源開關(guān)，將差動放大器的輸入端Ui短接并與地短接，輸出端Uo2接數(shù)顯電壓表（選擇2V檔）。設(shè)E為電橋電源電壓，則電橋輸出與各橋臂應(yīng)變有如下關(guān)系：圖 21電子稱實驗原理利用全橋測量原理，通過調(diào)節(jié)放大電路對電橋輸出的放大倍數(shù)使電路輸出電壓值為重量的對應(yīng)值，電壓量綱（V）改為重量量綱（g）即成一臺比較原始的電子稱。4V電源。學(xué)會繪制標(biāo)定曲線。表12V4（V）RPM五、實驗報告分析霍爾組件產(chǎn)生脈沖的原理，并根據(jù)記錄的驅(qū)動電壓和轉(zhuǎn)速，作V1RPM曲線。2~24V電壓輸出接到圖13三源板的“轉(zhuǎn)動電源”輸入，并將2～24V輸出調(diào)節(jié)到最小，+5V電源接到三源板“光電”輸出的電源端，光電輸出接到頻率/轉(zhuǎn)速表的“fin”?！?～24V”直流穩(wěn)壓電源接到“轉(zhuǎn)動源”的“轉(zhuǎn)動電源”輸入端。當(dāng)被測圓盤上裝上N只磁性體時，轉(zhuǎn)盤每轉(zhuǎn)一周磁場變化N次，每轉(zhuǎn)一周霍爾電勢就同頻率相應(yīng)變化，輸出電勢通過放大、整形和計數(shù)電路就可以測出被測旋轉(zhuǎn)物的轉(zhuǎn)速。實驗一 測速實驗一、實驗?zāi)康牧私饣魻杺鞲衅?、光電傳感器的測速原理及方法。設(shè)霍爾電勢的頻率為f，則被測轉(zhuǎn)速為：圖11光電轉(zhuǎn)速原理光電式轉(zhuǎn)速傳感器有反射型和透射型二種，本實驗裝置是透射型的，傳感器端部有發(fā)光管和光電池，發(fā)光管發(fā)出的光源通過轉(zhuǎn)盤上的孔透射到光電管上，并轉(zhuǎn)換成電信號，由于轉(zhuǎn)盤上有等間距的6個透射孔，轉(zhuǎn)動時將獲得與轉(zhuǎn)速及透射孔數(shù)有關(guān)的脈沖，將電脈計數(shù)處理即可得到轉(zhuǎn)速值。（3）合上主控臺電源，調(diào)節(jié)2～24V輸出，可以觀察到轉(zhuǎn)動源轉(zhuǎn)速的變化，在表11記錄下驅(qū)動電壓V1和轉(zhuǎn)速RPM數(shù)據(jù)。（2）合上主控制臺電源開關(guān)，逐漸增大2～24V輸出，使轉(zhuǎn)動源轉(zhuǎn)速加快，觀測頻率/轉(zhuǎn)速表的顯示。分析光電式傳感器測量轉(zhuǎn)速原理，并根據(jù)測的驅(qū)動電壓和轉(zhuǎn)速，作V4RPM曲線。驗證電橋的和差特性。三、實驗原理電阻絲在外力作用下發(fā)生機械變形時，其電阻值發(fā)生變化，這就是電阻應(yīng)變效應(yīng)，描述電阻應(yīng)變效應(yīng)的關(guān)系式為：，式中為電阻絲電阻相對變化，K為應(yīng)變靈敏系數(shù)，為電阻絲長度相對變化。四、實驗內(nèi)容與步驟應(yīng)變傳感器上的各應(yīng)變片已分別接到應(yīng)變傳感器模塊左上方的RRRR4上， R1=R2=R3=R4=350Ω。將電位器Rw3調(diào)到增益最大位置（順時針轉(zhuǎn)到底），調(diào)節(jié)電位器Rw4使電壓表顯示為0V。電橋輸出接到差動放大器的輸入端Ui，檢查接線無誤后，合上主控臺電源開關(guān)，預(yù)熱五分鐘，調(diào)節(jié)Rw1使電壓表顯示為零。將砝碼依次放到托盤上并讀取相應(yīng)的數(shù)顯表值，直到200g砝碼加完，計下實驗結(jié)果，填入表21。簡述標(biāo)定方法，并對實驗中出現(xiàn)的問題進行分析。二、實驗儀器ZK4VIC振動與控制實驗臺，集中質(zhì)量，手錘（激振器），壓電式加速度傳感器，ZK4JCZ型激振測振儀，虛擬式測試儀器庫。 固有頻率 2．振幅按幾何級數(shù)衰減用相隔個周期的兩個振幅之比來計算對數(shù)減幅系數(shù)：從而可得： 四、實驗內(nèi)容與步驟實驗裝置如圖33所示，用錘敲擊簡支梁使其產(chǎn)生自由衰減振動。五、實驗報告繪出單自由度自由衰減振動波形圖。學(xué)會測量、計算被動隔振系數(shù)和隔振效率。對于精密儀器和設(shè)備，為了使外界振動盡可能少地傳到系統(tǒng)中來，就需將它與地基隔離開來，稱為被動隔振或消積隔振。 圖41 被動隔振的振源是地基。當(dāng)頻率比趨于1時，即時，振動幅值很大，這一現(xiàn)象叫共振。當(dāng)時，隨著頻率比的不斷增大，隔振系數(shù)值越來越小，即隔振效果越來越好。四、實驗內(nèi)容與步驟實驗裝置如圖42所示。將激振頻率由低向高調(diào)節(jié)，分別測出簡支梁振幅A1和質(zhì)量塊振幅A2，將數(shù)據(jù)記錄在表41中。圖43120（英文版 ） easily blame, to prevent the broken window effect. Supervise the leading cadres to play an exemplary role, take the lead in the strict implementation of the code and rule , lead to safeguard the solemnity and authority of the party discipline, ensure that the party discipline and the laws and regulations for implementation in place. Throughout the discipline in the daily supervision and management, strengthen supervision and inspection, from the thorough investigation of violations of discipline behavior. Strengthen to key areas, key departments and key projects as well as the masses reflect the concentration of the units and departments for supervision. strengthening supervision, discipline inspection and supervision of cadres to set an example for pliance with the code and rule is a man must be hexyl, blacksmith needs its own hardware. Discipline inspection organs as the executor of the party discipline, and supervisor of the defenders, for its supervision must be more strictly, discipline inspection and supervision of cadres to firmly establish the awareness of Party Constitution, sense of discipline and rules consciousness, politics loyalty, sense obey. Action speak Ji Ordinance to set an example of the regulations of the rule of law, strengthen supervision and accept the supervision of the firmness and consciousness, do ply with and . To firmly establish the discipline must first be disciplined, the supervisor will be subject to the supervision of concept, and consciously safeguard and implement party passes party, take the lead in practicing three strict real strict, so loyal, clean, play. To be good at learning, the Constitution and the code as morality, politics and brought to fruition。 not disillusioned after the heart, such as ashes, but experience the storm after the enlightenment。t want to face, don39。t 6, when we are in a positive frame of mind, you will find many good things。 heart tired, calm. Grow up, mature, this society read. Tired and sad, squat down, to their a hug. Because the world no one can sympathize with you, have mercy on you. You cry, tears is your own。 to let strangers people care about your life in the good things, the original is not easy 10, do not blame, do not laugh at who, also don39。 and an exception is better to give than to what 13, don39。 you learn knowledge, is you have weapons, you can start from scratch, but not unarmed。t helpless, because they are still alive, is still a dream, the sun still, we still. Lost, keep memories。t miss to regret, don39。t demand, do to。clock, ice melting ice success, the road gradually returned to normal traffic. In the cold winter night, which people do not miss the warm bed, which people do not miss the warm home. However, our highway on the road to the owners of the masses can go home early, the night fighting to secure the avoidance of the road safety and smoothness, fulfill their responsibility. Xi General Secretary Every Party member cadre cautioned against said: blacksmith needs self hard . two regulations , is our own hard standard test, more exercise every party members and cadres of the fire. We should continue to strengthen the party two regulations, conscientiously in practical work, practical play road, the road for the development of the cause of Heyuan and struggle.In the industry domain report the situation of road traffic in recent years, in the province highway departments of the concern and support, our bureau management department based on the job, loyalty duty, best service, to further promote the highway management standardization, legal, scientific and information technology to improve the management level and service quality. This will be my last work is as follows: first, around the center, go all out to greet the seizure in 2015, meet national examination is my bureau work. As the highway management department, we focus on the work of the center to strengthen road renovation and management as the focal point, further optimize the service environment, improve se