【正文】
s suggestion that a special day be marked in the year for the global practice of the stressbusting regimen, which is already a multibillion dollar industry in the Uni。t conducive to raising a child. She planned to have children once she had achieved career success so she could provide a stable environment for her baby. After 10 years, Xiao felt the time was right, and she tried to conceive for about six months, but was unable to bee pregnant. I conducted prehensive physical checkups. The results suggested that Xiao39。s health. Poor technique harms the muscles and skeleton, and can cause secondary injures. And, jogging in a bad environment can cause circulation problems, said Lu Zhiyong, attending doctor, Sports Hospital, General Admin. of . Lu has some tips for joggers, and those who are thinking of taking it says people sh ould first evaluate their physical condition, to decide the amount and type of exercise, and jogging in the open air is better running on a treadmill. Conrad Macao will run special programs for the entire month of October this year to support the Hong Kong Cancer Fund39。ll hold off jogging for a while. But if I really want to get away from work, I39。s work can be a way to unwind. It is true for He Wenjun, whose workplace is right near the forest park. She discovered her athletic aptitude at the age of seven, when she began playing tennis. Then she turned to jogging, and she has persevered with it for 10 years. I e to jog almost every day after work, whenever I have time. I think jogging is good for my health. And for me, a girl, it helps me to achieve to eternal goal, to keep slim, He said. He says she prefers jogging alone, so she can focus better. She loves jogging, even during Beijing39。s digitized society, will also be attached on the report.Myopia is not only a disease that makes people see things blurrily, but also leads to severeplications, such as glaua (increased pressure within the eyeball), and can causeblindness, said Zhou Yuehua, an established eye care specialist with Beijing TongrenHospital.It is very important for parents and children to know about the risk and care for their eyes.There are about 450 million myopia patients in China. Among Chinese myopia patients,30million are severe patients, according to ZhouThe prevalence of myopia among high school and college students is more than 70 percent,and the situation is continuously worsening, he Zhu, director with the China Youth Development Service Center, said long hours ofstudy, lack of exercise, especially outdoor activities, and attachment to electronic screen aresome of the top reasons behind the widespread myopia problems, and the increase ofyounger patients, although China has made great progress in improving the hardwarefacilities and lighting conditions in said he hopes the survey will alert people on the threatening situation, and also helpmedical experts to better guideline parents and children39。 西安鐵路職業(yè)技術學院畢業(yè)設計 (論文) 23 參考文獻 [1] HXD3型大功率交流傳動電力機車【 M】 .蘭州西機務段 .2022. [2] 謝家的 .電力機車電器【 M】 .北京:中國鐵道出版社 .2022. [3] 宋文勝 .電力機車 電器分析【 M】 .北京:中國鐵道出版社 .2022. [4] 莫堅 .電力機車檢修【 M】 .北京:中國鐵道出版社 .2022. [5] 張曙光 .HXD3型電力機車【 M】 .北京:中國鐵道出版社 .2022. [6] 劉會巖 .HXD3型電力機車試驗【 M】 .北京:中國鐵道科學研究院 .2022. [7] 趙嘉濤 .電力機車電器【 M】 .北京:中國鐵道出版社 2022. [8] 陶若冰 .電力機車電子【 M】 .北京:中國鐵道出版社 . 2022. [9] 張立 .現(xiàn)代電力電子技術【 M】 .北京:高等教育出版社 .2022. [10]黃家善 .電力電 子技術【 M】 .北京:機械工業(yè)出版社 .2022. [11]陳堅 .電力電子學【 M】 .北京:高等教與出版社 . 2022. [12]那利和 .電力機車控制【 M】 . 北京:中國鐵道出版社 .2022. [13]楊守君 .劉會巖 , HXD3 型交流傳動電力機車【 M】 .株洲:株洲電力機車有限公司 .2022 [14] HXD3檢修手冊 HXD3 電力機車主型電器分析 24 您好,為你提供優(yōu)秀的畢業(yè)論文參考資料,請您刪除以下內容, O(∩_∩)O 謝謝?。?!A national survey was recently launched to evaluate the eye health of Chinese children June 6, China39。正是有了他們的悉心幫助和支持,才使我的畢業(yè)論文工作順利完成,在此向西安鐵路職業(yè)技術學院牽引動力系的全體老師表示由衷的謝意。在此向程懷汶老師 表示深深的感謝和崇高的敬意??傊?,電力機車在提高鐵路運輸能力、合理利用資源、保護生態(tài)環(huán) 境方面,已成為鐵路最理想的牽引動力。電力機車起動加速快,爬坡能力強,工作不受嚴寒的影響,運行時沒有煤煙,所以在運輸繁忙的鐵路干線和隧道多、坡度陡的山區(qū)線路上更能發(fā)揮優(yōu)越性。電力機車具有功率大、過載能力強、牽引力大、速度快、整備作業(yè)時間短、維修量少、運營費用低、便于實現(xiàn)多級牽引,能采用再生制動以及節(jié)約能量等優(yōu)點。 電力機車是通過受電弓從接觸網(wǎng)上獲得電能,由電動機驅動的機車或動車。如單節(jié)連接器的喇叭形頭部不能保持水平時,可以由十字支承件上的調整螺釘進行調整,順時針方向調高,逆時針方向調低。 3.經常檢查橡膠波紋管,如有破損要及時更換,以免雨水、灰塵進入喇叭形頭部和十字軸支承體內,造成零件銹蝕,影響動作性能。在進行連接操作前,注意觀察喇叭形頭部是否清潔,頭部蓋板內的叉形件是否有彈回的情況,如已經彈回,則需用勾形工具將其拉開成開啟狀態(tài),然后才能進行連接操作。絕緣電阻顯著下降時,一般是由密封不良而受潮或火花間隙短路所引起的,當?shù)陀诤细裰禃r,應作特性試驗;絕緣電阻顯著升高時,一般是由于內部并聯(lián)電,阻接觸不良或斷裂以及彈簧松馳和內部元 件分離等造成的。 避雷器的絕緣電阻應定期進行檢查。因此,當避雷器瓷套表面嚴重污穢時,必須及時清掃。在有并聯(lián)分路電阻的避雷器中,當其中一個元件的電壓分布增大時,通過 其并聯(lián)電阻中的電流將顯著增大,則可能燒壞并聯(lián)電阻而引起故障。 避雷器維護檢修 1)外觀檢查:檢查絕緣子或各部件有無破損; 2)絕緣電阻測試:用 1000V兆歐表測量避雷器的絕緣電阻不低于 1000MΩ。儲風缸排水操作:關閉隔離閥,慢慢擰開位于儲風缸下面的塞門( PB),釋放壓縮空氣;一旦壓力完全下降,完全打開塞門,慢慢打開主氣路的隔離閥,讓空氣從出氣口排出,直 到儲風缸積水排盡;關斷主氣路的隔離閥,擰緊塞門,檢查是否泄露。 對調壓閥與儲風缸積水進行排除,在冬季之前尤其注意排放氣路,以免積水凍結造成氣動元件誤操作。 真空斷路器的運用情況與其日常維護與正確操作息息相關,建議每 3個月對真空斷路器進行一次輔修,所有輔修及維護必須在機車斷電情況下操作,即把機車和電網(wǎng)斷開并接地,執(zhí)行完安全程序之后進行。 ( 3)電磁閥卡位,即由于空氣中的雜質滯留在閥內,當電磁閥失電后,閥體無法復位,產生漏風現(xiàn)象。 ( 2) 110V 控制單元延時繼電器壞,電磁閥一直得電,閥門處于常開狀態(tài),當機車斷掉電磁閥電源后,電磁閥因閥門長期打開變形,無法復位,因此導致外部風壓一直推動氣缸,真空保持合閘狀態(tài),無法斷開。導致真空斷路器斷不開的原因主要有 3種: ( 1)真空開關管真空度不夠。這種故障在 2022年出現(xiàn)多起,并導致多起機破,故障處理方式為更換插頭。壓力開關工作壓力必 須在工作狀態(tài)下才能調節(jié),已安裝到真空斷路器上壓力開關無法施展工具,因而壓力開關安裝前必須調節(jié)好。 ( 3)壓力開關損壞。 ( 2)電磁閥線圈燒損或脫落。導致真空斷路器合不上的原因主要有以下 4種: ( 1) 110V控制單元 損 壞(如 68Ω分壓電阻損壞,連接電纜燒損等),導致控制單元沒有對電磁閥輸出電源。如果條件允許,盡可能在機車上借助機車風源與電源進行操 作,如真空斷路器不得不吊下來,則可借助單獨的風源與 110V 電源進行動作試驗,并且在處理好真HXD3 電力機車主型電器分析 18 空斷路器故障后,必須執(zhí)行不低于 30 次真空分合閘動作試驗,確保真空斷路器能正常工作。 檢查扭緊力矩 ? 高壓連接器 ?接地開關 ?BVAC固定螺栓 扭矩扳手 3個月 氣路檢查: ?調壓閥 ?排空 BVAC儲風缸 ?檢查是否漏氣 無 3個月 (冬季之前) 每年冬季前必須檢查 輔助維護: ?檢查真空管的真空度 真空檢測器:HSBA433418P1 一年或在特殊情況下(例如:不明電流短路,不正常機械振動,無浪涌 避雷器下雷擊等)。 其調整方法是: ①檢查靜態(tài)接觸壓力值,并重新調整靜態(tài)接觸壓力,恢復到規(guī)定值; ②檢查扇形板靠彈簧側的調整螺釘是否過高; ③調整拉桿絕緣子的拉桿長度,使之增長,以便增加降弓彈簧的降弓力矩; ④檢查推桿長度是否超過規(guī)定值( 1580mm); ⑤檢查傳動風缸和受電弓之間在車頂蓋上的安裝距離是否發(fā)生變化; ⑥檢查傳動風缸內的降弓彈簧剛度是否變值。 ( 3)落弓不到位 受電弓在使用中有時出現(xiàn)落弓不到位。升弓太慢時,則將進氣閥座的豁口銼大些。 ( 2)升降弓時間的調整 如前所述,升降弓時間是通過調整緩沖閥進氣或排氣閥座的豁口大小來達到的。這樣 就調節(jié)了升弓轉矩大小,使