Establishing an human spine dynamic model is an significan event to study spine injured biomechanics of pilot " s ejective injury, parachute opening, landing and study the endurance to impact loading on human spine. in this paper, the huston " s method of kane " s equations is developed so that it can be applied to the multibodysystem including translation between the bodyies. the dynamic model of human spine is provided basing on these theories, while the big movement of spine is considered. the deformation of vetebra is far smaller comparing with the intervetebra disc, so the spine is considered into multibodysystem including rigid bodies ( vetebra ) and the flexible bodies ( intervetebra disc ). the computer solution correspond with the results of the large scale human impact test. the rigid coefficient factors and the damping factor of intervetebra joints are obtained
人體脊柱動力學模型的建立對研究飛行員彈射救生、傘兵跳傘開傘、著陸等脊柱損傷的生物力學以及研究人體脊柱耐受
沖擊載荷的極限問題都具有重要意義.首先發展了凱恩方程的休斯頓方法,使其可應用於變形體連接的多體系統,並以此理論為依據建立人體整椎脊柱
沖擊動力學模型,此時考慮脊柱的大位
移運動,每個椎骨的變形相對椎間盤的變形小得多,把脊柱看成由剛體(椎骨)和變形體(椎間盤)組成的多體系統.並以大型真人坐姿
沖擊實驗結果進行了擬合,最後得到腰椎間關節剛度系數因子和阻尼系數因子
It is advisable for people to face up to the future challenges by bettering themselves, because the future shock is independent of man ' s will
應用:人們最好通過完善自我來面對未來的挑戰,因為未來的
沖擊不是以人的意志為轉
移的。
In pumping fluid with gas, pressure boost can be improved by enhancing the pump rotation speed, thereby improving the performance of the pump to a certain degree ; when the gas content is constant, by increasing the inlet pressure, the pressure boost can be enhanced and the pump efficiency be improved remarkably ; when the gas content is rather high, there will be a problem of matching between the gas pressure and the fluid pressure ; the performance of the multiphase pump can also be improved by means of rational design of buffer vessel and homogenizer
試驗分析認為,氣液混輸工況下,提高泵轉速可以提高增壓,在一定程度上能改善多相泵的工作性能;含氣率一定時,增加進口壓力,可使多相泵增壓值增大,泵效明顯增加,最大含氣率點后
移,但含氣率很高時,存在氣液壓力相匹配問題;改進緩
沖罐和均化器的設計,有利於氣液互相夾帶,避免氣囊產生,可改善多相泵的輸送性能。
For the purpose of relieving and coordinating these conflicts, it is quite necessary and really significant to complete some works like : to push on area transfer of industrial, to push on area industrial schooling, to choose the leading industrial accurately, to push on coordinating development among regions, to push on area specialization division and realize update of industrial construction, to push on technology advance and technology transform and cultivate rational competitive superiority among the regions
為緩和並協調好區域發展中存在的這些
沖突與矛盾,應做好如下工作:加快產業區際轉
移與積極發展地區產業集群,選準主導產業並推動區域間的協調發展,推進地區專業化分工並藉此實現產業結構升級,加快技術進步與技術改造並藉此合理地培育起區域的競爭優勢。
Not only was the pattern of recordings along the artificial lateral line similar to the pattern recorded from the nerve cells of a real fish, but the computer could also decipher it to follow the source of the pulse as it moved along different paths
結果顯示不僅該系統記錄的圖形與從真正的魚身上的神經細胞所記錄的圖形相似,而且配套的電腦程序還能通過對記錄圖形的解讀來追蹤沿著不同路徑
移動的脈
沖水波的源頭。
The pges abundance patterns of residual mantle rock with a peleo - subduction background is characterized by pd, pt depletion and ir, ru relatively enrichment, while the basalt and basic dyke by the processing of partial melt in the same background take an opposite feature of pd, pt enrichment and ir, ru depletion. the existence of fluid in the subduction zone increases the degree of partial melt on the one hand, and on the other, activates the activity of pd, pt compare to ir, ru, and thus reduces the pd ir and pt ru in residual mantle rock. the pges patterns for basalt and basic dyke from two carboniferous volcano zones to south qoltag and north turpan - hami basin, xinjing uigur autonomous region, take a shape of gentle positive inclined curve with lower pt and pd differentiation and lower pges. all these features are obviously different from that of basic dyke and basalt from typical ophiolite and therefore the author believe that their fluid - rich paleo - subduction zone environment can be ruled out
古俯
沖帶背景下的殘餘地幔巖的pges配分以pd , pt明顯虧損和ir , ru相對富集為特徵,而部分熔融產物的玄武巖和基性巖脈則呈現相反的ir , ru明顯虧損和pd , pt相對富集特徵。俯
沖帶中流體的參與一方面增加了部分熔融程度,有利於pd , pt從原始地幔進入熔融相另一方面,流體的作用使得pd , pt相對于ir , ru遷
移活動性效率提高,造成地幔巖中
These internal tensions, plus border disputes, mass migrations, and perennial arab-israeli clashes, make the middle east particularly explosive.
這些內部的緊張關系,加上邊界糾紛,大量
移民以及阿拉伯和以色列的長期
沖突,使中東特別具有爆炸性。
The probability of obtaining a lattice atom displacement via the phonon kick process is evidently small.
很明顯,通過聲子反
沖過程而取得晶格原子位
移的幾率是不大的。
Then a vsc controller using on - off valve and two potentiometers are designed for cushioning control system. it can realize the balanced, no shock, no reversing cushioning. experiments under different air pressure, load mass are carried out, and the results prove that the vsc controller can be used in pneumatic cushioning
第五章首先介紹了變結構控制的原理和應用發展情況,然後針對本實驗系統設計了一個使用開關閥和端位位
移傳感器的變結構控制方案,實現緩
沖過程的平穩無
沖擊和無回彈要求,並在不同氣源壓力、不同負載質量下分析了控制性能的變化,實驗結果證明緩
沖控制採用變結構控制是可行的,並具有很強的魯棒性。
The limited sensitivity of present pulsar surveys and the greater frequency drift make the more distant pulsars difficult to observe.
目前脈
沖星普查的有限探測靈敏度和大的頻率漂
移,使我們難以觀測到更遙遠的脈
沖星。
The movement occurs on the trailing edge of the pulse.
移動是在脈
沖的下降沿產生的。
Transmission formula of interference from mobile base and conservative estimation from pulse radar are presented
對
移動通信基站產生的干擾作了傳播分析、計算,對脈
沖雷達干擾作了譜分析及保守計算。
7. in chapter 8, a new method for estimating the doppler and multipath time delay of the overlapping echoes for lfm pulse radar by only one period pulse signal is presented
7 .在第八章提出了一種對lfm脈
沖雷達回波d叩pler頻
移和多徑時延進行聯合估計的方法。
Red shift of pl spectra peak was observed, and pl lifetime would rise at the same time
發現加入ingaas及alas緩沖層后使inas量子點發光峰強度增大,譜峰紅移,發光壽命增大。