polar contact 中文意思是什麼
polar contact
解釋
極化接點-
The results indicated that the dimension, shape and purity of base material could meet the functional demand of solid lubricant ; the thermal decomposition temperature of ptfe resin exceeds 400 c, but organic and inorganic packing filler added in ptfe made the water absorption rate of composite material increased, melting temperature and decomposition temperature decreased, in the meanwhile oxidative decomposition reaction was accompanied ; polar groups such as c = o, c - o - c and so on in the carbon fiber surface is advantageous to increase compatibility with other components and interlayer shearing strength ; uniform design experimental method could help to find the relationship between formula and frictional property by relatively small tests. the developing trend of each formula ' s friction coefficient could be showed by fitting curve ; the friction coefficient with no copper powder or graphite in formula was relatively big. this fact showed that copper powder and graphite should be used cooperatively ; it was found that when the ratio of copper powder to graphite by weight is 15 : 60, 30 : 30 - 40 and 60 : 15 - 30 respectively, the friction coefficient was relatively small. the degree of crystallinity of pure ptfe reached maximum by air cooling and the abrasion loss also reached maximum among three ones ; at the same time, the abrasion loss of solid lubricant sample was also the biggest among three ones ; when solid lubricant matched with 45 # steel axle or gcrl5 steel axle, lubricant transfer film could be formed on metal surface, thus direct contact between the surface of metal friction pair rings was reduced. their working life was elongated extremely ; there was mainly much graphite, a little ptff, moo3, feso4, cus and so on in lubricant transfer film
試驗結果表明：所選原料的尺寸、形狀及純度可滿足固體潤滑劑的性能要求；聚四氟乙烯樹脂熱分解溫度超過400 ，但在ptfe中加入無機填料會使復合材料吸水率提高，熔融溫度及分解溫度降低，且伴有氧化分解反應；碳纖維表面含有c = o及c - o - c等極性基團，有利於提高其與其它組分的相容性，提高層間剪切強度；均勻設計試驗方法能夠用較少的試驗次數找出配方與摩擦性能間的關系，擬合曲線基本能表示各配方的摩擦系數發展趨勢；配方中不加銅粉或不加石墨，其摩擦系數均較高，說明銅粉和石墨應該配合使用；當銅粉15份、石墨60份時，銅粉30份、石墨30 - 40份時，銅粉60 、石墨15 - 30份時，摩擦系數均具有較低值；純聚四氟乙烯樹脂在空氣冷卻時結晶度最大，磨損量也是三者中最大的；同時，固體潤滑劑試樣在空氣冷卻時的磨損量也是三者中最大的：不論是固體潤滑劑與45 #鋼軸配副或是固體潤滑劑鑲嵌入銅套后與gcr15鋼軸配副，在金屬表面均可形成潤滑轉移膜，從而減少金屬摩擦副表面間的直接接觸，大大延長其使用壽命;轉移膜中主要含有較多的石墨、少量聚四氟乙烯、 moo 。 -
Nasa loses radio contact with the mars polar lander moments before the spacecraft enters the martian atmosphere
1999年，在火星極地登陸者號宇宙飛船進入火星大氣前的瞬間，美國航空航天局失去了與其的無線電聯系。 -
Base on the kinematics relation of ctp, the corresponding reynolds equation or average reynolds equation, fluid film thickness equation under qusi - stable state in polar coordinates, balance equations of load and moments under full - film contact and partial - film contact states were set up respectively. these model equations were calculated by the finite difference method, and the instantaneous 3 - d distribution of fluid pressure and the slurry film was simulated by the matlab software
根據ctp的運動關系，分別建立了極坐標下，全膜接觸工況時的非穩態牛頓流體在ctp過程中的一般reynolds方程、流體膜厚方程、載荷平衡方程和轉矩平衡方程，以及部分膜接觸工況下的平均reynolds方程、平均膜厚方程、接觸壓力方程、總載荷平衡方程和總轉矩平衡方程。
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