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下部钻具组合力学性能分析中,稳定器与井壁的间隙是影响其性能的重要因素。对于多稳定器组合,事先设定稳定器与井壁接触情况既困难也不准确。本文从有限单元的基本总势能表达式出发,采用最优化理论中的罚函数法,分析了稳定器间隙对下部钻具力学性能的影响,为解决稳定器与井壁的接触问题找到了一个新方向。     

Effect of Rare Earth Elements on the Induction Frequency of the Somatic Cell Embryo in The Fruit of Chinese Wolfoerry

ＥｆｆｅｃｔｏｆＲａｒｅＥａｒｔｈＥｌｅｍｅｎｔｓｏｎｔｈｅＩｎｄｕｃｔｉｏｎＦｒｅｑｕｅｎｃｙｏｆｔｈｅＳｏｍａｔｉｃＣｅｌｌＥｍｂｒｙｏｉｎＴｈｅＦｒｕｉｔｏｆＣｈｉｎｅｓｅＷｏｌｆｏｅｒｒｙＹａｎｇＨａｎ－Ｍｉｎ（杨汉民）；ＤｕＬｉｎ（杜琳）（...     

Thermodynamic Assessment of DyCl3-MCl （M= Na, K, Rb, Cs） Systems

Using the CALPHAD （Calculation of Phase Diagram） technique, the DyCl3-MCl （M = Na, K, Rb, Cs） systems were optimized and calculated. The modified quasi-chemical model in the pair approximation for short-range ordering was used to describe the Gibbs energies of the liquid phase in these systems. From the measured phase diagram data and experimental thermodynamic properties, a series of thermodynamic functions were optimized base on an interactive computer-assisted analysis. The optimized parameters and the experimental data were thermodynamically self-consistent. The optimized results were discussed.     

上马水库地裂缝成因及工程处理措施探讨

文中着重阐述了上马水库库坝区的地裂缝产生的原因及发育规律,分析了地裂缝对水库的直接危害,为水库除险加固设计提供了指导,并提出了切实可行的工程处理措施建议。     

Direct Spectroscopic Determination of Europium(Ⅱ) Concentration During Europium(Ⅲ) Electro-Reduction in Hydrochloric Acid Medium

UV-Vis spectroscopy was used to directly determine the concentration of Eu(Ⅱ) during electroreduction of Eu(Ⅲ) in hydrochloric acid medium. Electroreduction was carried out in a flow type electrolyzer with glassy carbon cathode at the constant potential of -800 mV vs. Ag/AgCl. The effects of oxygen and concentration of hydrochloric acid on the system were investigated. For 0.01 mol·L-1 hydrochloric acid, calibration curves for Eu(Ⅱ) absorption bands at 248 and 320 nm were constructed. Molar absorption coefficients were estimated to be 2016 and 648 L·mol-1·cm-1, respectively. The absorbance strongly decreased with decrease in pH of the solution, whereas concentration of chloride had only a negligible effect.     

Monolithic Catalysts with Low Noble-Metal Content for Exhaust Purification of Small Gasoline Engines

A series of low noble-metal coment monolithic catalysts for exhaust purification of small gasoline engines was investigated, and it was found that the Pt/Rh-OSM/Al2O3 （where OSM was oxygen storage material） catalyst with Ce0.5Zr0.5-MnOx（3%MnOx） OSM held low light-off temperature for CO, HC, and NO; quite wide three-way window, and outstanding thermal stability. The catalyst could efficiently comrol exhaust emission of small gasoline engines.     

Effect of Y2O3 Content on Microstructure of Gradient Bioceramic Composite Coating Produced by Wide-Band Laser Cladding

Hydroxyapatite (HA) ,a kind of bioactive materi-al , has wide application prospect in hard tissue re-placemen and repairment due to its si milar chemicalcomposition and crystallographic structure to that ofbone mineral[1 ,2]. Since HA has lowstrength (50 …     

碱土金属氧化物催化氧化异丙苯反应研究

考察了碱土金属氧化物CaO、MgO和SrO在催化氧化异丙苯合成过氧化氢异丙苯 (CHP)反应中的性能。3种催化剂的活性顺序为 :CaO >MgO >SrO。采用Hammett指示剂分别表征了碱土金属氧化物的碱强度。碱强度H-=15 0～ 18 4的碱性中心有利于异丙苯过氧化合成CHP反应。采用红外光谱分析了异丙苯在MgO、CaO催化剂表面的吸附态。异丙苯通过异丙基叔碳原子上的氢原子与CaO催化剂表面碱中心发生化学吸附 ,弱化了异丙基叔碳原子上的C—H键 ,从而有利于催化异丙苯氧化合成CHP的反应。MgO与异丙苯的异丙基叔碳上的氢原子的相互作用弱于CaO与异丙苯的异丙基叔碳上的氢原子的相互作用 ,使MgO催化异丙苯氧化的反应活性低于CaO催化异丙苯氧化的反应活性     

稀土永磁及磁记录材料的矫顽力与有效激活体积

指出了文献 [1]中的一个错误。给出了不同模型的稀土永磁材料以及磁记录材料的矫顽力 Hc和有效激活体积υ之间的正确关系 ,这样的关系被表示成一个复杂的函数关系 ,同时指出 ,对不同模型的稀土磁性材料 ,这个函数关系是不同的