Relativistic Treatment of Spinless Particles Subject to a Rotating Deng-Fan Oscillator

The bound state solutions of the Klein-Gordon equation with the rotating Deng-Fan molecular potential are presented by using a proper approximation to the centrifugal term within the framework of equal scalar and vector Deng-Fan potentials. It is shown that the solutions can be expressed by the generalized hypergeometric functions. The normalized wavefunctions are also derived.     

内圈离心位移对高速角接触球轴承刚度的影响

以弹性力学理论、滚动轴承动力学和沟道控制理论为基础,计算了角接触球轴承内圈在离心力作用下的径向位移,给出了计及内圈离心位移影响时,高速角接触球轴承滚动体与内、外圈的接触刚度与轴承整体的径向刚度、轴向刚度、角刚度的计算方法和相应程序。对7012/CD轴承的计算结果表明,轴承内圈外径的离心位移随转速增加而增大,在高速条件下其值较大,不容忽视;轴承内圈离心位移对内圈接触刚度和轴承径向刚度影响较大,导致内圈接触刚度和轴承径向刚度相对增大;对外圈的接触刚度、轴承轴向刚度和角刚度的影响很小;随着转速的增加与内圈离心位移的增大,对轴承内圈接触刚度与轴承径向刚度的影响会更加明显。因此,为使高速角接触球轴承的刚度分析更加精确、更加接近实际,必须考虑内圈离心位移的影响。     

Pyrolysis of oil at high temperatures: Gas potentials, chemical and carbon isotopic signatures

Although the gas cracked from oil has been believed to be one of the important sources in highly ma-tured marine basins, there are still some debates on its resource potentials and chemical and isotopic compositions. In this study a Cambrian-sourced marine oil sample from the Silurian reservoir of well TZ62 in the central Tarim basin was pyrolyzed using sealed gold tubes with two different pyrolysis schemes: continuous pyrolysis in a closed system and stepwise semi-open pyrolysis. The results show that the maximum weight yield of C_1–5 gases occurs at EasyRo=2.3% and the residual gas poten-tial after this maturity is only 43.4 mL/g, about 12% of the yield of 361 mL/g at EasyRo=2.3%. Combined with the results of kinetic modeling, the main stage of gas generation from oil cracking is believed within the EasyRo=1.6%―2.3%. The increase in the volume yield of C_1–5 gases at EasyRo>2.3% in a closed system is mainly related to the re-cracking of previously formed C_2–5 wet gases, not the direct cracking of oil. The stepwise pyrolysis experiments show that the gas from the cracking of residual oil at EasyRo>2.3% is characterized by very high dryness index (higher than 92%) and heavy methane carbon isotopes ranging from -28.7‰ to -26.7‰, which is quite different from the gases from the con-tinuous pyrolysis in a closed system. The kinetic modeling of methane carbon isotope fractionation shows that the carbon isotopes of methane within the main stage of gas generation (EasyRo<2.3%) are far lighter than the carbon isotopes of the precursor oils under a geological heating rate of 2 ℃/Ma. The above observations and results provide some new clues to the accurate recognition and objective re-source evaluation of oil cracking gas in highly mature marine basins.     

离心成型钢纤维混凝土劈裂抗拉强度试验研究

通过试验研究了离心工艺参数、骨料级配、钢纤维长度和体积率等因素对离心成型钢纤维混凝土环形截面构件的轴向和环向劈裂抗拉强度的影响规律.结果表明：增大离心加速度有利于提高钢纤维混凝土的轴向劈裂抗拉强度;选用长度较小的钢纤维时,适当延长中速阶段的离心时间也可提高钢纤维混凝土的轴向劈裂抗拉强度;选用长度较大的钢纤维时,适当延长中速阶段的离心时间或增大离心加速度可提高钢纤维混凝土的环向劈裂抗拉强度.选取粗骨料级配5—10mm可获得较高的轴向劈裂抗拉强度,选取粗骨料级配5—15mm可获得较高的环向劈裂抗拉强度.对于外径为550mm以内的离心成型环形截面构件,钢纤维长度宜为25—32mm,体积率不宜大于1.2%.经统计分析提出了离心成型钢纤维混凝土的劈裂抗拉强度计算公式.     

离心压缩机变转速特性曲线拟合法

基于压缩机特性曲线的形状相似性和位置渐进变化的规律,本文提出了一种"两步拟合"的压缩机特性线拟合方法,适用于进口条件不变、转速发生变化的压缩机特性曲线拟合,原理简单,方法实用,精度较高,文中还用具体算例加以证明,并说明了需要注意的问题.     

半拓扑线性空间及其性质(Ⅱ)

我们在文[9]引入了半拓扑线性空间的概念,并得到了半拓扑线性空间中半开集、半闭包、半内部、S邻域、局部S-基等方面的一些基本结果.本文进一步讨论了半拓扑线性空间的性质,得到了如下结果:(1)证明了半拓扑线性空间中凸集的半闭包和半内部均为凸集;半拓扑线性空间中平衡集的半闭包是,平衡集,并且当平衡集的半内部包含0点时,平衡集的半内部也是平衡集;在半拓扑线性空间中存在着由半闭的平衡集构成的0点的局部S-基.(2)证明了半拓扑线性空间中半拓扑线性有界集的子集是半拓扑线性有界的,有限个半拓扑线性有界集的并集也是半拓扑线性有界的,S-紧集是半拓扑线性有界的.(3)对具有C性质的半拓扑线性空间,证明了半拓扑线性有界集的半闭包是半拓扑线性有界的,有限个半拓扑线性有界集的和是半拓扑线性有界的.(4)对具有C性质的半拓扑线性空间,证明了α集A是S-紧集当且仅当A是完全半拓扑线性有界的S-完备集.     

等温淬火球墨铸铁渣浆泵叶片磨损试验的正交分析

采用正交试验分析了在实验室条件下影响奥贝球铁叶片磨损的因素,探讨了决定叶片材料特性的成分和热处理工艺以及叶、磨料种类等水力学条件对叶片磨损的综合影响,研究结果表明,渣浆泵叶片的磨损失效受到材料特性和水力条件的综合影响;叶片材料成分和热处理工艺交互作用是影响叶磨损的主要因素,其次是磨料种类及叶型症 交试验是研究 渣浆泵磨损规律的有效方法 。     

高速离心泵串联诱导轮的设计理论及工程实现

阐述了高速离心泵串联诱导轮的设计理论及工程实现,提出了第一级诱导轮采用变螺距结构而第二级诱导轮采用锥形等螺距结构的设计方案。经过理论分析、试验研究和工程应用表明,串联诱导轮可使高速泵获得比带单级诱导轮更高的汽蚀性能。     

离心叶轮内三维分离流态的拓扑分析

本文主要是用拓扑分析的方法,根据实验给出的流场信息,来确定流场结构的性质和研究这些性质随流动参数变化的规律,从而得到对流场特性的定性认识。这里着重讨论了离心叶轮内表面分离流态,指出叶片吸力面和压力面不同的分离形式,分析了叶片表面奇点分布规律,建立了叶道内三维流动分离模型。     

用PIV进行静电旋风除尘器流场的测定

研究静电旋风除尘器内的流场。采用ＰＩＶ（粒子图像速度场仪）对不同进口流速、不同截面位置的流场进行了测定。试验结果表明,在静电旋风除尘器的捕集空间内,径向速度值很小,切向速度沿轴向及径向的变化很大。应用ＰＩＶ测定流场具有流场完全无干扰,一次能够测量整个视场等优点。