Improved Pinning Center Morphology in HTS with Order-of-Magnitude Increase in J_c and B_pin Compared to Columnar Pinning

The motivation for continuous columnar pinning centers has been to provide maximum Upin. It has been assumed that this provides the best Jc and Bpin. Limitations on Jc and Spin observed for columnar pinning have been attributed to degradation of the order parameter and Tc. We examine columnar pinning by ionic damage and conclude instead that geometrical effects of columnar pinning on percolation path and on the number of pinning centers are the dominant limitations of columnar pinning, leading to a limit of Bpin- 4 T. Evidence suggests that multiple-in-line-defects (MILD) are far better suited to increase Jc and Bpin. The morphology of MILD pinning is reviewed. Ion energy loss per unit distance, Se, is found to be most promising in a regime almost diametrically opposite to that sought to maximize Upin. We expect Jc - 106 A/cm2 and Bpin > 40T from MILD pinning, despite sharply decreased Upin. Experimental confirmation is proposed.     

我国干灰干排的现状

介绍了我国粉煤灰干排系统的型式，对干灰干排系统在应用中存在的问题进行了分析。     

用局部组成活度系数模型计算原油中石蜡沉淀量

准确描述固相的非理想性是计算复杂流体的气液固相平衡的关键。从原油中沉淀出来的石蜡多由正构烷烃组成 ,其晶格结构主要是正交相 (斜方晶格 ) ,特别是在低温时可能是惟一的晶格结构 ,而局部组成模型能够较准确地描述正交相的非理想性。将局部组成活度系数模型用于复杂石油流体中石蜡沉淀量的计算 ,并与正规溶液理论模型进行了比较。结果表明 ,对于高温石蜡沉淀量的计算 ,两个模型均能给出较好的结果 ,但对于低温石蜡沉淀量的计算 ,局部组成活度系数模型能取得较满意的结果。     

串联系统的可靠性下限评估方法研究

本文针对小子样可靠性统计试验的特点,指出经典可靠性点估计和极大似然区间估计的不足。然后着重介绍了Ｂｕｅｈｌｅｒ精确置信下限评定方法以及ＭＭＬ方法、Ｌｉｎｄｓｔｒｏｍ－Ｍａｄ－ｄｅｎ方法、熵方法、似然比方法、贝叶斯方法等常用的可靠性评定方法及其特点。最后以具体数字实例将文中介绍的近似方法与精确评定方法进行比较,得出较好的适合于小子样无失效情况的核武器可靠性评估方法。本文“挑选”出来的可靠性评定方法还需作更进一步的研究。     

粗糙床面明槽水流能谱特性

对粗糙床面明槽水流能谱特性进行了研究,结果表明功率谱曲线、最大功率谱及相应的频率沿垂线的分布与相对光滑度大小紧密相关,据此得到了流动二维性及小尺度粗糙的判据;此外,在本实验条件下,能量主要集中在频率小于2Hz的涡体内。     

中国油气盆地演化机制及油气藏类型

中国含油气盆地形成机制及油气藏类型有很大的特殊性。中国东部地区主要受太平洋板块俯冲带向东迁移的控制,发育了一系列北北东向的张扭性裂谷盆地;西部地区主要受特提斯洋封闭和喜马拉雅运动的影响,发育了一系列北西向的压扭性断陷盆地。前者,基岩潜山、滚动背斜、被覆背斜、底辟构造和岩性圈闭油气藏很发育;后者,隐伏的逆冲断层及其有关的背斜及地层圈闭油气藏最常见。     

溶质在牛顿-微极分层流体中的分散

本文研究溶质在作圆管层流的牛顿—微极分层流体中的分散规律.在Taylor简化假定下导出速度、浓度和等效扩散系数的解析式,并作数值计算.分析外围层相对分子扩散系数、相对粘度和相对厚度等因素对分散过程的影响.     

Large-Eddy Simulations of turbulent flows with lattice Boltzmann dynamics and dynamical system sub-grid models

In this paper,two sub-grid scale (SGS) models are introduced into the Lattice Boltzmann Method (LBM),i.e.,the dynamics SGS model and the dynamical system SGS model,and applied to numerically solving three-dimensional high Re turbulent cavity flows.Results are compared with those obtained from the Smagorinsky model and direct numerical simulation for the same cases.It is shown that the method with LBM dynamics SGS model has advantages of fast computation speed,suitable to simulate high Re turbulent flows.In ...     

塔里木盆地塔中地区志留系油气成藏模式

 塔里木盆地塔中地区志留系油气显示丰富,成藏条件复杂,研究其油气成藏模式对推动塔中油气勘探有重大现实意义.本文主要对志留系沥青砂和可动油气的分布特征及成因机制进行分析,总结其成藏模式.研究结果表明:塔中地区志留系可动油气主要来自寒武系和奥陶系的混源,可动油气主要存在晚海西期和喜山期两期成藏,运移以垂向运移为主,侧向有限运移;塔中地区志留系沥青砂岩主要来源于寒武—下奥陶统烃源岩,沥青砂岩为油气边运移边破坏的产物;塔中志留系油气为两期成藏、两期改造的多点垂向输导,有限侧向输导成藏演化模式.