大系统分解协调在库群防洪优化调度中的应用

文章介绍了大系统分解协调理论,建立了串联、并联库群水库防洪优化调度模型.以澧水流域并联系统为例进行了优化调度计算,并以常规调度方案成果进行了分析比较论证.     

BINELOCA 程序与广东岭澳核电站大破口失水事故分析

ＢＩＮＥＬＯＣＡ程序是在吸收国外先进大破口失水事故分析计算机程序的基础上，针对我国现有大破口失水事故分析程序的不足和工程应用方面的问题，采用了一些成熟的、新型的和当今国际公认的瞬态热工水力数学物理模型以及水和蒸汽性质参数计算公式改编而成的大破口失水事故分析程序。通过对广东岭澳核电站大破口失水事故的计算表明，ＢＩＮＥＬＯＣＡ程序计算的结果与法国计算的结果是一致的。     

The magnetic applications choice among ferrite ceramics,metallic strips,or metal powder cores

Iron-based metallic strip materials such as iron, silicon-iron, and amorphous metal are used for low frequency (50–60 Hz. line) power applications. Low-loss Nickel-based alloys as high permeability strip or insulated powder cores are the choices for stable, low-level higher frequency applications. Iron-based powder cores offer low cost as power supply filter chokes. Ceramic ferrites combine highest frequency operation with low cost and reduced component size as transformers and chokes in telecommunication and high frequency power supply applications.     

Locality-preserving hash functions for general purpose parallel computation

Consider the problem of efficiently simulating the shared-memory parallel random access machine (PRAM) model on massively parallel architectures with physically distributed memory. To prevent network congestion and memory bank contention, it may be advantageous to hash the shared memory address space. The decision on whether or not to use hashing depends on (1) the communication latency in the network and (2) the locality of memory accesses in the algorithm.We relate this decision directly to algorithmic issues by studying the complexity of hashing in the Block PRAM model of Aggarwal, Chandra, and Snir, a shared-memory model of parallel computation which accounts for communication locality. For this model, we exhibit a universal family of hash functions having optimal locality. The complexity of applying these hash functions to the shared address space of the Block PRAM (i.e., by permuting data elements) is asymptotically equivalent to the complexity of performing a square matrix transpose, and this result is best possible for all pairwise independent universal hash families. These complexity bounds provide theoretical evidence that hashing and randomized routing need not destroy communication locality, addressing an open question of Valiant.This work was started when the author was a student at Oxford University, supported by a National Science Foundation Graduate Fellowship and a Rhodes Scholarship. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author and do not necessarily reflect the views of the National Science Foundation or the Rhodes Trust.     

两轴稳定平台大俯仰角状态控制技术研究

在对两轴稳定平台一般构型分析的基础上,指出了其在俯仰方向大角度时稳定控制存在的不足,提出了采用三正交陀螺稳定控制方式解决大俯仰角控制问题的方法,最后利用MATLAB进行了数学仿真,结果表明该方法有效提高了系统的稳定精度。     

Fully Developed Turbulence of Power-Law Fluids in Circular Pipe Based on Large Eddy Simulation

幂律流体圆管湍流的大涡模拟

王淑彦^1,2, 李淼¹, 王树青³, 李好婷¹, 陈羽佳¹, 马一玫¹, 孙启冀¹

（1.东北石油大学 石油工程学院, 黑龙江 大庆 163318;

2.提高采收率教育部重点实验室（东北石油大学）, 黑龙江 大庆 163318;

3.中国石油大庆油田股份有限公司第四采油厂, 黑龙江 大庆 163511）

摘 要：本文采用动态亚格子模型,对幂律流体在圆管内的充分发展湍流流动进行了大涡模拟（LES）,得到了不同幂律指数下的湍流流动信息。文中分析了平均轴向速度、脉动速度均方根和雷诺应力等随着幂律指数增加的变化趋势,得出随着幂律指数的增加对数区的平均轴向速度减小,脉动速度均方根和雷诺应力的值增大,模拟结果表明剪切稀化流体比剪切稠化流体的非牛顿特征更明显。同时对湍流流动的高阶统计量（偏斜因子和平坦因子）进行了分析,结果表明随着幂律指数的减小,轴向脉动的偏斜因子和平坦因子在近壁面区增大,随着幂律指数的减小轴向脉动的间歇性和非对称性更强。不同幂律指数下的湍流流动变化明显,进一步说明了幂律指数对幂律流体的湍流流动有重要影响。模拟结果与直接数值模拟结果吻合较好,证实了大涡模拟可以用来预测较大雷诺数情况下幂律流体流动的湍流特性。

关键词：大涡模拟;幂律流体;充分发展湍流

     

Molecular Dynamics Simulations Based on 1-Phenyl-4-Benzoyl-1-Hydro-Triazole ERRα Inverse Agonists

Estrogen-related receptor α (ERRα), which is overexpressed in a variety of cancers has been considered as an effective target for anticancer therapy. ERRα inverse agonists have been proven to effectively inhibit the migration and invasion of cancer cells. As few crystalline complexes have been reported, molecular dynamics (MD) simulations were carried out in this study to deepen the understanding of the interaction mechanism between inverse agonists and ERRα. The binding free energy was analyzed by the MM-GBSA method. The results show that the total binding free energy was positively correlated with the biological activity of an inverse agonist. The interaction of the inverse agonist with the hydrophobic interlayer composed of Phe328 and Phe495 had an important impact on the biological activity of inverse agonists, which was confirmed by the decomposition of energy on residues. As Glu331 flipped and formed a hydrogen bond with Arg372 in the MD simulation process, the formation of hydrogen bond interaction with Glu331 was not a necessary condition for the compound to act as an inverse agonist. These rules provide guidance for the design of new inverse agonists.     

Dynamic “Molecular Portraits” of Biomembranes Drawn by Their Lateral Nanoscale Inhomogeneities

To date, it has been reliably shown that the lipid bilayer/water interface can be thoroughly characterized by a sophisticated so-called “dynamic molecular portrait”. The latter reflects a combination of time-dependent surface distributions of various physicochemical properties, inherent in both model lipid bilayers and natural multi-component cell membranes. One of the most important features of biomembranes is their mosaicity, which is expressed in the constant presence of lateral inhomogeneities, the sizes and lifetimes of which vary in a wide range—from 1 to 10³ nm and from 0.1 ns to milliseconds. In addition to the relatively well-studied macroscopic domains (so-called “rafts”), the analysis of micro- and nanoclusters (or domains) that form an instantaneous picture of the distribution of structural, dynamic, hydrophobic, electrical, etc., properties at the membrane-water interface is attracting increasing interest. This is because such nanodomains (NDs) have been proven to be crucial for the proper membrane functioning in cells. Therefore, an understanding with atomistic details the phenomena associated with NDs is required. The present mini-review describes the recent results of experimental and in silico studies of spontaneously formed NDs in lipid membranes. The main attention is paid to the methods of ND detection, characterization of their spatiotemporal parameters, the elucidation of the molecular mechanisms of their formation. Biological role of NDs in cell membranes is briefly discussed. Understanding such effects creates the basis for rational design of new prospective drugs, therapeutic approaches, and artificial membrane materials with specified properties.     

露天矿山深-浅耦合台阶爆破方法研究及应用

爆破大块率高一直是困扰国内外众多露天矿山的技术难题,银山矿露天采矿场由于采区地质条件复杂,爆破大块率高的现象尤为明显。为此,针对露天采矿场岩性复杂易产生大块的区域,基于岩石的物理力学性质,计算出千枚岩和斑岩爆破区域需增设的短孔孔位。为减少爆破大块的产生率,提出了中深孔爆破方法—深-浅耦合台阶爆破方法。在银山矿露天采矿场实施深-浅耦合台阶爆破方法后,爆破大块率得到有效控制并取得了显著的社会及经济效益。     

涡流检测技术在宝钢热轧轧辊上的应用

介绍了轧辊涡流检测仪的工作要求、设备组成和使用方法,指出对轧辊进行涡流检测可防止爆辊,减少轧辊磨削量。