等离子体X射线吸收谱研究

计算高温高密等离子体吸收谱的理论方法;该方法基于相对论原子理论,可以计算任何单元素以及多元素等离子体的谱分辨X射线吸收谱;应用了量子数亏损理论,可以减少计算量. 利用该方法计算有机材料C_１０Ｈ_１６Ｏ_５等离子体的吸收谱,计算结果与实验符合良好.通过理论计算与实验相比较,可对惯性约束核聚变(ICF)等离子体进行诊断分析;不但可判断等离子体的温度和密度,还可提供等离子体内各电离度能级布居等重要物理参数. 同时经过有关“标准实验”验证的理论计算方法将是提供ICF“精密”辐射参数的重要基础.     

流量与环量对低扬程泵装置流道水头损失的交叉影响

流道水头损失与流量及环量之间的关系,是低扬程泵装置水力设计理论中对提高其水力性能的研究具有较大影响的重要问题.低扬程泵装置水泵导叶出口水流所具有的速度环量使上述关系变得复杂起来,需全面认识.研究结果表明:在无环量的条件下,进、出水流道水头损失与流量平方成正比;在Reynolds数达到阻力平方区要求的条件下,在一定转速范围内,对于不同转速下运行时的相似工况,流道水头损失与流量平方成正比,表现为泵装置效率保持不变;低扬程泵装置中设计流量时的出水流道水头损失决定于导叶出口水流的速度环量,两者之间的关系为一开口向上的曲线,存在最优环量;在低扬程泵装置变工况运行的条件下,出水流道水头损失受流量和环量的交叉影响,在水泵正常运行工况范围内,流道水头损失与流量之间呈现出接近于线性的关系,其机理有待进一步深入研究.     

弹性介质中充液井孔的漏模和井孔声场中的分波计算

在对井孔中与声场有关的不同Riemann叶上的复极点(泄漏模式)分析的基础上研究了纵波头波和其它分波的分离和计算问题,分析了现行的头波理论的缺陷,指出了泄漏模对横波头波和在高Poisson比地层中的纵波头波的贡献不能忽略,同时提出了正确的分离和计算纵波头波和其它分波的方法,改进了现行的声波测井理论.     

复杂产业网络上的技术创新博弈扩散研究

创新的价值在于扩散,但扩散依赖于路径选择与扩散规则.提出了技术创新扩散的一对多博弈模型,并求解出了Nash均衡解.Nash均衡表明,传播者采取扩散策略的概率与学习者的学习成本和拒绝代价之差成正比;学习者采取学习策略的概率不但与传播者的封锁成本成正比,而且与网络的平均度成正比;进而,基于马尔科夫链的吸收态,进一步分析了产业网络上技术创新博弈扩散的平均步数;基于平均场理论,分析了产业网络上技术创新博弈扩散的分布及其分布密度.最后,通过长三角IC产业网络给出了实证分析.     

材料多因素对24mm滤嘴长卷烟烟气递送量及过滤效率的影响

采用正交试验设计的方法研究24mm滤嘴长卷烟之卷烟纸、成型纸、接装纸及嘴棒组合搭配对卷烟焦油量、烟气烟碱量、烟气一氧化碳量、烟气水分及过滤效率的影响.结果表明:接装纸透气度、嘴棒吸阻分别是影响卷烟烟气递送量、过滤效率的显著因素及重要因素.重点对其进行调整和控制,可以很好地实现24mm滤嘴长卷烟烟气递送量及过滤效率的控制,减少产品质量波动,降低产品成本.使用该方法可快捷、高效、经济、准确地确定卷烟材料多因素对卷烟烟气递送量及过滤效率的影响规律.     

考虑损伤的修正梯度弹性理论

梯度弹性理论在描述材料微结构起主导作用的力学行为时具有显著优势,将其与损伤理论相结合,可在材料破坏研究中考虑微结构的影响.基于修正梯度弹性理论,将应变张量、应变梯度张量和损伤变量作为Helmholtz自由能函数的状态变量,并在自然状态附近对自由能函数作Taylor展开,进而由热力学基本定律,推导出修正梯度弹性损伤理论本构方程的一般形式.编制有限元程序,模拟土样损伤局部化带的发展演化过程.结果表明,修正梯度弹性损伤理论消除了网格依赖性;损伤局部化带不是与损伤同时发生,而是在损伤发展到一定程度后再逐渐显现出来.     

卷烟材料组合搭配对主流烟气量及过滤效率的影响

为研究卷烟纸、成型纸、接装纸及嘴棒组合搭配对"中式卷烟"焦油量、烟气烟碱量、烟气水分、烟气一氧化碳量及过滤效率的影响,尝试采用L_(27)(3~(13))裂区正交设计方法对RR卷烟进行在线试验和取样.检测结果经过直观分析、方差分析及贡献率分析,结果表明:嘴棒长度、吸阻及接装纸透气度是影响试验指标的高度显著因素及重要因素.所以重点对嘴棒长度、吸阻及接装纸透气度进行调整和控制,可以很好地实现卷烟产品的质量控制,减少产品质量波动,降低产品成本.使用该方法可快捷、高效、经济、准确地寻找并确定卷烟材料多因素对卷烟主流烟气量及过滤效率的影响规律及卷烟产品的材料搭配优化方案.从而实现卷烟产品材料搭配精益化,满足烟草企业的实际需求.     

政府补贴方式下排放许可交易生产优化

从学术上探讨了政府补贴方式下有排放许可交易的生产优化问题.分析了配额和补贴方式效果在管理上的差异,给出了补贴方式下的各经济核算关系及模型,给出了最低净化水平定理的证明;给出优化计算,求解了最优净化水平,并探讨了其与最优产量和企业最优收益间的关系;给出仿真计算,并对企业生产在这种支持方式下的优化管理进行了分析.研究表明:企业将对生产中产生的全部排放物进行相同净化水平α的处理时,所需要的处理费用最低;在线性反需求函数下,最优产量的变化量只与净化成本函数、排放交易价格、补助价格等几个量相关,最优收益与最优产量的平方成正比.     

一类最优EOQ模型的进一步扩展

对一类经济批量订购模型作如下进一步扩展:第一,允许短缺,短缺量部分拖后供给,且短缺期间损失率与实际缺货量成正比;第二,订购费用是可变的,且线性依赖于订购量.在此假定下,研究了有限计划时间水平及常数变质率下,部分短缺量拖后的变质性物品多阶段库存问题,给出了寻找最优订购策略的算法,证明了所给最优策略的存在唯一性及在该策略下费用函数取得最小值.最后给出应用实例.     

复数

1　考点简析新课教学与高三备考复习是有区别的 .但是新课教学又不能不顾及高考 ,不能对高考的要求心中无数 ,而应当循序渐进地、有机地渗透“考试说明”的有关要求 .1.1　知识点剖析本章的知识点有 7个 (见课本 7个小节的标题 ) ,其内涵与外延是 :复数的有关概念 (含模与共轭复数的有关性质 ) ,复数的整体形式、代数形式、三角形式及其转换 ;复数代数式与三角式的运算 ,复数的几何表示 ,复数运算的几何意义 ,几何意义与运算的转换 ,图形与方程的转换 ;在复数集中解一元二次方程和二项方程 .1.2　思想方法化复 (数 )为实 (数 ) ,数形结合 ,…     

Detecting nuclear materials smuggling: using radiography to improve container inspection policies

This paper proposes a layered container inspection system for detecting illicit nuclear materials using radiography information. We argue that the current inspection system, relying heavily on the Automated Targeting System (ATS) and passive radiation detectors, is inherently incapable of reliably detecting shielded radioactive materials, especially highly enriched uranium (HEU). This motivates the development of a new inspection system, which is designed to address a fundamental flaw of the ATS-based system, allowing for improved defense against sophisticated adversaries. In the proposed inspection system, all cargo containers go through x-ray imaging equipment first. From the x-ray image, a hardness measure of the container is computed. This hardness measure characterizes how likely it is that shielded HEU, if it does exist in the container, will not be detected in a subsequent passive detection step. Depending on the value of the hardness, the lower-hardness containers are sent to passive detection and the high-hardness containers are sent directly to active detection. This paper explores the trade-off between the detection probability of the new inspection system and the expected sojourn time a container spends in the system. The solution details and decision-making tools for using such a system are provided. Comparisons are made between the proposed system and the current ATS-based nuclear inspection system.     

含湿相变粗糙多孔材质的热质耦合分形研究

多孔材质复杂的内部结构和含湿状态对传热和传质特性有着重要意义,其热质耦合传递过程广泛存在于能源开发和工程隔热等领域。不同于在多孔材质理想状态下对传热和传质特性的单方面分析,该文将孔道的分布参数、粗糙表面、含湿状态和相变等因素考虑进去,运用分形理论推导出了含湿相变粗糙表面多孔材质的渗流系数和耦合等效导热系数的表达式。结果表明,渗流系数与面积分形维数、含湿饱和度呈正相关,与相对粗糙度、迂曲分形维数呈负相关;耦合等效导热系数与渗流系数、相变量呈正相关,与相对粗糙度呈负相关。此外,结果还表明,相变量以及相变引起的气体膨胀压强差对热质耦合传递也有着重要影响。     

Exploration of probabilistic mould growth assessment

A sufficiently long continuous duration of favourable conditions, particularly the availability of water and nutrients, is necessary for the mould growth on the surface of a building component. The availability of water is commonly quantified by the relative humidity on the building component surface. Some parameters, substantially affecting the relative humidity randomly fluctuate in time. Therefore, considering continuous duration of favourable conditions as a basic characteristic for mould growth assessment, its occurrence in time is represented by a stochastic process. Exploration and comparison of current methods for probabilistic assessment of mould growth resulted in emphasising the application of the theory of extreme values. Exceedance probabilities of practically important duration levels are estimated by the classical block maxima model for extremes and the point process model. As a quantification of potential mould risk the mean return period of a considered duration of favourable mould growth conditions is suggested. This quantification may be used for comparison of different designs, assessment of retrofitting effectiveness or as an input for cost–benefit analysis.     

负压抽液分装的数学模型

本文介绍了负压抽液分装的数学模型 .由于考虑到所讨论液态物质的渗透性及污染性大等特点 ,采用负压抽液的原理 ,根据能量守恒理论确定抽液所需的负压 (真空度 ) ;根据克拉珀龙方程、分子流运动论的 Knudsen公式等理论 ,确定达到额定压力 (真空度 )所需的时间 (即装置的起动时间 ) .据此设计了一套含有不完全真空保护系统的分装装置 ,用这套装置进行的实验和实际操作 ,其真空度、时间数据与确定值 (计算值 )基本相符 .表明所建立的数学模型正确 ,据此设计的这套装置已成功用于液态物质的分装 .     

平行双射流场纳米颗粒的形成与凝聚的研究

对平行双射流中H2SO4蒸气扩散进行了大涡模拟,给出了硫酸/水系统成核生成纳米颗粒及颗粒的凝聚过程中颗粒的分布特性,分析了燃料中硫的浓度、环境相对湿度以及射流Reynolds数对于颗粒浓度和粒径分布的影响．结果表明,硫酸/水系统会成核生成大量的纳米颗粒,在双管射流的中间和射流场周围,颗粒具有较高的浓度;颗粒的凝聚过程使颗粒的数量减少、直径变大;随着硫的浓度的增加,流场中的颗粒浓度有明显增加,而成核后形成的颗粒直径减小;环境湿度和Reynolds数的增大,有利于成核过程,因而导致形成更多的颗粒．     

A simulated annealing based hyperheuristic for determining shipper sizes for storage and transportation

The current drive to reduce packaging waste has led many companies to consider the use of multi-trip containers or shippers in which to transport their products in order to reduce packaging waste. The efficiency of such systems obviously depends on selecting shipper dimensions in such a way as to ensure high volumetric utilisation. As is the case with many practical problems the efficiency/solution quality can be improved if problem specific information is used to enhance the operation of a meta-heuristic solution approach. The problem can be modelled as a p-median problem but is too large to be solved in reasonable time without further modification. Four such modifications, all based on properties of the physical problem, are introduced and incorporated into a hyperheuristic driven simulated annealing solution approach.     

Modelling of coupled heat and moisture transfer in porous construction materials

In this paper, a mathematical model is proposed for predicting air temperature and humidity in a two-room region. The model contains a coupled relationship between temperature and humidity within the constructions and can be solved by using the numerical method. However, the two-room region can be reduced to a single region when the region with no ventilation is considered, and then the room temperature and relative humidity can be obtained analytically. The solution obtained in this paper is verified by comparing with the result of the analytical method. It shows that the two results are in agreement. In addition, the proposed model can also be applied to simultaneously obtain the transient temperature and humidity of a two-room region for different porous construction materials.     

New approach for consideration of adsorption/desorption data

In this paper we proposed a new approach to modify the Langmuir model by considering nonlinear effects such as diffusion of water molecules in/out of an adsorbing film for humidity adsorption and desorption kinetics. The model was tested on the humidity adsorption and desorption data of a spin coated 50 nm thick Ruthenium polypridyl complex (Ru-PC K314) film, measured under relative humidity between 11% and 97% using by Quartz Crystal Microbalance (QCM) technique.     

Integrated optimization of customer and supplier logistics at Robert Bosch LLC

Large automotive supply chains typically involve manufacturers pulling materials from their suppliers along the chain, usually by using round-trip truckload routes. The return trips on these routes are used to return empty containers back to the suppliers. The mismatch between the amount of materials and empty containers results in underutilization of the return trips. A supplier can utilize this unused capacity by identifying a subset of promising customer routes that can be combined with its existing supplier routes to save overall costs of the system. Such an integration also leads to other supply chain coordination benefits such as the potential of using crossdocks, more frequent milkruns and ensuing reductions in inventories.     

Geochemical studies in the uranium prospect at Umra,Rajasthan

With the objective of investigating the geochemistry of the natural waters of the uranium prospect at Umra, Rajasthan, the concentrations of uranium, nickel, cobalt, copper, vanadium, etc., in the natural waters have been determined and their distribution patterns have been interpreted in the light of the geology of the area, the climatic and hydrological conditions prevalent there and the geochemical behaviour of the elements concerned. It is found that there is a marked contrast in the uranium content of winze and well-waters. The presence of copper in waters despite their high pH is ascribed to the tendency of copper to form colloidal suspension of basic carbonates. The observation, that vanadium is present in the secondary uranium-vanadium minerals but is absent in the waters, could be explained in the light of the geochemical behaviour of the element. The concentration of cobalt in most of the water samples and its absence in some is traceable to the controlling effect of pH on the mobility of cobalt. Nickel in waters might have been ‘scavenged’ and absorbed on hydrated iron oxides, which explains the absence of nickel in waters. Mention is made of the health hazard involved in drinking water from one of the wells with high content of uranium.