l^1鲁棒辨识的快速算法

根据“时间宽度”思想,得到了ｌ＾１中有噪声时的时间宽度的上、下界函数,对两上具体的先验集,构造了确定最大降低系统不确定度的系统输入规划模型,并给出了混合遗传进化算法。     

考虑内部布局和出口宽度的教室人群疏散实验

研究了 3 种出口宽度和 4 种桌椅排列条件下教室内的人群疏散过程, 得到了疏散时间的空间分布. 对于双人课桌椅而言, 人们倾向于尽快进入最近的过道. 教室内桌椅的排列形式确定了上游的行人来流, 而出口宽度确定了出口的通行能力, 二者共同决定了教室内人群的疏散时间. 疏散时间并非随着过道数的增加而单调减少. 对于宽度固定的教室, 通常过道数越多, 越有利于疏散, 但过道宽度相应减小, 从两侧进入过道的人员冲突加剧, 又会影响疏散效率. 对于小出口情况, 由于在出口附近形成高密度阻塞区域, 使疏散时间明显增加, 可以通过控制上游的行人来流和减少行人之间的冲突来加快人群的疏散过程.     

延迟线型无线SAW传感器的访问信号

分析了声表面波 (SAW)传感器无线测量时访问信号的宽度对回波及测量的影响。访问系统通过发射访问信号和接收回波并加以处理来获得测量信息。访问信号是一定宽度的高频脉冲 ,回波信号必然在两端存在过渡区。通过分析声表面波的激发和反射 ,给出了回波信号由多个反射差拍叠加的数学描述。计算了过渡区的宽度 ,提出了访问信号宽度必须大于过渡区的宽度并给出了确定公式 ,分析了访问信号的频率对回波信号的影响 ,给出了实测结果。该工作可以为无线声表面波传感器的设计和访问系统参数的确定提供理论依据     

WGD-8A型多功能光栅光谱仪与分辨本领分析

以CCD为探测器,着重讨论和分析了测量系统中光谱仪的狭缝宽度、光栅参数和CCD像素尺寸对系统分辨本领的影响。通过测量低压汞灯的特征光谱,分析不同狭缝宽度对光谱分辨本领的影响。得到以下结论：测量系统分辨本领由狭缝、光栅和CCD三者中分辨本领最低的环节确定;系统的最高分辨本领由光栅或CCD像素尺度决定;系统达到最高分辨本领时可能存在一个最小狭缝宽度。     

多变量可微函数类在L2尺度下的相对宽度

研究了由重拉普拉斯导数及混合导数所确定的多变量可微函数类在L2空间中的相对宽度,确定了该宽度与相应kolmogorov n-宽度相等的条件,同时得到相对宽度的精确常数.     

离散时间疏散模型在建筑出口设计中的应用

针对单元疏散空间的疏散能力问题,提出了单元疏散空间(建筑物只有一个出口)的离散时间疏散模型.模型中考虑了人群密度对疏散能力的影响,改变以往把建筑出口疏散能力视为常数而带来的不能真实反应其疏散能力的状况.结果表明:初始疏散密度确定时,在不同的出口宽度下,C型疏散时间略小于L型疏散时间,这种时间差距随着出口宽度的减小而减小,计算结果与 Simulex 模拟得出的结果近似;建筑物的疏散能力与出口宽度之间呈非线性关系;根据滞留情况,可以确定建筑的最佳出口宽度.模型能够真实地反映出口疏散能力,研究结果可以用于建筑出口的性能化设计.     

机非混行车道最小宽度的研究探讨

道路宽度无法满足划线要求时,需设置机非混行的车道。本文阐述了机非混行车道的断面组成,参考机动车道宽度研究和实际使用的结论给出了确定车道宽度的参数修正,确定了合理的机非混行车道最小宽度值。     

电子变倍对直视型光电成像系统效能的信道宽度评价方法研究

根据信道宽度理论,给出了一种描述电子变倍在直视型光电成像系统中效能的方法,表明电子变倍对于光电成像系统的效能存在最佳值mm,适当的电子变倍可获得更好的成像视觉效果,过大或过小的电子变倍均可能降低视觉效果. 给出了在信道宽度最佳条件下最佳电子变倍值的定量确定方法,计算结果与实际光电成像系统的观察效果基本一致.     

资源约束下加工时间可变的工期窗口指派问题

研究单机排序下加工时间可变的工期窗口指派问题,任务的加工时间是关于所获资源分配量的一个凸函数,同时也考虑了学习、退化效应对任务加工时间的影响,即任务的实际加工时间依赖于该任务的加工位置和开始加工时间以及分配到该任务的资源量。每个任务都有一个独立的工期窗口,但所有任务的工期窗口宽度相同。目标是确定最优的工期窗口开始时间、工期窗口宽度、最优的资源分配量以及最优的任务排序。最小化提前、误工工件惩罚、工期窗口开始时间、工期窗口宽度、资源分配以及最大完工时间的总费用。证明了此问题是多项式时间可解的,并给出了最优算法。     

基于渗流稳定可靠性分析的黄河堤防合理淤背宽度研究

利用可靠性理论对黄河堤防淤背设计的合理宽度问题进行了系统的分析研究,充分考虑了黄河堤防土体参数的随机变异性,研制了蒙特卡洛渗流有限元可靠度程序,用来计算在设计洪水位下距黄河堤防背河坡脚不同距离的地层土体渗流稳定破坏概率,从而确定合理的淤背宽度。研究成果可应用于黄河堤防淤背宽度的设计中,对其它河流堤防的加固设计也有借鉴意义。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the