Focusing particles by induced charge electrokinetic flow in a microchannel

A novel method of sheathless particle focusing by induced charge electrokinetic flow in a microchannel is presented in this paper. By placing a pair of metal plates on the opposite walls of the channel and applying an electrical field, particle focusing is achieved due to the two pairs of vortex that constrain the flow of the particle solution. As an example, the trajectories of particles under different electrical fields with only one metal plate on one side channel wall were numerically simulated and experimentally validated. Other flow focusing effects, such as the focused width ratio (focused width/channel width) and length ratio (focused length/half‐length of metal plate) of the sample solution, were also numerically studied. The results show that the particle firstly passes through the gaps between the upstream vortices and the channel walls. Afterwards, the particle is focused to pass through the gap between the two downstream vortices that determine the focused particle position. Numerical simulations show that the focused particle stream becomes thin with the increases in the applied electrical field and the length of the metal plates. As regards to the focused length ratio of the focused stream, however, it slightly increases with the increase in the applied electrical field and almost keeps constant with the increase in the length of the metal plate. The size of the focused sample solution, therefore, can be easily adjusted by controlling the applied electrical field and the sizes of the metal plates.     

Stable local cohomology

For a module having a complete injective resolution, we define a stable version of local cohomology. This gives a functor to the stable category of Gorenstein injective modules. We show that in many ways this functor behaves like the usual local cohomology functor. Our main result is that when there is only one nonzero local cohomology module, there is a strong connection between that module and the stable local cohomology module; in fact, the latter gives a Gorenstein injective approximation of the former.     

基于机器人制样和激光诱导击穿光谱分析技术的选煤厂检测系统无人化

目前选煤厂煤质检测过程自动化程度低,采样与制样技术需要大量的人工参与。检测技术的落后直接影响数据的准确性从而对整个选煤厂生产过程控制与产品质量控制产生重要影响,直接关系选煤厂的经济效益。面对产业升级的需要,将先进的自动采制样技术引进煤炭生产经营企业是当务之急。机器人采制样系统包含:机械化采样与初制样技术、机器人精细化制样技术、煤炭快速检测技术、自动快速浮沉技术,为选煤厂提供了一种全自动采制检的新技术方案。     

Mesomorphic Characteristics of Induced Chiral Nematic Phase of [Smectic LCP,PS(4BC/DM)/Nematic LC,E7/Chiral Dopant,CB-15]-Ternary Composite System

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On complete congruence lattices of join-infinite distributive lattices

In [5] G. Gr?tzer and E. T. Schmidt raised the problem of characterizing the complete congruence lattices of complete lattices satisfying the Join-Infinite Distributive Identity (JID) and the Meet-Infinite Distributive Identity (MID) and proved the theorem: Any complete lattice with more than two elements and with a meet-irreducible zero cannot be represented as the lattice of complete congruence relations of a complete lattice satisfying the (JID) and (MID). In this note we generalize this result by showing that the complete congruence lattice of every complete lattice satisfying (JID) and (MID) is a zero-dimensional complete lattice satisfying (JID). Some consequences are discussed. Received March 6, 2000; accepted in final form September 12, 2000.     

Density functional theory and quadratic complete basis set ab initio studies of the HNSi to HSiN isomerization and hydrogen insertion reactions with further isomerizations of the insertion products

Ab initio and density functional theory (DFT) computational studies were performed in order to determine the potential energy profiles for the inter-conversions of the small silicon–nitrogen built chemical systems: HSiN, HNSi, HSiNH₂, and HNSiH₂. Three hybrid DFT methods demonstrated high reliability in computing structures and potential energy profiles for these chemical transformations. The stability of some of these molecular systems and their interconversions was discussed and computational results were compared with experimental observations when available.     

图的匹配设计的矩阵构造法

完全图Ｋ_ｎ（完全二部图Ｋ_ｎ,ｎ）的一个ｋ－匹配的集合Ｍ,若满足：Ｋ_ｎ（Ｋ_ｎ,ｎ）的每一对独立边恰出现在Ｍ的λ个元素中,则称Ｍ为一个匹配设计,记为ＭＡＴＣＨ（ｎ,ｋ,λ）（ＢＩＭＡＴＣＨ（ｎ;ｋ,λ））一设计．本文定义两个匹配设计对应的矩阵,并以此构造出某些新的匹配设计．     

模糊赋范线性空间的紧性与完备性

讨论了Fuzzy赋范线性中准紧集、完备集及有界集间的关系;给出完备Fuzzy赋范空间的闭球套定理与Baire定理;刻画了了有限维Fuzzy赋范空间的特征。     

质量控制中完全检验的一种最优设计

本文提出质量控制中完全检验的一种最优设计。所谓完全检验 ,也就是 1 0 0 %检验 ,是指生产出来的每一个产品都要经过检验。生产过程中有两种生产状态 :控制状态和失控状态。当一个产品的质量特征值超过预定的控制界限 ,就立即对生产过程进行检查 ,一旦发现生产失控 ,马上采取调整措施使生产恢复正常。检验后的产品按其质量特征值接受或者重新制作。根据本文所建立的质量成本模型 ,我们可以得到最优的产品质量的规格界限和控制界限 ,对实际企业的生产有积极的指导作用。     

Super-Magic Complete k-Partite Hypergraphs

 We deal with complete k-partite hypergraphs and we show that for all k≥2 and n≠2,6 its hyperedges can be labeled by consecutive integers 1,2,…,n ^k such that the sum of labels of the hyperedges incident to (k−1) particular vertices is the same for all (k−1)-tuples of vertices from (k−1) independent sets. Received: December 8, 1997 Final version received: July 26, 1999