Improving the properties of HDPE based separators for lithium ion batteries by blending block with copolymer PE-b-PEG

To improve the performances of HDPE-based separators, polyether chains were incorporated into HDPE membranes by blending with poly(ethylene-block-ethylene glycol) (PE-b-PEG) via thermally induced phase separation (TIPS) process. By measuring the composition, morphology, crystallinity, ion conductivity, etc, the influence of PE-b-PEG on structures and properties of the blend separator were investigated. It was found that the incorporated PEG chains yielded higher surface energy for HDPE separator and improved affinity to liquid electrolyte. Thus, the stability of liquid electrolyte trapped in separator was increased while the interfacial resistance between separator and electrode was reduced effectively. The ionic conductivity of liquid electrolyte soaked separator could reach 1.28 × 10-3 S.cm-1 at 25℃, and the electrochemical stability window was up to 4.5 V (versus Li + /Li). These results revealed that blending PE-b-PEG into porous HDPE membranes could efficiently improve the performances of PE separators for lithium batteries.     

Micromegas prototypes with thermo-bond film separators

In this paper we report the results of Micromegas prototypes constructed by attaching micromesh to an anode using thermo-bond films. The excellent metal attaching ability and good dielectical property of this kind of film make it a promising material to be used as avalanche gap spacers. Several prototypes are successfully made. The electron transmission properties are first studied and then the gas gain is measured in argon-isobutane mixtures. The maximum gain of more than 104 is easily obtained. The energy resolutions for 55Fe 5.9 keV Kα ray can be better than 20% over one magnitude in gain for different operational gas mixtures and the best energy resolution of 13.7% (FWHM) can be achieved with the gas mixture of 94% argon concentration. The preliminary test results of the prototypes with sensitive area of 45 mm×45 mm without internal support show good uniformity across the sensitive area.     

多功能锂硫电池隔膜

锂硫电池具有远超锂离子电池的高理论比容量（1675 mAh ·g^-1）,并且兼具硫资源丰富、生产成本低廉以及环境友好等优势。然而,多硫离子的穿梭效应造成金属锂负极钝化、引起电池容量和库仑效率下降、循环稳定性变差等严重问题,限制锂硫电池的实际应用。从正极和负极之间的隔膜层出发,引入多硫离子穿梭的阻挡层被认为是极为有效的研究策略。这些研究策略在缓解多硫离子穿梭、提高活性物质利用效率、延长循环寿命和循环稳定性方面具有显著效果。本文分类综述了近年来锂硫电池隔膜功能化的研究进展,并对未来隔膜功能化的研究趋势进行了预测。     

在线同位素分离器中空阴极靶离子源

本文描述兰州中国科学院近代物理研究所的在线同位素分离器中空气阴极靶离子源的设计原理、结构和特性。对Ar和Xe的调试结果。分离器的分辨本领达到700-1200。满足高分辨的要求。     

On the Cayley-Bacharach Property

The Cayley-Bacharach Property (CBP), which has been classically stated as a property of a finite set of points in an affine or projective space, is extended to arbitrary 0-dimensional affine algebras over arbitrary base fields. We present characterizations and explicit algorithms for checking the CBP directly, via the canonical module, and in combination with the property of being a locally Gorenstein ring. Moreover, we characterize strict Gorenstein rings by the CBP and the symmetry of their affine Hilbert function, as well as by the strict CBP and the last difference of their affine Hilbert function.     

Engineering quadrupole magnetic flow sorting for the isolation of pancreatic islets

Quadrupole magnetic flow sorting (QMS) is being adapted from the separation of suspensions of single cells (<15 μm) to the isolation of pancreatic islets (150–350 μm) for transplant. To achieve this goal, the critical QMS components have been modeled and engineered to optimize the separation process. A flow channel has been designed, manufactured, and tested. The quadrupole magnet assembly has been designed and verified by finite element analysis. Pumps have been selected and verified by test. Test data generated from the pumps and flow channel demonstrate that the fabricated channel and peristaltic pumps fulfill the requirements of successful QMS separation.     

k圈图的最大Laplace分离度

设$ G $是一个$ n $阶$ k $圈图, $ k $圈图为边数等于顶点数加$ k-1 $的简单连通图。$ \mu_{1}(G) $、$ \mu_{2}(G) $分别记为图$ G $的Laplace矩阵的最大特征值和次大特征值, 图$ G $的Laplace分离度定义为$ S_{L}(G)=\mu_{1}(G)-\mu_{2}(G) $。本文研究了给定阶数的$ k $圈图的最大Laplace分离度, 并刻画了相应的极图, 其结果推广了已有当$ k=1, 2, 3 $时的结论。     

Modeling liquid-liquid interface level in a horizontal three-phase separator with a bucket and weir

The flow behavior in a three-phase separator with a bucket and weir was analyzed, and a theoretical equation for calculating the liquid-liquid interface level (H_H) in gravity separation zone was derived. The analysis indicates that the H_H increases as the flow rate and the density ratio of heavy to light liquid increase, and decreases linearly with increasing height difference between heavy and light liquid overflow weirs. The calculated H_H under different operating conditions is in good agreement with the experimental. With the proposed equation, the thicknesses of heavy and light liquid layers can be calculated, and then the minimum lengths of two phase layers required for separation can be determined separately. From the minimum lengths it can be clearly indicated that the governing step of liquid-liquid separation is in heavy or light liquid layers, hence the sizing of the separator can be optimized.     

Influence of Discrete Particle Diameter and Separating Velocity on the Separation Efficiency of Wave-Plate Separator Including Coalescence and Breakup Model

Wave-plate separators are widely used to remove fine liquid droplet entrained in gas flow based on the inertia force difference of gas and liquid phase. The CFD method is adopted to simulate the separating process of wave-plate separator, the models and parameters used in the simulation were verified through comparing with the experimental data. It is validated that including the droplet coalescence and breakup model, which take place during the separating process, can depict the separating process better. The results indicate that the separation efficiency of wave-plate separator presents two peaks with the increasing of the separating velocity, the first peak is caused by gravity and the second peak is formed for the inertia separation, whereas with the increasing of the droplet diameter, the two peaks are no longer distinct. In addition, the separation efficiency is changed little with droplet diameter variation if the wave-plate separator is worked on the corresponding velocities of the two peaks, and changed a lot at other velocity. Researching results about droplet breakup also showed that only large diameter droplet will break up at lower flow velocity, and the droplet breakup diameter became smaller and smaller with the increasing of the flowing velocity.