Effects of coagulation bath temperature on structure and performance of poly （vinyl butyral） hollow fiber membranes via thermally induced phase separation

Poly （vinyl butyral） （PVB） hollow fiber membranes were fabricated via thermally induced phase separation （TIPS）. The effects of coagulation bath temperature （CBT） on the structure and performance of membranes were investigated in detail. The morphologies of the membranes were studied by scanning electron microscopy （SEM）, the performances of water permeability, rejection, breaking strength and elongation were measured, respectively. The results indicate that all the membranes have the asymmetric morphology and the thickness of the skin layer decreases and the pore size of the outer layer increases with the increase of CBT. The permeability of membranes prepared at air gap 1.0 cm and take-up speed 0.253 m/s increases from 1.047×10-7 to 5.909×10-7 m3/（m2·s-kPa） with the CBT increasing from 20 ℃ to 40℃, and sharply increases to 35.226×10 7 m3/（m2.s.kPa）once the CBT arrives at 50 ℃. While the carbonic ink rejections have no significant decrease, totally exceed 98%, but that of acid-maleic acid copolymer greatly decreases with the increase of CBT. Both the breaking strength and elongation decrease with the increase of CBT.     

铜离子印迹改性壳聚糖海绵的制备及应用研究

以醋酸铜为模板,甲醇、氯仿为溶剂,2-乙烯吡啶、丙烯酰胺为功能单体,乙二醇二甲基丙烯酸酯为交联剂,采用本体聚合法制备铜离子印迹聚合物;然后掺入到壳聚糖海绵的制备中,使壳聚糖海绵对铜离子的吸附率由27．1％提高到72．3％。制备的铜离子印迹改性壳聚糖海绵需要2d达到吸附平衡,吸附-解吸5次后,性能稳定。     

用双层辉光等离子法在钛表面制备的Ti-Pd合金层性能研究

采用双层辉光等离子冶金技术在纯钛表面制备了Ti—Pd合金层。其深度大约为90μm，Pd含量呈梯度变化，并出现了TiPd3，TiPd2，Ti2Pd3，Ti3Pd5，TiPd，Ti4Pd等6种化合物相和Pd相。合金层在100℃的NaCl饱和溶液＋HCl溶液以及40℃的8．6％H2SO4溶液中的耐缝隙腐蚀性能优于Ti0．2Pd合金；在室温80％H2SO4的溶液中，腐蚀速率仅为0．682mm／a，是Ti0．2Pd合金的18．2％：在室温30％HCl的溶液中，表面Ti—Pd的腐蚀速率仅为0．004mm／a，是Ti0．2Pd合金的12．5％。     

THERMODYNAMICS AND PHASE EQUILIBRIUM OF Cu－Y－O，Cu－Y－S，Cu－Y－O－S LIQUID SOLUTIONS

ＴＨＥＲＭＯＤＹＮＡＭＩＣＳＡＮＤＰＨＡＳＥＥＱＵＩＬＩＢＲＩＵＭＯＦＣｕ－Ｙ－Ｏ，Ｃｕ－Ｙ－Ｓ，Ｃｕ－Ｙ－Ｏ－ＳＬＩＱＵＩＤＳＯＬＵＴＩＯＮＳ￥Ｄｕ，Ｔｉｎｇ；Ｌｉ，Ｇｕｏｄｏｎｇ（ＣｅｎｔｒａｌＩｒｏｎａｎｄＳｔｅｅｌＲｅｓｅａｒｃｈｉｎｓｔｉｔ...     

机械镀锌过程中先导金属的研究

通过多次试验观察，借助于扫描电子显微镜，结合物理化学、电化学的基础理论知识，对机械镀锌过程中先导金属进行了研究。分析了先导金属在镀层中的分布以及先导金属对机械镀锌形层过程的影响。结果表明机械镀锌过程中的确有先导金属存在，在机械镀锌过程的不同阶段，有着不同的金属起着先导金属的作用。先导金属可以促进机械镀锌镀层的结合强度。     

隔直电容在弧焊逆变器中抗偏磁能力的分析

本文采用状态平均法建立了隔直电容在知式焊接逆变器中抗偏磁的动态模型，并进行了动态分析，为焊接逆变器的设计提供了理论依据。     

接收方预约信道的水声传感器网络MAC协议

为了获得更高的网络吞吐量,更低的端到端时延,设计出了一种适用于分簇网络的水声传感器网络MAC协议,该协议采用接收方建立握手机制,有效的获取邻居节点通信时的状态,动态分配发送时隙,实现数据包以报文序列方式无冲突的到达接收端.仿真结果表明,与同类MAC协议(FERI, RIPT)相比,该协议提高了网络吞吐量,降低了数据丢失率和端到端时延.     

Bounds on multipartite concurrence and tangle

We present an analytical lower bound of multipartite concurrence based on the generalized Bloch representations of density matrices. It is shown that the lower bound can be used as an effective entanglement witness of genuine multipartite entanglement. Tight lower and upper bounds for multipartite tangles are also derived. Since the lower bounds depend on just part of the correlation tensors, the result is experimentally feasible.     

Generalized incremental frequency method for topological designof continuum structures for minimum dynamic compliance subject to forced vibration at a prescribed low or high value of the excitation frequency

The application of multidisciplinary design optimisation is mostly confined to bi-disciplinary systems such as fluid-structure interaction problems. High fidelity models of three disciplines involving electromagnetic-thermal-structural designs are rare. Here, the multidisciplinary optimisation of such a design is presented. The device comprises a C-shaped iron core and a single coil. The problem is decomposed using a monolithic multidisciplinary feasible architecture. The multidisciplinary analyses involve a single three-dimensional finite element mesh for transient non-linear electromagnetic, non-linear-static thermal, and linear-static structural models. During each multidisciplinary iteration the mesh is linearly morphed. A gradient based optimisation algorithm in combination with a multi-start routine is applied to the constrained mass minimisation problem. Multidisciplinary feasibility is ensured by convergence of a single coupling parameter i.e. air-gap deformation. In conclusion, some multidisciplinary optimisation, analyses, and decomposition considerations are discussed.     

信息安全策略实施困难的原因与对策分析

随着企业生产规模的扩大,其所掌控的资产也越来越多。信息作为企业重要的资产,其安全性正得到越来越多的企业的关注,很多企业为了保证自身信息的安全与保密性,也制订了自身的信息安全策略。然而,很多企业的信息安全策略常常形同虚设,没有发挥其应有的作用,甚至存在着严重的漏洞,为企业的健康发展埋下了不小的隐患。笔者结合自身多年的工作经验,就企业信息安全策略实施过程中存在的问题进行分析,并针对性的提出几点对策,希望对相关人士能有所帮助。