Synthesis of Ionic Ultramicroporous Polymers for Selective Separation of Acetylene from Ethylene

The design of highly stable and efficient porous materials is essential for developing breakthrough hydrocarbon separation methods based on physisorption to replace currently used energy-intensive distillation/absorption technologies. Efforts to develop advanced porous materials such as zeolites, coordination frameworks, and organic polymers have met with limited success. Here, a new class of ionic ultramicroporous polymers (IUPs) with high-density inorganic anions and narrowly distributed ultramicroporosity is reported, which are synthesized by a facile free-radical polymerization using branched and amphiphilic ionic compounds as reactive monomers. A covalent and ionic dual-crosslinking strategy is proposed to manipulate the pore structure of amorphous polymers at the ultramicroporous scale. The IUPs exhibit exceptional selectivity (286.1–474.4) for separating acetylene from ethylene along with high thermal and water stability, collaboratively demonstrated by gas adsorption isotherms and experimental breakthrough curves. Modeling studies unveil the specific binding sites for acetylene capture as well as the interconnected ultramicroporosity for size sieving. The porosity-engineering protocol used in this work can also be extended to the design of other ultramicroporous materials for the challenging separation of other key gas constituents.     

油库发油过程中的HSE管理

叙述了石油库在发油过程中的HSE管理；发油过程中的危害识别，包括识别范围和内容；发油过程中风险评价的常用基本方法和常见问题；发油过程中危险源的管理控制，包括建立危险源网络图、加强现场监控和制定应急预案。     

A note on the Gauss-Jacobi quadrature formulae for singular integral equations of the second kind

A fast and efficient numerical method based on the Gauss-Jacobi quadrature is described that is suitable for solving Fredholm singular integral equations of the second kind that are frequently encountered in fracture and contact mechanics. Here we concentrate on the case when the unknown function is singular at both ends of the interval. Quadrature formulae involve fixed nodal points and provide exact results for polynomials of degree 2n − 1, where n is the number of nodes. Finally, an application of the method to a plane problem involving complete contact is presented.     

乙烯基硅氧烷改性苯丙乳液的研究

在苯乙烯 -丙烯酸酯乳液共聚反应后期 ,加入少量乙烯基硅氧烷 ,制得改性苯丙乳液 ,通过红外光谱初步确定了聚合物结构。研究了反应温度、反应时间、有机硅加入方式、乳化剂用量等因素对反应进程、乳液稳定性及涂膜性能的影响。     

Behaviour of Hydrogen in Nano-transition Metals

Nanocrystalline transition metals were prepared with Ar+H2 arc plasma method. The hydrogenmust be used during preparation to get a special nanrvparticles. The hydrogen plays an importantrole in the structure and state of nanocrystalline transition metals. The state of hydrogen andthe change of the nanocrystalline metal structure caused by hydrogen are called the behaviour ofhydrogen in nano-transition metals which includes the ability and function of storing hydrogenin the metals.     

磷脂产品的常用法规、术语、指标

介绍了有关组织对磷脂的法规、术语、指标及意义.     

静电驱动悬臂梁数模转换器设计、分析与模拟

提出了一种新型的微电子机械数模转换器 (MEMDAC)———静电驱动悬臂梁数模转换器 .与传统的静电驱动悬臂梁执行器相比 ,新的结构能更精确地控制梁的挠度 .文中给出了此MEMDAC的设计、分析和模拟过程 .有限元(FEA)分析表明此MEMDAC的最大输出位移为 1 5 1μm ,分辨率为 0 1μm ,其最大非线性误差为 0 0 3μm .     

Viscoelastic properties of polyarylene ether nitriles/thermotropic liquid crystalline polymer blend

Polyarylene ether nitriles (PEN)/thermotropic liquid crystalline polymer (TLCP) blend was prepared via melt mixing. The immiscible phase morphologies, linear and nonlinear, as well as transient viscoelastic properties of the blend were studied using SEM, rheometer, and DMA. The linear dynamic viscoelastic behavior of the blend shows temperature dependence due to further evolution of the immiscible morphology and, as a result, the principle of time‐temperature superposition (TTS) is invalid. In the steady shear flow, the discrete TLCP phase is difficult to be broken up because of the high viscosity ratio of the blend systems, while is easy to be coarsened and followed by elongation, and finally, to form fibrous morphology at high TLCP content and high shear level. During this morphological evolution process, the transient stress response presents step increase and nonzero residual relaxation behavior, leading to increase of the dynamic viscoelastic responses after steady preshear. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Mining diversity on social media networks

The fast development of multimedia technology and increasing availability of network bandwidth has given rise to an abundance of network data as a result of all the ever-booming social media and social websites in recent years, e.g., Flickr, Youtube, MySpace, Facebook, etc. Social network analysis has therefore become a critical problem attracting enthusiasm from both academia and industry. However, an important measure that captures a participant’s diversity in the network has been largely neglected in previous studies. Namely, diversity characterizes how diverse a given node connects with its peers. In this paper, we give a comprehensive study of this concept. We first lay out two criteria that capture the semantic meaning of diversity, and then propose a compliant definition which is simple enough to embed the idea. Based on the approach, we can measure not only a user’s sociality and interest diversity but also a social media’s user diversity. An efficient top-k diversity ranking algorithm is developed for computation on dynamic networks. Experiments on both synthetic and real social media datasets give interesting results, where individual nodes identified with high diversities are intuitive.