如何选择不同类型的锂原电池

在过去１０年内，不可充电的锂电池（原电池）已成为主电源和备用电源通常使用的碳锌电池、碱性电池和其他商用电池的优良替代物。锂电池．不管是锂氯化亚硫酸电池，还是锂二氧化硫电池或锂二氧化锰电池，都具有异常宽的工作特性。这些特性使得锂电池特别适合用作各种需要放电率低且能可靠地工作好几年的不同备用电源。锂电池还非常适用于以下一些场合：需要适中的或很高的连续供电或变化很大的中间脉冲供电场合；要求每个电池有很高工作电压的场合；以及从平坦的放电特性中得到好处的场合。如果您需要优异的能量密度，需要电池在很宽的工作…     

Exact Solution of an Extended Hubbard Model with Electron—Lattice Interaction for an Organic Ferromagnetic Polymer

Using an exact diagonalization method,we study an extended Hubbard model with an electron-lattice interaction for an organic ferromagnetic chain with radical coupling.The result shows that the ferromagnetic ground state originates from the antiferromagnetic correlation between adjoining sites,which is enhanced by the on-site e-e repulsion.The intersite e-e repulsion induces the inhomogeneous distribution of the charge density.The dimerization is decreased by the e-e interaction and the radical coupling.The electron-lattice interaction and the radical coupling can transfer the spin density and charge density between the main chain and the radicals.     

两亲性嵌段聚合物的同步辐射小角x射线散射研究

应用同步辐射小角x射线散射(SAXS)方法研究了不同聚合条件下苯乙烯对乙烯基苯甲酸两亲性嵌段聚合物的聚集行为,结果发现该聚合物在选择性溶液中自组装形成胶束.胶束的形态和结构取决于嵌段聚合物的组成、浓度以及溶剂的性质等因素 关键词： 小角x射线散射 两亲性嵌段聚合物 分形维数 粒径     

名厂风范 MOTOROKR EQ7蓝牙音箱

MOTO EQ7是摩托罗拉与音响大厂JBL合作推出的桌面型蓝牙音箱,强调音质和便携性能。EQ7为比较少见的飞碟造型。采用最常见的3.5mm音源输入孔,可以为它接上iPod、电脑、笔记本电脑或是手机来播放音乐,应用空间很宽广。EQ7底部有电池槽,使用两节AA电池即可     

Self-assembly behaviour of amphiphilic diblock copolymer in selective solvents studied by synchrotron small-angle x-ray scattering

The aggregation behaviour of styrene-vinyl benzoic acid (PSm-b-PVBAn) amphiphilic diblock copolymers in selective solvents with different m and n was investigated by synchrotron small-angle x-ray scattering (SAXS). We have carried out a detailed analysis of scattering intensity, dimension, shape and microstructure of the diblock copolymers of narrow distribution in water, methanol, ethanol and isopropanol selective solvents, respectively. We have found that the aggregation behaviour of the copolymer depends on the nature of the solvent and the micelle forms fiat disc objects with the ratio of radius ω=0.4. The average radius gyration Rg of the copolymer decreases as solvents change from isopropanol to ethanol and to methanol, and increases with increasing pH in aqueous solution, but decreases with the addition of COCl2 in ethanol solvent. The scattering intensity of diblock copolymer micelle follows I(h) ∝ h^-α in different selective solutions, suggesting that the PSm-b-PVBAn coils have self-similar structure behaviour or a fractal structure in the selective solvents. All of these revealed that the aggregation behaviour of the diblock copolymer changes dramatically with experimental condition in the selective solvent. The increase of mass fractal dimension (Dm) from 2.12 to 2.47 indicates that the copolymer chain changes from a swollen coil to a rather compact disc in the course of changing solvents, decreasing surface fractal dimension (Ds) from 2.98 to 2.58 indicates that the copolymer micelle change from a rather rough surface to a smooth form in the course of increasing pH in aqueous solutions, and increasing Dm and Ds from 2.29 to 2.35 and 2.70 to 2.90, respectively, indicates the shrinkage of copolymer micelle to a rather compact and rough disc form by adding COCl2 in ethanol solvents.     

七星华创电池设备新产品硕果累累

北京七星华创电子股份有限公司从1997年小批量进入二次电池（可充电电池）生产制造设备领域以来，始终保持国内技术领先，市场份额逐年扩大。近五年内，七星华创二次电池设备销售额平均每年增长在100％以上，已经成为国内最大、品种系列最全、配套能力最强的二次电池专用设备制造商。七星华创根据市场发展需要，加大开发力度，又开发出新型双辊轧膜机和卷绕机系列产品。     

中空光纤技术与应用特性

介绍一种采用环烯烃聚合物镀膜的中空光纤结构，阐述其传输特性，说明其使用特点，指出它在工业和医疗等领域中的应用前景。