Advanced Sn/C composite anodes for lithium ion batteries

Metallic tin was deposited in fine particulate form on the surface of carbonaceous mesophase spherules (CMS) and in the pores of porous carbon by the decomposition and reduction of tin(II) 2-ethylhexanoate at 450 °C. The Sn/C composite powders obtained were used as anode materials for lithium ion cells. Electrochemical cycling tests of coin cells show that the dispersion of tin into the carbonaceous materials enhances the reversible capacity of the electrodes. The capacity retention at the 50th cycle is 91 % for Sn/CMS composite containing 22% tin, against 428 mAh g^–1 at the first cycle. With further increase in tin content, the capacity fade upon cycling is more rapid.     

接插件的表面处理

综述了接插件连续镀金、钯、锡的电镀工艺，包括设备、镀液和镀层性质。     

Piezoresistivity in Polymer-Ceramic Composites

Composite materials composed of randomly dispersed semiconducting ceramic particles in an insulating polymer matrix show a pronounced change in resistivity with pressure. Different amounts of iron oxide (Fe₃O₄) powder and antimony-doped tin oxide (SnO₂:Sb) powder were dispersed in an epoxy polymer matrix to form pressure-sensitive composites. In each family of materials, an insulator-to-semiconductor transition is observed in agreement with percolation theory. Composites within a certain range of filler content showed substantial piezoresistive effect under both uniaxial and hydrostatic pressure in which sensitivity is controlled by the choice of filler material and the volume fraction. The effect of temperature on the piezoresistance effect was also examined. Piezoresistors made from Fe₃O₄ composites showed larger temperature changes than those filled with Sb-doped SnO₂.     

热稳定剂二月桂酸二丁基锡合成工艺改进

对新型热稳定剂二月桂酸二丁基锡合成条件进行了研究。根据直接法合成二月桂酸二丁基锡的反应机理,通过改变反应温度、反应时间和配料比,并对实验方法作了一定的改进。当碘丁烷13g,Sn粉3g,四丁基溴化铵0.7g时,反应温度为125～140℃,反应时间为4h,二月桂酸二正丁基锡产量为12.8g,产率为98.8%。分别加入了20mL水和20mL甲烷进行萃取分离后使二月桂酸二正丁基锡最终产率可达到80%以上。     

以SnO/ZnO为催化剂合成油酸正丁酯

研究了以SnO／ZnO为催化剂合成油酸正丁酯，优化的工艺条件为：催化剂中ZnO含量为0．04～0．05，催化剂用量为1．0％（占总投料量质量分数），酸醇投料比n油酸：n丁醇为1：1．6，反应温度140～145℃，反应时间1．0h，产品收率达95％以上，催化剂可重复使用4次，再生容易。     

Enhancement of the electrooxidation of ethanol on a Pt–PEM electrode modified by tin. Part I: Half cell study

The direct platinisation of a solid polymer electrolyte (Nafion^® membrane) was realized by chemical reduction of a platinum salt. The Pt–PEM electrodes thus obtained were modified by tin to improve the electrocatalytic activity towards the electrooxidation of ethanol. The Pt–PEM and Pt–Sn–PEM electrodes were characterized by TEM, EDX and XRD analysis, cyclic voltammetry, and their polarisation curves for the electrooxidation of ethanol were determined under quasisteady state conditions.     

抑制锡须的方法

无铅封装工艺是IC制造商为了顺应电子产品无铅化趋势而发展起来的,但存在晶须生成的潜在威胁。因此,锡须的抑制方法成为研究的关键。对电子集成电路封装行业中常见的9种抑制锡须的方法──避免局部镀纯锡,选择亚光或低应力镀锡,选择适宜的镀层厚度,选择适宜的阻挡层,纯锡镀层表面回流处理,退火处理,避免在纯锡镀层表面进行压负载操作,采用有机涂层或其它金属涂层,采用适宜的电镀添加剂等进行了总结,为IC业无铅电镀提供参考依据。     

酸性镀锡液的新进展

从近几年美国发明专利的角度扼要综述酸性镀锡液的新进展。说明酸性镀锡液由氟硼酸盐型发展为烷基磺酸盐型的改进过程。列出参考文献９篇。     

选择性螯合滴定法测定电镀液中的锡铜铅

提出了测定电镀液中锡铜铅的一个简易快速螯合滴定法.用EDTA螯合锡(Ⅳ)、铜(Ⅱ)、铅(Ⅱ)和其它金属离子,然后分别用三羟基苯甲酸、巯基丁二酸和氨荒丙酸解蔽.释放出的EDTA,用锌标准溶液反滴定(XO-CPB为混合指示剂).终点变化相当敏锐.研究了测定锡、铜、铅时一般共存离子的干扰.此法已被成功地用于测定锡-铜-铅合金电镀液和镀层锡铜铅合金中的锡、铜和铅.     

重铬酸钾滴定法测定甲基磺酸锡中Sn~(2+)和Sn~(4+)的含量

研究了以重铬酸钾间接滴定甲基磺酸锡中Sn2+和Sn4+含量的方法。在6mol/L盐酸中用锌粉把Sn4+还原为Sn2+,加入硫酸铁铵快速氧化Sn2+,硫酸铁铵中的Fe3+被还原为Fe2+。用重铬酸钾滴定Fe2+来间接测定Sn2+和Sn4+含量。方法相对标准偏差为1.65‰,回收率99.98%。该方法简便,快速,结果准确可靠。