不同锂源对尖晶石锰酸锂性能的影响

采用溶胶凝胶法,以氢氧化锂、醋酸锂、硝酸锂为锂源制备锂离子电池正极材料尖晶石LiMn2O4,分别用XRD和SEM对产物的结构和微观形貌进行表征,并对其电化学性能进行了测试。结果表明,用硝酸锂制备的LiMn2O4有较好的的微观形貌及较高的初始比容量,用氢氧化锂制备的LiMn2O4有较好的循环性能。     

Inhibitory effects of black tea theaflavin derivatives on 12-O-tetradecanoylphorbol-13-acetate-induced inflammation and arachidonic acid metabolism in mouse ears

Tea has been shown to possess several health beneficial properties primarily due to its polyphenolic content. The major polyphenolic compounds in black tea leaves are theaflavins (TFs) formed by oxidative coupling of catechins in tea leaves during its processing. In this paper, we report the characterization of 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced mouse ear inflammatory model and the inhibitory effects of major black tea TFs derivatives on this inflammation. In addition, the effect on inflammatory biomarkers, such as proinflammatory cytokines and arachidonic acid metabolites, are reported as well. A single topical application of TPA to ears of CD-1 mice induced a time- and dose-dependent increase in edema as well as formation of proinflammatory cytokine proteins interleukin-1beta (IL-1beta) and interleukin-6 (IL-6) in mouse ears. A single topical application of equimolar of black tea constituents (TF, theaflavin-3-gallate, theaflavin-3'-gallate, and theaflavin-3,3'-digallate) strongly inhibited TPA-induced edema of mouse ears. Application of TFs mixture to mouse ears 20 min prior to each TPA application once a day for 4 days inhibited TPA-induced persistent inflammation, as well as TPA-induced increase in IL-1beta and IL-6 protein levels. TFs also inhibited arachidonic acid (AA) metabolism via both cyclooxygenase (COX) and lipoxygenase pathways. This observation was substantiated by decreased amounts of AA metabolites prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) levels. Combined application of TF and sulindac, a nonsteroidal anti-inflammatory drug resulted a significant synergetic anti-inflammatory effect. Oral administration of TFs or the hot water extract of black tea leaves also significantly inhibited TPA-induced edema in mouse ears. In conclusion, proinflammatory cytokines, IL-1beta and IL-6, as well as the intermediated metabolites of AA, PGE2, and LTB4 are good biomarkers for inflammation. Black tea constituents, TF and its derivatives, had strongly anti-inflammatory activity in vivo which may be due to their ability to inhibit AA metabolism via lipoxygenase and COX pathways.     

碱性脂肪酶在正庚烷中催化合成乙酸乙酯的研究

用碱性脂肪酶在正庚烷中催化合成乙酸乙酯,探讨了加酶量、反应温度和反应时间以及采用不同的碱性脂肪酶等因素对乙酸转化率的影响。研究表明,当乙酸浓度为0.20mol/L、乙酸和乙醇的摩尔比为1∶1.25、摇床转速为150r/min、定时加入一定量的3A分子筛适当移走产物的水分时,最佳反应温度为36℃;产自扩展青霉碱性脂肪酶高产变株FS1884-1的酶A催化效果为最好;当酶A的加入量为0.30g/瓶(相当于碱性脂肪酶的加入量为1700u/g乙酸)、反应时间为48h,乙酸的转化率已基本趋于稳定,转化率达71.4%。     

水溶液型醋酸钴催化剂的工业运用研究

本文介绍了水溶液型醋酸钴催化剂在仪化年产33万t的PTA装置上的试用情况,试用过程中发现催化剂中黑色沉淀物可以抑制PX氧化主反应,促进燃烧副反应,影响产品质量和装置正常操作。     

Miscibility, free volume behavior and properties of blends from cellulose acetate and castor oil-based polyurethane

A series of blend films from cellulose acetate (CA) and castor oil-based polyurethane (PU) were prepared. Morphology, miscibility, free volume behavior and properties of such blend films were investigated by wide-angle X-ray diffraction (WXRD), infrared, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), positron annihilation lifetime spectroscopy (PALS), thermogravimetric analysis and tensile test. The results indicated that lager free volume cavities did not form at the interface of two polymers although a certain degree of phase separation was found by the studies of SEM and DSC. Strong intermolecular hydrogen bonding interactions at the interface, which was proved by Fourier transform infrared spectroscopy, favors even better molecular packing, that is, PU dispersed in CA continuous phase to form fine microphase separation domain in the CA-rich blends. Due to such special interactions in the fine microphase separation domain structure, optimized properties of tensile strength, breaking elongation and cold-resistivity were obtained in the blend film with 75 wt% CA. The toughness of all the blend films was significantly higher than that of the film CA, owing to the plasticizing of PU elastomer in the blends.     

新型耐水性聚醋酸乙烯酯乳液胶粘剂的制备

通过对乳化稳定剂聚乙烯醇缩醛化,以及用醋酸乙烯酯与甲基丙烯酸甲酯乳液共聚和加入松香改性树脂相结合的方法,制得新型聚醋酸乙烯酯乳液胶粘剂。经实验确定的最佳反应条件为：m（醋酸乙烯酯）：m(松香改性树脂）;m(甲基丙烯酸甲酯）＝1．0：0．12：0．06,反应温度75℃,反应时间3－4h,实验结果表明：该胶粘剂粘接强度和耐水性良好。     

乙酸异戊酯合成研究进展

综述了采用对甲苯磺酸、氨基磺酸、对氨基苯磺酸、Hβ型沸石、FeY、8种无机盐、铌酸、杂多酸和阳离子交换树脂等催化剂合成乙酸异戊酯的方法。阐述了在上述催化剂作用下的反应条件、催化剂的性质以及合成工艺的特点 ,列举了各催化剂在产率、反应时间、后处理工艺、是否可重复使用、带水剂以及是否易于保存和使用等方面所具有的优势 ,指出不加带水剂、前馏分的回用问题和高效催化剂的固载化是今后的研究方向     

双向可逆形状记忆乙烯⁃醋酸乙烯酯共聚物的制备和性能研究

以乙烯⁃醋酸乙烯酯共聚物（EVA）为原料,过氧化2⁃乙基己基叔丁酯（TBPE）为交联剂,合成了交联EVA双向形状记忆聚合物（SMP）,并且考察了TBPE含量对于交联EVA性能的影响。结果表明,交联EVA的T_m和T_c随着TBPE含量的上升呈现下降的趋势,可以通过交联剂比例调节材料的驱动温度;交联EVA的形状固定率会随着TBPE含量的增加呈现下降趋势,最低达到88.83 %,而样品的形状恢复率均超过99 %,并且都具有单向和双向形状记忆功能;交联EVA也具有双向记忆性能,R_a,_2W随着TBEC的含量增大而减小,R_r,_2W则相反;因此,通过改变交联剂EVA的量,对于双向交联EVA的性能有较大影响。     

新型聚醋酸乙烯乳液的研究进展

总结了普通聚醋酸乙烯乳液胶粘剂的缺点及其原因,综述了当前改性聚醋酸乙烯乳液胶粘剂的研究进展.     

Comparative analysis of sex-pheromone-response antagonists in three races of European corn borer

Behavioral responses of males from three New York races of European corn borer,Ostrinia nubilalis (Hübner), to various suspected sexpheromone-response antagonists were investigated with a flight tunnel protocol. Males from a bivoltine (Z) race and from a univoltine (Z) race utilizing a natural pheromone blend of 982 (Z)-(E)-11-tetradecenyl acetates and males from a bivoltine (E) race utilizing a 199 (Z)-(E)-11-tetradecenyl acetate ratio were flown to their natural blends and to blends containing 1 % of one of the following additional compounds: Z9–12OAc,E9–12OAc,Z9–14OAc, andE9–14OAc. In each race, the added components lowered significantly the number of individuals completing the behavioral sequence. The only exception was bivoltineE males flown to a blend withE9–12OAc added. The number completing the sequence in this case was statistically not significantly lower than the number that completed the sequence to the standard blend. In all three races, theZ9–14OAc produced the most dramatic reduction in completed flights, and in the univoltineZ race, this added component was significantly more effective in reducing completed flights than any other added component. The response to the Z9–14OAc is understandable given recently published findings of an electrophysiological study of single sensilla in the European corn borer.