萘降解菌LHJ38生物合成靛蓝的研究

萘降解菌LHJ38在金属盐培养基中加入水杨酸钠诱导培养后能提高其生物合成靛蓝的能力,在LB培养基中加入水杨酸钠反而抑制了其生物合成靛蓝的能力.与LHJ38最适生长pH值不同,LHJ38生物合成靛蓝的最佳pH值范围是8.45—9.45,在pH为8.95的情况下生物合成靛蓝能力是其在pH值为6.95的情况下的两倍.     

测定水性聚氨酯树脂平均相对分子质量及其分布的高效凝胶渗透色谱法

选用HP PL gel MIXED-B柱双柱串联，四氢呋喃作流动相，紫外吸收检测器测定了水性聚氨酯树脂的平均相对分子质量及其分布；通过一系列的条件试验，确定了最佳的凝胶色谱（GPC）条件，结果令人满意；该研究有助于了解水性聚氨酯树脂性能，有效地指导工艺生产和基础研究。     

Study on the Thermodynamic Stabilities of Te-Substituted Di-n-butyltellurium Ylide

SincethediscoveryofphosphoniumylidebyWittig',carbanionsstabilizedbyadjacentfifthorsixthgrouponiumionshavebeendevelopedasavaluablereactiveintermediate.However,despitethegreateffortsinylidechemistryinthepastfewdecades',relativelylittleisknownaboutthethermodynamicstabilitiesofylidecarbanions.Itiswellknowthatthequantitativemeasuresofthecarbanionstabilityhavecontributedagreatdealtothedevelopmentoforganicchemistry,thereforeitshouldbeexpectedthattheknowledgeaboutylidestabilitywillalsoprovidavaluableg…     

MALDI-TOF-MS法对重组人内皮抑素蛋白分子质量测定

肿瘤的生长依赖于血管的生成,新生血管不仅为肿瘤生长提供必需的营养物质,而且为肿瘤细胞扩散提供了重要的途径。1997年哈佛大学的O'Reilly等发现了一种内源性新血管生成抑制因子内皮抑素(Endoscatin),显示出特异抑制激活的血管内皮细胞增殖和肿瘤新血管生成的生物学活性,其抗肿瘤作用具有高效、低毒、无耐药性的优点。目前,内皮抑素的研究引起了国内外广泛的兴趣,在美国已进行以安全性为目的的I期临床实验,国内也有多家公司对内皮抑素进行了抗肿瘤研究并申报一类新药。内皮抑素有望成为医治肿瘤而又没有化疗和放疗的毒副作用的一种新的治疗方法,但是否能作为药物应用于临床,尚需对内皮抑素的结构特点及抑制肿瘤和内皮细胞的作用机制等方面进行许多深入的研究。     

基于SnO2为修饰层的Au-Pt / SnO2 / Au复合电极研究

用真空镀膜法在Au电极上沉积SnO₂薄膜，在HAuCl₄和H₂PtCl₄的混合溶液中利用直接还原法，将Au-Pt双金属纳米颗粒组装在SnO₂ / Au电极上，得到Au-Pt / SnO₂ / Au复合电极。采用SEM、TEM、XPS及CV曲线测定对Au-Pt / SnO₂ / Au复合电极进行了表征。结果表明:复合电极上双金属纳米颗粒分布均匀，粒子粒径约为25 nm左右。SnO₂作为修饰层以配位键与双金属纳米粒子结合。Au-Pt / SnO₂ / Au复合电极具有良好对甲醇氧化的电化学性能。     

Pt碘乙二胺配合物的DFT和DV-Xα研究

利用密度泛函DFT/LANL2DZ和DV-Xα，对两种Pt(IV)碘配合物trans，cis-[Pt (OAc)_2I_2(en)] (A)，trans，cis-[Pt(OH)_2I_2(en)] (B)及它们的光照产物 [Pt(OAc)_2(OH)I(en)] (C)，[Pt(OH)_3I(en)] (D)完成了几何优化；计算了配合 物能级、光谱、前线轨道组成、电荷布居等性质。计算结果能解释有关的实验现象 。     

WATER STATES IN SBR BASED WATER SWELLING RUBBER

Water swelling rubber (WSR) was prepared by reaction blending SBR andsodium polyacrylate (PAANa). The existing states of water in the WSR was studied bymeans of DSC and TG. It was found that water exists in three states: nonfreezing water,bound freezable water and free water. The relationships between water states and structureof PAANa were investigated. The results showed that the amount of non-freezing waterwas related to total water content, and the ratio of non-freezing water versus -COONagroups on PAANa (mol/mol) was about 4. However, total water content slightly affectedthe content of bound freezable water and remarkably affected the amount of free waer.     

Studies on Natural CXN Zeolite： Modification, Framework De-alumination and Ion-exchange

A natural CXN zeolite (stilbite, type code-STI) discovered in China was modified with NH4^ exchange by using ammonium salt and calcinations (procedure Ⅰ), or with NH4 exchange followed by treatment with acid (procedure Ⅱ). The coordination state of Si and A1 atoms in the framework, the property of ion exchange, and the adsorption of the H-STI zeolite samples prepared by different modification procedure were investigated with XRD,EDX,^29Si and ^27Al MAS NMR, Ag^ ion exchange and Ne adsorption. The results of the investigations indicate that different procedure of the modification made variety on the distribution of the framework Si atoms and A1 atoms,the content of non-framework aluminum, and the blocking channels and the shielding effect to the positions of the exchangeable cations. The H-STI zeolite prepared by the procedure Ⅱ possesses high ion exchange capacity, open and perfect pore system, and high thermal stability.     

非理想状态下的塔板理论模型

 在过程中 ,将流动相看成是由许多连续的塔板组成 ,每一塔板的高度与固定相塔板的高度相同。初始浓度的溶质被认为全部集中在流动相的第一塔板中 ;溶质在流动相和固定相之间动态分布。由于动力学因素的影响 ,当流动相流过一个塔板距离时 ,溶质不能够迅速地从固定相释放到流动相中 ,因此溶质在流动相和固定相中的分布浓度受到两个因素即反映系统热力学性质的分配系数P和反映系统动力学性质的释放概率因子α的影响。这一过程被认为是非理想状态下的过程。     

壁电荷对ACPDP中气体击穿电压的影响

用电容平衡法测量ACPDP宏放电单元在维持放电期的壁电荷变化,并根据宏放电单元壁电荷电压和外加最小维持电压的测量结果计算实际施加在放电气体上的击穿电压,探讨壁电荷电压对放电气体实际击穿电压的影响.实验结果表明:随着ACPDP外加最小维持电压的增加,壁电荷电压升高,气体的击穿电压也随之升高;有壁电荷时的气体击穿电压明显高于无壁电荷时的气体击穿电压,随着壁电荷电压从7.62 V升高到67.89 V,有壁电荷时的气体击穿电压比无壁电荷时的气体击穿电压分别提高了6.98 V到57.09 V;壁电荷增加会显著提高了放电气体的击穿电压阈值,使ACPDP内放电气体的击穿变得困难.