金属离子对纳豆激酶的化学修饰研究

纳豆激酶(Nattokinase,简称NK)是一种新型食源性纤溶酶,具有很强的溶血栓作用。本项研究采用金属离子对纳豆激酶进行置换修饰研究,找出最佳金属离子的种类和浓度,提高酶活性,以更大的发挥其药理学功能。实验结果表明,修饰后纳豆激酶的酶活性及稳定性有明显的提高,6mmol/L的Mg2+对酶有明显的激活作用,比天然酶提高了45%的活性。Ca2+、Mn2+、Ni2+则表现出不同程度的抑制作用。因此,可通过加入Mg2+来改善提高纳豆激酶的活性。     

住宅小区中的"携孙行为"与环境设计

在我国,老年人照看未成年的孙子女是一种普遍现象,但在住宅小区的规划设计中,这种"携孙行为"却往往被规划设计师们所忽视.本文运用环境心理学方法,对住宅小区"携孙行为"进行调研,并对其成因、社会意义及其活动特点等进行分析和论述,提出"携孙行为"对住宅小区环境的相应要求和设计原则,从而以人性化的角度进一步提高住宅小区的环境设计水平.     

中美俄防冰剂性能对比研究(I)-航空燃油闪点影响对比

选取了两种不同炼制工艺的航空燃油,考察了中美俄3国在用防冰剂对航空燃油闭口闪点的影响。结果表明:在规定的浓度范围内,中国在用乙二醇甲醚防冰剂可将航空燃油的闭口闪点降低2~3℃,美国在用二乙二醇甲醚防冰剂不会降低航空燃油的闭口闪点,俄罗斯在用乙二醇乙醚防冰剂可将航空燃油的闭口闪点降低1℃;为了避免防冰剂的加入引起航空燃油闪点的降低,我国应用二乙二醇甲醚防冰剂代替目前使用的乙二醇甲醚防冰剂。     

对监理工程师变更注册的几点思考

笔者因工作调动，从一家监理公司调到另一家监理公司工作，但变更注册却遇到种种麻烦。行业内和我类似遭遇的大有人在。探讨其中的原因，有利于建立合理的、有序的人才流动秩序，也希望能引起政府主管部门的高度重视，以加强对相关工作的领导。在变更注册中，政府主管部门要求提交的材料中有以下三条：一是监理工程师变更注册申请表（其中有原聘用监理企业意见的盖章栏）；二是原聘用单位出具的与申请人解除聘用合同及同意到新单位注册的证明（同时附人事关系调动或辞职、离退休等证明文件复印件）；三是原监理工程师岗位证书原件。我本人有…     

工程设计对商品房售价和造价的影响

从住宅工程设计阶段总体规划设计及具体建筑设计中软指标和硬指标的确定与控制，阐述其对工程造价的影响及对策。     

中美俄防冰剂性能对比研究(Ⅱ)——毒性对比

考察了乙二醇甲醚防冰剂(EGME)、二乙二醇甲醚防冰剂(DEGME)、乙二醇乙醚防冰剂(EGEE)3种防冰剂的毒性对比,分别进行了小鼠急性经口毒性实验、家兔皮肤刺激实验、家兔眼刺激实验、大鼠急性吸入毒性实验。结果表明3种防冰剂的毒性作用从大至小为EGME、EGEE、DEGME;为了避免防冰剂的加注及使用对人体造成伤害,我国应用二乙二醇甲醚防冰剂代替目前使用的乙二醇甲醚防冰剂。     

Optimized synthesis technology of LiFePO4 for Li-ion battery

The influence of factors of the carbon black content, sintering temperature, sintering time, molar ratio of Li to Fe, as well as the electrochemical properties of LiFePO4 for lithium ion battery were studied. The only technology was obtained by using range analysis through Latin orthogonal experiment of L4^4 (16). The results show that the optimization synthesis technology of LiFePO4 is content of 5% doping carbon, sintering temperature of 700℃,molar ratio of Li to Fe of 1.03 : 1 and sintering time of 16 h. The optimized cathode synthesis techniques can make LiFePO4 have good electrochemical properties.     

MC55型摩擦离合器的设计

针对多数离心式摩擦离合器存在散热能力不足,摩擦片易磨损等缺点的现状,根据实际情况和需要,依据经济、可靠、操作方便的原则,提出了MC55型摩擦离合器的设计原理、结构及主要参数的设计。     

Research on cathode material of Li-ion battery by yttrium doping

Modification of LiFePO4, LiMn2O4 and Li1 xV3O8 by doping yttrium was investigated. The influences of doping Y on structure, morphology and electrochemical performance of cathode materials were investigated systematically. The results indicated that the mechanisms of Y doping in three cathode materials were different, so the influences on the material performance were different. The crystal structure of the three materials was not changed by Y doping. However, the crystal parameters were influenced. The crystal parameters of LiMn2O4 became smaller, and the interlayer distance of (100) crystal plane of Li1 xV3O8 was lengthened after Y doping. The grain size of Y-doped LiFePO4 became smaller and grain morphology became more regular than that of undoped LiFePO4. It indicated that Y doping had no influence on crystal particle and morphology of LiMn2O4. The morphology of Li1 xV3O8 became irregular and its size became larger with the increase of Y. For LiFePO4 and Li1 xV3O8, both the initial discharge capacities and the cyclic performance were improved by Y doping. For LiMn2O4, the cyclic performance became better and the initial discharge capacities declined with increasing Y doping.