具分段常数变元时滞方程的振动准则(英文)

研究了一类具分段常数元的时滞微分方程解的振动性 ,获得了所有解振动的充分条件 .     

用含碱废液作碱源制备稻草黄原酸酯来处理含锌废水

用金属铬生产中排出的氢氧化铬反应废液作碱源制备稻草黄原酸酯,用来处理含锌废水．考察了废水的ｐＨ值、酯剂用量及反应时间对锌脱除率的影响．废水经处理后,锌的残留浓度降至１．０ｍｇ／Ｌ以下．     

L─噻唑烷─4─甲酸二硫代甲酸钠及莫Co~(2 )离子配合物合成和IR光谱研究

本文合成了L─噻唑烷─甲酸二硫代甲酸钠和Co2 配合物,其分子式为MX2（M＝Co2 ,X＝L─噻唑烷─4─甲酸二硫代甲酸离子）．红外光谱研究表明配体与Co2 为双齿配位．     

单柱离子色谱测定碱金属与碱土金属的研究及应用

本文用Shimadzu HIC-6A高效单柱离子色谱仪和Shim-pack IC-CI低容量阳离子色谱柱,研究了不同浓度与不同pH值的淋洗剂对金属离子保留行为的影响,优选4.0 m mol/L HNO_3淋洗同时测定Li~+、Na~+、K~+、R6~+和Cs~+离子以及优选1.25m mol/L乙二胺和5.00m mol/L柠檬酸淋洗同时测定Be~(2+)、Mg~(2+)、Ca~(2+)、Sr~(2+)和Ba~(2+)离子的最佳色谱条件,并用于饮水的测定.本法标准加入回收,碱金属5种离子的回收率达101.2%～103.5%;碱土金属5种离子的回收率达99.80%～107.7%.水样分析,Na~+和K~+离子的RSD为0.86%和1.02%,Mg~(2+)和Ca~(2+)离子的RSD为0.364%和0.70%。     

放射性重离子束在生命科学领域的应用

应用放射性重离子注入活细胞和生物大分子，然后采用放射自显影，放射性测量和分子操作等研究技术，可对重离子注入质量沉积效应开展进一步的研究。放射性束还可应用于一些基本生物学问题的阐明及放射性药物的研制等方面。     

改性木屑处理含Cr（Ⅵ）废水的研究

通过正交试验选择制备改性木屑的最佳条件，水解改性后的木屑能将Ｃｒ（Ⅵ）还原成Ｃｒ￣（３＋）每克改性木屑对Ｃｒ（Ⅵ）的最大还原能力为４９０ｍｇ将其装成柱子，让ρ＿（Ｃｒ）（Ⅵ）＝８６ｍｇ／Ｌ及ｐＨ＝２的含Ｃｒ（Ⅵ）电镀废水通过柱子，其接触时间不小于６ｍｉｎ，Ｃｒ（Ⅵ）的还原率在９９．５％以上．     

Cr（Ⅵ）的新富集剂──三聚氰酰胺甲醛树脂

天然水和工业废水中微量的铬Ｃｒ（Ⅵ）可以通过与三聚氰酰胺甲醛树脂的交换而被富集．本文研究了Ｃｒ（Ⅵ）的直接富集方法，并对Ｃｒ（Ⅵ）的富集能力、富集酸度、及回收率作了讨论．     

猪心肌乳酸脱氢酶的提纯工艺及酶反应最适条件

研究了适合于工业化生产的猪心肌乳酸脱氢酶的初步提取工艺，经硫酸铵分级沉淀得到酶的比活为86．5U／mg，再经DEAE离子交换层析比活可达525．0U／mg，酶活总收率为54．5％．并对酶促反应的最适条件进行了研究，其最适反应pH为7．6～7．8，最适反应底物浓度分别为NADH5mg／mL和丙酮酸钠25mmol／L。     

A practicable variant of the ion exchange method for the radiometric estimation of ornithine decarboxylase activity

Summary A known ornithine decarboxylase assay working with ion exchang separation of [³H]ornithine and [³H]putrescine has been revised. The assay can be performed in disposable 1.5 ml vessels with a total of four pipetting steps. The separation of enzyme substrate and product, respectively, requires 3 h per 50 samples. The detection limit is about 50 pmoles [³H]putrescine formed.     

The plasma membrane calcium pump: Recent developments and future perspectives

The Ca²⁺ pump of the plasma membrane (PMCA) is regulated by a number of agents. The most important is calmodulin (CaM), which binds to a domain located in the C-terminal portion of the pump, removing it from an autoinhibitory site next to the active site. The CaM-binding domain is preceded by an acidic sequence which contains a hidden signal for endoplasmic reticulum (ER) retention. Chimeras of the PMCA and endoplasmic reticulum (SERCA) pumps have revealed the presence of a strong signal for ER retention in the first 45 residues of the SERCA pump. Four gene products of the PMCA pump are known: two of them (1 and 4) are ubiquitously expressed, two (2 and 3) are specific for nerve cells and may be induced by their activation. Mutagenesis work has identified four residues in three of the transmembrane domains of the pump which may be components of the trans-protein Ca²⁺ path. The mutation of two of these residues alters the membrane targeting of the pump.