Blockade by zinc ions of K+-induced contraction and calcium in guinea pigTaenia coli

Preincubation with 0.3 mM Zn²⁺ markedly inhibited both the tonic response and Ca²⁺ binding at low affinity sites induced by K⁺ (60 mM), with smaller effects on the phasic response and the high affinity Ca²⁺ sites, inTaenia coli. However, when the muscle was kept in Zn²⁺-containing medium following the first stimulation with the K⁺, the phasic response and the high affinity Ca²⁺ sites were more severely inhibited during the second stimulation with K⁺. This probably indicates that Zn²⁺ reduced the tonic tension response to K⁺ mainly by inhibiting Ca²⁺ influx at the cell membranes ofTaenia coli. However, when Zn²⁺ is continuously present, Ca²⁺ is not supplied at the storage sites and is not available for the phasic response to a second stimulation with K⁺.     

绿茶对Pb^2＋和Cu^2＋及Fe^3＋吸附性能的研究

讨论了经甲醛处理的绿茶对水中的Ｐｂ￣（２＋）和Ｃｕ￣（２＋）及Ｆｅ￣（３＋）的吸附性能，采用示波极谱和原子吸收分光光度法为测试手段，测得Ｐｂ￣（２＋）、Ｃｕ￣（２＋）和Ｆｅ￣（３＋）的吸附率平均值分别为８３．７２％、８３．５６％和８１．８９％。还考察了绿茶用量、金属离子浓度及ｐＨ值等因素对吸附率的影响．并对绿茶吸附全属离子的机理进行了探讨     

LiF：Co~（2＋）和NaF：Co~（2＋）晶格中的Co~（2＋）－F~－键长

本文从光谱数据出发，用参量化的ｄ轨道理论确定了ＬｉＦ：Ｃｏ２＋和ＮａＦ：Ｃｏ２＋晶体中的Ｃｏ２＋－Ｆ－键长．结果表明：ＬｉＦ：Ｃｏ２＋中，Ｃｏ２＋－Ｆ－键长基本与未掺杂ＬｉＦ晶体中的Ｌｉ＋－Ｆ－距离相同；而ＮａＦ：Ｃｏ２＋中的Ｃｏ２＋－Ｆ－键长则有很大收缩，完全不同于未掺杂ＮａＦ晶格中的Ｎａ＋－Ｆ－键长．从杂质离子半径与被取代离子半径的差别引起的局域畸变及静电平衡机制引起局域畸变出发进行的讨论表明，所得结果是合理的     

Zinc ions block the intracellular calcium release induced by caffeine in guinea-pig taenia caeci

Zn²⁺ in low concentrations (0.005–0.1 mM) inhibited the transient contractions in response to caffeine (25 mM) in a dose-dependent manner in smooth muscle of intact guinea-pig taenia caeci. At Zn²⁺ concentrations higher than 0.1 mM, caffeine did not elicit any response. After saponin-treatment of the fibres, which leaves the Ca²⁺ storage sites intact, caffeine contraction was completely inhibited by Zn²⁺ at a relatively low concentration (0.03 mM). However, in Triton-X-100-treated fibres, in which the Ca²⁺ release sites are destroyed, the contraction could be induced in the presence of Zn²⁺ by an increase in Ca²⁺. In conclusion, Zn²⁺ can block the intracellular Ca²⁺ release from caffeine-sensitive release sites in taenia caeci.     

离心光度法测定酒中微量Zn（Ⅱ）的方法研究

研究了一种高灵敏测定酒中微量Ｚｎ（Ⅻ）的新方法－离心光度法，在ｐＨ为１．３０的Ｚｎ－ＳＣＮ－ＣＶ三元离子缔合物体系中，λｍａｘ为５９８ｎｍ的表观摩尔吸光系数ε５９８为３．３９×１０＾５Ｌ．ｍｏｌ＾－１ｃｍ＾－１，Ｚｎ（Ⅱ）在１．５×１０＾－６－１３．８×１０＾－６ｍｏｌ．Ｌ＾－１范围内呈线性关系。     

硫酸溶液中Br~－和C1~－离子对铁钝化膜破裂的影响

利用电化学方法研究了硫酸溶液中Ｂｒ－和Ｃｌ－离子对铁钝化过程的影响．相比之下对铁的钝化膜Ｂｒ－离子比Ｃｌ－离子具有更强的破坏作用．这种作用可以由卤素离子的吸附阻止无定形水合氧化铁的生成且生成可溶性络离子得到初步解释．     

不锈钢攻丝用的新型丝锥

本文介绍了一种用于不锈钢材料攻丝的新颖丝锥——双头丝维，通过对比锥构造的(几何)参数和涂层材料及方法进行合理选择，使之能够高效地、经济地对不锈钢进行攻丝加工。     

H+n(n=9,11,13)团簇离子的实验研究

报道了关于H9^ ,H11^ 和H13^ 团簇离子的实验研究结果，分析讨论了H9^ ，H11^ 和H13^ 团簇离子的形成和可能的分解途径。