2－（8′－羟基喹啉－5′－磺酸－7′－偶氮）变色酸双波长增敏法测定镁

本文报导了Ｍａ＿２Ｂ＿４Ｏ＿７－ＮａＯn缓冲体系中,２－（８’－羟基喹啉－５’－磺酸－７’－偶氮）变色酸（８Ｑ５ＳＡＣ）与镁形成络合物,以试剂的最大吸收６４２ｎｍ为参比波长λ,以络合物的最大吸收５２４ｎｍ为测量波长λ＿２,用双波长增敏法测得表现摩尔吸光系数为２．ｌ×ｌ０￣６。试剂与镁的络合比为１：１,镁量在０￣１５μｇ／２５ｍｌ符合比尔定律,方法用于铸造铝合金中镁的测定,结果满意。     

2－（2－苯并噻唑偶氮）－5－二乙氨基苯甲酸－TritonX－100双波长分光光度法测定铜（Ⅱ）的研究

本文研究了２－（２－苯并噻唑偶氮）－５－二乙氨基苯甲酸（ＢＴＡＥＢ）－ＴｒｉｔｏｎＸ－１００测定铜（Ⅱ）的显色反应。在ｐＨ３．８～５．５的ＨＡｃ－ＮａＡｃ缓冲介质和ＴｒｉｔｏｎＸ－１００存在下,Ｃｕ（Ⅱ）与ＢＴＡＥＢ形成稳定的１∶２蓝紫色配合物,λ＿（ｍａｘ）在６５４ｎｍ处,铜量在０～ｍμｇ／２５ｍｌ范围内符合比尔定律,用单波长法测得的ε＿（６５４）为５．７×１０￣４,双波长光度法测得的ε＿（６５４,５３２）值达９．６２×１０￣４。方法灵敏、稳定,有良好的选择性,用于铝合金中微量铜的测定,结果满意。     

5—（2－噻唑）偶氮－8－氨基喹啉的合成及光度法测定微量钴

合成了新试剂５－（２－噻唑）偶氮８－氨基喹啉（ＴＡＡＱ），测定了它的酸离解常数，并用于光度法测定微量钴。在ＣＴＭＡＢ存在下，０．０４～０．０２ｍｏｌ／１ＮａＯＨ介质中，ＴＡＡＱ与Ｃｏ￣２＋形成１：３的深蓝色络合物，最大吸收峰位于６３０ｎｍ，摩尔吸光系数ε＝１．２３×１０￣５１．ｍｏｌ￣－１·ｃｍ￣－１。Ｃｏ￣２＋在０～１０μｇ／２５ｍｌ范围内符合比尔定律。方法具有较好的选择性，已用于ＶＢ＿（１２）及矿石分析，结果满意。     

阳离子型微乳液介质中铜（Ⅱ）－苯基荧光酮的增敏试验

研究了在阳离子型微乳液介质中,用苯基荧光酮测定铜（Ⅱ）的分光光度试验。结果表明,以阳离子型ＣＴＭＡＢ－ｎ－Ｃ＿５Ｈ＿（１１）ＯＨ－ｎ－Ｃ＿７Ｈ＿１６－Ｈ＿２Ｏ微乳液为介质,Ｃｕ（Ⅱ）－ＰＦ的ε＿（５７２）＝１．３７×１０￣５,与以水为介质ε＿（５４０）＝４．３×１０￣４及相同含量ＣＴＭＡＢ胶束溶液为介质ε＿（５７２）＝８．９×１０￣４比较,测定灵敏度显著提高,并且某些实验条件更加宽容。经投入使用,结果满意。     

铱－钼酸盐－罗丹明B缔合显色反应的研究

在聚乙烯醇（ＰＶＡＶＡ）存在下,铱与钼酸盐和罗丹明Ｂ（ＲＢ）形成离了缔合物。缔台物的最大吸收位于５７０ｎｍ摩尔吸光系数ε８．３６×１０￣５’Ｌ·ｍｏｌ￣－１·ｃｍ￣－１,服从比尔定率范围为０～２．７５μｇｌｒ／２５ｍｌ。测定２．０μｇ铱的相对标准偏差为２．５％（ｎ＝７）,检出限４３ｎ／ｍｌ（ｎ＝１２）。测定铱的适宜条件为ＣＨＣｌＯ＿４＝０．９３ｍｏｌ／Ｌ,Ｃ＿ＭｏＯ￣２－＿４９．０×１０～－４ｍｏｌ／Ｌ,Ｃ＿ＲＢ＝３．３×ｌ０￣－５ｍｏｌ／Ｌ,ＰＶＡＯ０８％。试验了３０多种共存离子的影响,除形成杂多酸元素     

N－烯丙基－N＇－（氨基对苯磺酸钠）硫脲光度法测定微量铜

本文提出了以新合成的试剂Ｎ－烯丙基－Ｎ＇－（氨基对苯磺酸钠）硫脲（ＡＳＡＴｕ）为显色剂,光度法测定微量铜的新方法。在ｐＨ４．０的弱酸性溶液中,铜（Ⅱ）与ＡＳＡＴｕ形成配合物的最大吸收波长为３乙４ｎｍ,表观摩尔吸光系数ε＿（３３４）＝３．４２×１０￣４。铜量在１０～７０μｇ／２５ｍｌ范围内呈线性关系,相关系数ｒ＝０．９９９９。铜（Ⅱ）和ＡＳＡＴｕ配合物的组成比为１∶３。常见离子除Ｆｅ￣（３＋）、Ａｇ￣＋、Ｓ￣（２－）外,均无干扰。该法简单、灵敏度高,选择性好。对合成样品、食品及生物试样的分析和回收实验,均获     

锗（Ge）（Ⅳ）－P－CIPF－混合离子表面活化剂显色反应的研究和应用

本文研究了锗（Ⅳ）在混合离子表面活化剂（ＣＰＢ、ＴｒｉｔｏｎＸ－１００）存在下与Ｐ－ＣＩＰＦ形成多元配合物的显色特性。在１．５－４．０ｍｏｌ／ＬＨ＿２ＳＯ＿４介质中，Ｇｅ（Ⅳ）－Ｐ－ＣＩＰＦ－混合离子表面活化剂生成橙红色配合物，最大吸收波长（λ＿（ｍａｘ））位于５１５ｎｍ处，其摩尔吸光系数为ε＿（５１５）＝２．８×１０￣５Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１）。配合物的组成比为Ｇｅ：ＣＩＰＦ＝１：３（在混合离子表面活化剂存在时）。在０－１２βμｇ／Ｇｅ５０ｍＬ范围内符合比尔定律。本法具有良好的选择性，完全不经分离或富集。已成功地用于直接测定人参、枸杞、当归、大蒜和锅炉烟尘中的微量锗。     

5－Br－PADAT分光光度法测定微量铂

本文研究了显色剂５－（５－溴－２－吡啶偶氮）－２,４－二氨基甲苯（５－Ｂｒ－ｐＡＤＡ）与铂（Ⅱ）的显色反应。在正丙醇存在下,在０．２￣１．０ｍｏｌ／ＬＨ＿３ＰＯ＿４介质,Ｈ飞介质中,放置３５ｍｉｎ,铂与５－Ｂｒ－ｐＡＤＡＴ形成稳定的１：１蓝紫色配合物,其最大吸收波长在６０２ｎｍ处,表现摩尔吸光系数为７．９×１Ｏ￣４·ｍｏｌ￣－１·ｃｍ￣－１．铂量在０～２５μｇ／２５５ｍｌ范围内符合比尔定律。应用本法测定了催化剂中微量的铂,结果满意。     

二安替比林基－（4－溴）苯基甲烷与铈（Ⅳ）的显色反应及其分析应用

合成了二安替比林基－（４－溴）苯基甲烷（ＤＡｐＢＭ）,在Ｍｎ（Ⅱ）和吐温－６０存在下,Ｃｅ（Ⅳ）与ＤＡｐＢＭ反应生成有色化合物,λｍａｘ为４８０ｎｍ,ε＝３．２８×１０￣５Ｌ·ｍｏｌ－１．ｃｍ－１,Ｃｅ（Ⅳ）量在０．５～５．０μｇ／２５ｍｌ间符合比尔定律。该体系灵敏度颇高,选择性较好,用于镁合金和含锌矿石中微量铈的测定,结果满意。     

I~－－EDTA－Cu~（2＋）体系在分析化学中的应用

本文采用Ｐｔ／Ｉ＿２／Ｉ￣－电极电滴定法，系统地研究了，Ｉ￣－ＥＤＴＡ－Ｃｕ￣２＋体系在不同条件下的化学平衡，提出了用Ｃｕ￣２＋盐返滴法和Ｎａ＿２Ｓ＿２Ｏ＿３滴定法测定Ｎｉ￣２＋Ｓｎ￣４＋等金属离子的新方法，为多元素（如Ｃｕ－Ｓｎ、Ｃｕ－Ｎｉ、Ｃｕ－Ｎｉ－Ｆｅ等）连续测定提供了新途径。     

CeO2对不锈钢基SiO2-BaO-Al2O3-Cr2O3陶瓷涂层性能的影响

采用高温熔烧法于1Cr18Ni9Ti不锈钢基材表面制备掺CeO2的SiO2-BaO-Al2O3-Cr2O3陶瓷涂层,研究了不同含量CeO2对涂层的抗氧化性、抗热震性和硬度的影响。研究结果表明,含CeO2的不锈钢基SiO2-BaO-Al2O3-Cr2O3陶瓷涂层能有效阻止不锈钢基体的氧化增重,提高涂层的抗热震性能及硬度。本实验条件下,CeO2含量2.8%时,涂层具有最好的抗氧化性能和抗热震性能。     

Synthesis and biological investigations of 1-(tetrahydropyran-2'-yl)- and 1-(tetrahydrofuran-2'-yl)benzimidazoles and 1/2-(tetrahydropyran-2'-yl)- and 1/2-(tetrahydrofuran-2'-yl)benzotriazoles

Sets of benzimidazole and benzotriazole derivatives bearing on position 1 or 2 a tetrahydrofuranyl or tetrahydropyranyl moieties were prepared through the addition of the suitable benzazoles on 2,3-dihydrofuran and 3,4-dihydro-2H-pyran. The reactions were carried on either without solvent or in carbon tetrachloride solution. In the last case some peculiar chlorinated side products were isolated and characterized. Twenty compounds were screened for in vitro antitumoral and anti-HIV-1 activities and found poorly active or completely inactive. On the other hand several compounds exhibited good tracheal relaxant activity in vitro; compound 8, 11, 16, 24 and 26 resulted more active than theophylline in this test, while compound 11 was comparable to amrinone till the concentration of 3 micrograms/ml. Finally, compound 5 resulted endowed with a strong diuretic and saluretic activity at the dose of 3 mg/Kg, thus representing a new lead for discovering new diuretic agents.     

Texture and residual strain in two SiC/Ti-6-2-4-2 titanium composites

Residual strain and texture variations were measured in two titanium matrix composites reinforced with silicon carbide fibers (Ti/SiC) of similar composition but fabricated by different processing routes. Each composite comprised a Ti-6242 α/β matrix alloy containing vol 35 pct continuous SiC fibers. In one, the matrix was produced by a plasma sprayed (PS) route, and in the other by a wiredrawn (WD) process. The PS and WD composites were reinforced with SCS-6 (SiC) and Trimarc (SiC) fibers, respectively. The texture in the titanium matrices differed significantly. The titanium matrix for the PS material exhibited random texture pre and post fabrication of the composite. For the WD material, the starting texture of the monolithic titanium matrix was ≈17 times random, but after consolidation into composite form, it was ≈6 times random. No significant differences were noted in the fiber-induced matrix residual strains between the composites prepared by the two procedures. However, the Trimarc (WD) fibers recorded higher (≈1.3 times) compressive strains than the SCS-6 (PS) fibers. Stresses and stress balance results are reported. Plane-specific elastic moduli, measured in load tests on the unreinforced matrices, showed little difference. This article is based on a presentation made in the Symposium “Mechanisms and Mechanics of Composites Fracture” held October 11–15, 1998, at the TMS Fall Meeting in Rosemont, Illinois, under the auspices of the TMS-SMD/ASM-MSCTS Composite Materials Committee.     

Texture and residual strain in two SiC/Ti-6-2-4-2 titanium composites

Residual strain and texture variations were measured in two titanium matrix composites reinforced with silicon carbide fibers (Ti/SiC) of similar composition but fabricated by different processing routes. Each composite comprised a Ti-6242 α/β matrix alloy containing vol 35 pct continuous SiC fibers. In one, the matrix was produced by a plasma sprayed (PS) route, and in the other by a wiredrawn (WD) process. The PS and WD composites were reinforced with SCS-6 (SiC) and Trimarc (SiC) fibers, respectively. The texture in the titanium matrices differed significantly. The titanium matrix for the PS material exhibited random texture pre and post fabrication of the composite. For the WD material, the starting texture of the monolithic titanium matrix was ≈17 times random, but after consolidation into composite form, it was ≈6 times random. No significant differences were noted in the fiber-induced matrix residual strains between the composites prepared by the two procedures. However, the Trimarc (WD) fibers recorded higher (≈1.3 times) compressive strains than the SCS-6 (PS) fibers. Stresses and stress balance results are reported. Plane-specific elastic moduli, measured in load tests on the unreinforced matrices, showed little difference. This article is based on a presentation made in the Symposium “Mechanisms and Mechanics of Composites Fracture” held October 11–15, 1998, at the TMS Fall Meeting in Rosemont, Illinois, under the auspices of the TMS-SMD/ASM-MSCTS Composite Materials Committee.     

Biochemical basis for a cholesterol-lowering activity of 2-[2"-(1",3"-dioxolane)]-2-methyl-4-(2'-oxo-1'-pyrrolidinyl)-6- nitro-2H-1-benzopyran (SKP-450), a novel antihypertensive agent

Administration (p.o.) of SKP-450, 2-[2"-(1",3"-dioxolane)]-2-methyl-4-(2'-oxo-1'-pyrrolidinyl)-6-nitro-2H- 1-benzopyran, a novel antihypertensive agent, to hypercholesterolemic Syrian hamsters led to a significant reduction in plasma lipids in a dose-dependent manner, i.e., a 10.8% to 29% reduction in low-density lipoprotein cholesterol at doses of 0.3 to 10 mg/kg of SKP-450. SKP-450 was found to specifically inhibit the hepatic microsomal lanosterol 14alpha-methyl demethylase (14alpha-DM) in a competitive manner (Ki:2.65 microM). Furthermore, a dose-dependent decrease in the 14alpha-DM activity by SKP-450 parallelled the cholesterol synthetic rate in vitro in both the rat hepatic S10 fractions (supernatants at 10,000 g; IC50:20 microM) and Chinese hamster ovary cells (IC50:23 microM). However, this phenomenon was not seen in AR45 cells, which are deficient in 14alpha-DM, suggesting that 14alpha-DM is the major target for the inhibitory action of SKP-450 in regard to cholesterol biosynthesis.     

The free energies of mixing of melts in the systems 2FeO-SiO2-2MnO-SiO2 and 2.33FeO-TiO2-2.33MnOTiO2

The free energies of mixing in melts in the system 2FeO · SiO₂-2MnO · SiO₂ at 1450°C and the system 2.33FeO · TiO₂-2.33MnO · TiO₂ at 1475°C have been obtained from measurement of the equilibrium Mn + FeO = Fe + MnO established between the melts and ironmanganese foils. Both systems exhibit ideal silicate mixing. The phase diagram for the system 2FeO-SiO₂-2MnO ·SiO₂ is calculated.     

新显色剂2-(2-咪唑偶氮)-5-二乙氨基酚光度法测定铁(Ⅲ)

研究了新显色剂2-（2-咪唑偶氮）-5-二乙氨基酚（简称IZAPN）与Fe     

Synthesis and biological investigations of 2-(tetrahydropyran-2'-yl) and 2-(tetrahydrofuran-2'-yl)benzimidazoles

A set of benzimidazole derivatives bearing on position 2 a tetrahydropyranyl or tetrahydrofuranyl residue was prepared and tested for antitumoral, anti HIV-1 and other pharmacological activities. While the anti-HIV activity was completely lacking, moderate antitumoral activity was found in a few compounds; particularly the 5,6-dichloro-2-(tetrahydropyran-2-yl)-benzimidazole (8) was able to inhibit the growth of 19 cell lines of humane tumors at near micromolar concentration. On the other hand compounds 4, 6-8 and 10 exhibited significant tracheal relaxant activity in vitro at concentration 3-10 micrograms/ml, thus resulting superior to theophylline and comparable to amrinone.     

Electrical properties of phases in the ZrO2 - Y2O3 - La2O3 system

An investigation was made of the electrical properties of phases with the cubic fluorite, pyrochlor, and C-Y₂O₃ structures, and the tetragonal ZrO₂ structure (T-ZrO₂) in the ternary system ZrO₂ - Y₂O₃ - La₂O₃. For comparison, the electrical conductivity of a number of specimens with the fluorite structure in the binary system ZrO₂ - Y₂O₃ and with the pyrochlor structure in the ternary system HfO₂ - Y₂O₃ - La₂O₃ was also studied. The specimens were prepared from nanocrystalline powders synthesized by the hydrolysis of zirconium salts in an acid medium at high temperatures. Conductivity was measured over the range 300–950°C in air. It was shown that phases with the fluorite and T-ZrO₂ structures in the investigated systems possess the highest electrical conductivities. Translated from Poroshkovaya Metallurgiya, Nos. 3/4(412), pp. 40–46, March–April, 2000.     

2-(2-咪唑偶氮)-5-二甲氨基苯甲酸分光光度法测定铜

研究了新显色剂2-(2-咪唑偶氮)-5-二甲氨基苯甲酸(IZDBA)与铜的显色反应。结果表明,在pH 4.0的HAc-NaAc缓冲溶液中,IZDBA与Cu(Ⅱ)形成稳定的摩尔比为2∶1的紫红色络合物,其最大吸收波长为600 nm,表观摩尔吸光系数为3.62×104L.mol-1.cm-1,Cu(Ⅱ)质量浓度在0.08~0.8 mg/L范围内符合比尔定律。本方法可不经分离直接测定铝合金和镁合金样品中微量的铜,测定结果与认定值相符。