萃取伏安法测定铁矿样中的铜,铅,镉,锌

提出了一种用差示脉冲阳极溶出发法（ＤＰＡＳＶ）简便、快速、准确测定铁矿样中重金属（铜、铅、镉、锌）方法。用浓盐酸分解试样，用乙醚萃取分离铁，对酸性水提出物进行伏安法测定。４种金属的回收率在９３．５－１０１．０％之间。铜、铅、镉、锌的相对标准偏差分别为０．７２％、０．４８％、０．６４％、０．４７％。在９５％置信度下，临界值／ｔ／表明本法没有系统误差。     

分光光度法测定工业碳酸锶中氯化物

本文利用分光光度计进行比浊法测定工业碳酸锶中的氯化物，通过溶样方法，添加剂等条件的试验，方法具有良好的线性关系，回收率在101％～106％之间，相对标准偏差在1．15％～3．65％，结果准确、快速。     

提高铜精矿中金测定的精密度和准确度

研究了铜精矿的粒度分布及各粒级中金含量的赋存规律，发现由于铜精矿的特殊生产工艺，铜精矿的粒度85％集中在－200目，金量的90％也集中在－200目；并从磨样时间和磨样量两个方面试验了铜精矿的加工条件，得出铜精矿中分析测试金的较佳加工条件和加工粒度，加工制成的样品具有均匀性和代表性；从而建立了铜精矿中金的火焰原子吸收快速分析法。该方法操作简便、快速，分析结果稳定、准确，RSD≤4％。     

原子荧光光谱法测定铜精矿中的硒

本文介绍了用原子荧光光谱仪测定铜精矿中的硒的分析方法和分析条件，方法简单、准确、快速，是适合铜精矿中硒含量在0．002％～0．1％的分析方法。     

电热石英管氢化物法测定钢中痕量砷锑锡

采用氢化物原子吸收法测定钢中痕量As,Sb,Sn元素，系统考察了测定的最佳条件及共存元素对测定的影响。所拟方法操作简便、快速、准确，测定的相对标准偏差在4．8％－6．0％之间，加标回收率在98％－102％。     

氢化物发生原子吸收光谱法测定金属锌中的痕量汞

采用氢化物发生原子吸收光谱法测定金属锌中的痕量汞，研究了金属锌消解的最佳条件，本法简便、快速、重现性好，准确度高，灵敏度为0．73μg/L，检测限为0．22μg/L，相对标准偏差为3．1％，回收率为96％-102％。     

铝合金中硅,铁,锰,铜的联合比色测定

铝合金中各元素的含量范围大(硅0—13％,铁0—1.6％,锰0—1.6％,铜0—11％),不同牌号中各元素的含量高低相差也很大(如有的硅高达11％以上,而锰却低至0.1％以下)。化学分析各元素,一般是分别溶样,采用不同的测定方法。这样,虽然准确度高,但分析时间长,不能满足炉前需要快速分析几个元素的要求。快速分析方法近几年来已有专著和报导。我们参考分别溶样,分别测定的分析方法,从熔样、显色和测量等多方面试验选择合适的分析方法,经反复试验,拟定出铝合金中硅、铁、锰、铜四元素     

P5708,P350萃取分离铟,铁工艺研究

研究了Ｐ５７０８，Ｐ３５０混合萃取剂萃取分离铟，铁的最佳工艺条件。对锌置换渣浸出液和模拟液进行试验，经萃取，洗涤和反萃取三步处理，铟的回收率大于９０％，除铁率大于９８％。     

用连续流动——氢化物发生FAAS法对钢铁中微量元素砷,锡和锑分析的研究

本文阐述了用国内外正在研究发展的原子吸收光谱分析新技术－连续流动氢化物发生ＦＡＡＳ法来分析钢铁中微量元素Ａｓ，Ｓｎ，Ｓｂ的分析方法，并对分析仪器的最佳工作条件，基体元素的影响以及其它分析试验条件进行试验研究，提出准确，可靠，简单，快速适合于分析钢铁及其合金中含量在０．０００Ｘ～０．００Ｘ％数量级Ａｓ，Ｓｎ和Ｓｂ的分析方法。     

ICP-AES测定低合金钢中合金元素

本方法是采用硝酸（1＋3）在加热的条件下使试样分解、定容后导入ICP发射光谱仪等离子体炬焰中进行测定。测得结果表明，本方法快速准确，精密度好，相对标准偏差均小于5％，回收率在95％～105％之间，适用工业生产的需求。     

铂饰品中Pt, Pd, Au, Ag, Cu, Ni, Zn, Fe的测定

试验研究建立了同一试料溶液连续、同时测定铂饰品中各成分的分析方法。主体Pt以氯铂酸铵称量法及火焰原子吸收光谱(FAAS)法或电感耦合等离子发射光谱(ICP-AES)法测定滤液中残留Pt进行补差而测定。主成分Pd,Au,Ag,Cu和焊料成分Ni,Zn,Fe以FAAS法或ICP-AES法测定。其方法回收率分别为:Pt99.9%~100%;Pd99.3%~99.7%;Au99.5%~l01.5%;Ag98.0%~100%;Cu97.7%~99.3%;Zn98.0%~99.0%;Ni94.0%~105%;Fe95.0%~99.0%。实际试样分析时,各成分质量分数之和一般在99.12%~l01.2%之间,接近于100%,间接说明方法的可靠性。本法适用于Pt-Pd二元体系和Pt-Pd-Au-Cu多元复杂体系的铂饰品的破坏分析,可用于校正X荧光光谱法无损检测铂饰品的分析结果。     

稀土金属中14种非稀土杂质的ICP-MS法同时测定

本文研究了用 ICP- MS仪器同时测定稀土金属中 Mg、Al、Ti、Cr、Mo、Mn、Co、Ni、Cu、Zn、Pb、W、Nb、Ta等 14种非稀土杂质。研究了各稀土基体对被分析元素的基体效应 ,选择了相匹配的内标元素。比较了标准曲线法与标准加入法的测定结果。确定了用内标元素校正基体效应及仪器漂移 ,以标准曲线法直接测定。进行了加料回收和精密度实验 ,回收率在 94%～ 113%之间 ,RSD<10 %。被分析元素的检出限为 0 .0 1～ 0 .2 0 ng/ m L,测定下限为1～ 2 0 μg/ g。     

原子荧光光谱法测定土壤中的铅、铬、镉、汞、砷、锌、铜、镍等元素研究

土壤无机污染物铅、铬、镉、汞、砷、锌、铜、镍这八大重金属,是一般土壤检测中的必检项目。金属元素在土壤中积累富集后,有可能通过雨水迁移,造成地下水,地表水污染,或者通过农作物进入食物链,进而影响食品安全和人体健康,因此,对这些元素的检测显得尤为重要。本文采用原子荧光光谱法对土壤中的金属元素进行测量,同时结合微波消解技术对样品进行处理,确保测量数据的准确性。     

Increased-contrast, high-spatial-resolution, diffusion-weighted, spin-echo, echo-planar imaging

An insertable head gradient coil with a maximum gradient amplitude of 45 mT/m and a rise time of 150 musec along all three major axes was used to collect high-spatial-resolution, single-shot, spin-echo, echo-planar, diffusion-weighted magnetic resonance images with b values ranging from 0 to 2,200 sec/mm2. Improvements in spatial resolution allowed better visualization of large white matter tracts and their relation to adjacent anatomic structures. Excellent contrast and anatomic detail were revealed for most structures in the brain when a sufficient number of acquisitions were collected.     

Susceptibilities of non-Pseudomonas aeruginosa gram-negative nonfermentative rods to ciprofloxacin, ofloxacin, levofloxacin, D-ofloxacin, sparfloxacin, ceftazidime, piperacillin, piperacillin-tazobactam, trimethoprim-sulfamethoxazole, and imipenem

Agar dilution MICs of 10 agents against 410 non-Pseudomonas aeruginosa gram-negative nonfermentative rods were determined. MICs at which 50 and 90% of the isolates were inhibited, respectively, were as follows (in micrograms per milliliter): sparfloxacin, 0.5 and 8.0; levofloxacin, 1.0 and 8.0; ciprofloxacin, 2.0 and 32.0; ofloxacin, 2.0 and 32.0; D-ofloxacin, 32.0 and > 64.0; ceftazidime, 8.0 and 64.0; piperacillin with or without tazobactam, 16.0 and > 64.0; trimethoprim-sulfamethoxazole, 0.5 and > 64.0; imipenem, 2.0 and > 64.0. With the exception of those for Stenotrophomonas maltophilia, Burkholderia cepacia, and Alcaligenes faecalis-A. odorans, agar dilution MICs for all strains tested were within 1 dilution of inhibitory (bacteriostatic) levels as determined by time-kill methodology.     

Regional mapping panels for chromosomes 3, 4, 5, 11, 15, 17, 18, and X

The erm family of 23S rRNA adenine-N6-methyltransferases confers resistance to all macrolide-lincosamide-streptograminB (MLS) antibiotics, but not all MLS antibiotics induce synthesis of Erm methyltransferase with equal efficiency in a given organism. The induction efficiency of a test panel of MLS antibiotics was studied by using two translational attenuator-lac reporter gene fusion constructs, one based on ermSV from Streptomyces viridochromogenes NRRL 2860 and the other based on ermC from Staphylococcus aureus RN2442. Four types of responses which were correlated with the macrolide ring size were seen, as follows: group 1, both ermSV and ermC were induced by the 14-membered-ring macrolides erythromycin, lankamycin, and matromycin, as well as by the lincosamide celesticetin; group 2, neither ermSV nor ermC was induced by the 12-membered-ring macrolide methymycin or by the lincosamide lincomycin or the streptogramin type B antibiotic ostreogrycin B; group 3, ermSV was selectively induced over ermC by the 16-membered-ring macrolides carbomycin, chalcomycin, cirramycin, kitasamycin, maridomycin, and tylosin; and group 4, ermC was selectively induced over ermSV by the 14-membered-ring macrolide megalomicin. These data suggest that the leader peptide determines the specificity of induction by different classes of MLS antibiotics and that for a given attenuator, a major factor which determines whether a given macrolide induces resistance is its size.