反相液相色谱分析三苯基磷

介绍了用反相液相色谱法定量分析三苯基磷。使用 ODS( 2 50× 4 .6 mm,1 0μ)不锈钢柱 ,以甲醇水 ( 4∶1 )为流动相 ,流速为 1 .5m L/ min,紫外检测器 ,波长 2 54nm,在浓度 0 .4～ 0 .6 mg/ m L的范围内具有较好的线性关系 ,相关系数 r=0 .999。本方法适用于工业三苯基磷产品的定量分析     

STUDIES ON GERMINATION TESTS

To obtain reproducible results germination tests should be carried out at closely controlled temperatures, and in a water-saturated atmosphere. Tests carried out on a substratum of agar gel are more reproducible than those carried out on paper. It is proposed that the 1 ml and 3 ml (agar) tests, carried out at 18°C and in a water-saturated atmosphere, be evaluated in collaborative trials alongside the recommended 4 ml and 8 ml tests with a view to replacing the latter with the former, if their superiority is confirmed.     

Accuracy of amino acid analysis of fish meals by ion-exchange and gas chromatography

Variations in amino acid content of fish meals can be due to differences between meals or to analytical shortcomings. The purpose of the cooperative study reported here was to compare the accuracy of the ion-exchange (IE) and gas Chromatographic (GC) methods when applied to fish meal. The between-laboratory and within-laboratory variations were determined by analysing hidden duplicates of eight meals in four laboratories using IE and in a further three laboratories using GC. The work exposed certain pitfalls and inconsistencies in replicating results. A major source of variation in the IE method was identified as the instability of the ninhydrin reagent leading to the consequent variation in the colour yield of some amino acids which was not compensated by the use of norleucine as an internal standard. Significant between-laboratory variations and fish meal × laboratory interactions for certain amino acids existed. The work confirmed a need for replicate analysis of samples, whether done by IE or GC. Without discarding any outlying values, coefficients of variation for repeatability (Within-laboratory variation) varied from 3.5 to 9.7% for IE and 3.5 to 8.4% (histidine at 20%) for GC. coefficients of variation for reproducibility (between-laboratory variation) varied from 4.1 to 14.4% for IE and 4.5 to 11.9% (20% for histidine) for GC. The values for lysine reproducibility were 10.8% and 4.8% and for methionine wee 13.6% and 8.2% respectively for IE and GC. Neither of the methods was clearly superior for determining the amino acid content of fish meals. It would appear, however, that the GC method tended to result in lower within-laboratory variance, with arginine and histidine as exceptions. An amino acid mixture, a centrally prepared hydrolysate and a protein of known composition were also studied.     

Al_2O_3-WO_3材料的激光合成研究

采用大功率ＣＯ２激光器合成出了Ａｌ２Ｏ３－ＷＯ３陶瓷材料。测量其阻－温特性表明合成样品具有线性的ＮＴＣ热敏电阻特性，微观分析结果证明激光合成样品由Ａｌ２Ｏ３、ＷＯ３、Ａｌ２（ＷＯ４）３、ＡｌｘＷＯ３四相组成，而起导电作用的是ＡｌｘＷＯ３这一非平衡反应产物。常规烧结工艺合成Ａｌ２Ｏ３－ＷＯ３陶瓷材料所得试样没有线性的ＮＴＣ热敏电阻特性。     

A new method for the two-dimensional analysis of bone structure in human iliac crest biopsies

A new method is described for the analysis of the two-dimensional structural pattern of trabecular bone in human iliac crest biopsies. 8 μm thick undecalcified sections stained with the von Kossa technique were examined at a magnification of ×9. Using an Ibas II image analyser, the ratio of nodes to free ends and the length of different strut types (cortex to free end, node or cortex, free end to free end and node to node, loop or free end) expressed as a percentage of total strut length were assessed. The reproducibility of the method was good for most of the measured indices but inter-observer and inter-section variation were greater. Comparison of biopsy sections obtained from eleven young healthy control subjects and eleven patients with hepatic osteoporosis revealed a significantly higher node to free end ratio, node to loop and node to node strut length and significantly lower cortex to free end and free end to free end strut length in the controls. No significant differences were seen in node to free end, cortex to cortex or cortex to node strut length. This approach to trabecular bone structure analysis should prove useful in determining patterns of bone loss in health and disease and in examining the effects of treatment on bone structure in osteoporosis.     

Development of Detonation Flame Sprayed Cu-Base Coatings Containing Large Ceramic Particles

Metal-matrix composites (MMCs) containing large ceramic particles as superabrasives are typically used for grinding stone, minerals, and concrete. Sintering and brazing are the key manufacturing technologies for grinding tool production. However, restricted geometry flexibility and the absence of repair possibilities for damaged tool surfaces, as well as difficulties of controlling material interfaces, are the main weaknesses of these production processes. Thermal spraying offers the possibility to avoid these restrictions. The research for this paper investigated a fabrication method based on the use of detonation flame spraying technology to bond large superabrasive particles (150-600 μm, needed for grinding minerals and stones) in a metallic matrix. Layer morphology and bonding quality are evaluated with respect to superabrasive material, geometry, spraying, and powder-injection parameters. The influence of process temperature and the possibilities of thermal treatment of MMC layers are analyzed. This article is an invited paper selected from presentations at the 2007 International Thermal Spray Conference and has been expanded from the original presentation. It is simultaneously published in Global Coating Solutions, Proceedings of the 2007 International Thermal Spray Conference, Beijing, China, May 14-16, 2007, Basil R. Marple, Margaret M. Hyland, Yuk-Chiu Lau, Chang-Jiu Li, Rogerio S. Lima, and Ghislain Montavon, Ed., ASM International, Materials Park, OH, 2007.     

柱内径对堆积边界法富集重现性的影响

Breadmore提出了一种新型毛细管电泳富集方法（电渗流控制下的逆流等速电泳堆积边界法富集）,可对阴离子实现十万倍在线富集效果。本文以NO3-为模型分子考察了不同内径毛细管柱对该富集重现性的影响。实验发现,使用内径为75μm的毛细管柱时富集重现性极不稳定,富集阶段电流对富集时间的积分面积和NO3-电泳峰面积的RSD（n=10）分别高达6.98%和105.43%,而使用内径为25μm的毛细管柱时富集重现性稳定,富集阶段电流对富集时间的积分面积和NO3-电泳峰面积的RSD（n=7）分别为0.96%和4.43%。实验结果表明这种富集方法的稳定性依赖于富集阶段电流对富集时间的积分面积的重现性,进而依赖于实验中采用的毛细管柱内径的大小尺寸。