测定铁路客车空调机组制冷量的一种简便方法

测定铁路客车空调机组制冷量的一种简便方法王辉（锦州铁路司机学校）关键词：客车空调；参数测定；制冷量计算中图分类号：Ｕ２７０．３８３空调机组的制冷量是判定空调机组性能的一项主要指标。要精确地测定制冷量，需设置相应的场地及众多复杂的测试仪器，而目前大多数...     

无机结合料水泥剂量在不同龄期滴定的变化

通过对无机结合料在不同龄期下用EDTA滴定量的不同，表明结合料在不同龄期下对其滴定结果的影响程度。     

600t／h厂拌设备拌合二灰砂砾施工定额的测定

600t／h厂拌设备拌合二灰砂砾施工定额为交通部《公路工程施工定额》(1997版)的缺项定额，该施工定额的测定，填补了国内公路施工定额的空白。     

沥青路面抗滑的相关研究

通过对沥青路面抗滑机理、影响因素等相关内容的分析,以及抗滑能力的测定,为沥青路面抗滑研究提供了更多的理论依据。     

盐渍土的试样制备方法探讨

本文分析了按常规土工试验方法制备试样测定盐渍土基本性质指标所存在的问题,探讨了盐渍土主要是硫酸盐盐渍土的土样制备方法。     

Determination of enantiomeric impurity of etomidate by high performance liquid chromatography

Objective To determine enantiomeric impurity of etomidate using high performance liquid chromatography. Methods (R)-etomidate and (S)-etomidate were isopropanol-n-hexane. The flow rate of the mobile phase was 0.5mL/min. The detected wavelength was 242nm. Results (R)-etomidate and (S)-etomidate could be separated completely under these conditions. The precision of (R)-etomidate was 1.57% (n=3). The limit of detection of (R)-etomidate was 4.25ng/mL. The average percentage content of (S)-etomidate was 0.09% in the samples. Conclusion The method was repeatable and sufficiently sensitive to determine the enantiomeric impurity of etomidate. It allows the quantitation of the impurities at the 0.085% (w/w) level relative to etomidate at a concentration of the test solution of 5mg/mL.     

RP-HPLC method for the simultaneous determination of daidzein,genistein and formonetin in Solanum Lyratum Thunb

A rapid method for the simultaneous determination of daidzein, genistein and formonetin in solanum Lyratum Thunb by high performance liquid chromatography (HPLC) was developed. Separation was achieved on a Diamonsil C18 column (250 mm×4.6 mm, 5 μm) with isocratic elution, using a mobile phase of methanol-tetrahydrofuran-water (44∶3∶53, v/v). The wavelength was set at 260 nm and column was maintained at 35 ℃. The linear ranges of daidzein, genistein and formonetin were 1.0-40.0, 0.1-4.0 and 0.1-4.0 μg/mL, respectively. The average recoveries were between 98.4% and 101.3%. This method could be used for the quality control of Solanum lyratum Thunb due to its simplification, reliability, rapidity and excellent precision.     

试杆法测定水泥标准稠度用水量试验判定标准（6±1）mm调整研究

本文通过对试杆法测定水泥标准稠度用水量试验的分析研究,提出了将规程规定的试验结果判定标准（6±1）mm调整为距底板（6±2）mm的设想,以降低该试验的操作难度,提高工作效率。经过大量试验论证表明,该调整设想具有可行性。