999 resultados para perdas de MS
Resumo:
这篇论文里,我们对基于ms Windows的微机γ谱分析程序的数学原理,算法及程序设计进行了阐述;同时,我们也介绍了测试结果,此结果表明了拟合过程的高效性,高稳定性与准确性,并且,程序计算出的峰面积也是可接受的。 在第一部分里,全面阐述了数学原理与算法,包括由M. A. Mariscotti设计且已衍生出许多新算法的叫作DIFDIF的找峰算法,由BFGS方法实现的以χ2为拟合优值的拟合过程,在求峰下净面积及进行系统刻度中需要使用的公式等等。这些内客构成了γ谱分析程序设计哲学的核心,也是本论文的重点。 第二章里,我们一方面概括地介绍了基于面向对象思想的从系统分析到设计整个过程的系统开发文档;另一方面,我们也介绍了一些有用的程序片段,它们或者关于C++或MS Windows程序设计方法,或者关于运行时间错的处理。
Resumo:
建立了气相色谱-质谱-选择离子监测(GC-MS-SIM)同时测定土壤中10种农药(三嗪类除草剂、酰胺类除草剂和有机氯农药)的多残留分析方法.样品采用正己烷/丙酮(1:1,V/V)超声提取、氟罗里硅土柱层析净化、GC-MS-SIM测定.10种农药在0.01(0.02)—1.0(2.0)mg.l-1范围内线性良好,相关系数介于0.9963—0.9998之间;在10,50和250ng.g-1添加水平下,平均回收率介于81%—117%之间,相对标准偏差均小于14.4%;方法检出限达到ppb至sub-ppb级(0.1—1.3ng.g-1).将此方法应用于辽宁省不同性质土壤中70个实际土壤样品的分析,阿特拉津、乙草胺、六氯苯、丁草胺、狄氏剂和艾氏剂有检出,该法对不同性质土壤具有广泛适用性.
Resumo:
A high-throughput screening system for secondary catalyst libraries has been developed by incorporation of an 80-pass reactor and a quantified multistream mass spectrometer screening (MSMSS) technique. With a low-melting alloy as the heating medium, a uniform reaction temperature could be obtained in the multistream reactor (maximum temperature differences are less than 1 K at 673 K). Quantification of the results was realized by combination of a gas chromatogram with the MSMSS, which could provide the product selectivities of each catalyst in a heterogeneous catalyst library. Because the catalyst loading of each reaction tube is comparable to that of the conventional microreaction system and because the parallel reactions could be operated under identical conditions (homogeneous temperature, same pressure and WHSV), the reaction results of a promising catalyst selected from the library could be reasonably applied to the further scale-up of the system. The aldol condensation of acetone, with obvious differences in the product distribution over different kind of catalysts, was selected as a model reaction to validate the screening system.