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排序方式: 共有201条查询结果,搜索用时 15 毫秒
1.
Zarubitskii O. G. Budnik V. G. Omel'chuk A. A. Melekhin V. T. Opanasyuk V. P. Zakharchenko N. F. 《Russian Journal of Applied Chemistry》2002,75(4):558-561
Electrochemical separation of lead-silver alloys into the constituents by thin-layer electrolysis in molten electrolytes, with bismuth as metal separator, is studied. It is proposed to determine the extent of component recovery by potentiometry. 相似文献
2.
基于MATLAB的异步电动机线性化控制系统的仿真 总被引:1,自引:0,他引:1
从异步电动机在同步旋转坐标系下的状态方程出发,在一定的条件下,对其系数矩阵简化.推出异步电动机的线性化控制模型.并基于该模型得出异步电动机的线性化控制系统.以给定电机为例,对该模型的有效性、响应用MATLAB进行仿真分析.验证的结果说明上述模型具有实用价值. 相似文献
3.
CHEN Zhi-hong XU Li BA Xue-qing ZENG Xian-lu 《高等学校化学研究》2006,22(3):302-307
Introduction Migrationandrecruitmentofleukocytesfromblood toinflammatorylesionsitesaresequentiallyregulated byadhesionmoleculesandtheirreceptors[1].These lectinfamilyplaysamajorroleininitiatingattachement ofneutrophilstotheactivatedendothelium.P selectin,… 相似文献
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Jebanathirajah JA Pittman JL Thomson BA Budnik BA Kaur P Rape M Kirschner M Costello CE O'Connor PB 《Journal of the American Society for Mass Spectrometry》2005,16(12):1985-1999
The use of a new electrospray qQq Fourier transform ion cyclotron mass spectrometer (qQq-FTICR MS) instrument for biologic applications is described. This qQq-FTICR mass spectrometer was designed for the study of post-translationally modified proteins and for top-down analysis of biologically relevant protein samples. The utility of the instrument for the analysis of phosphorylation, a common and important post-translational modification, was investigated. Phosphorylation was chosen as an example because it is ubiquitous and challenging to analyze. In addition, the use of the instrument for top-down sequencing of proteins was explored since this instrument offers particular advantages to this approach. Top-down sequencing was performed on different proteins, including commercially available proteins and biologically derived samples such as the human E2 ubiquitin conjugating enzyme, UbCH10. A good sequence tag was obtained for the human UbCH10, allowing the unambiguous identification of the protein. The instrument was built with a commercially produced front end: a focusing rf-only quadrupole (Q0), followed by a resolving quadrupole (Q1), and a LINAC quadrupole collision cell (Q2), in combination with an FTICR mass analyzer. It has utility in the analysis of samples found in substoichiometric concentrations, as ions can be isolated in the mass resolving Q1 and accumulated in Q2 before analysis in the ICR cell. The speed and efficacy of the Q2 cooling and fragmentation was demonstrated on an LCMS-compatible time scale, and detection limits for phosphopeptides in the 10 amol/muL range (pM) were demonstrated. The instrument was designed to make several fragmentation methods available, including nozzle-skimmer fragmentation, Q2 collisionally activated dissociation (Q2 CAD), multipole storage assisted dissociation (MSAD), electron capture dissociation (ECD), infrared multiphoton induced dissociation (IRMPD), and sustained off resonance irradiation (SORI) CAD, thus allowing a variety of MS(n) experiments. A particularly useful aspect of the system was the use of Q1 to isolate ions from complex mixtures with narrow windows of isolation less than 1 m/z. These features enable top-down protein analysis experiments as well structural characterization of minor components of complex mixtures. 相似文献
7.
应用原子吸收光谱法测定了内蒙古地产的笃斯茎、叶中的Cu,Fe,Zn,Mn,Ca,Mg等六种人体必需微量元素及宏量元素的含量。从而为评价笃斯的品质及其药理、药效提供了具有一定价值的数据。 相似文献
8.
采用普通溶液法合成了配合物[Zn(eiqnthz)_2]·DMF(1)和[Zn3(piqnthz)_2Cl_2]·2H_2O(2)(Heiqnthz=N,N′-乙酰异喹啉甲酰肼,H2piqnthz=N,N′-丙酰异喹啉甲酰肼)。通过X射线单晶衍射分析、X射线粉末衍射分析、红外光谱分析、热重分析以及荧光光谱分析等分析方法对2个配合物进行结构测定和性质表征。结构分析表明配合物1是单核结构,单斜晶系,空间群为C2/c,锌离子周围有4个氮原子和2个氧原子与之配位,形成一个畸变的N4O2八面体构型。配合物2属于单斜晶系,C2/c空间群,三核结构。中心原子Zn(1)、Zn(2)、Zn(3)均为5配位,Zn(1)、Zn(3)位于分子两端并且是变形四角锥配位构型,Zn(2)位于中间形成三角双锥配位构型,整体呈V字型。荧光分析表明Heiqnthz、H2piqnthz与锌(Ⅱ)离子配位后其荧光都发生较大的红移。 相似文献
9.
Separation and determination of homogenous fatty alcohol ethoxylates by liquid chromatography with mulitstage mass spectrometry 下载免费PDF全文
Joanna Zembrzuska Irena Budnik Zenon Lukaszewski 《Journal of separation science》2014,37(13):1694-1702
Alcohol ethoxylates (AEs) are a significant component of a stream of surfactants directed to the aquatic environment. The aim of this work was the investigation of the dependence of the analytical signals of homogeneous AE homologues on liquid chromatography with tandem mass spectrometry conditions, as well as the separation of AEs from the water matrix and, on this basis, the development of an analytical procedure suitable for the determination of AEs in environmental samples. Homogeneous homologues containing dodecyl moiety and 2–9 oxyethylene subunits were investigated. The analytical signals of the investigated homologues were optimized in terms of concentration of ammonium acetate in the mobile phase (optimum 5 mM) and a column temperature (optimum 35°C) of the liquid chromatography with tandem mass spectrometry system. A separation of AEs from the water matrix by liquid–liquid extraction (ethyl acetate, chloroform) or solid‐phase extraction (C18, styrene divinylbenzene, H‐RX) was investigated. In a model investigation, the best recoveries (>90%) were obtained with a styrene divinylbenzene cartridge eluted with a 1:1 mixture of chloroform and methanol. However, much worse recoveries were obtained from the river water sample. Better results were obtained for liquid–liquid extraction with ethyl acetate. Recoveries of 62–80% were obtained for homologues having 4–9 oxyethylene subunits, at the lowest spike. 相似文献
10.
LIU Yan-Ping CHEN Zhao-Yang BA Wei-Zhen FAN Yan-Wei DU Yan-Zhao PAN Shi-Lie GUO Qi 《中国物理C(英文版)》2008,32(5)
The optically stimulated luminescent (OSL) radiation dosimeter technically surveys a wide dynamic measurement range and a high sensitivity.Optical fiber dosimeters provide capability for remote monitoring of the radiation in the locations which are difficult-to-acoess and hazardous.In addition.optical fiber dosimeters are immune to electrical and radio-frequency interference.In this paper,a novel remote optical fiber radiation dosimeter is described.The optical fiber dosimeter takes advantage of the charge trapping materials CaS:Ce, Sm that exhibit OSL.The measuring range of the dosimeter is from 0.1 to 100 Gy.The equipment is relatively simple and small in size,and has low power consumption.This device is suitable for measuring the space radiation dose and also can be used in high radiation dose condition and other dangerous radiation occasions. 相似文献