关于Lipschitz域上反射Brown运动的游程

本文具体刻画有界Lipschitz域上的反射Brown运动跨过某给定时刻t的离开Martin边界的游程.在此基础上,给出Lipschitz域上的反射Brown运动的边界过程的Levy系统.     

Effect of helium-neon laser on fast excitatory postsynaptic potential of neurons in the isolated rat superior cervical ganglia

The aim of this study is to further measure the effect of 632.8-nm helium-neon laser on fast excitatory postsynaptic potential (f-EPSP) of postganglionic neurons in isolated rat superior cervical ganglia by means of intracellular recording techniques. The neurons with f-EPSP were irradiated by different power densities (1 - 5 mW/cm2) laser. Irradiated by the 2-mW/cm2 laser, the amplitude of the f-EPSP could augment (P < 0.05, paired t test) and even cause action potential at the end of the first 1 - 2 minutes, the f-EPSP could descend and last for 3 8 minutes. But the amplitude of the f-EPSP of neurons irradiated by the 5-mW/cm2 laser could depress for the irradiating periods. The results show that: 1) the variation of the amplitude of f-EPSP caused by laser is power density-dependent and time-dependent; 2) there exist the second-order phases in the interaction of the helium-neon laser with neurons. These findings may provide certain evidence in explanation of the mechanisms of clinical helium-neon lase     

关于Lipschitz域上反射Brown运动的游程

本文具体刻画有界 Lipschitz 域上的反射 Brown 运动跨过某给定时刻 t 的离开 Martin 边界的游程．在此基础上,给出 Lipschitz 域上的反射 Brown 运动的边界过程的 L(?)vy 系统．     

小分子化合物在离子阱质谱中的分子离子反应研究

利用离子阱质谱的原理和特点，研究了小分子醇、醚、胺、醛、酮等有机化合 物（分子量小于200）在离子阱里的分子离子反应，总结了反应特点和规律，并把 它归类为自身化学电离（SCI）反应。以丁酮、丙烯醇为例，采用FTMS对反应产物 离子进行准确质量测定，验证了它们各自的分子离子反应结果。另外，把该类化合 物（30个）SCI反应的质谱图与NIST98库中的标准EI质谱图进行了比较，建立了 SCI质谱图库，提高了在离子阱质谱上对这类小分子化合物定性分析的准确率。     

有机质谱学法研究气相S_N2离子－分子反应进展

总结了近年来应用质谱方法研究气相SN2离子－分子反应的进展，主要包括气 相SN2离子－分子反应的机理，动力学和热力学的各种因素。与凝固相中反应对比 ，阐明了影响反应机理、方向与程度的决定性因素，及溶剂化效应对凝聚相中反应 的影响方式。还介绍了一些气相中特有的SN2离子－分子反应和研究气相反应特殊 的质谱学研究方法与技术。     

液相色谱/大气压化学电离飞行时间质谱分析氢化可的松中微量杂质

采用液相色谱/大气压化学电离飞行时间质谱测定氢化可的松对照品中微量杂 质，并采用源内碰撞诱导解离质谱进行了结构定性分析。方法简单，可靠，重现性 好。     

新鲜温郁金中姜黄与莪朮挥发性成分的顶空-气相色谱-质谱联用对比分析

本文用顶空-气相色谱-质谱的方法测定了温郁金的不同药用部位：莪朮与姜黄，有60多种挥发性化合物被检测到，通过NIST谱库检索结合保留指数数据分别定性了其中51和48种挥发性成分。实验中用β-榄香烯作为外标进行相对定量分析，比较了不同产期莪术中挥发油含量的变化，从而有利于最佳采收时间的确定。对于同产期的温郁金的不同药用部位：莪术和姜黄，本文也进行了比较，它们的有效成分相似，但是含量有差别。用H/D交换的方法进一步确定了含活泼H的化合物，g-萜品烯在烯丙位也发现了很明显的H/D交换，通过裂解途径的分析本文确定了H/D交换的位置。这种方法不仅可以用于含挥发油成分的药用植物有效成分的定性，还可以用于它们有效成分的相对定量。     

顶空-气相色谱法进展

回顾了顶空采样气相色谱分析法在复杂基质中挥发性成分中的应用．总结并详述了顶空分析的三种重要模式-介绍了顶空分析的相关原理和整个顶空分析系统的参数优化过程．综述了顶空．气相色谱分析在生物样本中挥发性有机物的测定、药品中有机残留溶剂的检测、聚合材料中挥发性有机物的分析、环境中有害的有机挥发性物质分析、挥发油分析和烟草分析等方面的进展．     

MALDI/FTMS中碰撞衰减机理对准确质量校正的影响

Collisional　damping　affects　the　relationship　between　ion　mass　and　effective　cyclotron　frequency　in　Fourier transform mass spectrometry. The exact mass calibration equation（m/z=A/f＋（mneutral/m^^＋mneutral）k＋B/f（f＋（mneutral/m^^＋mneutralk））was therefore derived from the characteristic equation of system model, force=m（dv/dt）=qE-qv×B0-ξv,a frictional damping force）, in which k is amended by the shift of observed frequency of matrix ion or other known ion in external calibration. The mass obtained by the amended calibration equation is therefore immune to collisional damping and space-charge effects on mass accuracy. The relative errors of ion mass measured were all less than 2×10^-6.     

新型除草剂及其杂质的LC-MS和GC-MS分析

High performance liquid chromatography (HPLC) and electrospray ionization mass spectrometry (ESI-MS) have been utilized to analyze the synthesized 2-(2-arylaminomethylphenoxy)pyrimidine derivatives, which are a new kind of environmentally benign herbicides and have passed the temporary pesticide registration. The identification of main product and impurities has been achieved according to the UV and mass spectra. Moreover, one impurity, introduced by the raw material in the last step of the synthetic route, was identified by GC-MS analysis. It can be concluded that the combination of chromatography and mass spectrometry, including LC-MS and GC-MS, provided a vital tool of the pesticide science.