查询词典 cation

On the other hand, the energy decomposition shows that dispersion and repulsive exchange forces play an important role in the organic cation-π interaction, although the electrostatic and induction forces dominate the interaction.

其次，能量分解结果显示，虽然静电能和诱导能在阳离子（NH4+）－π相互作用中占主导地位，但色散能和交换排斥能也是不可忽视的。

Methods Streptomycin and dihydrostreptomycin were extracted from honey samples using a liquid extraction with a phosphate buffer followed by a solid-phase extraction based on weak cation-exchange columns. After sample preparation, the hydrophilic interaction chromatography was used to retain streptomycin and dihydrostreptomycin on the column for the separation of the analytes from endogenous compounds. The aminoglycosides were detected and quantified with electrospray ionization tandem mass spectrometry.

方法用磷酸盐缓冲溶液提取蜂蜜中的链霉素和双氢链霉素后，经弱阳离子交换柱进行固相萃取，样品制备后采用亲水作用色谱，使链霉素和双氢链霉素实现保留，从而与内源性物质达到分离，采用电喷雾离子化串联质谱法检测和定量。

The influence of transition metal cation dissolved in DMSO on the generation of superoxide anion radical was also investigated.

论文还系统研究了DMSO中微量过渡金属离子的存在对DMSO／NaOH体系产生超氧孤离子自由基的影响。

The analysis procedure,classifi-cation of measurement error,calculating of radom uncertainty,bias limitsof systematic error and total uncertainty for this method are emphasised.The problems of future research for this method are investigated.

着重介绍这种方法的分析步骤、误差的分类、随机不确定度、系统误差限和总不确定度的计算方法，同时还探讨了这种方法尚待进一步研究的问题。

The main research work of this dissertation is as follows: Based on the chemical reaction engineering theory and the nitrobenzene electroreduction mechanism, the plate and frame electrolyzer was designed and applied to the process of electroreduction nitrobenzene to p-aminophenol. This dissertation measured the residence time distribution data of the electrolyzer by means of the pulse response method and studied the rule of flow pattern along with the current capacity change. Under different conditions ,this dissertation studied the cyclic voltammetry properties of nitrobenzene on different electrodes by means of the dynamic cyclic voltammetry method and the electrode materials applied to the NB electroreduction have been selected primarily.Baseed on the results of cyclic voltammetry tests, this dissertation used p-electrode systems to measure the steady-state- polarization curves of nitrobenzene on different electrodes in H-type diaphragm cell, and obtained each primary factor s influence rule and the exchange current density value of each electrode.And then on the basis of the conclusions of fundamental researchs upword, the effects of influence factors on the the yield of p-aminophenol and the current efficiency,such as electrode material, current density, quantity of electricity circulated, nitrobenzene concentration . sulpuric acid concentration and so on, have been studied in detail in the systems of hign temperature , strong acidity and oxygen-poorthrough a series of electrolysis experiments in this paper.After all using Pb as anode Monel metal as cathode Dupont Nafion 417 cation-exchange membrane as membrane, this dissertation obtained the optimum technological condition: reaction temperature about 85C, current density 500A m-2, sulphuric acid concentration 20%wt.

论文的主要研究工作为：运用化学反应工程理论，结合硝基苯的电还原机理，设计出用于硝基苯直接电还原合成对氨基苯酚实验的板框式电解槽，并利用脉冲响应法测定了该板框式电解槽的停留时间分布数据，研究了流型随流量变化的规律；通过动态循环伏安法研究了硝基苯在不同电极上、不同条件下的循环伏安特性，初步评选出了用于硝基苯电还原的电极材料；结合循环伏安的测定结果，在H型隔膜电解槽中采用三电极体系测定了硝基苯在不同电极上、不同条件下的稳态极化曲线，得到了各主要因素的影响规律及硝基苯在各个电极上电还原的交换电流密度数值；在基础研究结论指导下，采用板框式电解槽，在高温、强酸、贫氧系统中，进行了一系列的电解实验，分别考察了电极材料、电流密度、通电量、硝基苯浓度、硫酸浓度等因素对收率及电流效率的影响，最终选择以蒙乃尔合金电极作为阴极、铅合金为阳极、Dupont Nofion 417阳离子交换膜为隔膜，得到由硝基苯直接电还原制对氨基苯酚的最佳电解工艺条件：反应温度85℃，电流密度500A·m~(-2)，硫酸浓度20％wt。

The absorption and distribution of chromium were studied in ryeusing nutrient culture technique and pot experiment.

采用不同浓度K2CrO4(0，0.4，0.8和1.2 mmol/L)的Hoagland营养液处理黑麦幼苗，测定铬在黑麦体内的亚细胞分布、铬化学形态及不同部位的积累。

By analyzing theory foundation of mathematical morphology in the digital image processing, researching morphology arithmetic of the binary Image, discussing two basic forms for the least structure element: dilation and erosion.

通过分析数学形态学在图像中的理论基础，研究二值图像的形态分析算法，探讨最小结构元素的两种基本形态：膨胀和腐蚀；分析了数学形态学复杂算法的基本原理，把数学形态学的部分并行处理理念引入到家实际应用中。