硫增感AgBrI T颗粒乳剂光电子行为研究

利用微波相敏技术，获得了硫增感AgBrI T颗粒乳剂中自由光电子和束缚光电子时间衰减信号，分析了光电子衰减时间、电子陷阱效应、光电子寿命、有效陷阱深度及束缚电子转移时间与增感时间的关系，获得了最佳的增感时间、衰减时间、电子陷阱效应、光电子寿命、有效陷阱深度和转移时间数值，     

S+Au增感对AgBrI T-颗粒乳剂中光电子衰减行为的影响

利用35ps脉冲激光发源,采用微波吸收介电谱检测技术,获得了S+Au增感后的AgBrI-T颗粒微晶中光电子衰减时间分辨谱,通过分析自由光电子和浅束缚光电子衰减曲线的变化,得到了S+Au增感的不同时间与AgBrI-T颗粒乳剂自由光电子寿命和衰减时间及浅束缚光电子衰减时间的对应关系,给出最佳增感时间。     

温度对还原增感立方体氯化银乳剂中光电子衰减的影响

利用微波介电检测技术,测得还原增感立方体氯化银乳剂中自由光电子与浅束缚光电子衰减行为随还原增感温度的变化。实验发现还原增感温度变化会引起增感中心陷阱作用的变化:当还原增感温度较低时,增感中心起空穴陷阱作用,延缓光电子衰减;还原增感温度较高时,增感中心起深电子陷阱作用,加速光电子衰减。由此,我们得到了确定最佳增感温度的依据。     

微波水热合成NiGa2O4纳米粉体及其气敏性能

采用微波辅助水热法制备了NiGa_2O_4纳米粉体。用X射线衍射光谱、扫描电子显微镜、透射电子显微镜和X射线光电子能谱等研究了反应温度、时间和沉淀pH对NiGa_2O_4的相组成以及气敏性能的影响。结果表明:微波水热下,180℃反应2 h合成晶型较好的NiGa_2O_4粉体。在pH为10、180℃反应2 h合成的NiGa_2O_4于室温下对三甲胺有较高的响应和较好选择性。对10×10~(-6)(mL/m~3)三甲胺响应值达到3.5,响应时间约为75 s,恢复时间约为45 s;最低检测限为1×10~(-6),响应值约为1.8。     

温度条件对光谱增感AgCl晶体光电子特性的影响

利用微波吸收相敏技术检测了光谱增感AgCl立方体乳剂的光电子时间分辨谱,增感样品由于染料吸附引起填隙银离子浓度增加,其光电子衰减比未增感的要快。通过分析增感温度条件与光电子特性的关系,发现温度条件影响了染料吸附程度,进而影响了光电子的衰减特性。温度为45℃时,晶体受染料吸附的影响最大,光电子衰减最快。低于或高于此温度时染料吸附不充分或存在生成大聚集体的趋势,引起晶体填隙银离子浓度的变化较小,光电子衰减较慢。     

光谱增感AgBrI-T颗粒乳剂光电子特性

用微波吸收相敏技术检测了光谱增感AgBrI T颗粒乳剂的自由光电子时间分辨谱 ,观察到增感样品在染料增感吸收峰位置有明显的光电子信号 ,在AgBrI T颗粒固有吸收带自由光电子衰减时间比未增感样品的衰减时间短。     

金属离子对溴碘化银乳剂微晶体的掺杂效应——Ⅱ.Pb~(2+)的掺杂

应用常规感光测定法、电镜法、介电损耗仪和微波光导仪研究了Pb~(2+)对卤化银乳剂微晶的掺杂效应。结果表明:Pb~(2+)使乳剂的感光度降低,灰雾明显升高,而反差变化不大。由电子显微镜照片表明,Pb~(2+)对乳剂微晶大小和形状影响不大,但是离子电导和微波光导数据显示出,Pb~(2+)的掺杂使离子电导率降低0.15个对数单位,电子电导成倍降低。上述结果暗示:Pb~(2+)对照相性能的影响不是由于乳剂微晶大小和形状的变化,可能由以下两个原因引起:(1)Pb~(2+)起了深的电子陷阱作用,使光电子徙动路程缩短,影响潜影的形成效率,(2)Pb~(2+)(或PbBr_2)成为复合中心,加速光电子与空穴的复合,催化显影过程。     

还原增感立方体AgCl微晶光电子衰减特性

利用微波吸收介电谱检测技术测得了还原增感立方体氯化银微晶光电子衰减随增感条件的变化规律。实验发现,随增感条件的不同,增感中心发生了由空穴陷阱作用向深电子陷阱作用的转变。当增感中心起空穴陷阱作用时通过俘获空穴,降低了光电子与光空穴的复合几率,提高了光电子的利用率,从而有利于潜影的形成。由此得到在增感浓度一定时的最佳增感时间和最佳增感温度的组合。     

硫增感AgBr I T颗粒乳剂光电子行为研究

本文利用微波吸收相敏检测技术,同时获得了硫增感AgBrIT颗粒乳剂,在不同增感条件下自由光电子和浅俘获光电子的时间衰减曲线,分析了不同的硫增感产物的陷阱效应.结果表明:开始时,增感产物起电子陷阱作用,至45min时,浅电子陷阱作用最佳.如增感时间进一步增加,硫增感产物将变为深电子陷阱.本文还讨论了浅电子陷阱中浅俘获光电子衰减时间与阱深的依存关系.     

石墨相四氮化三碳/氧化锌复合材料的制备及其气敏性能

采用水热法制备了一系列石墨相四氮化三碳-氧化锌(g-C3N4-ZnO)复合材料,并使用X射线衍射、高分辨透射电子显微镜、Fourier变换红外光谱和X射线光电子能谱对复合材料进行了表征,研究了g-C3N4-ZnO复合材料的气敏性能。结果表明:加入9%(质量分数,下同)g-C3N4所制备的g-C3N4-ZnO复合材料在300℃对乙酸具有较好的气敏选择性和较高的气敏灵敏度,对10-3乙酸气体灵敏度达到260.4,响应和恢复时间分别为6 s和5 s,对10-6乙酸气体灵敏度可达到1.8。     

井下供电相敏短路保护技术的现状与研究

针对煤矿井下低压供电系统相敏短路保护技术的现状,对比了几种常用相敏保护装置的类型、保护方式及技术特点,展望了矿井智能化配电系统的发展趋势,对相敏短路保护器的选用具有参考价值。     

微波技术在煤脱硫领域中的应用及发展

主要介绍了微波技术在煤脱硫领域中的应用。较为系统地介绍了微波脱硫技术的原理、分类及发展,并着重对微波预处理磁选脱硫法和微波化学脱硫法的发展及效果进行了比较详细的讨论。     

NMR Spectra of Nitrobenzanthrones Obtained by Using Double-Pulsed Field-Gradient Spin Echo

We have synthesized several nitrobenzanthrones (NBAs) and investigated their structures in solution using NMR spectroscopy. In our study, however, low solubility of NBAs in organic solvents always became a serious problem and led to NMR spectra with low signal-to-noise ratios. To solve this problem, we adopted a new method of conventional coherence transfer pathway selection using pulsed field-gradients. The double-pulsed field-gradient spin echo (DPFGSE) sequence was used for selecting natural-abundance carbon-13 isotopomers by using a bilinear rotation decoupling (BIRD) sequence and a so-called gradient-BIRD pulse for the excitation sculpting technique. We performed NMR measurements on 3,9-dinitro-7 H -benz[ d,e ]anthracene-7-one (compound 1), 3,9,11-trinitro-7 H -benz[ d,e ]anthracene-7-one (compound 2), and 2-nitro-7 H -benz[ d,e ]anthracene-7-one (compound 3) by this method and obtained spectra of high quality. Combining the results from phase-sensitive 2D NOESY, HOHAHA, and DPFGSE-HMQC, DPFGSE-HMQC TOCSY, and phase-sensitive FG-HMBC permitted us to complete NMR assignments. It was confirmed that the present method enables us to improve the sensitivity and to assign the NMR signal readily, even for compounds with low solubility.     

环保型高强力再生橡胶微波辐射工艺的研究

为了优化环保高强力再生橡胶的微波辐射工艺,本文首先对微波再生原料进行预处理,然后选择合理的微波辐射方法,在微波再生过程中确定了适宜的加料顺序,在微波再生后确定了再生橡胶的冷却工艺,还确定了再生过程中的最佳工艺条件微波辐射时间、温度和功率。通过优化微波辐射工艺获得的环保型高强力再生橡胶,胶片表面光洁、质地均匀,适合压延、压出工艺。实验结果表明再生胶的拉伸强度和扯断伸长率能分别达到18．74MPa和443．00％。     

COMBINED SUPERHEATED STEAM AND MICROWAVE DRYING OF SINTERED GLASS BEADS: DRYING RATE CURVES

A new drying method of combined superheated steam and microwave drying is being proposed. The drying rates of sintered glass beads in combined superheated steam and microwave drying are experimentally and theoretically investigated. Drying experiments have been carried out in a waveguide where a standing wave is formed to uniformly heat a small sample. Concerning drying rate curves in combined superheated steam and microwave drying, a distinct constant rate period has been observed. For the falling rate period, high drying rates have been observed. For both periods, the drying rates in combined superheated steam and microwave drying are higher than those in superheated steam alone. Also, in comparison with the results of combined nitrogen and microwave drying, the normalized drying rates in combined superheated steam and microwave drying are higher than those at less than the critical moisture content in combined nitrogen and microwave drying. Moreover, theoretical drying rates for the falling rate period (predicted by a modified receding evaporation front model) in combined superheated steam and microwave drying, are in good agreement with the observed drying rates. The combined superheated steam and microwave drying method can attain higher drying rates under mild external conditions.     

微波介质陶瓷的研究现状及其粉末合成方法

微波介质陶瓷作为微波介质滤波器、微波介质谐振器及微波介质振荡器的重要材料,是现代通信技术中关键基础材料,它的研究越来越受到人们的重视。本文综述了目前微波介质陶瓷的主要三种结构体系,并且介绍了微波介质陶瓷的国内外研究现状,粉体的制备以及存在的问题和未来发展趋势。     

微波辐照对松香与丙烯酸加成反应产物酸值的影响

研究了微波对松香与丙烯酸发生Diels-Alder加成反应的促进作用,并通过FT-IR、紫外和HPLC对产物进行分析,确认主要产物即为目标产物。结果表明,微波可有效地加速反应。在35 g松香,7.2 mL丙烯酸加成反应体系中,微波辐照下常压反应90 min,或在密闭压力罐中反应 5 min,反应基本完成。产物的酸值远高于常规加热反应8 h所得产物。常规加热法制备丙烯酸松香时,增加反应时间、升高反应温度均有利于产物酸值的提高。而微波加热反应体系,加压体系中最佳微波功率是640 W,较高的功率和更长的反应时间反而导致产物酸值降低。     

Crystallization of aragonite particles from solution under microwave irradiation

The effect of intense electromagnetic fields, generated inside a multimode microwave applicators, on the crystallization of calcium carbonate polymorphs starting from calcium bicarbonate solutions has been investigated. The identification and quantitative analysis of the calcium carbonate polymorphs has been made by X-ray diffraction using Rietveld-Reference Intensity Ratio (RIR) method. Scanning Electron Microscopy analysis has also been performed to study the morphology of calcium carbonate samples. Crystallization tests have been conducted at atmospheric pressure while adjusting microwave power to maintain solution temperature between 80 °C and 90 °C. For the sake of comparison, calcium carbonate powders have also been prepared using conventional heating either in a oven or on a hot plate with a magnetic stirrer. The experiments conducted using microwave radiation gave in a high percentage yield of aragonite (99%) which has been favoured by increasing microwave exposure times. Low microwave exposure times, on the other hand, favours vaterite formation which crystallized in an unusual flower-like morphology.     

Drying of a Slip Casting for Tableware Product Using Microwave Continuous Belt Dryer

To demonstrate the potential of microwave drying in the ceramic industry, microwave demolding of tableware product by a continuous microwave belt drier has been investigated. This study focuses on the investigation of the effects of the irradiation time, sample size, microwave power and location of magnetron on overall drying kinetics. The results show that microwave drying has several advantages over the conventional method such as shorter processing time, volumetric dissipation of energy throughout a product, high energy efficiency, reduced amount of mold usage, and offering product quality. Further quantitative validation of experimental data could be very useful, especially in providing information for processing high-performance microwave drying for developing the ceramic industry in Thailand.