短脉冲激光与介质相互作用的扩散模型

推导了扩散近似方程,通过半无限大均匀介质计算,用扩散理论分析解验证了数值方法的有效性.模拟了光在非均匀介质内的传输过程,给出了介质内光通量随时间变化的空间分布.结果表明,该基于扩散模型的数值方法能够模拟短脉冲光在强散射介质中的传播过程以及漫散射光的时间变化特性,并且借助于光通量空间分布能够准确模拟非均匀介质内内含物的位置.     

回转窑多粒径颗粒流动与偏析的DEM模拟与实验研究

为明晰回转窑内颗粒的运动行为及偏析机理,以绿豆、黄豆和黑豆为颗粒介质,依次对3种装填顺序下的颗粒流动过程进行离散元模拟与实验研究,以颗粒质量分数和平均粒度为判据,对颗粒偏析进行评价。结果表明,回转窑内颗粒流动区可分为自由滚落区、渗流呆滞区以及窑壁携带区,自由滚落区颗粒流速最大,而渗流呆滞区流速最小。窑内颗粒沿轴向输运过程发生径向偏析,形成夹层结构,小颗粒受渗流作用在渗流呆滞区中心形成内核,大粒径和中等粒径颗粒集中在自由滚落区和窑壁携带区。窑内颗粒力链分布不均匀,强力链分布于近窑壁区,弱力链分布于自由滚落区和渗流呆滞区,且渗流呆滞区力链细而密集。当窑头附近不同粒径颗粒存在轴向速度差时,颗粒在轴向发生掺混,并产生径向偏析。     

技术导向路径与艺术理论建构

技术作为一种基础性的力量能对艺术发展起到关键作用,但在艺术理论建构过程中这一点却没有得到足够重视。技术从“能量”和“信息”两个维度对艺术产生根本性的影响,因此“为能量使用立法”和“阐释信息”则成为从技术维度建构艺术理论的路径。当下中国正经历一场以移动互联、5G等新引发的技术激变,艺术世界也面临一场崭新变革。艺术理论从技术维度的导向突破实现理论创新,不仅对艺术学自身建设有意义,对整个人文学科的创新发展也都有着不容忽视的意义。     

Adsorption of thorium(IV) on magnetic multi-walled carbon nanotubes

The influences of pH, contact time, solid-liquid ratio, temperature and C60(C(COOH)2)n on Th(IV) adsorption onto the magnetic multi-walled carbon nanotubes(MMWCNTs) were studied by batch technique. The dynamic process showed that the adsorption of Th(IV) onto MMWCNTs could reach equilibrium in 40 h and matched the pseudo-second-order kinetics model. The adsorption of Th(IV) onto MMWCNTs was significantly dependent on pH values, the adsorption ratio increased markedly at pH 3.0–5.0, and then maintained a steady state as pH values increased. At low pH, different C60(C(COOH)2)n content could enhance the adsorption content of Th(IV) onto MMWCNTs, but restrained it at higher pH. Through simulating the adsorption isotherms by Langmuir, Freundlich and Dubini-Radushkevich models, it could be seen respectively that the adsorption pattern of Th(IV) onto MMWCNTs was mainly surface complexation, and that the adsorption process was endothermic and irreversible.     

Characteristics of the magnetic analysis system for a compact MPR-type spectrometer

The magnetic proton recoil(MPR)spectrometer is a novel diagnostic instrument with high perfor-mance for measurements of neutron spectra in inertial confinement fusion(ICF)experiments and high power fusion devices.A compact MPR-type spectrometer dedicated to the research of pulsed deuterium-tritium(DT)neutron spectroscopy of special experimental conditions is currently under design.Analyses of the main parameters and performance of the magnetic analysis system through 3-D particle transport calculations and MonteCarlo simulations and calibration of the system performance as a test using CR-39 solid track detector and α particle from 239pu and 226Ra radioactive sources are presented in this paper.The results indicate that the magnetic analysis system will achieve a detection efficiency level of 10-5-10-4 at an energy resolution of 1.5%-2.1%,and fulfills the design goals of the spectrometer.     

Alkylation mechanism of benzene with 1-dodecene catalyzed by Et_3NHCl-AlCl_3

The isotope exchange method was employed to investigate the catalytic mechanism of ionic liquid in alkylation of benzenes with olefins.It is proposed that alkylation was induced by the Lewis acid AlCl3 which attracted π electrons of 1-dodecene to shift toward 1-carbon,thus forming a carbonium ion.The carbonium ion further reacted with benzenes to form a complex.Due to unstabilit of the complex,a deuterated ring proton was transferred into an electronegative 1-carbon of the side chain to substitute for the A...     

超声波辐照和臭氧氧化协同降解废水中的结晶紫

采用超声波辐照、臭氧氧化以及超声波辐照-臭氧氧化降解废水中的结晶紫;考察了废水初始pH、超声波功率和频率、氧气流量、反应温度等因素对降解效率的影响.结果表明:超声波和臭氧对结晶紫的降解具有协同作用;当废水溶液初始质量浓度为200mg.L-1、pH为10.0时,控制超声波功率和频率分别为100 W和30kHz,氧气流量为0.4L.min-1,反应温度为25℃,反应时间为90 min,则总有机碳(TOC)的去除率可达89.2%,相应的一级反应速率常数为2.38×10-2min-1.     

澳洲茄胺单糖苷的合成及其抗肿瘤活性

以单糖为原料,经苯甲酰化保护和溴代制备中间体酰化溴代糖(3a～3e)。通过Koenigs-Knorr合成法将3a～3e与澳洲茄胺甙化缩合并脱保护合成了5个澳洲茄胺单糖苷化合物(5a～5e,5d和5e为新化合物),其结构经1H NMR,13C NMR和MS表征。用MTT法对5a～5e进行体外抗肿瘤细胞活性试验结果表明,5c和5d显示了较好的抗肿瘤活性。     

电化学石英晶体微天平研究高氯酸钠水溶液中活性炭电极的离子存储行为

以电化学石英晶体微天平(EQCM)为主要测试手段,在不同浓度的高氯酸钠(NaClO4)水溶液中研究了水合离子吸附到活性炭电极孔隙过程中电极的质量变化.对于每种电解液,根据Raman光谱和EQCM数据分别计算了本体溶液中和电极/溶液界面上Na+的水合数.通过比对这两组Na+水合数,探讨了Na+存储到活性炭负极过程中的去溶剂化效应.