带单参数q的无限维Block型李代数的性质

研究了一类带单参数q的无限维Block型李代数,这类李代数是Virasoro-like李代数的推广. Virasoro-like李代数是一类非常重要的无限维李代数.本文研究了这类李代数子代数,同构和同态.     

利用色度传感器探究火柴头火药中硫的含量

借助创新实验装置,进行酸性高锰酸钾溶液吸收火柴头火药燃烧产生的二氧化硫气体而部分褪色的平行实验;借助色度传感器,建立梯度浓度酸性高锰酸钾溶液吸光度与浓度的标准曲线,得出平行实验中一定体积酸性高锰酸钾溶液褪色前后的浓度差,依据反应关系,分别算出火药燃烧产生的二氧化硫气体的质量,从而得出火柴头火药中硫的平均质量分数为6.03%。     

金属及其化合物掺杂PVDF介电/压电材料的研究进展

聚偏氟乙烯(PVDF)是一种具有热电性和压电性的聚合物,由于其具有良好的柔韧性、热稳定性和耐腐蚀性等优点,因此在电子电气领域具有广阔的应用前景,但相对于传统无机类压电材料来说,其介电常数和压电常数仍相对较低,因此提升PVDF的压电性能和介电性能已成为目前国内外的研究热点之一。本文对近年来国内外利用金属及其化合物来提高聚偏氟乙烯(PVDF)电性能的方法进行了概述,并对金属及其化合物掺杂PVDF的利弊及发展趋势进行了展望。     

罗格列酮二甲双胍加合物的合成及表征

报道了罗格列酮二甲双胍加合物(Rosiglitazone metformin adduct)的合成,红外和晶体结构,罗格列酮二甲双胍加合物属于单斜晶系,空间群为P-1,晶胞参数:a=0.6967(2)nm,b=1.1282(3)nm,c=1.7208(5)nm.α=72.374(6)°,β=81.835(6)°,γ=74.140(6)°,晶胞体积V=1.2374(6)nm3,晶胞内分子数Z=2.罗格列酮与二甲双胍之间的氢键为N(6)-H(6B)…O(2)(-x+1,-y,-z+1):0.2893(7)nm,N(8)-H(8C)…N(1)(-x+2,-y,-z+1):0.2951(7)nm,N(7)-H(7B)…O(1) (x-1,y,z):0.2883(6)nm,晶态下分子间以氢键作用力和范德华力维系其空间稳定性,罗格列酮分子内无氢键,二甲双胍分子内及分子间均有氢键联系.     

基于Blackboard的《大学物理实验》网络教学平台设计

简述如何运用Blackboard教学平台的功能解决实验教学的困难,如何建立网络教学平台辅助实验教学,以及平台使用后的效果.     

Micro-track structure analysis for 100 MeV Si ions in CR-39 by using atomic force microscopy

To analyze the micro-track structure of heavy ions in a polymer material,parameters including bulk etch rate,track etch rate,etch rate ratio,and track core size were measured.The pieces of CR-39 were exposed to 100 MeV Si ions with normal incidence and were etched in 6.25N NaOH solution at 70 C.Bulk etch rate was read out by a profilemeter after several hours of etching.The other parameters were obtained by using an atomic force microscope(AFM)after a short time of etching.We have measured the second etch pits and minute etch pits to obtain the track growth curve and three dimension track structures to track the core size and etch rate measurements.The local dose of the track core was calculated by theδ-ray theory.In our study,we figure out that the bulk etch rate Vb=(1.58±0.022)μm/h,the track etch rate Vt=(2.90±0.529)μm/h,the etch rate ratio V=1.84±0.031,and the track core radii r≈4.65 nm.In the meantime,we find that the micro-track development violates the traditional track-growth model.For this reason,a scenario is carried out to provide an explanation.     

Passive Q-Switching Modelocked Yb^3＋ -Doped Fibre Laser with GaAs Absorber Grown at Low Temperature

GaAs absorber was grown at low temperature (550℃) by metal organic chemical vapour deposition (MOCVD)and was used as an output coupler with which we realized Q-switching modelocked yb^3 -doped fibre laser. The shortest period of the envelope of the Q-switched modelocking is about 31μs. The modelocking threshold is 4.27 W and the highest average output pulse power is 290mW. The modelocking frequency is 12 MHz.     

双曲型守恒方程的一类MmB差分格式

给出了一维双曲型守恒律方程的一类高分辨率ＭｍＢ差分格式，并且推广到方程组情形，它具有不须解黎曼问题，计算工作量小且易于编程的优点。数值实验表明格式具有较高的分辨率，处理间断解的能力令人满意。     

脉冲放电激励的钡蒸气激光的研究

设计和制作了新型结构的金属蒸气激光放电管.用钡为激光介质,通过纵向高频快脉冲放电激励,在国内首次实现波长为1.13μm和1.50μm的红外钡蒸气激光振荡,激光成分主要集中在1.50μm这条谱线上,激光输出功率和功率密度分别达1.2W和33.3mW/cm3.测量并讨论了各工作参量和激光输出特性之间的关系.     

Hopping Conductivity in a Single-Walled Carbon Nanotube Network

We investigate the resistance and magnetoresistance （MR） of an entangled single-walled carbon nanotube （SWNT） network. The temperature dependence of conductance is fitted by formula G（T） = Go exp[-（To/T）^1/2] with To = 15.8 K at a wide temperature range from 4 K to 300K. The MR defined by [R（T, H） - R（T, 0）]/ R（T, 0） as a function of temperature and magnetic field perpendicular to the tube axis is negative at low temperatures. The MR amplitude increases as the temperature decreases at relative high temperature, but becomes decrease when temperature below 4 K. The results are explained in terms of the coherent hopping of carriers in the presence of a Coulomb gap at low temperature.