Admittance of a one-channel conductor containing a scattering region and Andreev reflection in an N-S mesoscopic system

We introduce local density of states in normal-conductor-superconductor compound systems and injectivity, emissivity to describe the transmission properties in these systems. Then we study the admittance of a one-channel conductor which contains a scattering region and Andreev reflection with the discrete potential model and effective scattering approach.     

钙、镁离子对淀粉酶催化激活作用的热动力学

利用热活性检测仪测定了无激活剂和有激活剂时淀粉在淀粉酶催化作用下的热功率－时间曲线,借助热动力学理论和对比进度法对曲线进行处理,得到了无激活剂时酶催化反应的米氏常数(Km)和最大速率(vmax),以及有激活剂(Ca2＋,Mg2＋)时酶催化反应的表观米氏常数（Km1）和最大速率（vmax）.通过比较,得到了金属离子对酶催化反应定量的激活效果.     

有机金属化合物的振动光谱 Ⅰ.环戊二烯夹心化合物的力常数计算

测定了过渡金属环戊二烯夹心化合物,(η~5-Cp)_2M(Cp=C_5H_5,M=Mn,Fe,Ru)的红外与激光拉曼光谱,在此基础上,用G-F矩阵法计算了这类化合物的力常数.讨论了Cp-M化学键的性质.     

有色多笼阻燃剂四PEPA氧基对苯醌的合成与应用

以四氯对苯醌与1-氧基磷杂-4-羟甲基-2,6,7-三氧杂双环[2.2.2]辛烷(PEPA)的钠盐为主要原料,合成有色阻燃剂四PEPA氧基对苯醌,即四-(1-氧代-1-磷杂-2,6,7-三氧杂双环[2,2,2]辛烷基-4-亚甲氧基)对苯醌(TOPTMBQ)。探讨了反应时间、温度及摩尔比等对产率的影响。最佳工艺条件为:将PEPA与金属钠等摩尔,在110℃下反应8h,控制四氯对苯醌与PEPA钠盐的摩尔比为1:4.8,在120℃下反应9h,得红棕色阻燃剂,产率为92.7%。通过FT-IR,~1H-NMR、TG-DTA、极限氧指数等表征了产物的结构及性能,结果表明该产物在聚对苯二甲酸丁二醇酯(PBT)和聚丙烯(PP)添加量为20%时,其极限氧指数为30%。     

一种新的凝析油形成模式

本文对中国主要凝析油的有机地球化学研究、证实这些凝析油大都以陆源高等植物有机质为主要母源,热演化程度处于低至中等成熟阶段,相应镜质体反射率R_c为0.7—1.0％。据此提出富含壳质体、树脂体的陆源有机质可在低—中等成熟阶段(R_o:0.6—1.2％)形成凝析油的一种新的成烃模式。     

Design of Second-Order Nonlinear Optical Molecules Exhibiting Improved Nonlinearity-Transparency Trade-off and Large Nonlinearity

The nonlinear second-order optical susceptibilities(β) of a series of multi-branched molecules with triphenylbenezene as π center have been calculated by means of a combination of intermediate neglect of differential overlap Hamiltonian with the configuration interaction(INDO/SDCI) method combined with sum-over-states expression(SOS) .the results show that the β values are increased by replacing benzene rings with thiophene rings in the branches,as well as by increasing the donating and accepting strength of the three terminal substituents.The properies of the intermolecular charge transfer were studied through the calculation of charge changes between the ground and the main excited states and the frontier orbitals of these molecules.The results also indicate that these molecules investigated here possess improved transparency-nonlinearity properties.     

多选择NTU对策核心的一个非空条件及公理化

提出了\pi-均衡多选择NTU对策的概念,证明了\pi-均衡多选择NTU对策的核心非空, 定义了多选择NTU对策的非水平性质和缩减对策,给出了相容性和逆相容性等概念. 用个体合理性、单人合理性、相容性和逆相容性对非水平多选择NTU对策的核心进行了公理化.     

Analysis of weak signal detection based on tri-stable system under Levy noise

Stochastic resonance system is an effective method to extract weak signal.However,system output is directly influenced by system parameters.Aiming at this,the Levy noise is combined with a tri-stable stochastic resonance system.The average signal-to-noise ratio gain is regarded as an index to measure the stochastic resonance phenomenon.The characteristics of tri-stable stochastic resonance under Levy noise is analyzed in depth.First,the method of generating Levy noise,the effect of tri-stable system parameters on the potential function and corresponding potential force are presented in detail.Then,the effects of tri-stable system parameters w,a,b,and Levy noise intensity amplification factor D on the resonant output can be explored with different Levy noises.Finally,the tri-stable stochastic resonance system is applied to the bearing fault detection.Simulation results show that the stochastic resonance phenomenon can be induced by tuning the system parameters w,a,and b under different distributions of Levy noise,then the weak signal can be detected.The parameter intervals which can induce stochastic resonances are approximately equal.Moreover,by adjusting the intensity amplification factor D of Levy noise,the stochastic resonances can happen similarly.In bearing fault detection,the detection effect of the tri-stable stochastic resonance system is superior to the bistable stochastic resonance system.     

PVT法同质外延制备大尺寸Al极性氮化铝晶体生长工艺及其表征分析研究

本文基于自主设计的氮化铝生长炉,开展了四组不同工艺条件下Al极性面氮化铝籽晶同质外延生长氮化铝单晶的生长特征及其结晶质量表征研究。研究发现:不同工艺条件下生长的晶体的拉曼图谱E₂(high)特征峰峰位表明,晶体内部均存在较小的拉应力;在坩埚顶部在相对较高温度2 210 ℃、坩埚底部与顶部温差42 ℃的低过饱和度生长条件下,晶体表面光滑,呈现阶梯流生长形貌,并具有典型的氮化铝单晶生长习性面,晶体初始扩张角大于40°,高分辨率X射线衍射(HRXRD)测得0002、1012反射摇摆曲线及拉曼光谱检测结果表明,该条件下生长的氮化铝晶体结晶质量优异,并可实现快速扩径。基于该生长条件,通过外延生长后成功获得尺寸ϕ45~47 mm的氮化铝单晶锭,相关表征结果表明生长的氮化铝晶体具有优越的结晶性能。     

湿热环境对挖补修理后复合材料层合板振动特性的影响

通过对湿热环境下阶梯挖补胶接修理后碳纤维/双马树脂(T300/QY8911)层合板振动特性的分析,探究了挖补修理后碳纤维/双马树脂层合板在不同湿热效应下的振动特性。基于Mindlin-Reissner板理论与最小势能变分原理,在考虑湿热效应前提下,推导了正交各向异性复合材料层合板的本构关系及四边简支条件下的自由振动控制方程;其次,利用ABAQUS软件建立了三维黏弹性有限元挖补修理模型,应用Fortran语言将湿热耦合下的应力-应变本构关系编入UMAT二次开发文件中,采用三维八节点五自由度等参单元进行了离散。通过与参考文献对照,验证了胶接修理后T300/QY8911层合板有限元模型和编译的湿热环境下UMAT子程序的合理性与有效性。算例结果表明:湿热环境对挖补修理后层合板固有频率的影响比对完整层合板严重;温度对材料性能的影响大于湿度;相比于材料性能变化对振动特性的影响,湿热残余应力对胶接修理后层合板振动特性的影响占主导;参考环境下,胶接修理后层合板的固有频率增大;湿应力对层合板固有频率的影响大于热应力。