以2,3-二苯基吡嗪或2,3-二苯基喹喔啉为配体的单核和双核金属铂配合物的晶体结构与光物理性质

以2,3-二苯基吡嗪(H_2dpp)、5-甲基-2,3-二苯基吡嗪(H2mdpp)和2,3-二苯基喹喔啉(H_2dpq)为配体,乙酰丙酮(Hacac)为辅助配体,合成了一类单核和双核金属铂配合物[Pt(Hdpp)(acac)](1)、[Pt2(dpp)(acac)2](2)、[Pt(Hmdpp)(acac)](3)和[Pt(Hdpq)(acac)](4),并且得到了配合物2、3和4的晶体结构数据。通过对单核配合物1的类似物配合物3和双核配合物2的配位平面、分子扭曲程度等的晶体结构分析,我们合理地推断以2,3-二苯基吡嗪为配体的双核配合物2具有比相应的单核配合物1更加扭曲的分子平面。通过对配合物1和2的紫外-可见吸收光谱和激发光谱的比较,发现由于双核配合物2在激发态的构型变化造成了激发光谱中最低能带比相应的最低能量吸收带光谱红移了18 nm。因此,尽管双核配合物2具有与单核配合物1类似的紫外-可见吸收光谱,最低能吸收带仅比单核配合物1红移5 nm,但是双核配合物2的最大发射峰值λmax为609 nm,比单核配合物1(λmax=546 nm)红移了63 nm。双核配合物2的发射光谱红移现象与配合物的分子构型直接相关。分子扭曲程度更大的双核配合物2在激发态可能发生了一个向平面性更好的构型转变过程,从而进一步降低了激发态能量,造成了发射光谱的红移。     

考虑底部隆起的浅埋隧道围岩压力计算分析

针对浅埋隧道开挖后底部隆起变形现象,应用极限分析上限法构造了考虑底部隆起变形的围岩压力计算模型,结合线性Mohr-Coulomb准则等推导出极限围岩压力的理论表达式。通过约束条件将围岩压力的计算转化为数学中的最优化问题,编制程序进行了优化计算。将计算结果与工程实测数据及文献计算结果进行了对比,验证了当前方法的可靠性。同时,指出在运用极限分析法处理浅埋隧道围岩压力问题过程中应将隧道底部一同考虑,对隧道底部支护会对整个围岩压力产生影响,有助于隧道结构的整体稳定。研究可以为浅埋隧道的开挖、支护提供一定的理论指导.     

用HLLC方法处理运动边界

针对含有运动边界非结构网格点的显式有限体积方法，研究了如何使用HLLC方法处理运动边界条件，计算了活塞拉伸、压缩问题，并和解析解进行了比较．作为应用示例，比较了静止圆柱绕流和静止流场中运动圆柱的绕流情形。结果表明：应用HLLC方法处理运动边界是可行的。     

Transverse profile expansion and homogenization at target for the injector Scheme-I test stand of China-ADS

For the injector Scheme- test stand of the China-ADS(Accelerator Driven subcritical System), a beam with the maximum power of 100 k W will be produced and transported to the beam dump. To solve the very high thermal load problem at the dump, two measures are taken to deal with the huge power density at the target.One is to enlarge the contact area between the beam and the target, and this is to be accomplished by expanding the beam profile at the target and using slanted target plates. The other is to produce a more homogenous beam profile at the target to minimize the maximum power density. Here the beam dump line is designed to meet the requirement of beam expansion and homogenization at 3 different energies(3.2 Me V, 5 Me V and 10 Me V), and the step-like field magnets are employed for the beam spot homogenization. Taking into account the fact that the space charge effects are very strong at such low beam energies, the simulations have included space charge effects and errors which show that the beam line can meet the requirements very well. In the meantime, the alternative beam design using standard multipole magnets is also presented.     

MilCAN总线同步及调度配置方法

MilCAN作为一种以陆军地面武器平台应用为目标的CAN高层协议,核心是通过时序控制保证总线通信的实时性和确定性;为了增强MilCAN总线通信时序控制,提出一种新的MilCAN总线同步和调度配置方法;采用STM32微控制器对MilCAN总线主控节点进行设计,将总线同步和总线调度配置任务集成至专用的主控节点进行,同时开展了总线通信测试;测试结果表明：以该方法设计的MilCAN总线主控节点可有效完成同步和总线调度配置任务,同步精度较高,性能稳定可靠。     

反相高效液相色谱法分析三羟乙基胺硬脂酸酯

提出了反相高效液相色谱法测定三羟乙基胺硬脂酸酯中单硬脂酸酯、双硬脂酸酯、三硬脂酸酯的含量。以C18硅胶键合柱(250 mm×4.6 mm,5μm)为分离柱,甲醇与氯仿混合溶液为流动相梯度淋洗,用电雾式检测器检测。三羟乙基胺单、双、三硬脂酸酯的线性范围分别为2.0～50.0,1.0～50.0,1.2～50.0 mg.L-1,方法的检出限(3S/N)分别为1.8,0.5,1.0 mg.L-1。     

Pd/MWCNTs(多壁碳纳米管)催化剂的制备及其Heck反应催化活性

以浓硝酸处理后的多壁碳纳米管(MWCNTs)为载体,通过微波辅助法简单而快速地制备了高度分散、粒径均一的Pd/MWCNTs催化剂。利用XRD、HRTEM、XPS等手段对催化剂进行了表征。考察了Pd/MWCNTs催化剂对Heck反应的催化活性,并优化了反应温度、碱的种类和用量等反应条件。结果表明,Pd/MWCNTs在Heck反应中具有良好的催化活性。     

冷原子荧光光谱法测定南宁市邕江支流水域中无机汞和总汞

采用氢化物发生-冷原子荧光光谱法,测定了南宁邕江支流水域中无机汞和总汞.实验结果表明,南宁邕江支流水域中汞含量均小于国家规定的地表水Ⅰ类水域的标准,水质良好.同时对样品的测量检出限及方法回收率进行实验,结果表明在优化的实验条件下检出限为0.021 ng/L,相对标准偏差为2.24％,无机汞和总汞的加标回收率分别为90....     

Density functional theory study of the mechanism of the acid-catalyzed decarboxylation of pyrrole-2-carboxylic acid and mesitoic acid

The mechanisms of the acid-catalyzed decarboxylation of pyrrole-2-carboxylic acid and mesitoic acid have been investigated based on density functional theory calculations at the B3LYP/6-311G (d,p) level. A polarizable continuum model (PCM) has been established in order to evaluate the effects of solvents on these reactions. The results of the calculations indicate that the first step of the acid-catalyzed decarboxylation of the pyrrole-2-carboxylic acid has two possible pathways,that is,the proton of H3O+ a...     

Theoretical research of multiphoton transition of HF in static electric and laser fields

A ‘modulated potential model’ is presented to describe the potential of diatomic molecules in static electric fields, and investigate the static electric effect on the multiphoton process. The multiphoton transition of HF in static electric and intense laser fields has been investigated using the Lie algebra approach. Multiphoton transition information is obtained by solving the time-evolution operator. This method makes the solving of the Schrödinger equation easier and makes the computation time shorter.