固相微萃取-气相色谱/质谱联用快速鉴定香稻香味特征化合物2-乙酰基吡咯啉

建立了固相微萃取-气相色谱/质谱(SPME-GC/MS)联用快速鉴定香稻香味特征化舍物2-乙酰基吡咯啉的方法.香米加入内标物2,4,6-三甲基吡啶,密封,在80℃水浴条件下经固相微萃取(萃取纤维头为100 μm聚二甲基硅氧烷)提取2 h,提取物经毛细管气相色谱柱HP-5MS(30 mx0.25mm×0.25μm)分离,...     

Hydrophobic/hydrophilic solvation: inferences from Monte Carlo simulations and experiments

In this study Monte Carlo simulations are used to determine the solvation properties of model hydrophobic (xenon and hard sphere) and hydrophilic (dimethyl ether) solutes in SPC/E water. Various contributions to the experimental solvation entropy, including the solvent reorganization entropy, have been determined. The main conclusion drawn, which is in accord with solubility data, is that poor solubility correlates with poor solute-water interaction. At room temperature, energy dominates the aqueous solubility of both hydrophobic and hydrophilic solutes, rather than entropy. However, at higher temperatures the solubility can pass through a minimum, and then entropy becomes dominant. Another interesting finding is the presence of larger than expected cavities in water. Two different simulation results support this finding. This unexpected hollow structure in water explains why a hard sphere solute is more soluble in water than in a comparable hard sphere or Lennard-Jones solvent. Hydrogen bonding causes water to aggregate into clusters that produce a few large cavities rather than many smaller cavities. The propensity for clustering also explains why water gives the illusion of being a low density liquid. Sufficient theoretical apparatus is developed to connect theoretical solvation properties to those measured by simulation and experiment. Finally, based on gas solubility, an intuitive hydrophobic/hydrophilic scale is developed.     

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.     

液体中的声处理应用和声空化工程

1引言 声波在好几个方面有它广泛不可替代的用途，像声通讯、声检测、控制声、声控制等。在几个方面的用途中有声处理一项，这时利用了声的能量。本文只讨论液体中的声处理应用。在长时期的实验室试验中它显示了，并且继续在显示，强大的潜力，但比较奇特的是，这么大量的实验室成果，只有很少数转化为生产力。本文强调转化为生产力的有利性和紧迫性。本文并且指出，液体中声处理的基本机理多是声空化，因此，分析研究在液体中大规模或生产化声处理时声空化的特征和行为，     

量子自旋系统的块自旋方案及其簇团Monte Carlo模拟方法

本文提出了一种关于一维和二维量子自旋系统的Monte Carlo模拟新算法。具体给出了对于一维和二维Heisenberg模型的计算方案。在s=1/2的铁磁和反铁磁链情况下的计算结果证实了此方法有效地克服了“临界慢化(CSD)”效应和能够达到更低的温度区域进行计算。该方法可推广到各向异性和高自旋(s=1,3/2,…)量子系统、二维经典8-顶角格点模型和低维费密系统。 关键词：     

MgB2/Fe带材Jc的各向异性及MgB2芯织构和成分不均一性的研究

本文研究了在不同磁场方向和温度下非原位Fe包套MgB2单芯带Jc的各向异性,通过对各种工艺条件下带材中MgB2芯的X-ray衍射图进行拟合分析和计算,比较了MgB2芯在Fe-MgB2界面和中心处的织构度和成份不均一性.研究发现带材Jc的各向异性受初始粉末颗粒尺寸的影响.由于受套管材料强度和形变加工工艺的影响,MgB2芯在Fe-MgB2界面处比在中心处有较强的织构.在MgB2-Fe的界面处,700℃淬火样品的X-ray衍射图中发现了由中间相Fe23B6生成的金属间化合物Fe2B.另外还研究了MgB4和MgO等主要杂质相的形成原因.     

多层导体超导电缆的交流输电特性

在完成设计和制造我国第一组并网运行的超导电缆系统的工作中，我们对不同结构的超导电缆短样样品的交流载流特性进行了系统的研究，内容包括层电流均流特性、电缆失超特性、失超恢复特性、电缆载流能力和抗短路冲击能力等．结果表明，对多层螺旋导体结构的超导电缆，影响其输运电流在各导体层分布的主要因素是邻近效应．由于其零电阻特性，在相同的结构中，超导体表现出比常规导体大得多的临近效应．显著的邻近效应使多层导体结构的超导电缆的均流问题变得更加复杂．此类超导电缆有很强的抗短路电流冲击能力，能够承受高于额定电流20倍以上的短路电流，并且有很好的超导性能恢复能力．由于交流超导电缆的电压与电流相位差对电阻的变化非常敏感，所以可以被用作判断失超的预警参数用来避免热溃式失超的发生．     

等离子体相位共轭理论

本文统一研究磁化和无磁化等离子体的相位共轭理论.这一理论可用于微波频段相位共轭器的研制.     

Gentzen型模糊推理

本文建立了能同时处理证据、规则的不确定性以及证据与规则近似匹配的Gentzen型模糊推理的语形方法．     

保险赔付中的最优对冲策略

本文对带有付费过程$A_t$的保险公司在金融市场$(S_t,Q_t,B_t)$上通过购买股票$S_t$、兑换外币$Q_t$以及购买无风险资产$B_t$的投资过程而采取的最优投资策略, 使保险公司所面临的风险最小进行探讨. 利用Galtchouk-Kunita-Watanabe分解定理将风险表达式重新表达, 从而找到保险公司所能采取的风险最小的最优对冲策略. 文中举出一个具有现实性意义的例子将文章的重要结论加以应用, 使本文更具有应用价值.