Effects of pressure ratio on population inversion in a DF chemical laser with concurrent lasing

A numerical simulation is presented for investigating the effects of pressure ratio of D₂ injector to supersonic nozzle on the population inversion in the DF chemical laser cavity, while a lasing concurrently takes place. The chemical laser is generally used for the industrial process and manufacturing as well as the military weapon system, which requires high power characteristic of laser system rather than the others. The population inversion is absolutely needed to generate the laser beam and is non-equilibrium process. The laser beam is generated between the mirrors in the cavity and it is important to obtain stronger population inversion and more uniform distribution of the excited molecules in the laser cavity in order to produce high-power laser beam with good quality. In this study, these phenomena are investigated by means of analyzing the distributions of the DF excited molecules and the F atom used as an oxidant, while simultaneously estimating the maximum small signal and saturated gains and power in the DF chemical laser cavity. For the numerical solution, a fully conservative implicit method and a second order total variation diminishing (TVD) scheme are used with the finite-volume method (FVM). An 11-species (including DF molecules in various excited states of energies), 32-step chemistry model is adopted for the chemical reaction of the DF chemical laser system. The results are discussed by comparison with two D₂ injector pressure cases; 192 and 388.64 torr. Major results reveal that in the resonator, stronger population inversions occur in the all transitions except DF(1)-DF(0), when the D₂ injection pressure is lower. But, the higher D₂ injection pressure provides a favorable condition for DF(1)-DF(0) transition to generate the higher power laser beam. In other words, as the pressure of D₂ injector increases, the maximum small signal gain in the v_1-0 transition, which is in charge of generating most of laser power, becomes higher. Therefore, the total laser beam power becomes higher.     

浅析Windows95的启动机制

详细介绍了Ｗｉｎｄｏｗｓ９５的启动机制,并对Ｗｉｎｄｏｗｓ９５的配置文件Ｍｓ－ｄｏｓ．ｓｙｓ作了全面的论述,最后给出了一般微机上Ｍｓｄｏｓ．ｓｙｓ设置．     

钼(钨)-钼-硫簇合物的~(95)Mo NMR研究

对含有[MS4]2-（M＝Mo，W）单元的一系列钼（钨）-钼-硫簇合物进行了95MoNMR研究，定性分析了95Mo化学位移随金属原子配位数、配位金属种类和配位金属配体改变而变化的规律。结果表明，随着[MoS4]2-配位金属原子数的增加，[MoS4]2-上Mo的化学位移逐渐向高场移动，这可归因于低氧化态MO0上的电子通过硫桥离域到高氧化态的Mo上。为了解析Mo0上化学位移的实验结果，采用MM＋力场对[（OC）4MOS2MoS2]2-和[｛（OC）4Mo｝MoS4]2-的晶体结构进行几何优化，使之更接近于溶液中的结构，然后利用Fenske－Hall方法计算Mo原子上的净电荷分布，计算结果较好地好择了Mo和Mo0化学位移的变化趋势。     

流行媒介文化对高校德育工作的影响探析--以中国首档青年电视公开课《开讲啦》为例

流行媒介对当代大学生核心价值观的形成和发展具有全息式影响。作为当下媒介影响高校德育的现象级文化符号，中国首档青年电视公开课《开讲啦》凭藉遵循核心价值观的思想导向、强调平等分享的互动精神、基于“TV2.0”的传播创新、演讲嘉宾集群的真诚表达而广受“95后”大学生点赞追捧。高校学生德育工作者应当努力汲取流行媒介所赋予的智慧正能量，借助偶像磁力、借力朋辈榜样、借鉴主播智慧，激发学生敢于有梦的信念、激活勇于追梦的理想，激荡勤于圆梦的情怀，切实提高教育实效性。     

Statistical Verification of Hydraulic Units in a Heterogeneous Reservoir of the Liaohe Oilfield

The Liaohe Oil Field has passed peak production and correct discrimination of hy-draulic units (HU) has vital significance for forecasting remaining oil distribution in a petroleum reservoir, enhancing...     

基于Windows95／98平台的纵横汉字输入系统的设计

本文主要介绍了 Ｗｉｎｄｏｗｓ ９５／９８平台上纵横汉字输入系统的设计．文章概要介绍了Ｗｉｎｄｏｗｓ平台上的纵横汉字输入系统的界面设计和功能设计，详细地阐述了Ｗｉｎｄｏｗｓ９５／９８平台上实现通用挂接的基本思想，并给出了实现纵横汉字输入系统的主要数据结构和算法，最后对系统实现中的一些关键技术作了讨论。     

大学英语等级考试听力训练多媒体系统的设计与实现

本文介绍了在Ｗｉｎｄｏｗｓ９５操作系统平台支撑下，利用ＶＢ５程序设计语言实现大学英语等级考试听力训练多媒体系统的方法，并对系统中的主要技术作了详细阐述。     

Pressure Sensitivity of SynGAP/PSD-95 Condensates as a Model for Postsynaptic Densities and Its Biophysical and Neurological Ramifications

Biomolecular condensates consisting of proteins and nucleic acids can serve critical biological functions, so that some condensates are referred as membraneless organelles. They can also be disease-causing, if their assembly is misregulated. A major physicochemical basis of the formation of biomolecular condensates is liquid–liquid phase separation (LLPS). In general, LLPS depends on environmental variables, such as temperature and hydrostatic pressure. The effects of pressure on the LLPS of a binary SynGAP/PSD-95 protein system mimicking postsynaptic densities, which are protein assemblies underneath the plasma membrane of excitatory synapses, were investigated. Quite unexpectedly, the model system LLPS is much more sensitive to pressure than the folded states of typical globular proteins. Phase-separated droplets of SynGAP/PSD-95 were found to dissolve into a homogeneous solution already at ten-to-hundred bar levels. The pressure sensitivity of SynGAP/PSD-95 is seen here as a consequence of both pressure-dependent multivalent interaction strength and void volume effects. Considering that organisms in the deep sea are under pressures up to about 1 kbar, this implies that deep-sea organisms have to devise means to counteract this high pressure sensitivity of biomolecular condensates to avoid harm. Intriguingly, these findings may shed light on the biophysical underpinning of pressure-related neurological disorders in terrestrial vertebrates.     

Fission studies of gold induced by (1665 MeV) π- using a CR-39 detector

The fission cross section and fission probability of ¹⁹⁷Au, induced by (1665 MeV) π^-, have been studied using CR-39 track detectors. A 4π-geometry was used to count track statistics. A beam of negative pions of 1665 MeV was produced at AGS of Brookhaven National Laboratory, USA, and allowed to fall normally on the stack. Two detectors from the stack were scanned for fission fragment tracks after etching in 6N NaOH at 70℃. The statistics of fission fragment tracks in both detectors were obtained. It was found that there was a marked asymmetry of registered tracks with respect to the forward and backward hemispheres. This asymmetry could be partly accounted for on the basis of momentum transfer to the struck nucleus. On the basis of counting statistics fission cross section was measured, and fission probability was determined by dividing the fission cross section with the reaction cross section. The fission cross-section and fission probability were compared with the computed values using the cascade-exciton model code CEM95.