关于含能材料硝胺撞击感度的研究

作者在利用Gaussian 98DFTB3P86/6-31G**水平研究了36种炸药分子的撞击感度与其分子结构关系并取得较好结果的基础上,又对33种硝胺炸药分子,仍采用人工神经网络方法进一步研究了撞击感度与分子结构特征量的关联关系.结果表明,所实验的硝胺其含特征量△E(原子化能)的输入方案预测结果最理想,即△E与撞击感度的关联度最强,说明△E可作为预测其撞击感度的标志性指标.     

低温下含多硝基烷基的四种炸药材料的能量迁移率与撞击感度

采用密度泛函理论中的B3LYP方法,取6-31G(d)基组,对含多硝基烷基的四类炸药分子的结构、能量和红外振动频率进行了分析计算和理论归属.以分子晶体含能材料多声子迁移理论为基础分析了各个分子的门模式振动频率,计算了含多硝基烷基的硝铵炸药、脂类炸药、苯酸盐炸药和芳香族炸药材料共19个分子与硝基相关的门模式振动的能量迁移率,发现材料分子在与C-NO2有关的门模式振动频率上的能量迁移率与材料的撞击感度实验值没有统一的相关关系,只有在分子的化学结构相似或相同的同一类别内部,材料分子与CNO2有关的门模式振动的能量迁移率与材料的撞击感度实验值才有较好的关联关系.因此可以认为:低温下理论地计算材料的能量迁移率预测其撞击感度的方法只适用于分子结构化学类别相同的材料.     

分子中alphaCH键对硝基芳香族炸药材料的能量迁移率的影响

利用密度泛函理论,在B3LYP∥6-31G(d)计算水平上对含alphaCH键的三硝基苯类炸药分子的电子结构和红外振动进行了理论计算,对相关的红外振动模式进行了理论归属.并计算了材料分子在alphaCH键邻位和对位处与硝基相关的门模式的能量迁移率,发现材料分子在alphaCH键邻位处与硝基相关的门模式的能量迁移率数值低于其在对位的数值.将计算结果与撞击感度实验值进行对比,发现当alphaCH键处取代基的结构相似时,分子在alphaCH键邻位的能量迁移率与撞击感度有较好的线性相关关系.将材料的能量迁移率的计算结果与用相同方法计算的分子的键离解能进行比较,发现alphaCH键邻位的能量迁移率与其C-NO2键离解能的数值都比对位的要小,且只有alphaCH键处取代基结构相似的分子的键离解能分别与撞击感度、与材料的能量迁移率有线性相关关系.可以认为:1三硝基苯环上的alphaCH键取代基对邻位NO2活性影响较大;2用低温下材料的能量迁移率或者最弱键离解能来理论预测含能材料的撞击感度都要受到材料分子在化学上的结构类别的影响.     

硝基苯衍生物的撞击感度与其静电势的关系研究

利用HONDO程序包,采用从头算法对硝基苯衍生物的分子结构和分子中C—NO2键中点的静电势进行了计算.讨论了这类炸药分子C—NO2键中点的静电势最大值Vmidmax与其撞击感度之间的关系;根据和Rs3的感度大小进行了比较.研究表明:对于硝基苯衍生物炸药,可用其、Rp2分子结构和静电势,对Ro2、Rm2、Rp2的感度大小的关系分子C—NO2键中点的静电势最大值Vmidmax来确定其撞击感度的变化趋势;Ro2、Rm2的感度大小的关系为:Ro2和Rs3.>Rs3>Rm2为:Ro2,Ro2>Rp2     

脂肪族硝基含能化合物撞击感度的QSPR研究

基于定量结构-性质相关性(QSPR)原理,研究脂肪族硝基化合物撞击感度与其分子结构间的内在定量关系.应用遗传函数算法筛选出与撞击感度密切相关的6个参数作为分子描述符;采用多元线性回归方法建立基于该6参数的脂肪族硝基化合物撞击感度预测模型.分别采用内部验证及外部验证的方式对模型性能进行验证,研究结果表明模型具有较高的稳定性、预测能力及泛化性能.     

芳香族硝基炸药感度和安定性的量子化学研究-IV.甲苯和苯酚类硝基衍生物

以CNDO/2法计算了甲苯和苯酚两类硝基衍生物,发现劳环上α-CH键和OH键的键级、双原子作用能和共振积分作用能等电子结构参数,与该两类炸药的实验撞击感度之间,存在平行一致的递交关系。α-CH键和OH键可能分别是它们热分解和引爆的引发键.其Mulliken键级与双原子作用能、共振积分作用能线性相关,表明在度量键强度和判别感度安定性方面。它们是等价的.本文的研究结果较Delpuech的类似研究似更合理些.     

多硝基炸药撞击感度与分子特征量关联度的BP神经网络方法研究

引入神经网络BP算法研究了36种炸药分子的撞击感度与其分子特征量间的关联关系.所有分子的特征量均采用DFTB3P86/6-31G**方法计算所得.共设计了8个不同的输入方案,训练和预测结果表明,在均方误差允许范围内(0.6245-4.4900),网络是可靠的.同时,含特征量(HOMO-LUMO)*BDE的方案训练预测结果最理想,说明在网络结构和训练参数基本相同的情况下,(HOMO-LUMO)*BDE与撞击感度的关联度最强,仅次于它的特征量是(HOMO-LUMO).     

从共振能的角度研究4种苦基三唑衍生物的撞击感度

共振结构在芳香族硝基化合物、杂环硝基化合物以及高氮化合物中普遍存在,准确计算这些化合物中的共振能,对预测含能材料的冲击波感度,合理设计与合成新型含能材料分子具有重要意义。采用密度泛函BLYP/DNP方法,结合等键反应方程计算了4种苦基三唑衍生物的共振能。计算结果表明,4种苦基三唑衍生物的共振能与其撞击感度(H50)有内在联系,共振能越大,撞击感度越低。     

WC,TiC,Fe3 C及Co2C的价电子结构与性能的分析

运用固体与分子经验电子理论计算了几种过渡族金属碳化物的价电子结构,发现碳化物的主要价电子结构参数主键键能与碳化物的熔点、硬度及生成焓之间存在着很好的相关性.     

多硝基芳烃撞击感度的电性拓扑研究

以原子类型电性拓扑态指数（Ek）表征多硝基芳烃的分子结构.通过多元线性回归及最佳变量子集方法建立多硝基芳烃撞击感度(lg H50)与电性拓扑态指数的五元线性相关模型(QSPR),其相关系数R为0.930,估计标准误差s为0.356.经Jacknnife检验,该模型具有良好的稳定性与预测能力.预测结果揭示影响多硝基芳烃撞击感度的主要结构因素为供电子基团-CH₂-,-O-,-NH₂以及吸电子基团=O,-Cl等5种结构碎片,它们与引发键C-NO₂离解能密切相关.因此,电性拓扑态指数可用于多硝基芳烃撞击感度的定量相关研究.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-