新型高聚合度聚磷酸铵阻燃材料的合成

对高聚合度聚磷酸铵的聚合条件进行了优化实验,制备了平均聚合度为600的聚磷酸铵．研究了磷酸铵、组分配比、反应温度、反应气氛、反应时间和处理温度、处理时间、处理气氛对平均聚合度的影响．结果表明高聚合度APP的生产工艺条件为：1：1：0．3（摩尔比）的（NH4）2HPO4,P2O5和尿素混合均匀后,于干燥氨气氛下280-300℃充分搅拌进行聚合反应,聚合反应时间为20min以上,聚合反应完全后于同样气氛下,250-280℃热处理100～120min,即得粉末状的APP聚合物,通过端基滴定法测定聚合度,其平均聚合度大于600．     

~（13）C－NMR研究乙烯醇－醋酸乙烯酯共聚物序列结构

１３Ｃ－ＮＭＲ方法对８种不同的国产乙烯醇－醋酸乙烯酯共聚物序列结构作了观测和表征．指出这一直接由ＰＶＡｃ（醋酸乙烯酯）皂化生成的共聚物均具有嵌段物性，并观测到它们与聚合度之间的关系．根据这些结果讨论了沿ＰＶＡｃ链皂化机制     

非均匀传输线时域响应的精细计算

应用精细计算法对非均匀传输线时域响应进行了分析．该方法考虑了非均匀传输线的非均匀性,避免了使用突变的级联模型及频域、时域转换,直接时域分析,极大地提高了分析的精度和效率．计算结果证实了该方法的可靠性．     

基于时域声辐射模态的结构噪声主动控制研究

以平板为例，在时域里对声辐射模态进行了初步研究．研究表明时域声辐射模态既与时间无关，也互相独立，使得计算和控制声功率得以简化．针对瞬时声功率主要由第一阶辐射模态的声功率所决定的特点，在时域里进行结构噪声的主动控制研究，提出了新的主动控制策略，即通过抵消第一阶辐射模态的声功率使得总的声功率得以有效降低．在此基础上，建立基于FXLMS算法的自适应前馈控制系统，进行仿真计算，结果证明了主动控制策略是有效的．     

FDTD计算功率变换器近场到近/远场的转换

从理论上分析了利用时间有限差分法由近场到近场或远场转换的频域和时域两种方法，并选择时域的方法计算在FDTD计算范围内一给定点的电场值，与直接利用FDTD法得到的结果相比较，两者非常一致；最后利用该方法计算了功率变换器FDTD计算范围外一给定点的电磁场时间响应．     

煤矸石胶凝材料水化产物及聚合度分析

采用XRD,IR和NMR等分析方法研究北京房山煤矸石在水化过程中的物相及29Si聚合度的变化规律.在29Si NMR基础上提出利用相对桥氧数(RBO)评价硅氧多面体聚合度的方法,并用该方法研究煅烧煤矸石在活化及水化前后的RBO变化规律.研究结果表明:煤矸石中的粘土矿物绿泥石和白云母等在活化过程中发生分解,表征硅氧多面体聚合度的指标RBO明显降低;而在水化过程中随着水化龄期的增加,氢氧化钙不断与硅铝质物料中的[SiO4]和[AlO4]四面体发生反应,生成水钙沸石和碳硅钙石,导致RBO升高,浆体材料的结构致密性增加.这表明煤矸石中的[SiO4]聚合度在煅烧活化过程中由高聚合度向低聚合度转变,在水化过程中则由低聚合度向高聚合度转变,聚合度或RBO的变化在一定程度上反映活化效果和胶凝活性的发挥程度.     

二维近场衍射的矢量角谱衍射理论的有效性

笔者依据时域有限差分法和矢量角谱理论研究了二维电磁场的近场衍射．理论分析了时域有限差分法和矢量角谱理论的机理,给出了电磁场量间的微分与积分关系,数值计算了狭缝的近场衍射,并将矢量角谱理论的结果与时域有限差分法进行了比较,结果表明矢量角谱理论在分析狭缝的近场衍射时存在偏差,笔者并对这一偏差给出了合理的解释．     

滞后阻尼在土层时域分析中的应用

采用滞后阻尼假定 ,分别应用时域和频域分析方法对土层的地震反应进行计算 .在简谐波和地震波激励作用下 ,通过比较时域和频域的计算结果 ,探讨了在土层时域分析中 ,如何由滞后阻尼系数形成阻尼矩阵的问题 .利用实际地震波的分析结果 ,进行回归分析 ,得到一个阻尼系数转换频率取值的经验公式 ,从而为利用滞后阻尼系数在时域中进行土层地震反应分析提供依据     

水中弹性球瞬态声散射的时域数值解

选用目标表面势函数为变量,结合弹性边界条件,给出了水中弹性球瞬态声散射的时域积分方程法数值计算公式．研究了时域积分方程法在实际计算中随时间步进解呈发散趋势的问题,并采用时域低通滤波技术,基本克服了实际计算中解发散问题．计算了高斯形脉冲入射下弹性铝球的无量纲反向散射声压,并和由频域的Ｒａｙｌｅｉｇｈ简正级数解与入射波的频谱的乘积作反变换得到的精确解做了比较,两者趋势基本一致     

二维光子晶体中负折射现象的研究与仿真

使用光子晶体能带结构和等频面（EFS）方法对二维光子晶体中的负折射现象进了研究和仿真．得到了二维光子晶体中出现负折射率现象的频率范围．使用时域有限差分法（FDTD）对光波在二维光子晶体界面和晶体中的传播进行了数值仿真研究．由仿真结果发现在一定的频率范围内,在二维光子晶体中确实可以发现光波的负折射传播现象．     

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

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.     

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-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the