对羟基苯甲酸丙酯的分子与晶体结构

利用单晶 X-射线衍射分析方法测定了对羟基苯甲酸丙酯的晶体结构 .单斜晶系 ,P2 1/c,a=1 .2 1 0 3 (3 ) nm,b=1 .3 881 (4) nm,c=1 .1 886 (4) nm,β=1 0 8.5 4 8o,V=1 .883 6 (9) nm3 ,最终偏离因子 R1=0 .0 5 0 4 .测定结果表明 ,晶胞中每个不对称单位由两个对羟基苯甲酸丙酯分子组成 ,两个分子中的酯基和苯基基本共平面 ;分子中的酚羟基氧原子 O(5 )和 O(6 )均与另一个不对称单位的羰基氧原子 O(3 )和 O(4)形成了分子间氢键 ,这表明分子在晶胞内堆积时 ,除了范德华力以外还靠氢键来维系 .     

新型负膨胀系数材料ZrW2O8的合成与特性

ZrW2 O8 是新发现的由 0 3K至分解温度 1 0 5 0K都具有各向同性的负热膨胀化合物 ,但由于其分解温度和窄的热稳定范围反应合成相当困难 .本文综述了氧化物直接合成、微波合成和溶胶 -凝胶法制备ZrW2 O8以及单晶ZrW2 O8的生长方法 ,讨论了ZrW2 O8的特性 ,介绍了其负膨胀机理和潜在的应用     

ZrW2O8薄膜的物相转变与负热膨胀系数

以高纯ZrO2和WO3复合氧化物为靶材,采用射频磁控溅射方法在石英基片上制备ZrW2O8薄膜.对不同热处理温度后的薄膜进行XRD分析,结果表明,在650 ℃下薄膜为无定形,ZrW2O8晶化起始温度为650 ℃,当热处理温度高于1 100 ℃时,薄膜主要由ZrO2相组成.进一步采用高温XRD分析薄膜物相,发现在720 ℃时,能获得较纯的ZrW2O8薄膜.根据ZrW2O8晶面(2 1 1)间距随温度变化的结果,计算所制备的薄膜态ZrW2O8的热膨胀系数为-2.54×10-5/℃.SEM分析结果显示在ZrW2O8相所存在的温度范围内,薄膜非常致密而无明显孔洞.     

ZrW2-xMoxO8晶体结构及热膨胀性能

采用共沉淀法,以硝酸氧锆、钨酸铵和钼酸铵为原料制备了纯度较高的ZrW2-xMoxO8粉体,分别采用热重-差热和X射线衍射分析了W/Mo摩尔比对ZrW2-xMoxO8的结晶行为、晶体结构以及热膨胀性能的影响.结果表明:Mo的掺杂不会影响其热膨胀性能,所得ZrW2-xMoxO8均具有良好的负热膨胀特性,而ZrW2-xMoxO8的室温晶胞参数和合成温度均随着Mo取代量的增加而降低.x<0.5时,ZrW2-xMoxO8室温晶体结构为α-ZrW2O8相,ZrW2O8由氧化物原料在高温反应生成.高温XRD结果表明:ZrW2O8和ZrW1.5Mo05O8在高温会发生α-β相变,负热膨胀系数随之发生明显变化;当x≥0.5时,ZrW2-xMoxO8则由其对应的三方相或单斜相在高温转变而成,如果其室温相为β相,则在高温转变为不具负热膨胀特性的三方相.     

ZrO2粒径对ZrO2/ZrW2O8复合材料性能的影响

分别采用Nano-ZrO2和Commercial-ZrO2制备ZrO2/ZrW2O8复合材料,并对所得复合材料的微观结构、烧结质量及其热膨胀性能进行了研究.结果表明,当ZrO2和ZrW2O8的质量比为2∶ 1时,ZrO2/ZrW2O8复合材料的热膨胀系数极低,接近于零.然而Commercial-ZrO2/ZrW2O8复合材料存在致密度不高,气孔率大的缺点.Nano-ZrO2的采用,可以降低基体的烧结温度,改善复合材料的烧结质量,Nano-ZrO2/ZrW2O8复合材料的相对密度达到94%,比Commercial-ZrO2/ZrW2O8的相对密度75%有明显提高.     

α-ZrW_2O_8/Cu复合材料的制备、微观结构和致密度

采用粉末冶金法制备了ZrW2O8/Cu复合材料.将所制备的ZrW2O8/Cu复合粉体在300～600 MPa压制成型,在H2和N2惰性还原混合气氛下600 ℃烧结2 h后获得含有不同体积分数α-ZrW2O8的α-ZrW2O8/Cu复合材料.XRD分析结果表明,在ZrW2O8表面包覆铜后进行烧结和后热处理所获得的α-ZrW2O8/Cu复合材料中,未发现因热应力产生的γ-ZrW2O8和杂相,有效减小了因ZrW2O8相变而导致其负热膨胀效应的降低.研究结果表明,α-ZrW2O8能均匀分布在Cu基体中.随着压力的提高和Cu的增加,复合材料的致密度提高至88.9%.     

靶材制备工艺与配比对ZrW2O8薄膜制备的影响

分别采用钨酸锆靶（ZrW2O8）和氧化锆（ZrO2）与氧化钨（WO3）的复合靶,在磁控溅射条件下制备钨酸锆（ZrW2O8）薄膜,研究了靶材制备工艺、复合靶成分配比以及热处理温度对薄膜成分的影响,并对薄膜生长方式进行了初步探讨．结果表明：ZrW2O8靶材制备的薄膜在700℃处理后薄膜中ZrW2O8纯度较高,相同配比下,复合靶制备的薄膜经750℃处理后薄膜中ZrW2O8含量最高;以凡（ZrO2）：n（WO3）为1：2．8的复合靶材制备的薄膜经热处理后,结晶度优于凡（ZrO2）：n（WO3）为1：2获得的薄膜,并且ZrW2O8最佳含量的热处理温度较低;热处理时薄膜的生长机制为岛状生长方式;ZrW2O8薄膜在（211）和（220）晶面上的热膨胀系数均为负值．     

共沉淀法制备负膨胀系数材料ZrW2O8

以H2WO4和ZrOCl2·8H2O为原料,先采用共沉淀法制备出前驱物,再加热合成出了ZrW2O8粉末. 用X射线衍射(XRD)对合成粉末进行物相分析,用扫描电子显微镜(SEM)分析粉末形貌,用差热-热重分析确定合成温度. 结果表明:溶液pH值控制在2～3范围内,溶液中Zr4 和WO2-4能同时发生沉淀;所得前驱物在1 200 ℃反应1 h,所得产物相主要为ZrW2O8,其粒度在100 nm左右,且分布均匀.     

ZrW_2O_8的负热膨胀特性表征

以分析纯ZrO2和WO3为原料,采用分步固相法合成负热膨胀ZrW2O8粉体和陶瓷.采用X射线衍射仪(XRD)、扫描电子显微镜(SEM)对产物结构及形貌进行表征,采用3种不同的方法测得ZrW2O8负热膨胀系数,研究了不同测量方法对ZrW2O8负热膨胀系数测量的影响.研究结果表明:合成的产物为单一的立方晶体结构的α-ZrW2O8,采用高温X射线衍射和Power X软件测得样品从室温至600 ℃范围内的平均热膨胀系数为-5.605×10-6 K-1;而采用热膨胀仪测得从室温至600 ℃范围内ZrW2O8陶瓷棒和冷压成型ZrW2O8粉体棒的平均热膨胀系数分别为-10.709×10-6 K-1和-4.490×10-6 K-1,测试方法、致密度和微观结构对样品的负热膨胀系数均有影响.     

[Co(2，6-二胺基甲基吡啶)(1，2-二胺基丙烷)Cl]ZnCl4体系配合物的合成及一异构体的晶体结构

用过氧化物法合成了 [Co(bamp) (cmen)Cl]ZnCl4(bamp =2 ,6 -二胺基甲基吡啶 ;cmen =1 ,2 -二胺基丙烷 ) ]中的两个经式异构体 ,解析了其中一个异构体阳离子的晶体结构为m1 .晶体学参数 :单斜晶系 ,空间群C2 /c,a =2 .0 1 2 0(6 )nm ,b =0 .940 8(3)nm ,c =2 .0 5 2 1 (6 )nm ,β =92 .0 45 (6 )° ,V =3.882 2(1 9)nm3,Dc =1 .786 g/cm3,Z =8,F0 0 0 =2 1 0 4,μ(MoKα) =2 7.83cm-1,R =0 .0 42 6 ,RW=0 .1 0 38.配合物离子中Co3 为六配位 .晶胞中含 4个配合物离子 ,对映体的比例为 1 :1     

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     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with