双固化萜烯基聚氨酯丙烯酸酯树脂的涂膜性能

以松节油为原料合成萜烯基聚酯,将聚酯与由不同量的异佛尔酮二异氰酸酯(IPDI)和季戊四醇三丙烯酸酯(PETA)合成的异氰酸酯基封端的预聚体单酯反应,制备萜烯基聚氨酯丙烯酸酯树脂,与光引发剂和固化剂制备可以光-热固化涂膜,并测试其性能。采用傅里叶红外光谱仪(FT-IR)和热分析仪(TG)分别对合成的产物分子结构和涂膜进行表征。考察光固化时间、热固化温度和涂膜厚度对凝胶含量的影响。结果表明:与光固化涂膜相比,光-热固化涂膜的柔韧性有所下降,铅笔硬度从F提高为2H,附着力从2级提高到0级,耐溶剂性、力学性能有很大的改善;萜烯-马来酸酐(TMA)的引入涂膜热稳定性也有提高。     

荧光素及其衍生物的荧光性质研究

以荧光素、荧光素甲酯和6-O-(乙氧基羧甲基)荧光素甲酯为研究对象,探讨了溶液中甲醇和乙腈的含量、溶液的pH值、光照时间以及温度四种因素对这3种物质荧光性质的影响,实验结果表明6-O-(乙氧基羧甲基)荧光素甲酯具有较好的耐溶剂性、光稳定性、热稳定性,并且其荧光强度受介质pH值影响小.     

聚芳硫醚砜纳滤膜的制备及耐溶剂特性表征

以聚芳硫醚砜（PASS）为材料,采用浸没沉淀相转化法制备出平板纳滤膜,研究了制膜过程中工艺参数如聚合物浓度等对膜结构与分离性能的影响,确定最佳制膜条件为：聚合物质量分数22%,刮膜温度80℃,滞空时间0s,凝固浴为纯水。在0.5MPa压力下,最佳条件下制备膜的纯水通量为50.0L/(m ²·h),质量分数为0.01%的刚果红水溶液通量为47.6L/(m ²·h),对刚果红截留率为96.0%。耐溶剂实验结果表明,有机溶剂包括甲苯、二乙醚、甲醇、乙酸乙酯、正己烷和酸碱处理（pH=0～14）对PASS膜通量有较大影响,而对截留率影响不明显,显示出膜具有良好的耐溶剂特性。     

云南大学学报1999年度的影响因子在全国综合性高等学校学报中排名为第4名

在中国科学技术信息研究所 (ＩＳＴＩＣ) 2 0 0 0年1 1月出版的《1 999年度中国科技期刊引证报告》中 ,《云南大学学报 (自然科学版 )》的影响因子为0 .2 ,被引频次为 1 1 6次 ,在全国综合性高等学校学报中排名第 4名 ,排在前 5名的全国高等学校学报分别为 :　　　　学报名称　　　　　　影响因子1 .中山大学学报 (自然科学版 )　　 0 .2 822 .南京大学学报 (自然科学版 )　　 0 .2 723.北京大学学报 (自然科学版 )　　 0 .2 4 74.云南大学学报 (自然科学版 )　　 0 .2 0 05.复旦学报 (自然科学版 )　　　　 0 .1 90所谓影响因子 ,这是一个…     

四川师范大学学报(自然科学版)入选《中文核心期刊要目总览》

本刊接到《中文核心期刊要目总览》2 0 0 4年版编委会的书面通知,《四川师范大学学报·自然科学版》被确定为综合性科学技术类核心期刊,并被编入《中文核心期刊要目总览》2 0 0 4年版(第四版)。该书定于2 0 0 4年7月由北京大学出版社出版。2 0 0 4年版核心期刊研究,被列为“2 0 0 1年国家社会科学基金项目”,课题组认真总结了前三版的研究经验,参考了大量国内外相关文献,对核心期刊评价的基础理论、评价方法(评价指标体系、核心期刊表的学科划分、核心期刊数量的界定)、评价软件的设计与使用、核心期刊的作用与影响等问题进行了深入研究,在…     

高聚合度PVC在硫酸中的老化

用红外光谱法研究了高聚合度PVC在硫酸中的老化现象。通过不同介质条件下硫酸对不同聚集合度PVC的作用。在对化硫酸作用前后和不同作用程度下的PVC光谱图中,发现硫酸先后与PVC中的稳定剂和不稳定基因作用,发生从降解到焦化的变化,是复杂的物理和化学过程。对高聚合度PVC在实际应用中的耐溶剂性和防老化工作,有较大参考价值。     

《广西师范大学学报》（自然科学版）被认定为“综合性科学技术类”核心期刊入编2004年版《中文核心期刊要目总览》（第四版）

《广西师范大学学报》(自然科学版)被北京大学图书馆等单位和专家共同认定为“综合性科学技术类”核心期刊,并于2 0 0 4年4月接到入编2 0 0 4年版《中文核心期刊要目总览》(第四版)的书面通知.该书定于2 0 0 4年7月由北京大学出版社出版.第四版核心期刊的评审工作历时两年,参加人员有北京高校图书馆期刊工作研究会成员馆、中国科学院文献中心、中国社会科学院文献中心、农业科学院文献中心、中国人民大学书报资料中心等相关单位的百余名专家和期刊工作者,以及1 873位学科专家.该版核心期刊研究,被列为“2 0 0 1年国家社会科学基金项目”,是…     

带高速光窗口的16×16 CMOS-SEED交换芯片

论述了一种带高速光窗口的 1 6× 1 6CMOS SEED交换芯片的设计及制作 .SEED像元光窗口阵列的大小为 1 0 μm× 1 0 μm ,间距为 2 5 0 μm ,光开关速率可达 1 0 ps量级 ,对其电逻辑和光调制特性进行了测试 ,并应用到 1 6× 1 6自由空间Crossbar光学交换实验系统中 ,实现了 1 6× 1 6光信号的Crossbar网络交换 .     

共振光散射法测定汞-硫氰酸盐-罗丹明B体系中的汞

研究了汞 (II)与硫氰酸盐和罗丹明B形成离子缔合物的共振光散射的增强效应 ,拟定了一种新的测定汞的共振光散射方法 .通过实验确定了适宜的反应条件以及共振光散射强度与汞 (II)浓度之间的关系 .在λ =6 15nm处 ,共振光散射有最大的散射强度 ,并且共振光散射强度与汞 (II)浓度成线性关系 ,线性范围为 0 .0～ 0 .0 6 0 μg mL ,检测限为 0 .38μg L .该法简便、快速 ,实测水中的汞 (II) ,结果较为满意     

浅议2000版ISO9000族标准草案（CD）

将 2 0 0 0版ISO 90 0 0族标准草案与 94版ISO 90 0 0族标准作了对比 ,并指出了草案中尚存在的问题。     

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.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

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