纤维素纳米晶对木薯淀粉基复合膜性能的影响

为改善提高木薯淀粉基复合膜的性能,以木薯淀粉为原料,附加甘油、壳聚糖,加入纤维素纳米晶,采用流延法制备淀粉基复合膜,研究纤维素纳米晶对木薯淀粉基膜理化性能的影响。实验结果显示纤维素纳米晶含量增加,淀粉基膜的吸水率、透光率及透油率均呈下降趋势,膜的生物降解性提高。纤维素纳米晶添加质量分数为2.5%、降解7 d时,降解率达18.28%。结果证明纤维素纳米晶改善了木薯淀粉基膜的性能,增强了膜的生物降解性。可为用作绿色生物包装材料、减少环境污染提供参考。     

聚3—羟基丁酸酯薄膜的环境微生物降解研究

利用海水、活性污泥及土壤埋藏降解实验对化学法合成的聚３－羟基了酸酯（ＰＨＢ）薄膜进行了生物降解性研究。结果表明,降解化学合成ＰＨＢ薄膜的微生物分布比较广泛;水解作用在ＰＨＢ生物降解过程中对其失重率影响很小;ＰＨＢ薄膜的结晶度增加则生物降解性降低,ＰＨＢ中Ｓ型单体的存在将明显降低其生物降解性。     

聚酯酰胺多聚物的微生物降解初步研究

聚酯酰胺是一种新开发的可生物降解的高分子聚合材料。采用堆肥法、失重测定法、CO2生成测定法、酶降解表面观察法和清晰带技术等，对微生物降解聚酯酰胺的特性进行了测试和研究，并分离出具解聚酶活性的菌株。结果表明，聚酯酰胺塑料具有良好可生物降解性，是很有潜力的环境友好材料。     

油脂废水的生物处理研究进展

综述了油脂废水的降解菌的类群，影响降解作用的因素，以及目前研究的生物处理技术方法，分析了油脂废水的生物降解机理，并展望油脂废水的生物处理技术的应用前景。     

阻垢剂的可生物降解性研究

参照OECD301B标准,以降解过程中的二氧化碳生成量作为表征指标,研究了五种常用阻垢剂和两种新型阻垢剂的可生物降解性,得出了阻垢剂的可生物降解性数据、生物降解规律及聚合物分子结构与可生物降解性的关系。研究结果表明,增加聚羧酸阻垢剂分子结构中羧基的数目、酯基支链以及向主链中插入氮、氧元素,均可提高其可生物降解性,后两种方法特别有效。     

可降解聚合物

简述可降解聚合物的降解机理及其研究现状和发展趋势,指出可降解聚合物的降解时空性研究,可控光－生物降解的降解性研究,合成及加工 改进仍是今后研究的重要课题。     

科技动态

绿色包装的发展趋势 1 材料的改进、选择 1.1 采用可降解材料利用新的高分子合成技术,在高分子链上接上可分解的结构单元,使这种材料可光解或生物降解及生物/光双重降解。水和化学分解的塑料也应运而生,如水溶性的发泡塑料。 1.2 可食性包装材料 可食性包装材料代替传统塑料包装     

改性塑制餐盒的好氧真菌降解及可堆肥性

采用好氧真菌降解和受控堆肥化试验分别测试了３种改性塑制餐盒的生物降解性及可堆肥性。试验结果显示，聚苯乙烯－淀粉共混餐盒的生物降解性与其淀粉添加量密切相关，并且餐盒淀粉的生物降解率随其添加量的减少而降低。热塑性淀粉餐盒易于生物降解率可达６７．０％。这种餐盒具有良好的可堆肥性，经堆肥化处理后能被完全消纳。     

绿色缓冲包装材料的现状及研究进展

基于目前面临的能源危机和环境保护问题,阐述了绿色包装的涵义及重要性,论述了生物降解塑料、植物纤维类缓冲材料、生物质复合塑料等4种绿色缓冲包装材料的研究发展及其在相关领域的应用现状,指出目前绿色包装材料发展过程中存在的诸多问题,可作为绿色包装材料的发展之借鉴。     

生物表面活性剂在疏水性VOCs生物降解中的应用潜力

介绍了生物法特别是生物滴滤法净化挥发性有机物(volatile organic compounds,VOCs)的研究进展,以及疏水性VOCs的生物降解存在的问题。针对这些问题,基于目前生物表面活性剂在疏水性有机物生物降解,以及化学表面活性剂在VOCs生物降解中的研究成果,分析了将生物表面活性剂应用于生物滴滤法降解疏水性VOCs的可行性及应用潜力,并对今后开展生物表面活性剂提高疏水性VOCs的处理效率及其作用机理等方面的研究进行了展望。     

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.     

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     

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     

Journal of Donghua University ( English Edition) Contents of Volume 31

正~~