绿色热塑性木薯淀粉材料制备与性能

用尿素和乙醇胺作为混合塑化剂对木薯淀粉进行塑化,制备绿色热塑性木薯淀粉材料(GTSM).扫描电镜表明,混合塑化剂尿素和乙醇胺已经渗透到木薯淀粉颗粒内部,塑化了木薯淀粉,使其颗粒被破坏,成为均一连续相.将不同塑化剂含量的GTSM在相对湿度为50%的环境下保存10 d,力学测试得出:质量分数为30%塑化剂的GTSM应力为8.51 MPa,应变为74.2%,杨氏模量为102.5 MPa,断裂能为2.309 N.m;X射线衍射说明GTSM长时间放置没有发生结晶行为,不影响材料的力学性能.TG分析得出质量分数20%     

交联木薯淀粉的制备及性能

以某有机物(代号CL)为交联剂,对木薯淀粉进行交联变性处理,研究了交联剂质量分数、氢氧化钠质量分数、反应温度和时间等因素对淀粉交联度的影响,并对交联淀粉进行了分析表征.结果表明:交联剂质量分数为0.5%、氢氧化钠质量分数为1.5%、反应时间为3h、反应温度为50℃时,交联工艺最佳,此时交联淀粉的沉降积为1.0mL.扫描电子显微镜形貌分析表明,木薯淀粉交联后颗粒表面粗糙、有凹坑出现;傅里叶变换红外光谱图中发现,交联淀粉较原淀粉在1 241cm-1处出现醚键吸收峰,表明木薯淀粉发生了交联反应;X-射线衍射曲线表明,交联反应可使淀粉部分结晶区非晶化,结晶度较原淀粉的下降率为16.94%;交联后淀粉黏度变大,黏度热稳定性明显提高.     

塑化剂及其含量对热塑性淀粉膜性能的影响

以玉米淀粉为原料,分别以甘油和尿素为塑化剂,在百克干淀粉塑化剂含量为20g、25g及30g配比下,采用涂层法和浆膜法制备了热塑性淀粉膜,并对制备的热塑性淀粉膜的拉伸性能和吸湿性进行了测试和分析.实验结果表明,热塑性淀粉膜的抗拉强度及吸湿性不仅受塑化剂类型及其含量影响,同时还与热塑性淀粉膜的制备方法密切相关.同等条件下,以尿素为塑化剂采用将膜法制备的热塑性淀粉膜,其抗拉强度较高,且百克干淀粉塑化剂含量为25g时,抗拉强度达到极值,但因吸湿造成抗拉强度下降的幅度也达到极值.     

全淀粉降解材料的制备及性能初探

在丙三醇、水、高温作用条件下,淀粉在挤出机中得到改性,可加工成热塑性淀粉.研究了丙三醇对淀粉塑化前后结构的影响,用X射线衍射仪对淀粉塑化前后的结晶性能进行了研究.结果表明,在高温下,剪切力使得丙三醇小分子进入到淀粉分子链间,破坏淀粉的微晶结构.当丙三醇质量分数在25%-30%间时,可得到力学性能适中的热塑性淀粉.聚己内酯的加入对热塑性淀粉的脆性有很大的改善,而且同时对热塑性淀粉的疏水性有所提高.     

干燥淀粉的热塑化研究

研究了淀粉的干燥预处理对淀粉塑化效果的影响.对原淀粉和干燥淀粉采用甘油塑化,双螺杆挤出机挤出,分别得到热塑性淀粉(GPTPS、GPTPDS-1和GPTPDS-2).采用X射线衍射、热失重分析、示差量热扫描和扫描电镜,对三者的塑化效果进行比较.结果表明,在塑化剂总量接近的情况下,干燥淀粉较原淀粉可以制得结晶度低的热塑性淀粉.加工温度控制在170℃以下,在加工温度范围内,热稳定性GPTPS强于GPTPDS-2,则GPTPDS-1最低.     

铝颗粒对乙醇胺凝胶性能的影响

采用乙醇胺、琼脂糖胶凝剂、含能颗粒铝制备系列燃料凝胶。利用量热仪、离心机、旋转流变仪等仪器考察了胶凝剂和铝颗粒添加量（质量分数）对凝胶热值、离心稳定性、流变性的影响；通过扫描电镜对铝、琼脂糖颗粒及凝胶微观形态进行了表征。结果表明：当铝颗粒质量分数为30%时，相较于纯凝胶，乙醇胺凝胶体积燃烧热提高了22.2%，离心析液率从26.5%下降到9.8%，稳定性大大增强；铝颗粒能够与凝胶相结合增强凝胶的网络结构、增加松弛时间和储能模量。     

苎麻纤维增强热塑性淀粉复合材料的制备及力学性能研究

为进一步研究天然纤维增强热塑性淀粉复合材料的制备工艺和力学性能,以预塑化淀粉为原料,甘油为塑化剂,利用苎麻纤维作为增强材料,热压制备纤维增强热塑性淀粉复合材料.分别研究了热压温度、热压时间、苎麻纤维含量和纤维表面处理方式等对苎麻增强热塑性淀粉复合材料力学性能的影响.得到最佳制备条件:热压温度135℃、热压时间18min、苎麻纤维含量1.5g、5%NaOH预处理纤维24h.     

阳离子淀粉改性碳酸钙在纸页抄造中的应用

采用新工艺使形成凝胶的阳离子淀粉颗粒均匀包覆沉淀碳酸钙(PCC)表面,得到一种新型的改 性PCC,并对改性PCC的各个性质尤其对纸页的增强效果进行研究。探索两种PCC的改性方法,一种是 使用糊化好的高浓度淀粉溶液包裹PCC;另一种是先混合未糊化淀粉乳液和PCC,再蒸煮混合物。结 果表明：第1种方法淀粉溶解率较低,并且淀粉糊化浓度对淀粉溶解和手抄片各种性质有较大影响。 分别对糊化淀粉溶液质量分数为20 %、30 %、40 %、50 %、60 %的淀粉进行试验比较,发现糊化淀 粉溶液质量分数30 %改性PCC不仅具有均匀的颗粒大小,较低的淀粉溶解率,而且抗张指数提高41.1 %,耐破指数提高50 %,表面强度提高45.3 %,灰分提高37.5 %。     

羟丙基木薯淀粉制备工艺的优化研究

应用正交试验和数理统计分析 ,探讨了制备羟丙基木薯淀粉的反应影响因素 ,确定了一组优化实验条件 :环氧丙烷质量分数 14 %,氢氧化钠质量分数 1.0 %,反应时间 11h,反应温度5 0℃ .     

球磨-酯化复合改性槟榔芋淀粉对Pickering乳液形成的影响

为了提高淀粉颗粒的乳化能力,以球磨-酯化复合改性槟榔芋淀粉为颗粒乳化剂,大豆油为油相,制备水包油型Pickering乳液。采用激光粒度仪、研究级正置显微镜、流变仪等对Pickering乳液外观、液滴粒径、显微形态及动态流变特性进行表征,考察淀粉颗粒质量浓度(1、5、10、20、30mg/mL)和油相体积分数(10%、20%、30%、40%、50%)对乳液稳定性和流变特性的影响。研究发现:增加颗粒质量浓度导致乳化相体积增加,液滴粒径减小;随着油相体积分数的增加,乳化相体积增加,液滴粒径增大。当颗粒质量浓度为20mg/mL,油相体积分数为40%时,乳液的乳析现象明显改善。球磨-酯化复合改性槟榔芋淀粉颗粒吸附在油/水界面,有效抵抗了液滴聚结,使乳液在储存30d后仍表现出良好的稳定性。流变特性表明:乳液内部存在弹性凝胶网络结构,随着颗粒质量浓度和油相体积分数的增加,液滴间堆积变得更紧密,从而增加了乳液黏度和凝胶强度,使其抵抗形变能力增强。球磨-酯化复合改性槟榔芋淀粉颗粒具有良好的作为Pickering乳液稳定剂的潜力。     

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

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