Dynamic mechanical and shape memory properties of copolymers based on o‐allylphenol type benzoxazines and diglycidyl ether of bisphenol‐A

Three benzoxazines based on o‐allylphenol and 1,6‐hexamethylenediamine (HDA) or 4,4′‐diaminodiphenyl methane (DDM) or 4,4′‐diaminodiphenyl ether (DDE) were respectively blended with diglycidyl ether of bisphenol‐A (DGEBA) in various weight ratios followed by thermal polymerization to prepare three series of benzoxazine/DGEBA copolymers. With increasing DGEBA content, the peak temperature of the exothermic peaks in the DSC curves shows a systematic increase for the three series of benzoxazine/DGEBA blends. Each copolymer shows a single glass transition temperature (T_g). As the content of DGEBA is increased, T_g reaches a minimum for the copolymer system based on HDA but a maximum for the two systems based on DDM and DDE. For the same benzoxazine/DGEBA weight ratio, copolymers based on DDM and DDE show high T_g values over those based on HDA. The three series of benzoxazine/DGEBA copolymers exhibit a one‐way dual shape memory effect based on T_g, and the shape memory properties of the copolymers under tensile deformation mode vary with the variation of both diamine bridge structure and DGEBA content. © 2018 Society of Chemical Industry     

喹硫磷合成研究

报导了采用复合相转移催化剂合成喹硫磷，并研究了各种因素对合成收率的影响，喹硫磷合成收率可达９４．８％以上。     

Lipase‐mediated methanolysis of soybean oils for biodiesel production

BACKGROUND: Biodiesel is increasingly perceived as an important component of solutions to the important current issues of fossil fuel shortages and environmental pollution. Biocatalysis of soybean oils using soluble lipase offers an alternative approach to lipase‐catalyzed biodiesel production using immobilized enzyme or whole‐cell catalysis. The central composite design (CCD) of response surface methodology (RSM) was used here to evaluate the effects of enzyme concentration, temperature, molar ratio of methanol to oil and stirring rate on the yield of fatty methyl ester. RESULTS: Lipase NS81006 from a genetically modified Aspergillus oryzae was utilized as the catalyst for the transesterification of soybean oil for biodiesel production. The experimental data showed that enzyme concentration, molar ratio of methanol to oil and stirring rate had the most significant impact on the yield of fatty methyl ester; a quadratic polynomial equation was obtained for methyl ester yield by multiple regression analysis. The predicted biodiesel yield was 0.928 (w/w) under the optimal conditions and the subsequent verification experiments with biodiesel yield of 0.936 ± 0.014 (w/w) confirmed the validity of the predicted model. CONCLUSION: RSM and CCD were suitable techniques to optimize the transesterification of soybean oil for biodiesel production by soluble lipase NS81006. The related lipase NS81006 reuse stability, chemical or genetic modification, and transesterification mechanism should be taken into consideration. Copyright © 2007 Society of Chemical Industry     

班主任工作对大学生科学精神和人文素质培养的实践

培养有专业知识技能、创新精神和社会实践能力的学生是新时期大学生的培养目标。班主任作为学生管理的基本单位是学生人文素质培养的重要组成力量。结合个人班主任工作的实践,从班主任常规工作制度化、抓学风塑学习化的生存习惯、课外活动增强团队意识几个方面介绍了班主任对学生科学精神和人文素质的培养。     

钙基添加剂对不同煤种解耦燃烧下硫释放的影响

煤燃烧后排放的硫氧化物导致的环境污染问题已经引起人们的日益关注。基于一段式和两段式卧式炉,本文探究在传统燃烧和解耦燃烧条件下,温度、煤种以及CaO对燃煤释放SO₂规律的影响。试验结果表明：不同煤种的SO₂释放规律存在差异。随着温度的升高,不同煤种燃烧SO₂的释放量均不断增加,硫的动态析出曲线逐渐由单峰分布转化为双峰分布。传统燃烧模式下,添加的CaO对烟煤、无烟煤和褐煤脱硫效率可以达到70%以上,高氯煤脱硫效率则较低,仅有12.09%～20.45%;随温度升高,烟煤、褐煤和高氯煤的脱硫效率呈现先略微下降,后升高再下降的趋势,烟煤脱硫效率则逐渐降低。解耦燃烧模式下,CaO对烟煤、无烟煤脱硫效率在42.35%～76.23%,褐煤在21.35%～52.63%,高氯煤脱硫效率仍然较低,在8.93%～10.57%;随温度升高,烟煤、褐煤和高氯煤的脱硫效率呈现先增加后降低的趋势,烟煤脱硫效率逐渐降低。解耦燃烧模式下,不同煤种SO₂的总释放量大于传统燃烧模式,添加CaO后脱硫效率小于传统燃烧模式。     

HSE管理体系在石油工程项目监理中的应用

结合作者监理工作的经验,阐述了在石油工程项目施工监理工作中如何运用HSE管理体系知识,来进行项目施工监理的HSE管理工作,从而有效推动HSE管理体系在工程项目建设中的实际应用,实现项目监理的HSE工作目标。     

杭州抗咸一期工程的软土地基处理

本文介绍了杭州市抗咸一期工程中钢筋混凝土输水渠道及钱塘江新江堤在软土地基上的加固处理方案、设计、检测等情况。     

我国蓄滞洪区规划与建设的思路

蓄滞洪区是我国江河防洪体系的重要组成部分,但长期以来蓄滞洪区建设与管理滞后,严重影响了蓄滞洪区作用的有效发挥。为切实加强蓄滞洪区建设与管理,水利部组织开展了全国和各流域蓄滞洪区建设与管理规划的编制,为全面推进和加快蓄滞洪区建设、强化蓄滞洪区管理奠定了基础。回顾了我国蓄滞洪区建设与管理历程,在梳理蓄滞洪区建设管理相关问题与经验的基础上,分析提出了新形势下我国蓄滞洪区规划与建设的思路。