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关键词： 物理化学   热塑性推进剂   聚氨酯热熔胶   流变性能   黏流活化能   增塑剂  

摘要： 以聚氨酯热熔胶、铝粉和高氯酸铵组成的复合固体推进剂为研究对象,首先通过压延物理混合方法制备了复合固体推进剂,采用SEM和EDS方法对其形貌和组分分布进行了表征,测试了其力学性能、密度和机械感度。为深入了解聚氨酯热熔胶基复合推进剂的流变性能,进一步使用哈克流变仪(HAAKE MARS)研究了增塑剂、剪切速率和温度对其黏度的影响。结果表明,聚氨酯热熔胶基热塑性复合推进剂为假塑性流体,符合Ostwald-de Wale模型。与纯热熔胶体系相比,加入增塑剂的聚氨酯热熔胶基热塑性复合推进剂的高温黏度由4×10^(6) Pa·s降至1.5×10^(6) Pa·s,黏流活化能由41.53 kJ/mol降至28.57 kJ/mol。此外,聚氨酯热熔胶基热塑性推进剂随温度升高和剪切速率的增加其黏度逐渐减小,纯热熔胶基推进剂的黏流活化能随剪切速率的增加由41.53 kJ/mol降至31.20 kJ/mol。

关键词： 本科教育   课程思政   教学改革   物理化学  

摘要： 详细梳理分析高校专业课课程思政的背景、原则和元素,提出专业课开展课程思政是基于新形势下意识形态领域斗争、完成我国新时代历史任务、新时代大学生个人发展三个需求,应遵循融合性、精简化、有效性三个基本原则,主要元素可梳理为人生观价值观、理想信念、民族精神、时代精神、道德修养、法治素养六个基本元素。针对物理化学课程总结部分思政元素实例,可以为其他专业课开展课程思政提供理论和实践参考。

关键词： Essential oils   Microencapsulation   Gamma and X-ray irradiation   Dry fermented sausage   Microbiological and physicochemical properties  

摘要： Essential oils (EOs) or EOs encapsulated in alginate and alginate-cellulose nanocrystal combined with 1.5 kGy X-ray (0.76 kGy/h) or gamma-ray (6.37 kGy/h) irradiation were applied on dry fermented sausages (DFS). Microbio-logical quality was tested in terms of the reduction of Escherichia coli O157:H7 cocktail, Listeria monocytogenes, molds and yeasts, lactic acid bacteria (LAB), and total mesophilic bacteria (TMF) during storage at room temperature (20 +/- 1 degrees C) for 8 weeks. Physicochemical quality was tested by following the changes of texture and color of sausages. Synergistic effects were observed with combined treatments with gamma-irradiation on inhibiting E. coli O157:H7 cocktail and LAB and with X-ray on inhibiting E. coli O157:H7 cocktail. Extensive inhibition of L. monocytogenes, molds and yeasts, and TMF was also noticed during storage. Antimicrobial formulations combined with gamma-irradiation did not show adverse effects on texture and color of sausages while treatment with X-ray resulted in the reduction of redness and increase of hardness. However, the differences of texture were eliminated during storage.

关键词： 物理化学综合实验   教学改革   人才培养   综合能力  

摘要： 物理化学综合实验是物理化学实验课程教学的重要组成部分之一,在人才培养方面具有重要作用。物理化学综合实验教学改革,应着重在实验平台建设、实验内容设计、大型仪器使用和教学模式创新等方面进行探索。实践经验与成果表明,物理化学综合实验教学的开展,不但能够促进物理化学实验教学水平的提高,也有助于培养学生发现问题、思考问题和解决问题的综合能力和创新意识,落实课程全程全方位育人使命。

关键词： 崩岗土体   理化性质   内部分异   广东省  

摘要： [目的]研究崩岗土体物理性质的内部分异和崩岗土体化学物质组成,为更好地理解崩岗的侵蚀过程提供理论参考。[方法]以广东省德庆县3个典型崩岗为例,采用筛分法、烘干法、激光粒度分析、液塑限分析、X射线衍射分析和X射线荧光光谱分析,对崩岗不同地貌部位的土体物理性质、矿物组成和化学元素进行测定。[结果]①崩壁土体容重略大于崩积体、沟道和洪积扇的土体容重;崩壁和崩积体的含水率和界限含水率大于沟道和洪积扇的土体含水率和界限含水率。②崩岗土体中值粒径表现为:崩壁<崩积体<沟道<洪积扇;崩壁和崩积体土体颗粒级配曲线呈双峰型,沟道和洪积扇土体颗粒级配曲线呈单峰型。③崩岗土体的矿物成分以黏土矿物高岭石为主,石英和白云母次之;化合物以SiO_(2)含量最多,其次为Al_(2)O_(3);化学元素以Ti含量最高,S含量次之。[结论]崩岗不同地貌部位的土体物理性质具有一定的分异现象,水力—重力复合侵蚀作用机制是这一内部分异形成的原因。强化学风化作用下,崩岗土体黏土矿物以高岭石为主,化学物质在崩岗内部没有出现明显的元素迁移和富集现象。

关键词： Opuntia humifusa   Lactic acid bacteria   Cellulolytic enzyme   Isorhamnetin   Antioxidant activity  

摘要： Eastern prickly cactus (Opuntia humifusa) has a substantial therapeutic and dietary value. In this study, O. humifusa plants were fermented at 25 C with cellulolytic enzymes (E, Viscozyme), lactic acid bacteria (LAB), Lactobacillus paraplantarum (Lp), Streptococcus salivarius (Ss), and Weissella confusa (Wc) in various combinations: E, LWS (Lp:Wc:Ss = 1:1:1, v/v/v), and E with LAB (E-Lp, E-Ss, E-Wc, and E-LWS). Significantly lower viscosity (14.5 cP) and higher yield (> 97.4%) were observed in O. humifusa extracts containing E (P < 0.05), whereas the extract with LWS showed the highest viscosity (36.9 cP) and lowest yield (58.8%). Total polyphenol content and antioxidant activity of O. humifusa extract were enhanced, and flavonoid glycosides (isorhamnetin-3-O-rutinoside and isorhamnetin-3-O-glucoside) were effectively converted to aglycones when fermentation was performed with E and LAB. The isorhamnetin and quercetin contents were highest in the E-Wc and E-LWS extracts fermented for 60 h. This study shows that the physical and functional properties of O. humifusa extract may be modulated by fermentation with selected LAB and cellulolytic enzymes.

关键词： Physicochemical properties   Piperazine   Structure-property relationship   Trypanosoma cruzi   Antitrypanosomal compounds  

摘要： Trypanosoma cruzi is the causing agent of Chagas disease, a parasitic infection without efficient treatment for chronic patients. Despite the efforts, no new drugs have been approved for this disease in the last 60 years. Molecular modifications based on a natural product led to the development of a series of compounds (LINS03 series) with promising antitrypanosomal activity, however previous chemometric analysis revealed a significant impact of excessive lipophilicity and low aqueous solubility on potency of amine and amide derivatives. Therefore, this work reports different modifications in the core structure to achieve adequate balance of the physicochemical properties along with biological activity. A set of 34 analogues were designed considering predicted properties related to lipophilicity/hydrosolubility and synthesized to assess their activity and selective toxicity towards the parasite. Results showed that this strategy contributed to improve the drug-likeness of the series while considerable impacts on potency were observed. The rational analysis of the obtained data led to the identification of seven active piperazine amides (28-34, IC50 8.7 to 35.3 mu M against intracellular amastigotes), devoid of significant cytotoxicity to mammalian cells. The addition of water-solubilizing groups and privileged substructures such as piperazines improved the physicochemical properties and overall drug-likeness of these compounds, increased potency and maintained selectivity towards the parasite. The obtained results brought important structure-activity relationship (SAR) data and new lead structures for further modifications were identified to achieve improved antitrypanosoma compounds.

关键词： 课程思政   教学改革   案例解析  

摘要： 当前的教育教学改革要求把大学生的思政教育贯穿于高等教育的每一门课程当中,因此将课程思政融入物理化学学科教学中迫在眉睫。物理化学学科因其独特的课程特点而蕴含了丰富的思政元素。文章简要总结了物理化学学科中融入思政元素的方法,并且结合学习对象的特点,以单组分系统的两相平衡及弯曲表面上的蒸气压为例说明在教学过程中融入课程思政的具体实施策略。

关键词： OBE教学理念   物理化学实验   中医药院校   以学生发展为中心  

摘要： OBE是成果导向教育,即Outcomes-Based Education,聚焦于学生受教育后获得什么能力和能够做什么。OBE理念下的教学质量及评价以学生学习结果为唯一标准。随着国内高校教育改革的推进,以培养高水平的中医药人才为己任的中医药高等教育,需要顺应社会的发展需要,不断加强人才培养体系建设。基于此背景,在中医药院校当中运用OBE理念,优化设计《物理化学实验》课程内容,探索新形势下的教学方法,确保学生获得相应的学习成果,为学生的全面发展服务。

关键词： 物理化学实验   课程思政   育人目标   协同育人  

摘要： 《物理化学实验》是很多工科院校开设的一门必修的、独立的基础实验课,它综合了化学领域中各分支所需要的基本研究工具和方法。本文就物理化学实验课程中思政元素的挖掘及实施进行了探索和讨论。通过本课程培养学生规范严谨的实验习惯、实事求是的科学态度、分工协作的团队精神、勇于探索的创新精神等良好品格,实现与思想政治理论课同向同行,协同育人。