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关键词： A   Sol-gel method   C   Antibacterial   D   Bioactive glass   D   Hydroxyapatite   Ag2O   E   Biomedical applications  

摘要： In the present study, bioactive glasses (BGs) in 60SiO2-(31-x) CaO?4P2O5?5Li2O-xAg2O systems (x = 0, 1, 5, and 10 mol %) with optimum fixed amount of Li2O (5 mol %) were successfully synthesized through sol-gel technique and the effects of Ag2O addition on in-vitro investigations, biological properties, and bactericidal efficiency were evaluated. Structural and morphological evaluations by X-ray diffraction (XRD), Fourier transform infrared (FTIR), transmission electron microscopy (TEM) as well as scanning electron microscopy (SEM) revealed that BG with chemical composition of 60SiO2?30CaO?4P2O5?5Li2O?1Ag2O (mol%) had a higher rate of hydroxyapatite (HA) formation than other synthesized specimens. While, BGs containing 5 and 10 mol% of Ag had a lower bioactivity because of the reduced dissolution rate of Si and Ca. The results obtained from the 3-(4,5dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide (MTT) assay and evaluation of alkaline phosphatase (ALP) activity exhibited that proliferation and differentiation of MC3T3-E1 osteoblast-like cells and osteoblastic activity were intensified by the presence of Ag in the BGs" composition. Meanwhile, BGs containing 1 mol% of Ag not only had no toxic effect on the cells, but also caused a significant enhancement in proliferation and differentiation of the cells within 7 days (**p < 0.01), as well as the highest ALP activity in this specimen (*p < 0.05). Additionally, all the synthesized specimens had significant antibacterial efficiency against E-coli bacteria. Our results showed that addition of 1 mol% of Ag to BG containing Li led to a significant antibacterial efficiency compared to the control (*p < 0.05). Afterwards, DAPI/actin and live/dead cell staining methods were applied, which well confirmed results of MTT assay. Finally, BG with chemical composition (LA01) of 60SiO2?30CaO?4P2O5?5Li2O?1Ag2O was introduced as an optimal novel co-doped BG in biomedical applications due to causing higher differentiation and pr

关键词： 虚拟仿真   物理化学实验   创新教学  

摘要： 实验是高等学校化学专业的基础必修课程,由于教学模式及客观因素的限制,传统实验教学方法不再适应新时代学生发展的需求。随着信息技术的发展,虚拟仿真技术逐渐走进课堂,通过虚拟仿真技术进行实验教学不仅使学生获得和真实课堂教学一致的体验,而且能够延伸实验教学内容的广度和深度,这对于提升实验教学质量和实现创新型人才培养目标极其有利。它所具有的可重复性、安全性、创新性等优点极大地弥补了传统实验教学的不足之处,为实验教学开辟了新的途径。以物理化学经典实验"二元合金相图的绘制"为例,从教学设计思路、教学设计过程和教学效果分析3个角度进行创新性教学改革探讨。

关键词： 物理化学   学习方法   开学第一课   自信心   学习动机  

摘要： 物理化学课程概念抽象难懂、公式繁多难学,开学第一课的启迪作用不言而喻。本文围绕物理化学的概念、内容和目标,引导学生了解物理化学课程的性质和重要作用,特别强调物理化学对生产实践具有广泛的指导意义。激发学生的学习动力和兴趣。并根据物理化学课程的特点,介绍学好物理化学的方法,使学生在第一次课就能重视该课程的学习并正确掌握学习方法,为后续课程的学习打开通往知识殿堂的大门。

关键词： 物理化学   二硝基乙腈钾   相容性   差示扫描量热法(DSC)  

摘要： 为了了解二硝基乙腈钾(DNCK)与火药常用组分之间的相容性,采用差示扫描量热法(DSC)研究了DNCK与这些组分之间的相互作用。结果表明:DNCK与DAGR吸收药、DA吸收药、硝化棉(NC)、硝基胍(NQ)、叠氮硝胺(DIANP)、1,3-二甲基-1,3-二苯基脲(C2)、2-硝基二苯胺(2-NDPA)相容性良好;与六硝基六氮杂异戊兹烷(CL-20)和N-甲基-4-硝基苯胺(MNA)轻微敏感;与黑索今(RDX)、三羟甲基乙烷三硝酸酯(TMETN)和间苯二酚(Res)敏感;DNCK与奥克托今(HMX)和N-丁基硝氧乙基硝胺(BUNENA)混合体系的分解峰温较HMX和BUNENA单质组分分别提前了35.2℃和17.4℃,因此,与HMX和BUNENA不相容。

关键词： 物理化学   CL-20粒度   高能推进剂   燃速   燃烧机理  

摘要： 为了研究CL-20粒度对含Al高能固体推进剂燃烧性能的影响,通过捏合浇铸工艺制备了含不同粒度CL-20(14μm、115μm)的GAP/AP/Al高能推进剂,采用靶线法测定了推进剂在不同压强下的燃速,并计算了压强指数;利用微型高温热电偶测温技术、燃烧火焰单幅照相技术研究了CL-20粒度对该推进剂燃烧性能影响的机理。结果表明,7~18MPa下含粗粒度(115μm)CL-20的GAP/AP/Al推进剂的燃速比含细粒度(14μm)CL-20的推进剂高7%~37%;2~10MPa下前者压强指数为0.52,后者为0.46;粗粒度CL-20较细粒度提前进行部分分解,分解产物除催化自身分解反应外,还促进了AP的分解,从而提高了相应推进剂凝聚相反应区的温度攀升速率,并使推进剂的燃速更高。

关键词： MOOC+SPOC   翻转课堂   物理化学   教学改革  

摘要： MOOC和SPOC相结合的混合式教学模式是新冠肺炎疫情背景下大学教学模式的主要发展方向。本文从《物理化学》课程网络教学的现状入手,探讨MOOC+SPOC翻转课堂教学模式在南疆高校化学专业《物理化学》课程教学中的实践。利用中国大学MOOC平台和钉钉,构建《物理化学》课程线上线下混合教学模式,从教学方法设计、课程教学、教学效果评价等几个方面探讨南疆高校《物理化学》课程教学改革。

关键词： 物理化学   燃烧催化剂   含能配位聚合物   四组元推进剂   催化作用   氧化石墨烯   燃烧调节   碳纳米材料  

摘要： 研究了3类典型氧化石墨烯基含能配位聚合物(GO-X)燃烧催化剂对四组元复合推进剂热分解特性和燃烧性能的影响;通过扫描电子显微镜(SEM)观察了推进剂截面微观形貌;采用同步热分析(DSC-TG)、傅里叶变换红外光谱仪(FTIR)对含不同GO-X的推进剂的热分解特性及其气相分解产物进行分析;采用综合燃烧诊断系统获得了该型推进剂的火焰结构与燃面推移速度,并采用X射线粉末衍射(XRD)对凝聚相燃烧产物物相结构进行了分析。结果表明,含GO-X的推进剂固化充分、组分界面结构完整,表明GO-X对固化交联反应没有明显影响;GO-CHZ-Cu对四组元推进剂的热分解催化效应十分显著,使其放热量增加到3064.1J/g,相比于空白配方增加了35.0%。GO-CHZ-Ni同样对推进剂有一定的催化效应,该样品放热量为2456.1J/g,增幅为8.2%。与纯GO相比,GO-CHZ-Ni与GO-CHZ-Cu可大幅提高四组元复合推进剂在低压段(0.5~1.5MPa)的燃速,除GO-CHZ-Cu外,其他催化剂使推进剂随着压强增大,燃速的增幅更加明显,因此压强指数提高。含GO-CHZ-Cu推进剂的压强指数为0.34,与空白配方差别不大,但整体上燃速提升46.4%,并且凝相产物分析表明GO-CHZ-Cu可使Al粉的燃烧更加完全,进一步提高了能量利用效率。

关键词： Viscosity   Tribological behavior   Physicochemical characteristic   Nano-ZnO   Nano-MoS2   Diesel oil-based nanofluid  

摘要： In this research, two different diesel oil-based nanofluids were prepared and the influence of temperature and nanoparticle content were examined on viscosity, tribological, and physicochemical features of diesel oil. The kinematic viscosity of samples was experimentally evaluated based on standard ASTM D445. The greatest viscosity increment was diagnosed at 0.7 wt% and 100 degrees C for both of the prepared nanofluids. The anti-friction behavior of the nanofluids was studied utilizing a pin-on-disc tribometer. The acquired outcomes revealed that ZnO and MoS2 nanoparticles (NPs) could promote the tribological characteristics of pure diesel oil. By analyzing the friction coefficient values and line roughness of the wear surface (Ra), an optimal concentration of ZnO and MoS2 nanoparticles (NPs) were found to be around 0.4 wt% and 0.7 wt%, respectively. The friction factor and pumping power were also measured at diverse content of nanoparticles and flow rates showing that the pumping power was enhanced by the incorporation of nanoparticles.

关键词： 海相页岩气   储集层   地层矿物   储集空间   有机质   物性特征  

摘要： 涪陵地区五峰-龙马溪组海相页岩地层矿物特征、页岩储集空间特征、页岩层有机质特征、物性及地球化学特征实验显示:镜质体反射率RO分别为2.4%和2.75%,孔隙度平均为4.5%,水平渗透率平均为23.9毫达西,基质渗透率平均0.27毫达西;无机孔隙主要包括粒间溶孔、粘土矿物晶间孔以及微裂隙;有机质表面的有机质孔面孔率平均为30%。页岩储集层以干气为主,实验结果对国内外同类页岩气储层评价及压裂过程作业具有重要指导价值。

关键词： 物理化学实验   教学改革   创新能力   环保意识  

摘要： 为满足新时期培养创新型人才的需要,从更新实验设备、优化与整合实验内容、健全和完善课程考核方式等方面对物理化学实验进行了基于科研创新、环境保护为目标的教学改革实践。教学改革不仅提高了实验教学质量,还增强了学生的自主创新能力和环保意识,促进了创新综合型人才的培养。