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关键词： 物理化学   硝酸酯类PBX   慢速烤燃   约束条件   泄压通道   响应等级  

摘要： 为了研究含能黏结剂体系硝酸酯类PBX炸药在不同约束条件下的慢烤响应特性,从而为战斗部缓释结构的设计提供依据,采用装药内嵌温度传感器和调节烤燃弹壳体泄压通道大小的方法,通过慢速烤燃试验研究了不同约束条件下Φ100mm×200mm装药慢烤过程的温度场变化、点火特征及响应规律。结果表明,该炸药在慢烤条件下,随着温度的升高装药先软化变为糊状,并从排气孔不断向外挤出,最后在端盖上堆积炸药的尖端处发生点火,点火过程包括火点区域扩张、瞬态喷溅燃烧、明火稳定燃烧3个阶段,且点火扩张阶段持续时间较短,明火燃烧阶段持续时间较长;排泄孔的大小对装药的响应温度和响应时间影响较小,但随着排泄孔面积(Sh)与装药截面面积(Sc)比值减小,装药的响应剧烈程度增大,当Sh/Sc大于16%,装药发生稳定的燃烧反应;当Sh/Sc在5%~10%,装药发生燃爆反应;当Sh/Sc小于5%,装药将发生爆炸及以上的反应;当Sh/Sc不小于5%,才可以控制装药不发生壳体破碎的响应等级。

关键词： 字母符号   规范书写   量和单位   化学元素   分子物理学   物理化学   核素符号   正体  

摘要： 根据GB3102.8-93《物理化学和分子物理学的量和单位》的规定,现将化学元素和核素符号书写的规范要求介绍如下:①元素或核素的单字母符号均用正体大写,双字母符号首字母正体大写,第二个字母用正体小写。

关键词： 物理化学实验   教学改革   综合性实验设计  

摘要： 地方院校物理化学实验受课时少,开设实验数目的有限性的影响,使化学类专业学生对物理化学理论在实际中的应用理解不足,限制了学生相关实践能力的培养。本文主要从本校化学,应用化学等专业开设的物理化学实验为研究对象,从课程教授模式和课程内容,包括实验计划,实验课时,实验开设项目等方面进行了改革研究。改革了两个基础实验,增设了两个综合性实验,并结合改革的方案设计了更合理的课程考核评价标准,一定程度上提高了学生的实践应用能力。

关键词： 原型启发   物理化学   创造性思维   同频共振  

摘要： 物理化学是用物理学的理论和实验方法,研究化学变化及其伴随的物理变化的本质与规律的科学。其理论、基本定律、公式的推导与应用抽象且逻辑性强,将原型启发理论应用于应用型本科物理化学的教学中。物理化学是用物理学的理论和实验方法,研究化学变化及其伴随的物理变化的本质与规律的科学。其理论、基本定律、公式的推导与应用抽象且逻辑性强,将原型启发理论应用于应用型本科物理化学的教学中。根据教学内容,合理设计原型情景,灵活运用原型启发和类比,有助于学生对抽象理论的理解,培养学生的创造性思维,更有助于学生清楚地认识创造性的思维形成过程,为创造性思维的培养提供依据。

关键词： block copolymers   nanoaggregates   nanocarriers   nanomedicine   nanoparticles   self-assembly  

摘要： Here, we demonstrate the applicability of self-assembling linear-dendritic block copolymers (LDBCs) and their nanoaggregates possessing varied surfaces as therapeutic nanocarriers. These LDBCs are comprised of a hydrophobic, linear polyester chemically coupled to a hydrophilic dendron polyamidoamine (PAMAM)-the latter of which acts as the surface of the self-assembled nanoaggregate in aqueous media. To better understand how surface charge density affects the overall operability of these nanomaterials, we modified the nanoaggregate surface to yield cationic (NH3+), neutral (OH), and anionic (COO-) surfaces. The effect of these modifications on the physicochemical properties (i.e., size, morphology, and surface charge density), colloidal stability, and cellular uptake mechanism of the polymeric nanocarrier were investigated. This comparative study demonstrates the viability of nanoaggregates formed from PDLLA-PAMAM LDBCs to serve as nanocarriers for applications in drug delivery.

关键词： 食用油   地沟油   运动黏度   水相电导率   折光率  

摘要： 基于红外光谱法对地沟油和合格食用油进行测定,研究了3种物理化学方法在食用油品质检测中的应用。结果表明:地沟油与合格食用油比较,运动黏度和水相电导率具有显著区别,可用于鉴别食用油掺伪,并具有快速、简单、价格低廉的优点;折光率区别不大,不能用于判断油脂品质。

关键词： Drylands   Mine wastes   Fertility islands   Community-level physiological profile   Microbial functional diversity   Soil functioning  

摘要： Spontaneous growth of native vegetation in abandoned metal(loid) mine tailings can be valuable for phytomanagement restoration projects. This study aimed to assess the degree to which spontaneous plant colonization of abandoned metal(loid) mine tailings from Mediterranean semiarid areas led to functional soil improvement, and to identify, if possible, a critical level indicating that this functionality was moving towards that of the vegetated soils from the surroundings. Vegetation ecological indexes, plant life forms and species functional roles, together with physicochemical and functional soils parameters, were studied in metal(loid) mine tailings abandoned similar to 40 years ago and surrounding forests in SE Spain. Vegetation patches showed only small differences in physicochemical parameters related to soil abiotic stress conditions (pH, salinity and metals), regardless of the vegetation. However, vegetation patches with greater species diversity and richness and presence of plants with contrasted life forms and functional traits that facilitate the growth of less stress-tolerant species showed an increase of the soil microbial functionality (higher microbial biomass C, (3-glucosidase activity, bacterial metabolic activity and functional diversity). Moreover, these vegetation patches showed a functional soil status comparable to that of the forests outside the mine tailings. In this sense, the present study showed the value of preserving these vegetation patches since they may act as nucleation spots favoring positive plant-soil feedbacks that may help to accelerate the functional recovery of these degraded areas. Furthermore, strategies to promote the creation of new vegetation patches including a variety of species with contrasted life forms and functional traits should be considered in phytomanagement restoration projects for abandoned metal(loid) mine tailings.

关键词： 工程认证   物理化学   教学改革  

摘要： 为贯彻落实我国工程教育认证所倡导的三个基本理念,从目前物理化学课程教育客观现状出发,发现其中存在的问题,分析问题起源,并提出有效的课程教学改革方案,以“发现问题—分析问题—解决问题”的理念为主线,提出对物理化学这门课程的内容、教学方法、教学评价体系三方面进行改革,使之深入到物理化学课堂中,为新时期物理化学教学改革提供有益参考。

关键词： 物理化学   活性燃料   活性金属配合物   推进剂   二氰胺阴离子复合含能材料  

摘要： 为探索新型活性燃料,以高还原性的二氰胺阴离子为基,结合含氮配体1-甲基-1,2,4三唑和过渡金属中心Mn、Co、Ni、Cu、Zn、Cd,制备出6种活性金属配合物燃料;通过红外光谱、X射线单晶衍射和粉末衍射对其结构进行了表征;采用差示扫描量热法(DSC)、热重分析法(TGA)对配合物的热分解过程进行了分析,并测试了机械感度;利用氧弹量热仪测定了燃烧热,并计算生成焓;将6种活性金属配合物与高氯酸铵(AP)以质量比为1∶4混合,制备出混合含能材料并用DSC进行热分析,采用EXPLO5计算了混合物的爆轰参数。结果表明,Mn、Zn、Cd配合物的分解峰温度为210.9~395.1℃;撞击感度均大于40J,摩擦感度大于360N,表明对机械钝感;6种配合物中,Co的配合物的最大燃烧热为9623.2kJ/mol,Cu的配合物有最大的生成焓为1731.9kJ/mol;6种含能混合物分解峰温为295.9~384.1℃;安全性能好,最小撞击感度和摩擦感度值分别为34J和288N;爆轰性能均优于TNT;燃速可达到18.5mm/s;理论计算每百克产气量最高可达3.37mol,表明活性金属配合物有潜力用于一些复合含能材料的燃料组分。

关键词： Thiohydantoin   Metallo-Schiff base   Spectroscopic study   SEM   Cytotoxicity  

摘要： A novel aminothiohydantoin Schiff base (ATHSB) ligand and its complexes {M(II)ATHSB;M = Mn(II), Cu(II), Zn (II)} have been successfully synthesized. The coordination modes, stoichiometry, geometry, thermal stability, and morphology of M(II)ATHSB were deduced based upon the outputs of different physicochemical, spectroscopic, and microscopic techniques. The comparative in-vitro anticancer studies revealed that all complexes are more cytotoxic than the parent ligands against human cancer cell lines (liver carcinoma (HepG2), colon carcinoma (HCT116)), whereas, they exhibited lower toxicity as compared to the free ligand against normal liver cells (HL7702). Complex Zn(II)ATHSB seems to be a superlative candidate;as it is the most cytotoxic one against HepG2 concomitantly with lowest toxicity toward the normal human liver cells (HL7702), thus may offering a potential alternative for conventional cancer chemotherapeutic agents.