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关键词： 物理化学   叠氮增塑剂   比热容   燃烧热   标准摩尔生成焓  

摘要： 为研究分子结构和组成对叠氮增塑剂热力学特性的影响规律,设计了几种结构相似的新型叠氮增塑剂;采用微量热差示扫描量热法测量了其比热容;采用氧弹量热法测量了其燃烧热,计算了生成焓;设计了含不同增塑剂的发射药配方,通过内能法计算了配方的能量性能。结果表明,增塑剂比热容值与分子中主链长度和侧链官能团数量有关;增塑剂燃烧热值与碳含量及碳氢比有关,标准摩尔生成焓随着氮含量的增加而升高,1,5-二叠氮基-3-氧杂戊烷(AZDEGDN)、1-叠氮乙酰氧基-2,2-叠氮甲基-3-叠氮丙烷(TAMPAA)具有较高的生成焓,分别为585kJ/mol和1212kJ/mol;与含叠氮硝胺(DIANP)配方相比,含AZDEGDN配方的火药力提高了5J/g,爆温降低了128K,含TAMPAA配方的火药力提高20J/g,爆温仅升高36K。

关键词： Microwave   Ionic liquid   Crystal structure   Thermal   N-alkyl-DMAP   DFT  

摘要： 1-(4-nitrobenzyl)-4-dimethylaminopyridinium chloride, [O2N-Ph-CH2-Py = N(Me)(2)](+)[Cl](-), was made available in good yield and within one minute using microwave assisted reaction (MW). The ionic liquid product resonance structure 4-(dimethylamino)-1-(4-nitrobenzyl)pyridin-1-ium (B) was confirmed by XRD-diffraction and solution N-15 NMR. Moreover, the FT-IR, UV-Vis., H-1- &C-13 NMR, were also performed and supported the structure. The packing XRD-data was compared to the molecular electronic potential (MEP) as well as Hirshfeld surface analysis (HSA). The XRD experimental angles/bonds lengths parameters, NMR and IR spectral matched to the theoretical values obtained by DFT/6-311++G(d,p) theory. The optical Tauc experimental energy gap, LUMO/HOMO and Density of State (DOS) energies were also evaluated. The thermal behavior of the ionic liquid under inert and open atmospheres were obtained via TG/DTG in different solvents. The experimental electronic absorption results matched with the Time-dependent (TD-DFT) results. (C) 2021 Elsevier B.V. All rights reserved.

关键词： 物理化学实验   混合式教学模式   网络平台  

摘要： 针对当前药学专业物理化学实验教学中存在的问题,结合物理化学实验教学的特点,利用网络平台进行混合式教学模式的改革。致力于提高物理化学实验的教学效果,优化评价体系,培养学生分析问题和解决问题的能力。

关键词： 物理化学   DFTNAN   DNAN   热分解动力学   共熔物   爆轰性能   体积收缩率  

摘要： 为了进一步研究DFTNAN及其低共熔物的相关性能,采用DSC、SEM对DNAN、DFTNAN及其低共熔物的热分解性能、晶体形貌和体积收缩率进行测试,并采用Kissinger法和Flynn-wall-ozawa法计算了其热分解动力学参数;采用撞击感度仪和摩擦感度仪测试了试样的机械感度,计算了其爆轰性能。结果表明,通过对T—X相图分析,制备的DNAN/DFTNAN低共熔物的质量比为40∶60;DNAN的热稳定性优于DFTNAN及其低共熔物,其中DFTNAN和其低共熔物的热分解峰温分别为279.7和262.2℃;DFTNAN的体积收缩率(13.1%)接近DNAN(13.2%),二者形成的低共熔物的体积收缩率(6.7%)最小且熔融结晶表面基本无收缩空隙区及固相聚集区;DFTNAN的氧平衡为-43.0%,爆速为8.54km/s,撞击感度和摩擦感度分别为52%和32%,其低共熔物的氧平衡和爆速分别为-64.6%和7.16km/s,撞击感度和摩擦感度分别为28%和12%,介于DNAN和DFTNAN之间,表明DNAN实现了对DFTNAN的有效降感,DFTNAN的存在提高了DNAN的爆轰性能。

关键词： 课程思政   专业基础课   立德树人  

摘要： 在专业基础课程课堂教学过程中实施课程思政,以职业操守和科创精神为主要思政方向。坚持贯彻"两性一度"的金课标准,优化课程实施方案,从学习者的角度构建课程,提升学生学习兴趣和学习主动性,提高课程育人效果,有效落实立德树人根本任务。

关键词： Anthropogenic impact   Land use   Nutrient availability   Physicochemical properties   Soil respiration   Urban ecosystem  

摘要： Urban ecosystems, the heterogeneous and rapidly changing landscape, showed a considerable impact on the global C cycle. However, studies encompassing the spatial differences in urban land uses on soil C dynamics are limited in tropical ecosystems. In this study, seasonal and temporal variability in soil CO2 efflux (SCE) and its regulatory physicochemical variables under five urban land use classes viz., Bare (BAR), Agriculture (AGR), Plantation (PLT), Grassland (GRA) and Lawns (LAW) were assessed from 2014 to 2016. Bare land use was considered as the reference for observing the variation for different land uses. Seasonal measurements of SCE, soil temperature, moisture content, pH, ammonium-N, nitrate-N and microbial biomass C (MBC) were performed whereas soil organic C (SOC), soil N, and soil physical properties were measured annually. Our results showed a significant (P < 0.01) increase in SCE by 89%, 117%, 132% and 166% for land use types from BAR to AGR, PLT, GRA and LAW, respectively. The results revealed a two-fold increase in SCE from anthropogenically managed urban lawns as compared to bare soil. PLT and LAW land use classes showed higher SOC and N contents. SCE was found positively correlated with temperature, moisture, SOC, soil N and MBC whereas negatively correlated with ammonium-N and nitrate-N (at P < 0.05) for the overall dataset. Soil moisture, temperature, SOC, porosity and pH were identified as the major determinant of urban SCE by explaining 63% of the variability in overall SCE. Further, temperature for BAR and LAW;moisture for PLT;ammonium-N for GRA;and nitrate-N for AGR were identified as the major regulators of SCE for different land use classes. The findings revealed that the interaction of soil temperature and moisture with nutrient availability regulates overall and seasonal variability in SCE in an urban ecosystem. Since these variables are highly affected by climate change, thus, the soil C source-sink relationships in tropical urban ecosy

关键词： 物理化学   理论教学   实验教学  

摘要： 物理化学理论及实验教学是化工、高分子、制药等相关专业的基础课程,对本科生的培养起着至关重要的作用。从教学内容和实验教学的方式方法出发,探讨独立学院在“3+1”人才模式下物理化学理论及实验教学应注重的实际问题及关于创新教学的一些想法。

关键词： Coal   Coalbed methane   Microwave irradiation   Pore structure   Oxygenic group   Adsorption and desorption hysteresis  

摘要： The influences of microwave irradiation on physicochemical properties and methane adsorption and desorption capability of four ranks of coals were investigated to explore the feasibility of enhancing coalbed methane (CBM) production by using controlled microwave field irradiation. The results indicate that the microwave irradiation changes coal pore structure characteristics. In particular, the micropore surface area and volume of low-rank coals decrease, whereas those of medium- and high-rank coals increase slightly. The mesopore surface area and volume of all the coals after microwave irradiation decrease. Overall, microwave irradiation decreases the adsorption pore volume with diameter less than 7.00 nm of all the coals for CH4. Furthermore, microwave irradiation enhances the connectivity of adsorption pores and seepage pores of low-rank coals and decreases the connectivity of adsorption pores of medium- and high-rank coals. With respect to surface chemistry property, microwave irradiation reduces the total amount of primary oxygenic groups including C-O, C = O and -COOH of all the coals. Finally, microwave irradiation decreases the maximum CH4 adsorption capability on all the coals by 2.50-18.18%, because of the decreasing number of adsorption pores for CH4. Moreover, microwave irradiation weakens CH4 adsorption and desorption hysteresis on coals, probably due to the decreasing CH4 adsorptioninduced coal matrix swelling. The decreasing hysteresis implies that controlled microwave field irradiation is beneficial to enhancing CBM recovery.

关键词： Heat-moisture treatment   Amylose inclusion complexes   Sodium stearate   Thermal transition   Gelatinization behavior   Granular structure  

摘要： Amylose-sodium stearate (SS) complexes (2, 5 and 8%) in heat-moisture treated potato starch (HPS) were evaluated for their physicochemical properties. Based on the DSC thermograms, the amylose - SS complexes were successfully formed with high thermal stability, indicated by a melt temperature (Tpeak) of > 112 degrees C for type I and >125 degrees C for type II complexes. Addition of 2% SS resulted in a single endothermal peak of the complexes, while 5 and 8% led to the formation of type I and II complexes with much higher enthalpy (Delta H) values. The XRD curve confirmed that the complexes were successfully formed. The pasting temperature increased from 66 degrees C for native to 91 degrees C for HPS145 complexed starch with 5% SS. Furthermore, the swelling power could be largely decreased, and the granular structure preserved. In addition, the inclusion complexation with SS on (HPS) succesfully improved the cook stabiliy.

关键词： Deep eutectic solvents   Physicochemical properties   Structural properties   Molecular dynamics simulations  

摘要： Deep eutectic solvents (DES) are engaging for their vast area of applicability, inexpensiveness, and easiness of handling compared to their ionic liquid analogous. In the current study, a set of DESs containing choline chloride/ ethylene glycol is synthesized in 1:2 and 1:3 M ratios. Physical properties of the prepared DESs including densities and viscosities were measured within the temperature range of 298.15-318.15 K at the pressure of 871 hPa. Moreover, a comparison between structural and physicochemical properties of these DESs was made by employing molecular dynamic simulation in a wide temperature range 298.15-398.15 K. The most reliable force filed model (FFM) for these eutectic mixtures acquired from the literature and exploited to get trustworthy physicochemical (density), transport (self-diffusion coefficient, viscosity, ionic conductivity), and some structural (radial distribution functions, spatial distribution function, hydrogen bonding) properties. (C) 2021 Elsevier B.V. All rights reserved.