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51.
虚拟仿真技术被广泛认为是一项重大技术进步,可以提供一种新颖的教学方式,能促进化学学习,打破传统教育方法的限制。三维交互式的气相色谱仪虚拟仿真实验系统使用当前主流的Unity 3D软件作为系统的主要开发工具。构建的系统主要包含仪器的动态原理展示、三维结构展示及仿真实验3部分。系统中的模型全部采用三维设计,场景逼真,能够全方位地向使用者展现真实仪器的外形及内部结构,令使用者如同置身于真实实验室中,获得身临其境的操作体验,从而更容易学习和掌握仪器组成、工作原理及相关的实验技能。系统不仅满足了仪器培训和化学实验教学的基本需求,而且对虚拟仿真技术在化学中的应用起了示范效应和推广作用。  相似文献   
52.
Liu  Wenwei  Shen  Jingfang  Cheng  Sijie  Wang  Siyan 《Russian Physics Journal》2021,64(7):1261-1280
Russian Physics Journal - Stiffness characterization of mechanical interfaces is quite crucial for the analysis of several tribological behaviors. In the research of industrial robots, joints exist...  相似文献   
53.
The chemistry of cationic forms of clusterfullerenes remain less explored than that of the corresponding neutral or anionic species. In the present work, M3N@Ih-C80 (M=Sc or Lu) cations were generated by both electrochemical and chemical oxidation methods. The as-obtained cations successfully underwent the typical Bingel–Hirsch reaction that fails with neutral Sc3N@Ih-C80. Two isomeric Sc3N@Ih-C80 cation derivatives, [5,6]-open and [6,6]-open adducts, were synthesized, and the former has never been prepared by means of a Bingel–Hirsch reaction with neutral clusterfullerenes. In the case of the Lu3N@Ih-C80 cation, however, only a [6,6]-open adduct was obtained. Density functional theory (DFT) calculations indicated that the oxidized M3N@Ih-C80 was much more reactive than the neutral compound upon addition of the diethyl bromomalonate anion. The Bingel–Hirsch reaction of M3N@Ih-C80 cations occurred by means of an unusual outer-sphere single-electron transfer (SET) process from the diethyl bromomalonate anion to the stable intermediate [M3N@C80(C2H5COO)2CBr].. Remarkably, the diethyl bromomalonate anion was found to act as both a nucleophile and an electron donor.  相似文献   
54.
Protein is one of the four most important biomacromolecules in living systems. The detection, quantification, localization, and characterization of proteins is essential for an understanding of biological fundamentals, as well as for the diagnostics and treatment of protein-related diseases. By using intrinsic and extrinsic fluorescence, different techniques have been established to study proteins, many of which are now being routinely used in research laboratories and clinics. This review summarizes the applications of aggregation-induced emission (AIE) fluorescence in protein science. In contrast to traditional fluorescent dyes, the activation of AIE dyes is mainly attributed to the restriction of intramolecular motions. This unique turn-on mechanism of AIE dyes allows researchers to develop novel fluorogenic strategies for sensitive, selective, and reliable analysis of proteins. This review focuses on introducing AIE strategies for 1) detection, localization, and quantification of proteins; 2) probing polymer conformational transitions of proteins; 3) characterization of protein–ligand interactions; and 4) evaluation of enzyme activities. Perspectives and challenges with respect to this emerging field of protein characterization are offered.  相似文献   
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56.
Maximizing adsorption and catalytic active sites and promoting the photo-excited charge separation are two key factors to achieve excellent photocatalytic performance. In this study, we report a sol-gel synthesis approach to obtain non-metal doped TiO2 with sponge-like structure and surface-phase junctions all at once. While doping of carbon and nitrogen shifted the activation wavelength to the visible-light region, the innovative use of perchloric acid as a pore-making agent led to the formation of three-dimensional lamellar and porous structure with surface-phase junctions. High surface area with catalytic active sites rendered by the sponge-like structure and surface-phase junctions contributed to the much improved photocatalytic degradation efficiency toward rhodamine B, tetracycline and Disperse Red 60 with excellent reusability and stability. The improved generation and separation efficiency of the photo-induced charge carriers of the as-prepared TiO2 were supported by electrochemical impedance measurements and transient photocurrent responses. This method could also be applied to other photocatalysts to achieve structural alteration and element doping simultaneously.  相似文献   
57.
Cooperative coupling of H2 evolution with oxidative organic synthesis is promising in avoiding the use of sacrificial agents and producing hydrogen energy with value-added chemicals simultaneously. Nonetheless, the photocatalytic activity is obstructed by sluggish electron-hole separation and limited redox potentials. Herein, Ni-doped Zn0.2Cd0.8S quantum dots are chosen after screening by DFT simulation to couple with TiO2 microspheres, forming a step-scheme heterojunction. The Ni-doped configuration tunes the highly active S site for augmented H2 evolution, and the interfacial Ni−O bonds provide fast channels at the atomic level to lower the energy barrier for charge transfer. Also, DFT calculations reveal an enhanced built-in electric field in the heterojunction for superior charge migration and separation. Kinetic analysis by femtosecond transient absorption spectra demonstrates that expedited charge migration with electrons first transfer to Ni2+ and then to S sites. Therefore, the designed catalyst delivers drastically elevated H2 yield (4.55 mmol g−1 h−1) and N-benzylidenebenzylamine production rate (3.35 mmol g−1 h−1). This work provides atomic-scale insights into the coordinated modulation of active sites and built-in electric fields in step-scheme heterojunction for ameliorative photocatalytic performance.  相似文献   
58.
刘斯婕  赵星  何敬宇  王娟 《化学通报》2021,84(9):981-984
以取代苯甲醛、溴乙腈和6-苄基-3-硫代-3,4-二氢-1,2,4-三嗪-5(2H)-酮为起始原料,在超声辅助下,一锅合成了9个新型6-苄基-2-亚苄基-2H-噻唑[3,2-b][1,2,4]三嗪-3,7-二酮类化合物,结构经1H NMR,13C NMR和MS(ESI)表征并对其合成机理进行了初步研究。测试了目标化合物(4a~4i)的体外乙酰胆碱酯酶的抑制活性,其中4a和4d抑制活性最好,有进一步研究的价值。  相似文献   
59.
选用2-(N,N-双(二苯基膦基甲基))胺基吡啶(bdppmapy)为膦配体、二吡啶并[3,2-a∶2′,3′-c]吩嗪(dppz)为氮配体、[Cu (CH3CN)4]BF4为铜盐,在常温下进行反应,制备了3种新型Cu (Ⅰ)配合物,分别为[Cu (dppz)(bdppmapy)]2(BF4)2·H2O (CuBF4-1)、[Cu (dppz)(bdppmapy)]BF4(CuBF4-2)和[Cu (dppz)(bdppmapy)]BF4(CuBF4-3)。获得了CuBF4-1和CuBF4-3的单晶,发现了单晶到单晶转化过程的现象,并探究了溶剂分子的存在对配合物结构和光物理性能的影响。通过单晶X射线衍射确定配合物CuBF4-1和CuBF4-3的结构,使用粉末X射线衍射(PXRD)、红外光谱(IR)和核磁共振氢谱/磷谱(1H/31P NMR)对合成的3个配合物进行结构表征。对配合物进行紫外可见吸收光谱(UV-Vis)、荧光光谱、荧光寿命及量子产率等光物理性质的表征和分析,比较了配合物发光性质的差异,探讨了溶剂分子对配合物结构和光物理性质的影响规律。太赫兹时域光谱对配合物的研究提供了帮助。  相似文献   
60.
The dependence of perovskite-based photovoltaic devices on toxic solvents limits their applications. Therefore, we added polyoxometalates into ionic liquids, as the green solvent and polyoxometalates synergistically improve the performance of devices. Firstly, methylammonium formate (MAFa) as solvent delayed the crystallization process of perovskite thin films, thus obtained an extended crystal domain, and the photocurrent of the device was increased from 35.51 μA to 63.18 μA. Secondly, introducing PW12 into this green solvent system, the matched energy level and good electron transmission rate promoted the separation of photogenerated excitons and accelerated the transmission of photogenerated electrons in perovskite. After dual adjustment of MAFa and PW12, the photocurrent of the champion device reached 95.99 μA (about 2.7 times of the original device), the unpacked devices can still maintain 80 % of initial value after being placed under environmental conditions for 700 h.  相似文献   
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