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铌多酸三维框架材料是近年来无机合成化学与材料化学领域的研究热点. 该类材料不但可以将铌多酸的优异特性与框架结构的优点复合起来, 而且在光催化、 主客体化学、 能源转化等领域具有重要的应用前景. 本文总结了近10年来铌多酸三维框架材料的研究进展, 包括了该类材料的合成策略、 结构调控、 性质及应用探索. 此外, 还对当前该类材料的发展所面临的挑战进行了总结, 并对其发展前景进行了展望. 相似文献
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共价有机框架材料催化研究进展 总被引:1,自引:0,他引:1
共价有机框架材料(COFs)是一类具有高比表面积、高孔隙率、高结晶度的结构多样性多孔材料.由于COFs具有可设计性、易功能化的特点,可通过"自上而下"或者后修饰策略将具有催化活性的官能团或金属颗粒嵌入到材料骨架当中,从而设计出高效催化剂. COFs已逐渐在多相催化及其它催化领域展现出非常大的应用价值.本文综述了COFs作为催化剂载体在多种催化反应中的合成策略与应用,对COFs催化剂的现状进行了总结与展望,同时指出该领域面临的问题与挑战. 相似文献
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The results of nearest-neighbor recognition experiments that have been carried out with exchangeable dimers derived from 1,2-dimyristoyl-sn-glycero-3-phosphoethanolamine and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine, in the presence of cholesterol, dihydrocholesterol, coprostanol, cholestane, cholesteryl methy ether, and sitosterol, provide strong support for a condensing mechanism in which the flexible acyl chains of the phospholipids complement, perfectly, the shape of neighboring sterols, thereby leading to a high number of hydrophobic contacts and tight packing. 相似文献
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Cui-Ting Ding Jin-Qiu Yuan Meng-Ying Xie Qing-Yuan Liu Zeng-Guang Yao Shi-Yu Zhang Run-Nan Zhang Hong Wu Zhong-Yi Jiang 《高分子科学》2024,(2):141-158
Membrane technology has become one of the most promising separation technologies for its energy saving, high separation efficiency, environmental friendliness, and economic feasibility. Covalent organic frameworks(COFs) with intrinsically high porosity, controllable pore size, uniform pore size distribution and long-range ordered channel structure, have emerged as next-generation materials to fabricate advanced separation membranes. This feature article summarizes some latest studies in the deve... 相似文献
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Ruthenium anticancer drugs have attracted an increasing interest in the last 20 years and two of them have entered clinical trials. Compared to platinum drugs, the complexes based on ruthenium are often identified as less toxic and capable of overcoming the resistance induced by platinum drugs in cancer cells. These activities were attributed to the transportation to tumour cells by transferrin and to the selective activation to more reactive species by the reducing environment of solid tumours as compared to healthy tissues. Ruthenium anticancer drugs have been almost always designed to mimic platinum drugs, particularly for targeting DNA. Indeed, none of the above properties has never been clearly demonstrated even for the ruthenium drugs that entered clinical trials. The suggestion for the future is to change the perspective when designing new chemical entities, abandoning the philosophy that guided the actual panel of ruthenium drugs and to look further into the fine mechanism by which the most relevant ruthenium complexes available kill the target tumour cells, then focusing on targets selective of tumour cells and responsible for cell growth and malignancy. 相似文献
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为庆祝中国科学院长春应用化学研究所70周年华诞,特邀请化学及相关领域著名专家学者撰写出版一期纪念刊专辑。 本专辑收录了在相关领域具有丰富研究经验的团队所撰写的17篇相关研究的综述文章和2篇研究论文。 综述和评价了蛋白质组学技术、表面增强拉曼光谱技术、高分子材料、无机材料、有机材料和纳米材料等在荧光检测、橡胶合成、高分子聚合、不对称合成、电化学催化、传感、电池、电化学储能、水处理与检测等方面的研究进展;报道了开放骨架磷酸铝合成中的模版剂结构导向效应,以及通过交联度调控聚氨酯弹性体摩擦性能方面的研究工作。 专辑内容体现了各相关领域前沿学术进展和热点,具有很好的学术价值。 对广大读者更深入地了解相关领域的研究现状和发展趋势,促进相关领域的学术进步具有重要的意义! 相似文献
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《Electrochemistry communications》2008,10(6):848-850
In the microelectrochemical capillary cell technique a silicone rubber gasket is used to avoid any electrolyte leakage between the pulled glass capillary and the working electrode (the metallic tested material). In this study, it is demonstrated that the oxygen reduction reaction (ORR) is strongly affected by the use of the silicone rubber. Experiments under a surrounding argon gas shielding of the pulled capillary in contact with the metallic surface have been performed showing a large effect on the ORR. Considering the high permeation rate of oxygen through silicone, the decrease of the reaction rate observed experimentally was validated by FEM modelling assuming that the air/silicone/water interface at the tip can be described as an air/water interface. 相似文献
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We study the influence of humidity on the transport and magnetic properties of DNA within the quantum chemistry methods. Strong influence of water molecules on these properties, observed in this study, opens up opportunities for application of DNA in molecular electronics. Interaction of the nucleobases with water molecules leads to breaking of some of the pi bonds and appearance of unbound pi electrons. These unbound electrons contribute significantly to the charge transfer at room temperature by up to 10(3) times, but at low temperature the efficiency of charge transfer is determined by the spin interaction of two unbound electrons located on the intrastrand nucleobases. The charge exchange between the nucleobases is allowed only when the spins of unbound electrons are antiparallel. Therefore, the conductance of DNA molecule can be controlled by a magnetic field. That effect has potentials for applications in developing nanoscale spintronic devices based on the DNA molecule, where efficiency of spin interaction will be determined by the DNA sequence. 相似文献
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V. V. Kanazhevskii V. P. Shmachkova N. S. Kotsarenko V. N. Kolomiichuk D. I. Kochubei 《Journal of Structural Chemistry》2006,47(5):860-868
EXAFS and SAXS methods have been used to examine zirconium hydroxide and oxychloride aqueous solutions in the presence of sulfuric acid in a wide range of concentrations, as well as a zirconium sulfate aqueous solution. The structure of the complexes and their transformation regularities were determined. Structures of the given complexes and structures of zirconium hydroxide and zirconium oxychloride and hydroxide complexes in aqueous solutions were compared. Complexes in zirconium hydroxide and oxychloride aqueous solutions have identical structures in the presence of sulfuric acid. When the concentration ratio of sulfuric acid and the initial compound is low (20–30), the complex is an open trimer with zirconium atoms bonded by sulfate groups. Bridge sulfate groups form Zr-O-S-O-Zr bonds. Apart from the bridge sulfate groups, there are three terminal sulfate groups and three terminal hydroxyl groups for each zirconium atom. When the concentration of sulfuric acid is increased (up to a ratio of 40–100), closed trimers are observed in the solution. 相似文献
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Dr. Lukas Zöphel Reinhard Berger Dr. Peng Gao Dr. Volker Enkelmann Prof. Dr. Martin Baumgarten Dr. Manfred Wagner Prof. Dr. Klaus Müllen 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(52):17821-17826
Based on modern pyrene chemistry, a new route toward the synthesis of the peri‐pentacene framework was developed. Firstly, the tetraketo form as stable precursor was targeted, because the fully aromatic peri‐pentacene is predicted to suffer from high instability and reactivity. Therefore, a recently developed 4,5,9,10‐tetrafunctionalization of pyrene was utilized to build up a planar and a dragonfly‐shaped derivative in five steps, which only differ in the two outer bonds between the peripheral benzene rings. The planar tetraketone could only be dissolved in strong acids upon protonation, which limited the use of analytical methods. In contrast, the dragonfly‐shaped form showed excellent organosolubility. In‐depth investigation by NMR spectroscopy revealed co‐existence of atropo‐isomers in solution. The optical and electronic properties were analyzed by UV/Vis spectroscopy and cyclic voltammetry. To approach aromatic conjugation, stepwise reduction in solution by using tetrabutylammonium borohydride was carried out. Reduced species were studied by ESR and UV/Vis spectroscopy, as well as by MALDI‐TOF MS, confirming the formation of the radical anion. 相似文献
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V. B. Kopylov K. A. Aleksandrov E. V. Sergeev 《Russian Journal of General Chemistry》2007,77(6):1002-1003
A comparative analysis of structural features of SiO2 polymorphic modifications was made by Raman, and high-resolution electronic spectroscopy. It was found that the presence of isolated Si-O, Si-Si, and O-O oscillators in the ground and electronically excited states is a characteristic feature of all the structures involving silicon atoms in oxygen tetrahedral coordination surrounding. It was shown that the increase in the silicon coordination number to six (stishovite) leads to a decrease in the extent of formation of electronically excited states due to removal of barriers to the relaxation of excitation energies. This conclusion is confirmed by the low-frequency shift of the fundamental absorption and by the disappearance of the high-frequency anomaly (Si-O) and characteristic lines of Si-Si oscillators. 相似文献
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通过水热法合成了不同硅铝比和硅铁比的FeZSM-5系列催化剂,并将其应用于对模拟烟气的氨气选择性催化还原(NH3-SCR)脱除氮氧化物(NOx)研究。通过XRD、 SEM、 TEM、 UV-Vis和N2吸附,探究了不同硅、铝铁含量对催化剂孔道结构、物相结构及脱硝活性的影响。结果表明:过高的铝、铁含量会造成催化剂结晶度的降低、物相结构不均一;FeZSM-5(60-60)最佳比例的铝、铁催化剂在低温条件下仍可以表现出较好的活性以及优异的抗硫抗水热稳定性,FeZSM-5(60-60)最佳脱硝效率达97%。通入SO2和H2O时,NOx转化率仍可保持在85%以上;停止通入SO2和H2O时,NOx的转化率恢复至97%。 相似文献
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沸石的骨架结构与酸强度 总被引:1,自引:0,他引:1
沸石分子筛是应用广泛的固体酸催化剂,其催化性能与沸石质子酸的强度和密度密切有关,对沸石酸性的研究是沸石催化领域内一个永恒的课题,国内外许多学者对此进行了长期工作,然而至今仍有许多问题认识不一致,关于沸石骨架结构与酸性的关系也是其中争议较多的问题之一.Sohn等N曾经根据脱铝Y沸石和ZSM-5沸石上正己烷反应结果,笼统地认为Si/Al比超过一定值以后,不同骨架结构的沸石的酸强度相同,催化活性只与酸位密度有关.Barthomeuf[2]则从沸石的结构参数出发,提出了一种较为精确的说法,即沸石的酸强度与骨架中铝的拓扑密度有… 相似文献