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71.
二甲双胍(MET)是一个非常优良的降血糖药,一直是治疗II型糖尿病(T2DM)的首选药物,但其脂溶性较差,也存在引起胃肠道不适等副作用,对其结构修饰和衍生化,特别是将其研制成前药(Prodrug)具有一定的临床意义。为了探明二甲双胍化学反应的性能特点,本文基于密度泛函理论(DFT)开展了二甲双胍的化学内禀性质研究,包括各种可能互变异构体的单点能和量子化学反应性指数。此外,还对各异构体互变过程的过渡态以及它们的反应路径进行了研究。在此基础上,本文还对二甲双胍与亲电试剂的化学反应机理进行了初探,并用化学合成反应来验证,从而让我们能够从理论上弄清楚二甲双胍化学反应的特殊性质。 相似文献
72.
《Arabian Journal of Chemistry》2022,15(4):103711
In the process of nitric acid dissolving precious metals, a large amount of NOx exhaust gas will be produced. This research aims at the development of a new method for the removal of low-concentration nitrogen oxides from metallurgical flue gas. In this process, a printed three-dimensional large-flow microstructure reactor and urea solution are used for the removal of NOx, which facilitates the greater efficiency of denitrification(≥94%). Urea plays an important role in the redox of NO2, such as NO2 is reduced to N2 in solution. Both the gas and the liquid phase simultaneously react in the microchannels of the microfluidic reactor. The channels allow the proper mixing of urea and NaClO2 during the flow which efficiently removes NOx at low concentrations. The optimum condition for high denitration efficiency is outlined: the urea solution with 3%,temperature of the mixed solution is 293.15 K, gas–liquid flow mass ratio is 1:1, pH value (8.0–10.0), CNaClO2 = 0.02 mol/L. This work successfully describes the use of a microfluidic reactor to enhance and maintain the denitration efficiency. This work describes how to successfully enhance and maintain the denitration efficiency while using a printed three-dimensional large-flow microstructure reactor. 相似文献
73.
Electrochemical hydrogen storage in porous carbon materials is emerging as a cost-effective hydrogen storage and transport technology with competitive power and energy densities. The merits of electrochemical hydrogen storage using porous conductive carbon-based electrodes are reviewed. The employment of acidic electrolytes in such storage systems is compared with alkaline electrolytes. The recent innovations of a proton battery for smaller-scale electricity storage, and a proton flow reactor system for larger (grid)-scale storage and bulk export of hydrogen produced from renewable energy, are briefly described. It is argued that such systems, along with variants proposed by others, all of which rely on electrochemical hydrogen storage in porous carbons, can contribute to the search for energy storage technologies essential for the transition to a zero-emission global economy. 相似文献
74.
Semihydrogenation of alkynes to alkenes is an important and fundamental reaction in many industrial and synthetic applications and often suffers low selectivity because of the overhydrogenation. Here, highly selective semihydrogenation of alkynes is achieved by using H2 ex situ generated from formic acid dehydrogenation with palladium (Pd)-based bimetallic catalysts through a two-chamber reactor in this work, realizing efficient utilization of H2 and selective production of alkenes under mild reaction conditions. The Pd-based bimetallic catalysts show excellent catalytic performances for semihydrogenation of alkynes (PdZn bimetallic catalyst) and dehydrogenation of formic acid (PdAg bimetallic catalyst) in the two-chamber reactor. 相似文献
75.
A. L. Vikharev A. M. Gorbachev M. A. Lobaev A. B. Muchnikov D. B. Radishev V. A. Isaev V. V. Chernov S. A. Bogdanov M. N. Drozdov J. E. Butler 《固体物理学:研究快报》2016,10(4):324-327
We report on building a novel chemical vapor deposition (CVD) reactor for diamond delta‐doping. The main features of our reactor are: a) the use of rapid gas switching system, (b) the reactor design providing the laminar gas flow. These features provide the creation of ultra‐sharp interfaces between doped and undoped material and minimize the prolonged ”tails” formation in the doping profile. It is proved by optical emission spectroscopy that gas switching time is not more than 10 seconds. Using the novel reactor we have grown the nanometer‐thin layers of boron doped diamond. The FWHM of boron concentration profile is about 2 nm which is proved by SIMS. It is shown that the both single delta‐layer and multiple delta‐layers could be grown using the novel CVD reactor. In principle, the reactor could be used for diamond delta doping with other dopants, like nitrogen, phosphorus etc. (© 2016 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim) 相似文献
76.
分子筛膜具有规整的微孔结构(<1 nm), 耐高温高压、 抗有机溶剂, 在液相和气相小分子分离中受到广泛关注. 分子筛膜可以与催化反应耦合于一体构成膜反应器, 使反应过程与组分分离同时进行, 促进反应平衡移动, 达到反应强化的效果. 本文概述了近十年不同类型分子筛膜反应器在催化反应中的应用研究进展, 并对分子筛膜反应器未来的发展趋势进行了展望. 相似文献
77.
This study investigates the recovery of electric resistivity in pure iron, Fe–0.6Ni and Fe–1.5Mn as related to isochronal annealing following 1 MeV proton irradiation at lower temperature than 70 K, focusing on the relationship between solute atoms and irradiation defects. Both nickel and manganese prevent stage ID recovery, which corresponds to correlated recombination. Stage II recovery is also changed by the addition of a solute, which corresponds to the migration of small interstitial clusters. In both pure iron and Fe–0.6Ni, no evident difference was observed in the stage III region, which corresponds to the migration of vacancies. In contrast, two substages appeared in the Fe–1.5Mn at a higher temperature than stage IIIB appeared in pure iron. These substages are considered to represent the release of irradiation-induced defects, which was trapped by manganese. 相似文献
78.
Electrochemical Biosensors Based on Enzymatic Reactor of Silver Solid Amalgam Powder for Measurements in Flow Systems
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An enzymatic reactor based on silver solid amalgam powder was suggested as the main part of biosensors in flow systems for the first time. Biosensors were tested with following enzymes: ascorbate oxidase, glucose oxidase, catalase, tyrosinase and laccase. The current response of each biosensor was optimized with respect to the detection potential, flow rate, the injection and reactor volume. Relative standard deviation for detection with the studied enzymes was found to be in the range of 0.81–2.1 %. The biosensor with the ascorbate oxidase reactor was used for determination of ascorbic acid in the vitamin tablets Celaskon. 相似文献
79.
利用均相反应器,在没有添加剂的条件下合成了具有多孔结构的Cu2O微球.考察了合成时间以及反应器旋转速度对Cu2O微球结构的影响.通过增加聚乙烯吡咯烷酮(PVP)的用量,使得Cu2O从多孔微球转变为立方体孪晶,最终形成十四面体孪晶结构.同时,将不同结构的Cu2O多晶应用于催化高氯酸铵(AP)的热分解,结果表明:多孔Cu2O微球较其它结构的Cu2O对AP的热分解具有更高的催化活性,使得AP的低温分解温度降低了37.4°C,而AP在低温阶段的分解量也由8.7%增加至49.0%. 相似文献
80.
F. Joseph Schork 《大分子反应工程》2020,14(3)
The equations for predicting molecular weight distribution, copolymer composition distribution, and copolymer sequence distribution for three polymerization mechanisms (monomer linkage with termination, monomer linkage without termination, and polymer linkage), and three reactor types (batch/plug flow, homogenous continuous stirred tank, and segregated continuous stirred tank) are assembled from various sources and compared and contrasted. 相似文献