检索结果-南通市图书馆

Study on the Intermediate in the o-Phenylenediamine Oxidative Reaction Using Hemoglobin as A Mimetic Peroxidase in Aqueous-Organic two phase

在线全文

学校读者我要写书评

暂无评论

Wuhan University Journal of Natural Sciences 2002年第1期7卷 117-121页

作者： Li Hai-cheng Li De-jia Huang Bo Jin De-long Zou Guo-lin College of Life Sciences Wuhan University Wuhan 430072 Hubei China

Hemoglobin was used as a mimetic enzyme for peroxidase to catalyze the oxidative reaction of o-phenylenediamine with H2O2 which functioned as an oxidant. The relationship between physicochemical properties of the intermediate and enzymatic activity of hemoglobin was studied. Since the solubility of the intermediate in the reaction is higher in butanol phase than in water phase, the intermediate itself diffused from the aqueous phase to the butanol phase. The experimental results showed that the rate of product and the stability of intermediate were associated with the temperature and the pH value of the buffer. The formation rate of intermediate and half-life period reveal the maximal in pH7, nevertheless, the whole rate of the catalytic reaction is the greatest in pH5, which the ratio of the initial rate in final product formation compared to that intermediate formation is the greatest.

关键词： hemoglobin mimetic enzyme intermediate two phase reaction mechanism

Experimental Investigation of two-phase Flow Maldistribution in Plate Heat Exchangers

在线全文

学校读者我要写书评

暂无评论

Fluid Dynamics & Materials Processing 2022年第4期18卷 1015-1024页

作者： Zhaiyk Tokhtarov Vitaly Perov Vitaly Borisov Evgeny Tikhomirov Olga Grunina Nadezhda Kapustina Elmira Cherkasova Natalya Suray Shakarim University of Semey Semey City070000Kazakhstan Plekhanov Russian University of Economics Moscow117997Russia National Research Mordovia State University Mordovia430005Russia Bauman Moscow State Technical University Moscow RegionMytischi105005Russia K.G.Razumovsky Moscow State University of Technologies and Management(The First Cossack University) Moscow119991Russia Financial University Under the Government of the Russian Federation Moscow125993Russia Russian State Agrarian University-Moscow Timiryazev Agricultural Academy Moscow127550Russia

After conducting a critical survey of the different categories of existing heat exchangers,the results of several experiments about the behaviour of a two-phase current in an open channel are *** results confirm the complexity of the problems induced in heat exchangers by flow maldistribution,especially when two-phase flows are considered in multi-channel *** is shown that severe misalignment of heat exchangers can lead to a loss of economic performance of more than 25%.Improper distribution of fluid flow causes longer fluid coils to form,and the liquid cochlea can eventually occupy a large space,thereby reducing heat transfer and disrupting the considered biphasic *** use of a small diameter distribution pipe with properly spaced outlet holes seems to be a promising approach to fix many of these *** is found that the current distribution in the channels,in addition to the header pressure distribution,also depends on factors such as the geometry and the initial flow regime in the header.

关键词： Maldistribution heat exchangers two phase open channel

PHOTOLUMINESCENCE OF two-phase COEXISTED NONSTOICHIOMETRIC BARIUM TITANATE BY LOW TEMPERATURE HYDROTHERMAL PROCESS

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

南京大学学报(自然科学) 1999年第1期 131-133页

作者： Yu Jian Zhang Weifeng Chen Qiang Zhang Mingsheng ( Center for Materials Analysis and National Laboratory of Solid State Microstructures, Nanjing University, 210093, Nanjing, PRC)

ＳｔｒｕｃｔｕｒａｌｓｔｕｄｉｅｓｏｆＢａＴｉＯ３ｕｌｔｒａｆｉｎｅｐｏｗｄｅｒｈａｖｅｓｈｏｗｎｔｈａｔｐａｒｔｉｃｌｅｓｉｚｅｉｎｄｕｃｅｓｐｈａｓｅｔｒａｎｓｆｏｒｍｆｒｏｍｔｅｔｒａｇｏｎａｌｔｏｃｕｂｉｃａ... 详细信息

ＳｔｒｕｃｔｕｒａｌｓｔｕｄｉｅｓｏｆＢａＴｉＯ３ｕｌｔｒａｆｉｎｅｐｏｗｄｅｒｈａｖｅｓｈｏｗｎｔｈａｔｐａｒｔｉｃｌｅｓｉｚｅｉｎｄｕｃｅｓｐｈａｓｅｔｒａｎｓｆｏｒｍｆｒｏｍｔｅｔｒａｇｏｎａｌｔｏｃｕｂｉｃａｔｃｒｉｔｉｃａｌｖａｌｕｅ．［１...

关键词： photoluminescence two phase low temperature hydrothermal

Transient air-water flow patterns in the vent tube in hydropower tailrace system simulated by 1-D-3-D coupling method

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2018年第4期30卷 715-721页

作者：王希晨张健俞晓东陈胜 College of Water Conservancy and Hydropower Engineering Hohai University

The vent tube is commonly used for the water hammer protection in the hydropower tailrace system. In transient processes, with air entering and exiting the vent tube, one sees complex hydraulic phenomena, which threaten the station＇s safe operation. It is necessary to investigate the transient mechanisms in the tailrace system with vent tube. In this paper, a 3-D, two-phase numerical model of a vent tube on the connection of the tailrace tunnel and the diversion tunnel, is developed based on the FLUENT with the volume of fluid（VOF） algorithm to investigate the transient air-water flow patterns and the complex hydraulic phenomena in the vent tube of the tailrace system. A 1-D and 3-D unidirectional adjacent coupling（1-D-3-D-UAC） approach with a linear interpolation method is adopted to adjust the timesteps between the 1-D model and the 3-D model on the tunnel inlet and outlet boundaries through the user defined function（UDF）, to transmit the data from the 1-D model to the 3-D model. The model is verified by comparing the results obtained by using the 1-D model alone and from the experiments in literature. The transient flow processes under the full load rejection consist of four stages： the water level dropping stage, the air entering stage, the air pocket collapsing stage, and the air exiting stage. Detailed hydraulic phenomena in the air pocket collapsing process are also discussed.

关键词： Vent tube tailrace tunnel two phase volume of fluid (VOF) 1-D-3-D coupling

ON THE MECHANISM OF DRAG REDUCTION IN HIGH CONCENTRATION NON-HOMOGENEOUS PIPE FLOW

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 1992年第1期4卷 91-97页

作者： Zhang, Xingrong Wuhan Univ of Hydraulic and Electric Engineering Wuhan China

In this paper, a method for calculating the resistance force of high concentration non-homogeneous pipe flow was presented. The experiments were conducted in the bedstead of a recirculating pipeline. The measurement system is composed of the equipments for measuring the discharge, pressure and concentration. Experimental results show that for the laminar and turbulent high concentration flow there exists flow-core region and non-flow-core region, each of them has different characteristics. The comparisons show that the theoretical results are in good agreement with the experimental results.

关键词： Flow of Fluids Pipes Flow of Fluids two phase

Enhanced conversion of α-cellulose to 5-HMF in aqueous biphasic system catalyzed by FeCl_(3)-CuCl_(2)

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2021年第7期32卷 2233-2238页

作者： Lilin Zhang Yinbing Tian Yuanyuan Wang Liyi Dai Shanghai Key Laboratory of Green Chemistry and Green Process College of Chemistry and Molecular EngineeringEast China Normal UniversityShanghai 200241China

This study was to investigate the optimal additions of the cellulose decomposition reaction to obtain the most yield of 5-HMF and other furan derivatives in various biphasic systems with FeCl_(3)-CuCl_(2) mixed catalysts,and explore its depolymerization kinetics.A series of controllable reactions have been performed under mild environmentally friendly *** experiment results showed that49.13 wt%of 5-HMF was the maximum production along with 2.98 wt%other furan derivatives catalyzed by mixed Lewis acid FeCl_(3)-CuCl_(2) under the two phases which included high concentration NaCl aqueous phase and n-butanol organic phase at 190℃for 45 *** conclusion suggested that two-phase systems benefited the yield of 5-HMF,furan derivatives via extracting the target products from reaction phase to organic phase to avoid rehydration of *** kinetic calculation revealed the conversion with mixed catalysts had lower reaction apparent activation energy(21.65 kJ/mol,190-230℃)and the reaction rate was faster than that with acid-based *** on experiment exploration,the probable mechanism of cellulose decomposition with FeCl_(3)-CuCl_(2) was proposed.

关键词： Cellulose two phase Mixed catalysts Depolymerization 5-HMF

NECESSARY PRINCIPLES FOR ESTABLISHING FUNDAMENTAL EQUATIONS OF MULTIphase FLOW

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 1991年第1期3卷 22-25页

作者： Zhong, Zhao-xin Ma, Geng-di Wang, Yun Univ of Science and Technology of China Hefei China

The fundamental equations of multiphase flow that have been established so far fall into two main groups, the multifluid model and the mixture model [1] [2]. Because of the different forms of the equations derived from these two models, many disputes arose [1] [3] [4]. This paper deals mainly with the basic principles for establishing the fundamental equations of multiphase flow, namely the principles of consistency, invariance of material coordinates and material indifference. The results lead to the consistent description of the two models.

关键词： Equations of Motion Flow of Fluids two phase Fluid Mechanics Mathematical Techniques Differential Equations

在线全文

学校读者我要写书评

暂无评论

帕司烟肼的合成

中国医药工业杂志 2015年第5期46卷 457-458页

作者：金国有姚柳端朱艺基广州白云山制药有限公司广州白云山化学制药厂广东广州510515

帕司烟肼(pasiniazide,1)又名百生肼、对氨基水杨酸异烟肼,为对氨基水杨酸(2)与异烟肼(3)的化学加合物,化学名为4-吡啶甲酰肼-4-氨基水杨酸。它由瑞士Geistlich Pharma AG研发,于2001年上市,是一种强效抗结核病药物,药效比3强5倍。该药... 详细信息

帕司烟肼(pasiniazide,1)又名百生肼、对氨基水杨酸异烟肼,为对氨基水杨酸(2)与异烟肼(3)的化学加合物,化学名为4-吡啶甲酰肼-4-氨基水杨酸。它由瑞士Geistlich Pharma AG研发,于2001年上市,是一种强效抗结核病药物,药效比3强5倍。该药品中2能有效地延缓和阻滞3在体内的乙酰化过程。

关键词： pasiniazide high purity two phase synthesis