检索结果-南通市图书馆

Photocatalytic degradation of formaldehyde by diffuser of solar light pipe coated with nanometer titanium dioxide thin films

引用

Science china(Technological Sciences) 2010年第1期53卷 150-154页

作者： WU YanPeng1,ZHANG WenMing1,MA ChongFang2,LU YuanWei2 & LIU Li1 1 School of Civil and environmental engineering,university of Science and technology beijing,beijing 100083,china 2 college of environmental and energy engineering,beijing university of technology,beijing 100022,china School of Civil and environmental engineering University of Science and Technology Beijing Beijing China college of environmental and energy engineering Beijing University of Technology Beijing China

The even and transparent nanometer TiO2 thin films named DegussaP25 as photocatalysis deposited on the surface of diffusers of solar light pipe were prepared by sol-gel *** rugged side of the diffusers of solar light pipe was coated evenly with DegussaP25 solution for the quality of 1.75 *** experiments had showed that when the coated side was away from the sun the lighting degree may be reduced compared with that facing the *** average reduction was only 3.03%,which would not have a significant impact on *** are important parts of a light pipe which can diffuse light evenly to the place needed to be *** experiments showed that in a sunny summer day under the direct sunlight,the solar light pipe combined with photocatalysis could reduce the formaldehyde volume fraction in a box of 0.1 m3 from 1.0×10-6 to 0.16×*** 1 h of photodegradation the formaldehyde volume changed from 1.0×10-6 down to 0.1×10-6 with faster and more complete degradation of *** rate of degradation under cloudy and partly cloudy conditions was slower than that under sunny *** was slower in winter than in summer under sunny *** experimental results also showed that the performance of photocatalysis combined with diffusers of light pipe had better effect in a small *** performance in large space,such as open space,will be the next work in the future,which will be a great challenge.

关键词： solar light pipes diffusers photocatalysis decomposition formaldehyde titanium dioxide

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

聚光条件下太阳电池的热电特性分析

引用

太阳能学报 2004年第3期25卷 337-340页

作者：吴玉庭朱宏晔任建勋梁新刚北京工业大学环境与能源工程学院北京100022 清华大学工程力学系传热强化与过程节能教育部重点实验室北京100084

为了为进一步开发聚光光伏发电系统提供指导和依据,建立了聚光光伏发电系统的数学模型,然后对不同聚光光伏发电系统方案的热电特性进行了计算,分析了串联内阻和换热系数对系统性能的影响。结果表明,在特定的串联内阻下,太阳电池的峰值... 详细信息

为了为进一步开发聚光光伏发电系统提供指导和依据,建立了聚光光伏发电系统的数学模型,然后对不同聚光光伏发电系统方案的热电特性进行了计算,分析了串联内阻和换热系数对系统性能的影响。结果表明,在特定的串联内阻下,太阳电池的峰值功率首先随光强的升高而直线升高,升高到一定程度后曲线变得平缓。曲线的拐点随串联内阻的降低而升高。换热系数越高,系统的性能越好,而且随着光强的升高,换热系数的影响越来越显著。

关键词：太阳电池聚光热电特征串联内阻换热系数

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

一种用于污垢监测的温差热阻新方法

引用

石油大学学报（自然科学版） 2004年第5期28卷 70-73页

作者：邢晓凯马重芳陈永昌宋磊北京工业大学环境与能源工程学院北京100022 中国石油化工股份有限公司兰州石化分公司生产处甘肃兰州730060

在恒壁温条件下,在结垢过程中,管内流体温度和垢层内壁面温度逐渐降低,会引起流体与内壁面间对流传热热阻增加,因而必须对现有的计算污垢热阻的公式进行修正。综合考虑各种因素,建立了恒壁温条件下计算污垢热阻的改进模型。计算实例表明... 详细信息

在恒壁温条件下,在结垢过程中,管内流体温度和垢层内壁面温度逐渐降低,会引起流体与内壁面间对流传热热阻增加,因而必须对现有的计算污垢热阻的公式进行修正。综合考虑各种因素,建立了恒壁温条件下计算污垢热阻的改进模型。计算实例表明,其他条件一定时,流体进口温度越低,流量越小,则修正值和修正系数越大。随着结垢过程的进行,修正值增大,修正系数减小。在结垢的初始阶段,修正系数最大,说明应用改进公式计算的结垢诱导期较长,更接近于实际情况。

关键词：差热结垢内壁污垢热阻新方法进口温度诱导期壁温对流传热流体温度

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Synthesis and study of λ-MnO_2 supported Pt nanocatalyst for methanol electro-oxidation

引用

Rare Metals 2010年第2期29卷 187-192页

作者： XIE Jia, LI Xiang, YU Zhihui, ZHANG Lijuan, LI Fan, and XIA Dingguo college of environmental and energy engineering, beijing university of technology, beijing 100124, china college of environmental and energy engineering Beijing University of Technology Beijing China

A λ-MnO2 supported Pt nanocatalyst（5 wt.% Pt/λ-MnO2） was synthesized using a facile approach.X-ray diffraction（XRD）, X-ray photoelectron spectroscopy（XPS）, scanning electronic microscope（SEM）, transmission electron microscopy（TEM）, and energy disperse spectroscopy（EDS） were used for catalyst structure and morphology characterization, which showed that the metallic Pt particles were attached on a λ-MnO2 surface through the interaction between Pt and λ-*** voltammetry（CV） was used to test the catalytic activity of Pt/λ-MnO2 toward methanol oxidation, which showed that Pt/λ-MnO2 catalyst has much higher catalytic activity than baseline Pt/C catalyst.

关键词： electrochemistry composite catalyst MnO2 Pt methanol oxidation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Cutting Performance and Mechanism of RE Carbide Tools

引用

Rare Metals 2001年第3期20卷 197-201页

作者： Jianbing Cheng, Yufang Wu, Qixun Yu 1) Department of Mechanical engineering, beijing technology and Business university, beijing 100037, china 2) college of Mechanical engineering and Automation, beijing Institute of technology beijing 100081, china 北京工商大学北京 100037 北京理工大学北京 100081

The research of rare earth elements (RE), added into cemented carbide tools, is one of the recent developments of new types of tool materials in china. Systematic experiments about RE carbides YG8R. (K30), YT14R (P20) and, YW1R (M10) were made to study on the cutting performance in comparison with non-RE carbides YG8, YT14 and YW1. The cutting experiments were as follows: tool life, cutting force, tool-chip friction coefficient and interrupted machining. The action of RE on the carbide materials and the cutting mechanism of the RE carbide tools in the cutting process were verified with the aid of SEM and energy spectrum analysis. Experimental results show that the RE carbide tools have a good overall performance.

关键词： rare earth elements cemented carbide tool cutting performance cutting mechanism

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Biogas recovery from microwave heated sludge by anaerobic digestion

引用

Science china(Technological Sciences) 2010年第1期53卷 144-149页

作者： QIAO Wei1,WANG Wei2,ZHU CuiPing3 & ZHANG ZhongZhi1 1 college of Chemical Science and engineering,china university of Petroleum,beijing 102249,china 2 Department of environmental Science and engineering,Tsinghua university,beijing 10084,china 3 J & K china Cleaning energy technology Co.Ltd.,beijing 100085,china college of Chemical Science and engineering China University of Petroleum Beijing China Department of environmental Science and engineering Tsinghua University Beijing China J & K china Cleaning energy technology Co. Ltd. Beijing China

Biogas generated from sewage sludge,livestock waste,and food waste by anaerobic digestion is a valuable renewable energy ***,conventional anaerobic digestion is not an efficient process.A long hydraulic retention time and low biogas recovery rate hinder the applications of those *** effective pretreatment method to destroy sludge microbial cells has been one of the major concerns regarding improvement of the biogas *** article focuses on the effects of microwave heating on sludge anaerobic *** suspended solid(VSS) and chemical organic demand solubilization of heated sludge were *** heating was found to be a rapid and efficient process for releasing organic substrates from *** increase of organic dissolution ratio was not obvious when holding time was over 5 min with microwave *** effect of the VSS solubilization was primarily dependent on heating *** highest value of VSS dissolving ratio,36.4%,was obtained at 170°C for 30 *** COD dissolving ratio was about 25% at 170°*** organic carbon of treated sludge liquor was 1.98 and 2.73 g/L at 150°C and 170°C for 5 min,respectively.A biochemical methane potential(BMP) test of excess sludge and a mixture of primary and excess sludge demonstrated an increase in biogas *** total biogas from microwave treated mixture sludge increased by 12.9% to 20.2% over control after 30 days of *** production was 11.1% to 25.9% higher for excess sludge than for untreated *** VS removal ratios of mixture sludge and excess sludge were 12% and 11% higher,respectively,compared to the untreated sludge.

关键词： biogas recovery microwave heating sludge anaerobic digestion

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Exploring binding mode for styrylquinoline HIV-1 integrase inhibitors using comparative molecular field analysis and docking studies

引用

Acta Pharmacologica Sinica 2004年第7期25卷 104-112页

作者： Xiao-hui MA, Xiao-yi ZHANG, Jian-jun TAN, Wei-zu CHEN, Cun-xin WANG2 college of LifeScience and Bioengineering, beijing university of technology, beijing 100022, china college of Life Science and Bioengineering Beijing University of Technology 北京 100022

AIM: To understand pharmacophore properties of styrylquinoline derivatives and to design inhibitors of HIV-1 integrase. METHODS: Comparative molecular field analysis (CoMFA) was performed to analyze three-dimen- sional quantitative structure-activity relationship (3D-QSAR) of styrylquinoline derivatives. Thirty-eight compounds were randomly divided into a training set of 28 compounds and a test set of 10 compounds. The stability of 3D- QSAR models was proved by the analysis of cross-validated and non-cross-validated methods. Moreover, the binding mode of these compounds and integrase was constructed by AutoDock program. RESULTS: The CoMFA model of the training compounds was reasonably predicted with cross-validated coefficient (q2) and conventional (r2) values (up to 0.696 and 0.754). Then the model was validated by the test set. The resulting CoMFA maps visualized structural requirements for the biological activity of these inhibitors. Docking results showed that a carboxyl group at C-7 and a hydroxyl group at C-8 in the quinoline subunit, bound closely to the divalent metal cofactor (Mg2+) around the integrase catalytic site. Moreover, there is a linear correlation between the binding energy of the inhibitors with integrase and their inhibitory effect. CONCLUSIONS: The present study indicated that the CoMFA model together with docking results could give us helpful hints for drug design as well as interpre- tation of the binding affinity between these inhibitors and integrase.

关键词： HIV integrase inhibitors quinolines comparative molecular field analysis AutoDock

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Fractal model for simulation of frost formation and growth

引用

Science china(Technological Sciences) 2010年第3期53卷 807-812页

作者： LIU YaoMin,LIU ZhongLiang,HUANG LingYan&SUN JunFang Education Ministry Key Laboratory of Enhanced Heat Transfer and energy Conservation,college of environmental and energy engineering,beijing university of technology,beijing 100124,china Education Ministry Key Laboratory of Enhanced Heat Transfer and energy Conservation College of Environmental and Energy Engineering Beijing University of Technology Beijing China

A planar fractal model for simulation of frost formation and growth was proposed based on diffusion limited aggregation(DLA)model and the computational simulation was carried out in this *** changing the times of program running circulation and the ratio of random particles generated,the simulation figures were gained under different conditions.A microscope is used to observe the shape and structure of frost layer and a digital camera with high resolution is used to record the pattern of frost layer at different *** comparing the simulation figures with the experimental images,we find that the simulation results agree well with the experimental images in shape and the fractal dimension of simulation figures is nearly equal to that of experimental *** results indicate that it is reasonable to represent frost layer growth time with the program circulation times and to simulate the frost layer density variation during its growth process by reducing the random particle generation *** feasibility of using the suggested model to simulate the process of frost formation and growth was *** insufficiencies and its causes of this fractal model are also discussed.

关键词： fractal frost formation and growth DLA simulation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Soluble protein and acid phosphatase exuded by ectomycorrhizal fungi and seedlings in response to excessive Cu and Cd

引用

Journal of environmental Sciences 2009年第12期21卷 1667-1672页

作者： ZHENG Weishuang, FEI Yingheng, HUANG Yi college of environmental Sciences and engineering, Peking university, beijing 100871, china. college of environmental Sciences and engineering Peking University Beijing 100871 China

Fungi and their symbionts can alleviate heavy metal stress by exuding soluble proteins and enzymes. This study examined the role of soluble protein and acid phosphatase （APase） exuded by Xerocomus chrysenteron, an ectomycorrhizal fungus, and the seedlings of its symbiont, Chinese pine （Pinus tabulaeformis）, under conditions of excessive Cu and Cd. The growth type showed that this poorly studied ectomycorrhizal fungus was capable of tolerating high concentrations of Cu, and may be useful in phytoremediation. X. chrysenteron grew well at 80 mg/L Cu, and the EC50 for Cd was 17.82 mg/L. X. chrysenteron also showed enhanced exudation of soluble protein in both isolated and inoculated cultivations under the influence of Cu and Cd. Soluble protein exudation, however, differed under Cu and Cd stress in isolates. In mediums containing Cu, soluble protein exudation increased with concentration, but in mediums containing Cd the content of soluble protein increased to a comparable level at all concentrations. This study demonstrated that soluble protein was related to heavy metal tolerance, although the different ions played different roles. While APase activity in exudates of fungi and seedlings decreased under Cu and Cd stress in comparison to the control, the APase activity in seedlings was maintained by inoculation. Thus, X. chrysenteron facilitated the ability of plant to maintain a normal nutrient uptake, and therefore to protect it from heavy metal toxicity.

关键词： soluble protein acid phosphatase exudate Cu, Cd Xerocomus chrysenteron

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A new type of dehydration unit of natural gas and its design considerations

引用

Progress in Natural Science:Materials International 2005年第12期15卷 1148-1152页

作者： LIU Hengwei,LIU Zhongliang,ZHANG Jian,GU Keyu and YAN Tingmin The Education Ministry Key Laboratory of Enhanced Heat Transfer & energy Conversation,beijing Municipal Key Laboratory of Heat Transfer and energy Utilization,college of environmental and energy engineering,beijing university of technology,beijing 100022,china Shengli engineering & Research Institute,Shengli Oil Field Ltd.,SINOPEC,Dongying 257026,china The Education Ministry Key Laboratory of Enhanced Heat Transfer and energy Conversation Beijing Municipal Key Laboratory of Heat Transfer and Energy Utilization Coll. of Environmental and Energy Eng. Beijing Univ. of Technology Beijing 100022 China Shengli engineering and Research Institute Shengli Oil Field Ltd. SINOPEC Dongying 257026 China

A new type of dehydration unit for natural gas is described and its basic structure and working principles are presented. The key factors affecting the performance and dehydration efficiency of the unit such as nucleation rate,droplet growth rate,the strength of the swirl,and the position at which the shock wave occurs are *** accordingly the design considerations of each component of the unit are *** investigations on the working performance of the unit justified the design considerations.

关键词： supersonic swirling flow dehydration natural gas

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：