检索结果-南通市图书馆

Journal of Wuhan University of Technology(Materials Science) 2013年第3期28卷 586-591页

作者：孟多 wang lijiu School of Civil and Architectural Engineering Liaoning University of Technology Institute of Building Materials Dalian University of Technology

We prepared and characterized a form-stable composite phase change material （PCM） with higher thermal conductivity. Capric acid（CA）-myristic acid（MA） eutectic as core, poly-methyl methacrylate （PMMA） as supportive matrix and modified graphite （MG） powders serving as the thermal conductance improver were blended by bulk- polymerization method. The composite PCMs with different MG mass fraction （2%, 5%, 7%, 10% and 15%） were characterized by FT-IR, SEM, DSC technique and mechanical tests. Thermal conductivities of the composites were measured by transient hot-wire method. The results indicate that MG powders have been successfully inserted into the CA-MA/PMMA matrix without any chemical reaction with each other. The MG/CA-MA/PMMA composites maintain good thermal storage performance while the thermal conductivity has been enhanced significantly. The composite PCM added with 15 wt% MG powders increases approximately as 195.9% in thermal conductivity. Moreover, the thermal conductivity improvement of the composite PCMs is also verified by the melting-freezing experiment, which is profitable for the heat transfer efficiency in latent heat thermal energy storage system.

关键词： form-stable composite PCM fatty acid eutectic poly-methyl methacrylate modified graphite thermal conductivity

A Russo-US Relationship Where Rivalry Coexists with Cooperation

在线全文

学校读者我要写书评

暂无评论

和平与发展 2006年第4期 59-64页

作者： By wang lijiu The author is a research fellow at China research Institute for Contemporary International relations and Guest Researcher of CPDS.

Effect of Heat Treatment on Silica Aerogels Prepared via Ambient Drying

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2007年第3期23卷 402-406页

作者： Fei SHI lijiu wang Jingxiao LIU Miao ZENG Building Materials Research Lab Dalian University of Technology Dalian 116024 China Department of Materials Science and Engineering Dalian Institute of Light Industry Dalian 116034 China

Silica aerogels were prepared at ambient drying by using ethanol/trimethylchlorosilane （TMCS）/heptane solution as pore water exchange and surface modification of the wet gel before drying. The obtained silica aerogels exhibit a sponge-like structure with uniform pore size distribution. The effects of heat-treatment on the hydrophobicity, specific surface area and other properties were investigated. The results indicated that the hydrophobicity of silica aerogels could be maintained up to 350℃. With increasing heating temperature, hydrophobicity decreased, and became completely hydrophilic after heat-treatment at 500℃. Brunaueremmitt-teller （BET） surface area results indicated that the specific surface area of silica aerogels increased with increasing heating temperature in the range of 150-500℃. The effects of heat-treatment on the morphology and chemical bonding state of silica aerogels were investigated by scanning electron microscopy （SEM）, differential temperature analysis （DTA） and Fourier-transform infrared spectroscopy （FT-IR）.

关键词： Silica aerogel Ambient drying Hydrophobicity Specific surface area Heat-treatment

Influence of Drying Methods on Fractal Geometric Characteristics of Mesoporous Silica Aerogels

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2013年第3期28卷 476-482页

作者：赵善宇 XU Haixun wang lijiu J William Suggs School of Environmental and Safety Engineering Changzhou University School of Civil and Hydraulic Engineering Dalian University of Technology Department of Chemistry Brown University

Chemical modification/ambient drying method and freeze drying method were introduced to research the synthesis of mesoporous silica aerogels. By analyzing N2 gas adsorption/desorption isotherms, the fractal geometric characteristics of gels were focused. The overall surface fractal dimensions were determined by analyzing N2 gas adsorption branch and a Frenkel-Halsey-Hill （FHH） equation was empolyed to determine surface fractal dimension Df It is found that, during ambient drying process, VTMCS/VWetgel ratio plays a crucial role in the changes of geometric feature, the key point is 50%, when the ratio is lower, and surface roughness increases with the ratio, when it exceeds 50%, the surface is almost unaffected by the modification. While freeze drying always tends to get larger Df freeze drying process could cause a rough surface of the gels. Compared with traditional porosity and specific surface area analyses, fractal geometry may be expected to be favorable for mesoporous structural analyses of materials.

关键词： silica aerogel N2 gas adsorption surface fractal dimension mesoporous structure

Structural Characteristics and Photocatalytic Activity of Ambient Pressure Dried SiO2/TiO2 Aerogel Composites by One-step Solvent Exchange/Surface Modification

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2016年第1期31卷 80-86页

作者：徐海珣朱平华 wang lijiu JIANG Zuqiang 赵善宇 Department of Environmental Engineering Changzhou UniversityChangzhou213164China Institute of Building Materials Dalian University of TechnologyDalian116024China CNBM International Engineering Co. L TDBeijing 100048China Swiss Federal Laboratories for Materials Science and Technology CH-8600 DiibendorfSwitzerland

An ambient pressure synthesis of SiO2/TiO2 binary aerogel was prepared through the low-cost precursors of titanium tetrachloride（TiCl4） and sodium silicate（Na2O·nSiO2）.After gelation,solvent exchange and surface modification were performed simultaneously and the modified gel was finally dried under ambient *** analyses by transmission electron microscope（TEM） indicate that fabricated SiO2/TiO2 aerogel composite shows similar sponge-like nanostructure as silica aerogel,and the Brunauer-EmmettTeller（BET） analysis shows that the specific surface area of the composite reaches 605 m^2/g,and the average pore size is 9.7 *** binary aerogel exhibits significant photocatalytic performance in this paper for treating model pollutant of methyl orange（MO）,and the decolorizing efficiency of MO is detected as 84.9%after 210 mins exposure to UV light *** gel suspends in the water so as to separate from solution for reuse,and after 4 times recycling,70%degradation efficiency can be easily reached when composite catalyzed system is exposed for 210 mins under UV irradiation.

关键词： photocatalytic activity water glass SiO2/TiO2 binary aerogel ambient drying

Russia's Eurasian Union Strategy and Its Impact on Sino-Russian Relations and SCO

在线全文

学校读者我要写书评

暂无评论

Contemporary International Relations 2012年第3期22卷 86-96,5页

作者： wang lijiu the Institute of Russian Studies of CICIR

No matter what period of history we choose, tsarist Russia or the Soviet Union, historically, Russia has wielded great power over bothEurope and Asia. However, this changed with the break-up of the Soviet Union. Over the past two decades, although Russia has played a major role in Europe and Asia with the support of the CIS and various mechanisms, its power has only been a fraction of that it held before. Aider Putin became president in 2000, he tried to integrate the different mechanisms of the CIS with varying success. Russia restructured the Collective Security Treaty Organization （CSTO）, but this is still far from Putin＇s goal. In October, 2011, Putin suggested setting up a Eurasian economic union using the framework of the CIS. It would be a much higher level organization than the CIS and have a much broader scope. Putin＇s initiative prompted strong reactions both for and against. Those who supported him called it ＂rain falling in a time of drought＂ as it would substantially boost Russia＇s self confidence and rebuild its image on the world stage as a superpower. Those who opposed it described it as Russia＇s colonial ambitions and a plan to restore the Soviet Union. This paper attempts to analyze the reasons behind this initiative of Putin＇s, the likelihood of its realization, and the impact it would have on the relationship between China and Russia and on the SCO.

关键词：合作组织俄罗斯上海联盟独联体国家对中普京苏联

Freezing Resistance of HPC with Nano-SiO_2

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2008年第1期23卷 85-88页

作者：王宝民 wang lijiu F C Lai School of Civil and Hydraullic Engineering Dalian University of Technology Dalian 116024 China Faculty of Engineering U.K.M Selangor Darul Ehsan 43600 Malaysia

The test of fast-freezing method is employed to research the freezing resistance of C60 and C80 high-performance concrete with nanometer-SiO2, and XRD and SEM are employed to analyze the mechanism of its influence. The experimental results show that the freezing resistance of high-performance concrete has been effectively improved. The compressive strength of C60, C70 and C80 high-performance concrete added with nano-SiO2 can be improved by 8%, 6% and 5% respectively, the weight loss can be reduced by 1%, 0.6% and 0.3% respectively and the relative dynamic elastic modulus can be improved by 7%, 4% and 6% respectively after the 300 times freeze-thaw cycle.

关键词： nano-SiO2 high-performance concrete freezing resistance

Fractal Dimension Analysis of the Fine Aggregate Gradation of Interlocking Skeleton Asphalt Mixture

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2011年第3期26卷 567-572页

作者：刘慧 School of Civil & Hydraulic Engineering Dalian University of Technology

By analyzing the fine aggregate gradation scales from standards,fine aggregate in the asphalt mixture is regarded as a whole research object and fractal dimensions X of the samples were obtained by linear regression and（AC-13）is 2.43-2.56,Sup-13 is 2.28-2.54,SMA-13 is 2.66-2.88 and SAC-13 is *** the dense gradation mixture,there are little different between fractal dimensions of coarse and fine aggregates but it makes sense for skeleton asphalt *** a given coarse aggregate gradation and the same percentage of coarse aggregates,the compressive strengths and splitting strengths of the asphalt mixture are studied when the fractal dimensions are selected as 2.60,2.65 and 2.70,*** asphalt-stone ratio is less than optimal asphalt-stone ratio,the higher compressive strength is,the bigger X can be *** asphalt-stone ratio is larger than optimal asphalt-stone ratio,little difference of compressive strength can be observed under these three *** largest splitting strength can be got when X is 2.65,and larger splitting strength can be observed with the ascending of the asphalt-stone ratio.

关键词： fractal dimension fine aggregate gradation compressive strength splitting strength

Experimental Research on the Autogenous Shrinkage of MK High Performance Concrete

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2007年第3期22卷 551-554页

作者：王宝民 School of Civil and Hydraulic Engineering Dalian University of Technology

Calcine and mill kaolin were used under agreeable technological conditions to generate matakaolin （MK）. The autogenous shrinkage performance of high performance concrete added with MK was researched. It is shown that MK has an effective inhibitory action to early autogenous shrinkage of cement concrete, and the inhibitory action increases with the increase of MK. The autogenous shrinkage values from 24 hours after placement to 56 days are all higher than those of the contrasted concrete, among which, the value of the concrete with 5% MK is the highest. But the total shrinkage values in 56 days are all less than those of the contrasted test pieces. The total contraction after 24 h of placement decreases as the increase of MK, moreover, it is greatly less than that of the contrasted ones.

关键词： high performance concrete MK autogenous shrinkage

在线全文

学校读者我要写书评

暂无评论

俄罗斯的独联体政策及其走势

现代国际关系 2005年第11期 34-39,56页

作者：王郦久中国现代国际关系研究院俄罗斯所

独联体对俄罗斯而言,具有战略屏障和战略借重的双重作用,也是俄国家振兴的依托条件之一。但因俄独联体政策有诸多失当、新独立国家自主意识增强,以及美国和西方采取诱压结合的方式分化独联体,目前独联体处于四分五裂中,俄与独联体其他... 详细信息

独联体对俄罗斯而言,具有战略屏障和战略借重的双重作用,也是俄国家振兴的依托条件之一。但因俄独联体政策有诸多失当、新独立国家自主意识增强,以及美国和西方采取诱压结合的方式分化独联体,目前独联体处于四分五裂中,俄与独联体其他成员国间关系总体呈纷争多于合作态势。经历了各式“颜色革命”的独联体未来内部矛盾还将扩大,俄与美国及西方在争夺后苏联战略空间的较量中谁是最后的赢家,尚需观察。

关键词：俄罗斯独联体 “颜色革命” 地缘战略