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湖南大学学报（自然科学版） 2009年第S1期36卷 141-145页

作者： ZENG Ruo-lang,WANG Xin,ZHANG Yin-ping,DI Hong-fa,ZHANG Qun-li(Department of Building science,Tsinghua University,beijing 100084,china) Department of Building science Tsinghua University Beijing 100084 China

The conventional solar heating floor system contains a big water tank to store energy in the day time for heating at night,which takes much building space and is very *** order to reduce the water tank volume even to cancel the tank,a novel structure of integrated water pipe floor heating system using shape-stabilized phase change materials(SSPCM)for thermal energy storage was developed.A numerical model was developed to analyze the performance of SSPCM floor heating system under the intermittent heating condition,which was verified by our experimental *** thermal performance of the heating system and the effects of various factors on it were analyzed *** factors including phase transition temperature,heat of fusion,thermal conductivity of SSPCM and thermal conductivity of the decoration material were *** results show that tm and kd are the most import influencing factors on the thermal performance of SSPCM floor heating system,since they determine the heat source temperature and thermal resistance between SSPCM plates and indoor air,*** should be large to store enough thermal energy in the day time for nighttimes *** effects of kp can be ignored in this *** SSPCM floor heating system has potential of making use of the daytime solar energy for heating at night efficiently in various climates when its structure is properly designed.

关键词： phase change material energy storage solar water heating

Generation of Broadband Frequency Entangled Biphotons for Quantum Clock Synchronization

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Generation of Broadband Frequency Entangled Biphotons for Qu...

Ontology-based Knowledge Representation for Resolution of Semantic Heterogeneity in GIS

第三届中国卫星导航学术年会

作者： Run-ai Quan 1 ,Rui-fang Dong 1 ,Fei-yan Hou 1 ,Yun Bai 1,2 ,Yu Zhang 1,2 ,Tao Liu 1 ,Shou-gang Zhang 1 1.Key Laboratory of Time and Frequency Primary Standards,National Time Service Center,chinese academy of science,Xian,710600,china 2.Graduate University of chinese academy of science,beijing,100039,china

Frequency entangled biphotons based on spontaneous parametric down conversion（SPDC）of nonlinear crystal are widely used in Quantum clock synchronization *** time-correlation width of the entangled source determines the accuracy of the attainable synchronization,which relies on the spectral bandwidth of the generated *** theoretically investigate the generation of frequency anti-correlated biphotons from chirped periodically-poled potassium titanyl phosphate（C-PPKTP）.It is demonstrated that an ultra-broadband entangled biphoton source with a width of 857nm was obtained,by using a 10mm-long crystal with a chirping of 9.7×10 -6 μm -2 , and a cw pumping source with a wavelength of *** corresponding time correlation width is only 3.5fs,which implies feasible clock synchronization accuracy in femtosecond *** further demonstrate that the narrowing of the time-correlation width slows down dramatically by increasing the chirping and the length of the nonlinear crystal, which provides a theoretical instruction for us to trade off between the complexity of the crystal fabrication and the sufficiently narrow time-correlation width.

关键词： quantum clock synchronization broadband entanglement C-PPKTP spontaneous parametric down conversion

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Ontology-based Knowledge Representation for Resolution of Se...

MORPHOLOGICAL TRANSITION BETWEEN VESICLES AND TUBULES FOR A GLYCOPOLYMER-CONTAINING AMPHIPHILIC DIBLOCK COPOLYMER IN AQUEOUS SOLUTIONS

2011 3rd IEEE International Conference on Information Management and Engineering(ICIME 2011)

作者： Ying Liu1 2 3 Bai Zhang*1 1Northeast Institute of Geography and Agroecology chinese academy of sciences Changchun 130012 china Nan Wang2 Zongming Wang1 2Jilin University of Finance and Economics Changchun 130117 china 3 Graduate University of chinese academy of sciences beijing 100049 china

Lack of semantic interoperability in geographical information systems has been identified as the main obstacle for data sharing and database ***,however, must develop methods to overcome the problems of semantic *** are considered to be one approach to support geographic information *** paper presents an ontology-driven integration approach to help in detecting and possibly resolving semantic *** originality is that each data source participating in the integration process contains an ontology that defines the meaning of its own data. This approach ensures the automation of the integration through regulation of semantic integration ***, land classification in field GIS is described related to the example.

关键词： ontology semantic integration semantic heterogeneity intelligent reasoning gis

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chinese Journal of Polymer science 2001年第3期19卷 297-301页

作者： Zi-chen Li Yue Shen Yu-zeng Liang Fu-mian Li Department of Polymer science & Engineering College of Chemistry Peking University beijing 100871, china beijing Univ Coll Chem Dept Polymer Sci & Engn Beijing 100871 Peoples R China

The morphological transition of molecular assemblies in aqueous solutions for a new amphiphilic diblock copolymer induced by changing the initial solvent conditions was studied by transmission electron microscopy (TEM). The copolymer was polystyrene(77)-b-poly[2-(beta -D-glucopyranosyloxy)ethyl acrylate (6)] (PSt(77)-b-PGEA(6)) and the solvent was a mixture of DMF and THF. PSt(77)-b-PGEA(6) yields vesicles and tubules when it is initially dissolved in THF and DMF respectively. The morphological transition between vesicles and tubules can be achieved by simply varying the amounts of THF and DMF, or changing the temperature at which the aggregates were prepared.

关键词： block copolymer amphiphile glycopolymer self-assembly tubule vesicle

Structural and mechanical properties of amorphous carbon films deposited by the dual plasma technique

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Journal of University of science and Technology beijing 2008年第5期15卷 622-626页

作者： Yaohui Wang,Xu Zhang,Xianying Wu,Huixing Zhang,and Xiaoji Zhang Key Laboratory of the Ministry of Education of china for Beam Technology and Material Modification,Institution of Low Energy Nuclear Physics,beijing Normal University beijing Radiation Center,beijing 100875,china [a]Key Laboratory of the Ministry of Education of china for Beam Technology Material Modification Institution of Low Energy Nuclear Physics Beijing Normal University beijing Radiation Center Beijing 100875 China

Direct current metal filtered cathodic vacuum arc （FCVA） and acetylene gas （C2H2） were wielded to synthesize Ti-containing amorphous carbon films on Si （100）. The influence of substrate bias voltage and acetylene gas on the microstructure and mechanical properties of the films were investigated. The results show that the phase of TiC in the （111） preferential crystallographic orientation exists in the film,and the main existing pattern of carbon is sp2. With increasing the acetylene flow rate,the contents of Ti and TiC phase of the film gradually reduce; however,the thickness of the film increases. When the substrate bias voltage reaches -600 V,the internal stress of the film reaches 1.6 GPa. The micro-hardness and elastic modulus of the film can reach 33.9 and 237.6 GPa,respectively,and the friction coefficient of the film is 0.25.

关键词： metal containing amorphous carbon amorphous carbon films filtered arc acetylene flow rate bias voltage structure and properties

Event Stratigraphy, Biostratigraphy and Sequence Stratigraphy of Neoproterozoic in North china

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Journal of Earth science 1999年第2期18卷 3-11页

作者： Qiao Xiufu Gao Linzhi Gao Mai Institute of Geology, chinese academy of Geological sciences, beijing 100037

The aim of this study is to discuss the chronostratigraphy, catastrophic event stratigraphy, biostratigraphy and sequence stratigraphy of Neoproterozoic. In the eastern part of the North china, the Neoproterozoic consists of Qingbaikou System (1 000-800 Ma) and Sinian System (800-600 Ma). The Qingbaikou System is widely distributed over the whole area and the Sinian System only in the eastern and southern parts of the plate. In this paper, we discuss the age limit of the formations, and try to establish the Neoproterozoic chronostratigraphic frame, the ages of which are partly based on recently obtained carbonate whole rock Pb Pb isotope. Based on the event records of ancient earthquake, which are well developed in Sinian carbonates, “a vibrational liquefaction seismic sequence” in carbonate rocks is established. We propose a time correlation for the Sinian formation in eastern North china, on the bases of event records of earthquake in combination with biostratigraphy, and thus revise the traditional correlation scheme that has been used for nearly 30 years. Some biostratigraphic results were obtained in fossil microplants, megafossils and metazoans in North china. A large amount of big double layered and complex ornamented acritarchs are found in Qingbaikou and Sinian systems. On the basis of the correlation by earthquake events, the Huainan fauna is regarded as Late Sinian, probably between 700 Ma and 600 Ma. Altogether 16 depositional sequences are distinguished in the Neoproterozoic, with an average time interval of about 15-16 Ma.

关键词： catastrophic event stratigraphy biostratigraphy sequence stratigraphy Neoproterozoic North china.

Two-dimensional Compact Perfect Shuffle Optical Interconnection

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chinese Journal of Lasers 1995年第2期B4卷 133-136页

作者： ZHANG Erping YU Chongxiu ZHOU Jing XU Daxiong(BOX 163#, Department of Applied science & Technology, beijing University ofPosts and Telecommunications, beijing 100088, china) beijing Univ of Posts and Telecommunications Beijing China

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Ｔｗｏ－ｄｉｍｅｎｓｉｏｎａｌＣｏｍｐａｃｔＰｅｒｆｅｃｔＳｈｕｆｆｌｅＯｐｔｉｃａｌＩｎｔｅｒｃｏｎｎｅｃｔｉｏｎ￥ＺＨＡＮＧＥｒｐｉｎｇ；ＹＵＣｈｏｎｇｘｉｕ；ＺＨＯＵＪｉｎｇ；ＸＵＤａｘｉｏｎｇ（ＢＯＸ１６３＃，ＤｅｐａｒｔｍｅｎｔｏｆＡｐｐｌ...

关键词： PS(perfect shuffle) HOE optical interconnection

Experimental study on visualization of the flow field in microtube

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science china Technological sciences 2005年第5期 43-51页

作者： LIU Zhigang & ZHAO Yaohua Institute of Engineering Thermophysics, chinese academy of sciences, beijing 100080, china

An experimental study was conducted to visualize the flow field and confirm the transitional Reynolds number from laminar to turbulent flow, as distilled water flows through quartz glass microtubes with inner diameter 315 and 520 μm. With gentian violet as colorant, the flow field pictures in the microtube, and therefore, is shot by a CCD camera with a microscope at different Reynolds numbers. Pressure drop data were also used to characterize the friction factor for those microtubes in the Reynolds number range of 200―2300. The experimental results clearly showed that the flow in the microtube was the laminar state and the friction factors agreed well with the Poiseuille equations when the Reynolds number was low. As the Reynolds number was larger than 1200 and 1500 for the microtube with inner diameter 315 and 520 μm, respectively, the friction factor departed from the classical laminar solution due to the earlier transition from laminar to turbulent flow. The flow turned into full turbulent when the Reynolds number reached 1500―1800.

关键词： visual experiment microtube microscale flow friction factor turbulent transition.

Genetic Diversity Conservation and Development of Some Rare and Endangered Species of Beech Forestsin china’s Subtropical Mou

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Forest Ecosystems 1995年第1期 1-16页

作者： $$$$Li Junqing( College of Forest Resources and Environment,beijing Forestry University,beijing 100083,P.R. china) Wang Xianpu( Botanical Institute, chinese academy of science,beijing 100044,P.R. china)

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ＧｅｎｅｔｉｃＤｉｖｅｒｓｉｔｙＣｏｎｓｅｒｖａｔｉｏｎａｎｄＤｅｖｅｌｏｐｍｅｎｔｏｆＳｏｍｅＲａｒｅａｎｄＥｎｄａｎｇｅｒｅｄＳｐｅｃｉｅｓｏｆＢｅｅｃｈＦｏｒｅｓｔｓｉｎＣｈｉｎａ’ｓＳｕｂｔｒｏｐｉｃａｌＭｏｕｎｔａｉｎｏｕｓＡｒｅａｓＧｅｎ...

关键词： Beech china