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The mathematical model of wetting angle of heterogeneous nucleation

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Science china(Technological Sciences) 2004年第4期47卷 391-397页

作者： HUANG Cheng1, SONG Bo1, MAO Jinghong2 & ZHAO Pei3.1. School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083. china 2. School of Material Science, University of Science and Technology Beijing, Beijing 100083. china 3. Central Iron and Steel research {3., Beijing 100081, china 1. School of Metallurgical and Ecological Engineering University of Science and Technology Beijing 100083 Beijing China 2. School of Material Science University of Science and Technology Beijing 100083 Beijing China 3. Central Iron and Steel research institute 100081 Beijing China

The heterogeneous nucleation has been analyzed in terms of the thermodynamic theory, and the mathematical model of wetting angle of heterogeneous nucleation has been developed based on the dynamic requirements of hetero- and homogeneous nucleation. With the wetting angel model, the wetting angles of different catalysts in liquid iron have been calculated. The result shows that the wetting angle of most catalysts is smaller than 40, and the value of f() is far less than 1. The wetting angles of TiN, TiC and RE2O3.are smaller, while the wetting angle of MnO is bigger among the ordinary nucleation catalysts. The wetting angles calculated by this model are in agreement with the results of other research work.

关键词： heterogeneous nucleation, mathematical model, wetting angle, undercooling.

Formal analysis and design of multi-party fair exchange protocols

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Science in china(Series F) 2006年第2期49卷 155-174页

作者： QING Sihan1,2,3.& LI Gaicheng1,3.1. Engineering research Center for Information Security Technology, institute of Software, Chinese Academy of Sciences, Beijing 100080, china 2. Beijing Zhongke Ansheng Corporation of Information Technology, Beijing 100080, china 3. Graduate School of the Chinese Academy of Sciences, Beijing 10003., china 1. Engineering research Center for Information Security Technology Institute of Software Chinese Academy of Sciences Beijing 100080 China 2. Beijing Zhongke Ansheng Corporation of Information Technology Beijing 100080 China 3. Graduate School of the Chinese Academy of Sciences Beijing 100039 China

Based on the origin of message items and channel combination between transacting parties, and events and relations among events, this paper presents a concise, precise, and hierarchical model for general fair exchange protocols, formally specifies various security requirements which are able to reflect inherent requirements for fair exchange protocols more rigorously, and partition these security requirements with fine granularity. This work helps analyze, debug, and design multi-party fair exchange protocols more effectively and elaborately,

关键词： fair exchange logical protocol formal model security requirement.

Finite Element Analysis of Die Geometry and Process Conditions Effects on Equal Channel Angular Extrusion for β-Titanium Alloy

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Journal of Iron and Steel research International 2012年第10期19卷 54-58页

作者： SI Jia-yong1,2, GAO Fan3. ZHANG Ji3.(1. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083. Hunan, china 2. College of Mechanical and Electrical Engineering, Central South University of Forestry and Technology, Changsha 410004, Hunan, china 3. High Temperature Material research Division, Central Iron and Steel research institute, Beijing 100081, china) [a] State Key Laboratory of Powder Metallurgy Central South University Changsha 410083 Hunan China [b] College of Mechanical and Electrical Engineering Central South University of Forestry and Technology Changsha 410004 Hunan China [c] High Temperature Material research Division Central Iron and Steel Research Institute Beijing 100081 China

The finite element analysis was applied to evaluate the respective influences of die geometry and process conditions on plastic strain distribution for β-titanium (Ti-13.11Cr3.l) alloy during the equal channel angular extrusion (ECAE). It was found that optimum equal channel angular extrusion die geometry is strongly material dependent. Optimal strain homogeneity in the Ti-13.11Cr3.l alloy may be achieved at r (inner radius)=5 mm, R (outer radius)=3.mm. The equivalent plastic strain increases with increasing friction coefficient. And the better homogeneity of the equivalent plastic strain distribution can be achieved when friction coefficient value is lower. The faster the ram speed is, the lower the homogeneity of the equivalent plastic strain distribution is and the influence is slight. The back-pressure does not help to improve the plastic strain homogeneity, and the increasing temperature has a slightly favourable effect on the plastic strain homogeneity between 400 and 600 ℃.

关键词： equal channel angular extrusion finite element analysis die geometry β-titanium

Hydrocarbon test in lower-layer atmosphere to predict deep-sea petroleum or hydrate in the Okinawa Trough: an example

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Acta Oceanologica Sinica 2003年第4期22卷 569-576页

作者： Gong Jianming1, Chen Jianwen 1, 2, Li Gang1, Zhang Xunhua1, Li Jipeng3. Huang Fulin1 1. Qingdao institute of Marine Geology, Qingdao 266071, china. 2. Ocean University of china, Qingdao 266003. china 3. Hefei institute of Petroleum Chemical Exploration, china Petroleum Exploration and Development research institute, Hefei 23.022,china Qingdao Inst Marine Geol Qingdao 266071 Peoples R China Ocean Univ china Qingdao 266003 Peoples R China china Petr Explorat & Dev Res Inst Hefei Inst Petr Chem Explorat Hefei 230022 Peoples R China

Light hydrocarbon (methane, ethane, propane, butane and CO2) test and C isotopic analysis of CO are conducted for over 100 lower-layer atmospheric samples from the East china Sea slope and the Okinawa Trough. The results show that the lower-layer atmosphere mainly consists of CO2 and then of CH4, and the CO2 concentrations are calculated to have a high average value of 0.87 omega/10(-2) about three times that of the regional background (0-3.omega/10(-2)). The result also shows that the average value of C isotope - 20.8 x 10(-3. is given to the CO2, inferring that it is inorganic gas. Thus, for the future 's work in the Okinawa Trough, special attention should be paid to CO2 hydrate, which is very possibly an important hydrate type.

关键词： lower-layer atmosphere hydrocarbon test C isotopic analysis deep-sea petroleum gas hydrate

LAND desertIFICATION(DEGRADATION) AND ITS CONTROL IN LOWER REACH REGION OF HEIHE RIVER

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干旱区资源与环境 1993年第Z1期7卷 63-65页

作者： Chen Longhen institute of desert research, Academia Sinica, {3., china

The lower reach of Heihe River, also known as Ejina River, was called Ruoshui Riverin ancient times. This area, although fallen into extremely arid temperate desert in the EjinaBanner, Inner Mongolia, has been a main line of communication since then and formed thefertile Ejina Oasis relying on the water source flowing from the Qilian mountains. However,in the recent years the land desertification (degradation) in this area has developed rapidly,

关键词： Heihe River Lower Reaches desertification Oasis

Spatial distribution of 10m firn temperature in the Antarctic Ice Sheet

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Science china Earth Sciences 2011年第5期54卷 655-666页

作者： WANG YeTang1,3.& HOU ShuGui2,3.1 Shandong Marine Fisheries research institute,Yantai 264006,china 2 MOE,Key Laboratory for Coast and Island Development,School of Geographic and Oceanographic Sciences,Nanjing University,Nanjing 210093.china 3.tate Key Laboratory of Cryospheric Science,Cold and Arid Regions Environmental and Engineering research institute,Chinese Academy of Sciences,lanzhou 73.000,china 1. Shandong Marine Fisheries research institute Yantai 264006 China3. State Key Laboratory of Cryospheric Science Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China2. MOE Key Laboratory for Coast and Island Development School of Geographic and Oceanographic Sciences Nanjing University Nanjing 210093 China

A database of Antarctic 10 m firn temperature was constructed using available borehole temperature measurements with data quality control to extend knowledge of Antarctic climate. Slopes from a high-resolution digital elevation model and the main ice divide were used to delineate main drainage sectors across Antarctica. In each drainage sector, a quantitative relationship between temperature and latitude, longitude and altitude was established using available tim temperature data. Quantitative relationships incorporating other factors affecting Antarctic air temperature such as atmospheric circulation and small-scale to- pography were used to derive a 10-km resolution grid map of surface temperature. The resulting temperature patterns presented a reasonable depiction of both large and small-scale variations in Antarctic 10 m firn temperature. This map is useful for many spatial variation studies, Antarctic ice sheet models, and comparison with satellite-derived temperature data and outputs of atmospheric general circulation models.

关键词： Antarctica 10 m firn temperature spatial distribution

Chronology of Holocene lacustrine sediments in Co Ngoin, central Tibetan Plateau

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Science china Earth Sciences 2006年第9期49卷 991-1001页

作者： WU Yanhong1, WANG Sumin1& HOU Xinhua1,3.1. Key Laboratory of Lake Sedimentation and Environment, Nanjing institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, china 2. institute of Tibetan Plateau {3., Chinese Academy of Sciences, Beijing 10085, china 3. Graduate University of Chinese Academy of Sciences, Beijing 10003., china 1. Key Laboratory of Lake Sedimentation and Environment Nanjing Institute of Geography and Limnology Chinese Academy of Sciences Nanjing 210008 China 2. institute of Tibetan Plateau research Chinese Academy of Sciences Beijing 10085 China 3. Graduate University of Chinese Academy of Sciences Beijing 100039 China

Chronology is the basis for using lacustrine sediments to reconstruct the history of en-vironmental change. Radioactive-nuclides such as 14C, 210Pb and 13.Cs dating are mainly used to establish the chronology for recent several ten thousand years. Because of being mixed with “dead carbon”, the measured 14C age is always older than the actual age which is recognized as “reservoir effect”. Cs is a kind of active metal element, and easy to migrate vertically in the sediment that leads to the error of the time marker. 210Pb dating should make sure to select CIC model or CRS model. On the Tibetan Plateau, most of the lakes are alkaline closed lake where Cs is more moveable in the sediment and the reservoir effect caused by “dead carbon” on 14C dating is stronger. Based on the analysis on results of 14C, 210Pb and 13.Cs of the lacustrine sediments from Co Ngoin, central Tibetan Plateau, we use the simple regression method to re-calculate the 14C calendar ages, and establish the time sequence for cores CE-1 and CE-2 with result of 210Pb CRS model for the upper 3. cm and re-calculated 14C calendar age for sediments bellow 3. cm. Since 1400 cal. a BP, sedimentation inter-rupted for more than 1000 years. According to this time sequence, variations of environmental proxies confidently reflect the major climatic events in Holocene.

关键词： 14C, 210Pb and 13.Cs, chronology, lacustrine sediments, climatic event, Co Ngoin, central Tibetan Plateau.

Gas formation mechanism of marine carbonate source rocks in china

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Science china Earth Sciences 2005年第4期48卷 441-453页

作者： ZHAO Wenzhi1, WANG Zhaoyun1, HE Haiqing2, ZHANG Mingjie3. WANG Hongjun1, WANG Yunpeng4 & QIN Yong5 1. research institute of Petroleum Exploration & Development, Petrochina, Beijing 100083.{3. 2. Petrochina Exploration & Production, Beijing 100011,{3. 3. Department of Geology, lanzhou University, lanzhou 73.000,{3. 4. Guangzhou Geochemical institute, Chinese Academy of Sciences, Guangzhou 510640,{3. 5.{3. University of Mining and Technology, Xuzhou 221000,{3. 1. research institute of Petroleum Exploration & Development 100083 PetroChinaBeijin China 2. Petrochina Exploration & Production 100011 Beijing China 3. Department of Geology Lanzhou University 730000 Lanzhou China 4. Guangzhou Geochemical institute Chinese Academy of Sciences 510640 Guangzhou China 5. china University of Mining and Technology 221000 Xuzhou China

By breaking through the conventional ideology on the study of gas-formation mechanism of source rocks which focused on merely the characteristics of source rocks them- selves, and based on the development and distribution characteristics of marine carbonate source rocks in the medium-to-bottom parts of the Chinese superimposed sedimentary basins as well as various processes in the course of gas generation and reservoir forming, the complex hydrocarbon-generating model of carbonates is established. Such a model concerns not only the “three-stage” gas formation characteristics of carbonates, but also the gas generation process due to a thermal cracking of oil and the re-generation process of gas from heated secondary organic matters during the gas-generation and reservoir-forming course. The high-quality hy- drocarbon generating matter of marine carbonate source rocks determined a high gas-oil ratio and tended to form paleo-oil-reservoirs, representing an enrichment process of organic matters. The thermal cracking of oil in palaeo-oil-reservoirs is an important means for the effective forma- tion of gas reservoirs. The secondary organic matters in carbonate reservoirs may regenerate gas after a secondary deep burial, thus becoming an effective gas source.

关键词： carbonate, three-stage hydrocarbon generation, inhibitive effect of maturity, oil-cracking gas, second-ary asphalt gas.

A distributed hydrological model with its application to the Jinghe watershed in the Yellow River Basin

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Science china(Technological Sciences) 2004年第z1期47卷 60-71页

作者： WANG Zhonggen1, ZHENG Hongxing1, LIU Changming1, , WU Xianfeng2 2 & ZHAO Weimin3.1. Key Laboratory of Water Cycle & Related Land Surface Processes, institute of Geographic Science and Natural Resources research, Chinese Academy of Sciences, Beijing 100101, china 2. institute of Environmental Science, Beijing Normal University, Beijing 100875, china 3. Water Resources Conservation Committee of Yellow River, Zhengzhou 450003. china Chinese Acad Sci Key Lab Water Cycle & Related Land Surface Proc Inst Geog Sci & Nat Resources Res Beijing 100101 Peoples R China Beijing Normal Univ Inst Environm Sci Beijing 100875 Peoples R China Water Resources Conservat Comm Yellow River Zhengzhou 450003 Peoples R China

For the purpose of water resources management in the Yellow River Basin with highly spatial difference, a daily distributed hydrological model was proposed, of which the determination of spatially-distributed parameters and model inputs processing were performed by means of GIS/RS. In the model, the computation of runoff yield was based on the topography index method and flow routing was modeled by Maskingum method. The operation of the model is followed by means of “command structure” technique based upon the topography of river network. A case study using the model was conducted for the Jinghe watershed, which locates at the middle Yellow River Basin. The simulation of the hydrological processes in 1996 has shown that water quantity balance errors were less than 5% and the Nash-Sutcliffe coefficient arrived at 0.7, indicating that the model structure is justifiable, and the precision of the model can satisfy the purpose of water resources management.

关键词： distributed hydrological model, structure and equation, GIS and RS, Jinghe Basin, Yellow River Basin.