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Cutting Performance and Mechanism of RE Carbide Tools

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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

Global analysis theory of climate system and its applications

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Chinese Science Bulletin 2003年第10期48卷 1034-1039页

作者： LI Jianping1,2 & CHOU Jifan2,3 1. LASG, institute of Atmospheric Physics, Chinese Academy of Sciences, beijing 100029, china 2. Department of Atmospheric Sciences, Lanzhou University, Lanzhou 730000, china 3. Training Center for china Meteorological administration, beijing 100081, china LASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Department of Atmospheric Sciences Lanzhou University Lanzhou 730000 China Training Center for china Meteorological administration Beijing 100081 China

The idea and main theoretical results of the global analysis theory of climate system are briefly summarized in this paper. A theorem on the global behavior of climate system is given, i.e. there exists a global attractor in the dynamical equations of climate, any state of climate system will be evolved into the global attractor as time increases, indicating the nonlinear adjustment process of climate system to external forcing. The different effects of external forcing, dissipation and nonlinearity on the long-term behavior of solutions are pointed out, and some main applications of the global analysis theory are also introduced. Especially, three applications, the adjustment and evolution processes of climate, the principle of numerical model design and the optimally numerical integration, are discussed.

关键词：整体分析理论气侯体系应用不定性计算法则气侯科学数字模型

Urban effects and summer thunderstorms in a tropical cyclone affected situation over Guangzhou city

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Science china Earth Sciences 2007年第12期50卷 1867-1876页

作者： MENG WeiGuang1,3,YAN JingHua1 & HU HaiBo2 1 institute of Tropical and Marine Meteorology,Chinese Meteorological administration(CMA),Guangzhou 510080,china 2 institute of Urban Meteorology,CMA,beijing 100089,china 3 State Key Laboratory of Severe Weather,Chinese Academy of Meteorological Sciences,beijing 100081,china institute of Tropical and Marine Meteorology Chinese Meteorological Administration (CMA) Guangzhou China State Key Laboratory of Severe Weather Chinese Academy of Meteorological Sciences Beijing China institute of Urban Meteorology CMA Beijing China

With data mainly from Guangzhou mesonet Automatic Weather Stations(AWS),Guangzhou Doppler Radar and satellite TBB data,characteristics and evolution of the urban heat island(UHI) over Guang-zhou City were analyzed in a tropical cyclone affected situation for early August *** particular,two thunderstorms occurring during this period respectively at the night of 4 August and in the afternoon of 7 August were investigated to study the relationships between the development of thunderstorms and the *** showed that two thunderstorms were associated with the UHI *** induced local air convergence and initiated the thunderstorm *** cases showed a general agreement in time and space for the locations of maximum UHI,convergence,convection,and *** was found to be more favorable to developing in time periods and locations with stronger intensity of *** also showed that,due to the urban effects,both thunderstorms got strengthened when moving over Guangzhou City,with maximum radar echoes observed right over the urban area and precipitation located within the *** these features reveal that two thunderstorms were urban-induced storms.

关键词： summer thunderstorms, urban heat islands (UHI), urban effects, tropical cyclone

Influence of obstacle disturbance in a duct on explosion characteristics of coal gas

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Science china(Physics,Mechanics & Astronomy) 2010年第2期53卷 269-278页

作者： WANG cheng1,MA TianBao1 & LU Jie2 1 State Key Laboratory of Explosion Science and Technology,beijing institute of Technology,beijing 100081,china 2 Taiyuan Gas Company,Taiyuan 030024,china State Key Laboratory of Explosion Science and Technology Beijing Institute of Technology Beijing China Taiyuan Gas Company Taiyuan China

In combination with experimental research,numerical simulation is performed to investigate the influence law of the obstacles in a duct on the explosion flame of premixed coal gas and air. The numerical method uses upwind WENO scheme and two-step chemical reaction model. The interaction mechanism is addressed between the compression wave from reflection on the right end of the duct and flame propagation. The reflected wave is found to result in the decrease of flame velocity. On this basis,we analyze the mechanism of the obstacles on flame as well as the law of flow field variation thus caused. The results suggest that,due to the obstacles,deflagration wave is repeatedly reflected,combustible gas mixture is fully compressed,temperature and pressure rise,chemical reaction speed increases,and hence flame intensity is strengthened. At the same time,a tripe point forms as a result of wall reflection of the deflagration wave from the obstacles and furthermore local flame speed increases. As the triple point propagates forward,the flame speed gradually decreases due to dissipation of energy. These conclusions provide a valuable theoretical foundation for the prediction of explosion field,prevention of fire and explosion and effective control of the com-bustion speed and flame propagation speed in detonation propulsion.

关键词： coal gas obstacle explosion overpressure flame speed reflected wave triple point WENO scheme

Improving the accuracy of image-based forest fire recognition and spatial positioning

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Science china(Technological Sciences) 2010年第S1期53卷 184-190页

作者： JIANG LiLi 1,QI QingWen 1,ZHANG An 1,GUO ChaoHui 2 & cheng Xi 1,3 1 institute of Geographical Sciences and Natural Resources Research,Chinese Academy of Sciences,beijing 100101,china 2 china Center for Resources Satellite Data and Applications,beijing 100094,china 3Graduate University of Chinese Academy of Sciences,beijing 100049,china institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing China china Center for Resources Satellite Data and Applications Beijing China Graduate University of Chinese Academy of Sciences Beijing China

Forest fires are frequent natural *** is necessary to explore advanced means to monitor,recognize and locate forest fires so as to establish a scientific system for the early detection,real-time positioning and quick fighting of forest *** paper mainly expounds methods and algorithms for improving accuracy and removing uncertainty in image-based forest fire recognition and spatial ***,we discuss a method of forest fire recognition in visible-light *** are four aspects to improve accuracy and remove uncertainty in fire recognition:(1)eliminating factors of interference such as road and sky with high brightness,red leaves,other colored objects and objects that are lit up at night,(2)excluding imaging for specific periods and azimuth angles for which interference phenomena repeatedly occur,(3)improving the thresholding method for determining the flame border in image processing by adjusting the threshold to the season,weather and region,and (4)integrating the visible-light image method with infrared image ***,we examine infrared-image-based methods and approaches of improving the accuracy of forest fire recognition by combining the spectrum threshold with an object feature value such as the normalized difference vegetation index and excluding factors of disturbance such as interference signals,extreme weather and high-temperature ***,a method of visible analysis to enhance the accuracy of forest fire positioning is examined and realized;the method includes decreasing the visual angle,selecting central points,selecting the largest spots,and judging the selection of fire spots according to the central *** studies are examined and the results are found to be satisfactory.

关键词： forest fire monitoring spatial positioning accuracy improvement

Dislocation structure of the crust-mantle boundary and low-velocity body within the crust beneath the Dabie Shan collision orogen

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Science china Earth Sciences 2005年第7期48卷 875-885页

作者： LIU Qiyuan1, Rainer Kind2, CHEN Jiuhui1, YUAN Xiaohui2, LI Shuncheng1, GUO Biao1, Kurt Wylegalla2 & LAI Yuangen1 1. State Key Laboratory of earthquake Dynamics, institute of geology, china earthquake administration, beijing 100029, china 2. GeoForschungZentrum Potsdam, Telegrafenburg A17, Potsdam, D-14473, Germany State Key Laboratory of earthquake Dynamics Institute of Geology China Earthquake Administration Beijing 100029 China GeoForschungZentrum Potsdam Telegrafenburg A17 Potsdam D-14473 Germany

From April of 2001 to March of 2002, a passive seismic array experiment was car- ried out in the Dabie Shan and its adjacent region. In this experiment, totally 34 broadband seismic stations were deployed along a profile across the Dabie Shan orogen and North-china platform. This profile is about 500 km long from Cuilin (34°40′N, 114°49′E), Henan Province, to Dajipu (30°20′N, 115°03′E), Hubei Province. The space between stations is about 3?8 km in the Dabie Shan orogenic belt and about 15?20 km in other area. The receiver function profile and S-wave velocity structure of the crust and upper mantle down to 100 km depth along the profile are investigated in terms of the receiver function techniques (Liu et al., 1996, 2000). Our results show that the crust beneath the Dabie Shan orogen has an obviously asymmetric blocked structure in the direction perpendicular to the mountain strike. The maximal crustal thickness reaches to 42 km. The crust-mantle boundary has a dislocation structure correlated to the crustal blocks and the largest offset reaches to 8 km. In the kernel of the orogen exists a low-velocity body inside the crust, which is separated into two parts corresponding to the South Dabie and North Dabie on the surface, respectively. Probably a vertical divergent movement between both took place in history. The crust below this low-velocity area has a positive gradient velocity structure with the depth, and the upper mantle down to the depth of 70 km has the lower S-wave velocity than its both sides. Beneath the Dabie Shan, however, a high-velocity anomaly exists in the upper mantle below 70 km.

关键词： receiver function low-velocity body Moho discontinuity Dabei Shan collision orogen.

Sporopollen analysis of Core B10 in the southern Yellow Sea and the reflected characteristics of climate changes

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Chinese Science Bulletin 2003年第B6期48卷 42-48页

作者： FU Mingzuo~(1,2,3), LI Zhen~1, XU Xiaowei~1 & SHl Xuefa~1 1. Key Laboratory of Marine Sedimentology and Environmental geology, First institute of Oceanography. State Oceanic administration, Qingdao 266061. china 2. institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071. china 3. Graduate School, Chinese Academy of Sciences, beijing 100039. china Key Laboratory of Marine Sedimentology and Environmental geology First institute of Oceanography State Oceanic Administration Qingdao China institute of Oceanology Chinese Academy of Sciences Qingdao China Graduate School Chinese Academy of Sciences Beijing China

Eight sporopollen zones have been divided based on the results of high-resolution sporopollen analysis of Core B10 in the southern Yellow Sea. Based on the results along with ^14C datings and the subbottom profiling data,climatic and environmental changes since the last stage of late Pleistocene are discussed. The main conclusions are drawn as follows: (1) the vegetation evolved in the process of coniferous forest-grassland containing broad-leaved trees→coniferous and broad-leaved mixed forest→coniferons and broad-leaved mixed forest-grassland prevailed by coniferous trees→coniferous and broad-leaved mixed forest-grassland containing evergreen broad-leaved trees→coniferons and broad-leaved mixed forest-grassland prevailed by broadleaved trees→deciduous broad-leaved forest-meadow containing evergreen broad-leaved trees→coniferous and broadleaved mixed forest-grassland prevailed by broad-leaved trees→coniferous and broad-leaved mixed forest containing evergreen broad-leaved trees; (2) eight stages of climate changes are identified as the cold and dry stage, the temperate and wet stage, the cold and dry stage, the warm and dry stage, the temperate and wet stage, the hot and dry stage, the temperate and dry stage, then the warm and dry stage in turn; (3) the sedimentary environment developed from land,to littoral zone, to land again, then to shore-neritic zone; and (4) the Yellow Sea Warm Current formed during early-Holocene rather than Atlantic stage.

关键词：中国黄海气候变化碳14年代测定底基压型数据更新世沉积环境大西洋

The onset and advance of the Asian summer monsoon

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Science Bulletin 2006年第1期51卷 80-88页

作者： Lü Junmei1,2,4, ZHANG Qingyun1, TAO Shiyan1 & JU Jianhua3 1. State Key Laboratory of Numerical Modeling for Atmospheric Sci- ences and Geophysical Fluid Dynamics, institute of Atmospheric Physics, Chinese Academy of Sciences, beijing 100029, china 2. Department of Atmospheric Sciences, Yunnan University, Kunming 650091, china 3. china Meteorological administration Training Centre, beijing 100081, china 4. Graduate School of Chinese Academy of Sciences, beijing 100039, china State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China Department of Atmospheric Sciences Yunnan University Kunming China Graduate School of Chinese Academy of Sciences Beijing China china Meteorological administration Training Centre Beijing China

Based on the daily outgoing longwave radiation (OLR) data from National Oceanic and At- mospheric administration (NOAA) satellites, the Cli- mate Prediction Center’s merged analysis of pre- cipitation (CMAP) data and the National Centers for Environmental Prediction/National Center for At- mospheric Research (NCEP/NCAR) reanalysis dataset, the mean intraseasonal variability of the Asian summer monsoon (ASM) is investigated by using power spectrum analysis, band-pass filter, and diagnostic analyses. The processes of the onset and advance of monsoon over the southern part of Indo- china Peninsula, the east coast of Bay of Bengal, the South china Sea and the Indian subcontinent are explored. It is found that there is an abrupt change in OLR, precipitation and zonal wind during the onset and advance of the ASM. It is also indicated that the southern part of Indochina Peninsula and the adja- cent Andaman Sea is the region where the earliest onset of the ASM occurs in the 2nd pentad of May.

关键词： Asian summer monsoon intraseasonal variability onset advance.

Mineral provinces and material provenance of the surficial sediments near the Zhongsha Islands in the South china Sea

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Acta Oceanologica Sinica 2007年第1期26卷 66-76页

作者： YAN Quanshu1, 2, 3, SHI Xuefa2*, WANG Kunshan21. institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, china2. Key Laboratory of Marine Sedimentology and Environment geology of State Oceanic administration, First institute of Oceanograghy, State Oceanic administration, Qingdao 266061, china3. Graduate School, Chinese Academy of Sciences, beijing 100049, china institute of Oceanology Chinese Academy of Sciences Qingdao 266071 First institute of Oceanograghy State Oceanic Administration Key Laboratory of Marine Sedimentology and Environment Geology of State Oceanic Administration Qingdao 266061

Characteristics and distribution patterns of clastic minerals (0.063～0.125 mm) in bottom sediments represent a significant indicator for the identification of the origin of sediment. One hundred and fourteen surface sediment samples, which were collected from the area near the Zhongsha Islands in the South china Sea, were analysed to identify the mineral suites and their distributions in the study area. The area can be divided into three mineral provinces: (Ⅰ) a province of biogenic minerals, which mainly originate from the Zhongsha Atoll; (Ⅱ) a province of volcanogenic minerals, which are mainly derived from local basaltic seamounts and small-scale volcanoes that are probably erupting, with some influences from the island-arc volcanic region around the South china Sea; and (Ⅲ) a mixed mineral province whose material source includes biogenic minerals, volcanogenic minerals and terrigenous minerals; the last province can be subdivided into a mixed mineral sub-province of the northeastern part of the study area, in which terrigenous minerals are mainly derived from china’s Mainland and do not exceed 17°N, and a mixed mineral sub-province of the southeastern part of the study area, in which terrigenous minerals are derived from Kalimantan and Indochina Peninsula and might be further transported into the deep sea basin through submarine canyons.

关键词： South china Sea Zhongsha Islands light mineral minerals province material provenance