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Frontal genesis of moisture atmosphere during the early 2008 persistent freezing-rain event in southern China

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Science China Earth Sciences 2010年第3期53卷 454-464页

作者： QIAN WeiHong1 & FU JiaoLan1,2 1 Department of Atmospheric Sciences, School of Physics, Peking University, Beijing 100871, China 2 National Meteorological Center of CMA, Beijing, 100081, China Department of Atmospheric Sciences School of Physics Peking University Beijing China National Meteorological Center of CMA Beijing China

From January 10 to February 2, 2008, a severe and persistent freezing-rain event occurred in southern and southwestern China. Here we use an observational analysis to compare the persistent freezing-rain event in the early 2008 with the winter precipita- tion in the late 2007 over south of the Yangtze River (Jiangnan). The persistent freezing-rain event was directly linked to the activity of quasi-stationary front. The gradient of equivalent temperature (ET) can well indicate the frontal genesis of moist atmosphere (moisture front) and its activity as well as its relationship with precipitation belt. The precipitation types (snow and freezing rains) are related to the vertical structure of moisture front. The inversion profile of ET vertical distribution is a typical synoptic condition that caused the freezing-rain event. The horizontal gradient of ET with a criterion of 10℃ / 100 km, which reflects the accumulation and release of atmospheric energy, can be applied to predict the precipitation 5-10 days in advance.

关键词： freezing-rain event frontal genesis extended-range weather forecast winter Jiangnan

Velocity structure and active fault of Yanyuan-Mabian seismic zone―The result of high-resolution seismic refraction experiment

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Science China Earth Sciences 2008年第9期51卷 1284-1296页

作者： WANG FuYun1↑, DUAN YongHong1, YANG ZhuoXin1, ZHANG ChengKe1, ZHAO JinRen1, ZHANG JianShi1, ZHANG XianKang1, LIU QiYuan2, ZHU AiLan2, XU XiWei2 & LIU BaoFeng1 1 Geophysical Exploration Center, China Earthquake Administration, Zhengzhou 450002, China 2 Institute of Geology, China Earthquake Administration, Beijing 100029, China Geophysical Exploration Center China Earthquake Administration

The authors processed the seismic refraction Pg-wave travel time data with finite difference tomography method and revealed velocity structure of the upper crust on active block boundaries and deep features of the active faults in western Sichuan Province. The following are the results of our investigation. The upper crust of Yanyuan basin and the Houlong Mountains consists of the superficial low-velocity layer and the deep uniform high-velocity layer, and between the two layers, there is a distinct, and gently west-dipping structural plane. Between model coordinates 180-240 km, P-wave velocity distribution features steeply inclined strip-like structure with strongly non-uniform high and low velocities alternately. Xichang Mesozoic basin between 240 and 300 km consists of a thick low-velocity upper layer and a high-velocity lower layer, where lateral and vertical velocity variations are very strong and the interface between the two layers fluctuates a lot. The Daliang Mountains to the east of the 300 km coordinate is a non-uniform high-velocity zone, with a superficial velocity of approximately 5 km/s. From 130 to 150 km and from 280 to 310 km, there are extremely distinct deep anomalous high-velocity bodies, which are supposed to be related with Permian magmatic activity. The Yanyuan nappe structure is composed of the superficial low-velocity nappe, the gently west-dipping detachment surface and the deep high-velocity basement, with Jinhe-Qinghe fault zone as the nappe front. Mopanshan fault is a west-dipping low-velocity zone, which extends to the top surface of the basement. Anninghe fault and Zemuhe fault are east-dipping, tabular-like, and low-velocity zones, which extend deep into the base-ment. At a great depth, Daliangshan fault separates into two segments, which are represented by drastic variation of velocity structures in a narrow strip: the west segment dips westward and the east segment dips eastward, both stretching into the basement. The east margin f

关键词： western Sichuan high-resolution seismic refraction active fault velocity structure of the upper crust

Heat treatment of novel low-carbon multi-alloyed anti-wear marine steel

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Progress in Natural Science:Materials International 2011年第3期21卷 254-261页

作者： Jing-hua JIANG~(1,2),Qiu-yue WANG~1,Ai-bin MA~(1,2),Jun SHI~1,Liu-yan ZHANG~1, Hui-dong YANG~(2,3),Fu-min LU~2,Qi ZHOU~2 1.National Engineering Research Center of Water Resources Efficient Utilization and Engineering Safety, Hohai University,Nanjing 210098,China 2.College of Mechanics and Materials,Hohai University,Nanjing 210098,China 3.Department of Mechanical and Aerospace Engineering,North Carolina State University, Raleigh,North Carolina 27695-7919,USA National Engineering Research Center of Water Resources Efficient Utilization and Engineering Safety Hohai University Nanjing 210098 China College of Mechanics and Materials Hohai University Nanjing 210098 China Department of Mechanical and Aerospace Engineering North Carolina State University Raleigh North Carolina 27695-7919 USA

A low-carbon anti-wear steel,multi-alloyed with Si-Cr-Mn-Al-Ni-Mo-（Nb,RE）,was designed for vane pumps of ships. The novel cast steel after various heat treatments was characterized by microstructure observations and mechanical properties measurement in order to achieve an optimal process correlated with good abrasive resistance for a long marine *** scanning calorimetry and hardness analyses deduced a complete austenitizing temperature of 1 000℃,based on the alloying element homogenization and defective structure elimination without grain *** optimal austempering process（austenitized at 1 000℃,quick cooled for holding at 350℃for 1.5 h and then air-cooled to room temperature） produced a uniform mixture structure of fine carbide-free aciculate bainites and few lath martensites,resulting in the tensile strength increase of 34%and impact toughness increase of 50%compared with that of the as-cast *** abrasive wheel tests show that the austempered steel has good wear resistance with a mass-loss rate of 170 mg/（km·cm2） under applied load of 70 N in acidic *** new grade steel （containing anti-corrosion elements of Cr and rare earth） can find wide application in marine engineering,with further enhanced comprehensive properties via melting process improvement.

关键词： abrasive resistance carbide-free bainite marine steel mechanical performance heat treatment

THE EFFECT OF LESSER HIMALAYAN CALC-SILICATES ON THE ^(87)Sr/^(86)Sr OF THE BHOTE KOSI RIVER OF NEPAL—IMPLICATIONS FOR HIMALAYAN WEATHERING, THE MARINE ^(87)Sr/^(86)Sr RECORD AND GLOBAL CLIMATE

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地学前缘 2000年第S1期7卷 396-397页

作者： lee Oliver 1,Nigel Harris 1, Nancy Dise 1,Mike Bickle 2[WT5,5”BX](1 Department of Earth Sciences, Open University, Milton Keynes MK7 6AA, UK 2 Department of Earth Sciences, Cambridge University, Cambridge CB2 3EQ, UK)

During the last 40Ma the marine 87 Sr/ 86 Sr record shows a rapid rise (from 0 7078 to 0 7092) [1] , a trend which has been linked to the Himalayan Orogeny [2] . Indeed, many Himalayan rivers, principally those of the Ganges\|Brahmaputra system, display high 87 Sr/ 86 Sr relative to [Sr] [3] . Theories concerning the cause of this radiogenic Sr enrichment are diverse, but our results suggest that Lesser Himalayan carbonate\|rich lithologies play a vital role [4,5] .The Bhote Kosi originates in Tibet at ca.5km elevation from Tibetan Sedimentary Series (TSS) bedrock, before traversing the High Himalayan Crystalline Series (HHCS) and Lesser Himalaya (LH) of eastern Nepal, joining the Indrawati (at ca.0 6km elevation) to form the Sun Kosi, part of the Ganges system. Carbonates, calc\|silicates and silicates have been identified from the TSS, HHCS and LH, and the Bhote Kosi provides an opportunity to study the influence of these upon fluvial chemistry. Interest is focused on the cause of a rapid rise in riverine Sr\|isotope ratios immediately downstream of the Main Central Thrust (MCT) and the role of carbonate\|rich lithologies exposed in this section. Similar lithologies are lacking in the catchment of a second Nepalese river system, the Lantang Khola—Trisuli, sampled during the same period, and used as a baseline indicator for the effect of LH carbonates on the dissolved load of the Bhote Kosi.

关键词： weathering strontium isotopes Himalayan rivers carbonates

Aoyitake plagiogranite in western Tarim Block, NW China: Age, geochemistry, petrogenesis and its tectonic implications

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Science China Earth Sciences 2006年第11期49卷 1121-1134页

作者： ZHANG Chuanlin1,2, YU Haifeng3, YE Haimin2, ZHAO Yu2 & ZHANG Dongsheng4 1. Key Laboratory of Isotope Geochronology and Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China 2. Nanjing Institute of Geology and Mineral Resources, Nanjing 210016, China 3. Tianjin Institute of Geology and Mineral Resources, Tianjin 300170, China 4. The 2nd Regional Geological Investigation Party, Xinjiang Bureau of Geology and Mineral Resources, Changji 831100, China Key Laboratory of Isotope Geochronology and Geochemistry Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou China Nanjing Institute of Geology and Mineral Resources Nanjing China Tianjin Institute of Geology and Mineral Resources Tianjin China The 2nd Regional Geological Investigation Party Xinjiang Bureau of Geology and Mineral Resources Changji China

SHRIMPP U-Pb zircon age and geochemical and Nd isotopic data are reported for the Aoyitake plagiogranite in western Tarim Block, NW China. The plagiogranite intruded the Middle Pro- terozoic and Lower Carboniferous with an exposure area of ca. 60 km2 and crystallized at 330.7±4.8 Ma. Rock types mainly include tonalite, trondhjemite and minor amounts of diorite and quartz-diorite. Feldspars in the rocks are dominated by oligoclase-andesine, and minor perthite observed locally. The granites are sodic with Na/K ratios (molar) between 4 and 87. Total REE (50-220 ppm) show a clear positive correlation with SiO2. There is no LRRE/HREE fractionation (LaN/YbN=0.5-1.5), me- dium negative Eu anomalies (δ Eu=0.3-0.6), high Y content and low Sr/Y ratio (~1.0). These granites exhibit relatively juvenile Nd T2DM model ages of 470 to 580 Ma and positive εNd(331 Ma) values of 6.23 to 7.65. The aforementioned characteristics are similar to those of ocean island or ocean ridge plagiogranites. However, the regional geology, especially its scale, precludes that the plagiogranite pluton was derived directly from fractionational crystallization of mantle-derived basaltic magma. We interpreted that the primary magma of the pluton might be tonalitic in composition generated by ca. 50% partial melting of the juvenile basaltic crust. The primary magma experienced intensive frac- tionational crystallization, and intruded into the middle to upper crusts to form the granite pluton. In combination with the previous regional geological data, it is concluded that the plagiogranite pluton was emplaced within the Tarim Block in respond to the Carboniferous continental rifting along the Tianshan orogenic belt.

关键词： western Tarim, Aoyitake plagiogranite, age, geochemistry, tectonic implications.

Near generalized balanced tournament designs with block sizes 4 and 5

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Science China Mathematics 2009年第9期52卷 1927-1938页

作者： SHAN XiuLing1, 2 1 Department of Mathematics, Beijing Jiaotong University, Beijing 100044, China 2 College of Mathematics and Information Science, Hebei Normal University, Shijiazhuang 050016, China Department of Mathematics Beijing Jiaotong University Beijing China College of Mathematics and Information Science Hebei Normal University Shijiazhuang China

A near generalized balanced tournament design, or an NGBTD(k,m) in short, is a (km+1,k,k-1)-BIBD defined on a (km+1)-set V . Its blocks can be arranged into an m×(km+1) array in such a way that (1) the blocks in every column of the array form a partial parallel class partitioning V\{x} for some point x, and (2) every element of V is contained in precise k cells of each row. In this paper, we completely solve the existence of NGBTD(4,m) and almost completely solve the existence of NGBTD(5,m) with four exceptions.

关键词： near generalized balanced tournament designs frame generalized doubly resolvable packing constructions existence 05B05

Corrosion resistance properties of AZ31 magnesium alloy after Ti ion implantation

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Rare Metals 2007年第2期26卷 142-146页

作者： CHEN Fei ZHOU Hai CAI Suo LV Fanxiu LI Chengming College of Mechanical Engineering Beijing Institute of Petrochemical Technology Beijing 102617 China Materials Science and Engineering School University of Science and Technology Beijing Beijing 100083 China

Magnesium alloys have a wide range of applications in industry; however, their corrosion resistance, wear resistance, and hardness are rather poor, which limit their applications. Ti ion was implanted into the AZ31 magnesium alloy surface by metal vapor vacuum arc （MEVVA） implanter. This metal arc ion source has a broad beam and high current capabilities. The implantation energy was fixed at 45 keV and the dose was at 9×10^17 cm^-2. Through ion implantation, Ti ion implantation layer with approximately 900 um in thickness was directly formed on the surface of AZ31 magnesium alloy, by which its surface property greatly improved. The chemical states of some typical elements of the ion implantation layer were analyzed by means of X-ray photoelectron spectroscopy （XPS）, while the cross sectional morphology of the ion implantation layer and the phase structure were observed by means of scanning electron microscopy （SEM） and X-ray diffraction （XRD）. The property of corrosion resistance of the Ti ion implanted layer was studied by the CS300P electrochemistry corrosion workstation in 3.5% NaCl solution. The results showed that the property of corrosion resistance was enhanced remarkably, while the corrosion velocity was obviously slowed down.

关键词： magnesium alloy ion implantation component distribution corrosion resistance

850nm光纤中1.1km量子密钥分发实验

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物理学报 2001年第8期50卷 1429-1433页

作者：梁创符东浩梁冰廖静吴令安姚德成吕述望中国科学院物理研究所光物理开放实验室北京100080 中国科学院研究生院北京100039

在 8 5 0nm波长完成了一个全光纤量子密钥分发系统原型 .该系统以单光子为信息载体 ,以光纤为量子信道 ,在通信双方建立起共享的密钥 ,从而完成量子密钥的分发 ,其安全性由量子力学基本原理———不确定性原理和量子不可克隆定理所保证 ... 详细信息

在 8 5 0nm波长完成了一个全光纤量子密钥分发系统原型 .该系统以单光子为信息载体 ,以光纤为量子信道 ,在通信双方建立起共享的密钥 ,从而完成量子密钥的分发 ,其安全性由量子力学基本原理———不确定性原理和量子不可克隆定理所保证 .所采取的信息调制方式为相位调制 ,通信协议采取BB84协议 .通信距离为 1.1km ,有效数据传送速率为 3bit s,误码率为

关键词：量子密钥分发 BB84协议单光子光纤量子力学密码学

Calculating soil moisture by remote sensing and analyzing hydrologic cycle process in the Yellow River basin

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Science China(Technological Sciences) 2004年第z1期47卷 1-13页

作者： YANG Shengtian1 & LIU Changming1, 2 1. School of Environmental Sciences, Beijing Normal University, Beijing 100875, China 2. Institute of Geographic Science and Natural Resources Research, Beijing 100101, China School of Environmental Sciences Beijing Normal University Institute of Geographic Science and Natural Resources Research

Based on the AVHRR pathfinder remote sensing data, soil moisture, precipitation and evaporation during the period of 1982—1998, soil moisture of all layers of soil-profile (0—1 m) in the Yellow River basin over the 17 years are calculated by the remote sensing model of calculating soil water. The Yellow River basin is divided into seven subcatchments as control sections at the location of six hydrologic stations (Lanzhou, Toudaoguai, Longmen, Sanmenxia, Huayuankou and Lijin). After calculating soil moisture and obtaining runoff data and precipitation data, the dynamical features of hydrological cycle in the Yellow River basin are analyzed for the period from 1982 to 1988 using water balance method. The conclusions are as follows: It is feasible to calculate the soil water on the macro-scale, in the soil profile with temporal continuity by means of remote sensing and survey in land. Some values of the key water cycle factors in the Yellow River are obtained, which include the annual precipitation of 4000 km3, the evapotranspiration of 3000-3500 km3, and the soil moisture transformation of ?500- 500 km3. Consequently, we analyzed the process of the water cycle in the Yellow River over the 17 years, and the results show that the segment upstream of Lanzhou city is a relatively humid region, and the area of internal waters and the reaches of Shanshan is the most desiccated region. Therefore, the runoff in the depth process is intensive and the runoff-generating process is weak in more arid regions.

关键词： the Yellow River, soil moisture, remote sensing, hydrologic cycle.