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Strong decays of N~*(153.) in an extended chiral quark model

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Science china(Physics,Mechanics & Astronomy) 2009年第10期52卷 1452-1457页

作者： AN ChunSheng1,2,3.& ZOU BingSong1,2,3.1 Institute of High Energy Physics,chinese academy of sciences,Beijing 100049,{3. 2 Theoretical Physics Center for Science Facilities,chinese academy of sciences,Beijing 100049,{3. 3.graduate University of chinese academy of sciences,Beijing 100049,{3. Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China Theoretical Physics Center for Science Facilities Chinese Academy of Sciences Beijing 100049 China graduate University of chinese academy of {3. Beijing 100049 China

The strong decays of the N*(153.) resonance are investigated in an extended chiral quark model by including the low-lying $ qqqq\bar q $ components in addition to the qqq component. The results show that these five-quark components in N*(153.) contribute significantly to the N*(153.) → Nπ and N*(153.) → Nη decays. The contributions to the Nη decay come from both the lowest energy and the next-tolowest energy five-quarks components, while the contributions to the Nπ decay come from only the latter one. Taking these contributions into account, the description for the strong decays of N*(153.) is improved, especially for the puzzling large ratio of the decays to Nη and Nπ.

关键词： N*(153.) strong decays five-quark components

Simulations for terrestrial planets formation

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Science china(Physics,Mechanics & Astronomy) 2009年第5期52卷 794-803页

作者： ZHANG Niu 1,2 &JI JiangHui 2,3.1graduate University of chinese academy of {3.,Beijing 100049,china 2Purple Mountain Observatory,chinese academy of {3.,Nanjing 210008,china 3.National Astronomical Observatories,chinese academy of {3.,Beijing 100012,china graduate University of chinese academy of {3. Beijing 100049 China Purple Mountain Observatory Chinese Academy of Sciences Nanjing 210008 China National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China

In this paper,the formation of terrestrial planets in the late stage of planetary formation is investigated using the two-planet *** that time,the protostar formed for about 3.Ma and the gas disk *** the model,the perturbations from Jupiter and Saturn are *** of the mass of outer planet,and the initial eccentricities and inclinations of embryos and planetesimals are also *** results show that,terrestrial planets are formed in 50 Ma,and the accretion rate is about 60%-80%.In each simulation,3.4 terrestrial planets are formed inside"Jupiter"with masses of 0.15 -3.6M⊕.In the 0.5-4 AU,when the eccentricities of planetesimals are excited,planetesimals are able to accrete material from wide radial *** plenty of water material of the terrestrial planet in the Habitable Zone may be transferred from the farther places by this *** could also happen a few times between two major planets only if the outer planet has a moderate mass and the small terrestrial planet could survive at some resonances over time scale of 10 8 *** one of our simulations,commensurability of the orbital periods of planets is very ***,a librating-circulating 3.2 configuration of mean motion resonance is found.

关键词： astrophysics exoplanet planetary formation n-body simulation

Debris Flow Hazard Assessment Based on Support Vector Machine

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Wuhan University Journal of Natural sciences 2006年第4期11卷 897-900页

作者： YUAN Lifeng 1, 2 , ZHANG Youshui 3. 1. Institute of Mountain Hazards and Environment, chinese academy of sciences, Chengdu 610041, Sichuan, {3. 2. graduate University of chinese academy of sciences, Beijing 100049, {3. 3. Institute of Geographical sciences and Natural Resources Research, chinese academy of sciences, Beijing 100101, {3. Institute of Mountain Hazards Environment Chinese Academy of Sciences 610041 Chengdu Sichuan China graduate University of chinese academy of {3. 100049 Beijing China Institute of Geographical sciences Natural Resources Research Chinese Academy of Sciences 100101 Beijing China

Seven factors, including the maximum volume of once flow , occurrence frequency of debris flow , watershed area , main channel length , watershed relative height difference , valley incision density and the length ratio of sediment supplement are chosen as evaluation factors of debris flow hazard degree. Using support vector machine （SVM） theory, we selected 259 basic data of 3. debris flow channels in Yunnan Province as learning samples in this study. We create a debris flow hazard assessment model based on SVM. The model was validated though instance applications and showed encouraging results.

关键词： debris flow hazard assessment support vector machine (SVM)

Formal Verification under Unknown Constraints

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Wuhan University Journal of Natural sciences 2005年第1期10卷 43-46页

作者： LI Guang-hui 1,2,3., LI Xiao-wei 2,3.. school of Information Engineering, Zhejiang Forestry College, Hangzhou 3.13.0, Zhejiang, china 2. Institute of Computing Technology, chinese {3. of sciences, Beijing 100080, china 3. graduate school of the chinese {3. of sciences, Beijing 10003., china school of Information Engineering Zhejiang Forestry College Hangzhou 311300 Zhejiang China

We present a formal method of verifying designs with unknown constraints (e.g., black boxes) using Boolean satisfiability (SAT). This method is based on a new encoding scheme of unknown constraints, and solves the corresponding conjunctive normal form (CNF) ***,this method can avoid the potential memory explosion, which the binary decision diagram (BDD) based techniques maybe suffer from, thus it has the capacity of verifying large designs. Experimental results demonstrate the efficiency and feasibility of the proposed method.

关键词： formal verification unknown constraints black box Boolean satisfiability Boolean comparison

Cloning and expression of putative ethylene receptor genes in soybean plant

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Progress in Natural Science:Materials International 2007年第10期17卷 1152-1160页

作者： Xie Zongming1,2,3. Lei Gang1,2, Wuriyanghan Hada1,2, Tian Aiguo1, Zhang Jinsong1 and Chen Shouyi1(1. National Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, chinese academy of sciences, Beijing 100101, {3. 2. graduate school of chinese academy of sciences, Beijing 10003., {3. 3. Xinjiang academy of Agricultural and Reclamation Science, Shihezi 83.000, {3.) National Key Laboratory of Plant Genomics Institute of Genetics and Developmental Biology Chinese Academy of Sciences Beijing 100101 China graduate school of chinese {3. of sciences Beijing 100039 China Xinjiang academy of Agricultural and Reclamation Science Shihezi 832000 China

Ethylene plays important roles in plant growth, development, and stress responses, and ethylene receptors have been identified and studied extensively in various plant species. Here we report the cloning of four ethylene receptor genes from soybean, i.e. GmETR1, GmERS1, GmETR2 and GmEIN4. Construction of the phylogenic tree showed that GmETR1 and GmERS1 belong to subfamily I whereas GmETR2 and GmEIN4 belong to subfamily II. The four ethylene receptor genes showed different tissue-specific expression patterns in roots, stems, leaves, cotyledons, flowers, pods and seeds of soybean. These genes were differentially regulated by various abiotic stresses and plant hormones. The possible roles of the four genes in soybean plant were also discussed.

关键词： abiotic stress expression analysis ethylene receptor plant hormone soybean.

Teleconnection between the Indian summer monsoon onset and the Meiyu over the Yangtze River Valley

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Science china Earth sciences 2008年第7期51卷 1021-1035页

作者： LIU YunYun1,2,3.& DING YiHui2 1 chinese academy of Meteorological sciences, Beijing 100081, {3. 2 National Climate Center, Beijing 100081, {3. 3.graduate University of chinese academy of sciences, Beijing 100049, {3. 1. chinese academy of Meteorological sciences Beijing 100081 China 2. National Climate Center Beijing 100081 China 3. graduate University of chinese academy of {3. Beijing 100049 China

Based on the Indian and chinese precipitation data and the NCEP-NCAR reanalysis circulation data, the relationship between the Indian summer monsoon (ISM) onset and the Meiyu over the Yangtze River Valley has been discussed by the methods of correlation analysis and composite analysis. The results show that the date of ISM onset over Kerala in the southwestern coast of the Indian Peninsula is about two weeks earlier than the beginning of the Meiyu over the Yangtze River Valley. After the outbreak of ISM, the teleconnection mode sets up from the western coast of India via the Bay of Bengal (BOB) to the Yangtze River Valley and southern Japan. It is different both in time and space from the telecon- nection mode which is from the northwest of India via the Tibetan Plateau to northern china. The for- mer mode is defined as the "south" teleconnection of the Asian summer monsoon, forming in the pe- riod of ISM onset; while the latter mode is called the "north" teleconnection, mainly occurring in the Asian monsoon culminant period. During the process of the "south" teleconnection’s formation, the Asian monsoon circulation has experienced a series of important changes: ISM onset, the northward movement of the south Asia high (SAH), the onset vortex occurrence, the eastward extension of the stronger tropical westerly belt, and the northeastward jump of the western Pacific subtropical high (WPSH), etc. Consequently, since ISM sets up over Kerala, the whole Asian continent is covered by the upper SAH after about two weeks, while in the mid- and lower troposphere, a strong wind belt forms from the Arabian Sea via the southern India, BOB and the South china Sea (SCS), then along the western flank of WPSH, to the Yangtze River Valley and southern Japan. With the northward moving of the subtropical jet streams, the upper westerly jet stream and the low level jet have been coupled ver- tically over east Asia, while the Yangtze River Valley happens to locate in the ascending motion

关键词： Indian summer monsoon (ISM) the Meiyu over the Yangtze River Valley teleconnection mode

Environmental characteristics of Mid-Holocene recorded by lacustrine sediments from Lake Daihai, north environment sensitive zone, china

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Science china Earth sciences 2006年第9期49卷 968-981页

作者： SUN Qianli1,2, ZHOU Jie1, SHEN Ji3. CHEN Peng1,2, WU Feng1,2 & XIE Xiuping1,2 1. State Key Lab of Loess and Quaternary Geology, Institute of Earth Environment, chinese academy of sciences, Xi’an 710075, {3. 2. graduate University of chinese academy of sciences, Beijing 10003., {3. 3. Nanjing Institute of Geography and Limnology, chinese academy of sciences, Nanjing 210008, {3. 1. State Key Lab of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences Xi’an 710075 China 2. graduate University of chinese academy of {3. Beijing 100039 China 3. Nanjing Institute of Geography and Limnology Chinese Academy of Sciences Nanjing 210008 China

Climate proxies, such as total organic carbon and nitrogen (TOC, TN), carbonate content (CaCO3., grain-size and pollen of the sediment core retrieved from enclosed Lake Daihai which lies in the north china environment sensitive zone are analyzed to reconstruct the environment evolution of the area based on high-resolution radiocarbon chronology. The results reveal that the TOC and TN contents of the sediments correlate well with pollen percentage and pollen flux variations during the Holocene, and both reach their peak values simultaneously at 6.7―3.5 ka BP (calendar age, 7.6―3.6 ka BP). Since 6.7 ka BP, both the CaCO3.and organic matter contents of the core have simultaneous variations, and their high values also occur during 6.7―3.5 ka BP. While during 9.0―6.7 ka BP (calendar age, 10―7.6 ka BP) relatively lower level of organic matter content and pollen flux corre- spond to the higher level of carbonate content. The above relations suggest that during 6.7―3.5 ka BP, the productivity and effective precipitation were greatly improved in the lake drainage area, and this would probably strengthen the hydrodynamic conditions, enhancing organic matter, pollen and carbonate inputs from terrestrial sources. Such processes would account for the enrichment of both organic matter and carbonate in the sediments. While during 9.0―6.7 ka BP, the lower level of or- ganic matter, pollen flux but high carbonate content show depressed productivity and declined vege- tation coverage. The higher carbonate content at this stage would have probably resulted from the higher evaporation ratio of the lake water under relatively drier climate conditions. Therefore, it is in- ferred that during 6.7―3.5 ka BP, the climate was more humid with abundant rainfalls and vegetation was more flourishing in the Lake Daihai area. This can be seen as Holocene Climate Optimum (HCO). As a result, this has evident discrepancies with the traditional notion that the HCO occurs at Early Holocene or early Mid

关键词： Lake Daihai, Mid-Holocene, lacustrine sediments, environmental characteristics.

Mechanism and Defense on Malicious Code

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Wuhan University Journal of Natural sciences 2005年第1期10卷 83-88页

作者： WEN Wei-ping 1,2,3. QING Si-han 1,2,3.1. Institute of Software, the chinese academy of sciences, Beijing 100080, {3. 2.Engineering Research Center for Information Security Technology, the chinese academy of sciences, Beijing 100080, {3. 3.graduate school of the chinese academy of sciences, Beijing 100080, {3. Institute of Software the Chinese Academy of Sciences Beijing 100080 China

With the explosive growth of network applications, the threat of the malicious code against network security becomes increasingly serious. In this paper we explore the mechanism of the malicious code by giving an attack model of the malicious code, and discuss the critical techniques of implementation and prevention against the malicious code. The remaining problems and emerging trends in this area are also addressed in the paper.

关键词： malicious code attacking model mechanism defense system security network security

Isotopic feature and uranium dating of the volcanic rocks in the Okinawa Trough

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中国科学：地球科学英文版 2006年第4期49卷 375-383页

作者： HUANG Peng1,2, LI Anchun1, HU Ningjing2,3. FU Yongtao1& MA Zhibang4 1. Institute of Oceanology, chinese academy of sciences, Qingdao 266071, {3. 2. graduate school of the chinese academy of sciences, Beijing 10003., {3. 3. Institute of Soil Science, chinese academy of sciences, Nanjing 210008, {3. 4. Institute of Geology and Geophysics, chinese academy of sciences, Beijing 100029, {3. 1. Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China 2. graduate school of the chinese {3. of sciences Beijing 100039 China 3. Institute of Soil Science Chinese Academy of Sciences Nanjing 210008 China 4. Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China

Volcanic rocks from the northern and middle Okinawa Trough were dated by ura- nium-series dating method. Differential fractions using magnetic procedure were designed to separate samples. New report on the ages and isotopic data of rocks in the northern trough (especially black pumice) was discussed. Based on the uranium dates and Sr-Nd isotopic ratio, magmatic evolution process of the Okinawa Trough was noted. Firstly, there have been wide silicic volcanic activities in the Okinawa Trough from late Pleistocene to present, and the volcanic rocks can be divided into three subgroups. Secondly, magma generally came from PREMA source area under the Okinawa Trough. Magmatic evolution in the northern trough was similar to the middle, but different to the south. Finally, volcanic activities indicated that opening of the southern Okinawa Trough did not happen due to the collision between Luson Arc and Eurasian Plate until the early Pleistocene.

关键词： Okinawa Trough, black pumice, uranium-series dating, Sr-Nd isotopic ratio, magmatic evolution.