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Computational properties of a new horizontal staggered grid

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Science China Earth sciences 2005年第9期48卷 1559-1568页

作者： LIU YudiState Key Laboratory of Numerical Modeling for atmospheric sciences and Geophysical Fluid Dynamics, institute of atmospheric Physics, Chinese Academy of sciences, Beijing 100029, China institute of meteorology, PLA University of Science and Technology, nanjing 211101, China 1. State Key Laboratory of Numerical Modeling for atmospheric sciences and Geophysical Fluid Dynamics Institute of Atmospheric Ph Chinese Academy of Sciences 100029 Beijing China 2. institute of meteorology PLA University of Science and Technology 211101 Nanjing China

This paper presents a new horizontal staggered grid (LE grid), which defines h at a gridpoint, and both u and v at the same mid-gridpoint along the x and y directions. A general method is used to deduce the dispersion relationships of describing inertia gravity waves on LE grid and Arakawa A―E grids, which are then compared with the analytical solution (AS) in re- solved or under-resolved cases, using two-order central difference or four-order compact differ- ence scheme from the frequency and group velocity. Results show that in both resolved and under-resolved cases, no matter whether two-order central difference or four-order compact dif- ference scheme is used, the frequency and group velocity discrete errors on LE grid in describing inertia gravity waves are smaller than those of Arakawa A―E grids. At the same time, it is only on LE or Arakawa grid C that the employment of a compact difference scheme of higher difference precision can improve their accuracy in describing inertia gravity waves. However, as for the other four grids (Arakawa A,B,D and E), when the difference precision increases, the accuracy of simulating inertia gravity waves decreases.

关键词： horizontal staggered grid, inertia gravity wave, LE grid, Arakawa A-E grid, compact difference scheme, central difference.

New progress of lake sediments and environmental changes research in China

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Chinese Science Bulletin 1999年第19期44卷 1744-1754页

作者： WANG Sumin and ZHANG ZhenkeLaboratory of Lake Sediment and Environment, nanjing institute of Geography and Limnology, Chinese Academy of {3. , nanjing 210008, China department of Geography and Oceanology, nanjing University , nanjing 210093., China Laboratory of Lake Sediment and Environment Nanjing Institute of Geography and Limnology Chinese Academy of Sciences Nanjing China department of Geography and Oceanology Nanjing University Nanjing China

Environmental change recorded by lake sediments is one of the important branches of the past global changes study. The new progress of lake sediments and environmental changes in China since the late 1980s has been comprehensively discussed. The highlights emphasized are Asian paleomonsoon migration reflected by lake level fluctuation, uplift of the Qinghai-Xizang Plateau recorded by lacustrine sediments, saltlake sediments and

关键词： lake sediments environmental change.

Distributed modeling of the beginning and ending dates and durations of limited temperatures over the rugged terrain of Chongqing

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Progress in Natural Science:Materials International 2009年第12期19卷 1739-1746页

作者： Xinfa Qiu~a,Guoping Shi~a,Yan Zeng~(b,*),Zongya Bian~a,Jingmei Wei~c a department of GIS,School of Remote Sensing,nanjing University of Information Science & Technology,nanjing{4.,China b Jiangsu institute of meteorological sciences,nanjing 210008,China c Jinling College,nanjing University,nanjing 210089,China [a]department of GIS School of Remote Sensing Nanjing University of Information Science & Technology Nanjing 210044 China [b]Jiangsu institute of meteorological sciences Nanjing 210008 China [c]Jinling College Nanjing University Nanjing 210089 China

A physically based empirical model was established for the beginning and ending dates(BED) of limited *** used were daily mean temperatures from 3.0}conventional stations in the Chongqing region,measured from 1961 to *** this model in combination with the distributed modeling results of monthly mean temperatures,we developed a method for creating a distributed simulation of the BED and durations of limited temperatures in the rugged terrain of *** distribution maps were generated at a resolution of 100×100 m for the BED and durations of the limited temperatures of 0,10,15 and *** suggest that the distributed model is able to successfully reveal the macroscopic trends and local *** the modeled BED,the mean absolute bias error is 0.6-2.4.d. Cross-validation and case-year tests show mean absolute bias errors of 1.3.2.8 d and 0.7-2.5 d,*** shows that the simulation results are consistent with the field *** implies that the simulations are as good as observations,thus providing a viable technique for simulating mountainous heat resources using conventional meteorological data.

关键词： Distributed modeling Chongqing Limited temperature Beginning and ending date

The reconstruction and interpretations of lake status at 6 ka and 18 ka *** inland mainland Asia

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Chinese Science Bulletin 1998年第14期43卷 1145-1157页

作者： QIN Boqiang 1, SHI Yafeng 1 and YU Ge 2, 3.1. nanjing institute of Geography & Limnology, Chinese Academy of {3., nanjing 210008, China 2. Dynamic Palaeoclimatology, Lund University, PO Box 117, S 221 00, Lund, Sweden 3. department of nanjing institute of Geography & Limnolagy Chinese Academy of Sciences Nanjing China Dynamic Palaeoclimatology Lund University Lund Sweden department of Geology and Ocean sciences Nanjing University Nanjing China

By means of survey of literature through compilations of sedimentological, biogeological and geomorphologic data, the inland lake level changes in arid or semi arid mainland Asia at 6 and 18 ka B.P. have been reconstructed. The results showed that the lakes from western and northwestern Asia were characterized by very high water levels at 18 ka B.P., but low or intermediate water stands at 6 ka B.P. The high lake level in this region was associated with the southward displacement of westerlies, therefore, the extent of the high lake stand indicated the southern flank of westerlies during the glaciation. Conversely, the lakes from the eastern and southern Asia registered comparative low levels at 18 ka B.P. and significantly high one at 6 ka B.P. The lowering of lake level at 18 ka B.P. was caused by the weakened summer monsoon and the high lake level at 6 ka B.P. by the enhanced summer monsoon induced by the enlarged thermal contrast between land and ocean. The extent of high lake levels indicated the northern boundary of monsoon expansion. Between the above two regions, there is a climatic transitional zone in the Central Asia where the lake behavior was close to that in southeastern Asia at 6 ka B.P. but became similar to that in northwestern Asia at 18 ka B.P. Thus this zone became a transitional sector from the monsoon to the westerlies.

关键词： lake status inland mainland Asia westerlies monsoon.

Low-complexity distributed differential spacetime coding scheme for amplify-and-forward cooperative networks

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Science in China(Series F) 2009年第8期52卷 1418-1427页

作者： YU XiangBin1,2, BI GuangGuo3.& XU WeiYe4.1 College of Information Science and Technology, nanjing University of Aeronautics and Astronautics, nanjing 210016, China 2 department of Electronic Engineering, City University of Hong Kong, Hong Kong, China 3.National Mobile Communications Research Laboratory, Southeast University, nanjing 210096, China 4.department of Communication Engineering, nanjing institute of Technology, nanjing 211167, China College of Information Science and Technology Nanjing University of Aeronautics and Astronautics Nanjing 210016 China department of Electronic Engineering City University of Hong Kong Hong Kong China National Mobile Communications Research Laboratory Southeast University Nanjing 210096 China department of Communication Engineering Nanjing Institute of Technology Nanjing 211167 China

By introducing a space-time coding scheme based on amicable orthogonality, we develop a distributed differential space-time coding scheme with the amplify-and-forward （AF） method for wireless cooperative networks. The scheme requires no knowledge of the channel state information at both transmitters and receivers, and effectively decreases the realization complexity due to no channel estimation. Moreover, it has lower decoding complexity and higher coding advantage than the existing scheme, thus avoiding the shortcoming of exponential decoding complexity of some existing schemes. According to the pairwise error probability （PEP） analysis of the system, the power allocations of source and relay terminals are jointly optimized, and as a result, the PEP is minimized, which will provide a helpful guideline for system design. Numerical calculation and simulation results show that the developed scheme is superior to the existing scheme. Moreover, the scheme with optimal power allocation yields obvious performance improvement over that with equal power allocation.

关键词： differential space-time coding cooperative communication amplify-and-forward method power allocation

Covarying modes of the Pacific SST and northern hemispheric midlatitude atmospheric circulation anomalies during winter

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Progress in Natural Science:Materials International 2008年第10期18卷 1261-1270页

作者： Yimin Zhu~(a,b,*) Xiuqun Yang~a Qian Xie~b Yongqiang Yu~c ~a department of A tmospheric Science,nanjing University,nanjing 210093.China ~b{3. of {4.ogy,PLA University of Science and Technology,nanjing 211101,China ~c LASG,institute of atmospheric Physics,Chinese Academy of sciences,Beijing 100029,China department of atmospheric Science Nanjing University Nanjing 210093 China institute of meteorology PLA University of Science and Technology Nanjing 211101 China LASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

The interannual-to-interdecadal relationship between the Pacific sea surface temperature (SST) and the northern hemispheric midlati- tude’s atmosphere represented by the circumpolar vortex was documented with the global oceanic and atmospheric reanalysis data of recent 50 *** covarying modes of the Pacific SST and northern circumpolar vortex anomalies during winter were examined using the sin- gular value decomposition and wavelet analysis *** is the interannual,ENSO-related mode and the other is the interdecadal, North Pacific SST-related mode with a period of around 20 *** two modes exhibit distinct spatial *** the interannual mode,the SST anomaly is characterized by a typical ENSO pattern with the principal signature in the tropical eastern Pacific and secondary one in the central North Pacific,while the atmospheric anomaly is regional,characterized by a Pacific-North American *** the inter- decadal mode,large SST anomaly is located in the central North Pacific,while the atmospheric anomaly is zonally global,associated with the midlatitute’s standing long-wave *** the central North Pacific is colder,the long-wave is stronger,and vice *** investigations suggest that the interdecadal mode could involve an interaction between "two oceans and an atmosphere".

关键词： Sea surface temperature atmospheric circulation ENSO Decadal variability

General gambogic acids inhibited growth of human hepatoma SMMC-7721 cells in vitro and in nude mice

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Acta Pharmacologica Sinica 2004年第6期25卷 67-72页

作者： Qing-long GUO2, Qi-dong YOU3. Zhao-qiu WU, Sheng-tao YUAN4.Li ZHAO department of Physiology, department of Medicinal Chemistry, China Pharmaceutical University, nanjing 210009 3. 4.4. of Materia Medica, Shanghai {3.s for Biological sciences, ChineseAcademy ofsciences, Shanghai 20003., China department of Physiology Department of Medicinal Chemistry China Pharmaceutical University institute of Materia Medica Shanghai Institutes for Biological Sciences Chinese Academy of Sciences Shanghai 200031 China

AIM: To study the inhibitory effect of general gambogic acids (GGA) on transplantation tumor SMMC-7721 in experimental animal model and SMMC-7721 cells in vitro. METHODS: Anti-tumor activity of GGA in the experi- mental transplantation tumor SMMC-7721 was evaluated by relative tumor growth ratio. Cell morphology was observed with inverted microscope and electron microscope. Cell proliferation was measured by MTT assay and the telomerase activity was determined by PCR. RESULTS: In vivo study indicated that GGA (2, 4. and 8 mg/kg, iv, 3.times per week for 3.weeks) displayed an inhibitory effect on the growth of transplantation tumor SMMC- 7721 in nude mice compared with the normal saline group (Pogy of SMMC-7721 cells and inhibited the telomerase activity in SMMC-7721 cells. CONCLUSION: GGA had inhibitory effect on the growth of SMMC-7721, which might be related to its inhibition of telomerase activity.

关键词： gamboge gambogic acid hepatoma SMMC-7721 cells telomerase nude mice

Global dimension and left derived functors of Hom

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Science China Mathematics 2007年第6期50卷 887-898页

作者： Li-xin MAO & Nan-qing DING institute of Mathematics, nanjing institute of Technol{3., nanjing 211167, China department of Mathematics, nanjing University, nanjing 210093. China 1. institute of Mathematics Nanjing Institute of Technology Nanjing 211167 China 2. department of Mathematics Nanjing University Nanjing 210093 China

It is well known that the right global dimension of a ring R is usually computed by the right derived functors of Hom and the left projective resolutions of right R-modules. In this paper, for a left coherent and right perfect ring R, we characterize the right global dimension of R, from another point of view, using the left derived functors of Hom and the right projective resolutions of right R-modules. It is shown that rD(R) ? n (n ? 2) if and only if the gl right Proj-dim M R ? n?2 if and only if Ext n?1(N,M) = 0 for all right R-modules N and M if and only if every (n?2)th Projcosyzygy of a right R-module has a projective envelope with the unique mapping property. It is also proved that rD(R) ? n (n ? 1) if and only if every (n?1)th Proj-cosyzygy of a right R-module has an epic projective envelope if and only if every nth Proj-cosyzygy of a right R-module is projective. As corollaries, the right hereditary rings and the rings R with rD(R) ? 2 are characterized.

关键词： global dimension projective resolution envelope 16E10 16E3. 16E05

Experimental Study on Superficial Sliding of a New Type of Offshore Platform

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China Ocean Engineering 1996年第1期11卷 121-128页

作者： Wang Zhaojing Zhang Ling Senior Engineer, Geotechnical Engineering department, nanjing Hydraulic Research institute, nanjing 210024.Engineer, Geotechnical Engineering department, nanjing Hydraulic Research institute, nanjing 210024 Geotechnical Engineering department Nanjing Hydraulic Research Institute Nanjing 210024

In order to verify the theoretical design and computation of a new type of platform, laboratory model test of the superficial sliding of the platform is carried out. Test results show that the requirement for the stability of the platform can be satisfied, and the API-82 criterion can be met. It is also suggested that, in order to enhance the stability of the platform, a buried- pad with porous holes and a long apron-board should be adopted in the design of the new type of platform.

关键词： superficial sliding model test offshore platform