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Regioselective aminohalogenation of β-nitrostyrenes using NCS and NBS as nitrogen/halogen sources

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Science China Chemistry 2010年第1期53卷 140-146页

作者： ZHI SanJun1,2.SUN Hao2.LIN Chen2.ZHANG GuangQian2.LI GuiGen4 & PAN Yi2.3 1 department of Chemistry,Huaiyin Normal university,Huai’an 2.1003,China 2.School of Chemistry and Chemical Engineering,{2. university,{2. 2.0093,China 3 State Key Lab of Coordination Chemistry,{2. university,{2. 2.0093,China 4 department of Chemistry and Biochemistry,Texas Tech university,Lubbock,Texas 79409-1061,USA 1. department of Chemistry Huaiyin Normal University Huai’an 221003 China2. School of Chemistry and Chemical Engineering Nanjing University Nanjing 210093 China4. Department of Chemistry and Biochemistry Texas Tech University Lubbock Texas 79409-1061 USA3. State Key Lab of Coordination Chemistry Nanjing University Nanjing 210093 China

Aminohalogenation reaction of β-nitrostyrenes with N-halosuccinimides(N-chloro and N-bromosuccinimides) has been successfully conducted by using nickel acetate as a catalyst in the presence of potassium carbonate and succinimide as *** reaction was easily performed at room temperature under nitrogen gas protection to give dihalorinaed haloamino products in good to excellent yields(60%-98%).The structure has been confirmed by X-ray crystal structure analysis.

关键词： aminohalogenation vicinal haloamines β-nitrostyrenes NBS NCS

Global existence and blow-up of solutions to a parabolic system with nonlocal sources and boundaries

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Science China mathematics 2007年第9期50卷 1251-1266页

作者： Ling-hua KONG~(1+) Ming-xin WANG~(2.3) 1 department of Applied mathematics,Dalian{2. of Technology,Dalian 11602.,China 2.department of mathematics,Southeast{2.,nanjing 2.0018,China 3 department of mathematics,Xuzhou Normal{2.,Xuzhou 2.1116,China 1. department of Applied mathematics Dalian University of Technology Dalian 116024 China 2. department of mathematics Southeast University Nanjing 210018 China 3. department of mathematics Xuzhou Normal University Xuzhou 221116 China

This paper deals with a semi-linear parabolic system with nonlinear nonlocal sources and nonlocal boundaries. By using super-and sub-solution techniques, we first give the sufficient conditions that the classical solution exists globally and blows up in a finite time respectively, and then give the necessary and sufficient conditions that two components u and ν blow up simultaneously. Finally, the uniform blow-up profiles in the interior are presented.

关键词： parabolic system nonlocal sources nonlocal boundary conditions blow-up set simultaneous blow-up uniform blow-up profile 35K15 35K65

A possible Younger Dryas-type event during Asian monsoonal Termination 3

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Science China Earth Sciences 2006年第9期49卷 982-990页

作者： CHEN Shitao1, WANG Yongjin1, KONG Xinggong1, LIU Dianbing1, CHENG Hai2.& R.L. Edwards2.1. College of Geography Science, nanjing Normal university, Jiangsu Key Laboratory of Environmental Change and Ecological Construction, nanjing 2.0097, China 2. department of Geology and Geophysics, university of Minnesota, Minneapolis MN55455, USA 1. College of Geography Science Nanjing Normal University Jiangsu Key Laboratory of Environmental Change and Ecological Construction Nanjing 210097 China 2. department of Geology and Geophysics University of Minnesota Minneapolis MN 55455 USA

Seven U-Th dates, 560 δ 18O data and microscopic sequences were measured for sta- lagmites from two high-altitude caves in Shennongjia area, Hubei Province. Variations of the de- cadal-resolution stalagmite δ 18O record from Swan Cave (1600 m elevation) reflect large spatial changes in circulation strength and precipitation of Asian monsoon. The evidence comes from a great similarity among the stalagmite δ 18O records from nanjing, Jiangsu Province; Libo, Guizhou Province and here studied area during the last deglaciation, including a part interval of Younger-Dryas event and Bolling-Allerod. A 30-year-resolution stalagmite δ 18O record from Yongxing Cave (1400 m eleva- tion), 70 km away from Swan Cave, reveals a rapid transition of Asian monsoon climate during Ter- mination 3 at about 2.5±5 kaBP. Based on 3 U-Th dates and about 5000 continuous annual bands, a millennial dry episode has been observed during Asian monsoonal Termination 3 from the Yongxing δ 18O profile. With respect to its structure, duration and transition, the dry reversal, as indicated by our stalagmite δ 18O record, generally agrees with the pattern of the YD event well-expressed in the Chi- nese stalagmite δ 18O records. This YD-type event is characterized by a large decrease in δ 18O value as much as 2.30‰, more than half of the δ 18O excursion between glacial/interglacial periods, and lasts 1371±59 a determined by the annual counting chronology. After this event, the monsoon climate shifted abruptly into the interglacial period within 74±4 a. Our data corroborate the view that the re- peated occurrence of YD-type event was not an “accident”, possibly resulted from the coupling of ice-sheet and oceanic/atmospheric circulations.

关键词： stalagmite, Termination 3, Asian monsoon, YD-type event, Shennongjia, Hubei Province.

Two-dimensional Riemann problems of simplified Euler equation

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Chinese Science Bulletin 1998年第6期43卷 441-444页

作者： YANG Xiaozhou 1,2.and HUANG Feimin+1 1. Institute of Applied mathematics, Chinese Academy of Sciences, Beijing 100080, China 2. department of mathematics, Shantou{2., Guangdong 515063, China Institute of Applied mathematics Chinese Academy of Sciences Beijing China department of mathematics Shantou University Guangdong China

The two-dimensional Riemann problem of simplifed Euler equation is discussed, in which initial value contains two different constant states that are separated by a smooth curve. This problem is a natural description of realistic phenomena, but it is hard to study by conventional idea. So a new approach is proposed. Some new properties about two-dimensional rarefaction wave, shock wave and intermediate state of solutions are disclosed.

关键词： D Riemann problem implicit functions cylindrical surface pencil of cylindrical surface.

Surface pollen and vegetation reconstruction from central and northern mountains of Taiwan

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Chinese Science Bulletin 2003年第3期48卷 291-295页

作者： YU Ge1, LIEW Pingmei2. XUE Bin1 & LI Zhengyi2.1. nanjing Institute of Geography & Limnolog of the Chinese Academof Sciences, nanjing 2.0008, China 2.{2. of Geology, Taiwan university, Taibei 106-17, Taiwan, China nanjing Institute of Geography & Limnolog of the Chinese Academy of Sciences Nanjing 210008 China

Surface pollen from various montane vegeta-tions in Shalixian Mt. and Lepei Mt. of central and northern Taiwan have been explored and analyzed. The pollen datawere used to simulate vegetation types by using the biomisa-tion technique. Computing three matrixes of pollen taxa,plant functional types and combined biomes, vegetation types at each site have been finally defined through the fuzselections of a tie-breaking rule. The results show that sur-face pollen data can simulate the subtropical Castanopsis andCyclobalanopsis forests, alpine warm-temperate Quercus and Quercus-Pinus forests, and alpine temperate/cool-temperate conifers of Tsuga-Picea and Picea-Abies forests. Simulatedelevations of the forests are similar to actual locations of the forests. This study can add vertical surface pollen data forextending investigation of various vegetation types in China, provide PFT schemes and vegetation types in low-latitude and montane areas, and be applied as modern analogues for fossil pollen in order to reconstruct Quaternary

关键词：台湾省北部山区中部山区表层花粉植被重建植被类型

Density-functional formula for strongly correlated systems

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Progress in Natural Science:Materials International 2005年第5期15卷 395-401页

作者： WANG Huaiyu1*, HAN Rushan2.and CHEN Nanxian1(1. department of Physics, Tsinghua university, Beijing 100084, China 2. department of Physics, Peking university, Beijing 100871, China) department of Physics Tsinghua University Beijing 100084 China department of Physics Peking University Beijing 100871 China

Density functional method is applied for strongly correlated systems. Based on the assumption that the systems are composed of electrons in singly-occupied orbitals and those in doubly-occupied orbitals, a set of self-consistent equations are obtained by standard variation procedure. The equations consist of two parts. One part is to solve the wave functions of the electrons in singly-occupied orbitals and the other is to solve the wave functions of the electrons in doubly-occupied orbitals. The physical meanings of the terms appearing in the equations are discussed.

关键词： density-functional theory strongly correlated systems doubly-occupied orbital two-particle wave function self-consistent equations.

A new definition of restricted Lie superalgebras

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Chinese Science Bulletin 2000年第4期45卷 316-321页

作者： WANG Ying & ZHANG Yongzheng1. department of mathematics, Harbin Institute Technology, Harbin 150001, China {2., Northeast Normal university, Changchun 13002., China department of mathematics Harbin Institute Technology Harbin China department of mathematics Northeast Normal University Changchun China

A new definition of restricted Lie superalgebras has been given; some important results on the representation theory of restricted Lie superalgebra have been obtained.

关键词： restricted Lie superalgebra p-mapping p-semilinear mapping α-representation.

Asymptotic bound on binary self-orthogonal codes

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Science China mathematics 2009年第4期52卷 631-638页

作者： DING Yang department of mathematics, Southeast{2., nanjing 2.0096, China 1. department of mathematics Southeast University Nanjing 210096 China

We present two constructions for binary self-orthogonal codes. It turns out that our constructions yield a constructive bound on binary self-orthogonal codes. In particular, when the in-formation rate R = 1/2. by our constructive lower bound, the relative minimum distance δ≈ 0.0595 (for GV bound, δ≈ 0.110). Moreover, we have proved that the binary self-orthogonal codes asymptotically achieve the Gilbert-Varshamov bound.

关键词： algebraic geometry codes concatenated codes Gilbert-Varshamov bound Reed-Muller codes self-dual basis self-orthogonal codes 11T71

Probing proton halo of the exotic nucleus ^(2.)S by elastic electron scattering

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Science China(Physics,Mechanics & Astronomy) 2004年第1期47卷 42-51页

作者： WANG Zaijun1 & REN Zhongzhou1’2.1. department of Physics, nanjing university,{2. 2.0008, China 2. Center of Theoretical Nuclear Physics, National Laboratory of Heavy-Ion Accelerator at Lanzhou, Lanzhou 730000, China Correspondence should be addressed to Ren Zhongzhou (email: zren@*** zren99@***) Received June 16, 2.03 1. department of Physics Nanjing University 210008 Nanjing China 2. Center of Theoretical Nuclear Physics National Laboratory of Heavy-Ion Accelerator at Lanzhou 730000 Lanzhou China

Elastic electron scattering on the exotic light nucleus 2.S is investigated in the plane wave Born approximation. The variation of the squared form factors of 2.S with momentum transfer is compared with that of 32.. It is found that the behavior of the form factors near the second minimum (with a moderate momentum transfer) is sensitive to the alteration of the charge density distribution of halo protons in 2.S. This indicates that elastic electron scattering can be a good probe of the structure of proton-halo nuclei.

关键词： elastic electron scattering, cross section, form factor, proton-halo nucleus.