检索结果-南通市图书馆

science China Chemistry 2004年第3期47卷 251-256页

作者： JIANG Yinzhi1,2 & HU Weixiao1 1. department of Pharmaceutical science, Zhejiang university of {3., Hangzhou 3.003., China 2. department of Applied Chemistry, Zhejiang Institute of science and {3., Hangzhou 3.003., China 1. department of Pharmaceutical science Zhejiang University of Technology 310032 Hangzhou China 2. department of Applied Chemistry Zhejiang Institute of Science and Technology 310033 Hangzhou China

The reaction of 3.6-di-(3.methyl-pyridin-2-yI)-s-tetrazine (DMPTZ, II) with CeIII salt [Ce(NO3.3.· 6H2O] generates a new ligand, N-(3.methyl-pyridin-2-yl)-formimidoyl-(3.methyl-pyridin-2-yl) hydrazone (L), and forms a new complex: a mononuclear complex [Ce(L)(NO3.2 (H2O)3. · NO3.(III). Crystal data for III: space group P-1, with a = 0.713.(4) nm, b = 1.113.(2) nm, c = 1.4572(3. nm, α= 102.13.2)°, β= 99.81(3.°, γ= 91.10(3.°, Z = 2, V = 1113.6(7) nm3. μ = 2.123.mm?1 and F(000) = 63.. L acts as a tri-dentate chelating ligand in III. There are 10 coordination sites around Ce3. of III, which are respectively occupied by seven oxygen atoms (four from two nitrate anions and three from three H2O molecules) and three nitrogen atoms (all from L). The cerium atom and three chelating nitrogen atoms are coplanar. The mechanism of the metal assisted decomposition is discussed briefly.

关键词： rare earth, complex, crystal structure, synthesize, 3.6-bis (3.methyl-pyridin-2-yl)-s-tetrazine, N-(3.methyl-pyridin- 2-yl)-formimidoyl-(3.methyl-pyridin-2-yl) hydrazone.

The estimation-valued property of B-valued asymptotic martingale

在线全文

学校读者我要写书评

暂无评论

Progress in Natural science:Materials International 2006年第7期16卷 773-776页

作者： KONG Fanliang (department of Mathematics, Harbin university of science and {3., Harbin 150080, China) [a]department of Mathematics Harbin University of Science and Technology Harbin China

In this paper, with the Doob decomposition of B-valued asymptotic martingale, we study the estimation-valued property of B-valued asymptotic martingale in Banach space B, which has the Radon-Nikodym Property and is du... 详细信息

关键词： Banach space asymptotic martingale Doob decomposition uniformly compact bounded variation topological convergence.

DISRUPTION OF CHARGED DUST GRAINS IN COMETARY PLASMA ENVIRONMENTS

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

中国科学院上海天文台年刊 2000年 182-185页

作者： Shi Zhidong Li Zhongyuan Chen Yao (department of earth and space {3., university of {3. and technology of China, hefei 2.0026) (Advanced Center for earth {3. and Astronomy, Third World Academy of {3.)

The equilibrium potential and dust fragmentation criterion of fluffy dust grains in plasma are calculated for comet P/Halley . It is found that the dust grain acquires its largest negative potential and disruptive pro... 详细信息

关键词： comets - plasma - dust - charging

The Effect of Heterogeneity on Rock's Ultrasonic Attenuation and Its Correction

在线全文

学校读者我要写书评

暂无评论

earthquake Research in China 2001年第3期15卷 222-229页

作者： Wang Baoshan, Sun Daoyuan,Li Shengjie, Li Weidong, Shi Xingjue, and Liu Bin department of earth and space {3., university of {3. and technology of China, hefei 2.0026, China department of earth and space {3. University of Science and Technology of China Hefei 230026 China

The effect of Rayleigh scatter caused by the heterogeneity of rocks, on attenuation measurement has been considered adequately. According to the related theory and calculation, we can distinguish the intrinsic attenuation from the scattering attenuation. And we amended the classic spectral ratio method, based on the homogeneous medium hypothesis. Using the improved spectral ratio method, we can obtain Q value within a wider frequency range, so we can eliminate the uncertainty condition in classic spectral ratio, where Q value depends on the frequency range. The frequency shift method has been introduced and improved. Those three methods on one set of data had been applied. The results obtained by using the classic and improved spectral ratio and frequency shift methods fit well.

关键词： Scatter Ultrasonic attenuation Q value Frequency shift Spectral ratio

Chaotic attitude and reorientation maneuver for completely liquid-filled spacecraft with flexible appendage

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2009年第2期25卷 271-277页

作者： B. Yue department of Mechanics, School of science,Beijing Institute of technology, 100081 Beijing, China department of Mechanics School of Science Beijing Institute of Technology 100081 Beijing China

The present paper investigates the chaotic attitude dynamics and reorientation maneuver for completely viscous liquid-filled spacecraft with flexible appendage. All of the equations of motion are derived by using Lagrangian mechanics and then transformed into a form consisting of an unperturbed part plus perturbed terms so that the system＇s nonlinear characteristics can be exploited in phase space. Emphases are laid on the chaotic attitude dynamics produced from certain sets of physical parameter values of the spacecraft when energy dissipation acts to derive the body from minor to major axis spin. Numerical solutions of these equations show that the attitude dynamics of liquid-filled flexible spacecraft possesses characteristics common to random, non- periodic solutions and chaos, and it is demonstrated that the desired reorientation maneuver is guaranteed by using a pair of thruster impulses. The control strategy for reorientation maneuver is designed and the numerical simulation results are presented for both the uncontrolled and controlled spins transition.

关键词： Nonlinear attitude dynamics Attitude reorientation maneuver Control strategyLiquid-filled spacecraft

Monitoring of rice crop using ENVISAT ASAR data

在线全文

学校读者我要写书评

暂无评论

science China earth sciences 2006年第7期49卷 755-763页

作者： DONG Yanfang1, 2, SUN Guoqing1,3.& PANG Yong4 1. State Key Laboratory of Remote Sensing science, Institute of Remote Sensing Applications, Chinese Academy of sciences, Beijing 100101, China 2. Graduate university of Chinese Academy of sciences, Beijing 10003., China 3. department of Geography, university of Maryland, College Park, MD 20742, USA 4. Forest Remote Sensing Lab, Research Institute of Forest Resource and Information technology, Chinese Academy of For-estry, Beijing 100091, China 1. State Key Laboratory of Remote Sensing science Institute of Remote Sensing Applications Chinese Academy of Sciences Beijing 100101 China 2. Graduate university of Chinese Academy of sciences Beijing 100039 China 3. department of Geography University of Maryland College Park MD 20742 USA 4. Forest Remote Sensing Lab Research Institute of Forest Resource and Information Technology Chinese Academy of Forestry Beijing 100091 China

Because of the cloudy conditions during the rice growth period, rice is one of the agri-cultural crops most suited to monitoring with the SAR instruments. Backscatter response measured by SAR is correlated with rice conditions, including height, density, biomass and structure, which are variable at different growing stages. In this paper, multi-date ENVISAT ASAR Alternating Polarization Mode (APMode) imageries were acquired during the rice crop growing cycle. At the same time, the rice parameters were measured in field. A continuous canopy model was used to compute the back-scattering from rice fields during the growth cycle, and the relationship between rice parameters and radar backscattering coefficients from both ASAR and modeling was analyzed. The effects of polari-zation, incidence angle and polarization on radar backscattering coefficients were analyzed. It was found that simulated radar backscatter has similar trends as ASAR data. This will be meaningful for the further research of rice parameters estimation from ASAR data. Different features show signifi-cantly different signatures in ASAR images and they follow some certain laws, so rice area can be accurately mapped by using multi-temporal SAR images, then rice yield can be estimated.

关键词： rice, ASAR, radar backscattering, model.

Multi-isotopic system geochronology of low temperature eclogite from Huangzhen,Southern Dabie Terrain

在线全文

学校读者我要写书评

暂无评论

science China earth sciences 2004年第10期47卷 931-942页

作者： CHEN Daogong1, E. Deloule2, CHENG Hao1, XIA Qunke1 & WU Yuanbao1 1. School of earth and space sciences, {3. of science and technology of China, hefei 2.0026, China 2. CRPG-CNRS Nancy, 54501, France 1. School of earth and space sciences University of Science and Technology of China 230026 Hefei China 2. CRPG-CNRS 54501 Nancy France

Zircon U-Pb thermal ionization mass-spectrometer (TIMS) and secondary ion mass-spectrometer (SIMS) dating, mica and amphibole 40Ar-3.Ar dating and mineral Sm-Nd isotopic compositions of Huangzhen low temperature eclogite and country granitic gneiss are carried out. The zircon U-Pb weighted average SIMS age is (23..6?9.7) Ma for one eclogite. The mica 40Ar-3.Ar isochron age is (23..6?2.1) Ma and the lowest plateau age is (221.7?2.4) Ma from same sample. U-Pb TIMS concordant ages from other eclogite zircons are from (221.3.1.4) Ma to (222.5?2.3. Ma. U-Pb SIMS low intercept age from country granitic gneiss is (221?3.) Ma. The retrograde amphibole 40Ar-3.Ar isochron age is (205.9?1.0) Ma. Except for mica, which may contain excess 40Ar, all the ages represent peak and retrograde metamorphism of low temperature eclogites. It is indicated that the Huangzhen low temperature eclogites differ from Xiongdian low temperature eclogites of north of the Northern Dabie Terrain in metamorphic ages. Huangzhen low temperature eclogites share one coherent HP-UHP terrain with high temperature eclogites from Southern Dabie Terrain and they may have differences in subduction depth and cooling rates during exhumation.

关键词： low temperature eclogite, multi-isotopic dating, HP-UHP metamorphism, Dabieshan.

The deformation pattern and fault rate in the Tianshan Mountains inferred from GPS observations

在线全文

学校读者我要写书评

暂无评论

science China earth sciences 2008年第8期51卷 1064-1080页

作者： YANG ShaoMin1,2, LI Jie1,3.& WANG Qi2,1 1 Research Center of space science and technology, China {3. of Geosciences, Wuhan 43.074, China 2 Institute of Seismology, China earthquake Administration, Wuhan 43.071, China 3.earthquake Administration of Xinjiang Uygur Autonomous Region, Urumqi 83.011, China 1. Research Center of space science and technology China University of Geosciences Wuhan 430074 China 2. Institute of Seismology China Earthquake Administration Wuhan 430071 China 3. earthquake Administration of Xinjiang Uygur Autonomous Region Urumqi 830011 China

Based on GPS measurements conducted from 1992 to 2.06, we present the current crustal movement velocity field for approximately 400 sites in the Tianshan Mountains and their adjacent areas, and estimate slip rates on the major faults using a 2-D elastic dislocation model. Our studies show slip rates within the range of 1―4 mm/a on the NW-SE trending strike-slip faults (such as Talas-Fergana fault) in the Tianshan Mountains. We also found the slip rates on the approximately WE-SN trending gently-dipping detachment fault vary from 10―13.mm/a for the southwest Tianshan Mountains to 2―5 mm/a for the eastern Tianshan Mountains, and to 6―12 mm/a for the Kyrgrz Tianshan. The GPS velocity field reveals that the total convergence is not uniformly distributed across the Tianshan Mountains, with 80%―90% of the N-S shortening absorbed along the southern and northern edges, and relatively little deformation accommodated within the interior. This first-order feature of strain pattern is explained best by underthrusting of adjacent blocks beneath the Tianshan Mountains along a basal detachment fault. We found the occurrence of historical M7―8 earthquakes somewhere in the locked ramp that connects the creeping and locking segments of the detachment, thereby resulting in elastic strain concentration and accumulation around it. The elastic strain confined in the upper crustal layer above the detachment ultimately releases through infrequent great earthquakes in the Tianshan Mountains, resulting in considerable folding and faulting at their margins. The Tianshan Mountains propagated outward and rose progressively as a wedge-shaped block.

关键词： Tianshan Mountains GPS slip rates tectonic deformation

Oxidation Experiment of Natural Megacrystal Ch'nopyroxene: Implications for Assignment of Mossbauer Spectra

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2001年第1期 51-58页

作者： ZHI Xiachen, CHEN Pengdepartment of earth and space {3.s, university of {3. and technology of China Laboratory of Chemical Geodynamics, USTC Advanced Research Center for earth {3. and Astronomy in USTC, Third World Academy of {3., hefei 2.0026 LIN Chengzhong, CHEN Shuqing, ZHANG GuilanInstitute of Mineral Resources, Chinese Academy of Geology {3.s, Beijing 10003.LI Yuzhi and LIN Lei Open Laboratory of Structure Analysis, USTC, hefei 2.0026

The Mossbauer spectra of natural megacrystal clinopyroxene are usually fitted by 4 sets of symmetric doublets, A-A', B-B', C-C' and D-D', respectively, in terms of increasing Qs value in literature. But the assignments of those doublets are quite different, except the D-D' doublet assigned to Fe3. at the lattice site Ml in previous papers. Particularly, the assignment and interpretation of the C-C' doublet are *** oxidation experiments of natural megacrystal clinopyroxene collected from the Hannuoba basalt, North China, were performed under controlled conditions of temperature at 1000℃ and oxygen fugacity of FMQ buffer in 1, 2, 3.and 5 days respectively. The oxidized samples were then measured by X-ray diffraction spectrometry and Mossbauer spectrometry. The oxidation of clinopyroxene is characterized by Fe2+→ Fe3. at Ml under the subsolidus conditions, which is consistent with the increase of the area of the D-D' doublet when the heating time increases. Accordingly, the area of the A-A' and B

关键词： megacrystal clinopyroxene Mossbauer spectrum oxidation experiment anomalous doublet

An algebraic invariant for Jordan automorphisms on B(H):The set of idempotents

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

science China Mathematics 2005年第12期48卷 1585-1596页

作者： CUI Jianlian & HOU Jinchuan department of Mathematical science, Tsinghua university, Beijing 100084, China department of Applied Mathematics, Taiyuan university of technology, Taiyuan 03.024, China department of Mathematics, Shanxi Teachers university, Linfen 041004, China department of Mathematical science Tsinghua University Beijing 100084 China department of Applied Mathematics Taiyuan University of Technology Taiyuan 030024 China department of Mathematics Shanxi Teachers University Linfen 041004 China

Let H be an infinite dimensional complex Hilbert space. Denote by B(H) the algebra of all bounded linear operators on H, and by I(H) the set of all idempo-tents in B(H). Suppose that Φ is a surjective map from B(H) onto itself. If for every λ ∈ {-1,1,2,3.1/2,1/3. and A, B ∈ B(H), A - λB ∈ I(H) (?) Φ(A) - λΦ(B) ∈ I(H), then Φ is a Jordan ring automorphism, i.e. there exists a continuous invertible linear or conjugate linear operator T on H such that Φ(A) = TAT-1 for all A ∈ B(H), or Φ(A) = TA*T-1 for all A ∈ B(H); if, in addition, A-iB ∈ I(H) (?) Φ(A) -ιΦ(B) ∈ I(H), here ι is the imaginary unit, then Φ is either an automorphism or an anti-automorphism.

关键词： Hilbert space operators,Jordan automorphisms,idempotents.