检索结果-南通市图书馆

Existence of the solutions and the attractors for the large-scale atmospheric equations

在线全文

学校读者我要写书评

暂无评论

Science china Earth Sciences 2006年第6期49卷 650-660页

作者： HUANG Haiyang1 & guo Boling2 1. department of mathematics, beijing normal university, beijing 100875, china 2. Institute of Applied Physics and Computational mathematics, beijing 100080, china 1. department of mathematics Beijing Normal University Beijing 100875 China 2. Institute of Applied Physics and Computational mathematics Beijing 100080 China

In this paper, firstly, the proper function space is chosen, and the proper expression of the operators is introduced such that the complex large-scale atmospheric motion equations can be described by a simple and abstract equation, by which the definition of the weak solution of the atmospheric equations is made. Secondly, the existence of the weak solution for the atmospheric equations and the steady state equations is proved by using the Galerkin method. The existence of the non-empty global attractors for the atmospheric equations in the sense of the Chepyzhov-Vishik’s definition is obtained by constructing a trajectory attractor set of the atmospheric motion equations. The result obtained here is the foundation for studying the topological structure and the dynamical behavior of the atmosphere attractors. Moreover, the methods used here are also valid for studying the other atmospheric motion models.

关键词： atmosphere equations, weak solution, trajectory attractor, global attractor, equilibrium.

Pointwise estimates for the maximal multilinear singular integral operators

在线全文

学校读者我要写书评

暂无评论

Science china mathematics 2005年第12期48卷 1696-1706页

作者： HU guo’en, LI Dengfeng & LU Shanzhen department of Applied mathematics, university of Information Engineering, P. O. Box 1001 -747, Zhengzhou 450002, china College of Mathematical and Information Sciences, Henan university, Kaifeng 475001, china department of mathematics, beijing normal university, beijing 100875, china 1. department of Applied mathematics University of Information Engineering P.O.Box 1001-747 450002 Zhengzhou China 2. College of Mathematical and Information Sciences Henan University 475001 Kaifeng China 3. department of mathematics Beijing Normal University 100875 Beijing China

Two pointwise estimates relating the maximal multilinear singular integral operators and some classical maximal operators are established. These pointwise estimates imply the rearrangement estimate and the BLO(Rn) est... 详细信息

关键词： multilinear singular integral,maximal operator,BMO (Rn),BLO (Rn).

Formation of 3-Arylpyrazolines and 1-Aroylethyl-3-arylpyrazolines via 3-Aroylethylsydnone with HCl in Ethyl Acetate

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 1998年第9期9卷 803-804页

作者： Zhan Bin ZHANG Cheng Lie YIN Yong ren WU (department of Chemistry, beijing normal university, beijing 100875) beijing normal Univ Dept Chem Beijing 100875 Peoples R China

Treatment of 3-aroylethylsydnone 1 with HCl leads to 3-arylpyrazoline 2 or 1-aroylethyl-3-arylpyrazoline 3 under different conditions.

关键词： sydnone pyrazoline hydrolysis

Theoretical studies on the mechanism of α-hydroxy-acid gas-phase elimination process and its substituent effect

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 1997年第4期15卷 313-317页

作者： SONG,Wei-Ping HE,Shao-ren FU,Xiao-Yuandepartment of Chemistry,beijing normal university,beijing 100875.china department of Chemistry Beijing Normal University Beijing 100875 China

The α-hydroxy-acid gas-phase elimination process has been studied theoretically by HF/*** calculated results can be summed up as follows:(1) The elimination process is a stepwise *** the first step,a 3-membered ring intermediate is formed via a 5-membered ring transition state;while the product is formed in the second step via a 3-membered ring transition state.(2) The obtained results of the substituent effect show that the increase of electronic donation of the alkyl groups is favorable for the *** substituents which show the electron-withdrawing inductive effect (e.g.-Cl,-CN,-CF3) are unfavorable for this process.

关键词： α-Hydroxy-acid gas-phase elimination mechanism

A highly sensitive fluorescent HClO probe for discrimination between cancerous and normal cells/tissues

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第6期35卷 417-420页

作者： Linfang Wang Jing Liu Minghao ren Wei guo department of Chemistry Changzhi UniversityChangzhi 046011China School of Chemistry and Chemical Engineering Shanxi UniversityTaiyuan 030006China

Elevated level of hypochlorous acid(HClO)is closely associated with cancer *** HClO level in cancer cells would provide important evidence in either early-stage cancer diagnostics or monitoring of its treatment *** this work,a new pyronine-based fluorescent probe for rapid and sensitive detection of HClO was developed by condensing meso-formyl pyronine(PyCHO)with 2-hydrazinopyridine to form meso-pyridylhydrazone-functionalized pyronine PyHP,PyHP is nonfluorescent due to the excited-state C=N isomerization nonradiative decay,whereas the HClO-triggered formation of meso-triazolopyridyl pyronine PyTP abolishes the C=N isomerization and thus greatly enhances the *** the probe,the cancer cells/tumor were distinguished with high-contrast from normal ones by laser confocal fluorescence imaging,and the tumor-to-normal(T/N)ratios obtained exceed the clinically acceptable threshold of ***,its capability of in vivo imaging tumor was also *** results indicate the potential of PyHP as an effective tool in the early clinical diagnosis of cancers.

关键词： Meso-pyridylhydrazone-functionalized pyronine Meso-substituents Tumor-to-normal(T/N)ratios Fluorescent probes Hypochlorous acid

Difference discrete connection and curvature on cubic lattice

在线全文

学校读者我要写书评

暂无评论

Science china mathematics 2006年第11期49卷 1458-1476页

作者： WU Ke, ZHAO Weizhong & guo Hanying department of mathematics, Capital normal university, beijing 100037, china Institute of Theoretical Physics, Chinese Academy of Sciences, beijing 100080, china 1. department of mathematics Capital Normal University Beijing 100037 China 2. Institute of Theoretical Physics Chinese Academy of Sciences Beijing 100080 China

In a way similar to the continuous case formally, we define in different but equivalent manners the difference discrete connection and curvature on discrete vector bundle over the regular lattice as base space. We deal with the difference operators as the discrete counterparts of the derivatives based upon the differential calculus on the lattice. One of the definitions can be extended to the case over the random lattice. We also discuss the relation between our approach and the lattice gauge theory and apply to the discrete integrable systems.

关键词： discrete connection, discrete curvature, noncommutative calculus, lattice gauge theory, discrete Lax pair.

Fractal structure reconstruction for alumina-silicate refractory fiber and simulation of the thermal conductivity

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2010年第1期19卷 80-86页

作者： XIA Dehong,guo Shanshan,and ren Ling department of Thermal Engineering,university of Science and Technology beijing,beijing 100083,china department of Thermal Engineering University of Science and Technology Beijing Beijing China

In this paper, it is proved that the intemal porous structure of alumina-silicate refractory fiber has fractal characteristics, which is reconstructed by the computer and the reconstructed structure further proved to have fractal characteristics. Based on the reconstructed structure, the network-thermal-resistance model is established to calculate the thermal conductivity of the fiber. It is shown that the calculated results agree well with the previous experimental ones, proving the correctness of the method.

关键词： fractal refractory fiber thermal conductivity

Weighted estimates for commutators of singular integral operators with non-doubling measures

在线全文

学校读者我要写书评

暂无评论

Science china mathematics 2007年第11期50卷 1621-1641页

作者： guo-en HU~1 Da-chun YANG~(2+) Dong-yong YANG~2 1 department of Applied mathematics,university of Information Engineering,Zhengzhou 450002,china 2 School of Mathematical Sciences,beijing normal university,beijing 100875.china department of Applied mathematics University of Information Engineering Zhengzhou 450002 China School of Mathematical Sciences Beijing Normal University Beijing 100875 China

Letμbe a nonnegative Radon measure on R^d which only satisfiesμ(B(x,r))≤C_0r^n for all x∈R^d,r>0,and some fixed constants C_0>0 and n∈(0,d].In this paper,some weighted weak type estimates with A_(p,(log L)~σ)~ρ(μ) weights are established for the commutators generated by Calder■n-Zygmund singular integral operators with RBMO(μ) functions.

关键词： non-doubling measure weight singular integral operator commutator

A COUPLED MODEL OF HYDRODYNAMICS AND WATER QUALITY FOR YUQIAO RESERVOIR IN HAIHE RIVER BASIN

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2008年第5期20卷 574-582页

作者： LIU Xiao-bo PENG Wen-qi HE guo-jian LIU Jing-ling WANG Yu-chun School of Environment Beijing Normal University Beijing 100875 China department of Water Environment China Institute of Water Resources and Hydropower Research Beijing100038 China department of Hydraulic Engineering State Key Laboratory of Hydroscience and Engineering TsinghuaUniversity Beijing 100084 China

In order to simulate the characteristics of hydrodynamic field and mass transport processes in the Yuqiao Reservoir （YQR）, a 2-D coupled model of hydrodynamics and water quality was developed, and the water-quality related state variables in this model included CODMn, TN and TP. The hydrodynamic model was driven by employing observed winds and daily measured flow data to simulate the seasonal water cycle of the reservoir. The simulation of the mass transport and transformation processes of CODMn, TN and TP was based on the unsteady diffusion equations, driven by observed meteorological forcing and external loadings, with the fluxes form the bottom of reservoir and the plant photosynthesis and respiration as internal sources and sinks. A finite volume method and Alternating Direction Implicit （ADI） scheme were used to solve these equations. The model was calibrated and verified by using the data observed from YQR in two different years. The results showed that in YQR, the wind-driven current was an important style of lake current, while the concentration of water quality item was decreasing from east to west because of the external pollutant loadings. There was a good agreement between the simulated and measured values, with the minimal calculation error percent of 0.1% and 2.6% and the mean error percent of 44.0% and 51.2% for TN and TP separately. The simulation also showed that, in YQR, the convection was the main process in estuaries of inflow river, and diffusion and biochemical processes dominate in center of reservoir. So it was necessary to build a pre-pond to reduce the external loadings into the reservoir.

关键词： model simulation Yuqiao Reservoir (YQR) wind driven current water quality