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Large-scale Purification and Acute Toxicity of Hygromycin B PhoSphotransferase

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Biomedical and Environmental Sciences 2009年第1期22卷 22-27页

作者： QIN ZHUO,JIAN-HUA PIAO,YUAN TIAN,JIE XU,AND XIAO-GUANG YANG~2 Institutefor Nutrition and Food Safety,Chinese Centerfor Disease Control and Prevention, Beijing 100050,china Institute for Nutrition and Food Safety Chinese Center for Disease Control and Prevention Beijing 100050 China

Objective To provide the acute toxicity data of hygromycin B phosphotransferase （HPT） using recombinant protein purified from E. coli. Methods Recombinant HPT protein was expressed and purified from E. coli. To exclude the potential adverse effect of bacteria protein in recombinant HPT protein, bacterial control plasmid was constructed, and bacteria control protein was extracted and prepared as recombinant HPT protein. One hundred mice, randomly assigned to 5 groups, were administrated 10 g/kg, 5 g/kg, or 1 g/kg body weight of HPT or 5 g/kg body weight of bacterial control protein or phosphate-buffered saline （PBS） respectively by oral gavage. Results All animals survived with no significant change in body weight gain throughout the study. Macroscopic necropsy examination on day 15 revealed no gross pathological lesions in any of the animals. The maximum tolerated dose （MTD） of HPT was 10 g/kg body weight in mice and could be regarded as nontoxic. Conclusion HPT protein does not have any safety problems to human health.

关键词： Hygromycin B phosphotransferase Selectable marker Acute toxicity Safety assessment

Julia sets and complex singularities in diamond-like hierarchical Potts models

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Science china.Mathematics 2005年第3期48卷 388-412页

作者： QIAO Jianyong Center of Mathematics China University of Mining & Technology Beijing 100083 China

We study the phase transition of the Potts model on diamond-like hierarchical lattices. It is shown that the set of the complex singularities is the Julia set of a rational mapping. An interesting problem is how are these singularities continued to the complex plane. In this paper, by the method of complex dynamics, we give a complete description about the connectivity of the set of the complex singularities.

关键词： Julia set, phase transition, iteration, rationalmapping.

L^p-boundedness of multilinear oscillatory singular integrals with Calderón-Zygmund kernel

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Science china.Mathematics 2002年第2期45卷 196-213页

作者：陆善镇燕敦验 Department of Mathematics Beijing Normal University Beijing 100875 China Institute of Mathematics Acad. of Math. and System Sciences Chinese Academy of Sciences Beijing 100080 China

LP-boundedness is obtained for a class of multilinear oscillatory singular integrals with CalderonZygmund kernel.

关键词： multilinear oscillatory integrals, Calderon-Zygmund kernel, BMO space.

On Fatou sets concerning Yang-Lee theory

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Science china.Mathematics 2005年第4期48卷 433-447页

作者： QIAO Jianyong Center of Mathematics China University of Mining and Technology Beijing100083 China

The sets of the points corresponding to the complexphases of the Potts model on the diamond hierarchcal lattice arestudied. These sets are the Fatou sets of a family of rationalmappings. The topological structures of ... 详细信息

关键词： Fatou set, phase transition, iteration, rational mapping.

Deep learning characterization of rock conditions based on tunnel boring machine data

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Underground Space 2023年第5期12卷 89-101页

作者： Xu Li Min Yao Ji-dong Yuan Yu-jie Wang Peng-yu Li Key Laboratory of Urban Underground Engineering of Ministry of Education Beijing Jiaotong UniversityBeijing 100044China School of Computer and Information Technology Beijing Jiaotong UniversityBeijing 100044China china.Institute of Water Resources and Hydropower Research Beijing 100048China china.Railway Engineering Equipment Group Co. Ltd.Zhengzhou 450000China

Rock condition perception based on tunnel boring machine(TBM)data is of great importance for not only ensuring tunnel boring safety but also improving construction efficiency.The prediction of TBM boring responses(i.e.,torque and total thrust of the cutterhead)largely determines the reliability of rock condition perception.In this paper,a new architecture of a two-dimensional convolutional neural network(2D-CNN)with a dual-input strategy is proposed to predict the TBM responses.The TBM Lot 3 of the Yinsong project in Jilin province,china.is taken as the case study in this paper.Two types of models that follow different learning strategies are compared:one is defined as the point model,which only learns data of the stable phase,and the other is defined as the line model,which learns data from both the loading and stable boring phases.The line model is further improved by the weighted loss function method.The results indicate that the strategy of learning data from both the loading phase and stable boring phase and increasing the weight of samples from the stable phase is shown to be optimal in predicting TBM boring responses.In terms of learning strategies,the line model can learn the influence of active control parameters on passive response parameters,but the point model cannot.In terms of machine learning algorithms,2D-CNN has the best performance,with R2 values of 0.865 and 0.923 for torque and total thrust,respectively.The proposed line model can overcome the problem that the traditional model failed to learn the influence of control parameters.Such a model can provide a solid base for the timely optimization of the control parameters in TBM boring process.

关键词： TBM Rock condition perception 2D-CNN Weighted loss function Line model

Preparation of a self-humidifying membrane electrode assembly for fuel cell and its performance analysis

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Science china.Physics,Mechanics & Astronomy) 2003年第5期46卷 501-508页

作者：王诚毛宗强徐景明谢晓峰杨立寨 Institute of Nuclear Energy Technology Tsinghua University Beijing 100084 China

A novel nano-porous material SiO2-gel was prepared. After being purified by H2O2, then protonized by H2SO4 and desiccated in vacuum, the SiO2-gel, mixed with Nafion solution, was coated between an electrode and a solid electrolyte, which made a new type of self-humidifying membrane electrode assembly. The SiO2 powder was characterized by FTIR, BET and XRD. The surface of the electrodes was characterized by SEM and EDS. The performances of the self-hu- midifying membrane electrodes were analyzed by polarization discharge and AC impedance under the operation modes of external humidification and self-humidification respectively. Experimental results indicated that the SiO2 powder held super-hydrophilicity, and the layer of SiO2 and Nafion polymer between electrode and solid electrolyte expanded three-dimension electrochemistry reaction area, maintained stability of catalyst layer and enhanced back-diffusion of water from cathode to anode, so the PEM Fuel cell can generate electricity at self-humidification mode. The power density of single PEM fuel cell reached 1.5 W/cm2 under 0.2 Mpa, 70℃ and dry hydrogen and oxygen.

关键词： fuel cell, proton exchange membrane, water management, self-humidifying, silica gel.

Weighted Boundedness for a Class of Rough Multilinear Operators

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Acta Mathematica Sinica,English Series 2001年第3期17卷 517-526页

作者： Yong DING Shan Zhen LU Department of Mathematics,Beijing Normal University,Beijing 100875,P.R.china.E-mail:dingy@*** lusz@*** Department of Mathematics Beijing Normal University Beijing 100875 P. R. China

In this paper we give the (L^p(ω~p),L^q(ω~q)) boundedness for a class of multilinear operators, which is similar to the higher-order commutator for the rough fractional integral.In our results the kernel function is... 详细信息

关键词： Multilinear operator Fractional integral Rough kernel BMO A(p,q) weight

WEIERSTRASS REPRESENTATION FORSURFACES WITH PRESCRIBED NORMALGAUSS MAP AND GAUSS CURVATURE IN H^3

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Chinese Annals of Mathematics,Series B 2004年第4期25卷 567-586页

作者： SHISHUGUO InstituteofMathematics FudanUniversityShanghai200433China.

The author obtains a Weierstrass representation for surfaces with prescribed normal Gauss map and Gauss curvature in H3. A differential equation about the hyperbolic Gauss map is also obtained, which characterizes the relation among the hyperbolic Gauss map, the normal Gauss map and Gauss curvature. The author discusses the harmonicity of the normal Gauss map and the hyperbolic Gauss map from surface with constant Gauss curvature in H3 to S2 with certain altered conformal metric.Finally, the author considers the surface whose normal Gauss map is conformal and derives a completely nonlinear differential equation of second order which graph must satisfy.

关键词：双曲空间高斯映射调和映射 Weierstrass表示曲率

Transformations and non-degenerate maps

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Science china.Mathematics 2005年第Z1期48卷 195-205页

作者： LI Baokui & WANG Yuefei Institute of Mathematics, Academy of Mathematics and System Sciences, Chinese Academy of Sciences, Beijing 100080, china.Graduate School, Chinese Academy of Sciences, Beijing 100080, china Institute of Mathematics Academy of Mathematics and System Sciences Chinese Academy of Sciences Beijing China Graduate School Chinese Academy of Sciences Beijing China

We shall prove the equivalences of a non-degenerate circle-preserving map and a M(o)bius transformation in ^Rn, of a non-degenerate geodesic-preserving map and an isometry in Hn of a non-degenerate line-preserving map and an affine transformation in Rn. That a map is non-degenerate means that the image of the whole space under the map is not a circle, or geodesic or line respectively. These results hold without either injective or surjective, or even continuous assumptions, which are new and of a fundamental nature in geometry.

关键词： M(o)bius transformation, circle-preserving map, non-degenerate map.