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Investigation of natural contamination layer growth on optical substrates

Chinese Physics C 2018年第11期42卷 107-119页

作者： Li Jiang Qiu-Shi Huang Igor V.Kozhevnikov Yi-Yun Yao Jiang-Tao Feng Yu-fei Feng Bin Ma hong-fei jiao hong Chen Zhong Zhang Zhan-Shan Wang Key Laboratory of Advanced Micro-Structured Materials MOE Institute of Precision Optical Engineering School of Physics Science and Engineering Tongji University Shanghai 200092 China Shubnikov Institute of Crystallography of Federal Scientific Research Centre "Crystallography and Photonics" of the Russian Academy of Sciences Leninskiy pr. 59 Moscow 119333 Russia

The surface contamination layer on mirrors can cause significant degradation of the optical performance, which is widely observed in applications, particularly in the fabrication of X-ray focusing telescopes. In this paper, we study the natural contamination layer arising from adsorption precipitation of hydrocarbons or other organic and water molecules in the absence of any external factor. Temporal evolution of the layer formed on super-smooth fused silica, borosilicate glass, and silicon substrates is studied by X-ray reflectometry, atomic force microscopy, and transmission electron microscopy for a one-year period after surface cleaning. The general characteristics of adhesion layer growth are established and discussed. The reconstructed dielectric constant profiles demonstrate that an increase in the adhesion layer thickness, deposited mass and density over time obeys power laws with extremely small exponents. Therefore, the adhesion layer growth is rapid immediately after surface cleaning, with a - 1 nm thick layer formed within the first day on all three substrates studied, while the layer density is low （- 1 g/cm^3）. The layer growth on the fused silica and silicon substrates became very slow in the succeeding days, with only a 1.4-1.5 nm thick layer and 1.2-1.3 g/cm^3 density after one year of storage in air. At the same time, the adhesion layer growth on the glass substrate showed unexpected acceleration about two months after cleaning, so that the layer thickness reached - 2.2 nm after one year of storage. The reason for this effect, which is connected with leaching of the glass, is discussed briefly.

关键词： X-ray telescope surface contamination surface dynamics X-ray reflectometry inverse problem

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Convenient Synthesis of Two Novel Oxazolidines and Primary Research on their Biological Activities

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Chinese Chemical Letters 2006年第7期17卷 891-894页

作者： Ying jiao LI fei YE College of Science Northeast Agricultural University Harbin 150030

Two novel N-dichloroacetyl oxazolidines were synthesized with a simple, mild and convenient method in good yields. The compounds were Characterized by IR, 1^H NMR and elemental analysis. The preliminary biological tes... 详细信息

关键词： Herbicide safener oxazolidines biological activity.

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Studies on a Novel Characteristic Atom-pair Holographic Code Applied to Quantitative Structure-chromatographic Retention Relationship of Organic Compounds

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Chinese Journal of Structural Chemistry 2006年第11期25卷 1337-1342页

作者： ZHOU Peng TIAN fei-fei WANG jiao-Na LI Zhi-Liang College of Chemistry and Chemical Engineering Chongqing University Chongqing 400044 China State Key Laboratory of Chemo/Biosensing and Chemometrics Changsha 410012 China

6 Atomic fragment types of organic compound have been defined, and the multilevel atom-pair frequency matrix has been constructed according to the occurrence number in pairs of atomic fragments with different bond lengths in the molecule. On the basis of them, a novel molecular coding technique： characteristic atom-pair holographic code （CAHC）, is obtained. To some extent, this method exhibits a large number of benefits at the same time. For example, it can calculate 2D molecular topological descriptor easily, operate without difficulty and possess definite physicochemical meaning of 3D molecular structural characterization methods, and may fetch the complicated information of molecule, etc. Therefore, it is appropriate for the study on quantitative structure-property/activity relationship （QSPR/QSAR） of medicines and biological molecules. We attempt in this paper to utilize the method of CAHC to the quantitative prediction of reversed-phase liquid chromatogram （RPLC） retention data of 33 purine derivatives and 24 steroids. The fitting multiple correlation coefficient R2, cross-validated multiple correlation coefficient Q2 and predicted ability Q^2 pred over test set＇s samples of obtained partial least-square （PLS） regression model are respectively 0.990, 0.893 and 0.977, 0.897, 0.941.

关键词： characteristic atom-pair holographic code quantitative structure-chromatographic retention relationship characterization of molecular structure partial least-square regression

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Molecular Mechanisms of Leaf Morphogenesis

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Molecular Plant 2018年第9期11卷 1117-1134页

作者： fei Du Chunmei Guan Yuling jiao State Key Laboratory of Plant Genomics Institute of Genetics and Developmental Biology Chinese Academy of Sciences Beijing 100101 China College of Life Sciences University of Chinese Academy of Sciences Beijing 100049 China These authors contributed equally to this article

Plants maintain the ability to form lateral appendages throughout their life cycle and form leaves as the principal lateral appendages of the stem. Leaves initiate at the peripheral zone of the shoot apical meristem and then develop into flattened structures. In most plants, the leaf functions as a solar panel, where photosynthesis converts carbon dioxide and water into carbohydrates and oxygen. To produce structures that can optimally fulfill this function, plants precisely control the initiation, shape, and polarity of leaves. Moreover, leaf development is highly flexible but follows common themes with conserved regulatory mechanisms. Leaves may have evolved from lateral branches that are converted into determinate, flattened structures. Many other plant parts, such as floral organs, are considered specialized leaves, and thus leaf development underlies their morphogenesis. Here, we review recent advances in the understanding of how threedimensional leaf forms are established. We focus on how genes, phytohormones, and mechanical properties modulate leaf development, and discuss these factors in the context of leaf initiation, polarity establishment and maintenance, leaf flattening, and intercalary growth.

关键词： leaf lateral organ morphogenesis meristem blastozone shoot

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Improvement of contact calculation in spherical discontinuous deformation analysis

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Science China(Technological Sciences) 2017年第5期60卷 765-771页

作者： WANG Long jiao YuYong HUANG GangHai ZHENG fei ZHAO ZhiYe TAN fei State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil Mechanics Chinese Academy of Sciences Department of Civil and Environmental Engineering University of California School of Civil and Environmental Engineering Nanyang Technological University

Discontinuous deformation analysis （DDA） method is a newly developed discrete element method which employs the implicit time-integration scheme to solve the governing equations and the open-close iteration （OCI） method to deal with contact prob- lem, its computational efficiency is relatively low. However, spherical element based discontinuous deformation analysis （SDDA）, which uses very simple contact type like point-to-point contact, has higher calculation speed. In the framework of SDDA, this paper presents a very simple contact calculation approach by removing the OCI scheme and by adopting the maximal displacement increment （MDI）. Through some verification examples, it is proved that the proposed method is correct and effective, and a higher computational efficiency is obtained.

关键词： 3D-DDA spherical element open-close iteration calculation efficiency

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Desulfurization of liquid hydrocarbon fuels via Cu_2O catalyzed photooxidation coupled with liquid–liquid extraction

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Chinese Journal of Chemical Engineering 2018年第7期26卷 1508-1512页

作者： Xiaoming Gao jiao fei Yanyan Shang Feng Fu Department of Chemistry and Chemical Engineering Shaanxi Key Laboratory of Chemical Reaction Engineering Yan'an University

By combining the photochemical reaction and liquid–liquid extraction(PODS), we studied desulfurization of model fuel and FCC gasoline. The effects of air flow, illumination time, extractants, volume ratios of extractant/fuel, and catalyst amounts on the desulfurization process of PODS were analyzed in detail. Under the conditions with the air as oxidant(150 ml·min^(-1)), the mixture of DMF–water as extractant(the volume ratio of extractant/oil of 0.5) and photo-irradiation time of 2 h, the sulfur removal rate reached only 42.63% and 39.54% for the model and FCC gasoline, respectively. Under the same conditions, the sulfur removal rate increased significantly up to79% for gasoline in the presence of Cu_2O catalyst(2 g·L^(-1)). The results suggest that the PODS combined with a Cu_2O catalyst seems to be a promising alternative for sulfur removal of gasoline.

关键词： Desulfurization Photo-oxidative Gasoline Extraction Cu2O Catalyst

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Wire-like nano-polyaniline deposited electrochemically in a reverse micelle electrolyte as a p H sensor

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International Journal of Minerals,Metallurgy and Materials 2015年第10期22卷 1115-1119页

作者： fei Zhao Han-dong jiao Shi-qiang Zhao State Key Laboratory of Advanced Metallurgy University of Science and Technology Beijing

Wire-like polyaniline(PANI) films were successfully electrodeposited onto an indium tin oxide(ITO) substrate using a pulse galvanostatic method(PGM) in a reverse micelle electrolyte. The as-prepared PANI films were electrochemically analyzed by cyclic voltammetry and electrochemical impedance spectroscopy in 1 mol·L-1 HCl O4 solution. It is found that the as-prepared PANI films are highly porous, exhibit the diameters of approximately 100 nm and the lengths exceeding 3 μm, and have favorable electrochemical activities. Furthermore, the as-prepared wire-like PANI films show a good linear relationship of the potentiometric response curve over the p H value range of 3–10 with a slope of 74.13 m V·p H-1 in 0.5 mol·L-1 K2HPO4 basal solutions. The results demonstrate that the prepared wire-like PANI films are promising p H sensors.

关键词： electrodeposition polymers sensors thin films

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Study on the Modern Value of Marxist Responsibility Ethics

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学术界 2014年第4期 249-254页

作者： Chen fei jiao Yuansheng School of Humanities and Social Sciences Xi'an jiaotong University

The theory of Marxist responsibility ethics is based on the survival and development of human beings,having a strong humanistic color. Generally speaking,M arxist responsibility ethics includes the responsibility for human beings,the responsibility for nature and the responsibility for society. As far as the modern value function of M arxist responsibility is concerned,such a theory advocates respecting the natural environment,promoting the construction of ecological civilization,regulating the operation of the public power,strengthening the construction of responsible governments,promoting humanistic care,promoting the development of the principles of the political education in colleges and universities,advocating social responsibilities and encouraging enterprises to shoulder social responsibilities and so on.

关键词：马克思主义道德责任现代价值生态文明建设社会责任自然环境人文色彩价值功能

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The BEM based on conformal Duffy-distance transformation for three-dimensional elasticity problems

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Science China(Technological Sciences) 2020年第12期63卷 2575-2583页

作者： TAN fei LIANG JiaWei jiao YuYong ZHU Shuai LV JiaHe Faculty of Engineering China University of GeosciencesWuhan 430074China

Here,we describe the robust and efficient application of the conventional 3D BEM in solving elasticity problems. We have focused on the precise computation of weakly singular integrals. The conformal Duffy-distance transformation was employed to alleviate near singularities caused from two aspects:(1) the large aspect ratio of elements,i.e.,element shape distortions;and(2)the closeness of element boundaries to field points,i.e.,ill-shaped patches. Then,the rigid body motion method was employed to evaluate strongly singular integrals. Numerical solutions of 3D elastostatic problems demonstrated the high accuracy of the proposed method with coarse meshes and high convergence rates with mesh refinement. Compared with the Duffy transformation and original polar coordinate transformations,the proposed method is insensitive to element shapes.

关键词： singular integrals boundary element method elasticity problems conformal transformation Duffy transformation distance transformation

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Regulation of substrate surface topography on differentiation of mesenchymal stem cells

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Acta Mechanica Sinica 2020年第5期36卷 1158-1169,I0004页

作者： Bo Huo Yang Zhao Xue Bai Qing Sun fei jiao Biomechanics Lab Department of MechanicsSchool of Aerospace EngineeringBeijing Institute of TechnologyBeijing 100081China

Mesenchymal stem pells(MSCs)have been extensively used in the field of tissue engineering and regenerative *** effect of surface properties on the differentiation of MSCs is a very important issue for the design and fabrication of scaffolds or *** review is mainly focused on the morphological or topographic characteristics of cell adhesion substrate,*** area and shape for individual cell,cell density and cell-cell contact for multiple cells,substrate roughnessridge width,micropillar height,nanoparticle diameter and aspect ratio of *** results from different studies were quantitativcly analyzed using comparable or unified parameters and definitions under the specific experimental conditions such as cell source,culture time,induction medium,matrix material and differentiation *** interesting phenomena and properties were discovered by this integrated and systematic analysis,which might give insights into the regulatory mechanism of surface morphology or topography on MSCs differentiation.

关键词： Mesenchymal stem cell Adhesion morphology Surface topography Differentiation Biomaterial

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