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Diversified calcimicrobes in dendrolites of the Zhangxia Formation, Miaolingian Series(Middle Cambrian) of the North China craton

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Journal of Palaeogeography 2021年第2期10卷 157-181页

作者： Ming-Xiang Me Muhammad Riaz Zhen-Wu Zhang qing-fen meng Yuan Hu School of Earth Sciences and Resources China University of GeosciencesBeijing 100083China State Key Laboratory of Biogeology and Environmental Geology China University of GeosciencesBeijing 100083China State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Chengdu University of TechnologyChengdu 610059China College of Energy Resources Chengdu University of TechnologyChengdu 610059China Centre for Geographical Information System University of the PunjabLahore 54590Pakistan.

As a type of non-laminated microbial carbonates, dendrolites are dominated by isolated dendritic clusters of calcimicrobes and are distinct from stromatolites and thrombolites. The dendrolites in the upper part of the Miaolingian Zhangxia Formation at Anjiazhuang section in Feicheng city of Shandong Province, China, provide an excellent example for further understanding of both growth pattern and forming mechanism of dendrolites. These dendrolites are featured by sedimentary fabrics and composition of calcified microbes as follows.(1) The strata of massive limestones, composed of dendrolites with thickness of more than one hundred meters, intergrade with thick-bedded to massive leiolites, formimg the upper part of a third-order depositional sequence that constitutes a forced regressive systems tract.(2) A centimeter-sized bush-like fabric(shrub) typically produced by calcified microbes is similar to the mesoclot in thrombolites but distinctive from clotted fabrics of thrombolites. This bushlike fabric is actually constituted by diversified calcified microbes like the modern shrub as a result of gliding mobility of filamentous cyanobacteria. Such forms traditionally include: the Epiphyton group(which actually has uncertain biological affinity), the Hedstroemia group which closely resembles modern rivulariacean cyanobacteria,and the possible calcified cyanobacteria of the Lithocodium–Bacinella group.(3) Significantly, dense micrite of leiolite is associated with sponge fossils and burrows, and is covered by microstromatolite. The Lithocodium–Bacinella group is a controversial group of interpreted calcified cyanobacteria in the Cambrian that has also been widely observed and described in the Mesozoic. Therefore, dendrolites with symbiosis of leiolites in the studied section provide an extraordinary example for further understanding of growing style of bush-like fabrics(shrubs) of the dendrolites dominated by cyanobacterial mats. Furthermore, the present research provid

关键词： Calcified microbe Dendrolite Leiolite Epiphyton Lithocodium–Bacinella Cambrian Miaolingian Zhangxia Formation

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随机磁场对静电波驱动的速度扩散的影响

物理学报 1984年第5期 678-683页

作者：仇韵清夏蒙棼北京大学物理系北京大学物理系

随机磁场改变了波与粒子之间的耦合关系。因而使波驱动的速度扩散受到影响。其结果是:波电场的横向分量可以对纵向速度扩散有贡献;ε1情形,扩散系数的共振峰被展宽;ε1情形,扩散系数的振荡效应被削弱。当随机磁场的关联时间与波的特征... 详细信息

随机磁场改变了波与粒子之间的耦合关系。因而使波驱动的速度扩散受到影响。其结果是:波电场的横向分量可以对纵向速度扩散有贡献;ε1情形,扩散系数的共振峰被展宽;ε1情形,扩散系数的振荡效应被削弱。当随机磁场的关联时间与波的特征时间之间相对大小不同时,随机磁场产生影响的具体机制不完全相同,所造成的后果也有差别。对于接近于在垂直方向传播的波,随机磁场对速度扩散的影响一般是重要的。

关键词：静电波相对大小共振峰特征时间纵向速度空间扩散电子运动随机性特征系综差分方程

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单波驱动的过渡粒子效应

物理学报 1988年第4期 666-669页

作者：仇韵清夏蒙棼北京大学物理系北京大学物理系

本文讨论单波在环等离子体中引起的过渡粒子及其有关效应。

关键词：单波扩散流马尔可夫近似尺度结构系综静电波共振线纵向速度粒子数动力学系统

Effects of cooling rate and Al on MnS formation in medium-carbon non-quenched and tempered steels

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International Journal of Minerals,Metallurgy and Materials 2015年第6期22卷 589-597页

作者： meng-long Li Fu-ming Wang Chang-rong Li Zhan-bing Yang qing-yong meng and Su-fen Tao State Key Laboratory of Advanced Metallurgy University of Science and Technology Beijing School of Metallurgical and Ecological Engineering University of Science and Technology Beijing School of Materials Science and Engineering University of Science and Technology Beijing

The effect of Al on the morphology of MnS in medium-carbon non-quenched and tempered steel was investigated at three different cooling rates of 0.24, 0.43, and 200°C·s^-1. The formation mechanisms of three types of MnS were elucidated based on phase diagram information combined with crystal growth models. The morphology of MnS is governed by the precipitation mode and the growth conditions. A monotectic reaction and subsequent fast solidification lead to globular Type I MnS. Type II MnS inclusions with different morphological characteristics form as a result of a eutectic reaction followed by the growth in the Fe matrix. Type III MnS presents a divorced eutectic morphology. At the cooling rate of 0.24°C·s^-1, the precipitation of dispersed Type III MnS is significantly enhanced by the addition of 0.044wt% acid-soluble Al（Als）, while Type II MnS clusters prefer to form in steels with either 0.034wt% or 0.052wt% Als. At the relatively higher cooling rates of 200°C·s^-1 and 0.43°C·s^-1, the formation of Type I and Type II MnS inclusions is promoted, and the influence of Al is negligible. The results of this work are expected to be employed in practice to improve the mechanical properties of non-quenched and tempered steels.

关键词： medium carbon steels cooling rate aluminum content manganese sulfide formation mechanisms

Mosaic structure ZnO formed by secondary crystallization with enhanced photocatalytic performance

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International Journal of Minerals,Metallurgy and Materials 2021年第3期28卷 495-502页

作者： Hai-xia Liu meng-yuan Teng Xu-guang Wei Tian-duo Li Zai-yong Jiang qing-fen Niu Xu-ping Wang Shandong Provincial Key Laboratory of Molecular Engineering School of Chemistry and Pharmaceutical EngineeringQilu University of Technology(Shandong Academy of SciencesJinan 250353China State Key Laboratory of Biobased Material and Green Papermaking Qilu University of Technology(Shandong Academy of SciencesJinan 250353China Advanced Materials Institute Qilu University of Technology(Shandong Academy of SciencesJinan 250014China

Zinc acetate is used as a raw material to synthesize the desired ZnO in hot solvent by controlling the amount of citric acid(CA)***,the amount of CA added has a significant relationship with the control of the morphology of *** ZnO wrapped in nanosheets is synthesized through the secondary crystallization of Zn^(2+).The optical properties of the ZnO sample are tested through the degradation of organic ***,the photocatalytic properties of ZnO vary with the different amounts of CA *** of the active crystal face increases the photocatalytic activity of *** addition,the number of defects on the surface of the ZnO sample increases because of its large specific surface area,thus changing the bandgap of ***,the resulting sample can respond under visible light.

关键词： active crystal face citric acid secondary crystallization photocatalysis

Bayesian dual neural networks for recommendation

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Frontiers of Computer Science 2019年第6期13卷 1255-1265页

作者： Jia HE Fuzhen ZHUANG Yanchi LIU qing HE fen LIN Key Lab of Intelligent Information Processing of Chinese Academy of Sciences Institute of Computing TechnologyChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Rutgers University Newark 07102USA Search Product Center WeChat Search Application DepartmentTencentBeijing 100080China

Most traditional collaborative filtering(CF)methods only use the user-item rating matrix to make recommendations,which usually suffer from cold-start and sparsity *** address these problems,on the one hand,some CF methods are proposed to incorporate auxiliary information such as user/item profiles;on the other hand,deep neural networks,which have powerful ability in learning effective representations,have achieved great success in recommender ***,these neural network based recommendation methods rarely consider the uncertainty of weights in the network and only obtain point estimates of the ***,they maybe lack of calibrated probabilistic predictions and make overly confident *** this end,we propose a new Bayesian dual neural network framework,named BDNet,to incorporate auxiliary information for ***,we design two neural networks,one is to learn a common low dimensional space for users and items from the rating matrix,and another one is to project the attributes of users and items into another shared latent *** that,the outputs of these two neural networks are combined to produce the final ***,we introduce the uncertainty to all weights which are represented by probability distributions in our neural networks to make calibrated probabilistic *** experiments on real-world data sets are conducted to demonstrate the superiority of our model over various kinds of competitors.

关键词： collaborative filtering Bayesian neural network hybrid recommendation algorithm

Corrosion resistance of Mg（OH）2/Mg-Al-layered double hydroxide coatings on magnesium alloy AZ31:influence of hydrolysis degree of silane

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Rare Metals 2019年第7期38卷 629-641页

作者： qing-Song Yao Zhong-Chao Li Zai-meng Qiu fen Zhang Xiao-Bo Chen Dong-Chu Chen Shao-Kang Guan Rong-Chang Zeng College of Materials Science and Engineering Shandong University of Science and Technology Qingdao 266590 China School of Engineering RMIT University Carlton VIC 3053 Australia School of Materials Science and Energy Engineering Foshan University Foshan 528000. China School of Materials Science and Engineering Zhengzhou University Zhengzhou 450002 China

Mg(OH)2/Mg-Al-layered double hydroxide (LDH) coatings were modified with methyltrimethoxysilane (MTMS) on magnesium alloys. Effect of hydrolysis degree of silane solution on coating formation was investigated. Chemical compositions and surface morphologies of the coatings were examined using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and field-emission scanning electronic microscopy (FESEM). Results indicated that the composite coatings consisted of polymethyltrimethoxysilane (PMTMS), LDH and Mg(OH)2. Electrochemical and hydrogen evolution measurements revealed that the composite coatings possessed good corrosion resistance, especially the ones prepared in a high hydrolysis degree of silane. The optimum corrosion resistance of the composite coati ng was LDH/PMTMS-3 coating, which had the lowest value of corrosion current density (5.537×10^-9 A·cm^-2) and a dense *** mechanism for coating formation and corrosion process of MTMS-modified Mg(OH)2/Mg-Al-LDH coatings were discussed.

关键词： Magnesium alloy Layered double hydroxide (LDH) Silane Coating Corrosion resistance

Interconnected Ni(OH)_(2)and polyether amine on carbon fiber surface for simultaneously improving interfacial adhesion of epoxy composites and electrochemical properties

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Chinese Journal of Aeronautics 2022年第5期35卷 419-428页

作者： qing WU Qinqin WAN Qianli LIU fen WANG Xin LIU Jianfeng ZHU School of Materials Science and Engineering Shaanxi Key Laboratory of Green Preparation and Functionalization for Inorganic MaterialsShaanxi University of Science&TechnologyXi’an 710021China Shanghai Composites Science&Technology Co. Ltd.Shanghai 201112China

Interconnected Ni(OH)_(2)nanoflakes and polyether amine(PEA)were deposited on carbon fiber tows via a facial and effective process of chemical bath deposition and dip *** on this,a win–win benefit of simultaneously improvements in interfacial shear strength(IFSS)of carbon fiber/epoxy composites and the electrochemical activity has been *** with CF and CF-Ni(OH)_(2)composites,the IFSS of CF-Ni(OH)_(2)-PEA/epoxy composite respectively increased 7.9%and 45.4%,which was put down to the covalent bonding of Ni(OH)_(2)-PEA coating with fiber and epoxy matrix,as well as the effective stress transfer by the uniform honeycomb structure of Ni(OH)_(2).In aqueous KOH electrolyte,the CF-Ni(OH)_(2)-PEA electrode presented the maximum specific capacitance of 689.98 F·g^(-1)at 5 m V·s^(-1),572.28 F·g^(-1)at a current density of 0.5 A·g^(-1)due to the strong adhesion of carbon fiber with Ni(OH)_(2)by PEA,the reservation of the threedimensional hollow honeycomb structure of Ni(OH)_(2)for easy ion-transport and–NH_(2)functional groups from PEA for providing more active *** excellent performance of CF-Ni(OH)_(2)-PEA reinforcement demonstrates its promising potential for application in high performance composites with integrated structure and function,which shows great advantages in various fields of aerospace,energy,electronics,automobile,civil engineering,sports,etc.

关键词： Carbon fiber Electrochemical properties Interface/interphase Polymer-matrix composites Surface modification

Assembly of a New Fluorescent Cd(Ⅱ)Coordination Compound with a Versatile Multidentate N-Donor Building Block 3-(2-Pyridyl)-5-(3'-pyridyl)-1,2,4-triazole

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Chinese Journal of Structural Chemistry 2015年第10期34卷 1525-1532页

作者： LI Ting meng qing-fen LI Bing JIN Xiao-Dong GAO Hui CHEN Xiao-Yan SONG Wei-Ming LIU Wan-Yi Department of Chemistry and Chemical Engineering Ningxia University qinghai Institute of Salt Lakes Chinese Academy of Sciences

Assembly of Cd（Ⅱ） nitrate with a new dipyridyltriazole building block 3-（2-pyridyl）-5-（3＇-pyridyl）-1H-1,2,4-triazole（2,3＇-Hbpt） and benzoic acid（Hba） yields a new coordination compound [Cd（2,3A-bpt）（ba）（H2O）] which was characterized by single-crystal X-ray diffraction, elemental analysis, IR spectrum, TGA and XRPD analysis. Single-crystal X-ray diffraction analysis indicates that the complex belongs to triclinic system, space group P1 with a = 6.8972（6）, b = 8.8182（7）, c = 16.0484（1） A, α = 75.6330（1）, β = 85.294（2）, γ = 69.3450（1）°, V = 884.76（13） A3, Z = 2, Dc = 1.778 g/cm^3, μ = 1.276 mm-1, Mr = 473.76, F（000） = 472, the final R = 0.0380 and wR = 0.1054 with I 2σ（I）. The Cd（Ⅱ） ion is coordinated by three N-terminal atoms from two 2,3A-Hbpt ligands as well as three O-terminal atoms from ba- and lattice water forming a distorted octahedral coordinated geometry. With the lattice water as hydrogen bond donor, the structure of the title complex is linked into a 2D layer-hole structure from the 0D motif. Theoretical calculation based on density functional theory（DFT） for the ligand is also employed to explicate the stability of different conformations. Moreover, the complex exhibits strong solid state fluorescent emission at room temperature which indicates that the title complex could be a good candidate for potential photoactive materials.

关键词： 2,3'-Hbpt benzoic acid cadmium(Ⅱ)complex crystal structure luminescence