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Effect of traveling-wave magnetic field on dendrite growth of high-strength steel slab: Industrial trials and numerical simulation

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International Journal of minerals,Metallurgy and Materials 2023年第9期30卷 1716-1728页

作者： cheng Yao min wang Youjin Ni Dazhi wang Haibo Zhang Lidong Xing Jian Gong Yanping Bao State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China Technical Support Center for Prevention and Control of Disastrous Accidents in Metal Smelting University of Science and Technology BeijingBeijing 100083China Qianshun Technology Center Shougang Qian’an Iron and Steel CompanyQian’an 064404China

The dendrite growth behavior of high-strength steel during slab continuous casting with a traveling-wave magnetic field was studied in this paper. The morphology of the solidification structure and composition distribution were analyzed. Results showed that the columnar crystals could deflect and break when the traveling-wave magnetic field had low current intensity. With the increase in current intensity, the secondary dendrite arm spacing and solute permeability decreased, and the columnar crystal transformed into an equiaxed crystal. The electromagnetic force caused by the traveling-wave magnetic field changed the temperature gradient and velocity magnitude and promoted the breaking and fusing of dendrites. Dendrite compactness and composition uniformity were arranged in descending order as follows:columnar-toequiaxed transition (high current intensity), columnar crystal zone (low current intensity), columnar-to-equiaxed transition (low current intensity), and equiaxed crystal zone (high current intensity). Verified numerical simulation results combined with the boundary layer theory of solidification front and dendrite breaking–fusing model revealed the dendrite deflection mechanism and growth process. When thermal stress is not considered, and no narrow segment can be found in the dendrite, the velocity magnitude on the solidification front of liquid steel can reach up to 0.041 m/s before the dendrites break.

关键词： high-strength steel traveling-wave magnetic field dendrite growth numerical simulation

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Carbon dots-confined CoP-CoO nanoheterostructure with strong interfacial synergy triggered the robust hydrogen evolution from ammonia borane

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Journal of Energy Chemistry 2021年第6期30卷 198-205,I0006页

作者： Han Wu Yaojia cheng Boyang wang Yao wang min Wu Weidong Li Baozhong Liu Siyu Lu College of Chemistry and Institute of Green CatalysisZhengzhou UniversityZhengzhou 450001HenanChina College of Chemistry and Chemical Engineering Henan Polytechnic UniversityJiaozuo 454000HenanChina Guangdong Provincial Key Laboratory of Optical Information Materials and Technology Guangzhou 510631GuangdongChina College of Materials Science and Engineering Zhejiang University of TechnologyHangzhou 310014ZhejiangChina

Ammonia borane(NH_(3)BH_(3),AB) is promising for chemical hydrogen sto rage;however,current systems for rapid hydrogen production are limited by the expensive noble metal catalysts required for AB *** we report the design and synthesis of a highly efficient and robust non-noble-metal catalyst for the hydrolysis of AB at 298 K(TOF=89.56 molH_(2) min^(-1) molCo^(-1)).Experiments and density functional theory calculations were performed to explore the catalyst’s hybrid nanoparticle heterostructure and its catalytic *** catalyst comprised nitrogen-doped carbon dots confining CoO and CoP,and exhibited strong interface-induced synergistic catalysis for AB hydrolysis that effectively decreased the energy barriers for the dissociation of both AB and water *** co-doping of N and P introduced numerous defects,and further regulated the reactivity of the carbon *** heterogeneous interface design technique presented here provides a new strategy for developing efficient and inexpensive non-noblemetal catalysts that may be applicable in other fields related to energy catalysis.

关键词： Nano-heterostructure Interface engineering Ammonia borane Hydrolysis mechanism Hydrogen

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Effects of Vegetation Succession on Soil Fertility Within Farming-Plantation Ecotone in Ziwuling Mountains of the Loess Plateau in China

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Agricultural Sciences in China 2010年第10期9卷 1481-1491页

作者： LIANG Jian wang Xiao-an YU Zhong-dong DONG Zhong-min wang Jin-cheng School of Life Sciences Shaanxi Normal University Xi'an 710062 P.R.China College of Forestry Northwest A&F University Yangling 712100 P.R. China Department of Biology Saint Mary 's University Halifax B3H 3C3 Canada

To further understand the relationship between vegetation succession and soil fertility within farming-plantation ecotone in Ziwuling Mountains of the Loess Plateau, nine kinds of widely distributed communities at different succession stages were selected, and the effects of vegetation succession on soil fertility were studied through the methods of comparing two hierarchical clustering （similarity index： B） and other multivariate analysis. The results showed that：（i） the similarity in clustering pattern of nine communities which classified by plant species and soil nutrients respectively showed a trend of B ^-overall plant-soil0-10cn〉B^-overall plant-soil 10-20 cm 〉B^- overall plant-soil 20-40 cm, and for the top soil, it showed a trend of B^- grass-soil 0-10 cm 〉 B^-shrub-soil 0-10 cm 〉 Btree-soil0-10 cm; （ii） soil fertility increased during the succession process from abandoned land to forest community, and the soil fertility of forest community showed an increased order of coniferous forest →mixed forest →broadleaf forest; （iii） during the process of vegetation succession, the variation of topsoil fertility was higher than that of the subsurface soil （coefficient of variation： CV0-10 cm 〉CV 10-20 cm 〉 CV20-40 cm）, and when the succession developed into the stages of shrub and forest communities, the top soil fertility had been improved significantly; and （iv） for the subsurface soil of the communities at the advanced succession stages, the soil fertility also increased to some extent. Our results suggested that the method of comparing two hierarchical clustering reflected the similarity level of different cluster patterns, therefore, it was helpful to study the relationship between vegetation succession and soil fertility. There was a corresponding relationship between the change process of soil fertility from the top soil to subsurface soil and the process of vegetation succession from the early stages to the advanced stage. The differentiations of soil fertil

关键词： vegetation succession soil fertility vegetation-soil communities multivariate statistical analysis LoessPlateau

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Interlayer and intralayer co-modified flexible V_(2)CT_(X) MXene@SWCNT films for high-power Li-ion capacitors

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Journal of Energy Chemistry 2023年第4期79卷 101-109页

作者： Wanli wang min Feng Enze Hu Zhaowei Hu cheng Fan Huifang Li Peng wang Xiaojun wang Zhiming Liu College of Electromechanical Engineering Shandong Engineering Laboratory for Preparation and Application of High-performance Carbon-MaterialsQingdao University of Science&TechnologyQingdao 266061ShandongChina Qingdao Industrial Energy Storage Research Institute Qingdao Institute of Bioenergy and Bioprocess Technology Chinese Academy of Sciences Qingdao 266101ShandongChina Key Laboratory of Advanced Energy Materials Chemistry(ministry of Education) College of ChemistryNankai UniversityTianjin 300071China

As an emerging member of the two-dimensional(2D)material family,V_(2)CT_(X)MXene shows great potential in the application of lithium-ion capacitors(LICs)due to its unique structure and excellent electrical ***,severe nanosheets stacking and intra-layer transport barriers have limited the further development of V_(2)CT_(X)MXene-based ***,we prepared Kions and–O functional group co-modified V_(2)CT_(X)MXene(VCT-K)and further incorporated it with single-walled carbon nanotube(SWCNT),obtaining freestanding V_(2)CT_(X)composite films(VCT-K@C)with the 3D conductive ***,K+ions were introduced into V_(2)CT_(X)MXene to stabilize the interlayer structure and prevent the aggregation of nanosheets,the terminal group of–O was controllably modified on the surface of MXene to improve the Li+ions storage reversible capacities and the SWCNT acted as the bridge between MXene nanosheets to opens up the channels for ion/electron transportation in the longitudinal *** from the synergistic effect of VCT-K and SWCNT,the VCT-K@C exhibits superior reversible specific capacities of 671.8 mA h g^(-1)at 0.1 A g^(-1)and 318 mA h g^(-1)at 1.0 A g^(-1).Furthermore,the assembled LICs with VCT-K@C anode coupling activated carbon(AC)cathode deliver an outstanding power density of 19.0 kW kg^(-1)at 67.4 Wh kg^(-1),a high energy density of 140.5 Wh kg^(-1)at 94.8 W kg^(-1)and a stable capacitance retention of 86%after 6000 cycles at 10 A g^(-1).Such unique structures and excellent electrochemical properties are expected to pave the way for the large-scale application in LICs of MXene-based materials.

关键词： Interlayer and intralayer co-modification MXene SWCNT Flexible self-supported anodes Lithium-ion capacitors

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丙型肝炎病毒核心蛋白反式激活基因HCTP4的克隆化研究

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胃肠病学和肝病学杂志 2003年第3期12卷 233-236页

作者：刘敏成军王琳张树林解放军第302医院传染病研究所基因治疗研究中心北京100039

目的　探索丙型肝炎病毒 (HCV)核心 (core)蛋白反式激活作用的新的靶基因 ,以有助于阐明HCV感染相关疾病的发病机制。方法　应用表达谱芯片分析等分子生物学技术 ,结合生物信息学 (bioinformatics)技术 ,筛选、克隆HCV核心蛋白反式激活... 详细信息

目的　探索丙型肝炎病毒 (HCV)核心 (core)蛋白反式激活作用的新的靶基因 ,以有助于阐明HCV感染相关疾病的发病机制。方法　应用表达谱芯片分析等分子生物学技术 ,结合生物信息学 (bioinformatics)技术 ,筛选、克隆HCV核心蛋白反式激活作用的新的靶基因。结果　构建了真核表达载体pcDNA3 core ,经过限制性内切酶作图分析和核苷酸序列分析证实正确无误。以pcDNA3 core转染HepG2后提取总RNA ,逆转录后进行表达谱基因芯片技术分析。应用分子克隆技术结合生物信息学技术克隆核心蛋白反式激活的新型靶基因 ,命名为HCTP4,新基因的编码基因序列全长为 2 2 44个核苷酸 (nt) ,编码产物由 748个氨基酸残基(aa)组成。结论　HCV核心蛋白是具有反式激活作用的蛋白。DNA微矩阵技术 (DNAmicroarray)是分析基因表达谱变化的有效和高通量技术。发现了HCV核心蛋白反式激活作用的新的靶基因。

关键词：丙型肝炎病毒核心蛋白反式激活 HCTP4 基因克隆化 DNA微矩阵

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BOT+EPC模式的委托代理:广佛肇高速公路的例证

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经济数学 2017年第3期34卷 66-70页

作者：张远辉徐一鸣刘翔王成皿广东省长大公路工程有限公司广东广州510000 长沙理工大学经济与管理学院湖南长沙410114

依据委托代理理论,结合广佛肇高速公路建设的经验,对于我国高速公路建设的BOT+EPC投融资和运营模式进行分析.广佛肇高速公路建设模式表明,若采用一种适合高速公路投融资需要的运行管理模式,可以解决我国高速公路建设当中存在的资金缺口... 详细信息

依据委托代理理论,结合广佛肇高速公路建设的经验,对于我国高速公路建设的BOT+EPC投融资和运营模式进行分析.广佛肇高速公路建设模式表明,若采用一种适合高速公路投融资需要的运行管理模式,可以解决我国高速公路建设当中存在的资金缺口问题,以及提高高速公路投融资的管理效率.

关键词：高速公路委托代理 BOT+EPC模式

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Alloying design and microstructural control strategies towards developing Mg alloys with enhanced ductility

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Journal of Magnesium and Alloys 2022年第5期10卷 1191-1206页

作者： Zhong-Zheng Jin min Zha Si-Qing wang Shi-Chao wang cheng wang Hai-Long Jia Hui-Yuan wang Key Laboratory of Automobile Materials of ministry of Education&School of Materials Science and Engineering Nanling CampusJilin UniversityNo.5988 Renmin StreetChangchun 130025China International Center of Future Science Jilin UniversityChangchun 130012China State Key Laboratory of Superhard Materials Jilin UniversityChangchun 130012China

Nowadays,magnesium(Mg)alloys are promising lightweight structural materials,especially in transportation and aerospace fields,due to their inherent low density and high specific *** of the high-strength Mg alloys exhibit poor formability and ductility at room temperature,which limit their wide ***,by proper alloying design and/or delicate microstructural control,some newly developed Mg alloys,including rare-earth(RE)and RE-free ones,show enhanced ductility without significant loss of *** identify the critical reasons,recent researches on ductile Mg alloys have been reviewed from the aspects of alloying design strategies and microstructural control via advanced processing ***,some outlooks on enhanced ductility of Mg alloys are suggested,*** the beneficial effect of solute atoms,introducing second phase particles,tailoring bimodal-grained structures,introducing pre-twinning structures,*** current research progresses in alloying design and/or novel microstructural control have shed some lights on designing and producing Mg alloys with enhanced ductility.

关键词： Mg alloys Alloying Microstructure Ductility Strength

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Audio Zero-Watermark Scheme Based on Discrete Cosine Transform-Discrete Wavelet TransformSingular Value Decomposition

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China Communications 2016年第7期13卷 117-121页

作者： min Lei Yu Yang Xiaoming Liu mingZhi cheng Rui wang Information Security Center Beijing University of Posts and TelecommunicationsBeijingChina Nanjing University of Information Science&Technology(NUIST) NanjingChina National Computer Network Emergency Response Technical Team/Coordination Center of China Information Engineering School of Beijing Institute of Graphic Communication BeijingChina Information Science&Technology Northwest UniversityXi'anChina

Traditional watermark embedding schemes inevitably modify the data in a host audio signal and lead to the degradation of the host *** this paper,a novel audio zero-watermarking algorithm based on discrete wavelet transform(DWT),discrete cosine transform(DCT),and singular value decomposition(SVD) is *** watermark is registered by performing SVD on the coefficients generated through DWT and DCT to avoid data modification and host signal *** results show that the proposed zero-watermarking algorithm is strongly robust to common signal processing methods such as requantization,MP3 compression,resampling,addition of white Gaussian noise,and low-pass filtering.

关键词： zero-watermark discrete wavelet transform discrete cosine transform singular value decomposition

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Novel Zero-Watermarking Scheme Based on DWT-DCT

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China Communications 2016年第7期13卷 122-126页

作者： Yu Yang min Lei Xiaoming Liu Zhiguo Qu cheng wang Information Security Center Beijing University of Posts and TelecommunicationsBeijingChina Nanjing University of Information Science&Technology(NUIST) NanjingChina National Computer Network Emergency Response Technical Team/Coordination Center of China College of Electronic and Information Engineering Nanjing University of Aeronautics and AstronauticsNanjingChina

Essential characteristics for watermark registration and detection without data modification can be used in anaudio zero-watermarking *** this paper,a novel audio zero-watermarking scheme based on discrete wavelet transform(DWT) and discrete cosine transform(DCT) is *** is registered by comparing the mean absolute values of the adjacent frame coefficients after DWT and *** results show that the proposed scheme is stronglyrobusttocommon attacks such as AWGN,downsampling,low-pass filtering,requantization,and MP3 compression.A performance analysis of the proposed scheme shows that all bit error rates after attacks are zero.

关键词： zero-watermark discrete wavelets transform discrete cosine transform

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Synthesis and Crystal Structure of 3,3'-Dimethyl-dibenzo-18-crown-6

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Chinese Journal of Structural Chemistry 2006年第6期25卷 757-760页

作者： NIU Mei-Ju DOU Jian-min wang Da-Qi LI Da-cheng Department of Chemistry Liaocheng University Liaocheng 252059 China

3,3′-Dimethyl-dibenzo-18-crown-6 was synthesized and characterized by elemental analysis, FT-IR, ^1H NMR, UV, MS spectra and X-ray single-crystal diffraction. It belongs to orthorhombic, space group Pna21 with a = 8.0790（18）, b = 16.780（4）, c = 15.222（3） .A, Z= 4, V= 2063.6（8） A3 Dc = 1.250 g/cm^3,μ = 0.090 mm^-1, F（000） = 832, R = 0.0474 and wR = 0.1103. According to structural analysis, the title compound possesses a boat-like configuration.

关键词： crown ether 3,3'-dimethyl-dibenzo-18-crown-6 synthesis crystal structure

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