检索结果-南通市图书馆

Powder transport behavior in RH degasser with powder injection through up snorkel: a transient numerical model

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2023年第6期30卷 1156-1170页

作者： zhuang Liu wen-tao Lou Miao-yong zhu Key Laboratory for Ecological Metallurgy of Multimetallic Mineral(Ministry of Education) Northeastern UniversityShenyang 110819LiaoningChina School of Metallurgy Northeastern UniversityShenyang 110819LiaoningChina

A transient numerical model was established to predict the dispersion,distribution,and circulation behavior of the powder injected through the up snorkel in a Ruhrstahl–Heraeus(RH)*** effects of the powder diameter,the lifting gas flow rate,and the powder injection rate on the powder transport were *** powder concentration was measured by a cold *** results showed that the predicted powder concentration agreed well with the *** powder injection process is divided into three periods,named dispersion period,aggregation and circulation period,and dynamically stable period according to the powder transport *** powder diameter has a great effect on the particle *** the particles size changes from 30 to 500μm,the powder dispersion characteristic index changes from 0.110 to 0.741,and the ladle top zone powder mass ratio changes from 0.118 to *** powder circulation mass flow rate increases to 101.0 kg min^(-1)(150μm)and then decreases to 46.6 kg min^(-1)(500μm).Powders with a diameter of more than 220μm can change the steel flow mode in the RH *** the lifting gas flow could slightly improve the powder *** in the powder injection rate has almost no effect on the powder dispersion.

关键词： RH degasser Powder injection Numerical simulation Eulerian-granular flow Powder transport behavior Optical probe

Film mulching reduces antibiotic resistance genes in the phyllosphere of lettuce

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2022年第2期34卷 121-128页

作者： Beiqi Deng wen Li Huijie Lu Lizhong zhu College of Environmental and Resource Sciences Zhejiang UniversityHangzhou310058China Zhejiang Provincial Key Laboratory of Organic Pollution Process andControl Hangzhou310058China

Phyllosphere is an important reservoir of antibiotic resistance genes(ARGs),but the transfer mechanism of ARGs from soil and air to phyllosphere remains *** study demonstrated that soil-air-phyllosphere was the dominant ARG transfer pathway,and blocking it by film mulching can reduce typical phyllosphere ARGs in lettuce by 80.7%-98.7%(89.5%on average).To further eliminate phyllosphere ARGs in lettuce grown with film mulching,the internal soil-endosphere-phyllosphere transfer pathway deserves more *** analyzed the ARG hosts and the resistome in lettuce rhizosphere and phyllosphere with film mulching via hybrid Illumina-Nanopore *** sp.7SR1 was more abundant than other ARG hosts,accounting for 1.0%and 47.1%of the total bacteria in rhizosphere and phyllosphere,*** species has flagella that can promote mobility and can excrete extracellular polymeric substances and/or surfactant-like microbial products,which benefits its colonization in the *** the migration of Pseudomonas sp.7SR1 via the soil-endosphere-phyllosphere pathway would be effective to further reduce ARGs in *** resistant genes were predominant in phyllosphere(40.3%of the total),and 87.6%of the phyllosphere ARGs were located on chromosomes,indicating relatively low horizontal gene transfer(HGT)*** study provides insights into the transfer mechanism,hosts,and control strategies of phyllosphere ARGs in typical plants.

关键词： Antibiotic resistance genes Phyllosphere Rhizosphere Transfer pathway Host bacteria

Effect of tempering on bonding characteristics of cross wedge rolling 42CrMo/Q235 laminated shafts

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2020年第10期27卷 1170-1178页

作者： Shuai zhu wen-fei Peng Xue-dao Shu Zhejiang Provincial Key Laboratory of Part Rolling Technology Ningbo UniversityNingbo 315211ZhejiangChina

To further improve the comprehensive properties of 42CrMo/Q235 laminated shafts produced by cross wedge *** treatment of the shafts was *** and bending tests were carried out to compare the changes in mechanicalproperties before and after heat *** results showed that the interfacial bonding strength increased most aftertempering at 350℃for 45 *** microstructure of the interface was observed using a digital *** resultsshowed that the dispersed oxides on the interface were basically eliminated by using the scheme of tempering at 350 cand holding for 45 *** reasons for the change in mechanical properties were explained from the point of theinterfacial *** electron microscopy was used to analyze the micro-morphology of the tensile *** was observed that after tempering at 350℃and holding for 45 min,the dimple holes became larger and deeper,and thestructure of fracture became more uniform and *** the point of the tensile fracture *** reasons for thechange in mcchanical propcrties wcrc explained as well.

关键词： Heat treatment Cross wedge rolling Interface Microstructure Fracture morphology

A Novel Obstacle Avoidance Consensus Control for Multi-AUV Formation System

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2023年第5期10卷 1304-1318页

作者： Linling Wang Daqi zhu wen Pang Chaomin Luo the Shanghai Engineering Research Center of Intelligent Maritime Search&Rescue and Underwater Vehicles Shanghai Maritime UniversityShanghai 201306China the Shanghai Maritime University Shanghai 201306China the School of Mechanical Engineering University of Shanghai for Science and TechnologyShanghai 200093China the Department of Electrical and Computer Engineering Mississippi State UniversityMississippi StateMS 39762 USA

In this paper, the fixed-time event-triggered obstacle avoidance consensus control for a multi-AUV time-varying formation system in a 3D environment is presented by using an improved artificial potential field and leader-follower strategy(IAPF-LF). Firstly, the proposed fixed-time control can achieve the desired multi-AUV formation within a fixed settling time in any initial system state. Secondly, an event-triggered communication strategy is developed to govern the communication among AUVs, and the communication energy consumption can be decremented. The time-varying formation obstacle avoidance control algorithm based on IAPF-LF is designed to avoid static and dynamic obstacles, the desired formation is maintained in the presence of external disturbances, and there is no Zeno behavior under the fixed-time event-triggered consensus control *** stability of the system is proved by the Lyapunov function and inequality scaling. Finally, simulation examples and water pool experiments are reported to verify the performance of the proposed theoretical algorithms.

关键词： Autonomous underwater vehicle(AUV) event-triggered control fixed-time consensus formation obstacle avoidance improved artificial potential field and leader-follower strategy(IAPF-LF)

Quantum Size Effects on Two Electrons and Two Holes in Double-Layer Quantum Dots

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2002年第7期38卷 99-102页

作者： XIE wen-Fang zhu Wu Department of Physics Guangzhou University Guangzhou 510405 China Department of Physics Guangzhou University Guangzhou 510405 China

We propose a procedure to solve exactly the Schrodinger equation for a system of two electrons and two holes in a double-layer quantum dot by using the method of few-body physics. The features of the low-lying spectra have been deduced based on symmetry. The binding energies of the ground state are obtained as a function of the electron-to-hole mass ratio σ for a few values of the quantum dot size.

关键词： two-electron and two-hole system, quantum dot, method of few-body physics

Tool path generation and simulation of dynamic cutting process for five-axis NC machining

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2010年第30期55卷 3408-3418页

作者： DING Han bi QingZhen zhu LiMin XIONG YouLun State Key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and Technology Wuhan 430074 China State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong University Shanghai 200240 China

Five-axis NC machining provides a valid and efficient way to manufacture the mechanical parts with complex shapes,which are widely used in aerospace,energy and national defense industries. Its technology innovations have attracted much attention in recent years. In this paper,the state-of-the-art techniques for five-axis machining process planning are summarized and the challenging problems are analyzed from the perspectives of tool path generation,integrated geometric/mechanistic simulation and machining stability analysis. The recent progresses in accessibility-based tool orientation optimization,cutter location (CL) planning for line contact and three-order point contact machining,shape control of cutter envelope surface and milling stability prediction are introduced in detail. Finally,the emerging trends and future challenges are briefly discussed.

关键词：五轴数控加工刀具轨迹生成五轴联动过程仿真动态切削形状复杂技术创新稳定性分析

Facile Synthesis of Nitrogen-Doped Graphene Aerogels for Electrode Materials in Supercapacitors

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2017年第7期35卷 1069-1078页

作者： Yong Zhang Jiayi zhu Hongbo Ren Yutie bi Lin Zhang Department of Physics University of Science and Technology of China Hefei Anhui 230026 China Joint Laboratory for Extreme Conditions Matter Properties Southwest University of Science and Technology and Research Center of Laser Fusion Mianyang Sichuan 621000 China School of National Defense and Techonology Southwest University of Science and Technology Mianyang Sichuan 621010 China Science and Technology on Plasma Physics Laboratory Research Center of Laser Fusion China Academy of Engineering Physics Mianyang Sichuan 621900 China

Three-dimensional porous nitrogen-doped graphene aerogels （NGAs） were synthesized by using graphene oxide （GO） and chitosan （CS） via a self-assembly process by one-pot hydrothermal method. The morphology and struc- ture of the as-prepared materials were characterized by means of scanning electron microscopy, transmission elec- tron microscopy, X-ray diffraction, XPS spectroscopy, Raman spectroscopy, nitrogen adsorption/desorption meas- urement and Fourier transform infrared spectroscopy. The electrochemical performance of NGAs was studied by cyclic voltammetry, galvanostatic charge/discharge and impedance spectroscopy measurements. The microstructure, surface area and capacitance of NGAs could be facilely controlled by adding different amounts of chitosan. The prepared NGA-4 showed a specific capacitance of 148.0 F/g at the discharge current density of 0.5 A/g and also re- tained 95.3% of the initial capacitance after 5000 cycles at the scan rate of 10 mV/s. It provided a possible way to obtain graphene based materials with high surface area and capacitance.

关键词： mesoporous materials hydrothermal synthesis electrochemistry nitrogen-doped graphene aerogels,chitosan supercapacitors

Trace Elements Characteristics of Black Shales from the Ediacaran Doushantuo Formation, Hubei Province, South China： Implications for Redox and Open vs. Restricted Basin Conditions

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Earth Science 2018年第2期29卷 342-352页

作者： bi zhu Shaoyong Jiang Daohui Pi Lu Ge Jinghong Yang Institute of Isotope Hydrology School of Earth Sciences and Engineering Hohai University Nanjing 210098 China State Key Laboratory of Geological Processes and Mineral Resources Faculty of Earth Resources Collaborative Innovation Center for Exploration of Strategic Mineral Resources China University of Geosciences Wuhan 430074 China State Key Laboratory for Mineral Deposits Research School of Earth Sciences and Engineering Nanjing University Nanjing 210093 China

In the present study, we carried out trace element analyses of black shales of the Edia- caran Doushantou Formation from two sections （Jiulongwan, Baiguoyuan） in Hubei Province, South China. Mo-U characteristics of black shales from the two sections and compiled Mo-U data of Dou- shantuo black shales from sections of a variety of sedimentary facies described the temporal/spatial variability in the redox conditions of paleo-seawater during deposition of the Donshantuo Formation. Changes in Mo-U patterns of the Doushantuo Member II （DST2） shales of open marine environments are consistent with a shift from a predominately oxic to a predominately anoxic ocean during their deposition. Mo-U patterns of the DST2 black shales from intra-shelf sections reflect basin restriction may have happened in the intra-shelf basin and are compatible with the redox-stratified model of the intra-shelf basin. Mo-U patterns of black shales of the Doushantuo Member IV （DST4） reveal that the shales from intra-shelf sections have more pronounced Mo enrichment and more significant enrich- ment of Mo over U than the slope shales, indicating the operation of a Mn particulate shuttle in the intra-shelf basin. High Mo/TOC ratios of the DST4 at the intra-shelf sections, in combination with similar Mo-TOC patterns of the DST4 from both intra-shelf and slope sections, indicate the intra- shelf basin was well connected to the open ocean during deposition of the DST4.

关键词： Doushantuo Formation Mo-U eovariation Mo/TOC South China.

Safety and immunogenicity of human papillomavirus-16/18 AS04-adjuvanted vaccine in healthy Chinese females aged 15 to 45 years:a phase Ⅰ trial

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Cancer 2011年第8期30卷 559-564页

作者： Feng-Cai zhu Chang-Gui Li Hong-Xing Pan Yi-Ju Zhang Dan bi Hai-wen Tang Sanjoy Datta Jiangsu Provincial Center for Disease Control and Prevention Nanjing Jiangsu 210009 P. R. China National Institutes for Food and Drug Control Beijing 100050 P. R. China GlaxoSmithKline biologicals B-1300 Wavre Belgium GlaxoSmithKline Shanghai 200001 P. R. China.

Globally,about 70% of cervical cancers are associated with human papillomavirus (HPV)-16 or HPV-18 infection.A meta-analysis of epidemiologic studies in China showed that HPV was present in 98% of cervical cancer *** HPV-16/18 AS04-adjuvanted vaccine Cervarix has shown a high level of protection against HPV-16/18 infections and associated cervical *** phase Ⅰ trial (NCT00549900) assessed the safety,tolerability,and immunogenicity of the vaccine in *** healthy Chinese females,aged 15 to 45 years with a median age of 29.5 years,received three doses of Cervarix in Months 0,1,and *** was assessed via recording solicited local and systemic symptoms within 7 days and unsolicited symptoms within 30 days after each *** adverse events,new onset of chronic diseases,and other medically significant conditions were recorded throughout this *** an exploratory objective,HPV-16/18 antibody titers were determined by enzyme-linked immunosorbent assay in serum samples collected in Months 0 and *** at the injection site was the most frequently reported local *** subjects reported medically significant adverse *** cases were assessed as unrelated to vaccination by the *** Month 7,100% seroconversion was observed for both anti-HPV-16 and anti-HPV-18 with high geometric mean antibody ***-16/18 AS04-adjuvanted vaccine,evaluated for the first time in Chinese females,was generally well tolerated and immunogenic,as previously shown in global studies.

关键词：疫苗接种免疫原性安全性中国佐剂临床试验女性人类