检索结果-南通市图书馆

An internal ballistic model of electromagnetic railgun based on PFN coupled with multi-physical field and experimental validation

在线全文

学校读者我要写书评

暂无评论

Defence technology（防务技术） 2024年第2期32卷 254-261页

作者： Benfeng Gu Haiyuan Li Baoming Li National key laboratory of Transient Physics Nanjing University of Science and TechnologyNanjing 210094China

To accelerate the practicality of electromagnetic railguns,it is necessary to use a combination of threedimensional numerical simulation and experiments to study the mechanism of bore *** this paper,a three-dimensional numerical model of the augmented railgun with four parallel unconventional rails is introduced to simulate the internal ballistic process and realize the multi-physics field coupling calculation of the rail gun,and a test experiment of a medium-caliber electromagnetic launcher powered by pulse formation network(PFN)is carried *** test methods such as spectrometer,fiber grating and high-speed camera are used to test several parameters such as muzzle initial velocity,transient magnetic field strength and stress-strain of *** the simulation results and experimental data,the damage condition of the contact surface is analyzed.

关键词： Internal ballistic modeling Electromagnetic rail gun Multi-physics field coupling Experimental validation PFN

Pore Formation Mechanism in W-C Hard Coatings Using Directed Energy Deposition on Tungsten Alloy

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2024年第1期37卷 89-101页

作者： Xinrui Zhang Weijie Fu Chen Wang Zhenglong Lei Haoran Sun Xudong Li State key laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin150001China

Porosity is a common phenomenon and can significantly hinder the quality of the ***,the pore formation mechanism and the characteristics of the single tracks of the W-C coating using directed energy deposition(DED)are systematically *** forming quality of the tracks,the distribution of the pores,and the elemental distribution near the pores are analyzed by the observations of the cross-sections of the *** temperature field of the melt pool is discussed comprehensively to reveal the pore formation *** results confirm that Ni and Co evaporated during the DED process due to the high temperature of the melt *** were continuously produced adjacent to the fusion line when the melt pool was about to solidify since the temperature at the solidification front was higher than the boiling point of *** vaporization area at the fusion line was proposed,where Ni could also evaporate at the time the melt pool started to *** relationship between the solidification rate,the size of the vaporization area and the DED parameters(laser power and scanning speed)was established to discuss the causes of severe pores above the fusion *** work contains a practical guide to reduce or eliminate the porosity in the coating preparation process on the surface of the tungsten alloy.

关键词： Directed energy deposition(DED)process Tungsten alloy W-C coating Pores Binder phase

Effect of Sodium Tripolyphosphate and Silica Fume on Hydration of High Alumina Cement

维普期刊数据库评论

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 Wuhan University of technology(Materials Science) 2024年第5期39卷 1246-1252页

作者： WANG Jingran YANG Zongyuan ZHANG Shuai ZHANG Jinhua HAN Bingqiang KE Changming The State key laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081China

It was found that silica fume can reduce the maximum hydration heat release rate of cement by microcalorimetry,inhibit CAH_(10),promote the generation of C_(3)AH_(6)and strätlingite C_(2)ASH_(8),or promote the conversion of CAH_(10)to C_(3)AH_(6).Sodium tripolyphosphate can retard the early hydration of cement,have a slight effect on 1 d hydration products of cement and inhibit the generation hydration *** tripolyphosphate and silica fume can promote the early hydration of cement,advance the formation of C_(2)ASH_(8)or the conversion from CAH_(10)to C_(3)AH_(6)at 1 d.

关键词： high aluminum cement silica fume dispersing agent hydration

Global Dynamic Responses and Progressive Failure of Submerged Floating Tunnel Under Cable Breakage Conditions

在线全文

学校读者我要写书评

暂无评论

China Ocean Engineering 2024年第4期38卷 676-688页

作者： ZHOU Xiang-bo QIAO Dong-sheng WANG Ming TANG Guo-qiang LU Lin OU Jinping State key laboratory of Coastal and Offshore Engineering Dalian University of TechnologyDalian 116024China

The Submerged Floating Tunnel(SFT)relies on a tensioned mooring system for precise *** sudden breakage of a single cable can trigger an immediate alteration in the constraint conditions of the tube,inducing a transient heave response within the structure along with a transient increase in cable tension experienced by adjacent *** more severe cases,this may even lead to a progressive failure culminating in the global destruction of the *** study used ANSYS/AQWA to establish a numerical model of the entire length SFT for the hydrodynamic response analysis,and conducted a coupled calculation of the dynamic responses of the SFT-mooring line model based on Orca Flex to study the global dynamic responses of the SFT at the moment of cable breakage and the redistribution of cable internal *** most unfavorable position for SFT cable breakage was identified,the influence mechanism of cable breakage at different positions on the global dynamic response was revealed,and the progressive chain failure pattern caused by localized cable breakage are also clarified.

关键词： submerged floating tunnel cable breakage global dynamic responses progressive failure

Heavy-atom-free orthogonal configurative dye 1,7-di-anthra-aza-BODIPY for singlet oxygen generation

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第10期35卷 317-320页

作者： Yan Zhu Jia Liu Meiheng Lv Tingting Wang Dongxiang Zhang Rong Shang Xin-Dong Jiang Jianjun Du Guiling Wang Liaoning & Shenyang key laboratory of Functional Dye and Pigment Shenyang University of Chemical Technology Department of Cell Biology China Medical University Department of Chemistry Graduate School of Advanced Science and Engineering Hiroshima University State key laboratory of Fine Chemicals Dalian University of Technology

Spin-orbit,charge-transfer intersystem crossing （SOCT-ISC） can directly overcome the disadvantages of the traditional heavy-atom effect and improve the generation efficiency of reactive oxygen species （ROS）.Since orthogonal molecular orbitals of donor-acceptor （D-A） pairs favor the SOCT-ISC transition,herein aza-borondipyrromethenes （aza-BODIPYs） with 1,7-di-anthracyl groups （An-azaBDP） was successfully prepared,owing to steric hindrance to produce a big dihedral angle between the two molecular orbital （MO）***,according to density functional theory （DFT） and time-dependent density functional theory （TDDFT）,the energy difference between the S1-T1orbitals of An-aza BDP is small and more inclined towards ***-aza BDP can effectively generate singlet oxygen under light ***-aza BDP with light irradiation can induce apoptosis in SW620 cells,and can serve as a potential candidate for the treatment of cancer cells and tumors.

关键词： Anthracene Aza-BODIPY Heavy-atom-free Orthogonal configuration Singlet oxygen

New steelmaking process based on clean deoxidation technology

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2024年第6期31卷 1249-1262页

作者： Zhongliang Wang Yanping Bao State key laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China

After the converter steelmaking process,a considerable number of ferroalloys are needed to remove dissolved oxygen from the molten steel,but it also forms a lot of oxide inclusions that cannot be completely *** the same time,it increases the carbon emis-sions in the steel production *** years of research,our team have developed a series of clean deoxidation technologies,includ-ing carbon deoxidation,hydrogen deoxidation,and waste plastic deoxidation of molten steel to address the aforementioned *** this study,thermodynamic calculations and laboratory experiments were employed to verify that carbon and hydrogen can reduce the total oxygen content in the molten steel melt to below 5×10^(-6) and 10×10^(-6),*** analysis of the deoxidation mechanisms and ef-fects of polyethylene and polypropylene was also *** addition,the applications of carbon deoxidation technology in different steels with the hot-state experiment and industrial production were discussed *** carbon deoxidation experimental results of different steels were as follows:(1)the oxygen content of bearing steel was effectively controlled at 6.3×10^(-6) and the inclusion number density was lowered by 74.73%compared to aluminum deoxidized bearing steel;(2)the oxygen content in gear steel was reduced to 7.7×10^(-6) and a 54.49%reduction of inclusion number density was achieved with almost no inclusions larger than 5μm from the average level of industry gear steels;(3)a total oxygen content of M2 high-speed steel was as low as 3.7×10^(-6).In industrial production practice,car-bon deoxidation technique was applied in the final deoxidation stage for non-aluminum deoxidized bearing steel,and it yielded excellent results that the oxygen content was reduced to below 8×10^(-6) and the oxide inclusions in the steel mainly consist of silicates,along with small amounts of spinel and calcium aluminate.

关键词： clean deoxidation carbon deoxidation hydrogen deoxidation waste plastics deoxidation

Effect of Al_(2)O_(3)/SiO_(2) mass ratio and CaO content on viscosity and structure of slag for pyrometallurgical processing of spent automotive catalysts

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2024年第3期31卷 608-621页

作者： Zhe Wang Qi-long Wei Cheng-bin Shi Zhan-cheng Guo State key laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China

The effect of Al_(2)O_(3)/SiO_(2) mass ratio and CaO content on the viscosity and structure of the CaO-Al_(2)O_(3)-SiO_(2)-6MgO-1.5ZrO_(2)-1.5CeO_(2) slag was *** results show that with the increase in Al_(2)O_(3)/SiO_(2) mass ratio,the viscous flow units within the slag gradually change from Si-O-Si to Al-O-Al and ***,the substitution of Al_(2)O_(3) for SiO_(2) leads to the transformation of Si-O bonds towards weaker Al-O bonds,which weaken the bond strength of the aluminosilicate networks,thus leading to a decrease in the viscosity of *** increase in CaO content effectively promotes the depolymerization of the aluminosilicate networks,resulting in a significant decrease in the viscosity of the *** slag with Al_(2)O_(3)/SiO_(2) of 0.7-1.5 and CaO of 30 wt.%shows promise as the reference slag system for the Fe-collection smelting of spent automotive catalysts due to its good comprehensive performance.

关键词： Aluminosilicate slag Al_(2)O_(3)/SiO_(2)mass ratio CaO content Viscosity Slag structure

Optical manipulation of ratio-designable Janus microspheres

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Photonics Research 2024年第6期12卷 1239-1249页

作者： YULU CHEN CONG ZHAI XIAOQING GAO HAN WANG ZUZENG LIN XIAOWEI ZHOU CHUNGUANG HU State key laboratory of Precision Measuring technology and Instruments Tianjin UniversityTianjin 300072China

Angular optical trapping based on Janus microspheres has been proven to be a novel method to achieve controllable *** contrast to natural birefringent crystals,Janus microspheres are chemically synthesized of two compositions with different refractive ***,their structures can be artificially regulated,which brings excellent potential for fine and multi-degree-of-freedom manipulation in the optical ***,it is a considerable challenge to model the interaction of heterogeneous particles with the optical field,and there has also been no experimental study on the optical manipulation of microspheres with such designable refractive index *** the specific structure affects the kinematic properties of Janus microspheres remains ***,we report systematic research on the optical trapping and rotating of various ratio-designable Janus *** employ an efficient T-matrix method to rapidly calculate the optical force and torque on Janus microspheres to obtain their trapped postures and rotational characteristics in the optical *** have developed a robust microfluidic-based scheme to prepare Janus *** experimental results demonstrate that within a specific ratio range,the rotation radii of microspheres vary linearly and the orientations of microsphere are always aligned with the light polarization *** is of great importance in guiding the design of Janus *** their orientations flip at a particular ratio,all consistent with the *** work provides a reliable theoretical analysis and experimental strategy for studying the interaction of heterogeneous particles with the optical field and further expands the diverse manipulation capabilities of optical tweezers.

关键词： polarization ratio refractive

NaBH4-induced phase transition of CoSe_(2) with abundant Se deficiency for acidic oxygen reduction to hydrogen peroxide

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第2期43卷 500-510页

作者： Cai-Di Han Yong-Chao Zhang Qian Zhang Jin-Ting Wu Jian Gao Ji-Jun Zou Xiao-Dong Zhu State key laboratory Base of Eco-Chemical Engineering College of Chemical Engineering Qingdao University of Science and TechnologyQingdao266042China key laboratory for Green Chemical technology of Ministry of Education School of Chemical Engineering and TechnologyTianjin UniversityTianjin300072China

Electrocatalytic oxygen reduction(ORR)via the 2e−pathway to form H_(2)O_(2) in acidic medium has attracted extensive ***,the low activity,insufficient selectivity and high cost of catalysts have been the ***,CoSe_(2) with abundant Se deficiency was synthesized by a simple hydrothermal method,and the addition of NaBH4-induced CoSe_(2) phase transition from orthorhombic to cubic phase with more Se *** cubic phase CoSe_(2) with abundant Se deficiency can effectively regulate the surface electronic structure with suitable binding energies of*OOH and*O,which shows high activity,selectivity and long-term stability for acidic ORR to H_(2)O_(2).The onset potential is as low as 0.73 V *** hydrogen electrode(RHE),the H_(2)O_(2) selectivity is 84%(0 V ***),and the average electron transfer number is about ***,the H_(2)O_(2) yield measured using a flow cell is as high as 115.92 mmol·gcat.^(−1)·h^(−1) and the Faradaic efficiency is 70%at 0 V ***,which presents high potential in electrocatalytic acidic ORR to H_(2)O_(2) and organic pollutant degradation using the electron-Fenton process.

关键词： Se defected CoSe_(2) Crystal phase transition Electrocatalysis Acidic oxygen reduction Hydrogen peroxide