检索结果-南通市图书馆

Development of a novel fabricating thin-walled TA2 titanium tube via high-frequency induction welding

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:materials International 2024年第2期34卷 314-322页

作者： Yanfeng Liu Qi Chen Jibing Chen Junsheng Yang Shijie Dong School of Mechanical engineering Wuhan Polytechnic University Hubei Sanjiang aerospace Jiangbei Mechanical engineering Co. Ltd

Due to the problems of low welding efficiency, large heat-affected zone, and poor welding quality in the process of welding thin-walled titanium tubes by argon arc welding, there are few studies on the use of high-frequency induction welding(HFIW) of thin-walled titanium alloy tubes. The evolution law of weld microstructure and mechanical properties of the thin-walled titanium tube needs to be further studied because of rapid welding speed and the small heat-affected zone of HFIW. Therefore, a novel manufacturing method via high-frequency induction welding is proposed in this paper to solve the existing problems. With an industrial-grade titanium TA2 tube(wall's thickness is 0.5 mm) as the research object, a comparative study is conducted in this research to examine the morphology, microstructure, microhardness, and tensile characteristics of welded joints at different welding power. The findings demonstrated a significant efficacy of HFIW in resolving these challenges. The mechanical properties and microstructue of heat-affected zone(HAZ) were characterized. The lowest hardness is measured at202 HV, while the base material was recorded as 184 HV, when the welding speed of HFIW is set at 50 m/min.Meanwhile, the heat-affected zone has the highest hardness at 224 HV, a tensile strength of 446.8 MPa and a postfracture elongation of 16%. The results showed that HFIW can not only greatly improve the welding efficiency,significantly improve the microstructure of weld joint and HAZ, and improve the mechanical properties of thinwalled titanium pipe, but also provide a highly feasible welding method for welding ultra-thin-walled pipes.

关键词： Heat-affected zone High-frequency induction welding Mechanical property Microstructure TA2 titanium Thin-walled tube

Superwetting Ag/α-Fe_(2)O_(3) anchored mesh with enhanced photocatalytic and antibacterial activities for efficient water purification

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Green Energy & Environment 2024年第1期9卷 89-103页

作者： Jiakai Li Changpeng Lv Jiajia Song Xiaoling Zhang Xizhen Huang Yingzhuo Ma Haijie Cao Na Liu Department of Chemistry Tsinghua UniversityBeijing100084China Anhui Provincial engineering Laboratory of Silicon-based materials Engineering Technology Research Center of Silicon-based Materials(Anhui)School of Material and Chemical EngineeringBengbu UniversityBengbu233030China Institute of materials for Energy and Environment College of Materials Science and EngineeringQingdao UniversityQingdao266071China

Superwetting materials have drawn unprecedented attention in the treatment of oily wastewater due to their preferable anti-fouling property and selective oil/water separation.However,it is still a challenge to fabricate multifunctional and environmentally friendly materials,which can be stably applied to purify the actual complicated wastewater.Here,a Ag/Ag/α-Fe_(2)O_(3) heterostructure anchored copper mesh was intentionally synthesized using a facile two-step hydrothermal method.The resultant mesh with superhydrophilicity and underwater superoleophobicity was capable of separating various oil/water mixtures with superior separation efﬁciency and high permeationﬂux driven by gravity.Beneﬁting from the joint effects of the smaller band gap of Ag/α-Fe_(2)O_(3) heterojunction,inherent antibacterial capacity of Ag/α-Fe_(2)O_(3) and Ag nanoparticles,favorable conductive substrate,as well as the hierarchical structure with superwettability,such mesh presented remarkably enhanced degradation capability toward organic dyes under visible light irradiation and antibacterial activity against both Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)compared with the pure Ag/α-Fe_(2)O_(3) coated mesh.Impressively,the mesh exhibited bifunctional water puriﬁcation performance,in which organic dyes were eliminated simultaneously from water during oil/water separation in oneﬁltration process.More importantly,this mesh behaved exceptional chemical resistance,mechanical stability and long-term reusability.Therefore,this material with multifunctional integration may hold promising potential for steady water puriﬁcation in practice.

关键词： Superwetting Ag/α-Fe_(2)O_(3)heterostructure Enhanced photocatalytic and antibacterial activities Water purification Long-term reusability

Honeycomb-like biochar framework coupled with Fe_(3)O_(4)/FeS nanoparticles as efficient heterogeneous Fenton catalyst for phenol degradation

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第2期136卷 390-399页

作者： Aihua Cheng Yi He Xiaohe Liu Chi He Department of Environmental engineering College of Geology and EnvironmentXi’an University of Science and TechnologyXi’an 710054China State Key Laboratory of Multiphase Flow in Power engineering School of Energy and Power EngineeringXi’an Jiaotong UniversityXi’an 710049China National engineering Laboratory for VOCs Pollution Control material and Technology University of Chinese Academy of SciencesBeijing 101408China

Achieving an efficient and stable heterogeneous Fenton reaction over a wide pH range is of great significance for wastewater treatment.Here,a pollen-derived biochar catalyst with a unique honeycomb-like structure,coupled with the dispersion of magnetic Fe_(3)O_(4)/FeS(Fe/S)nanoparticles,was synthesized by simple impregnation precursor,followed by pyrolysis.The prepared Fe/S-biochar catalyst demonstrated outstanding phenol degradation efficiency across a wide pH range,with 98%of which eliminated even under neutral conditions(pH 7.0).The high catalytic activity was due to the multilevel porous structure of pollenderived biochar provided enough active sites and allowed for better electron transfer,then increases oxidation ability to promote the reaction.Moreover,the acid microenvironment formed by SO_(4)^(2-)group from Fe/S composite extended the pH range for Fenton reaction,and S^(2-)facilitated the conversion of≡Fe^(3+)to≡Fe^(2+),resulting in remarkable degradation efficiency.Further,biochar can effectively promote cycling stability by limiting Fe leaching.This work may provide a general strategy for designing 3D framework biochar-based Fe/S catalysts with excellent performance for heterogeneous Fenton reactions.

关键词： Biomass Biochar Fenton reaction Fe_(3)O_(4)/FeS(Fe/S) Phenol degradation

节流式燃氧分离固体发动机准一维内弹道数值研究

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2024年第1期40卷 85-101页

作者：王立民王富祺王志邦王英男王革关奔周星 college of aerospace Science and engineering National University of Defense TechnologyChangsha 410073China Inner Mongolia Dynamic and Mechanical Institute Hohhot 010011China college of aerospace and Civil engineering Harbin Engineering UniversityHarbin 150001China college of engineering Peking UniversityBeijing 100871China

本文建立了用于计算节流式燃氧分离固体发动机内弹道的准一维数值模型。节流式燃氧分离固体发动机通过改变富燃燃烧室和富氧燃烧室之间的节流阀开口半径来实现其推力的调节。数值模型采用简化的反应机理来描述化学非平衡过程,且考虑了... 详细信息

本文建立了用于计算节流式燃氧分离固体发动机内弹道的准一维数值模型。节流式燃氧分离固体发动机通过改变富燃燃烧室和富氧燃烧室之间的节流阀开口半径来实现其推力的调节。数值模型采用简化的反应机理来描述化学非平衡过程,且考虑了燃烧室中的质量添加、壁面摩擦和推进剂燃面退移过程。利用该数值模型展示了节流式燃氧分离固体发动机的内部流动参数分布和工作性能.发动机稳定工作状态结果显示,当节流阀开度半径由10.5mm调节至1.4mm时,发动机推力由121.82N增加至250.60N,推力提升了206%,验证了节流式燃氧分离固体发动机概念的可行性.流动参数也表明节流阀的调节作用仅在阀门开度较小时才得以充分体现.发动机动态工作过程结果显示,在调节阀停止作动时,节流式燃氧分离固体发动机性能会产生负调现象,因而需要对发动机采取额外的保护措施.对节流式燃氧分离固体发动机调节能力的理论预测发现,发动机的推力调节能力受限于富燃燃烧室压力和初始质量流量比,需要在多个参数之间进行权衡以实现合理的推力调节比.最后对推进剂的布置方式进行了初步探讨结果表明,燃氧推进剂布置下发动机的推力调节能力优于氧燃推进剂布置。

关键词：固体发动机化学非平衡燃烧室压力阀门开度质量流量比流动参数节流阀开度准一维

Oxygen-vacancy-rich MnOx supported RuOx for efficient base-free oxidation of 5-hydroxymethylfurfural and 5-methoxymethylfurfural to 2,5-furandicarboxylic acid

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 Energy Chemistry 2024年第8期95卷 670-683页

作者： Jiali Wu Weizhen Xie Yining Zhang Xixian Ke Tianyuan Li Huayu Fang Yong Sun Xianhai Zeng Lu Lin Xing Tang Xiamen Key Laboratory of Clean and High-valued Applications for Biomass Fujian Engineering and Research Center of Clean and High-valued Technologies for Biomass College of Energy Xiamen University Key Lab for Sport Shoes Upper materials of Fujian Province Fujian Engineering and Research Center for New Functional Fiber Materials(Fujian Huafeng New Material Co.Ltd.Putian Dakai New Material Co. Ltd.)

2,5-Furandicarboxylic acid（FDCA） is a promising biomass-derived polymeric monomer that serves as an attractive alternative to terephthalic acid derived from fossil resources. However, the green and efficient production of FDCA through the oxidation of 5-hydroxymethylfurfural（HMF） and its derivatives is still rudimentary under base-free conditions. In this work, oxygen-vacancy-rich Mn Oxwas prepared and displayed a strong adsorption and anchoring ability to Ru species that mainly exposed the（2 1 0） plane of RuO2, bringing about highly dispersed and active interfacial Ru-O-Mn structures. Experimental results and density functional theory calculations confirm that these above features greatly facilitate the adsorption/activation of oxygen and the dehydrogenation-oxidation of HMF/5-methoxymethylfurfural（MMF）,which enables an efficient FDCA production under base-free and mild conditions. Notably, a desirable FDCA yield of 86.56% was still obtained from concentrated HMF（10 wt%） under base-free conditions over oxygen-vacancy-rich Mn Oxsupported Ru Ox（1.0 MPaO2, 120 °C, 6 h）. This work delineates a facile catalyst preparation strategy for HMF/MMF oxidation, and might open a new avenue for the green synthesis of FDCA under base-free conditions.

关键词： 2,5-Furandicarboxylic acid 5-Hydroxymethylfurfural 5-Methoxymethylfurfural Base-free oxidation Oxygen-vacancy-rich

Research on the macro-and meso-mechanical properties of frozen sand mold based on Hertz-Mindlin with Bonding model

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Particuology 2024年第5期88卷 176-191页

作者： Jianpei Shi Zhongde Shan Haoqin Yang college of Mechanical and Electrical engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and AstronauticsNanjing 210016China college of material Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 210016China

In this study,macro-and meso-mechanical properties of frozen sand molds were discussed based on the Hertz-Mindlin with Bonding(HMB)model.Plackett-Burman,steepest ascent,and central composite designs were utilized to propose a parameter calibration methodology.The effects of mesoscopic parameter variations on the compressive strength and average gradient of stress-strain were investigated through response surface method analysis.Results showed that the relative error between the simulated and measured repose angle is 3.1%under calibrated intrinsic contact parameters.The compressive strength and average stress-strain gradient primarily depend on the normal and shear stiffness per unit area,as well as the particle size and porosity of the silica sand.Furthermore,taking load-displacement curves of three frozen sand molds with different geometric characteristics as the target value,the reliability and effectiveness of the frozen sand mold HMB model were verified through uniaxial compression tests and discrete element simulations.

关键词： Frozen sand mold Hertz-Mindlin with Bonding model Uniaxial compression test Discrete element method Mechanical properties

Highly-chlorinated inert and robust interphase without mineralization of oxide enhancing high-rate Li metal batteries

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

Chinese Chemical Letters 2024年第6期35卷 239-243页

作者： Long Li Kang Yang Chenpeng Xi Mengchao Li Borong Li Gui Xu Yuanbin Xiao Xiancai Cui Zhiliang Liu Lingyun Li Yan Yu Chengkai Yang Key Laboratory of Advanced materials Technologies International(HongKong Macao and Taiwan)Joint Laboratory on Advanced Materials TechnologiesSchool of Materials Science and EngineeringFuzhou UniversityFuzhou 350108China college of material Sciences and Chemical engineering Harbin Engineering UniversityHarbin 150001China

Side reactions and dendrite growth triggered by the unstable interface and inhomogeneous deposition have become the biggest obstacle to the commercialization for lithium metal batteries.In this study,a highly-chlorinated organic-inorganic hybrid interfacial protective layer is developed by rationally tuning the interfacial passivation and robustness to achieve the convenient and efficient Li metal anode.The polyvinyl chloride(PVC)can effectively resist water and oxygen,which is confirmed by density functional theory.The organic-dominant solid electrolyte interphases(SEI)with lithium chloride are investigated by the X-ray photoelectron spectroscopy(XPS)with little mineralization of oxide,such as Li_(2)O and Li_(2)CO_(3).With such artificial SEI,a uniform and dense lithium deposition morphology are formed and an ultra-long stable cycle of over 500 h are achieved even at an ultra-high current density of 10 m A/cm^(2).Moreover,the simple and convenient protected anode also exhibits excellent battery stability when paired with the LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)and LiFePO_(4)(LFP)cathode,showing great potential for the commercial application of lithium metal batteries.

关键词： Highly-chlorinated Water/oxygen resistance Stable interphase Dendrite-free lithium metal batteries High-rate

Supposition of graphene stacks to estimate the contact resistance and conductivity of nanocomposites

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2024年第4期45卷 663-676页

作者： Y.ZARE M.T.MUNIR G.J.WENG K.Y.RHEE Biomaterials and Tissue engineering Research Group Department of Interdisciplinary TechnologiesBreast Cancer Research CenterMotamed Cancer InstituteTehran ***Iran college of engineering and Technology American University of the Middle EastEgaila 54200Kuwait Department of Mechanical and aerospace engineering Rutgers UniversityNew BrunswickNJ 08903U.S.A. Department of Mechanical engineering(BK21 Four) College of EngineeringKyung Hee UniversityYongin 446701Republic of Korea

In this study,the effects of stacked nanosheets and the surrounding interphase zone on the resistance of the contact region between nanosheets and the tunneling conductivity of samples are evaluated with developed equations superior to those previously reported.The contact resistance and nanocomposite conductivity are modeled by several influencing factors,including stack properties,interphase depth,tunneling size,and contact diameter.The developed model's accuracy is verified through numerous experimental measurements.To further validate the models and establish correlations between parameters,the effects of all the variables on contact resistance and nanocomposite conductivity are analyzed.Notably,the contact resistance is primarily dependent on the polymer tunnel resistivity,contact area,and tunneling size.The dimensions of the graphene nanosheets significantly influence the conductivity,which ranges from 0 S/m to90 S/m.An increased number of nanosheets in stacks and a larger gap between them enhance the nanocomposite's conductivity.Furthermore,the thicker interphase and smaller tunneling size can lead to higher sample conductivity due to their optimistic effects on the percolation threshold and network efficacy.

关键词： graphene polymer composite stacked nanosheet tunneling conductivity contact resistance interphase

Promotion effect of epoxy group neighboring single-atom Cu site on acetylene hydrochlorination

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第6期35卷 258-262页

作者： Junchen Peng Xue Yin Dandan Dong Zhongyuan Guo Qinqin Wang Minmin Liu Fei He Bin Dai Chaofeng Huang School of Chemistry and Chemical engineering/State Key Laboratory Incubation Base for Green Processing of Chemical engineering Shihezi UniversityShihezi 832000China college of Chemistry&Chemical engineering Yantai UniversityYantai 264010China School of material Science and engineering University of JinanJi’nan 250022China

Carbon materials have been used as the support for catalysts in the field of acetylene hydrochlorination,the influence of inevitable oxygen-containing moieties on the reaction is often ignored and the mechanism of the oxygen-doping structure remains ambiguous.Herein,we explored the effect of the oxygen-containing group(C-O-C)in the support on the activity of single-atom dispersed Cu catalysts.By immersing the Cu single-atom catalyst in an alkaline solution,the epoxy species on the carbon support was cleaved to obtain a pure ether species while the Cu site was modified to a more electron-deficient state.The turnover frequency value of Cu/O-FLP catalyst with epoxy groups was 1.6-fold higher than that of alkaline treated catalyst.Our result indicated that the epoxy groups could assist adjacent single-atom Cu sites to synergistically promote the adsorption and cleavage of the reactant hydrogen chloride toward form C-OH and Cu-Cl bonds,and reduce the reaction energy barrier.The presence of electron deficient Cu sites and ether species could induce competitive adsorption of the acetylene and hydrogen chloride,thereby reducing the activity of the catalyst.This study highlights the influence of surface oxygen species and the tunability of the support,providing the foundation for the fabrication of higher-activity Cu catalysts for acetylene hydrochlorination.

关键词： Epoxy group Acetylene hydrochlorination Single-atom Cu catalyst Synergistic dissociation