检索结果-南通市图书馆

China Foundry 2025年第1期22卷 33-44页

作者： Wei Yuan Hai-dong Zhao Xu shen Chun Zou Yuan Liu Qing-yan Xu National Engineering Research Center of Near-Net-Shape Forming for Metallic Materials South China University of TechnologyGuangzhou 510640China Key Laboratory for Advanced Materials Processing Technology(Ministry of Education) Tsinghua UniversityBeijing 100084China

Microporosity formed in the solidification process of Al alloys is detrimental to the alloy properties.A two-dimensional cellular automaton(CA)model was developed to simulate the microstructure and microporosity formation in Al-Cu alloys,considering variations in Cu content and solidification *** results indicate that the Cu content primarily influences the growth of *** validate the model,directional solidification experiments were conducted on Al-Cu alloys with varing Cu contents and withdrawal *** experimental results of dendrites and microporosity characteristics agree well with the predictions from the developed model,thus confirming the validity of the *** alloy’s liquidus temperature,dendrite morphology,and hydrogen saturation solubility arising from different Cu contents have significant effects on microporosity *** withdrawal rate primarily affects the nucleation of hydrogen microporosity by altering cooling rates and dendritic growth rates,resulting in different microporosity characteristics.

关键词： microporosity dendrites cellular automaton Al-Cu alloys directional solidification

Theoretical calculation on degradation mechanism of novel copolyesters under CALB enzyme

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2025年第3期149卷 242-253页

作者： Yuanyang Ren Zhiwen Cheng Luwei Cheng Yawei Liu Mingyue Li Tao Yuan Zhemin shen School of Environmental Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants Shanghai 200240China Shanghai Institute of Pollution Control and Ecological Security Shanghai 200092China

Poly(butylene succinate-co-furandicarboxylate)(PBSF)and poly(butylene adipateco-furandicarboxylate)(PBAF)are novel furandicarboxylic acid-based biodegradable copolyesters with great potential to replace fossil-derived terephthalic acid-based copolyesters such as poly(butylene succinate-co-terephthalate)(PBST)and poly(butylene adipate-co-terephthalate)(PBAT).In this study,quantum chemistry techniques after molecular dynamics simulations are employed to investigate the degradationmechanism of PBSF and PBAF catalyzed by Candida antarctica lipase B(CALB).Computational analysis indicates that the catalytic reaction follows a four-step mechanism resembling the ping-pong bibi mechanism,with the initial two steps being acylation reactions and the subsequent two being hydrolysis ***,the first step of the hydrolysis is identified as the rate-determining ***,by introducing single-point mutations to expand the substrate entrance tunnel,the catalytic distance of the first acylation step ***,energy barrier of the rate-determining step is decreased in the PBSF system by site-directed mutations on key residues increasing hydrophobicity of the enzyme’s active *** study unprecedently show the substrate binding pocket and hydrophobicity of the enzyme’s active site have the potential to be engineered to enhance the degradation of copolyesters catalyzed by CALB.

关键词： Poly(butylene succinate-co-furandicarboxylate) Poly(butylene adipate-co-furandicarboxylate) Candida antarctica lipase B Degradation mechanism Site-directed mutations

On the Riemann–Hilbert problem for the reverse space-time nonlocal Hirota equation with step-like initial data

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2025年第2期77卷 32-40页

作者： Bei-Bei Hu Ling Zhang Zu-Yi shen Ji Lin School of Mathematics and Finance Chuzhou University Applied Mathematics Research Center Chuzhou University Department of Physics Zhejiang Normal University

In this paper, we use the Riemann–Hilbert(RH) method to investigate the Cauchy problem of the reverse space-time nonlocal Hirota equation with step-like initial data: q(z, 0) = o(1) as z →-∞ and q(z, 0) = δ + o(1) as z → ∞, where δ is an arbitrary positive constant. We show that the solution of the Cauchy problem can be determined by the solution of the corresponding matrix RH problem established on the plane of complex spectral parameter λ. As an example, we construct an exact solution of the reverse space-time nonlocal Hirota equation in a special case via this RH problem.

关键词： nonlocal Hirota equation Cauchy problem Riemann-Hilbert problem step-like initial data

Ru doping triggering reconstruction of cobalt phosphide for coupling glycerol electrooxidation with seawater electrolysis

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2025年第1期100卷 317-326页

作者： Binglu Deng Jie shen Jinxing Lu Chuqiang Huang Zhuoyuan Chen Feng Peng Yunpeng Liu School of Materials Science and Hydrogen Energy Foshan UniversityFoshan 528000GuangdongChina School of Chemistry and Chemical Engineering Guangzhou UniversityGuangzhou 510006GuangdongChina Guangdong Key Laboratory for Hydrogen Energy Technologies Foshan 528000GuangdongChina

Seawater electrolysis is a promising approach for sustainable energy without relying on precious ***,the large-scale seawater electrolysis is hindered by low catalytic efficiency and severe anode corrosion caused by the harmful *** contrast to the oxygen evolution reaction (OER)and chlorin ion oxidation reaction (ClOR),glycerol oxidation reaction (GOR) is more thermodynamically and kinetically favorable ***,a Ru doping cobalt phosphide (Ru-CoP_(2)) is proposed as a robust bifunctional electrocatalyst for seawater electrolysis and GOR,for the concurrent productions of hydrogen and value-added *** in situ and ex situ characterization analyses demonstrated that Ru doping featured in the dynamic reconstruction process from Ru-CoP_(2)to Ru-CoOOH,accounting for the superior GOR *** coupling GOR with hydrogen evolution was realized by employing Ru-CoP_(2)as both anode and cathode,requiring only a low voltage of 1.43 V at 100 mA cm^(-2),which was 250 m V lower than that in alkaline *** work guides the design of bifunctional electrocatalysts for energy-efficient seawater electrolysis coupled with biomass resource upcycling.

关键词： Glycerol electrooxidation Hydrogen evolution Ru doping Cobalt phosphide Bifunctional electrocatalysts

Magnetism and cryogenic magnetocaloric effect of triangular-lattice LnOF(Ln=Gd,Dy,Ho,and Er) compounds

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2025年第1期43卷 98-104,I0004页

作者： Jianjian Gong Lu Tian Lei Zhang Zhaojun Mo Yuanpeng Wang Jun shen School of Rare Earths University of Science and Technology of ChinaHefei230026China Key Laboratory of Rare Earths Ganjiang Innovation AcademyChinese Academy of SciencesGanzhou34119China Department of Energy and Power Engineering School of Mechanical EngineeringBeijing Institute of TechnologyBeijing00081China

Frustrated lanthanide oxides with dense magnetic lattice and suppressed ordering temperature have potential applications in cryogenic magnetic ***,the crystal structure,magnetic properties,magnetic phase transition(MPT)together with magnetocaloric effect(MCE)of LnOF(Ln=Gd,Dy,Ho,and Er)compounds were *** study shows that these compounds crystallize in the centrosymmetric space group R3m with an ideal triangular *** long-range magnetic ordering is observed above 2 K for LnOF(Ln=Gd,Ho,and Er).However,DyOF compound undergoes an MPT from paramagnetic(PM)to antiferromagnetic(AFM)at the Neel temperature(TN≈4 K).Considerable reversible MCE is observed in these triangular-lattice *** the magnetic field change(μ0ΔH)of 0-2 T,the maximum values of magnetic entropy change(-ΔSMmax)of them are 6.1,9.4,12.7,and 14.1 J/(kg·K),***,the value of ErOF with Ising-like spin is 2.3 times that of GdOF,which provides an approach for exploring magnetic refrigerants with excellent low-field cryogenic magnetocaloric effect.

关键词： Geometric magnetic frustration Magnetic phase transition Magnetocaloric effect Magnetic refrigeration Rare earths

Experimental study on the buckling of composite cylinders with reinforced circular hole under hydrostatic pressure

在线全文

学校读者我要写书评

暂无评论

Defence Technology(防务技术) 2025年第2期44卷 231-247页

作者： Zhun Li Xinhu Zhang Kechun shen Jing Liu Jian Zhang Guang Pan School of Marine Science and Technology Northwestern Polytechnical UniversityXi'an 710072China Northwest Institute of Mechanical and Electrical Engineering Xianyang 712099China Jiangsu University of Science and Technology Zhenjiang 212003China

In this paper,a type of reinforcing structure for composite shell with single and through hole is *** experimental tests for the composite shells without hole,with single hole and reinforced structure,with through hole and reinforced structure subjected to hydrostatic pressure were carried out by the designed experimental test *** mechanical responses of the composite shells under hydrostatic pressure are obtained by the high-speed camera and strain *** results show that the entire deformation process of the shell can be divided into three:uniform compression,"buckling mode formation"and ***"buckling mode formation"process is captured and reported for the first *** the composite shell with single hole,the proposed reinforcing structure has a significant reinforcement effect on the shell and the buckling capacity of the shell is not weaker than the complete composite *** the composite shell with through hole,sealing effect can be achieved by the proposed reinforcing structure,but the buckling capacity of the shell after reinforcement can only reach 77%of the original buckling capacity.

关键词： Composite cylindrical shell Circular hole Reinforcing structure Buckling Hydrostatic pressure

Numerical Analysis of Urban-Rail Vehicle/Tunnel Aerodynamic Interaction

在线全文

学校读者我要写书评

暂无评论

Fluid Dynamics & Materials Processing 2025年第1期21卷 161-178页

作者： Haoran Meng Nianxun Li Xukui shen Hong Zhang Tian Li Beijing Infrastructure Investment Co. Ltd.Beijing100101China Beijing Rail Transit Technology Equipment Group Co. Ltd.Beijing100070China Department of Mechanical Engineering Tsinghua UniversityBeijing100084China State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong UniversityChengdu610031China

The pressure wave generated by an urban-rail vehicle when passing through a tunnel affects the comfort of passengersand may even cause damage to the train and related tunnel ***,controlling the trainspeed in the tunnel is extremely *** this study,this problem is investigated numerically in the frameworkof the standard k-εtwo-equation turbulence *** particular,an eight-car urban rail train passingthrough a tunnel at different speeds(140,160,180 and 200 km/h)is *** results show that the maximumaerodynamic drag of the head and tail cars is most affected by the running *** pressure at selectedmeasuring points on the windward side of the head car is very high,and the negative pressure at the side windowof the driver’s cab of the tail car is also very *** the head car to the tail car,the pressure at the same heightgradually *** positive pressure peak at the head car and the negative pressure peak at the tail car aregreatly affected by the speed.

关键词： Urban-rail vehicle vehicle speed aerodynamic force surface pressure numerical simulation

Electrochemical removal of nitrate in high-salt wastewater with low-cost iron electrode modified by phosphate

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 2025年第2期148卷 38-45页

作者： Fengjiao Quan Guangming Zhan Pengfei Xu Xiaolan Chen Wenjuan shen Falong Jia Yun He Jianfen Li College of Chemical and Environmental Engineering Wuhan Polytechnic UniversityWuhan 430023China College of Chemistry Central China Normal UniversityWuhan 430079China School of Environmental Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China

Nitrate(NO3-)is a widespread pollutant in high-salt wastewater and causes serious harm to human *** electrochemical removal of nitrate has been demonstrated to be a promising treatment method,the development of low-cost electro-catalysts is still *** this work,a phosphate modified iron(P-Fe)cathode was prepared for electrochemical removal of nitrate in high-salt *** phosphate modification greatly improved the activity of iron,and the removal rate of nitrate on P-Fe was three times higher than that on Fe *** experiments and density functional theory(DFT)calculations demonstrated that the modification of phosphoric acid improved the stability and the activity of the zero-valent iron electrode effectively for *** nitrate was firstly electrochemically reduced to ammonium,and then reacted with the anodic generated hypochlorite to *** this study,a strategy was developed to improve the activity and stability of metal electrode for NO_(3)^(-)removal,which opened up a new field for the efficient reduction of NO3-removal by metal electrode materials.

关键词： Nitrate removal High-salt wastewater Electrocatalysis Phosphate modified Iron

Dual-role regulator of a novel miR-3040 in photoperiod-mediated wing dimorphism and wing development in green peach aphid

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Insect Science 2025年第1期32卷 80-94页

作者： Yun-Hui Zhang Xin Qian Xin Zong Shi-Heng An Shuo Yan Jie shen College of Plant Protection Henan Agricultural UniversityZhengzhouChina Department of Plant Biosecurity College of Plant ProtectionChina Agricultural UniversityBeijingChina

Wing dimorphism is regarded as an important phenotypic plasticity involved in the migration and reproduction of ***,the signal transduction and regulatory mechanism of wing dimorphism in aphids are still ***,the optimal environmental conditions were first explored for inducing winged offspring of green peach aphid,and the short photoperiod was the most important environmental cue to regulate wing *** to 16 L:8 D photoperiod,the proportion of winged offspring increased to 90%under 8 L:16 D ***,5 differentially expressed microRNAs(miRNAs)in aphids treated with long and short photoperiods were identified using small RNA sequencing,and a novel miR-3040 was identified as a vital miRNA involved in photoperiod-mediated wing *** specifically,the inhibition of miR-3040 expression could reduce the proportion of winged offspring induced by short photoperiod,whereas its activation increased the proportion of winged offspring under long ***,the expression level of miR-3040 in winged aphids was about 2.5 times that of wingless aphids,and the activation or inhibition of miR-3040 expression could cause wing deformity,revealing the dual-role regulator of miR-3040 in wing dimorphism and wing *** summary,the current study identified the key environmental cue for wing dimorphism in green peach aphid,and the first to demonstrate the dual-role regulator of miR-3040 in photoperiod-mediated wing dimorphism and wing development.

关键词： miR-3040 Myzus persicae photoperiod wing development wing dimorphism

From waste to wealth:Coal tar residue derived carbon materials as low-cost anodes for potassium-ion batteries

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 464-475页

作者： Zhonghua Lu Jun shen Xin Zhang Lingcong Chao Liang Chen Ding Zhang Tao Wei Shoudong Xu College of Chemical Engineering and Technology Taiyuan University of TechnologyTaiyuan 030024China College of Chemistry Taiyuan University of TechnologyTaiyuan 030024China School of Chemical Engineering and Pharmacy Wuhan Institute of TechnologyWuhan 430205China School of Energy and Power Jiangsu University of Science and TechnologyZhenjiang 212003China

Carbon materials are widely recognized as highly promising electrode materials for various energy storage system *** tar residues(CTR),as a type of carbon-rich solid waste with high value-added utilization,are crucially important for the development of a more sustainable *** this study,we employed a straightforward direct carbonization method within the temperature range of 700-1000℃to convert the worthless solid waste CTR into economically valuable carbon materials as anodes for potassium-ion batteries(PIBs).The effect of carbonization temperature on the microstructure and the potassium ions storage properties of CTR-derived carbons(CTRCs)were systematically explored by structural and morphological characterization,alongside electrochemical performances *** on the co-regulation between the turbine layers,crystal structure,pore structure,functional groups,and electrical conductivity of CTR-derived carbon carbonized at 900℃(CTRC-900H),the electrode material with high reversible capacity of 265.6m Ah·g^(-1)at 50 m A·g^(-1),a desirable cycling stability with 93.8%capacity retention even after 100 cycles,and the remarkable rate performance for PIBs were ***,cyclic voltammetry(CV)at different scan rates and galvanostatic intermittent titration technique(GITT)have been employed to explore the potassium ions storage mechanism and electrochemical kinetics of *** indicate that the electrode behavior is predominantly governed by surface-induced capacitive processes,particularly under high current densities,with the potassium storage mechanism characterized by an“adsorption-weak intercalation”*** work highlights the potential of CTR-based carbon as a promising electrode material category suitable for high-performance PIBs electrodes,while also provides valuable insights into the new avenues for the high value-added utilization of CTR.

关键词： coal tar residue carbon materials anode potassium-ion batteries high value-added