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China Ocean Engineering 2024年第2期38卷 285-296页

作者： du Zun-feng ZHU Hai-ming YU Jian-xing State Key Laboratory of Hydraulic Engineering Intelligent Construction and Operation School of Civil EngineeringTianjin UniversityTianjin 300350China

When investigating the vortex-induced vibration(VIV)of marine risers,extrapolating the dynamic response on the entire length based on limited sensor measurements is a crucial step in both laboratory experiments and fatigue monitoring of real *** problem is conventionally solved using the modal decomposition method,based on the principle that the response can be approximated by a weighted sum of limited vibration ***,the method is not valid when the problem is underdetermined,i.e.,the number of unknown mode weights is more than the number of known *** study proposed a sparse modal decomposition method based on the compressed sensing theory and the Compressive Sampling Matching Pursuit(Co Sa MP)algorithm,exploiting the sparsity of VIV in the modal *** the validation study based on high-order VIV experiment data,the proposed method successfully reconstructed the response using only seven acceleration measurements when the conventional methods failed.A primary advantage of the proposed method is that it offers a completely data-driven approach for the underdetermined VIV reconstruction problem,which is more favorable than existing model-dependent solutions for many practical applications such as riser structural health monitoring.

关键词： motion reconstruction vortex-induced vibration(VIV) marine riser modal decomposition method compressed sensing

Numerical Study on Reduction in Aerodynamic Drag and Noise of High-Speed Pantograph

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Computer Modeling in Engineering & Sciences 2024年第5期139卷 2155-2173页

作者： Deng Qin xing.du Tian Li Jiye Zhang State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong UniversityChengdu610031China School of Electrical Engineering Southwest Jiaotong UniversityChengdu610031China

Reducing the aerodynamic drag and noise levels of high-speed pantographs is important for promoting environmentally friendly,energy efficient and rapid advances in train *** computational fluid dynamics theory and the K-FWH acoustic equation,a numerical simulation is conducted to investigate the aerodynamic characteristics of high-speed pantographs.A component optimization method is proposed as a possible solution to the problemof aerodynamic drag and noise in high-speed *** results of the study indicate that the panhead,base and insulator are the main contributors to aerodynamic drag and noise in high-speed ***,a gradual optimization process is implemented to improve the most significant components that cause aerodynamic drag and *** optimizing the cross-sectional shape of the strips and insulators,the drag and noise caused by airflow separation and vortex shedding can be *** aerodynamic drag of insulator with circular cross section and strips with rectangular cross section is the *** insulators and optimizing the chamfer angle and height of the windward surface of the strips can improve the aerodynamic performance of the *** addition,the streamlined fairing attached to the base can eliminate the complex flow and shield the radiated *** contrast to the original pantograph design,the improved pantograph shows a 21.1%reduction in aerodynamic drag and a 1.65 dBA reduction in aerodynamic noise.

关键词： High-speed pantograph aerodynamic drag aerodynamic noise reduction optimizing

Tuning heterogeneous microstructures to enhance mechanical properties of nano-TiN particle reinforced Haynes 230 composites by laser powder bed fusion

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Rare Metals 2024年第9期43卷 4548-4565页

作者： Wen-Jie Liu Hui Li Qian-xing Yin He-Jun du School of Power and Mechanical Engineering Wuhan UniversityWuhan 430072China The Institute of Technological Sciences Wuhan UniversityWuhan 430072China School of Mechanical&Aerospace Engineering Nanyang Technological UniversitySingapore 639798Singapore

Laser powder bed fusion(LPBF)is considered to be one of the most promising additive manufacturing technologies for producing components with geometries and high geometrical precision that are unattainable by traditional *** superalloy exhibits exceptional mechanical and high-temperature performances,rendering it a prime candidate for advanced aero-engine *** the high demand for LPBF-manufactured superalloys,the superalloy is one of the materials manufactured difficultly by LPBF due to their large laser absorptivity fluctuation,poor molten pool stability and sharp temperature ***,superalloys are characterized by severe pores,undesirable coarse columnar grains and poor mechanical *** this work,the effect of nano-TiN particles on defects,molten pool characteristics and microstructure and performance of the composites were *** 4.5 wt%TiN/Haynes230 samples exhibited exceptional nanohardness and elastic modulus with maximum values reaching 5.53 GPa and 240.03 GPa,*** superior mechanical properties were attributed to the combined effects of spatter and gas pore inhibition,grain refinement and duplex nanophases ***,the stability of molten pool was enhanced,and spatter was effectively suppressed by adding nano-TiN particles,while grain refinement and columnar to equiaxed transitions were ***,the matrix exhibited a high dislocation density due to a significant hindrance of dislocation movement caused by massive nano-phases(e.g.,TiN and M_(23)C_(6)),resulting in the formation of extensive dislocation tangles and *** work offers novel insights into the role of nanoparticles reinforced superalloy composites by LPBF.

关键词： Composites Laser powder bed fusion Molten pool characteristics Microstructure Mechanical properties

Effects of environment and genotype-by-environment interaction on phenotype of Rorippa elata(Brassicaceae),an endemic alpine plant in the Hengduan mountains

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Journal of Plant Ecology 2024年第4期17卷 42-55页

作者： Zhi-Qiang du Yao-Wu xing Ting-Shen Han CAS Key Laboratory of Tropical Forest Ecology Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesMengla 666303China University of Chinese Academy of Sciences Beijing 100049China State Key Laboratory of Plant Diversity and Specialty Crops Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesMengla 666303China

Global climate change poses a severe threat to mountain *** plasticity and local adaptation are two common strategies for alpine plant to cope with such *** may facilitate organismal adaptation to contrasting environments,depending on the influences of the environment or genotype or their interacted *** this study,we use an endemic alpine plant(Rorippa elata)in the Hengduan mountains(HDM)to unravel its phenotypic basis of adaptation strategy and evaluate the relative contributions of environment and genotype to its *** transplanted 37 genotypes of *** into two common gardens across low and high elevations(2800 vs.3800 m)during *** fitness-related traits were measured,including flowering probability and glucosinolates(GS)*** estimated the environmental or genotypic contributions to the phenotype and identified the main environmental *** results revealed that both environment and genotype-by-environment interactions contributed to the phenotypes of *** heterogeneity was identified as a key factor that explained 24%of the total phenotypic *** particular,genotypes of the northern HDM showed significantly higher plasticity in flowering probability than those of the southern ***,within the southern HDM,GS content indicated local adaptation to herbivory stresses for *** genotypes along *** conclusion,our results suggest that *** may have adapted to the alpine environment through species-level plasticity or regional-level local *** processes were shaped by either complex topography or interactions between genotype and mountain *** study provides empirical evidence on the adaptation of alpine plants.

关键词： alpine plant common garden genotype-by-environment Hengduan mountains local adaptation phenotypic plasticity

miR‑423 sponged by lncRNA NORHA inhibits granulosa cell apoptosis

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Journal of Animal Science and Biotechnology 2024年第2期15卷 632-644页

作者： Yuqi Li Zhuofan Zhang Siqi Wang xing.du Qifa Li College of Animal Science and Technology Nanjing Agricultural UniversityNanjing 210095China

Background Atresia and degeneration,a follicular developmental fate that reduces female fertility and is triggered by granulosa cell(GC)apoptosis,have been induced by dozens of ***,we report a miRNA,miR-423,that inhibits the initiation of follicular atresia(FA),and early apoptosis of *** We showed that miR-423 was down-regulated during sow FA,and its levels in follicles were negatively correlated with the GC density and the P4/E2 ratio in the follicular fluid in *** in vitro gain-of-function experiments revealed that miR-423 suppresses cell apoptosis,especially early apoptosis in *** speaking,the miR-423 targets and interacts with the 3’-UTR of the porcine SMAD7 gene,which encodes an apoptosis-inducing factor in GCs,and represses its expression and pro-apoptotic ***,FA and the GC apoptosis-related lncRNA NORHA was demonstrated as a ceRNA of ***,we showed that a single base deletion/insertion in the miR-423 promoter is significantly associated with the number of stillbirths(NSB)trait of *** These results demonstrate that miR-423 is a small molecule for inhibiting FA initiation and GC early apoptosis,suggesting that treating with miR-423 may be a novel approach for inhibiting FA initiation and improving female fertility.

关键词： Granulosa cell apoptosis miR-423 NORHA SMAD7 Sow fertility traits

Adjustment mechanism of blasting dynamic-static action in the water decoupling charge

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International Journal of Mining Science and Technology 2024年第6期34卷 821-836页

作者： Hao Zhang Xueyang xing Yiteng du Tingchun Li Jianxin Yu Qingwen Zhu College of Civil Engineering and Architecture Shandong University of AeronauticsBinzhou 256600China Shandong Key Laboratory of Civil Engineering Disaster Prevention and Mitigation Shandong University of Science and TechnologyQingdao 266590China School of Civil Engineering Henan Polytechnic UniversityJiaozuo 454003China

Water decoupling charge blasting excels in rock breaking,relying on its uniform pressure transmission and low energy *** water decoupling coefficients can adjust the contributions of the stress wave and quasi-static ***,the quantitative relationship between the two contributions is unclear,and it is difficult to provide reasonable theoretical support for the design of water decoupling *** this study,a theoretical model of blasting fracturing partitioning is *** mechanical mechanism and determination method of the optimal decoupling coefficient are *** reliability is verified through model experiments and a field *** results show that with the increasing of decoupling coefficient,the rock breaking ability of blasting dynamic action decreases,while quasi-static action increases and then *** ability of quasi-static action to wedge into cracks changes due to the spatial adjustment of the blast hole and crushed *** quasi-static action plays a leading role in the fracturing range,determining an optimal decoupling *** optimal water decoupling coefficient is not a fixed value,which can be obtained by the proposed theoretical *** with the theoretical results,the maximum error in the model experiment results is 8.03%,and the error in the field test result is 3.04%.

关键词： Water decoupling blasting Blasting dynamic-static action Optimal decoupling coefficient Adjustment mechanism

Engineered interface of three-dimensional coralliform NiS/FeS_(2)heterostructures for robust electrocatalytic water cleavage

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Nano Research 2024年第6期17卷 4693-4701页

作者： Xin Yu Jing Mei Yeshuang du Xiaohong Cheng xing Wang Qi Wu State Key Laboratory of New Textile Materials and Advanced Processing Technologies Wuhan Textile UniversityWuhan 430073China Hubei Key Laboratory of Pollutant Analysis&Reuse Technology College of Chemistry and Chemical EngineeringHubei Normal UniversityHuangshi 435002China Hubei Key Laboratory of Low Dimensional Optoelectronic Materials and Devices Hubei University of Arts and ScienceXiangyang 441053China

Heterojunction structures improve the intrinsic activity of electrocatalysts by enhancing the charge transfer between the catalyst and the *** this paper,the NiS/FeS_(2)heterostructured electrocatalyst is fabricated by a simple sulfidation method using an interface engineering strategy to adjust the surface electron density of the *** expected,NiS/FeS_(2)electrocatalyst exhibits superior activity and durable oxygen evolution reaction(OER)stability,requiring only a low overpotential of 183 mV to achieve a current density of 10 mA·cm^(−2)and can be stable for more than 80 h,superior to NiS,FeS_(2)electrocatalyst individually,and precious RuO_(2).Notably,NiS/FeS_(2)is also a good bifunctional electrocatalyst with good overall water splitting performance,and it only requires a voltage 1.56 V to obtain a current density of 10 mA·cm^(−2)for more than 12 ***,the NiS/FeS_(2)hybridization facilitates the formation of coral-like structures,increasing the electrochemical surface area(ECSA)and enhancing the charge transfer efficiency,thus leading to excellent electrocatalytic *** work proposes a constructive strategy for designing efficient electrocatalysts based on interface engineering,and lays a foundation for designing a new class of electrocatalysts.

关键词： NiS/FeS_(2) interface engineering nanorods bifunctional water splitting

A Detailed Thermal Resistance Network Analysis of FCBGA Package

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Journal of Thermal Science 2024年第1期33卷 18-28页

作者： DANG Hao LU Yang du Yanzheng ZHANG Xiu ZHANG Qian MA Weigang ZHANG xing Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Department of Engineering MechanicsTsinghua UniversityBeijing 100084China Zhongxing Telecom Equipment Corporation Shanghai 201203China

Using thermal models to describe the heat dissipation process of FCBGA is a significant topic in the field of ***,the thermal resistance model considering the structure of each part of the chip is still ambiguous and rare,but it is quite desirable in *** this work,we propose a detailed thermal resistance network model,and describe it by using thermal conduction resistance and thermal spreading *** a striking FCBGA case,we calculated the thermal resistance of each part of the structure according to the temperature field simulated by *** thermal resistance network can be used to predict the temperatures in the chip under different *** example,when the power changes by 40%,the relative error of junction temperature prediction is only 0.24%.The function of the detailed thermal resistance network in evaluating the optimization space and determining the optimization direction is *** work illustrates a potential thermal resistance analysis method for electronic devices such as FCBGA.

关键词： FCBGA package thermal resistance network thermal spreading resistance junction temperature

Review on regulation of MnS in non-qquenched and tempered steel

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Journal of Iron and Steel Research International 2024年第4期31卷 779-789页

作者： Guo-xing Qiu Qing du Feng Lu De-jun Miao Yong-kun Yang Xiao-ming Li School of Metallurgical Engineering Xi'an University of Architecture and TechnologyXi'an 710055ShaanxiChina Laigang Technique Center Shandong Iron and Steel Group Co.Ltd.Jinan 271104ShandongChina

An overview of the current research status and control methods of MnS in non-quenched and tempered steel was *** a low-melting plastic inclusion,the morphology and distribution of MnS were influenced by various production ***,control of MnS is a systematic problem that must be integrated into the entire production *** on the production process,the factors affecting the morphology and distribution of MnS in steel were *** effects of oxygen activity,manganese,sulfur,and some alloys on MnS inclusion precipitation were summarized,mainly including MnS modification treatment and oxygen-sulfide composite precipitation *** is believed that MnS precipitates during the solidification process of steel,and controlling the solidification cooling rate could effectively regulate the size and morphology of MnS,avoiding the precipitation of ***,by changing the deformation rate,deformation amount,deformation temperature during the hot deformation process,and heating time and temperature during heat treatment,the distribution and morphology of MnS could be *** the fine control of the above process parameters,the number of II-MnS in steel could be effectively reduced,and their morphology could be improved,thereby enhancing the performance of non-quenched and tempered steel and promoting its wider ***,applying laboratory research results to industrial production is an important direction for future research efforts in this field.

关键词： MnS Non-quenched and tempered steel Control technology Process parameter Morphology Distribution

Defect-modulated and heteroatom-functionalized Ti_(3−x)C_(2)T_(y)MXene 3D nanocavities induce growth of MoSe_(2)nanoflakes toward electrocatalytic hydrogen evolution in all pH electrolytes

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Nano Research 2024年第7期17卷 6294-6304页

作者： Ming du Xianzhi Yang Jian Zhang Wei Chen Huajie Huang Xinbao Zhu xing’ao Li State Key Laboratory for Organic Electronics and Information Displays and Institute of Advanced Materials(IAM) Jiangsu National Synergetic Innovation Centre for Advanced Materials(SICAM)Nanjing University of Posts and Telecommunications(NJUPT)Nanjing 210023China College of Electronic and Optical Engineering and College of Flexible Electronics Nanjing University of Posts and Telecommunications(NJUPT) Nanjing 210023China New Energy Technology Engineering Lab of Jiangsu Province College of ScienceNanjing University of Posts and Telecommunications(NJUPT)Nanjing 210023China College of Pharmaceutical and Chemical Engineering Taizhou UniversityJiaojiang 318000China College of Mechanics and Materials Hohai UniversityNanjing 210098China College of Chemical Engineering Nanjing Forestry UniversityNanjing 210037China

Reducing kinetic energy barriers and developing accessible active sites are critical to deliver high hydrogen evolution reaction(HER)*** this paper,we synthesized defect-modulated and heteroatom(boron)-functionalized three-dimensional(3D)bowl-shaped Ti_(3−x)C_(2)T_(y)MXene(B-TCT)nanocavities coupled with the vertical growth of MoSe_(2)*** B-TCT@MoSe_(2)nanohybrids catalyst delivers the overpotentials of 49.9,52.7,and 67.8 mV to reach a HER current density of 10 mA·cm^(−2)under acidic,alkaline,and neutral conditions,*** outstanding HER activity is predominantly attributed to the heteroatom functionalization,self-adapting Ti vacancy(VTi)defect modulation,and spatial configuration design in the 3D B-TCT nanocavity,which synergistically regulate the electronic structure,activate the basal plane/edge unsaturated sites,and reduce the reaction energy *** and theoretical calculations demonstrate that strong heterogeneous interfacial bonding interactions between B-TCT and MoSe_(2)can dramatically reduce the free energy of hydrogen adsorption and facilitate efficient interfacial charge migration,thus essentially improving the HER *** used this 3D porous nanohybrid system assembled by defectrich lamellar structures to elucidate the advantageous synergistic effects of multiple mechanisms among defect structure,heteroatom functionalization,and interfacial coupling,which provided important insights for the development of efficient hybridtype catalysts.

关键词： electrocatalytic H_(2)evolution three-dimensional(3D)MXene nanocavity MoSe_(2)nanoflake self-adapting Ti vacancy defect heteroatom-functionalized interfacial interaction