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Research on the mechanism of the two-dimensional ultrasonic surface burnishing process to enhance the wear resistance for aluminum alloy

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Friction 2024年第3期12卷 490-509页

作者： Zhen-Yu ZHOU qiu-yang zheng Yu LI Cong DING Guang-Jian PENG Zhong-Yu PIAO College of Mechanical Engineering Zhejiang University of TechnologyHangzhou 310023China Key Laboratory of Special Purpose Equipment and Advanced Processing Technology Ministry of Education and Zhejiang ProvinceZhejiang University of TechnologyHangzhou 310014China

The gradient nanostructure is machined on the aluminum(Al)alloy by the two-dimensional ultrasonic surface burnishing process(2D-USBP).The mechanism of why the gradient nanostructure enhances wear resistance is *** mechanical properties and microstructure characterization for the gradient nanostructure are performed by operating a nanoindenter,transmission electron microscopy(TEM),and electron backscattered diffraction(EBSD).Dry wear tests are performed on the samples before and after machining to evaluate the wear resistance and *** effect of the gradient nanostructure on the wear resistance is explored by developing the crystal plasticity(CP)finite element and molecular dynamics(MD)*** characterization results show that the 2D-USBP sample prepared a gradient structure of~600μm thick on the aluminum surface,increasing the surface hardness from 1.13 to 1.71 GPa and reducing the elastic modulus from 78.84 to 70.14 *** optimization of the surface microstructure and the increase of the mechanical properties effectively enhance the wear resistance of the sample,with 41.20%,39.07%,and 54.58% of the wear scar areas for the 2D-USBP treated samples to the original samples under 5,10,and 15 N loads,*** gradient nanostructure hinders the slip of dislocations inside the sample during the wear process and reduces the size and scope of plastic deformation;meanwhile,the resistance to deformation,adhesion,and crack initiation and propagation of the sample surface is improved,resulting in enhanced wear resistance.

关键词： structural superlubricity lattice registry elastic deformation strained solitons crystal plasticity molecular dynamics simulations

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Alleviated photoinhibition on nitrification in the Indian Sector of the Southern Ocean

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Acta Oceanologica Sinica 2024年第7期43卷 52-69页

作者： Lingfang Fan Min Chen Zifei yang Minfang zheng Yusheng qiu College of Ocean and Earth Sciences Xiamen UniversityXiamen 361102China

Nitrification,a central process in the marine nitrogen cycle,produces regenerated nitrate in the euphotic zone and emits N_(2)O,a potent greenhouse gas as a *** regulatory mechanisms of nitrification in the Southern Ocean,which is a critical region for CO_(2)sequestration and radiative benefits,remain poorly ***,we investigated the in situ and dark nitrification rates in the upper 500 m and conducted substrate kinetics experiments across the Indian Sector in the Cosmonaut and Cooperation seas in the late austral *** findings indicate that light inhibition of nitrification decreases exponentially with depth,exhibiting a light threshold of 0.53%photosynthetically active radiation.A positive relationship between dark nitrification and apparent oxygen utilization suggests a dependence on substrate availability from primary ***,an increased NH_(4)^(+) supply can act as a buffer against photo-inhibitory ***,substrate affinity(α)increases with depth and transitions from light to dark,decreases with increasing ambient NH_(4)^(+)and exhibits a latitudinal distribution,reflecting substrate utilization *** also reveal that upwelling in Circumpolar Deep Water(CDW)stimulates nitrification through the introduction of potentially higher iron and deep diverse nitrifying microorganisms with higherα.We conclude that although light is the primary limiting factor for nitrification in summer,coupling between substrate availability and CDW upwelling can overcome this limitation,thereby alleviating photoinhibition by up to 45%±5.3%.

关键词： nitrification light inhibition substrate affinity circumpolar deep water(CDW)upwelling the Southern Ocean

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Understanding livelihood vulnerability:a perspective from Western Sichuan’s ethnic rural settings

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Journal of Mountain Science 2024年第2期21卷 380-396页

作者： YU Yongqian JING zheng WANG Yan qiu Xiaoping yang Xueting XU Yun School of Geography and Resource Science Sichuan Normal UniversityChengdu 610101China Key Laboratory of land Resources Evaluation and Monitoring in Southwest Ministry of EducationSichuan Normal UniversityChengdu 610101China Sichuan County Economic Development Research Center Mianyang Normal UniversityMianyang 621000China Institute of Mountain Hazards and Environment Chinese Academy of SciencesChengdu 610041China

To explore the livelihood status and key influencing factors of rural households in the minority areas,we collected flat data from 284 rural households in 32 villages across 12 counties of Western Sichuan from 2021 to *** conducted participatory household survey on the livelihood status of the rural households and try to identify the key factors to influence their livelihood vulnerability using multiple linear *** results showed that:the livelihood situation of the rural households is relatively *** vulnerability varies significantly with the income levels,education levels,and income *** vulnerability of farm households,categorized from low to high livelihood types,follows the sequence:non-agricultural dominant households,non-agricultural households,agricultural dominant households,and pure agricultural *** degree of damage to the natural environment,education costs,loan opportunities,the proportion of agricultural income to annual household income,and the presence of sick people in the household have significant positive effects on the livelihood vulnerability index(LVI)of rural households;while help from relatives and friends,net income per capita,household size,household education,agricultural land area,participation in industrial organizations,number of livestock,purchase of commercial houses,drinking water source,and self-supply of food have significant negative *** on the findings,we believe that local rural households operate in a complex livelihood system and recommend continuous interventions targeting key influences to provide empirical research support for areas facing similar situations.

关键词： Livelihood Vulnerability Rural households Ethnic areas

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Dimension by Dimension Finite Volume HWENO Method for Hyperbolic Conservation Laws

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Communications on Applied Mathematics and Computation 2024年第1期6卷 605-624页

作者： Feng zheng Jianxian qiu College of Mathematics and Statistics Fujian Normal UniversityFuzhou350117FujianChina School of Mathematical Sciences and Fujian Provincial Key Laboratory of Mathematical Modeling&High-Performance Scientific Computing Xiamen UniversityXiamen361005FujianChina

In this paper,we propose a finite volume Hermite weighted essentially non-oscillatory(HWENO)method based on the dimension by dimension framework to solve hyperbolic conservation *** can maintain the high accuracy in the smooth region and obtain the high resolution solution when the discontinuity appears,and it is compact which will be good for giving the numerical boundary ***,it avoids complicated least square procedure when we implement the genuine two dimensional(2D)finite volume HWENO reconstruction,and it can be regarded as a generalization of the one dimensional(1D)HWENO *** numerical tests are performed to verify the high resolution and high accuracy of the scheme.

关键词： Finite volume Dimension by dimension HWENO Hyperbolic conservation laws

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Study on Optimal Water ControlMethods for Horizontal Wells in Bottom Water Clastic Rock Reservoirs

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Fluid Dynamics & Materials Processing 2024年第10期20卷 2377-2392页

作者： Xianghua Liu Hai Song Lu Zhao Yan zheng Neng yang Dongling qiu Sinopec Northwest Oilfield Branch Northwest Oilfield Branch of China Petroleum and Chemical CorporationUrumqi830011China School of Petroleum and Natural Gas Engineering Southwest Petroleum UniversityChengdu610500China

The segmented water control technology for bottom water reservoirs can effectively delay the entry of bottom water and adjust the production *** clarify the impact of different methods on horizontal well production with different reservoir conditions and to provide theoretical support for the scientific selection of methods for bottom water reservoirs,a numerical simulation method is presented in this study,which is able to deal with wellbore reservoir coupling under screen tube,perforation,and ICD(Inflow Control Device)*** the geological characteristics of the bottom-water conglomerate reservoir in the Triassic Formation of the Tahe Block 9 as a test case,the three aforementioned completion methods are tested to predict the transient production *** impact of completion parameters,reservoir permeability,bottom-water energy,and individual well control on the time to encounter water in horizontal wells(during a water-free production period)is discussed.A boundary chart for the selection of completion methods is introduced *** results show that the optimized ICD completion development effect for heterogeneous reservoirs is the best,followed by optimized perforation *** is the main factor affecting the performances of completion methods,while bottom water energy and single well controlled reserves have a scarce *** average permeability of the reservoir is less than 500 mD,and ICD has the best water control *** the permeability is greater than 500 mD,the water control effect of perforation completion becomes a better option.

关键词： Completion method bottom water low-permeability oil reservoir horizontal well development effect

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Present-day movement characteristics of the Qinghai Nanshan fault and its surrounding area from GPS observation

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Geodesy and Geodynamics 2024年第2期15卷 133-141页

作者： yang Liu Yuxuan qiu Jialiang Liu Luyun Xiong Caijun Xu Jianghui Geng Gang zheng Tianchen Sheng School of Geodesy and Geomatics Wuhan UniversityWuhan 430079China Key Laboratory of Geospace Environment and Geodesy Ministry of EducationWuhan UniversityWuhan 430079China Key Laboratory of Geophysical Geodesy Ministry of Natural ResourcesWuhan UniversityWuhan 430079China GNSS Research Center Wuhan UniversityWuhan 430079China School of Earth and Environment University of LeedsLeeds LS29JTUK Qinghai Basic Surveying and Mapping Institute Xining 810101China

The Qinghai Nanshan fault is a larger fault in the Northeastern Xizang *** previous studies,its movement characteristics are mainly investigated with geological and seismic observations,and the tectonic transformation role of the fault on its east is not yet *** study uses data fusion to obtain denser GPS observations near the Qinghai Nanshan *** on tectonic characteristics,we establish a block model to investigate the fault slip rate,locking degree,and slip *** results show that the Qinghai Nanshan fault slip rate is characterized by sinistral and convergent *** the sinistral and convergent rates display a decreasing trend from west to *** locking degree and slip deficit are higher in the western segment(with an average of about 0.74 and 1.1 mm/a)and lower in the eastern ***,we construct a strain rate field using GPS observations to analyze the regional strain *** results indicate that along the fault,the western segment shows a larger shear strain rate and negative dilation *** earthquake records show that the frequency of earthquakes is lower near the *** joint results suggest that the western segment may have a higher earthquake *** addition,the insignificant fault slip rate in the eastern segment may indicate that it does not participate in the tectonic transformation among the Riyueshan,Lajishan,and West Qinling faults.

关键词： The Qinghai Nanshan fault Movement characteristics Block model Slip rate GPS

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Targeted drug approvals in 2023:breakthroughs by the FDA and NMPA

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Signal Transduction and Targeted Therapy 2024年第3期9卷 813-821页

作者： Lang zheng Wenjing Wang qiu Sun Department of Biotherapy Cancer Center and State Key Laboratory of BiotherapyWest China HospitalSichuan UniversityChengdu 610041China West China Medical Publishers West China HospitalSichuan UniversityChengdu 610041China

According to the official website of China’s National Medicines and Pharmaceutical Administration(NMPA),a total of 87 novel drugs were approved in China in 2023,with targeted drugs accounting for 67.8%of the total,amounting to 59 drugs(Fig.1a;Table 1)[https://***/yaopin/ypjgdt/***].Notably,domestic innovation is flourishing,with five first-in-class drugs,including Glumetinib,a c-Met inhibitor from Haihe Biopharma;Leritrelvir,a 3CL protease inhibitor from Raynovent;Anaprazole,a proton pump inhibitor from Xuanzhu Biopharm;Pegol-Sihematide,an EPO drug from Hansoh Pharma;and Zuberitamab from BioRay Biopharmaceutical Co.,***,the world’s first allosteric inhibitor targeting TYK2,Sotyktu(deucravacitinib),has been approved for the treatment of psoriasis and Selumetinib,a MEK inhibitor co-developed by AstraZeneca and Merck Sharp&Dohme(MSD),became the first approved drug in China for the treatment of neurofibromatosis type I(NF1).Beyond these drugs,the approval of novel drug types such as CAR-T cell products,siRNA,monoclonal antibodies,dual antibodies,and ADCs in China is a significant development in the country’s pharmaceutical industry(Fig.1a).

关键词： drugs Merck approval

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Demonstration of acousto-optical modulation based on a thin-film AlScN photonic platform

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Photonics Research 2024年第6期12卷 1138-1149页

作者： KEWEI BIAN ZHENYU LI YUSHUAI LIU SUMEI XU XINGYAN ZHAO yang qiu YUAN DONG QIZE ZHONG TAO WU SHAONAN zheng TING HU School of Microelectronics Shanghai UniversityShanghai 201800China School of Information Science and Technology ShanghaiTech UniversityShanghai 201210China Shanghai Institute of Microsystem and Information Technology Chinese Academy of SciencesShanghai 200050China University of Chinese Academy of Sciences Beijing 100049China

Acousto-optic(AO)modulation technology holds significant promise for applications in microwave and optical signal ***-film scandium-doped aluminum nitride(AlScN),with excellent piezoelectric properties and a wide transparency window,is a promising candidate for achieving on-chip AO modulation with a fabri-cation process compatible with complementary metal-oxide-semiconductor(CMOS)*** study presents,to the best of our knowledge,the first demonstration of AO modulators with surface acoustic wave generation and photonic waveguides monolithically integrated on a 400-nm-thick film of AlScN on an *** intramodal AO modulation is realized based on an AlScN straight waveguide,and the modulation efficiency is significantly enhanced by 12.3 dB through the extension of the AO interaction length and the utilization of bidirectional acoustic *** intermodal AO modulation and non-reciprocity are further demonstrated based on a multi-mode spiral waveguide,achieving a high non-reciprocal contrast(>10 dB)across an optical bandwidth of 0.48 *** research marks a significant stride forward,representing an advancement in the realization of microwave photonic filters,magnet-free isolators,and circulators based on the thin-film AlScN photonic platform.

关键词： waveguide film microwave

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Bioinspired mineral-in-shell nanoarchitectonics:Functional empowerment of mineral precursors for guiding intradentinal mineralization

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Nano Research 2024年第5期17卷 4338-4349页

作者： Xiaoran zheng yang Liu Mingjing Li Yuyan Li Wanshan Gao Rongmin qiu Jiaqi Xing Jiaojiao yang Yantao Chen Xinyuan Xu Mingming Ding Jun Luo Jianshu Li College of Polymer Science and Engineering State Key Laboratory of Polymer Materials EngineeringSichuan UniversityChengdu 610065China College of Stomatology Hospital of Stomatology Guangxi Medical UniversityGuangxi Key Laboratory of Oral and Maxillofacial Rehabilitation and ReconstructionGuangxi Clinical Research Center for Craniofacial DeformityGuangxi Key Laboratory of Oral and Maxillofacial Surgery Disease TreatmentGuangxi Health Commission Key Laboratory of Prevention and Treatment for Oral Infectious DiseasesNanning 530021China State Key Laboratory of Oral Diseases West China Hospital of StomatologySichuan UniversityChengdu 610041China Shenzhen Key Laboratory of Environmental Chemistry and Ecological Remediation College of Chemistry and Environmental EngineeringShenzhen UniversityShenzhen 518060China Med-X Center for Material Sichuan UniversityChengdu 610041China

Effective mineralization of biological structures poses a significant challenge in hard tissue engineering as it necessitates overcoming geometric complexities and multistep biomineralization *** this regard,we propose“mineral-in-shell nanoarchitectonics”,inspired by the nanostructure of matrix vesicles,which can influence multiple mineralization *** nanostructural design empowers mineral precursors with tailorable properties through encapsulating amorphous calcium phosphate within a multifunctional tannic acid(TA)and silk fibroin(SF)*** bioinspired nanosystem facilitates efficient recruitment of mineral precursors throughout the dentin structures,followed by large-scale intradentinal mineralization both in vitro and in vivo,which provides persistent protection against external *** simulations combined with experimental studies attribute the success of intradentinal mineralization to the TA-SF nanoshell,which exhibits a strong affinity for the dentin structure,stabilizing amorphous precursors and thereby facilitating concomitant mineral ***,this bioinspired mineral-in-shell nanoarchitectonics shows a promising prospect for hard tissue repair and serves as a blueprint for next-generation biomineralization-associated materials.

关键词： mineral-in-shell nanohybrids self-assembly biomineralization dentinal tubule occlusion dental hypersensitivity

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Train-induced aerodynamic characteristics of vertical sound barriers influenced by several factors

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Railway Engineering Science 2024年第2期32卷 177-193页

作者： Xiaowei qiu Xiaozhen Li Jing zheng Ming Wang State Key Laboratory of Bridge Intelligent and Green Construction Southwest Jiaotong UniversityChengdu 611756SichuanChina Wind Engineering Key Laboratory of Sichuan Province Southwest Jiaotong UniversityChengdu 611756SichuanChina School of Architecture and Civil Engineering West Anhui UniversityLu’anAnhuiChina

Investigations into the aerodynamic properties of vertical sound barriers exposed to high-speed operations employ computational fluid *** primary focus of this research is to evaluate the influence of train speed and the distance(D)from the track centerline under various operating *** findings elucidate a marked elevation in the aerodynamic effect amplitude on sound barriers as train speeds *** single-train passages,the aerodynamic effect amplitude manifests a direct relationship with the square of the train *** two trains pass each other,the aerodynamic amplitude intensifies due to an additional aerodynamic increment on the sound *** increment exhibits an approximate quadratic correlation with the retrograde train ***,the impact of high-speed trains on sound barrier aerodynamics surpasses that of low-speed trains,and this discrepancy amplifies with larger speed differentials between ***,the train-induced aerodynamic effect diminishes significantly with greater distance(D),with occurrences of pressure coefficient(CP)exceeding the standard thresholds during dual-train *** study culminates in the formulation of universal equations for quantifying the influence of train speed and distance(D)on sound barrier aerodynamic characteristics across various operational scenarios.

关键词： Aerodynamic characteristic Sound barrier Two trains passing each other Distance from track centerline CFD simulation

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