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Measurement of acceleration and angular velocity of particles during a 3D silo discharge

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Particuology 2024年第9期92卷 61-71页

作者： Tongtong Mu yiming Li Quan chen Ran Li Hui Yang College of Medical Instrument Shanghai University of Medicine and Health SciencesShanghai201318China School of Optical-Electrical and Computer Engineering University of Shanghai for Science and TechnologyShanghai200093China

Accurate measurement of the three-dimensional(3D)movement of discrete particles is crucial for comprehending complex granular rheology in *** this paper,the acceleration and angular velocity of particles in 3D silos are measured by using a spherical detector based on inertial technology and magnetic positioning *** acceleration of particles is the largest in the center of silos,which suggest that the resistance generated by friction and extrusion is the ***,the angular velocity distribution follows lognormal function except for particles near the *** correlation between acceleration and angular velocity is opposite in different flow *** reveals for the first time that the extent to which the resultant force on the particles affects their rotational motion is related to the flow *** results have practical significance for regulating the granular flow pattern and optimizing the structural design of silos.

关键词： Granularflow Silo Angular velocity Acceleration

Legacy and emerging per-and polyfluoroalkyl substances(PFAS) in the atmosphere: A comprehensive review

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Science China Technological Sciences 2024年第10期67卷 3032-3050页

作者： QIAO BiTing SONG DongBao chen Hao YAO yiming SUN HongWen MOE Key Laboratory of Pollution Processes and Environmental Criteria College of Environmental Science and EngineeringNankai University

With long-term production and widespread application, per-and polyfluoroalkyl substances(PFAS) have been detected in various media worldwide, including the atmosphere. Since the gradual restriction and phase-out of C8perfluoroalkyl acids(PFAAs), environmental contamination by emerging PFAS substitutes such as short-chain PFAA homologues, perfluoroether carboxylic, and sulfonic acids has been reported. Although there has been extensive monitoring of emerging PFAS substitutes in the aquatic environment, few studies have conducted target analysis and nontarget screening(NTS) of emerging unknown PFAS in the atmosphere over the past decade. To fill the gap, this review focused on emerging PFAS in the atmosphere in addition to legacy PFAS. The reported sampling, pretreatment, and instrumental analysis methods for target analysis and NTS of both neutral and ionic PFAS in the atmosphere are summarized, along with the advantages and current limitations of different sampling and NTS methods for PFAS in the atmosphere. The global levels, composition, and spatiotemporal distribution characteristics of legacy and emerging PFAS in the atmosphere are summarized and their transport, transformation, and dry/wet deposition are elucidated. The review highlights the importance of developing and applying the all-in-one strategy integrating target, suspect screening, and NTS to gain insights into emerging PFAS in the atmosphere and provide a reference for future research.

关键词： emerging PFAS atmosphere nontarget screening spatiotemporal distribution fate

Influences of mechanized tillage and sowing modes on soil physical properties,soybean yield and economic benefits in mollisols region of Northeast China

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International Journal of Agricultural and Biological Engineering 2024年第3期17卷 130-139页

作者： Haitao chen Jian Sun yiming Zhang Jinyou Qiao College of Engineering Northeast Agricultural UniversityHarbin 150030China Heilongjiang Province Technology Innovation Center of Mechanization and Materialization of Major Crops Production Harbin 150030China College of Mechanical and Electrical Engineering East University of HeilongjiangHarbin 150066China

Appropriate mechanized straw returning and tillage sowing techniques were effective means to optimize soil physical properties and enhance agricultural productivity,as well as important measures for the conservation and restoration of mollisols region in Northeast *** the condition of full-scale maize straw returning,four mechanized tillage and sowing modes were set,including plough tillage and sowing(PTS),combined tillage and sowing(CTS),no-tillage and sowing(NTS),and no-tillage and sowing with straw mulching(NTSM).In 2020 and 2021,the study investigated the effects of different mechanized tillage and sowing modes on soil physical properties,soybean yield and economic *** results showed that during the pod-setting and pod-filling period of soybean,the NTS and NTSM treatments exhibited better effects on deep soil insulation and shallow soil moisture retention,the soil physical structure of PTS and CTS treatments were relatively *** with PTS and CTS treatments,NTS and NTSM treatments significantly increased soil gravimetric water content(SWC)by 2.35%to 7.98%in the 5-15 cm soil layer and increased soil temperature(ST)by 3.94%to 10.42%in the 25-35 cm soil layer(p15-25 cm soil layers,which caused soil three-phase ratio(STPR)of PTS and CTS treatment in 15-25 cm soil layer were relatively *** soybean yield of NTSM treatment in 2020 was not significantly different from PTS and CTS treatment(p>0.05),the soybean yield of NTSM treatment in 2021 significantly increased by 7.30%and 5.84%over PTS and CTS treatments,*** the average annual profit per unit area of NTSM treatment increased by 12.84%,12.41%and 8.57%compared with PTS,CTS and NTS treatments,***,it was recommended to combine NTS

关键词： mechanized tillage and sowing modes full-scale straw returning soil physical properties soybean yield economic benefits mollisols conservation

Improved cyclic stability of LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2) cathode enabled by a novel CEI forming additive

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Frontiers in Energy 2024年第4期18卷 535-544页

作者： Zulipiya SHADIKE yiming chen Lin LIU Xinyin CAI Shuiyun SHEN Junliang ZHANG Institute of Fuel Cells School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China

The undesired side reactions at electrode/electrolyte interface as well as the irreversible phase evolution during electrochemical cycling significantly affect the cyclic performances of nickel-rich NMCs electrode *** optimization is an effective approach to suppress such an adverse side reaction,thereby enhancing the electrochemical ***,a novel boron-based film forming additive,tris(2,2,2-trifluoroethyl)borate(TTFEB),has been introduced to regulate the interphasial chemistry of LiNi0.8Mn0.1Co0.1O2(NMC811)cathode to improve its long-term cyclability and rate *** results of multi-model diagnostic study reveal that formation lithium fluoride(LiF)-rich and boron(B)containing cathode electrolyte interphase(CEI)not only stabilizes cathode surface,but also prevents electrolyte ***,homogenously distributed B containing species serves as a skeleton to form more uniform and denser CEI,reducing the interphasial ***,the Li/NMC811 cell with the TTFEB additive delivers an exceptional cycling stability with a high-capacity retention of 72.8%after 350 electrochemical cycles at a 1 C current rate,which is significantly higher than that of the cell cycled in the conventional electrolyte(59.7%).These findings provide a feasible pathway for improving the electrochemical performance of Ni-rich NMCs cathode by regulating the interphasial chemistry.

关键词： NMC811 cathode electrolyte interphase film forming additives cyclic stability

Attack based on data: a novel perspective to attack sensitive points directly

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Cybersecurity 2024年第3期7卷 111-123页

作者： Yuyao Ge Zhongguo Yang Lizhe chen yiming Wang chengyang Li School of Information Science and Technology North China University of TechnologyBeijingChina Bejing Key Laboratory on Integration and Analysis of Large-Scale Stream Data North China University of TechnologyBeijingChina School of Computer Science Peking UniversityBeijingChina

Adversarial attack for time-series classification model is widely explored and many attack methods are *** there is not a method of attack based on the data *** this paper,we innovatively proposed a black-box sparse attack method based on data *** method directly attack the sensitive points in the time-series data accord-ing to statistical features extract from the *** frst,we have validated the transferability of sensitive points among DNNs with different ***,we use the statistical features extract from the dataset and the sensi-tive rate of each point as the training set to train the predictive ***,predicting the sensitive rate of test set by predictive ***,perturbing according to the sensitive *** attack is limited by constraining the LO norm to achieve one-point *** conduct experiments on several datasets to validate the effectiveness of this method.

关键词： Black-box adversarial attack Time series classification Data mining

Bio-inspired Design and Inverse Kinematics Solution of an Omnidirectional Humanoid Robotic Arm with Geometric and Load Capacity Constraints

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Journal of Bionic Engineering 2024年第2期21卷 778-802页

作者： Zhichao Zhu Zirong Luo yiming Zhu Tao Jiang Minghai Xia Shanjun chen Boyu Jin College of Intelligence Science and Technology National University of Defense TechnologyChangshaChina

Inspired by the driving muscles of the human arm,a 4-Degree of Freedom(DOF)concentrated driving humanoid robotic arm is proposed based on a spatial double parallel four-bar *** four-bar mechanism design reduces the inertia of the elbow-driving unit and the torque by 76.65%and 57.81%,*** the human pose regulation strategy that the human arm picks up a heavy object by adjusting its posture naturally without complicated control,the robotic arm features an integrated position-level closed-form inverse solution method considering both geometric and load capacity *** method consists of a geometric constraint model incorporating the arm angle(φ)and the Global Configuration(GC)to avoid joint limits and singularities,and a load capacity model to constrain the feasible domain of the arm ***,trajectory tracking simulations and experiments are conducted to validate the feasibility of the proposed inverse solution *** simulated maximum output torque,maximum output power and total energy consumption of the robotic arm are reduced by up to 2.0%,13.3%,and 33.3%,*** experimental results demonstrate that the robotic arm can bear heavy loads in a human-like posture,effectively reducing the maximum output torque and energy consumption of the robotic arm by 1.83%and 5.03%,respectively,while avoiding joints beyond geometric and load capacity *** proposed design provides a high payload–weight ratio and an efficient pose control solution for robotic arms,which can potentially broaden the application spectrum of humanoid robots.

关键词： Humanoid robotic arm Bio-inspired design Inverse kinematics solution Load capacity constraint Geometric constraint

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Journal of Rare Earths 2024年第4期42卷 743-748页

作者： Hao Zhang Yi Bian Yuxuan Xia Yuchen Cui Ziang Li Fang Zhang yiming Bai Nuofu chen Jikun chen School of New Energy North China Electric Power UniversityBeijing102206China School of Materials Science and Engineering University of Science and Technology BeijingBeijing100083China

While the metal to insulator transition(MIT)of d-band correlated perovskite nickelates(RENiO_(3))are widely adjustable via their rare-earth composition,the roles of potential valence variabilities associated with the rare-earth elements were rarely ***,we demonstrate the material synthesis and MIT properties of RENiO_(3) containing valence variable rare-earth compositions,such as Ce,Pr,Sm,Eu and *** metastable perovskite structure of SmNiO_(3) and EuNiO_(3) with a rare-earth valence states variable towards+2 can be effectively synthesized under high oxygen pressures as it is necessary to reduce their formation free *** is in contrast to Ce and Tb,in which situations the variable rare-earth valence state towards+4 reduces their ionic radius and prohibits their occupation or co-occupation of the rare-earth site within the perovskite structured RENiO_(3).Nevertheless,PrNiO_(3) with MIT properties can be effectively synthesized at lower oxygen pressures,owing to the higher stability to form a fully occupied 6s orbit associated Pr3+compared to the half-filled one related to Pr4+.The present work provides guidance for regulating the MIT properties of RENiO_(3).

关键词： Metal to insulator transition Metastable perovskites Rare-earth nickelates Oxides

Effect of Temperature and Grain Boundary on Void Evolution in Irradiated Copper:A Phase-Field Study

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Acta Metallurgica Sinica(English Letters) 2024年第9期37卷 1621-1632页

作者： Qionghuan Zeng yiming chen Zhongsheng Yang Yunhao Huang Zhijun Wang Junjie Li Jincheng Wang tate Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an710072China Science and Technology On Reactor Fuel and Materials Laboratory Nuclear Power Institute of ChinaChengdu610213China

The continued existence of high-energy radiation in nuclear reactors at high temperatures results in the formation of radiation-induced voids,which will further lead to inevitable swellings of polycrystalline structural components and thus premature failures.A deep understanding of the effect of temperature and grain boundary on void evolution in irradiated copper is significant for preventing this kind of ***,the phase-field method was employed to study void evolution in irradiated copper under different temperatures and grain *** results show that,due to the different sensitivities of point defect production rate and vacancy diffusion rate to temperature changes,both the nucleation-growth rate and the coarsening rate during void evolution increase first and then decrease with increasing temperature;moreover,the nucleation mechanism exhibits site-saturated nucleation at low temperatures while continuous nucleation at high *** presence of grain boundary can accelerate the emergence of void because grain boundaries can absorb more interstitials than *** finer the grain size,the stronger inhibitory effect of grain boundaries on the growth rate of void,due to the formation of void denuded zone near grain *** high temperatures,the growth rate of void in fine grains is significantly reduced due to the increase of vacancy diffusion rate and the enhancement of sink effect of grain boundary on vacancy.

关键词： Void evolution Phase-field method Temperature Grain boundary

Ag-doped Ti_(3)C_(2)T_(x) sensor:A promising candidate for lowconcentration H_(2)S gas sensing

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High Voltage 2024年第3期9卷 537-545页

作者： Fuping Zeng Xiaoxuan Feng Xiaoyue chen Hao Qiu yiming Yan Qiang Yao Ju Tang School of Electrical Engineering and Automation Wuhan UniversityWuhanChina Hubei Key Laboratory of Power Equipment&System Security for Integrated Energy Resources WuhanChina State Grid chengdu Electric Power Supply Company ChengduChina State Grid Chongqing Electric Power Research Institute ChongqingChina State Key Laboratory of Power Transmission Equipment&System Security and New Technology Chongqing UniversityChongqingChina

Trace hydrogen sulphide(H_(2)S)could reflect the severity of insulation faults in gas-insulated switchgear(GIS),therefore,accurate and fast detection of low-concentration H_(2)S is important for on-line monitoring,fault diagnosis,and state evaluation in ***-Ti_(3)C_(2)T_(x) chemiresistive-type sensors were fabricated via drop-coating with self-reduction synthesised Ag-doped Ti_(3)C_(2)T_(x).The as-prepared sensors exhibited an excel-lent sensitivity and selectivity to H_(2)S with an extremely low detection of limit of 18.57 parts per billion(ppb)at 25℃(room temperature).The response of Ag-Ti_(3)C_(2)T_(x) sensor to 10 parts per million(ppm)H_(2)S was enhanced~12 times than that of the pristine Ti_(3)C_(2)T_(x) *** compositing of Ti_(3)C_(2)T_(x) with Ag nanoparticles(NPs)enabled the fast response/recovery time for H_(2)S *** analysis found that the enhanced H_(2)S sensing performances could be attributed to chemical sensitisation,adsorbed oxygen species regulation and high Brunauer–Emmett–Teller(BET)surface *** study paves the way for Ag-Ti_(3)C_(2)T_(x) as room-temperature sensing materials to detect low-concentration H_(2)S in GIS.

关键词： insulation diagnosis attributed