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Frontiers of Mechanical Engineering 2021年第3期16卷 504-527页

作者： Xiaolong zhang Yu HUANG Shuting WANG Gen LI Yuanlong XIE wei MENG School of Mechanical Science and Engineering Huazhong University of Science and TechnologyWuhan 430074China School of Information Engineering Wuhan University of TechnologyWuhan 430070China

Safe and effective autonomous navigation in dynamic environments is challenging for four-wheel independently driven steered mobile robots(FWIDSMRs)due to the flexible allocation of multiple maneuver *** address this problem,this study proposes a novel multiple mode-based navigation system,which can achieve efficient motion planning and accurate tracking *** reduce the calculation burden and obtain a comprehensive optimized global path,a kinodynamic interior-exterior cell exploration planning method,which leverages the hybrid space of available modes with an incorporated exploration guiding algorithm,is *** utilizing the sampled subgoals and the constructed global path,local planning is then performed to avoid unexpected obstacles and potential *** the desired profile curvature and preselected mode,a fuzzy adaptive receding horizon control is proposed such that the online updating of the predictive horizon is realized to enhance the trajectory-following *** tracking controller design is achieved using the quadratic programming(QP)technique,and the primal-dual neural network optimization technique is used to solve the QP *** results on a real-time FWIDSMR validate that the proposed method shows superior features over some existing methods in terms of efficiency and accuracy.

关键词： mobile robot multiple maneuvering mode motion planning tracking control receding horizon control

Elastohydrodynamic Lubrication Interface Stiffness and Damping Considering Asperity Lateral Contact

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Acta Mechanica Solida Sinica 2024年第1期37卷 109-123页

作者： Zhiqiang Gao Yu zhang Xian wei Yanfang Zhu Lixia Peng weiping Fu Wen Wang School of Mechanical and Precision Instrument Engineering Xi'an University of TechnologyXi'an 710048China School of Intelligent Manufacturing Panzhihua UniversityPanzhihua 617000China Material Corrosion and Protection Key Laboratory of Sichuan Province Sichuan University of Light Chemical TechnologyYibin 644002China School of Mechanical Engineering Anyang Institute of TechnologyAnyang 455099China

Elastohydrodynamic lubrication(EHL)point contact occurs between two rough surfaces at the mesoscopic level,while the interaction of rough surfaces involves contact between asperities at the microscale *** most cases,the contact between asperities within an interface takes the form of lateral contact rather than peak *** devoid of contact asperities are filled with lubricating ***,conventional models often oversimplify lateral contact forms as interactions between asperities and a smooth,rigid *** simplifications fail to accurately represent the true contact conditions and can lead to inaccuracies in the analysis of EHL’s contact *** address this issue,we have developed a novel EHL interface model comprising two rough *** model allows us to explore the influence of asperity height,contact angle,and contact azimuth angle on EHL interface performance.

关键词： EHL interface Asperity lateral contact Contact stiffness Damping

Identify the contribution of vehicle non-exhaust emissions:a single particle aerosol mass spectrometer test case at typical road environment

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Frontiers of Environmental Science & Engineering 2023年第5期17卷 117-128页

作者： Qijun zhang Jiayuan Liu Ning wei Congbo Song Jianfei Peng Lin Wu Hongjun Mao Tianjin Key Laboratory of Urban Transport Emission Research&State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control College of Environmental Science and EngineeringNankai UniversityTianjin 300071China School of Geography Earth and Environment Sciences University of BirminghamBirmingham B152TTUK

A single particle aerosol mass spectrometer(SPAMS)was used to accurately quantify the contribution of vehicle non-exhaust emissions to particulate matter at typical road *** PM_(2.5),black carbon,meteorological parameters and traffic flow were recorded during the test *** daily trend for traffic flow and speed on TEDA Street showed obvious“M”and“W”characteristics.6.3 million particles were captured via the SPAMS,including 1.3 million particles with positive and negative spectral map *** Metal,High molecular Organic Carbon,Organic Carbon,Mixed Carbon,Elemental Carbon,Rich Potassium,Levo-rotation Glucose,Rich Na,SiO_(3) and other categories were *** particle number concentration measured by SPAMS showed a good linear correlation with the mass concentrations of PM_(2.5) and BC,which indicates that the particulate matter captured by the SPAMS reflects the pollution level of fine particulate ***,ECOC,OC,HM and crustal dust components were found to show high values from 7:00–9:00 AM,showing that these chemical components are directly or indirectly related to vehicle *** on the PMF model,7 major factors are *** relative contributions of each factor were determined:vehicle exhaust emission(44.8%),coal-fired source(14.5%),biomass combustion(12.2%),crustal dust(9.4%),ship emission(9.0%),tires wear(6.6%)and brake pads wear(3.5%).The results show that the contribution of vehicle non-exhaust to particulate matter at roadside environment is approximately 10.1%.Vehicle non-exhaust emissions are the focus of future research in the vehicle pollutant emission control field.

关键词： Non-exhaust emissions SPAMS PMF Roadside environment

Electrochemically exfoliated WS_(2)in molten salt for sodium-ion battery anode

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Rare Metals 2023年第4期42卷 1227-1237页

作者： Bei-Lei zhang Xiang Chen Hai-Jia Zhao Hong-wei Xie Hua-Yi Yin Key Laboratory for Ecological Metallurgy of Multimetallic Mineral of Ministry of Education School of MetallurgyNortheastern UniversityShenyang110819China School of Resource and Environmental Science Wuhan UniversityWuhan430072China

The poor crystallinity and unstable crystal structure of tungsten disulfide(WS2)limit its application in *** this paper,a molten salt electrolysis method is proposed to intercalate metal ions into the interlayers of layered WS2 to obtain few-layer sheetlike *** effect of the molten salt system,applied constant current and electrolysis duration on the exfoliation degree of WS2 bulk has been *** results show that the products electrolyzed in molten LiCl-NaCl-KCl and NaClKCl salts under 25 mA were more transparent and thinner flakes sheets due to the uniform intercalation of Li^+and Na^+with smaller *** exfoliated WS_(2)was used as an anode material for sodium-ion batteries with a potential of 0.01-2.50 *** comparison,the WS_(2)-NaCl-25 mA electrode displays a high reversible capacity of 373 mAh·g^(-1)at0.1 A·g^(-1)after cycling for 100 cycles at the same time showing great rate and cycle *** also presents a high capacitive ratio of 90.65%at 1.0 mV·s^(-1).The molten salt electrolysis provides a new perspective on the exfoliation of layered material,while demonstrating the great potential of WS2 as an anode material for sodium-ion battery.

关键词： Tungsten disulfide Molten salt electrolysis Exfoliation Sodium-ion battery(SIB)anode

QAAS:quick accurate auto-scaling for streaming processing

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Frontiers of Computer Science 2024年第1期18卷 5-15页

作者： Shiyuan LIU Yunchun LI Hailong YANG Ming DUN Chen CHEN Huaitao zhang wei LI State Key Laboratory of Software Development Environment Beijing 100191China School of Computer Science and Engineering Beihang UniversityBeijing 100191China School of Cyber Science and Technology Beihang UniversityBeijing 100191China School of Computer Science and Technology Xi’an Jiaotong UniversityXi’an 710049China

In recent years,the demand for real-time data processing has been increasing,and various stream processing systems have *** the amount of data input to the stream processing system fluctuates,the computing resources required by the stream processing job will also *** resources used by stream processing jobs need to be adjusted according to load changes,avoiding the waste of computing *** present,existing works adjust stream processing jobs based on the assumption that there is a linear relationship between the operator parallelism and operator resource consumption(e.g.,throughput),which makes a significant deviation when the operator parallelism *** paper proposes a nonlinear model to represent operator *** divide the operator performance into three stages,the Non-competition stage,the Non-full competition stage,and the Full competition *** our proposed performance model,given the parallelism of the operator,we can accurately predict the CPU utilization and operator *** with actual experiments,the prediction error of our model is below 5%.We also propose a quick accurate auto-scaling(QAAS)method that uses the operator performance model to implement the auto-scaling of the operator parallelism of the Flink *** to previous work,QAAS is able to maintain stable job performance under load changes,minimizing the number of job adjustments and reducing data backlogs by 50%.

关键词： stream processing performance model auto-scaling

Response of soil respiration to nitrogen addition in two subtropical forest types

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Pedosphere 2020年第4期30卷 478-486页

作者： Wende YAN Xiaoyong CHEN Yuanying PENG Fan ZHU wei ZHEN Xuyuan zhang College of Life Science and Technology Central South University of Forestry and TechnologyChangsha 410004(China) National Engineering Laboratory for Applied Forest Ecological Technology in Southern China Changsha 410004(China) Division of Science College of Arts and Sciences.Governors State UniversityUniversity ParkIllinois 60484(USA) Natural Sciences Division College of DuPageGlen EllynIllinois 60137(USA)

Anthropogenic activities have increased nitrogen(N)deposition in terrestrial ecosystems,which directly and indirectly affects soil biogeochemical processes,including soil ***,the effects of the increases in N availability on soil respiration are not fully *** this study,soil respiration was measured using an infrared gas analyzer system with soil chambers under four N treatments(0,5,15,and 30 g Nm^-2 year^-1 as control,low N(LN),moderate N(MN),and high N(HN),respectively)in camphor tree and slash pine forests in subtropical *** showed that soil respiration rates decreased by 37% in the camphor tree forest and 27% in the slash pine forest on average on an annual base,respectively,in the N-fertilized treatments when compared with the *** significant differences were found in the soil respiration rate among the LN,MN,and HN treatments in both forest types as these fertilized plots reached an adequate N content *** addition,soil microbial biomass carbon(C)content and fine root biomass declined in N-treated plots compared to the *** results indicated that elevated N deposition might alter the tree growth pattern,C partitioning,and microbial activity,which further affect soil C sequestration by reducing soil respiration in subtropical forests of China.

关键词： camphor tree forest fine root slash pine forest soil microbial biomass soil moisture soil temperature

Risk identification and safety assessment of human-computer interaction in integrated avionics based on STAMP

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Journal of Systems Engineering and Electronics 2024年第3期35卷 689-706页

作者： ZHAO Changxiao LI Hao zhang wei DAI Jun DONG Lei School of Safety Science and Engineering Civil Aviation University of ChinaTianjin 300300China Shenzhen Dajiang Innovation Technology Co. Ltd.Shenzhen 518057China Key Laboratory of Civil Aircraft Airworthiness Technology Civil Aviation Administration of ChinaTianjin 300300China

To solve the problem of risk identification and quantitative assessment for human-computer interaction(HCI)in complex avionics systems,an HCI safety analysis framework based on system-theoretical process analysis(STPA)and cognitive reliability and error analysis method(CREAM)is *** can identify unsafe control actions and find the causal path during the interaction of avionics systems and pilot with the help of formal verification tools *** common performance conditions(CPC)of avionics systems in the aviation environment is established and a quantitative analysis of human failure is carried *** the head-up display(HUD)system interaction process as an example,a case analysis is carried out,the layered safety control structure and formal model of the HUD interaction process are *** the interactive behavior“Pilots approaching with HUD”,four unsafe control actions and35 causal scenarios are identified and the impact of common performance conditions at different levels on the pilot decision model are *** results show that HUD's HCI level gradually improves as the scores of CPC increase,and the quality of crew member cooperation and time sufficiency of the task is the key to its *** case analysis,it is shown that STPACREAM can quantitatively assess the hazards in HCI and identify the key factors that impact safety.

关键词： avionics human-computer interaction(HCI) safety assessment system-theoretic accident model and process human reliability analysis

Short-DNA Specific Blocker PCR for Efficient and Simple Enrichment of Cell Free Fetal DNAs with Short Lengths

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Chinese Journal of Chemistry 2021年第8期39卷 2101-2106页

作者： Yangwei Liao Xiaofeng Tang Zhihao Ming Lida Ren wei zhang Xianjin Xiao Institute of Reproductive Health Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanHubei 430030China NHC Key Laboratory of Birth Defect for Research and Prevention(Hunan Provincial Maternal and Child Health Care Hospital) ChangshaHunan 410008China

As an inn ate characteristic,DNA length has attracted more and more atte *** length of some import ant biomarkers such as ctDNA(Circulating tumor DNA)and cffDNA(Cell free fetal DNA)is shorter than that of cell-free *** have utilized the differe nee in length to in crease the abunda nee of ctDNA or cffDNA in total cell-free DNA to overcome the difficulties in detecti on due to their low abundance.

关键词： DNA Enrichment Polymerase chain reaction Gene seque ncing Non-invasive prenatal testing

Comparisons of Jet Properties between GeV Radio Galaxies and Blazars

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Research in Astronomy and Astrophysics 2017年第9期 17-26页

作者： Zi-wei Xue Jin zhang wei Cui En-wei Liang Shuang-Nan zhang Key Laboratory of Space Astronomy and Technology National Astronomical Observatories Chinese Academy of Sciences University of Chinese Academy of Sciences Department of Physics and Astronomy Purdue University Guangxi Key Laboratory for Relativistic Astrophysics Department of Physics Guangxi University Key Laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences

We compile a sample of spectral energy distributions(SEDs) of 12 GeV radio galaxies(RGs),including eight FR Ⅰ RGs and four FR Ⅱ RGs. These SEDs can be represented with the one-zone leptonic model. No significant unification, as expected in the unification model, is found for the derived jet parameters between FR Ⅰ RGs and BL Lacertae objects(BL Lacs) and between FR Ⅱ RGs and flat spectrum radio quasars(FSRQs). However, on average FR Ⅰ RGs have a larger γb(break Lorentz factor of electrons) and lower B(magnetic field strength) than FR Ⅱ RGs, analogous to the differences between BL Lacs and FSRQs. The derived Doppler factors(δ) of RGs are on average smaller than those of blazars, which is consistent with the unification model such that RGs are the misaligned parent populations of blazars with smaller δ. On the basis of jet parameters from SED fits, we calculate their jet powers and the powers carried by each component, and compare their jet compositions and radiation efficiencies with blazars. Most of the RG jets may be dominated by particles, like BL Lacs, not ***, the jets of RGs with higher radiation efficiencies tend to have higher jet magnetization. A strong anticorrelation between synchrotron peak frequency and jet power is observed for GeV RGs and blazars in both the observer and co-moving frames, indicating that the "sequence" behavior among blazars, together with the GeV RGs, may be intrinsically dominated by jet power.

关键词： galaxies active—galaxies general—galaxies jets—gamma rays galaxies—radiation mechanisms non-thermal

Dopamine-triggered one-step functionalization of hollow silica nanospheres for simultaneous lubrication and drug release

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Friction 2023年第3期11卷 410-424页

作者： Qiangbing wei Tian FU Lele LEI Huan LIU Yixin zhang Shuanhong MA feng ZHOU Key Laboratory of Eco-functional Polymer Materials of the Ministry of Education Key Laboratory of Polymer Materials of Gansu ProvinceCollege of Chemistry and Chemical EngineeringNorthwest Normal UniversityLanzhou 730070China State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China Shandong Laboratory of Yantai Advanced Materials and Green Manufacture Yantai 264006China

Osteoarthritis(OA)has been regarded as a lubrication deficiency related joint *** of both joint lubrication and drug intervention may provide a promising nonsurgical strategy for treatment of *** novel and simple approaches to fabricate superlubricating nanoparticles with drug release property is highly ***,dopamine triggered one-step polymerization method was employed to fabricate polydopamine/poly(3-sulfopropyl methacrylate potassium salt)(PDA-PSPMA)conjugate coating on hollow silica(h-SiO_(2))nanosphere surfaces to engineer functional nanoparticles(h-SiO_(2)/PDA-PSPMA).The as-prepared h-SiO_(2)/PDA-PSPMA exhibits excellent aqueous lubrication performance on biomaterial substrates as well as natural bovine articular cartilage based on hydration effect of negatively charged PDA-PSPMA coating and"rolling"effect of h-SiO_(2)*** vitro drug loading-release experiments demonstrate that PDA-PSPMA coating functionalized h-SiO_(2)nanospheres show high drug-loading and sustained-release capability of an anti-inflammatory drug,diclofenac sodium(DS).Such h-SiO_(2)/PDA-PSPMA nanospheres can be potentially used as a synergistic therapy agent for OA treatment combining by simultaneous joint lubrication anddrugrelease.

关键词： osteoarthritis treatment functionalized nanoparticles injectable biolubricant friction reduction drug release