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Towards direct superlubricity and superlow wear via amino modification of polyhydroxy alcohol solutions

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Friction 2024年第9期12卷 1980-1990页

作者： qiang MA Chengpeng yan Rui yan Xin XU Haifeng wang State Key Laboratory of Solidification Processing Center of Advanced Lubrication and Seal MaterialsNorthwestern Polytechnical UniversityXi'an 710072China Chongqing Innovation Center Northwestern Polytechnical UniversityChongqing 401135China Research&Development Institute of Northwestern Polytechnical University in Shenzhen Shenzhen 518063China

Friction remains as the primary mode of energy dissipation and components wear,and achieving superlubricity shows high promise in energy conservation and lifetime wear *** results in this work demonstrate that direct superlubricity combined with superlow wear can be realized for steel/Si_(3)N_(4)contacts on engineering scale when polyhydroxy alcohol solution was selectively modified by amino *** direct superlubricity occurs because 3-amino-1,2-propanediol molecules at the friction interface could be induced to rotate and adsorb vertically on the friction surface,forming in-situ thick and dense molecular films to passivate the asperity ***,amino modification is also conducive to improving the lubrication state from boundary to mixed lubrication regime by strengthening the intermolecular hydrogen bonding interaction,presenting enhanced load-bearing capability and reduced direct solid asperity ***,direct superlow average friction of 0.01 combined with superlow wear are achieved *** design principle of direct superlubricity and superlow wear in this work indeed offers an effective strategy to fundamentally improve energy efficiency and provide lifetime wear protection for moving mechanical assemblies.

关键词： direct superlubricity amino modification molecular layer superlow wear

Elevation change of the Urumqi Glacier No.1 derived from Sentinel-1A data

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Journal of Mountain Science 2021年第10期18卷 2656-2671页

作者： LIU Jia-liang ZHAO Jun LI Zhong-qin wang yan-qiang SHEN Si-min College of Geography and Environmental Science Northwest Normal UniversityLanzhou 730070China State Key Laboratory of Cryospheric Science Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China Tian Shan Glaciological Station Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China

Accurate measurements of glacier elevation changes play a crucial role in various glaciological studies related to glacier dynamics and mass balance. In this paper, glacier elevation changes of Urumqi Glacier No.1 between August 2015 and August 2017 were investigated using Sentinel-1 A data and DInSAR technology. Meanwhile, the atmospheric delay error was corrected with the MODIS MOD05L2 products. The weight selection iteration method was applied to calibrate the glacier elevation changes in the mass balance years 2015-2016 and 2016-2017. Finally, the geodetic method was employed to calculate the elevation change values of individual stakes of Urumqi Glacier No.1. Moreover, the elevation change values corrected by the weight selection iteration method were verified. Results showed as follows:(1) the elevation of Urumqi Glacier No.1 glacier affected by atmospheric delay was 1.270 cm from 2015 to 2016. The glacier elevation affected by atmospheric delay from 2016 to 2017 was 1.071 cm.(2) The elevation change value of Urumqi Glacier No.1 was-1.101 m from 2015 to 2016, and the elevation of Urumqi Glacier No.1 decreased by 1.299 m from 2016 to 2017. The overall thickness of Urumqi Glacier No. 1 was thinning.(3) By comparing the elevation change results of individual stakes with corresponding points corrected by the weight selection iteration method, the mean squared errors of difference were 0.343 m and 0.280 m between the two mass balance years, respectively.(4) The accuracy of elevation change in non-glaciated areas was 0.039 m from 2015 to 2016 and 0.034 m from 2016 to 2017. Therefore, it is reliable to use Sentinel-1 A data and the study method proposed in this paper to calculate the elevation change of mountain glaciers with very low horizontal movement.

关键词： Glacier elevation change Urumqi Glacier No.1 DInSAR Cryospheric remote sensing Sentinel-1A

LncRNA PCGEM1 facilitates cervical cancer progression via miR-642a-5p/KIF5B axis

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Oncology Research 2024年第7期32卷 1221-1229页

作者： YUANLIN LIU yan LIU yan wang qiang wang yan yan DANDAN ZHANG HUIQIN LIU Department of Obstetrics and Gynecology Shanghai First Maternity and Infant HospitalSchool of MedicineTongji UniversityShanghai200092China Department of Obstetrics and Gynecology The Second People’s Hospital of Nantong CityNantong226002China Department of Obstetrics and Gynecology Affiliated Hospital of Nantong UniversityNantong226002China

At present,the role of many long non-coding RNAs(lncRNAs)as tumor suppressors in the formation and development of cervical cancer(CC)has been ***,lncRNA prostate cancer gene expression marker 1(PCGEM1),whose high expression not only aggravates ovarian cancer but also can induce tumorigenesis and endometrial cancer progression,has not been studied in *** objective of this study was to investigate the expression and the underlying role of PCGEM1 in *** relative expression of PCGEM1 in CC cells was detected by real-time *** the suppression of PCGEM1 expression by shRNA,the changes in the proliferation,migration,and invasion capacities were detected via CCK-8 assay,EdU assay,and colony formation assay wound healing *** assay and the changes in expressions of epithelial-to-mesenchymal transition(EMT)markers were determined by western blot and immunoﬂ*** interplay among PCGEM1,miR-642a-5p,and kinesin family member 5B(KIF5B)was conﬁrmed by bioinformatics analyses and luciferase reporter *** showed that PCGEM1 expressions were up-regulated within CC *** viabilities,migration,and invasion were remarkably reduced after the suppression of PCGEM1 expression by shRNA in Hela and SiHa cells.N-cadherin was silenced,but E-cadherin expression was elevated by ***,by sponging miR-642a-5p in CC,PCGEM1 was veriﬁed as a competitive endogenous RNA(ceRNA)that modulates KIF5B ***-642a-5p down-regulation partially rescued sh-PCGEM1’s inhibitory effects on cell proliferation,migration,invasion,and EMT *** conclusion,the PCGEM1/miR-642a-5p/KIF5B signaling axis might be a novel therapeutic target in *** study provides a research basis and new direction for targeted therapy of CC.

关键词： Cervical cancer PCGEM1 KIF5B MiR-642a-5p tumorigenesis

Numerical Analysis of PRISM-PY Calculations for Hard-and Soft-Core Generic Polymer Models

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Chinese Journal of Polymer Science 2024年第4期42卷 532-543页

作者： qiang wang Department of Chemical and Biological Engineering Colorado State University1370 Campus DeliveryFort CollinsCO80523-1370USA

Generic polymer models capturing the chain connectivity and excluded-volume interactions between polymer segments can be classified, according to whether or not the 3D integral of the latter diverges, into hard- and soft-core models. Taking homogeneous systems of compressible homopolymer melts (or equivalently homopolymer solutions in an implicit, good solvent) in the continuum as an example, we recently compared the correlation effects on the structural and thermodynamic properties of the hard- and soft-core models given by the polymer reference interaction site model (PRISM) theory with the Percus-Yevick (PY) closure (Polymers 2023, 15, 1180). Here we analyzed in detail the numerical errors and behavior of the interchain pair correlation functions (PCFs) given by the PRISM-PY calculations of these models using an efficient numerical approach that we proposed. Our numerical approach has the least number of independent variables to be iteratively solved, analytically treats the discontinuities caused by the non-bonded pair potential (such as that of the hard spheres) and takes only the inverse Fourier transform of the interchain indirect PCF between polymer segments (which is continuous and decays towards 0 with increasing wavenumber much faster than both the interchain direct and total PCFs), and is essential for us to accurately solve the PRISM-PY theory for chain length N as large as 106. To capture the correlation-hole effect, the real-space cut-off in the PRISM calculations should be proportional to the square root of N.

关键词： Generic polymer models Soft potentials Polymer reference interaction site model theory

A human-sensitive frequency band vibration isolator for heavy-duty truck seats

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Applied Mathematics and Mechanics(English Edition) 2024年第10期45卷 1733-1748页

作者： Qingqing LIU Shenlong wang Ge yan Hu DING Haihua wang qiang SHI Xiaohong DING Huijie YU School of Mechanical Engineering University of Shanghai for Science and TechnologyShanghai 200093China State Key Laboratory of Mechanical System and Vibration School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai Frontier Science Center of MechnoinformaticsShanghai Institute of Applied Mathematics and MechanicsSchool of Mechanics and Engineering ScienceShanghai UniversityShanghai 200072China State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body College of Mechanical and Vehicle EngineeringHunan UniversityChangsha 410082China yanfeng Adient Seating Co. Ltd.Shanghai 201315China College of Mechanical and Electrical Engineering Jiaxing Nanhu UniversityJiaxing 314001Zhejiang ProvinceChina

In this study,a human-sensitive frequency band vibration isolator(HFBVI)with quasi-zero stiffness(QZS)characteristics for heavy-duty truck seats is designed to improve the comfort of heavy-duty truck drivers on uneven ***,the analytical expressions for the force and displacement of the HFBVI are derived with the Lagrange equation and d'Alembert's principle,and are validated through the prototype restoring force ***,the harmonic balance method(HBM)is used to obtain the dynamic responses under harmonic excitation,and further the influence of pre-stretching on the dynamic characteristics and transmissibility is ***,the experimental prototype of the HFBVI is fabricated,and vibration experiments are conducted under harmonic excitation to verify the vibration isolation performance(VIP)of the proposed vibration *** experimental results indicate that the HFBVI can effectively suppress the frequency band(4-8 Hz)to which the human body is sensitive to vertical *** addition,under real random road spectrum excitation,the HFBVI can achieve low-frequency vibration isolation close to 2 Hz,providing new prospects for ensuring the health of heavy-duty truck drivers.

关键词： human-sensitive frequency band quasi-zero stiffness(QZS) heavy-duty truck seat real random road spectrum low-frequency vibration isolation

Zeolites for the separation of ethylene,ethane,and ethyne

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Frontiers of Chemical Science and Engineering 2024年第9期18卷 137-146页

作者： Binyu wang qiang Li Haoyang Zhang Jia-Nan Zhang Qinhe Pan Wenfu yan State Key Laboratory of Inorganic Synthesis&Preparative Chemistry College of ChemistryJilin UniversityChangchun 130012China Key Laboratory of Advanced Energy Catalytic and Functional Materials Preparation College of Materials Science and EngineeringZhengzhou UniversityZhengzhou 450012China Key Laboratory of Advanced Materials of Tropical Island Resources(Ministry of Education) School of Chemistry and Chemical EngineeringHainan UniversityHaikou 570228China

The cost-effective separation of ethylene(C_(2)H_(4)),ethyne(C_(2)H_(2)),and ethane(C_(2)H_(6))poses a significant challenge in the contemporary chemical *** contrast to the energy-intensive high-pressure cryogenic distillation process,zeolite-based adsorptive separation offers a low-energy *** review provides a concise overview of recent advancements in the adsorptive separation of C_(2)H_(4),C_(2)H_(2),and C_(2)H_(6)using zeolites or zeolite-based *** commences with an examination of the industrial significance of these compounds and the associated separation ***,it systematically examines the utilization of various types of zeolites with diverse cationic species in such separation *** then it explores how different zeolitic structures impact adsorption and separation capabilities,considering principles such as cation-πinteraction,π-complexation,and steric separation concerning C_(2)H_(4),C_(2)H_(2),and C_(2)H_(6)***,it discusses methods to enhance the separation performance of zeolites and zeolite-based adsorbents,encompassing structural design,modifications,and ion exchange ***,it summarizes current research trends and future directions,highlighting the potential application value of zeolitic materials in the field of C_(2)H_(4),C_(2)H_(2),and C_(2)H_(6)separation and offering recommendations for further investigation.

关键词： zeolite ethylene ethane cation-πinteraction π-complexation

Atmospheric transmission algorithm for pulsed X-rays from high-altitude nuclear detonations based on scattering correction

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Nuclear Science and Techniques 2024年第3期35卷 40-52页

作者： Ding-Han Zhu Xiong Zhang Xiao-qiang Li Peng Li yan-Bin wang Shuang Zhang State Key Laboratory of NBC Protection for Civilian Beijing 102205China

In high-altitude nuclear detonations,the proportion of pulsed X-ray energy can exceed 70%,making it a specific monitoring signal for such *** pulsed X-rays can be captured using a satellite-borne X-ray detector following atmospheric *** quantitatively analyze the effects of different satellite detection altitudes,burst heights,and transmission angles on the physical processes of X-ray transport and energy fluence,we developed an atmospheric transmission algorithm for pulsed X-rays from high-altitude nuclear detonations based on scattering *** proposed method is an improvement over the traditional analytical method that only computes direct-transmission *** traditional analytical method exhibits a maximum relative error of 67.79% compared with the Monte Carlo *** improved method reduces this error to within 10% under the same conditions,even reaching 1% in certain ***,its computation time is 48,000 times faster than that of the Monte Carlo *** results have important theoretical significance and engineering application value for designing satellite-borne nuclear detonation pulsed X-ray detectors,inverting nuclear detonation source terms,and assessing ionospheric effects.

关键词： High-altitude nuclear detonation Atmospheric transmission Pulsed X-rays Scattering correction Analytical method Monte Carlo method

Large eddy simulation study on drag reduction performance of array-based plasma synthetic jet actuators

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Chinese Journal of Aeronautics 2024年第10期37卷 118-135页

作者： Yunan wang Zhenbing LUO Wei XIE yan ZHOU qiang LIU Wenqiang PENG Yinxin ZHU College of Aerospace Science and Engineering National University of Defense TechnologyChangsha 410073China

Large Eddy Simulation(LES)is first used to investigate the drag reduction effect of an array-based configuration of Plasma Synthetic Jet Actuators(PSJAs)on a hemisphere in supersonic inflow,and analyze the effect of energy allocation and array angle on the drag reduction performance of opposing Plasma Synthetic Jet(PSJ)in this *** simulation results have been compared with experimental data,confirming the validity of the simulation *** results show that different energy allocations have a significant effect on the drag of the ***,the effect of the change in array angle on the drag of the hemisphere is not as noticeable as the effect caused by energy *** regions between the two PSJAs occur,which undermine the effectiveness of drag *** Turbulent Kinetic Energy(TKE)regions primarily concentrate on the core region of the jet and downstream of the bow *** influence of the array angle on TKE is most evident in the downstream region of the exits of the PSJs on both *** evolution of the coherent structures reveals that as the PSJ intensity decreases,the largescale vortices progressively break up into smaller-scale vortices,and energy is also transferred from large-scale structures to small-scale structures.

关键词： Plasma synthetic jet Shock wave Large eddy simulation Drag reduction Flow control

Experimental investigation for temperature and emissivity by flame emission spectrum in a cavity of rocket based combined cycle combustor chamber

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Defence Technology（防务技术） 2024年第9期39卷 114-122页

作者： Weiguang Cai Shu Zheng yan wang Bing Liu Shaohua Zhu Li Zhao qiang Lu National Engineering Research Center of New Energy Power Generation North China Electric Power UniversityBeijing 102206China Science and Technology on Combustion Internal Flow and Thermal-structure LaboratoryNorthwestern Polytechnical UniversityXi'an 710072China

Flame temperature and spectral emissivity were the important parameters characterizing the sufficient degree of fuel combustion and the particle radiative characteristics in the Rocket Based Combined Cycle(RBCC)*** investigate the combustion characteristics of the complex supersonic flame in the RBCC combustor,a new radiation thermometry combined with Levenberg-Marquardt(LM)algorithm and the least squares method was proposed to measure the temperature,emissivity and spectral radiative properties based on the flame emission ***-situ measurements of the flame temperature,emissivity and spectral radiative properties were carried out in the RBCC direct-connected test bench with laser-induced plasma combustion enhancement(LIPCE)and without *** flame average temperatures at fuel global equivalence ratio(a)of 1.0b and 0.6 with LIPCE were 4.51%and 2.08%higher than those without *** flame combustion oscillation of kerosene tended to be stable in the recirculation zone of cavity with the thermal and chemical effects of laser induced *** differences of flame temperature at a=1.0b and 0.6 were 503 K and 523 K with LIPCE,which were 20.07%and42.64%lower than those without *** flame emissivity with methane assisted ignition was 80.46%lower than that without methane assisted ignition,due to the carbon-hydrogen ratio of kerosene was higher than that of *** spectral emissivities at 600 nm with LIPCE were 1.25%,22.2%,and 4.22%lower than those without LIPCE at a=1.0a(with methane assisted ignition),1.0b(without methane assisted ignition)and *** effect of concentration in the emissivity was removed by normalization to analyze the flame radiative properties in the RBCC combustor *** maximum differences of flame normalized emissivity were 50.91%without LIPCE and 27.53%with *** flame radiative properties were stabilized under the thermal and chemical effects of laser induced plasma at a=0.6.

关键词： Rocket-based combined-cycle Supersonic combustion Flame temperature measurement Emissivity Laser induced plasma combustion enhancement