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A Transparent Photoresist Made of Titanium Dioxide Nanoparticle-Embedded Acrylic Resin with a Tunable Refractive Index for UV-Imprint Lithography

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Engineering 2024年第6期37卷 96-104页

作者： Yinglu Liu Dan Wang Changlin Liu Qianqian Hao jian Li Jie-Xin Wang Xiuyun chen Peng Zhong Xibin Shao jian-Feng chen State Key Laboratory of Organic–Inorganic Composites Beijing University of Chemical TechnologyBeijing 100029China research center of the Ministry of Education for High Gravity Engineering and Technology Beijing University of Chemical TechnologyBeijing 100029China BOE Technology Group Co. Ltd.Beijing 100176China

Transparent photoresists with a high refractive index(RI)and high transmittance in visible wavelengths have promising functionalities in optical *** work reports a kind of tunable optical material composed of titanium dioxide nanoparticles embedded in acrylic resin with a high RI for ultraviolet(UV)-imprint *** hybrid film exhibits a tunable RI of up to 1.67(589 nm)after being cured by UV light,while maintaining both a high transparency of over 98%in the visible light range and a low haze of less than 0.05%.The precision machining of optical microstructures can be imprinted easily and efficiently using the hybrid resin,which acts as a light guide plate(LGP)to guide the light from the side to the top in order to conserve the energy of the display *** preliminary studies based on both laboratory and commercial experiments pave the way for exploiting the unparalleled optical properties of nanocomposite resins and promoting their industrial application.

关键词： Photoresist Tunable refractive index Hanson solubility Ultraviolet imprint Organic-inorganic composites

Machine learning optimization strategy of shaped charge liner structure based on jet penetration efficiency

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Defence Technology（防务技术） 2024年第9期39卷 23-41页

作者： Ziqi Zhao Tong Li Donglin Sheng jian chen Amin Yan Yan chen Haiying Wang Xiaowei chen Lanhong Dai State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of SciencesBeijing 100190China School of Future Technology University of Chinese Academy of SciencesBeijing 100049 China School of Engineering Science University of Chinese Academy of SciencesBeijing 100049China State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China

Shaped charge liner(SCL)has been extensively applied in oil recovery and defense *** superior penetration capability through optimizing SCL structures presents a substantial challenge due to intricate rate-dependent processes involving detonation-driven liner collapse,high-speed jet stretching,and *** study introduces an innovative optimization strategy for SCL structures that employs jet penetration efficiency as the primary objective *** strategy combines experimentally validated finite element method with machine learning(FEM-ML).We propose a novel jet penetration efficiency index derived from enhanced cutoff velocity and shape characteristics of the jet via machine *** index effectively evaluates the jet penetration ***,a multi-model fusion based on a machine learning optimization method,called XGBOOST-MFO,is put forward to optimize SCL structure over a large input *** strategy's feasibility is demonstrated through the optimization of copper SCL implemented via the FEM-ML ***,this strategy is extended to optimize the structure of the recently emerging CrMnFeCoNi high-entropy alloy conical liners and hemispherical copper ***,the strategy can provide helpful guidance for the engineering design of SCL.

关键词： Jet penetration efficiency Shaped charge liner FEM-ML XGBOOST MFO High-entropy alloy

Influence of cutterhead opening ratio on soil arching effect and face stability during tunnelling through non-uniform soils

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Underground Space 2024年第4期17卷 45-59页

作者： Xue-jian chen Pei-Pei Fang Qiu-Nan chen Jun Hu Kai Yao Yong Liu State Key Laboratory of Water Resources Engineering and Management Wuhan UniversityWuhan 430072China Hubei Technology Innovation center for Smart Hydropower Wuhan 430000China College of Civil Engineering Anhui Jianzhu UniversityHefei 230601China School of Civil Engineering Hunan University of Science and TechnologyXiangtan 411201China School of Civil and Architectural Engineering Hainan UniversityHaikou 570228China School of Qilu Transportation Shandong UniversityJinan 250002China

Tunnelling has increasingly become an essential tool in the exploration of underground space.A typical construction problem is the face instability during tunnelling,posing a great threat to associated *** face instability often occurs with the soil arching *** study investigates the combined effect of cutterhead opening ratio and soil non-uniformity on soil arching effect and face stability,via conducting random finite-element analysis coupled with Monte–Carlo *** results underscore that the face stability is strongly associated with the evolution of stress *** obtained stability factors in the uniform soils can serve as a reference for the design of support pressure in practical tunnelling *** addition,non-uniform soils exhibit a lower stability factor than uniform soils,which implies that the latter likely yields an underestimated probability of face *** tunnel face is found to have a probability of failure more than 50%if the spatial non-uniformity of soil is *** the end,a practical framework is established to determine factor of safety(FOS)corresponding to different levels of probability of face failure considering various opening ratios in non-uniform *** required FOS is 1.70 to limit the probability of face instability no more than 0.1%.Our findings can facilitate the prediction of probability of instability in the conventionally deterministic design of face pressure.

关键词： Tunnel Face stability Soil arching effect Cutterhead opening ratio Non-uniform soil Random field

A symmetric substructuring method for analyzing the natural frequencies of conical origami structures

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Theoretical & Applied Mechanics Letters 2024年第3期14卷 203-210页

作者： chenhao Lu Yao chen Weiying Fan {2. Feng Pooya Sareh Key Laboratory of Concrete and Prestressed Concrete Structures of Ministry of Education and National Prestress Engineering Research CenterSoutheast UniversityNanjing 211189China School of Engineering University of LiverpoolLiverpool L693BXUnited Kingdom Creative Design Engineering Lab(Cdel) School of EngineeringNewcastle UniversityNewcastle upon Tyne NE17RUUnited Kingdom Escuela Técnica Superior de Ingeniería y Diseño Industrial Universidad Politécnica de Madrid(UPM)Madrid 28012Spain

Conical origami structures are characterized by their substantial out-of-plane stiffness and *** investigations have commonly focused on the static characteristics of these lightweight ***,the efficient analysis of the natural vibrations of these structures is pivotal for designing conicalorigami structures with programmable stiffness and *** this paper,we propose a novel method to analyzethe natural vibrations of such structures by combining a symmetric substructuring method(SSM)and a gener-alized eigenvalue *** exploits the inherent symmetry of the structure to decompose it into a finiteset of repetitive *** doing so,we reduce the dimensions of matrices and improve computationalefficiency by adopting the stiffness and mass matrices of the substructures in the generalized eigenvalue *** element simulations of pin-jointed models are used to validate the computational results of the ***,the parametric analysis of the structures demonstrates the influences of the number of seg-ments along the circumference and the radius of the cone on the structural mass and natural frequencies of ***,we present a comparison between six-fold and four-fold conical origami structures anddiscuss the influence of various geometric parameters on their natural *** study provides a strategyfor efficiently analyzing the natural vibration of symmetric origami structures and has the potential to contributeto the efficient design and customization of origami metastructures with programmable stiffness.

关键词： Natural structural vibration Origami design Group theory Symmetric substructuring method(SSM) Generalized eigenvalue analysis

Creep constitutive model considering nonlinear creep degradation of fractured rock

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International Journal of Mining Science and Technology 2024年第1期34卷 105-116页

作者： Wang Chunping Liu jianfeng chen Liang Liu jian Wang Lu Liao Yilin Beijing research Institute of Uranium Geology Beijing 100029China CAEA Innovation center for Geological Disposal of High-Level Radioactive Waste Beijing 100029China State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan UniversityChengdu 610065China School of Architecture and Civil Engineering Xihua UniversityChengdu 610039China

Stability analysis of underground constructions requires a model study of rock masses’ long-term performance. Creep tests under different stress conditions was conducted on intact granite and granite samples fractured at 30° and 45° angles. The experimental results indicate that the steady creep strain rates of intact and fractured rock present an exponential increase trend with the increase of stress level. A nonlinear creep model is developed based on the experimental results, in which the initial damage caused by fracture together with the damage caused by constant load have been taken into consideration. The fitting analysis results indicated that the model proposed is more accurate at identifying the full creep regions in fractured granite, especially the accelerated stage of creep deformation. The least-square fit error of the proposed creep model is significantly lower than that of Nishihara model by almost an order of magnitude. An analysis of the effects of elastic modulus, viscosity coefficient, and damage factors on fractured rock strain rate and creep strain is conducted. If no consideration is given to the effects of the damage, the proposed nonlinear creep model can degenerate into to the classical Nishihara model.

关键词： Fractured rock Damage Creep Beishan granite Geological disposal

Initial precursor reaction mechanism of CVD-HfC coating based on density functional theory

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Chinese Journal of Aeronautics 2024年第7期37卷 511-521页

作者： Yunzhou LIN Yulei ZHANG Yanqin FU jian ZHANG Jing’an KONG Ruicong chen State Key Laboratory of Solidification Processing Carbon/Carbon Composites Research CenterNorthwestern Polytechnical UniversityXi’an 710072China Henan Key Laboratory of High Performance Carbon Fiber Reinforced Composites Carbon Matrix Composites Research InstituteHenan Academy of SciencesZhengzhou 450046China

Recently,the preparation of ultra-high temperature HfC ceramic coating has gained significant attention,particularly through the application of the HfCl_(4)-CH_(4)-H_(2.-Ar system via Chemical Vapor Deposition(CVD),which has been found widely applied to C/C ***,an analysis of the reactions that occur in the initial stage of the CVD-HfC coating process is presented using Density Functional Theory(DFT)and Transition State Theory(TST)at the B3LYP/Lanl2.Z *** results reveal that HfCl4 can only cleave to produce hypochlorite,which will further react with methyl to synthesize intermediates to form *** to the analysis of the energy barrier and reaction constant,HfCl preferentially reacts with methyl groups to form complex adsorptive intermediates at 1573 *** a C—Hf bond production energy of 2.2.8 kcal/mol(1 kcal=4.18 kJ),the reaction rate constant of HfCl+CH is calculated to be 2.15×10^(-18) cm^(3)/s at 1573 ***,both the simulation and experimental results exhibit that the upward trend of reaction rate constants with temperature is also consistent with the deposition rate,indicating that the growth curve of the reaction rate constants tends to flatten *** proposed reaction model of the precursor’s decomposition and reconstruction during deposition process has significant implication for the process guidance.

关键词： Carbon composite HfC coating Chemical vapor deposition Density functional theory Precursor reaction mechanism

Three-dimensional thermohaline structure estimation derived from HY-2.satellite data over the Maritime Silk Road and its applications

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Acta Oceanologica Sinica 2024年第5期43卷 41-53页

作者： Zhiqiang chen Xidong Wang Xiangyu Wu Yuan Cao Zikang He Dakui Wang jian chen Key Laboratory of Marine Hazards Forecasting Ministry of Natural ResourcesHohai UniversityNanjing 210024China Laboratory for Regional Oceanography and Numercial Modeling Qingdao Marine Science and Technology CenterQingdao 266061China National Marine Environmental Forecasting center Ministry of Natural ResourcesBeijing 100081China Beijing Institute of Applied Meteorology Beijing 100029China

Estimated ocean subsurface fields derived from satellite observations provide potential data sources for operational marine environmental monitoring and prediction *** study employs a statistic regression reconstruction method,in combination with domestic autonomous sea surface height and sea surface temperature observations from the Haiyang-2.HY-2.satellite fusion data,to establish an operational quasi-realtime three-dimensional(3D)temperature and salinity products over the Maritime Silk *** products feature a daily temporal resolution and a spatial resolution of 0.2.°×0.2.°and exhibit stability and *** have demonstrated the accuracy of the reconstructed thermohaline fields in capturing the 3D thermohaline variations through comprehensive statistical evaluations,after comparing them against Argo observations and ocean analysis data from *** results illustrate that the reconstructed fields effectively represent seasonal variations in oceanic subsurface structures,along with structural changes resulting from mesoscale processes,and the upper ocean’s responses to tropical ***,the incorporation of HY-2.satellite observations notably enhances the accuracy of temperature and salinity reconstructions in the Northwest Pacific Ocean and marginally improves salinity reconstruction accuracy in the North Indian Ocean when compared to the World Ocean Atlas 2.18 monthly climatology thermohaline *** a result,the reconstructed product holds promise for providing quasi-real-time 3D temperature and salinity field information to facilitate fast decisionmaking during emergencies,and also offers foundational thermohaline fields for operational ocean reanalysis and forecasting *** contributions enhance the safety and stability of ocean subsurface activities and navigation.

关键词： HY-2.satellite observations subsurface structures reconstruction Maritime Silk Road operational thermohaline product

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 2.2. and 2.2.,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 2.-35 cm soil layer(p2.98%to 6.72.and significantly reduced soil total porosity(STP)by 3.88%to 6.53%in the 5-2. cm soil layer,and significantly reduced soil gas phase ratio by 8.2.%to 6.2.%at the 15-2. cm soil layers,which caused soil three-phase ratio(STPR)of PTS and CTS treatment in 15-2. cm soil layer were relatively *** soybean yield of NTSM treatment in 2.2. was not significantly different from PTS and CTS treatment(p>0.05),the soybean yield of NTSM treatment in 2.2. 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

MARS and RNAcmap3:The Master Database of All Possible RNA Sequences Integrated with RNAcmap for RNA Homology Search

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Genomics, Proteomics & Bioinformatics 2024年第1期22卷 143-150页

作者： Ke chen Thomas Litfin Jaswinder Singh jian Zhan Yaoqi Zhou Institute of Systems and Physical Biology Shenzhen Bay LaboratoryShenzhen 518055China Peking University Shenzhen Graduate School Shenzhen 518055China University of Science and Technology of China Hefei 230026China Suzhou Institute for Advanced research University of Science and Technology of ChinaSuzhou 215123China Institute for Glycomics Griffith UniversitySouthportQLD 4222Australia

sequences found in the huge,integrated database of protein sequences(Big Fantastic Database).In contrast,the existing nucleotide databases were not consolidated to facilitate wider and deeper homology ***,we built a comprehensive database by incorporating the non-coding RNA(ncRNA)sequences from RNAcentral,the transcriptome assembly and metagenome assembly from metagenomics RAST(MG-RAST),the genomic sequences from Genome Warehouse(GWH),and the genomic sequences from MGnify,in addition to the nucleotide(nt)database and its subsets in National center of Biotechnology Information(NCBI).The resulting Master database of All possible RNA sequences(MARS)is 2.-fold larger than NCBI’s nt database or 60-fold larger than *** new dataset along with a new split-search strategy allows a substantial improvement in homology search over existing state-of-the-art *** also yields more accurate and more sensitive multiple sequence alignments(MSAs)than manually curated MSAs from Rfam for the majority of structured RNAs mapped to *** results indicate that MARS coupled with the fully automatic homology search tool RNAcmap will be useful for improved structural and functional inference of ncRNAs and RNA language models based on *** is accessible at https://***/omix/release/OMIX003037,and RNAcmap3 is accessible at http://***/download/.

关键词： RNA sequence database Homology search Secondary structure MARS RNAcmap3