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A redundant subspace weighting procedure for clock ensemble

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Chinese Physics B 2024年第4期33卷 435-442页

作者：徐海陈煜刘默驰王玉琢 National Institute of Metrology Beijing 100029China Key Laboratory of State Administration for Market Regulation Beijing 100029China China National intellectual property Administration Beijing 100088China

A redundant-subspace-weighting(RSW)-based approach is proposed to enhance the frequency stability on a time scale of a clock *** this method,multiple overlapping subspaces are constructed in the clock ensemble,and the weight of each clock in this ensemble is defined by using the spatial covariance *** superimposition average of covariances in different subspaces reduces the correlations between clocks in the same laboratory to some *** optimizing the parameters of this weighting procedure,the frequency stabilities of virtual clock ensembles are significantly improved in most cases.

关键词： weighting method redundant subspace clock ensemble time scale

A Strong,Tough,and Self-Healing Strengthening Thioctic Acid-based Elastomer for Highly Reliable Flexible Strain Sensor

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Chinese Journal of Polymer Science 2024年第10期42卷 1610-1618,I0016页

作者： Xin-Yu Chen Yu-Bing Fu Xue-Ling Yan Lan Liu school of Materials Science and Engineering Key Lab of Guangdong Province for High Property and Functional Polymer MaterialsSouth China University of TechnologyGuangzhou510641China

Elastomers with high strength and toughness,excellent self-healing properties,and biocompatibility have broad application prospects in wearable electronics and other fields,but preparing it remains a *** this work,we propose a highly adaptable strategy by introducing the small molecule crosslinking agent of triethanolamine(TEA)to the poly(thioctic acid)(PTA)chains and preparing the PAx Ey elastomers using a simple synthesis *** strategy stabilizes the PTA chains by constructing multiple non-covalent cross-linked dynamic networks,endowing materials with excellent strength and toughness(tensile strength of 288 kPa,toughness of 278.2 kJ/m3),admirable self-healing properties(self-healing efficiency of 121.6%within 7 h at 70℃),and good *** PAx Ey elastomers can also be combined with MWNTs to become flexible strain sensors,which can be used to monitor human joint movements with high sensitivity,repeatable responses,and stability.

关键词： Thioctic acid Ion clusters Multiple dynamic networks Self-healing strengthening Flexible strain sensor

Design and synthesis of thiol-terminated imidothioether oligomer as thermally latent hardener and modifier for high-performance epoxy/thiol thermosets

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Science China Chemistry 2024年第2期67卷 632-641页

作者： Xing Liu Jianjun Zhou Shumei Liu Jianqing Zhao school of Materials Science and Engineering South China University of TechnologyGuangzhou510640China Key Lab Guangdong High property&Functional Polymer Materials Key Laboratory of Polymer Processing EngineeringMinistry of EducationGuangzhou510640China

Conventional base-catalyzed epoxy/aliphatic thiol systems have a poor storage stability,and are impossible to be one-pot systems.A widely accepted solution is to use the latent catalysts,which are usually insoluble anionic initiators sensitive to impurities and moisture,and have many limitations in practical *** this work,a soluble thiol-terminated imidothioether oligomer(TPI) was synthesized and used as a latent hardener and modifier to prepare one-pot epoxy/thiol systems without the latent *** latent behavior and curing mechanism of epoxy systems(EP/TPI series),consisted of bisphenol A diglycidyl ether(DGEBA),pentaerythritol tetrakis(mercaptoacetate)(PETMP) and TPI,were *** thiol exchange reaction between TPI and PETMP preceded the curing reaction of DGEBA,and produced aromatic thiols,which were unreactive at ambient conditions and reacted with DGEBA to form the thermosets at temperatures above 130 ℃.At the loading of 24.4 wt%TPI,the epoxy system(EP/TPI-3) had a shelf life of 13 days and was completely cured within 20 min at 180 ℃.Meanwhile,the catalyst-free curing process of EP/TPI-3 system was insensitive to impurities and ***,the thermal and mechanical properties of EP/TPI-3 thermoset were simultaneously improved,thereinto,the glass transition temperature,Young's modulus and ultimate tensile strength were increased by 16.7 ℃,12.9%,and 13.6%,respectively,compared with those of the commercial DGEBA/PETMP *** work shows that TPI has the potential to be a powerful alternative to commercial latent catalysts,and EP/TPI thermosets with high performance have broad application prospects.

关键词： thiol-terminated imidothioether oligomer epoxy systems thiol exchange reaction thermal latency high performance

Volume-averaged modeling of multiphase solidification with equiaxed crystal sedimentation in a steel ingot

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China Foundry 2024年第3期21卷 229-238页

作者： Xiao-lei Zhu Shuang Cao Rui Guan Ji Yang Zhe Ning Xin-gang Ai Sheng-li Li Xin-cheng Miao The key Laboratory of Material Forming and Structure property Control Anshan 114051LiaoningChina State Key Laboratory of Metal Material for Marine Equipment and Application Anshan 114009LiaoningChina school of Materials and Metallurgy University of Science and Technology LiaoningAnshan 114051LiaoningChina

Macrosegregation is a critical factor that limits the mechanical properties of *** impact of equiaxed crystal sedimentation on macrosegregation has been extensively studied,as it plays a significant role in determining the distribution of alloying elements and impurities within a *** improve macrosegregation in steel connecting shafts,a multiphase solidification model that couples melt flow,heat transfer,microstructure evolution,and solute transport was established based on the volume-averaged Eulerian-Eulerian *** this model,the effects of liquid phase,equiaxed crystals,columnar dendrites,and columnar-to-equiaxed transition(CET)during solidification and evolution of microstructure can be considered *** sedimentation of equiaxed crystals contributes to negative macrosegregation,where regions between columnar dendrites and equiaxed crystals undergo significant A-type positive macrosegregation due to the ***,noticeable positive macrosegregation occurs in the area of final solidification in the *** improvement in macrosegregation is beneficial for enhancing the mechanical properties of connecting *** mitigate the thermal convection of molten steel resulting from excessive superheating,reducing the superheating during casting without employing external fields or altering the design of the ingot mold is indeed an effective approach to control macrosegregation.

关键词： ingot casting multiphase solidification model equiaxed crystal sedimentation microstructure macrosegregation

Regulating Effect of Substrate Temperature on Sputteringgrown Ge/Si QDs under Low Ge Deposition

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Journal of Wuhan University of Technology(Materials Science) 2024年第4期39卷 888-894页

作者：舒启江 YANG Linjing LIU Hongxing 黄鹏儒 Institute of Information Yunnan University of Chinese MedicineKunming 650500China Guangxi Key Laboratory of Information Materials and Guangxi Collaborative Innovation Center of Structure and property for New Energy and Materials School of Material Science&EngineeringGuilin University of Electronic TechnologyGuilin 541004China

The effect of deposition temperature on the morphology and optoelectronic performance of Ge/Si QDs grown by magnetron sputtering under low Ge deposition(~4 nm)was investigated by atomic force microscopy,Raman spectroscopy,and photoluminescence(PL)*** experimental results indicate that temperatures higher than 750℃effectively increase the crystallization rate and surface smoothness of the Si buffer layer,and temperatures higher than 600℃significantly enhance the migration ability of Ge atoms,thus increasing the probability of Ge atoms meeting and nucleating to form QDs on Si buffer layer,but an excessively high temperature will cause the QDs to undergo an Ostwald ripening process and thus develop into super large *** addition,some PL peaks were observed in samples containing small-sized,high-density Ge QDs,the photoelectric properties reflected by these peaks were in good agreement with the corresponding structural characteristics of the grown *** results demonstrate the viability of preparing high-quality QDs by magnetron sputtering at high deposition rate,and the temperature effect is expected to work in conjunction with other controllable factors to further regulate QD growth,which paves an effective way for the industrial production of QDs that can be used in future devices.

关键词： Ge/Si QDs deposition temperatures evolution law photoelectric performance

Highly efficient catalyzed by imidazolium-based dual-sulfonic acid functionalized ionic liquids for liquid phase Beckmann rearrangement:experiments and COSMO-RS calculations

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Green Chemical Engineering 2024年第1期5卷 108-118页

作者： Xin Guo Zhiyuan Wang Ye Yang Jiahui Zhang Yanduo Liu Zhiyuan Mu Siqi Jiang Chunxiao Ren Dan Lv Yufeng Hu Zhichang Liu State Key Laboratory of Heavy Oil Processing and High Pressure Fluid Phase Behavior&property Research Laboratory China University of PetroleumBeijing102249China school of Chemistry and Materials Science University of Science and Technology of ChinaHefei230026China school of Light Industry and Engineering South China University of TechnologyGuangzhou510641China

A production technique with the high yield and environmentally friendly process need be developed forε-Caprolactam(CPL)in the chemical *** technology is highly desired to design and synthesize high--performance catalysts for liquid phase Beckmann rearrangement of cyclohexanone oxime(CHO)to *** this work,3-methyl-1-(propyl-4-sulfonyl)imidazolium methanesulfonate([PHSO_(3)MIM][MSA])with highly efficient and excellent yield is synthesized *** the optimum molar ratio of ZnCl_(2)over[PHSO_(3)MIM][MSA]was 0.02,it exhibits the high selectivity(94%)of CPL at 90℃for 1 ***,Fourier-transform infrared(FT-IR)investigations show that the functional Br∅nsted-Lewis acidic types of ionic liquids(ILs)are formed by the uniformly distributed ZnCl_(2)and[PHSO_(3)MIM][MSA].In addition,the hydrogen bond(H-bond)is formed between CHO and *** ten reaction cycles,no significant structure changes are observed in the recovered[PHSO_(3)MIM][MSA]-ZnCl_(2).The solubilities of ILs are predicted by using COSMO-RS model,the results show that[PHSO_(3)MIM][MSA]is a promising candidate for the liquid phase Beckmann rearrangement of CHO into ***,a theoretical model of the H-bond interactions between ILs and CHO is further confirmed to support the advance of reaction mechanism.A feasible way is provided for the CPL production technique in the liquid phase Beckmann rearrangement reaction.

关键词： Liquid phase Beckmann rearrangement Imidazolium-based ionic liquids COSMO-RS calculations H-bond

Borohydride Ammoniate Solid Electrolyte Design for All-Solid-State Mg Batteries

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Energy & Environmental Materials 2024年第1期7卷 100-106页

作者： Yuepeng Pang Zhengfang Nie Fen Xu Lixian Sun Junhe Yang Dalin Sun Fang Fang Shiyou Zheng school of Materials and Chemistry University of Shanghai for Science and TechnologyShanghai 200093China Guangxi Key Laboratory of Information Materials&Guangxi Collaborative Innovation Centre of Structure and property for New Energy and Materials Guilin University of Electronic TechnologyGuilin 541004China Department of Materials Science Fudan UniversityShanghai 200433China

Searching for novel solid electrolytes is of great importance and challenge for all-solid-state Mg *** this work,we develop an amorphous Mg borohydride ammoniate,Mg(BH_(4))_(2)·2NH_(3),as a solid Mg electrolyte that prepared by a NH_(3)redistribution between 3D framework-γ-Mg(BH_(4))_(2)and Mg(BH_(4))_(2)·6NH_(3).Amorphous Mg(BH_(4))_(2)·2NH_(3)exhibits a high Mg-ion conductivity of 5×10^(-4)S cm^(-1)at 75℃,which is attributed to the fast migration of abundant Mg vacancies according to the theoretical ***,amorphous Mg(BH_(4))_(2)·2NH_(3)shows an apparent electrochemical stability window of 0-1.4 V with the help of in-situ formed interphases,which can prevent further side reactions without hindering the Mg-ion *** on the above superiorities,amorphous Mg(BH_(4))_(2)·2NH_(3)enables the stable cycling of all-solid-state Mg cells,as the critical current density reaches 3.2 mA cm^(-2)for Mg symmetrical cells and the reversible specific capacity reaches 141 mAh g^(-1)with a coulombic efficiency of 91.7%(first cycle)for Mg||TiS_(2)cells.

关键词： all-solid-state Mg batteries amorphization Mg borohydride ammoniate Mg vacancy migration solid electrolyte

Uncertainty-Aware Physical Simulation of Neural Radiance Fields for Fluids

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Computer Modeling in Engineering & Sciences 2024年第7期140卷 1143-1163页

作者： Haojie Lian Jiaqi Wang Leilei Chen Shengze Li Ruochen Cao Qingyuan Hu Peiyun Zhao Key Laboratory of In-Situ property-Improving Mining of Ministry of Education Taiyuan University of TechnologyTaiyuan030024China Henan International Joint Laboratory of Structural Mechanics and Computational Simulation College of Architectural and Civil EngineeringHuanghuai UniversityZhumadian463000China National Innovation Institute of Defense Technology Academy of Military ScienceBeijing100091China school of Software Taiyuan University of TechnologyJinzhong030600China school of Science Jiangnan UniversityWuxi214122China

This paper presents a novel framework aimed at quantifying uncertainties associated with the 3D reconstruction of smoke *** approach reconstructs color and density fields from 2D images using Neural Radiance Field(NeRF)and improves image quality using frequency *** NeRF model is obtained via joint training ofmultiple artificial neural networks,whereby the expectation and standard deviation of density fields and RGB values can be evaluated for each *** addition,customized physics-informed neural network(PINN)with residual blocks and two-layer activation functions are utilized to input the density fields of the NeRF into Navier-Stokes equations and convection-diffusion equations to reconstruct the velocity *** velocity uncertainties are also evaluated through ensemble *** effectiveness of the proposed algorithm is demonstrated through numerical *** presentmethod is an important step towards downstream tasks such as reliability analysis and robust optimization in engineering design.

关键词： Uncertainty quantification neural radiance field physics-informed neural network frequency regularization twolayer activation function ensemble learning

Design and verification of a 10-bit 1.2-V 100-MSPS D/A IP core based on a 0.13-μm low power CMOS process

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Journal of Semiconductors 2010年第9期31卷 99-103页

作者：徐步陆邵博闻林霞易伟刘芸 Shanghai Silicon intellectual property Exchange

Based on a low supply voltage curvature-compensated bandgap reference and central symmetry Q;random walk NMOS current source layout routing method,a 1.2-V 10-bit 100-MSPS CMOS current-steering digital-to-analog converter is implemented in a SMIC 0.13-μm CMOS *** total consumption is only 10 mW from a single 1.2-V power supply,and the integral and differential nonlinearity are measured to be less than 1 LSB and 0.5 LSB, *** the output signal frequency is 1-5 MHz at 100-MSPS sampling rate,the SFDR is measured to be 70 *** die area is about 0.2 mm;.

关键词： current-steering digital-to-analog converter low power matching error current source array mixedsignal integrated circuits