检索结果-南通市图书馆

Effects of temperature and alloying content on the phase transformation and{10■1}twinning in Zr during rolling

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2020年第6期41卷 76-80页

作者： Xinglong An Hao Zhang Song Ni xiaoqin ou Xiaozhou Liao Min Song State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China School of Aerospace Mechanical and Mechatronic EngineeringThe University of SydneySydneyNSW 2006Australia

The effects of temperature and Ti content on the deformation mechanisms of pure Zr and Zr-Ti alloys were investigated by transmission electron microscopy.The results indicate the existence of a relation between deformation-induced phase transformation from a hexagonal close-packed structure to a facecentered cubic structure and{10■1}deformation twinning.That is,when one is suppressed,the other will be promoted.The phase transformation was suppressed while the{10■1}compressive twinning was promoted with increasing the rolling temperature and/or Ti content.This can be attributed to the activation of basaldislocations at high temperature and the increased stacking fault energy with Ti content.

关键词： Zr Zr-Ti alloy Twinning Phase transformation Stacking fault energy

在线全文

学校读者我要写书评

暂无评论

肛周脓肿四季中医证素分布规律研究

中国民间疗法 2024年第4期32卷 8-10页

作者：罗丹欧小琴重庆市渝北区中医院重庆401120

目的:探究肛周脓肿四季中医证素总体分布规律,以及各季节的中医证素分布规律,以便对肛周脓肿进行更有效的中医药预防及治疗。方法:参考朱文锋教授所著《证素辨证学》设计而成的中医证素调查表,并对126例肛周脓肿患者进行调查分析,其中... 详细信息

目的:探究肛周脓肿四季中医证素总体分布规律,以及各季节的中医证素分布规律,以便对肛周脓肿进行更有效的中医药预防及治疗。方法:参考朱文锋教授所著《证素辨证学》设计而成的中医证素调查表,并对126例肛周脓肿患者进行调查分析,其中春季有28例,夏季有39例,秋季有27例,冬季有32例。结果:肛周脓肿的病位证素主要在肝、肾。春夏季节多涉及肝,秋冬季节多涉及肾。病性证素在1年中的总体分布以热盛证多见,其次为阴虚证、湿热证、痰浊证、气虚证等。春季肛周脓肿患者以气滞证为主;夏季肛周脓肿患者以热盛证为主;秋季肛周脓肿患者以热盛证及湿热证为主;冬季肛周脓肿患者以痰浊证为主。结论:1年中肛周脓肿患者多表现为实证及虚实夹杂证,病性多与热盛证、阴虚证、湿热证有关。肛周脓肿患者的病位主要涉及肝、肾。

关键词：肛周脓肿病位证素病性证素四季肝肾气滞证热盛证湿热证痰浊证规律研究

The low Mach number limit of non-isentropic magnetohydrodynamic equations with large temperature variations in bounded domains

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2024年第4期67卷 787-818页

作者： Min Liang Yaobin ou School of Mathematics Renmin University of ChinaBeijing 100872China

This paper verifies the low Mach number limit of the non-isentropic compressible magnetohydrodynamic(MHD)equations with or without the magnetic diffusion in a three-dimensional bounded domain when the temperature variation is large but finite.The uniform estimates of strong solutions are established in a short time interval independent of the Mach number,provided that the slip boundary condition for the velocity and the Neumann boundary condition for the temperature are imposed and the initial data is well-prepared.

关键词： low Mach number limit non-isentropic compressible magnetohydrodynamic equations large temperature variations bounded domains

High-throughput screening of single-atom catalysts confined in monolayer black phosphorus for efficient nitrogen reduction reaction

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第4期17卷 2360-2367页

作者： Xiao-Yan Li Manyi Duan Pengfei ou Department of Electrical and Computer Engineering University of TorontoTorontoOntario M5S 1A4Canada School of Physics and Electronic Engineering Sichuan Normal UniversityChengdu 610101China Department of Chemistry Northwestern UniversityEvanstonIL 60208USA

The discovery of metal-nitrogen centers as the active sites for electrolysis has aroused significant interest in utilizing single-atom catalysts for nitrogen reduction reaction(NRR).Properly designed nanostructured catalysts that strongly interact with nitrogen molecules(N_(2))can promote adsorption and activation,thereby resulting in efficient catalysts with high stability,activity,and selectivity.In this study,using density functional theory calculations,we selected monolayer black phosphorus(BP)as the substrate and screened a series of single-atom transition metals confined in tri-coordinated and tetra-coordinated active centers(without and with N dopants)to electro-catalyze NRR.As a result,we have identified two promising candidates(Hf_(1)-N_(1)P_(2)-1 and Tc_(1)-N_(4)),which exhibit not only low overpotentials of 0.56 and 0.49 V but also high thermodynamic and electrochemical stability,as well as good selectivity towards NRR over the competing hydrogen evolution reaction.We also demonstrate the ability of Hf_(1)-N_(1)P_(2)-1 and Tc_(1)-N_(4) to activate and hydrogenate N_(2) by donating electrons and regulating charge transfer.This study not only predicts new BP-based promising catalysts but also provides guidance for the rational design of high-performance NRR electrocatalysts under ambient conditions.

关键词： N_(2) electroreduction reaction single-atom catalysts black phosphorus density functional theory high-throughput calculations

Block Basis for Modular Coinvariants of Pseudo-Reflection Groups

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Algebra Colloquium 2024年第1期31卷 41-48页

作者： Ke ou School of Statistics and Mathematics Yunnan University of Finance and Economics Kunming 650221China

We investigate the block basis for modular coinvariants of finite pseudo-reflection groups.We are particularly interested in the case of a subgroup G of the parabolic subgroups of GLn(q)which generalizes the Weyl grou... 详细信息

关键词： modular invariant theory pseudo-reflection group block basis coinvariant

Side-Channel Leakage Analysis of Inner Product Masking

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第4期79卷 1245-1262页

作者： Yuyuan Li Lang Li Yu ou College of Computer Science and Technology Hengyang Normal UniversityHengyang421002China Hunan Provincial Key Laboratory of Intelligent Information Processing and Application Hengyang Normal UniversityHengyang421002China

The Inner Product Masking(IPM)scheme has been shown to provide higher theoretical security guarantees than the BooleanMasking(BM).This scheme aims to increase the algebraic complexity of the coding to achieve a higher level of security.Some previous work unfolds when certain(adversarial and implementation)conditions are met,and we seek to complement these investigations by understanding what happens when these conditions deviate from their expected behaviour.In this paper,we investigate the security characteristics of IPM under different conditions.In adversarial condition,the security properties of first-order IPMs obtained through parametric characterization are preserved in the face of univariate and bivariate attacks.In implementation condition,we construct two new polynomial leakage functions to observe the nonlinear leakage of the IPM and connect the security order amplification to the nonlinear function.We observe that the security of IPMis affected by the degree and the linear component in the leakage function.In addition,the comparison experiments from the coefficients,signal-to-noise ratio(SNR)and the public parameter show that the security properties of the IPM are highly implementation-dependent.

关键词： Side-channel analysis inner product masking mutual information nonlinear leakage

Performance Prediction Based Workload Scheduling in Co-Located Cluster

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2024年第5期139卷 2043-2067页

作者： Dongyang ou Yongjian Ren Congfeng Jiang School of Computer Science and Technology Hangzhou Dianzi UniversityHangzhou310018China

Cloud service providers generally co-locate online services and batch jobs onto the same computer cluster,where the resources can be pooled in order to maximize data center resource utilization.Due to resource competition between batch jobs and online services,co-location frequently impairs the performance of online services.This study presents a quality of service(QoS)prediction-based schedulingmodel(QPSM)for co-locatedworkloads.The performance prediction of QPSM consists of two parts:the prediction of an online service’s QoS anomaly based on XGBoost and the prediction of the completion time of an offline batch job based on randomforest.On-line service QoS anomaly prediction is used to evaluate the influence of batch jobmix on on-line service performance,and batch job completion time prediction is utilized to reduce the total waiting time of batch jobs.When the same number of batch jobs are scheduled in experiments using typical test sets such as CloudSuite,the scheduling time required by QPSM is reduced by about 6 h on average compared with the first-come,first-served strategy and by about 11 h compared with the random scheduling strategy.Compared with the non-co-located situation,QPSM can improve CPU resource utilization by 12.15% and memory resource utilization by 5.7% on average.Experiments show that the QPSM scheduling strategy proposed in this study can effectively guarantee the quality of online services and further improve cluster resource utilization.

关键词： Co-located cluster workload scheduling online service batch jobs data center

Crowdsourcing RTK:a new GNSS positioning framework for building spatial high-resolution atmospheric maps based on massive vehicle GNSS data

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Satellite Navigation 2024年第1期5卷 91-108页

作者： Hongjin Xu Xingyu Chen Jikun ou Yunbin Yuan State Key Laboratory of Geodesy and Earth’s Dynamics Innovation Academy for Precision Measurement Science and Technology(APM)Chinese Academy of Sciences(CAS)Wuhan430071China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijingChina

High-quality spatial atmospheric delay correction information is essential for achieving fast integer ambiguity resolution(AR)in precise positioning.However,traditional real-time precise positioning frameworks(i.e.,NRTK and PPP-RTK)depend on spatial low-resolution atmospheric delay correction through the expensive and sparsely distributed CORS network.This results in limited public appeal.With the mass production of autonomous driving vehicles,more cost-effective and widespread data sources can be explored to create spatial high-resolution atmospheric maps.In this study,we propose a new GNSS positioning framework that relies on dual base stations,massive vehicle GNSS data,and crowdsourced atmospheric delay correction maps(CAM).The map is easily produced and updated by vehicles equipped with GNSS receivers in a crowd-sourced way.Specifically,the map consists of between-station single-differenced ionospheric and tropospheric delays.We introduce the whole framework of CAM initialization for individual vehicles,on-cloud CAM maintenance,and CAM-augmented user-end positioning.The map data are collected and preprocessed in vehicles.Then,the crowdsourced data are uploaded to a cloud server.The massive data from multiple vehicles are merged in the cloud to update the CAM in time.Finally,the CAM will augment the user positioning performance.This framework forms a beneficial cycle where the CAM’s spatial resolution and the user positioning performance mutually improve each other.We validate the performance of the proposed framework in real-world experiments and the applied potency at different spatial scales.We highlight that this framework is a reliable and practical positioning solution that meets the requirements of ubiquitous high-precision positioning.

关键词： New GNSS positioning framework Spatial high-resolution atmospheric delay correction Crowdsourced atmospheric delay correction maps Crowdsourced ionosphere Crowdsourced troposphere Ubiquitous

Turbo Message Passing Based Burst Interference Cancellation for Data Detection in Massive MIMO-OFDM Systems

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

China Communications 2024年第2期21卷 143-154页

作者： Wenjun Jiang Zhihao ou Xiaojun Yuan Li Wang National Key Laboratory of Wireless Communications University of Electronic Science and Technology of ChinaChengdu 611731China

This paper investigates the fundamental data detection problem with burst interference in massive multiple-input multiple-output orthogonal frequency division multiplexing(MIMO-OFDM) systems. In particular, burst interference may occur only on data symbols but not on pilot symbols, which means that interference information cannot be premeasured. To cancel the burst interference, we first revisit the uplink multi-user system and develop a matrixform system model, where the covariance pattern and the low-rank property of the interference matrix is discussed. Then, we propose a turbo message passing based burst interference cancellation(TMP-BIC) algorithm to solve the data detection problem, where the constellation information of target data is fully exploited to refine its estimate. Furthermore, in the TMP-BIC algorithm, we design one module to cope with the interference matrix by exploiting its lowrank property. Numerical results demonstrate that the proposed algorithm can effectively mitigate the adverse effects of burst interference and approach the interference-free bound.

关键词： burst interference cancellation data detection massive multiple-input multiple-output(MIMO) message passing orthogonal frequency division multiplexing(OFDM)