检索结果-南通市图书馆

同方期刊数据库

A PAIR OF COUPliNG METRICS FOR SOFTWARE NETWORKS

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2011年第1期24卷 51-60页

作者： Huan li bing li Center of Modern Educational Technology Shanghai University of Political Science and Law Shanghai 201701 China State Key Laboratory of Software Engineering Wuhan University Wuhan 430072 China

Complex networks are everywhere. A typical example is software network. How to measure and control coupling interactions of software components is a largely explored research problem in software network. In terms of graph theory and linear algebra, this paper investigates a pair of coupling metrics to evaluate coupling interactions between the classes of object-oriented systems. These metrics differ from the majority of existing metrics in three aspects： Taking into account the strength that one class depends on other ones, reflecting indirect coupling, and distinguishing various coupling interaction. An empirical comparison of the novel measures with one of the most widely used coupling metrics is described. Specifically, an experiment about the relationships of this pair metrics is conducted. The result shows that software complexity derived from coupling interaction could not be accurately reflected by one dimension of coupling metric for negative correlation.

关键词： Complex network coupling metric software network software system

Electrochemical reduction and electrocrystallization process of B(Ⅲ) in the liF-NaF-KF-KBF_4 molten salt

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2007年第1期26卷 74-78,96页

作者： li Jun li bing School of Materials Engimeting Shanghai University of Engineering Science Shanghai 201600 China School of Resource and Environment Engineering East China University of Science and Technology Shanghai 200237 China

The mechanisms of the electrochemical reduction and nucleation process of B（Ⅲ） on the platinum electrode in the liF-NaF-KF-KBF4 molten salt at 700℃ were first investigated using cyclic voltammetry and chronoamperometry techniques. It was found that the electrochemical reduction of B（Ⅲ） occurs in single-step charge transfer： B（Ⅲ）＋ 3e → B, and the cathode process is reversible. The electrocrystallization process of B（Ⅲ） is instantaneous.

关键词： electrochemical reduction boron coatings molten salt

顶空固相微萃取/气相色谱法快速萃取-解吸土壤中7种芳香族化合物

在线全文

学校读者我要写书评

暂无评论

分析测试学报 2025年第1期44卷 172-179页

作者：李丙阳王钊陈佳邱洪灯新疆师范大学化学化工学院新疆乌鲁木齐830000 中国科学院兰州化学物理研究所甘肃省天然药物重点实验室甘肃兰州730000

利用氧化石墨烯功能化修饰固相微萃取(GO@SPME)针,结合气相色谱(GC)-氢火焰离子化检测器(FID)建立了检测土壤中7种挥发性芳香烃及其衍生物(包括甲苯、氯苯、乙苯、对二甲苯、邻二甲苯、硝基苯和萘)的快速萃取和解吸策略。考察了萃取液... 详细信息

利用氧化石墨烯功能化修饰固相微萃取(GO@SPME)针,结合气相色谱(GC)-氢火焰离子化检测器(FID)建立了检测土壤中7种挥发性芳香烃及其衍生物(包括甲苯、氯苯、乙苯、对二甲苯、邻二甲苯、硝基苯和萘)的快速萃取和解吸策略。考察了萃取液体积、搅拌速率、萃取温度、加盐量、解吸温度、萃取时间和解吸时间对目标物萃取效果的影响,确定在土壤样品中加入内标物质(氘代甲苯),经甲醇提取,顶空固相微萃取快速富集,再结合GC-FID进行检测,基质匹配内标法定量分析。在优化的实验条件下,该方法在15 s内可实现对目标物的快速萃取与解吸(萃取时间12 s,解吸时间3 s)。土壤样品中7种挥发性芳香烃及其衍生物的线性关系良好,相关系数(r^(2))均不小于0.9989,方法检出限(LOD,S/N=3)为1.71~11.60μg/g,定量下限(LOQ,S/N=10)为5.70~38.67μg/g;在3个不同加标水平(60、120、180μg/g)下的平均回收率为87.3%~109%,相对标准偏差(RSD)不大于12%。该方法前处理简单快速,成本较低,数据稳定可靠,适用于土壤样品中芳香族类化合物的快速检测。

关键词：芳香烃及其衍生物氧化石墨烯顶空固相微萃取气相色谱法快速萃取-解吸策略土壤

维普期刊数据库博看期刊

A dynamic PUF anti-aging authentication system based on restrict race code

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2016年第1期59卷 149-160页

作者： bing li Shuai CHEN Southeast University School of Integrated Circuit

This paper presents a PUF(physical unclonable functions) authentication mechanism which can combat aging based on restrict race code(RRC). PUF provide a mechanism for identifying an integrated circuit based on the intrinsic variations of physical components uniquely and provide a cheap and secure alternative to random message storage on devices. However, due to its own characteristics, the chip-level PUF circuit reliability is easily affected by environment. The effect of reversible temporal noise on PUF is well studied and has obtained good effect(e.g. temperature, voltage), but sufficient attention has not been given so far to analyze the effect of the irreversible temporal variabilities(e.g. aging on PUF). This paper proposes a dynamic PUF authentication method, which is based on the RRC with two-ring strong characteristics structure. A combination of hardware and software system is used to improve the efficiency of authentication, and in an FPGA(field-programmable gate array)-based SRAM(static random access memory) PUF are used as an experimental object to verify the feasibility of this design. And this system can enhance the authentication system safety from the CVC(characteristic value challenge) randomness test.

关键词： aging PUF dynamically maintain RRC characteristic value

Self-converse Large Sets of Pure Hybrid Triple Systems

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2017年第2期33卷 515-528页

作者： bing-li FAN Institute of Mathematics Beijing Jiaotong University Beijing 100044 China

A hybrid triple system of order v, briefly by HTS （v）, is a pair （X,/3） where X is a v-set and /3 is a collection of cyclic and transitive triples （called blocks） on X such that every ordered pair of X belongs to exactly one block of/3. An HTS （v） is called pure and denoted by PHTS （v） if one element of the block set {（x,y,z）, （z,y, ss）, （z,sc,y）, （y,x,z）, （y,z,x）, （x,z,y）, （x,y,z）, （z,y,x）} is contained in 13 then the others will not be contained in/3. A self-converse large set of disjoint PHTS （v）s, denoted by LPHTS＊（v）, is a collection of 4（v - 2） disjoint PHTS （v）s which contains exactly （v - 2）/2 converse octads of PHTS （v）s. In this paper, some results about the existence for LPHTS＊（v） are obtained.

关键词： large set hybrid triple system pure converse

Estimation of the Misclassification Error for Multicategory Support Vector Machine Classification

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2008年第3期24卷 511-528页

作者： bing Zheng li Department of Mathematics Zhejiang University Hangzhou 310028 P. R. China

The purpose of this paper is to provide an error analysis for the multicategory support vector machine （MSVM） classificaton problems. We establish the uniform convergency approach for MSVMs and estimate the misclassification error. The main difficulty we overcome here is to bound the offset vector. As a result, we confirm that the MSVM classification algorithm with polynomial kernels is always efficient when the degree of the kernel polynomial is large enough. Finally the rate of convergence and examples are given to demonstrate the main results.

关键词： multicategory support vector machine classifier misclassification error reproducing kernel Hilbert space approximation error

Extraction of vanadium from high calcium vanadium slag using direct roasting and soda leaching

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2012年第7期19卷 595-601页

作者： Xin-sheng li bing Xie College of Materials Science and Engineering Chongqing University Chongqing 400044 China

The extraction of vanadium from high calcium vanadium slag was attempted by direct roasting and soda leaching. The oxidation process of the vanadium slag at different temperatures was investigated by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and energy dispersive spectroscopy （EDS）. The effects of roasting temperature, roasting time, Na2CO3 concentration, leaching tem- perature, leaching time, and liquid to solid ratio on the extraction of vanadium were studied. The results showed that olivine phases and spinel phases in the vanadium slag were completely decomposed at 500 and 800℃, respectively. Vanadium-rich phases were formed at above 850℃. The leaching rate of vanadium reached above 90% under the optimum conditions： roasting temperature of 850℃, roasting time of 60 min, Na2CO3 concentration of 160 g/L, leaching temperature of 95℃, leaching time of 150 min, and liquid to solid ratio of 10：1 mL/g. The main impurities were Si and P in the leach liquor.

关键词： vanadium metallurgy extraction slag roasting leaching

Hausdorff dimensions of some irregular sets associated with β-expansions

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2016年第3期59卷 445-458页

作者： li Jin Jun li bing School of Mathematics and Statistics Minnan Normal University School of Mathematics South China University of Technology

The Hausdorff dimensions of some refined irregular sets associated with β-expansions are determined for any β > 1. More precisely, Hausdorff dimensions of the sets {x ∈ [0, 1) :lim inf(n→∞) S_n(x, β)/n= α_1, lim sup (n→∞) S_n(x, β)/n= α_2}, α_1, α_2≥0 are obtained completely, where S_n(x, β) =sum ε_k(x, β) from k=1 to n denotes the sum of the first n digits of the β-expansion of x. As an application, we present another concise proof of that the set of points x ∈ [0, 1) satisfying lim_(n→∞) S_n(x,β)/n does not exist is of full Hausdorff dimension.

关键词： β-expansion irregular sets Hausdorff dimension

Preparation of TiB_2 coatings by electroplating in molten salt

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2005年第3期24卷 261-266页

作者： li Jun li bing DONG Zheng＇e School of Resource and Environment Engineering East China University of Science and Technology Shanghai 200237 China School of Materials Engineering Shanghai University of Engineering Science Shanghai 200336 China School of Textile Xi＇an Institute of Science and Technology Xi＇an 710048 China

Titanium diboride （TIB2） coatings were prepared by electroplating in fluoride-chloride electrolytes （KF-KC1） containing K2T1F6 and KBF4 as the electrochemically-active components. An attempt was made to correlate the thermodynamic prediction and experimental observations. Thick, adherent, and uniform TtB2 coatings were obtained and the coating microhardness reaches the value of 33 GPa. The effects of the current density on the mechanical properties, structures, and morphologies of the coatings were studied. XRD analysis indicates that the preferred orientation of the coatings is （001）, which is in accordance with the prediction of the two-dimensional crystal nuclei theory. Thermodynamic prediction and experimental results show that some phases such as TixCy and BaCb are absent at the interface, which indicates the substrate and coatings bind mechanically or physically. Some cracks exist at the interface, which is attributed to the difference between the coefficients of thermal expansion of TiB2 and graphite.

关键词： electrodeposition titanium diboride coatings molten salt