检索结果-南通市图书馆

Reliability modeling of mutual DCFP considering failure physical dependency

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2023年第4期34卷 1063-1073页

作者： chen Ying YANG Tianyu WANG yanfang Science and Technology on Reliability and Environmental Engineering Laboratory Beihang UniversityBeijing 100191China

Degradation and overstress failures occur in many electronic systems in which the operation load and environmental conditions are complex.The dependency of them called dependent competing failure process(DCFP),has been widely studied.Electronic system may experience mutual effects of degradation and shocks,they are considered to be interdependent.Both the degradation and the shock processes will decrease the limit of system and cause cumulative effect.Finally,the competition of hard and soft failure will cause the system failure.Based on the failure mechanism accumulation theory,this paper constructs the shock-degradation acceleration and the threshold descent model,and a system reliability model established by using these two models.The mutually DCFP effect of electronic system interaction has been decomposed into physical correlation of failure,including acceleration,accumulation and competition.As a case,a reliability of electronic system in aeronautical system has been analyzed with the proposed method.The method proposed is based on failure physical evaluation,and could provide important reference for quantitative evaluation and design improvement of the newly designed system in case of data deficiency.

关键词： electronic system dependent competing failure process(DCFP) failure physical dependency threshold descent model competition failure modes

Higher order implicit CNDG-PML algorithm for left-handed materials

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2021年第1期32卷 31-37页

作者： chen yanfang WANG Liwei School of Electrical and Information Engineering Tianjin UniversityTianjin 300072China Tianjin Key Laboratory of Intelligent Information Processing in Remote Sensing Tianjin Zhongwei Aerospace Data System Technology Co.Ltd.Tianjin 300450China

By incorporating the higher order concept,the piecewise linear recursive convolution(PLRC)method and CrankNicolson Douglas-Gunn(CNDG)algorithm,the unconditionally stable complex frequency shifted nearly perfectly matched layer(CFS-NPML)is proposed to terminate the left-handed material(LHM)domain.The proposed scheme takes advantages of CFSNPML formulation,the higher order concept PLRC method and the unconditionally stable CNDG algorithm in terms of absorbing performance,computational efficiency,calculation accuracy and convenient implementation.A numerical example is carried out to demonstrate the effectiveness and efficiency of the proposed scheme.The results indicate that the proposed scheme can not only have considerable absorbing performance but also maintain the unconditional stability of the algorithm with the enlargement of time steps.

关键词： complex frequency shifted nearly perfectly matched layer(CFS-NPML) Crank-Nicolson Douglas-Gunn(CNDG) left-handed material(LHM) piecewise linear recursive convolution(PLRC)

Shamanskii-Like Levenberg-Marquardt Method with a New Line Search for Systems of Nonlinear Equations

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2020年第5期33卷 1694-1707页

作者： chen Liang MA yanfang School of Mathematical Sciences Huaibei Normal UniversityHuaibei 235000China School of Compuler Science and Technology Huaibei Normal UniversityHuaibei 235000China

To save the calculations of Jacobian,a multi-step Levenberg-Marquardt method named Shamanskii-like LM method for systems of nonlinear equations was proposed by Fa.Its convergence properties have been proved by using a trust region technique under the local error bound condition.However,the authors wonder whether the similar convergence properties are still true with standard line searches since the direction may not be a descent direction.For this purpose,the authors present a new nonmonotone m-th order Armijo type line search to guarantee the global convergence.Under the same condition as trust region case,the convergence rate also has been shown to be m+1 by using this line search technique.Numerical experiments show the new algorithm can save much running time for the large scale problems,so it is efficient and promising.

关键词： Armijo line search Levenberg-Marquardt method local error bound condition systems of nonlinear equations unconstrained optimization

System reliability evaluation method considering physical dependency with FMT and BDD analytical algorithm

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2022年第1期33卷 222-232页

作者： chen Ying WANG yanfang YANG Song KANG Rui School of Reliability and System Engineering Beihang UniversityBeijing 100191China Science and Technology on Reliability and Environmental Engineering Laboratory Beihang UniversityBeijing 100191China China Academy of Launch Vehicle Technology Bejing 100076China

Recently, the physics-of-failure(PoF) method has been more and more popular in engineering to understand the failure mechanisms(FMs) of products.However, due to the lack of system modeling methods and problem-solving algorithms,the information of FMs cannot be used to evaluate system reliability.This paper presents a system reliability evaluation method with failure mechanism tree(FMT) considering physical dependency(PDEP) such as competition, trigger, acceleration, inhibition, damage accumulation, and parameter combination.And the binary decision diagram(BDD) analytical algorithm is developed to establish a system reliability model.The operation rules of ite operators for generating BDD are discussed.The flow chart of system reliability evaluation method based on FMT and BDD is proposed.The proposed method is applied in the case of an electronic controller drive unit.Results show that the method is effective to evaluate system reliability from the perspective of FM.

关键词： system reliability modeling failure physical dependency failure mechanism tree(FMT) binary decision diagram(BDD)

Hollow-fiber gas penetration electrodes efficiently produce renewable synthetic fuels

在线全文

学校读者我要写书评

暂无评论

Frontiers in Energy 2022年第5期16卷 700-705页

作者： yanfang SONG Xiao DONG Wei chen Wei WEI Low-Carbon Conversion Science and Engineering Center Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201210China University of Chinese Academy of Sciences Beijing 100049China

Increasing CO_(2) levels in the atmosphere due to the consumption of large amounts of fossil fuels is exacerbating global climate change,which seriously threatens sustainable human development.As a responsible and respectable country,China has announced remarkable goals of reaching a carbon emission peak and achieving carbon neutrality,which are challenging missions with enormous contributions to the world.As a strategic support,disruptive and transformative energy technologies are urgently required to develop new green and low-carbon energy industries.Renewable energy sources such as wind and sun,which can generate zero-carbon electric power,have been rapidly developed in recent years.

关键词： fuels fiber seriously

Observer-based boundary control for an asymmetric output-constrained flexible robotic manipulator

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

Science China(Information Sciences) 2022年第3期65卷 280-282页

作者： Yu LIU Xiongbin chen yanfang MEI Yilin WU School of Automation Science and Engineering South China University of Technology Guangzhou Institute of Modern Industrial Technology Department of Computer Science Guangdong University of Education

Dear editor,With the rapid development of robotics, flexible robotic manipulators have played an important role in industrial production and manufacture because of their lightweight, higher operation speed and better energy efficiency [1]. However, flexible materials will result in vibration. Besides, in practical applications, external disturbances and constraints caused by environmental factors or technique requirements diffusely exist, which will affect the operation accuracy of the manipulators. Thus, we focus on the angle tracking and vibration problem of the flexible robotic manipulator with external disturbances and output constraints.

关键词： Distributed parameter system vibration control asymmetric constraint disturbance observer well-posedness Partial differential equation

Covalent organic nanospheres as a fiber coating for solid-phase microextraction of genotoxic impurities followed by analysis using GC-MS

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Pharmaceutical Analysis 2022年第4期12卷 583-589页

作者： yanfang Zhao Jingkun Li Hanyi Xie Huijuan Li Xiangfeng chen School of Pharmaceutical Sciences Qilu University of Technology(Shandong Academy of Sciences)Jinan250014China Shandong Analysis and Test Center Qilu University of Technology(Shandong Academy of Sciences)Jinan250014China

Covalent organic nanospheres(CONs)were explored as a fiber coating for solid-phase microextraction of genotoxic impurities(GTIs)from active ingredients(AIs).CONs were synthesized by an easy solutionphase procedure at 25℃.The obtained nanospheres exhibited a high specific surface area,good thermostability,high acid and alkali resistance,and favorable crystallinity and porosity.Two types of GTIs,alkyl halides(1-iodooctane,1-chlorobenzene,1-bromododecane,1,2-dichlorobenzene,1-bromooctane,1-chlorohexane,and 1,8-dibromooctane)and sulfonate esters(methyl p-toluenesulfonate and ethyl ptoluenesulfonate),were chosen as target molecules for assessing the performance of the coating.The prepared coating achieved high enhancement factors(5097-9799)for the selected GTIs.The strong affinity between CONs and GTIs was tentatively attributed to π-π and hydrophobicity interactions,large surface area of the CONs,and size-matching of the materials.Combined with gas chromatography-mass spectrometry(GC-MS),the established analytical method detected the GTIs in capecitabine and imatinib mesylate samples over a wide linear range(0.2-200 ng/g)with a low detection limit(0.04-2.0 ng/g),satisfactory recovery(80.03%-109.5%),and high repeatability(6.20%-14.8%)and reproducibility(6.20%-14.1%).Therefore,the CON-coated fibers are promising alternatives for the sensitive detection of GTIs in AI samples.

关键词： Covalent organic nanospheres Solid-phase microextraction Genotoxic impurities Gas chromatography-mass spectrometry

Progress and prediction of multicomponent quantification in complex systems with practical LC-UV methods

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

Journal of Pharmaceutical Analysis 2023年第2期13卷 142-155页

作者： Xi chen Zhao Yang Yang Xu Zhe Liu yanfang Liu Yuntao Dai Shilin chen Institute of Chinese Materia Medica China Academy of Chinese Medical SciencesBeijing100700China Key Lab of Separation Science for Analytical Chemistry Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian116023China Institute of Herbgenomics Chengdu University of Traditional Chinese MedicineChengdu611137China

Complex systems exist widely,including medicines from natural products,functional foods,and biological samples.The biological activity of complex systems is often the result of the synergistic effect of multiple components.In the quality evaluation of complex samples,multicomponent quantitative analysis(MCQA)is usually needed.To overcome the difficulty in obtaining standard products,scholars have proposed achieving MCQA through the“single standard to determine multiple components(SSDMC)”approach.This method has been used in the determination of multicomponent content in natural source drugs and the analysis of impurities in chemical drugs and has been included in the Chinese Pharmacopoeia.Depending on a convenient(ultra)high-performance liquid chromatography method,how can the repeatability and robustness of the MCQA method be improved?How can the chromatography conditions be optimized to improve the number of quantitative components?How can computer software technology be introduced to improve the efficiency of multicomponent analysis(MCA)?These are the key problems that remain to be solved in practical MCQA.First,this review article summarizes the calculation methods of relative correction factors in the SSDMC approach in the past five years,as well as the method robustness and accuracy evaluation.Second,it also summarizes methods to improve peak capacity and quantitative accuracy in MCA,including column selection and twodimensional chromatographic analysis technology.Finally,computer software technologies for predicting chromatographic conditions and analytical parameters are introduced,which provides an idea for intelligent method development in MCA.This paper aims to provide methodological ideas for the improvement of complex system analysis,especially MCQA.

关键词： Multicomponent quantification analysis Single standard to determine multiple components Predictive software

Flammulina velutipes polysaccharide-iron (Ⅲ) complex used to treat iron deficiency anemia after being absorbed via GLUT2 and SGLT1 transporters

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

Food Science and Human Wellness 2023年第5期12卷 1828-1840页

作者： chenying Shi chen cheng Xiaotong Lin yanfang Qian Yufeng Du Guitang chen Department of Food Nutrition and Safety/National R&D Center for Chinese Herbal Medicine Processing China Pharmaceutical UniversityNanjing 211198China College of Pharmacy China Pharmaceutical UniversityNanjing 211198China

Iron deficiency anemia(IDA)is a common nutritional problem, but traditional iron supplements cause many adverse reactions. Thus, the development of a novel iron supplement might be significant for the treatment of IDA. This study aimed to study the transport mechanism of Flammulina velutipes polysaccharide-iron complex(FVP1-Fe(Ⅲ))in Caco-2 cells and the therapeutic effect on IDA rats, as well as the influence on gut microbiota in vivo. These results showed that in vitro, the uptake of FVP1-Fe(Ⅲ)was mediated by sodium-dependent glucose transporter-1(SGLT1)and facilitated glucose transporter-2(GLUT2)and GLUT2 played a dominant function. The multidrug resistance-associated protein-2(MRP-2)was involved in the efflux of FVP1-Fe(Ⅲ)across the Caco-2 cells. In vivo, FVP1-Fe(Ⅲ)had a better restorative effect on blood parameters and iron status indicators in rats with IDA as compared with FeSO_4 and exerted this effect by downregulating the expression of hepcidin. FVP1-Fe(Ⅲ)could also regulate gut microbiota dysbiosis in iron deficiency rats by returning the relative abundance of gut microbiota to the normal level. Besides, as a dietary factor, vitamin C(vit C)could enhance the therapeutic effect of FVP1-Fe(Ⅲ). These present findings showed that FVP1-Fe(Ⅲ)could be exploited as a novel iron supplement to treat IDA.

关键词： Flammulina velutipes polysaccharide Iron deficiency anemia Iron supplement Caco-2 cell model Gut microbiota