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A novel approach of testability modeling and analysis for PHM systems based on failure evolution mechanism

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Chinese Journal of Aeronautics 2013年第3期26卷 766-776页

作者： Tan Xiaodong qiu Jing Liu Guanjun lv Kehong Yang Shuming Wang chao Laboratory of Science and Technology on Integrated Logistics Support College of Mechatronics and Automation National University of Defense Technology

Prognostics and health management （PHM） significantly improves system availability and reliability, and reduces the cost of system operations. Design for testability （DFT） developed concurrently with system design is an important way to improve PHM capability. Testability modeling and analysis are the foundation of DFT. This paper proposes a novel approach of testability modeling and analysis based on failure evolution mechanisms. At the component level, the fault progression-related information of each unit under test （UUT） in a system is obtained by means of failure modes, evolution mechanisms, effects and criticality analysis （FMEMECA）, and then the failure-symptom dependency can be generated. At the system level, the dynamic attributes of UUTs are assigned by using the bond graph methodology, and then the symptom-test dependency can be obtained by means of the functional flow method. Based on the failure-symptom and symptom-test dependencies, testability analysis for PHM systems can be realized. A shunt motor is used to verify the application of the approach proposed in this paper. Experimental results show that this approach is able to be applied to testability modeling and analysis for PHM systems very well, and the analysis results can provide a guide for engineers to design for testability in order to improve PHM performance.

关键词： Design for testability Failure evolution mechanism Failure-symptom dependency Prognostics and health management Symptom-test dependency Testability modeling and analysis Unit under test

One-dimensional sp carbon:Synthesis,properties,and modifications

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Chinese Physics B 2022年第12期31卷 567-589页

作者： chao-Fan lv Xi-Gui Yang Chong-Xin Shan State Key Laboratory of Luminescence and Applications Changchun Institute of OpticsFine Mechanics and PhysicsChinese Academy of SciencesChangchun 130033China University of Chinese Academy of Sciences Beijing 100049China Henan Key Laboratory of Diamond Optoelectronic Materials and Devices Key Laboratory of Material PhysicsMinistry of EducationSchool of Physics and MicroelectronicsZhengzhou UniversityZhengzhou 450052China

Carbyne,as the truly one-dimensional carbon allotrope with sp-hybridization,has attracted significant interest in recent years,showing potential applications in next-generation molecular devices due to its ultimate one-atom *** excellent properties of carbyne have been predicted,however,free-standing carbyne sample is extremely unstable and the corresponding experimental researches and modifications are under-developed compared to other known carbon *** synthesis of carbyne has been slowly developed for the past ***,there have been several breakthroughs in in-situ synthesis and measurement of carbyne related materials,as well as the preparation of ultra-long carbon chains toward infinite *** progresses have aroused widespread discussion in the academic *** this review,the latest approaches in the synthesis of sp carbon are *** then discuss its extraordinary properties,including mechanical,electronic,magnetic,and optical properties,especially focusing on the regulations of these ***,we provide a perspective on the development of carbyne.

关键词： carbyne polyyne linear carbon chains

Induced transformation of antimony trioxide by Mn(II) oxidation and their co-transformed mechanism

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Journal of Environmental Sciences 2023年第7期129卷 69-78页

作者： You lv Caixiang Zhang chao Nan Zenghui Fan Shuxin Huang State Key Laboratory of Biogeology and Environmental Geology China University of GeosciencesWuhan 430074China Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science Wuhan 430074China

Antimony(Sb)is a toxic and carcinogenic element that often enters soil in the form of antimony trioxide(Sb_(2)O_(3))and coexists with manganese(Mn)in weakly alkaline *** oxides such as birnessite have been found to promote the oxidative dissolution of Sb_(2)O_(3),but few researches concerned the co-transformations of Sb_(2)O_(3) and Mn(II)in *** study investigated themutual effect of abiotic oxidation of Mn(II)and the coupled oxidative dissolution of Sb_(2)O_(3).The influencing factors,such as Mn(II)concentrations,pH and oxygen were also ***,their co-transformed mechanism was also explored based on the analysis of Mn(II)oxidation products with or without Sb_(2)O_(3) using XRD,SEM and *** results showed that the oxidative dissolution of Sb_(2)O_(3) was enhanced under higher pH and higher Mn(II)*** a lower Mn(II)concentration such as 0.01 mmol/L Mn(II)at pH 9.0,the improved dissolution of Sb_(2)O_(3) was attributed to the generation of dissolved intermediate Mn(III)species with strong oxidation ***,under higher Mn(II)concentrations,both amorphous Mn(III)oxides and intermediate Mn(III)species were responsible for promoting the oxidative dissolution of Sb_(2)O_(3).Most released Sb(∼72%)was immobilized by Mn oxides and Sb(V)was dominant in the adsorbed and dissolved total ***,the presence of Sb_(2)O_(3) not only inhibited the removal of Mn(II)by reducing Mn(III)to Mn(II)but also affected the final products of Mn *** example,amorphous Mn oxides were formed instead of crystalline Mn(III)oxides,such as ***,rhodochrosite(MnCO_(3))was formed with the high Mn(II)/Sb_(2)O_(3) ratio,but without being observed in the low Mn(II)/Sb_(2)O_(3) *** results of study could help provide more understanding about the fate of Sb in the environment and the redox transformation of Mn.

关键词： Antimony trioxide Mn(II)oxidation Oxidative dissolution Co-transformed mechanism

Pulmonary sarcoidosis:A novel sequelae of drug reaction with eosinophilia and systemic symptoms:A case report

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World Journal of Clinical Cases 2022年第35期10卷 13074-13080页

作者： Yu-qi Hu Chen-Yang lv Ai Cui Department of Pulmonary and Critical Care Medicine Beijing Chao-Yang HospitalCapital Medical UniversityBeijing 100020China Department of Pulmonary and Critical Care Medicine The First Hospital of Fangshan DistrictBeijing 102499China

BACKGROUND Drug reaction with eosinophilia and systemic symptoms(DRESS)syndrome is an uncommon yet serious adverse drug hypersensitivity reaction with the presentations including rash,fever,lymphadenopathy,and internal organ *** is a systematic granulomatous disease with unknown *** herein report a case of pulmonary sarcoidosis secondary to allopurinol-induced *** SUMMARY A 37-year-old man with a history of hyperuricemia was treated with allopurinol for three weeks at a total dose of 7000 milligrams before developing symptoms including anorexia,fever,erythematous rash,and elevated *** patient was diagnosed with DRESS and was treated with prednisone for 6 mo until all the symptoms completely *** months later,the patient presented again because of a progressively worsening dry *** chest computed tomography images showed bilateral lung parenchyma involvement with lymph node enlargement,which was confirmed to be nonnecrotizing granuloma by pathological *** on radiologic and pathological findings,he was diagnosed with sarcoidosis and was restarted on treatment with prednisone,which was continued for another 6 *** of chest imaging revealed complete resolution of parenchymal lung lesions and a significant reduction in the size of the mediastinal and hilar lymph *** a 6-month follow-up of completion of treatment,the patient's clinical condition remained stable with no clinical evidence of *** This is the first case in which pulmonary sarcoidosis developed as a late complication of allopurinol-induced *** case indicated that the autoimmune reaction of DRESS may play an important role in the pathogenesis of sarcoidosis.

关键词： Pulmonary sarcoidosis Drug reaction with eosinophilia and systemic symptoms Autoimmune sequelae Allopurinol Case report

Effect of blade tilt angle on fluid flow characteristics in spray-blowing agitation composite process:a simulation

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Journal of Iron and Steel Research International 2024年第9期31卷 2142-2155页

作者： chao lv Hai-wei Zhang Tao Yang Hong-liang Zhao Zhao-xiang Ji School of Control Engineering Northeastern University at QinhuangdaoQinhuangdao066000HebeiChina State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization Kunming University of Science and TechnologyKunming650093YunnanChina School of Metallurgy and Ecological Engineering University of Science and Technology BeijingBeijing100083China

Aiming at the paddle tilt angle of the spray-blowing agitation composite process,the four-blade stirring and blowing composite desulfurization agitator was chosen as the research object,and the computational fluid dynamics numerical simulation was used to investigate the changes in flow field velocity,turbulent kinetic energy magnitude,and distribution caused by the blade tilt ***,the impact of blade tilt angle on the flow fragmentation behavior of individual bubbles and the coalescence process of multiple bubbles at different positions was *** the same stirring and blowing process parameters,with the increase in the blade tilt angle of the agitator,the velocity of the flow field and the average turbulent kinetic energy inside the agitator decreased,and the bubble fragmentation speed decreased while the merging speed *** turbulent kinetic energy at the agitator bottom was greater when the blade tilt angle was 3.2°compared to when it was 13.2°,while the turbulent kinetic energy at the agitator upper part was relatively *** results for single bubbles represented the state and trajectory of the bubble fragmentation process,and the results for multiple bubbles illustrated the state and trajectory of the bubble aggregation process.

关键词： Blade tilt angle Numerical simulation Stirring Spray-blowing Bubble fragmentation Bubble aggregation

Endoscopic magnetic compression stricturoplasty for congenital esophageal stenosis:A case report

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World Journal of Clinical Cases 2022年第33期10卷 12313-12318页

作者： Shi-qi Liu Yi lv Rui-Xue Luo Department of Nursing The Medical CollegeXijing UniversityXi’an 710123Shaanxi ProvinceChina Department of Hepatobiliary Surgery The First Affiliated Hospital of Xi’an Jiaotong UniversityXi’an 710061Shaanxi ProvinceChina The Corrosion&Protection Research Lab Northwest Institute for Nonferrous Metal ResearchXi’an 710016Shaanxi ProvinceChina

BACKGROUND Congenital esophageal stenosis(CES)is a rare malformation of the digestive *** dilation and thoracotomy have been the main treatments for ***,there is no well-defined management *** compression stricturoplasty(MCS)has been used in refractory esophageal stricture in children after esophageal *** SUMMARY We describe the first case of MCS for CES in one female child *** child(aged 3 years and 1 mo)was admitted due to frequent vomiting and choking after eating complementary food since 7 mo *** and gastroendoscopy showed that there was stenosis in the lower esophagus,suggesting a diagnosis of *** patient did not receive any treatment for esophageal stricture including surgery or endoscopic dilation procedures before *** procedure was smoothly conducted without *** 24 mo after MCS,durable esophageal patency without dysphagia was *** MCS may serve as an alternative and efficient method for patients with CES.

关键词： Congenital esophageal stenosis Magnetic compression stricturoplasty Endoscopy Case report

Soil micro-penetration resistance as an index of its infiltration processes during rainfall

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Journal of Rock Mechanics and Geotechnical Engineering 2022年第5期14卷 1580-1587页

作者： chao-Sheng Tang Xue-Peng Gong Zhengtao Shen qing Cheng Hilary Inyang chao lv Bin Shi School of Earth Sciences and Engineering Nanjing University163 Xianlin AvenueNanjing210023China Global Institute for Sustainable Development CharlotteNCUSA

Rainfall infiltration is one of the most important driving factors of geological hazards, ecological environment problems, and engineering accidents. Understanding the principle of soil wetting during rainfall infiltration and its influence on soil mechanical properties is crucial for preventing geological hazards. In this study, micro-penetration tests coupled with moisture monitoring were performed to investigate the infiltration process during wetting through the measured change in mechanical characteristics. Results show that penetration resistance increases in the deep layer gradually. With increasing infiltration time,the wetting front keeps moving downward, and its range becomes wider. A slight increase of the penetration resistance in the shallow layer(d ≤ 17.5 mm) is observed. However, the penetration resistance in the middle layer(22.5 mm ≤ d ≤ 32.5 mm) decreases firstly before a slight increase. In the deep layer(d ≥ 37.5 mm), the penetration resistance decreases continuously during infiltration. Based on the measured water content profile during infiltration, it is found that the evolution of soil mechanical characteristics is fully responsible by the infiltration-induced re-distribution of water content along depth. Generally, the penetration resistance decreases exponentially with increasing water content in the soil. When the water content is low, wetting can weaken soil strength significantly, whereas this effect diminishes when the moisture surpasses a certain threshold. The results highlight that the penetration curves and water content profile show close inter-dependency and consistency, which verifies the feasibility of using micro-penetration to investigate rainfall infiltration and wetting process in surface soil layer or laboratory small-scale soil samples. This method enables fast, versatile and high-resolution measurements of infiltration process and moisture distribution in soil.

关键词： Micro-penetration test Soil wetting Rainfall infiltration Water content Hydro-mechanical behavior Microstructure

Improvement in the Orthogonal Protein Degradation in Escherichia coli by Truncated mf-ssrA Tag

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Transactions of Tianjin University 2019年第4期25卷 357-363页

作者： Lu lv Yang Wu Guozhen Zhao Hao qi School of Chemical Engineering and Technology Tianjin University

SsrA peptide tag from Mycoplasma fl orum has been developed as a versatile biotechnology tool to control orthogonal degradation of tagged proteins in Escherichia coli . Here, using the systematic deletion mutants of mf -ssrA tag, we demonstrated that the residues in two separate regions have diff erent functions in mf -Lon-mediated specifi c orthogonal target protein degradation in E. coli . The deletion of multiple residues, up to six amino acids, did not fatally abolish its specifi c degradation activity, instead of being able to improve the stability of the tagged protein in the presence of endogenous proteases before mf -Lon expression in E. coli . Except for previously identifi ed essential residues, the region adjacent to the C-terminal of the mf -ssrA tag was involved in mf -Lon and endogenous protease-mediated degradation. Moreover, the deletion of specifi c residues made the mf -ssrA tag more eff ective and compact. The mf -ssrA tag can be implemented in synthetic biology and bioengineering for development of synthetic circuits.

关键词： mf -ssrA Protein degradation Escherichia coli L region R region

Understanding the mechanism of social tie in the propagation process of social network with communication channel

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Frontiers of Computer Science 2019年第6期13卷 1296-1308页

作者： Kai LI Guangyi lv Zhefeng WANG qi LIU Enhong CHEN Lisheng qiAO Anhui Province Key Laboratory of Big Data Analysis and Application University of Science and Technology of ChinaHefei 230027China

The propagation of information in online social networks plays a critical role in modern life,and thus has been studied *** have proposed a series of propagation models,generally,which use a single transition probability or consider factors such as content and time to describe the way how a user activates her/his ***,the research on the mechanism how social ties between users play roles in propagation process is still ***,comprehensive summary of factors which affect user’s decision whether to share neighbor’s content was lacked in existing works,so that the existing models failed to clearly describe the process a user be activated by a *** this end,in this paper,we analyze the close correspondence between social tie in propagation process and communication channel,thus we propose to exploit the communication channel to describe the information propagation process between users,and design a social tie channel(STC)*** model can naturally incorporate many factors affecting the information propagation through edges such as content topic and user preference,and thus can effectively capture the user behavior and relationship characteristics which indicate the property of a social *** experiments conducted on two real-world datasets demonstrate the effectiveness of our model on content sharing prediction between users.

关键词： information propagation social networks mechanism of social tie communication channel