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Grey Problems of a Mechanical Transmission System in a Reliability Study

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International Journal of Plant Engineering and Management 2001年第2期6卷 104-109页

作者： LUO You-xin, CAI An-hui, ZHANG Long-ting, GUO Hui-xin department of Mechanical Engineering, Changde Normal College, Changde 415003, P. R. China department of Mechanical Engineering Changde Normal CollegeChangde 415003 P. R. China

In the light of the Grey characters of reliability on a mechanical transmission system, Grey problems that could assist in the study on mechanical transmission system were analyzed. For example, the factors of time function，the factors of environment and the factors of people have some relationships with the system in this paper. And then, the methods and procedures, which were based upon the theory of Grey system, were elaborated.

关键词： mechanical transmission system reliability Grey system factor

Photo-assisted electrochemical hydrogen evolution by plasmonic Ag nanoparticle/nanorod heterogeneity

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InfoMat 2019年第3期1卷 417-425页

作者： Hao Wu Husam N.Alshareef Ting Zhu department of Electrical and Computer Engineering National University of SingaporeSingaporeSingapore Materials Science and Engineering Physical Science and Engineering DivisionKing Abdullah University of Science and Technology(KAUST)ThuwalSaudi Arabia School of Materials Science and Engineering Central South UniversityChangshaChina

Transition metal sulfide-based hydrogen evolution electrocatalysts still lag in catalytic activity due to the zero-deviated free energy of*H *** metals bridge the gap between light utilization and plasmon-mediated redox reactions for substantially enhanced electrocatalytic *** this work,a strategic broadband light utilization heterostructure,composed of two distinct Ag nanostructures(discontinuous Ag nanorods and monodispersed nanoparticles),is achieved through in situ sulfurization and metal *** heterostructure benefits the electrocatalytic hydrogen evolution reactivity thanks to the localized surface plasmon resonance induced hot electrons injection and inter-gap electric fields revealed by the finite-difference time-domain ***,the prudent heterostructured catalyst exhibits a significantly improved overpotential(at 10 mA cm−2)from 151 to 95 mV along with a Tafel slope from 74 to 45 mV dec−1 toward hydrogen ***,this instructional study sheds light on the design of hybrid photo-assisted electrocatalysts with cooperative effect of solar energy toward sustainable electrocatalysis.

关键词： hydrogen evolution interface photo-assisted plasmonic

Velocity-Free MS/AE Source Location Method for Three-Dimensional Hole-Containing Structures

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Engineering 2020年第7期6卷 827-834页

作者： Longjun Dong Qingchun Hu Xiaojie Tong Youfang Liu School of Resources and Safety Engineering Central South UniversityChangsha 410083China department of Geophysics Colorado School of MinesGoldenCO 80401USA

Microseismic/acoustic emission(MS/AE)source localization method is crucial for predicting and controlling of potentially dangerous sources of complex ***,the locating errors induced by both the irregular structure and pre-measured velocity are poorly understood in existing *** meet the high-accuracy locating requirements in complex three-dimensional hole-containing structures,a velocity-free MS/AE source location method is developed in this *** avoids manual repetitive training by using equidistant grid points to search the path,which introduces A*search algorithm and uses grid points to accommodate complex structures with irregular *** also takes advantage of the velocity-free source location *** verify the validity of the proposed method,lead-breaking tests were performed on a cubic concrete test specimen with a size of 10 cm10 cm10 *** was cut out into a cylindrical empty space with a size of/6cm10 *** on the arrivals,the classical Geiger method and the proposed method are used to locate lead-breaking *** show that the locating error of the proposed method is 1.20 cm,which is less than 2.02 cm of the Geiger ***,the proposed method can effectively locate sources in the complex three-dimensional structure with holes and achieve higher precision requirements.

关键词： Microseismic source Acoustic emission Velocity-free location method Three-dimensional hole-containing structures

Arsenic availability and transportation in soil-rice system affected by iron-modified biochar

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Journal of Central South University 2021年第6期28卷 1901-1918页

作者： QIAN Zi-yan XUE Sheng-guo CUI Meng-qian WU Chuan LI Wai-chin School of Metallurgy and Environment Central South UniversityChangsha 410083China department of Science and Environmental Studies the Education University of Hong KongTai PoHong KongChina

Iron-modified biochar(FeOS)is known to be effective at immobilization of arsenic(As)in soils.A pot experiment was conducted to investigate the effects of FeOS on As availability and ttransportation in the soil-rice system at different growth stages of rice with different pollution *** results showed that Fe concentration decreased and As concentration increased in paddy soils with the FeOS addition,especially in 120 mg/kg As treatment,the As concentration decreased by 16.46%and 30.56%at the maturity stage with 0.5%and 1%FeOS additions,*** with the control,the application of FeOS reduced the arsenic content in rice tissues and increased the biomass,with the root biomass increased by 12.68%and the shoot biomass was increased by 8.94%with the addition of 1%*** may be related to the promotion of iron plaque formation and the transformation of microbial community structure in FeOS treatments,in accordance with the result of gene abundance and Fe/As contents of iron plaque in the *** study is expected to provide further support and theoretical basis for the application of FeOS in the remediation of As contaminated paddy soil.

关键词： arsenic rice iron-modified biochar(FeOS) iron plaque speciation uptake

Picard Boundary Value Problems of Second Order p-Laplacian Differential Equations

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Chinese Quarterly Journal of Mathematics 2011年第1期26卷 77-84页

作者： LIU Yu-ji department of Mathematics Guangdong University of Business StudiesGuangzhou 510320China

Suffcient conditions for the existence of at least one solution of two-point boundary value problems for second order nonlinear differential equations [φ(x(t))] + kx(t) + g(t,x(t)) = p(t),t ∈(0,π) x(0) = x(π) = 0 are established,where [φ(x)] =(|x |p-2x) with p > *** result is new even when [φ(x)] = x in above problem,i.e.p = *** are presented to illustrate the effciency of the theorem in this paper.

关键词： solutions second order p-Laplacian differential equation two-point boundary value problem fixed-point theorem

Optimization Solvers for Convex L1-Regularization Problems

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Optimization Solvers for Convex L1-Regularization Problems

PetroChina to Establish Command Center on Oil Dispatch

作者： Tingwei Huang department of Electronic Information Engineering Technology Chongqing University Of Posts And Telecommunications

The convex l1-regularization problem has been received special attentions in the last two decades because of its properties of improving model *** far,there exists plentiful optimization methods to solve this *** this paper,we review the existing optimization methods and compare them to help users choose the most proper solver in their own scenarios.

关键词： Optimization L1-Regularization

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China Oil & Gas 2008年第1期15卷 22-23页

作者： Zhang Dexin No 2 Oil department of No.5 Oil Production Factory of PetroChina Daqing Oilfield Company

PetroChina will install a command center on the distribution of refined oil products in 2008 to improve supply efficiency amidst oil shortage. The center with its layout designed by the China Petroleum and Petrochemical Engineering Institute has entered feasibility study, and may be put to use in August at the earliest, according to the recent reports from China news media. The oil giant announced in early January the set-up of an oil storage tank in Changde City, the first of its kind in Central China's hunan province, which has a capacity of 20,000 cubic meters.

关键词：中国石油集团石油供应石油储备战略石油价格

Determination and Analysis of Amino Acid Content in Maca from Different Habitats and Varieties

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Medicinal Plant 2022年第3期13卷 1-5,8页

作者： Yuting LI Ziyi LI Lin JIANG Deli XIAO department of Pharmacology Yongzhou Vocational Technical College Yongzhou 425000 China department of Analytical Chemistry China Pharmaceutical University Nanjing 210009 China Key Laboratory of Biomedical Functional Materials China Pharmaceutical University Nanjing 210009 China

[Objectives]To determine and analyze amino acid content in Maca from different habitats and varieties.[Methods]Maca from two habitats and three colors were selected and a kind of turnip commonly used was to fake *** optimizing the hydrolysis conditions,100 mg Maca samples were hydrolyzed in the concentration of 6 mol/L hydrochloric acid at 110℃for 24 *** content range of amino acids in each sample was detected by HPLC.[Results]The average total content of amino acids in Maca was 9.52 g/100 *** yellow Maca contained 16 kinds of amino acids,including 7 kinds of human essential amino acids,accounting for 17.2%of the total amino acids while Yunnan purple Maca held 16 kinds of amino acids,counting 7 kinds of human essential amino acids,accounting for 16.5%of the total amino *** amino acid ratio coefficient method also showed that the two kinds of Maca had higher nutritional value than the others.15 kinds of amino acids were detected in Yunnan black Maca,including 6 kinds of essential amino acids,accounting for 9.60%of the total amino *** amino acids in Yunnan Maca,the highest content was Arg.A total of 12 kinds of amino acids,together with 6 essential human amino acids,were determined in Peru black Maca,accounting for 11.6%of the total amino *** Peru black Maca the highest concentration of amino acid was *** was noteworthy that the amino acid species were comprehensive in Maca,and high level of amino acids resulted in high nutritional *** specific amino acid composition ratio was obviously different from Turnip,the counterfeit goods to deceive customers.[Conclusions]The method of automatic amino acid analyzer is simple and accurate,and can be used for the identification and content determination of amino acids in Maca as amino acid is an essential nutrient in Maca.

关键词： Maca Habitats Varieties Amino acid content

Application of Remote Sensing and GIS to the Study of Land Use/Cover Change and Urbanization Expansion in Basrah province, Southern Iraq

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Geo-Spatial Information Science 2009年第2期12卷 135-141页

作者： Hadeel A.S. Mushtak T.Jabbar 陈晓玲 Geographic department Al-Basrah University State Key Laboratory of Information Engineering in Surveying Map-ping and Remote Sensing Wuhan University

In recent years, land use/cover dynamic change has become a key subject that needs to be dealt with in the study of global environmental change. In this paper, remote sensing and geographic information systems (GIS) are integrated to monitor, map, and quantify the land use/cover change in the southern part of Iraq (Basrah province was taken as a case) by using a 1:250 000 mapping scale. Remote sensing and GIS software were used to classify Landsat TM in 1990 and Landsat ETM+ in 2003 imagery into five land use and land cover (LULC) classes: vegetation, sand, urban area, unused land, and water bodies. Supervised classification and normalized difference build-up index (NDBI) were used respectively to retrieve its urban boundary. An accuracy assessment was performed on the 2003 LULC map to determine the reliability of the map. Finally, GIS software was used to quantify and illustrate the various LULC conversions that took place over the 13-year span of time. Results showed that the urban area had increased by the rate of 1.2% per year, with area expansion from 3 299.1 km2 in 1990 to 3 794.9 km2 in 2003. Large vegetation area in the north and southeast were converted into urban construction land. The land use/cover changes of Basrah province were mainly caused by rapid development of the urban economy and population immigration from the countryside. In addition, the former government policy of "returning farmland to transportation and huge expansion in military camps" was the major driving force for vegetation land change. The paper concludes that remote sensing and GIS can be used to create LULC maps. It also notes that the maps generated can be used to delineate the changes that take place over time.

关键词： urbanization LULC RS GIS classification NDBI AI-Basrah Iraq