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Microstructure and Mechanical Properties of Martensitic Stainless Steel 6Cr15MoV

Journal of Iron and Steel Research International 2012年第3期19卷 56-61页

作者： MA Dang-shen1, CHI Hong-xiao1,2, ZHOU Jian1, YONG Qi-long1,2 (1. Institute for Structural Materials, Central Iron and Steel Research Institute, Beijing 100081, China 2. faculty of Materials science and Engineering, Kunming University of science and Technology, Kunming 650093, Yunnan, China) Institute for Structural Materials Central Iron and Steel Research Institute Beijing China faculty of Materials science and Engineering Kunming University of Science and Technology Kunming Yunnan China

Martensitic stainless steel containing Cr of 12% to 18%（mass percent） are common utilized in quenching and tempering processes for knife and cutlery steel. The properties obtained in these materials are significantly influ- enced by matrix composition after heat treatment, especially as Cr and C content. Comprehensive considered the hardness and corrosion resistance, a new type martensitic stainless steel 6Crl5MoV has been developed. The effect of heat treatment processes on microstructure and mechanical properties of 6Crl5MoV martensitic stainless steel is emphatically researched. Thermo-Calc software has been carried out to thermodynamic calculation; OM, SEM and TEM have been carried out to microstructure observation; hardness and impact toughness test have been carried out to evaluate the mechanical properties. Results show that the equilibrium carbide in 6Cr15MoV steel is M23 C6 car- bide, and the M23 C6 carbides finely distributed in annealed microstructure. 6Crl5MoV martensitic stainless steel has a wider quenching temperature range, the hardness value of steel 6Cr15MoV can reach to HRC 60.8 to HRC 61.6 when quenched at 1 060 to 1 100 ℃. Finely distributed carbides will exist in quenched microstructure, and effectively inhabit the growth of austenite grain. With the increasing of quenching temperature, the volume fraction of undis- solved carbides will decrease. The excellent comprehensive mechanical properties can be obtained by quenched at 1 060 to 1 100℃ with tempered at 100 to 150 ℃, and it is mainly due to the high carbon martensite and fine grain size. At these temperature ranges, the hardness will retain about HRC 59.2 to HRC 61.6 and the Charpy U-notch impact toughness will retain about 17.3 to 20 J. A lot of M23C6 carbides precipitated from martensite matrix, at the same time along the boundaries of martensite lathes which leading to the decrease of impact toughness when tempered at 500 to 540 ℃. The MaC precipitants also existed in the martensite mat

关键词： martensitic stainless steel microstructure mechanical property

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Earthquake dynamic response behavior of Xiangchong valley type tailings impoundment in Yunnan, China

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Journal of Mountain science 2018年第1期15卷 82-99页

作者： REN Zhe WANG Kun ZHANG Qi-shu XU Ze-min TANG Zheng-guang CHEN Ji-pu YANG Ji-qing XU Zong-heng faculty of Civil Engineering and Mechanics Kunming University of Science and Technology College of Architectural Engineering Yunnan Agricultural University School of Tourism and Geographical science Yunnan Normal University

Tailings impoundments can potentially collapse due to damage caused by earthquakes,which has frequently occurred around the *** study takes the proposed valley type tailings impoundment in Yunnan as the research object to analyze the dynamic response behavior under earthquake action with both numerical simulation and physical model test(1:300).The results of both tests show that the dynamic response of the valley type tailings impoundment is characterized by"medium stiffness effect",in other words,in a certain range,the"softer"the unsaturated tailings sand is,the more energy it can dissipate,which leads the decrease of the value of the acceleration amplification *** addition,the peak acceleration of the monitoring points increases with the vertical elevation,which indicates that the"elevation amplification effect"exists in the tailings impoundment dynamic *** middle part of the outer side of the raised embankment reacts more sensitive than the crest,which is similar to the slope dynamic *** starter dam reacts sensitively under the earthquake excitation,which should be given more attention during the seismic *** dynamic response rules reflected by the numerical simulation are consistent with the results monitored on the physical model test,although there are some differences between their *** dynamic response rules of the valley type tailings impoundment can provide basis for the design of the similar projects in this region.

关键词： Tailings impoundment Dynamic response Shaking table test Medium stiffness effect

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Evaluation of formaldehyde emission from particleboard using the large chamber and desiccator method at various loading ratios

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Journal of Forestry Research 2013年第1期24卷 137-142页

作者： QUE Ze-li WANG Fei-bin MA Ling-fei Furuno Takeshi Nanjing Forestry University Research Institute for Sustainable Humanosphere Kyoto University College of Wood science and Technology Zhejiang A & F University faculty of science and Engineering Shimane University

We studied formaldehyde emission from uncoated particleboard with 16-mm thickness using the large chamber and the desiccator method. A chamber of 28.4 m3 was installed to simulate a mobile home. The formaldehyde off-gassing properties of particleboard were evaluated using the chamber. The relationship between the concentration obtained by the chamber and the values by the desiccator test was discussed in this study under different conditions of conditioning day, air exchange, and loading ratio. These two methods were compared and discussed regarding the formaldehyde emission level. Three loading ratios, 0.429 m2/m3, 0.264 m2/m3, and 0.132 m2/m3, were chosen to represent different applications of particleboard products. There was strong correlation between emissions and air exchange rates at equal product-loading ratios in the large chamber, the related coefficient R 2 exceeded 0.90. There was also an indication of a generic correlation between the large chamber and the two-hour desiccator test with a single product designated loading ratio, air exchange rate, and climatic conditions.

关键词： formaldehyde emission particleboard large chamber desiccator

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Adsorptive stripping voltammetric methods for determination of aripiprazole

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Journal of Pharmaceutical Analysis 2012年第3期2卷 193-199页

作者： Derya Asangil brahim Hüdai Tasdemir Esma KIlI Ankara University Faculty of ScienceDepartment of Chemistry06100 AnkaraTurkey Amasya University Faculty of Arts and ScienceDepartment of Chemistry05100 AmasyaTurkey

Anodic behavior of aripiprazole(ARP) was studied using electrochemical *** transfer,diffusion and surface coverage coefcients of adsorbed molecules and the number of electrons transferred in electrode mechanisms were calculated for quasi-reversible and adsorp-tion-controlled electrochemical oxidation of ARP at 1.15 V versus Ag/AgCl at pH 4.0 in Britton-Robinson buffer(BR) on glassy carbon *** methods for direct determination of ARP in pharmaceutical dosage forms and biological samples were *** range is found as from 11.4 μM(5.11 mg/L) to 157 μM(70.41 mg/L) without stripping mode and it is found as from 0.221 μM(0.10 mg/L) to 13.6 μM(6.10 mg/L) with stripping *** of detection(LOD) was found to be 0.11 μM(0.05 mg/L) in stripping *** were successfully applied to assay the drug in tablets,human serum and human urine with good recoveries between 95.0% and 104.6% with relative standard deviation less than 10%.

关键词： Adsorptive stripping voltammetry Aripiprazole Electrochemical behavior Human serum and urine Pharmaceuticals

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LOCAL REGULARITY RESULT IN OBSTACLE PROBLEMS

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Acta Mathematica Scientia 2010年第1期30卷 208-214页

作者：高红亚郭静左亚丽褚玉明 College of Mathematics and Computer science Hebei University Hebei Provincial Center of Mathematics Department of Mathematics Chengde Teachers College for Nationalities faculty of science Huzhou Teachers College

We obtain a local regularity result for solutions to kφ,θ-obstacle problem of A-harmonic equation divA（x, u（x）, ↓△u（x）） = 0, where .A ： Ω ×R × Rn → Rn is aCarath^odory function satisfying some coercivity and growth conditions with the naturalexponent 1 〈 p 〈 n, the obstacle function φ≥ 0, and the boundary data θ ∈ W1mp（Ω）.

关键词： local regularity A-harmonic equation obstacle problem

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Thermodynamics of Third Order Lovelock Anti-de Sitter Black Holes Revisited

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Communications in Theoretical Physics 2011年第3期55卷 449-456页

作者： ZOU De-Cheng YUE Rui-Hong YANG Zhan-Ying Department of Physics Northwest University Xi＇an 710069 China faculty of science Ningbo University Ningbo 315211 China

We compute the mass and temperature of third order Lovelock black holes with negative Gauss-Bonnet coefficient a2 〈 0 in anti-de Sitter space and perform the stability analysis of topological black holes. When k = -1, the third order Lovelock black holes are thermodynamically stable for the whole range r＋. When k = 1, we found that the black hole has an intermediate unstable phase for D = 7. In eight dimensional spacetimes, however, a new phase of thermodynamically unstable small black holes appears if the coefficient a is under a critical value. For D ≥ 9, black holes have similar the distributions of thermodynamically stable regions to the case where the coefficient ＆ is under a critical value for D = 8. It is worth to mention that all the thermodynamic and conserved quantities of the black holes with fiat horizon do not depend on the Loveloek coefficients and are the same as those of black holes in general gravity.

关键词： third order Lovelock gravity AdS space thermodynamics

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Modeling of Unsteady Flow through Junction in Rectangular Channels: Impact of Model Junction in the Downstream Channel Hydrograph

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Computational Water, Energy, and Environmental Engineering 2017年第3期6卷 304-319页

作者： Seidou Kane Soussou Sambou Issa Leye Raymond Diedhiou Seni Tamba Mouhamed Talla Cisse Didier Maria Ndione Mousse Landing Sane faculty of sciences and technics Department of Physics Cheikh Anta Diop University Dakar Senegal Polytechnic High School of Thies Thies Senegal

Open channel junctions are encountered in urban water treatment plants, irrigation and drainage canals, and natural river systems. Junctions are very important in municipal sewerage systems and river engineering. Adequate theoretical description of flow through an open channel junction is difficult because numerous variables are to be considered. Equations of junction models are based on mass and momentum or mass and energy conservation. The objective of this study is to compare two junction models for subcritical flows. In channel branches, we solve numerically the Saint-Venant hyperbolic system by combining Preissmann scheme and double sweep method. We validate our results with HEC-RAS using Nash and Sutcliffe efficiency. In junction models, equality of water stage and complete energy conservation equation from HEC-RAS are compared. Outcome of the research clearly indicates that the complete conservation energy model is more suitable in flow through junction than equality of water stage model in serious situations.

关键词： Junction Model HEC RAS Saint-Venant’s Equations Double Sweep Method Equality of Water Stages Energy Conservation Modelling of Flow

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A PRIORI ERROR ESTIMATES OF A FINITE ELEMENT METHOD FOR DISTRIBUTED FLUX RECONSTRUCTION＊

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Journal of Computational Mathematics 2013年第4期31卷 382-397页

作者： Mingxia Li Jingzhi Li Shipeng Mao School of science China University of Geosciences (Beijing) Beijing 100083 China faculty of science South University of Science and Technology of China Shenzhen 518055 China LSEC ICMSEC Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100190 China

This paper is concerned with a priori error estimates of a finite element method for numerical reconstruction of some unknown distributed flux in an inverse heat conduction problem. More precisely, some unknown distributed Neumann data are to be recovered on the interior inaccessible boundary using Dirichlet measurement data on the outer ac- cessible boundary. The main contribution in this work is to establish the some a priori error estimates in terms of the mesh size in the domain and on the accessible/inaccessible boundaries, respectively, for both the temperature u and the adjoint state p under the lowest regularity assumption. It is revealed that the lower bounds of the convergence rates depend on the geometry of the domain. These a priori error estimates are of immense interest by themselves and pave the way for proving the convergence analysis of adaptive techniques applied to a general classes of inverse heat conduction problems. Numerical experiments are presented to verify our theoretical prediction.

关键词： Distributed flux Inverse heat problems Finite element method Error esti-mates.

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Scheduling Multi-Mode Resource-Constrained Projects Using Heuristic Rules Under Uncertainty Environment

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Computers, Materials & Continua 2022年第1期70卷 847-874页

作者： Mohamed Abdel-Basset Ahmed Sleem Asmaa Atef Yunyoung Nam Mohamed Abouhawwash faculty of Computers and Informatics Zagazig UniversityZagazig44519Egypt Department of Computer science and Engineering Soonchunhyang UniversityAsan31538Korea Department of Mathematics Faculty of ScienceMansoura UniversityMansoura35516Egypt Department of Computational Mathematics Scienceand Engineering(CMSE)Michigan State UniversityEast Lansing48824MIUSA

Project scheduling is a key objective of many models and is the proposed method for project planning and *** scheduling problems depend on precedence relationships and resource constraints,in addition to some other limitations for achieving a subset of *** scheduling problems are dependent on many limitations,including limitations of precedence relationships,resource constraints,and some other limitations for achieving a subset of *** project scheduling models consider all information about the scheduling problem such as activity durations and precedence relationships information resources available and required,which are known and stable during the implementation *** concept of deterministic project scheduling conflicts with real situations,in which in many cases,some data on the activity’s durations of the project and the degree of availability of resources change or may have different modes and strategies during the process of project implementation for dealing with multi-mode conditions surrounded by projects and their activity *** the multi-mode resource-constrained project problem is an optimization problem whose minimum project duration subject to the availability of resources is of particular interest to *** use the multi-mode resource allocation and schedulingmodel that takes into account the dynamicity features of all parameters,that is,the scheduling process must be flexible to dynamic environment *** this paper,we propose five priority heuristic rules for scheduling multi-mode resource-constrained projects under dynamicity features for more realistic situations,in which we apply the proposed heuristic rules(PHR)for scheduling multi-mode resource-constrained *** projects are considered test problems for the *** obtained results rendered by these priority rules for the test problems are compared by the results obtained from 10 well-known heuristics rules rendered for

关键词： Constrained resource scheduling multi-mode durations dynamic scheduling resource allocation heuristic rules

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Text-Independent Algorithm for Source Printer Identification Based on Ensemble Learning

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Computers, Materials & Continua 2022年第10期73卷 1417-1436页

作者： Naglaa F.El Abady Mohamed Taha Hala H.Zayed Department of Computer science Faculty of Computers and Artificial IntelligenceBenha University13518Egypt School of Information Technology and Computer science(ITCS) Nile University12677Egypt

Because of the widespread availability of low-cost printers and scanners,document forgery has become extremely *** or signatures are used to protect important papers such as certificates,passports,and identification *** the origins of printed documents is helpful for criminal investigations and also for authenticating digital versions of a document in today’s *** printer identification(SPI)has become increasingly popular for identifying frauds in printed *** paper provides a proposed algorithm for identifying the source printer and categorizing the questioned document into one of the printer classes.A dataset of 1200 papers from 20 distinct(13)laser and(7)inkjet printers achieved significant identification results.A proposed algorithm based on global features such as the Histogram of Oriented Gradient(HOG)and local features such as Local Binary Pattern(LBP)descriptors has been proposed for printer *** classification,Decision Trees(DT),k-Nearest Neighbors(k-NN),Random Forests,Aggregate bootstrapping(bagging),Adaptive-boosting(boosting),Support Vector Machine(SVM),and mixtures of these classifiers have been *** proposed algorithm can accurately classify the questioned documents into their appropriate printer *** adaptive boosting classifier attained a 96%*** proposed algorithm is compared to four recently published algorithms that used the same dataset and gives better classification accuracy.

关键词： Document forensics source printer identification(SPI) HOG LBP principal component analysis(PCA) bagging AdaBoost

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