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Influence of parameters on the microstructure of a duplex stainless steel joint welded by a GMAW welding process

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Progress in Natural Science:Materials International 2022年第4期32卷 415-423页

作者： Sandra Chacón-Fernández Antonio Portolés García Gerardo Romaní Labanda Universidad Politécnica de Madrid Escuela Técnica Superior de Ingenieros Industriales UPM

Duplex stainless steels（DSSs） are widely used in industry for their desirable properties. Any fusion welding technique modifies the microstructure and, consequently, the properties of the material. This paper presents a parametric study of the variables that determine the energy contribution（current, voltage and welding speed） and the structural modifications produced during gas metal arc welding. The analysis comprises metallographic study,phase balance, dimensioning of the weld beads and tensile and hardness tests. The influence of the variables studied on the thermal cycles obtained（temperatures reached and cooling rate） was determined by using a finite element model. The results showed that, in addition to the indicated parameters, the parameter power transfer per volume（W/m3） and the geometry in the bead must be controlled due to their influence on the heat flow distribution and phase balance.

关键词： Welding Heat input GMAW Duplex stainless steels (DSS) Finite element model (FEM)

Macroseismic formula for determining hypocentral depth and its precise calculative method

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Acta Seismologica Sinica(English Edition) 1998年第3期11卷 36-47页

作者：段星北 1. 4 Entrance to no. 110 of Building 911 Zhongguancun 100086 Beijing China

In this paper, under condition I 1= I 0 and r 1= r 0, proved h=r 0 . That is when meizoseismal region has become epicentral area, the hypocentral depth is equal to the radius of isoseismal curves of epicentral area. It is theoretical standard of hypocentral depth from which the precise calculative methods of macroseismic formula for determining hypocentral depth can be deduced. Comparing the computations with one ano.her indicated that the routine calculative method of complete macroseismic formula for determining hypocentral depth is the optimum selection.

关键词： hypocentral depth intensity meizoseismal region

Characterization of nitrogen-fixing moderate halophilic cyano.acteria isolated from saline soils of Songnen Plain in China

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Progress in Natural Science:Materials International 2008年第6期18卷 769-773页

作者： Wei Zhang,Yujie Feng* State Key Laboratory of Urban Water Resource and Environment,Harbin Institute of Techno.ogy,Campus no.1,Apartment no.10,A 901,Harbin 150090,China State Key Laboratory of Urban Water Resource and Environment Harbin Institute of Technology Campus No. 1 Apartment No. 10 A 901 Harbin 150090 China

Twenty out of 200 isolates of cyano.acteria mainly from saline soils of Songnen Plain of China were successfully grown on BG11 N-free *** nitrogen-fixing activity was then demonstrated for the 20 isolates in modified BG11 medium using the acetylene reduction *** of them possessed appreciable nitrogenase activity(acetylene reduction)under no.-saline conditions;however,at 5%NaCl only 60%of the isolates exhibited a high rate of this activity and 25%were completely negative under these *** cyano.acteria isolates grew well in BG11 medium;nevertheless,growth of the majority of isolates was reduced by about 25-85% in the same medium containing 5%*** activity was detected in 50%of the 20 strains,amylolytic in 45%,and pectino.ytic in 10%of the *** cyano.acteria isolates showed also enzymatic activity under saline conditions(6%).The preliminary identi-fication indicated that seven isolates were no.toc,two were Microcystis,four were Oscillatoria,six were Anabaena,and one isolate was Synechococcus.

关键词： Isolation Songnen Plain of China Nitrogenase activity Salt tolerance Filamentous and globular cyano.acteria

An execution control method for the Aerostack aerial robotics framework

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Frontiers of Information Techno.ogy & Electronic Engineering 2019年第1期20卷 60-75页

作者： Martin MOLINA Alberto CAMPORREDONDO Hriday BAVLE AlejANDro RODRIGUEZ-RAMOS Pascual CAMPOY Department of Artificial Intelligence Universidad Politécnica de Madrid Centre for Automation and Robotics Universidad Politécnica de Madrid

Execution control is a critical task of robot architectures which has a deep impact on the quality of the final system. In this study, we describe a general method for execution control, which is a part of the Aerostack software framework for aerial robotics, and present technical challenges for execution control and design decisions to develop the method. The proposed method has an original design combining a distributed approach for execution control of behaviors(such as situation checking and performance monitoring) and centralizes coordination to ensure consistency of the concurrent execution. We conduct experiments to evaluate the method. The experimental results show that the method is general and usable with acceptable development efforts to efficiently work on different types of aerial missions. The method is supported by standards based on a robot operating system(ROS) contributing to its general use, and an open-source project is integrated in the Aerostack framework. Therefore, its technical details are fully accessible to developers and freely available to be used in the development of new aerial robotic systems.

关键词： Aerial robotics Control architecture Behavior-based control Executive system

A Study on the Behavior of Mercury in Weathering Environment in Wanshan District

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Acta Geochimica 1985年第4期4卷 325-334页

作者：花永丰 Metallurgical-geological Team no. 1 of Guizhou Province

Studies on the mechanism of supergenic dispersion, migration and enrichment of mercuryand other elements in strata-bound ore deposits are of great importance both in theory andin practice. In special reference to the Wanshan mercury ore deposits, this paper discusses themechanism of supergenic migration of mercury and the associated elements lead, zinc, antimony,etc. In this paper the focus of the discussion is placed on the existing forms of mercury, therules governing the migration and enrichment of mercury and associated elements in the processof weathering and some aspects of the simulating experiments on weathering of carbonaterocks. Three existing forms of mercury are recognized in carbonate rocks. The migration of met-cury together with the associated dements in the process of weathering follows the sequence:SiO;→Pb→Hg→Sb→Zu. The results of simulating experiments on weathering of car-bonate rocks show that weathered materials contain more mercury and associated elementsthan the original rocks.

关键词： A Study on the Behavior of Mercury in Weathering Environment in Wanshan District

Differences in brain pathological changes between roteno.e and 6-hydroxydopamine Parkinson＇s disease models

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Neural Regeneration Research 2018年第7期13卷 1276-1280页

作者： Lan-Xiang Liu Dan Du Zhan-Qiu Wang Yuan Fang Tao Zheng Yan-Chao Dong Qing-Lei Shi Min Zhao Fang Xiao Juan Du Department of Magnetic Resonance Imaging Qinhuangdao Municipal No. 1 Hospital Qinhuangdao Hebei Province China Department of Intervention Qinhuangdao Municipal No. 1 Hospital Qinhuangdao Hebei Province China Siemens Ltd. Beijing China Department of Pathology Qinhuangdao Municipal No. 1 Hospital Qinhuangdao Hebei Province China Hebei Medical University Shijiazhuang Hebei Province China

Roteno.e and 6-hydroxydopamine are two drugs commonly used to generate Parkinson＇s disease animal *** no. only achieve degenerative changes of dopaminergic neurons in the substantia nigra,but also satisfy the requirements for iron ***,few studies have compared the characteristics of these two models by magnetic resonance *** this study,rat models of Parkinson＇s disease were generated by injection of 3 μg roteno.e or 10 μg 6-hydroxydopamine into the right substantia *** 1,2,4,and 6 weeks after injection,coronal whole-brain T2-weighted imaging,transverse whole-brain T2-weighted imaging,and coronal diffusion tensor weighted imaging were conducted to measure fractional anisotropy and T2＊ values at the injury *** fractional anisotropy value on the right side of the substantia nigra was remarkably lower at 6 weeks than at other time points in the roteno.e *** the 6-hydroxydopamine group,the fractional anisotropy value was decreased,but T2＊ values were increased on the right side of the substantia nigra at 1 *** findings confirm that the 6-hydroxydopamine-induced model is suitable for studying dopaminergic neurons over short periods,while the roteno.e-induced model may be appropriate for studying the pathological and physiological processes of Parkinson＇s disease over long periods.

关键词： nerve regeneration fractional anisotropy T2* roteno.e 6-hydroxydopamine Parkinson's disease magnetic resonance imaging diffusion tensor imaging dopaminergic neurons neural regeneration

Complete fuzzy scheduling and fuzzy earned value management in construction projects

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2012年第1期13卷 56-68页

作者： José Luís PONZ-TIENDA Eugenio PELLICER Víctor YEPES School of Building Engineering Universitat Politècnica de València School of Civil Engineering Universitat Politècnica de València Department of Construction Engineering ICITECHUniversitat Politècnica de València

This paper aims to present a comprehensive proposal for project scheduling and control by applying fuzzy earned *** goes a step further than the existing literature:in the formulation of the fuzzy earned value we consider no. only its duration,but also cost and production,and alternatives in the scheduling between the earliest and latest *** mathematical model is implemented in a prototypical construction project with all the estimated values taken as fuzzy *** findings suggest that different possible schedules and the fuzzy arithmetic provide more objective results in uncertain environments than the traditional *** proposed model allows for controlling the vagueness of the environment through the adjustment of the α-cut,adapting it to the specific circumstances of the project.

关键词： Construction Earned value method(EVM) Fuzzy logic Fuzzy set Project management Scheduling

Ultrasound/Microbubble Enhances Foreign Gene Expression in ECV304 Cells and Murine Myocardium

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Acta Biochimica et Biophysica Sinica 2004年第12期36卷 824-831页

作者： Dongping GUO, Xiaoyu LI, Ping SUN, Zhiguang WANG, Xiuying CHEN, Qi CHEN, Leming FAN*, Bin ZHANG1, Lizheng SHAO1, and Xiaorong LI1 Atherosclerosis Research Center, Nanjing Medical University, Nanjing 210029, China 1 Cardiovascular Division, Wuxi no. 1 Hospital, Wuxi 214002, China Atherosclerosis Research Center Nanjing Medical UniversityNanjing 210029 China Cardiovascular DivisionWuxi no. 1 Hospital Wuxi 214002 China

Although viral vectors are efficient systems to transfer foreign genes into cells or target tissues, safety issues remain in relation to human gene therapy. Microbubbles currently used as ultrasound contrast agents have been applied in transfection of genes. This study was designed to test the transfection efficiency and the expression of exogeno.s gene mediated by ultrasound irradiation enhanced air filled albumin microbubbles in ECV304 cell line in vitro and the heart of the mouse in vivo. Air filled microbubbles (2.0– 4.0 μm in diameter) were created by sonicating the mixture of human albumin, glucose, mannitol and special additive that was designed for stabilization. Plasmid DNA loading the reporter geneswas gently mixed with microbubbles. The mixture of plasmid DNA and microbubbles was administrated to cultured ECV304 cells and BALB/c mice (tail vein injection) under different ultrasound/microbubble conditions, and then the trans- fection and expression efficiency were examined. The results both in vivo and in vitro demonstrated that microbubble with ultrasound irradiation could significantly elevate the exogeno.s gene expression as compared with microbubble or ultrasound only. Overall, the present study showed that the ultrasound-target microbubble destruction method enhanced the exogeno.s gene expression in vivo and in vitro, and provided a gene therapy way no. only efficient but also easy to be manipulated and carried out in clinical.

关键词： microbubble ultrasound transfection gene therapy

Revisiting the analytical solutions for ultimate bearing capacity of pile embedded in rocks

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第6期15卷 1506-1519页

作者： A.Picardo M.A.Millán R.Galindo A.Alencar Escuela Técnica Superior de Arquitectura Universidad Politécnica de MadridMadrid28040Spain Escuela Técnica Superior de Ingenieros de Camino. Canales y Puertos de MadridUniversidad Politécnica de MadridMadrid28040Spain

This paper investigates the validity and shortcomings of the existing analytical solution for the ultimate bearing capacity of a pile embedded in a rock mass using the modified HoekeBrown failure *** this criterion is considered a reference value for empirical and numerical calculations,some limitations of its basic simplifications have no. been clarified *** research compares the analytical results obtained from the no.el discontinuity layout optimization(DLO)method and the numerical solutions from the finite difference method(FDM).The limitations of the analytical solution are considered by comparing different DLO failure modes,thus allowing for the first time a critical evaluation of its scope and conditioning for *** of up to 40%in the bearing capacity and unrealistic failure modes are the main issues in the analytical *** main aspects of the DLO method are also analyzed with an emphasis on the linearization of the rock failure criterion and the accuracy resulting from the discretization *** analysis demonstrates DLO as a very efficient and accurate tool to address the pile tip bearing capacity,presenting considerable advantages over other methods.

关键词： Discontinuity layout optimization(DLO) Analytical solution Bearing capacity Deep foundations HoekeBrown failure criterion Finite difference method(FDM)