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Microstructure and Strength of Brazed Joints of Ti_(3)Al Base Alloy with Cu-P Filler Metal

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Journal of Materials Science & Technology 2005年第4期21卷 493-498页

作者： Peng HE Jicai FENG Heng ZHOU National Key Laboratory of Advanced Welding Production Technology Harbin Institute of Technology Harbin 15{}001 China

Brazing of Ti3Al alloys with the filler metal Cu-P was carried out at 1173-1273 K for 60-1800 s. When products are brazed, the optimum brazing parameters are as follows： brazing temperature is 1215-1225 K; brazing time is 250-300 s. Four kinds of reaction products were observed during the brazing of Ti3Al alloys with the filler metal Cu-P, i.e., Ti3Al phase with a small quantity of Cu （Ti3Al（Cu）） formed close to the Ti3Al alloy; the TiCu intermetallic compounds layer and the Cu3P intermetallic compounds layer formed between Ti3Al（Cu） and the filler metal, and a Cu-base solid solution formed with the dispersed Cu3P in the middle of the joint. The interracial structure of brazed Ti3Al alloys joints with the filler metal Cu-P is Ti3Al/Ti3Al（Cu）/TiCu/Cu3P/Cu solid solution （Cu3P）/Cu3P/TiCu/Ti3Al（Cu）/Ti3Al, and this structure will not change with brazing time once it forms. The thickness of TiCu＋Cu3P intermetallic compounds increases with brazing time according to a parabolic law. The activation energy Q and the growth velocity/to of reaction layer TiCu＋Cu3P in the brazed joints of Ti3Al alloys with the filler metal Cu-P are 286 kJ/mol and 0.0821 m2/s, respectively, and growth formula was y2=O.O821exp（-34421.59/T）*** control of the growth for the reaction layer TiCu＋Cu3P can influence the final joint strength. The formation of the intermetallic compounds TiCu＋Cu3P results in embrittlement of the joint and poor joint properties. The Cu-P filler metal is not fit for obtaining a high-quality joint of Ti3Al brazed.

关键词： Brazed joints Microstructure Ti3Al base alloy

Positron emission particle tracking——Application and labelling techniques

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Particuology 2008年第1期6卷 16-23页

作者： David J. Parker School of Physics and Astronomy the University of Birmingham Edgbaston Birmingham B15 2TT UK

The positron emission particle tracking （PEPT） technique has been widely used in science and engineering to obtain detailed information on the motion and flow fields of fluids or granular materials in multiphase systems, for example, fluids in rock cracks, chemical reactors and food processors; dynamic behaviour of granular materials in chemical reactors, granulators, mixers, dryers, rotating kilns and ball mills. The information obtained by the PEPT technique can be used to optimise the design, operational conditions for a wide range of industrial process systems, and to evaluate modelling work. The technique is based on tracking radioactively labelled particles （up to three particles） by detecting the pairs of backto-back 511 keV γ-rays arising from annihilation of emitted positrons. It therefore involves a positron camera, location algorithms for calculating the tracer location and speed, and tracer labelling techniques. This paper will review the particle tracking technique from tracking algorithm, tracer labelling to their application.

关键词： PEPT Tracer Algorithm Tracking

Mechanisms Modeling the Double Rotation of the Elytra in Beetles （Coleoptera）

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Journal of Bionic Engineering 2011年第4期8卷 395-405页

作者： Leonid Frantsevich Schmalhausen-Institute of Zoology B. Chmielnicki str. 15 Kiev-3 O 01601 Ukraine

We recorded transient movements, i.e. opening and closing, of beetle elytra. The beetles were tethered from below and filmed under a skew mirror; two markers were glued on each elytron at the apex and at the base. Body-fixed 3D traces of the apical and basal markers were reconstructed. The trace of the basal marker was, as a rule, non-parallel to the apical trace. The costal edge of the elytron uniformly supinated in the course of adduction of the apical marker. We found two essential attributes of double rotation：（1） the elytron to body articulation is approximately a spherical mechanism; （2） transient opening and closing possess single degree of freedom. The double rotation was modeled with two mechanisms：（1） a flexagon model of the Haas and Wootton＇s type simulated the elytral movement relative to the movement of one facet of the flexagon; （2） a screw and nut model provided traces as two sectors of a helical thread, one sector was phase shifted with respect to other one. Screw guideways in a spherical mechanism give rise to discrepancies. Exact solution for a spherical mechanism with two guideways was proposed. The modeling revealed the attribute （3）： the elytron is actuated by two linked but differently directed drives. Experimental investigations on the elytron to body articulation may be oriented at search of those mechanisms.

关键词： insect flight insect thorax flexagon screw and nut joint

Invasive micropapillary carcinoma:A distinct type of adenocarcinomas in the gastrointestinal tract

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World Journal of Gastroenterology 2014年第16期20卷 4597-4606页

作者： Katarzyna Guzińska-Ustymowicz Katarzyna Niewiarowska Anna Pryczynicz Department of General Pathomorphology Medical University of Bialystok15-269 BialystokPoland

Invasive micropapillary carcinoma (IMPC) is a rare histological type of tumor, first described in invasive ductal breast cancer, than in malignancies in other organs such as lungs, urinary bladder, ovaries or salivary glands. Recent literature data shows that this histological lesion has also been found in cancers of the gastrointestinal system. The micropapillary components are clusters of neoplastic cells that closely adhere to each other and are located in distinct empty spaces. Moreover, clusters of neoplastic cells do not have a fibrous-vascular core. The IMPC cells show reverse polarity resulting in typical ‘’inside-out’’ structures that determines secretary properties, disturbs adhesion and conditions grade of malignancy in gastrointestinal (GI) tract. Invasive micropapillary carcinoma in this location is associated with metastases to local lymph nodes and lymphovascular invasion. IMPC can be a prognostic factor for patients with cancers of the stomach, pancreas and with colorectal cancer since it is related with disease-free and overall survival. The purpose of this review is to present the characterization of invasive micropapillary carcinoma in colon, rectum, stomach and others site of GI tract, and to determine the immunohistological indentification of IMPC in those localization.

关键词： Invasive micropapillary carcinoma MUC-1 Lymph node metastases

Multicellular Systems Biology: Quantifying Cellular Patterning and Function in Plant Organs Using Network Science

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Molecular Plant 2019年第6期12卷 731-742页

作者： George W.Bassel School of Biosciences University of Birmingham Birmingham B15 2TT UK

Organ function is at least partially shaped and constrained by the organization of their constituent cells. Extensive investigation has revealed mechanisms explaining how these patterns are generated, with less being known about their functional relevance. In this paper, a methodology to discretize and quantitatively analyze cellular patterning is described. By performing global organ-scale cellular interaction mapping, the organization of cells can be extracted and analyzed using network science. This provides a means to take the developmental analysis of cellular organization in complex organisms beyond qualitative descriptions and provides data-driven approaches to inferring cellular function. The bridging of a structure- function relationship in hypocotyl epidermal cell patterning through global topological analysis provides support for this approach. The analysis of cellular topologies from patterning mutants further enables the contribution of gene activity toward the organizational properties of tissues to be linked, bridging molecular and tissue scales. This systems-based approach to investigate multicellular complexity paves the way to uncovering the principles of complex organ design and achieving predictive genotypephenotype mapping.

关键词： organ network connectivity transport tissue topology connectome

Evaluating performance of lignite pillars with 2D approximation techniques and 3D numerical analyses

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International Journal of Mining Science and Technology 2017年第6期27卷 929-936页

作者： Deliveris Alexandros V. Benardos Andreas Centre for Research and Technology Hellas (CERTH) Chemical Process & Energy Resources Institute (CPERI) Athens GR15 125 Greece National Technical University of Athens (NTUA) School of Mining and Metallurgical Engineering (SMME) Athens GR15 780 Greece

This paper attempts to investigate the use of approximate 2D numerical simulation techniques for the evaluation of lignite pillar geomechanical response, formed via the room and pillar mining *** and applicability of the developing methodology are assessed through benchmarking with a more direct and accurate 3D numerical model. This analysis utilizes an underground lignite mine which is being developed in soft rock environment. Through the decisions made for the optimum room and pillar layout, the design process highlights the strong points and the weaknesses of 2D finite element analysis, and provides useful recommendations for future reference. The interpretations of results demonstrate that 2D approximation techniques come near quite well to the actual 3D ***, external load approximation technique seems to fit even better with the respective outcomes from the 3D analyses.

关键词： Geomechanics Room and pillar Underground lignite mine Finite element method 3D numerical analysis Average pillar stress

Metabolic P systems for biochemical dynamics

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Progress in Natural Science:Materials International 2007年第4期17卷 384-391页

作者： Vincenzo Manca 15 37134 Verona Department of Computer Science University of Verona Italy Strada Le Grazie

Metabolic P systems are a special class of P systems which seem to be adequate for expressing biological phenomena, especially, metabolism and signaling transduction. Basic motivations for their introduction are given and their main aspects are explained by means of an example of biological modeling. A new kind of regulation mechanism is outlined, which could be the basis for a more efficient construction of computational models from experimental data of specific metabolic processes.

关键词： biological dynamics biochemical reactions metabolic algorithm P systems.

“一带一路”倡议沿线国家健康状况时空特征及影响因素

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地理研究 2024年第10期43卷 2541-2557页

作者：李颉许泽嘉朱竑广州大学地理科学与遥感学院广州510006 广东省城市与移民研究中心广州510006 广东省哲学社会科学重点实验室(广州大学海上丝绸之路重点实验室GD22TWCXGC15) 广州510006

卫生健康合作是“一带一路”倡议的重要组成部分,合作的前提是深入了解沿线国家人民健康状况及其影响因素。现有关于“一带一路”倡议的研究主要以政策、贸易、经济为主,对沿线国家的健康状况、健康状况的时空分布特征及其自然和社会经... 详细信息

卫生健康合作是“一带一路”倡议的重要组成部分,合作的前提是深入了解沿线国家人民健康状况及其影响因素。现有关于“一带一路”倡议的研究主要以政策、贸易、经济为主,对沿线国家的健康状况、健康状况的时空分布特征及其自然和社会经济影响因素的研究较少。本文首先构建健康指标体系,客观、全面地对沿线国家2013—2019年间的健康状况进行量化;然后,采用探索性空间分析、莫兰指数等空间分析方法对沿线国家健康状况的时空分异特征进行分析;最后,基于自然环境、社会发展水平、经济水平和个人生活习惯等健康影响因素,综合运用地理探测器、空间杜宾模型等空间分析方法,对沿线国家健康状况的影响因素进行分析。结果表明:①总体而言,“一带一路”沿线国家的健康状况好于世界平均水平,但国家之间的差异显著且具有空间相关性。欧洲及其周边区域预期寿命较高,死亡率较低,而非洲以及拉丁美洲部分区域预期寿命较低、死亡率较高。中国健康状况处于中等偏高水平。②2013—2019年沿线国家健康状况持续改善,体现在预期寿命持续上升,生育率与死亡率持续下降,并且改善的幅度显著大于非沿线国家。③多种因素在国家尺度上影响沿线国家健康状况,其中反映健康服务水平的政府健康支出、反映卫生服务可达性的全民健康覆盖程度、以及反映个人健康习惯的酒精消费和吸烟率等指标的影响最为显著。“一带一路”倡议提出以来,沿线国家的健康状况有了显著的提高,但区域发展不平衡的问题依然存在。未来,有必要继续深化与沿线国家在卫生健康方面的合作,继续提高人民健康水平,促进经济社会发展。

关键词：健康状况空间格局空间分析社会经济因素可持续发展目标 “一带一路”倡议

Kinetics study of CO_(2) absorption in potassium carbonate solution promoted by diethylenetriamine

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Green Energy & Environment 2021年第1期6卷 83-90页

作者： Rouzbeh Ramezani Renzo Di Felice Department of Civil Chemical and Environmental EngineeringUniversity of GenoaVia Opera Pia 1516145GenovaItaly

In this work,characterization and kinetics of CO2 absorption in potassium carbonate(K_(2)CO_(3))solution promoted by diethylenetriamine(DETA)were *** measurements were performed using a stirred cell reactor in the temperature range of 303.15–323.15 K and total concentration up to 2.5 kmol m*** density,viscosity,physical solubility,CO_(2) diffusivity and absorption rate of CO_(2) in the solution were *** reaction kinetics between CO_(2) and K2CO3þDETA solution were ***-first order kinetic constants were also predicted by zwitterion *** was revealed that the addition of small amounts of DETA to K_(2)CO_(3) results in a significant enhancement in CO_(2) absorption *** reaction order and activation energy were found to be 1.6 and 35.6 kJ mol1,*** terms of reaction rate constant,DETA showed a better performance compared to the other promoters such as MEA,EAE,proline,arginine,taurine,histidine and alanine.

关键词： Gas absorption CO_(2)capture Reaction rate constant Kinetic study Absorption rate