检索结果-南通市图书馆

A novel solution treatment and aging for powder bed fusion-laser beam Ti-6Al-2Sn-4Zr-6Mo alloy:Microstructural and mechanical characterization

引用

International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 414-424页

作者： Gianluca Pirro Alessandra Martucci Alessandro Morri Mariangela Lombardi Lorella Ceschini department of industrial engineering(DIN) Alma Mater Studiorum-University of BolognaBologna 40136Italy department of Applied Science and Technology(DISAT) Politecnico di TorinoTorino TO 10129Italy

Ti-6Al-4Zr-2Sn-6Mo alloy is one of the most recent titanium alloys processed using powder bed fusion-laser beam(PBF-LB)*** alloy has the potential to replace Ti-6Al-4V in automotive and aerospace applications,given its superior mechanical properties,which are approximately 10%higher in terms of ultimate tensile strength(UTS)and yield strength after appropriate heat *** as-built conditions,the alloy is characterized by the presence of soft orthorhombicα″martensite,necessitating a postprocessing heat treatment to decompose this phase and enhance the mechanical properties of the ***,PBFed Ti6246 components undergo an annealing process that transforms theα″martensite into anα-βlamellar *** primary objective of this research was to develop a solution treatment and aging(STA)heat treatment tailored to the unique microstructure produced by the additive manufacturing process to achieve an ultrafine bilamellar microstructure reinforced by precipitation *** study investigated the effects of various solution temperatures in theα-βfield(ranging from 800 to 875℃),cooling media(air and water),and aging time to determine the optimal heat treatment parameters for achieving the desired bilamellar *** each heat treatment condition,differentα-βmicrostructures were found,varying in terms of theα/βratio and the size of the primaryα-phase *** attention was given to how these factors were influenced by increases in solution temperature and how microhardness correlated with the percentage of the metastableβphase present after *** tests were performed on samples subjected to the most promising heat treatment parameters.A comparison with literature data revealed that the optimized STA treatment enhanced hardness and UTS by13%and 23%,respectively,compared with those of the annealed *** surface analyses were conducted to investigate fracture mechanisms.

关键词： powder bed fusion-laser beam titanium alloys heat treatments mechanical properties fractographic analysis

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Sniffing Bacteria with a Carbon-Dot Artificial Nose

引用

Nano-Micro Letters 2021年第7期13卷 138-152页

作者： Nitzan Shauloff Ahiud Morag Karin Yaniv Seema Singh Ravit Malishev Ofra Paz-Tal Lior Rokach Raz Jelinek department of Chemistry Ben Gurion University of the Negev84105 Beer ShevaIsrael department of Biotechnology engineering Ben Gurion University of the Negev84105 Beer ShevaIsrael Chemistry department Nuclear Research CenterNegevP.O.Box 900184190 Beer ShevaIsrael department of Software and Information System engineering Ben-Gurion University of the NegevBeer ShevaIsrael Ilse Katz Institute for Nanotechnology Ben Gurion University of the Negev84105 Beer ShevaIsrael

Continuous,real-time monitoring and identification of bacteria through detection of microbially emitted volatile molecules are highly sought albeit elusive *** introduce an artificial nose for sensing and distinguishing vapor molecules,based upon recording the capacitance of interdigitated electrodes(IDEs)coated with carbon dots(C-dots)exhibiting different *** of the C-dot-IDEs to volatile molecules induced rapid capacitance changes that were intimately dependent upon the polarities of both gas molecules and the electrode-deposited *** deciphered the mechanism of capacitance transformations,specifically substitution of electrode-adsorbed water by gas molecules,with concomitant changes in capacitance related to both the polarity and dielectric constants of the vapor molecules *** C-dot-IDE gas sensor exhibited excellent selectivity,aided by application of machine learning *** capacitive C-dot-IDE sensor was employed to continuously monitor microbial proliferation,discriminating among bacteria through detection of distinctive“volatile compound fingerprint”for each bacterial *** C-dot-IDE platform is robust,reusable,readily assembled from inexpensive building blocks and constitutes a versatile and powerful vehicle for gas sensing in general,bacterial monitoring in particular.

关键词： Carbon dots Bacterial detection Bacterially emitted volatile molecules Capacitive gas sensors Gas polarity

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Convective Heat Transfer by Turbulent Melt Flow Excited by Travelling Magnetic Field at the Inductive Heating

引用

Journal of Iron and Steel Research International 2012年第S2期19卷 771-774页

作者： A.Kapusta A.Levy B.Mikhailovich Center for MHD Studies Ben-Gurion University of the Negev department of Mechanical engineering Ben-Gurion University of the Negev

We examine a convective dissipation-free heat transfer in melts under the action of a stationary component of electromagnetic body force induced by frequency-modulated travelling magnetic *** influence of MHD paramete... 详细信息

关键词： electromagnetic body force velocity field induction heating external friction model

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Heat dissipation in graphene foams

引用

Nano Research 2021年第3期14卷 829-833页

作者： Yaniv Cohen Siva K.Reddy Assaf Ya’akobovitz department of Mechanical engineering Faculty of Engineering SciencesBen-Gurion University of the NegevBeer-Sheva8410501Israel

Graphene foam(GF)—a three-dimensional network of hollow graphene branches—is a highly attractive material for diverse ***,to date,the heat dissipation characteristics of GFs have not been *** fill this gap,we synthesized GF devices,subjected them to high temperatures,and investigated their thermal behavior by using infrared *** find that while the convective area of GF devices is comparable to that of bulk materials(such as metals),the coefficient of convection of these devices is several orders of magnitude higher than that of *** addition,the GF devices showed a reproducible thermal behavior,which we attribute to negligible temperature-induced morphological changes(as confirmed by Raman analysis).Taken together,our findings suggest GF as a promising candidate material for advanced cooling applications where efficient heat dissipation is needed,e.g.,in electrical circuits.

关键词： convection graphene foam heat transfer

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Analysis of Solidification in Spray Atomized and Codeposited Metal-matrix Composites Part Ⅰ: Atomization

引用

Journal of Materials Science & Technology 1995年第3期11卷 79-90页

作者： V.Erukhimovitch and J.Baram(Materials engineering department, ben-gurion university of negev, Beer-Sheva, Israel) ben-gurion Univ of negev Beersheva Israel

Fluid mechanics, heat transfer and liquid-to-solid phase transformation are assessed in optimizing the spray atomization and codeposition process parameters for size refinement and microstructural uniformity of the deposited material. Atomization gas velocities, atomized droplets velocities, convective heat transfer coefficients, thermal histories of the solidifying droplets, freezing rates, fraction solid evolution and solid-liquid interface propagation velocity are calculated. The influence, on the deposit microstructural features, of process parameters like the atomization gas pressure, the pouring tube orifice diameter, the geometrical features of the atomization device,the potency of , pre-existing or injected as reinforcement, nucleation sites, the wetting angle between the liquid melt bnd impurity particles acting as preferred nucleation sites, the in-flight distance of the solidifying droplets in the atomization chamber, i5 evaluated. As a result of the evaluation, appropriate choice of the adjustable process parameters for the production of powders and/or deposits with desired grain size and microstructure, can be made.

关键词： Co Figure Atomization Analysis of Solidification in Spray Atomized and Codeposited Metal-matrix Composites Part

来源：

维普期刊数据库

同方期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

All carbon non-covalent exohedral hybrids:C60 aggregates on nanotube networks

引用

Journal of Energy Chemistry 2018年第4期27卷 957-961页

作者： Evgenee Yekymov Celine Bounioux Racheli Itzhak-Cohen Leila Zeiri Emil Shahnazaryan Eugene A.Katz Rachel Yerushalmi-Rozen department of Chemical engineering the Ben-Curion University of the NegevBeer-ShevaIsrael The Ilse Katz Institute for Nanoscience and Technology the Ben-Gurion University of the NegevBeer-ShevaIsrael department of Solar Energy and Envirornental Physics Jacob Blaustein Institute of Desert ResearchBen-Garion University of the NegevSde-Boker CampusMidreshet Ben-GurionIsrael

Exohedral van der Waals （vdW） hybrids comprising pristine carbon nanotubes （CNTs） and C60 fullerenes are expected to enable the engineering of carbonaceous materials with tunable physical and chemical properties due to the unperturbed sp2 hybridization of the comprising allotropes. In spite of theoretical predictions, experimental realization of exohedral non-covalent hybridization of unmodified C60 fullerenes and CNTs was not reported before, probably due to the relatively strong inter-fullerene and inter-tube interactions that drive the system toward phase separation and the formation of fullerene crystals and CNTs bundles. Here we describe a two-step process for preparation of C60-CNTs hybrids. The first step is based on solution-assembly of random, 3D-networks of individual, pristine CNTs followed by fast solvent-quenching. In the second step sublimated fullerenes are deposited onto the pre-assembled networks where structural defects serve as nucleation points for fullerite nanocrystals. Annealing at low temperature （80 ℃） results in re-organization of the C6o nanocrystals into nanometric layers, forming a CNT-C6o core-shell like cylindrical hybrids. Raman characterization and the observed high mobility of the fullerenes at the CNT surface support the assumption that the exohedral hybrids are of vdW type. The approach presented here offers a pathway for preparation of exohedral hybrids with controlled nano- morphology： CNTs-networks decorated by nanometric C60 crystals and CNTs-3D-networks coated by a shell of non-covalently bonded mono- or multi-layers of C60 molecules that may serve to shape the nanomorphology of the active layer in polymer-fullerene bulk-heterojunction solar cells.

关键词： Fullerenes Exohedral hybrids Carbon-nanotubes

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

ConfDTree: A Statistical Method for Improving Decision Trees

引用

Journal of Computer Science & Technology 2014年第3期29卷 392-407页

作者： Gilad Katz Asaf Shabtai Lior Rokach Nir Ofek department of Information Systems engineering Ben-Gurion University of the NegevBeer Sheva 8410501Israel Telekom Innovation Laboratories Ben-Gurion University of the NegevBeer Sheva 8410501Israel

Decision trees have three main disadvantages： reduced performance when the training set is small; rigid decision criteria; and the fact that a single ＂uncharacteristic＂ attribute might ＂derail＂ the classification process. In this paper we present ConfDTree （Confidence-Based Decision Tree） -- a post-processing method that enables decision trees to better classify outlier instances. This method, which can be applied to any decision tree algorithm, uses easy-to-implement statistical methods （confidence intervals and two-proportion tests） in order to identify hard-to-classify instances and to propose alternative routes. The experimental study indicates that the proposed post-processing method consistently and significantly improves the predictive performance of decision trees, particularly for small, imbalanced or multi-class datasets in which an average improvement of 5%-9% in the AUC performance is reported.

关键词： decision tree confidence interval imbalanced dataset

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A Mathematical Model of Baculovirus Infection on Insect Cells at Low Multiplicity of Infection

引用

Acta Biochimica et Biophysica Sinica 2004年第11期36卷 729-740页

作者： José C.MERCHUK department of Chemical engineering ben-gurion university of the negev P.O. Box 653 Beer-Sheva 84105 Israel

The expression efficiency of the insect cells-baculovirus system used for insecticidal virus production and the expression of medically useful foreign genes is closely related with the dynamics of infection. The prese... 详细信息

关键词： modeling infection insect cells baculovirus multiplicity of infection (MOI)

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Categorizing methods for integrating machine learning with executable specifications

引用

Science China(Information Sciences) 2024年第1期67卷 5-19页

作者： David HAREL Raz YERUSHALMI Assaf MARRON Achiya ELYASAF department of Computer Science and Applied Mathematics Weizmann Institute of Science department of Software and Information Systems engineering Ben-Gurion University of the Negev

Deep learning(DL),which includes deep reinforcement learning(DRL),holds great promise for carrying out real-world tasks that human minds seem to cope with quite *** promise is already delivering extremely impressive results in a variety of ***,while DL-enabled systems achieve excellent performance,they are far from *** has been demonstrated,in several domains,that DL systems can err when they encounter cases they had not hitherto ***,the opacity of the produced agents makes it difficult to explain their behavior and ensure that they adhere to various requirements posed by human *** the other end of the software development spectrum of methods,behavioral programming(BP) facilitates orderly system development using self-standing executable modules aligned with how humans intuitively describe desired system *** this paper,we elaborate on different approaches for combining DRL with BP and,more generally,machine learning(ML) with executable specifications(ES).We begin by defining a framework for studying the various approaches,which can also be used to study new emerging approaches not covered *** then briefly review state-of-the-art approaches to integrating ML with ES,continue with a focus on DRL,and then present the merits of integrating ML with *** conclude with guidelines on how this categorization can be used in decision making in system development,and outline future research challenges.

关键词： machine learning artificial intelligence grey box learning domain knowledge rules behavioral programming deep reinforcement learning survey

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

“Hot”electrons in metallic nanostructures—nonthermal carriers or heating?

引用

Light(Science & Applications) 2019年第1期8卷 368-375页

作者： Yonatan Dubi Yonatan Sivan department of Chemistry and the Ilse Katz Center for nanoscale Science and Technology Ben-Gurion University of the NegevBeer ShevaIsrael School of Electrical and Computer engineering and the Ilse Katz Center for nanoscale Science and Technology Ben-Gurion University of the NegevBeer ShevaIsrael

Understanding the interplay between illumination and the electron distribution in metallic nanostructures is a crucial step towards developing applications such as plasmonic photocatalysis for green fuels,nanoscale photodetection and *** this interplay is challenging,as it requires taking into account all channels of energy flow in the electronic ***,we develop such a theory,which is based on a coupled Boltzmann-heat equations and requires only energy conservation and basic thermodynamics,where the electron distribution,and the electron and phonon(lattice)temperatures are determined *** this theory to realistic illuminated nanoparticle systems,we find that the electron and phonon temperatures are similar,thus justifying the(classical)singletemperature *** show that while the fraction of high-energy“hot”carriers compared to thermalized carriers grows substantially with illumination intensity,it remains extremely small(on the order of 10^(-8)).Importantly,most of the absorbed illumination power goes into heating rather than generating hot carriers,thus rendering plasmonic hot carrier generation extremely *** formulation allows for the first time a unique quantitative comparison of theory and measurements of steady-state electron distributions in metallic nanostructures.

关键词： illumination theory rendering

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：