Gold Bulletin最新文献_第7页

Effect of the composition and production process parameters on the microstructure, residual stresses, and mechanical and corrosion properties of gold alloys used in industrial jewelry processes 工业珠宝加工中使用的金合金的成分和生产工艺参数对其显微组织、残余应力、机械和腐蚀性能的影响

IF 2.2 4区工程技术

Gold Bulletin Pub Date : 2017-08-19 DOI: 10.1007/s13404-017-0215-y

C. Cason, L. Pezzato, K. Brunelli, F. Furlan, M. Dabalà

{"title":"Effect of the composition and production process parameters on the microstructure, residual stresses, and mechanical and corrosion properties of gold alloys used in industrial jewelry processes","authors":"C. Cason, L. Pezzato, K. Brunelli, F. Furlan, M. Dabalà","doi":"10.1007/s13404-017-0215-y","DOIUrl":"https://doi.org/10.1007/s13404-017-0215-y","url":null,"abstract":"Gold alloys, used in the production of both hollow and solid gold chains, influence the optical and mechanical properties of various gold products. Also, the microstructure of the alloys strongly influences the mechanical properties, which have a key role in both the machinability and quality of the plates. In the present work, different compositions of gold alloys and various industrial deformation processes (annealing and rolling steps) were analyzed and optimized. The change in the production parameters and in the compositions of the alloys may lead to the formation of different levels of residual stresses within the material, which can generate a variation in the behavior of gold sheets. The microstructures after the different production processes were analyzed by OM and SEM observations, whereas the variation of mechanical properties by microhardness tests. The residual stresses were evaluated using XRD analysis and the corrosion resistance by potentiodynamic polarization tests. The results showed that with the optimized process, a higher homogeneity of the microstructure, with an increase of the quality of semi-finished products and without ruptures under roller trains, was obtained. Moreover, the grain refiner was changed and a totally non-magnetic gold alloy was developed. Finally, to improve the weldability of the final chains, a different gold welding alloy, with a lower melting point, was developed and optimized.","PeriodicalId":55086,"journal":{"name":"Gold Bulletin","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2017-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s13404-017-0215-y","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4741375","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Shape-selective purification of gold nanorods with low aspect ratio using a simple centrifugation method 用简单的离心法对低纵横比金纳米棒进行形状选择纯化

IF 2.2 4区工程技术

Gold Bulletin Pub Date : 2017-01-27 DOI: 10.1007/s13404-017-0197-9

Maxime Boksebeld, Nicholas P. Blanchard, Ali Jaffal, Yann Chevolot, Virginie Monnier

{"title":"Shape-selective purification of gold nanorods with low aspect ratio using a simple centrifugation method","authors":"Maxime Boksebeld, Nicholas P. Blanchard, Ali Jaffal, Yann Chevolot, Virginie Monnier","doi":"10.1007/s13404-017-0197-9","DOIUrl":"https://doi.org/10.1007/s13404-017-0197-9","url":null,"abstract":"This work presents a new and simple procedure for the shape selective purification of gold nanorods from a mixture of rods and spheres. Previously reported methods were time-consuming and revealed several drawbacks such as low yields and difficulty to recover the purified nanoparticles. Additionally, they were mostly applied to high aspect ratio (AR) nanorods. Our process is based on only simple and short centrifugation steps in order to precipitate specifically gold nanospheres. Samples containing low AR nanorods (AR?<?6) were selected to perform the purification process. The supernatant content was followed by UV-Visible absorption spectroscopy after each centrifugation step. Then, transmission electron microscopy (TEM) allowed extract the purification efficiency thanks to shape analyses performed on more than 1000 nanoparticles. These results showed that our centrifugation process was applied successfully to three sizes of nanorods (2.4, 3.7, and 5.3). High purification yields of 72 and 78% were attained for AR?=?3.7 and AR?=?5.3 nanorods, respectively.","PeriodicalId":55086,"journal":{"name":"Gold Bulletin","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2017-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s13404-017-0197-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5037456","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 11

Intermetallic growth kinetics of 2N gold wire ball bonds on aluminium bond pads annealed at 175 °C 175℃退火铝键垫上2N金丝球键的金属间生长动力学

IF 2.2 4区工程技术

Gold Bulletin Pub Date : 2016-10-03 DOI: 10.1007/s13404-016-0184-6

C. D. Breach

{"title":"Intermetallic growth kinetics of 2N gold wire ball bonds on aluminium bond pads annealed at 175 °C","authors":"C. D. Breach","doi":"10.1007/s13404-016-0184-6","DOIUrl":"https://doi.org/10.1007/s13404-016-0184-6","url":null,"abstract":"Gold ball bonding wires of 2N purity were bonded to Si devices with aluminium alloy bond pad metallisation. Specimens were subjected to isothermal annealing at 175?°C in a fan-circulated oven in an air environment for various times t. Samples of ball bonds from each specimen were cross-sectioned, and the total intermetallic thickness x at the centre of the ball bonds was measured. The kinetics of x versus t were modelled using a power law expression ( x(t)={x}_0+{theta}_1{t}^{theta_2} ) with growth parameter θ\u0000 1 and constrained parameter 0?<?θ\u0000 2?≤?1. The parameter θ\u0000 2 is supposedly capable of differentiating between diffusion controlled intermetallic growth (grain boundary and/or volume diffusion) and interfacial reaction controlled growth with the presence/absence of grain growth solely based on its numerical value. The parameters θ\u0000 1?and θ\u0000 2 and the regression function were obtained by log-transformation of both the response variable x and the explanatory variable t and data fitting using simple linear regression (SLR), taking care to perform diagnostic checks to confirm that transformed data satisfied the requirements of SLR. Simulated intermetallic thickness data obtained by sampling from lognormal distributions was observed to closely approximate the experimental observations. Values of the exponent θ\u0000 2 were observed in the range 0.2–0.4, which was interpreted as indicative of grain boundary dominated interdiffusion with grain growth.","PeriodicalId":55086,"journal":{"name":"Gold Bulletin","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2016-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s13404-016-0184-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4139053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Catalytic activity of gold-perovskite catalysts in the oxidation of carbon monoxide 金-钙钛矿催化剂在一氧化碳氧化中的催化活性

IF 2.2 4区工程技术

Gold Bulletin Pub Date : 2016-07-06 DOI: 10.1007/s13404-016-0180-x

Leboheng Mokoena, Gary Pattrick, Mike S Scurrell

{"title":"Catalytic activity of gold-perovskite catalysts in the oxidation of carbon monoxide","authors":"Leboheng Mokoena, Gary Pattrick, Mike S Scurrell","doi":"10.1007/s13404-016-0180-x","DOIUrl":"https://doi.org/10.1007/s13404-016-0180-x","url":null,"abstract":"Perovskites (ABO3 structures), which can be manipulated by partial substitution, are reported to be active supports for CO oxidation, but only at high temperatures, with no activity being shown for temperatures below 200?°C. In this study, these perovskites were investigated at low temperatures (below 100?°C) with improved activity found upon gold deposition. The presence of gold nanoparticles therefore significantly enhanced the catalytic activity, while the support itself was suspected to be involved in the reaction mechanism. A series of perovskites of the type ABO3 (LaMnO3, LaFeO3, LaCoO3, and LaCuO3) were prepared using the citrate method, while the gold was deposited on them using the deposition-precipitation method. The supports were calcined at different temperatures for optimization. With the support calcined at 800?°C, the best catalyst was 1?wt% Au supported on LaFeO3. Calcium-doping of this system showed decreased surface area, poorer crystallinity, and a drop in catalytic activity relative to the Au-LaFeO3. In addition, Au-LaFeO3 showed online stability over 21?h. Calcining the support improved the incorporation of gold nanoparticles into the perovskite lattice, resulting in superior catalytic activity. Nevertheless, at higher calcination temperatures, the catalytic activity of Au-CaTiO3 was depressed while that of Au-LaFeO3 was enhanced. XPS revealed that in the active catalysts, both cationic and metallic gold coexisted, while in the inactive catalysts, the gold existed predominantly either as cationic or metallic gold.","PeriodicalId":55086,"journal":{"name":"Gold Bulletin","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2016-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s13404-016-0180-x","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4255302","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7

Colour tuneable anisotropic, water-dispersible gold nanoparticles stabilized by chitosan 颜色可调各向异性、水分散的壳聚糖稳定金纳米颗粒

IF 2.2 4区工程技术

Gold Bulletin Pub Date : 2016-02-23 DOI: 10.1007/s13404-016-0176-6

Andrea N. D. Kolb, James H. Johnston

引用次数: 2

Use of a synthetic foot-and-mouth disease virus peptide conjugated to gold nanoparticles for enhancing immunological response 利用合成的口蹄疫病毒肽偶联金纳米颗粒增强免疫反应

IF 2.2 4区工程技术

Gold Bulletin Pub Date : 2015-07-25 DOI: 10.1007/s13404-015-0165-1

Lev A. Dykman, Sergey A. Staroverov, Pavel V. Mezhenny, Alexander S. Fomin, Sergey V. Kozlov, Alexey A. Volkov, Vladislav N. Laskavy, Sergei Yu. Shchyogolev

{"title":"Use of a synthetic foot-and-mouth disease virus peptide conjugated to gold nanoparticles for enhancing immunological response","authors":"Lev A. Dykman, Sergey A. Staroverov, Pavel V. Mezhenny, Alexander S. Fomin, Sergey V. Kozlov, Alexey A. Volkov, Vladislav N. Laskavy, Sergei Yu. Shchyogolev","doi":"10.1007/s13404-015-0165-1","DOIUrl":"https://doi.org/10.1007/s13404-015-0165-1","url":null,"abstract":"Foot-and-mouth disease is an acute, highly contagious infection of domestic and wild cloven-hoofed animals, which can be transmitted to humans. In many cases, the existing vaccines are not quite effective. The purpose of this study was to test the possibility of using gold nanoparticles as an antigen carrier and an adjuvant. The immunogenic properties of gold nanoparticles were assessed by conjugating the particles to a synthetic peptide of the VP1 capsid protein of the foot-and-mouth disease virus. The resulting conjugate (with or without the use of complete Freund’s adjuvant), a commercial vaccine, and the native peptide served to immunize guinea pigs. The titer and sensitivity of the raised antibodies were maximal for the combination comprising the nanoparticle–peptide conjugate and complete Freund’s adjuvant. Antibody biosynthesis was accompanied by increased production of proinflammatory cytokines (especially IFN-γ) and by stimulation of the respiratory activity of peritoneal macrophages. The use of gold nanoparticles as a hapten carrier enhanced the immune response even when complete Freund’s adjuvant was not used.","PeriodicalId":55086,"journal":{"name":"Gold Bulletin","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2015-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s13404-015-0165-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4968741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 19

New deeply coloured 18-K gold materials built by nanotechnologies 纳米技术制造的新型深颜色18k金材料

IF 2.2 4区工程技术

Gold Bulletin Pub Date : 2014-12-12 DOI: 10.1007/s13404-014-0154-9

Anne Serin, Mathieu Bourlion, Frédéric Diologent, René Ziegenhagen, Vincent Germain

{"title":"New deeply coloured 18-K gold materials built by nanotechnologies","authors":"Anne Serin, Mathieu Bourlion, Frédéric Diologent, René Ziegenhagen, Vincent Germain","doi":"10.1007/s13404-014-0154-9","DOIUrl":"https://doi.org/10.1007/s13404-014-0154-9","url":null,"abstract":"A new way to elaborate coloured carat gold materials has been developed. Instead of using traditional metallurgy route, we built a new 18-K bulk material using nanostructured gold particles. The resulting colour is the consequence of a well-known property of gold nanoparticles: the surface plasmon resonance effect. Depending on the chemical environment around the nanoparticles, their shape and size, it is possible to tune the colour of gold. Thanks to this property, it is possible to obtain a large panel of colours not achievable via conventional alloying route. Here, we focus on one hybrid nanostructured material: Au-SiO2. The development of a new synthesis route enables us to obtain nanostructured micrometric powders that can then be pressed to obtain a bulk material. The resulting nanocomposites are characterized by means of energy-dispersive X-ray spectroscopy (EDX), fire assay, TEM and spectrophotocolorimetry. All these characterizations have shown that our composites exhibit a gold content superior to 75?% by weight and have a much more vivid colour than classical coloured gold. The new composites are therefore deeply coloured 18-K materials.","PeriodicalId":55086,"journal":{"name":"Gold Bulletin","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2014-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s13404-014-0154-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4487151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Alumina hollow microspheres supported gold catalysts for low-temperature CO oxidation: effect of the pretreatment atmospheres on the catalytic activity and stability 氧化铝空心微球负载金催化剂的低温CO氧化:预处理气氛对催化活性和稳定性的影响

IF 2.2 4区工程技术

Gold Bulletin Pub Date : 2014-09-17 DOI: 10.1007/s13404-014-0152-y

Yu-Xin Miao, Lei Shi, Li-Na Cai, Wen-Cui Li

{"title":"Alumina hollow microspheres supported gold catalysts for low-temperature CO oxidation: effect of the pretreatment atmospheres on the catalytic activity and stability","authors":"Yu-Xin Miao, Lei Shi, Li-Na Cai, Wen-Cui Li","doi":"10.1007/s13404-014-0152-y","DOIUrl":"https://doi.org/10.1007/s13404-014-0152-y","url":null,"abstract":"Hierarchically organized γ-Al2O3 hollow microspheres were prepared via a hydrothermal method using potassium aluminum sulfate and urea as reactants. The corresponding Au/Al2O3 catalysts were obtained using a deposition-precipitation (DP) method. The effect of the pretreatment under different atmospheres (N2, air, and H2) on the activity and stability of the Au/Al2O3 catalysts in CO oxidation was investigated. The results showed that the pretreatment under H2 atmosphere improved the low-temperature CO oxidation activity. Furthermore, a 50?h long-term test at 30?°C showed no significant deactivation for the H2-pretreated catalyst. Moreover, the catalytic activity was promoted by H2O vapor in all cases, and the H2-pretreated catalyst exhibited a good tolerance in the co-presence of CO2 and H2O. Finally, oxygen temperature-programmed desorption (O2-TPD) and in situ diffuse reflectance infrared Fourier transform spectra (DRIFTS) revealed that the reductive atmosphere pretreatment greatly improved the CO adsorption capacity and facilitated the oxygen activation.","PeriodicalId":55086,"journal":{"name":"Gold Bulletin","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2014-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s13404-014-0152-y","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4706336","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 15

Hardening effect of pre- and post-firing heat treatment for a firing-simulated Au-Pd-In metal-ceramic alloy 一种模拟烧成Au-Pd-In金属陶瓷合金烧前和烧后热处理的硬化效应

IF 2.2 4区工程技术

Gold Bulletin Pub Date : 2014-08-19 DOI: 10.1007/s13404-014-0149-6

Byung-Wook Jeon, Sung-Min Kim, Hyung-Il Kim, Yong Hoon Kwon, Hyo-Joung Seol

{"title":"Hardening effect of pre- and post-firing heat treatment for a firing-simulated Au-Pd-In metal-ceramic alloy","authors":"Byung-Wook Jeon, Sung-Min Kim, Hyung-Il Kim, Yong Hoon Kwon, Hyo-Joung Seol","doi":"10.1007/s13404-014-0149-6","DOIUrl":"https://doi.org/10.1007/s13404-014-0149-6","url":null,"abstract":"The hardening effect of the pre- and post-firing heat treatments and their dual treatment was examined for a firing-simulated Au-Pd-In metal-ceramic alloy to determine if an additional post-firing heat treatment is effective in the hardening of an Au-Pd-In metal-ceramic alloy as well as to compare the hardening effects of pre- and post-firing heat treatments for a firing-simulated Au-Pd-In metal-ceramic alloy. The post-firing heat treatment was much more effective than the pre-firing heat treatment or dual treatments. The hardening effect of the pre- and post-firing heat treatments was caused by the induction of fine grain interior precipitation. In the pre-firing heat-treated specimen after casting, the apparent hardening was achieved during simulated porcelain firing, but an additional post-firing heat treatment did not introduce severe grain interior precipitation, resulting in very weak hardening. In the as-cast specimen without the pre-firing heat treatment, apparent hardening by grain interior precipitation was achieved only by post-firing heat treatment and not by simulated porcelain firing.","PeriodicalId":55086,"journal":{"name":"Gold Bulletin","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2014-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s13404-014-0149-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4743595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 13

Gold’s evolving role in the electronics industry 黄金在电子工业中不断演变的角色

IF 2.2 4区工程技术

Gold Bulletin Pub Date : 2014-08-16 DOI: 10.1007/s13404-014-0151-z

Trevor Keel

引用次数: 0