Gold Bulletin最新文献_第5页

Study on the growth kinetics of Au nanorods based on local surface plasmon resonance 基于局部表面等离子体共振的金纳米棒生长动力学研究

IF 2.2 4区工程技术

Gold Bulletin Pub Date : 2021-10-29 DOI: 10.1007/s13404-021-00299-0

Liqing Meng, Zongxiao Li, Yousheng Deng

引用次数: 0

The age hardenability of 22 karat gold (Au-5.8wt.%Cu-2.5wt.%Ag) alloyed with titanium 研究了22k金(Au-5.8wt.%Cu-2.5wt.%Ag)与钛合金的时效淬透性

IF 2.2 4区工程技术

Gold Bulletin Pub Date : 2021-10-27 DOI: 10.1007/s13404-021-00301-9

K. M. Saradesh, K. R. Ravi, G. S. Vinodkumar

{"title":"The age hardenability of 22 karat gold (Au-5.8wt.%Cu-2.5wt.%Ag) alloyed with titanium","authors":"K. M. Saradesh, K. R. Ravi, G. S. Vinodkumar","doi":"10.1007/s13404-021-00301-9","DOIUrl":"10.1007/s13404-021-00301-9","url":null,"abstract":"<div>The age hardenability of 22 karat gold (Au-5.8wt.%Cu-2.5wt.%Ag) alloyed with Ti at various concentrations (0.5, 0.75, and 1 wt.%) was studied. The addition level of Ti is compensated with Ag to maintain the purity of gold in 22 karat, i.e., 91.75 wt.%. The Ti containing 22 karat gold was prepared by melting Au, Cu, and Ag and adding Ti via Au-6wt.%Ti master alloy. The castings obtained were cold-rolled into thin sheet (90% reduction). Both the cast and cold-rolled sheets were subjected to age hardening treatment (solutionizing and artificial aging). Artificial aging was performed as a function of time at 550 °C to identify the peak aging. At all addition level of Ti, the 22 karat gold responded well to the age hardening treatment. The cold-worked sheet samples showed faster peak aging within 30 min. and higher peak hardness than their cast counterpart. Increasing the Ti concentration increases the peak hardness of both cold-rolled sheet and casting samples. Transmission electron microscopic analysis of the peak aged cold-rolled sheet samples shows uniformly distributed coherent Au4Ti precipitates in Au matrix which contribute to the higher hardness.</div>","PeriodicalId":581,"journal":{"name":"Gold Bulletin","volume":"54 2","pages":"105 - 113"},"PeriodicalIF":2.2,"publicationDate":"2021-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13404-021-00301-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5064971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Do LBMA gold price follow random-walk? LBMA黄金价格遵循随机游走吗?

IF 2.2 4区工程技术

Gold Bulletin Pub Date : 2021-09-15 DOI: 10.1007/s13404-021-00300-w

Biswabhusan Bhuyan, Subhamitra Patra, Ranjan Kumar Bhuian

引用次数: 1

Anglo-Saxon bling — a warrior king’s Golden Helmet 盎格鲁-撒克逊人的珠宝——勇士国王的金头盔

IF 2.2 4区工程技术

Gold Bulletin Pub Date : 2021-06-11 DOI: 10.1007/s13404-021-00297-2

Frank Cooper

{"title":"Anglo-Saxon bling — a warrior king’s Golden Helmet","authors":"Frank Cooper","doi":"10.1007/s13404-021-00297-2","DOIUrl":"10.1007/s13404-021-00297-2","url":null,"abstract":"<div>In 2009, a metal detectorist discovered a hoard of Anglo-Saxon gold and silver in a field in Staffordshire. Hence, it quickly became known as ‘The Staffordshire Hoard’. It was, and remains, the biggest collection of Anglo-Saxon gold (4 kg) and silver (1.7 kg) ever discovered and comprised of more than 4000 fragments that equated to over 600 discrete objects and larger pieces. The Staffordshire Hoard is co-owned by Birmingham and Stoke-on-Trent City Councils and is cared for on behalf of the nation by Birmingham Museums Trust and The Potteries Museum & Art Gallery. Over the intervening years, most of the larger and recognisably important pieces have now been identified and catalogued. We now also know an exceptional amount about their probable methods of manufacture, artistic styles, date, and function. This paper focuses on what is now known to be one of the most fragmented yet magnificent of its objects, a Helmet that has been declared as being ‘fit for a king’, but which was found scattered into well over 1000 disparate fragments. Fragments that are now considered to make up around one-third of the Hoard’s total of finds and compose this single high-status Golden Helmet. Too damaged and incomplete to be re-joined or displayed in a form that delivers to the casual observer a true sense of the majesty of the original. Thus, the museums responsible for the collection commissioned an experimental reconstruction project to create two of the helmets for display in their shared Hoard collections.</div>","PeriodicalId":581,"journal":{"name":"Gold Bulletin","volume":"54 2","pages":"115 - 149"},"PeriodicalIF":2.2,"publicationDate":"2021-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s13404-021-00297-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4468743","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

Synthesis, characterization, and in vitro drug release properties of AuNPs/p(AETAC-co-VI)/Q nanocomposite hydrogels AuNPs/p(AETAC-co-VI)/Q纳米复合水凝胶的合成、表征及体外释药性能

IF 2.2 4区工程技术

Gold Bulletin Pub Date : 2021-04-14 DOI: 10.1007/s13404-021-00295-4

Seçil Durmuş, Betul Yilmaz, Mehmet Rıza Kıvanç, Alper Onder, Pinar Ilgin, Hava Ozay, Ozgur Ozay

{"title":"Synthesis, characterization, and in vitro drug release properties of AuNPs/p(AETAC-co-VI)/Q nanocomposite hydrogels","authors":"Seçil Durmuş, Betul Yilmaz, Mehmet Rıza Kıvanç, Alper Onder, Pinar Ilgin, Hava Ozay, Ozgur Ozay","doi":"10.1007/s13404-021-00295-4","DOIUrl":"10.1007/s13404-021-00295-4","url":null,"abstract":"In this study, the cationic monomer [2-(acryloyloxy)ethyl]trimethylammonium chloride solution (AETAC) and vinyl imidazole (VI) were used with the free radical polymerization technique, which is a simple and rapid synthesis method, to synthesize p(AETAC-co-VI) hydrogels. To increase the density of cationic charge on the hydrogel, it underwent the protonation process with HCl. The obtained p(AETAC-co-VI)/Q hydrogel was modified with Au nanoparticles to increase bactericidal effect to obtain the AuNPs/p(AETAC-co-VI)/Q nanocomposite hydrogel. The morphology and chemical structure of the hydrogels were characterized with SEM and FTIR. Additionally, the swelling capabilities were tested in different pH media. XRD and TEM confirmed the formation of the nanocomposite hydrogel. The antibacterial activity of the hydrogels was tested against E. coli and S. aureus, and controlled release implementations were completed with sodium diclofenac (NaDc) drug. The NaDc drug release profiles of the hydrogels were researched using the Korsmeyer–Peppas model at 37 °C in different simulated buffer (pH 6.0, 7.2, and 8.0) solutions. It was found that both the hydrogel and nanocomposite hydrogel followed non-Fickian diffusion mechanisms as free release mechanism. Here, the maximum drug release efficacy was found to be 97%, and drug release was more rapid in basic media when release media were compared. The AuNPs/p(AETAC-co-VI)/Q nanocomposite hydrogels produced in this study with advanced antibacterial features were suitable for recommendation as good carriers for in vitro release of NaDc drugs in areas like the biomedical and pharmaceutical industries.","PeriodicalId":581,"journal":{"name":"Gold Bulletin","volume":"54 2","pages":"75 - 87"},"PeriodicalIF":2.2,"publicationDate":"2021-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s13404-021-00295-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4559402","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: 10

The facile synthesis of aerogel-like alumina highly-loaded with gold nanoparticles 高负载金纳米颗粒的气凝胶状氧化铝的简易合成

IF 2.2 4区工程技术

Gold Bulletin Pub Date : 2021-03-01 DOI: 10.1007/s13404-021-00294-5

N. S. Nesterov, A. S. Shalygin, T. S. Glazneva, V. P. Pakharukova, O. N. Martyanov

{"title":"The facile synthesis of aerogel-like alumina highly-loaded with gold nanoparticles","authors":"N. S. Nesterov, A. S. Shalygin, T. S. Glazneva, V. P. Pakharukova, O. N. Martyanov","doi":"10.1007/s13404-021-00294-5","DOIUrl":"https://doi.org/10.1007/s13404-021-00294-5","url":null,"abstract":"A facile approach is proposed for the stabilization of gold nanoparticles within alumina matrix based on fast coprecipitation of colloidal gold and alumina sol in the supercritical carbon dioxide used as antisolvent. Acetylacetone was used as a stabilizer agent for the synthesis of alumina sol. Gold nanoparticles were synthesized from HAuCl4 directly in liquid alumina sol in reaction with acetylacetone. Acetylacetone played the role of both a stabilizer agent for gold nanoparticles and a reducing agent. Obtained system is characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), infrared (IR) spectroscopy, and UV–Vis adsorption spectroscopy. The method allows us to synthesize aerogel-like alumina highly loaded with gold nanoparticles firmly fixed on oxide surface and uniformly distributed within alumina matrix. The proposed approach combines sol-gel and supercritical fluid methods for the synthesis and opens the wide prospects for preparation composites consisting of gold nanoparticles in oxide matrix with a uniform distribution. These gold-bearing systems may be of interest to a wide range of applications.","PeriodicalId":581,"journal":{"name":"Gold Bulletin","volume":"54 1","pages":"69 - 74"},"PeriodicalIF":2.2,"publicationDate":"2021-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s13404-021-00294-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4043386","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: 4

Preparation of Aunanorods@B-SiO2 准备Aunanorods@B-SiO2

IF 2.2 4区工程技术

Gold Bulletin Pub Date : 2021-02-20 DOI: 10.1007/s13404-021-00289-2

Liqing Meng, Huiqin Li

引用次数: 0

Potential application of gold nanoparticles in food packaging: a mini review 金纳米颗粒在食品包装中的潜在应用综述

IF 2.2 4区工程技术

Gold Bulletin Pub Date : 2021-02-20 DOI: 10.1007/s13404-021-00290-9

Saeed Paidari, Salam Adnan Ibrahim

引用次数: 50

QM study of interaction between arginine amino acid and Au clusters and the effects on arginine acidity 精氨酸氨基酸与金簇相互作用及其对精氨酸酸度影响的QM研究

IF 2.2 4区工程技术

Gold Bulletin Pub Date : 2021-01-22 DOI: 10.1007/s13404-021-00292-7

Mina Ghiasi, Shadi Bavafa, Mansour Zahedi

{"title":"QM study of interaction between arginine amino acid and Au clusters and the effects on arginine acidity","authors":"Mina Ghiasi, Shadi Bavafa, Mansour Zahedi","doi":"10.1007/s13404-021-00292-7","DOIUrl":"https://doi.org/10.1007/s13404-021-00292-7","url":null,"abstract":"Understanding the various structures of gold clusters and the interaction modes between Au clusters and biomolecules is an important issue in material science such as biosensors and catalysts. The binding of small gold clusters (Aun n?=?2–5) with neutral and anionic forms of arginine (Arg) amino acid is investigated in this study using density functional theory (DFT) and B3LYP level. The relative stability among different forms of Au clusters including linear, zigzag, planar, and three-dimensional Au clusters was estimated, initially. The calculated findings show that the zigzag structure for Au3 and the planar structure for Au4 and Au5 are the best form. Furthermore, the different modes of interaction were taken into account from thermodynamic view point between the most stable conformers of Arg and Arg? with gold clusters. Finally, the arginine is considered as a weak organic acid to investigate the impact of Au clusters on the gas phase acidity. The acidity of isolated arginine and the acidity of [Aun/Arg] complexes were also compared. Based on the obtained results, upon the complexation with Au clusters at 298?K, for the interaction of Au, Au2, Au3, Au4, and Au5 clusters with arginine, the gas phase acidity (GPA) of arginine alters from 342.12 to 314.17, 303.04, 299.42, 303.41, and 331.66?kcal/mol respectively. These calculated values predict that when a weak organic acid is complexed with Au clusters, it will be altered to super acid. Furthermore, for isolated and complexed species of Arg, pKa values were evaluated in water solvent.","PeriodicalId":581,"journal":{"name":"Gold Bulletin","volume":"54 1","pages":"45 - 57"},"PeriodicalIF":2.2,"publicationDate":"2021-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s13404-021-00292-7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4862782","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: 3

Synthesis of gold nanoparticles in aqueous solutions not containing additional interfering components using sulfite method: the effect of thiol-containing acid additives 亚硫酸盐法在不含干扰成分的水溶液中合成金纳米粒子:含硫醇酸添加剂的影响

IF 2.2 4区工程技术

Gold Bulletin Pub Date : 2021-01-15 DOI: 10.1007/s13404-021-00291-8

Igor V. Mironov, Viktoria Yu. Kharlamova

{"title":"Synthesis of gold nanoparticles in aqueous solutions not containing additional interfering components using sulfite method: the effect of thiol-containing acid additives","authors":"Igor V. Mironov, Viktoria Yu. Kharlamova","doi":"10.1007/s13404-021-00291-8","DOIUrl":"https://doi.org/10.1007/s13404-021-00291-8","url":null,"abstract":"Stable solutions of gold nanoparticles with an average diameter of 13 nm and CAu = 5×10–4 M were obtained by the reduction of HAuCl4 with an equivalent amount of sodium sulfite at 80–100 °C in the presence of 2% PEG 6000 as a stabilizer: AuCl4– + 3/2 SO32– + 3/2 H2O → Au0 + 3/2 SO42– + 3 H+ + 4 Cl–. The resulting solutions of nanoparticles do not contain additional components capable of complexation, redox, and acid-based interactions. The effect of additives of thiourea, cysteine, thiomalate, and glutathione at various pH on the stability of such solutions to the aggregation has been studied. It was shown that the values of the protonation constants and charges of species of a thiol-containing component are not the only factors determining stability. Using thiomalate (HTM2–) as an example, it was shown also that at pH 7–8, the chemisorption is not followed by the release of H+ ions into the solution.","PeriodicalId":581,"journal":{"name":"Gold Bulletin","volume":"54 1","pages":"37 - 44"},"PeriodicalIF":2.2,"publicationDate":"2021-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s13404-021-00291-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4608413","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