Crystals最新文献_第10页

Nanoindentation Stress Relaxation to Quantify Dislocation Velocity–Stress Exponent 通过纳米压痕应力松弛量化差排速度-应力指数

IF 2.7 4区材料科学

Crystals Pub Date : 2024-07-26 DOI: 10.3390/cryst14080680

Tzu-Yi Chang, Gavin Vandenbroeder, David M. Frazer, Dewen Yushu, Stephanie Pitts, Tianyi Chen

引用次数: 0

Characterizing Malysheva Emeralds (Urals, Russia) by Microscopy, Spectroscopy, Trace Element Chemistry, and Machine Learning 通过显微镜、光谱学、微量元素化学和机器学习鉴定 Malysheva 祖母绿（俄罗斯乌拉尔山脉

IF 2.7 4区材料科学

Crystals Pub Date : 2024-07-26 DOI: 10.3390/cryst14080683

Yu-Yu Zheng, Xiao-Yan Yu, Bo Xu, Yu-Jie Gao

{"title":"Characterizing Malysheva Emeralds (Urals, Russia) by Microscopy, Spectroscopy, Trace Element Chemistry, and Machine Learning","authors":"Yu-Yu Zheng, Xiao-Yan Yu, Bo Xu, Yu-Jie Gao","doi":"10.3390/cryst14080683","DOIUrl":"https://doi.org/10.3390/cryst14080683","url":null,"abstract":"The Malysheva emerald mine (Urals, Russia) boasts a long history and extraordinary emerald output. However, recent studies indicate that Malysheva emeralds share highly similar inclusion varieties, UV-visible-near infrared (UV-Vis-NIR) spectra, and compositional characteristics with other tectonic-magmatic-related (type I) emeralds from Zambia, Brazil, and Ethiopia. This similarity poses challenges for determination of the emeralds’ origin. This paper systematically investigates the microscopy, spectroscopy, and trace element chemistry of Malysheva emerald samples and compiles previously reported compositional data for the aforementioned Type I emeralds. Based on this dataset, principal component analysis (PCA) and machine learning methods are employed to construct models for emerald provenance discrimination. The results have updated the provenance characteristics of Malysheva emeralds, confirming the solid phase component of their three-phase inclusions as siderite and revealing two UV-Vis-NIR spectral patterns. Furthermore, the unique infrared absorptions related to HDO and D2O molecules within the 2600–2830 cm−1 range were discovered, which can be indicative of the origin of Malysheva. The prediction results of the machine learning model demonstrate an accuracy rate of 98.7%, and for an independent validation set of Malysheva emeralds, the prediction accuracy reached 100%. The feature importance ranking of the model highlights trace elements and parameters strongly correlated with the emeralds’ origin. These results illustrate the enormous potential of machine learning in the field of emerald origin determination, offering new insights into the traceability of precious gemstones.","PeriodicalId":10855,"journal":{"name":"Crystals","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141775275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of Cold Metal Transfer Welding Repair Parameters on the Forming for the Repair of Surface Defects of Cast Magnesium Alloy 冷金属转移焊接修复参数对铸造镁合金表面缺陷修复成形的影响

IF 2.7 4区材料科学

Crystals Pub Date : 2024-07-26 DOI: 10.3390/cryst14080679

Zenghui Cai, Faming Shen, Qihao Chen, Zhien Chen, Yanfeng Cui, Tongge Shao, Bolun Dong, Sanbao Lin, Xiaoyu Cai

{"title":"Effect of Cold Metal Transfer Welding Repair Parameters on the Forming for the Repair of Surface Defects of Cast Magnesium Alloy","authors":"Zenghui Cai, Faming Shen, Qihao Chen, Zhien Chen, Yanfeng Cui, Tongge Shao, Bolun Dong, Sanbao Lin, Xiaoyu Cai","doi":"10.3390/cryst14080679","DOIUrl":"https://doi.org/10.3390/cryst14080679","url":null,"abstract":"It is of great significance in the field of engineering to repair the surface defects of ZM6 cast magnesium alloy by an arc welding method. Compared with the traditional tungsten inert gas (TIG) welding repair technology, cold metal transfer (CMT) welding repair has the advantages of low heat input, small repair deformation, and high efficiency. It is of great research value to repair the surface defects of ZM6 cast magnesium alloy by CMT welding. In this paper, the effect of CMT welding repair parameters on defect repair forming is systematically studied, and a repair process window free of unfused defects is obtained. The effects of preheating temperature of base material, wire-feeding speed, welding speed, stick-out length of welding wire and shielding gas flow on the spread of magnesium alloy melt and weld formation were investigated by a surface surfacing method. During the welding process, a camera was used to capture images of the arc and droplet features. A pit defect with a depth of 11.5 mm was machined on the surface of the casting, and the effect of five different repair paths on the formation of the repair area was studied. In order to make the repair area have better fusion, reasonable repair parameters are as follows: The preheating temperature range is 310–450 °C, the wire-feeding speed range is 5–7 m/min, the welding speed range is 8–10 mm/s, the stick-out length of the welding wire is 12 mm, the shielding gas flow rate is 20 L/min, and the repair path adopts a continuous linear reciprocating welding path. This study has important significance for guiding the development of CMT repair technology of cast magnesium alloy.","PeriodicalId":10855,"journal":{"name":"Crystals","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141775267","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Investigation of the Effect of the Trifluoropropynyl Ligand on Pt(N^C^N)X (X = Cl, C2CF3) Complexes 研究三氟丙炔配体对 Pt(N^C^N)X（X = Cl，C2CF3）配合物的影响

IF 2.7 4区材料科学

Crystals Pub Date : 2024-07-25 DOI: 10.3390/cryst14080678

John H. Zimmerman, Benjamin J. Cahill, Wilson M. Thomas, Jackson S. McCarthy, Colin D. McMillen, Paul S. Wagenknecht

{"title":"Investigation of the Effect of the Trifluoropropynyl Ligand on Pt(N^C^N)X (X = Cl, C2CF3) Complexes","authors":"John H. Zimmerman, Benjamin J. Cahill, Wilson M. Thomas, Jackson S. McCarthy, Colin D. McMillen, Paul S. Wagenknecht","doi":"10.3390/cryst14080678","DOIUrl":"https://doi.org/10.3390/cryst14080678","url":null,"abstract":"The tuning of the luminescent properties of PtII complexes for possible use in organic light-emitting diodes (OLEDs) and sensing applications is commonly achieved by altering the electronic properties of the ligands. Our group recently demonstrated that the trifluoropropynyl ligand is strongly electron-withdrawing and possibly useful for blueshifting emission. Herein, we report the synthesis of two complexes of this trifluoropropynyl ligand, namely PtLC2CF3 and PtLFC2CF3 (L = 1,3-di(2-pyridyl)benzene; LF = 4,6-difluoro-1,3-di(2-pyridyl)benzene). The PtLC2CF3 complex crystallized in the monoclinic space group P21/n with Z = 4. The PtLFC2CF3 complex crystalized in the triclinic space group P-1 with Z = 2. Changing the tridentate ligand from L to LF resulted in a change in the packing structure, with the latter showing a metallophilic interaction (Pt-Pt distance = 3.3341(3) Å). The solution photophysics of the trifluoropropynyl complexes is compared with that of the corresponding Cl complexes, PtLCl and PtLFCl. Replacement of the chloro ligand with the trifluoropropynyl ligand blueshifted the monomer emission by less than 5 nm but blueshifted the excimer emission peaks by 15–20 nm. The complexes of the trifluoropropynyl ligand also favor the excimer emission more than the complexes of the chloro ligand. The excimer emission is quenched by dissolved oxygen significantly more than the corresponding monomer emission. The excimer emission and monomer emission are well separated, and the ratio of monomer to excimer emission is strongly dependent on oxygen concentration.","PeriodicalId":10855,"journal":{"name":"Crystals","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141775027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Prevention of Crystal Agglomeration: Mechanisms, Factors, and Impact of Additives 防止晶体凝聚：机理、因素和添加剂的影响

IF 2.7 4区材料科学

Crystals Pub Date : 2024-07-24 DOI: 10.3390/cryst14080676

Huixiang Zhang, Shichao Du, Yan Wang, Fumin Xue

引用次数: 0

Wafer-Scale ALD Synthesis of MoO3 Sulfurized to MoS2 晶圆级 ALD 合成硫化成 MoS2 的 MoO3

IF 2.7 4区材料科学

Crystals Pub Date : 2024-07-24 DOI: 10.3390/cryst14080673

Sachin Shendokar, Moha Feroz Hossen, Shyam Aravamudhan

{"title":"Wafer-Scale ALD Synthesis of MoO3 Sulfurized to MoS2","authors":"Sachin Shendokar, Moha Feroz Hossen, Shyam Aravamudhan","doi":"10.3390/cryst14080673","DOIUrl":"https://doi.org/10.3390/cryst14080673","url":null,"abstract":"Silicon has dimensional limitations in following Moore’s law; thus, new 2D materials complementing Silicon are being researched. Molybdenum disulfide (MoS2) is a prospective material anticipated to bridge the gap to complement Silicon and enhance the performances of semiconductor devices and embedded systems in the package. For a synthesis process to be of any relevance to the industry. it needs to be at the wafer scale to match existing Silicon wafer-processing standards. Atomic Layer Deposition (ALD) is one of the most promising techniques for synthesizing wafer-scale monolayer MoS2 due to its self-limiting, conformal, and low-temperature characteristics. This paper discusses the wafer-scale ALD synthesis of Molybdenum trioxide (MoO3) using Mo (CO)6 as a precursor with Ozone as a reactant. An ALD-synthesized wafer-scale MoO3 thin film was later sulfurized through Chemical Vapor Deposition (CVD) to transform into stoichiometric MoS2, which was evaluated using X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, Scanning Electron Microscopy (SEM), and Atomic Force Microscopy (AFM). The roles of activation energy and first-order reaction kinetics in determining the ALD recipe parameters of the pulse time, reactor temperature, and purge time are explicitly discussed in detail. Discretized pulsing for developing one-cycle ALD for monolayer growth is suggested. Remedial measures to overcome shortcomings observed during this research are suggested.","PeriodicalId":10855,"journal":{"name":"Crystals","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141775024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Directional Acoustic Bulk Waves in a 2D Phononic Crystal 二维声波晶体中的定向声波体波

IF 2.7 4区材料科学

Crystals Pub Date : 2024-07-24 DOI: 10.3390/cryst14080674

Pierre A. Deymier, Jérôme O. Vasseur, Keith Runge, Krishna Muralidharan, Alexander Khanikaev, Andrea Alù

引用次数: 0

Effect of Laser Heat Input on the Microstructures and Low-Cycle Fatigue Properties of Ti60 Laser Welded Joints 激光热输入对 Ti60 激光焊接接头微观结构和低循环疲劳性能的影响

IF 2.7 4区材料科学

Crystals Pub Date : 2024-07-24 DOI: 10.3390/cryst14080677

Qunbing Zhang, Lina Ren, Xiaowei Lei, Jiadian Yang, Kuo Zhang, Jianxun Zhang

{"title":"Effect of Laser Heat Input on the Microstructures and Low-Cycle Fatigue Properties of Ti60 Laser Welded Joints","authors":"Qunbing Zhang, Lina Ren, Xiaowei Lei, Jiadian Yang, Kuo Zhang, Jianxun Zhang","doi":"10.3390/cryst14080677","DOIUrl":"https://doi.org/10.3390/cryst14080677","url":null,"abstract":"In this paper, the effects of laser heat input on the microstructures, tensile strength, and fatigue properties of Ti60 laser welded joints were investigated. The results show that with the increase in laser heat input, the macro morphology of the weld zone (WZ) changes from the Y-type to X-type. In the Y-type WZ, the porosity defects are almost eliminated. In contrast, there are a lot of porosity defects in the lower part of the X-type WZ. The microstructure of the base metal (BM) comprises equiaxed α phases, and β phases are mainly distributed at the boundaries of α phases. The heat-affected zone (HAZ) is comprised of α phases and acicular α′ phases, while the WZ mainly contains acicular α′ phases. With the increase in laser heat input, the quantity of the α phase gradually decreases and the acicular α′ phase gradually increases in the HAZ, and the size of the acicular α′ phase in the WZ gradually decreases. Due to the different microstructures, the hardness of BM is lower than the HAZ and WZ under different laser heat input conditions. In the tensile tests and low-cycle fatigue tests, the welded joints are fractured in BM. The porosity defects do not have decisive effects on the tensile and low-cycle fatigue properties of Ti60 laser welded joints.","PeriodicalId":10855,"journal":{"name":"Crystals","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141775028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Electrochemical Recovery of N and P from Municipal Wastewater 电化学回收城市污水中的氮和磷

IF 2.7 4区材料科学

Crystals Pub Date : 2024-07-24 DOI: 10.3390/cryst14080675

Panagiota D. Natsi, Petros G. Koutsoukos

{"title":"Electrochemical Recovery of N and P from Municipal Wastewater","authors":"Panagiota D. Natsi, Petros G. Koutsoukos","doi":"10.3390/cryst14080675","DOIUrl":"https://doi.org/10.3390/cryst14080675","url":null,"abstract":"Phosphorus, P, is a vital element of paramount importance for both humans and for the Environment. Wastewater contains often relatively high concentrations of P which can be recovered as crystalline struvite (MgNH4PO4·6H2O, MAP). This option is quite attractive in assisting sustainable development because struvite can be used as a slow-release fertilizer. Domestic wastewater is usually high in P and nitrogen, N, but relatively poor in magnesium, Mg. It is necessary to develop low-cost solutions for the enrichment of wastewater with Mg. In the present work, sacrificial magnesium anodes were used, which dissolve upon anodic polarization, releasing sufficient magnesium for the selective precipitation of MAP. The application of constant current between two electrodes of which the anode is a low-cost magnesium cylindrical rod (4 cm2 exposed surface area) and the other a platinum cathode electrode, both immersed in ammonium phosphate solutions, without adjustment of the solution pH, was investigated. Constant current density over the range 10–100 A·m−2, between the Mg- Pt electrodes immersed in solutions of ammonium hydrogen phosphate of exactly known initial concentration, was applied using a potentiostat. In the presence of sodium chloride solutions, on the magnesium anode and in the bulk solution, Mg(OH)2 (brucite) formed because of the passivation of the Mg electrode. In dilute ammonium hydrogen phosphate solutions, the magnesium anode dissolution resulted in struvite precipitation, even at a low applied current (10 mA). Struvite crystals with an average size of 20 μm were precipitated. The behavior of the cell for the electrolyte solutions used was Faradaic as long as the surface coverage of the anode was relatively low. The anodic dissolution of Mg resulted in high pH values (pH 11) eliminating the need for alkali addition.","PeriodicalId":10855,"journal":{"name":"Crystals","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141775025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A Visualized Microstructure Evolution Model Integrating an Analytical Cutting Model with a Cellular Automaton Method during NiTi Smart Alloy Machining 镍钛智能合金加工过程中的可视化微结构演变模型，将分析切削模型与细胞自动机方法相结合

IF 2.7 4区材料科学

Crystals Pub Date : 2024-07-23 DOI: 10.3390/cryst14080672

Jiaqi Wang, Ming Li, Qingguang Li, Xianchao Pan, Zixuan Wang, Jing Jia, Renti Liu, Yunguang Zhou, Lianjie Ma, Tianbiao Yu

{"title":"A Visualized Microstructure Evolution Model Integrating an Analytical Cutting Model with a Cellular Automaton Method during NiTi Smart Alloy Machining","authors":"Jiaqi Wang, Ming Li, Qingguang Li, Xianchao Pan, Zixuan Wang, Jing Jia, Renti Liu, Yunguang Zhou, Lianjie Ma, Tianbiao Yu","doi":"10.3390/cryst14080672","DOIUrl":"https://doi.org/10.3390/cryst14080672","url":null,"abstract":"In this study, a visualized microstructure evolution model for the primary shear zone during NiTi smart alloy machining was established by integrating an analytical cutting model with a cellular automaton method. Experimental verification was conducted using an invented electromagnet rotation-type quick-stop device. The flow stress curve during the dynamic recrystallization of the NiTi smart alloy, the influence of relevant parameters on the dynamic recrystallization process, and the distribution of dynamic recrystallization in the primary shear zone were studied via the model. The simulation results showed that strain rate and deformation temperature significantly affect the relevant parameters during the dynamic recrystallization process. Three typical shear planes were selected for a comparison between simulation results and experimental results, with a minimum error of 3.76% and a maximum error of 11.26%, demonstrating that the model accurately simulates the microstructure evolution of the NiTi smart alloy during the cutting process. These results contribute theoretical and experimental insights into understanding the cutting mechanism of the NiTi smart alloy.","PeriodicalId":10855,"journal":{"name":"Crystals","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141775034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0