A micromechanism in an atomic level of crystallization of transition metal-metalloid TM(80)M(20) metallic glass is thermodynamically proposed by taking Bernal polyhedra as the starting structure of metallic glass. It ...A micromechanism in an atomic level of crystallization of transition metal-metalloid TM(80)M(20) metallic glass is thermodynamically proposed by taking Bernal polyhedra as the starting structure of metallic glass. It is composed of two competitively processes: (i) densification process of atom cluster leads to the formation of the precursor in amorphous matrix; (ii) the growth of atom cluster leads to the decreasing packing density. The preferential precipitation sequence of metastable phase is bcc, bet, cpc (close-packed crystal, hcp or fee structure). A metastable phase decomposition (Fe,Mo)(23)B-6 (fcc)-Fe2B highly strained bet phase was observed during crystallization of (Fe(0.99)M(0.01))(78)Si9B13 metallic glass, which is related to the occurrence of nanocrystalline.展开更多
The structure and processes of nickel induced lateral crystallization are studied.The structure of metal induced lateral crystallization(MILC) is improved by opening a seed window on the buried oxide,which is helpfu t...The structure and processes of nickel induced lateral crystallization are studied.The structure of metal induced lateral crystallization(MILC) is improved by opening a seed window on the buried oxide,which is helpfu to get superior quality of large grain poly Si at low temperature.By optimizing the temperature and time of annealing based on others' pervious work,the large grain poly Si with few defects are obtained,and the typical grain size is 70~80μm.The methods of etching NiSi 2 which is created after the long time annealing are also studied for the first time.Finally,a method is successfully chosen to reduce the possible contamination of Ni and to guarantee the MILC for the submicron VLSI application.展开更多
With transition metal complex, a discrete cuprous iodide compound, namely, [Ni(phen)3]2Cu6I10(1, phen = 1,10-phenanthroline) has been solvothermally synthesized and structurally characterized. Single-crystal X-ray...With transition metal complex, a discrete cuprous iodide compound, namely, [Ni(phen)3]2Cu6I10(1, phen = 1,10-phenanthroline) has been solvothermally synthesized and structurally characterized. Single-crystal X-ray diffraction studies revealed that compound 1 crystallizes in triclinic space group P1(No. 2) with a = 11.2694(2), b = 12.3699(3), c = 15.0387(3) ?, α = 102.840(2), β = 105.215(2), γ = 96.388(2)°, V = 1940.04(7) ^3, Z = 1, Dc = 2.438 g·cm^-3, F(000) = 1324, R = 0.0256 and w R = 0.0555(I 〉 2σ(I)). Compound 1 features a discrete anionic moiety of [Cu6I10]^4- charge-balanced by two metal complexes of [Ni(phen)3]2+. The optical absorption edge of compound 1 was estimated to be 2.24 eV. Interestingly, nearly 95% of contaminant(crystal violet aqueous solution(CV), 50 m L, 1.0 × 10^-5 M) could be decolorized after exposure to visible light within 30 min, illustrating an impressive photocatalytic activity of compound 1. The thermal stability of 1 has also been studied.展开更多
A novel zinc complex [Zn(BIB)(bdc)]n(1, BIB = 1,3-bis(imidazol-1-yl)benzene, bdc = 1,3-benzenedicarboxylate) has been synthesized in solvothermal conditions. The title complex was characterized by elemental an...A novel zinc complex [Zn(BIB)(bdc)]n(1, BIB = 1,3-bis(imidazol-1-yl)benzene, bdc = 1,3-benzenedicarboxylate) has been synthesized in solvothermal conditions. The title complex was characterized by elemental analysis, IR spectra, thermal analysis, single-crystal and powder X-ray diffraction. The result proved that the alliance of BIB and aromatic carboxylic acids is good for the diversity of getatable structure. Complex 1 crystallizes in the monoclinic system of P2/c space group with a = 11.5591(10), b = 9.6239(8), c = 33.727(3)A, β = 103.816(3)°, V = 3643.4(5) A^3, Z = 8, μ = 1.385 mm^-1, F(000) = 1792, Dc = 1.603 g/cm^3 and Mr = 439.72 g/mol. Additionally, luminescent properties of complex 1 are also investigated and it shows good fluorescence.展开更多
This paper investigates a simplified metal induced crystallization (MIC) of a-Si, named solution-based MIC (SMIC). The nickel inducing source was formed on a-Si from salt solution dissolved in de-ionized water or ...This paper investigates a simplified metal induced crystallization (MIC) of a-Si, named solution-based MIC (SMIC). The nickel inducing source was formed on a-Si from salt solution dissolved in de-ionized water or ethanol, a-Si thin film was deposited with low pressure chemical vapour deposition or plasma enhanced chemical vapour deposition as precursor material for MIC. It finds that the content of nickel source formed on a-Si can be controlled by solution concentration and dipping time. The dependence of crystallization rate of a-Si on annealing time illustrated that the linear density of nickel source was another critical factor that affects the crystallization of a-Si, besides the diffusion of nickel disilicide. The highest electron Hall mobility of thus prepared S-MIC poly-Si is 45.6 cm^2/(V· s). By using this S-MIC poly-Si, thin film transistors and display scan drivers were made, and their characteristics are presented.展开更多
The inclusion crystal formed by the hexamethylenamine with p-nitrophenol has a layer type structure,and is divided or- ganic layer and inorganic layer,the latter has a width of 1.0136nm.Metal ions can enter hydrated ...The inclusion crystal formed by the hexamethylenamine with p-nitrophenol has a layer type structure,and is divided or- ganic layer and inorganic layer,the latter has a width of 1.0136nm.Metal ions can enter hydrated layer of the crystal,the con- tents of the cations and water in the crystal are determined.The XRD analysis of the layer type structure of the crystal is also giv- en.展开更多
The crystal structure of the title complex salt has been determined by single-crystal X-ray structure analysis. The crystal data are as follows; Monoclinic, P21/c, a=15.6480(10)A,b=16.7870(10)A, c=10.347(2)A, β=90.79...The crystal structure of the title complex salt has been determined by single-crystal X-ray structure analysis. The crystal data are as follows; Monoclinic, P21/c, a=15.6480(10)A,b=16.7870(10)A, c=10.347(2)A, β=90.790(10), V=2717.7(6)A3, Z=3, and R=0.0333 for 4789 unique reflections. The complex anion has a pseudo-octahedral structure distorted more than the CrⅢand CoⅢ analogs, in which cach iminodiacetato ligand (ida2-) is coordinated in a facial fashion with the two N atoms in a cis configuration, resulting in an unsyin-fac structure.展开更多
This paper deals with the technology of computer graphics and its application in ana-lyzing complex nonlinear proceas. We have investigated metal crystallization, which is a complexnonlinear process and is difficult t...This paper deals with the technology of computer graphics and its application in ana-lyzing complex nonlinear proceas. We have investigated metal crystallization, which is a complexnonlinear process and is difficult to analyze by using the conventional numerical rnethod to estab-lish a complete and accurate mathematical modcl. Based on the principles of metal crystallizationand Cellular Automata algorithm, the author separated, in time and space, the process ofccystailization into periodically growing airays, so that the simulation of metal crystallization isrealized.展开更多
Process of crystal growth can be controlled by both surface kinetics and by volume transport as well.Although the complicated relation between the surface kinetics and volume transport exsits,generally,they are studie...Process of crystal growth can be controlled by both surface kinetics and by volume transport as well.Although the complicated relation between the surface kinetics and volume transport exsits,generally,they are studied seprately.Due to the mathematical complexity of heat and mass transport equations,the in depth studies of heat and mass transport process become difficult.Most of the studies on the transport were performed for the growth from melt.Most of the work on Surface kinetics has been done for crystal growth from aqueous solution because the in situ observation of crystal growth is easily carried out.In recent years,the surface kinetics studies on the nanometer scale,even atomic scale,are demonstrated by using AFM.展开更多
The effect of electropulsing treatment(EPT)on the microstructure of a Ti-based bulk metallic glass(BMG)has been studied.The maximum current density applied during EPT can exert a crucial role on tuning the microst...The effect of electropulsing treatment(EPT)on the microstructure of a Ti-based bulk metallic glass(BMG)has been studied.The maximum current density applied during EPT can exert a crucial role on tuning the microstructure of the BMG.When the maximum current density is no more than 2 720A/mm^2,the samples retains amorphous nature,whereas,beyond that,crystalline phases precipitate from the glassy matrix.During EPT,the maximum temperature within the samples EPTed at the maximum current densities larger than 2 720A/mm^2 is higher than the crystallization temperature of the BMG,leading to the crystallization event.展开更多
The hydrothermal reaction of 5-methoxyisophthalic acid(MeO-H2ip), 1,3-bis(2-methylimidazol-1-yl)propane(bmip) and Zn(NO3)2·6H2O in the presence of NaOCH3 gave rise to a three-dimensional(3-D) metal-orga...The hydrothermal reaction of 5-methoxyisophthalic acid(MeO-H2ip), 1,3-bis(2-methylimidazol-1-yl)propane(bmip) and Zn(NO3)2·6H2O in the presence of NaOCH3 gave rise to a three-dimensional(3-D) metal-organic framework containing octanuclear Zn(II) units, [Zn4(MeO-ip)3(OH)2(bmip)]n. Single-crystal X-ray diffraction analysis reveals that the complex crystallizes in the triclinic space group P1 with a = 11.348(3), b = 14.163(4), c = 15.088(4) , α = 108.537(2), β = 106.542(2), γ = 103.106(1)o, V = 2065.4(9) -3, Z = 2, Mr = 334.62, Dc = 1.740 g·cm-(-3), μ = 2.375 mm-(-1), S = 1.015, F(000) = 1096, the final R = 0.0272 and w R = 0.0715 for 8929 observed reflections(I 〉 2σ(I)). The complex is thermally stable up to 370 oC, and exhibits photoluminescent emission at 450 nm on 350 nm excitation.展开更多
We propose and demonstrate a pseudo Fabry–Pérot filter in the terahertz frequency range of 0.1–0.5 THz. It consists of alternative liquid crystal layers and metallic slats. Separate sharp resonant peaks are sho...We propose and demonstrate a pseudo Fabry–Pérot filter in the terahertz frequency range of 0.1–0.5 THz. It consists of alternative liquid crystal layers and metallic slats. Separate sharp resonant peaks are shown in the simulated transmission spectra, and their positions shift toward higher frequencies when the refractive index of liquid crystal decreases. The measured transmission spectra are consistent with corresponding simulations. Via thermally tuning the refractive index of the filled liquid crystal, the resonant transmission frequencies shift accordingly. The work supplies a novel design for tunable terahertz filters, which would play important roles in terahertz imaging, sensing, high speed communication, and security applications.展开更多
A dynamic phosphor-silicate glass (PSG) gettering method is proposed in which the processes of the gettering of Ni by PSC and the crystallizing of α-Si into poly-Si by Ni take place simultaneously. The effects of P...A dynamic phosphor-silicate glass (PSG) gettering method is proposed in which the processes of the gettering of Ni by PSC and the crystallizing of α-Si into poly-Si by Ni take place simultaneously. The effects of PSC gettering process on the performances of solution-based metal induced crystallized (S-MIC) poly-Si materials and their thin film transistors (TFTs) are discussed. The crystallization rate is much reduced due to the fact that the Ni as a medium source of crystallization is extracted by the PSC during crystallization at the same time. The boundary between two neighbouring grains in S-MIC poly-Si with PSG looks blurrier than without PSG. Compared with the TFTs made from S-MIC poly-Si without PSC gettering, the TFTs made with PSC gettering has a reduced gate induced leakage current.展开更多
The structural evolution of Cu_(45)Zr_(45)Ag_(10) metallic glass was investigated by in situ transmission electron microscopy heating experiments. The relationship between phase separation and crystallization wa...The structural evolution of Cu_(45)Zr_(45)Ag_(10) metallic glass was investigated by in situ transmission electron microscopy heating experiments. The relationship between phase separation and crystallization was elucidated. Nucleation and growth-controlled nanoscale phase separation at early stage were seen to impede nanocrystallization, while a coarser phase separation via aggregation of Ag-rich nanospheres was found to promote the precipitation of Cu-rich nanocrystals.Coupling of composition and dynamics heterogeneities was supposed to play a key role during phase separation preceding crystallization.展开更多
We present a both theoretical and experimental investigation into the effect of array periodicity on the filtering characteristics of metal/dielectric photonic crystals(MDPhCs) with hexagonal arrays of subwavelength...We present a both theoretical and experimental investigation into the effect of array periodicity on the filtering characteristics of metal/dielectric photonic crystals(MDPhCs) with hexagonal arrays of subwavelength holes in gold/silicon dioxide films,varying the array periodicity from 6 to 8μm every 1μm while the ratio of hole radius to array periodicity is kept constant(1/4).The results indicate that the reflectance spectrum is highly dependent on the array periodicity.When the array periodicity increases,the reflectance spectrum exhibits a large redshift regularly.The finite difference time domain(FDTD) simulations agree well with the experimental results. By analyzing the relationship between the position of the reflectance minimum and the array periodicity,we find that the filtering characteristics of MDPhCs have an almost linear relationship with the array periodicity under the conditions of keeping the same ratio of hole radius to array periodicity(1/4).This finding provides an effective way to control the filtering characteristics of MDPhCs,which have potential applications in optical filters,plasmonic thermal emitters and so on.展开更多
The functionalized calix[4]pyrrole meso-substituted Schiff bases were conveniently prepared by four- step synthetic route. Furthermore, the nickel and copper complexes of calix[4]pyrrole meso-substituted Schiff base w...The functionalized calix[4]pyrrole meso-substituted Schiff bases were conveniently prepared by four- step synthetic route. Furthermore, the nickel and copper complexes of calix[4]pyrrole meso-substituted Schiff base with 1:2 stoichiometry were obtained. The crystal structures of the calix[4]pyrroles and their metal complexes were determined by X-ray diffraction.展开更多
An efficient method for the synthesis of some difunctionalized copillar[5]arene Schiff bases from condensation of salicylaldehyde and its 5-chloro,5-bromo,3,5-di(t-butyl) substituted derivatives with corresponding d...An efficient method for the synthesis of some difunctionalized copillar[5]arene Schiff bases from condensation of salicylaldehyde and its 5-chloro,5-bromo,3,5-di(t-butyl) substituted derivatives with corresponding diamino-functionalized copillar[5]arene,which were prepared by Gabriel reaction according to the reported method.Single-crystals of six copillar[5]arenes were determined by X-ray diffraction.An ORTEP of compounds showed that the two chains units of Schiff base exist in the outside of the cavity of pillar[5]arene.Furthermore,the complexing ability of these Schiff bases to transition metal ions were investigated by UV and fluorescence spectroscopy.展开更多
There are limited studies in the literature about machinability of bulk metallic glass (BMG). As a novel and promising structural material, BMG material machining characteristics need to be verified before its utili...There are limited studies in the literature about machinability of bulk metallic glass (BMG). As a novel and promising structural material, BMG material machining characteristics need to be verified before its utilization. In this paper, the effects of cutting speed, feed rate, depth of cut, abrasive particle size/type on the BMG grinding in dry conditions were experimentally investigated. The experimental evaluations were carried out using cubic boron nitride (CBN) and A1203 cup wheel grinding tools. The parameters were evaluated along with the results of cutting force, temperature and surface roughness measurements, X-ray, scanning electron microscope (SEM) and surface roughness analyse. The results demonstrated that the grinding forces reduced with the increasing cutting speed as specific grinding energy increased. The effect of feed rate was opposite to the cutting speed effect, and increasing feed rate caused higher grinding forces and substantially lower specific energy. Some voids like cracks parallel to the grinding direction were observed at the edge of the grinding tracks. The present investigations on ground surface and grinding chips morphologies showed that material removal and surface formation of the BMG were mainly due to the ductile chip formation and ploughing as well as brittle fracture of some particles from the edge of the tracks. The roughness values obtained with the CBN wheels were found to be acceptable for the grinding operation of the structural materials and were in the rangeof 0.34-0.58 lam. This study also demonstrates that con- ventional A1203 wheel is not suitable for grinding of the BMG in dry conditions.展开更多
Developing efficient separation materials for recovering metal resources from aqueous environments is crucial for the sustainable water–food–energy nexus,which addresses the interdependence between energy production...Developing efficient separation materials for recovering metal resources from aqueous environments is crucial for the sustainable water–food–energy nexus,which addresses the interdependence between energy production,water production,and energy consumption.Various material-based separation processes have demonstrated outstanding performance.However,electric energy and chemicals are used to frequently replace the separation materials used in such processes owing to their short life span.This study presents a methodology for designing the self-regenerable fiber(SRF)according to the types of metals through a self-regeneration model.The SRF can semi-permanently recover the metal resources from water through a repetitive adsorption–crystallization–detachment process of metal ions on its surface.The ionic metal resources are adsorbed and crystallized with the counter-anions on the SRF surface.Next,the metal crystals are self-detached from the SRF surface by the collision between the crystals and curvature and non-sticky surface of the SRF.Thus,a module containing the SRF maintains its metal recovery capability even during continuous injection of the metal solution without its replacement.These findings highlight the significance of interfacial engineering and further guide the rational design of energy/environmentally friendly resource recovery modules.展开更多
A novel interesting d^(10) metal hybrid, [1,2-C_6H_(10)(NH_3)_2]ZnCl_4; 1,2-diammoniumcyclohexane tetrachlorozincate(II) was grown, structurally characterized and their vibrational as well as thermal and diele...A novel interesting d^(10) metal hybrid, [1,2-C_6H_(10)(NH_3)_2]ZnCl_4; 1,2-diammoniumcyclohexane tetrachlorozincate(II) was grown, structurally characterized and their vibrational as well as thermal and dielectric proprieties were studied. A preliminary single crystal X-ray diffraction structural analysis has revealed that the latter crystallizes in the monoclinic system(space group C2/c). Its unit cell dimensions are a = 32.394(9) ?, b = 12.217(4) ?, c = 10.175(3) ?, β = 97.852(13)° with Z = 12 and the refinement converged to R = 0.034 and ωR = 0.065. Hirshfeld surface analyses, especially d_(norm)surface and fingerprint plots were used for decoding intermolecular interactions in the crystal network. The optimized geometric parameters, normal mode frequencies and corresponding vibrational assignments of the present compound were theoretically examined by the DFT/B3 LYP method with the Lan L2 DZ basis set. The thermal and dielectric analyses suggested the presence of ferroelectric phase transition at 314 K.展开更多
文摘A micromechanism in an atomic level of crystallization of transition metal-metalloid TM(80)M(20) metallic glass is thermodynamically proposed by taking Bernal polyhedra as the starting structure of metallic glass. It is composed of two competitively processes: (i) densification process of atom cluster leads to the formation of the precursor in amorphous matrix; (ii) the growth of atom cluster leads to the decreasing packing density. The preferential precipitation sequence of metastable phase is bcc, bet, cpc (close-packed crystal, hcp or fee structure). A metastable phase decomposition (Fe,Mo)(23)B-6 (fcc)-Fe2B highly strained bet phase was observed during crystallization of (Fe(0.99)M(0.01))(78)Si9B13 metallic glass, which is related to the occurrence of nanocrystalline.
文摘The structure and processes of nickel induced lateral crystallization are studied.The structure of metal induced lateral crystallization(MILC) is improved by opening a seed window on the buried oxide,which is helpfu to get superior quality of large grain poly Si at low temperature.By optimizing the temperature and time of annealing based on others' pervious work,the large grain poly Si with few defects are obtained,and the typical grain size is 70~80μm.The methods of etching NiSi 2 which is created after the long time annealing are also studied for the first time.Finally,a method is successfully chosen to reduce the possible contamination of Ni and to guarantee the MILC for the submicron VLSI application.
基金Supported by the NNSFC(No.21373223)Chunmiao project of Haixi Institute of Chinese Academy of Sciences(CMZX-2014-001)
文摘With transition metal complex, a discrete cuprous iodide compound, namely, [Ni(phen)3]2Cu6I10(1, phen = 1,10-phenanthroline) has been solvothermally synthesized and structurally characterized. Single-crystal X-ray diffraction studies revealed that compound 1 crystallizes in triclinic space group P1(No. 2) with a = 11.2694(2), b = 12.3699(3), c = 15.0387(3) ?, α = 102.840(2), β = 105.215(2), γ = 96.388(2)°, V = 1940.04(7) ^3, Z = 1, Dc = 2.438 g·cm^-3, F(000) = 1324, R = 0.0256 and w R = 0.0555(I 〉 2σ(I)). Compound 1 features a discrete anionic moiety of [Cu6I10]^4- charge-balanced by two metal complexes of [Ni(phen)3]2+. The optical absorption edge of compound 1 was estimated to be 2.24 eV. Interestingly, nearly 95% of contaminant(crystal violet aqueous solution(CV), 50 m L, 1.0 × 10^-5 M) could be decolorized after exposure to visible light within 30 min, illustrating an impressive photocatalytic activity of compound 1. The thermal stability of 1 has also been studied.
基金supported by grants from Provincial Key Projects of Anhui Natural Science Research in Universities(No.KJ2015A203)the Natural Science Foundation of Anhui Province(No.1408085MB40)Projects of Anhui Key Laboratory of Spin Electron and Nanomaterials,Suzhou University(No.2014YKF51)
文摘A novel zinc complex [Zn(BIB)(bdc)]n(1, BIB = 1,3-bis(imidazol-1-yl)benzene, bdc = 1,3-benzenedicarboxylate) has been synthesized in solvothermal conditions. The title complex was characterized by elemental analysis, IR spectra, thermal analysis, single-crystal and powder X-ray diffraction. The result proved that the alliance of BIB and aromatic carboxylic acids is good for the diversity of getatable structure. Complex 1 crystallizes in the monoclinic system of P2/c space group with a = 11.5591(10), b = 9.6239(8), c = 33.727(3)A, β = 103.816(3)°, V = 3643.4(5) A^3, Z = 8, μ = 1.385 mm^-1, F(000) = 1792, Dc = 1.603 g/cm^3 and Mr = 439.72 g/mol. Additionally, luminescent properties of complex 1 are also investigated and it shows good fluorescence.
基金supported by Key Project of National Natural Science Foundation of China (Grant No 60437030)"863" Project of National Ministry of Science and Technology of China (Grant No 2004AA33570)Tianjin Natural Science Foundation of China (Grant No 05YFJMJC01400)
文摘This paper investigates a simplified metal induced crystallization (MIC) of a-Si, named solution-based MIC (SMIC). The nickel inducing source was formed on a-Si from salt solution dissolved in de-ionized water or ethanol, a-Si thin film was deposited with low pressure chemical vapour deposition or plasma enhanced chemical vapour deposition as precursor material for MIC. It finds that the content of nickel source formed on a-Si can be controlled by solution concentration and dipping time. The dependence of crystallization rate of a-Si on annealing time illustrated that the linear density of nickel source was another critical factor that affects the crystallization of a-Si, besides the diffusion of nickel disilicide. The highest electron Hall mobility of thus prepared S-MIC poly-Si is 45.6 cm^2/(V· s). By using this S-MIC poly-Si, thin film transistors and display scan drivers were made, and their characteristics are presented.
基金This work is supported by the Excellent Young Tcachers Foundation the State Education Commission of China
文摘The inclusion crystal formed by the hexamethylenamine with p-nitrophenol has a layer type structure,and is divided or- ganic layer and inorganic layer,the latter has a width of 1.0136nm.Metal ions can enter hydrated layer of the crystal,the con- tents of the cations and water in the crystal are determined.The XRD analysis of the layer type structure of the crystal is also giv- en.
文摘The crystal structure of the title complex salt has been determined by single-crystal X-ray structure analysis. The crystal data are as follows; Monoclinic, P21/c, a=15.6480(10)A,b=16.7870(10)A, c=10.347(2)A, β=90.790(10), V=2717.7(6)A3, Z=3, and R=0.0333 for 4789 unique reflections. The complex anion has a pseudo-octahedral structure distorted more than the CrⅢand CoⅢ analogs, in which cach iminodiacetato ligand (ida2-) is coordinated in a facial fashion with the two N atoms in a cis configuration, resulting in an unsyin-fac structure.
文摘This paper deals with the technology of computer graphics and its application in ana-lyzing complex nonlinear proceas. We have investigated metal crystallization, which is a complexnonlinear process and is difficult to analyze by using the conventional numerical rnethod to estab-lish a complete and accurate mathematical modcl. Based on the principles of metal crystallizationand Cellular Automata algorithm, the author separated, in time and space, the process ofccystailization into periodically growing airays, so that the simulation of metal crystallization isrealized.
文摘Process of crystal growth can be controlled by both surface kinetics and by volume transport as well.Although the complicated relation between the surface kinetics and volume transport exsits,generally,they are studied seprately.Due to the mathematical complexity of heat and mass transport equations,the in depth studies of heat and mass transport process become difficult.Most of the studies on the transport were performed for the growth from melt.Most of the work on Surface kinetics has been done for crystal growth from aqueous solution because the in situ observation of crystal growth is easily carried out.In recent years,the surface kinetics studies on the nanometer scale,even atomic scale,are demonstrated by using AFM.
基金Item Sponsored by National Natural Science Foundation of China(51371065)Postdoctoral Science-Research Developmental Foundation of Heilongjiang Province of China(LBH-Q12073)
文摘The effect of electropulsing treatment(EPT)on the microstructure of a Ti-based bulk metallic glass(BMG)has been studied.The maximum current density applied during EPT can exert a crucial role on tuning the microstructure of the BMG.When the maximum current density is no more than 2 720A/mm^2,the samples retains amorphous nature,whereas,beyond that,crystalline phases precipitate from the glassy matrix.During EPT,the maximum temperature within the samples EPTed at the maximum current densities larger than 2 720A/mm^2 is higher than the crystallization temperature of the BMG,leading to the crystallization event.
基金supported by the Natural Science Foundation of Fujian Province(2015J01038)Provincial Education Department of Fujian(JA12070)State Key Laboratory of Structural Chemistry(20150015)
文摘The hydrothermal reaction of 5-methoxyisophthalic acid(MeO-H2ip), 1,3-bis(2-methylimidazol-1-yl)propane(bmip) and Zn(NO3)2·6H2O in the presence of NaOCH3 gave rise to a three-dimensional(3-D) metal-organic framework containing octanuclear Zn(II) units, [Zn4(MeO-ip)3(OH)2(bmip)]n. Single-crystal X-ray diffraction analysis reveals that the complex crystallizes in the triclinic space group P1 with a = 11.348(3), b = 14.163(4), c = 15.088(4) , α = 108.537(2), β = 106.542(2), γ = 103.106(1)o, V = 2065.4(9) -3, Z = 2, Mr = 334.62, Dc = 1.740 g·cm-(-3), μ = 2.375 mm-(-1), S = 1.015, F(000) = 1096, the final R = 0.0272 and w R = 0.0715 for 8929 observed reflections(I 〉 2σ(I)). The complex is thermally stable up to 370 oC, and exhibits photoluminescent emission at 450 nm on 350 nm excitation.
基金supported by the National Natural Science Foundation of China(Nos.11304151,61490714,61435008,and 61575093)the Ph.D.Programs Foundation of the Ministry of Education of China(No.20120091120020)the Fundamental Research Funds for the Central Universities(Nos.021314380020 and 021314380023)
文摘We propose and demonstrate a pseudo Fabry–Pérot filter in the terahertz frequency range of 0.1–0.5 THz. It consists of alternative liquid crystal layers and metallic slats. Separate sharp resonant peaks are shown in the simulated transmission spectra, and their positions shift toward higher frequencies when the refractive index of liquid crystal decreases. The measured transmission spectra are consistent with corresponding simulations. Via thermally tuning the refractive index of the filled liquid crystal, the resonant transmission frequencies shift accordingly. The work supplies a novel design for tunable terahertz filters, which would play important roles in terahertz imaging, sensing, high speed communication, and security applications.
基金Project supported by the National High Technology Research and Developments Program of China (Grant No 004AA33570)Key Project of National Natural Science Foundation of China (NSFC) (Grant No 60437030)Tianjin Natural Science Foundation(Grant No 05YFJMJC01400)
文摘A dynamic phosphor-silicate glass (PSG) gettering method is proposed in which the processes of the gettering of Ni by PSC and the crystallizing of α-Si into poly-Si by Ni take place simultaneously. The effects of PSC gettering process on the performances of solution-based metal induced crystallized (S-MIC) poly-Si materials and their thin film transistors (TFTs) are discussed. The crystallization rate is much reduced due to the fact that the Ni as a medium source of crystallization is extracted by the PSC during crystallization at the same time. The boundary between two neighbouring grains in S-MIC poly-Si with PSG looks blurrier than without PSG. Compared with the TFTs made from S-MIC poly-Si without PSC gettering, the TFTs made with PSC gettering has a reduced gate induced leakage current.
基金supported by the National Natural Science Foundation of China (Grant No. 51101004)the financial support of China Scholarship Council. Z.Q. Liu is gratefulsupport by the IMR SYNL-T.S. Kê Research Fellowship
文摘The structural evolution of Cu_(45)Zr_(45)Ag_(10) metallic glass was investigated by in situ transmission electron microscopy heating experiments. The relationship between phase separation and crystallization was elucidated. Nucleation and growth-controlled nanoscale phase separation at early stage were seen to impede nanocrystallization, while a coarser phase separation via aggregation of Ag-rich nanospheres was found to promote the precipitation of Cu-rich nanocrystals.Coupling of composition and dynamics heterogeneities was supposed to play a key role during phase separation preceding crystallization.
文摘We present a both theoretical and experimental investigation into the effect of array periodicity on the filtering characteristics of metal/dielectric photonic crystals(MDPhCs) with hexagonal arrays of subwavelength holes in gold/silicon dioxide films,varying the array periodicity from 6 to 8μm every 1μm while the ratio of hole radius to array periodicity is kept constant(1/4).The results indicate that the reflectance spectrum is highly dependent on the array periodicity.When the array periodicity increases,the reflectance spectrum exhibits a large redshift regularly.The finite difference time domain(FDTD) simulations agree well with the experimental results. By analyzing the relationship between the position of the reflectance minimum and the array periodicity,we find that the filtering characteristics of MDPhCs have an almost linear relationship with the array periodicity under the conditions of keeping the same ratio of hole radius to array periodicity(1/4).This finding provides an effective way to control the filtering characteristics of MDPhCs,which have potential applications in optical filters,plasmonic thermal emitters and so on.
基金financially supported by the National Natural Science Foundation of China (No.21172190)the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘The functionalized calix[4]pyrrole meso-substituted Schiff bases were conveniently prepared by four- step synthetic route. Furthermore, the nickel and copper complexes of calix[4]pyrrole meso-substituted Schiff base with 1:2 stoichiometry were obtained. The crystal structures of the calix[4]pyrroles and their metal complexes were determined by X-ray diffraction.
基金financially supported by the National Natural Science Foundation of China (Nos. 21172190, 21372192)the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘An efficient method for the synthesis of some difunctionalized copillar[5]arene Schiff bases from condensation of salicylaldehyde and its 5-chloro,5-bromo,3,5-di(t-butyl) substituted derivatives with corresponding diamino-functionalized copillar[5]arene,which were prepared by Gabriel reaction according to the reported method.Single-crystals of six copillar[5]arenes were determined by X-ray diffraction.An ORTEP of compounds showed that the two chains units of Schiff base exist in the outside of the cavity of pillar[5]arene.Furthermore,the complexing ability of these Schiff bases to transition metal ions were investigated by UV and fluorescence spectroscopy.
文摘There are limited studies in the literature about machinability of bulk metallic glass (BMG). As a novel and promising structural material, BMG material machining characteristics need to be verified before its utilization. In this paper, the effects of cutting speed, feed rate, depth of cut, abrasive particle size/type on the BMG grinding in dry conditions were experimentally investigated. The experimental evaluations were carried out using cubic boron nitride (CBN) and A1203 cup wheel grinding tools. The parameters were evaluated along with the results of cutting force, temperature and surface roughness measurements, X-ray, scanning electron microscope (SEM) and surface roughness analyse. The results demonstrated that the grinding forces reduced with the increasing cutting speed as specific grinding energy increased. The effect of feed rate was opposite to the cutting speed effect, and increasing feed rate caused higher grinding forces and substantially lower specific energy. Some voids like cracks parallel to the grinding direction were observed at the edge of the grinding tracks. The present investigations on ground surface and grinding chips morphologies showed that material removal and surface formation of the BMG were mainly due to the ductile chip formation and ploughing as well as brittle fracture of some particles from the edge of the tracks. The roughness values obtained with the CBN wheels were found to be acceptable for the grinding operation of the structural materials and were in the rangeof 0.34-0.58 lam. This study also demonstrates that con- ventional A1203 wheel is not suitable for grinding of the BMG in dry conditions.
基金the National R&D program through the National Research Foundation of Korea(NRF)funded by the Ministry of Science and ICT(MSIT)(No.2020M3H4A3106366 and RS-2023-00209565)by an institutional program grant(2E32442)From the Korea Institute of Science and Technology.
文摘Developing efficient separation materials for recovering metal resources from aqueous environments is crucial for the sustainable water–food–energy nexus,which addresses the interdependence between energy production,water production,and energy consumption.Various material-based separation processes have demonstrated outstanding performance.However,electric energy and chemicals are used to frequently replace the separation materials used in such processes owing to their short life span.This study presents a methodology for designing the self-regenerable fiber(SRF)according to the types of metals through a self-regeneration model.The SRF can semi-permanently recover the metal resources from water through a repetitive adsorption–crystallization–detachment process of metal ions on its surface.The ionic metal resources are adsorbed and crystallized with the counter-anions on the SRF surface.Next,the metal crystals are self-detached from the SRF surface by the collision between the crystals and curvature and non-sticky surface of the SRF.Thus,a module containing the SRF maintains its metal recovery capability even during continuous injection of the metal solution without its replacement.These findings highlight the significance of interfacial engineering and further guide the rational design of energy/environmentally friendly resource recovery modules.
文摘A novel interesting d^(10) metal hybrid, [1,2-C_6H_(10)(NH_3)_2]ZnCl_4; 1,2-diammoniumcyclohexane tetrachlorozincate(II) was grown, structurally characterized and their vibrational as well as thermal and dielectric proprieties were studied. A preliminary single crystal X-ray diffraction structural analysis has revealed that the latter crystallizes in the monoclinic system(space group C2/c). Its unit cell dimensions are a = 32.394(9) ?, b = 12.217(4) ?, c = 10.175(3) ?, β = 97.852(13)° with Z = 12 and the refinement converged to R = 0.034 and ωR = 0.065. Hirshfeld surface analyses, especially d_(norm)surface and fingerprint plots were used for decoding intermolecular interactions in the crystal network. The optimized geometric parameters, normal mode frequencies and corresponding vibrational assignments of the present compound were theoretically examined by the DFT/B3 LYP method with the Lan L2 DZ basis set. The thermal and dielectric analyses suggested the presence of ferroelectric phase transition at 314 K.