To resolve the strength-ductility trade-off problem for high-strength Mg alloys,we prepared a high performance Mg-8Gd-3Y-0.5 Zr(wt%)alloy with yield strength of 371 MPa,ultimate tensile strength of 419MPa and elongati...To resolve the strength-ductility trade-off problem for high-strength Mg alloys,we prepared a high performance Mg-8Gd-3Y-0.5 Zr(wt%)alloy with yield strength of 371 MPa,ultimate tensile strength of 419MPa and elongation of 15.8%.The processing route involves extrusion,pre-deformation and aging,which leads to a bimodal structure and nano-precipitates.Back-stress originated from the deformationincompatibility in the bimodal-structure alloy can improve ductility.In addition,dislocation density in coarse grains increased during the pre-deformation strain of 2%,and the dislocations in coarse grains can promote the formation of chain-like nano-precipitates during aging treatment.The chain-like nanoprecipitates can act as barriers for dislocations slip and the existing mobile dislocations enable good ductility.展开更多
Chain-like MoS2assemblies consisting of hexagonal MoS2nanoparticles(20-60 nm) have been successfully synthesized in a Triton X-100/cyclohexane/hexanol/water W/O reverse microemulsion in the presence of(NH 4)2MoS 4 as ...Chain-like MoS2assemblies consisting of hexagonal MoS2nanoparticles(20-60 nm) have been successfully synthesized in a Triton X-100/cyclohexane/hexanol/water W/O reverse microemulsion in the presence of(NH 4)2MoS 4 as the molybdenum source and NH2OH·HCl as the reducing agent.The products were characterized by X-ray powder diffraction(XRD),transmission electron microscopy(TEM) and UV-vis diffuse reflectance absorption spectra.The influence of synthetic parameters such as acidity,water/oil ratio(0),aging time and annealing temperature on the formation of MoS2assemblies was investigated.TEM analysis showed that these synthetic factors played important roles in controlling the size of MoS2nanoparticles and the length of the chain-like MoS2assemblies.XRD analysis indicated that the well-crystallized MoS2nanoparticles could be obtained by annealing the precursors at 700 C for2h under a flow of N2atmosphere.In addition,the as-prepared chain-like MoS2nanoparticles exhibited excellent photocatalytic H2activity in Ru(bpy) 3 2+-MoS2-H2A three-component molecular systems under visible light irradiation.展开更多
Gaining an understanding of the growth mechanism from single atoms to clusters and bulk materials continues to present a challenge.Thus,it is important to explore the evolving trends of clusters in the structure and p...Gaining an understanding of the growth mechanism from single atoms to clusters and bulk materials continues to present a challenge.Thus,it is important to explore the evolving trends of clusters in the structure and properties during the size evolution.In this work,we report the synthesis and characterization of two medium-sized chain-like polyarsenic anions.[As_(21)]^(3-)represents a trimeric example of polyarsenic anion assembled through oxidative coupling of As_(7)^(3-)anions.The anion As_(18)^(4-)included in[As_(18)MO_(2)(CO)_(8)]^(4-)is regarded as formed by two realgar-type As_(8)subunits connected by a dinuclear AsAs dumbbell.The As_(18)cluster was previously predicted by theory,and this is the first time successfully synthesized using wet chemistry method.Besides,small-sized polyarsenides As_(2)^(2-)and As_(10)^(2-)were found in compound[K(18-crown-6)]_(3)[As_(10)]_(0.5)[As_(4){Mo(CO)_(3)}_(2)]_(0.5)·2en.Among these,the former exhibits coordination with metal atoms.Single-crystal X-ray diffraction combined with quantum chemical calculations revealed the formation of double bonded As_(2)^(2-)stabilized by metal carbonyl groups.This work demonstrates a novel synthetic approach for the preparation of new polyarsenides and highlights their intriguing bonding characteristics,laying the foundation for the synthesis of such compounds and paving the way for their potential applications.展开更多
A simple process to fabricate chain-like carbon nanotube （CNT） films by microwave plasma-enhanced chemical vapor deposition （MPCVD） was developed successfully. Prior to deposition, the Ti/Al2O3 substrates were gro...A simple process to fabricate chain-like carbon nanotube （CNT） films by microwave plasma-enhanced chemical vapor deposition （MPCVD） was developed successfully. Prior to deposition, the Ti/Al2O3 substrates were ground with Fe-doped SiO2 powder. The nano-structure of the deposited films was analyzed by scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, and Raman spectroscopy. The field electron emission characteristics of the chain-like carbon nanotube films were measured under the vacuum of 10-5 Pa. The low turn-on field of 0.80 V/μm and the emission current density of 8.5 mA/cm2 at the electric field of 3.0 V/μm are obtained. Based on the above results, chain-like carbon nanotube films probably have important applications in cold cathode materials and electrode materials.展开更多
High-purity magnetic CoNi submicrospherical chains, each of length 20 μm - 30 μm and self-assembled from fcc-phase CoNi submicrospheres of average diameter 800 nm, are synthesized via a surfactant-assisted solvother...High-purity magnetic CoNi submicrospherical chains, each of length 20 μm - 30 μm and self-assembled from fcc-phase CoNi submicrospheres of average diameter 800 nm, are synthesized via a surfactant-assisted solvothermal route without the aid of nucleation agent. The effects of surfactant and reducing agent on the morphology and size of the CoNi chains are studied, and a possible growth mechanism for the CoNi chains is proposed. The CoNi chains show ferromagnetic characteristics with a similarly small saturation magnetization of 104.1 emu/g and a larger coercivity of 150 Oe at room temperature compared to the monodispersed CoNi submicrospheres of 105 emu/g and 34 Oe as a result of the increased shape anisotropy.展开更多
Chain-like zircona （ZrO2） nanofibers were prepared by microwave sinter- ing without any surfactants or solid templates. Microwave sintering was conducted in a multimode microwave cavity with TE666 resonant mode at 2...Chain-like zircona （ZrO2） nanofibers were prepared by microwave sinter- ing without any surfactants or solid templates. Microwave sintering was conducted in a multimode microwave cavity with TE666 resonant mode at 2.45 GHz. Carbon particles were used to activate unique thermal processes when mixed with ZrO2 precursor. The sintering condition was at 1300℃ for 10 min. Samples were characterized by XRD, SEM, TEM techniques. It was found that both monolithic and tetragonal ZrO2 co-existed in samples prepared from the mixture of ZrO2 precursors and carbon by either microwave or conventional sintering. Only m-ZrO2 exists in samples prepared by ZrO2 precursors without carbon. ZrO2 appeared as chain-like nanofibers, which might be attributed to a so- called carbon-induced self-assembly growth mechanism.展开更多
Using AFM,we observed linear chain-like complexes formed by some specific proteins and the multi-mRNAs during the in vitro expression of some active genes on the DNA fragments. The LDH mRNA in the multi-mRNA complex c...Using AFM,we observed linear chain-like complexes formed by some specific proteins and the multi-mRNAs during the in vitro expression of some active genes on the DNA fragments. The LDH mRNA in the multi-mRNA complex can in vitro translate LDH. Via AFM, we also discovered that nmRNA prepared from heart muscles, along with some specific proteins can form linear chain-like nmRNA complexes in which LDH mRNA can also translate LDH in vitro. Our work shows the prospective application of AFM in the research of the biological reaction of the active genes on the DNA fragments.展开更多
A new cerium polyoxomolybdate { [Ce （ H2 O） 7 Al （ OH ） 6 Mo6 O18 ] · 4H20 } （ compound 1 ） was synthesized and characterized by X-ray diffraction analysis, elemental analysis, TG analysis and IR spectromet...A new cerium polyoxomolybdate { [Ce （ H2 O） 7 Al （ OH ） 6 Mo6 O18 ] · 4H20 } （ compound 1 ） was synthesized and characterized by X-ray diffraction analysis, elemental analysis, TG analysis and IR spectrometry. Compound 1 exhibits a zigzag chain-like structure, which is constructed from an Anderson type anion and rare earth metal, Ce（ Ⅲ ）. These 1-D chains are further extended into a 3-D network by the aid of muhipoint hydrogen-bonding interactions.展开更多
A novel one-dimensional chain-like coordination polymer constructed from 3-nitrobenzene- 1,2-dicarboxylic acid, [Cd2（C8H3NO6）2（H2O）4]n·2nH2O, has been synthesized and its structure was determined by X-ray cry...A novel one-dimensional chain-like coordination polymer constructed from 3-nitrobenzene- 1,2-dicarboxylic acid, [Cd2（C8H3NO6）2（H2O）4]n·2nH2O, has been synthesized and its structure was determined by X-ray crystallography method. The crystal belongs to monoclinic, space group P21/c with a = 6.1252（8）, b = 20.706（3）, c = 8.8067（11）A, β = 95.608（2）^o, V = 1111.6（2）A^3, Mr = 751.12, De= 2.244 g/cm^3, F（000） = 736,μ = 2.011 mm^-1, Z= 2, the final R = 0.0262 and wR = 0.0692 for 2338 observed reflections with I 〉 2a（I）. The structure of the title compound presents a 1-D chain-like structure constructed by dimer units, [Cd2（C8H3NO6）2（H2O）4]n, through two carboxylate oxygen atoms. The fluorescence of the title compound has been also discussed in this paper.展开更多
A new organic-inorganic hybrid coordinated polymer [Zn(C8H23N5)]2(Pb3I10) (C8H23N5 = tetraethylene pentamine) was synthesized by hydrothermal reaction. It crystallizes in triclinic, space group P1 with a = 9.781(2), b...A new organic-inorganic hybrid coordinated polymer [Zn(C8H23N5)]2(Pb3I10) (C8H23N5 = tetraethylene pentamine) was synthesized by hydrothermal reaction. It crystallizes in triclinic, space group P1 with a = 9.781(2), b = 11.442(3), c = 11.565(3) ?, α = 99.075(8), β = 90.540(9), γ = 109.967(5)o, Zn2C16H46N10Pb3I10, Mr = 2399.94, V = 1198.4(5) ?3, Z = 1, Dc = 3.325 g/cm3, F(000) = 1048.0, μ(MoKα) = 17.951 mm-1, the final R = 0.0412 and wR = 0.0993 for 3375 observed reflections with I > 2σ(I). The title compound consists of [Zn(C8H23N5)]2+ cations and anionic chains [Pb3I10]n4n-, which are combined with each other via electrostatic attractive forces and N–H…I hydrogen bonds.展开更多
The chain-like prior particle boundaries(PPBs)as a kind of stubborn harmful precipitate will hinder atomic diffusion and particle connection.They can only be broken into nanoscale through thermal deformation(1160–120...The chain-like prior particle boundaries(PPBs)as a kind of stubborn harmful precipitate will hinder atomic diffusion and particle connection.They can only be broken into nanoscale through thermal deformation(1160–1200℃).Here,treated by the pulsed electric current at 800℃,PPBs were dissolved quickly as a result of the interaction between the pulsed electric current and the chain-like structure.According to the electromigration theory and the calculation results,the high current density regions will be mainly produced at the gaps due to the conductivity difference between the precipitates and the matrix.The atomic diffusion flux caused by the pulsed electric current is proportional to the current density.Therefore,the existence of a large number of gaps in the chain-like PPBs will make the high current density regions play a more positive role in fast-dissolution.展开更多
基金This work was supported financially by the National Key Research and Development Plan(No.2016YFB0301103)the National Natural Science Foundation of China(Nos.51771109 and 51631006)the Shanghai Rising-Star Program(No.16QB1402800).
文摘To resolve the strength-ductility trade-off problem for high-strength Mg alloys,we prepared a high performance Mg-8Gd-3Y-0.5 Zr(wt%)alloy with yield strength of 371 MPa,ultimate tensile strength of 419MPa and elongation of 15.8%.The processing route involves extrusion,pre-deformation and aging,which leads to a bimodal structure and nano-precipitates.Back-stress originated from the deformationincompatibility in the bimodal-structure alloy can improve ductility.In addition,dislocation density in coarse grains increased during the pre-deformation strain of 2%,and the dislocations in coarse grains can promote the formation of chain-like nano-precipitates during aging treatment.The chain-like nanoprecipitates can act as barriers for dislocations slip and the existing mobile dislocations enable good ductility.
基金supported by the National Natural Science Foundation of China (20803033)the National Basic Research Program of China(2009CB220010)+1 种基金the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministrythe Scientific Research Fund of Liaoning Provincial Education Department (L2010225)
文摘Chain-like MoS2assemblies consisting of hexagonal MoS2nanoparticles(20-60 nm) have been successfully synthesized in a Triton X-100/cyclohexane/hexanol/water W/O reverse microemulsion in the presence of(NH 4)2MoS 4 as the molybdenum source and NH2OH·HCl as the reducing agent.The products were characterized by X-ray powder diffraction(XRD),transmission electron microscopy(TEM) and UV-vis diffuse reflectance absorption spectra.The influence of synthetic parameters such as acidity,water/oil ratio(0),aging time and annealing temperature on the formation of MoS2assemblies was investigated.TEM analysis showed that these synthetic factors played important roles in controlling the size of MoS2nanoparticles and the length of the chain-like MoS2assemblies.XRD analysis indicated that the well-crystallized MoS2nanoparticles could be obtained by annealing the precursors at 700 C for2h under a flow of N2atmosphere.In addition,the as-prepared chain-like MoS2nanoparticles exhibited excellent photocatalytic H2activity in Ru(bpy) 3 2+-MoS2-H2A three-component molecular systems under visible light irradiation.
基金supported by the National Natural Science Foundation of China(Nos.92161102,21971118 to Z.-M.Sun)the Natural Science Foundation of Tianjin City(Nos.20JCYBJC01560 and 21JCZXJC00140 to Z.-M.Sun)+1 种基金the Fundamental Research Program of Shanxi Province(No.202203021222248)the Taiyuan Normal University College Students Science and Technology Innovation Project(No.CXCY2278)。
文摘Gaining an understanding of the growth mechanism from single atoms to clusters and bulk materials continues to present a challenge.Thus,it is important to explore the evolving trends of clusters in the structure and properties during the size evolution.In this work,we report the synthesis and characterization of two medium-sized chain-like polyarsenic anions.[As_(21)]^(3-)represents a trimeric example of polyarsenic anion assembled through oxidative coupling of As_(7)^(3-)anions.The anion As_(18)^(4-)included in[As_(18)MO_(2)(CO)_(8)]^(4-)is regarded as formed by two realgar-type As_(8)subunits connected by a dinuclear AsAs dumbbell.The As_(18)cluster was previously predicted by theory,and this is the first time successfully synthesized using wet chemistry method.Besides,small-sized polyarsenides As_(2)^(2-)and As_(10)^(2-)were found in compound[K(18-crown-6)]_(3)[As_(10)]_(0.5)[As_(4){Mo(CO)_(3)}_(2)]_(0.5)·2en.Among these,the former exhibits coordination with metal atoms.Single-crystal X-ray diffraction combined with quantum chemical calculations revealed the formation of double bonded As_(2)^(2-)stabilized by metal carbonyl groups.This work demonstrates a novel synthetic approach for the preparation of new polyarsenides and highlights their intriguing bonding characteristics,laying the foundation for the synthesis of such compounds and paving the way for their potential applications.
文摘A simple process to fabricate chain-like carbon nanotube （CNT） films by microwave plasma-enhanced chemical vapor deposition （MPCVD） was developed successfully. Prior to deposition, the Ti/Al2O3 substrates were ground with Fe-doped SiO2 powder. The nano-structure of the deposited films was analyzed by scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, and Raman spectroscopy. The field electron emission characteristics of the chain-like carbon nanotube films were measured under the vacuum of 10-5 Pa. The low turn-on field of 0.80 V/μm and the emission current density of 8.5 mA/cm2 at the electric field of 3.0 V/μm are obtained. Based on the above results, chain-like carbon nanotube films probably have important applications in cold cathode materials and electrode materials.
文摘High-purity magnetic CoNi submicrospherical chains, each of length 20 μm - 30 μm and self-assembled from fcc-phase CoNi submicrospheres of average diameter 800 nm, are synthesized via a surfactant-assisted solvothermal route without the aid of nucleation agent. The effects of surfactant and reducing agent on the morphology and size of the CoNi chains are studied, and a possible growth mechanism for the CoNi chains is proposed. The CoNi chains show ferromagnetic characteristics with a similarly small saturation magnetization of 104.1 emu/g and a larger coercivity of 150 Oe at room temperature compared to the monodispersed CoNi submicrospheres of 105 emu/g and 34 Oe as a result of the increased shape anisotropy.
基金The authors appreciate the financial support from the National Natural Science Foundation of China （Grant Nos. 51672254, 51602287 and 51402264） and the China Postdoctoral Science Foundation （Grant No. 2016M602266）.
文摘Chain-like zircona （ZrO2） nanofibers were prepared by microwave sinter- ing without any surfactants or solid templates. Microwave sintering was conducted in a multimode microwave cavity with TE666 resonant mode at 2.45 GHz. Carbon particles were used to activate unique thermal processes when mixed with ZrO2 precursor. The sintering condition was at 1300℃ for 10 min. Samples were characterized by XRD, SEM, TEM techniques. It was found that both monolithic and tetragonal ZrO2 co-existed in samples prepared from the mixture of ZrO2 precursors and carbon by either microwave or conventional sintering. Only m-ZrO2 exists in samples prepared by ZrO2 precursors without carbon. ZrO2 appeared as chain-like nanofibers, which might be attributed to a so- called carbon-induced self-assembly growth mechanism.
文摘Using AFM,we observed linear chain-like complexes formed by some specific proteins and the multi-mRNAs during the in vitro expression of some active genes on the DNA fragments. The LDH mRNA in the multi-mRNA complex can in vitro translate LDH. Via AFM, we also discovered that nmRNA prepared from heart muscles, along with some specific proteins can form linear chain-like nmRNA complexes in which LDH mRNA can also translate LDH in vitro. Our work shows the prospective application of AFM in the research of the biological reaction of the active genes on the DNA fragments.
文摘A new cerium polyoxomolybdate { [Ce （ H2 O） 7 Al （ OH ） 6 Mo6 O18 ] · 4H20 } （ compound 1 ） was synthesized and characterized by X-ray diffraction analysis, elemental analysis, TG analysis and IR spectrometry. Compound 1 exhibits a zigzag chain-like structure, which is constructed from an Anderson type anion and rare earth metal, Ce（ Ⅲ ）. These 1-D chains are further extended into a 3-D network by the aid of muhipoint hydrogen-bonding interactions.
基金Supported by the Project of Fujian Science & Technology Committee (2006F5067)National Natural Science Foundations of China(20705031)
文摘A novel one-dimensional chain-like coordination polymer constructed from 3-nitrobenzene- 1,2-dicarboxylic acid, [Cd2（C8H3NO6）2（H2O）4]n·2nH2O, has been synthesized and its structure was determined by X-ray crystallography method. The crystal belongs to monoclinic, space group P21/c with a = 6.1252（8）, b = 20.706（3）, c = 8.8067（11）A, β = 95.608（2）^o, V = 1111.6（2）A^3, Mr = 751.12, De= 2.244 g/cm^3, F（000） = 736,μ = 2.011 mm^-1, Z= 2, the final R = 0.0262 and wR = 0.0692 for 2338 observed reflections with I 〉 2a（I）. The structure of the title compound presents a 1-D chain-like structure constructed by dimer units, [Cd2（C8H3NO6）2（H2O）4]n, through two carboxylate oxygen atoms. The fluorescence of the title compound has been also discussed in this paper.
文摘A new organic-inorganic hybrid coordinated polymer [Zn(C8H23N5)]2(Pb3I10) (C8H23N5 = tetraethylene pentamine) was synthesized by hydrothermal reaction. It crystallizes in triclinic, space group P1 with a = 9.781(2), b = 11.442(3), c = 11.565(3) ?, α = 99.075(8), β = 90.540(9), γ = 109.967(5)o, Zn2C16H46N10Pb3I10, Mr = 2399.94, V = 1198.4(5) ?3, Z = 1, Dc = 3.325 g/cm3, F(000) = 1048.0, μ(MoKα) = 17.951 mm-1, the final R = 0.0412 and wR = 0.0993 for 3375 observed reflections with I > 2σ(I). The title compound consists of [Zn(C8H23N5)]2+ cations and anionic chains [Pb3I10]n4n-, which are combined with each other via electrostatic attractive forces and N–H…I hydrogen bonds.
基金financially supported by the National Natural Science Foundation of China(Nos.51874023 and U1860206)the Fundamental Research Funds for the Central Universities(FRF-TP20-02B)the Recruitment Program of Global Experts。
文摘The chain-like prior particle boundaries(PPBs)as a kind of stubborn harmful precipitate will hinder atomic diffusion and particle connection.They can only be broken into nanoscale through thermal deformation(1160–1200℃).Here,treated by the pulsed electric current at 800℃,PPBs were dissolved quickly as a result of the interaction between the pulsed electric current and the chain-like structure.According to the electromigration theory and the calculation results,the high current density regions will be mainly produced at the gaps due to the conductivity difference between the precipitates and the matrix.The atomic diffusion flux caused by the pulsed electric current is proportional to the current density.Therefore,the existence of a large number of gaps in the chain-like PPBs will make the high current density regions play a more positive role in fast-dissolution.
