The copper complexes of biuret have been synthesized by solid phase react ion with microwave irradiation. The compositions and structures of the complexes are characterized by elemental analysis, molar conductance, in...The copper complexes of biuret have been synthesized by solid phase react ion with microwave irradiation. The compositions and structures of the complexes are characterized by elemental analysis, molar conductance, infrared spectra, e lectronic spectra, magnetic susceptibility, thermogravimetric and differential t hermal analysis, X-ray powder diffraction. The two complexes have the composit ions of Cl2(A) and (NO3)2(B)(bi=NH2CONHCONH2) and the molecula r formulae of CuC4H10O4N6Cl2 and CuC4H10O10N8, respectively. The molar conductan ce data show that the complexes are 1∶2 electrolyte. Infrared spectra of the c omplexes show oxygen atoms have been coordinated with divalent copper ion. The t hermal decomposition processes of the complexes show that the final residues are all cupper oxide. The results of indexes to the X-ray powder diffraction data indicate that the crystal structure of the complexes belong to monoclinic syste m, the lattice parameters are: a=0.6976nm,b=1.1546 nm,c=2.1689nm,a=96.80 1.7346nm3 for A; and a=0.7096nm,b=1.1359 nm,c=2.1002 nm,a=97.05nm3 for B, respectively.展开更多
Potassium bis(biureto) cuprate tetrahydrate was synthesized by solid phase reaction.The composition and structure of the complex was characterized by elemental analysis,molar conductance,infrared spectra,electronic sp...Potassium bis(biureto) cuprate tetrahydrate was synthesized by solid phase reaction.The composition and structure of the complex was characterized by elemental analysis,molar conductance,infrared spectra,electronic spectra,magnetic susceptibility,thermogravimetric and differential thermal analysis,and X ray powder diffraction.The complex has the composition of K 2·4H 2O and the molecular formula of K 2CuC 4H 14 O 8N 6.展开更多
In order to reduce the oxidation and volatilization caused by Mg element in the traditional methods for synthesizing Mg2Si compounds,Mg2Si thermoelectric materials were prepared by solid state reaction and microwave r...In order to reduce the oxidation and volatilization caused by Mg element in the traditional methods for synthesizing Mg2Si compounds,Mg2Si thermoelectric materials were prepared by solid state reaction and microwave radiation techniques.Structure and phase composition of the materials were investigated by X-ray diffraction.The electrical conductivity,Seebeck coefficient and thermal conductivity were measured as a function of temperature from 300 to 700 K.It is found that high purity Mg2Si powders can be obtained with excessive content of 8% Mg from the stoichiometric Mg2Si at 853 K and 2.5 kW for 30 min.A maximum dimensionless figure of merit,ZT,of about 0.13 was obtained for Mg2Si at 600 K.展开更多
采用常规的固相反应法结合机械球磨制备了含碳质量分数23.7%的Li_(2)Ni_(2)(MoO_(4))3@C复合材料,并应用于锂离子电池负极。与纯Li_(2)Ni_(2)(MoO_(4))3相比,Li_(2)Ni_(2)(MoO_(4))3@C具有优异的电化学性能,在电流密度为200 mA ·g^...采用常规的固相反应法结合机械球磨制备了含碳质量分数23.7%的Li_(2)Ni_(2)(MoO_(4))3@C复合材料,并应用于锂离子电池负极。与纯Li_(2)Ni_(2)(MoO_(4))3相比,Li_(2)Ni_(2)(MoO_(4))3@C具有优异的电化学性能,在电流密度为200 mA ·g^(-1)时,50周循环后,可逆容量高达845 mAh·g^(-1)。值得注意的是,Li_(2)Ni_(2)(MoO_(4))3@C的首周库仑效率高达85%。此外,运用循环伏安法对Li_(2)Ni_(2)(MoO_(4))3@C复合物存储锂行为进行了初步探索。展开更多
W-doped Li4TisO12 in the form of Li4Ti4.95W0.osO12 was firstly synthesized via solid state reaction. X-ray diffraction （XRD） and scanning electron microscope （gEM） were employed to characterize the structure and m...W-doped Li4TisO12 in the form of Li4Ti4.95W0.osO12 was firstly synthesized via solid state reaction. X-ray diffraction （XRD） and scanning electron microscope （gEM） were employed to characterize the structure and morphology of Li4Ti4.psW0.05Ol2. W-doping does not change the phase composition and particle morphology, while remarkably improves its cycling stability at high charge/discharge rate. Li4Ti4.95W0.05O12 exhibits an excellent rate capability with a reversible capacity of 131.2 mA.h/g at 10C and even 118.6 mA.h/g at 20C. The substitution of W for Ti site can enhance the electronic conductivity of Li4TisO12 via the generation of mixing Ti4＋/Ti3＋, which indicates that Li4Ti4.psW0.05O12 is promising as a high rate anode for the lithium-ion batteries.展开更多
Li3V2（PO4）3 samples were synthesized by sol-gel route and high temperature solid-state reaction. The influence of Li3V2（PO4）3 as cathode materials for lithium-ion batteries on electrochemical performances was inve...Li3V2（PO4）3 samples were synthesized by sol-gel route and high temperature solid-state reaction. The influence of Li3V2（PO4）3 as cathode materials for lithium-ion batteries on electrochemical performances was investigated. The structure of Li3Va（PO4）3 as cathode materials for lithium-ion batteries and morphology of Li3V2（PO4）3 were characterized by X-ray diffractometry （XRD） and scanning electron microscopy （SEM）. Electrochemical performances were characterized by charge/discharge and AC impedance measurements. Li3V2（PO4）3 with smaller grain size shows better performances in terms of the discharge capacity and cycle stability. The improved electrochemical properties of Li3V2（PO4）3 are attributed to the refined grains and enhanced electrical conductivity. AC impedance measurements also show that the Li3V2（PO4）3 synthesized by sol-gel route exhibits significantly decreased charge-transfer resistance and shortened migration distance of lithium ions.展开更多
Solid-state grinding is a simple and effective method to introduce guest species into the channels of microporous materials through filling.The structure and the surface acidity of the materials were obtained from BET...Solid-state grinding is a simple and effective method to introduce guest species into the channels of microporous materials through filling.The structure and the surface acidity of the materials were obtained from BET isotherms and NH3-TPD,respectively.XRD,UV-vis,UV diffuse-reflectance,and TEM were used to characterize the phases,and the morphology,respectively.The clustered layers of MgO-Al2O3phases were formed in the internal pore surface and were highly dispersed inside the channels of the ZSM-5 host.So the volume of MgO-Al2O3/ZSM-5 composite was larger than the ZSM-5 zeolite itself and some mesoporous channels appeared when Mg/Al species entered the channels.Meanwhile,new acid sites emerged in MgO-Al2O3/ZSM-5 composite and the acid amount of the sample changed.The improved Pt dispersion and the increased acid content would cause the increase of propane conversion and the modification of selectivity during the reaction.展开更多
The title compound Cu3PSe4 was synthesized by the reaction of CuCl, P2Se5 and Se in a molar ratio of 1:1:1 at 500 C and structurally characterized by X-ray crystallography. The crystal belongs to orthorhombic, space g...The title compound Cu3PSe4 was synthesized by the reaction of CuCl, P2Se5 and Se in a molar ratio of 1:1:1 at 500 C and structurally characterized by X-ray crystallography. The crystal belongs to orthorhombic, space group Pmn21 with cell parameters: a = 7.685(2), b = 6.656(1), c = 6.377(1) , V = 326.2(1) 3, Z = 2, Dc = 5.472 g/cm3, Mr = 537.43, F(000) = 476, m = 32.12 mm-1, R = 0.0642, wR = 0.1481 and S = 1.037. The 3-D structure can be regarded as constructed from the alternately stacking of [Cu(2)Se4] tetrahedral layers and Cu(1)PSe tetrahedral layers along the b direction, in which the Cu(2)Se layer is comprised of corner-sharing [Cu(2)Se4] tetrahedra along the a and c directions, and the Cu(1)PSe layer is consisted of alternately corner-sharing [Cu(1)Se4] tetrahedra and [PSe4] tetrahedra along the a and c directions.展开更多
The title compound Ag3PSe4 was synthesized by the reaction of Ag powder, P2Se5 and Se in a molar ratio of 1:1:1 at 500 C and structurally characterized by X-ray crystallography. The crystal belongs to orthorhombic, sp...The title compound Ag3PSe4 was synthesized by the reaction of Ag powder, P2Se5 and Se in a molar ratio of 1:1:1 at 500 C and structurally characterized by X-ray crystallography. The crystal belongs to orthorhombic, space group Pmn21 with cell parameters: a = 7.689(4), b = 6.660(3), c = 6.379(4) , V = 326.7(3) 3, Z = 2, Dc = 6.816 g/cm3, Mr = 670.42, F(000) = 584, m = 31.302 mm-1, R = 0.0606, wR = 0.1289 and S = 1.012. The 3-D structure can be regarded as constructed from the stacking of puckered AgPSe honeycomb-like sheets along the c direction, in which the Ag, P and Se atoms are bonded to each other to form a chair-like six-membered ring, and the rings then build the sheets by sharing edges.展开更多
The synthesis, structure and performance of Li2Mg0.15Mn0.4Co0.45SiO4/C cathode material were studied. The Li2Mg0.15Mn0.4Co0.45SiO4/C solid solution with orthorhombic unit cell （space group Pmn21） was synthesized suc...The synthesis, structure and performance of Li2Mg0.15Mn0.4Co0.45SiO4/C cathode material were studied. The Li2Mg0.15Mn0.4Co0.45SiO4/C solid solution with orthorhombic unit cell （space group Pmn21） was synthesized successfully by combination of wet process and solid-state reaction at high temperature, and its electrochemical performance was investigated primarily. Li2Mg0.15Mn0.4Co0.45SiO4/C composite materials deliver a charge capacity of 302 mA-h/g and a discharge capacity of 171 mA.h/g in the first cycle. The discharge capacity is stabilized at about 100 mA-h/g after 10 cycles at a current density of 10 mA/g in the voltage of 1.5-4.8 V vs Li/Li^＋. The results show that Mg-substitution for the Co ions in Li2Mn0.4Co0.6SiO4 improves the stabilization of initial structure and the electrochemical nerformance.展开更多
Solid phase peptide synthesis(SPPS)based on Fmoc chemistry has become a commonly used technique in peptide chemistry,as it can be easily conducted using automated machine,and not requiring highly toxic HF in compariso...Solid phase peptide synthesis(SPPS)based on Fmoc chemistry has become a commonly used technique in peptide chemistry,as it can be easily conducted using automated machine,and not requiring highly toxic HF in comparison to Boc-SPPS.With the fast development in the emerging field of protein chemical synthesis,many efforts have been endeavored aiming to find more efficient methods for preparing peptide fragments required in ligation reactions.This review briefly summarizes recent advances in the engineering and modification of Fmoc-SPPS-derived peptides,which can be used as the N-terminal fragments in a native chemical ligation(NCL)or NCL-type ligation reactions.展开更多
文摘The copper complexes of biuret have been synthesized by solid phase react ion with microwave irradiation. The compositions and structures of the complexes are characterized by elemental analysis, molar conductance, infrared spectra, e lectronic spectra, magnetic susceptibility, thermogravimetric and differential t hermal analysis, X-ray powder diffraction. The two complexes have the composit ions of Cl2(A) and (NO3)2(B)(bi=NH2CONHCONH2) and the molecula r formulae of CuC4H10O4N6Cl2 and CuC4H10O10N8, respectively. The molar conductan ce data show that the complexes are 1∶2 electrolyte. Infrared spectra of the c omplexes show oxygen atoms have been coordinated with divalent copper ion. The t hermal decomposition processes of the complexes show that the final residues are all cupper oxide. The results of indexes to the X-ray powder diffraction data indicate that the crystal structure of the complexes belong to monoclinic syste m, the lattice parameters are: a=0.6976nm,b=1.1546 nm,c=2.1689nm,a=96.80 1.7346nm3 for A; and a=0.7096nm,b=1.1359 nm,c=2.1002 nm,a=97.05nm3 for B, respectively.
文摘Potassium bis(biureto) cuprate tetrahydrate was synthesized by solid phase reaction.The composition and structure of the complex was characterized by elemental analysis,molar conductance,infrared spectra,electronic spectra,magnetic susceptibility,thermogravimetric and differential thermal analysis,and X ray powder diffraction.The complex has the composition of K 2·4H 2O and the molecular formula of K 2CuC 4H 14 O 8N 6.
基金Project (2009BB4228) supported by the Natural Science Foundation Project of Chongqing Science and Technology Commission,ChinaProject (CK2010Z09) supported by the Research Foundation of Chongqing University of Science and Technology,China
文摘In order to reduce the oxidation and volatilization caused by Mg element in the traditional methods for synthesizing Mg2Si compounds,Mg2Si thermoelectric materials were prepared by solid state reaction and microwave radiation techniques.Structure and phase composition of the materials were investigated by X-ray diffraction.The electrical conductivity,Seebeck coefficient and thermal conductivity were measured as a function of temperature from 300 to 700 K.It is found that high purity Mg2Si powders can be obtained with excessive content of 8% Mg from the stoichiometric Mg2Si at 853 K and 2.5 kW for 30 min.A maximum dimensionless figure of merit,ZT,of about 0.13 was obtained for Mg2Si at 600 K.
文摘采用常规的固相反应法结合机械球磨制备了含碳质量分数23.7%的Li_(2)Ni_(2)(MoO_(4))3@C复合材料,并应用于锂离子电池负极。与纯Li_(2)Ni_(2)(MoO_(4))3相比,Li_(2)Ni_(2)(MoO_(4))3@C具有优异的电化学性能,在电流密度为200 mA ·g^(-1)时,50周循环后,可逆容量高达845 mAh·g^(-1)。值得注意的是,Li_(2)Ni_(2)(MoO_(4))3@C的首周库仑效率高达85%。此外,运用循环伏安法对Li_(2)Ni_(2)(MoO_(4))3@C复合物存储锂行为进行了初步探索。
文摘W-doped Li4TisO12 in the form of Li4Ti4.95W0.osO12 was firstly synthesized via solid state reaction. X-ray diffraction （XRD） and scanning electron microscope （gEM） were employed to characterize the structure and morphology of Li4Ti4.psW0.05Ol2. W-doping does not change the phase composition and particle morphology, while remarkably improves its cycling stability at high charge/discharge rate. Li4Ti4.95W0.05O12 exhibits an excellent rate capability with a reversible capacity of 131.2 mA.h/g at 10C and even 118.6 mA.h/g at 20C. The substitution of W for Ti site can enhance the electronic conductivity of Li4TisO12 via the generation of mixing Ti4＋/Ti3＋, which indicates that Li4Ti4.psW0.05O12 is promising as a high rate anode for the lithium-ion batteries.
基金Projects(0991025,0842003-5 and 0832259) supported by Natural Science Foundation of Guangxi Province,ChinaProject supported by the Joint Graduate Innovation Talent Cultivation Base of Guangxi Province,ChinaProject(GuiJiaoRen[2007]71) supported by the Research Funds of the Guangxi Key Laboratory of Environmental Engineering,Protection and Assessment Program to Sponsor Teams for Innovation in the Construction of Talent Highlands in Guangxi Institutions of Higher Learning,China
文摘Li3V2（PO4）3 samples were synthesized by sol-gel route and high temperature solid-state reaction. The influence of Li3V2（PO4）3 as cathode materials for lithium-ion batteries on electrochemical performances was investigated. The structure of Li3Va（PO4）3 as cathode materials for lithium-ion batteries and morphology of Li3V2（PO4）3 were characterized by X-ray diffractometry （XRD） and scanning electron microscopy （SEM）. Electrochemical performances were characterized by charge/discharge and AC impedance measurements. Li3V2（PO4）3 with smaller grain size shows better performances in terms of the discharge capacity and cycle stability. The improved electrochemical properties of Li3V2（PO4）3 are attributed to the refined grains and enhanced electrical conductivity. AC impedance measurements also show that the Li3V2（PO4）3 synthesized by sol-gel route exhibits significantly decreased charge-transfer resistance and shortened migration distance of lithium ions.
基金the financial supports of the National Natural Science Foundation of China(Grant No.21376051,21106017,21306023 and 51077013)the Natural Science Foundation of Jiangsu(Grant No.BK20131288)+3 种基金the Fund Project for Transformation of Scientific and Technological Achievements of Jiangsu Province of China(Grant No.BA2011086)the Specialized Research Fund for the Doctoral Program of Higher Education of China(Grant No.20100092120047)the Key Program for the Scientific Research Guiding Fund of Basic Scientific Research Operation Expenditure of Southeast University(Grant No.3207043101)Instrumental Analysis Fund of Southeast University
文摘Solid-state grinding is a simple and effective method to introduce guest species into the channels of microporous materials through filling.The structure and the surface acidity of the materials were obtained from BET isotherms and NH3-TPD,respectively.XRD,UV-vis,UV diffuse-reflectance,and TEM were used to characterize the phases,and the morphology,respectively.The clustered layers of MgO-Al2O3phases were formed in the internal pore surface and were highly dispersed inside the channels of the ZSM-5 host.So the volume of MgO-Al2O3/ZSM-5 composite was larger than the ZSM-5 zeolite itself and some mesoporous channels appeared when Mg/Al species entered the channels.Meanwhile,new acid sites emerged in MgO-Al2O3/ZSM-5 composite and the acid amount of the sample changed.The improved Pt dispersion and the increased acid content would cause the increase of propane conversion and the modification of selectivity during the reaction.
基金This work was supported by the National Natural Science Foundation of China (20001007 20131020) Natural Science Foundation of the Chinese Academy of Sciences (KJCX2-H3) and Fujian Province (2000F006)
文摘The title compound Cu3PSe4 was synthesized by the reaction of CuCl, P2Se5 and Se in a molar ratio of 1:1:1 at 500 C and structurally characterized by X-ray crystallography. The crystal belongs to orthorhombic, space group Pmn21 with cell parameters: a = 7.685(2), b = 6.656(1), c = 6.377(1) , V = 326.2(1) 3, Z = 2, Dc = 5.472 g/cm3, Mr = 537.43, F(000) = 476, m = 32.12 mm-1, R = 0.0642, wR = 0.1481 and S = 1.037. The 3-D structure can be regarded as constructed from the alternately stacking of [Cu(2)Se4] tetrahedral layers and Cu(1)PSe tetrahedral layers along the b direction, in which the Cu(2)Se layer is comprised of corner-sharing [Cu(2)Se4] tetrahedra along the a and c directions, and the Cu(1)PSe layer is consisted of alternately corner-sharing [Cu(1)Se4] tetrahedra and [PSe4] tetrahedra along the a and c directions.
基金This work was supported by the National Natural Science Foundation of China (20001007 20131020) Natural Science Foundation of the Chinese Academy of Sciences (KJCX2-H3) and Fujian province (2000F006)
文摘The title compound Ag3PSe4 was synthesized by the reaction of Ag powder, P2Se5 and Se in a molar ratio of 1:1:1 at 500 C and structurally characterized by X-ray crystallography. The crystal belongs to orthorhombic, space group Pmn21 with cell parameters: a = 7.689(4), b = 6.660(3), c = 6.379(4) , V = 326.7(3) 3, Z = 2, Dc = 6.816 g/cm3, Mr = 670.42, F(000) = 584, m = 31.302 mm-1, R = 0.0606, wR = 0.1289 and S = 1.012. The 3-D structure can be regarded as constructed from the stacking of puckered AgPSe honeycomb-like sheets along the c direction, in which the Ag, P and Se atoms are bonded to each other to form a chair-like six-membered ring, and the rings then build the sheets by sharing edges.
基金Project(10B054)supported by Scientific Research Fund of Hunan Provincial Education Department,ChinaProjects(2011GK2002,2011FJ3160)supported by the Planned Science and Technology Program of Hunan Province,China
文摘The synthesis, structure and performance of Li2Mg0.15Mn0.4Co0.45SiO4/C cathode material were studied. The Li2Mg0.15Mn0.4Co0.45SiO4/C solid solution with orthorhombic unit cell （space group Pmn21） was synthesized successfully by combination of wet process and solid-state reaction at high temperature, and its electrochemical performance was investigated primarily. Li2Mg0.15Mn0.4Co0.45SiO4/C composite materials deliver a charge capacity of 302 mA-h/g and a discharge capacity of 171 mA.h/g in the first cycle. The discharge capacity is stabilized at about 100 mA-h/g after 10 cycles at a current density of 10 mA/g in the voltage of 1.5-4.8 V vs Li/Li^＋. The results show that Mg-substitution for the Co ions in Li2Mn0.4Co0.6SiO4 improves the stabilization of initial structure and the electrochemical nerformance.
基金supported by the Peking University Health Science Center(BMU20130354)State Key Laboratory of Natural and Biomimetic Drugs,the National Recruitment Program of Global Youth Experts(1000 Plan)the National Natural Science Foundation of China (21502005)
文摘Solid phase peptide synthesis(SPPS)based on Fmoc chemistry has become a commonly used technique in peptide chemistry,as it can be easily conducted using automated machine,and not requiring highly toxic HF in comparison to Boc-SPPS.With the fast development in the emerging field of protein chemical synthesis,many efforts have been endeavored aiming to find more efficient methods for preparing peptide fragments required in ligation reactions.This review briefly summarizes recent advances in the engineering and modification of Fmoc-SPPS-derived peptides,which can be used as the N-terminal fragments in a native chemical ligation(NCL)or NCL-type ligation reactions.
