Research on the synthesis of superoxide dismutase mimics by chemical and biologi-cal synthetic methods were reviewed.The advantages and limitations were analyzed.A prospect for the future development of superoxide dis...Research on the synthesis of superoxide dismutase mimics by chemical and biologi-cal synthetic methods were reviewed.The advantages and limitations were analyzed.A prospect for the future development of superoxide dismutase mimics is proposed.展开更多
Monodisperse zinc phosphate microspheres were synthesized by a facile solvothermal method in the presence of oleic acid.X-ray powder diffraction（XRD）,Fourier transform infrared spectrum（FT-IR）,emission scanning el...Monodisperse zinc phosphate microspheres were synthesized by a facile solvothermal method in the presence of oleic acid.X-ray powder diffraction（XRD）,Fourier transform infrared spectrum（FT-IR）,emission scanning electron microscopy（SEM）,and energy dispersive X-ray spectrum（EDX） were used to characterize the microstructures and morphologies of the as-obtained zinc phosphate samples.The experimental results indicate that the zinc phosphate products are well crystallized,and the morphologies of the samples can be easily controlled by the elaborate choice of oleic acid addition and the content of NaOH.Furthermore,self-activated luminescent properties of the products are observed.The as-obtained samples show an intense blue emission under a long-wavelength UV light excitation of 400 nm.The possible luminescent mechanism may be ascribed to the carbon-related surface impurities or defects.展开更多
The regioselective acylation of unprotected phenylethyl glucoside withcinnamoyl chloride leads to 6-OH cin-namoylated glucoside. In this manner, thirteen phenylpropanoidglycoside analogs were designed and prepared. Th...The regioselective acylation of unprotected phenylethyl glucoside withcinnamoyl chloride leads to 6-OH cin-namoylated glucoside. In this manner, thirteen phenylpropanoidglycoside analogs were designed and prepared. Their structure was confirmed by ~1H NMR and ^(13)CNMR spectra.展开更多
Thermodynamics for chemical vapor synthesis （CVS） of Nb nanopowder in NbCl5-H2-Ar system was investigated by using FactSage software. The validation experiments were conducted to confirm the thermodynamics points. T...Thermodynamics for chemical vapor synthesis （CVS） of Nb nanopowder in NbCl5-H2-Ar system was investigated by using FactSage software. The validation experiments were conducted to confirm the thermodynamics points. The results indicate that under the atmospheric pressure, the reduction approach from NbCl5（g） to Nb（s） is a stage-wise process with the formation of complex sub-chlorides, and is controllable at low hydrogen ratio （mole ratio of n（NbCl5）：n（H2）＆lt;1：180） and low temperature （＆lt;1050 ＆#176;C）. Furthermore, a reasonable amount of inert loading gas is favorable to increase the reduction ratio of NbCl5 and the powder yield. The as-synthesized Nb nanopowder with the homogeneous size of 30-50 nm and the powder yield of 85% （mass fraction） is obtained by the CVS process under n（NbCl5）：n（H2）：n（Ar）=1：120：1 and 950 ＆#176;C with the NbCl5 reduction rate of 96.1%.展开更多
Molybdenum disulfide nanoflakes were synthesized by a simple hydrothermal process using sodium molybdate and thiourea as reactants at a relatively low temperature. X-ray diffraction(XRD) and transmission elec-tron mic...Molybdenum disulfide nanoflakes were synthesized by a simple hydrothermal process using sodium molybdate and thiourea as reactants at a relatively low temperature. X-ray diffraction(XRD) and transmission elec-tron microscopy(TEM) indicate that the samples have the structure of 2H-MoS2 and the morphology of nanoflakes with the average thickness around 5-10 nm. The results of electrochemical properties indicate that the morphology and size of MoS2 particles have effects on their capacity when they are used as the anode for lithium ion battery. The as-prepared MoS2 samples have high reversible discharge capacity up to 994.6 mA·h·g-1 for the MoS2-1 elec-trode and 930.1 mA·h·g-1 for the MoS2-2 electrode and show excellent cycling performances. The MoS2-1 electrode has a better cycling stability than the MoS2-2 electrode due to their difference in the uniformity of the samples.展开更多
Hexagonal microtubes with hexagonal phase Y（OH）3 were successfully synthesized by a facile solvothermal method at 160°C for 12 h in the absence of surfactants or templates via a crystal transformation route. Sc...Hexagonal microtubes with hexagonal phase Y（OH）3 were successfully synthesized by a facile solvothermal method at 160°C for 12 h in the absence of surfactants or templates via a crystal transformation route. Scanning electron microscopy （SEM） results demonstrate that the prepared hexagonal microtubes are with a wall thickness of 50-100 nm, an outer diameter of 1 μm, and lengths going up tens of micrometers. Cubic phase Y2O3 microtubes were obtained after thermal treatment of the Y（OH）3 microtubes at 700 oC for 4 h. Eu^3＋-doped Y2O3 microtubes with strong red emission at 610 nm were also prepared and their photoluminescence （PL） properties were studied. The possible mechanism for the formation of the microtubes was briefly discussed.展开更多
Aim To design and synthesize a series of 2-（E）-（4-cyclopentyloxy-3-methoxylbenzylidene）cyclopentanone derivatives, and to determine their antitumor activities in vitro. Method The target compounds were synthesized...Aim To design and synthesize a series of 2-（E）-（4-cyclopentyloxy-3-methoxylbenzylidene）cyclopentanone derivatives, and to determine their antitumor activities in vitro. Method The target compounds were synthesized. Their antitumor activities were assayed using human hepatic carcinoma ceil line （Bel-7402） and human oral cavity epidermis squamoceilular carcinoma cell line （KB）. Results Five compounds were obtained. Three of them were not reported in the literature and their chemical structures were confirmed by IR, ^1H NMR, MS and elemental analysis. Preliminary screening results showed that compound 5 possessed better biological activity with IC50 1.62 μmol·L^-1 against Bel-7402 and 8.04 μmol·L^-1 against KB, but much weaker than 5- Fluorouracil. Conclusion Mannich base derivatives of 2-（E）-（4-cyclopentyloxy-3-methoxylbenzylidene）cyclopentanone exhibited some antitumor activities.展开更多
Nd and Sb doped SnO2 conductive nanoparticles were prepared by the complexation-coprecipitation method with Sn, Sb2O3 and Nd2O3 as the raw materials. Thermal behavior, crystal phase, and structure of the prepared cond...Nd and Sb doped SnO2 conductive nanoparticles were prepared by the complexation-coprecipitation method with Sn, Sb2O3 and Nd2O3 as the raw materials. Thermal behavior, crystal phase, and structure of the prepared conductive nanoparticles were characterized by TG/DSC/DTG, FTIR, XRD and TEM techniques, respectively. The resistivity of the prepared conductive nanoparticles was 0.12Ω·cm. TG/DSC/DTG curves show that the precursors lose weight completely before 750℃. FTIR spectrum shows that the vibration peaks are wide peaks in 731 ~ 617 cm-1, and the Nd and Sb doped SnO2 conductive nanoparticles have intense absorption in 4000 ~ 2000 cm-1. Nd and Sb doped SnOi have a structure of tetragonal rutile, and complex doping is achieved well by complexation-coprecipitation method and is recognized as replacement doping or caulking doping. TME shows that the particles are weakly agglomerated, and the size of the particles calcined at 1000℃ranges about 10 nm to 30 nm.展开更多
Electroceramic calcium copper titanates(CaCu3Ti4O12,CCTO),with high dielectric permittivities（e） of approximately 105 and 104,respectively,for single crystal and bulk materials,are produced for a number of wellestab...Electroceramic calcium copper titanates(CaCu3Ti4O12,CCTO),with high dielectric permittivities（e） of approximately 105 and 104,respectively,for single crystal and bulk materials,are produced for a number of wellestablished and emerging applications such as resonator,capacitor,and sensor.These applications take advantage of the unique properties achieved through the structure and properties of CCTO.This review comprehensively focuses on the primary processing routes,effect of impurity,dielectric permittivity,and deposition technique used for the processing of electroceramics along with their chemical composition and micro and nanostructures.Emphasis is given to versatile and basic approaches that allow one to control the microstructural features that ultimately determine the properties of the CCTO ceramic.Despite the intensive research in this area,none of the studies available in the literature provides all the possible relevant information about CCTO fabrication,structure,the factors influencing its dielectric properties,CCTO immobilization,and sensing applications.展开更多
La and Sb doped SnO_2 conductive nanoparticles were prepared by the coprecipitation method with SnCl_4·5H_2O, SbCl_3 and La_2O_3 as the raw materials. Thermal behavior, crystal phase, and structure of the prepare...La and Sb doped SnO_2 conductive nanoparticles were prepared by the coprecipitation method with SnCl_4·5H_2O, SbCl_3 and La_2O_3 as the raw materials. Thermal behavior, crystal phase, and structure of the prepared conductive nanoparticles were characterized by TG/DSC/DTG, FTIR, XRD and TEM techniques, respectively. The resistivity of the prepared conductive nanoparticles is 2.5 Ω·cm. TG/DSC/DTG curves show that the precursors lose weight completely before 750 ℃. FTIR spectrum show that the vibration peak are wide peak in 718～615 cm -1, and the La and Sb doped SnO_2 conductive nanoparticles have intense absorption in 4000～2000 cm -1. X-ray powder diffraction pattern of the conductive nanoparticles indicates that the Sb-doping in SnO_2 is replacement doping and La 3+ combines with Sn 4+ and O 2- form La_2Sn_2O_7. TME shows that the particles are weakly agglomerated, and the size of the particles calcined at 1000 ℃ ranged about 20～30 nm.展开更多
ZrO_2-SnO_2 composite nanoparticles were prepared by heating the hydrateprecursors synthesized by the chemical co-precipitation reaction of ZrOCl_2 and SnCl_4. Theprecursors were examined by differential thermal analy...ZrO_2-SnO_2 composite nanoparticles were prepared by heating the hydrateprecursors synthesized by the chemical co-precipitation reaction of ZrOCl_2 and SnCl_4. Theprecursors were examined by differential thermal analysis (DTA) and thermogravimetric analysis(TGA). The composite powder was characterized using X-ray diffraction (XRD), transmission electronmicroscopy (TEM) and desorption isotherm (Barrett-Joyner-Halenda method). The average crystal sizeof the nanoparticle ranges from 15 to 30 nm for the sample containing 5%-25% ZrO_2 (mass fraction).Most of the pores in the ZrO_2-SnO_2 nanoparticles are about 10-20 nm in diameter. The compositepowder is promising for chemical sensors.展开更多
The molybdotungstogallic acids were prepared for the first time by stepwise acidification and the addition of reagents, and were characterized by chemical analysis, conductometric titration and UV absorption spectrosc...The molybdotungstogallic acids were prepared for the first time by stepwise acidification and the addition of reagents, and were characterized by chemical analysis, conductometric titration and UV absorption spectroscopy. Molybdotungstogallate of thallium was also synthesized by double decomposition.展开更多
Monodisperse Fe-based and Co-based nanopar-ticles exhibit unique magnetic properties. They play important roles in magnetic storage and biomedical application. Their chemical synthesis and performance enhancement draw...Monodisperse Fe-based and Co-based nanopar-ticles exhibit unique magnetic properties. They play important roles in magnetic storage and biomedical application. Their chemical synthesis and performance enhancement draw a lot of study interest. Investigations of magnetic metallic nano-particles are very active in many scientific fields. This paper reviews the present advances in chemical synthesis, perfor-mance enhancement, and potential applications of monodis-perse Fe-based and Co-based nanoparticles.展开更多
The cell adhesive motif RGD tripeptide was synthesized by using a novel chemical method. First, Gly-Asp（GD） was synthesized in two steps including the chloroacetylation of free L-aspartic acid and the ammonolysis of...The cell adhesive motif RGD tripeptide was synthesized by using a novel chemical method. First, Gly-Asp（GD） was synthesized in two steps including the chloroacetylation of free L-aspartic acid and the ammonolysis of the chloroacetylated L-aspartic acid. The yield of chloroacetylated L-aspartic acid was 83.0%. For the ammonolysis of chloroacetylated L-aspartic acid, the yield of the ammonolyzed product was 92. 3%. Second, the coupling between Arg and Gly-Asp was carried out by using the NCA method. The maximum yield of RGD was about 50% at 0℃ and pH = 9. 5. The prepared RGD tripeptide was confirmed by using amino acid component analysis and mass spectrographic analysis.展开更多
Eu-doped ZnO nanosheets were synthesized successfully by means of the hydrothermal method. The X-ray diffraction（XRD） pattern shows that the sample is a single phase with the ZnO-like wurtzite structure. And the X-r...Eu-doped ZnO nanosheets were synthesized successfully by means of the hydrothermal method. The X-ray diffraction（XRD） pattern shows that the sample is a single phase with the ZnO-like wurtzite structure. And the X-ray photoelectron spectrum suggests that there are Eu3＋ ions in the matrix of the sample. Eu3＋-related red emissions resulted from energy transfer were observed for the nanosheets under UV laser excitation. The UV, green and yellow emissions were also seen in the photoluminescence spectra.展开更多
Saturated Ca（OH）2 and AlCl3 solutions were used to synthesize calcium aluminate hydrate precipitates at room temperature; high purity calcium aluminate powders with stable phases were made by calcination of the prec...Saturated Ca（OH）2 and AlCl3 solutions were used to synthesize calcium aluminate hydrate precipitates at room temperature; high purity calcium aluminate powders with stable phases were made by calcination of the precursors at a temperature as low as 1100℃. PSD and BET analysis revealed the particles with sizes ranging from submicrometer to several micrometers and with a specific area of 13 m^2/g. The measurement of hydraulic exotherm revealed that the exothennal rate is in peak for about 2 h. The exothermal quantities are 449.24 J/g at 12 h and 488.38 J/g at 24 h. Its strength development is quick and the 1 day curing strength is almost equal to 100% of the 3 days curing strength in the mortar test.展开更多
A novel soft chemical approach was developed to synthesize tin oxide-based powders. The microstructure, morphology, and electrochemical performance of the materials were investigated by X-ray diffraction, scanning ele...A novel soft chemical approach was developed to synthesize tin oxide-based powders. The microstructure, morphology, and electrochemical performance of the materials were investigated by X-ray diffraction, scanning electron microscope and electrochemical methods. The results show that the particles of tin oxide-based materials form an interconnected network structure like mesoporous material. The average size of the particles is about 200 nm. The materials deliver a charge capacity of more than 570 mA·h·g-1. And the capacity loss per cycle is about 0.15% after being cycled for 30 times. The good electrochemical performance indicates that tin oxide-based materials are promising anodes for lithium ion batteries.展开更多
One dimensional rod like NaV 2O 5 was synthesized by hydrothermal method, which draws much attention as an exotic spin Peierls compound. The samples have been characterized by X ray diffraction (XRD), transmission ele...One dimensional rod like NaV 2O 5 was synthesized by hydrothermal method, which draws much attention as an exotic spin Peierls compound. The samples have been characterized by X ray diffraction (XRD), transmission election microscopy (TEM), and magnetic susceptibility measurements. The pH value and the reducing agent are critical for synthesizing NaV 2O 5 nanorods. The reducing agent NH 2OH may play a key role in the assembly and growth of nanorods of products. [展开更多
The Al/TiC composites were prepared by reaction synthesis. The temperature characteristics and the effect of Al content on it have also been investigated. It has been shown that the Al melts before the reaction synthe...The Al/TiC composites were prepared by reaction synthesis. The temperature characteristics and the effect of Al content on it have also been investigated. It has been shown that the Al melts before the reaction synthesis occurs and with increasing of Al content the temperature maximum decreases, but the start temperature and the reaction lasting time do not change during the process. In addition, the effect of Al content on the reaction synthesis phase has been studied. The result shows that when the Al content is less than 60 at%, the TiC will be synthesized; when the Al content is more than 60 at%, the Al3Ti will also be synthesized. The micrograph of Al3Ti and TiC have been observed by SEM.展开更多
Sm3＋-activated Y2028 red phosphors were prepared by the combustion method and microemulsion method at the first time. X-ray characterization and electron diffraction show that, Y202S：Sm3＋, Ti4＋, Mg2＋ samples prep...Sm3＋-activated Y2028 red phosphors were prepared by the combustion method and microemulsion method at the first time. X-ray characterization and electron diffraction show that, Y202S：Sm3＋, Ti4＋, Mg2＋ samples prepared by these two methods are pure hexagonal crystals in structure with a trivial change due to dopants. Scanning electron microscopy （SEM） results show that the product presents an almond-like sheet in uniform size. Under the excitation of 269 nm ultraviolet light, Y202S：Sm3＋ samples fabricated by these two methods exhibit three main groups of red emission lines located at 564, 604, and 656 nm, respectively, which are attributed to the transitions of 4G5/2 →6H5/2, 4G~/2 →6H7/2, 4G5/2 →6H9/2, respectively. The samples prepared by microemulsion are seven times higher in fluorescent emission intensity and half time longer in afterglow time than that prepared by combustion.展开更多
文摘Research on the synthesis of superoxide dismutase mimics by chemical and biologi-cal synthetic methods were reviewed.The advantages and limitations were analyzed.A prospect for the future development of superoxide dismutase mimics is proposed.
基金Project(21101013) supported by the National Natural Science Foundation of ChinaProjects(FRF-SD-13-002B,FRF-BR-09-004A) supported by the Fundamental Research Funds for the Central Universities,China
文摘Monodisperse zinc phosphate microspheres were synthesized by a facile solvothermal method in the presence of oleic acid.X-ray powder diffraction（XRD）,Fourier transform infrared spectrum（FT-IR）,emission scanning electron microscopy（SEM）,and energy dispersive X-ray spectrum（EDX） were used to characterize the microstructures and morphologies of the as-obtained zinc phosphate samples.The experimental results indicate that the zinc phosphate products are well crystallized,and the morphologies of the samples can be easily controlled by the elaborate choice of oleic acid addition and the content of NaOH.Furthermore,self-activated luminescent properties of the products are observed.The as-obtained samples show an intense blue emission under a long-wavelength UV light excitation of 400 nm.The possible luminescent mechanism may be ascribed to the carbon-related surface impurities or defects.
文摘The regioselective acylation of unprotected phenylethyl glucoside withcinnamoyl chloride leads to 6-OH cin-namoylated glucoside. In this manner, thirteen phenylpropanoidglycoside analogs were designed and prepared. Their structure was confirmed by ~1H NMR and ^(13)CNMR spectra.
基金Project(51102015)supported by the National Natural Science Foundation of China
文摘Thermodynamics for chemical vapor synthesis （CVS） of Nb nanopowder in NbCl5-H2-Ar system was investigated by using FactSage software. The validation experiments were conducted to confirm the thermodynamics points. The results indicate that under the atmospheric pressure, the reduction approach from NbCl5（g） to Nb（s） is a stage-wise process with the formation of complex sub-chlorides, and is controllable at low hydrogen ratio （mole ratio of n（NbCl5）：n（H2）＆lt;1：180） and low temperature （＆lt;1050 ＆#176;C）. Furthermore, a reasonable amount of inert loading gas is favorable to increase the reduction ratio of NbCl5 and the powder yield. The as-synthesized Nb nanopowder with the homogeneous size of 30-50 nm and the powder yield of 85% （mass fraction） is obtained by the CVS process under n（NbCl5）：n（H2）：n（Ar）=1：120：1 and 950 ＆#176;C with the NbCl5 reduction rate of 96.1%.
基金Supported partially by the State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology,Zhejiang University of TechnologyPriority Research Centers Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education,Science and Technology (2009-0094047)
文摘Molybdenum disulfide nanoflakes were synthesized by a simple hydrothermal process using sodium molybdate and thiourea as reactants at a relatively low temperature. X-ray diffraction(XRD) and transmission elec-tron microscopy(TEM) indicate that the samples have the structure of 2H-MoS2 and the morphology of nanoflakes with the average thickness around 5-10 nm. The results of electrochemical properties indicate that the morphology and size of MoS2 particles have effects on their capacity when they are used as the anode for lithium ion battery. The as-prepared MoS2 samples have high reversible discharge capacity up to 994.6 mA·h·g-1 for the MoS2-1 elec-trode and 930.1 mA·h·g-1 for the MoS2-2 electrode and show excellent cycling performances. The MoS2-1 electrode has a better cycling stability than the MoS2-2 electrode due to their difference in the uniformity of the samples.
基金support from Projects under Scientific and Technological Planning of Education Office of Jiangxi Province, China.
文摘Hexagonal microtubes with hexagonal phase Y（OH）3 were successfully synthesized by a facile solvothermal method at 160°C for 12 h in the absence of surfactants or templates via a crystal transformation route. Scanning electron microscopy （SEM） results demonstrate that the prepared hexagonal microtubes are with a wall thickness of 50-100 nm, an outer diameter of 1 μm, and lengths going up tens of micrometers. Cubic phase Y2O3 microtubes were obtained after thermal treatment of the Y（OH）3 microtubes at 700 oC for 4 h. Eu^3＋-doped Y2O3 microtubes with strong red emission at 610 nm were also prepared and their photoluminescence （PL） properties were studied. The possible mechanism for the formation of the microtubes was briefly discussed.
基金Natural Science Foundation of GuangdongProvince(Grant No.994615).
文摘Aim To design and synthesize a series of 2-（E）-（4-cyclopentyloxy-3-methoxylbenzylidene）cyclopentanone derivatives, and to determine their antitumor activities in vitro. Method The target compounds were synthesized. Their antitumor activities were assayed using human hepatic carcinoma ceil line （Bel-7402） and human oral cavity epidermis squamoceilular carcinoma cell line （KB）. Results Five compounds were obtained. Three of them were not reported in the literature and their chemical structures were confirmed by IR, ^1H NMR, MS and elemental analysis. Preliminary screening results showed that compound 5 possessed better biological activity with IC50 1.62 μmol·L^-1 against Bel-7402 and 8.04 μmol·L^-1 against KB, but much weaker than 5- Fluorouracil. Conclusion Mannich base derivatives of 2-（E）-（4-cyclopentyloxy-3-methoxylbenzylidene）cyclopentanone exhibited some antitumor activities.
基金Project supported by Shanghai Key Subject (China P1501)Shanghai Colleges and Universities Key Subject (China 2001-71)Science Technology Foundation of Shanghai (0452nm032)
文摘Nd and Sb doped SnO2 conductive nanoparticles were prepared by the complexation-coprecipitation method with Sn, Sb2O3 and Nd2O3 as the raw materials. Thermal behavior, crystal phase, and structure of the prepared conductive nanoparticles were characterized by TG/DSC/DTG, FTIR, XRD and TEM techniques, respectively. The resistivity of the prepared conductive nanoparticles was 0.12Ω·cm. TG/DSC/DTG curves show that the precursors lose weight completely before 750℃. FTIR spectrum shows that the vibration peaks are wide peaks in 731 ~ 617 cm-1, and the Nd and Sb doped SnO2 conductive nanoparticles have intense absorption in 4000 ~ 2000 cm-1. Nd and Sb doped SnOi have a structure of tetragonal rutile, and complex doping is achieved well by complexation-coprecipitation method and is recognized as replacement doping or caulking doping. TME shows that the particles are weakly agglomerated, and the size of the particles calcined at 1000℃ranges about 10 nm to 30 nm.
基金supported by the Universiti Sains Malaysia(USM) fellowship(APEX 91002/JHEA/ATSG4001)fundamental research grant scheme(FRGS) under grant number of 203/PBAHAN/6071263
文摘Electroceramic calcium copper titanates(CaCu3Ti4O12,CCTO),with high dielectric permittivities（e） of approximately 105 and 104,respectively,for single crystal and bulk materials,are produced for a number of wellestablished and emerging applications such as resonator,capacitor,and sensor.These applications take advantage of the unique properties achieved through the structure and properties of CCTO.This review comprehensively focuses on the primary processing routes,effect of impurity,dielectric permittivity,and deposition technique used for the processing of electroceramics along with their chemical composition and micro and nanostructures.Emphasis is given to versatile and basic approaches that allow one to control the microstructural features that ultimately determine the properties of the CCTO ceramic.Despite the intensive research in this area,none of the studies available in the literature provides all the possible relevant information about CCTO fabrication,structure,the factors influencing its dielectric properties,CCTO immobilization,and sensing applications.
文摘La and Sb doped SnO_2 conductive nanoparticles were prepared by the coprecipitation method with SnCl_4·5H_2O, SbCl_3 and La_2O_3 as the raw materials. Thermal behavior, crystal phase, and structure of the prepared conductive nanoparticles were characterized by TG/DSC/DTG, FTIR, XRD and TEM techniques, respectively. The resistivity of the prepared conductive nanoparticles is 2.5 Ω·cm. TG/DSC/DTG curves show that the precursors lose weight completely before 750 ℃. FTIR spectrum show that the vibration peak are wide peak in 718～615 cm -1, and the La and Sb doped SnO_2 conductive nanoparticles have intense absorption in 4000～2000 cm -1. X-ray powder diffraction pattern of the conductive nanoparticles indicates that the Sb-doping in SnO_2 is replacement doping and La 3+ combines with Sn 4+ and O 2- form La_2Sn_2O_7. TME shows that the particles are weakly agglomerated, and the size of the particles calcined at 1000 ℃ ranged about 20～30 nm.
基金This project is financially supported by the National Natural Science Foundation of China (No. 50304014) and the Postgraduate Educational Innovation Engineering of Central South University (No. 030702).
文摘ZrO_2-SnO_2 composite nanoparticles were prepared by heating the hydrateprecursors synthesized by the chemical co-precipitation reaction of ZrOCl_2 and SnCl_4. Theprecursors were examined by differential thermal analysis (DTA) and thermogravimetric analysis(TGA). The composite powder was characterized using X-ray diffraction (XRD), transmission electronmicroscopy (TEM) and desorption isotherm (Barrett-Joyner-Halenda method). The average crystal sizeof the nanoparticle ranges from 15 to 30 nm for the sample containing 5%-25% ZrO_2 (mass fraction).Most of the pores in the ZrO_2-SnO_2 nanoparticles are about 10-20 nm in diameter. The compositepowder is promising for chemical sensors.
文摘The molybdotungstogallic acids were prepared for the first time by stepwise acidification and the addition of reagents, and were characterized by chemical analysis, conductometric titration and UV absorption spectroscopy. Molybdotungstogallate of thallium was also synthesized by double decomposition.
基金partially supported by the National Basic Research Program of China(No.2012CB932702)the National Natural Science Foundation of China(Nos.51071022,51271020,and 11174031)+3 种基金the Program for Changjiang Scholars and Innovative Research Teams in University(PCSIRT)Beijing Nova Program(No.2011031)the Fundamental Research Funds for the Central Universitiesthe State Key Laboratory of Advanced Metals and Materials(No.2011-Z03)
文摘Monodisperse Fe-based and Co-based nanopar-ticles exhibit unique magnetic properties. They play important roles in magnetic storage and biomedical application. Their chemical synthesis and performance enhancement draw a lot of study interest. Investigations of magnetic metallic nano-particles are very active in many scientific fields. This paper reviews the present advances in chemical synthesis, perfor-mance enhancement, and potential applications of monodis-perse Fe-based and Co-based nanoparticles.
基金Supported by the Special Research Grant from the State Administration of Traditional Chinese Medicine of China( No.2004ZDZX003).
文摘The cell adhesive motif RGD tripeptide was synthesized by using a novel chemical method. First, Gly-Asp（GD） was synthesized in two steps including the chloroacetylation of free L-aspartic acid and the ammonolysis of the chloroacetylated L-aspartic acid. The yield of chloroacetylated L-aspartic acid was 83.0%. For the ammonolysis of chloroacetylated L-aspartic acid, the yield of the ammonolyzed product was 92. 3%. Second, the coupling between Arg and Gly-Asp was carried out by using the NCA method. The maximum yield of RGD was about 50% at 0℃ and pH = 9. 5. The prepared RGD tripeptide was confirmed by using amino acid component analysis and mass spectrographic analysis.
基金Supported by the National Natural Science Foundation of China(Nos.60778040 60878039)+7 种基金the Program for the Development of Science and Technology of Jilin ProvinceChina(Nos.20090140 20090331)the Eleventh Five-Year Program for Science and Technology of Education Department of Jilin Province China(No.20090422)the Open Project Program of National Laboratory of Superhard Materials of China(No.201004)the Program for the Master Students’ Scientific and Innovative Research of Jilin Normal University China(No.S09010104)
文摘Eu-doped ZnO nanosheets were synthesized successfully by means of the hydrothermal method. The X-ray diffraction（XRD） pattern shows that the sample is a single phase with the ZnO-like wurtzite structure. And the X-ray photoelectron spectrum suggests that there are Eu3＋ ions in the matrix of the sample. Eu3＋-related red emissions resulted from energy transfer were observed for the nanosheets under UV laser excitation. The UV, green and yellow emissions were also seen in the photoluminescence spectra.
基金financially supported by the National Natural Science Foundation of China Key Program (No. 50332010)the National Natural Science Foundation of China (No. 50172007)
文摘Saturated Ca（OH）2 and AlCl3 solutions were used to synthesize calcium aluminate hydrate precipitates at room temperature; high purity calcium aluminate powders with stable phases were made by calcination of the precursors at a temperature as low as 1100℃. PSD and BET analysis revealed the particles with sizes ranging from submicrometer to several micrometers and with a specific area of 13 m^2/g. The measurement of hydraulic exotherm revealed that the exothennal rate is in peak for about 2 h. The exothermal quantities are 449.24 J/g at 12 h and 488.38 J/g at 24 h. Its strength development is quick and the 1 day curing strength is almost equal to 100% of the 3 days curing strength in the mortar test.
文摘A novel soft chemical approach was developed to synthesize tin oxide-based powders. The microstructure, morphology, and electrochemical performance of the materials were investigated by X-ray diffraction, scanning electron microscope and electrochemical methods. The results show that the particles of tin oxide-based materials form an interconnected network structure like mesoporous material. The average size of the particles is about 200 nm. The materials deliver a charge capacity of more than 570 mA·h·g-1. And the capacity loss per cycle is about 0.15% after being cycled for 30 times. The good electrochemical performance indicates that tin oxide-based materials are promising anodes for lithium ion batteries.
文摘One dimensional rod like NaV 2O 5 was synthesized by hydrothermal method, which draws much attention as an exotic spin Peierls compound. The samples have been characterized by X ray diffraction (XRD), transmission election microscopy (TEM), and magnetic susceptibility measurements. The pH value and the reducing agent are critical for synthesizing NaV 2O 5 nanorods. The reducing agent NH 2OH may play a key role in the assembly and growth of nanorods of products. [
文摘The Al/TiC composites were prepared by reaction synthesis. The temperature characteristics and the effect of Al content on it have also been investigated. It has been shown that the Al melts before the reaction synthesis occurs and with increasing of Al content the temperature maximum decreases, but the start temperature and the reaction lasting time do not change during the process. In addition, the effect of Al content on the reaction synthesis phase has been studied. The result shows that when the Al content is less than 60 at%, the TiC will be synthesized; when the Al content is more than 60 at%, the Al3Ti will also be synthesized. The micrograph of Al3Ti and TiC have been observed by SEM.
基金financially supported by the Basic Theory Research Fund of Research Institute of Metallurgy Engineering,University of Science and Technology Beijing(No.YJ2012-009)
文摘Sm3＋-activated Y2028 red phosphors were prepared by the combustion method and microemulsion method at the first time. X-ray characterization and electron diffraction show that, Y202S：Sm3＋, Ti4＋, Mg2＋ samples prepared by these two methods are pure hexagonal crystals in structure with a trivial change due to dopants. Scanning electron microscopy （SEM） results show that the product presents an almond-like sheet in uniform size. Under the excitation of 269 nm ultraviolet light, Y202S：Sm3＋ samples fabricated by these two methods exhibit three main groups of red emission lines located at 564, 604, and 656 nm, respectively, which are attributed to the transitions of 4G5/2 →6H5/2, 4G~/2 →6H7/2, 4G5/2 →6H9/2, respectively. The samples prepared by microemulsion are seven times higher in fluorescent emission intensity and half time longer in afterglow time than that prepared by combustion.
