In order to establish a new method for making cellulose and lignin from Masson pine, a high boiling solvent(HBS) pulping process with an aqueous solvent of 1,4-butanediol was investigated. Masson pine chips were pulpe...In order to establish a new method for making cellulose and lignin from Masson pine, a high boiling solvent(HBS) pulping process with an aqueous solvent of 1,4-butanediol was investigated. Masson pine chips were pulped with a 70%—90% aqueous solution of 1,4-butanediol containing a small amount of a catalyst at 200—220 ℃ for 60—180 min. HBS Masson pine cellulose is suitable for making paper. Water-insoluble HBS lignin was separated from the liquor reaction mixture by water precipitation. The recovered high boiling solvent(RHBS) is able to be recycled as a pulping solvent, indicating that the HBS method is a pulping process of Masson pine which is energy saving, resources saving and pollution free. HBS lignin has a better chemical reactivity and a lower ash content than lignin sulfonate.展开更多
Dy0.8Sr0.2FeO3 nano powder, a synthetic oxide, is made by sol-gel method from metal nitrate and diethylenetriaminepentaacetic acid (DTPA), and the processing parameters are optimized. The process of the preparation, t...Dy0.8Sr0.2FeO3 nano powder, a synthetic oxide, is made by sol-gel method from metal nitrate and diethylenetriaminepentaacetic acid (DTPA), and the processing parameters are optimized. The process of the preparation, thermal decomposition and the property of the powder are studied by TG-DTA, IR, TEM, and XRD. The diameter of the average grain is about 70 nm. This new technique can be used in the preparation and the studying of na'no materials in the complex oxide system.展开更多
With sodium dodecyl sulfonate(SDS) as the phase transferring catalyst, N,N-Dilauryl chitosans with a high degree of alkyl group substitution were prepared and characterized by means of FTIR, 1H NMR and elemental ana...With sodium dodecyl sulfonate(SDS) as the phase transferring catalyst, N,N-Dilauryl chitosans with a high degree of alkyl group substitution were prepared and characterized by means of FTIR, 1H NMR and elemental analyses. The results indicate that the average degree of alkyl group substitution on the chitosan increases with decreasing the molecular weight of the chitosan. The fully N,N-dilaurylated chitosan was found to be dissolvable in chloroform. The collapsed pressures of the samples derived from chitosan with 3000, 5000 and 10000 dalton are 47.6, 48.2 and 51.0 mN/m, respectively. The surface area occupied by the monomer unit(glucosamine) of all those samples is 0.6 nm2.展开更多
The isothermal solubility data of aqueous two-phase system ethanol+water+K 2HPO 4 were determined with the turbidity titration method at 303.2 K. The binodal curves were described by using the Mistry equation very w...The isothermal solubility data of aqueous two-phase system ethanol+water+K 2HPO 4 were determined with the turbidity titration method at 303.2 K. The binodal curves were described by using the Mistry equation very well. An experimental procedure for measuring the liquid-liquid equilibrium data of the aqueous two-phase system was proposed, in which the concentrations of the coexisting phases were determined with the corresponding densities of the solution. The tie lines were satisfactorily described by using the Othmer-Tobias and Bancroft equations.展开更多
It is observed by scanning tunneling microscopy (STM) that theadsorbed Benzotriazole (BTA) on copper is long in shape and has anirregular rectangle. The growth of BTA on copper is in the form ofpolymeric chain and mai...It is observed by scanning tunneling microscopy (STM) that theadsorbed Benzotriazole (BTA) on copper is long in shape and has anirregular rectangle. The growth of BTA on copper is in the form ofpolymeric chain and mainly in one dimension rather than twodimensions. The copper surface covered by BTA becomes flatter,smoother and the roughness was smaller than that of bare copper, sothe corrosion is largely decreased. However, many grooves can be seenbetween BTA polymeric chains in which corrosion may exist to adegree.展开更多
The polymerization of amphiphilic self assemblies is a promising method to synthesize nano structured materials with novel properties. These materials have many attractive features for their application in biomedica...The polymerization of amphiphilic self assemblies is a promising method to synthesize nano structured materials with novel properties. These materials have many attractive features for their application in biomedical area and materials science, such as catalysis, separation, surface modification, and therapeutics areas. A general review on the polymerization of lipids and surfactant self assemblies to amphiphilic self assemblies is given in this paper with 49 references. The polymerization and the subsequently resulted structure of lipids in different morphologies are summarized. The polymerization of polymerizable surfactants(surfmers) in emulsion and liquid crystalline phases are also discussed. The potential application of new nano porous materials is briefly described.展开更多
Fully acylated chitosan and N, N-diacyl chitosan were prepared. The products were characterized by elemental analysis, FTIR and 1H NMR. The experimental results indicate that the average degree of acylation depends ...Fully acylated chitosan and N, N-diacyl chitosan were prepared. The products were characterized by elemental analysis, FTIR and 1H NMR. The experimental results indicate that the average degree of acylation depends on the volume ratio of pyridine to chloroform in the reaction medium, the chain length of the acylation agent used, and the molecular weight of chitosan raw materials. The XRD measurements were carried out for pure chitosan, fully acylated chitosan and N, N-diacyl chitosan to verify the crystallinity change caused by the acylation.展开更多
The extraction of palladium(Ⅱ) from acidic media with cyclic sulfoxidedervva-tive-α-octyl-tetrahydrothiophene-1-oxide (OTMSO) was investigated. The extraction efficiencyof palla-dium(Ⅱ) with OTMSO is 97.1% at 0.3 m...The extraction of palladium(Ⅱ) from acidic media with cyclic sulfoxidedervva-tive-α-octyl-tetrahydrothiophene-1-oxide (OTMSO) was investigated. The extraction efficiencyof palla-dium(Ⅱ) with OTMSO is 97.1% at 0.3 mol·L^(-1) OTMSO. The plots of the extractionefficiency for palla-dium(Ⅲ) appear to lie on a convex curve having a minimum of extractionefficiency at 1-2 mol·L^(-1) HCl. The extraction reaction of palladium(Ⅱ) with OTMSO isendothermic, and ΔH_(OTMSO)~θ = 12.2 kJ·mol^(-1). The coordination number was studied with slopemethod. The result indicates that coordination number is 2. FT-IR spectra were used to analyze thestructure of complex and coordinated atom in complex. Pd is coordinated with both oxygen and sulfuratom in S=O group in OTMSO. The situation and intensity of peaks contributed by complex preparedfrom various acidity were different. The recovery of palladium(Ⅱ) with OTMSO from scrap containingpalladium was discussed. After silver and bismuth were removed, the feed solution was extractedthree times by 40% (volume fraction) OTMSO-kerosene. The loaded organic phase was scrubbed threetimes, and stripped three times by 2 mol·L^(-1) NH_3·H_2O solution. The total recovery ofpalladium was 99.8%, and the purity of palladium was 99.8 %.展开更多
A high-speed photographic method is mainly used to analyze metal transfer ofa cellulose covered electrode in the vertical down welding. The experimental results show that finedroplets spraying transfer and globular tr...A high-speed photographic method is mainly used to analyze metal transfer ofa cellulose covered electrode in the vertical down welding. The experimental results show that finedroplets spraying transfer and globular transfer are the dominant transfer characteristic. The largedroplet spatter, especially the upwards spatter, is a particular phenomenon. It is found that thecombination action of gas blow force, surface tension, gravitational force and electromagnetic forcelead to globular transfer. Gravitational force and electromagnetic force, which hasten big dropletspatter, should not be neglected.展开更多
The desulfurization experiment of an Al2O3-CaO base pre-molten refining slag containing SrO was carried out. Experimental samples were made from industrial materials. In order to predict the slag's desulfurization...The desulfurization experiment of an Al2O3-CaO base pre-molten refining slag containing SrO was carried out. Experimental samples were made from industrial materials. In order to predict the slag's desulfurization ability, sulphur capacity was calculated by means of optical basicity, and there is consistency between calculated results and experimental data. A mathematical model between components and sulphur partition ratio was established with the experimental data. Based on the regression equation, the effects of single and interactive components on sulphur partition ratio were discussed. The results show that the sulphur capacity and distribution ratio decrease with the increment of Al2O3/CaO. SrO and MgO can increase the sulphur partition ratio. The best content of SrO in the slag should not be more than 10%, and the MgO content should be about 8%. The effect of CaF2 on sulphur partition ratio is not obvious, therefore the addition should be limited for environmental protection.展开更多
Amphiphilic block copolymers can exhibit rich and complex morphologies in aqueous solutions, but these structures are usually delicate, easily disturbed by composition change or temperature change. In this work, the u...Amphiphilic block copolymers can exhibit rich and complex morphologies in aqueous solutions, but these structures are usually delicate, easily disturbed by composition change or temperature change. In this work, the use of different methods to cross link block copolymer self assemblies in the presence of a selective solvent and to stabilize the structures is reviewed. In addition, the cross linking reaction kinetics of block copolymer amphiphilic self assemblies is briefly discussed.展开更多
Two new symmetric chromophores: 2, 8-bis-[(2-4′-ethoxy phenyl-5-4′-styryl)-1, 3, 4- oxadiazole] didibenzothiophene (abbreviated as SO-G1) and 2, 8-bis-[(2-4′-ethoxy phenyl-5-4′- styryl)-1, 3, 4-oxadiazole]-N-ethyl...Two new symmetric chromophores: 2, 8-bis-[(2-4′-ethoxy phenyl-5-4′-styryl)-1, 3, 4- oxadiazole] didibenzothiophene (abbreviated as SO-G1) and 2, 8-bis-[(2-4′-ethoxy phenyl-5-4′- styryl)-1, 3, 4-oxadiazole]-N-ethyl carbazole (abbreviated as NO-G1) have been synthesized and characterized. Both chromophores exhibit strong two-photon absorption (TPA) with the cross-sections of 2.99×10-48 and 3.48×10-48 cm4?s?photon-1 in THF and large up-conversion emission, when pumped by Ti:sapphire femto-second laser at 720 nm.展开更多
The nickel hydroxide prepared by micro-emulsion method was doped by coprecipitated Zn. The effect of the amount of zinc-doped on the properties of Ni(OH)2 such as the reversibility of the electrode reaction, the charg...The nickel hydroxide prepared by micro-emulsion method was doped by coprecipitated Zn. The effect of the amount of zinc-doped on the properties of Ni(OH)2 such as the reversibility of the electrode reaction, the charge efficiency and active material utilization ratio of nickel electrode, and discharge specific capacity was studied by cyclic voltammetry and constant current charge-discharge tests. The results indicate that the specific discharge capacity of nickel hydroxide obtained by micro-emulsion method is much less than its theoretical value because the transfer of electrons and the diffusion of protons H+ are hindered owing to its crystal grain size in a nanometer range and thus possessing higher crystal interface resistance. The crystal cells are swelled and the crystal defects increased in prepared material due to part of Ni2+ substituted by Zn2+ when zinc and nickel hydroxide are coprecipitated. Hence, the electrons and protons H+ in the electrode reaction are transferred easily, the electrochemical behavior of nickel electrode is improved and discharge specific capacity is promoted. However, the performance of Ni(OH)2 is gradually enhanced with the addition of zinc-doped at first, while slowly decreased after the content of zinc is added to a certain value. The best electrode reaction reversibility, the highest electrode charge efficiency, the highest active material utilization ratio and the largest specific capacity on discharge are available when the mass fraction of Zn doped in nickel hydroxide by coprecipitation reaches 2.5 %.展开更多
The tensile deformation hot simulation test of as-cast 1420 Al-Li alloy was performed on Gleeble-1500 Thermal Simulator in the deformation temperature range from 350 to 450 ℃ and the strain rate range from 0.01 to l0...The tensile deformation hot simulation test of as-cast 1420 Al-Li alloy was performed on Gleeble-1500 Thermal Simulator in the deformation temperature range from 350 to 450 ℃ and the strain rate range from 0.01 to l0.0s-1.The tensile fracture behavior of the 1420 Al-Li alloy at high temperature was studied experimently. The results show that the tensile fracture mode of the 1420 Al-Li alloy at high temperature is changed from typical transgranular ductile fracture to intergranular brittle fracture with the increase of the deformation temperature and the strain rate. It is made out that the precipitation of LiH is the fundamental reason for the intergranular brittle fracture of the 1420 Al-Li alloy at high temperature. The mechanism of hydrogen embrittlement of the 1420 Al-Li alloy at high temperature was discussed, and it was proposed that the hydrogen embrittlement at high temperature is an integrated function of the dynamic and the static force, which enrichs the theories of hydrogen embrittlemen t.展开更多
Three new naphthaline-type chromophores end-capped with different (p-substituted amino) styryl groups on the both sides (named as BPASN, BHMASN and BMASN) have been synthesized. Under excitation of 380 nm, strong gree...Three new naphthaline-type chromophores end-capped with different (p-substituted amino) styryl groups on the both sides (named as BPASN, BHMASN and BMASN) have been synthesized. Under excitation of 380 nm, strong green light-emitting locating at 517 nm with the fluorescence quantum yield of 0.88 in CH2Cl2 has been obtained. In the presence of b-cyclodextrin (b-CD), strong blue-emitting at 456 nm in DMF was also recorded.展开更多
The effect of lithium on the casting microstructure of Cu-Li alloys was studied via the Wild MPS 46 Automatic camera, Deitz Diaplan, and scanning electron microscope. The result shows that trace lithium added to coppe...The effect of lithium on the casting microstructure of Cu-Li alloys was studied via the Wild MPS 46 Automatic camera, Deitz Diaplan, and scanning electron microscope. The result shows that trace lithium added to copper coarsens the grains of Cu-Li alloys in equiaxed crystal area because of the excellent purification effect. With the amount of lithium increasing, the average grain size increases sharply. But when the amount of lithium increases more, the average grain size decreases instead. At the same time, the typical dentritic crystal area of copper is diminished when lithium is added to pure copper.展开更多
基金Supported by the Science and Technology Fund of Fujian Education Departm ent(No.JB 0 2 0 5 8) ,Scientific Develop-ment Fund of Econom y and Trade Comm ission of Fujian Province(No.2 0 0 30 7) ,Science and Technology Department Fund ofFuzhou City(No.
文摘In order to establish a new method for making cellulose and lignin from Masson pine, a high boiling solvent(HBS) pulping process with an aqueous solvent of 1,4-butanediol was investigated. Masson pine chips were pulped with a 70%—90% aqueous solution of 1,4-butanediol containing a small amount of a catalyst at 200—220 ℃ for 60—180 min. HBS Masson pine cellulose is suitable for making paper. Water-insoluble HBS lignin was separated from the liquor reaction mixture by water precipitation. The recovered high boiling solvent(RHBS) is able to be recycled as a pulping solvent, indicating that the HBS method is a pulping process of Masson pine which is energy saving, resources saving and pollution free. HBS lignin has a better chemical reactivity and a lower ash content than lignin sulfonate.
文摘Dy0.8Sr0.2FeO3 nano powder, a synthetic oxide, is made by sol-gel method from metal nitrate and diethylenetriaminepentaacetic acid (DTPA), and the processing parameters are optimized. The process of the preparation, thermal decomposition and the property of the powder are studied by TG-DTA, IR, TEM, and XRD. The diameter of the average grain is about 70 nm. This new technique can be used in the preparation and the studying of na'no materials in the complex oxide system.
基金Supported by the National Natural Science Foundation of China(No.2 0 2 74 0 13) ,Key Project of the Fujian ProvincialScience and Technology(No.2 0 0 2 I0 0 4 ) and the Fujian Provincial Science Foundation of China(No.E0 110 0 2 7and C0 310 0 0 9)
文摘With sodium dodecyl sulfonate(SDS) as the phase transferring catalyst, N,N-Dilauryl chitosans with a high degree of alkyl group substitution were prepared and characterized by means of FTIR, 1H NMR and elemental analyses. The results indicate that the average degree of alkyl group substitution on the chitosan increases with decreasing the molecular weight of the chitosan. The fully N,N-dilaurylated chitosan was found to be dissolvable in chloroform. The collapsed pressures of the samples derived from chitosan with 3000, 5000 and 10000 dalton are 47.6, 48.2 and 51.0 mN/m, respectively. The surface area occupied by the monomer unit(glucosamine) of all those samples is 0.6 nm2.
基金Supported by Naturd Science Foundation of Fujian Province(No. E0 2 10 0 2 2 ),Japan Science and Technology Corpora-tion(JST)
文摘The isothermal solubility data of aqueous two-phase system ethanol+water+K 2HPO 4 were determined with the turbidity titration method at 303.2 K. The binodal curves were described by using the Mistry equation very well. An experimental procedure for measuring the liquid-liquid equilibrium data of the aqueous two-phase system was proposed, in which the concentrations of the coexisting phases were determined with the corresponding densities of the solution. The tie lines were satisfactorily described by using the Othmer-Tobias and Bancroft equations.
基金Supported by Study Foundation of the Hong Kong Polytechnic University.
文摘It is observed by scanning tunneling microscopy (STM) that theadsorbed Benzotriazole (BTA) on copper is long in shape and has anirregular rectangle. The growth of BTA on copper is in the form ofpolymeric chain and mainly in one dimension rather than twodimensions. The copper surface covered by BTA becomes flatter,smoother and the roughness was smaller than that of bare copper, sothe corrosion is largely decreased. However, many grooves can be seenbetween BTA polymeric chains in which corrosion may exist to adegree.
基金Supported by National Natural Science Foundation(No.0 5 1730 0 3) Beijing Science and Technology New Star Program(No.H0 10 4 10 0 10 112 ) and Im portant Natural Science Foundation of Beijing(No.2 0 310 0 1) .
文摘The polymerization of amphiphilic self assemblies is a promising method to synthesize nano structured materials with novel properties. These materials have many attractive features for their application in biomedical area and materials science, such as catalysis, separation, surface modification, and therapeutics areas. A general review on the polymerization of lipids and surfactant self assemblies to amphiphilic self assemblies is given in this paper with 49 references. The polymerization and the subsequently resulted structure of lipids in different morphologies are summarized. The polymerization of polymerizable surfactants(surfmers) in emulsion and liquid crystalline phases are also discussed. The potential application of new nano porous materials is briefly described.
文摘Fully acylated chitosan and N, N-diacyl chitosan were prepared. The products were characterized by elemental analysis, FTIR and 1H NMR. The experimental results indicate that the average degree of acylation depends on the volume ratio of pyridine to chloroform in the reaction medium, the chain length of the acylation agent used, and the molecular weight of chitosan raw materials. The XRD measurements were carried out for pure chitosan, fully acylated chitosan and N, N-diacyl chitosan to verify the crystallinity change caused by the acylation.
文摘The extraction of palladium(Ⅱ) from acidic media with cyclic sulfoxidedervva-tive-α-octyl-tetrahydrothiophene-1-oxide (OTMSO) was investigated. The extraction efficiencyof palla-dium(Ⅱ) with OTMSO is 97.1% at 0.3 mol·L^(-1) OTMSO. The plots of the extractionefficiency for palla-dium(Ⅲ) appear to lie on a convex curve having a minimum of extractionefficiency at 1-2 mol·L^(-1) HCl. The extraction reaction of palladium(Ⅱ) with OTMSO isendothermic, and ΔH_(OTMSO)~θ = 12.2 kJ·mol^(-1). The coordination number was studied with slopemethod. The result indicates that coordination number is 2. FT-IR spectra were used to analyze thestructure of complex and coordinated atom in complex. Pd is coordinated with both oxygen and sulfuratom in S=O group in OTMSO. The situation and intensity of peaks contributed by complex preparedfrom various acidity were different. The recovery of palladium(Ⅱ) with OTMSO from scrap containingpalladium was discussed. After silver and bismuth were removed, the feed solution was extractedthree times by 40% (volume fraction) OTMSO-kerosene. The loaded organic phase was scrubbed threetimes, and stripped three times by 2 mol·L^(-1) NH_3·H_2O solution. The total recovery ofpalladium was 99.8%, and the purity of palladium was 99.8 %.
基金This project is supported by Provincial Natural Science Foundation of Shanxi (No.546).
文摘A high-speed photographic method is mainly used to analyze metal transfer ofa cellulose covered electrode in the vertical down welding. The experimental results show that finedroplets spraying transfer and globular transfer are the dominant transfer characteristic. The largedroplet spatter, especially the upwards spatter, is a particular phenomenon. It is found that thecombination action of gas blow force, surface tension, gravitational force and electromagnetic forcelead to globular transfer. Gravitational force and electromagnetic force, which hasten big dropletspatter, should not be neglected.
文摘The desulfurization experiment of an Al2O3-CaO base pre-molten refining slag containing SrO was carried out. Experimental samples were made from industrial materials. In order to predict the slag's desulfurization ability, sulphur capacity was calculated by means of optical basicity, and there is consistency between calculated results and experimental data. A mathematical model between components and sulphur partition ratio was established with the experimental data. Based on the regression equation, the effects of single and interactive components on sulphur partition ratio were discussed. The results show that the sulphur capacity and distribution ratio decrease with the increment of Al2O3/CaO. SrO and MgO can increase the sulphur partition ratio. The best content of SrO in the slag should not be more than 10%, and the MgO content should be about 8%. The effect of CaF2 on sulphur partition ratio is not obvious, therefore the addition should be limited for environmental protection.
基金Supported by National Natural Science Foundation of China(No.0 5 1730 0 3) Beijing Science and Technology New StarProgram(No.H0 10 4 10 0 10 112 ) and Important Natural Science Foundation of Beijing(No.2 0 310 0 1) .
文摘Amphiphilic block copolymers can exhibit rich and complex morphologies in aqueous solutions, but these structures are usually delicate, easily disturbed by composition change or temperature change. In this work, the use of different methods to cross link block copolymer self assemblies in the presence of a selective solvent and to stabilize the structures is reviewed. In addition, the cross linking reaction kinetics of block copolymer amphiphilic self assemblies is briefly discussed.
基金This work was supported by the NNSFC(No.50273024)the Natural Foundation of Jiangsu Province(No.BK2002041 and BK2003031)the Foundation of Jiangsu Province Education Committee(No.02KJB430001 and 03KJB150115).
文摘Two new symmetric chromophores: 2, 8-bis-[(2-4′-ethoxy phenyl-5-4′-styryl)-1, 3, 4- oxadiazole] didibenzothiophene (abbreviated as SO-G1) and 2, 8-bis-[(2-4′-ethoxy phenyl-5-4′- styryl)-1, 3, 4-oxadiazole]-N-ethyl carbazole (abbreviated as NO-G1) have been synthesized and characterized. Both chromophores exhibit strong two-photon absorption (TPA) with the cross-sections of 2.99×10-48 and 3.48×10-48 cm4?s?photon-1 in THF and large up-conversion emission, when pumped by Ti:sapphire femto-second laser at 720 nm.
文摘The nickel hydroxide prepared by micro-emulsion method was doped by coprecipitated Zn. The effect of the amount of zinc-doped on the properties of Ni(OH)2 such as the reversibility of the electrode reaction, the charge efficiency and active material utilization ratio of nickel electrode, and discharge specific capacity was studied by cyclic voltammetry and constant current charge-discharge tests. The results indicate that the specific discharge capacity of nickel hydroxide obtained by micro-emulsion method is much less than its theoretical value because the transfer of electrons and the diffusion of protons H+ are hindered owing to its crystal grain size in a nanometer range and thus possessing higher crystal interface resistance. The crystal cells are swelled and the crystal defects increased in prepared material due to part of Ni2+ substituted by Zn2+ when zinc and nickel hydroxide are coprecipitated. Hence, the electrons and protons H+ in the electrode reaction are transferred easily, the electrochemical behavior of nickel electrode is improved and discharge specific capacity is promoted. However, the performance of Ni(OH)2 is gradually enhanced with the addition of zinc-doped at first, while slowly decreased after the content of zinc is added to a certain value. The best electrode reaction reversibility, the highest electrode charge efficiency, the highest active material utilization ratio and the largest specific capacity on discharge are available when the mass fraction of Zn doped in nickel hydroxide by coprecipitation reaches 2.5 %.
文摘The tensile deformation hot simulation test of as-cast 1420 Al-Li alloy was performed on Gleeble-1500 Thermal Simulator in the deformation temperature range from 350 to 450 ℃ and the strain rate range from 0.01 to l0.0s-1.The tensile fracture behavior of the 1420 Al-Li alloy at high temperature was studied experimently. The results show that the tensile fracture mode of the 1420 Al-Li alloy at high temperature is changed from typical transgranular ductile fracture to intergranular brittle fracture with the increase of the deformation temperature and the strain rate. It is made out that the precipitation of LiH is the fundamental reason for the intergranular brittle fracture of the 1420 Al-Li alloy at high temperature. The mechanism of hydrogen embrittlement of the 1420 Al-Li alloy at high temperature was discussed, and it was proposed that the hydrogen embrittlement at high temperature is an integrated function of the dynamic and the static force, which enrichs the theories of hydrogen embrittlemen t.
文摘Three new naphthaline-type chromophores end-capped with different (p-substituted amino) styryl groups on the both sides (named as BPASN, BHMASN and BMASN) have been synthesized. Under excitation of 380 nm, strong green light-emitting locating at 517 nm with the fluorescence quantum yield of 0.88 in CH2Cl2 has been obtained. In the presence of b-cyclodextrin (b-CD), strong blue-emitting at 456 nm in DMF was also recorded.
文摘The effect of lithium on the casting microstructure of Cu-Li alloys was studied via the Wild MPS 46 Automatic camera, Deitz Diaplan, and scanning electron microscope. The result shows that trace lithium added to copper coarsens the grains of Cu-Li alloys in equiaxed crystal area because of the excellent purification effect. With the amount of lithium increasing, the average grain size increases sharply. But when the amount of lithium increases more, the average grain size decreases instead. At the same time, the typical dentritic crystal area of copper is diminished when lithium is added to pure copper.
