Two new compounds containing triarylamine and benzoic hydrazide units, 4- [N,N-di(4-toyl)amino]benzaldehyde-N-(4-ethoxylphenyl)-formyl hydrazone 3a and 4-[N,N-di(4- toyl) amino]benzaldehyde-N-(2-ethoxylphenyl)-formyl ...Two new compounds containing triarylamine and benzoic hydrazide units, 4- [N,N-di(4-toyl)amino]benzaldehyde-N-(4-ethoxylphenyl)-formyl hydrazone 3a and 4-[N,N-di(4- toyl) amino]benzaldehyde-N-(2-ethoxylphenyl)-formyl hydrazone 3b, have been synthesized and their crystal structures (C30H29N3O2, Mr = 463.56) were interpreted by a combination technique of 1HNMR, IR, elemental analysis, mass spectra, UV-Vis spectra and X-ray crystallography, respec- tively. The crystal of 3a belongs to monoclinic, space group P21/n with a = 9.321(3) ? b = 11.046(4) ? c = 24.335(9) ? b =92.649(7), V = 2502.7(16) ?, Z = 4, m = 0.078 mm-1, Dc =1.230 g/cm3, F(000) = 984, the final R = 0.0590 and wR = 0.1316 for 4367 observed reflections with I > 2s(I). The crystal of 3b belongs to monoclinic, space group P21/c with a = 10.637(4) ? b = 24.138(10) ? c = 10.398(4) ? b = 104.913(8), V = 2579.8(17) ?, Z = 4, m = 0.075 mm-1, Dc = 1.194 g/cm3, F(000) = 984, the final R =0.0631 and wR =0.1006 for 4463 observed reflections with I > 2s(I). X-ray crystallography revealed that the nitrogen atom in the triarylamine moiety is of sp2 hybridization with the three phenyl rings twisted to each other.展开更多
A new process of enriching germanium from coal ash was developed. The processinvolves in mixing the coal ash and ammonium chloride and then roasting the mixture to producegermanium chloride that is then absorbed by di...A new process of enriching germanium from coal ash was developed. The processinvolves in mixing the coal ash and ammonium chloride and then roasting the mixture to producegermanium chloride that is then absorbed by dilute hydrochloric acid and hydrolyzed to germaniumoxide. The germanium recovery reached to 80.2% at the optimum condition: mass ratio of NH_4Cl/coalash is 0.15, roasting temperature 400℃ and roasting time 90 min.展开更多
A one dimension solid and a two dimension solid consisting of polyoxoanions bridged by {CoO 3N 2} and {CoO 4} groups respectively have been synthesized by the hydrothermal method and structurally characterized by...A one dimension solid and a two dimension solid consisting of polyoxoanions bridged by {CoO 3N 2} and {CoO 4} groups respectively have been synthesized by the hydrothermal method and structurally characterized by X Ray crystallography. Each structure has the [(PO 4) 4Mo 6O 15 ] 12- cluster that is commonly observed in many molybdophosphates. In compound 1, [(PO 4) 4Mo 6O 15 ] 12- clusters are linked by {CoO 3N 2} groups to form a chain like structure, and the chains are hydrogen bonded into a network. Compound 2 is a layer structure with channnels constructed from [(PO 4) 4Mo 6O 15 ] 12- clusters and {CoO 4} groups, the organic molecules and the lattice water molecules are distributed disorderly in the interlamellar region and form strong hydrogen bonds with inorganic framework. The IR and the fluorescent spectra were investigated and discussed.展开更多
A capillary electrophoresis (CE) method has been firstly used for the separation of the therapeutically important xanthones from Securidaca inappendiculata. The separation of the nine xanthones was systematically opt...A capillary electrophoresis (CE) method has been firstly used for the separation of the therapeutically important xanthones from Securidaca inappendiculata. The separation of the nine xanthones was systematically optimized with respect to pH, concentration of running buffers, addition of sulfated b-CD, applied voltage and column temperature. Baseline separation was achieved for the nine xanthones in less than 15 minutes using a background electrolyte consisting of 200 mmol/L borate (pH 9.5) and 10 mmol/L sulfated b-CD.展开更多
Regularity of the initial atmospheric corrosion of A3 steel in the presence of NaCI was investigated. The results showed that NaCI can accelerate the corrosion of A3 steel. Dry mass gain of A3 steel in the presence of...Regularity of the initial atmospheric corrosion of A3 steel in the presence of NaCI was investigated. The results showed that NaCI can accelerate the corrosion of A3 steel. Dry mass gain of A3 steel in the presence of NaCI deposition increases with the exposure time, which can be correlated by using exponential decay function. The relationship between dry mass gain and amount of NaCI deposition at a certain exposure time follows a quadratic function. More amount of NaCI deposition will slow down the corrosion rate to some extent after exposure for a certain time. SEM/EDAX was used to characterize the corrosion surface and products. The surfaces of the NaCI treated A3 steel were obviously uneven, and some tiny crevices appear in the corrosion products that could help O2 transmit to the inner layer. The amount of oxygen in atomic percentage in the corrosion products increases with the amount of NaCI deposition.展开更多
Via layer-by-layer assembly, the polyoxometalates of Keggin type, SiW_ 11O_ 39Ni(H_2O) 6-(SiNiW_ 11) and {SiW_ 11O_ 39Mn(H_2O) 6-}(SiMnW_ 11) were first immobilized on a 4-aminothiophenol(4-ATP) modified glassy carbon...Via layer-by-layer assembly, the polyoxometalates of Keggin type, SiW_ 11O_ 39Ni(H_2O) 6-(SiNiW_ 11) and {SiW_ 11O_ 39Mn(H_2O) 6-}(SiMnW_ 11) were first immobilized on a 4-aminothiophenol(4-ATP) modified glassy carbon electrode surface. The electrochemical behavior of these polyoxometalates was investigated. They exhibited some special properties in the films, which are different from those in a homogeneous aqueous solution. Their reaction mechanism in a multilayer film is proposed. The electrocatalytic behavior of these multilayer film electrodes for the reduction of BrO-_3 and NO-_2 were comparatively studied.展开更多
This study of the thermal decomposition kinetics of various average diameter nano-particles of cal-cium carbonate by means of TG-DTA(thermogravimetry and differential thermal analysis) showed that the thermal decompos...This study of the thermal decomposition kinetics of various average diameter nano-particles of cal-cium carbonate by means of TG-DTA(thermogravimetry and differential thermal analysis) showed that the thermal decomposition kinetic mechanisms of the same crystal type of calcium carbonate samples do not vary with decreasing of their average diameters ; their pseudo-active energy Ea; and that the top-temperature of decom-position Tp decreases gently in the scope of micron-sized diameter, but decreases sharply when the average di-ameter decreases from micron region to nanometer region. The extraordinary properties of nano-particles were explored by comparing the varying regularity of the mechanisms and kinetic parameters of the solid-phase reac-tions as well as their structural characterization with the variation of average diameters of particles. These show that the aggregation, surface effect as well as internal aberrance and stress of the nano-particles are the main reason causing both Ea and Tp to decline sharply with the decrease of the average diameter of nano-particles.展开更多
The structure and proton conducting mechanism of solid polymer electrolyte (SPE) are described. Since
the conductivity of electrolyte is important in SPE electrochemical cell research and development, we investigate ...The structure and proton conducting mechanism of solid polymer electrolyte (SPE) are described. Since
the conductivity of electrolyte is important in SPE electrochemical cell research and development, we investigate
quantitatively the conductivity of Nafion membrane and its dependence on temperature and relative humidity. Ex
perimental results show that the conductivity of Nafion membrane increases with temperature and relative humidity.
We also reports on the preparation and development of SPE membrane electrode with the emphasis on the mix
ture pressing method and impregnation-reduction process to prepare SPE composite electrode assemblies and their
application to electrochemical sensors. We also investigate and fabricate a potentiometric electrochemical sensor of hydrogen and ethylene to measure the hydrogen and ethylene partial pressure.展开更多
Water-conserving membrane is a new material of improving sandy soil. It is based on the rule that a compound with organic and inorganic components can produce colloid after its integrating with Ca2+ in soil. The water...Water-conserving membrane is a new material of improving sandy soil. It is based on the rule that a compound with organic and inorganic components can produce colloid after its integrating with Ca2+ in soil. The water-conserving membrane will obstruct capillary and increase viscidity of sandy soil, so as to decrease leakage and evaporation in sandy soil. The water-conserving membrane contains polyacrylic acid (PAA) and bentonite. When PAA concentration and pH of solution are different, water-conserving membrane can be made in different depth of soil. This experiment shows that the solution with 0.2% PAA does not harm and poison the crops, on the contrary, promotes crop germination. The solution with 0.2% or 0.4% PAA can accelerate corn growth. Accordingly, different crops need the application of the different PAA concentrations in the cultivation. Therefore, on the basis of different vadose coefficient in sandy soil, the solution with different PAA concentration can improve sandy soil and increase its water-conserving competence very well. The solution can be used to improve sandy soil and control desert enlargement in arid, semi-arid and semi-humid areas.展开更多
Two new ent-kauranoids, named maoyecrystals A (1) and B (2), were isolated from the EtOAc extract of the dried leaves of Isodon japonica (Burman f.) Hara collected in Tongbai mountains, Henan Province. Their structur...Two new ent-kauranoids, named maoyecrystals A (1) and B (2), were isolated from the EtOAc extract of the dried leaves of Isodon japonica (Burman f.) Hara collected in Tongbai mountains, Henan Province. Their structures were determined on the basis of spectral data, especially by 2D NMR.展开更多
The coastal seawater of Mediterranean of Alexandria receives large amount of discharged waters containing industrial wastes, sewage, and agricultural and domestic drainage. Fluoride and some parameters were(chemical a...The coastal seawater of Mediterranean of Alexandria receives large amount of discharged waters containing industrial wastes, sewage, and agricultural and domestic drainage. Fluoride and some parameters were(chemical and physical) determined. The data gave indication that the content and the amount of the discharged water largely affect the chemical composition of the coastal water. Stepwise regression analysis was highly significant and the model was very fruitful, where the observed and calculated values were mostly concordant. This may indicated that there was a relation between fluoride content in coastal seawater and its content in the discharged water.展开更多
Necessary and sufficient conditions for azeotropy in reactive mixtures axe derived in terms of elemental composition, which shows that in the space of elemental compositions, they take the same functional form as the ...Necessary and sufficient conditions for azeotropy in reactive mixtures axe derived in terms of elemental composition, which shows that in the space of elemental compositions, they take the same functional form as the conditions for azeotropy in non-reactive mixtures. The production of methyl tert-butyl ether (MTBE) is taken as an example. It is found that there are a 'pseudo' intermediate-boiling ternary reactive azeotrope at p=101.325 kPa and two 'real' ternary reactive azeotropes at p=101.325 Pa. The introduced elemental compositions also reduce the dimensionality of the phase diagrams and provide a natural set of variables for visualization of phase behavior.展开更多
The molecular structure of the title compound, ph3AsC (COCH3 )Seph, has been determined by X--ray diffraction. Crystallographic data: Mr= 517. 36'monoclinic, P21,/c, a=11. 499(4), b=9. 619(4), c=20. 919(7),A, β=9...The molecular structure of the title compound, ph3AsC (COCH3 )Seph, has been determined by X--ray diffraction. Crystallographic data: Mr= 517. 36'monoclinic, P21,/c, a=11. 499(4), b=9. 619(4), c=20. 919(7),A, β=98. 82(2)°,V= 2286(l) A 3, Z=4, Dc= 1. 509 g/cm3, μ(MoKa) = 3. 073 cm-1, F(000) = 1040and the final R=0. 042, Rw= 0. 041. In the molecule, the geometry of arsenic atom isa distorted tetrahedron, the bonds of Se--C (3) and As--C(31 ) have striking characteristics of double bond, the delocalization of electronic density occurs to be restrictedfrom O(1 ) to Se atoms.展开更多
The procedure of nebulization was studied with the introducationof ethanol into a lower power argon ICP. It was found that as ethanolintroduced, the physical properties of solutions changed, whichresults in an improve...The procedure of nebulization was studied with the introducationof ethanol into a lower power argon ICP. It was found that as ethanolintroduced, the physical properties of solutions changed, whichresults in an improvement on the nebulization efficiency. Anempirical relationship between the concentration of the aerosol andthe solution properties (viscosity, density, and surface tension) ispresented.展开更多
A new MEEKC method assisted with pressure-driven mobile phase was presented for the separation of felted explosives. Microemulsion solution was composed of 80 mmol/L heptane -120 mmol/L SDS (sodium dodecyl sulphate) -...A new MEEKC method assisted with pressure-driven mobile phase was presented for the separation of felted explosives. Microemulsion solution was composed of 80 mmol/L heptane -120 mmol/L SDS (sodium dodecyl sulphate) - 900 mmol/L butanol - 10 mmol/L borate at pH 9.4 and a pressure-driven flow of 0.020 mL/min under 1.3 MPa was employed to manipulate the separation. Explosives HMX (1, 3, 5, 7-tetranitro-l, 3, 5, 7-tetrazacyclooctane) and TATB (triamino-trinitrobenzene), which were felted on fluorine rubber F2311 (polytrifluorochlorethylene and polyvinylidene fluoride 1/1 co-polymerization) and F2314 (polytrifluorochlorethylene and polyvinylidene fluoride 4/1 co-polymerization) were well separated with very good peak shapes.展开更多
Nicotinic acetylcholine receptors(nChRs) are involved in the various pharmacological effects or disease states.In order to study the central nChRs by PET or SPECT,some radioligands have been investigated.In this paper...Nicotinic acetylcholine receptors(nChRs) are involved in the various pharmacological effects or disease states.In order to study the central nChRs by PET or SPECT,some radioligands have been investigated.In this paper,the procedure for synthesis of 2-[^18F] fluoro-3-[2(S)-2-azetidinylmethoxy]pyridine(2-[^18F0-A-85380),a potential PET ligand for in vivo imaging nicotinic acetylcholine receptor was described.2-[^18F]-A-85380 was prepared from the precursor,2-nitro-3-[(1-(tert-butoxycarbonyl)-2-(S0-azetidinyl)methoxy] pyridine(4),which was synthesized with commercial (S)-2-zaetid-inecarboxylic acid as starting material.The whole procedure for radiosynthesis and purification was executed in about 1h and 45-55% of the added fluorine-18 was found in the purified 2-[^18F]-A-85380,with specific activity of 1.0-2.2×10^11 Bq/umol.展开更多
Pt(Ⅱ) and Pd(Ⅱ) complexes with 2′,3′,4′,5,7-pentahydroxy-flavone weresynthesized and characterized by elemental analysis, molar conductance, IR, ~1HNMR, TG-DTA, UV-Visspectroscopic techniques, and fluorescence an...Pt(Ⅱ) and Pd(Ⅱ) complexes with 2′,3′,4′,5,7-pentahydroxy-flavone weresynthesized and characterized by elemental analysis, molar conductance, IR, ~1HNMR, TG-DTA, UV-Visspectroscopic techniques, and fluorescence analysis. The scavenging effect on the superoxide radical(O_2^-) and the inhibitory effect on lipid peroxides were also investigated. Both the ligand andthe complexes exhibit scavenging effect on superoxide radicals, and the effect of the complexes isgreater than that of the ligand. The Pt(Ⅱ) complex exhibits the strongest scavenging efficiency.Both Pt(Ⅱ) and Pd(Ⅱ) complexes have the inhibitory effect on lipid peroxides, and the effect ofthe complexes is greater than that of the ligand, but the Pt(Ⅱ) complex has a high effect ofpromoting lipid peroxides.展开更多
基金This project was supported by the National Natural Science Foundation of China (No. 20072018 and 29832030)
文摘Two new compounds containing triarylamine and benzoic hydrazide units, 4- [N,N-di(4-toyl)amino]benzaldehyde-N-(4-ethoxylphenyl)-formyl hydrazone 3a and 4-[N,N-di(4- toyl) amino]benzaldehyde-N-(2-ethoxylphenyl)-formyl hydrazone 3b, have been synthesized and their crystal structures (C30H29N3O2, Mr = 463.56) were interpreted by a combination technique of 1HNMR, IR, elemental analysis, mass spectra, UV-Vis spectra and X-ray crystallography, respec- tively. The crystal of 3a belongs to monoclinic, space group P21/n with a = 9.321(3) ? b = 11.046(4) ? c = 24.335(9) ? b =92.649(7), V = 2502.7(16) ?, Z = 4, m = 0.078 mm-1, Dc =1.230 g/cm3, F(000) = 984, the final R = 0.0590 and wR = 0.1316 for 4367 observed reflections with I > 2s(I). The crystal of 3b belongs to monoclinic, space group P21/c with a = 10.637(4) ? b = 24.138(10) ? c = 10.398(4) ? b = 104.913(8), V = 2579.8(17) ?, Z = 4, m = 0.075 mm-1, Dc = 1.194 g/cm3, F(000) = 984, the final R =0.0631 and wR =0.1006 for 4463 observed reflections with I > 2s(I). X-ray crystallography revealed that the nitrogen atom in the triarylamine moiety is of sp2 hybridization with the three phenyl rings twisted to each other.
基金This project is financially supported by the National Nature Science Foundation of China (No. 59804004) and (No.50274046)
文摘A new process of enriching germanium from coal ash was developed. The processinvolves in mixing the coal ash and ammonium chloride and then roasting the mixture to producegermanium chloride that is then absorbed by dilute hydrochloric acid and hydrolyzed to germaniumoxide. The germanium recovery reached to 80.2% at the optimum condition: mass ratio of NH_4Cl/coalash is 0.15, roasting temperature 400℃ and roasting time 90 min.
文摘A one dimension solid and a two dimension solid consisting of polyoxoanions bridged by {CoO 3N 2} and {CoO 4} groups respectively have been synthesized by the hydrothermal method and structurally characterized by X Ray crystallography. Each structure has the [(PO 4) 4Mo 6O 15 ] 12- cluster that is commonly observed in many molybdophosphates. In compound 1, [(PO 4) 4Mo 6O 15 ] 12- clusters are linked by {CoO 3N 2} groups to form a chain like structure, and the chains are hydrogen bonded into a network. Compound 2 is a layer structure with channnels constructed from [(PO 4) 4Mo 6O 15 ] 12- clusters and {CoO 4} groups, the organic molecules and the lattice water molecules are distributed disorderly in the interlamellar region and form strong hydrogen bonds with inorganic framework. The IR and the fluorescent spectra were investigated and discussed.
基金The authors would like to acknowledge Agilent Technologies for providing the capillary electrophoresis system and Bioanalytical System for present of sulfated b-CD. The study is supported by NSFC Grant No. 29875001.
文摘A capillary electrophoresis (CE) method has been firstly used for the separation of the therapeutically important xanthones from Securidaca inappendiculata. The separation of the nine xanthones was systematically optimized with respect to pH, concentration of running buffers, addition of sulfated b-CD, applied voltage and column temperature. Baseline separation was achieved for the nine xanthones in less than 15 minutes using a background electrolyte consisting of 200 mmol/L borate (pH 9.5) and 10 mmol/L sulfated b-CD.
基金This work was financially supported by the National Natural Science Foundation of China. The number of the project is 5989914. The authors are grateful to Ms. Ping Wan for English diction.
文摘Regularity of the initial atmospheric corrosion of A3 steel in the presence of NaCI was investigated. The results showed that NaCI can accelerate the corrosion of A3 steel. Dry mass gain of A3 steel in the presence of NaCI deposition increases with the exposure time, which can be correlated by using exponential decay function. The relationship between dry mass gain and amount of NaCI deposition at a certain exposure time follows a quadratic function. More amount of NaCI deposition will slow down the corrosion rate to some extent after exposure for a certain time. SEM/EDAX was used to characterize the corrosion surface and products. The surfaces of the NaCI treated A3 steel were obviously uneven, and some tiny crevices appear in the corrosion products that could help O2 transmit to the inner layer. The amount of oxygen in atomic percentage in the corrosion products increases with the amount of NaCI deposition.
文摘Via layer-by-layer assembly, the polyoxometalates of Keggin type, SiW_ 11O_ 39Ni(H_2O) 6-(SiNiW_ 11) and {SiW_ 11O_ 39Mn(H_2O) 6-}(SiMnW_ 11) were first immobilized on a 4-aminothiophenol(4-ATP) modified glassy carbon electrode surface. The electrochemical behavior of these polyoxometalates was investigated. They exhibited some special properties in the films, which are different from those in a homogeneous aqueous solution. Their reaction mechanism in a multilayer film is proposed. The electrocatalytic behavior of these multilayer film electrodes for the reduction of BrO-_3 and NO-_2 were comparatively studied.
文摘This study of the thermal decomposition kinetics of various average diameter nano-particles of cal-cium carbonate by means of TG-DTA(thermogravimetry and differential thermal analysis) showed that the thermal decomposition kinetic mechanisms of the same crystal type of calcium carbonate samples do not vary with decreasing of their average diameters ; their pseudo-active energy Ea; and that the top-temperature of decom-position Tp decreases gently in the scope of micron-sized diameter, but decreases sharply when the average di-ameter decreases from micron region to nanometer region. The extraordinary properties of nano-particles were explored by comparing the varying regularity of the mechanisms and kinetic parameters of the solid-phase reac-tions as well as their structural characterization with the variation of average diameters of particles. These show that the aggregation, surface effect as well as internal aberrance and stress of the nano-particles are the main reason causing both Ea and Tp to decline sharply with the decrease of the average diameter of nano-particles.
基金Supported by the National Natural Science Foundation of China (No. 29875002) and the Natural Science Foundation of Beijing (No. 2002017).
文摘The structure and proton conducting mechanism of solid polymer electrolyte (SPE) are described. Since
the conductivity of electrolyte is important in SPE electrochemical cell research and development, we investigate
quantitatively the conductivity of Nafion membrane and its dependence on temperature and relative humidity. Ex
perimental results show that the conductivity of Nafion membrane increases with temperature and relative humidity.
We also reports on the preparation and development of SPE membrane electrode with the emphasis on the mix
ture pressing method and impregnation-reduction process to prepare SPE composite electrode assemblies and their
application to electrochemical sensors. We also investigate and fabricate a potentiometric electrochemical sensor of hydrogen and ethylene to measure the hydrogen and ethylene partial pressure.
基金Undertheauspicesof the of Ministry of ScienceandTechnologyofChina(No.2001BA508B05)
文摘Water-conserving membrane is a new material of improving sandy soil. It is based on the rule that a compound with organic and inorganic components can produce colloid after its integrating with Ca2+ in soil. The water-conserving membrane will obstruct capillary and increase viscidity of sandy soil, so as to decrease leakage and evaporation in sandy soil. The water-conserving membrane contains polyacrylic acid (PAA) and bentonite. When PAA concentration and pH of solution are different, water-conserving membrane can be made in different depth of soil. This experiment shows that the solution with 0.2% PAA does not harm and poison the crops, on the contrary, promotes crop germination. The solution with 0.2% or 0.4% PAA can accelerate corn growth. Accordingly, different crops need the application of the different PAA concentrations in the cultivation. Therefore, on the basis of different vadose coefficient in sandy soil, the solution with different PAA concentration can improve sandy soil and increase its water-conserving competence very well. The solution can be used to improve sandy soil and control desert enlargement in arid, semi-arid and semi-humid areas.
文摘Two new ent-kauranoids, named maoyecrystals A (1) and B (2), were isolated from the EtOAc extract of the dried leaves of Isodon japonica (Burman f.) Hara collected in Tongbai mountains, Henan Province. Their structures were determined on the basis of spectral data, especially by 2D NMR.
文摘The coastal seawater of Mediterranean of Alexandria receives large amount of discharged waters containing industrial wastes, sewage, and agricultural and domestic drainage. Fluoride and some parameters were(chemical and physical) determined. The data gave indication that the content and the amount of the discharged water largely affect the chemical composition of the coastal water. Stepwise regression analysis was highly significant and the model was very fruitful, where the observed and calculated values were mostly concordant. This may indicated that there was a relation between fluoride content in coastal seawater and its content in the discharged water.
基金Supported by the National Natural Science Foundation of China (No.29976035) and Zhejiang and Fujian Provincial Natural Science Foundation of China.
文摘Necessary and sufficient conditions for azeotropy in reactive mixtures axe derived in terms of elemental composition, which shows that in the space of elemental compositions, they take the same functional form as the conditions for azeotropy in non-reactive mixtures. The production of methyl tert-butyl ether (MTBE) is taken as an example. It is found that there are a 'pseudo' intermediate-boiling ternary reactive azeotrope at p=101.325 kPa and two 'real' ternary reactive azeotropes at p=101.325 Pa. The introduced elemental compositions also reduce the dimensionality of the phase diagrams and provide a natural set of variables for visualization of phase behavior.
文摘The molecular structure of the title compound, ph3AsC (COCH3 )Seph, has been determined by X--ray diffraction. Crystallographic data: Mr= 517. 36'monoclinic, P21,/c, a=11. 499(4), b=9. 619(4), c=20. 919(7),A, β=98. 82(2)°,V= 2286(l) A 3, Z=4, Dc= 1. 509 g/cm3, μ(MoKa) = 3. 073 cm-1, F(000) = 1040and the final R=0. 042, Rw= 0. 041. In the molecule, the geometry of arsenic atom isa distorted tetrahedron, the bonds of Se--C (3) and As--C(31 ) have striking characteristics of double bond, the delocalization of electronic density occurs to be restrictedfrom O(1 ) to Se atoms.
文摘The procedure of nebulization was studied with the introducationof ethanol into a lower power argon ICP. It was found that as ethanolintroduced, the physical properties of solutions changed, whichresults in an improvement on the nebulization efficiency. Anempirical relationship between the concentration of the aerosol andthe solution properties (viscosity, density, and surface tension) ispresented.
文摘A new MEEKC method assisted with pressure-driven mobile phase was presented for the separation of felted explosives. Microemulsion solution was composed of 80 mmol/L heptane -120 mmol/L SDS (sodium dodecyl sulphate) - 900 mmol/L butanol - 10 mmol/L borate at pH 9.4 and a pressure-driven flow of 0.020 mL/min under 1.3 MPa was employed to manipulate the separation. Explosives HMX (1, 3, 5, 7-tetranitro-l, 3, 5, 7-tetrazacyclooctane) and TATB (triamino-trinitrobenzene), which were felted on fluorine rubber F2311 (polytrifluorochlorethylene and polyvinylidene fluoride 1/1 co-polymerization) and F2314 (polytrifluorochlorethylene and polyvinylidene fluoride 4/1 co-polymerization) were well separated with very good peak shapes.
文摘Nicotinic acetylcholine receptors(nChRs) are involved in the various pharmacological effects or disease states.In order to study the central nChRs by PET or SPECT,some radioligands have been investigated.In this paper,the procedure for synthesis of 2-[^18F] fluoro-3-[2(S)-2-azetidinylmethoxy]pyridine(2-[^18F0-A-85380),a potential PET ligand for in vivo imaging nicotinic acetylcholine receptor was described.2-[^18F]-A-85380 was prepared from the precursor,2-nitro-3-[(1-(tert-butoxycarbonyl)-2-(S0-azetidinyl)methoxy] pyridine(4),which was synthesized with commercial (S)-2-zaetid-inecarboxylic acid as starting material.The whole procedure for radiosynthesis and purification was executed in about 1h and 45-55% of the added fluorine-18 was found in the purified 2-[^18F]-A-85380,with specific activity of 1.0-2.2×10^11 Bq/umol.
文摘Pt(Ⅱ) and Pd(Ⅱ) complexes with 2′,3′,4′,5,7-pentahydroxy-flavone weresynthesized and characterized by elemental analysis, molar conductance, IR, ~1HNMR, TG-DTA, UV-Visspectroscopic techniques, and fluorescence analysis. The scavenging effect on the superoxide radical(O_2^-) and the inhibitory effect on lipid peroxides were also investigated. Both the ligand andthe complexes exhibit scavenging effect on superoxide radicals, and the effect of the complexes isgreater than that of the ligand. The Pt(Ⅱ) complex exhibits the strongest scavenging efficiency.Both Pt(Ⅱ) and Pd(Ⅱ) complexes have the inhibitory effect on lipid peroxides, and the effect ofthe complexes is greater than that of the ligand, but the Pt(Ⅱ) complex has a high effect ofpromoting lipid peroxides.