The in-situ FTIR spectroscopic results show that a hemi-ketal in- termediate may be produced in the electroreduction of benzoquinone or electro- oxidation of benzohydroquinone,which provides a valuable insight into th...The in-situ FTIR spectroscopic results show that a hemi-ketal in- termediate may be produced in the electroreduction of benzoquinone or electro- oxidation of benzohydroquinone,which provides a valuable insight into the me- chanism of the redox process.展开更多
Mechanical alloying (MA) was employed to produce supersaturated solid solutions of Fe1-xCux,which is virtually immiscible under an equilibrium condition at ambjent temperature. The X-ray diffraction results show that ...Mechanical alloying (MA) was employed to produce supersaturated solid solutions of Fe1-xCux,which is virtually immiscible under an equilibrium condition at ambjent temperature. The X-ray diffraction results show that the solutions formed in the concentration ranges of x≤0.1 5 and x≥0.40 are of bcc structure of iron and fcc structure of copper. respectively. For the region in between.however, the alloy obtained is a mixture of bcc plus fcc phases. The Mossbauer spectrum of the solid solution of a single phase could be fitted by two sub-spectra with hyperfine magnetic fields of 200 and 250 kOe. respectively. suggesting that there must exist two forms of coordination in the solution. While to fit the spectrum for the solution with mixed structu re. three Sub-spectra. including a spectrum of α-Fe, should be used. The variation of the Mossbauer spectra of Fe60Cu40 with milling time as well as annealing temperature was systematically studied. This may be ascribed to the changes of the number of nearest neighboring atoms of iron in the processes of formation and decomposition of the solid solution during milling and annealing展开更多
The interactions of La( Ⅲ ), Pr( Ⅲ ), Nd( Ⅲ ), Sm( Ⅲ ), Eu(Ⅲ), Gd( Ⅲ ), Dy( Ⅲ ), and Yb( Ⅲ ) with cytosine, 5-bromocytosine, 5-azacytosine and 5-flurocytosine as primary ligands (L) and guani...The interactions of La( Ⅲ ), Pr( Ⅲ ), Nd( Ⅲ ), Sm( Ⅲ ), Eu(Ⅲ), Gd( Ⅲ ), Dy( Ⅲ ), and Yb( Ⅲ ) with cytosine, 5-bromocytosine, 5-azacytosine and 5-flurocytosine as primary ligands (L) and guanine (A) as secondary ligand for both binary ( 1 : 1 ) as well as ternary ( 1 : 1 : 1 ) systems were investigated by potentiometric equilibrium measurements at 25, 35 and 45 ℃ in aqueous solution (ionic strength, μ = 0.1 mol·dm^-3 NaNO3). The stability constants of the binary ( 1 : 1 ) and ternary ( 1 : 1 : 1 ) metal-ligand complexes follow the following order La 〈 Pr 〈 Nd 〈 Sm 〈 Eu 〉 Gd 〈 Dy 〉 Yb. Results also indicate that the ternary lanthanide complexes of La(Ⅲ), Pr(Ⅲ), Nd(Ⅲ), Sm(Ⅲ), Eu(Ⅲ), Gd(Ⅲ), Dy(Ⅲ), and Yb( Ⅲ ) are more stable than corresponding binary lanthanide complexes. The enthalpy (△Hf^o) and entropy (△Sf^o) changes for the formation of binary and ternary complexes were calculated from temperature coefficient data. The △△Sf^o values are positive for all the metal ligand systems. The negative △△Hf^o values indicate the extra stability of the ternary complexes by the exothermic enthalpy changes (△△Sf^o = △TSf^o - △BSf^o and △△Hf^o = △THf^o - △BHf^o where △TSf^o, △THf^o and △BSf^o, △BHf^o are the entropy and enthalpy values associated with the ternary and binary complexes, respectively). It was also proposed that the guanine is bonded to metal ions through N1/C6 = O and N7 whereas cytosine and its derivatives are bonded through N3 atoms in ternary complexes.展开更多
In-situ time-resolved Raman spectroscopy(TRRS)has been applied on studies of electrochemical adsorption of thiocyanate at silver electrode during potential cycles and potential step.It is shown that some dynamic infor...In-situ time-resolved Raman spectroscopy(TRRS)has been applied on studies of electrochemical adsorption of thiocyanate at silver electrode during potential cycles and potential step.It is shown that some dynamic information about the adsorption and desorption processes can be obtained.展开更多
The clinical study of solute removal index (SRI) was performed in 20 stable maintenance hemodialysis patients in order to find a proper hemodialydsis dosage and improve the life quality of the patients.Plasma BUN leve...The clinical study of solute removal index (SRI) was performed in 20 stable maintenance hemodialysis patients in order to find a proper hemodialydsis dosage and improve the life quality of the patients.Plasma BUN levels were tested pre-hemodialysis and 0, 1 hr post-hemodialysis. Urea generation rate (G)、protein catabolic rate(PCR)、solute removal amount(R)、SRI were calculated by double pools urea kinetic model . The result showed that urea rebound rate was 18.5±3.35 % 1 hr after hemodialysis,R was 13.82±5.48 g, G was 4.85±1.39 g, PCR was 0.94±0.29 g/kg.d, SRI was 71.33±6.8% respectively, which indicated that SRI was a better index to quantitate the adequacy of hemodialysis.展开更多
The reaction of bis-[2-amino-4-pheny1-5-thiazolyl] disulfide with 5-nitro-salicylaldehyde in absolute ethanol resulted in the formation of a new Schiff base ligand H<sub>2</sub>L (1). Characterization of t...The reaction of bis-[2-amino-4-pheny1-5-thiazolyl] disulfide with 5-nitro-salicylaldehyde in absolute ethanol resulted in the formation of a new Schiff base ligand H<sub>2</sub>L (1). Characterization of the ligand was performed by FT-IR, <sup>1</sup>H NMR, <sup>13</sup>C NMR, UV-Vis, elemental analysis and single crystal X-ray diffraction. The ligand, (1), possesses a disulfide –S–S– bridge of 2.1121 (3) ? length, and the molecule adopts a cis-conformation around this bond. In the crystal structure of (1), an intramolecular O–H···N hydrogen bond with D… A distance of 2.69 (3) ? was present. The reaction of (1) with Co(NO<sub>3</sub>)<sub>2</sub>·6H<sub>2</sub>O and CuCl<sub>2</sub>·2H<sub>2</sub>O in methanol afforded the corresponding metal complexes. The obtained solids were further investigated by elemental analysis and UV-Vis titration that confirmed the formation of [CoL] and [ClCuHL] complexes. However, recrystallizaion of the Co(II) complex in dimethylsulfoxide caused the complete hydrolysis of the imine bond and afforded a Co(II) complex in which two 5-nitro-salicylaldehyde and two DMSO molecules were coordinated to the central metal in an octahedral fashion. This structure (2) was also confirmed by single crystal X-ray analysis.展开更多
Based on the Reddy's theory of plates with the effect of higher-order shear deformations, the governing equations for bending of orthotropic plates with finite deformations were established. The differential quadr...Based on the Reddy's theory of plates with the effect of higher-order shear deformations, the governing equations for bending of orthotropic plates with finite deformations were established. The differential quadrature (DQ) method of nonlinear analysis to the problem was presented. New DQ approach, presented by Wang and Bert (DQWB), is extended to handle the multiple boundary conditions of plates. The techniques were also further extended to simplify nonlinear computations. The numerical convergence and comparison of solutions were studied. The results show that the DQ method presented is very reliable and valid. Moreover, the influences of geometric and material parameters as well as the transverse shear deformations on nonlinear bending were investigated. Numerical results show the influence of the shear deformation on the static bending of orthotropic moderately thick plate is significant.展开更多
文摘The in-situ FTIR spectroscopic results show that a hemi-ketal in- termediate may be produced in the electroreduction of benzoquinone or electro- oxidation of benzohydroquinone,which provides a valuable insight into the me- chanism of the redox process.
文摘Mechanical alloying (MA) was employed to produce supersaturated solid solutions of Fe1-xCux,which is virtually immiscible under an equilibrium condition at ambjent temperature. The X-ray diffraction results show that the solutions formed in the concentration ranges of x≤0.1 5 and x≥0.40 are of bcc structure of iron and fcc structure of copper. respectively. For the region in between.however, the alloy obtained is a mixture of bcc plus fcc phases. The Mossbauer spectrum of the solid solution of a single phase could be fitted by two sub-spectra with hyperfine magnetic fields of 200 and 250 kOe. respectively. suggesting that there must exist two forms of coordination in the solution. While to fit the spectrum for the solution with mixed structu re. three Sub-spectra. including a spectrum of α-Fe, should be used. The variation of the Mossbauer spectra of Fe60Cu40 with milling time as well as annealing temperature was systematically studied. This may be ascribed to the changes of the number of nearest neighboring atoms of iron in the processes of formation and decomposition of the solid solution during milling and annealing
基金Project supported by UGC, New Delhi ,in the formof a major research scheme (12-107/2001(SR-I))
文摘The interactions of La( Ⅲ ), Pr( Ⅲ ), Nd( Ⅲ ), Sm( Ⅲ ), Eu(Ⅲ), Gd( Ⅲ ), Dy( Ⅲ ), and Yb( Ⅲ ) with cytosine, 5-bromocytosine, 5-azacytosine and 5-flurocytosine as primary ligands (L) and guanine (A) as secondary ligand for both binary ( 1 : 1 ) as well as ternary ( 1 : 1 : 1 ) systems were investigated by potentiometric equilibrium measurements at 25, 35 and 45 ℃ in aqueous solution (ionic strength, μ = 0.1 mol·dm^-3 NaNO3). The stability constants of the binary ( 1 : 1 ) and ternary ( 1 : 1 : 1 ) metal-ligand complexes follow the following order La 〈 Pr 〈 Nd 〈 Sm 〈 Eu 〉 Gd 〈 Dy 〉 Yb. Results also indicate that the ternary lanthanide complexes of La(Ⅲ), Pr(Ⅲ), Nd(Ⅲ), Sm(Ⅲ), Eu(Ⅲ), Gd(Ⅲ), Dy(Ⅲ), and Yb( Ⅲ ) are more stable than corresponding binary lanthanide complexes. The enthalpy (△Hf^o) and entropy (△Sf^o) changes for the formation of binary and ternary complexes were calculated from temperature coefficient data. The △△Sf^o values are positive for all the metal ligand systems. The negative △△Hf^o values indicate the extra stability of the ternary complexes by the exothermic enthalpy changes (△△Sf^o = △TSf^o - △BSf^o and △△Hf^o = △THf^o - △BHf^o where △TSf^o, △THf^o and △BSf^o, △BHf^o are the entropy and enthalpy values associated with the ternary and binary complexes, respectively). It was also proposed that the guanine is bonded to metal ions through N1/C6 = O and N7 whereas cytosine and its derivatives are bonded through N3 atoms in ternary complexes.
文摘In-situ time-resolved Raman spectroscopy(TRRS)has been applied on studies of electrochemical adsorption of thiocyanate at silver electrode during potential cycles and potential step.It is shown that some dynamic information about the adsorption and desorption processes can be obtained.
文摘The clinical study of solute removal index (SRI) was performed in 20 stable maintenance hemodialysis patients in order to find a proper hemodialydsis dosage and improve the life quality of the patients.Plasma BUN levels were tested pre-hemodialysis and 0, 1 hr post-hemodialysis. Urea generation rate (G)、protein catabolic rate(PCR)、solute removal amount(R)、SRI were calculated by double pools urea kinetic model . The result showed that urea rebound rate was 18.5±3.35 % 1 hr after hemodialysis,R was 13.82±5.48 g, G was 4.85±1.39 g, PCR was 0.94±0.29 g/kg.d, SRI was 71.33±6.8% respectively, which indicated that SRI was a better index to quantitate the adequacy of hemodialysis.
文摘The reaction of bis-[2-amino-4-pheny1-5-thiazolyl] disulfide with 5-nitro-salicylaldehyde in absolute ethanol resulted in the formation of a new Schiff base ligand H<sub>2</sub>L (1). Characterization of the ligand was performed by FT-IR, <sup>1</sup>H NMR, <sup>13</sup>C NMR, UV-Vis, elemental analysis and single crystal X-ray diffraction. The ligand, (1), possesses a disulfide –S–S– bridge of 2.1121 (3) ? length, and the molecule adopts a cis-conformation around this bond. In the crystal structure of (1), an intramolecular O–H···N hydrogen bond with D… A distance of 2.69 (3) ? was present. The reaction of (1) with Co(NO<sub>3</sub>)<sub>2</sub>·6H<sub>2</sub>O and CuCl<sub>2</sub>·2H<sub>2</sub>O in methanol afforded the corresponding metal complexes. The obtained solids were further investigated by elemental analysis and UV-Vis titration that confirmed the formation of [CoL] and [ClCuHL] complexes. However, recrystallizaion of the Co(II) complex in dimethylsulfoxide caused the complete hydrolysis of the imine bond and afforded a Co(II) complex in which two 5-nitro-salicylaldehyde and two DMSO molecules were coordinated to the central metal in an octahedral fashion. This structure (2) was also confirmed by single crystal X-ray analysis.
文摘Based on the Reddy's theory of plates with the effect of higher-order shear deformations, the governing equations for bending of orthotropic plates with finite deformations were established. The differential quadrature (DQ) method of nonlinear analysis to the problem was presented. New DQ approach, presented by Wang and Bert (DQWB), is extended to handle the multiple boundary conditions of plates. The techniques were also further extended to simplify nonlinear computations. The numerical convergence and comparison of solutions were studied. The results show that the DQ method presented is very reliable and valid. Moreover, the influences of geometric and material parameters as well as the transverse shear deformations on nonlinear bending were investigated. Numerical results show the influence of the shear deformation on the static bending of orthotropic moderately thick plate is significant.