The denaturational behaviour of bovine β-lactoglobulin B has been studied in solutions containing guanidine hydrochloride by differential scanning calorimetry. The experiments have shown that complete peaks of cold d...The denaturational behaviour of bovine β-lactoglobulin B has been studied in solutions containing guanidine hydrochloride by differential scanning calorimetry. The experiments have shown that complete peaks of cold denaturation can be recorded also in high concentration of protein solutions. The cold denaturation and the renaturation of the protein are reproducible, but the thermal denaturation is irreversible. The activation energy of thermal denaturation calculated is about 285 kJ/mol.展开更多
The modified shear lag model proposed recently was applied to calculate thermal residual stresses and subsequent stress distributions under tensile and compressive loadings. The expressions for the elastic moduli and ...The modified shear lag model proposed recently was applied to calculate thermal residual stresses and subsequent stress distributions under tensile and compressive loadings. The expressions for the elastic moduli and the yield strengths under tensile and compressive loadings were derived which take account of thermal residual stresses. The asymmetries in the elastic modulus and the yield strength were interpreted using the derived expressions and the obtained results of the stress calculations. The model predictions have exhibited good agreements with the experimental results and also with the other theoretical predictions展开更多
This paper proposes a 3-D convection-heat dispersion model for a confined aquifer. The governing equation of the model contains not only the traditional convection and conduction terms, but also a heat dispersion term...This paper proposes a 3-D convection-heat dispersion model for a confined aquifer. The governing equation of the model contains not only the traditional convection and conduction terms, but also a heat dispersion term which has often been overlooked in many similar researches. The model is used to describe a series of aquifer thermal energy storage experiments conducted at the Shanghai experimental site, including single-well injection, double-well injection/production and multiple-well injection/prodution tests. The simulated temperatures agree very well with the field data (relative error: 2.8%-4.5%). A detailed description of the model is given, followed by a detailed comparison of simulated and measured temperature distributions.展开更多
In this paper, on the basis of the heat conduction equation without consideration of the advection and turbulence effects, one-dimensional model for describing surface sea temperature ( T1), bottom sea temperature ( T...In this paper, on the basis of the heat conduction equation without consideration of the advection and turbulence effects, one-dimensional model for describing surface sea temperature ( T1), bottom sea temperature ( Tt ) and the thickness of the upper homogeneous layer ( h ) is developed in terms of the dimensionless temperature θT and depth η and self-simulation function θT - f(η) of vertical temperature profile by means of historical temperature data.The results of trial prediction with our one-dimensional model on T, Th, h , the thickness and gradient of thermocline are satisfactory to some extent.展开更多
Lanthanide（III） complexes of 4-butyl-1-（4-hydroxyphenyl）-2-phenyl-3,5-pyrazolidinedione （OPB） were prepared by ho-mogeneous precipitation. The solid complexes were characterized by elemental analysis, magnetic s...Lanthanide（III） complexes of 4-butyl-1-（4-hydroxyphenyl）-2-phenyl-3,5-pyrazolidinedione （OPB） were prepared by ho-mogeneous precipitation. The solid complexes were characterized by elemental analysis, magnetic susceptibility data, molar conduc-tivity measurements and IR, UV-Vis, mass, 1H NMR and 13C NMR spectral methods. The thermal decomposition of the complexes under static air atmosphere was investigated by simultaneous TG/DTG at a heating rate of 10 °C/min. The final decomposition prod-ucts were found to be metal oxides. The spectroscopic data suggested that OPB acted as a bidentate, mono-ionic ligand coordinating through two carbonyl oxygens of the pyrazolidinedione ring. The kinetic and thermodynamic parameters such as activation energy, pre-exponential factor and entropy of activation for each step of the decomposition reactions were evaluated using Coats-Redfern and MacCallum-Tanner equations. The negative entropy values of the complexes indicated that the activated complexes had a more or-dered structure than the reactant and that the reactions were slower than normal. Investigations of antimicrobial activity of the com-pounds were carried out by the disk diffusion technique.展开更多
Complexes of La（Ⅲ）, Ce（Ⅲ）, Pr（Ⅲ）, Nd（Ⅲ）, Sm（Ⅲ）, Eu（Ⅲ）, Gd（Ⅲ）, Dy（Ⅲ）, Yb（Ⅲ）, and Lu0ID with 2-（N-o- hydroxyacetophenone）amino-3-carboxyethyl-4,5,6,7-tetrahydrobenzo[b]thiophene （HAAT） for...Complexes of La（Ⅲ）, Ce（Ⅲ）, Pr（Ⅲ）, Nd（Ⅲ）, Sm（Ⅲ）, Eu（Ⅲ）, Gd（Ⅲ）, Dy（Ⅲ）, Yb（Ⅲ）, and Lu0ID with 2-（N-o- hydroxyacetophenone）amino-3-carboxyethyl-4,5,6,7-tetrahydrobenzo[b]thiophene （HAAT） formed by the condensation of o-hydroxyacetophenone and 2-amino-3-carboxyethyl-4,5,6,7-tetrahydrobenzo[b]thiophene were synthesized and characterized on the basis of elemental analyses, molar conductance measurements, magnetic susceptibility data, UV-Visible, IR, and NMR spectral studies. The spectral data revealed that the ligand acted as a neutral tridentate coordinating to the metal ion through ONO donor sequence. A coordination number nine was proposed for the complexes. Thermal decomposition studies of the ligand and lanthanum（Ⅲ） complex were carried out and kinetic parameters were calculated using Coats-Redfem equation. The decomposition reactions followed random nucleation mechanism with one nucleus on each particle.展开更多
In the present study, bond-coats for thermal barrier coatings were deposited via air plasma spraying（APS） techniques onto Inconel 800 and Hastelloy C-276 alloy substrates. Scanning electron microscopy（SEM）, transm...In the present study, bond-coats for thermal barrier coatings were deposited via air plasma spraying（APS） techniques onto Inconel 800 and Hastelloy C-276 alloy substrates. Scanning electron microscopy（SEM）, transmission electron microscopy（TEM）, X-ray diffraction（XRD）, and atomic force microscopy（AFM） were used to investigate the phases and microstructure of the as-sprayed, APS-deposited Co Ni Cr Al Y bond-coatings. The aim of this work was to study the suitability of the bond-coat materials for high temperature applications. Confirmation of nanoscale grains of the γ/γ′-phase was obtained by TEM, high-resolution TEM, and AFM. We concluded that these changes result from the plastic deformation of the bond-coat during the deposition, resulting in Co Ni Cr Al Y bond-coatings with excellent thermal cyclic resistance suitable for use in high-temperature applications. Cyclic oxidative stability was observed to also depend on the underlying metallic alloy substrate.展开更多
Thermal sensitive MnZn ferrite is a kind of soft magnetic ferrite material with lower Curie temperature (Tc) and can be used to make many kinds of magnetic thermal sensitive sensors with high sensitivity. In this pape...Thermal sensitive MnZn ferrite is a kind of soft magnetic ferrite material with lower Curie temperature (Tc) and can be used to make many kinds of magnetic thermal sensitive sensors with high sensitivity. In this paper, the relation between the composition of thermal sensitive ferrite and TC was studied. It was found that TC changes linearly with ZnO extent when the content of Fe2O3 is fixed. Based on lots of experiments, an experimential formula to determine was given out.展开更多
SAfter leached from municipal solid waste landfill was treated by recirculation, the concentration of pollutants decreases greatly, and the moisture content of the solid waste in landfill site was increased and waste ...SAfter leached from municipal solid waste landfill was treated by recirculation, the concentration of pollutants decreases greatly, and the moisture content of the solid waste in landfill site was increased and waste stabilization rate was accelerated. Compared with traditional treatment methods, this method offers more important practical values, including short investment, enhanced treatment efficiency and facilitated operation and management. The experimental results indicated that a 99.9% removal of ammonia nitrogen and an 80.5% removal of COD were obtained, when hydraulic power surface load is 15.92 L/m^2·d, and organic surface load is 25.54 g/m^2·d.展开更多
Some new heteropolyoxometalates of large organic cations with molybdotungstosilicic acids （general formula： （CTMA）4SiMoxW12-xO40·mH2O·nDMF, x=0,2,4,6,8,10,12） were prepared by the reaction of cetyltrime...Some new heteropolyoxometalates of large organic cations with molybdotungstosilicic acids （general formula： （CTMA）4SiMoxW12-xO40·mH2O·nDMF, x=0,2,4,6,8,10,12） were prepared by the reaction of cetyltrimethylammonium bromide （CTMAB,C16H33N（CH3）3Br） with H4SiMoxW12-xO40（x=0,2,4,6,8,10,12） in aqueous solution and recrystallization in DMF, and characterized by elemental analysis, IR spectra,TG- DTA and XRD techniques. The IR spectrum confirms the presence of Keggin structure and organic cations in these compounds, and it is indicated that the stretching vibration of the M-Od, M-Ob-M and Si-Oa becomes more red-shifted when molybdenum is gradually substituted for the tungsten atom. In particular, the thermal decomposition of the heteropolyoxometalates was studied in nitrogen atmosphere. The TG-DTA curves show that their thermal behaviors not only contain the release of water molecule, DMF molecule, CTMA and its fragments but also contains simultaneous collapse of Keggin anion. Their end products of the thermal decomposition are the mixture of WO3, MoO3 and SiO2. And from the final decomposition temperature of view, it is found that the thermal stability of these compounds gradually is decreased when the number of molybdenum atoms is increased.展开更多
A novel organic-inorganic chromium(III) hybrid salt, triethylammonium<em> trans</em>-diaquabis(oxalato-<em>κ</em><sup>2</sup>O<sup>1</sup>,O<sup>2</sup>)chr...A novel organic-inorganic chromium(III) hybrid salt, triethylammonium<em> trans</em>-diaquabis(oxalato-<em>κ</em><sup>2</sup>O<sup>1</sup>,O<sup>2</sup>)chromate(III), (C<sub>6</sub>H<sub>16</sub>N)[Cr(C<sub>2</sub>O<sub>4</sub>)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>] (1), has been synthesized in aqueous solution and characterized by elemental and thermal analyses, FTIR and UV-Vis spectroscopies, and by single crystal X-ray structure determination. Compound 1 crystallizes in the orthorhombic system, <em>Pbcn</em> space group with the unit cell parameters <em>a</em> = 11.1776(10), <em>b </em>= 7.6105(10), <em>c</em> = 17.5654(2) <span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">Å</span>, <em>α</em> = <em>β</em> = <em>γ</em> = 90<span style="white-space:nowrap;">°</span>, <em>V</em> = 1494.24(3) <span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">Å</span>3, <em>Z</em> = 4 and <em>Z’</em> = 1/2. The structure of 1 consists of [Cr(C<sub>2</sub>O<sub>4</sub>)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>]<span style="white-space:nowrap;"><sup>−</sup></span> mononuclear anions and triethylammonium [(C<sub>2</sub>H<sub>5</sub>)<sub>3</sub>NH]<sup>+</sup> cations. In the anionic unit, the CrIII ion is six coordinated, in a distorted octahedral geometry, by four equatorial O atoms of two oxalate anions acting as chelating ligands and two O atoms from <em>trans</em>-coordinated water molecules occupying the apical positions with longer metal-oxygen distances. In the solid, O-H … O and N-H … O intra and inter molecular hydrogen bonding interactions connect the components into a 3D network. The triethylammonium cations are disordered among two possible orientations with occupancies rates around 50% for C4, N1, C1a, C1b, C4<sup>ii</sup>, N1<sup>ii</sup>, C1a<sup>ii</sup>, C1b<sup>ii</sup> (ii = <span style="white-space:nowrap;">−</span><em>x</em> + 1, <em>y</em>, <span style="white-space:nowrap;">−</span> <em>z</em> + 1/2). The IR spectrum of 1 is consistent with the presence of the various molecular building constituents. The UV-Vis spectrum shows two absorption bands around 564 and 416 nm which are compatible with an anionic chromium (III) complex in an octahedral environment. Thermal studies carried out in air between 25<span style="white-space:nowrap;">°</span>C and 700°C confirm the anhydrous character of 1 and show that it is stable up to 210<span style="white-space:nowrap;">°</span>C.展开更多
基金This project was supported by the National Natural Science Foundation of China
文摘The denaturational behaviour of bovine β-lactoglobulin B has been studied in solutions containing guanidine hydrochloride by differential scanning calorimetry. The experiments have shown that complete peaks of cold denaturation can be recorded also in high concentration of protein solutions. The cold denaturation and the renaturation of the protein are reproducible, but the thermal denaturation is irreversible. The activation energy of thermal denaturation calculated is about 285 kJ/mol.
文摘The modified shear lag model proposed recently was applied to calculate thermal residual stresses and subsequent stress distributions under tensile and compressive loadings. The expressions for the elastic moduli and the yield strengths under tensile and compressive loadings were derived which take account of thermal residual stresses. The asymmetries in the elastic modulus and the yield strength were interpreted using the derived expressions and the obtained results of the stress calculations. The model predictions have exhibited good agreements with the experimental results and also with the other theoretical predictions
基金This project is partly supported by the National Natural Science Foundation of China.
文摘This paper proposes a 3-D convection-heat dispersion model for a confined aquifer. The governing equation of the model contains not only the traditional convection and conduction terms, but also a heat dispersion term which has often been overlooked in many similar researches. The model is used to describe a series of aquifer thermal energy storage experiments conducted at the Shanghai experimental site, including single-well injection, double-well injection/production and multiple-well injection/prodution tests. The simulated temperatures agree very well with the field data (relative error: 2.8%-4.5%). A detailed description of the model is given, followed by a detailed comparison of simulated and measured temperature distributions.
文摘In this paper, on the basis of the heat conduction equation without consideration of the advection and turbulence effects, one-dimensional model for describing surface sea temperature ( T1), bottom sea temperature ( Tt ) and the thickness of the upper homogeneous layer ( h ) is developed in terms of the dimensionless temperature θT and depth η and self-simulation function θT - f(η) of vertical temperature profile by means of historical temperature data.The results of trial prediction with our one-dimensional model on T, Th, h , the thickness and gradient of thermocline are satisfactory to some extent.
文摘Lanthanide（III） complexes of 4-butyl-1-（4-hydroxyphenyl）-2-phenyl-3,5-pyrazolidinedione （OPB） were prepared by ho-mogeneous precipitation. The solid complexes were characterized by elemental analysis, magnetic susceptibility data, molar conduc-tivity measurements and IR, UV-Vis, mass, 1H NMR and 13C NMR spectral methods. The thermal decomposition of the complexes under static air atmosphere was investigated by simultaneous TG/DTG at a heating rate of 10 °C/min. The final decomposition prod-ucts were found to be metal oxides. The spectroscopic data suggested that OPB acted as a bidentate, mono-ionic ligand coordinating through two carbonyl oxygens of the pyrazolidinedione ring. The kinetic and thermodynamic parameters such as activation energy, pre-exponential factor and entropy of activation for each step of the decomposition reactions were evaluated using Coats-Redfern and MacCallum-Tanner equations. The negative entropy values of the complexes indicated that the activated complexes had a more or-dered structure than the reactant and that the reactions were slower than normal. Investigations of antimicrobial activity of the com-pounds were carried out by the disk diffusion technique.
文摘Complexes of La（Ⅲ）, Ce（Ⅲ）, Pr（Ⅲ）, Nd（Ⅲ）, Sm（Ⅲ）, Eu（Ⅲ）, Gd（Ⅲ）, Dy（Ⅲ）, Yb（Ⅲ）, and Lu0ID with 2-（N-o- hydroxyacetophenone）amino-3-carboxyethyl-4,5,6,7-tetrahydrobenzo[b]thiophene （HAAT） formed by the condensation of o-hydroxyacetophenone and 2-amino-3-carboxyethyl-4,5,6,7-tetrahydrobenzo[b]thiophene were synthesized and characterized on the basis of elemental analyses, molar conductance measurements, magnetic susceptibility data, UV-Visible, IR, and NMR spectral studies. The spectral data revealed that the ligand acted as a neutral tridentate coordinating to the metal ion through ONO donor sequence. A coordination number nine was proposed for the complexes. Thermal decomposition studies of the ligand and lanthanum（Ⅲ） complex were carried out and kinetic parameters were calculated using Coats-Redfem equation. The decomposition reactions followed random nucleation mechanism with one nucleus on each particle.
基金provided by Technical Education Quality Improvement Programme-Ⅱ(TEQIP-Ⅱ)at MNNIT Allahabad
文摘In the present study, bond-coats for thermal barrier coatings were deposited via air plasma spraying（APS） techniques onto Inconel 800 and Hastelloy C-276 alloy substrates. Scanning electron microscopy（SEM）, transmission electron microscopy（TEM）, X-ray diffraction（XRD）, and atomic force microscopy（AFM） were used to investigate the phases and microstructure of the as-sprayed, APS-deposited Co Ni Cr Al Y bond-coatings. The aim of this work was to study the suitability of the bond-coat materials for high temperature applications. Confirmation of nanoscale grains of the γ/γ′-phase was obtained by TEM, high-resolution TEM, and AFM. We concluded that these changes result from the plastic deformation of the bond-coat during the deposition, resulting in Co Ni Cr Al Y bond-coatings with excellent thermal cyclic resistance suitable for use in high-temperature applications. Cyclic oxidative stability was observed to also depend on the underlying metallic alloy substrate.
基金National Natural Science Foundation of China!(No. 59972011).
文摘Thermal sensitive MnZn ferrite is a kind of soft magnetic ferrite material with lower Curie temperature (Tc) and can be used to make many kinds of magnetic thermal sensitive sensors with high sensitivity. In this paper, the relation between the composition of thermal sensitive ferrite and TC was studied. It was found that TC changes linearly with ZnO extent when the content of Fe2O3 is fixed. Based on lots of experiments, an experimential formula to determine was given out.
基金the Key Scientific and Technological Project of Hubei Province(No.2002AA301C102)
文摘SAfter leached from municipal solid waste landfill was treated by recirculation, the concentration of pollutants decreases greatly, and the moisture content of the solid waste in landfill site was increased and waste stabilization rate was accelerated. Compared with traditional treatment methods, this method offers more important practical values, including short investment, enhanced treatment efficiency and facilitated operation and management. The experimental results indicated that a 99.9% removal of ammonia nitrogen and an 80.5% removal of COD were obtained, when hydraulic power surface load is 15.92 L/m^2·d, and organic surface load is 25.54 g/m^2·d.
基金the Natural Science Foundation of the Educational Commission of Hubei Province(No.J200522002 and Z200622001)
文摘Some new heteropolyoxometalates of large organic cations with molybdotungstosilicic acids （general formula： （CTMA）4SiMoxW12-xO40·mH2O·nDMF, x=0,2,4,6,8,10,12） were prepared by the reaction of cetyltrimethylammonium bromide （CTMAB,C16H33N（CH3）3Br） with H4SiMoxW12-xO40（x=0,2,4,6,8,10,12） in aqueous solution and recrystallization in DMF, and characterized by elemental analysis, IR spectra,TG- DTA and XRD techniques. The IR spectrum confirms the presence of Keggin structure and organic cations in these compounds, and it is indicated that the stretching vibration of the M-Od, M-Ob-M and Si-Oa becomes more red-shifted when molybdenum is gradually substituted for the tungsten atom. In particular, the thermal decomposition of the heteropolyoxometalates was studied in nitrogen atmosphere. The TG-DTA curves show that their thermal behaviors not only contain the release of water molecule, DMF molecule, CTMA and its fragments but also contains simultaneous collapse of Keggin anion. Their end products of the thermal decomposition are the mixture of WO3, MoO3 and SiO2. And from the final decomposition temperature of view, it is found that the thermal stability of these compounds gradually is decreased when the number of molybdenum atoms is increased.
文摘A novel organic-inorganic chromium(III) hybrid salt, triethylammonium<em> trans</em>-diaquabis(oxalato-<em>κ</em><sup>2</sup>O<sup>1</sup>,O<sup>2</sup>)chromate(III), (C<sub>6</sub>H<sub>16</sub>N)[Cr(C<sub>2</sub>O<sub>4</sub>)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>] (1), has been synthesized in aqueous solution and characterized by elemental and thermal analyses, FTIR and UV-Vis spectroscopies, and by single crystal X-ray structure determination. Compound 1 crystallizes in the orthorhombic system, <em>Pbcn</em> space group with the unit cell parameters <em>a</em> = 11.1776(10), <em>b </em>= 7.6105(10), <em>c</em> = 17.5654(2) <span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">Å</span>, <em>α</em> = <em>β</em> = <em>γ</em> = 90<span style="white-space:nowrap;">°</span>, <em>V</em> = 1494.24(3) <span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">Å</span>3, <em>Z</em> = 4 and <em>Z’</em> = 1/2. The structure of 1 consists of [Cr(C<sub>2</sub>O<sub>4</sub>)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>]<span style="white-space:nowrap;"><sup>−</sup></span> mononuclear anions and triethylammonium [(C<sub>2</sub>H<sub>5</sub>)<sub>3</sub>NH]<sup>+</sup> cations. In the anionic unit, the CrIII ion is six coordinated, in a distorted octahedral geometry, by four equatorial O atoms of two oxalate anions acting as chelating ligands and two O atoms from <em>trans</em>-coordinated water molecules occupying the apical positions with longer metal-oxygen distances. In the solid, O-H … O and N-H … O intra and inter molecular hydrogen bonding interactions connect the components into a 3D network. The triethylammonium cations are disordered among two possible orientations with occupancies rates around 50% for C4, N1, C1a, C1b, C4<sup>ii</sup>, N1<sup>ii</sup>, C1a<sup>ii</sup>, C1b<sup>ii</sup> (ii = <span style="white-space:nowrap;">−</span><em>x</em> + 1, <em>y</em>, <span style="white-space:nowrap;">−</span> <em>z</em> + 1/2). The IR spectrum of 1 is consistent with the presence of the various molecular building constituents. The UV-Vis spectrum shows two absorption bands around 564 and 416 nm which are compatible with an anionic chromium (III) complex in an octahedral environment. Thermal studies carried out in air between 25<span style="white-space:nowrap;">°</span>C and 700°C confirm the anhydrous character of 1 and show that it is stable up to 210<span style="white-space:nowrap;">°</span>C.
