We have studied the microstructure and photoluminescent properties of porous Si.High resolution observations revealed that the microstructure of porous Si consists with nano-crystaliites Si embedded in the surrounding...We have studied the microstructure and photoluminescent properties of porous Si.High resolution observations revealed that the microstructure of porous Si consists with nano-crystaliites Si embedded in the surrounding amorphous matrix.The struc-ture of nano-crystallites of porous Si is not consis tent with the usual diamond struc-ture of bulk Si.The photoluminescence from porous Si is due to the quantum com finement of carriers in this structure.展开更多
The fabric structures for both the base structures and thecover of multilayer conveyer belts are introduced in thispaper.It is also of general significances to use these fab-rics in composite materials.
Deformed soft-sediment deformation structures(SSDS)can indicate polyphase deformation events and provide valuable insights into the inversion process of a basin.Herein,we present the Miocene–Quaternary deformation in...Deformed soft-sediment deformation structures(SSDS)can indicate polyphase deformation events and provide valuable insights into the inversion process of a basin.Herein,we present the Miocene–Quaternary deformation inversion history of the Bomun sub-basin in the Gyeongju area of SE Korea.The inferred ENE compression direction(σHmax)based on paleostress analysis of the fault system,displacing Miocene sediments and SSDS,corresponds to the current stress field.The widespread occurrence of clear liquefaction structures and the vertical repetition of SSDS indicate substantial seismic activity during the basin opening stage.Brittle deformation features observed at both outcrop-and microstructural-scale along the faults suggest a reactivation as reverse faulting associated with a tilting process.The tectonic history of the study area is distinguished by SSDS associated with seismic activity,and reverse faulting associated with inversion process under ENE orientedσHmax.The Environmental Seismic Intensity Scale(ESI-07)based on the SSDS indicates seismic intensity of IX-X,which might be related with the opening of the Bomun sub-basin.Therefore,detailed analyses of SSDS could provide valuable insights on the dynamics of local geology and contribute to further extensive research on seismic hazards and basin inversion.展开更多
We investigated the plant population structure and the phy- tosociological and regeneration status in two disturbed tropical forests in Assam Province, the Hojai Reserve Forest and Kumorakata Reserve Forest. A total o...We investigated the plant population structure and the phy- tosociological and regeneration status in two disturbed tropical forests in Assam Province, the Hojai Reserve Forest and Kumorakata Reserve Forest. A total of 166 species （80 trees, 20 shrubs and 66 herbs） of 136 genera and 63 families were recorded in both study sites. The disturbance index at the two sites, Kumorakata Reserve Forest and Hojai Reserve Forest, were recorded at 11.4% and 3.70% respectively. Reverse J-shaped population curve and exploitation of tree species in higher girth classes were recorded at both study sites. In the girth classes （10-30 cm, 30-60 cm, 60-90 cm and 90-120 cm in size） the percentage of cut stump density was higher than the percentage of individual living trees. The 18% （Kumorakata Reserve Forest） and 7% （Hojai Reserve Forest） spe- cies were recorded as not regenerating. Illegal felling and over-exploitation of forest resources may lead to species-specific changes in the population structure and can alter the future structure and composi- tion of the forests.展开更多
This paper presents a 3D topology optimization approach for designing shell structures with a porous or void interior. It is shown that the resulting structures are significantly more robust towards load perturbations...This paper presents a 3D topology optimization approach for designing shell structures with a porous or void interior. It is shown that the resulting structures are significantly more robust towards load perturbations than completely solid structures optimized under the same conditions. The study indicates that the potential benefit of using porous structures is higher for lower total volume fractions.Compared to earlier work dealing with 2D topology optimization, we found several new effects in 3D problems. Most notably, the opportunity for designing closed shells significantly improves the performance of porous structures due to the sandwich effect. Furthermore, the paper introduces improved filter boundary conditions to ensure a completely uniform coating thickness at the design domain boundary.展开更多
Based on the differential forms and exterior derivatives of fractional orders, Wu first presented the generalized Tu formula to construct the generalized Hamiltonian structure of the fractional soliton equation. We ap...Based on the differential forms and exterior derivatives of fractional orders, Wu first presented the generalized Tu formula to construct the generalized Hamiltonian structure of the fractional soliton equation. We apply the generalized Tu formula to calculate the fractional Dirac soliton equation hierarchy and its Hamiltonian structure. The method can be generalized to the other fractional soliton hierarchy.展开更多
The nano-particle-based planar laser scattering （NPLS） technique is used to measure the density distribution in the supersonic mixing layer of the convective Mach number 0.12, and the optical path difference （OPL）...The nano-particle-based planar laser scattering （NPLS） technique is used to measure the density distribution in the supersonic mixing layer of the convective Mach number 0.12, and the optical path difference （OPL）, which is quite crucial for the study of aero-optics, is obtained by post processing. Based on the high spatiotemporal resolutions of the NPLS, the structure of the OPL is ana]ysed using wavelet methods. The coherent structures of the OPL are extracted using three methods, including the methods of thresholding the coefficients of the orthogonal wavelet transform and the wavelet packet transform, and preserving a number of wavelet packet coefficients with the largest amplitudes determined by the entropy dimension. Their performances are compared, and the method using the wavelet packet is the best. Based on the viewpoint of multifractals, we study the OPL by the wavelet transform maxima method （WTMM）, and the result indicates that its scaling behaviour is evident.展开更多
Viologens (<i>N,N'</i>-dimethyl-4,4-bipyridinium) are advanced functional materials, found important applications in electrochromic devices, molecular machines, organic batteries, and carbohydrate oxid...Viologens (<i>N,N'</i>-dimethyl-4,4-bipyridinium) are advanced functional materials, found important applications in electrochromic devices, molecular machines, organic batteries, and carbohydrate oxidation catalysts in alkaline fuel. In this article, we investigated the design, synthesis and photophysical properties of <i>N,N'</i>-dimethyl-2,5-Bis(pyridinium)oxadiazole <b>4</b> and its precursor 2,5- Bis(pyridine)oxadiazole<b> 2</b>. The crystal structure and photophysical properties of viologen <b>4</b> and precursor <b>2</b> have been determined. The viologen molecule <b>4</b> crystallized in monoclinic form, space group <i>P</i>2<sub>1</sub>/<i>n</i> with four molecules in unit cell. Precursor molecule <b>2</b> also crystalized in monoclinic form, space group <i>C</i>2/<i>c</i> with four molecules in unit cell. From X-rd data, we found three cations in the molecular structure of viologen molecule <b>4</b>, which is unusual in viologens. In the three-dimensional molecular packing diagram of molecule <b>4</b>, the three cations and iodate anions are stabilized by C···C, C···I, N···I, N···H, H···I, N—H···I and C—H···I. The dihedral angle between planes having oxadiazole and two benzene rings are 5°and 8°, suggesting the molecule <b>4</b> is a slightly strained one. The molecular structure of precursor molecule <b>2</b> stabilized by C···C and N···H short contacts between the molecules. The molecule <b>4</b> displayed strong absorbance at 315 nm and emissions between 390 - 410 nm.展开更多
The dislocation structure of specimens of a duplex stainless steel with precharged hydrogen has been investigated by transmission electron microscopy.The result showed the hydrogen acti- vated dislocation source on ph...The dislocation structure of specimens of a duplex stainless steel with precharged hydrogen has been investigated by transmission electron microscopy.The result showed the hydrogen acti- vated dislocation source on phase boundaries of ferrite/austenite and makes certain dislocations in austenite grains move.The dislocation appearances in each phase in specimens uncharged with hydrogen have been given for comparison.展开更多
Semiconductor devices are often operated at elevated temperatures that are well above zero Kelvin,which is the temperature in most first-principles density functional calculations.Computational approaches to com-putin...Semiconductor devices are often operated at elevated temperatures that are well above zero Kelvin,which is the temperature in most first-principles density functional calculations.Computational approaches to com-puting and understanding the properties of semiconductors at finite temperatures are thus in critical demand.In this review,we discuss the recent progress in computationally assessing the electronic and phononic band structures of semiconductors at finite temperatures.As an emerging semiconductor with particularly strong temperature-induced renormalization of the electronic and phononic band structures,halide perovskites are used as a representative example to demonstrate how computational advances may help to understand the band struc-tures at elevated temperatures.Finally,we briefly illustrate the remaining computational challenges and outlook promising research directions that may help to guide future research in this field.展开更多
In this paper, 87 farmers' specialized cooperatives in Sichuan Province were investigated firstly, and then their governance structure was analyzed from the aspects of authority, decision-making mechanism, supervi...In this paper, 87 farmers' specialized cooperatives in Sichuan Province were investigated firstly, and then their governance structure was analyzed from the aspects of authority, decision-making mechanism, supervision mechanism and executive body based on the corporative governance structure in narrowest sense, finally corresponding policy suggestions for improving the governance structure of farmers' specialized cooperatives in Sichuan Province were put forward. It is concluded that human control is serious within farmers' specialized cooperatives; inner supervision is effective; council has great effects on governance structure; the cooperatives give limited incentive to managers.展开更多
In this paper,from the authority,decision-making body,supervisory body and implementing body,we analyze the governance structure evaluation indicators of farmers' specialized cooperatives,using objective and subje...In this paper,from the authority,decision-making body,supervisory body and implementing body,we analyze the governance structure evaluation indicators of farmers' specialized cooperatives,using objective and subjective combination weighting approach.And we draw the following conclusions:the rate of return of profits for membership,frequency of council convened and the number of members of board of supervisors have a great impact on the governance structure of cooperatives; the insider control phenomenon in cooperatives is more serious and the level of incentives is limited.Finally we put forward corresponding policy recommendations.展开更多
Anyone visiting Rabat,capital of Morocco and a city with rich historical heritage,is struck by the majesty of the Hassan Tower.This vestige dating from the Almohad Dynasty(12th century)consists of a minaret and a larg...Anyone visiting Rabat,capital of Morocco and a city with rich historical heritage,is struck by the majesty of the Hassan Tower.This vestige dating from the Almohad Dynasty(12th century)consists of a minaret and a large prayer area with colonnades.With a height of 44 meters,today,this skyscraper of the Middle Ages is a testimony to the influence of Rabat and its past domination over a territory ranging from Spain to Tunisia.展开更多
Reaction products of 2,4,6-tris(4-phenyl-phenoxy)-1,3,5-triazine derived from 4-phenylphenol cyanate ester and phenyl glycidyl ether were analyzed. In addition to an isocyanurate compound and an oxazolidone compound w...Reaction products of 2,4,6-tris(4-phenyl-phenoxy)-1,3,5-triazine derived from 4-phenylphenol cyanate ester and phenyl glycidyl ether were analyzed. In addition to an isocyanurate compound and an oxazolidone compound which were well known as reaction products of cyanate esters and epoxy resins, compounds with hybrid ring structure of cyanurate/isocyanurate were determined. Gibbs free energies of the compound having hybrid ring structure of cyanurate/isocyanurate with two isocyanurate moiety were found to be lower than that of the compound with cyanurate ring structure through calculations. Calculation data supported the existence of hybrid ring structure of cy-anurate/isocyanurate. It was revealed that isomerization from cyanurate to isocyanurate occurs via hybrid ring structure of cyanurate/isocyanurate in the reaction of aryl cyanurate and epoxy.展开更多
Guanidimium-4,4-azo-l-hydro-1,2,4-triazol-5-one （GZTO·H2O） was synthesized from 4-amino-1,2,4-triazol- 5-one as a starting material by two-step including oxidation coupling using acid KMnO4 and reaction with （...Guanidimium-4,4-azo-l-hydro-1,2,4-triazol-5-one （GZTO·H2O） was synthesized from 4-amino-1,2,4-triazol- 5-one as a starting material by two-step including oxidation coupling using acid KMnO4 and reaction with （NH2）2C=NHoHNO3 （GN） in KOH solution. The single crystal of the title compound was obtained by slow evapo- ration method at room temperature, and its structure was firstly determined with X-ray single-crystal diffractometer. It is a orthorhombic crystal, space group Pbca with cell dimensions of a = 1.0459（2） nm, b =- 1.3584（3） nm, c= 1.6103（3） nm, a= 90.00（10）°, β=90.00（11）°,γ=90.00（11）°, V=2.2878（8） nm3, Z=8, De= 1.587 gocm-3, F（000） = 1136,/l = 0.132 mm- 1, R1 = 0.0455, wR2 = 0. 1397. The thermal behavior of GZTO·H2O was studied under a non-isothermal condition by DSC-TGA method, and its thermal decomposition process can be divided into three stages, and the first stage is an intense exothermic decomposition process. The second stage and the third stage are slow exothermic decomposition processes. The critical temperature of thermal explosion is 237.74℃.展开更多
The techniques of oxygen electrode polarogra-phy and Fourier transform infrared (FT-IR) spectroscopy were employed to explore the roles of polar head-group of phosphatidylglycerol (PG) molecules in the functional and ...The techniques of oxygen electrode polarogra-phy and Fourier transform infrared (FT-IR) spectroscopy were employed to explore the roles of polar head-group of phosphatidylglycerol (PG) molecules in the functional and structural aspects of photosystem Ⅱ (PS Ⅱ) through enzymatic approach. It was shown that the depletion of PG by treatment of phospholipase C (PLC) on PS Ⅱ particles caused the inhibition of oxygen evolving activity in PS Ⅱ. This effect also gave rise to changes in the protein secondary structures of PS Ⅱ, that is, an increase in a-helical conformation which is compensated by the loss of p-strand structures. It revealed that the head-group of PG molecules plays an important structural role in the maintenance of normal structure of PS Ⅱ proteins, which is required to maintain the appropriate physiological activity of the PS Ⅱ complex such as the oxygen evolving activity. It is suggested that there most probably exist hydrogen-bonding interactions between PG molecules and PS Ⅱ proteins.展开更多
The injection of HBsAg into mammals can cause the synthesis of antibodies. These antibodies can bind HBsAg specifically. Experiments show that the antigenic specificity of protein antigen not only relates to the local...The injection of HBsAg into mammals can cause the synthesis of antibodies. These antibodies can bind HBsAg specifically. Experiments show that the antigenic specificity of protein antigen not only relates to the local conformation of the molecule surface, the properties and number of the antigenic determinants, but also to their arrangement in three-dimensional space, i.e. the overall conformation of the molecule.展开更多
文摘We have studied the microstructure and photoluminescent properties of porous Si.High resolution observations revealed that the microstructure of porous Si consists with nano-crystaliites Si embedded in the surrounding amorphous matrix.The struc-ture of nano-crystallites of porous Si is not consis tent with the usual diamond struc-ture of bulk Si.The photoluminescence from porous Si is due to the quantum com finement of carriers in this structure.
文摘The fabric structures for both the base structures and thecover of multilayer conveyer belts are introduced in thispaper.It is also of general significances to use these fab-rics in composite materials.
基金supported by a grant(2022-MOIS62-001(RS-2022-ND640011))from the National Disaster Risk AnalysisManagement Technology in Earthquake funded by the Ministry of Interior and Safety(MOIS,Korea).
文摘Deformed soft-sediment deformation structures(SSDS)can indicate polyphase deformation events and provide valuable insights into the inversion process of a basin.Herein,we present the Miocene–Quaternary deformation inversion history of the Bomun sub-basin in the Gyeongju area of SE Korea.The inferred ENE compression direction(σHmax)based on paleostress analysis of the fault system,displacing Miocene sediments and SSDS,corresponds to the current stress field.The widespread occurrence of clear liquefaction structures and the vertical repetition of SSDS indicate substantial seismic activity during the basin opening stage.Brittle deformation features observed at both outcrop-and microstructural-scale along the faults suggest a reactivation as reverse faulting associated with a tilting process.The tectonic history of the study area is distinguished by SSDS associated with seismic activity,and reverse faulting associated with inversion process under ENE orientedσHmax.The Environmental Seismic Intensity Scale(ESI-07)based on the SSDS indicates seismic intensity of IX-X,which might be related with the opening of the Bomun sub-basin.Therefore,detailed analyses of SSDS could provide valuable insights on the dynamics of local geology and contribute to further extensive research on seismic hazards and basin inversion.
文摘We investigated the plant population structure and the phy- tosociological and regeneration status in two disturbed tropical forests in Assam Province, the Hojai Reserve Forest and Kumorakata Reserve Forest. A total of 166 species （80 trees, 20 shrubs and 66 herbs） of 136 genera and 63 families were recorded in both study sites. The disturbance index at the two sites, Kumorakata Reserve Forest and Hojai Reserve Forest, were recorded at 11.4% and 3.70% respectively. Reverse J-shaped population curve and exploitation of tree species in higher girth classes were recorded at both study sites. In the girth classes （10-30 cm, 30-60 cm, 60-90 cm and 90-120 cm in size） the percentage of cut stump density was higher than the percentage of individual living trees. The 18% （Kumorakata Reserve Forest） and 7% （Hojai Reserve Forest） spe- cies were recorded as not regenerating. Illegal felling and over-exploitation of forest resources may lead to species-specific changes in the population structure and can alter the future structure and composi- tion of the forests.
基金financial support from the Villum Foundation (the Next Top Project)DTU Mechanical Engineering
文摘This paper presents a 3D topology optimization approach for designing shell structures with a porous or void interior. It is shown that the resulting structures are significantly more robust towards load perturbations than completely solid structures optimized under the same conditions. The study indicates that the potential benefit of using porous structures is higher for lower total volume fractions.Compared to earlier work dealing with 2D topology optimization, we found several new effects in 3D problems. Most notably, the opportunity for designing closed shells significantly improves the performance of porous structures due to the sandwich effect. Furthermore, the paper introduces improved filter boundary conditions to ensure a completely uniform coating thickness at the design domain boundary.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 11271008,61072147,and 11071159 )the Shanghai Leading Academic Discipline Project,China (Grant No. J50101)
文摘Based on the differential forms and exterior derivatives of fractional orders, Wu first presented the generalized Tu formula to construct the generalized Hamiltonian structure of the fractional soliton equation. We apply the generalized Tu formula to calculate the fractional Dirac soliton equation hierarchy and its Hamiltonian structure. The method can be generalized to the other fractional soliton hierarchy.
基金Projected supported by the Innovation Research Foundations for Postgraduates of National University of Defense Technology and Hunan Provincethe National Natural Science Foundation of China (Grant No. 61008037)
文摘The nano-particle-based planar laser scattering （NPLS） technique is used to measure the density distribution in the supersonic mixing layer of the convective Mach number 0.12, and the optical path difference （OPL）, which is quite crucial for the study of aero-optics, is obtained by post processing. Based on the high spatiotemporal resolutions of the NPLS, the structure of the OPL is ana]ysed using wavelet methods. The coherent structures of the OPL are extracted using three methods, including the methods of thresholding the coefficients of the orthogonal wavelet transform and the wavelet packet transform, and preserving a number of wavelet packet coefficients with the largest amplitudes determined by the entropy dimension. Their performances are compared, and the method using the wavelet packet is the best. Based on the viewpoint of multifractals, we study the OPL by the wavelet transform maxima method （WTMM）, and the result indicates that its scaling behaviour is evident.
文摘Viologens (<i>N,N'</i>-dimethyl-4,4-bipyridinium) are advanced functional materials, found important applications in electrochromic devices, molecular machines, organic batteries, and carbohydrate oxidation catalysts in alkaline fuel. In this article, we investigated the design, synthesis and photophysical properties of <i>N,N'</i>-dimethyl-2,5-Bis(pyridinium)oxadiazole <b>4</b> and its precursor 2,5- Bis(pyridine)oxadiazole<b> 2</b>. The crystal structure and photophysical properties of viologen <b>4</b> and precursor <b>2</b> have been determined. The viologen molecule <b>4</b> crystallized in monoclinic form, space group <i>P</i>2<sub>1</sub>/<i>n</i> with four molecules in unit cell. Precursor molecule <b>2</b> also crystalized in monoclinic form, space group <i>C</i>2/<i>c</i> with four molecules in unit cell. From X-rd data, we found three cations in the molecular structure of viologen molecule <b>4</b>, which is unusual in viologens. In the three-dimensional molecular packing diagram of molecule <b>4</b>, the three cations and iodate anions are stabilized by C···C, C···I, N···I, N···H, H···I, N—H···I and C—H···I. The dihedral angle between planes having oxadiazole and two benzene rings are 5°and 8°, suggesting the molecule <b>4</b> is a slightly strained one. The molecular structure of precursor molecule <b>2</b> stabilized by C···C and N···H short contacts between the molecules. The molecule <b>4</b> displayed strong absorbance at 315 nm and emissions between 390 - 410 nm.
基金The present work was supported by the National Science Foundation of China.
文摘The dislocation structure of specimens of a duplex stainless steel with precharged hydrogen has been investigated by transmission electron microscopy.The result showed the hydrogen acti- vated dislocation source on phase boundaries of ferrite/austenite and makes certain dislocations in austenite grains move.The dislocation appearances in each phase in specimens uncharged with hydrogen have been given for comparison.
基金supported by the National Natural Science Foundation of China(Grant Nos.11991060,52172136,12088101,12074029,and U2230402).
文摘Semiconductor devices are often operated at elevated temperatures that are well above zero Kelvin,which is the temperature in most first-principles density functional calculations.Computational approaches to com-puting and understanding the properties of semiconductors at finite temperatures are thus in critical demand.In this review,we discuss the recent progress in computationally assessing the electronic and phononic band structures of semiconductors at finite temperatures.As an emerging semiconductor with particularly strong temperature-induced renormalization of the electronic and phononic band structures,halide perovskites are used as a representative example to demonstrate how computational advances may help to understand the band struc-tures at elevated temperatures.Finally,we briefly illustrate the remaining computational challenges and outlook promising research directions that may help to guide future research in this field.
文摘In this paper, 87 farmers' specialized cooperatives in Sichuan Province were investigated firstly, and then their governance structure was analyzed from the aspects of authority, decision-making mechanism, supervision mechanism and executive body based on the corporative governance structure in narrowest sense, finally corresponding policy suggestions for improving the governance structure of farmers' specialized cooperatives in Sichuan Province were put forward. It is concluded that human control is serious within farmers' specialized cooperatives; inner supervision is effective; council has great effects on governance structure; the cooperatives give limited incentive to managers.
文摘In this paper,from the authority,decision-making body,supervisory body and implementing body,we analyze the governance structure evaluation indicators of farmers' specialized cooperatives,using objective and subjective combination weighting approach.And we draw the following conclusions:the rate of return of profits for membership,frequency of council convened and the number of members of board of supervisors have a great impact on the governance structure of cooperatives; the insider control phenomenon in cooperatives is more serious and the level of incentives is limited.Finally we put forward corresponding policy recommendations.
文摘Anyone visiting Rabat,capital of Morocco and a city with rich historical heritage,is struck by the majesty of the Hassan Tower.This vestige dating from the Almohad Dynasty(12th century)consists of a minaret and a large prayer area with colonnades.With a height of 44 meters,today,this skyscraper of the Middle Ages is a testimony to the influence of Rabat and its past domination over a territory ranging from Spain to Tunisia.
文摘Reaction products of 2,4,6-tris(4-phenyl-phenoxy)-1,3,5-triazine derived from 4-phenylphenol cyanate ester and phenyl glycidyl ether were analyzed. In addition to an isocyanurate compound and an oxazolidone compound which were well known as reaction products of cyanate esters and epoxy resins, compounds with hybrid ring structure of cyanurate/isocyanurate were determined. Gibbs free energies of the compound having hybrid ring structure of cyanurate/isocyanurate with two isocyanurate moiety were found to be lower than that of the compound with cyanurate ring structure through calculations. Calculation data supported the existence of hybrid ring structure of cy-anurate/isocyanurate. It was revealed that isomerization from cyanurate to isocyanurate occurs via hybrid ring structure of cyanurate/isocyanurate in the reaction of aryl cyanurate and epoxy.
基金Project Supported by the National Natural Science Foundation of China （No. 20803058） and the Natural Science Foundation of Shaanxi Province （No. 2007B08）.
文摘Guanidimium-4,4-azo-l-hydro-1,2,4-triazol-5-one （GZTO·H2O） was synthesized from 4-amino-1,2,4-triazol- 5-one as a starting material by two-step including oxidation coupling using acid KMnO4 and reaction with （NH2）2C=NHoHNO3 （GN） in KOH solution. The single crystal of the title compound was obtained by slow evapo- ration method at room temperature, and its structure was firstly determined with X-ray single-crystal diffractometer. It is a orthorhombic crystal, space group Pbca with cell dimensions of a = 1.0459（2） nm, b =- 1.3584（3） nm, c= 1.6103（3） nm, a= 90.00（10）°, β=90.00（11）°,γ=90.00（11）°, V=2.2878（8） nm3, Z=8, De= 1.587 gocm-3, F（000） = 1136,/l = 0.132 mm- 1, R1 = 0.0455, wR2 = 0. 1397. The thermal behavior of GZTO·H2O was studied under a non-isothermal condition by DSC-TGA method, and its thermal decomposition process can be divided into three stages, and the first stage is an intense exothermic decomposition process. The second stage and the third stage are slow exothermic decomposition processes. The critical temperature of thermal explosion is 237.74℃.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 39890390) the State Basic Research Development Plan of China (Grant No. G1998010100)the Innovative Foundation of Laboratory of Photosynthesis Basic Research, Insti
文摘The techniques of oxygen electrode polarogra-phy and Fourier transform infrared (FT-IR) spectroscopy were employed to explore the roles of polar head-group of phosphatidylglycerol (PG) molecules in the functional and structural aspects of photosystem Ⅱ (PS Ⅱ) through enzymatic approach. It was shown that the depletion of PG by treatment of phospholipase C (PLC) on PS Ⅱ particles caused the inhibition of oxygen evolving activity in PS Ⅱ. This effect also gave rise to changes in the protein secondary structures of PS Ⅱ, that is, an increase in a-helical conformation which is compensated by the loss of p-strand structures. It revealed that the head-group of PG molecules plays an important structural role in the maintenance of normal structure of PS Ⅱ proteins, which is required to maintain the appropriate physiological activity of the PS Ⅱ complex such as the oxygen evolving activity. It is suggested that there most probably exist hydrogen-bonding interactions between PG molecules and PS Ⅱ proteins.
文摘The injection of HBsAg into mammals can cause the synthesis of antibodies. These antibodies can bind HBsAg specifically. Experiments show that the antigenic specificity of protein antigen not only relates to the local conformation of the molecule surface, the properties and number of the antigenic determinants, but also to their arrangement in three-dimensional space, i.e. the overall conformation of the molecule.
