Jianshanzi volcanic rocks at Qinghe valley in the northern Liaoning were considered belonging to Early Proterozoie Gaojiayu Formation of Liaohe Group, or to Early Cambrian Beidagou Formation of Qinghezhen Group, or Mi...Jianshanzi volcanic rocks at Qinghe valley in the northern Liaoning were considered belonging to Early Proterozoie Gaojiayu Formation of Liaohe Group, or to Early Cambrian Beidagou Formation of Qinghezhen Group, or Middle-Late Proterozoic Shenjiapu Formation-Complex of Kaiyuan Group-complex. Dating the zircons from the dacite with schistosity is 2 506 Ma in method of U-Pb (SHRIMP). This evidence indicates the rocks may be referred to Late Permian in age. Discovery of the rocks is significant to re-recognize stratigraphic property of "Liaohe Group", regional geoteetonie location and revolution of orogenic zone in Qinghe valley of the northern Liaoning.展开更多
Objective. To evaluate the effects of alendronate on the structural properties of trabecular bone.Methods. Alendronate was administered at a daily p. o. dose of 0. 5 mg/kg over a 12-week period in hound dogs (n = 8 fo...Objective. To evaluate the effects of alendronate on the structural properties of trabecular bone.Methods. Alendronate was administered at a daily p. o. dose of 0. 5 mg/kg over a 12-week period in hound dogs (n = 8 for both the control and treated group), and the structural indices of the lumbar vertebral (LI and L2) trabecular bone were assessed directly from 3-D images.Results. Treatment with alendronate increased bone volume fraction by 9. 5% and 7. 7% in L1 and L2 respectively. Trabecular thickness significantly increased after alendronate treatment, whereas trabecular separation remained constant. The degree of anisotropy for the alendronate - treated group was decreased compared with that of the control group. Bone surface to volume ratio declined significantly in the alendronate-reated group, whereas alendronate induced a higher bone surface density.Conclusion. Alendronate increased the structural properties of canine trabecular bone after short-term treatment at a dose of 0. 5 mg · kg-1·day-1.展开更多
Water exploits an essential part in all the durable development, the exploitation of this natural resource, its management and its position, its mineralization, its underground course and the mode o fits resurgence. T...Water exploits an essential part in all the durable development, the exploitation of this natural resource, its management and its position, its mineralization, its underground course and the mode o fits resurgence. The area of Gafsa is known by its very important hydrous potential which is geographically in the zone of transition between central Tunisia and the Saharan platform, these two great fields are separated by the fault of Gafsa which plays an important part in the structuring of the basins of the area, the hydrous resources of Gafsa make subsoil water the principal source of supply water, in the absence of an important network of surface. The zones of studies present requirements out of water which do not cease growing with the progress of the industrial activities and the concentration of the agricultural activities: The objective of this work is to analyze the water of the various zones of the area of Gafsa and to treat it to make it possible most drinkable. The analyzes like measurement of pH, measurement of electric conductivity and measurement of dry residue were made in the laboratory of the chemical group of Mdhila in Tunisia and in laboratory of Ion exchanger Materials of Vitry in France, the processes of treatment as opposite osmosis are also programmed in this same laboratory. The results are very encouraging to start the study and the design of a station of potabilisation of water in the area of Gafsa.展开更多
The hypothesis "happy productive worker" states that happy employees, whose needs are satisfied in their workplace, have greater performance than unhappy employees. Therefore, the purpose of this research is to exam...The hypothesis "happy productive worker" states that happy employees, whose needs are satisfied in their workplace, have greater performance than unhappy employees. Therefore, the purpose of this research is to examine empirically the effects that job satisfaction and well-being at work generate on the individual job performance, investigating the moderating role that the components of the organizational structure play in this relationship. To achieve the main objective, some secondary objectives were proposed: (1) test the predictive effect of well-being, satisfaction, personal, and professional variables on individual performance; and (2) test the moderating effect of the components of the organizational structure in the relationship among well-being, satisfaction, and individual job performance. This research originates of a consolidated statement for the business society, but very few empirical studies. This way, the hypothesis consisted in the components of the organizational structure will positively enhance the relationship among well-being at work, job satisfaction, and individual job performance. The final sample consisted of 134 participants, of a clinical laboratory and of federal court of justice. For the development of the questionnaire, four instruments were used; one for each construct. The proposal has four relationship variables and the statistical procedure used to test this hypothesis was multiple linear regressions. Considering the hypothetical theoretical model presented, personal and professional variables are predictors of job performance; thus, these variables were also included as independent variables. The results of the regression model showed that the variables "age", "well-being at work", "job satisfaction", and "components of organizational structure" are responsible for explaining 64% of the variance of the variable criteria and individual job performance The moderating role of the variable "components of organizational structure" was also observed, because its inclusion increased the explained variance of the dependent variable. After all the discussions developed, the two main contributions appear: (1) the predictive effect of well-being at work in relation to performance and (2) identifying the moderating effect of the components of the organizational structure.展开更多
The inter-diffusion of N,N-dimethylformamide solution of Zn(phen)2Cl2 and (NH4)2MS4 (M = W, Mo) in an H-shape tube produced crystals of Zn(phen)2WS4 1 and Zn(phen)2MoS4 2 (phen = 1,10-phenanthroline). The structures o...The inter-diffusion of N,N-dimethylformamide solution of Zn(phen)2Cl2 and (NH4)2MS4 (M = W, Mo) in an H-shape tube produced crystals of Zn(phen)2WS4 1 and Zn(phen)2MoS4 2 (phen = 1,10-phenanthroline). The structures of isomorphous complexes 1 and 2 have been determined by X-ray single-crystal structure analyses. Four nitrogen atoms from the phenanthroline ligands and two sulfur atoms from the MS42- anion forming a distorted octahedron coordinate each zinc atom. Through p-p interactions of adjacent aromatic rings of the phenanthroline ligands, a quasi one-dimensional zigzag-stacking column is formed in each complex. Complex 1 crystallizes in monoclinic space group C2/c, with a = 10.447(8), b = 22.016(9), c = 12.824(8) ? b = 103.56(6)? V = 2867.7(8) 3, Z = 4, C24H16N4S4WZn, Mr=737.90, Dc = 1.71 g/cm3, F(000) = 1424, m = 5.25 mm-1, the final R = 0.054 and Rw = 0.075 for 2315 observations with I > 3s (I). Complex 2 crystallizes in monoclinic space group C2/c, with a = 10.410(6), b = 22.095(7), c = 12.830(6) ? b = 103.19(8)? V = 2873.1(5) 3, Z = 4, C24H16MoN4S4Zn, Mr=649.99, Dc = 1.50 g/cm3, F(000) = 1296, m = 1.58 mm-1, the final R = 0.072 and Rw = 0.100 for 1631 observations with I > 3s(I).展开更多
Chickpea is a major food crop and the world's third most widely-grown legume after bean (phaseolus vulgaris L.) and pea (pisum sativam L.). The yield of chickpea can be improved by planting of optimum density of ...Chickpea is a major food crop and the world's third most widely-grown legume after bean (phaseolus vulgaris L.) and pea (pisum sativam L.). The yield of chickpea can be improved by planting of optimum density of chickpea cultivars. The purpose of this research was to investigate the effect of plant density on yield and some characteristics of chickpea (Cicer arietinum L. var. Philips). A field experiment was conducted on research farm of, Gonbad High Education Center, Iran. The study was laid out factorial in randomized block design with four replications. The treatments were factorial row spacing (A1=35 cm, A2=45 cm and A3=55 cm) and plant spacing in the row (Plant-within-spacing row) (B1=5 cm, B2=7.5 cm and B3=10 cm). AIBI=(35×5)=57.14, AIB2= (35×7.5)=38.09, A1B3=(35×10)=28.57, A2B1=(45×7)=44.44, A2B2=(45×7.5)=29.26, A2B3=(45× 10)=22.23, A3B1=(55×5)=36.36, A3B2=(55 ×.5)=24.24, A3B3=(55 × 10)=18.18 plant.m^-2. At the harvest time, 5 plants of each plot were selected randomly and used for determination of pods per plant, unfilled pod per plant, height and number of branches. Result showed the yield was not affected by density. The maximum yield obtained in row spacing 55 cm and plant spacing in the row 7.5 cm which was equal 1802.87 kg·ha^-1. Row spacing had statistically significant effect on the pod number per plant, branches number per plant and plant height.展开更多
In this study, one mononuclear zinc(II) complex with 1,2-bis CAP ((5-chlorosalicylidene amino)-phenylene): C22C13N2035Znl5 H0125 (Zn-CAP) was synthesized. The binding properties of Zn-CAP with G-quadruplex DN...In this study, one mononuclear zinc(II) complex with 1,2-bis CAP ((5-chlorosalicylidene amino)-phenylene): C22C13N2035Znl5 H0125 (Zn-CAP) was synthesized. The binding properties of Zn-CAP with G-quadruplex DNA and ctDNA (calf thymus DNA) were examined by fluorescence, CD (circular dichroism) spectroscopic and FRET (fluorescence resonance energy transfer) assay. In the fluorescence emission spectral analysis, the addition of three series of G-quadruplex DNA (G4-HTG21, G4-Pu27 and G4-c-kit-l) into the Zn-CAP solution induced moderate or add hypochromicity with total quenching ratios of 10.73%, 15.07% and 8.59% in the presence of K+ were achieved, respectively. While the addition of ctDNA under same condition only caused 7.08% quenching on the fluorescence emission of Zn-CAP. In the CD spectral analysis, the interaction with Zn-CAP could induce significant spectral changes on the CD absorption of G4-HTG21, G4-Pu27 and G4-c-kit-1, with 106.00%, 93.06%, 113.47% increment at 232 nm absorption, along with a 81.11%, 92.80%, 83.72% decrement at 295 nm or 270 nm absorption, which demonstrated that the antiparallel structure of G-quadruplex DNA is more stable in the presence of Zn-CAP. Comparatively, the addition of Zn-CAP could induce significant spectral changes on the CD absorption of double helix ctDNA, with 64.17% decrement on the positive peak absorption, along with a 90.91% increment on the negative peak absorption. On the other hand, in the FRET-melting assay analysis, it was clear that Zn-CAP at 0.5 equivalences could raise the melting temperature of G-quadruplex (F2 IT or FPul 8T) by 3.45℃ and 15.85℃, indicating an obvious stabilization effect of Zn-CAP on G-quadruplex in Pu27. All the results indicated that Zn-CAP exhibited higher binding affinity and binding intensity to G-quadruplex DNA than ctDNA, especially G-quadruplex Pu27.展开更多
Generating the rogue waves in offshore engineering is investigated,first of all,to forecast its occurrence to protect the offshore structure from being attacked,to study the mechanism and hydrodynamic properties of ro...Generating the rogue waves in offshore engineering is investigated,first of all,to forecast its occurrence to protect the offshore structure from being attacked,to study the mechanism and hydrodynamic properties of rouge wave experimentally as well as the rouge/structure interaction for the structure design.To achieve these purposes demands an accurate wave generation and calculation.In this paper,we establish a spatial domain model of fourth order nonlinear Schrdinger(NLS) equation for describing deep-water wave trains in the moving coordinate system.In order to generate rogue waves in the experimental tank efficiently,we take care that the transient water wave(TWW) determines precisely the concentration of time/place.First we simulate the three-dimensional wave using TWW in the numerical tank and modeling the deepwater basin with a double-side multi-segmented wave-maker in Shanghai Jiao Tong University(SJTU) under the linear superposing theory.To discuss its nonlinearity for guiding the experiment,we set the TWW as the initial condition of the NLS equation.The differences between the linear and nonlinear simulations are presented.Meanwhile,the characteristics of the transient water wave,including water particle velocity and wave slope,are investigated,which are important factors in safeguarding the offshore structures.展开更多
The electrocatalytic activity toward oxygen reduction reaction is studied on the perovskite oxide La~_xbrxMnt)3, as preparea under different firing temperatures. X-ray diffraction shows that three different crystal p...The electrocatalytic activity toward oxygen reduction reaction is studied on the perovskite oxide La~_xbrxMnt)3, as preparea under different firing temperatures. X-ray diffraction shows that three different crystal phases featuring tetragonal, cubic, and orthorhombic symmetries form with increasing crystallinities. The electrocatalytic activity is characterized by cyclic voltam- metry and linear sweeping voltammetry for the three phases of La1-xSrxMnO3. We find that the tetragonal phase has the best catalytic activity among the three crystal phases, with the largest onset potential of 0.147 V. The synergistic effect between the volume per unit cell and crystallinity is indicated to account for the good catalytic activity of the tetragonal phase.展开更多
Compaction and silicon cementation are the dominant processes reducing porosity and permeability in quartzose sandstones during diagenesis. Despite the wealth of information about quartz cementation, there are still u...Compaction and silicon cementation are the dominant processes reducing porosity and permeability in quartzose sandstones during diagenesis. Despite the wealth of information about quartz cementation, there are still unanswered questions related to mechanisms of growth of quartz cement and the diagenesis processes. In this study we present an electron backscatter diffraction (EBSD) analysis, combined with optics and cathodoluminescence (CL) information, for the quartz sandstones from the Upper Triassic Xujiahe Formation of Sichuan Basin, in order to reveal the microstructural and crystallographic features of the silica cementation and detrital grain during the compaction. The EBSD is a crucial technique to provide essential crystallographic data on the quartz grain and its cement. Quartz cement is shown to be syntaxial to its host quartz grain. EBSD data-based orientation maps show dauphin6 twinning and low angle boundary to be common in the host grains and quartz cement of the samples. The dauphin6 twins occurred in grain-grain contacts and in cement-crystal boundaries, and commonly crossed grain cement boundaries. These features indicate that there may be two types of dauphin6 twins, one inherited twins from the source area and the other developed by compaction-induced grain boundary deformation. These investigations suggest that strong mechanical compaction may occur after and/or during quartz cement growth in the later diagenesis of the Xujiahe sandstones. EBSD has a capability of revealing microstructural information and regarding mechanisms of diagenesis crystal growth in quartzose sandstones.展开更多
A clear understanding of the nucleation, growth, coarsening, the preparation of highly controlled nanostructures. Among and aggregation processes of nanomaterials is necessary to enable wet chemical synthetic methods,...A clear understanding of the nucleation, growth, coarsening, the preparation of highly controlled nanostructures. Among and aggregation processes of nanomaterials is necessary to enable wet chemical synthetic methods, ultrasound-assisted preparation has become an important tool in material science. The formation and crystal growth mechanism under ultrasound is special compared with other wet chemical synthetic routes. In this review, we discussed the chemical and physical effect of ultrasound and summarized the ultrasonic effect on crystallization. The sonolysis of water and the cavitation-induced microjet impact and shockwave are the two key factors in the sonochemieal formation of inorganic nanomaterials. The ultrasonic-assisted Ostwald ripening and oriented attachment processes have been reviewed for the possible crystal growth mechanisms in the fabrication of inorganic nanostructures.展开更多
文摘Jianshanzi volcanic rocks at Qinghe valley in the northern Liaoning were considered belonging to Early Proterozoie Gaojiayu Formation of Liaohe Group, or to Early Cambrian Beidagou Formation of Qinghezhen Group, or Middle-Late Proterozoic Shenjiapu Formation-Complex of Kaiyuan Group-complex. Dating the zircons from the dacite with schistosity is 2 506 Ma in method of U-Pb (SHRIMP). This evidence indicates the rocks may be referred to Late Permian in age. Discovery of the rocks is significant to re-recognize stratigraphic property of "Liaohe Group", regional geoteetonie location and revolution of orogenic zone in Qinghe valley of the northern Liaoning.
文摘Objective. To evaluate the effects of alendronate on the structural properties of trabecular bone.Methods. Alendronate was administered at a daily p. o. dose of 0. 5 mg/kg over a 12-week period in hound dogs (n = 8 for both the control and treated group), and the structural indices of the lumbar vertebral (LI and L2) trabecular bone were assessed directly from 3-D images.Results. Treatment with alendronate increased bone volume fraction by 9. 5% and 7. 7% in L1 and L2 respectively. Trabecular thickness significantly increased after alendronate treatment, whereas trabecular separation remained constant. The degree of anisotropy for the alendronate - treated group was decreased compared with that of the control group. Bone surface to volume ratio declined significantly in the alendronate-reated group, whereas alendronate induced a higher bone surface density.Conclusion. Alendronate increased the structural properties of canine trabecular bone after short-term treatment at a dose of 0. 5 mg · kg-1·day-1.
文摘Water exploits an essential part in all the durable development, the exploitation of this natural resource, its management and its position, its mineralization, its underground course and the mode o fits resurgence. The area of Gafsa is known by its very important hydrous potential which is geographically in the zone of transition between central Tunisia and the Saharan platform, these two great fields are separated by the fault of Gafsa which plays an important part in the structuring of the basins of the area, the hydrous resources of Gafsa make subsoil water the principal source of supply water, in the absence of an important network of surface. The zones of studies present requirements out of water which do not cease growing with the progress of the industrial activities and the concentration of the agricultural activities: The objective of this work is to analyze the water of the various zones of the area of Gafsa and to treat it to make it possible most drinkable. The analyzes like measurement of pH, measurement of electric conductivity and measurement of dry residue were made in the laboratory of the chemical group of Mdhila in Tunisia and in laboratory of Ion exchanger Materials of Vitry in France, the processes of treatment as opposite osmosis are also programmed in this same laboratory. The results are very encouraging to start the study and the design of a station of potabilisation of water in the area of Gafsa.
文摘The hypothesis "happy productive worker" states that happy employees, whose needs are satisfied in their workplace, have greater performance than unhappy employees. Therefore, the purpose of this research is to examine empirically the effects that job satisfaction and well-being at work generate on the individual job performance, investigating the moderating role that the components of the organizational structure play in this relationship. To achieve the main objective, some secondary objectives were proposed: (1) test the predictive effect of well-being, satisfaction, personal, and professional variables on individual performance; and (2) test the moderating effect of the components of the organizational structure in the relationship among well-being, satisfaction, and individual job performance. This research originates of a consolidated statement for the business society, but very few empirical studies. This way, the hypothesis consisted in the components of the organizational structure will positively enhance the relationship among well-being at work, job satisfaction, and individual job performance. The final sample consisted of 134 participants, of a clinical laboratory and of federal court of justice. For the development of the questionnaire, four instruments were used; one for each construct. The proposal has four relationship variables and the statistical procedure used to test this hypothesis was multiple linear regressions. Considering the hypothetical theoretical model presented, personal and professional variables are predictors of job performance; thus, these variables were also included as independent variables. The results of the regression model showed that the variables "age", "well-being at work", "job satisfaction", and "components of organizational structure" are responsible for explaining 64% of the variance of the variable criteria and individual job performance The moderating role of the variable "components of organizational structure" was also observed, because its inclusion increased the explained variance of the dependent variable. After all the discussions developed, the two main contributions appear: (1) the predictive effect of well-being at work in relation to performance and (2) identifying the moderating effect of the components of the organizational structure.
基金grants from the National Natural Science Foundation of China the Natural Science Foundation of Fujian Province and Chinese Academy of Sciences.
文摘The inter-diffusion of N,N-dimethylformamide solution of Zn(phen)2Cl2 and (NH4)2MS4 (M = W, Mo) in an H-shape tube produced crystals of Zn(phen)2WS4 1 and Zn(phen)2MoS4 2 (phen = 1,10-phenanthroline). The structures of isomorphous complexes 1 and 2 have been determined by X-ray single-crystal structure analyses. Four nitrogen atoms from the phenanthroline ligands and two sulfur atoms from the MS42- anion forming a distorted octahedron coordinate each zinc atom. Through p-p interactions of adjacent aromatic rings of the phenanthroline ligands, a quasi one-dimensional zigzag-stacking column is formed in each complex. Complex 1 crystallizes in monoclinic space group C2/c, with a = 10.447(8), b = 22.016(9), c = 12.824(8) ? b = 103.56(6)? V = 2867.7(8) 3, Z = 4, C24H16N4S4WZn, Mr=737.90, Dc = 1.71 g/cm3, F(000) = 1424, m = 5.25 mm-1, the final R = 0.054 and Rw = 0.075 for 2315 observations with I > 3s (I). Complex 2 crystallizes in monoclinic space group C2/c, with a = 10.410(6), b = 22.095(7), c = 12.830(6) ? b = 103.19(8)? V = 2873.1(5) 3, Z = 4, C24H16MoN4S4Zn, Mr=649.99, Dc = 1.50 g/cm3, F(000) = 1296, m = 1.58 mm-1, the final R = 0.072 and Rw = 0.100 for 1631 observations with I > 3s(I).
文摘Chickpea is a major food crop and the world's third most widely-grown legume after bean (phaseolus vulgaris L.) and pea (pisum sativam L.). The yield of chickpea can be improved by planting of optimum density of chickpea cultivars. The purpose of this research was to investigate the effect of plant density on yield and some characteristics of chickpea (Cicer arietinum L. var. Philips). A field experiment was conducted on research farm of, Gonbad High Education Center, Iran. The study was laid out factorial in randomized block design with four replications. The treatments were factorial row spacing (A1=35 cm, A2=45 cm and A3=55 cm) and plant spacing in the row (Plant-within-spacing row) (B1=5 cm, B2=7.5 cm and B3=10 cm). AIBI=(35×5)=57.14, AIB2= (35×7.5)=38.09, A1B3=(35×10)=28.57, A2B1=(45×7)=44.44, A2B2=(45×7.5)=29.26, A2B3=(45× 10)=22.23, A3B1=(55×5)=36.36, A3B2=(55 ×.5)=24.24, A3B3=(55 × 10)=18.18 plant.m^-2. At the harvest time, 5 plants of each plot were selected randomly and used for determination of pods per plant, unfilled pod per plant, height and number of branches. Result showed the yield was not affected by density. The maximum yield obtained in row spacing 55 cm and plant spacing in the row 7.5 cm which was equal 1802.87 kg·ha^-1. Row spacing had statistically significant effect on the pod number per plant, branches number per plant and plant height.
文摘In this study, one mononuclear zinc(II) complex with 1,2-bis CAP ((5-chlorosalicylidene amino)-phenylene): C22C13N2035Znl5 H0125 (Zn-CAP) was synthesized. The binding properties of Zn-CAP with G-quadruplex DNA and ctDNA (calf thymus DNA) were examined by fluorescence, CD (circular dichroism) spectroscopic and FRET (fluorescence resonance energy transfer) assay. In the fluorescence emission spectral analysis, the addition of three series of G-quadruplex DNA (G4-HTG21, G4-Pu27 and G4-c-kit-l) into the Zn-CAP solution induced moderate or add hypochromicity with total quenching ratios of 10.73%, 15.07% and 8.59% in the presence of K+ were achieved, respectively. While the addition of ctDNA under same condition only caused 7.08% quenching on the fluorescence emission of Zn-CAP. In the CD spectral analysis, the interaction with Zn-CAP could induce significant spectral changes on the CD absorption of G4-HTG21, G4-Pu27 and G4-c-kit-1, with 106.00%, 93.06%, 113.47% increment at 232 nm absorption, along with a 81.11%, 92.80%, 83.72% decrement at 295 nm or 270 nm absorption, which demonstrated that the antiparallel structure of G-quadruplex DNA is more stable in the presence of Zn-CAP. Comparatively, the addition of Zn-CAP could induce significant spectral changes on the CD absorption of double helix ctDNA, with 64.17% decrement on the positive peak absorption, along with a 90.91% increment on the negative peak absorption. On the other hand, in the FRET-melting assay analysis, it was clear that Zn-CAP at 0.5 equivalences could raise the melting temperature of G-quadruplex (F2 IT or FPul 8T) by 3.45℃ and 15.85℃, indicating an obvious stabilization effect of Zn-CAP on G-quadruplex in Pu27. All the results indicated that Zn-CAP exhibited higher binding affinity and binding intensity to G-quadruplex DNA than ctDNA, especially G-quadruplex Pu27.
基金the "Knowledge-based Ship Design Hyper-Integrated Platform (KSHIP)",a key project of the Ministry of Education and the Ministry of Finance of China
文摘Generating the rogue waves in offshore engineering is investigated,first of all,to forecast its occurrence to protect the offshore structure from being attacked,to study the mechanism and hydrodynamic properties of rouge wave experimentally as well as the rouge/structure interaction for the structure design.To achieve these purposes demands an accurate wave generation and calculation.In this paper,we establish a spatial domain model of fourth order nonlinear Schrdinger(NLS) equation for describing deep-water wave trains in the moving coordinate system.In order to generate rogue waves in the experimental tank efficiently,we take care that the transient water wave(TWW) determines precisely the concentration of time/place.First we simulate the three-dimensional wave using TWW in the numerical tank and modeling the deepwater basin with a double-side multi-segmented wave-maker in Shanghai Jiao Tong University(SJTU) under the linear superposing theory.To discuss its nonlinearity for guiding the experiment,we set the TWW as the initial condition of the NLS equation.The differences between the linear and nonlinear simulations are presented.Meanwhile,the characteristics of the transient water wave,including water particle velocity and wave slope,are investigated,which are important factors in safeguarding the offshore structures.
基金supported by the National Basic Research Program of China(2012CB215504)the National High Technology Research and Development Program of China(2009AA034401)the National Natural Science Foundation of China(50632050)
文摘The electrocatalytic activity toward oxygen reduction reaction is studied on the perovskite oxide La~_xbrxMnt)3, as preparea under different firing temperatures. X-ray diffraction shows that three different crystal phases featuring tetragonal, cubic, and orthorhombic symmetries form with increasing crystallinities. The electrocatalytic activity is characterized by cyclic voltam- metry and linear sweeping voltammetry for the three phases of La1-xSrxMnO3. We find that the tetragonal phase has the best catalytic activity among the three crystal phases, with the largest onset potential of 0.147 V. The synergistic effect between the volume per unit cell and crystallinity is indicated to account for the good catalytic activity of the tetragonal phase.
基金supported by National Natural Science Foundation of China(Grant Nos. 40802050,40872149)China Postdoctoral Science Foundation (Grant No. 20070420065)
文摘Compaction and silicon cementation are the dominant processes reducing porosity and permeability in quartzose sandstones during diagenesis. Despite the wealth of information about quartz cementation, there are still unanswered questions related to mechanisms of growth of quartz cement and the diagenesis processes. In this study we present an electron backscatter diffraction (EBSD) analysis, combined with optics and cathodoluminescence (CL) information, for the quartz sandstones from the Upper Triassic Xujiahe Formation of Sichuan Basin, in order to reveal the microstructural and crystallographic features of the silica cementation and detrital grain during the compaction. The EBSD is a crucial technique to provide essential crystallographic data on the quartz grain and its cement. Quartz cement is shown to be syntaxial to its host quartz grain. EBSD data-based orientation maps show dauphin6 twinning and low angle boundary to be common in the host grains and quartz cement of the samples. The dauphin6 twins occurred in grain-grain contacts and in cement-crystal boundaries, and commonly crossed grain cement boundaries. These features indicate that there may be two types of dauphin6 twins, one inherited twins from the source area and the other developed by compaction-induced grain boundary deformation. These investigations suggest that strong mechanical compaction may occur after and/or during quartz cement growth in the later diagenesis of the Xujiahe sandstones. EBSD has a capability of revealing microstructural information and regarding mechanisms of diagenesis crystal growth in quartzose sandstones.
基金supported by the National Natural Science Foundation of China (20805022, 21075061, 21121091)China Postdoctoral Science Foundation ( 20100471294)
文摘A clear understanding of the nucleation, growth, coarsening, the preparation of highly controlled nanostructures. Among and aggregation processes of nanomaterials is necessary to enable wet chemical synthetic methods, ultrasound-assisted preparation has become an important tool in material science. The formation and crystal growth mechanism under ultrasound is special compared with other wet chemical synthetic routes. In this review, we discussed the chemical and physical effect of ultrasound and summarized the ultrasonic effect on crystallization. The sonolysis of water and the cavitation-induced microjet impact and shockwave are the two key factors in the sonochemieal formation of inorganic nanomaterials. The ultrasonic-assisted Ostwald ripening and oriented attachment processes have been reviewed for the possible crystal growth mechanisms in the fabrication of inorganic nanostructures.