This paper elaborated the special geological conditions of Chongqing City and the characteristics of urban bridges formed by natural environment, and put forth the ecological landscape design ideas of urban bridges. 3...This paper elaborated the special geological conditions of Chongqing City and the characteristics of urban bridges formed by natural environment, and put forth the ecological landscape design ideas of urban bridges. 3 principles of ecological landscape design were presented including paying attention to the creation of great environment, focusing on the comparison and harmony between natural and artificial factors and seeking for simple lines and unified colors, and the application of ecological landscape design principles in constructing ecological landscape of bridges in Chongqing City was analyzed. By discussing the existing problems of ecological landscape design of bridges in Chongqing City, some suggestions were summarized, which were expected to produce positive effects for the researches of ecological landscape design of bridges.展开更多
The amino acid composition and the biased auto-correlation function are considered as features, BP neural network algorithm is used to synthesize these features. The prediction accuracy of this method is verified by u...The amino acid composition and the biased auto-correlation function are considered as features, BP neural network algorithm is used to synthesize these features. The prediction accuracy of this method is verified by using the independent non-homologous protein database. It is shown that the average absolute errors for resubstitution test are 0.070 and 0.068 with the standard deviations 0.049 and 0.047 for the prediction of the content of α-helix and β-sheet respectively. For cross-validation test, the average absolute errors are 0.075 and 0.070 with the standard deviations 0.050 and 0.049 for the prediction of the content of α-helix and β-sheet respectively. Compared with the other methods currently available, the BP neural network method combined with the amino acid composition and the biased auto-correlation function features can effectively improve the prediction accuracy.展开更多
In English teaching, it is necessary to pay attention to students' psychology and cognition in order to make them harmonious and effective. Therefore, English teacher would change their teaching opinions, realizing t...In English teaching, it is necessary to pay attention to students' psychology and cognition in order to make them harmonious and effective. Therefore, English teacher would change their teaching opinions, realizing teaching object, guiding student's minds and ideas to study by some measures, such as accordant teaching and study, making students as a base in study, and students' self-study. In other words, making student study actively rather than passively is much better for their English abilities.展开更多
Consider two dependent renewal risk models with constant interest rate. By using some methods in the risk theory, uniform asymptotics for finite-time ruin probability is derived in a non-compound risk model, where cla...Consider two dependent renewal risk models with constant interest rate. By using some methods in the risk theory, uniform asymptotics for finite-time ruin probability is derived in a non-compound risk model, where claim sizes are upper tail asymptotically independent random variables with dominatedly varying tails, claim inter-arrival times follow the widely lower orthant dependent structure, and the total amount of premiums is a nonnegative stochastic process. Based on the obtained result, using the method of analysis for the tail probability of random sums, a similar result in a more complex and reasonable compound risk model is also obtained, where individual claim sizes are specialized to be extended negatively dependent and accident inter-arrival times are still widely lower orthant dependent, and both the claim sizes and the claim number have dominatedly varying tails.展开更多
Coupled with partial least squares(PLS),near infrared(NIR)spectroscopy was applied to develop a fast and nondestructive method to identify the production date of Rizhao green tea aiming at the deficiencies of the exis...Coupled with partial least squares(PLS),near infrared(NIR)spectroscopy was applied to develop a fast and nondestructive method to identify the production date of Rizhao green tea aiming at the deficiencies of the existing methods.In the modeling process,the raw spectra were first processed by five-point smoothing and first derivative.And then,moving window back propagation artificial neural network(MW-BP-ANN)was applied to select the characteristic spectral variables.After that,the calibration model was built by PLS,and the optimum model was achieved when 9 principal component scores(PCs)were included.The performances of the calibration models were evaluated according to root mean square error of predictionεRMSEP,correlation coefficient(C p)and residual prediction deviation(σRPD).The optimum results of the calibration model was achieved,andεRMSEP=19.965,C p=0.943 andσRPD=3.07.The overall results sufficiently demonstrate that NIR spectroscopy combined with PLS can be efficiently applied in the rapid identification of green tea production date.展开更多
To feed an increasing population, large amounts of chemical nitrogen fertilizer have been used to produce much of our food, feed and fiber thereby increasing nitrogen levels in soils, natural waters, crop residues, li...To feed an increasing population, large amounts of chemical nitrogen fertilizer have been used to produce much of our food, feed and fiber thereby increasing nitrogen levels in soils, natural waters, crop residues, livestock wastes,and municipal and agricultural wastes, with national and international concern about its potential adverse effects on environmental quality and public health. To understand these phenomena and problems, first the nitrogen cycle and the environment are described. Then recent trends for nitrogen cycling through the food and feed system, N2O emissions from fertilized upland and paddy soils, and NO-3 pollution in ground water in Japan are reported. Finally, mitigation strategies in Japan for reducing N2O emission and NO-3 pollution are proposed, including nitrification inhibitors, controlled release fertilizers, utilization of plant species that could suppress nitrification, utilizing the toposequence, government policy, and appropriate agricultural practices. Of all the technologies presented, use of nitrification inhibitors and controlled release fertilizers are deemed the most important with further development of these aspects of technologies being expected. These practices, if employed worldwide, could help reduce the load, or environmental deterioration, on the Earth's biosphere.展开更多
Studies on acute toxicity of Cu2+,Mn2+and Zn2^to Artemianauplii(36h)and adults were carried out at15±3°C in the natural seawater where salinity is30using single-factor acute toxicity;on this basis,equi-toxic...Studies on acute toxicity of Cu2+,Mn2+and Zn2^to Artemianauplii(36h)and adults were carried out at15±3°C in the natural seawater where salinity is30using single-factor acute toxicity;on this basis,equi-toxicity test was used to evaluate the effect of joint toxicity of Cu2+,Mn2+and Zn2+to Artemia nauplii(36h)in the same conditions.Results show that Artemia has different tolerances for the three heavy metal ions when it is in different growth period,and the interaction of heavy metal ions varied with growth period,adults are more sensitive of the three heavy metals;The48h LC50of these three heavy metal to the Artemia nauplii is4.0,27.19and115.95mg/L,and to the adults is1.31,6.86and34.23mg/L;the order of toxicity of cuprum,manganese and zinc for Artemia nauplii and adults was Cu2^>Mn2+>Zn2+;the safe concentration of the three heavy metal ions(Cu2+,Mn2+and Zn2+)to Artemia nauplii(36h)and adults were0.4,2.72,11.6,0.13,0.69and3.42mg/L.The results of combined toxicity test showed that Cu-Mn,Cu-Zn and Mn-Zn were all antagonistic to the Artemia naupli.展开更多
H1-Galerkin mixed methods are proposed for viscoelasticity wave equation.Depending on the physical quantities of interest,two methods are discussed.The optimal error estimates and the proof of the existence and unique...H1-Galerkin mixed methods are proposed for viscoelasticity wave equation.Depending on the physical quantities of interest,two methods are discussed.The optimal error estimates and the proof of the existence and uniqueness of semidiscrete solutions are derived for problems in one space dimension.And the methods don't require the LBB condition.展开更多
The adoption by the 18th Congress of the Communist Party of China in November 2012 of a policy on ecological civilization is a landmark event for the nation and the world community. China's vision for building an eco...The adoption by the 18th Congress of the Communist Party of China in November 2012 of a policy on ecological civilization is a landmark event for the nation and the world community. China's vision for building an ecological civilization is comprehensive, multi-sectoral and systemic and is intended to direct and balance progress among ecological, economic, social, cultural and political dimensions of change. Some on-going efforts and potential future activities that meet China's vision of an ecological civilization are described. Establishment of dedicated ecological civilization areas for experimenting with legal, regulatory and administrative incentives that would facilitate the march towards the ideal is encouraged. Chinese biosphere reserves which are designated with the explicit aim of building harmony between humans and nature would be suitable candidates for designing and developing such dedicated ecological civilization areas.展开更多
An analytical solution was presented to the unsaturated soil with a finite thickness under confinement in the lateral direction and sinusoidal cyclic loading in the vertical direction based on Fredlund's one-dimen...An analytical solution was presented to the unsaturated soil with a finite thickness under confinement in the lateral direction and sinusoidal cyclic loading in the vertical direction based on Fredlund's one-dimensional consolidation equation for unsaturated soil. The transfer relationship between the state vectors at the top surface and any depth was gained by applying the Laplace transform and Cayley-Hamilton mathematical methods to the governing equations of water and air, Darcy's law and Fick's law. The excess pore-air and pore-water pressures and settlement in the Laplace-transformed domain were obtained by using the Laplace transform with the initial and boundary conditions. The analytical solutions of the excess pore-air and pore-water pressures at any depth and settlement were obtained in the time domain by performing the inverse Laplace transforms. A typical example illustrates the consolidation characteristics of unsaturated soil under sinusoidal loading from analytical results. Finally, comparisons between the analytical solutions and results of the numerical method indicate that the analytical solution is correct.展开更多
One-pot synthesis of cyclic aldol tetramer and α, β-unsaturated aldol from C3-C8 linear aldehydes using phase-transfer catalyst(PTC), quaternary ammonium, combined with sodium hydroxide as catalysts was investigat...One-pot synthesis of cyclic aldol tetramer and α, β-unsaturated aldol from C3-C8 linear aldehydes using phase-transfer catalyst(PTC), quaternary ammonium, combined with sodium hydroxide as catalysts was investigated. Butanal was subjected for detail investigations to study the effect of parameters. It was found that the selectivity of cyclic aldol tetramer depends greatly on the operating conditions of the reaction, especially the PTC/butanal molar ratio. The average selectivity of 2-hydroxy-6-propyl-l, 3, 5-triethyl-3-cyclohexene-1-carboxaldehyde(HPTECHCA) was 54.41% using tetrabutylammonium chloride combined with 14%(mass fraction) Na OH as catalysts at 60 ℃for 2 h with a PTC-to-butanal molar ratio of 0.09:1. Pentanal was more likely to generate cyclic aldol tetramer compared with other aldehydes under the optimum experimental conditions. Recovery of the PTC through water washing followed by adding enough sodium hydroxide from the washings was also demonstrated.展开更多
In this paper,the existence,the uniqueness,the asymptotic behavior and the non-existence of the global generalized solutions of the initial boundary value problems for the non-linear pseudo-parabolic equation ut-αuxx...In this paper,the existence,the uniqueness,the asymptotic behavior and the non-existence of the global generalized solutions of the initial boundary value problems for the non-linear pseudo-parabolic equation ut-αuxx-βuxxt=F(u)-βF (u)xx are proved,where α,β 0 are constants,F(s) is a given function.展开更多
Density functional theory was used to study the NH3 behavior on Ni monolayer covered Pt(111) and WC(001). The electronic structure of the surfaces, and the adsorption and decomposition of NH3 were calculated and c...Density functional theory was used to study the NH3 behavior on Ni monolayer covered Pt(111) and WC(001). The electronic structure of the surfaces, and the adsorption and decomposition of NH3 were calculated and compared. Ni atoms in the monolayer behave different from that in Ni(111). More dz2 electrons of Ni in monolayer covered systems were shifted to other regions compared to Ni(111), charge density depletion on this orbital is crucial to NH3 adsorption. NH3 binds more stable on Ni/Pt(lll) and Ni/WC(001) than on Ni(111), the energy barriers of the first N-H bond scission were evidently lower on Ni/Pt(111) and Ni/WC(001) than on Ni(111), these are significant to NH3 decomposition. N recombination is the rate-limiting step, high reaction barrier implies that N2 is produced only at high temperatures. Although WC has similar properties to Pt, differences of the electronic structure and catalytic activities are observed for Ni/Pt(111) and Ni/WC (001), the energy barrier for the rate-determined step increases on Ni/WC(001) instead of decreasing on Ni/Pt(lll) when compared to Ni(111). the N recombination barrier by modifying To design cheaper and better catalysts, reducing Ni/WC(001) is a critical question to be solved.展开更多
Nonlinear distortion introduced by an amplifier when subjected to a multisine excitation decreases the measurement accuracy in many metrological and measurement areas. In this paper, we performed qualitative and quant...Nonlinear distortion introduced by an amplifier when subjected to a multisine excitation decreases the measurement accuracy in many metrological and measurement areas. In this paper, we performed qualitative and quantitative analyses of the nonlinear distortion with the multisine excitations constrained by a constant power spectral density. We present the numerical results with respect to different tone spacings,nonlinear orders, harmonic phases and tone distributions. Moreover, three as-pects of contributions are made to further reveal the distortion mechanism. First, we find that the type Ⅱ components for Schr- oeder-phase multisines distribute uniformly but not all in anti-phase to the type I components for the second order nonlinearity. Second,we simulate the variance of the type I and Ⅱ components and their summation to explain the principle of reducing the type Ⅱ distortion by averaging the results obtained using multiple realizations of random-phase multisines. Third, we observe a special distortion distribution mechanism for the Schroeder-phase multisine excitation The results contribute to a better estima-tion and understanding of the nonlinear distortion.展开更多
We conducted two-stage acidification-bioleaching experiments to probe the feasibility of bioleaching for a kind of mixed alkaline copper oxide and sulphide mineral. We used the uniform design method for data analysis ...We conducted two-stage acidification-bioleaching experiments to probe the feasibility of bioleaching for a kind of mixed alkaline copper oxide and sulphide mineral. We used the uniform design method for data analysis and experimental optimization, with initial pH value, pulp density, inoculation of bacteria and ferrous iron concentration selected as the influential factors. Polynomial regression shows that the four factors sequentially influence the copper recovery by 14.430%, 8.555%, 1.982% and 3.895%. Acid equilibrium in the bioleaching system is mainly influenced by alkaline gangue content, chemical reactions and bacterial activity. A maximal portion of refractory copper extracted reaches 71.08%. The dynamic analysis of copper recovery indicates that bioleaching goes through a lag leaching phase, prime leaching phase and leaching stationary phase corresponding to the growth phases of bacteria. Compared with the predicted value of 80.87%, the confirmatory experiment observes a 78.21% copper recovery under the optimal conditions of pH of 1.5, pulp density of 5%, bacteria inoculation of 30% and initial ferrous iron concentration of 9 g L-1. Results suggest that bioleaching is technically feasible to improving total copper recovery.展开更多
Based on non-Darcian flow law described by exponent and threshold gradient within a double-layered soil, the classic theory of one-dimensional consolidation of double-layered soil was modified to consider the change o...Based on non-Darcian flow law described by exponent and threshold gradient within a double-layered soil, the classic theory of one-dimensional consolidation of double-layered soil was modified to consider the change of vertical total stress with depth and time together. Because of the complexity of governing equations, the numerical solutions were obtained in detail by finite difference method. Then, the numerical solutions were compared with the analytical solutions in condition that non-Darcian flow law was degenerated to Dary's law, and the comparison results show that numerical solutions are reliable. Finally, consolidation behavior of double-layered soil with different parameters was analyzed, and the results show that the consolidation rate of double-layered soil decreases with increasing the value of exponent and threshold of non-Darcian flow, and the exponent and threshold gradient of the first soil layer greatly influence the consolidation rate of double-layered soil. The larger the ratio of the equivalent water head of external load to the total thickness of double-layered soil, the larger the rate of the consolidation, and the similitude relationship in classical consolidation theory of double-layered soil is not satisfied. The other consolidation behavior of double-layered soil with non-Darcian flow is the same as that with Darcy's law.展开更多
In order to validate the control effects of integrated technology of medicine and fertilizer on tobacco bacterial wilt,field experiments were conducted by using youmeili and tetracycline as the test agents.The results...In order to validate the control effects of integrated technology of medicine and fertilizer on tobacco bacterial wilt,field experiments were conducted by using youmeili and tetracycline as the test agents.The results obtained were listed as follows:(1)The incidence rate of bacterial wilt ascended more quickly after July 10 th,the incidence of CK reached 78.30%on July 25 th.(2)The control effect of“youmeili 3 g+tetramycin 200 times liquid”reached 69.47%,significantly higher than other treatments.(3)The output value of“Youmeil 3 g+tetramycin 200 times liquid”served as 1635.66 yuan/667m^2,with the highest economic character in all treatments.In a word,integrated technology of medicine and fertilizer was a feasible approach to control tobacco bacterial wilt.展开更多
Music is the soul of sports dance. Sports dance can be carried out smoothly by the accompaniment of music. Therefore the two should be in harmony and unity to perform the essence of sports dance totally. This article ...Music is the soul of sports dance. Sports dance can be carried out smoothly by the accompaniment of music. Therefore the two should be in harmony and unity to perform the essence of sports dance totally. This article tries analyzing the impact of music in sports dance teaching for students in physiological, psychological, creativity, imagination, aesthetic and so on to explore the important role of music in the development of students' comprehensive quality, in order to help sports dance teaching.展开更多
In this paper, I revisit the question of the consistency of Thrasymachus' position on justice in the First Book of the Republic. The paper falls into four parts. (The first part is an introduction.) In the second p...In this paper, I revisit the question of the consistency of Thrasymachus' position on justice in the First Book of the Republic. The paper falls into four parts. (The first part is an introduction.) In the second part, I examine two influential interpretations of the sophist's views, George B. Kerferd's and Timothy D. J. Chappell's, and argue that neither one fully resolves the riddle of Thrasymachus. In the third part, I claim that the sophist has a "descriptive" theory of justice, not a "prescriptive" one, and that no moral command to act in any particular way follows from this theory. In the fourth and final part, I propose a new approach to the whole issue by arguing that the essential problem with Thrasymachus' theory is not the incompatibility between his two definitions of justice in 338c and 343c, as it is usually assumed, but the fact that in Book One he uses two different and irreconcilable conceptions of justice. It is because the sophist uses the term "justice" to mean different things in different parts of the text that his overall position is ultimately inconsistent.展开更多
文摘This paper elaborated the special geological conditions of Chongqing City and the characteristics of urban bridges formed by natural environment, and put forth the ecological landscape design ideas of urban bridges. 3 principles of ecological landscape design were presented including paying attention to the creation of great environment, focusing on the comparison and harmony between natural and artificial factors and seeking for simple lines and unified colors, and the application of ecological landscape design principles in constructing ecological landscape of bridges in Chongqing City was analyzed. By discussing the existing problems of ecological landscape design of bridges in Chongqing City, some suggestions were summarized, which were expected to produce positive effects for the researches of ecological landscape design of bridges.
文摘The amino acid composition and the biased auto-correlation function are considered as features, BP neural network algorithm is used to synthesize these features. The prediction accuracy of this method is verified by using the independent non-homologous protein database. It is shown that the average absolute errors for resubstitution test are 0.070 and 0.068 with the standard deviations 0.049 and 0.047 for the prediction of the content of α-helix and β-sheet respectively. For cross-validation test, the average absolute errors are 0.075 and 0.070 with the standard deviations 0.050 and 0.049 for the prediction of the content of α-helix and β-sheet respectively. Compared with the other methods currently available, the BP neural network method combined with the amino acid composition and the biased auto-correlation function features can effectively improve the prediction accuracy.
文摘In English teaching, it is necessary to pay attention to students' psychology and cognition in order to make them harmonious and effective. Therefore, English teacher would change their teaching opinions, realizing teaching object, guiding student's minds and ideas to study by some measures, such as accordant teaching and study, making students as a base in study, and students' self-study. In other words, making student study actively rather than passively is much better for their English abilities.
基金The National Natural Science Foundation of China(No.11001052,11171065,71171046)China Postdoctoral Science Foundation(No.2012M520964)+1 种基金the Natural Science Foundation of Jiangsu Province(No.BK20131339)the Qing Lan Project of Jiangsu Province
文摘Consider two dependent renewal risk models with constant interest rate. By using some methods in the risk theory, uniform asymptotics for finite-time ruin probability is derived in a non-compound risk model, where claim sizes are upper tail asymptotically independent random variables with dominatedly varying tails, claim inter-arrival times follow the widely lower orthant dependent structure, and the total amount of premiums is a nonnegative stochastic process. Based on the obtained result, using the method of analysis for the tail probability of random sums, a similar result in a more complex and reasonable compound risk model is also obtained, where individual claim sizes are specialized to be extended negatively dependent and accident inter-arrival times are still widely lower orthant dependent, and both the claim sizes and the claim number have dominatedly varying tails.
基金National Basic Research Program of China(No.JSJL2016210A001)State Key Laboratory of Sensor Technology Fund(No.SKT1507)
文摘Coupled with partial least squares(PLS),near infrared(NIR)spectroscopy was applied to develop a fast and nondestructive method to identify the production date of Rizhao green tea aiming at the deficiencies of the existing methods.In the modeling process,the raw spectra were first processed by five-point smoothing and first derivative.And then,moving window back propagation artificial neural network(MW-BP-ANN)was applied to select the characteristic spectral variables.After that,the calibration model was built by PLS,and the optimum model was achieved when 9 principal component scores(PCs)were included.The performances of the calibration models were evaluated according to root mean square error of predictionεRMSEP,correlation coefficient(C p)and residual prediction deviation(σRPD).The optimum results of the calibration model was achieved,andεRMSEP=19.965,C p=0.943 andσRPD=3.07.The overall results sufficiently demonstrate that NIR spectroscopy combined with PLS can be efficiently applied in the rapid identification of green tea production date.
基金Project supported by the Canadian International Development Agency, Canada and the Chinese Academy of Scicences, China (No. KZCX2-413)
文摘To feed an increasing population, large amounts of chemical nitrogen fertilizer have been used to produce much of our food, feed and fiber thereby increasing nitrogen levels in soils, natural waters, crop residues, livestock wastes,and municipal and agricultural wastes, with national and international concern about its potential adverse effects on environmental quality and public health. To understand these phenomena and problems, first the nitrogen cycle and the environment are described. Then recent trends for nitrogen cycling through the food and feed system, N2O emissions from fertilized upland and paddy soils, and NO-3 pollution in ground water in Japan are reported. Finally, mitigation strategies in Japan for reducing N2O emission and NO-3 pollution are proposed, including nitrification inhibitors, controlled release fertilizers, utilization of plant species that could suppress nitrification, utilizing the toposequence, government policy, and appropriate agricultural practices. Of all the technologies presented, use of nitrification inhibitors and controlled release fertilizers are deemed the most important with further development of these aspects of technologies being expected. These practices, if employed worldwide, could help reduce the load, or environmental deterioration, on the Earth's biosphere.
文摘Studies on acute toxicity of Cu2+,Mn2+and Zn2^to Artemianauplii(36h)and adults were carried out at15±3°C in the natural seawater where salinity is30using single-factor acute toxicity;on this basis,equi-toxicity test was used to evaluate the effect of joint toxicity of Cu2+,Mn2+and Zn2+to Artemia nauplii(36h)in the same conditions.Results show that Artemia has different tolerances for the three heavy metal ions when it is in different growth period,and the interaction of heavy metal ions varied with growth period,adults are more sensitive of the three heavy metals;The48h LC50of these three heavy metal to the Artemia nauplii is4.0,27.19and115.95mg/L,and to the adults is1.31,6.86and34.23mg/L;the order of toxicity of cuprum,manganese and zinc for Artemia nauplii and adults was Cu2^>Mn2+>Zn2+;the safe concentration of the three heavy metal ions(Cu2+,Mn2+and Zn2+)to Artemia nauplii(36h)and adults were0.4,2.72,11.6,0.13,0.69and3.42mg/L.The results of combined toxicity test showed that Cu-Mn,Cu-Zn and Mn-Zn were all antagonistic to the Artemia naupli.
基金Supported by NNSF(10601022,11061021)Supported by NSF of Inner Mongolia Au-tonomous Region(200607010106)Supported by SRP of Higher Schools of Inner Mongolia(NJ10006)
文摘H1-Galerkin mixed methods are proposed for viscoelasticity wave equation.Depending on the physical quantities of interest,two methods are discussed.The optimal error estimates and the proof of the existence and uniqueness of semidiscrete solutions are derived for problems in one space dimension.And the methods don't require the LBB condition.
文摘The adoption by the 18th Congress of the Communist Party of China in November 2012 of a policy on ecological civilization is a landmark event for the nation and the world community. China's vision for building an ecological civilization is comprehensive, multi-sectoral and systemic and is intended to direct and balance progress among ecological, economic, social, cultural and political dimensions of change. Some on-going efforts and potential future activities that meet China's vision of an ecological civilization are described. Establishment of dedicated ecological civilization areas for experimenting with legal, regulatory and administrative incentives that would facilitate the march towards the ideal is encouraged. Chinese biosphere reserves which are designated with the explicit aim of building harmony between humans and nature would be suitable candidates for designing and developing such dedicated ecological civilization areas.
基金Project(2010G016-B)supported by Science and Technology Research and Development of China
文摘An analytical solution was presented to the unsaturated soil with a finite thickness under confinement in the lateral direction and sinusoidal cyclic loading in the vertical direction based on Fredlund's one-dimensional consolidation equation for unsaturated soil. The transfer relationship between the state vectors at the top surface and any depth was gained by applying the Laplace transform and Cayley-Hamilton mathematical methods to the governing equations of water and air, Darcy's law and Fick's law. The excess pore-air and pore-water pressures and settlement in the Laplace-transformed domain were obtained by using the Laplace transform with the initial and boundary conditions. The analytical solutions of the excess pore-air and pore-water pressures at any depth and settlement were obtained in the time domain by performing the inverse Laplace transforms. A typical example illustrates the consolidation characteristics of unsaturated soil under sinusoidal loading from analytical results. Finally, comparisons between the analytical solutions and results of the numerical method indicate that the analytical solution is correct.
基金Project(2013AA064102)supported by the National High-Tech Research Program of ChinaProject(11JJ6014)supported by the Hunan Provincial Natural Science Foundation of China
文摘One-pot synthesis of cyclic aldol tetramer and α, β-unsaturated aldol from C3-C8 linear aldehydes using phase-transfer catalyst(PTC), quaternary ammonium, combined with sodium hydroxide as catalysts was investigated. Butanal was subjected for detail investigations to study the effect of parameters. It was found that the selectivity of cyclic aldol tetramer depends greatly on the operating conditions of the reaction, especially the PTC/butanal molar ratio. The average selectivity of 2-hydroxy-6-propyl-l, 3, 5-triethyl-3-cyclohexene-1-carboxaldehyde(HPTECHCA) was 54.41% using tetrabutylammonium chloride combined with 14%(mass fraction) Na OH as catalysts at 60 ℃for 2 h with a PTC-to-butanal molar ratio of 0.09:1. Pentanal was more likely to generate cyclic aldol tetramer compared with other aldehydes under the optimum experimental conditions. Recovery of the PTC through water washing followed by adding enough sodium hydroxide from the washings was also demonstrated.
基金Supported by the National Natural Science Foundation of China(10671182)
文摘In this paper,the existence,the uniqueness,the asymptotic behavior and the non-existence of the global generalized solutions of the initial boundary value problems for the non-linear pseudo-parabolic equation ut-αuxx-βuxxt=F(u)-βF (u)xx are proved,where α,β 0 are constants,F(s) is a given function.
文摘Density functional theory was used to study the NH3 behavior on Ni monolayer covered Pt(111) and WC(001). The electronic structure of the surfaces, and the adsorption and decomposition of NH3 were calculated and compared. Ni atoms in the monolayer behave different from that in Ni(111). More dz2 electrons of Ni in monolayer covered systems were shifted to other regions compared to Ni(111), charge density depletion on this orbital is crucial to NH3 adsorption. NH3 binds more stable on Ni/Pt(lll) and Ni/WC(001) than on Ni(111), the energy barriers of the first N-H bond scission were evidently lower on Ni/Pt(111) and Ni/WC(001) than on Ni(111), these are significant to NH3 decomposition. N recombination is the rate-limiting step, high reaction barrier implies that N2 is produced only at high temperatures. Although WC has similar properties to Pt, differences of the electronic structure and catalytic activities are observed for Ni/Pt(111) and Ni/WC (001), the energy barrier for the rate-determined step increases on Ni/WC(001) instead of decreasing on Ni/Pt(lll) when compared to Ni(111). the N recombination barrier by modifying To design cheaper and better catalysts, reducing Ni/WC(001) is a critical question to be solved.
基金National Natural Science Foundation of China(No.61372041,No.61001034)
文摘Nonlinear distortion introduced by an amplifier when subjected to a multisine excitation decreases the measurement accuracy in many metrological and measurement areas. In this paper, we performed qualitative and quantitative analyses of the nonlinear distortion with the multisine excitations constrained by a constant power spectral density. We present the numerical results with respect to different tone spacings,nonlinear orders, harmonic phases and tone distributions. Moreover, three as-pects of contributions are made to further reveal the distortion mechanism. First, we find that the type Ⅱ components for Schr- oeder-phase multisines distribute uniformly but not all in anti-phase to the type I components for the second order nonlinearity. Second,we simulate the variance of the type I and Ⅱ components and their summation to explain the principle of reducing the type Ⅱ distortion by averaging the results obtained using multiple realizations of random-phase multisines. Third, we observe a special distortion distribution mechanism for the Schroeder-phase multisine excitation The results contribute to a better estima-tion and understanding of the nonlinear distortion.
基金Funded by the National Natural Science Foundation of China (No. 50934002)New Century Excellent Talents (No. NECT-07-0070)Yunnan Provincial Programs for Science and Technology Innovation (No. 2007AD001)
文摘We conducted two-stage acidification-bioleaching experiments to probe the feasibility of bioleaching for a kind of mixed alkaline copper oxide and sulphide mineral. We used the uniform design method for data analysis and experimental optimization, with initial pH value, pulp density, inoculation of bacteria and ferrous iron concentration selected as the influential factors. Polynomial regression shows that the four factors sequentially influence the copper recovery by 14.430%, 8.555%, 1.982% and 3.895%. Acid equilibrium in the bioleaching system is mainly influenced by alkaline gangue content, chemical reactions and bacterial activity. A maximal portion of refractory copper extracted reaches 71.08%. The dynamic analysis of copper recovery indicates that bioleaching goes through a lag leaching phase, prime leaching phase and leaching stationary phase corresponding to the growth phases of bacteria. Compared with the predicted value of 80.87%, the confirmatory experiment observes a 78.21% copper recovery under the optimal conditions of pH of 1.5, pulp density of 5%, bacteria inoculation of 30% and initial ferrous iron concentration of 9 g L-1. Results suggest that bioleaching is technically feasible to improving total copper recovery.
基金Projects(50878191,51109092)supported by the National Natural Science Foundation of China
文摘Based on non-Darcian flow law described by exponent and threshold gradient within a double-layered soil, the classic theory of one-dimensional consolidation of double-layered soil was modified to consider the change of vertical total stress with depth and time together. Because of the complexity of governing equations, the numerical solutions were obtained in detail by finite difference method. Then, the numerical solutions were compared with the analytical solutions in condition that non-Darcian flow law was degenerated to Dary's law, and the comparison results show that numerical solutions are reliable. Finally, consolidation behavior of double-layered soil with different parameters was analyzed, and the results show that the consolidation rate of double-layered soil decreases with increasing the value of exponent and threshold of non-Darcian flow, and the exponent and threshold gradient of the first soil layer greatly influence the consolidation rate of double-layered soil. The larger the ratio of the equivalent water head of external load to the total thickness of double-layered soil, the larger the rate of the consolidation, and the similitude relationship in classical consolidation theory of double-layered soil is not satisfied. The other consolidation behavior of double-layered soil with non-Darcian flow is the same as that with Darcy's law.
基金Supported by Science and Technology Project of Yunnan Tobacco Company(2015YN07,2017YN26)~~
文摘In order to validate the control effects of integrated technology of medicine and fertilizer on tobacco bacterial wilt,field experiments were conducted by using youmeili and tetracycline as the test agents.The results obtained were listed as follows:(1)The incidence rate of bacterial wilt ascended more quickly after July 10 th,the incidence of CK reached 78.30%on July 25 th.(2)The control effect of“youmeili 3 g+tetramycin 200 times liquid”reached 69.47%,significantly higher than other treatments.(3)The output value of“Youmeil 3 g+tetramycin 200 times liquid”served as 1635.66 yuan/667m^2,with the highest economic character in all treatments.In a word,integrated technology of medicine and fertilizer was a feasible approach to control tobacco bacterial wilt.
文摘Music is the soul of sports dance. Sports dance can be carried out smoothly by the accompaniment of music. Therefore the two should be in harmony and unity to perform the essence of sports dance totally. This article tries analyzing the impact of music in sports dance teaching for students in physiological, psychological, creativity, imagination, aesthetic and so on to explore the important role of music in the development of students' comprehensive quality, in order to help sports dance teaching.
文摘In this paper, I revisit the question of the consistency of Thrasymachus' position on justice in the First Book of the Republic. The paper falls into four parts. (The first part is an introduction.) In the second part, I examine two influential interpretations of the sophist's views, George B. Kerferd's and Timothy D. J. Chappell's, and argue that neither one fully resolves the riddle of Thrasymachus. In the third part, I claim that the sophist has a "descriptive" theory of justice, not a "prescriptive" one, and that no moral command to act in any particular way follows from this theory. In the fourth and final part, I propose a new approach to the whole issue by arguing that the essential problem with Thrasymachus' theory is not the incompatibility between his two definitions of justice in 338c and 343c, as it is usually assumed, but the fact that in Book One he uses two different and irreconcilable conceptions of justice. It is because the sophist uses the term "justice" to mean different things in different parts of the text that his overall position is ultimately inconsistent.