In recent years,China’s property rights trading market has been extremely competitive,but there are also new contradictions and challenges.This paper aims to analyze the external and internal competitive market of th...In recent years,China’s property rights trading market has been extremely competitive,but there are also new contradictions and challenges.This paper aims to analyze the external and internal competitive market of the property rights market through Porter’s five forces competition model,then find out the problems and defects in the development,thereby promoting the better development and progress of China’s property rights trading market.展开更多
为了探究中国土地利用变化驱动机制和未来土地利用状况,该文利用中国科学院资源环境科学数据库中的2000年和2005年土地利用数据,结合区域土地利用变化与影响模型CLUE-S(the conversion of land use and its effects at small regional e...为了探究中国土地利用变化驱动机制和未来土地利用状况,该文利用中国科学院资源环境科学数据库中的2000年和2005年土地利用数据,结合区域土地利用变化与影响模型CLUE-S(the conversion of land use and its effects at small regional extent)和面向地理过程动态环境模型Dinamica EGO(environment for geoprocessing objects)模拟2000-2020年中国土地利用状况,并借助于Logistic回归结果和贝叶斯估计结果,探讨了中国2000-2005年土地利用适宜性和土地利用变化的驱动力空间特征。以2005年土地利用数据对模拟结果进行验证表明,CLUE-S模型和Dinamica EGO模型在LUCC预测上与实际结果一致性较好,并且CLUE-S模型在预测总体精度上优于Dinamica EGO模型。但在土地利用变化类型的数量预测上,Dinamica EGO模型的Markov过程可以准确预测,并且Dinamica EGO模拟的土地利用变化在空间分布上与经验结果较一致。从2020年中国土地利用预测结果来看,耕地、林地、水域和建设用地将会增加,草地会出现大面积的缩减,未利用地在CLUE-S模型预测中出现增加,而在Dinamica EGO模型中减少。该文可为国土资源规划和耕地资源保护政策的制定提供科学依据。展开更多
The dielectric constant in Coulomb’s Law, D, can quantify an empirical reduction of force. It can also quantify a reduction of electrostatic field as seen in classical electrostatic theory where the induced charge la...The dielectric constant in Coulomb’s Law, D, can quantify an empirical reduction of force. It can also quantify a reduction of electrostatic field as seen in classical electrostatic theory where the induced charge layer is assumed to be infinitely thin. The two approaches exemplify two traditions that have been used in parallel for decades. They produce Potential Energy Functions (PEFs) that differ by a factor of the permittivity, εr. The classical electrostatic theory result can be incorporated into force field models with an effective dielectric function, Deff, which spans the induced charge layer and accommodates both traditions. The Deff function increases the magnitude of local terms as compared with cumulative long distance terms. It is shown that the Deff function reduces distance dependence of the radial PEF within the induced charge layer and improves computational stability for some systems including substrate in dilute salt solution. End use applications include pharmaceutical development (e.g. protein calculations with docking), materials development, solvation energy calculations and QM/MM calculations.展开更多
As the impact of the global energy crisis deepens,traditional oil resources are exhausted,and the harm caused by air pollution and rising global temperatures is increasingly severe;the government and automobile enterp...As the impact of the global energy crisis deepens,traditional oil resources are exhausted,and the harm caused by air pollution and rising global temperatures is increasingly severe;the government and automobile enterprises generally believe that energy saving and emission reduction is the future technology development direction of the automobile industry.The main direction of the attack is the general trend of new energy vehicles to replace traditional vehicles.As a leader in new energy pure electric vehicles,Tesla Motors has created a new concept of using the Internet for manufacturing cars and opened up a new brand segment of the automobile market.This paper mainly uses the PEST analysis model and Porter’s Five Forces analysis model to understand the essence of Tesla is not a pure electric vehicle manufacturer,but a high-tech innovation driver at the forefront of the world.Based on the PEST model analysis,Tesla’s development is still at the right time and place despite the impact of COVID-19.From Porter’s Five Forces model,Tesla has higher bargaining power and a strong dominant position with upstream suppliers and service providers.Tesla has a first-mover advantage due to its customers’weak bargaining power,which lets Tesla’s leading position in the industry cannot be surpassed in the short term.展开更多
Seismic oscillations of the “building-building” system which is interconnected buildings built close to each other, and “building-stack-like structure” system which is adjacent and connected in different ways to e...Seismic oscillations of the “building-building” system which is interconnected buildings built close to each other, and “building-stack-like structure” system which is adjacent and connected in different ways to existing building are considered in the paper. Different types of connections, such as dampers, including the ones suggested by the authors, are studied. Seismic impact is given as a harmonic function and various existing accelerograms, including synthesized ones. Distinctive feature of this paper from previously published ones [1] [2] is the fact that the emphasis falls on the influence of soil-foundation interaction properties, which are described using various models of load-displacement connections. Calculation results are compared in the case of representation of the building as concentrated masses and spatial systems. Ways to reduce seismic response of buildings during the earthquakes are pointed out. Results of experimental studies are given in the paper and are compared with calculations.展开更多
A new method for analysis of counter beams is presented in the paper. The analysis has taken into account their stiffness EI, Winkler’s space with modulus of subgrade reaction k and equality deformities of the founda...A new method for analysis of counter beams is presented in the paper. The analysis has taken into account their stiffness EI, Winkler’s space with modulus of subgrade reaction k and equality deformities of the foundation beam with the ground. The solution is found by using the numerical analysis of the Winkler’s model, with variation of different moduli of the subgrade reaction k2 outside the force zone r, while under the force P exists the modulus of the subgrade reaction k, up to the definition of minimum bending moments. The exponential function k2(r), as the geometric position of the minimum moments is approximately assumed. From the potential energy conditions of the reciprocity of displacement and reaction, the width of the zone r and the modulus of the subgrade reaction k2 are explicitly determined, introducing in the calculation initial and calculation soil displacement wsi successively. At the end of the paper, it presented numerical example in which the influence of k and k2 values on bending moments of the counter beam is analyzed. The essential idea of this paper is to decrease the quantity of the reinforcement in the foundations, beams, i.e. to obtain a cost-efficient foundation construction.展开更多
文摘In recent years,China’s property rights trading market has been extremely competitive,but there are also new contradictions and challenges.This paper aims to analyze the external and internal competitive market of the property rights market through Porter’s five forces competition model,then find out the problems and defects in the development,thereby promoting the better development and progress of China’s property rights trading market.
文摘为了探究中国土地利用变化驱动机制和未来土地利用状况,该文利用中国科学院资源环境科学数据库中的2000年和2005年土地利用数据,结合区域土地利用变化与影响模型CLUE-S(the conversion of land use and its effects at small regional extent)和面向地理过程动态环境模型Dinamica EGO(environment for geoprocessing objects)模拟2000-2020年中国土地利用状况,并借助于Logistic回归结果和贝叶斯估计结果,探讨了中国2000-2005年土地利用适宜性和土地利用变化的驱动力空间特征。以2005年土地利用数据对模拟结果进行验证表明,CLUE-S模型和Dinamica EGO模型在LUCC预测上与实际结果一致性较好,并且CLUE-S模型在预测总体精度上优于Dinamica EGO模型。但在土地利用变化类型的数量预测上,Dinamica EGO模型的Markov过程可以准确预测,并且Dinamica EGO模拟的土地利用变化在空间分布上与经验结果较一致。从2020年中国土地利用预测结果来看,耕地、林地、水域和建设用地将会增加,草地会出现大面积的缩减,未利用地在CLUE-S模型预测中出现增加,而在Dinamica EGO模型中减少。该文可为国土资源规划和耕地资源保护政策的制定提供科学依据。
文摘The dielectric constant in Coulomb’s Law, D, can quantify an empirical reduction of force. It can also quantify a reduction of electrostatic field as seen in classical electrostatic theory where the induced charge layer is assumed to be infinitely thin. The two approaches exemplify two traditions that have been used in parallel for decades. They produce Potential Energy Functions (PEFs) that differ by a factor of the permittivity, εr. The classical electrostatic theory result can be incorporated into force field models with an effective dielectric function, Deff, which spans the induced charge layer and accommodates both traditions. The Deff function increases the magnitude of local terms as compared with cumulative long distance terms. It is shown that the Deff function reduces distance dependence of the radial PEF within the induced charge layer and improves computational stability for some systems including substrate in dilute salt solution. End use applications include pharmaceutical development (e.g. protein calculations with docking), materials development, solvation energy calculations and QM/MM calculations.
文摘As the impact of the global energy crisis deepens,traditional oil resources are exhausted,and the harm caused by air pollution and rising global temperatures is increasingly severe;the government and automobile enterprises generally believe that energy saving and emission reduction is the future technology development direction of the automobile industry.The main direction of the attack is the general trend of new energy vehicles to replace traditional vehicles.As a leader in new energy pure electric vehicles,Tesla Motors has created a new concept of using the Internet for manufacturing cars and opened up a new brand segment of the automobile market.This paper mainly uses the PEST analysis model and Porter’s Five Forces analysis model to understand the essence of Tesla is not a pure electric vehicle manufacturer,but a high-tech innovation driver at the forefront of the world.Based on the PEST model analysis,Tesla’s development is still at the right time and place despite the impact of COVID-19.From Porter’s Five Forces model,Tesla has higher bargaining power and a strong dominant position with upstream suppliers and service providers.Tesla has a first-mover advantage due to its customers’weak bargaining power,which lets Tesla’s leading position in the industry cannot be surpassed in the short term.
文摘Seismic oscillations of the “building-building” system which is interconnected buildings built close to each other, and “building-stack-like structure” system which is adjacent and connected in different ways to existing building are considered in the paper. Different types of connections, such as dampers, including the ones suggested by the authors, are studied. Seismic impact is given as a harmonic function and various existing accelerograms, including synthesized ones. Distinctive feature of this paper from previously published ones [1] [2] is the fact that the emphasis falls on the influence of soil-foundation interaction properties, which are described using various models of load-displacement connections. Calculation results are compared in the case of representation of the building as concentrated masses and spatial systems. Ways to reduce seismic response of buildings during the earthquakes are pointed out. Results of experimental studies are given in the paper and are compared with calculations.
文摘A new method for analysis of counter beams is presented in the paper. The analysis has taken into account their stiffness EI, Winkler’s space with modulus of subgrade reaction k and equality deformities of the foundation beam with the ground. The solution is found by using the numerical analysis of the Winkler’s model, with variation of different moduli of the subgrade reaction k2 outside the force zone r, while under the force P exists the modulus of the subgrade reaction k, up to the definition of minimum bending moments. The exponential function k2(r), as the geometric position of the minimum moments is approximately assumed. From the potential energy conditions of the reciprocity of displacement and reaction, the width of the zone r and the modulus of the subgrade reaction k2 are explicitly determined, introducing in the calculation initial and calculation soil displacement wsi successively. At the end of the paper, it presented numerical example in which the influence of k and k2 values on bending moments of the counter beam is analyzed. The essential idea of this paper is to decrease the quantity of the reinforcement in the foundations, beams, i.e. to obtain a cost-efficient foundation construction.
