The method of inputting the seismic wave determines the accuracy of the simulation of soil-structure dynamic interaction. The wave method is a commonly used approach for seismic wave input, which converts the incident...The method of inputting the seismic wave determines the accuracy of the simulation of soil-structure dynamic interaction. The wave method is a commonly used approach for seismic wave input, which converts the incident wave into equivalent loads on the cutoff boundaries. The wave method has high precision, but the implementation is complicated, especially for three-dimensional models. By deducing another form of equivalent input seismic loads in the fi nite element model, a new seismic wave input method is proposed. In the new method, by imposing the displacements of the free wave fi eld on the nodes of the substructure composed of elements that contain artifi cial boundaries, the equivalent input seismic loads are obtained through dynamic analysis of the substructure. Subsequently, the equivalent input seismic loads are imposed on the artifi cial boundary nodes to complete the seismic wave input and perform seismic analysis of the soil-structure dynamic interaction model. Compared with the wave method, the new method is simplifi ed by avoiding the complex processes of calculating the equivalent input seismic loads. The validity of the new method is verifi ed by the dynamic analysis numerical examples of the homogeneous and layered half space under vertical and oblique incident seismic waves.展开更多
A method for the optimal fiber input power determination is presented by employing the variation characteristics of signal to noise ratio(SNR) in spontaneous Brillouin-scattering-based sensing system. And a heterodyne...A method for the optimal fiber input power determination is presented by employing the variation characteristics of signal to noise ratio(SNR) in spontaneous Brillouin-scattering-based sensing system. And a heterodyne detection system is constructed for measuring the Brillouin scattering spectra with different fiber input powers. The Brillouin spectrum width and system SNR can be simultaneously measured from these spectra, and the optimal fiber input power can be obtained from such information. In the experiment, for 48.8-km-long standard single-mode fiber(SSMF), the optimal fiber input power values are all approximately 0 dBm obtained by the maximum SNR position for different local oscillator power values and average times.展开更多
It has been found that a large amount of students are not able to communicate fluently and lack self-confidence. Therefore, they lost interest in English. This paper first introduces Stephen Krashen's Input Hypoth...It has been found that a large amount of students are not able to communicate fluently and lack self-confidence. Therefore, they lost interest in English. This paper first introduces Stephen Krashen's Input Hypothesis. Through analyzing the influencing factors of oral English learning and the significance of reciting methods, the article explored the concrete reciting methods. I hope it will shed some light on the English teaching and learning practice.展开更多
Based on 2012 input-output table of Shandong province and the official statistics, this article uses the input-output analysis method to build the input-output table. On the basis of the development of service industr...Based on 2012 input-output table of Shandong province and the official statistics, this article uses the input-output analysis method to build the input-output table. On the basis of the development of service industry in Shandong province's ability, we make a theoretical analysis framework of a comprehensive in-depth analysis on pull employment, creatively will cost tax rate, fully and completely labor capital and the combination of both the industry development space. So that the industry's ability to pull the employment can be considered, and to realize rapid and sustained development of service industry in Shandong province.展开更多
In the present paper the analytical formulas for calculating the equivalent deterministic transients for multivariable cross correlated random processes are developed.The formulas permit the determination of the Root-...In the present paper the analytical formulas for calculating the equivalent deterministic transients for multivariable cross correlated random processes are developed.The formulas permit the determination of the Root-mean-square of the responses of a linear time-invariant system to stationary multiple random inputs in the time domain.The method is applicable in the study of flight of airplanes in atmospheric turbulence and is also useful for general engineering applications of stochastc processes control.展开更多
【目的】深度剖析近年来我国油菜碳足迹的时空演变及来源构成变化趋势,并提出油菜种植减排增产的可行方向,为制定油菜种植产业政策和优化种植结构提供参考依据。【方法】基于油菜投入产出数据,采用生命周期评价法测算2004—2022年我国1...【目的】深度剖析近年来我国油菜碳足迹的时空演变及来源构成变化趋势,并提出油菜种植减排增产的可行方向,为制定油菜种植产业政策和优化种植结构提供参考依据。【方法】基于油菜投入产出数据,采用生命周期评价法测算2004—2022年我国15个油菜种植省份的油菜碳足迹,分析油菜碳足迹变化特征,并有针对性提出减排策略。【结果】2004—2022年我国油菜温室气体排放总量、单位面积碳足迹和单位产量碳足迹总体上呈增长趋势,温室气体排放总量年均增长量约0.34×10^(9)kg CO_(2)eq,单位产量碳足迹年均增长量约0.01 kg CO_(2)eq/kg,单位面积碳足迹年均增长量约0.049×10^(3)kg CO_(2)eq/ha;在省份层面,长江中上游及西南、西北种植区的油菜温室气体排放总量呈正增长趋势,以湖南省增长最快,年均增长量为20.668×10^(7)kg CO_(2)eq,而江苏省、安徽省、河南省和浙江省呈下降趋势,对应的年均变化量分别为-9.925×10^(7)、-8.606×10^(7)、-2.869×10^(7)和-2.324×10^(7)kg CO_(2)eq。除重庆市外,我国主要油菜种植区的单位面积碳足迹均随时间的推移而增长,其中增长较快的有湖南省、贵州省和甘肃省,年均增长量分别为98.632、103.165和120.070 kg CO_(2)eq/ha。我国大部分油菜种植区的单位产量碳足迹随时间的推移而增加,仅重庆市、江苏省、云南省、浙江省、江西省和四川省的单位产量碳足迹呈降低趋势。从碳足迹构成来看,化肥生产和化肥施用是我国油菜种植中碳足迹的主要来源,二者的单位面积碳足迹占比合计为70.94%,其次是灌溉和人工产生的碳排放,即控制化肥和灌溉投入量是我国油菜种植减排的主要方向。我国各省油菜种植各环节单位面积碳足迹占比存在一定差异,但总体上与全国油菜单位面积碳足迹构成保持一致。【建议】积极推广油菜化肥减量增效技术,提高化肥利用效率;普及推广油菜节水节能灌溉技术,着力减少灌溉能耗;科学规划油菜产业短长期目标,优化生产区域布局。展开更多
基金National Natural Science Foundation of China under Grant No.51478247National Key Research and Development Program of China under Grant No.2016YFC1402800
文摘The method of inputting the seismic wave determines the accuracy of the simulation of soil-structure dynamic interaction. The wave method is a commonly used approach for seismic wave input, which converts the incident wave into equivalent loads on the cutoff boundaries. The wave method has high precision, but the implementation is complicated, especially for three-dimensional models. By deducing another form of equivalent input seismic loads in the fi nite element model, a new seismic wave input method is proposed. In the new method, by imposing the displacements of the free wave fi eld on the nodes of the substructure composed of elements that contain artifi cial boundaries, the equivalent input seismic loads are obtained through dynamic analysis of the substructure. Subsequently, the equivalent input seismic loads are imposed on the artifi cial boundary nodes to complete the seismic wave input and perform seismic analysis of the soil-structure dynamic interaction model. Compared with the wave method, the new method is simplifi ed by avoiding the complex processes of calculating the equivalent input seismic loads. The validity of the new method is verifi ed by the dynamic analysis numerical examples of the homogeneous and layered half space under vertical and oblique incident seismic waves.
基金supported by the National Natural Science Foundation of China(No.61377088)the Natural Science Foundation of Hebei Province of China(Nos.E2015502053 and F2014502098)
文摘A method for the optimal fiber input power determination is presented by employing the variation characteristics of signal to noise ratio(SNR) in spontaneous Brillouin-scattering-based sensing system. And a heterodyne detection system is constructed for measuring the Brillouin scattering spectra with different fiber input powers. The Brillouin spectrum width and system SNR can be simultaneously measured from these spectra, and the optimal fiber input power can be obtained from such information. In the experiment, for 48.8-km-long standard single-mode fiber(SSMF), the optimal fiber input power values are all approximately 0 dBm obtained by the maximum SNR position for different local oscillator power values and average times.
文摘It has been found that a large amount of students are not able to communicate fluently and lack self-confidence. Therefore, they lost interest in English. This paper first introduces Stephen Krashen's Input Hypothesis. Through analyzing the influencing factors of oral English learning and the significance of reciting methods, the article explored the concrete reciting methods. I hope it will shed some light on the English teaching and learning practice.
基金supported by the National Social Science Fund of China (Grant No. 15CGL048)
文摘Based on 2012 input-output table of Shandong province and the official statistics, this article uses the input-output analysis method to build the input-output table. On the basis of the development of service industry in Shandong province's ability, we make a theoretical analysis framework of a comprehensive in-depth analysis on pull employment, creatively will cost tax rate, fully and completely labor capital and the combination of both the industry development space. So that the industry's ability to pull the employment can be considered, and to realize rapid and sustained development of service industry in Shandong province.
文摘In the present paper the analytical formulas for calculating the equivalent deterministic transients for multivariable cross correlated random processes are developed.The formulas permit the determination of the Root-mean-square of the responses of a linear time-invariant system to stationary multiple random inputs in the time domain.The method is applicable in the study of flight of airplanes in atmospheric turbulence and is also useful for general engineering applications of stochastc processes control.
文摘【目的】深度剖析近年来我国油菜碳足迹的时空演变及来源构成变化趋势,并提出油菜种植减排增产的可行方向,为制定油菜种植产业政策和优化种植结构提供参考依据。【方法】基于油菜投入产出数据,采用生命周期评价法测算2004—2022年我国15个油菜种植省份的油菜碳足迹,分析油菜碳足迹变化特征,并有针对性提出减排策略。【结果】2004—2022年我国油菜温室气体排放总量、单位面积碳足迹和单位产量碳足迹总体上呈增长趋势,温室气体排放总量年均增长量约0.34×10^(9)kg CO_(2)eq,单位产量碳足迹年均增长量约0.01 kg CO_(2)eq/kg,单位面积碳足迹年均增长量约0.049×10^(3)kg CO_(2)eq/ha;在省份层面,长江中上游及西南、西北种植区的油菜温室气体排放总量呈正增长趋势,以湖南省增长最快,年均增长量为20.668×10^(7)kg CO_(2)eq,而江苏省、安徽省、河南省和浙江省呈下降趋势,对应的年均变化量分别为-9.925×10^(7)、-8.606×10^(7)、-2.869×10^(7)和-2.324×10^(7)kg CO_(2)eq。除重庆市外,我国主要油菜种植区的单位面积碳足迹均随时间的推移而增长,其中增长较快的有湖南省、贵州省和甘肃省,年均增长量分别为98.632、103.165和120.070 kg CO_(2)eq/ha。我国大部分油菜种植区的单位产量碳足迹随时间的推移而增加,仅重庆市、江苏省、云南省、浙江省、江西省和四川省的单位产量碳足迹呈降低趋势。从碳足迹构成来看,化肥生产和化肥施用是我国油菜种植中碳足迹的主要来源,二者的单位面积碳足迹占比合计为70.94%,其次是灌溉和人工产生的碳排放,即控制化肥和灌溉投入量是我国油菜种植减排的主要方向。我国各省油菜种植各环节单位面积碳足迹占比存在一定差异,但总体上与全国油菜单位面积碳足迹构成保持一致。【建议】积极推广油菜化肥减量增效技术,提高化肥利用效率;普及推广油菜节水节能灌溉技术,着力减少灌溉能耗;科学规划油菜产业短长期目标,优化生产区域布局。
