Since the beginning of grape cultivation in the 1980 s in Wuhan City,the grape industry has shown a steady growth trend. Through the survey of the local grape industry,it found out the regional distribution,scale and ...Since the beginning of grape cultivation in the 1980 s in Wuhan City,the grape industry has shown a steady growth trend. Through the survey of the local grape industry,it found out the regional distribution,scale and benefits of the grape,as well as the variety structure and cultivation management mode. It analyzed main problems in the grape production,including low degree of organization,concentrated maturity,low rate of good fruit,small cultivation scale,and low labor-saving and high-efficiency cultivation technologies. On the basis of the development status,it came up with pertinent recommendations,including optimizing the variety structure,implementing standardized management,strengthening construction of sightseeing parks,promoting integration of primary and tertiary industries,and developing the gardening experience,to promote healthy and sustainable development of the grape industry.展开更多
In this paper, we propose a unified differential operator method to study mechanical vibrations, solving inhomogeneous linear ordinary differential equations with constant coefficients. The main advantage of this new ...In this paper, we propose a unified differential operator method to study mechanical vibrations, solving inhomogeneous linear ordinary differential equations with constant coefficients. The main advantage of this new method is that the differential operator D in the numerator of the fraction has no effect on input functions (i.e., the derivative operation is removed) because we take the fraction as a whole part in the partial fraction expansion. The method in various variants is widely implemented in related fields in mechanics and engineering. We also point out that the same mistakes in the differential operator method are found in the related references [1-4].展开更多
基金Agricultural Science Innovation Project of Wuhan City"Demonstration and Extension of Grape,Citrus and Other Fruit Tree Facilities Cultivation Technologies and Green Prevention and Control"(CXQYDJ201804)
文摘Since the beginning of grape cultivation in the 1980 s in Wuhan City,the grape industry has shown a steady growth trend. Through the survey of the local grape industry,it found out the regional distribution,scale and benefits of the grape,as well as the variety structure and cultivation management mode. It analyzed main problems in the grape production,including low degree of organization,concentrated maturity,low rate of good fruit,small cultivation scale,and low labor-saving and high-efficiency cultivation technologies. On the basis of the development status,it came up with pertinent recommendations,including optimizing the variety structure,implementing standardized management,strengthening construction of sightseeing parks,promoting integration of primary and tertiary industries,and developing the gardening experience,to promote healthy and sustainable development of the grape industry.
文摘In this paper, we propose a unified differential operator method to study mechanical vibrations, solving inhomogeneous linear ordinary differential equations with constant coefficients. The main advantage of this new method is that the differential operator D in the numerator of the fraction has no effect on input functions (i.e., the derivative operation is removed) because we take the fraction as a whole part in the partial fraction expansion. The method in various variants is widely implemented in related fields in mechanics and engineering. We also point out that the same mistakes in the differential operator method are found in the related references [1-4].
