Buprofezin and imidacloprid are selective insecticides against Homoptera insects. This paper investigated stimulating effect of the two insecticides on the number of laid eggs by yellow rice borer, Tryporyza incertula...Buprofezin and imidacloprid are selective insecticides against Homoptera insects. This paper investigated stimulating effect of the two insecticides on the number of laid eggs by yellow rice borer, Tryporyza incertulas(Walker) of three generations in 20012002. The results showed that the reproductive rate of emergence months during the larvae feeding on the rice plants of Xiushui63 treated with the two insecticides was significantly higher than that of control, indicating that the numbers of laid eggs by the borer was stimulated following buprofezin and imidacloprid applications. However, there was no such effect for the larvae feeding on rice variety Zhendao2 which showed moderate resistance to the insect. In addition, the incidence of stimulating egg laid for the first instar treated with the two insecticides was greater than that for the third instar. Biochemical tests showed that oxalic acid concentration declined, and photosynthetic rate of rice leaves following the two insecticide applications declined significantly compared to control, whereas reducing sugar concentration increased significantly for all other treatments of two varieties except Xiushui63 treated with buprofezin. The level of glutathione-S-transferase varied with rice variety and insecticide.展开更多
The paper deals with the fluid field of web forming in wet-laid non-woven production.The influence of the turbulent flow on blending fiber and occluded fluid produced in pulp flow has been discussed in theory and prac...The paper deals with the fluid field of web forming in wet-laid non-woven production.The influence of the turbulent flow on blending fiber and occluded fluid produced in pulp flow has been discussed in theory and practice.The suitable use of the imported velocity of pulp is very important in producing wet-laid products of good quality.展开更多
Through hydraulic model experiment and site investigation, this paper has derived a calculation formula of dry-laid stone armour layer thickness of rubble mound breakwaters for fishery harbours. The influences of the ...Through hydraulic model experiment and site investigation, this paper has derived a calculation formula of dry-laid stone armour layer thickness of rubble mound breakwaters for fishery harbours. The influences of the friction force between stone blocks and the variations of wave length or period and water depth are considered in the formula. The calculated results of several existing structures are in good agreement with field data. This formula is more practical than those ever published both at home and abroad, and has been adoptted by the technical standards of aquatic projects published by the Ministry of Agriculture of China. It is applicable for the calculation of dry-laid stone armour layer of breakwater for small- or medium-size harbours.展开更多
In this paper, the bending problem of rectangular thin plates with free edges laid on tensionless Winkler foundation has been solved by employing Fourier series with supplementary terms. By assuming proper form of ser...In this paper, the bending problem of rectangular thin plates with free edges laid on tensionless Winkler foundation has been solved by employing Fourier series with supplementary terms. By assuming proper form of series for deflection, the basic differential equation with given boundary conditions can be transformed into a set of infinite algebraic equations. Because the boundary of contact region cannot bedetermined in advance, these equations are weak nonlinear ones. They can be solved by using iterative procedures.展开更多
基金supported by the National Natural Science Foundation of China(30070122).
文摘Buprofezin and imidacloprid are selective insecticides against Homoptera insects. This paper investigated stimulating effect of the two insecticides on the number of laid eggs by yellow rice borer, Tryporyza incertulas(Walker) of three generations in 20012002. The results showed that the reproductive rate of emergence months during the larvae feeding on the rice plants of Xiushui63 treated with the two insecticides was significantly higher than that of control, indicating that the numbers of laid eggs by the borer was stimulated following buprofezin and imidacloprid applications. However, there was no such effect for the larvae feeding on rice variety Zhendao2 which showed moderate resistance to the insect. In addition, the incidence of stimulating egg laid for the first instar treated with the two insecticides was greater than that for the third instar. Biochemical tests showed that oxalic acid concentration declined, and photosynthetic rate of rice leaves following the two insecticide applications declined significantly compared to control, whereas reducing sugar concentration increased significantly for all other treatments of two varieties except Xiushui63 treated with buprofezin. The level of glutathione-S-transferase varied with rice variety and insecticide.
文摘The paper deals with the fluid field of web forming in wet-laid non-woven production.The influence of the turbulent flow on blending fiber and occluded fluid produced in pulp flow has been discussed in theory and practice.The suitable use of the imported velocity of pulp is very important in producing wet-laid products of good quality.
文摘Through hydraulic model experiment and site investigation, this paper has derived a calculation formula of dry-laid stone armour layer thickness of rubble mound breakwaters for fishery harbours. The influences of the friction force between stone blocks and the variations of wave length or period and water depth are considered in the formula. The calculated results of several existing structures are in good agreement with field data. This formula is more practical than those ever published both at home and abroad, and has been adoptted by the technical standards of aquatic projects published by the Ministry of Agriculture of China. It is applicable for the calculation of dry-laid stone armour layer of breakwater for small- or medium-size harbours.
文摘In this paper, the bending problem of rectangular thin plates with free edges laid on tensionless Winkler foundation has been solved by employing Fourier series with supplementary terms. By assuming proper form of series for deflection, the basic differential equation with given boundary conditions can be transformed into a set of infinite algebraic equations. Because the boundary of contact region cannot bedetermined in advance, these equations are weak nonlinear ones. They can be solved by using iterative procedures.
