Edge detection and enhancement techniques are commonly used in recognizing the edge of geologic bodies using potential field data. We present a new edge recognition technology based on the normalized vertical derivati...Edge detection and enhancement techniques are commonly used in recognizing the edge of geologic bodies using potential field data. We present a new edge recognition technology based on the normalized vertical derivative of the total horizontal derivative which has the functions of both edge detection and enhancement techniques. First, we calculate the total horizontal derivative （THDR） of the potential-field data and then compute the n-order vertical derivative （VDRn） of the THDR. For the n-order vertical derivative, the peak value of total horizontal derivative （PTHDR） is obtained using a threshold value greater than 0. This PTHDR can be used for edge detection. Second, the PTHDR value is divided by the total horizontal derivative and normalized by the maximum value. Finally, we used different kinds of numerical models to verify the effectiveness and reliability of the new edge recognition technology.展开更多
A second look has been given at the mechanism of convective heat transfer based on the analogy between convection and conduction with heat sources. The strength of convective heat transfer depends not only on the flui...A second look has been given at the mechanism of convective heat transfer based on the analogy between convection and conduction with heat sources. The strength of convective heat transfer depends not only on the fluid velocity and fluid properties, but also on the coordination of fluid velocity and heat flow fields. Hence, based on the included angle of velocity and temperature gradient vectors, the presence of fluid motion may enhance or reduce heat transfer. With this concept, the known heat transfer phenomena may be understood in a deeper way. More important is that some novel approaches of heat transfer control can be developed.展开更多
We study a generalized nonlinear KdV system is studied by using the homotopic mapping method. Firstly, a homotopic mapping transform is constructed; secondly, the suitable initial approximation is selected; then the h...We study a generalized nonlinear KdV system is studied by using the homotopic mapping method. Firstly, a homotopic mapping transform is constructed; secondly, the suitable initial approximation is selected; then the homotopic mapping is used. The accuracy of the approximate solution for the solitary wave is obtained. From the obtained approximate solution, the homotopic mapping method exhibits a good accuracy.展开更多
Reinforcement property of structural silicon sealant as a function of the size and loading of nano CaCO 3 particles has been investigated by mechanical measurement and DMA experiments. The tensile strength and elongat...Reinforcement property of structural silicon sealant as a function of the size and loading of nano CaCO 3 particles has been investigated by mechanical measurement and DMA experiments. The tensile strength and elongation at break of silicone sealant were found greatly enhanced by nano CaCO 3 particles. The smaller the particle size, the higher the tensile strength and the elongation will be. The storage modulus is also remarkably increased with the increasing of CaCO 3 loading and decreasing of CaCO 3 particle sizes, as revealed by DAM. Two relaxation peaks are seen for silicon sealant. One is around 153 K, corresponding to the glass transition temperature(T g), and the other is around 233 K, corresponding to the melting temperature(T m). Both T g and T m increase with the increasing of CaCO 3 loading and decreasing of CaCO 3 particle sizes. DMA results suggest that the interaction between nano CaCO 3 particles and silicon sealant is quite strong. The molecular motion of silicon sealant is highly limited by the dispersed nano CaCO 3 particles.展开更多
Film cooling is an indispensable scheme in the design of highly-efficient cooling configurations to satisfy the thermal protection requirement of turbine hot section components.During the last few decades,vast efforts...Film cooling is an indispensable scheme in the design of highly-efficient cooling configurations to satisfy the thermal protection requirement of turbine hot section components.During the last few decades,vast efforts have been paid on the discrete-hole film cooling enhancement.In this paper,some of the recent literatures related to the passive strategies(such as shaped film cooling holes,upstream ramps,shallow trenches,mesh-fed slots)and the active strategies(such as the use of pulsation modulating device or plasma actuator)for film cooling enhancement are surveyed,with the aim at presenting an updated overview about the state of the art in advanced film cooling.In addition,some challenging issues are also outlined to motivate further investigations in such a broad topic.展开更多
基金supported by the National Science and Technology Major Projects (2008ZX05025)the Project of National Oil and Gas Resources Strategic Constituency Survey and Evaluation of the Ministry of Land and Resources,China (XQ-2007-05)
文摘Edge detection and enhancement techniques are commonly used in recognizing the edge of geologic bodies using potential field data. We present a new edge recognition technology based on the normalized vertical derivative of the total horizontal derivative which has the functions of both edge detection and enhancement techniques. First, we calculate the total horizontal derivative （THDR） of the potential-field data and then compute the n-order vertical derivative （VDRn） of the THDR. For the n-order vertical derivative, the peak value of total horizontal derivative （PTHDR） is obtained using a threshold value greater than 0. This PTHDR can be used for edge detection. Second, the PTHDR value is divided by the total horizontal derivative and normalized by the maximum value. Finally, we used different kinds of numerical models to verify the effectiveness and reliability of the new edge recognition technology.
基金the State Basic Research Program of China (Grant No. G20000263).
文摘A second look has been given at the mechanism of convective heat transfer based on the analogy between convection and conduction with heat sources. The strength of convective heat transfer depends not only on the fluid velocity and fluid properties, but also on the coordination of fluid velocity and heat flow fields. Hence, based on the included angle of velocity and temperature gradient vectors, the presence of fluid motion may enhance or reduce heat transfer. With this concept, the known heat transfer phenomena may be understood in a deeper way. More important is that some novel approaches of heat transfer control can be developed.
基金Supported by the National Natural Science Foundation of China under Grant No 40676016, the National Basic Research Programme of China under Grant Nos 2003CB415101-03 and 2004CB418304, the Knowledge Innovation Project of Chinese Academy of Sciences under Grant No KZCX3-SW-221, in part by E-Institutes of Shanghai Municipal Education Commission under Grant No E03004.
文摘We study a generalized nonlinear KdV system is studied by using the homotopic mapping method. Firstly, a homotopic mapping transform is constructed; secondly, the suitable initial approximation is selected; then the homotopic mapping is used. The accuracy of the approximate solution for the solitary wave is obtained. From the obtained approximate solution, the homotopic mapping method exhibits a good accuracy.
文摘Reinforcement property of structural silicon sealant as a function of the size and loading of nano CaCO 3 particles has been investigated by mechanical measurement and DMA experiments. The tensile strength and elongation at break of silicone sealant were found greatly enhanced by nano CaCO 3 particles. The smaller the particle size, the higher the tensile strength and the elongation will be. The storage modulus is also remarkably increased with the increasing of CaCO 3 loading and decreasing of CaCO 3 particle sizes, as revealed by DAM. Two relaxation peaks are seen for silicon sealant. One is around 153 K, corresponding to the glass transition temperature(T g), and the other is around 233 K, corresponding to the melting temperature(T m). Both T g and T m increase with the increasing of CaCO 3 loading and decreasing of CaCO 3 particle sizes. DMA results suggest that the interaction between nano CaCO 3 particles and silicon sealant is quite strong. The molecular motion of silicon sealant is highly limited by the dispersed nano CaCO 3 particles.
基金financial support for this project from the National Natural Science Foundation of China(Nos.U1508212 and 51706097)National Science and Technology Major Project,China(No.2017-III-00110037)。
文摘Film cooling is an indispensable scheme in the design of highly-efficient cooling configurations to satisfy the thermal protection requirement of turbine hot section components.During the last few decades,vast efforts have been paid on the discrete-hole film cooling enhancement.In this paper,some of the recent literatures related to the passive strategies(such as shaped film cooling holes,upstream ramps,shallow trenches,mesh-fed slots)and the active strategies(such as the use of pulsation modulating device or plasma actuator)for film cooling enhancement are surveyed,with the aim at presenting an updated overview about the state of the art in advanced film cooling.In addition,some challenging issues are also outlined to motivate further investigations in such a broad topic.
