As one of the main reasons causing leakage heat load in a refrigerator,mass and heat transfer through refrigerator door seal is of great importance to be studied.In this paper,a model is presented for numerical simula...As one of the main reasons causing leakage heat load in a refrigerator,mass and heat transfer through refrigerator door seal is of great importance to be studied.In this paper,a model is presented for numerical simulation of mass and heat transfer process through refrigerator door seal,and an experiment apparatus is designed and set up as well for comparison.A two-dimensional model and tracer gas method are used in simulation and experiment,respectively.It can be found that the relative deviations of air infiltration rate between the simulated results and experimental results were less than 1%,and the temperature difference errors at two special points of the door seal were less than 2.03℃.In conclusion,the simulated results are in good agreement with the experimental results.This paper initially sets up a model that can accurately simulate the heat and mass transfer through the refrigerator door seal,and the model can be used in refrigerator door seal optimization research in the follow-up study.展开更多
Crowd density is an important factor of crowd stability.Previous crowd density estimation methods are highly dependent on the specific video scene.This paper presented a video scene invariant crowd density estimation ...Crowd density is an important factor of crowd stability.Previous crowd density estimation methods are highly dependent on the specific video scene.This paper presented a video scene invariant crowd density estimation method using Geographic Information Systems(GIS) to monitor crowd size for large areas.The proposed method mapped crowd images to GIS.Then we can estimate crowd density for each camera in GIS using an estimation model obtained by one camera.Test results show that one model obtained by one camera in GIS can be adaptively applied to other cameras in outdoor video scenes.A real-time monitoring system for crowd size in large areas based on scene invariant model has been successfully used in 'Jiangsu Qinhuai Lantern Festival,2012'.It can provide early warning information and scientific basis for safety and security decision making.展开更多
In the structures whose long-term behavior should be monitored and controlled, creep and shrinkage effects have to be included precisely in the analysis and design procedures. Creep and shrinkage, vary with the consti...In the structures whose long-term behavior should be monitored and controlled, creep and shrinkage effects have to be included precisely in the analysis and design procedures. Creep and shrinkage, vary with the constituent and mixtures proportions, and depend on the curing conditions and work environment as well. Self-compacting concrete （SCC） contains combinations of various components, such as aggregate, cement, superplasticizer, water-reducing agent and other ingredients which affect the properties of the SCC including creep and shrinkage of the SCC. Hence, the realistic prediction creep and shrinkage strains of SCC are an important requirement of the design process of this type of concrete structures. In this study, three proposed creep models and four shrinkage models available in the literature are compared with the measured results of 52 mixtures for creep and 165 mixtures for shrinkage of SCC. The influence of various parameters, such as mixture design, cement content, filler content, aggregate content, and water cement ratio （w/c） on the creep and shrinkage of SCC are also compared and discussed.展开更多
We introduce the double-Hamiltonian evolution technique approach to investigate the unconventional geometric quantum logical gate with dissipation under the model of many identical three-level atoms in a cavity~ drive...We introduce the double-Hamiltonian evolution technique approach to investigate the unconventional geometric quantum logical gate with dissipation under the model of many identical three-level atoms in a cavity~ driven by a classical fieM. Our concrete calculation is made for the case of two atoms for the large-detuning interaction of the atoms with the cavity mode. The main advantage of our scheme is of eliminating the photon flutuation in the cavity mode during the gating. The corresponding analytical results will be helpful for experimental realization of speed geometric quantum logical gate in real cavities.展开更多
OBJECTIVE:To study the use of a bone-strengthening pill to treat ischemic necrosis of the femoral head.METHODS:A model of castration in rats with osteoporosis and a model of ischemic necrosis in the bilateral femoral ...OBJECTIVE:To study the use of a bone-strengthening pill to treat ischemic necrosis of the femoral head.METHODS:A model of castration in rats with osteoporosis and a model of ischemic necrosis in the bilateral femoral heads of young rats were used to detect bone density,bone formation measurements,lipid deposition in the femoral head,the distribution of capillaries in the femoral head and other relevant biochemical indices.RESULTS:In model rats,bone-strengthening pills were able to increase the bone density,the unit volume of bony trabeculae,the width of bony trabeculae,and the unit volume of the bony cortex.They could also enhance the mineral apposition rate in the femoral head and the seam width of osteoid deposition.Furthermore,there was a reduction in lipid deposition in the femoral head,and enriched distribution of arteries in the femoral head.Bone-related biochemical detections showed an increase in alkaline phosphatase staining and a decrease in tartaric acidic phosphatase staining.CONCLUSION:The results show that bone-strengthening pills can obviously promote bony growth,cause an increase in bone density,restore blood circulation,inhibit the occurrence and development of bony necrosis,and accelerate the repair of necrotic bones,with no toxic side-effects.展开更多
基金Supported by the National Science Fund for Distinguished Young Scholar(51525604)111 project B16038
文摘As one of the main reasons causing leakage heat load in a refrigerator,mass and heat transfer through refrigerator door seal is of great importance to be studied.In this paper,a model is presented for numerical simulation of mass and heat transfer process through refrigerator door seal,and an experiment apparatus is designed and set up as well for comparison.A two-dimensional model and tracer gas method are used in simulation and experiment,respectively.It can be found that the relative deviations of air infiltration rate between the simulated results and experimental results were less than 1%,and the temperature difference errors at two special points of the door seal were less than 2.03℃.In conclusion,the simulated results are in good agreement with the experimental results.This paper initially sets up a model that can accurately simulate the heat and mass transfer through the refrigerator door seal,and the model can be used in refrigerator door seal optimization research in the follow-up study.
基金The authors would like to thank the reviewers for their detailed reviews and constructive comments. We are also grateful for Sophie Song＇s help on the improving English. This work was supported in part by the ‘Fivetwelfh＇ National Science and Technology Support Program of the Ministry of Science and Technology of China （No. 2012BAH35B02）, the National Natural Science Foundation of China （NSFC） （No. 41401107, No. 41201402, and No. 41201417）.
文摘Crowd density is an important factor of crowd stability.Previous crowd density estimation methods are highly dependent on the specific video scene.This paper presented a video scene invariant crowd density estimation method using Geographic Information Systems(GIS) to monitor crowd size for large areas.The proposed method mapped crowd images to GIS.Then we can estimate crowd density for each camera in GIS using an estimation model obtained by one camera.Test results show that one model obtained by one camera in GIS can be adaptively applied to other cameras in outdoor video scenes.A real-time monitoring system for crowd size in large areas based on scene invariant model has been successfully used in 'Jiangsu Qinhuai Lantern Festival,2012'.It can provide early warning information and scientific basis for safety and security decision making.
文摘In the structures whose long-term behavior should be monitored and controlled, creep and shrinkage effects have to be included precisely in the analysis and design procedures. Creep and shrinkage, vary with the constituent and mixtures proportions, and depend on the curing conditions and work environment as well. Self-compacting concrete （SCC） contains combinations of various components, such as aggregate, cement, superplasticizer, water-reducing agent and other ingredients which affect the properties of the SCC including creep and shrinkage of the SCC. Hence, the realistic prediction creep and shrinkage strains of SCC are an important requirement of the design process of this type of concrete structures. In this study, three proposed creep models and four shrinkage models available in the literature are compared with the measured results of 52 mixtures for creep and 165 mixtures for shrinkage of SCC. The influence of various parameters, such as mixture design, cement content, filler content, aggregate content, and water cement ratio （w/c） on the creep and shrinkage of SCC are also compared and discussed.
基金Supported by the National Natural Science Foundation of China under Grant Nos.10774042,10774163,and 11074070the Natural Science Foundation of Hunan Province under Grant No.09JJ3121the Key Project of Science and Technology of Hunan Province under Grant No.2010FJ2005
文摘We introduce the double-Hamiltonian evolution technique approach to investigate the unconventional geometric quantum logical gate with dissipation under the model of many identical three-level atoms in a cavity~ driven by a classical fieM. Our concrete calculation is made for the case of two atoms for the large-detuning interaction of the atoms with the cavity mode. The main advantage of our scheme is of eliminating the photon flutuation in the cavity mode during the gating. The corresponding analytical results will be helpful for experimental realization of speed geometric quantum logical gate in real cavities.
文摘OBJECTIVE:To study the use of a bone-strengthening pill to treat ischemic necrosis of the femoral head.METHODS:A model of castration in rats with osteoporosis and a model of ischemic necrosis in the bilateral femoral heads of young rats were used to detect bone density,bone formation measurements,lipid deposition in the femoral head,the distribution of capillaries in the femoral head and other relevant biochemical indices.RESULTS:In model rats,bone-strengthening pills were able to increase the bone density,the unit volume of bony trabeculae,the width of bony trabeculae,and the unit volume of the bony cortex.They could also enhance the mineral apposition rate in the femoral head and the seam width of osteoid deposition.Furthermore,there was a reduction in lipid deposition in the femoral head,and enriched distribution of arteries in the femoral head.Bone-related biochemical detections showed an increase in alkaline phosphatase staining and a decrease in tartaric acidic phosphatase staining.CONCLUSION:The results show that bone-strengthening pills can obviously promote bony growth,cause an increase in bone density,restore blood circulation,inhibit the occurrence and development of bony necrosis,and accelerate the repair of necrotic bones,with no toxic side-effects.
