A thermodynamic consistent phase field model is developed to describe the sintering process with multiphase powders. In this model, the interface region is assumed to be a mixture of different phases with the same che...A thermodynamic consistent phase field model is developed to describe the sintering process with multiphase powders. In this model, the interface region is assumed to be a mixture of different phases with the same chemical potential, but with different compositions. The interface diffusion and boundary diffusion are also considered in the model. As an example, the model is applied to the sintering process with Fe-Cu powders. The free energy of each phase is described by the well-developed thermodynamic models, together with the published optimized parameters. The microstructure and solute distribution during the sintering process can both be obtained quantitively.展开更多
In order to check the validity of the mathematical model for analyzing the flow field in the air-agitated seed precipitation tank,a scaled down experimental apparatus was designed and the colored tracer and KCl tracer...In order to check the validity of the mathematical model for analyzing the flow field in the air-agitated seed precipitation tank,a scaled down experimental apparatus was designed and the colored tracer and KCl tracer were added in the apparatus to follow the real flow line.Virtue tracers were considered in the mathematical model and the algorithm of tracers was built.The comparison of the results between the experiment and numerical calculation shows that the time of the tracer flows out of stirring tube are 40 s in the experiment and 42 s in numerical calculated result.The transient diffusion process and the solution residence time of the numerical calculation are in good agreement with the experimental results,which indicates that the mathematical model is reliable and can be used to predict the flow field of the air-agitated seed precipitation tank.展开更多
The pyramidal multiphase level set framework （PMLSF） based on the technique of painting background （TPBG） and the Chan-Vese model can detect multiple objects on a given image. However, the boundaries of the sub-ob...The pyramidal multiphase level set framework （PMLSF） based on the technique of painting background （TPBG） and the Chan-Vese model can detect multiple objects on a given image. However, the boundaries of the sub-object obtained by PMLSF-TPBG are not variable since a specialcolor parameter is used in TPBG. To solve the problem, a new technique utilizing a varying parameter is proposed to ensure that PMLSF is effective for the detection of the desired boundaries of the sub-object. The interval of the variable color parameter is proved and the effects of the parameter are also discussed. Experimental results for the brain tumor detection show that different boundaries of the brain tumors can be detected with different color parameters. It is especially useful for clinical diagnoses.展开更多
To avoid missing track caused by the target maneuvers in automatic target tracking system, a new maneuvering target tracking technique called threshold interacting multiple model （TIMM） is proposed. This algorithm i...To avoid missing track caused by the target maneuvers in automatic target tracking system, a new maneuvering target tracking technique called threshold interacting multiple model （TIMM） is proposed. This algorithm is based on the interacting multiple model （IMM） method and applies a threshold controller to improve tracking accuracy. It is also applicable to other advanced algorithms of IMM. In this research, we also compare the position and velocity root mean square （RMS） errors of TIMM and IMM algorithms with two different examples. Simulation results show that the TIMM algorithm is superior to the traditional IMM alzorithm in estimation accuracy.展开更多
By analyzing the observed phenomena and the data collected in the study, a multi-compartment linear circulation model for targeting drug delivery system was developed and the function formulas of the drug concentratio...By analyzing the observed phenomena and the data collected in the study, a multi-compartment linear circulation model for targeting drug delivery system was developed and the function formulas of the drug concentration-time in blood and target organ by computing were figured out. The drug concentration-time curve for target organ can be plotted with reference to the data of drug concentration in blood according to the model. The pharmacokinetic parameters of the drug in target organ could also be obtained. The practicability of the model was further checked by the curves of drug concentration-time in blood and target organ(liver) of liver-targeting nanoparticles in animal tests. Based on the liver drug concentration-time curves calculated by the function formula of the drug in target organ, the pharmacokinetic behavior of the drug in target organ(liver) was analyzed by statistical moment, and its pharmacokinetic parameters in liver were obtained. It is suggested that the (relative targeting index( can be used for quantitative evaluation of the targeting drug delivery systems.展开更多
The polymorphism of MHC class II B gene in 14 Chinese alligators was analyzed, which came from three different areas： a wild population from Xuancheng, Anhui, a captive population from Changxing, Zhejiang, and a capt...The polymorphism of MHC class II B gene in 14 Chinese alligators was analyzed, which came from three different areas： a wild population from Xuancheng, Anhui, a captive population from Changxing, Zhejiang, and a captive population from Anhui Research Center for Reproduction of Chinese Alligators. The gene fragment was amplified using a pair of specific primers designed from the MHC gene sequence of the spectacled caiman. A total of 34 sequence haplotypes of exon 3 were detected in the sampled Chinese alligators. The numbers of haplotypes of the 3 Chinese alligator populations were 15, 10, and 9, respectively. The overall estimation of the MHC polymorphism in the Chinese alligator population was higher than those in mammals and in cypdnid fish, The rates of nonsynonymous substitutions （dN） occurred at a significantly lower frequency than that of synonymous substitutions （ds）, which were not consistent with the common rule. This result might suggest that the polymorphism of exon 3 seemed not to be maintained by the balancing selection. The neutrality test of Tajima excluded the null hypothesis that the polymorphism of exon 3 was generated by a random drift, and the fact that D = -0.401 indicated an excess of rare mutations in the Chinese alligator. The nucleotide diversity of the sequences and the phylogenetic relations were also analyzed, and the results suggested that there was no significant difference in genetic diversity among the 3 populations of Chinese alligator.展开更多
By interpreting the remote sensing data of aerial photos and satellite images in different time, combining with field investigation, landform and water level observation, collecting data of weather, hydrology in Chaoh...By interpreting the remote sensing data of aerial photos and satellite images in different time, combining with field investigation, landform and water level observation, collecting data of weather, hydrology in Chaohu Lake, Anhui Province from 1957 to 2003, the reasons for collapse of Chaohu lakeshore were analyzed. The results are as follows: 1) The collapse of the Chaohu lakeshore is controlled macroscopically by two sets of north-east and the north-west faults, and the degree of collapse is determined microcosmically by lithology. 2) The constant change of water level, resulting from precipitation, wind speed and its direction, is one of the main reasons for intermittence collapse. 3) The soil and water loss or mud and sand filling up, resulting from artificial factors, such as inconsequence control of Chaohu sluice or irrational agricultural and industrial activities, etc., can uplift the lake′s bed and drive water level up. The high water level also results in the collapse. Judging from the above mentioned reasons for the collapse, we have proposed some countermeasures: 1) Putting the lakeshore slope protection project such as stone and cement mortar into practice, and upstream slope should be 1∶2.5 or 1∶3, some parts of them should be 1∶4, if they were not stable. The back slope, which is from Gui Mountain to Zhongmiao Temple, should be 1∶1.5-1∶3. 2) Constructing a greenbelt for the lakeshore, planting some vegetation such as osier, bulrush and poplar, to resist waves between the high and the low water level. 3) Controlling Chaohu Lake water level scientifically. Corrosion of lakeshore that contains gravel clay and ferruginous-manganese concretionary structures, can decrease at low water level. 4) Renovating Chaohu Lake drainage area, strengthening the administration and supervision, breaking regionalism and establishing special administration organization.展开更多
基金Project(2011CB606306)supported by the National Basic Research Program of ChinaProject(51101014)supported by the National Natural Science Foundation of ChinaProject(SKLSP201214)supported by the State Key Laboratory of Solidification Processing in Northwestern Polytechnical University,China
文摘A thermodynamic consistent phase field model is developed to describe the sintering process with multiphase powders. In this model, the interface region is assumed to be a mixture of different phases with the same chemical potential, but with different compositions. The interface diffusion and boundary diffusion are also considered in the model. As an example, the model is applied to the sintering process with Fe-Cu powders. The free energy of each phase is described by the well-developed thermodynamic models, together with the published optimized parameters. The microstructure and solute distribution during the sintering process can both be obtained quantitively.
基金Project(07JJ4016) supported by the Natural Science Foundation of Hunan Procvince,China
文摘In order to check the validity of the mathematical model for analyzing the flow field in the air-agitated seed precipitation tank,a scaled down experimental apparatus was designed and the colored tracer and KCl tracer were added in the apparatus to follow the real flow line.Virtue tracers were considered in the mathematical model and the algorithm of tracers was built.The comparison of the results between the experiment and numerical calculation shows that the time of the tracer flows out of stirring tube are 40 s in the experiment and 42 s in numerical calculated result.The transient diffusion process and the solution residence time of the numerical calculation are in good agreement with the experimental results,which indicates that the mathematical model is reliable and can be used to predict the flow field of the air-agitated seed precipitation tank.
文摘The pyramidal multiphase level set framework （PMLSF） based on the technique of painting background （TPBG） and the Chan-Vese model can detect multiple objects on a given image. However, the boundaries of the sub-object obtained by PMLSF-TPBG are not variable since a specialcolor parameter is used in TPBG. To solve the problem, a new technique utilizing a varying parameter is proposed to ensure that PMLSF is effective for the detection of the desired boundaries of the sub-object. The interval of the variable color parameter is proved and the effects of the parameter are also discussed. Experimental results for the brain tumor detection show that different boundaries of the brain tumors can be detected with different color parameters. It is especially useful for clinical diagnoses.
文摘To avoid missing track caused by the target maneuvers in automatic target tracking system, a new maneuvering target tracking technique called threshold interacting multiple model （TIMM） is proposed. This algorithm is based on the interacting multiple model （IMM） method and applies a threshold controller to improve tracking accuracy. It is also applicable to other advanced algorithms of IMM. In this research, we also compare the position and velocity root mean square （RMS） errors of TIMM and IMM algorithms with two different examples. Simulation results show that the TIMM algorithm is superior to the traditional IMM alzorithm in estimation accuracy.
文摘By analyzing the observed phenomena and the data collected in the study, a multi-compartment linear circulation model for targeting drug delivery system was developed and the function formulas of the drug concentration-time in blood and target organ by computing were figured out. The drug concentration-time curve for target organ can be plotted with reference to the data of drug concentration in blood according to the model. The pharmacokinetic parameters of the drug in target organ could also be obtained. The practicability of the model was further checked by the curves of drug concentration-time in blood and target organ(liver) of liver-targeting nanoparticles in animal tests. Based on the liver drug concentration-time curves calculated by the function formula of the drug in target organ, the pharmacokinetic behavior of the drug in target organ(liver) was analyzed by statistical moment, and its pharmacokinetic parameters in liver were obtained. It is suggested that the (relative targeting index( can be used for quantitative evaluation of the targeting drug delivery systems.
基金the National Natural Science Foundation of China (No. 30270213 and 30470244)a grant of Special Scholar Foundation from Anhui Province (No. 04043049)the Key Laboratory of Biotic Environment and Ecological Safety in Anhui Province.
文摘The polymorphism of MHC class II B gene in 14 Chinese alligators was analyzed, which came from three different areas： a wild population from Xuancheng, Anhui, a captive population from Changxing, Zhejiang, and a captive population from Anhui Research Center for Reproduction of Chinese Alligators. The gene fragment was amplified using a pair of specific primers designed from the MHC gene sequence of the spectacled caiman. A total of 34 sequence haplotypes of exon 3 were detected in the sampled Chinese alligators. The numbers of haplotypes of the 3 Chinese alligator populations were 15, 10, and 9, respectively. The overall estimation of the MHC polymorphism in the Chinese alligator population was higher than those in mammals and in cypdnid fish, The rates of nonsynonymous substitutions （dN） occurred at a significantly lower frequency than that of synonymous substitutions （ds）, which were not consistent with the common rule. This result might suggest that the polymorphism of exon 3 seemed not to be maintained by the balancing selection. The neutrality test of Tajima excluded the null hypothesis that the polymorphism of exon 3 was generated by a random drift, and the fact that D = -0.401 indicated an excess of rare mutations in the Chinese alligator. The nucleotide diversity of the sequences and the phylogenetic relations were also analyzed, and the results suggested that there was no significant difference in genetic diversity among the 3 populations of Chinese alligator.
基金Under the auspices of Sciences Fund of Anhui Provincial Bureau of Education (No. 2004kj165 zd), High Edu-cation Teaching Research of Anhui Province (No. 2005021), the Natural Sciences Fund of Anhui Province, Key Subject of Physi-cal Geographyof Anhui Normal University
文摘By interpreting the remote sensing data of aerial photos and satellite images in different time, combining with field investigation, landform and water level observation, collecting data of weather, hydrology in Chaohu Lake, Anhui Province from 1957 to 2003, the reasons for collapse of Chaohu lakeshore were analyzed. The results are as follows: 1) The collapse of the Chaohu lakeshore is controlled macroscopically by two sets of north-east and the north-west faults, and the degree of collapse is determined microcosmically by lithology. 2) The constant change of water level, resulting from precipitation, wind speed and its direction, is one of the main reasons for intermittence collapse. 3) The soil and water loss or mud and sand filling up, resulting from artificial factors, such as inconsequence control of Chaohu sluice or irrational agricultural and industrial activities, etc., can uplift the lake′s bed and drive water level up. The high water level also results in the collapse. Judging from the above mentioned reasons for the collapse, we have proposed some countermeasures: 1) Putting the lakeshore slope protection project such as stone and cement mortar into practice, and upstream slope should be 1∶2.5 or 1∶3, some parts of them should be 1∶4, if they were not stable. The back slope, which is from Gui Mountain to Zhongmiao Temple, should be 1∶1.5-1∶3. 2) Constructing a greenbelt for the lakeshore, planting some vegetation such as osier, bulrush and poplar, to resist waves between the high and the low water level. 3) Controlling Chaohu Lake water level scientifically. Corrosion of lakeshore that contains gravel clay and ferruginous-manganese concretionary structures, can decrease at low water level. 4) Renovating Chaohu Lake drainage area, strengthening the administration and supervision, breaking regionalism and establishing special administration organization.
