In this paper,the variable cofficient KdV equation with dissipative loss and nonuniformity terms and the variable coefficient SG equation with nonuniformity term are studied. The exact solutions of the KdV and SG equa...In this paper,the variable cofficient KdV equation with dissipative loss and nonuniformity terms and the variable coefficient SG equation with nonuniformity term are studied. The exact solutions of the KdV and SG equations are obtained.In particular,the soliton solutions of two equations are found. Received November 25,1996.Revised June 30,1997.1991 MR Subject Classification:35Q53.展开更多
空中接口标准在移动通信网络中是最关键部分,而空中接口中最核心的是多址与复用技术。首先给出了第5代移动通信系统(5G)对空中接口技术的新要求,然后对OFDM(orthogonal frequency division multiplexing)存在的问题进行了分析,在此基础...空中接口标准在移动通信网络中是最关键部分,而空中接口中最核心的是多址与复用技术。首先给出了第5代移动通信系统(5G)对空中接口技术的新要求,然后对OFDM(orthogonal frequency division multiplexing)存在的问题进行了分析,在此基础上,重点讨论了滤波器组多载波传输(filterbank based multi carrier,FBMC),通用滤波多载波(universal filtered multi carrier,UFMC)和广义频分复用传输(generalized frequency division multiplexing,GFDM)等3种基于OFDM改进的新型多址与复用技术。展开更多
Anoplophora glabripennis(Asian longhorn beetle,ALB)and Anoplophora chinensis(Citrus longhorn beetle,CLB)are native forest pests in China;they have become important international quarantine pests.They are found using t...Anoplophora glabripennis(Asian longhorn beetle,ALB)and Anoplophora chinensis(Citrus longhorn beetle,CLB)are native forest pests in China;they have become important international quarantine pests.They are found using the same Salix aureopendula host tree of Cixi,Zhejiang province,China.On this host tree,we collected additional beetles that appeared to be morphologically intermediate between ALB and CLB.By using a stereoscope,we observed that there were several bumps on the base of the elytra,which was inconsistent with ALB,which typically has a smooth elytral base,but was more like CLB,which has numerous short tubercles on the elytral base.Given their sympatry and intermediate morphology,we hypothesized that these may represent ALB×CLB hybrids.We studied the genomic profiles for 46 samples(ALB,CLB,and putative hybrids)using genotyping-by-sequencing(GBS)providing a reduced representation of the entire genome.Employing principal component analyses on the 163 GBS-derived single nucleotide polymorphism data,we found putative hybrids tightly clustered with ALB,but genetically distinct from the CLB individuals.Therefore,our initial hybrid hypothesis was not supported by genomic data.Further,while mating experiments between adult ALB and CLB were successful in 4 separate years(2017,2018,2020,and 2021),and oviposition behavior was observed,no progeny was produced.Having employed population genomic analysis and biological hybridization experiments,we conclude that the putative hybrids represent newly discovered morphological variants within ALB.Our approach further confirmed the advantage of genome-wide information for Anoplophora species assignment in certain ambiguous classification cases.展开更多
In order to investigate the asymmetry of thermal conditions during directional solidification, the temperature evolution and correspondingly developed undercooling in a simplified single crystal blade cluster were num...In order to investigate the asymmetry of thermal conditions during directional solidification, the temperature evolution and correspondingly developed undercooling in a simplified single crystal blade cluster were numerically simulated. Simulation results demonstrate that the temperature distribution at the blade platforms is obviously asymmetrical. On the outside of the blade which directly faces the heating element, the liquidus(TL) isotherms progress relatively smoothly. On the inside of the blades facing the central rod, however, the TLisotherms are in concave shape and the slope goes upwards to the platform extremities. The average undercooling extent ?T and undercooling time ?t at the inside are much higher than those at the outside. It was then predicted that the inside platform extremities have significantly higher probabilities of stray grain formation compared to the outside ones. A corresponding experiment was carried out and the metallographic examination exhibited the same side-and height-dependence of stray grain formation in the blades as predicted. On the inside of the blades, all platforms are occupied by stray grains, while the platforms on the outside are nearly stray grain free. The simulation result agrees very well with the experimental observation.展开更多
文摘In this paper,the variable cofficient KdV equation with dissipative loss and nonuniformity terms and the variable coefficient SG equation with nonuniformity term are studied. The exact solutions of the KdV and SG equations are obtained.In particular,the soliton solutions of two equations are found. Received November 25,1996.Revised June 30,1997.1991 MR Subject Classification:35Q53.
文摘空中接口标准在移动通信网络中是最关键部分,而空中接口中最核心的是多址与复用技术。首先给出了第5代移动通信系统(5G)对空中接口技术的新要求,然后对OFDM(orthogonal frequency division multiplexing)存在的问题进行了分析,在此基础上,重点讨论了滤波器组多载波传输(filterbank based multi carrier,FBMC),通用滤波多载波(universal filtered multi carrier,UFMC)和广义频分复用传输(generalized frequency division multiplexing,GFDM)等3种基于OFDM改进的新型多址与复用技术。
基金supported by the Fundamental Research Funds for the Central Universities(No.QNTD202304)National Natural Science Foundation ofChina(No.32171794).
文摘Anoplophora glabripennis(Asian longhorn beetle,ALB)and Anoplophora chinensis(Citrus longhorn beetle,CLB)are native forest pests in China;they have become important international quarantine pests.They are found using the same Salix aureopendula host tree of Cixi,Zhejiang province,China.On this host tree,we collected additional beetles that appeared to be morphologically intermediate between ALB and CLB.By using a stereoscope,we observed that there were several bumps on the base of the elytra,which was inconsistent with ALB,which typically has a smooth elytral base,but was more like CLB,which has numerous short tubercles on the elytral base.Given their sympatry and intermediate morphology,we hypothesized that these may represent ALB×CLB hybrids.We studied the genomic profiles for 46 samples(ALB,CLB,and putative hybrids)using genotyping-by-sequencing(GBS)providing a reduced representation of the entire genome.Employing principal component analyses on the 163 GBS-derived single nucleotide polymorphism data,we found putative hybrids tightly clustered with ALB,but genetically distinct from the CLB individuals.Therefore,our initial hybrid hypothesis was not supported by genomic data.Further,while mating experiments between adult ALB and CLB were successful in 4 separate years(2017,2018,2020,and 2021),and oviposition behavior was observed,no progeny was produced.Having employed population genomic analysis and biological hybridization experiments,we conclude that the putative hybrids represent newly discovered morphological variants within ALB.Our approach further confirmed the advantage of genome-wide information for Anoplophora species assignment in certain ambiguous classification cases.
基金supported by the“Shenzhen Peacock Plan”the“Guangdong Innovative&Entrepreneurial Research Team Program”
文摘In order to investigate the asymmetry of thermal conditions during directional solidification, the temperature evolution and correspondingly developed undercooling in a simplified single crystal blade cluster were numerically simulated. Simulation results demonstrate that the temperature distribution at the blade platforms is obviously asymmetrical. On the outside of the blade which directly faces the heating element, the liquidus(TL) isotherms progress relatively smoothly. On the inside of the blades facing the central rod, however, the TLisotherms are in concave shape and the slope goes upwards to the platform extremities. The average undercooling extent ?T and undercooling time ?t at the inside are much higher than those at the outside. It was then predicted that the inside platform extremities have significantly higher probabilities of stray grain formation compared to the outside ones. A corresponding experiment was carried out and the metallographic examination exhibited the same side-and height-dependence of stray grain formation in the blades as predicted. On the inside of the blades, all platforms are occupied by stray grains, while the platforms on the outside are nearly stray grain free. The simulation result agrees very well with the experimental observation.
