CuO nanoparticle was synthesized via wet chemical method and was characterized diffraction （XRD）, nitrogen adsorption-desorption, and scanning electron microscopy （SEM） by X-ray Catalytic oxidation of cumene with ...CuO nanoparticle was synthesized via wet chemical method and was characterized diffraction （XRD）, nitrogen adsorption-desorption, and scanning electron microscopy （SEM） by X-ray Catalytic oxidation of cumene with molecular oxygen was studied over CuO nanoparticle. The catalysts showed markedly higher activities as compared to CuO prepared by conventional method, CuO/Al2O3, or homogeneous copper catalyst under comparable reaction conditions. The cumene conversion, cumene hydroperoxide （CHP） yield, and selectivity using 0.25 g CuO nanoparticle catalyst and 0.1 mol cumene at 358 K for 7 h were 44.2%, 41.2% and 93.2%, respectively. The catalyst can be recycled. After 6 recycled experiments, no loss of catalytic activity was observed.展开更多
The spectrum allocation for cognitive radio networks(CRNs) has received considerable studies under the assumption that the bandwidth of spectrum holes is static. However, in practice, the bandwidth of spectrum holes i...The spectrum allocation for cognitive radio networks(CRNs) has received considerable studies under the assumption that the bandwidth of spectrum holes is static. However, in practice, the bandwidth of spectrum holes is time-varied due to primary user/secondary user(PU/SU) activity and mobility, which result in non-determinacy. This paper studies the spectrum allocation for CRNs with non-deterministic bandwidth of spectrum holes. We present a novel probability density function(PDF) through order statistics as well as its simplified form to describe the statistical properties of spectrum holes, with which a statistical spectrum allocation model based on stochastic multiple knapsack problem(MKP) is formulated for spectrum allocation with non-deterministic bandwidth of spectrum holes. To reduce the computational complexity, we transform this stochastic programming problem into a constant MKP through exploiting the properties of cumulative distribution function(CDF), which can be solved via MTHG algorithm by using auxiliary variables. Simulation results illustrate that the proposed statistical spectrum allocation algorithm can achieve better performance compared with the existing algorithms when the bandwidth of spectrum holes is time-varied.展开更多
Based on the current development situation of tea industry in Leiyang City,this paper analyzes the existing problems such as small scale of high quality tea plantation,insufficient brand awareness,inadequate funding i...Based on the current development situation of tea industry in Leiyang City,this paper analyzes the existing problems such as small scale of high quality tea plantation,insufficient brand awareness,inadequate funding input,extensive tea plantation management,rising labor costs and outdated mechanical equipment. Finally this paper expounds the development goal and sets forth the corresponding recommendations.展开更多
基金This work is supported by the Natural Science Foundation of South China University of China(143E5041280)
文摘CuO nanoparticle was synthesized via wet chemical method and was characterized diffraction （XRD）, nitrogen adsorption-desorption, and scanning electron microscopy （SEM） by X-ray Catalytic oxidation of cumene with molecular oxygen was studied over CuO nanoparticle. The catalysts showed markedly higher activities as compared to CuO prepared by conventional method, CuO/Al2O3, or homogeneous copper catalyst under comparable reaction conditions. The cumene conversion, cumene hydroperoxide （CHP） yield, and selectivity using 0.25 g CuO nanoparticle catalyst and 0.1 mol cumene at 358 K for 7 h were 44.2%, 41.2% and 93.2%, respectively. The catalyst can be recycled. After 6 recycled experiments, no loss of catalytic activity was observed.
基金supported by the National Natural Science Foundation of China (No.61501065, 91438104,No.61571069 and No.61601067)the Fundamental Research Funds for the Central Universities (No.106112015CDJXY160002,No.106112016CDJXY160001)the Chongqing Research Program of Basic Research and Frontier Technology (No.CSTC2016JCYJA0021)
文摘The spectrum allocation for cognitive radio networks(CRNs) has received considerable studies under the assumption that the bandwidth of spectrum holes is static. However, in practice, the bandwidth of spectrum holes is time-varied due to primary user/secondary user(PU/SU) activity and mobility, which result in non-determinacy. This paper studies the spectrum allocation for CRNs with non-deterministic bandwidth of spectrum holes. We present a novel probability density function(PDF) through order statistics as well as its simplified form to describe the statistical properties of spectrum holes, with which a statistical spectrum allocation model based on stochastic multiple knapsack problem(MKP) is formulated for spectrum allocation with non-deterministic bandwidth of spectrum holes. To reduce the computational complexity, we transform this stochastic programming problem into a constant MKP through exploiting the properties of cumulative distribution function(CDF), which can be solved via MTHG algorithm by using auxiliary variables. Simulation results illustrate that the proposed statistical spectrum allocation algorithm can achieve better performance compared with the existing algorithms when the bandwidth of spectrum holes is time-varied.
文摘Based on the current development situation of tea industry in Leiyang City,this paper analyzes the existing problems such as small scale of high quality tea plantation,insufficient brand awareness,inadequate funding input,extensive tea plantation management,rising labor costs and outdated mechanical equipment. Finally this paper expounds the development goal and sets forth the corresponding recommendations.
