首次以天然红辉沸石水热合成了 Y 型、P 型分子筛,以 IR 研究了水热合成体系中分子筛结构的演变及晶相分布规律。研究表明,在高 H_2O/Na_2O、低Ca^(2+)/Na^+体系中,主晶相为 Y 型分子筛,在低 H_2O/Na_2O、高 Ca^(2+)/Na^+体系中,主晶相...首次以天然红辉沸石水热合成了 Y 型、P 型分子筛,以 IR 研究了水热合成体系中分子筛结构的演变及晶相分布规律。研究表明,在高 H_2O/Na_2O、低Ca^(2+)/Na^+体系中,主晶相为 Y 型分子筛,在低 H_2O/Na_2O、高 Ca^(2+)/Na^+体系中,主晶相为 P 型分子筛。展开更多
Web IR presents a new challenge due to the heterogeneity,the dynamic characteristic and the size of theWeb. A practical IR system that can satisfy the users' demand is very important ,in this paper we research the...Web IR presents a new challenge due to the heterogeneity,the dynamic characteristic and the size of theWeb. A practical IR system that can satisfy the users' demand is very important ,in this paper we research the charac-teristics of Web IR in detail and give out the ideal Web IR service model:it should include search engine spectrum,search engine hierarchy,search engine cooperative network. We also analyze the key technique of this model,propose asimple way for the Web IR service to deal with the huge-scale of Web resources easily,and test part of the ideas in ourprototype system SAInSE.展开更多
文摘首次以天然红辉沸石水热合成了 Y 型、P 型分子筛,以 IR 研究了水热合成体系中分子筛结构的演变及晶相分布规律。研究表明,在高 H_2O/Na_2O、低Ca^(2+)/Na^+体系中,主晶相为 Y 型分子筛,在低 H_2O/Na_2O、高 Ca^(2+)/Na^+体系中,主晶相为 P 型分子筛。
文摘将无人机与频谱共享技术相结合,可建立高质量通信链路,提高频谱资源利用效率。然而,由于主、次用户间交叉链路干扰的存在,实现次用户的高可达速率变得十分困难。为了解决该问题,设计了一种智能反射面(Intelligent Reflective Surface,IRS)辅助的无人机认知中继通信网络。通过联合优化无人机的位置部署、次基站的波束成形和IRS的相移矩阵,最大化频谱共享网络中次用户的加权和速率(Weighted Sum Rate,WSR)。为了解决所建立的非凸问题,将其解耦为3个子问题,然后提出了一种交替优化算法来迭代优化变量。利用连续凸逼近(Successive Convex Approxi‑mation,SCA)法对无人机的位置进行优化;利用直接分式规划(Dire ct Fractional Programming,DFP)法对次基站的波束成形进行优化;利用DFP结合交替方向乘子法(Alternating Direction Method of Multipliers,ADMM)对IRS的相移矩阵进行优化。仿真结果表明,与基准算法相比,所提算法能实现更高的次用户WSR。
文摘Web IR presents a new challenge due to the heterogeneity,the dynamic characteristic and the size of theWeb. A practical IR system that can satisfy the users' demand is very important ,in this paper we research the charac-teristics of Web IR in detail and give out the ideal Web IR service model:it should include search engine spectrum,search engine hierarchy,search engine cooperative network. We also analyze the key technique of this model,propose asimple way for the Web IR service to deal with the huge-scale of Web resources easily,and test part of the ideas in ourprototype system SAInSE.
