REPETITIVE CLUSTER-TILTED ALGEBRAS

Let H be a finite-dimensional hereditary algebra over an algebraically closed field k and C F m be the repetitive cluster category of H with m ≥ 1. We investigate the properties of cluster tilting objects in C F m and the structure of repetitive clustertilted algebras. Moreover, we generalize Theorem 4.2 in [12] (Buan A, Marsh R, Reiten I. Cluster-tilted algebra, Trans. Amer. Math. Soc., 359(1)(2007), 323-332.) to the situation of C F m , and prove that the tilting graph KCFm of C F m is connected.     

沸石和SAPO分子筛催化卤代甲烷转化制烯烃和汽油:一种新的MTO和MTG路线(英文)

Rational and efficient conversion of methane to more useful higher hydrocarbons is one of the most important topics of natural gas utilization.Although methane activation and its conversion to valuable compounds attract an increasing attention,methane conversion is often made in indirect way through the very energy-consuming step for syngas production from steam reforming of methane.Some promising results appeared to be of significance for the development of an alternative and potential route for the production of high value-added products from methane.Efficient conversion of methane to higher hydrocarbons could be realized via methyl halide as the intermediate.After the production of halomethane,they could be transformed to gasoline and light olefins over modified zeolites and SAPO molecular sieves.High conversion efficiency and selectivity indicated the feasibility of industrial application.The research gained recently growing interest from the point of view in both fundamental research and industrial application.The study on the reaction mechanism shed light on the possible route of C-C bond construction from methyl halide,which is the very important issue of the C1-reactant conversion to higher hydrocarbons.Hydrogen halide generation during methyl halide conversion did not exert apparent impact on the reaction mechanism and the structure stability of the catalysts.This review deals with the evolution of the field and comments the advantages to be explored and the drawbacks to be prevented for the development of new and sustainable methane-to-olefins(MTO) and methane-to-gasoline(MTG) routes via methyl halides.     

带导数项的半正Right Focal边值问题单调正解的存在性

研究下列半正Right F0cal边值问题单调正解的存在性其中λ>0是一个参数,n≥3,1相似文献   

固定平滑参数的Pickands估计量的大分位数之估计

{X_i}_(i=1)~∞是具有公共分布函数F(x)的i.i.d序列,F(x)属于吸引场D(G_γ)(γ∈R)之一.在一定条件下,给出了固定平滑参数的F(x)的大分位数估计量的渐进分布,进而可得其渐进置信区间.     

多小波采样定理的拓展

采样定理在数字信号通讯中发挥了十分重要的作用,因为信号通常由它的离散采样数据来恢复.Han Bin等人在[J.Comput.Appl.Math.,2009,227:254-270]中构造了广义插值加细函数向量.本文研究与广义插值加细函数向量有关的采样定理的拓展问题.具体而言,对于已知的广义插值d-加细函数向量φ=(φ_1,…,φ_r)~T,即φe(m/r+k)=δ_kδ_(e-1-m),k∈Z,m=0,1,…,r-1,e=1,…,r我们将构造一组函数{φ_(r+1),…,φ_(dr)},使得φ~ロ=(φ~T,φ_(r+1),…,φ_(dr))~T也是d-加细的,而且满足φ_e(m/(dr)+k)=δ_kδ_(θ_(d,r(e)-m))k∈Z,m=0,1,…,dr-1,e=r+1,…,dr,其中θ_(d,r(e))=e-r+R_(e-1-r,d-1),R_(e-1-r,d-1)=「(e-1-r)/(d-1)」.我们建立与φ~■有关的采样定理.显然,φ的多小波子空间采样定理的适用范围得到了拓展.给出φ~■的多小波子空间采样级数的截断误差估计.     

纵向数据下广义估计方程估计

广义估计方程方法是一种最一般的参数估计方法,广泛地应用于生物统计、经济计量、医疗保险等领域.在纵向数据下,由于组间数据是相关的,为了提高估计的效率,广义估计方程方法一般需要考虑个体组内相关性.因此,大多数文献对个体组内的协方差矩阵进行参数假设,但假设的合理性及协方差矩阵估计的好坏对参数估计效率产生很大影响,同时参数假设也可能导致模型误判.针对纵向数据下广义估计方程,本文提出了改进的GMM方法和经验似然方法,并对给出的估计量建立了大样本性质.其中分块的思想,避免了对个体组内相关性结构进行假设,从这种意义上说,这种方法具有一定的稳健性.我们还通过两个模拟的例子,考察了文中提出估计量的有限样本性质.     

缺项幂级数表示的超越整函数Fatou分支有界性

讨论了几类用缺项幂级数表示的超越整函数Fatou集分支的有界性,并给出了其Fatou分支均有界的充分条件.     

非线性光学中薛定谔型方程的整体吸引子

研究了一类非线性薛定谔型方程,描述了光波在光折射晶体中的传播.首先构造了该模型整体弱的吸引子,然后通过能量方程的精确分析,证明整体弱吸引子实际为系统整体强吸引子.最后给出了整体吸引子的分形维数和Hausdorff维数的上界估计.     

多线性分数次积分迭代型交换子的加权不等式

研究了多线性分数次积分算子的迭代型交换子,给出了双权强型不等式的充分条件,即Fefferman -Phong型条件.对此迭代型交换子,还给出了Fefferman-Stein型加权不等式和Coifman型加权不等式.     

The separation single-wall carbon nanotubes on length by sepharose gel

The separations of single-wall carbon nanotubes on length by sepharose gel were investigated in this work. The solutions of sodium dodecyl sulfate and sodium deoxycholate were applied as the eluent in sequence. SEM and Raman were used to characterize the length of nanotube bundles. The results show that the longer nanotubes were eluted out first, and then the shorter tubes were followed by the sodium dodecyl sulfate. However, the separated order was totally reversed by the sodium deoxycholate. By this method, the process generated nanotube fractions not only were narrower in length distributions, but also could control the separation orders by changing the eluents. Moreover, the separation principle was also discussed.