Continuous and perfect single-layer B-Al-ZSM-5 zeolite membranes with c-axis orientation, self-transformation from B-containing porous gla ss disks w ith rough and uneven surfaces full of pits, have been in-situ prepa...Continuous and perfect single-layer B-Al-ZSM-5 zeolite membranes with c-axis orientation, self-transformation from B-containing porous gla ss disks w ith rough and uneven surfaces full of pits, have been in-situ prepared on the su bstrates surfaces in a mixed vapor of ethylenediamine, tri-n-propylamine a nd H 2O . The thickness of the membranes is ca. 60 μm. Under the conditions of 20 ℃ and 0.1 MPa pressure difference, the permeabilities of H 2, O 2 and N 2 thro ugh the calcined B-Al-ZSM-5 zeolite membranes are 2 298×10 -8 , 1 176 ×10 -8 and 1 368×10 -9 mol/(m 2·s·Pa), respectively. The calculated values of ideal se lectivities of H 2 an d O 2 over N 2 are 16 8 and 8 60, respectively. The data indicate that the c alcin ed zeolite membranes are non-pinhole, non-crack, continuous and perfect.展开更多
In this article, we first study the trace for the heat kernel for the sub-Laplacian operator on the unit sphere in ? n+1. Then we survey some results on the spectral zeta function which is induced by the trace of the ...In this article, we first study the trace for the heat kernel for the sub-Laplacian operator on the unit sphere in ? n+1. Then we survey some results on the spectral zeta function which is induced by the trace of the heat kernel. In the second part of the paper, we discuss an isospectral problem in the CR setting.展开更多
文摘Continuous and perfect single-layer B-Al-ZSM-5 zeolite membranes with c-axis orientation, self-transformation from B-containing porous gla ss disks w ith rough and uneven surfaces full of pits, have been in-situ prepared on the su bstrates surfaces in a mixed vapor of ethylenediamine, tri-n-propylamine a nd H 2O . The thickness of the membranes is ca. 60 μm. Under the conditions of 20 ℃ and 0.1 MPa pressure difference, the permeabilities of H 2, O 2 and N 2 thro ugh the calcined B-Al-ZSM-5 zeolite membranes are 2 298×10 -8 , 1 176 ×10 -8 and 1 368×10 -9 mol/(m 2·s·Pa), respectively. The calculated values of ideal se lectivities of H 2 an d O 2 over N 2 are 16 8 and 8 60, respectively. The data indicate that the c alcin ed zeolite membranes are non-pinhole, non-crack, continuous and perfect.
基金supported by National Security Agency,United States Army Research Offfice and a Hong Kong RGC Competitive Earmarked Research (Grant No. 600607)
文摘In this article, we first study the trace for the heat kernel for the sub-Laplacian operator on the unit sphere in ? n+1. Then we survey some results on the spectral zeta function which is induced by the trace of the heat kernel. In the second part of the paper, we discuss an isospectral problem in the CR setting.
