A series of MCM 41 molecular sieves have been prepared on an industrial scale, and the effect of preparation factors such as aging temperature, pH values on the structure and pore distribution of the MCM 41 product ...A series of MCM 41 molecular sieves have been prepared on an industrial scale, and the effect of preparation factors such as aging temperature, pH values on the structure and pore distribution of the MCM 41 product have been studied by using X ray diffraction(XRD), thermogravimetric(TG) and electron microscopy(TEM). It is shown that the pH values have a significant effect on the crystallinity of the synthesized product. Under proper conditions, the MCM 41 prepared on an industrial scale has the same performance as the samples prepared on an Lab scale. The prepared MCM 41 was used as a modifier of zeolite Y for fluid catalytic cracking(FCC) of residual oil. It is shown that the addition of the MCM 41 in the zeolite Y catalyst increases the pore size, and surface area of the catalysts, which helps to increase the yield of gasoline and diesel and decrease the production of gaseous product and carbon deposition in the catalyst. The better performance of the MCM 41 modified zeolite Y catalyst is believed to be due to its adjustment on the acidity and increase of the pore size.展开更多
Let A be a completely decomposable homogeneous torsion-free abelian group of rank n(n≥2).Let m(n)=A×(a)be the split extension of A by an automorphismαwhich is a cyclic permutation of the direct components twist...Let A be a completely decomposable homogeneous torsion-free abelian group of rank n(n≥2).Let m(n)=A×(a)be the split extension of A by an automorphismαwhich is a cyclic permutation of the direct components twisted by a rational integer m.Then Om(n)is an infinite soluble group.In this paper,the residual finiteness of Om(n)is investigated.展开更多
Let F be a saturated fusion system over a finite p-group S, and let Z ≤ Zn （F）, which is strongly closed in S with respect to F. In this paper, we prove that there is a natural bijection from the set of normal subs...Let F be a saturated fusion system over a finite p-group S, and let Z ≤ Zn （F）, which is strongly closed in S with respect to F. In this paper, we prove that there is a natural bijection from the set of normal subsystems of 7 containing Z to the set of normal subsystems of the factor system F＋ =F/Z. This generalizes a result of Aschbacher.展开更多
文摘A series of MCM 41 molecular sieves have been prepared on an industrial scale, and the effect of preparation factors such as aging temperature, pH values on the structure and pore distribution of the MCM 41 product have been studied by using X ray diffraction(XRD), thermogravimetric(TG) and electron microscopy(TEM). It is shown that the pH values have a significant effect on the crystallinity of the synthesized product. Under proper conditions, the MCM 41 prepared on an industrial scale has the same performance as the samples prepared on an Lab scale. The prepared MCM 41 was used as a modifier of zeolite Y for fluid catalytic cracking(FCC) of residual oil. It is shown that the addition of the MCM 41 in the zeolite Y catalyst increases the pore size, and surface area of the catalysts, which helps to increase the yield of gasoline and diesel and decrease the production of gaseous product and carbon deposition in the catalyst. The better performance of the MCM 41 modified zeolite Y catalyst is believed to be due to its adjustment on the acidity and increase of the pore size.
基金Supported by the National Natural Science Foundation of China(Grant No.11771129,11971155,12071117).
文摘Let A be a completely decomposable homogeneous torsion-free abelian group of rank n(n≥2).Let m(n)=A×(a)be the split extension of A by an automorphismαwhich is a cyclic permutation of the direct components twisted by a rational integer m.Then Om(n)is an infinite soluble group.In this paper,the residual finiteness of Om(n)is investigated.
基金This research is supported by the National Natural Science Foundation of China under Grant No. 10771015 and the Start-Up Funds for Doctoral Scientific Research of Shandong University of Finance.
基金supported by the National Natural Science Foundation of China under Grant Nos.11126243 and 11071015Funding Project for Academic Human Resources Development in Institutions of Higher Learning under the Jurisdiction of Beijing Municipality(PHR 201107123)School Scientific Found under Grant No. 101002207
文摘Let F be a saturated fusion system over a finite p-group S, and let Z ≤ Zn （F）, which is strongly closed in S with respect to F. In this paper, we prove that there is a natural bijection from the set of normal subsystems of 7 containing Z to the set of normal subsystems of the factor system F＋ =F/Z. This generalizes a result of Aschbacher.
