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拓扑空间的次分离性
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作者 荆佩 李生刚 +1 位作者 伏文清 曹婷 《西安石油大学学报(自然科学版)》 CAS 北大核心 2012年第5期106-110,12,共5页
旨在研究T4拓扑空间的一般化.为此定义了拓扑空间的次T2、次正则、次正规、遗传次正规等次分离性,详细地讨论了它们之间以及它们与已有分离性之间的联系,并且研究了这些次分离性的遗传性、可乘性以及与Wallman紧化和非标准紧化的联系.
关键词 次T2空间 次正则空间 次正规空间 遗传次正规空间 似仿紧空间 闭映射 Wallman紧化 非标准紧化
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Commuting Involutions with Fixed Point Set of Constant Codimension 被引量:6
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作者 Yanying Wang Zhende Wu Yanhong Ding, Department of Mathematics, Hebei Normal University, Shijiazhuang 050016, P. R. China 《Acta Mathematica Sinica,English Series》 SCIE CSCD 1999年第2期181-186,共6页
Special generators of the unoriented cobordism ring MO* are constructed to determine the groups J<sub>n,k</sub><sup>τ</sup> of n-dimensional cobordism classes in MO<sub>n</sub> con... Special generators of the unoriented cobordism ring MO* are constructed to determine the groups J<sub>n,k</sub><sup>τ</sup> of n-dimensional cobordism classes in MO<sub>n</sub> containing a representative M<sup>n</sup> admitting a (Z<sub>2</sub>)<sup>k</sup> -action with fixed point set of constant codimension. 展开更多
关键词 Cobordism class Fixed point set Projective space bundle (Z<sub>2sub>)k-action
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Low-Temperature Selective Catalytic Reduction of NO with NH_3 over Fe–Ce–O_x Catalysts 被引量:5
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作者 Yan Sun Ying Guo +1 位作者 Wei Su Yajuan Wei 《Transactions of Tianjin University》 EI CAS 2017年第1期35-42,共8页
In this study, we used a simple impregnation method to prepare Fe-Ce-O<sub> x </sub> catalysts and tested them regarding their low-temperature (200-300 °C) selective catalytic reduction (SCR) of ... In this study, we used a simple impregnation method to prepare Fe-Ce-O<sub> x </sub> catalysts and tested them regarding their low-temperature (200-300 °C) selective catalytic reduction (SCR) of NO using NH<sub>3</sub>. We investigated the effects of Fe/Ce molar ratio, the gas hourly space velocity (GHSV), the stability and SO<sub>2</sub>/H<sub>2</sub>O resistance of the catalysts. The results showed that the FeCe(1:6)O<sub> x </sub> (Ce/Fe molar ratio is 1:6) catalyst, which has some ordered parallel channels, exhibited good SCR performance. The FeCe(1:6)O<sub> x </sub> catalyst had the highest NO conversion with an activity of 94-99% at temperatures between 200 and 300 °C at a space velocity of 28,800 h<sup>−1</sup>. The NO conversion for the FeCe(1:6)O<sub> x </sub> catalyst also reached 80-98% between 200 and 300 °C at a space velocity of 204,000 h<sup>−1</sup>. In addition, the FeCe(1:6)O<sub> x </sub> catalyst demonstrated good stability in a 10-h SCR reaction at 200-300 °C. Even in the presence of SO<sub>2</sub> and H<sub>2</sub>O, the FeCe(1:6)O<sub> x </sub> catalyst exhibited good SCR performance. 展开更多
关键词 Fe-Ce-O<sub> x sub> Low-temperature selective catalytic reduction Fe/Ce molar ratio Gas hourly space velocity Stability SO<sub>2sub>/H<sub>2sub>O resistance
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Ceramide induces release of mitochondrial proapop-totic proteins in caspase-dependent and -independent manner in HT-29 cells 被引量:5
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作者 ZHANG XiaoFeng1, LI BaiXiang1, ZHANG Yang1 & LIU JiaRen2 1 Public Health College, Harbin Medical University, Harbin 150081, China 2 Department of Food Science, Cornell University, New York 14853-7201, USA 《Science China(Life Sciences)》 SCIE CAS 2008年第1期66-71,共6页
In this study, the release of mitochondrial proapoptotic intermembrane space proteins induced by ex-ogenous C2-ceramide in human colon carcinoma (HT-29) cell line was investigated. HT-29 cells were treated with 12.5, ... In this study, the release of mitochondrial proapoptotic intermembrane space proteins induced by ex-ogenous C2-ceramide in human colon carcinoma (HT-29) cell line was investigated. HT-29 cells were treated with 12.5, 25 and 50 μmol/L C2-ceramide in vitro. Flow cytometer was used to detect the mito-chondrial membrane potential (ΔΨm). Subcellular fractions were extracted by Mitochondrial/Cytosol Fractionation Kit after C2-ceramide treatment for 24 h. SDS-PAGE was used to determine the level of cytochrome c (Cyt c), high temperature requirement A2 (HtrA2) and second mitochondrial-derived ac-tivator of caspases (Smac) released from mitochondria, the expression of X-linked inhibitor of apop-tosis protein (XIAP) and caspase-3 for 24 h. The results showed that ΔΨm began to decrease from 6 h after 25 and 50 μmol/L C2-ceramide treatment (P<0.05) and cyclosporin A (CsA) could inhibit the col-lapse of ΔΨm through regulating mitochondrial membrane permeability transition pore. There was no effect of C2-ceramide on the expression of Cyt c, HtrA2 and Smac in the total levels. 12.5, 25 and 50 μmol/L C2-ceramide could induce Cyt c, HtrA2 and Smac to release from mitochondria to cytosol and down-regulate the expression of XIAP (P<0.05). Also there was expression of cleaved caspase-3 with C2-ceramide treatment. After the treatment with caspase inhibitor, C2-ceramide still induced the release of Cyt c and HtrA2, but Smac did not. Therefore, C2-ceramide could induce apoptosis of HT-29 cells through the mitochondria pathway. The release of Cyt c, HtrA2 and Smac from mitochondria did not occur via the same mechanism, the release of Cyt c and HtrA2 was caspase-independent and the re-lease of Smac was caspase-dependent. 展开更多
关键词 C_2-ceramide mitochondria proapoptotic intermembrane space proteins mitochondrial membrane potential human colon carcinoma cells CASPASE
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Commuting Involutions with Fixed Point Set of Variable Codimension 被引量:1
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作者 Yan Ying WANG Zhen De WU Zhao Jing MENG Department of Mathematics,Hebei Normal University,Shijiazhuang 050016.P.R.China E-mail:Wang Yangying@263.net 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2001年第3期425-430,共6页
Special generators of the unoriented cobordism ring MO<sub>*</sub> are constructed to determine some groups J<sub>n,k</sub><sup>l<sub>1</sub>,l<sub>2</sub>,…,l<... Special generators of the unoriented cobordism ring MO<sub>*</sub> are constructed to determine some groups J<sub>n,k</sub><sup>l<sub>1</sub>,l<sub>2</sub>,…,l<sub>m</sub></sup> of cobordism classes in MO<sub>n</sub> containing a representative M<sup>n</sup> admitting a (Z<sub>2</sub>)<sup>k</sup>-action with the fixed point set of(n-l<sub>i</sub>)-dimensional submanifolds of M<sup>n</sup>. 展开更多
关键词 Indecomposable class Fixed point set Projective space bundle (Z<sub>2sub>)k-action
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K-Spaces Property of Product Spaces 被引量:1
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作者 Liu Chuan Lin Shou Department of Mathematics, Guangxi University, Nanning 530004, China Department of Mathematics, Ningde Teachers College, Fujian 352100, China 《Acta Mathematica Sinica,English Series》 SCIE CSCD 1997年第4期537-544,共8页
Let K be a class of spaces which are eigher a pseudo-open s-image of a metric space or a k-space having a compact-countable closed k-network. Let K′ be a class of spaces which are either a Fréchet space with a p... Let K be a class of spaces which are eigher a pseudo-open s-image of a metric space or a k-space having a compact-countable closed k-network. Let K′ be a class of spaces which are either a Fréchet space with a point-countable k-network or a point-G_δ k-space having a compact-countable k-network. In this paper, we obtain some sufficient and necessary conditions that the products of finitely or countably many spaces in the class K or K′ are a k-space. The main results are that Theorem A If X, Y ∈ K. Then X x Y is a k-space if and only if (X, Y) has the Tanaka’s condition. Theorem B The following are equivalent: (a) BF(w2) is false. (b) For each X, Y ∈ K′, X x Y is a k-space if and only if (X, Y) has the Tanaka’s condition. 展开更多
关键词 K--space K--network Weak base Product space BF(ω<sub>2sub>) Tanaka’s condition
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Statistical Multi-Fragmentation in Hot Compound Nuclei
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作者 G.X.Dai H.Y.Wu L.M.Duan Z.Y.Li Q.Z.Luo Z.Y.He B.G.Zhang W.X.Wen Institute of Modern Physics,the Chinese Academy of Scienoes,P.O.Bax 31,Lanzhou 730000 《Chinese journal of nuclear physics》 1996年第4期187-199,共13页
The first three-fold and four-fold fragmentation measurements in hot compound nuclei pro-duced in the reactions of a 25 MeV/u <sup>40</sup>At beam with targets of <sup>209</sup>Bi,<sup>19... The first three-fold and four-fold fragmentation measurements in hot compound nuclei pro-duced in the reactions of a 25 MeV/u <sup>40</sup>At beam with targets of <sup>209</sup>Bi,<sup>197</sup>Au,<sup>159</sup>Tb,<sup>115</sup>In,<sup>103</sup>Rh,and<sup>93</sup>Nb are presented.Various distributions are measured for these fragments,including distributions of ve-locities,relative velocities,angles,relative angles,masses,fragment mass ratios,total kinetic energies(TKE),as well as the yield ratios of three-fold fragmentation to fission P<sub>32</sub> and the time difference △t be-tween two scissions after the formation of one compound nucleus. 展开更多
关键词 —Three-fold and four-fold fragmentation SCISSION time difference Yield ratio P<sub>3sub>2 BIAXIAL DEFORMATION TRIAXIAL DEFORMATION space-time model
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π_1空间上循环自共轭算子的谱系特型
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作者 陈铭 《青海师范大学学报(自然科学版)》 1992年第3期20-22,共3页
本文利用πk上自共轭算子的三角模型刻画给出了π1上循环自共轭算子的谱系特型,从而指出了在不定度规空间上建立自共轭算子相应谱测度的极为困难性。
关键词 π<sub>1sub>空间 自共轭算子 π<sub>2sub>空间 循环自共轭算子 谱系
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Musielak-Orlicz空间的可微性
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作者 叶以宁 吕世兴 黄亚锋 《哈尔滨商业大学学报(自然科学版)》 CAS 1991年第6期36-41,51,共7页
给出了Musielak—Orlicz空间L_M~*具G-可微性的充要条件及梯度表达式。
关键词 MUSIELAK-ORLICZ空间 G—可微 △<sub>2sub>条件
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再生核空间W_2~1(R)中的分段投影插值
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作者 谢树森 《山东理工大学学报(自然科学版)》 CAS 1994年第3期35-38,共4页
本文在具有再生核的空间W<sub>2</sub><sup>1</sup>(R)中讨论分段插值问题,给出W<sub>2</sub><sup>1</sup>(R)的再生核的解析式,并构造一个分段插值公式。
关键词 W<sub>2sub>1(R)空间 再生核 分段插值
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