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排序方式: 共有206条查询结果,搜索用时 31 毫秒
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Nonlinear Dynamics - Conventional tuned liquid column dampers (TLCDs) are deficient in multidirectionality. In contrast, toroidal TLCDs are designed to extend the application to multidirectional... 相似文献
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在正常金属铁磁绝缘层dx2-y2 idxy混合波超导隧道结中,考虑到铁磁绝缘层的磁散射和界面的粗糙散射效应,运用BogoliubovdeGennes(BdG)方程和BlonderTinkhamKlapwijk(BTK)理论,计算了隧道结中的准粒子传输系数和微分电导.研究表明:(1)磁散射和界面粗糙散射均可以压低电导峰,其中磁散射能使电导峰滑移,而粗糙界面散射却能阻止这种滑移,且两散射的共同作用可抑制由混合波两序参数的幅值比不同所导致的电导峰滑移;(2)随铁磁层离超导表面距离的增加,隧道谱在零偏压处由凹陷变成了零偏压电导峰,继而又演化为凹陷中的中心峰;(3)当铁磁层离开超导表面有若干相干长度时,隧道谱中将呈现一些子能级谐振峰. 相似文献
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时间分辨激光光散射测量系统 总被引:1,自引:1,他引:1
自选设计,装配了一套时间分辨的激光光散射测量系统,该系统摄像机,录像机,计算机和自编的软件实现了一体化的数据采集,显示和分析过程,本文给出了该系统的应用实例,球晶的光散射和环氧树脂的固化反应诱导的相分离过程。 相似文献
4.
CrOx/ SBA-15介孔催化剂上丙烷在二氧化碳气氛中脱氢反应的研究 总被引:2,自引:0,他引:2
The structure and catalytic properties based on Chromium Oxide supported on mesoporous SBA-15 for oxidative dehydrogenation of propane by CO2 have been studied by using X-ray diffraction (XRD), ultraviolet-visible diffuse reflectance spectra (UV-Vis DRS), electron spin resonance (ESR), X-ray photoelectron spectroscopy (XPS) and propane pulsing experiments in the absence of gas-phase O2. It has been shown that propane conversion and propene yield increase with Cr loadings. The propane conversion and propene yield on CrOx(Cr: 10wt%)/SBA-15 catalyst for oxidative dehydrogenation of propane by CO2 at 550 ℃ reach 24.8% and 21.8%, respectively .The results of ESR, UV-Vis DRS and propane pulsing experiments indicate that CrⅢ in the CrOx/ SBA-15 catalyst is the main active species in oxidative dehydrogenation of propane by CO2 and CrⅥ, CrⅤ is inactive in dehydrogenation. 相似文献
5.
SrTi0.9M0.1O3-δ钙钛矿型氧化物催化剂甲烷氧化偶联反应性能的研究 总被引:2,自引:0,他引:2
The structure and catalytic properties of SrTi0.9M0.1O3-δ (M=Mg,Al, Zr) perovskite-type catalysts for ox-idative coupling of methane (OCM) have been studied by using X-ray diffraction (XRD),X-ray photoelectron spectroscopy (XPS) and temperature-programmed desorption of oxygen(O2-TPD) methods. It has been shown that doping the cations of lower valence (e.g. Mg2+, Al3+) to the B site of SrTi0.9M0.1O3-δ perovskite-type catalysts results in the higher content of adsorbed oxygen species on the surface of catalysts and thus higher C2-selectivity for OCM reaction. It is suggested that the oxygen vacancies of SrTi0.9M0.1O3-δ (M=Mg, Al, Zr) perovskite-type catalysts are the sites responsible for oxygen activation, and the adsorbed oxygen species on the surface of SrTi0.9M0.1O3-δ catalysts are the main active species for OCM reaction. 相似文献
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水热合成了2个以D-樟脑酸(D-H2cam)与1,4-二(咪唑-1-基)丁烷(1,4-bimb)为配体的配位聚合物:[Co(D-cam)(1,4-bimb)]n·4nH2O(1)和[Ni(D-cam)(1,4-bimb)]n(2)。通过X-射线单晶衍射,元素分析,红外光谱,XRD分析,热重,和磁性分析对其结构进行了表征。测定了这两个聚合物的磁性。结构分析表明,1为P2空间群,其链状结构由氢键作用连接形成二维结构;2为Pna21空间群,呈四重穿插的dia网络结构。 相似文献
9.
Jian-Wen ShiHao-Jie Cui Jian-Wei ChenMing-Lai Fu Bin XuHong-Yuan Luo Zhi-Long Ye 《Journal of colloid and interface science》2012,388(1):201-208
In order to more easily separate TiO2 photocatalyst from the treated wastewater, TiO2 film was immobilized on the surface of activated carbon fibers (ACFs) by employing two kinds of coating procedures, dip-coating, and hydrothermal treatment. The effects of coating procedures on microstructure of TiO2-coated ACFs (TiO2/ACFs), such as morphology, porous property, crystal structure, and light absorption characteristics were investigated in detail. The adhesion property between TiO2 film and ACFs was evaluated by ultrasonic vibration, and the photocatalytic activity of TiO2/ACFs was tested by the photocatalytic decoloration of methylene blue solution. The results show that hydrothermal treatment presented many advantages to obtain high-performance TiO2/ACFs photocatalyst in comparison with dip-coating. Hydrothermal treatment could improve the binding property between TiO2 films and ACFs, which endowed the as-obtained TiO2/ACFs photocatalyst with improved reusable performance, and TiO2/ACFs synthesized by hydrothermal treatment presented higher photocatalytic activity. 相似文献
10.
Hydrothermal reactions of rare earth oxides with racemic tartaric acid (H2tar) yielded 7 rare earth(III) MOFs with general formulas [R2(tar)3(H2O)2]n (R=Y (1), Sm (4), Eu (5), Tb (6), Dy (7)) and [R2(tar)2(C2O4)(H2O)2]n·4nH2O (R=La (2), Nd (3)). X-ray powder diffraction analysis and single-crystal X-ray diffraction analysis reveal that they present two different structural types. MOFs 1, 4, 5, 6 and 7 are isostructural and crystallize in the orthorhombic non-centrosymmetric space group Iba2, and feature unusual fsc-3,4-Iba2 topology. MOFs 2 and 3 are isostructural and crystallize in monoclinic P21/c space group and display rare fsx-4,5-P21/c topology containing hydrophilic channels bounded by triple helical chains along a axis. MOFs 3, 4, 5, 6 and 7 exhibit intense lanthanide characteristic photoluminescence at room temperature. 相似文献