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51.
对 Duhamel积分引入了改进的脉冲响应函数 ,建立了激励演变谱矩阵与总动力响应演变谱之间的关系 ,并对实际大跨度斜拉桥进行了数值计算。这一成果实现了全面考虑各种地震动时空变化特性下的直接求解结构总动力响应的时域法和频域法计算列式 ,使得地震动多点激励下考虑拟静力位移影响的结构响应计算过程大为简化。  相似文献   
52.
In the paper, generalized orders and generalized types of Dirichlet series in the right half-plane are given. Some interesting relationships on maximum modulus, the maximum term and the coefficients of entire function defined by Dirichlet series of in the right half-plane are obtained.  相似文献   
53.
54.
Regarding gel poly (vinyl alcohol)/H3PW12O40 as precursor, the ultra-fine fibers tungsten oxide (WO3) was prepared by using electrospinning and calcinating techniques. Scanning electron microscope (SEM) shows that the average diameter of fibrous WO3 were changed from 200 nm to 600 nm after calcined PVA/H3PW12O40 fibers at 600 and 800 °C, respectively. X-ray diffraction (XRD) and Raman spectroscope revealed that the fibrous WO3 was monoclinic phase, and the band-gap energies were observed by UV-vis diffuse reflectance spectra. The small size WO3 exhibits excellent photocatalytcic activity in degradation of Rhodamine B at 365 nm wavelength.  相似文献   
55.
In situ viscosity kinetics models for blue light induced radical polymerization of acrylamide (AM) were proposed and established with camphorquinone/4-(dimethylamino)-2-ethylbenzoate/diphenyl iodonium hexafluorophosphateas the photoinitiators. In order to minimize the impact of shear effect on polymer network, a constant shear stress technique of photo-rheometry was proposed to characterize in-situ viscosity behavior of acrylamide solution during the photopolymerization. The effect of various factors, for example, the dosages of initiator, monomer, and light intensities, on viscosity, polymerization and gelation behavior of AM solution was systematically analyzed. The viscosity advancement behavior was shaped by the joint action of the movement, growth and entanglement of molecular chains, and shear orientation. Different power-law kinetic models were found in three curves, time-related viscosity, shear rate-related viscosity and time-related shear rate. Such school of thought on constructing the viscosity advancement model provides a new theory and method of systematical studying on the photorheological theories. Furthermore, a trinitarian theoretical model that represented the access from the microscopic kinetics of free radical polymerization to the movement behavior of polymer chains was successfully established by mapping the photoinduced viscosity kinetics model onto the polymerization and crosslinking kinetics model.  相似文献   
56.
一种制作多色彩全息图的新方法   总被引:2,自引:0,他引:2  
本文首先提出了一种制作二维透射物彩虹全息图的新方法,即利用一专门设计的全息光学元件──色编码板,采用单光束制作所需物体的彩虹全息图;在此基础上,通过对色编码板的进一步理论设计,制作了一组对应不同主波长的色编码板,实现了记录物体的多色彩虹再现全息图。实验结果表明,此方案简便易行,光路布置灵活性高,且能有效地消除纵向色差的影响,特别适合于模压全息图制造中母全息图的拍摄,并降低了对环境稳定性的要求。  相似文献   
57.
对Cn中某一Reinhardt域上以及复Hilbert空间单位球上推广的Roper-Suffridge算子保持α(0<α<1)次的β(-π/2<β<π/2)型螺形性进行了讨论.所得的结果推广了以前相应的结论.  相似文献   
58.
Two new spirostanol saponins, (25S)-spirostane-1β,3β,5β-trio1 3-O-β-D-glucopyranoide 1 and rhodeasapogenin 3-O-β-D-glucopyranosyl-(1→4)-β-D-glucopyranoside 2, together with a known saponin, rhodeasapogenin 3-O-β-D-glucopyranoside 3, were isolated from the underground parts of Tupistra chinensis Bak.. Their structures were determined by spectroscopic analysis.  相似文献   
59.
Using a computational model, we investigate the motion of microcapsules inside a microchannel that encompasses a narrow constriction. The microcapsules are composed of a compliant, elastic shell and an encapsulated fluid; these fluid-filled shells model synthetic polymeric microcapsules or biological cells (e.g., leukocytes). Driven by an imposed flow, the capsules are propelled along the microchannel and through the constricted region, which is formed by two pillars that lie in registry, extending from the top and bottom walls of the channels. The tops of these pillars (facing into the microchannel) are modified to exhibit either a neutral or an attractive interaction with the microcapsules. The pillars (and constriction) model topological features that can be introduced into microfluidic devices or the physical and chemical heterogeneities that are inherently present in biological vessels. To simulate the behavior of this complex system, we employ a hybrid method that integrates the lattice Boltzmann model (LBM) for fluid dynamics and the lattice spring model (LSM) for the micromechanics of elastic solids. Through this LBM/LSM technique, we probe how the capsule's stiffness and interaction with the pillars affect its passage through the chambers. The results yield guidelines for regulating the movement of microcarriers in microfluidic systems and provide insight into the flow properties of biological cells in capillaries.  相似文献   
60.
采用(NH4)2SO4分步沉淀法对诺维信中国公司生产的漆酶制剂DeniLiteIIS进行了纯化,并用丁二酸酐(SA)对纯化酶进行了化学修饰,运用三硝基苯磺酸法、紫外光谱法及荧光光谱法对修饰效果进行了初步表征,比较了天然酶和修饰酶的pH稳定性、热稳定性及除酚效率.结果表明,修饰酶的平均氨基修饰度为85%,其紫外吸收峰和荧光发射峰均出现蓝移,而且紫外吸收减小、荧光强度增加.尽管采用SA化学修饰未能改变漆酶的最适反应温度,但使其最适反应pH值由4.5提高到5.5,并且使酶活提高60%.与天然酶相比,修饰酶的pH稳定性和热稳定性更高,催化效率(kcat)和酶与底物的亲和力(kcat/Km)分别提高了53%和122%,对邻、间和对苯二酚的除酚效率分别提高了48%,57%和18%.这预示着这些修饰漆酶可望应用于工业生产和酚类污染废水的治理.  相似文献   
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