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1.
本文根据文[1]获得的多夹层扁壳非线性基本方程,求解了各种载荷及边界条件下矩形底面多夹层扁壳的非线性弯曲问题,多夹层板、扁柱亮在轴向压力作用下的稳定问题,以及一般形状的扁壳在边界作用力下的变形. 相似文献
2.
Advanced analytical models have been developed at the ILK, which offer a possibility of calculating the vibro-acoustic and damping behavior of textile-reinforced composite shells and plates with account of shear effects. The simulation models elaborated have been verified on selected examples, and the analytical results were fully corroborated by accompanying numerical calculations for typical lay-ups.__________Russian translation published in Mekhanika Kompozitnykh Materialov, Vol. 41, No. 3, pp. 289–302, May–June, 2005. 相似文献
3.
The authors consider the exact controllability of the vibrations of a thin shallow shell, of thickness 2εwith controls imposed on the lateral surface and at the top and bottom of the shell. Apart from proving the existence of exact controls, it is shown that the solutions of the three dimensional exact controllability problems converge, as the thickness of the shell goes to zero, to the solution of an exact controllability problem in two dimensions. 相似文献
4.
Enzymatic determination of phenols using peanut peroxidase 总被引:4,自引:0,他引:4
The influence of phenol and its derivatives on the kinetics of oxidation of aryldiamines (indicator-substrates) catalyzed by novel plant peroxidase—cationic peanut peroxidase—was studied. The character of influence of phenols on the kinetics of enzymatic oxidation of benzidine, o-dianisidine, and 3,3′,5,5′-tetramethylbenzidine (TMB) with hydrogen peroxide was found to depend on a correlation between redox properties of phenols and the indicator-substrate of peroxidase. Thus, the catalytic activity of peanut peroxidase is inhibited by phenols with redox potentials higher than that of aryldiamines mentioned above, whereas phenols with potentials below those of aryldiamines, play the role of second substrates of the enzyme. The enzymatic procedures for the determination of numerous phenols on the level of their concentrations 0.05–80 μM were developed using the reactions of benzidine, o-dianisidine, and TMB oxidation. Different analytical signals—the indicator reaction rate and the induction period duration—were used for the determination of phenols, belonging to various groups—the inhibitors and second substrates of the enzyme, respectively. 相似文献
5.
6.
Laura S. Zamorano Francisco Gavilanes Ivan Yu. Sakharov Robert B. van Huystee Valery L. Shnyrov 《Thermochimica Acta》2004,417(1):67-73
Detailed differential scanning calorimetry (DSC), steady-state tryptophan fluorescence and far-UV circular dichroism (CD) studies, together with enzymatic assays, were carried out to monitor the thermal stability of anionic peanut peroxidase (aPrx) at pH 3.0. The spectral parameters were seen to be good complements to the highly sensitive but integral method of DSC. Thus, changes in far-UV CD corresponded to changes in the overall secondary structure of the enzyme, while changes in intrinsic tryptophan fluorescence emission corresponded to changes in the tertiary structure of the enzyme. The results, supported with data concerning changes in enzymatic activity with temperature, show that thermally induced transitions for aPrx are irreversible and strongly dependent upon the scan rate, suggesting that denaturation is under kinetic control. It is shown that the process of aPrx denaturation can be interpreted with sufficient accuracy in terms of the simple kinetic scheme, , where k is a first-order kinetic constant that changes with temperature, as given by the Arrhenius equation; N is the native state, and D is the denatured state. On the basis of this model, the parameters of the Arrhenius equation were calculated. 相似文献
7.
本文从顺序扫描式双通道电感耦合等离子体原子发射光谱仪(ICP-AES)的特点出发,对微克级介形虫壳体样品中的低含量元素选择最灵敏谱线和最佳通道,对各项条件进行最优化。Mg、Sr、Mn、Fe、Ba、Zn的检测限分别为0.6~5.2μg/L,Ca和Na的检测限分别为16μg/L和52μg/L,测定了微克级样品的多元素含量,回收率为90%~106%。 相似文献
8.
Wen HW Borejsza-Wysocki W DeCory TR Durst RA 《Analytical and bioanalytical chemistry》2005,382(5):1217-1226
A competitive lateral flow assay for detecting the major peanut allergen, Ara h1, has been developed. The detector reagents are Ara h1-tagged liposomes, and the capture reagents are anti-Ara h1 polyclonal antibodies. Two types of rabbit polyclonal antibodies were raised either against the entire Ara h1 molecules (anti-Ara h1 Ab) or against an immunodominant epitope on Ara h1 (anti-peptide Ab). All of them reacted specifically with Ara h1 in Western Blot against crude peanut proteins. Moreover, the anti-Ara h1 Ab was chosen for this assay development because of its highest immunoactivity to Ara h1-tagged liposomes in the lateral flow assay. The calculated limit of detection (LOD) of this assay is 0.45 g mL–1 of Ara h1 with a dynamic range between 0.1 and 10 g mL–1 of Ara h1 in buffer. Additionally, the visually determined detection range is from 1 to 10 g mL–1 of Ara h1 in buffer. Results using this assay can be obtained within 30 min without the need of sophisticated equipment or techniques; therefore, this lateral flow assay has the potential to be a cost-effective, fast, simple, and sensitive method for on-site screening of peanut allergens. 相似文献
9.
扁球面网壳的混沌运动研究 总被引:3,自引:0,他引:3
在圆形三向网架非线性动力学基本方程的基础上,用拟壳法给出了圆底扁球面三向网壳的非线性动力学基本方程.在固定边界条件下,引入了异于等厚度壳的无量纲量,对基本方程和边界条件进行无量纲化,通过Galerkin作用得到了一个含二次、三次的非线性动力学方程.为求Melnikov函数,对一类非线性动力系统的自由振动方程进行了求解,得到了此类问题的准确解.在无激励情况下,讨论了稳定性问题.在外激励情况下,通过求Melnikov函数,给出了可能发生混沌运动的条件.通过数字仿真绘出了平面相图,证实了混沌运动的存在. 相似文献
10.
The rod-shaped Co-Ni-P shells were prepared by metalling Bacillus. The microstructures and composition of the shells were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive analysis (EDS). The electromagnetic parameters were measured by the coaxial line method in the frequency of 2-18 GHz. It was found that the Bacillus were successfully coated with Co-Ni-P, and the inner structure of the shells are hollow in structure. The shells exhibit excellent microwave absorption properties in 5-17 GHz frequency. The microwave reflection loss is above −10 dB in 5.38-16.6 GHz frequency. The maximum microwave reflection loss reaches −35.83 dB at 9.12 GHz for samples thickness 2.4 mm, and the widest bandwidth for microwave reflection loss above −10 dB is about ∼5.32 GHz for samples thickness 2.0 mm. These results confirm the feasibility of applying Bacillus as biotemplates for fabrication of the metallic shells as lightweight microwave absorption materials are very promising for applications. 相似文献