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Jia-Yong Wang 《Experimental Mechanics》1990,30(4):367-371
This paper presents the numerical and analytical expressions for the relieved strain coefficients to take account of the size
of the gage grid when a drilled hole is off center with respect to the rosette center. It also presents a simple method for
calculation of these coefficients involving the reduction of the resistances of the side filaments. 相似文献
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建立了土壤中8种羟基化多溴联苯醚(Hydroxylated polybrominated diphenyl ethers,OH-PBDEs)的Qu ECh ERS-超高效液相色谱串联质谱(UPLC-MS/MS)分析方法。样品前处理采用Qu ECh ERS方法,土壤样品用水浸润之后,以甲酸和乙腈提取目标物,C18填料和正丙基乙二胺(PSA)净化,C18色谱柱分离,乙腈和水梯度洗脱,多反应监测负离子模式扫描。在最佳实验条件下,8种目标物在9 min内分离良好,并在2~200μg/L范围内线性良好,相关系数范围在0.9936~0.9990,检出限范围为0.23~1.21 ng/g。在5.0和50 ng/g 2个浓度水平6次平行加标实验中,8种OH-PBDEs平均回收率为73.2%~117.7%,相对标准偏差为5.6%~19.7%。本方法操作简便,灵敏度高,适用于大批量样品的快速分析。 相似文献
15.
Jia-Yong Wu 《Journal of Mathematical Analysis and Applications》2010,361(1):10-18
Let L=Δ−∇φ⋅∇ be a symmetric diffusion operator with an invariant measure on a complete Riemannian manifold. In this paper we give an upper bound estimate on the first eigenvalue of the diffusion operator L on the complete manifold with the m-dimensional Bakry-Émery Ricci curvature satisfying Ricm,n(L)?−(n−1), and therefore generalize a Cheng's result on the Laplacian (S.-Y. Cheng (1975) [8]) to the case of the diffusion operator. 相似文献
16.
We establish a one-parameter family of Harnack inequalities connecting the constrained trace Li–Yau differential Harnack inequality
for the heat equation to the constrained trace Chow–Hamilton Harnack inequality for the Ricci flow on a 2-dimensional closed
manifold with positive scalar curvature, and thereby generalize Chow’s interpolated Harnack inequality (J. Partial Diff. Eqs.
11 (1998), 137–140). 相似文献
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Zhang L Wang XC Gong QT Zhang L Luo L Zhao S Yu JY 《Journal of colloid and interface science》2008,327(2):451-458
The dilational rheological properties of absorbed film of three pairs of structural isomers, tri-substituted alkyl benzene sulfonates, at the air-water and decane-water interfaces have been investigated by drop shape analysis method. The influences of bulk concentration on dilational elasticity and viscosity were expounded. Interfacial tension relaxation method was employed to obtain dilational parameters in a reasonably broad frequency range. The experimental results showed that the meta-alkyl to sulfonate group plays a crucial role in the interfacial dilational properties: the longer meta-alkyl will lead to higher dilational parameters for air-water interface and lower ones for decane-water interface when the total alkyl carbon numbers are equal. For alkyl benzene sulfonates with shorter meta-alkyl, the surface dilational properties are similar to interfacial dilational properties, whereas the surface dilational parameters are obviously higher than the interfacial dilational parameters for alkyl benzene sulfonates with longer meta-alkyl in general. The possible mechanism has been proposed and ensured by Cole-Cole plots. 相似文献
19.
Polymeric surfactants are used extensively in food and pharmaceutical industry. It can be used as a flocculant agent for separation of solid-liquid in the down-stream of chemical engineering, and also as an emulsifier/demulsifier in food industry. In order to understand the mechanism of adsorption of polymer towards particles, it is important to detect the adsorption amount of polymer on the surface of particles. 相似文献
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