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191.
Víctor Leiva 《商业与工业应用随机模型》2019,35(1):133-137
Sam C. Saunders, the son of Elizabeth Cundiff and Winston E. Saunders, was born in Richland, OR, on February 24, 1931. The family moved to La Grande, OR, in 1944, where Sam completed high school and two years at Eastern Oregon College. He then received the BSc degree in Mathematics from the University of Oregon, Eugene, OR, in 1952, and he attended the University of Washington, Seattle, WA, receiving a PhD degree under Z. W. Birnbaum. After graduating, he accepted employment at the Boeing Company in its Mathematical Services Unit and, in 1972, a position as a Full Professor at Washington State University, Pullman, WA, from which he retired in 1996. 相似文献
192.
制备低亚表面损伤的超光滑光学基底,是获得高损伤阈值薄膜的前提条件。针对石英材料在不同加工工序中引入亚表面损伤层的差异,首先利用共焦显微成像结合光散射的层析扫描技术,对W10和W5牌号SiC磨料研磨后的亚表面缺陷进行了检测,讨论了缺陷尺寸与散射信号强度、磨料粒径与损伤层深度间的对应关系;同时,采用化学腐蚀处理技术对抛光后样品的亚表面形貌进行了刻蚀研究,分析了化学反应生成物和亚表面缺陷对刻蚀速率的影响、不同深度下亚表面缺陷的分布特征,以及均方根粗糙度与刻蚀深度间的联系。根据各道加工工艺的不同采用了相应的亚表面检测技术,由此来确定下一道加工工序,合理的去除深度,最终获得了极低亚表面损伤的超光滑光学基底。 相似文献
193.
Micropolar and micromorphic solids are continuum mechanics models, which take into account, in some sense, the microstructure of the considered real material. The characteristic property of such continua is that the state functions depend, besides the classical deformation of the macroscopic material body, also upon the deformation of the microcontinuum modeling the microstructure, and its gradient with respect to the space occupied by the material body. While micropolar plasticity theories, including non-linear isotropic and non-linear kinematic hardening, have been formulated, even for non-linear geometry, few works are known yet about the formulation of (finite deformation) micromorphic plasticity. It is the aim of the three papers (Parts I, II, and III) to demonstrate how micromorphic plasticity theories may be formulated in a thermodynamically consistent way.In the present article we start by outlining the framework of the theory. Especially, we confine attention to the theory of Mindlin on continua with microstructure, which is formulated for small deformations. After precising some conceptual aspects concerning the notion of microcontinuum, we work out a finite deformation version of theory, suitable for our aims. It is examined that resulting basic field equations are the same as in the non-linear theory of Eringen, which deals with a different definition of the microcontinuum. Furthermore, geometrical interpretations of strain and curvature tensors are elaborated. This allows to find out associated rates in a natural manner. Dual stress and double stress tensors, as well as associated rates, are then defined on the basis of the stress powers. This way, it is possible to relate strain tensors (respectively, micromorphic curvature tensors) and stress tensors (respectively, double stress tensors), as well as associated rates, independently of the particular constitutive properties. 相似文献
194.
采取355 nm激光脉冲辐照熔石英样品,利用Nomarski微分干涉差显微镜、原子力显微镜和扫描电子显微镜观测手段对前后表面产生的损伤点进行了观察分析。对前后表面损伤形态做出详细的描述和分类,从理论上对每种损伤类型产生的条件与机理做出推测。实验结果表明:熔石英前表面存在小麻点群损伤和星状裂纹损伤两种损伤形态,横向尺寸分别为0.8~2.5和1.0~5.5 μm;后表面存在小麻点群损伤、壳状剥离损伤和火山口3种损伤形态,损伤横向尺寸分别为0.48~1.33,4~20和12~30 μm。实验证明了1 μm尺度损伤点的产生与再沉积层密切相关。 相似文献
195.
Dr. Shumeng Li Prof. Yuncong Chen Yanping Wu Shankun Yao Hao Yuan Yehong Tan Fen Qi Prof. Weijiang He Prof. Zijian Guo 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(72):e202202680
Organelle-targeted type I photodynamic therapy (PDT) shows great potential to overcome the hypoxic microenvironment in solid tumors. The endoplasmic reticulum (ER) is an indispensable organelle in cells with important biological functions. When the ER is damaged due to the production of reactive oxygen species (ROS), the accumulation of misfolded proteins will interfere with ER homeostasis, resulting in ER stress. Here, an ER-targeted benzophenothiazine-based photosensitizer NBS-ER was presented. ER targeting modification significantly reduced the dark toxicity and improved phototoxicity index (PI). NBS-ER could effectively produce O2−⋅ with near-infrared irradiation, making its phototoxicity under hypoxia close to that under normoxia. Meanwhile, the photoinduced ROS triggered ER stress and induced apoptosis. In addition, NBS-ER possessed excellent photodynamic therapeutic effect in 4T1-tumor-bearing mice. 相似文献
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199.
研究了高功率激光装置光路中的分子级污染程度。采用专用空气采样动力设备及吸附管,在一定时间内对光路中的空气进行采样并作痕量分析后,得出了卤素、含硫化合物、可溶性胺类和氨、碳氢化合物 (C6~C16有机物) 4类物质在打靶前后的数密度变化。结果显示:除含硫化合物外,其余3种物质数密度超过了美国NIF标准的上限,其中氨和可溶性胺类、碳氢化合物的数密度超过较多;卤素、含硫化合物、氨和可溶性胺类的数密度在打靶后比打靶前有所降低,而碳氢化合物的数密度在打靶后比打靶前有所升高。结果表明在该装置中存在比较严重的气载分子污染物污染。分析了气载分子污染物数密度变化的原因以及可能的产生源,并对如何去除这些气载分子污染物提出了建议。 相似文献
200.
L. D. Bogomolova V. A. Jachkin S. A. Prushinsky S. A. Dmitriev S. V. Stefanovsky Yu. G. Teplyakov F. Caccavale E. Cattaruzza R. Bertoncello F. Trivillin 《Journal of Non》1997,210(2-3)
Radiation defects induced by ion bombardment of multicomponent oxide glasses of five compositions (phosphates and borosilicates) were investigated by means of electron paramagnetic resonance (EPR). The samples were implanted with N+, O+, Ar+, Mn+, Cu+ and Pb+ ions at energy E=150 keV at three different doses between 3×1015 and 1017 ions/cm2. The broad anisotropic EPR spectra with principal g-values answering the relationship gz>gy>gx˜ge (ge is g-factor of free electron) were observed for the samples of all five compositions. The g-values depend on glass composition. For example, gz ranges from 2.016 to 2.057. Computer simulation shows that the spectra of many samples are superpositions of two spectra with g-values answering the mentioned relationship. These spectra are attributed to molecular O2− ions weakly coupled with glass network. In some samples narrow almost symmetric lines with g=2.0025±0.0005 were observed. The possible radiation defects responsible for this signal are discussed. 相似文献