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31.
32.
Congo red (CR) is an azo dye which not only preferentially binds to elastin, an extracellular matrix protein found in the media of arterial vessel walls, but also fluoresces when it binds to this protein. Protein solubilization data following laser irradiation of elastin:CR suspensions determined that the amount of elastin solubilized by laser irradiation increased with the increase in CR. The saturation point of CR to elastin was attained when 400 g CR was added to 20 mg elastin suspension. When 20 ml of a 5% CR solution in 5% dextrose was administered intravenously, the CR was absorbed in levels sufficient to produce fluorescence of the main arteries in rabbits. Layers of tissue both in the media of the vessels and at the endothelial/intimal interface were clearly differentiated. Therefore, the elastin:CR complex appears to be an ideal system in which the elastin fluorescence could aid in distinguishing between normal and diseased tissue in certain pathological conditions, such as atherosclerosis and some types of breast tumors.  相似文献   
33.
Carbon nanohoop,a class of constrained molecular architecture consisting of linked arene units,has attracted considerable interest from both experimental and th...  相似文献   
34.
金占雷  谭久彬  张山  王雷 《光学学报》2008,29(9):1730-1734
为了提高激光直写加工衍射光学元件时的线条质量,提出一种离焦激光直写的线宽稳定方法.该方法通过同时调节激光功率和离焦量,使光刻胶的曝光阈值处于线宽对曝光量的变化率较小位置,从而可以弱化线宽对实际曝光量或光刻胶阈值等变化的敏感度,提高利用离焦方法进行衍射光学元件制作时的线宽稳定性.推导了稳定线宽后的光功率控制模型和线宽模型,模型中的变量仅为离焦量,降低了光功率控制的复杂性.利用632.8 nm的He-Ne激光和NA-0.1的物镜在CCD上对采用该方法后的离焦线宽模型进行验证,实验结果与理论模型吻合较好.该方法对于线宽稳定度较高的衍射光学元件制作具有重要价值.  相似文献   
35.
To develop new compounds with high activity, broad spectrum and low-toxicity, 17 benzamides substituted with quinoline-linked 1,2,4-oxadiazole were designed using the splicing principle of active substructures and were synthesized. The biological activities were evaluated against 10 fungi, indicating that some of the synthetic compounds showed excellent fungicidal activities. For example, at 50 mg/L, the inhibitory activity of 13p (3-Cl-4-Cl substituted, 86.1%) against Sclerotinia sclerotiorum was superior to that of quinoxyfen (77.8%), and the inhibitory activity of 13f (3-CF3 substituted, 77.8%) was comparable to that of quinoxyfen. The fungicidal activities of 13f and 13p to Sclerotinia sclerotiorum were better than that of quinoxyfen (14.19 mg/L), with EC50 of 6.67 mg/L and 5.17 mg/L, respectively. Furthermore, the acute toxicity of 13p was 19.42 mg/L, classifying it as a low-toxic compound.  相似文献   
36.
As the most advanced aerogel material, silica aerogel has had transformative industrial impacts. However, the use of silica aerogel is currently limited to the field of thermal insulation materials, so it is urgent to expand its application into other fields. In this work, silica aerogel/resin composites were successfully prepared by combining silica aerogel with a resin matrix for dental restoration. The applications of this material in the field of dental restoration, as well as its performance, are discussed in depth. It was demonstrated that, when the ratio of the resin matrix Bis-GMA to TEGDMA was 1:1, and the content of silica aerogel with 50 μm particle size was 12.5%, the composite achieved excellent mechanical properties. The flexural strength of the silica aerogel/resin composite reached 62.9546 MPa, which was more than five times that of the pure resin. Due to the presence of the silica aerogel, the composite also demonstrated outstanding antibacterial capabilities, meeting the demand for antimicrobial properties in dental materials. This work successfully investigated the prospect of using commercially available silica aerogels in dental restorative materials; we provide an easy method for using silica aerogels as dental restorative materials, as well as a reference for their application in the field of biomedical materials.  相似文献   
37.
 运用序列二次规划法设计了靶区光路。由ICF 柱面靶间接驱动实验对多路激光束排布的要求, 建立靶区数学模型, 用本文设计结果构筑光路排布线框实体。该三维线框以特征线代表60路激光驱动光束实体, 以特征线段的转折点代表240面反射镜的空间位置。  相似文献   
38.
基于质量守恒和Fick第一定律,模拟了水滴在超疏水聚合物表面的蒸发全过程.研究从以往的接触角<90±扩展到>150±,液滴形貌扩展为椭球球帽模型进行疏水表面蒸发模拟.水滴在超疏水PC和FPU/PMMA表面蒸发的实验结果显示,计算的椭球球帽模型可以更好的反映出液滴接触角和高度的变化情况,并且不同聚合物表面接触角的相同变化趋势也揭示出微-纳二级结构表面结构不仅影响液滴接触角,也影响液滴蒸发模式.  相似文献   
39.
谭文长 《中国物理》2006,15(11):2644-2650
Stokes' first problem has been investigated for a Maxwell fluid in a porous half-space for gaining insight into the effect of viscoelasticity on the start-up flow in a porous medium. An exact solution was obtained by using the Fourier sine transform. It was found that at large values of the relaxation time the velocity overshoot occurs obviously and the system exhibits viscoelastic behaviours. On the other hand, for short relaxation time the velocity overshoot disappears and the system exhibits viscous behaviours. A critical value of the relaxation time was obtained for the emergence of the velocity overshoot. Furthermore, it was found that the velocity overshoot is caused by both the viscoelasticity of the Maxwell fluid and the Darcy resistance resulting from the structure of the micropore in the porous medium.  相似文献   
40.
The filter made up of two gratings performs as a two-dimensional non-spatial filtering. This paper reports that the volume Bragg gratings are fabricated by interfering two collimated coherent laser beams in photopolymer. Diffraction efficiency of a single grating is up to 78% in Bragg's condition, then a two-dimensional non-spatial filter, which consists of two volume Bragg gratings and a half-wave plate, enables the laser beam filtered in two dimensions with the diffraction efficiency of 54%. The Bragg's condition and effect of polarisation on performances of the two-dimension filter are also discussed.  相似文献   
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