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991.
采用氨水浸渍法制备氮掺杂Ti O2,在掺氮前,对沉淀法制备的无定形Ti O2粉末进行不同温度的煅烧,考察样品的前处理温度对掺氮效果的影响。实验证明,氮掺杂对Ti O2的晶相组成、晶粒尺寸和比表面积影响很小,所制备的掺氮样品具有可见光吸收,其中又以120TN样品的可见光吸收最显著。可见光光催化反应实验结果表明,掺氮样品(120TN)对乙烯的转化率为14.6%,矿化率92.0%;对苯的转化率43.0%,矿化率32.3%。紫外光光催化实验结果表明该样品基本上维持了Ti O2的紫外光光催化活性。模拟太阳光催化实验表明,该样品比Ti O2的光催化活性有大幅提高。SPX测试表明,氮是掺杂在Ti O2的氧空位或该位置的间隙处。综合分析表明Ti O2掺杂氮的结构形式应为O-Ti-N结构。并探讨了氨水浸渍法中N氮掺杂Ti O2催化剂的形成过程。 相似文献
992.
Zha Wenhua Zhou Hongyuan Liu Zaobao Shao Jianfu Zhang Yulong Hua Xinzhu 《Bulletin of Engineering Geology and the Environment》2021,80(10):7847-7863
Bulletin of Engineering Geology and the Environment - The evolution of permeability of tight sandstone was investigated under different stress states. A series of hydrostatic compression, triaxial... 相似文献
993.
Dongyang Jiang Jing Ge Qinyuan Liao Junfan Ma Yang Liu Jing Huang Chong Wang Weiyan Xu Jie Zheng Wenwei Shao Gregory Lee Xiaoyan Qiu 《International journal of molecular sciences》2015,16(2):2574-2590
The innate immune system of the skin is thought to depend largely on a multi-layered mechanical barrier supplemented by epidermis-derived antimicrobial peptides. To date, there are no reports of antimicrobial antibody secretion by the epidermis. In this study, we report the expression of functional immunoglobulin G (IgG) and immunoglobulin A (IgA), previously thought to be only produced by B cells, in normal human epidermal cells and the human keratinocyte line HaCaT. While B cells express a fully diverse Ig, epidermal cell-expressed IgG or IgA showed one or two conservative VHDJH rearrangements in each individual. These unique VDJ rearrangements in epidermal cells were found neither in the B cell-derived Ig VDJ databases published by others nor in our positive controls. IgG and IgA from epidermal cells of the same individual had different VDJ rearrangement patterns. IgG was found primarily in prickle cells, and IgA was mainly detected in basal cells. Both epidermal cell-derived IgG and IgA showed potential antibody activity by binding pathogens like Staphylococcus aureus, the most common pathogenic skin bacteria, but the microbial-binding profile was different. Our data indicates that normal human epidermal cells spontaneously express IgG and IgA, and we speculate that these Igs participate in skin innate immunity. 相似文献
994.
Analysis‐preserving video microscopy compression via correlation and mathematical morphology 下载免费PDF全文
Chong Shao Alfred Zhong Jeremy Cribb Lukas D. Osborne E. Timothy O'Brien III Richard Superfine Ketan Mayer‐Patel Russell M. Taylor II 《Microscopy research and technique》2015,78(12):1055-1061
The large amount video data produced by multi‐channel, high‐resolution microscopy system drives the need for a new high‐performance domain‐specific video compression technique. We describe a novel compression method for video microscopy data. The method is based on Pearson's correlation and mathematical morphology. The method makes use of the point‐spread function (PSF) in the microscopy video acquisition phase. We compare our method to other lossless compression methods and to lossy JPEG, JPEG2000, and H.264 compression for various kinds of video microscopy data including fluorescence video and brightfield video. We find that for certain data sets, the new method compresses much better than lossless compression with no impact on analysis results. It achieved a best compressed size of 0.77% of the original size, 25× smaller than the best lossless technique (which yields 20% for the same video). The compressed size scales with the video's scientific data content. Further testing showed that existing lossy algorithms greatly impacted data analysis at similar compression sizes. Microsc. Res. Tech. 78:1055–1061, 2015. © 2015 Wiley Periodicals, Inc. 相似文献
995.
Predictive Modeling of Surface Roughness in Grinding of Ceramics 总被引:1,自引:0,他引:1
The surface roughness represents the quality of ground surface since irregularities on the surface may form nucleation for cracks or corrosion and thus degrade the mechanical properties of the component. The surface generation mechanism in grinding of ceramic materials could behave as a mixture of plastic flow and brittle fracture, while the extent of the mixture hinges upon certain process parameters and material properties. The resulting surface profile can be distinctively different from these two mechanisms. In this article, a physics-based model is proposed to predict the surface roughness in grinding of ceramic materials considering the combined effect of brittle and ductile material removal. The random distribution of cutting edges is first described by a Rayleigh probability function. Afterwards, surface profile generated by brittle mode grinding is characterized via indentation mechanics approach. Last, the surface roughness is modeled through a probabilistic analysis of ductile and brittle generated surface profile. The model expresses the surface finish as a function of the wheel microstructure, the process conditions, and the material properties. The predictions are compared with experimental results from grinding of silicon carbide and silicon nitride workpieces (SiC and Si3N4, respectively) using a diamond wheel. 相似文献
996.
以绵竹市回澜立交桥为工程实例,结合匝道桥实际震害,采用有限元软件SAP2000对该桥在地震作用下的抗震性能进行了分析计算。研究了匝道桥采用增加截面法和减隔震法进行抗震加固设计后的抗震性能。研究表明:采用增加截面法和减隔震法均能有效满足匝道桥的抗震安全性要求。 相似文献
997.
高大空间分层空调设计冷负荷通常采用经验系数法计算,对于航站楼类高大空间,经验系数的取值研究较少。以无锡某航站楼的远机位候机厅、近机位候机厅和办票大厅3个高大空间为例,利用CFD软件,在夏季空调设计工况下通过调整送风参数使工作区温度达到室内参数设计要求,求出分层空调冷负荷,并获得分层空调负荷相比于全室空调负荷的减小率,1减去该减小率所得数值即为航站楼类高大空间冷负荷计算所用的经验系数。结果表明,航站楼因围护结构形成的冷负荷占总冷负荷的比例较小且顶部不能设置排风口,分层空调设计冷负荷计算所用的经验系数取0.85~0.95较为合适。 相似文献
998.
999.
简要介绍了化学植筋在隧道工程中的特点,并通过其在施工中的应用详细介绍了化学植筋施工工艺、植筋材料以及拉拔检测方法,最后对化学植筋技术在隧道主体结构中的应用作了总结阐述,为植筋技术的应用积累了经验。 相似文献
1000.