排序方式: 共有96条查询结果,搜索用时 0 毫秒
81.
83.
84.
针对传统畸变校正方法无法完成镀膜双镜头多光谱相机影像畸变校正的问题,提出了一种基于数字畸变模型采样的单波段影像畸变校正方法。采用多片后方交会完成相机检校得到各类参数,建立起原始影像的数字畸变模型;对原始数字畸变模型采样得到各波段数字畸变模型;利用各波段数字畸变模型完成对应波段影像畸变的校正。实验结果表明,数字畸变模型采样法能够有效解决镀膜双镜头多光谱相机单波段影像畸变的校正问题,校正精度较高;通过进一步实验证明,经畸变校正后的单波段影像配准误差达到亚像素级,数据可用性高。 相似文献
85.
采用水热法合成了4种过渡金属配合物{[Mn(2,4-Hoba)_2(bipy)(H_2O)_2]·2H_2O}_n(1),[Mn(2,4-oba)(phen)]n(2),[Co (2,4-oba)(bimyb)_(0.5)]n(3)和[Ni(2,4-oba)(bimyb)_(0.5)]_n(4)(2,4-H2oba=2,4-氧基双(苯甲酸),bipy=4,4′-联吡啶,phen=1,10-菲咯啉,bimyb=1,4-双(咪唑-1-甲基)苯),并用X射线单晶衍射、热重分析、红外光谱和元素分析等手段对其进行了表征。单晶结构表明:配合物1是一维链状结构,通过O-H…O氢键扩展为二维超分子结构。配合物2是一维波浪链状结构,通过芳香环π-π堆积作用扩展为二维波状网络结构。配合物3和4是由配体桥联双核桨轮单元产生的二维层状结构。此外,对配合物2~4的磁性进行了研究,磁交换耦合常数分别为-0.79、-8.97和-11.42 cm-1。根据配合物2~4的晶体结构,利用DFT-BS方法对配合物2~4的磁耦合行为进行了研究。结果表明,计算的交换耦合常数J与实验数据吻合较好。 相似文献
86.
重离子诱导的质粒DNA双链断裂分布研究 总被引:1,自引:0,他引:1
利用能量为7.2MeV/u氖离子束辐照体外质粒DNA:pUC18,采用恒场凝胶电泳结合多功能荧光成像系统研究了pUC18双链断裂片段的分布。证实了双链断裂片段分布的非随机性,结果还发现DNA断裂后片段的交联现象,而且交联片段的分布也是非随机的。DNA is considered to be the most important and sensitive target in biological systems. In addition to the base damage, DNA strand breaks are the major lesion in the genome due to exposure to ionizing radiation. Mutation can be introduced to DNA as a result of enzymatic processing of DNA lesions or post irradiation replication. However, the mechanisms of radiation induced mutations are not well clarified at the molecular level. To study the effect on the simple plasmid DNA of heavy ion is even predominant or more feasible. Plasmid pUC18 DNA was prepared and irradiated by neon beam (7.199 MeV/u). The fragment distributions were determined by quantifying the ethidium bromide fluorescence. It can be seen that the shape of the intensity distributions is vastly different for the used radiation Dose. The distribution produced shows an excess of fragments particularly in 3 000 and 10 000 Gy the size range between 20—40 kbp and 20—50 bp. This clustering of double stranded fragments might be influenced by the higher order chromatin structure of genomic DNA. If so, DNA loop structures could correspond to the size range for which we observed DSB clustering. Further studies aim at elucidating the heterogeneity of DSB induction within the genome and investigate the influence of chromatin structure on the non random fragment distribution. 相似文献
87.
88.
A three-dimensional(3 D) Cd-based metal-organic framework(MOF), [Cd(H2 O)(PAA)]·(H2 O)2(complex 1) has been rationally designed and synthesized by using 4-(pyrimidin-5-yl)isophthalic acid(H2 PAA) and Cd(NO3)2·4 H2 O under solvothermal conditions. The structure has been determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectra, powder X-ray diffraction(PXRD) and thermogravimetric analyses(TGA). Single-crystal X-ray diffraction analyses reveal that complex 1 consists of a 3 D network with one-dimensional(1 D) channels. Moreover, 1 exhibits strong luminescent emission in solid state at room temperature. Fluorescence quenching was observed when treating complex 1 with picric acid(PA), 2,4-dinitrophenylhydrazine(2,4-DNPH) and p-nitroaniline(p-NA), revealing that the as-synthesized complex could be used as a luminescence sensor for the detection of PA, 2,4-DNPH and p-NA. 相似文献
89.
90.
高性能忆阻器件的开发适应了大数据时代的需求,尤其是以结构可灵活调变的有机/高分子材料为活性层的新型忆阻器件,正日益成为光电传感和人工智能研究领域的热点。受贻贝灵感化学启发,在蒸镀有氧化铟锡(ITO)的玻璃基底上自组装聚多巴胺(PDA)薄膜形成活性层,随后通过点击化学反应接枝具有光致异构化特性的偶氮苯(Azo),制备了结构为Al/PDAAzo/ITO的忆阻器件。对其结构和电学性能进行的研究结果表明:偶氮苯共价接枝在平整的聚多巴胺表面;器件在施加电压扫描下表现出稳定的非易失性可擦写阻变存储特性,并且电导率在紫外光照射后增加30倍,而在可见光照射后恢复,实现了对电场和光场的双重响应。 相似文献