排序方式: 共有28条查询结果,搜索用时 31 毫秒
11.
喻其炳 《重庆工商大学学报(自然科学版)》2003,20(1):64-66
详细介绍了多媒体信息处理的各个环节,包括多媒体信息处理的捕获,压缩以及播放等,给出了一种在Windows环境下,方便,快捷,高效地实现多媒体信息处理的方法,最后给出了其程序实现的方法。 相似文献
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Marcos Revilla-Vallejo Jesús Poza Javier Gomez-Pilar Roberto Hornero Miguel ngel Tola-Arribas Mnica Cano Carlos Gmez 《Entropy (Basel, Switzerland)》2021,23(5)
Alzheimer’s disease (AD) is a neurodegenerative disorder which has become an outstanding social problem. The main objective of this study was to evaluate the alterations that dementia due to AD elicits in the distribution of functional network weights. Functional connectivity networks were obtained using the orthogonalized Amplitude Envelope Correlation (AEC), computed from source-reconstructed resting-state eletroencephalographic (EEG) data in a population formed by 45 cognitive healthy elderly controls, 69 mild cognitive impaired (MCI) patients and 81 AD patients. Our results indicated that AD induces a progressive alteration of network weights distribution; specifically, the Shannon entropy (SE) of the weights distribution showed statistically significant between-group differences (p < 0.05, Kruskal-Wallis test, False Discovery Rate corrected). Furthermore, an in-depth analysis of network weights distributions was performed in delta, alpha, and beta-1 frequency bands to discriminate the weight ranges showing statistical differences in SE. Our results showed that lower and higher weights were more affected by the disease, whereas mid-range connections remained unchanged. These findings support the importance of performing detailed analyses of the network weights distribution to further understand the impact of AD progression on functional brain activity. 相似文献
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用自编程序计算了24种一溴代烷的1 ̄4阶共20种分子连接性指数(MCI)及价分子连续性指数(VMCI),用逐步咽归法将其与标题化合物的密度折光度和沸点等物理性质相关分析,得到了10个有显著意义的定量结构-性能关系式(QSPR),各方程的预报值与实验值符合得较好,表明这些关系不仅从分子水平上较好地描述了标题化合物的定量构效关系,而且对该类化合物中未知物的上述物理化学性质的预报有实际意义。 相似文献
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Electrospray droplet impact (EDI)/SIMS is a new desorption/ionization technique for mass spectrometry. EDI/SIMS utilizes large multiply charged water clusters produced by atmospheric pressure electrospray as primary projectiles. It was found to afford extremely soft desorption/ionization compared with conventional SIMS, and has been used for detection of peptides and proteins. In this study, EDI/SIMS was applied to the detection of peptide in a highly concentrated NaCl solution. The persistent appearance of peptide ions for 1 ppm peptides in NaCl is probably because of the segregation of peptides on the crystallized salts. The samples dried under vacuum gave better EDI/SIMS mass spectra than those under ambient atmospheric pressure. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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用组态相互作用方法计算了He原子基态电子关联能,为了既得到较高精度又克服计算机上遇到的困难,采用了并行分块消去迭代法,同时在多个处理器上并行计算。得到了较好的结果,并且对进一步开展对三个以上电子体系的关联能并行计算有一定的参考意义。 相似文献
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Energies for the ground states of double-electron systems in a uniform magnetic fieldB≤109 G are calculated by using the modified Slater basis and configuration interaction method, and the result for energy in zero
magnetic field is comparable with those obtained by different methods.
Supported by the Opening Foundation of Wuhan Institute of Physics, Chinese Academy of Science
Wu Liangkai: born in 1970, Graduate student 相似文献
18.
陈爱民 《福建师范大学学报(自然科学版)》2002,18(4):22-25
分析Microsoft集成的MCI控件中的设备类型和使用方法,利用VFP提供强大的多媒体编程技术,通过MCI控件来访问视频文件,实现视频文件的播放功能,并由此来说明VFP并非只能用于对数据库的数据处理上,它与其它可视化语言一样,有着广泛的应用空间。 相似文献
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介绍了基于WINDOWS环境,利用VB3.0这种可视化编程语言开发多媒体应用程序的两种方法. 相似文献
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Damiano Librizzi Nicole Cabanel Maxim Zavorotnyy Elisabeth Riehl Tilo Kircher Markus Luster Behrooz Hooshyar Yousefi 《Molecules (Basel, Switzerland)》2021,26(5)
PET of β-Amyloid plaques (Aβ) using [18F]florbetaben ([18F]FBB) and [18F]fluorodeoxyglucose ([18F]FDG) increasingly aid clinicians in early diagnosis of dementia, including Alzheimer’s disease (AD), frontotemporal disease, dementia with Lewy bodies, and vascular dementia. The aim of this retrospective analysis was to evaluate clinical relevance of [18F]FBB, [18F]FDG PET and complimentary CSF measurements in patients with suspected dementia. In this study, 40 patients with clinically suspected or history of dementia underwent (1) measurement of Aβ peptides, total tau, and p-tau protein levels in the cerebrospinal fluid (CSF) compared with healthy controls (HC); (2) clinical and neuropsychological assessment, which included Consortium to Establish a Registry for Alzheimer’s Disease neuropsychological assessment battery (CERAD-NAB); (3) [18F]FBB and [18F]FDG PET imaging within an average of 3 weeks. The subjects were within 15 days stratified using PET, CSF measurements as HC, mild cognitive impaired (MCI) and dementia including Alzheimer´s disease. The predictive dementia-related cognitive decline values were supporting the measurements. PET images were evaluated visually and quantitatively using standard uptake value ratios (SUVR). Twenty-one (52.5%) subjects were amyloid-positive (Aβ+), with a median neocortical SUVR of 1.80 for AD versus 1.20 relative to the respective 19 (47.5 %) amyloid-negative (Aβ-) subjects. Moreover, the [18F]FDG and [18F]FBB confirmed within a sub-group of 10 patients a good complimentary role by correlation between amyloid pathology and brain glucose metabolism in 8 out of 10 subjects. The results suggest the clinical relevance for [18F]FBB combined with [18F]FDG PET retention and CFS measurements serving the management of our patients with dementia. Therefore, [18F]FBB combined with [18F]FDG PET is a helpful tool for differential diagnosis, and supports the patients’ management as well as treatment. 相似文献