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排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
992.
Zebrafish is a useful animal model for studying human diseases such as muscle disorders. However, manual monitoring of fish motion is time-consuming and prone to subjective variations. In this paper, an automatic fish motion analytics framework is proposed. The proposed framework could be exploited to help validate zebrafish models of transgenic zebrafish that express human genes carrying mutations which lead to muscle disorders, thus affecting their ability to swim normally. To differentiate between wild-type (normal) and transgenic zebrafish, the proposed framework consists of two approaches to exploit discriminative spatial–temporal kinematic features which are extracted to represent zebrafish movements. First, the proposed approach studies precise quantitative measurements of motor movement abnormalities using a camera with the capability to record videos with high frames rates (up to 1,000 frames per second). This differs from previous works, which only tracked each fish as a single point over time. Second, the proposed approach studies multi-view spatial–temporal swimming trajectories. This differs from previous works which typically only considered single-view analysis of fish swimming trajectories. The proposed motion features are then incorporated into a supervised classification approach to identify abnormal fish movements. Experimental results have shown that the proposed approach is capable of differentiating between wild-type and transgenic zebrafish, thus helping to validate the zebrafish models.  相似文献   
993.
经济的发展加快了城市建设步伐,建筑业也乘此时机获得了繁荣的发展,经济的发展与居民收入的增加加剧了对建筑的需求量,对建筑物的结构设计与安全质量等也提出了更具挑战性的要求。在这种客观形势下,必须加强工民建筑结构设计。  相似文献   
994.
995.
The interaction between an ethoxylated alkylphenol polymer with formaldehyde (EAPPF) and a triblock polyEO–polyPO–polyEO copolymer (TBCP) in aqueous solutions has been investigated in detail by means of surface tension, steady-state fluorescence, dynamic light scattering (DLS) measurements and computer simulations. For comparison, the ethoxylated alkylphenol oligomer (EAPO), which is the monomer unit of EAPPF, and another nonionic water-soluble polymer PEG were also selected to get more information about the interaction between different types of surfactants and polymers. The surface properties of mixed systems at the air/water surface were evaluated from surface tension measurements. Information about the hydrophobic microenvironment and size of the aggregates was obtained from steady-state fluorescence using pyrene as a hydrophobic probe and DLS measurements, respectively. The dissipative particle dynamics simulation method was applied to simulate the interaction between EAPPF (or EAPO) and TBCP (or PEG) in aqueous solutions. The synergetic interaction between EAPPF (or EAPO) and TBCP in binary mixed solution enhanced the adsorption of surfactant molecules (EAPPF or EAPO) at the interface, while no obvious interaction between EAPPF (or EAPO) and PEG was observed.  相似文献   
996.
Beam lifetime of a synchrotron is dominated by Touschek scattering.In the beamline Phase Ⅱ project of Shanghai synchrotron radiation facility,a passive third harmonic cavity is to be installed for bunch lengthening and instability suppressing.In this paper,the beam dynamics of the cavity is investigated.The parameters of passive operation are optimized to cancel the slope of RF voltage and lengthen the bunches.The Touschek lifetime increases are estimated for optimum and non-optimum voltage flattening.A tolerance of the operation is studied in case that there is a shift on detuning angle.The effect caused by reduction in harmonic voltage generated by lengthened bunch distribution is also estimated using iteration method.An increase in synchrotron frequency spread due to nonlinearity of the voltage giving to the bunch is found by using tracking simulation.This spread can help in damping coupled bunch instability through Landau damping.  相似文献   
997.
Growth hormone (GH) has been considered as a candidate gene for growth traits in fish. In this study, polymorphisms of the GH gene were evaluated for associations with growth traits in 282 Siniperca chuatsi individuals. Using directly sequencing, four single nucleotide polymorphisms (SNPs) were identified in GH gene, with two mutations in intron 4 (g.4940A>C, g.4948A>T), one mutation in exon 5 (g.5045T>C) and one in intron 5 (g.5234T>G). Notably, three of them were significantly associated with growth performance, particularly for g.4940A>C which was highly correlated with all the four growth traits. In conclusion, our results demonstrated that these SNPs in GH gene could influence growth performance of S.chuatsi and could be used for marker-assisted selection (MAS) in this species.  相似文献   
998.
The combustion behaviour and temperature of pulverised coal in a tuyere zone of the blast furnace could benefit to adjust the operation parameters, assure the stable state as well as maintaining high quality of hot metal of the blast furnace. However, there have been rare studies about this subject. In this paper, the digital imaging system based on the colour charge coupled device within gas-cooling and dustproof functions was established to capture the combustion radiation in the tuyere zone. For instance, images of tuyere zones of 2000 and 2500?m3 blast furnaces were detected through a peephole in front of the blowpipe by the application of digital imaging and image processing techniques, and the temperature distributions were also calculated. Some measurements were used to improve the accuracy of the results, and the combustion behaviour was also analysed.  相似文献   
999.
1000.
针对信息检索隐式多样化算法展开研究。介绍了检索结果重排序中的最大边际相关度(MMR)算法、相对熵(KL)算法、现代投资组合理论(MPT)3个隐式多样化算法,采用此3个算法对所选的已排序的文档数据集进行重排,通过对排序结果进行评价来对比三者的性能。得出隐式多样化方法中当相关性和多样性以一定比例的线性组合时,会使最终的检索结果在一些评价指标上相对于原始结果有所提高。  相似文献   
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