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51.
52.
Hepatic vessel skeletonization serves as an important means of hepatic vascular analysis and vessel segmentation. This paper presents a survey of techniques and algorithms for hepatic vessel skeletonization in medical images. We summarized the latest developments and classical approaches in this field. These methods are classified into five categories according to their methodological characteristics. The overview and brief assessment of each category are provided in the corresponding chapters, respectively. We provide a comprehensive summary among the cited publications, image modalities and datasets from various aspects, which hope to reveal the pros and cons of every method, summarize its achievements and discuss the challenges and future trends. 相似文献
53.
Sun YX Huang YX Li FL Wang HY Fan C Bao YL Sun LG Ma ZQ Kong J Li YX 《Chemistry Central journal》2012,6(1):2
Background
The virtual screening (VS) of lead compounds using molecular docking and pharmacophore detection is now an important tool in drug discovery. VS tasks typically require a combination of several software tools and a molecular graphics system. Thus, the integration of all the requisite tools in a single operating environment could reduce the complexity of running VS experiments. However, only a few freely available integrated software platforms have been developed. 相似文献54.
Solventless Formation of G‐Quartet Complexes Based on Alkali and Alkaline Earth Salts on Au(111) 下载免费PDF全文
Chi Zhang Likun Wang Lei Xie Huihui Kong Prof. Dr. Qinggang Tan Liangliang Cai Qiang Sun Prof. Dr. Wei Xu 《Chemphyschem》2015,16(10):2099-2105
Template cations have been extensively employed in the formation, stabilization and regulation of structural polymorphism of G‐quadruplex structures in vitro. However, the direct addition of salts onto solid surfaces, especially under ultra‐high‐vacuum (UHV) conditions, to explore the feasibility and universality of the formation of G‐quartet complexes in a solventless environment has not been reported. By combining UHV‐STM imaging and DFT calculations, we have shown that three different G‐quartet‐M (M: Na/K/Ca) complexes can be obtained on Au(111) using alkali and alkaline earth salts as reactants. We have also identified the driving forces (intra‐quartet hydrogen bonding and electrostatic ionic bonding) for the formation of these complexes and quantified the interactions involved. Our results demonstrate a novel route to fabricate G‐quartet‐related complexes on solid surfaces, providing an alternative feasible way to bring metal elements to surfaces for constructing metal–organic systems. 相似文献
55.
BEM for simulation of a 2D elastic body with randomly distributed circular inclusions 总被引:7,自引:0,他引:7
Based on our 2D BEM software THBEM2 which can be applied to the simulation of an elastic body with randomly distributed identical
circular holes, a scheme of BEM for the simulation of elastic bodies with randomly distributed circular inclusions is proposed.
The numerical examples given show that the boundary element method is more accurate and more effective than the finite element
method for such a problem. The scheme presented can also be successfully used to estimate the effective elastic properties
of composite materials.
Project supported by the National Natural Science Foundation of China (No. 19772025). 相似文献
56.
Enyuan Wang Xiangguo Kong Shaobin Hu Zhonghui Li Quanlin Liu 《Transport in Porous Media》2018,121(3):703-724
With coal mining entering the geological environment of “high stress, rich gas, strong adsorption and low permeability,” the difficulty of joint coal and gas extraction clearly augments, the risk of solid–gas coupling dynamic disasters greatly increases, and the underlying mechanisms become more complex. In this paper, based on the characteristics of coal’s multi-scale structure and spatiotemporal variation, the multi-scale fractured coal gas–solid coupling model (MSFM) was built. In this model, the interaction between coal matrix and its fractures and the mechanical characteristics of gas-bearing coal were considered, as well as their coupling relationship. By MATLAB software, the stress–damage–seepage numerical computation programs were developed, which were applied into Comsol Multiphysics to simulate gas flow caused by coal mining. The simulation results showed the spatial variability of coal elastic modulus and cross-flow behaviors of coal seam gas, which were superior to the results of traditional gas–solid coupling model. And the numerical results obtained from MSFM were closer to the measured results in field, while the computation results of traditional model were slightly higher than the measured results. Furthermore, the MSFM in a large scale was verified by field engineering project. 相似文献
57.
Wei Huang Mi Wang Zhou Hu Lingling Wang Junxin Cao Dewen Kong 《Acta Mechanica Solida Sinica》2021,34(1):137-148
In this study,the strain rate-dependent dynamic tensile behavior of ZrB2-20%SiC ceramic composite was investigated using experimental and numerical approaches.The split Hopkinson pressure bar apparatus was used to measure the dynamic splitting tensile response at strain rates of 17-67 s?1.The experiment results demonstrate a significant strain rate dependence of the dynamic tensile behavior of the ZrB2-SiC ceramic composite.The dynamic tensile strength increased linearly with the strain rate,from 288 MPa at 17 s?1to 654 MPa at 67 s?1.Moreover,a strain rate-dependent tensile strength was introduced into a modified JH-2 model to describe the dynamic tensile behavior and fracture process of ZrB2-SiC ceramics.The numerical results of dynamic tensile strength agree well with the experimental result.Moreover,the fracture process of ZrB2-SiC ceramics under dynamic tension was further studied by combining high-speed images and numerical results.The effect of strain rate on the fracture process and failure patterns of the ZrB2-SiC ceramic composite could be verified by the modified JH-2 model. 相似文献
58.
Han Luo Wei Qin Hong Zhang Fu-Cai Ren Wen-Tao Fang Qing-Hua Kong Liu Yang Jian-Mei Zhang Cheng-Wu Fang Jiang-Miao Hu Shou-Jin Liu 《Molecules (Basel, Switzerland)》2022,27(5)
The present study aimed to identify the composition of the aerial parts of Rubia cordifolia L. A chemical investigation on the EtOAc extracts from the aerial parts of Rubia cordifolia resulted in the isolation of four new anthraquinones, namely Cordifoquinone A–D (1–4), along with 16 known anthraquinones. Their structures were elucidated on the basis of NMR and HR-ESIMS data. All isolates were assessed for their inhibitory effects on NO production in LPS-stimulated RAW 264.7 macrophage cells. Compounds 1, 3 and 10 exhibited significant inhibitory activities with IC50 values of 14.05, 23.48 and 29.23 μmol·L−1, respectively. Their antibacterial activities of four bacteria, Escherichia coli (ATCC 25922), Staphylococcus aureus subsp. aureus (ATCC 29213), Salmonella enterica subsp. enterica (ATCC 14028) and Pseudomonas aeruginosa (ATCC 27853), were also evaluated. Our results indicated that the antibacterial activity of these compounds is inactive. 相似文献
59.
60.
光谱相似性测度是高光谱遥感影像定量化分析和精细地物直接识别的基础,光谱特征的选择和刻画方式是光谱相似性测度的关键.研究表明,利用光谱的单一特征无法全面反应地物光谱间的相似性,光谱识别时需要综合考虑光谱的多种特征.本文在几何距离、相关系数和相对熵的基础上提出了一种结合多种光谱特征的新型光谱相似性测度,即光谱泛相似测度(s... 相似文献