提交时间: 2017-05-02
摘要: In this manuscript, a toughened PLA/nanosilica composite with good storage stability was obtained in the presence of the epoxidized soybean oil [ESO]. The composite was fabricated via a twin-screw extruder, and characterized by the FTIR, selective distrib
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-04-06
摘要: SnOx films were fabricated by reactive rf magnetron sputtering under various oxygen partial pressures (PO = 1.6%–50%) and then annealed in an air ambient. Four operating window regions of the SnOx films are demonstrated such as metallic Sn dominated films with n-type conduction, polycrystalline SnO dominated films with p-type conduction, SnO-SnO2 composite films with high resistivity, and amorphous SnO2 dominated films with n-type characteristics. TFT devices using the SnO dominated films as channels are investigated. The TFTs with the channels of a hole concentration over 1018 cm−3 show depletion p-type characteristics. The hole concentration can be tunable by changing PO, the channel thickness, and the annealing durations. An ambipolar operating mode is obtained by modulating the hole concentration.
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-04-06
摘要: The magnetic circular permeability extracted from impedance measurements of arrays composed of Co- based amorphous wires was studied as a function of the number and distance between the wires. The results showed that a linear array with higher number of wires increased the permeability and thereby magnetoimpedance (MI) response up to 10 MHz. It was also proposed that such variation in circular permeability originated from the magnetostatic interaction among the wires gave rise to a change in the skin depth and finally in impedance. Increasing the distance between the wires had a detrimental effect on permeability and MI ratio due to a weaker mutual interaction. These observations provide support to the complex inductance formalism as an alternative approach to explain MI change in wire arrays.
提交时间: 2017-05-02
摘要: Template-free synthesis of TiO2 architectures with controlled morphology evolution has been developed through solvothermal reaction in 1,4-dioxane. By simply varying the molar ratio of the concentrated HCl over Titanium isopropoxide [TTIP] from 0 to 5.0,
分类: 材料科学 >> 材料科学(综合) 提交时间: 2017-05-09
摘要: For exploring more types of suitable polymeric membranes for application in alkaline fuel cells (AFCs), a series of 1,2-dimethylimidazolium functionalized poly(arylene ether sulfone)s containing 4-phenyl- pyridine units in the main chain (named as DIm-PPYPAES) were firstly synthesized as anion exchange membranes (AEMs) in this work. Proton nuclear magnetic resonance (1H NMR) and Fourier transform infrared (FT-IR) spectroscopy were employed to characterize and confirm the chemical structure of the synthesized copolymers and the derived membranes. The DIm-PPYPAES membranes with different ionized levels ranging from 1.15 meq. g 1 to 1.77 meq. g 1, exhibited good thermal stability, solubility behavior and a relatively high level of hydroxide conductivity. The highest hydroxide conductivity of 83.35 mS cm 1 at 80 C was achieved for the DIm-PPYPAES-4 membrane with a moderate IEC of 1.77 meq. g 1. Moreover, after 15 days of treatment with a 2 M NaOH solution at 60 C, the DIm-PPYPAES membrane still exhibited relatively high ionic conductivity even above 10 mS cm 1 at 30 C and retained their integrated shapes.
提交时间: 2017-05-02
分类: 生物学 >> 生物物理学 >> 肿瘤学 提交时间: 2016-05-12
摘要: The signal transduction pathway initiated by vascular endothelial growth factor-vascular endothelial growth factor receptor 2 (VEGF-VEGFR2) plays an important role in the angiogenesis of tumors. The effective antagonists of VEGFR2 would behave as potent drugs for the treatment of malignant cancers. In our study, specific binding peptides with high affinity to VEGFR2 were obtained through bacterial display technology. Conserved motif (FF/YEXWGVK) among those peptide sequences was discovered. One of the selected peptides, VRBP1 (YDGNSFYEMWGVKPASES) was identified by screening the biased bacterial peptide library and its physiochemical feature was further characterized. The results of surface plasmon resonance (SPR) assay indicated that the dissociation constant (K-D) value of VRBP1 was 228.3 nM and this peptide competed with VEGF binding to VEGFR2. Particles conjugated with VRBP1 could recognize the human umbilical vein endothelial cells (HUVEC) which express VEGFR2 on the surface. Further therapeutic effect of VRBP1 was examined by in vivo experiments. VRBP1 could result in a significant decrease in tumor size of H460 xenografts. The results from the immunohistochemical assay showed that CD31 positive signals in VRBP1-treated group were fewer than those in the control ones. These data highlighted the potential of VEGFR2-binding peptides as effective molecules for cancer diagnosis and therapy.
分类: 测绘科学技术 >> 测绘科学技术其他学科 提交时间: 2024-04-15 合作期刊: 《干旱区科学》
摘要: Gobi spans a large area of China, surpassing the combined expanse of mobile dunes and semi-fixed dunes. Its presence significantly influences the movement of sand and dust. However, the complex origins and diverse materials constituting the Gobi result in notable differences in saltation processes across various Gobi surfaces. It is challenging to describe these processes according to a uniform morphology. Therefore, it becomes imperative to articulate surface characteristics through parameters such as the three-dimensional (3D) size and shape of gravel. Collecting morphology information for Gobi gravels is essential for studying its genesis and sand saltation. To enhance the efficiency and information yield of gravel parameter measurements, this study conducted field experiments in the Gobi region across Dunhuang City, Guazhou County, and Yumen City (administrated by Jiuquan City), Gansu Province, China in March 2023. A research framework and methodology for measuring 3D parameters of gravel using point cloud were developed, alongside improved calculation formulas for 3D parameters including gravel grain size, volume, flatness, roundness, sphericity, and equivalent grain size. Leveraging multi-view geometry technology for 3D reconstruction allowed for establishing an optimal data acquisition scheme characterized by high point cloud reconstruction efficiency and clear quality. Additionally, the proposed methodology incorporated point cloud clustering, segmentation, and filtering techniques to isolate individual gravel point clouds. Advanced point cloud algorithms, including the Oriented Bounding Box (OBB), point cloud slicing method, and point cloud triangulation, were then deployed to calculate the 3D parameters of individual gravels. These systematic processes allow precise and detailed characterization of individual gravels. For gravel grain size and volume, the correlation coefficients between point cloud and manual measurements all exceeded 0.9000, confirming the feasibility of the proposed methodology for measuring 3D parameters of individual gravels. The proposed workflow yields accurate calculations of relevant parameters for Gobi gravels, providing essential data support for subsequent studies on Gobi environments.