排序方式: 共有39条查询结果,搜索用时 0 毫秒
1.
Jin?ZhouEmail author Hui?Zhou Jinbao?Tang Shue?Deng Fang?Yan Wenjing?Li Meihua?Qu 《Mikrochimica acta》2017,184(2):343-368
Carbon dots (CDs) possess superior fluorescent properties in that they do not blink, are biocompatible, chemically inert, have small size and well tunable photoluminescence (PL), can be easily functionalized with biomolecules, and can be multi-photon excited to give up-converted PL. This review (with 141 refs.) summarizes recent progress in the field of imaging using carbon dots doped with heteroatoms (X-CDs). Following an introduction, we discuss top-down and bottom-up strategies for synthesis and methods for surface modification. We also compare the differences in synthesis for undoped CDs and X-CDs. Specifically, CDs doped with heteroelemets nitrogen, phosphorus, sulfur, selenium, boron and silicium are treated. We then discuss method for determination of the properties (particle size, ZP), how doping affects fluorescence (spectra, quantum yields, decay times), and how dopants affect upconversion (UC, anti-Stokes luminescence). We finally review the progress made in fluorescent imaging of cells tissue, and other biomatter. This review also gives new hints on how to use synthetic methods for tuning the structure of X-CDs, how doping affects properties, and how to achieve new bioimaging applications. 相似文献
2.
We have developed an approach to implement a real time admissible heuristic search algorithm to solve project scheduling problems. This algorithm is characterised by the complete heuristic learning process: state selection, heuristic learning, and search path review. This implementation approach is based on the dynamic nature of the activity status and the resource availability of a project. It consists of states, state transition operator, heuristic estimate, and the cost of transition between states. The performance analysis shows that the accumulation of heuristic learning during the search process has led to the re-scheduling of resource dominating activities, which is a major factor in controlling the overall project completion time. 相似文献
3.
4.
Xing Gao Weijun Zhong Shue Mei 《Communications in Nonlinear Science & Numerical Simulation》2012,17(12):5249-5255
The analysis of asymptotical convergence for the oligopoly game has always been important to characterize the firms’ long-term behavior. In the nonlinear oligopoly competition possibly involving chaotic fluctuations, non-convergent trajectories are particularly undesirable since the resulting behavior will become unpredictable. In this paper, consistent with a traditional assumption that the firms update their outputs simultaneously, we at first construct an adjustment process and discuss the convergence to the equilibrium for a nonlinear Cournot duopoly game with the isoelastic demand function. We indicate that the tendency to instability does rise with the number of firms and the adjustment speeds. In particular, we alter this assumption from simultaneous decisions to sequential decisions so that the latter firms are able to observe the former ones at every time periods. We finally arrive at a conclusion that the unique equilibrium is convergent as long as the adjustment speeds are less than a fixed threshold, no matter what the number of the firms. Our findings show that the firms with sequential decisions can achieve the equilibrium more easily. 相似文献
5.
重视物理实验教学中的创新能力培养和科学素质教育 总被引:4,自引:0,他引:4
通过分析物理学的教育功能和文化价值 ,阐述了物理实验教学中加强学生能力培养和科学素质教育的优势和做法。 相似文献
6.
Meccanica - In gear pair actual alternating meshing process, the comprehensive errors of the transmission system and the thermal elastic deformation of the teeth body cause the gears in the meshing... 相似文献
7.
8.
Wei‐De Zhang In Yee Phang Lu Shen Shue Yin Chow Tianxi Liu 《Macromolecular rapid communications》2004,25(21):1860-1864
Summary: Carbon nanotubes (CNTs) have been grown on MCM‐41 supported Fe nanoparticles and the as‐prepared (no further purification) CNT‐silica hybrid was directly incorporated into nylon‐6 (PA6) by simple melt‐compounding. The urchin‐shaped CNT‐silica hybrid filler was observed to be homogeneously dispersed throughout the matrix by scanning electron and transmission electron microscopy. Compared with neat PA6, the tensile modulus and strength of the composite are greatly improved by about 110%, with incorporation of only 1 wt.‐% CNT‐silica filler.
9.
Huang J Liu Z Liu X He C Chow SY Pan J 《Langmuir : the ACS journal of surfaces and colloids》2005,21(2):699-704
Platinum nanoparticles synthesized by a unique synthetic approach, the hydrosilylation reaction, have been reported previously. However, the interaction between the underlying platinum nanosupport and the capping agents is poorly understood. Here we continue to investigate Pt nanoparticles from the hydrosilylation reaction to address this issue and present the characterization results of nuclear magnetic resonance, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. These characterization results conclude that two different modes of binding of the aliphatic capping agents with the platinum surface are attributed to the formation of Pt-C bonds under excess olefin concentration and Pt-Si bonds under excess hydrosilane concentration. Morphology and UV-vis spectra of the platinum nanoparticles were explored by transmission electron microscopy, X-ray diffraction, and UV-vis spectroscopy. Moreover, electrochemical properties of the platinum nanoparticles were also studied by cyclic voltammetry and chronoamperometry. 相似文献
10.
Eveline H Shue Eleanor B Carson-Walter Yang Liu Bethany N Winans Zarina S Ali Jun Chen Kevin A Walter 《BMC neuroscience》2008,9(1):29