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排序方式: 共有2392条查询结果,搜索用时 15 毫秒
1.
超支化聚合物,具有多端基的“缺陷核壳”空间结构,化学反应性活泼,易于改性,与相应的线型聚合物相比,拥有特殊的性能,在多领域展现出广阔的应用前景。随着合成技术的进步,它们的应用研究,尤其是功能化的应用研究,成为多年来的研究热点。主要介绍超支化聚合物的结构、性能、合成及其功能化应用研究概况。 相似文献
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《Minerals Engineering》2006,19(1):12-18
This paper presents an experimental technique to measure maximum bubble loads, which are then compared with geometrical model estimations. The geometrical models studied assume that a particle monolayer, having a square arrangement, covers the entire bubble surface. Comparison of the experimental and analytical results gave a fairly high statistical correlation (R2 = 0.89), when a shape factor was used for particle volume estimation (λ = 0.32–0.41; [Kelly, E.G., Spottiswood, D.J. Introduction to Mineral Processing, John Wiley & Sons, 1982, p. 491]). This supports the applicability of geometrical models for maximum bubble load estimation. 相似文献
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本文对非线性锥形梯度折射率透镜进行了分析,根据稳态自聚焦理论以及ABCD定律,导出了高斯光束通过这种透镜光斑尺寸及其位置的公式。讨论了几种特殊的情况,得到了一些重要的结果。 相似文献
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Biomimetic synthesis of spherical nano-hydroxyapatite in the presence of polyethylene glycol 总被引:1,自引:0,他引:1
Spherical nano-hydroxyapatite (nano-HA) was synthesized successfully by a biomimetic method using Ca(NO3)2·4H2O and (NH4)3PO4·3H2O as reagents in the presence of polyethylene glycol (PEG). The crystalline phase, microstructure, chemical composition, and morphology of the obtained samples were characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM). The results show that spherical nano-HA with diameter of 30–50 nm can be synthesized in the presence of a certain concentration (2–6%) of PEG. The crystallinity of HA powder synthesized in the presence of PEG was higher than that synthesized in the absence of PEG, but the crystallinity of HA reduced with increasing the concentration of PEG. The electrical conductivity (EC) of the solution revealed that PEG reduced the transfer rate of Ca2+ in the process of HA crystallization, indicating the interaction between PEG and HA. The possible mechanism of formation spherical nano-HA was discussed. 相似文献
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《Computers & Mathematics with Applications》2005,49(9-10):1403-1411
Hypercube and Kautz network each possess certain desirable properties. However, some of the attractive features of one network are not found in the other. A novel class of network topologies proposed in this paper has the generalized hypercube and the Kautz network as its two extremes. The proposed network inherits the topological properties of both the Kautz network and the generalized hypercube to a varying degree. This allows us to trade-off cost and performance effectively and construct networks which are most suitable for a particular purpose. In the present paper, we investigate the connectivity, wide-diameter, fault-tolerance, Hamiltonicity. 相似文献
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双MCU架构航标监控终端的研制 总被引:3,自引:0,他引:3
针对航标监控终端对低功耗、高可靠性的要求,采用双MCU架构设计.在软件系统中建立多任务消息机制,引入时限服务策略对任务的运行时间进行约束,只需定时器和少量资源,提高了软件的可靠性.实际应用表明,该终端的性能指标完全满足设计要求. 相似文献
9.
王秋霞 《西华大学学报(自然科学版)》2021,40(4):61-66
电动汽车处于不同行驶工况时,固定采样率的无迹卡尔曼滤波(Fixed Sampling Rate Unscented Kalman Filter, FSR-UKF)算法不能精确估算荷电状态(State of Charge,SOC)。为克服这一缺点,以传统的UKF算法为基础,针对电动汽车不同行驶状态下电池电流的变化特点,将变采样率采集方法与UKF算法融合,根据受控电压源电池等效电路模型及其参数辨识结果,将变采样率UKF(Variable Sampling Rate UKF, VSR-UKF)算法应用于电池SOC的估算中,并设计估算流程图。最后,通过仿真实验,获得最大相对误差不超过1%的电池端电压仿真结果以及最大相对误差不超过5%的SOC估算结果,验证了本研究的正确性和准确性。 相似文献
10.
《中国稀土学报(英文版)》2022,40(10):1519-1526
Lanthanide doped fluorescent nanoparticles have gained considerable attention in biomedical applications. However, the low uptake efficiency of nanoparticles by cells has limited their applications. In this work, we demonstrate how the uptake efficiency is affected by the size of nanoparticles under flow conditions. Using the same size NaYF4:20% Yb3+,2% Er3+,2% Ce3+ (the contents of rare earths elements are in molar fraction) nanoparticles as core, NaYF4:20% Yb3+,2% Er3+,2% Ce3+@NaYF4 core–shell structured nanorods (NRs) with different sizes of 60–224 nm were synthesized by thermal decomposition and hot injection method. Under excitation at 980 nm, a strong upconversion green emission (541 nm, 2H11/2 → 4I15/2 of Er3+) is observed for all samples. The emission intensity for each size nanorod was calibrated and is found to depend on the width of NRs. Under flow conditions, the nanorods with 96 nm show a maximum uptake efficiency by endothelial cells. This work demonstrates the importance of optimizing the size for improving the uptake efficiency of lanthanide-doped nanoparticles. 相似文献