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31.
We have experimentally investigated pump-to-Stokes intensity noise transfer in both the frequency domain and the time domain in all-fiber single-frequency Brillouin ring lasers. In the high-frequency region (>1MHz), the pump-to-Stokes noise transfer function can be much smaller than unity, indicating that the Brillouin fiber lasers act as an efficient low-pass filter. The maximum noise reduction of 40-60 dB was observed at antiresonant frequencies that are multiples of half the cavity free spectral range. This is the first experimental demonstration, to the authors' knowledge, of intensity noise reduction in Brillouin fiber lasers. 相似文献
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Yang W Li J Na T Xu J Wang L Yu J Xu R 《Dalton transactions (Cambridge, England : 2003)》2011,40(11):2549-2554
A new three-dimensional (3-D) open-framework manganese borophosphate, (NH(4))(6)[Mn(3)B(6)P(9)O(36)(OH)(3)]·4H(2)O (denoted as MnBPO-CJ31), has been synthesized by using boric acid flux method. Its anionic framework structure is constructed by the connection of MnO(6) octahedra and BO(4), PO(4) and PO(3)(OH) tetrahedra. It contains 12-ring channels along the [001] direction with a pore diameter of 7.1 ?. It is the first borophosphate featuring a 3-D anionic partial structure with a B/P ratio of 2/3 and an unprecedented fifteen mer tetrahedral fundamental building unit (FBU) [B(6)P(9)O(36)(OH)(3)] exists in this compound. NH(4)(+) ions locate in the void space to balance the negative charge of the inorganic framework. The compound is further characterized by powder XRD, ICP, CHN, TGA and IR analyses. Magnetic study reveals that MnBPO-CJ31 shows interesting canted antiferromagnetic behaviour at low temperature. 相似文献
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DNA sequences can be translated into 2D graphs and into numerical sequences; we call the numerical sequences nonlinear signal sequences. We can use the empirical mode decomposition (EMD) method to divide nonlinear signal sequences into a group of well-behaved intrinsic mode functions (IMFs) and a residue, so that we can compare the similarities among DNA sequences conveniently and intuitively. This work tests the method’s suitability by using the mitochondria of four different species. 相似文献
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An aggregation-induced emission (AIE) luminogen, tetraphenylethene, has been successfully grafted onto mesoporous silica SBA-15 for the first time. The materials emit blue light upon UV irradiation, and are photostable for the ibuprofen (IBU) drug loading and release process, indicating their great potential for biomedical applications. 相似文献
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Wei Liu Wenxiao Shi Yaowen Lv Jingtai Cao Yumei Yin Yuanhao Wu Jihong Wang Xuefen Chi 《Optik》2013,124(24):6840-6845
Camera pose estimation is a basic and crucial problem in computer vision, accordingly a novel method is proposed for pose estimation based on parabolic motion in our paper. Firstly, the intersection of lines which are the image plane projection of free-falling trajectories in different locations is computed. According to the properties of vanishing point, the intersection is defined as the vanishing point in gravity direction. Secondly, the image plane projected curve of parabolic trajectory is obtained by Sampson Approximation. Finally, the camera pose is estimated by employing the projective geometry properties of vanishing point and vanishing line implicated in the projected parabola, provided that the intrinsic parameters of camera are specified. The absolute Euclidean distance of translation is obtained innovatively with the known frame frequency. Numerical simulation as well as practical experiment in this paper demonstrates the correctness and feasibility of our method, with the known frame frequency, as the experiment show that compared with the traditional checkerboard method the mean errors of rotation axis, rotation angle and translation are respectively 0.017 rad, 0.007 rad and 11.650 mm by our method. It can generally satisfy the accuracy requirements of camera. 相似文献
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采用正硅酸乙酯,硼酸,乙醇钠为先驱体,乙醇,乙二醇甲醚和乙醇为先驱体溶剂,并采用氯化金的水溶液为掺杂金微粒的先驱体,通过热处理使氯化金分解出金原子而使其长出金微粒,达到制备掺杂金微粒玻璃的目的。在钠硼硅系统干胶的制备过程中,详细地研究了氯化金的引入量等对大块干胶性质的影响,并确定了引入氯化金的适宜浓度。详细研究了干胶向玻璃转变的制备工艺,并成功地制备了掺杂金微粒的大块玻璃。采用X-射线衍射仪进行掺杂金微粒干胶和玻璃的桥晶与否分析,用紫外-可见吸收光谱研究了它们的光学性质。用透射电镜表征了金微粒在玻璃基质中的颗粒大小及分布,采用Z-Scan装置表征了此种玻璃的三阶非线性光学性质,得到折射率n2=8.22×10-12esu。 相似文献