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931.
Streak camera has high temporal resolution and high sensitivity, and is a powerful tool in biomedical study to measure fluorescence lifetime and perform fluorescence lifetime imaging. However, nonuniformity of the gain in the streak tube and nonlinearity of the sweeping speed limit the precision of fluorescence lifetime measurement, particularly when fluorescence lifetimes are short. We have constructed a two-photon excitation fluorescence lifetime measurement system that is based on a synchroscan streak camera and have developed accordingly a method to correct the effect of gain nonuniformity and nonlinearity of sweeping speed on the measurement precision. A continuous-wave laser of high stability is used to calibrate the gain of the streak camera, and a Fabry-Perot etalon is used to calibrate the nonlinearity of the sweeping speed. Fitting algorithms are used to correct the gain of the streak camera and nonlinearity of the sweeping speed respectively, which significantly improves the measurement precision of the system, as characterized through the fluorescence lifetime of the short-lived fluorescence dye, Rose Bengal. Experimental results show that the measurement fluctuation of the lifetime has been improved from more than 10% to 2% after correcting the effects of gain nonuniformity and sweeping speed nonlinearity. 相似文献
932.
933.
934.
文研究了 N 指标 d 维广义α-stable过程自相交局部时增量的Holder律. 并利用所得自相交局部时的性质, 证明了该过程重点的存在性, 得到了该过程多重时的Hausdorff维数及测度的下界.所得结论包含并推广了广义布朗单及stable单相应的结果. 相似文献
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936.
采用反向悬浮聚合法,丙烯酸(AA)和丙烯酰胺(AM)为单体,过硫酸钾(KBS)作引发剂,N,N-亚甲基双丙烯酰胺(MBA)作交联剂,制备了一种非包覆遇水膨胀型自修复剂LF-1,其结构经SEM和IR表征。结果表明,LF-1分散均匀,表观形态呈多孔、粗糙褶皱状。将2%LF-1加入水泥浆中,水泥浆流动度为20.1 cm,失水52 mL,稠化时间217 min;用5000 mg/L的盐水养护造缝水泥石,12 h内即无渗透性;水泥石24 h抗压强度为16.1 MPa,抗折强度为4.92 MPa。
相似文献
937.
N-soliton solutions of the hierarchy of non-isospectral mKdV equation with self-consistent sources and the hierarchy of non-isospectral sine-Gordon equation with self-consistent sources are obtained via the inverse scattering transform. 相似文献
938.
We propose a method to construct the integrable Rosochatius deformations for an integrable couplings equations hierarchy. As applications, the integrable Rosochatius deformations of the coupled CKdV hierarchy with self-consistent sources and its Lax representation are presented. 相似文献
939.
WANG Fei YAN Yu YUAN Zhou BAI Xue DU Xiao-Bo WANG Wen-Quan SU Feng JIN Han-Min 《中国物理快报》2010,27(6):210-212
Ribbons of nominal compositions YCo5 Cx (x = 0, 0.2, 0.4, 0.6) are prepared by melt spinning at surface velocities v = 5, 10, 15, 20, 25, 30 and 35 m/s. YCo5 ribbon is crystallized in a single YCo5 phase of hexagonal CaCu5 structure. A small quantity of YCoC2 phase appears in the ribbons with C addition besides the YCo5 phase. With the increase of x the lattice constant c increases and a along with the unit cell volume decreases. The largest values of iHc = 888 kA/m and (BH)max = 58.4 k Jim3 at present for the YCo5 ribbon system were obtained with x = 0.4 and v = 20 m/s. The improvement of the permanent magnetic properties is rooted in the refinement of the microstructure and the appearance of the YCoC2 phase which can act as domain wall pinning centers. 相似文献
940.
Effect of Annealing on Microstructure and Electrical Characteristics of Doped Poly (3-Hexylthiophene) Films 下载免费PDF全文
The effect of annealing on the microstructure and electrical characteristics of poly (3-hexylthiophene) (P3HT) films doped with very small amounts of the electron acceptor 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ) is studied. X-ray diffraction and UV-vis spectrum studies show that unlike the pure P3HT film, the thermal treatment on the doped fihns under an Ar atmosphere can effectively enhance the crystalline order of P3HT films, as well as successfully facilitate the orientation of the polymer chains. This improvement is attributed to the electrostatic force between P3HT and F4-TCNQ molecules. This force induces the polymer chains to crystallize and orient during the annealing process. As a result, annealing significantly improves performance, especially for the Ion/Ioff ratio of the TFTs based on the doped P3HT films. 相似文献