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991.
稀土芦丁配合物的合成、表征及抗肿瘤活性研究   总被引:1,自引:0,他引:1  
合成了稀土离子Tb3+的芦丁配合物,通过元素分析、核磁共振氢谱、摩尔电导、红外光谱、紫外光谱,确定了配合物的组成和结构,结果表明,配合物的组成为Na5TbLCl7·6H2O(L=C27H29O16),同时采用噻唑蓝还原法(MTT比色法)测定了配体及配合物对HepG2肝癌细胞株的抗肿瘤活性,实验结果表明,配合物对HepG...  相似文献   
992.
利用高效液相色谱法测定了广西、云南两地不同产区的催吐萝芙木根茎样本中利血平含量,并与该产区的气候特点进行了对照分析,比较了不同产区催吐萝芙木药用价值,分析了光照对催吐萝芙木药用价值的影响。  相似文献   
993.
杨俊  王文辉  王齐  孙晓东 《光谱实验室》2011,28(6):2849-2854
建立了超高效液相色谱串联质谱法检测土壤中甲磺隆、苄嘧磺隆残留的方法。土壤中的甲磺隆和苄嘧磺隆经C18固相萃取小柱萃取,然后用Waters Acquity UPLC BEH C18色谱柱(50mm×2.1mm,1.7μm)分离,以0.05%乙酸-甲醇为流动相进行梯度洗脱,流速0.4mL.min-1,采用正离子电喷雾电离模式测定,外标法定量。本方法简便、快速、准确、可靠,甲磺隆、苄嘧磺隆在1.0—100.0μg.L-1的浓度范围内呈良好的线性关系,相关系数(r)分别为0.9997和0.9999;检出限分别为0.02μg.kg-1和0.03μg.kg-1,回收率为86.2%—96.5%,相对标准偏差不大于5.1%。  相似文献   
994.
给出用线偏振光产生椭圆(或圆)偏振光的另两种方法.  相似文献   
995.
996.
We use the idea in [33] to develop the energy law preserving method and compute the diffusive interface (phase-field) models of Allen–Cahn and Cahn–Hilliard type, respectively, governing the motion of two-phase incompressible flows. We discretize these two models using a C0 finite element in space and a modified midpoint scheme in time. To increase the stability in the pressure variable we treat the divergence free condition by a penalty formulation, under which the discrete energy law can still be derived for these diffusive interface models. Through an example we demonstrate that the energy law preserving method is beneficial for computing these multi-phase flow models. We also demonstrate that when applying the energy law preserving method to the model of Cahn–Hilliard type, un-physical interfacial oscillations may occur. We examine the source of such oscillations and a remedy is presented to eliminate the oscillations. A few two-phase incompressible flow examples are computed to show the good performance of our method.  相似文献   
997.
Water-soluble CdSe quantum dots (QDs) were synthesized using mercaptosuccinic acid (MSA) as a stabilizer. The growth process and characterization of CdSe quantum dots were determined by transmission electron microscopy (TEM), X-ray diffraction (XRD), photoluminescence (PL) spectroscopy, Ultraviolet-visible (UV-vis) spectroscopy, and Fourier transform infrared (FT-IR) spectroscopy. Results demonstrated the MSA-capped CdSe QDs were highly crystalline and possessed good optical properties. Further, the resulting products could be used as fluorescent probes to detect Cu2+ ions in physiological buffer solution. The response was linearly proportional to the concentration of Cu2+ ion in the range 2×10−8- 3.5×10−7 mol L−1 with a detection limit of 3.4 nmol L−1.  相似文献   
998.
Particle Swarm Optimization (PSO) algorithms, including standard PSO, Stochastic PSO, and Multi-Phase PSO, are applied to solve the time-domain inverse transient radiation problems in the present research. Time-resolved transmittance and reflectance signals of four different measuring models serve as the measurement data, which estimate absorption, scattering coefficients, and geometric position within one-dimensional non-homogeneous media by inverse simulation. To check retrieval performances and accuracies of PSO-based approaches, four different inverse transient radiation cases are investigated to deal with one homogeneous layer, two-layer, three-layer, and continuous non-homogenous media. The influences of different searching ranges, swarm sizes, and maximum fly velocities on the fitness function of PSO are discussed. Meanwhile, the effects of measurement errors on the reconstruction accuracy are also investigated. All the results confirm that radiative parameters could be estimated accurately with measurement noise using PSO-based approaches.  相似文献   
999.
As it is not possible to obtain an accurate point spread function (PSF) in remote sensing imaging, classic deconvolution methods such as Wiener filtering often introduce strong noise and ringing artifacts, which contaminate the restored images. In this paper, we modify the standard Richarson-Lucy (RL) algorithm with a piecewise local regularization term and combine it with residual deconvolution method. Experimental results show that it is effective in suppressing negative effects, and images with rich details and sharp edges are obtained.  相似文献   
1000.
Based on the vector angular spectrum representation of electromagnetic beams and the method of stationary phase, the vectorial structure of a Hermite-cosine-Gaussian (HcosG) beam in the far field is derived in analytical form. Energy flux distributions for the TE term, TM term and the whole beam are represented. The vectorial structures of HcosG beams with different Hermite models are depicted. The effects of cosine displacement parameters on the vectorial structure are also demonstrated. The results may provide a flexible approach to manipulate HcosG beams in free space.  相似文献   
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