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101.
102.
由于可见光成像系统的聚焦范围有限,因而在成像过程中,除聚焦良好的物体能生成清晰的图像外,该物体前后一定距离外的所有物体都将呈现不同程度的模糊.为了获得场景内所有物体均清晰的图像,在分析了多聚焦图像成像机理的基础上,提出了一种基于小波包变换的融合方法.它是将成像系统先聚焦在一部分对象上,得到其清晰的图像;然后再将其聚焦在另一部分对象上,得到另一清晰的图像;最后把这两幅实验图像加以融合,从而获得场景内所有物体均清晰的图像.实验结果表明,基于小波包变换的融合方法能够将信号的频带进行多层次划分,对高频成分也能进一步地分解,可有效综合多聚焦图像. 相似文献
103.
实验确定了自行研制的L波段三维电子自旋共振成像(3D-ESRI)系统的检测灵敏度及成像分辨率指标. 用Tempo水溶液模型测量灵敏度结果表明: 样品体积为10 mm, 高30 mm,测量浓度1×10-4 mol/L水溶液的信噪比为S/N=4∶1;加梯度磁场后,样品浓度需>5×10-4 mol/L,样品体积为19 mm, 高30 mm时,获得的投影谱的信噪比可满足图像重建的需要. 用DPPH固体样品确定的成像分辨率结果<1 mm. 文中还对ESRI系统的
各项总体性能做了归纳总结. 相似文献
各项总体性能做了归纳总结. 相似文献
104.
以PCl3为脱水剂,将邻氨基硫酚与水杨酸脱水环化合成出2-(2-羟基苯基)苯并噻唑,并进一步将所得产物与乙酸锌反应合成出2-(2-羟基苯基)苯并噻唑螯合锌(Zn(BTZ)2)材料。以该配合物作为发光层制备出结构为ITO/PVK:TPD/Zn(BTZ)2/Al近白色电致发光器件,其色坐标位于白场之内(x=0.242,y=0.359),在驱动电压为16V时,亮度达3200cdm2,对应的量子效率为0.32%。进一步在Zn(BTZ)2中掺入橙红色染料Rubrene,制成ITO/PVK:TPD/Zn(BTZ)2:Rubrene/Al结构器件,实现了纯白色发光(色坐标值:x=0.324,y=0.343),非常接近于白色等能点,且量子效率达0.47%。最后对上述器件的发光和电学性能进行了深入的研究和探讨。 相似文献
105.
将爆磁压缩等效为电流源的方法,对爆磁压缩发生器通过脉冲变压器对脉冲形成线充电进行了理论分析,得出爆磁压缩发生器在负载上产生电流波形(简称负载电流)为直线情况和任意电流波形情况下充电电流和充电电压的表达式。分析表明变压器耦合互感与负载电流随时间变化增长率是脉冲形成线充电的两个重要参数,脉冲形成线第一个充电电压峰值与变压器的耦合互感和负载电流波形斜率成正比,负载电流波形斜率的变化可以改变充电电压峰值的时间,斜率不断增加可以延长第一个充电电压峰值时间,从而可能增加充电电压的幅值,提高爆磁压缩发生器能量的利用效率。 相似文献
106.
在喷气Z pinch内爆等离子体研究中,雪铲模型是一种常用的、比较简单的物理模型。根据实验中提供的电流波形,负载线质量和初始半径,可以通过雪铲模型来估算内爆到心的时刻。根据一维运动方程和不同构形下的解析解以及部分实验结果相结合,讨论了雪铲模型的适用范围。数值计算的内爆时间和实验(Gamble II, Double EAGLE, BLACKJACK 5)测量值符合得较好。结果表明,雪铲模型在喷气Z pinch实验的负载优化设计研究中是很有参考价值的方法。 相似文献
107.
Cationic polymer as a kind of flocculant is widely applied in purification treatment of waste water. Because it has positive charge group, it is able to connect strongly the suspended matters, short cellulose and other microparticles. The research on synthesis of cationic polymer and application in treatment of waste water is very universal abroad. But domestic research on those is not general. The technology of synthesis of PEM is simple, and the production cost is low. It is easy to apply in treatment of waste water.Synthesis of PEM Emulsion FlocculantSome distilled water, PVA(poly(vinyl alcohol)), EA(ethyl acrylate), and K2S2O8(potassium persulfate) were put into reaction vessel. Kept stirring up under nitrogen. When heated the solution to 40℃, dropped the water solution of MTA[(2-methacryloxylethyl)trimethyl ammonium].Maintained the temperature at 70℃, reacted about 7-8 hours. Then got the PEM emulsion. Changed the ratio of EA and MTA. Obtained a series of PEM emulsions.Stability and Convertibility of PEM EmulsionThe test results showed that when the EA/MTA was 85/15, the PEM emulsion was most stable.When the total monomer quantity was 35%, the convertibility of PEM emulsion was the highest,i.e.98.6%.The MTA Copolymerization Ratio and Morphology of PEM EmulsionWhen the monomers EA/MTA=85/15 and total monomer quantity was 35%, the MTA copolymerization ratio of PEM emulsion was 95.15%(the highest), and the PEM emulsion was some microspheres with 100-180nm of diameter.The Test Results of PEM Emulsion in Treatment of Waste Water The PEM emulsion flocculant was applied in treatment of waste water of paper mill, and measured the precipitation time(t) and transmittancy(T). The test results were showed in table 1. The optimum value of PEM which was able to make the waste water of paper mill into clear water was 0.008%. 相似文献
108.
氯敌鼠(chlorophacinone)为第一代抗凝血杀鼠剂,主要是拮抗维生素K1的活性,阻碍凝血酶原的合成,损害微血管,降低血液凝固能力,因而造成皮下出血和内脏大量出血而引起死亡。中毒潜伏期3~5天,死亡高峰为4~6天。氯敌鼠由于中毒潜伏期长,体内检测有一定难度,特别是经过抢救以后,体内含量降低,因此需要高灵敏度的方法进行检验。生物检材中氯敌鼠的分析,国内外均有报道,检测方法多用有机溶剂提取,HPLC法和紫外导数法分析。中国刑警学院谭家镒等人,采用GDX101大孔树脂提取,紫外导数法进行测定。有关用硅胶柱提取,LC-MS测定的方法未见报道。 相似文献
109.
LI Shufeng LI Qian YANG Xinlin HUANG Wenqiang** State Key Laboratory of Functional Polymer Materials for Adsorption Separation Institute of Polymer Chemistry Nankai University Tianjin China 《Chinese Journal of Reactive Polymers》2004,(Z1)
1. INTRODUCTION The development of efficient polymer-supported catalysts has attracted much attention [1]. For obtaining polymeric catalysts, catalytically active groups were introduced onto polymers mostly by copolymerization of the appropriate monomers bearing the desired catalyticfunctionalities (e.g. imidazole, OH, and COOH) or by modification of preformed polymers.Another possibility involves the attachment of side chains, containing the desired arrangement of functional groups, o… 相似文献
110.
ZHANG Zhi-bin LI Min SONG Hong FANG Yi Hua Hui CHEN Li-guo ZHOU Wei WANG Zheng-rong 《合成化学》2004,12(Z1)
Microcapsulation is a technology that enwrapped the solid or liquid or some gas matter with membrane materials to form microparticles(i.e.microcapsules). The materials of microcapsule is composed of naturnal polymers or modified naturnal polymers or synthesized polymers. The water-soluble core matter can only use oil-soluble wall materials, and vice versa.Synthesized methods of polymer microcapsulesSynthesized methods with monomers as raw materialsThis kind of methods include suspension polymerization, emulsion polymerization, dispersal polymerization, precipitation polymerization,suspension condensation polymerization, dispersal condensation polymerization, deposition condensation polymerization, interface condensation polymerization, and so on.Synthesized methods with polymers as raw materialsThese methods are suspension cross-linked polymerization, coacervation phase separation,extraction with solvent evaporation, polymer deposition, polymer chelation, polymer gel,solidification of melting polymer, tray-painted ways, fluidized bed ways, and so forth.Polymer materials to synthesize microcapsules2.1. Naturnal polymer materialsThe characteristics of this kind of materials are easy to form membrane, good stability and no toxicity. The polymer materials include lipids(liposome), amyloses, proteins, plant gels, waxes, etc.2.2. Modified polymer materialsThe characteristics of these materials are little toxicity, high viscidity(viscosity), soluble salt materials. But they cannot be used in water, acidic environment and high temperature environment for a long time. The materials include all kind of derivants of celluloses.2.3. Synthesized polymer materialsThe characteristics of the materials are easy to form membrane, good stability and adjustment of membrane properties. The synthesized polymer materials include degradable polymers(PLA, PGA,PLGA, PCL, PHB, PHV, PHA, PEG, PPG and the like) and indegradable polymers(PA, PMMA,PAM, PS, PVC, PB, PE, PU, PUA, PVA and otherwise).The applications of polymer microcapsules in cell technologyThe "artificial cell" is the biological active microcapsule used in biological and medical fields.The applications of cells (including transgenic cells, the same as artificial cells) technology include several aspects as follows:3.1. Microcapsulation of artificial red cell3.2. Microcapsule of artificial cell of biological enzyme3.3. Microcapsule of artificial cell of magnetic material3.4. Microcapsule of artificial cell of active carbon3.5. Microcapsule of active biological cell 相似文献