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71.
连续照明时成像对比度与气象条件的关系   总被引:6,自引:2,他引:4       下载免费PDF全文
 通过同轴激光连续照明成像模型分析了大气后向散射对成像对比度的影响,得出了考虑散射因素时成像对比度的计算公式。基于不同气象条件下大气粒子散射特点,讨论了霾和雾两种不同天气时成像对比度随照明距离的变化规律,并与实验结果进行了对比,计算结果与实验吻合较好。  相似文献   
72.
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   
73.
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   
74.
2-Chloro-5-methylpyridine is an important intermediate for the preparation of biological active compounds, especially insecticides1, e.g. imidacloprid2, and is usually manufac- tured from 3-methylpyridine N-oxide. However, the manufacturing process also forms the by-products: 3-methylpyridine and its isomer 2-chloro-3-methylpyridine3. The pro- perties of the isomers are similar, it is difficult to separate by ordinary methods, such as distillation. Scheme 1 79.4%13.6%5.2%NClCH3NCH3ClNC…  相似文献   
75.
From the dried aerial part ofParepigynumfuningesis Tsiang et P. T. Li (Apocynaceae),a new cardiac glucoside, named parefuningoside (1) had been isolated. Its structure was determined by means of hydrolysis and spectral analysis.  相似文献   
76.
A mono-funtionalised tetraphenylporphyrin (TPP) bearing valine moiety at the phenyl ring was synthesized for photocytotoxicity examination in four steps, starting from regiospecific mono-nitration of TPP at the phenyl ring. The in vitro photocytotoxicitic effect against SPC-Al adenocarcinona cell line was tested.  相似文献   
77.
张毅 《物理学报》2004,53(12):4026-4028
研究了Birkhoff系统的Hojman定理的几何基础.建立了系统的运动微分方程和Hojman守恒 定理,利用现代微分几何给出了Birkhoff系统的Hojman定理的一个证明. 关键词: Birkhoff系统 Hojman定理 对称性 微分几何  相似文献   
78.
辐射加热金X光再发射时间测量   总被引:4,自引:3,他引:1       下载免费PDF全文
利用星光Ⅱ三倍频激光打双盘靶,研究了辐射加热材料的X光发射时间。激光脉冲能量40~60J、脉冲宽度600~700ps。通过两台时间关联的亚千X光能谱仪分别监测双盘靶初、次级发射X光谱,给出了辐射加热次级X光再发射时间。  相似文献   
79.
花丝内插物强化竖直管内凝结换热的实验研究   总被引:1,自引:1,他引:0  
1前言大空隙率多孔体管内插物-绕花丝内插物,被认为是强化管内凝结换热的最有效途径之一[1].但以往的研究,由于实验雷诺数范围较小,蒸汽速度较低,要正确全面评价其性能尚显不够。本文在原有工作的基础上,进一步完善了实验系统,改进了测试手段,扩大了实验雷诺数范围,并测试了其阻力性能,对花丝内插物强化管内凝结换热进行了较深入全面的实验研究,以全面评价花丝内插物对管内凝结换热的强化效果。2实验系统本文实验系统如图1所示。实验段是一个竖直套管冷凝器,如图2所示.本试验研究蒸汽完全凝结时的传热。凝结水流量采用容积法计…  相似文献   
80.
沈为民  张艺 《光学学报》1998,18(12):741-1745
提出了折射率温敏式光纤温度传感器的理论模型,包括子午光线和偏射光线的影响,讨论了多模光纤的弯曲损耗,理论的分析和结果与实验相当一致。  相似文献   
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