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排序方式: 共有711条查询结果,搜索用时 15 毫秒
1.
The possibility of realizing SASE Free Election Laser in x-ray waveband with EM-wave wiggler is studied in this paper. SASE effect including saturation length, saturation power and nonlinear process is explored through a 3-D simulation code. A utilization of seed light from laser plasma x-ray is also analyzed, which demonstrates the feature of shortening the interaction length for saturation. The results show that sizeable output power of x-ray laser would be generated with a middle energy electron beam. 相似文献
2.
A two-step swelling procedure was adopted to synthesize mono-dispersed and highly cross-linked poly (St-divinylbenzene) particles
with PSt micro-spheres (1.80 μm in diameter). The PSt micro-spheres were prepared by a dispersion polymerization method and
used as seeds. The effects of monomer concentration, ratio of ethanol to water, swelling reagents, crosslinking reagents,
swelling temperature and agitation speed on particle size were investigated in detail. The morphologies and size distributions
of these micro-spheres were examined by SEM and particle size analysis (PSA). The T
g of the micro-spheres was measured by DSC. The results indicate that the particles (6.20 μm in diameter) exhibit excellent
mono dispersed property and high crosslinking degree when the concentration of the swelling reagent was 25%, the concentration
of the crosslinking reagents was 23%, the swelling temperature was 30°C and the stirring speed was 150 r/min.
__________
Translated from Chinese Journal of Applied Chemistry, 2007, 24(11): 1289–1294 相似文献
3.
新疆野生黑加仑与马林果实的营养成分分析 总被引:2,自引:0,他引:2
通过对新疆野生黑加仑和野生马林的脂肪油,8种微量元素,17种氨基酸以及维生素C的含量进行测定得出:黑加仑脂肪油含量为17.9%,马林的脂肪油含量为22.3%,其中,黑加仑脂肪油中,r-亚麻酸的含量为19.02%,而马林中,其含量为9.40%,黑加仑中K,Na,Ca,Cu,Zn,Fe的含量比马林中的含量高,而Mn,Mg元素的含量却比马林含量低;马林的维生素C含量为16.22mg/g,黑加仑的含量为108mg/g,黑加仑的氨基酸的总量为1.63%,马林为1.14%。 相似文献
4.
研究玉米淀粉接枝聚丙烯酸酯共聚物的各级结构,主要探讨去除均聚物和玉米淀粉侧链的方法。发现以环己烷为溶剂,用索氏萃取法除去均聚物比用苯萃取法时间短、效果好;用HCl酸解法除去淀粉侧链比用HClO4氧化法简单实用。用红外光谱进一步验证了各级结构的官能团,证实了所合成的共聚物是玉米淀粉接枝聚丙烯酸酯共聚物。 相似文献
5.
通过对气吹式精密播种机田间试验资料的相关分析,发现合格指数A与|D-M|(重播指数与漏播指数之差的绝对值)之间里极显著负相关(r=-0.9312)。在对数据作进一步回归分析的基础上,本文建立了一套“由排种粒数预测排种质量”的方法。 相似文献
6.
重金属Pb2+对玉米苗生长的影响 总被引:11,自引:1,他引:10
以水栽培的玉米幼苗为材料,用不同浓度的醋酸铅溶液处理后,分别在第10天、第20天、第30天对玉米苗的根、茎、叶分别进行Pb^2+含量测定。分析结果:Pb^2+在玉米体内的分布表现为根〉叶〉茎;玉米中的叶绿素含量均降低;随着Pb^2+浓度的增大,玉米细胞的膜透性表现根〉叶〉茎依次升高;Pb^2+对玉米的伤害率的大小表现为根〉叶〉茎。该实验为进一步研究农作物对重金属Pb^2+的耐性和重金属Pb^2+在农作物体内的分布提供了可参考的数据。 相似文献
7.
Bonnie R. Hames Steven R. Thomas Amie D. Sluiter Christine J. Roth David W. Templeton 《Applied biochemistry and biotechnology》2003,105(1-3):5-16
New, rapid, and inexpensive methods that monitor the chemical composition of corn stover and corn stover-derived samples are
a key element to enabling the commercialization of processes that convert stover to fuels and chemicals. These new techniques
combine near infrared (NIR) spectroscopy and projection to latent structures (PLS) multivariate analysis to allow the compositional
analysis of hundreds of samples in 1 d at a cost of about $10 each. The new NIR/PLS rapid analysis methods can also be used
to support a variety of research projects that would have been too costly to pursue by traditional methods. 相似文献
8.
The unseeded non-hydrolytic sol-gel synthesis of ZrW2O8 and ZrMo2O8 produces trigonal ZrM2O8 (M = W, Mo) at 740 and 300–400°C, respectively. Cubic ZrW2O8 can be prepared using non-hydrolytic sol-gel methods by seeding with small amounts of preprepared cubic material, and the formation of the trigonal polymorph can be suppressed completely. Seeds with a small particle size are necessary for the preparation of cubic ZrW2O8. In contrast, seeding of ZrMo2O8 gels with either cubic ZrMo2O8 or cubic ZrW2O8 only lowers the temperature at which the trigonal phase crystallizes. 相似文献
9.
P. Pissis A. A. Konsta S. Ratkovič S. Todorovič J. Laudat 《Journal of Thermal Analysis and Calorimetry》1996,47(5):1463-1483
Broad-band ac dielectric relaxation spectroscopy (DRS) and various techniques of thermally stimulated currents (TSC) have been used to investigate molecular mobility in cereal and legume seeds, over wide ranges of water content and temperature. We focused our interest on the detailed study of the interactions between water and seed constituents. The results are quantitatively discussed, using various concepts dictated by the experimental techniques employed and in relation to the protein and carbohydrate contents of the seeds. In addition, the glass transition in the seeds, freezing and melting of water, and the protonic conduction process have been studied in some detail.Financial support through the Greek Ministry of Industry, Energy and Technology (Secretariat of Research and Technology), the Czech Ministry of Education, Youth and Sport (Dept. of International Scientific and Technological Cooperation), and the Empirikos Foundation is gratefully acknowledged. 相似文献
10.
对烘烤前后南瓜籽中的化学成分进行分析并对比。采用同时蒸馏萃取装置萃取南瓜籽中的挥发性成分,采取超临界CO2萃取技术萃取南瓜籽油脂,并将其分为酸、碱、中性三个部分,用气相色谱-质谱联用方法分析其中化学成分并进行对比。结果表明,南瓜籽挥发性成分中含有多种醛类和酯类化合物,烘烤后产生了大量的烷基吡嗪,其在碱性部分中的相对含量比烘烤前提高14倍多,不饱和醛类化合物含量也有明显提高。南瓜籽油脂中的主要化学成分是油酸、亚油酸及其酯类。还含有生物活性功能成分如植物甾醇、角鲨烯和维生素E等。烘烤后除角鲨烯含量有所降低,维生素E、植物甾醇、亚麻酸等均有提高。 相似文献