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101.
Ruili?ZhangEmail author Jianming?Dai Wenhai?Song Yongqing?Ma Jie?Yang Yuping?Sun 《中国科学G辑(英文版)》2004,47(1):113-120
It is helpful to study the photo-induced effect in the perovskite manganites not only for elucidating the mechanism of colossal
magnetoresistance (CMR) effect but also for potential applications in technology. The laser-induced effect in the Co doping
layered perovskite manganites La1.2Sr1.8Mn1.8Co0.2O7, is studied in this paper and the obtained results are also compared with that gained in the Nd-doping manganites with cubic
perovskite structure. 相似文献
102.
对西安地区150例0~3岁儿童进行了六种微量元素:钙、锌、铜、铁、镁、硒的检测,发现微量元素缺乏可导致急慢性感染、免疫力低下、小儿营养不良、贫血、发育迟缓等症状。并对小儿营养不良、喂养不当进行矫正。其中铁、钙、锌同时缺乏占50%。 相似文献
103.
Spirals generated from the excitable media within the Barkley model is investigated under the gradient electric fields by a numerical simulation. The spiral drift and spiral break up are observed when the amplitude of the electric fields is modulated by a constant signal or a chaotic signal. It is also verified that, even in the presence of the white noise, the whole system can reach homogeneous states after the spiral breakup, by using an adaptive strategy. 相似文献
104.
105.
ChujiangCai ZhigangShen MingzhuWang ShulinMa YushanXing 《中国颗粒学报》2003,1(4):156-161
This paper reports the use of a colloidal Pd^0 catalysis system to metallize the surface of precipitators separated from coal fly-ash, and metals such as Cu, Ni etc. are deposited on the precipitators surface. Alternatively, according to the characteristic surface of cenospheres, an Ag coating catalysis system is adopted to first deposit Ag on the cenospheres surface, followed, if necessary, by the deposition of other metals such as Cu, Ni, etc. on the Ag coating to produce monolayer and multilayer metal-coated cenospheres. The surface characteristics and the morphologies of the metal coatings are examined in detail with scanning electron microscopy (SEM), energy dispersive spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS) techniques. It can be shown that the quality of metal coatings derived from the Aa coatina catalysis system, is better than that of the colloidal Pd^0 catalysis system. 相似文献
106.
Summary The potential of liquid chromatography-mass spectrometry (LC-MS) has been studied for the simultaneous determination of sixteen carbamate and organophosphorus pesticides in honeybees using a traditional sample preparation protocol based on acetone extraction and dichloromethane partitioning. The performances of both atmospheric pressure chemical ionization (APCI) and electrospray (ES) interfaces were compared. APCI offered better sensitivity and specificity for a higher range of pesticides. Limits of quantification were from 0.01 to 0.17 mg kg–1, at which recoveries obtained were between 64 and 93%, except for pirimicarb that was at 13%, with relative standard deviations ranging from 7 to 20%. Fenitrothion, fenoxycarb, methiocarb and phoxim were found in bees from Valencian Community beehives at concentrations between 0.03 and 3.75 mg kg–1. 相似文献
107.
108.
聚合物分散液晶光栅的衍射特性的研究 总被引:9,自引:4,他引:5
报道了一种由聚合物分散液晶膜与具有周期性条状电极结构板结合的新型光栅器件,借助于聚合物分散液晶膜的电光特性,这种栅对入射光的散射或衍射取决于对其施加的电压,即它是电场可调的,实验结果显示出当驱动电压超过器件器件阈值电压时,衍射光的强度和衍射斑的可见级次被电场调制,而且它能入射光的线性偏振态变为椭圆偏振态。 相似文献
109.
110.
本文研究由双障碍问题导出的一类B可微函数的性质,并在一定条件下证明了求解相应的B可微方程阻尼牛顿法的全局收效性和二阶收效性.数值例子表明这一算法是有效的. 相似文献