Influence of Charge Doping on Thermal Diffusivity of Double Perovskite Sr2FeMoO6 Studied by Mirage Effect

Effects of charge doping on thermal diffusivity have been investigated in double perovskite ferromagnetic Sr_2–x La _x FeMoO₆ (0 x 0.4) by means of the mirage effect at 300 K ( the critical temperature T _c 420 K). Substitution of the La³⁺ ions for the Sr²⁺ ions significantly increases the value of the thermal diffusivity from 0.39 cm² · s^–1 at x = 0 to 0.54 cm² · s^–1 at x = 0.4. The increased thermal diffusivity is ascribed to the extra itinerant electrons on the Mo4d band.     

Appropriate lemmae discovery

An inductive proof attempt may fail as the available induction hypotheses cannot be applied to simplify the conclusion. One of the major problems which arise when performing inductive proofs is to transform the conclusion of an induction step in order to make the hypothesis applicable. Often, to overcome this problem, several additional lemmae are needed. However, most inductive theorem provers rely upon user intervention in supplying the required lemmae. In contrast, we present a method for generating automatically lemmae. Generation of lemmae is motivated by attempts to find appropriate instantiations for non-induction variables in the inductive step. We consider implicative formulae of the form , where ΓandΔ are conjunction of atoms and x? and ? are vectors of universal and of existential variables respectively.     

Classification Using Φ-Machines and Constructive Function Approximation

This article presents a new classification algorithm, called CLEF, which induces a -machine by constructing its own features based on the training data. The features can be viewed as defining subsets of the instance space, and they allow CLEF to create useful non-linear functions over the input variables. The algorithm is guaranteed to find a classifier that separates the training instances, if such a separation is possible. We compare CLEF empirically to several other classification algorithms, including a well-known decision tree inducer, an artificial neural network inducer, and a support vector machine inducer. Our results show that the CLEF-induced -machines and support vector machines have similar accuracy on the suite tested, and that both are significantly more accurate than the other classifiers produced. We argue that the classifiers produced by CLEF are easy to interpret, and hence may be preferred over support vector machines in certain circumstances.     

Accuracy and precision of quantitative energy-dispersive x-ray spectrometry in the environmental scanning electron microscope

The accuracy and precision of quantitative energy-dispersive x-ray spectrometry in the environmental scanning electron microscope have been estimated using a series of copper / gold alloys of known composition. The mean values (five to six replicate experiments) had relative errors within +/- 5%, and most were within +/- 3.5%. All relative standard deviations were < 5% and most were < 3%. Since the standard specimens were large (approximately 500 microm) in diameter, electron scattering in the 2 torr of water vapor above the specimen did not affect the results. This level of accuracy and precision was possible only by using a novel specimen surface charge neutralization scheme.     

Anti-static properties of some cationic polymers used in hair care products

Anti-static properties of cationic polymers on hair have been measured by using an electrostatic voltmeter. Comparisons are made with conventional cationic surfactants. Behaviour of cationic polymers from a cationic base and an anionic base have been explained. Experiments are performed to arrive at the hypothesis that cationic polymers form a complex with anionic detergent and that this cation-anion complex solubilizes in excess of anionic detergent, but on dilution with water it forms a turbid solution.
Propriétés anti-statiques de certains polymères cationiques utilisés dans les produits de soins pour les cheveux     

压电传感器现场监测石英表面电荷分布

理论上解析了石英表面电荷分布情况,利用双液隔电极压电传感器(ESPS)与溶液直接接触的特点,对阴、阳离子表面活性剂的吸附情况进行了现场监测,间接地证明了理论分析,这对传感器本身以及石英表面改性处理有重要参考价值。     

Possibility of charge contrast imaging of polymeric materials

Preliminary results illustrate the possibility of charge contrast imaging (CCI) of polymeric materials. Possible CCI images of low-density polyethylene and polyvinyl chloride reveal details that may aid in the characterization of the microstructure of polymeric materials. These pictures were obtained with a Hitachi S-3000N variable pressure scanning electron microscope with the environmental secondary electron detector (ESED).     

A Mathematical-Physical Model for the Charge Transport in p-Type SrTiO3 Ceramics Under dc Load: Maxwell-Wagner Relaxation

A mathematical-physical model to describe the current response of p-type SrTiO₃ ceramics in the low-temperature regime upon dc voltage step was developed, utilizing the numerical class library DIFFPACK (Numerical Objects, Norway). The current response in the time domain shows the experimentally observed Maxwell-Wagner relaxation (space charge polarization), followed by leakage current, and, eventually, resistance degradation. The relaxation behavior is analyzed by means of the simulation results for the spatial profiles of the electrical potential and the respective point defects. The impact of bias voltage and grain boundaries on the relaxation time is investigated. The simulation results are compared with experimental data.     

HT-6M托卡马克杂质输运行为研究

以HT -6M托卡马克在欧姆加热条件下的氧、碳杂质空间分布的实际测量结果及该装置背景等离子体的具体特征为基础 ,建立起杂质输运分析程序 ,并由此展开模拟分析 .结果表明 ,该装置氧、碳杂质的浓度分别为 5 %ne和 3 %ne(ne为电子密度 ) ,杂质输运行为是反常的 ;扩散系数为 2 0m2 ·s- 1,有效电荷数Zeff接近 4     

国际机场石方供料峒室控制大爆破

根据机场对填方石料粒径的严格要求及石料场周围的复杂环境。我司技术人员根据多年,多次硐室大爆破成功的经验,从导洞布置方面严格要求各药室最小抵抗线均一化,从药包布置、药量分布、装药结构、起爆顺序等方面作了许多科学改进,精心设计,严密施工。终于使大爆破获得圆满成功。