Glass forming regions and dielectric properties of Na2O-Bi2O3-TiO2-P2O5 glasses

The glass forming regions have been determined in the quaternary systems Na₂O-Bi₂O₃-0.05TiO₂-P₂O₅ and Na₂O-0.05Bi₂O₃-TiO₂-P₂O₅. The largest vitreous do main has been found in the diagram with 5mol% of titanium oxide TiO₂- The variation of dielectric constant has been followed along two lines inside the glass regions. e'_r increases with increasing amount of sodium oxide Na₂O and diminishes with increasing percentage of either Bi₂O₃ or TiO₂.     

Low false reject rate and false accept rate multi-step fire detection method

This paper proposes an efficient fire detection method for intelligent monitoring of self-service banks. This method includes the following steps: motion region detection, color-based fire detection and fire region refinement. These steps are as follows. First, the method uses four Gaussian distributions to construct an adaptive background model of the scene, and exploits this model to obtain the moving regions of the image. Second, the method uses RGB color and HSI color to determine whether the moving regions are fire candidates or not. These two steps are able to detect almost all of the true fire regions but it also takes a portion of non-fire regions as the fire. Third, the proposed frame difference procedure and the distance of two fire regions of two adjacent frames to eliminate the false fire regions obtained using the first two steps. The experimental results show that the proposed method performs very well in small-scale fire detection. The false reject rate (FRR) and false accept rate (FAR) of our method are 10.4%, and 6.02%, respectively.     

Entangled orbital angular momentum states of multi-Laguerre Gaussian Schell beams pumping in a Zernike tilt corrected turbulence

Based on the paraxial approximation of the beams propagation in communication system, the square approximation of the wave structure function, the Zernike polynomial expansion of the non-Kolmogorov atmospheric turbulence-aberration and the assumption of the signal photon propagation in slant Zernike tilt corrected turbulence-channel, we analyze the effect of the multi-beam on entangled orbital angular momentum states. The joint detection probability of orbital angular momentum state entangled photons is modeled. Our work shows that the correction of the Zernike tilt aberration by adaptive optics is a method to improve the joint detection probability of orbital angular momentum state entangled photons. The crosstalk probability of the entangled orbital angular momentum states decreases as increasing of the degree of the spatial coherence of the partially coherent source and the beamlet number of the multil-Laguerre Gaussian Schell model beams.     

New Cholesteric and Nematic Lyotropic Mesophases from Di-Sodium N-Lauroyl-Aspartate

Lyotropic liquid crystals are prepared from racemic and optically active di-sodium N-lauroyl aspartate (SNLA). The optically active levo enantiomer is a suitable amphiphile for obtaining cholesteric lyotropic mesophases. In the present work, different types of mesophases, including cholesteric and nematic, were prepared and their type I or II magnetic behavior characterized by deuterium and ²³Na NMR. The polarizing microscope textures were investigated, particularly with regards to magnetic field effects upon the samples. The usual chevron pattern was obtained for particular sample orientations and several characteristic effects were observed for the type I cholesteric lyomesophase in the first few minutes following removal of the sample from the magnetic field. Although the head group of di-sodium N-lauroyl aspartate possesses two negative charges, compositions are not too different from those reported for other amphiphile lyotropic systems.     

Inductively Coupled Plasma Optical Emission Spectrometry in the Vacuum Ultraviolet Region

Abstract

Inductively coupled plasma optical emission spectrometry has been applied for trace metal determination in a myriad of sample types. However, the detection of nonmetals is a challenge. For example, the high excitation energies associated with most nonmetals is a barrier for populating the excited state of these elements. Even in the presence of sufficient excitation energy, the principal resonance lines for nonmetals usually lie in the vacuum ultraviolet region, where atmospheric species like oxygen and water vapor absorb the radiation. Several nonmetals (nitrogen, oxygen, and carbon) are also present in the atmosphere, so contamination or background emission signals can hinder quantification. A common approach to solving these problems is to increase throughput by purging the optical path with an inert gas. In addition, unnecessary mirrors or lenses are eliminated when possible. This review provides a survey of the applications of inductively coupled plasma optical emission spectrometry in the vacuum ultraviolet region, with particular emphasis on the detection of sulfur, phosphorus, iodine, and carbon. The alternative of employing nonresonance lines for these elements in the near-infrared region is discussed briefly as well.     

Neuroprotective effect of agmatine in rats with transient cerebral ischemia using MR imaging and histopathologic evaluation

Purpose

This study aimed to further investigate the effects of agmatine on brain edema in the rats with middle cerebral artery occlusion (MCAO) injury using magnetic resonance imaging (MRI) monitoring and biochemical and histopathologic evaluation.

Materials and methods

Following surgical induction of MCAO for 90 min, agmatine was injected 5 min after beginning of reperfusion and again once daily for the next 3 post-operative days. The events during ischemia and reperfusion were investigated by T2-weighted images (T2WI), serial diffusion-weighted images (DWI), calculated apparent diffusion coefficient (ADC) maps and contrast-enhanced T1-weighted images (CE-T1WI) during 3 h–72 h in a 1.5 T Siemens MAGNETON Avanto Scanner. Lesion volumes were analyzed in a blinded and randomized manner. Triphenyltetrazolium chloride (TTC), Nissl, and Evans Blue stainings were performed at the corresponding sections.

Results

Increased lesion volumes derived from T2WI, DWI, ADC, CE-T1WI, and TTC all were noted at 3 h and peaked at 24 h–48 h after MCAO injury. TTC-derived infarct volumes were not significantly different from the T2WI, DWI-, and CE-T1WI-derived lesion volumes at the last imaging time (72 h) point except for significantly smaller ADC lesions in the MCAO model (P < 0.05). Volumetric calculation based on TTC-derived infarct also correlated significantly stronger to volumetric calculation based on last imaging time point derived on T2WI, DWI or CE-T1WI than ADC (P < 0.05). At the last imaging time point, a significant increase in Evans Blue extravasation and a significant decrease in Nissl-positive cells numbers were noted in the vehicle-treated MCAO injured animals. The lesion volumes derived from T2WI, DWI, CE-T1WI, and Evans blue extravasation as well as the reduced numbers of Nissl-positive cells were all significantly attenuated in the agmatine-treated rats compared with the control ischemia rats (P < 0.05).

Conclusion

Our results suggest that agmatine has neuroprotective effects against brain edema on a reperfusion model after transient cerebral ischemia.     

北京一号,环境星,Landsat TM传感器估算草地覆盖度、叶面积指数、地上生物量比较研究

以京津风沙源区的草地为研究对象,选取中国自主B J-1、HJ数据及国外应用最为广泛的LandsatTM为数据源,结合地面同步实测草地植被覆盖度、叶面积指数和地上生物量数据,系统比较三个传感器在草地生理参数估算方面的差异与能力.研究结果表明:(1)HJ-1B与Landsat TM的红光波段与草地生理参量有更高相关性,而B J-1相对较弱,但BJ-1近红外波段在草地生理参量遥感估算上明显优于HJ-1B与Landsat TM; (2)Landsat TM的植被指数在估测草地生理参量时好于HJ-1B与BJ-1数据,HJ-1B植被指数的表现优于BJ-1;(3)相对于植被指数,全波段多元回归模型可以提升草地生理参量估测精度,基于Landsat TM与HJ-1B的提升效果微弱,而基于BJ-1数据的估算精度有明显提高,其中基于BJ-1估算叶面积指数达到了最高精度(R2 =0.61,RMSEP=0.15).总体来说,自主国产遥感数据有其自己特色,可供深入研究及推广应用的潜力很大.     

类锂离子双电子复合过程中辐射光子角分布和极化特性的理论研究

基于多组态Dirac-Fock 方法和密度矩阵理论,本文详细计算了高电荷态类锂离子（26 ≤ Z ≤ 92）KLL 双电子复合过程中,自由电子被共振俘获到中间双激发态1s2s²2p_3/2J = 1 的磁子能级截面以及该双激发态的取向参数,进而得到了此激发态向基态电偶极辐射跃迁1s2s²2p_3/2J = 1→1s²2s²J = 0 所发出光子的角分布和极化度,重点讨论了Breit 相互作用对相关物理量的影响. 研究表明,Breit 相互作用极大地改变了中间双激发态1s2s²2p_3/2J = 1 不同磁子能级的截面,从而导致了随后退激发放出光子的角分布和极化特性的显著变化. 关键词： 角分布和极化特性 多组态Dirac-Fock方法 密度矩阵理论     

Influence of molecular orientation on the photodissociation process of LiH molecules

Regulation of photodissociation dynamics of oriented LiH molecules in different dissociation channels is proposed based on time dependent quantum wave packet theory. The enhancement of molecular orientation on the photodissociation of LiH is obvious with our theoretical scheme. The results show that the molecular orientation in the ground state has a great effect on the angular distributions of wave packets. By using the proper laser pulses and controlling the polarization direction of the laser pulses, the enhancement of the photodissociation could be realized. After the molecular orientation, an optimal dissociation channel is observed with an improved dissociation probability. Compared with the results without molecular orientation, the maximal dissociation probability is increased by 8.1% in the indirect dissociation channel and 30.7% in the direct dissociation channel. The enhancement effect is more obvious in the direct dissociation channel, which provides a possible method to manipulate the dissociation of LiH molecules experimentally. Additionally, the photodissociation process of LiH also relies on the electric intensity and delay time of two pump pulses.     

国家战略下的中原经济区经济发展现状分析

选取能够反映经济发展水平的15个指标,运用因子分析法和聚类分析法对当前中原经济区32个市(县)的经济发展现状进行分类比较、排名和综合评价,并提出相关建议为中原经济区的决策者和建设者提供参考.