Correlation between radon exhalation and radium content in granite samples used as construction material in Saudi Arabia

Measurements of radon exhalation for a total of 205 selected samples of construction materials used in Saudi Arabia were carried out using an active radon gas analyzer with an emanation container. It was found that granite samples were the main source of radon exhalation. The radon exhalation rates per unit area from these granite samples varied from below the minimum detection limit up to with an average of 1.5 . The radium contents of 27 granite samples were measured using an HPGe-based γ spectroscopy setup. The ²²⁶Ra content of the granites varied from below the minimum detection limit up to , with an average of . The linear correlation coefficient between exhaled radon and radium content was found to be 0.90.     

Effect of glutaphen on generation of active oxygen species, photosynthetic electron transport, and the functional activity of photosystem 2 in Chlorella cells

Treatment of chlorella green algae (Chlorella sp.) for 2 h in the dark with the photodynamic herbicide glutaphen (GTP), consisting of 0.3 mM 1,10-phenanthroline and 0.6 mM glutamic acid, followed by illumination leads to efficient generation of active oxygen species (AOS). After 15 min of illumination, AOS accumulation reaches 200% compared with the level in cells of the control culture, then it decreases down to 130% and 115% after 1 day and 3 days of illumination. During the first few days after treatment, we observe inhibition of synthesis of a specific precursor of chlorophyll (Chl): 5-aminolevulinic acid molecules, and then we observe stimulation of the synthesis. The effect of GTP on the photosynthetic activity of chlorella does not depend on the AOS level but rather remains uniform, in contrast to its effect on the Chl biosynthesis system. GTP does not change the efficiency of light harvesting and charge separation at the reaction centers of photosystem (PS) 2, but significantly lowers the functional efficiency of the electron transport chain: the photochemical quenching constants for Chl a fluorescence and the effective quantum yield of photochemical reactions in photosystem 2 decrease. The major mechanism of action for GTP is probably displacement of the secondary quinone acceptor Q_B from its binding site on the D1 protein by the 1,10-phenanthroline, consequent inhibition of electron efflux from Q _A ⁻ and increase in the fraction of Q_B-nonreducing centers of PS 2. The active oxygen species generated in the cells have a photodegradative effect on the Chl biosynthesis system, in particular on its initial steps, and do not involve already formed pigment-protein complexes of PS 2. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 6, pp. 801–806, November–December, 2006.     

基于小波变换和形态学的图像内容认证方法

提出了一种新的图像内容认证方法。在发送端根据小波系数对图像的亮度及边缘纹理特性进行分析，将这些特性分类后编码为特征值，并将特征值加密后生成签名以水印方式嵌入图像。在接收端将待测图像的特征值与从中抽取出的水印进行比较，用形态学滤波的方法自动鉴别是否有内容被篡改，并给出篡改的位置和强度信息。实验表明，这种图像内容认证方法可有效的检测出恶意篡改，并可容忍由压缩、滤波、噪声污染等操作引起的失真。     

硒酵母对鱼酱油品质的影响

以鱼蛋白为原料，在酶解与曲酶发酵相结合的基础上，于后熟阶段加入硒酵母作为有机硒的载体和增香工具，生产品质优良的富硒营养鱼酱油。试验结果表明：采用后熟温度35℃，酵母液量10％，酱醅盐度8％和12％，后熟发酵周期12d的工艺条件，可生产出优质的富硒鱼酱油。产品的氨基氮、有机酸等营养成分均高于国家标准，有机硒的含量达到国内专用硒保健品的水平。     

3G计费系统的探索:时不我待

3G时代是移动多媒体时代，但是移动多媒体时代并不会等着3G的来临才出现，全球的移动运营商已在2.5G网络上提供移动内容服务并在应对由内容计费带来的新挑战。明确了由于移动内容服务在移动网络中的发展给计费模式带来的挑战，并讨论了计费模式在过渡期的发展，其中还介绍了一些欧洲运营商的经验：它们正面临的问题以及采取的应对方法。     

利用温度和植被指数进行地物分类和土壤水分反演

首先利用地物表面温度和植被指数，成功地对北京精准农业示范区内生长旺盛小麦、稀疏小麦、池塘水体、水草、淤泥和裸露土壤等6种地物进行了分类，其次，利用地物表现温度（LST）和归一化植被指数（NDVI）作为坐标系，建立LST－NDVI三角形分布的散点图，分析了散点图的地物特征分布及其物理意义，与植被的红外和近红外两个特征波段构造的散射图相比，同类样本的离散度更小，不同类别样本之间的距离更大。最后，提出了植被指数－－表面温度的土壤水分反演模型，结合地面采样数据成功地反演了实验区内作物地块的土壤水分。     

改性Y沸石上苯与二异丙苯烷基转移反应活性及结炭失活的研究Ⅰ.沸石的钠含量和硅铝比对表面酸性的影响

用调节交换液ｐＨ值、高温水蒸气处理和不同浓度磷酸溶液等三种不同的改性方法对国产Ｙ型沸石进行了改性处理，运用ＴＰＤ、红外光谱、ＸＲＤ、原子吸收光谱测试了催化剂的物理性质，考察了不同改性方法对催化剂中的钠含量及骨架硅铝比的影响，以及由此造成对催化剂表面酸性质的影响。实验结果表明，这三种改性方法均能将沸石中深层次的钠交换下来。钠的减少主要产生的是Ｂｒｏｎｓｔｅｄ酸中心，而当Ｎａ２Ｏ含量低于０．２‰时，产生的又主要是强Ｂｒｏｎｓｔｅｄ酸中心。其中，高温水蒸气处理不仅影响钠的含量，而且影响硅铝比。催化剂酸性质是钠含量和硅铝比两个相反因素结合作用的结果。此外，实验结果还发现高温水蒸气处理一方面影响Ｂｒｏｎｓｔｅｄ酸量，一方面又能降低Ｂｒｏｎｓｔｅｄ酸强度。而磷酸改性只能同时改变各种强度的Ｂｒｏｎｓｔｅｄ酸量，对酸强度则没有影响。     

Al含量对Fe-Al合金Zener弛豫的影响

在多功能内耗仪上用自由衰减和强迫振动方法研究了Al含量对退火态Fe-Al合金Zener弛豫的作用.结果显示：中等Al含量的Fe-Al合金产生强的Zener弛豫，而较低和较高Al含量的Fe-Al合金只产生微弱的Zener弛豫峰.Fe-Al合金中的Zener弛豫产生于次近邻Al原子对的重新取向以及它们之间的相互作用，而不是来源于最近邻的Al原子对，后者因为形成短程有序结构不能产生Zener弛豫. 关键词： Zener弛豫 Al含量     

(AgCu28)80InxSn(20-x)钎料的熔化特性及其铺展性研究

采用差示扫描量热仪研究了合金的熔化特性。结果表明：该合金在489～496℃处具有554～604℃两个明显的吸热带，添加11wt％的In时，其只存在496℃与603．6℃两个吸热峰。润湿与铺展性能测试表明该合金能很好地润湿紫铜，在In添加量大于12wt％时，随着In含量的增加铺展率变大。     

On the size of multivariate polynomial lemniscates and the convergence of rational approximants

In a previous paper, the author introduced a class of multivariate rational interpolants, which are called optimal Padé-type approximants (OPTA). The main goal of this paper is to extend classical results on convergence both in measure and in capacity of sequences of Padé approximants to the multivariate case using OPTA. To this end, we obtain some estimations of the size of multivariate polynomial lemniscates in terms of the Hausdorff content, which we also think are of some interest.