基于区间数度量的区间值模糊集合的归一化距离、相似度、模糊度和包含度的关系研究

区间值模糊集合的距离、相似度、模糊度和包含度及其关系研究是区间值模糊集合的一个研究热点.考虑到区间值模糊集合所表示信息的丰富性,本文使用区间数而非实数来刻画区间值模糊集合的距离,首先给出基于区间数度量的区间值模糊集合的归一化距离的公理化定义,然后通过五个定理详细研究了基于公理化定义的区间值模糊集合的归一化距离、相似度、模糊度和包含度之间的相互转换关系,最后,给出了若干公式来计算基于区间数度量的区间值模糊集合的相似度、模糊度和包含度.这些结论,一方面丰富了区间值模糊集合的信息测度(距离、相似度、模糊度和包含度)的内容,另一方面也为区间值模糊集合的近似推理、决策分析、模式识别等领域的应用提供了新方法和新理论.     

Communication and organizational social networks: a simulation model

Recent management research has evidenced the significance of organizational social networks, and communication is believed to impact the interpersonal relationships. However, we have little knowledge on how communication affects organizational social networks. This paper studies the dynamics between organizational communication patterns and the growth of organizational social networks. We propose an organizational social network growth model, and then collect empirical data to test model validity. The simulation results agree well with the empirical data. The results of simulation experiments enrich our knowledge on communication with the findings that organizational management practices that discourage employees from communicating within and across group boundaries have disparate and significant negative effect on the social network’s density, scalar assortativity and discrete assortativity, each of which correlates with the organization’s performance. These findings also suggest concrete measures for management to construct and develop the organizational social network.     

A normal criterion about two families of meromorphic functions concerning shared values

In this paper, we mainly discuss the normality of two families of functions concerning shared values and proved: Let F and G be two families of functions meromorphic on a domain D■C,a1, a2, a3, a4 be four distinct finite complex numbers. If G is normal, and for every f ∈ F , there exists g ∈ G such that f(z) and g(z) share the values a1, a2, a3, a4, then F is normal on D.     

A blind color image watermarking based on DC component in the spatial domain

Color image watermarking has become essential and important copyright protection or authentication scheme. It is noted that most of the existing color image watermarking algorithms are performed only in the single domain (spatial domain or frequency domain), and not to integrate these merits of the different domains. By utilizing the generating principle and distribution feature of the direct current (DC) coefficient, a novel blind watermarking algorithm is proposed for color host images in this paper. Firstly, the Y luminance of host image is divided into 8 × 8 sub-blocks and the DC coefficients of each block are directly calculated in the spatial domain without DCT transform. Secondly, according to the watermark information and the quantization step, the DC coefficients are calculated and their increments are further utilized to modify directly the values of all pixels in the spatial domain instead of the DCT domain to embed watermark. When watermark extraction, only the watermarked image and the quantization step are needed in the spatial domain. Experimental results show that the proposed method not only can resist both traditional signal processing attacks and geometric attacks, but also has more efficient in computational complexity. Comparisons also demonstrate the advantages of the method.     

Determination of the calcium species in coal chars by Ca K-edge XANES analysis

Ca-based additives have been widely used as a sulfur adsorbent during coal pyrolysis and gasification. The Ca speciation and evolution during the pyrolysis of coal with Ca additives have attracted great attention. In this paper, Ca species in the coal chars prepared from the pyrolysis of Ca(OH)2 or CaCO3-added coals are studied by using Ca K-edge X-ray absorption near-edge structural spectroscopy. The results demonstrate that Ca(OH)2 , CaSO4 , CaS and CaO coexist in the Ca(OH)2-added chars, while Ca(OH)2 and CaSO4 are the main species in the Ca(OH)2-added chars. Besides, a carboxyl-bound Ca is also formed during both the pyrolysis for the Ca(OH)2-added and the CaCO3-added coals. A detailed discussion about the Ca speciation is given.     

Morphology-Controlled Synthesis and Applications of Silver Halide Photocatalytic Materials

Semiconductor photocatalysis is considered to be one of the most promising technologies to solve the worldwide environmental and energy issues. In recent years, silver halide (AgX)-based photocatalytic materials have received increasing research attention owing to its excellent visible light-driven photocatalytic performances in the applications of organic pollutant degradation, H₂/O₂ generation, and disinfection. AgX-based materials used in photocatalytic fields can be classified into three categories: AgX (Ag/AgX), AgX composites, and supported AgX materials. For the AgX (Ag/AgX) photocatalysts, it has been widely accepted that the final photocatalytic performances of photocatalysts are severely dependent on their morphological structures as well as exposed crystal facets. As a result, considerable efforts have been devoted to fabricating different morphological AgX photocatalysts as well as exploring the relationship between the morphological structures and photocatalytic performances. In this review, we mainly introduce the recent developments made in fabricating morphology and facet-controllable AgX (Ag/AgX) photocatalytic materials. Moreover, this review also deals with the photocatalytic mechanism and applications of AgX (Ag/AgX) and supported AgX materials.     

8′-取代吲哚螺噁嗪光致变色化合物的合成及光谱性质

通过在螺噁嗪结构中的萘环8′-位上引入不同的取代基,合成了三种螺噁嗪光致变色化合物;对三种产物的光谱性质进行了对比研究,并考察了其光照褪色速率和抗疲劳性能.结果表明:改变8′-位取代基,合成化合物的闭环吸收峰的位置几乎不受影响,但开环吸收峰发生显著变化,随着取代基极性增加明显红移.增加溶剂的极性,可使同一化合物的开环吸收峰红移.