Phase Relations in the System Al2O3–B2O3–Nd2O3

The phase relations at a temperature below "subsolidus" in the system Al₂O₃–B₂O₃–Nd₂O₃ are reported. Specimens were prepared from various compositions of Al₂O₃, B₂O₃, and Nd₂O₃ of purity 99.5%, 99.99%, and 99.9%, respectively, and fired at 1100°C. There are six binary compounds and one ternary compound in this system. The ternary compound, NdAl₃(BO₃)₄ (NAB), has a phase transition at 950°C ± 15°C. The high-temperature form of NAB has a second harmonic generation (SHG) efficiency of KH₂PO₄ (KDP) of the order of magnitude of the form which has been used as a good self-activated laser material, and the low-temperature form of NAB has no SHG efficiency.     

Surface Modification of Titania Nanoparticles Using Ultrathin Ceramic Films

Surface modification of titania nanoparticles was achieved by coating them with ultrathin alumina films using atomic layer deposition. The coating process was performed in a fluidized bed reactor at low pressure and under mechanical vibration. Films were deposited using self-limiting, sequential surface reactions of trimethylaluminum and water. The composition of alumina-coated particles was verified using infrared spectroscopy. The deposited films had an average growth rate of 0.2 nm/coating cycle and were highly uniform and conformal as demonstrated by transmission electron microscopy and X-ray spectroscopy. Deposited alumina films were amorphous as verified through X-ray diffraction and high-resolution electron microscopy. The coating process did not promote particle sintering as validated via particle size and surface area analysis.     

Preparation and properties of T300 carbon fiber‐reinforced thermoplastic polyimide composites

In this study, a series of T300 carbon fiber‐reinforced polyimide (CFRPI) composites were prepared by laminating premolding polyimide (PI) films with unidirectional carbon fiber (CF) layers. On the basis of PI systems design, the effect of CF volume fraction, processing conditions, and PI molecular structure on the properties of CFRPI composites was studied in detail. In addition, two kinds of nano‐particles, including carbon nano‐tube (CNT) and SiO₂ were filled into the premolding PI films with different concentrations. And the effect of nano‐particles on the properties of CFRPI composites was also investigated. The surface characteristic of T300 CF was measured by X‐ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). The properties of premolding PI film and CFRPI composites were measured by dynamic mechanical analysis (DMTA), SANS testing machine, scanning electron microscopy (SEM), and so forth. These experimental results showed that the properties of CFRPI composites were mainly affected by the premolding PI film and molding condition. The change of CF volume fraction from 55% to 65% took little effect on the mechanical properties of CFRPI composites. In addition, the incorporation of nano‐particle SiO₂ could further improve the properties of CFRPI composites, but CNT hardly improved the properties of CFRPI composites. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 646–654, 2006     

千年前的求爱诗：震旦之恋·扶桑之情——《关雎》与《天皇御制歌》之比较研究

从主题、内容、形式结构、语言特色、视点、表现手法、诗歌风格等方面比较<关雎>与<天皇御制歌>的异同,探寻产生其异同的原因以及由此给日本文学发展带来的影响.     

化学教学与思想教育的融汇

本文阐述了在化学教学中要进行辩证唯物主义和爱国主义教育,要关注社会问题,要融汇政治思想教育。思想教育融汇在化学教学环节中首先要求我们对学生进行科学素养的培养;思想教育融汇在化学教学环节中要求我们的教学要与工农业生产相结合;思想教育融汇在化学教学环节中还要求我们的教学要与思想道德教育相结合,要与法制教育相结合;思想教育融汇在化学教学环节中还要求我们的教学要与现代教育技术相结合。     

A recognition method of vibration parameter image based on improved immune negative selection algorithm for rotating machinery

To overcome the limitations of traditional monitoring methods, based on vibration parameter image of rotating machinery, this paper presents an abnormality online monitoring method suitable for rotating machinery using the negative selection mechanism of biology immune system. This method uses techniques of biology clone and learning mechanism to improve the negative selection algorithm to generate detectors possessing different monitoring radius, covers the abnormality space effectively, and avoids such problems as the low efficiency of generating detectors, etc. The result of an example applying the presented monitoring method shows that this method can solve the difficulty of obtaining fault samples preferably and extract the turbine state character effectively, it also can detect abnormality by causing various fault of the turbine and obtain the degree of abnormality accurately. The exact monitoring precision of abnormality indicates that this method is feasible and has better on-line quality, accuracy and robustness.     

Robust and Low-Complexity Synchronization for Energy Detection UWB Receiver

A simple method using aided sliding rectangular windows for synchronization in e nergy detector (ED) receiver is proposed for impulse-based ultra wideband radio s (IR-UWB) under binary pulse position modulation (PPM), therefore grants an at tractive solution for gaining low complexity while the accompanying performance loss in terms of UWB signal reception is comparatively low. Also, a method is de veloped to suppress noise through accumulation of integrated results before sync hronization point is reached....     

基于主成分分析的中国区域创新能力比较研究

通过建立区域创新能力评价指标体系,利用数据统计和SPSS13.0计算机软件进行主成分分析,对我国31个省(市)的创新能力进行综合排序,并对结果做了详细的评价与分析。     

S变换时频分析在隧道岩溶地震勘探解释中的应用

介绍了短时傅立叶变换、小波变换和S变换的优缺点及其彼此间的相互关系。详述了S变换的概念及性质,认为S变换方法具有良好的自适应性和时频分辨率,能提供高质量的时频谱信息。将S变换时频分析用于宜万铁路隧道地震映像法数据解释。结果表明,S变换时频剖面上的溶洞异常显示比时间剖面更为清晰,在推断岩溶的分布位置、大小、埋藏深度等方面具有良好效果。S变换方法有助于提高地震数据解释的精度和准确性。     

服务协同环境中的业务过程建模与验证

服务协同环境是以服务协同中间件为底层平台,面向企业级BPM、EAI和B2B应用的软件环境。文章基于进程代数方法研究了服务协同环境中服务基本活动建模、控制模式建模和业务过程的建模等问题。提出一种从用户设计界面有向图到服务过程表达式的生成算法。同时,文中还研究了如何用μ演算描述流程性质,并使用验证工具研究了流程正确性验证问题。