Preparation and Catalytic Performance of Mesostructured Aluminosilicate Nano-particles with Wormhole-Like Framework Structure

A facile two-step sol–gel method has been developed for the preparation of mesostructured aluminosilicate nano-particles (Si/Al = 7.5) with wormhole-like but uniform pore structures and highly catalytic activities towards bulky hydrocarbon cracking. It is desirable that, as this synthesis takes place in the absence of alkali cations, the mesoporous nano-particulate material is directly obtained in the acid form, making a subsequent ion-exchange and calcination treatment superfluous.     

管材超声波分层缺陷检测中盲区的构成探析

管材超声波分层检测作为控制产品质量的关键步骤,必须引起相关从业人员的重视,特别是要重点分析分层缺陷检测中盲区的构成原因和分布特征。只有这样,才能切实保证检测结果的准确性,更好地控制管材质量。通过对超声波分层缺陷检测的重要性进行阐释,分析了其中盲区的构成和分布等问题。     

聚丙烯催化剂进展及应用

介绍了聚丙烯（ＰＰ）催化剂、工艺技术的进展及近十几年世界新开发的金属茂催化剂的结构、特点及用于生产问规聚丙烯的实例。金属茂催化剂用于ＰＰ生产，为开发高性能ＰＰ产品，提高市场竞争能力提供了可能。     

一种低温高光泽艺术陶瓷装饰用大红釉的研制

使用低温含铅透明釉为基础釉，选用适宜的包裹红色料，研制成功一种艺术瓷用高光泽大红釉，并探讨了不同因素对大红釉呈色的影响。     

Preparation of porous poly(lactic acid)/Sio2 hybrid microspheres

With 3‐aminopropyltriethoxysilane (APTES) as coupling agent, poly(lactic acid) (PLA)/SiO₂ hybrid material was prepared to produce poly(lactic acid)/SiO₂ hybrid microspheres (PLAHs) with porous structure bythe oil‐in‐water, single‐emulsion solvent evaporation method. Field scanning electron microscopy results show that the PLAHs were porous microspheres about 20 μm in diameter. The holes in the PLAHs opened outside and were not complicated. A nitrogen adsorption–desorption experiment showed that the nitrogen adsorbed in the holes was easily desorbed, and the specific surface area of the PLAHs was calculated to be 6.87 m²/g according to the Brunauer–Emmett–Teller equation. Fourier transform infrared spectroscopy results show that PLA was amidated with APTES successfully and formed a kind of organic–inorganic hybrid material by hydrolysis and con‐condensation with tetraethoxysilane. Moreover, the molecular structure of the hybrid material was confirmed by X‐ray photoelectron spectroscopy. Differential scanning calorimetry results show that the melting point ofthe PLAHs was higher than that of PLA by about 11.2°C. These PLAHs may be used in the controlled release of drugs by the embedding of the drugs in the holes of the PLAHs, and the drug loading amount can be controlled by the size and number of holes in the PLAHs. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 679–683, 2006     

纳米电路交叉冗余容错技术研究

提出了一种针对纳米电路的数字电路容错设计新方法．该方法基于交叉冗余原理,利用两种二进制错误的不对称性,采用模块化方法对纳米电路进行容错设计．以阵列乘法器为例,采用新方法对电路进行设计和仿真,并结合实验结果与传统的可重构和三模冗余容错方法进行比较．交叉冗余方法无需检测模块及表决器,不会增加系统延时,并且在资源消耗方面远低于传统方法,对纳米电路尤其适用．     

虚拟机在计算机实践教学中的应用

针对目前计算机实践教学中存在的问题,提出了一种虚拟机技术的解决方法。该方法不仅充分有效地利用现有设备,而且对硬件及系统具有很好的安全性,并能够增加学生的实践动手机会。教学上更加灵活、方便地设计实践项目,从而提高实践教学的质量。     

基于小波神经网络的无线电引信目标识别新方法

设计了基于小波神经网络的无线电引信目标识别新方法.根据无线电引信回波多普勒信号功率主要集中在低频部分的特点,对淹没在噪声中的无线电引信同波信号进行小波分解,提取在不同频带内信号能量作为特征,用小波神经网络对目标进行检测.针对不同信噪比,对某典型无线电引信回波信号进行定量研究,实验结果表明该方法处理信号信噪比达-7 dB.     

现代城市综合管理的本质、功能与体系再认识

城市综合管理需要建立一个超越部门的协调体制,包括建构一个市长牵头的城市综合管理委员会,下设专门的办公室,并与专门设置或指定的城市综合管理部门合署办公,同时建立与城市基础功能有关的部门、单位之间的公务协助机制,制定履行城市综合管理职能的评价指标和奖惩标准,完善城市综合管理的相关法规或文件,引入数字技术等现代化手段和社会公众等监督与评价机制。     

定向井技术在白庙气田产能建设中的应用

东濮凹陷白庙气田构造破碎、储层相变快、储量分布不均匀。如何以较少的钻井投资，尽量多地钻遇气层层数，以较少的钻井数最大限度地控制气田地质储量，是高效开发白质气田的难点。通过气田地质研究及气藏工程论证，提出定向井设计思路，并根据不同的地质条件，研究设计出不同类型的定向井，应用于白庙气田产能建设中，效果显著。