Facile synthesis of ordered nanocrystalline alumina thin films with tunable mesopore structures

Mesoporous alumina layers have attracted attention for their potential use in ultrafiltration of salts, as a heterogeneous catalyst support, an adsorbent in environmental cleanup, and in petroleum refinement. The ability to control the fast hydrolysis rate of the inorganic precursors using simple and inexpensive routes is important for that potential to be realized. Herein, we introduce a novel and facile route to synthesize mesoporous alumina thin films from the combination of inexpensive and commercially available copolymer with aluminum chloride or nitrate (salts) in an EtOH–surfactant–NH₃ · H₂O–salts (EsNs) system through the evaporation-induced self-assembly (EISA) method. Mesoporous alumina layers obtained utilizing the EsNs system have ordered and tunable pore structures. The ability to easily control the mesophases of the alumina layers within a short time provides distinct advantages over previously reported synthesis procedures. Most importantly, we demonstrate that the binding of surfactant and NH₃ · H₂O for the formation of hydrogen bond between them in the EsNs system controls the fast hydrolysis rate of the inorganic species. This allows for the synthesis of nanocrystalline alumina layers via the aluminum oxo-clusters’ assembly with the surfactant. Such simple route may be applied in the synthesis of other non-silica mesostructured oxides.     

Comparing alternative cellulosic biomass biorefining systems: Centralized versus distributed processing systems

This study explores how two different cellulosic ethanol production system configurations (distributed versus centralized processing) affect some aspects of the economic and environmental performance of cellulosic ethanol, measured as minimum ethanol selling price (MESP) and various environmental impact categories. The eco-efficiency indicator, which simultaneously accounts for economic and environmental features, is also calculated. The centralized configuration offers better economic performance for small-scale biorefineries, while the distributed configuration is economically superior for large-scale biorefineries. The MESP of the centralized configuration declines with increased biorefinery size up to a point and then rises due to the cost of trucking biomass to the biorefinery. In contrast, the MESP in the distributed configuration continuously declines with increasing biorefinery size due to the lower costs of railroad transportation and the greater economies of scale achieved at much larger biorefinery sizes, including biorefineries that reach the size of an average oil refinery—about 30,000 tons per day of feedstock. The centralized system yields lower environmental impacts for most impact categories than does the distributed system regardless of the biorefinery size. Eco-efficiency analysis shows that the centralized configuration is more sustainable for small-scale biorefineries, while the distributed configuration with railroad transport is more sustainable for large-scale biorefineries. Compared with gasoline from petroleum, cellulosic ethanol fuel offers sustainability advantages for the following environmental impact categories: fossil energy consumption, global warming, human health impacts by particulate matter, ozone layer depletion, ecotoxicity, human health cancer, and human health non-cancer, depending somewhat on the biorefinery sizes and the system configurations.     

COSIX64设备驱动程序开发技术综述

该文论述了在Alpha系列计算机以及COSIX64操作系统平台下,开发基于EISAISA总线专用板的驱动程序的技术路线、技术难点及其解决方法。总结了开发COSIX64驱动程序的一般步骤。     

EISA总线扩展板的设计

ＥＩＳＡ总线广泛应用于微机。本文介绍了ＥＩＳＡ总线的信号及特点，着重说明了在ＥＩＳＡ，总线上设计Ｉ／Ｏ扩展板、存储器扩展板、总线主设备扩展板的方法。     

RAID系统的设计与实现

容错盘阵列通过采用多盘并发操作和冗余技术，可显著改善Ｉ／Ｏ系统的数据传输率和可靠性。在本文中，我们描述了一个高性能ＲＡＩＤ系统的设计与实现。该ＲＡＩＤ系统基于标准接口（ＥＩＳＡ，总线和ＳＣＳＩ总线）和高效纠错码（Ｒｅｅｄ－Ｓｏｌｏｍｏｎ码），具有高性能、高可靠性和通用性强的特点。本文重点是所设计的ＲＡＩＤ控制器的逻辑结构、设计方法、以及ＲＡＩＤ系统的软件构成、性能评价。最后我们提出了进一步改进设计的努力方向。     

灵活方便的EISA总线

EISA总线广泛应用于IBM PC系列机及其兼容机。本文介绍了EISA总线的定义及功能,阐明了EISA在几种应用场合下的时序波形图,突出了EISA总线灵活方便的特色。     

Effect of variation of average pore size and specific surface area of ZnO electrode (WE) on efficiency of dye-sensitized solar cells

Mesoporous ZnO nanoparticles have been synthesized with tremendous increase in specific surface area of up to 578 m²/g which was 5.54 m²/g in previous reports (J. Phys. Chem. C 113:14676-14680, 2009). Different mesoporous ZnO nanoparticles with average pore sizes ranging from 7.22 to 13.43 nm and specific surface area ranging from 50.41 to 578 m²/g were prepared through the sol-gel method via a simple evaporation-induced self-assembly process. The hydrolysis rate of zinc acetate was varied using different concentrations of sodium hydroxide. Morphology, crystallinity, porosity, and J-V characteristics of the materials have been studied using transmission electron microscopy (TEM), X-ray diffraction (XRD), BET nitrogen adsorption/desorption, and Keithley instruments.     

EISA Ethernet高档网卡的开发

本文给出的ＥＩＳＡ总线结构下的３２位网络接口卡产品的实例，介绍了采用存储器映射技术的高性能价格比网卡的设计方案。     

国产核医学仪器面临的一个问题及对策

阐述了计算机扩展槽的发展过程，将对国产核医学仪器产生的深刻影响，以及几种对应策略。