部分预应力砼构件按两类极限状态的直接设计

本文提出了部分预应力砼构件基于两类极限状态直接控制的设计方法,并给出了具体的设计公式和设计步骤。同时,还对预应力砼超静定结构中的部分预应力砼构件的设计方法进行了说明。本文方法基本属一次性设计且具有较为经济的特点。     

尿失禁及其治疗药物

尿失禁是一种严重影响患者生活质量的慢性病，现将其分类、病因及治疗药物作一综述，为医药工作者提供参考。     

三江平原水利综合规划的重新编制问题

三江平原是我国重要的商品粮基地和粮食战略后备基地。原有规划距今已过30年，远不能适应现代发展要求。结合新的形势，提出了重新编制三江平原综合规划的现实意义、目标设想及主要修编内容。     

奥钢联板坯连铸计算机系统升级研究

某钢厂板坯连铸过程控制系统采用的奥钢联(VAI)技术,运行数年来,由于模型不透明,维护和调整困难,迫切需要升级改造。改造后的计算机系统充分考虑现有资源和需求,能够达到升级改造的目的。     

沁水盆地北端煤层气储层特征及富集机制

煤层气的富集与储层特征密切相关,并受地质条件的制约。在详细研究煤储层特征及煤层气富集机制的基础上,对沁水盆地北端煤层气的开发前景进行了初步评价。煤岩、煤质、煤体结构及孔渗性、吸附性的观察和测试显示,该区煤层厚度大,热演化程度高,局部发育构造煤,裂隙较发育,吸附性能力强,含气量高,含气饱和度偏低,适合煤层气的开发。该区煤层气的富集主要受控于热演化史和埋藏史。在区域变质的背景上,叠加了岩浆热变质作用,生气强度大。另外,煤层的埋深、顶底板封闭性及水文地质条件都会影响煤层含气量的大小,煤层气富集是多因素有效配置的结果。      

Conformational Molecular Switches for Post-CMOS Nanoelectronics

Theoretical treatments forecast that bistable CMOS devices using electronic charge as a state variable will operate at their maximum thermal dissipation limit possibly as early as 2012. The problem is further compounded by increasing manufacturing challenges associated with the ever decreasing logic switch dimensions. These challenges require the development of new fabrication strategies that replace or complement current top-down lithography with bottom-up protocols using controlled self-assembly of nanomaterial building blocks. To answer some of these issues, this paper focuses on a new device paradigm consisting of an arene-metal-arene conformational switch, addressable through capacitive, inductive, or resonant-tunneling field coupling. The operating principle is based on voltage-tunable modulation in quantum electron transmission. The switch is open (off) when the metal ion is displaced to a position at a C-H bond on the arene ring due to an externally applied bias. Conversely, when the external bias is removed, the metal ion moves to an axis- symmetric position on the arene ring, and the switch is closed (on). The paper presents a summary of the architecture, operating principle, and advantages of the conformational switch, along with associated findings from proof-of-concept theoretical and experimental studies of its target specifications and performance. The paper also discusses opportunities and challenges related to the integration of conformational switches into hybrid CMOS-molecular and monolithic (all molecular) circuits.     

根本技术创新产品需求的获取及评价研究

根本技术创新对企业的发展具有决定性的意义。并对工程作为现代产品开发中新发展的系统化方法，在应用其对根本技术创新产品需求搜集及评价时，出现了满足顾客需求和创造顾客需求、资源需求与技术创新、理性决策与非理性决策、企业文化与技术创新等之间的矛盾。本文对产生这些矛盾的原因进行了分析，提出了相应的解决办法。     

宣钢1260 m3高炉扩容大修改造设计

宣钢l260m^3高炉大修改造时将炉容扩大到l350m^3，对高炉本体系统设备及冷却系统、自动控制及检测系统进行了全面的改造更新，在炉腹、炉腰及炉身下部高热负荷区域采用铜冷却壁，取消炉身中上部铸铁冷却壁凸台，并采用薄内衬等先进、适用、可靠、成熟的技术。     

微型构造表征技术在八面河油田的应用

通过对八面河油田井网密集区及井网稀疏的欠开发区的微构造研究,探讨了微构造表征技术。首先在储层多层次逐级对比的基础上,建立主力油层对比关系;密集井网条件下,则利用钻井资料编制油层顶底微型构造图;对于欠开发地区,通过人机联作自动追踪成图技术,输出2m等值线间隔构造图,建立微构造模型。以微构造模型为基础进行潜力评价,部署关键井寻找优质储量或进行开发动态调整。应用该项技术在八面河油田滚动发现了角15块等断鼻翼部局部高点,增加石油地质储量488×10~4t。     

Facile synthesis of nanocrystalline zinc ferrite via a self-propagating combustion method

Macroporous nanocrystalline zinc ferrite with single spinel-phase was prepared by a facile self-propagating combustion method using zinc nitrate, iron nitrate and glycine. The as-prepared ZnFe₂O₄ were characterized by X-ray diffraction (XRD) analysis, N₂ adsorption, scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED) and energy dispersive X-ray spectrum (EDS). The magnetic properties of the prepared ZnFe₂O₄ were also studied.