悬臂施工波形钢腹板组合梁桥施工工艺

南京长江第四大桥北接线滁河特大桥采用波形钢腹板预应力混凝土组合箱梁桥。该类型桥是一种高效、经济、施工简便的新型桥梁形式。该类型桥恰当地将钢和混凝土两种不同材料结合起来，提高了结构稳定性、强度及材料的使用效率等。该桥的施工可为同类型桥的施工提供参考。     

Thermal conductivity measurement of methanol-based nanofluids with Al2O3 and SiO2 nanoparticles

In this study, the methanol-based nanofluids with Al₂O₃ and SiO₂ nanoparticles are prepared by dispersing nanoparticles in pure methanol using an ultrasonic equipment. The main objective of this paper is to measure the thermal conductivity of the methanol-based nanofluids. We have also measured the zeta potential, particle size and Tyndall effect for the present nanofluids. The transient hot-wire method is applied for measuring the thermal conductivity of methanol-based nanofluids. The measurement uncertainty in repeatability is obtained as 1.95% for deionized (DI) water and 1.34% for pure methanol, respectively. The effective thermal conductivity of methanol-based nanofluids is measured at a temperature of 293.15 K. The results show that the thermal conductivity increases with an increase of the nanoparticle volume fraction, and the enhancement is observed to be 10.74% and 14.29% over the basefluid at the volume fraction of 0.5vol% for Al₂O₃ and SiO₂ nanoparticles, respectively. Clustering of nanoparticles is considered to be the main reason for the thermal conductivity enhancement.     

Intergranular Strain Evolution in a Zircaloy-4 Alloy with Basketweave Morphology

A Zircaloy-4 alloy with Widmanst?tten-Basketweave microstructure has been used to study the deformation behavior at the grain level. The evolution of internal strain and bulk texture is investigated using neutron diffraction and conventional microscopic techniques. The macroscopic behavior and intergranular strain development, parallel and perpendicular to the loading direction, were measured in situ during uniaxial tensile loading. It was observed that twinning plays a major role in both microstructural changes and polycrystalline plasticity.     

Removal of DDT in drinking water using nanofiltration process

The removal of DDT[(1,1-bis(4-chlorophenyl)-2,2,2-trichloroethane)] with synthetic waters was carried out on a nanofiltration (NF) pilot unit. The influence of initial DDT concentration, pH, flux and recovery on the removal of DDT was studied. The presence of humic acid and some inorganic (CaCl₂, NaCl, and CaSO₄) matters was also tested in the experiment. The removal percent and that of their adsorption on the membrane have been calculated. The results reveal that DDT was easy to be adsorbed on the membranes and the higher the applied pressure the more rapidly saturation of the membrane was achieved. At the initial concentration of 77 μg/L, the equilibrium for DDT adsorption can be achieved in 30 min. With the initial DDT concentration from 5 to 20 μg/L, the removal percent was from 95 to 85%. On condition that recovery was not changed, higher flux can lead to low rejection of DDT. On the other hand, low recovery can have a high rejection when the fluxes were the same. Humic acid can hinder DDT from passing through the membrane by adsorption and inorganic matter (NaCl, CaCl₂ and CaSO₄) can improve the removal percent by reducing the pore size of the membrane.     

拍卖——无线频谱管理的有效手段

无线通信、尤其是移动通信的迅速发展，使原本有限的无线频谱资源越来越显得珍贵。保证无线频谱资源合理有效地利用，特别是要保证有利于新技术的发展，就必须具有有效的管理。本文从这一角度出发，先简单介绍美国和新西兰利用经济手段拍卖无线频谱的情况，又指出了像俄罗斯这样刚考虑引入“竞拍”方法来分配频率的国家应解决的问题。     

一种预测模糊集成控制系统的设计方法

将预测控制方法与模糊控制方法相结合，构成一类预测模糊集成控制系统。用以解决工业过程控制系统中存在的且难以处理的大滞后与非最小相位问题。文章最后给出仿真结果。     

溢流碎流型气液分配器的开发研究

国内在役和设计的加氢反应器内构件多数使用抽吸型气液分配器的分配技术。洛阳石油化工工程公司对抽吸型和溢流型气液分配器的特点进行了技术分析，开发出一种具有碎流板结构的溢流碎流型气液分配器。在主体为直径600mm的有机玻璃塔实验装置上，采用空气和水介质，将溢流碎流型气液分配器与典型的抽吸型气液分配器进行对比实验，结果表明，溢流碎流型气液分配器的压力降比抽吸型的低，对液相的分配均匀性比抽吸型的好，操作弹性比抽吸型的大。     

测控系统测轨数据的时间校正问题

本文分析了航天测控系统几类测轨数据的时间校正问题及相应的校正计算方法,指出在同一系统时标形成的测轨数据不一定是同一时的目标参数,提出了使各测轨数据同步的一种方案.     

满南地区中-上奥陶统生物礁地震解释及其含油气性

在塔里木盆地满南地区的地震剖面上,中-上奥陶统有一种类似背斜形态的丘状异常反射,曾被认为是沉积过程中形成的岩隆,但与塔北中-上奥陶统生物礁及国内外生物礁的地震反射特点对比后确认,该丘状异常反射为生物礁的反映.礁属枢纽带碳酸盐岩沉积体系的台地边缘堤礁,礁后发育滩,礁前缘发育倒石锥,礁体宽2～4km,东西方向延伸90km,呈S形展布,与塔北中-上奥陶统生物瞧构成马蹄形礁群,礁体最大厚度可达500m,礁体储集性能良好.满南礁体将是今后盆地油气勘探的一个重要目标.     

准噶尔盆地气藏开采特征研究

在分析准噶尔盆地气藏生产特征的基础上,对特纳等人提出的临界参数公式进行校正,得出了适合准噶尔盆地气藏生产规律的临界参数计算公式,为气藏的配产及开发提供了有益的指导.