花坝二级电站引水隧洞混凝土裂缝成因与对策

混凝土的裂缝问题是一个普遍存在而又难于解决的工程实际问题，现对花坝二级电站引水隧洞工程中衬砌混凝土出现裂缝的原因进行分析，并针对出现的混凝土裂缝的具体情况，提出一些简单的预防和处理对策。     

相变储能材料研究进展

综述了固-固相变储能材料（s-S PCMs：sofid-solid phase change materials）、固-液相变储能材料（s-1 PCMs：solid—liquid phase change materials）的主要优缺点，并主要介绍了以下2种封装方式：（1）PCMs与基体材料复合制成定型PCMs，包括：与有机高分子材料机械共混、用无机多孔材料封装；（2）PCMs微囊化。此外，还分析了PCMs的主要应用领域及PCMs的主要研究方向。     

Ultra-wideband bandpass filter with hybrid microstrip/CPW structure

A novel ultra-wideband (UWB) bandpass filter (BPF) is presented using the hybrid microstrip and coplanar waveguide (CPW) structure. A CPW nonuniform resonator or multiple-mode resonator (MMR) is constructed to produce its first three resonant modes occurring around the lower end, center, and higher end of the UWB band. Then, a microstrip/CPW surface-to-surface coupled line is formed and modeled to allocate the enhanced coupling peak around the center of this UWB band, i.e., 6.85GHz. As such, a five-pole UWB BPF is built up and realized with the passband covering the entire UWB band (3.1-10.6GHz). A predicted frequency response is finally verified by the experiment. In addition, the designed UWB filter, with a single resonator, only occupies one full-wavelength in length or 16.9mm.     

清涧河流域不同水土保持措施配置下蓄水拦沙效益分析

从分析清涧河流域不同年代水土保持措施配置人手，以蓄水拦沙效益为研究目标，探讨了水土保持措施优化配置问题。分析认为：水土保持措施配置与蓄水拦沙效益是密切相关的，淤地坝在水土保持措施配置中应占有合理比重，坡面治理措施配置中需进一步加大封禁治理比例。     

黄河下游河道萎缩致灾机理探讨

本文基于水力学原理，结合实体模型试验及原型实测资料分析，探讨了黄河下游河道萎缩的概念、致灾效应和致灾机理。分析表明，河道萎缩是造床过程中河道排洪输沙功能衰退的一种演变现象，其致灾效应是使洪水涨率增大，同流量下洪水水位不断抬升。致灾的现象主要表现在畸型河势增加、工程险情增多、直接造成工程损失及滩区经济损失等。试验研究揭示，主河槽宽度缩窄造成洪水水位涨幅增大，河底平均高程抬升和过水断面面积减小造成洪水水位起涨的基准面抬升是河道萎缩致灾的主要原因。河道萎缩致灾效应的大小与萎缩模式有关，其中以“集中淤槽”模式所形成的致灾效应尤为明显。     

Peracetic acid pretreatment of sugarcane bagasse for enzymatic hydrolysis: a continued work

Previous work has shown that the enzymatic hydrolysis of sugarcane bagasse could be greatly enhanced by peracetic acid (PAA) pretreatment. There are several factors affecting the enzymatic digestibility of the biomass, including lignin and hemicelluloses content, cellulose crystallinity, acetyl group content, accessible surface area and so on. The objective of this work is to analyze the mechanism of the enhancement of enzymatic digestibility caused by PAA pretreatment. Delignification resulted in an increase of the surface area and reduction of the irreversible absorption of cellulase, which helped to increase the enzymatic digestibility. The Fourier transform infrared (FTIR) spectrum showed that the absorption peaks of aromatic skeletal vibrations were weakened or disappeared after PAA pretreatment. However, the infrared crystallization index (N.O'KI) was increased. X‐ray diffraction (XRD) analysis indicated that the crystallinity of PAA‐treated samples was increased owing to the partial removal of amorphous lignin and hemicelluloses and probable physical change of cellulose. The effect of acetyl group content on enzymatic digestibility is negligible compared with the degree of delignification and crystallinity. The results indicate that enhancement of enzymatic digestibility of sugarcane bagasse by PAA pretreatment is achieved mainly by delignification and an increase in the surface area and exposure of cellulose fibers. Copyright © 2008 Society of Chemical Industry     

未增塑聚氯乙烯(PVC-U)异型材配方基础

PVC-U异型材配方十分复杂,常用原料通常在10种以上。根据大连实德集团实际生产情况,这10多种原料通常以7大组分的方式进行配料和生产。文中就该配方中7大组分的分类、特点及应用情况分别进行了详细介绍。     

Dye adsorption characteristics of alginate/polyaspartate hydrogels

This study examined the removal of some basic dyes, such as Methylene Blue, Malachite Green and Methyl Orange, using alginate or alginate/polyaspartate composite gel beads. The adsorption of dyes from aqueous solutions at 25 °C was examined using a batch sorption technique. The effects of CaCl₂ and the dye concentration on the adsorption were examined. Type-S adsorption isotherms were obtained, which is characteristic of a weak solute–solid interaction. The ionic interaction between the dye molecule and gel matrix appears to be responsible for the efficient adsorption of cationic dyes in this system. These results suggest that an alginate/polyaspartate gel can be used as an effective sorbent for water pollutants such as dyes, and the immobilization of these organic contaminants in the hydrogels from wastewater can solve one of the most important environmental problems in the related industry.     

水库突发事件应急预案研究现状与关键技术初探

水库突发事件应急预案是大坝风险管理中非常重要的一个环节,是降低水库大坝风险的非工程措施.本文总结了国内水库突发事件应急预案的研究现状,并结合我国实际国情,初步提出了开展应急预案的关键技术,供大坝安全管理及科研人员参考.