纸浆纤维聚丙烯酰胺接枝水解物吸水材料的研究

纸浆纤维与丙烯酰胺的接枝共聚物经水解后可制成一种膜片状吸水材料。这种膜片既具有纤维的柔软、舒适,多毛细管作用等特性,又具有较好的形状保持能力,加压后不出水,吸水率可达近百倍。本文讨论了该材料的制备及各种因素对其吸水性的影响。并借助偏光显微镜、扫描电镜等手段对其结构进行了表征。     

顺应环保的新型纤维素纤维

本文介绍符合环保要求的新型纤维素纤维的发展历程、工艺特点、性能水平及今后的发展展望,并对我国的发展提出建议．     

Autohydrogenotrophic denitrification of drinking water using a polyvinyl chloride hollow fiber membrane biofilm reactor

A hollow fiber membrane biofilm reactor (MBfR) using polyvinyl chloride (PVC) hollow fiber was evaluated in removing nitrate form contaminated drinking water. During a 279-day operation period, the denitrification rate increased gradually with the increase of influent nitrate loading. The denitrification rate reached a maximum value of 414.72 g N/m³ d (1.50 g N/m² d) at an influent NO₃⁻–N concentration of 10 mg/L and a hydraulic residence time of 37.5 min, and the influent nitrate was completely reduced. At the same time, the effluent quality analysis showed the headspace hydrogen content (3.0%) was lower enough to preclude having an explosive air. Under the condition of the influent nitrate surface loading of 1.04 g N/m²d, over 90% removal efficiencies of the total nitrogen and nitrate were achieved at the hydrogen pressure above 0.04 MPa. The results of denaturing gel gradient electrophoresis (DGGE), 16S rDNA gene sequence analysis, and hierarchical cluster analysis showed that the microbial community structures in MBfR were of low diversity, simple and stable at mature stages; and the beta-Proteobacteria, including Rhodocyclus, Hydrogenophaga, and beta-Proteobacteria HTCC379, probably play an important role in autohydrogenotrophic denitrification.     

紫外-湿热老化对天然纤维增强复合材料力学性能的影响(英文)

用热压成型的方法制作了天然纤维(剑麻,红麻)增强酚醛复合材料,并测试和比较了紫外老化前后复合材料的力学性能。同时,也研究了表面处理对天然纤维增强复合材料力学性能的影响。结果表明,天然纤维复合材料的力学性能随着老化而不断下降。最后,引入了一个半经验模型来对天然纤维增强复合材料的服役行为进行了预测。     

Reinforced concrete beam–column joint strengthened with carbon fiber reinforced polymer

An effective rehabilitation strategy is proposed to enhance the strength and stiffness of the beam–column joint in this study. An analytical model is proposed to predict the column shear of the joints strengthened with carbon fiber reinforced polymer (CFRP). Three full scale interior beam–column joints, including two specimens strengthened with CFRP and one prototype specimen, are tested in this study. The specimens are designed to represent the pre-seismic code design construction in which there is no transverse reinforcement. A new optical non-contact technique, digital image correlation (DIC), which can measure the full strain field of specimen, is used to measure and observe the full strain field of the joint. The experimental results show that the beam–column joints strengthened with CFRP can increase their structural stiffness, strength, and energy dissipation capacity. The rehabilitation strategy is effective to increase the ductility of the joint and transform the failure mode to beam or delay the shear failure mode. By observing the measured results, it is found that the mechanical anchorages can prevent the debonding of CFRP. Comparing the analytical and experimental results, the proposed model can accurately predict the column shear and shear strength of the joints strengthened with CFRP.     

实用化565Mbit／s光发送机

本文介绍实用于565Mbit/s速率上的光发送机,并叙述其工作性能及指标。     

FBG解调实时校正技术研究

在基于可调谐F-P的FBG解调系统中,由于驱动电压与扫描波峰的关系不固定,增加了系统误差。为此研究了实时校正技术。首先,通过方案比较和分析,设计了并联型的实时校正系统,此系统可以通过多个参考点实时校正PZT的非线性问题以及可调谐F-P滤波器的结构性误差。然后,通过实验分析了PZT驱动电压与可调谐F-P波峰的关系,设计了快速分段算法。最后,针对此系统,设计了以现场可编程门阵列(FPGA)为核心的信号处理单元,将解调系统的控制、滤波计算和数据压缩等电路集成在FPGA芯片内部,保证了系统的实时性。实验结果表明,该系统的均方误差为2.2pm,最大误差为6pm。解决了此类解调系统受可调谐F-P滤波器精度限制的问题,提高了测量精度。     

关于光纤涂层特性的研究

本文从涂层粘附力，涂层切入力，静态疲劳参数及色标保持力等几个方面，对ＡＴ＆Ｔ光纤所用的Ｄ－ＬＵＸ１００一次涂层及由其构成的ＡＴ＆ＴＤ－ＬＵＸ１００光纤的性能进行了实验研究。     

碳纤维加固技术在某通信机房改造中的应用

碳纤维加固技术是一种新兴的加固技术，本结合某通信机房加固改造工程，对该加固技术的原理、设计体会和施工方法进行了介绍。     

Empirical approaches to estimate the nonlinear dynamic responses of earth-core rockfill dams subjected to earthquake ground motions

This study investigates three aspects of the dynamic response of earth-core rockfill dams (ECRDs) under earthquake loadings, including induced shear strain, increased fundamental period, and shear modulus reduction. A database of the recorded ground motions of ECRD cases in Japan is analyzed to carry out this study. The required response parameters as mentioned above are extracted by analyzing the acceleration time histories recorded at the dams’ crests and foundations. Subsequently, statistical analyses are performed to achieve the objectives of this study. A graph is developed describing the change in the dam’s fundamental period with the induced shear strain, and it is observed that the increase of the dam’s period is dependent on the increase in the shear strain levels. A relationship is established to estimate the anticipated levels of shear strain from the intensity measure (IM) of the earthquake signals. In the proposed predictive relationship, a new IM is used that can adequately characterize the severity of an earthquake. Finally, a curve and a range are suggested for the average shear modulus degradation of the ECRD’s core materials. The presented empirical graphs and relationships in this study are valuable tools to obtain an appropriate perception of dams’ nonlinear behaviour under strong earthquake excitations.