用光谱仪检测材料元素时的注意事项

阐述了使用光谱仪检测材料时需注意的一些问题.     

电镀工艺条件变化对片状铁吸收剂吸波性能的影响

通过电镀法制备片状磁性吸收剂，用SEM、XRD等手段对其进行表征。用网络分析仪测试了不同工艺条件下吸收剂样品2～18GHz的电磁参数，并结合晶粒尺寸因素研究了不同工艺条件下对吸收剂电磁参数的影响．结果表明，不同的工艺条件对吸收剂电磁参数的影响具有规律性，可通过合理配置工艺参数来提高吸收剂的吸波性能。     

石泉水电站扩机工程机组进水口污物清理措施

石泉水电站扩机工程自投运发电以来,一直深受机组进水口污物的困扰,致使两台机组不能正常发电,造成了严重的经济损失.本文详细介绍了机组进水口污物情况、污物处理难度以及所采取的污物处理措施,通过拦污和清污的综合方案,有效解决了污物堆积问题.     

Specific interactions in blends containing Chitosan and functionalized polymers. Molecular dynamics simulations

Chitosan (CS)/poly(vinyl alcohol) (PVA) and Chitosan/poly(2-hydroxyethyl methacrylate) (P2HEM) blends have been studied through molecular dynamic simulations. In a previous work it was found miscibility between these polymers and it was attributed to hydrogen bonding formation. However, the experimental information obtained was not enough to know which of the interacting groups of Chitosan, i.e. -CH₂OH or -NH₂, are responsible of the interaction. Therefore, we have performed molecular dynamics simulation runs of 1 ns in order to calculate radial distribution functions (RDF) for the groups tentatively involved in the interaction. The results are correlated with our previous experimental data. This way, we have obtained a more precise conclusive information about the interactions involved as function of the blends composition. For low compositions of PVA and P2HEM the interaction is predominantly with the hydroxymethyl groups of CS while as the composition of PVA and P2HEM increases, the interaction with the amine groups increases.     

水文整编软件HDPS在佛山分局的应用

该文介绍水文资料整编软件——HDPS。该软件完全能实现过去的“微机水文资料整编软件包”和全国统一的“潮水位整编程序”的所有功能。     

二维多波束蜂窝网覆盖方法研究

提出一种基于二维多波束形成的蜂窝网覆盖方法,该方法旨在通过对平面阵阵元权矢量的控制,使所形成的波束在空域上呈非均匀蜂窝网结构,达到重点地区覆盖密度高,非重点区域覆盖密度低的目的,减小资源利用率,并重点分析了波束设计思路和权值的计算方法,仿真结果表明:该覆盖方法是有效的.     

情境故事法在产品设计开发中的应用

从产品设计中"以使用者为中心"的设计要求出发,引入情境故事法的相关内容.详细论述了情境故事法的概念、流程、操作方法,并以商务笔记本为研究载体,对商务笔记本的典型用户的使用特性,以及使用过程中的最初情境和遇到的问题进行综合分析.站在用户的角度建立情境故事以寻求商务笔记本设计的创新点,从而得到新的故事方案.最后对情境故事法使用的局限性作了些简要评述.     

天津独流减河工程监控系统现地通信单元设计

提出一种配电网电容电流测量的新方法，在零序电压互感器的开口三角侧串联一个可调电感，通过注入一个变频恒流信号寻找配电网的谐振频率，改变可调电感的数值后寻找另一谐振频率，联立2个谐振方程求解电容电流，该方法消除了电压互感器漏抗对测量的影响。开发了配电网电容电流测量仪，经模拟试验和现场测试表明，该方法具有安全、快捷、准确等特点，适用于中性点不接地或经随调式消弧线圈接地配电网。     

Elimination of organic matter present in wastewaters from the cork industry by membrane filtration

BACKGROUND: The first stage of the cork industrial process generates great volumes of wastewater with moderate to high organic pollutant content that must be purified using different procedures, such as filtration by membranes. RESULTS: The tangential filtration of these wastewaters was studied using two different laboratory equipments. In the first one, three ultrafiltration (UF) membranes were tested, with molecular weight cut‐off (MWCO) 100 kDa and 30 kDa, and two operating modes were used: total recycling of permeate and retentate streams, and in continuous mode, without recycling both streams. In the total recycling UF experiments, the influence of the operating variables on the permeate flux was first established. The effectiveness of the different membranes was determined by evaluating the rejection coefficients for several parameters that measure the global pollutant content of the effluent. The values found for these rejection coefficients were in the following order: ellagic acid and color > absorbance at 254 nm > tannic content > COD (chemical oxygen demand). In the continuous mode experiments, the fouling mechanism for each membrane was established by fitting the experimental data to various filtration fouling models given in the literature. The operating mode in the second equipment was batch concentration, and additional experiments were carried out with an UF membrane (2 kDa), and with a NF membrane (with MWCO in the range 150–300 Da). CONCLUSIONS: The three operating modes tested provided different rejection levels of organic matter; among them, the most effective procedure tested was batch concentration mode using a NF membrane. Copyright © 2007 Society of Chemical Industry