发电机绝缘故障局部放电监测系统开发与应用

通过对发电机绝缘故障局部放电机理进行研究,总结出了发电机在发生绝缘故障时的局部放电模型特性,通过现代在线监测技术、数据库技术和人工智能技术的应用,把这些放电特性进行软件化开发,形成了实际可用的软件系统。该系统由在线监测模块和专家库系统模块构成,具有很好的相对性和先进性。应用实践表明,采用该系统可以提高发电机的故障诊断效率,从而也提高了发电机的运行安全性。     

基于区间拟shannon小波配点法的供水系统水锤计算技术方法研究

文中将区间拟shannon小波配点法应用于水锤方程求解,通过将水锤方程中的待求函数用一系列拟shannon小波基函数逼近,对空间域进行离散,从而建立起关于时间的常微分方程组,构造出了水锤方程在小波空间的计算方法,并推演了管道中水锤波的传播。最后通过仿真实例计算出水锤方程的数值解,说明该方法对水锤计算具有较好的数值模拟性,从而为确保供水系统的安全和稳定运行提供技术支持。     

糯扎渡水电站高心墙堆石坝施工技术

糯扎渡水电站心墙堆石坝具有填筑工程量大、施工期短、填筑强度高等特点。为此,采用了合理的坝体填筑施工技术,主要包括上坝道路布置、坝体填筑分期、坝料供应、掺砾石土料掺合工艺、坝体填筑施工工艺等。数字大坝工程质量与安全信息管理系统的采用,对提高坝体施工质量起到了重要作用。     

Influence of surface treatment on properties of Cocos nucifera L. Var typica fiber reinforced polymer composites

Natural fibers are a powerful competitor in the polymer composite market due to their availability, sustainability, obtainability, cost, and biodegradability. The surface of natural fibers was changed to increase mechanical qualities, hydrophobicity, and bonding with polymer matrix. This study exposes the influence of several surface treatments of coconut tree peduncle fibers (CTPFs) on the thermomechanical and water absorption properties of CTPF-reinforced polymer composites. The CTPFs were treated with sodium hydroxide, benzoyl peroxide, potassium permanganate and stearic acid at a constant 40 wt% and individually reinforced in an unsaturated polyester resin matrix containing 60 wt% CTPFs. Chemically treated CTPFs improved reinforcement-matrix adhesion and enhanced composite mechanical characteristics. In addition, the scanning electron microscope fractographical study of stressed composite specimens shows improved reinforcement-matrix bonding. Moreover, the treated CTPFs have a higher cellulose wt%, which improves the composites crystalline nature, hydrophobicity and thermal stability. The potassium permanganate treated CTPF composite's maximum tensile strength of 128 MPa, flexural strength of 119 MPa, impact strength of 9.9 J/cm², hardness value of 99 HRRW and thermal stability up to 193°C make them appropriate for lightweight mobility and structural applications.     

Direct-methane anode-supported solid oxide fuel cells fabricated by aqueous gel-casting

Direct methane Solid Oxide Fuel Cells (SOFCs) operated under catalytic partial oxidation (CPOX) conditions are investigated, focusing on the processing of the anode support and the anode deactivation caused by carbon deposition. Anode-supported SOFCs based on gadolinium-doped ceria (GDC) electrolyte, and NiO-GDC anode support were fabricated by the gel-casting method. Suitable aqueous slurries formulations of NiO–GDC were prepared, starting NiO-GDC nanocomposite powders, agarose as gelling agent and rice starch as pore former. Electrochemical and mechanical tests evidenced that the support of 550 ± 50 µm thickness and 10 wt% pore former is a good candidate for direct-methane SOFCs. The cells operating under stoichiometric conditions of CPOX reached a performance of 0.64 W·cm^?2 at 650 ºC, a very close value to that measured under humidified hydrogen (0.71 W·cm^?2). The best electrochemical stability of the cell is achieved at a CH₄/O₂ ratio of 2.5, showing no evidence of carbon deposition and reducing nickel re-oxidation significantly.     

茭白中过氧化物酶的部分纯化及其性质的初步研究

采用硫酸铵沉淀及DEAE-SepharoseFF离子交换色谱对茭白中过氧化物酶进行了初步纯化,得到了部分纯化的两种过氧化物酶(组分A和组分B),其中组分A为酸性过氧化物酶,而组分B为碱性过氧化物酶。两种过氧化物酶的最适pH分别为5.0(A)和5.5(B),同时两种酶的热稳定性有一定的差异。     

喷气织机纬缩成因探析及解决措施

针对喷气织机设备状态和织造工艺等设置不当。易产生纬缩，在织造高密织物时，纬缩对织造效率和产品质量的影响尤为突出的现状，详细探析了由纱线质量、引纬受阻、引纬装置调节不当及引纬工艺参数配置不合理等因素引起的纬缩，指出应提高纬纱质量，减少毛羽，校正主、辅喷嘴安装位置及喷射时间等工艺参数，并提高织轴质量，优选开口机构，稳定供气压力，才能减少纬缩、提高喷气织机效率。     

基于GC/HPLC检测和苦味评定解析黄酒苦味

为分析黄酒苦味与其成分的关系,使用气相色谱（GC）和高效液相色谱仪（HPLC）测定16种半干型黄酒样品中的挥发性成分、氨基酸及理化指标,采用Pearson相关性分析计算各成分与苦味值的相关系数,并以测定成分为X变量、以苦味值为Y变量,建立偏最小二乘法回归（PLSR）分析模型,验证苦味相关成分和模型预测的准确性。结果表明,黄酒中的苦味物质以挥发性成分为主,集中在异戊醇（R=0.808）、异丁醇（R=0.642）、正丙醇（R=0.623）和乳酸乙酯（R=0.771）,氨基酸与苦味相关性不高（R=-0.536～0.464）,酒精与苦味相关性最高（R=0.850）,总酸对苦味有促进作用（R=0.649）,总糖对苦味有明显抑制作用（R=-0.735）。PLSR分析模型证实了Pearson相关性分析的可靠性,且能很好的预测黄酒苦味值,预测准确性达到90%,这为确定黄酒苦味提供了科学分析的客观方法。     

微交联丙烯酸树脂的改性合成及其作为皮革填充剂的性质研究

采用半连续种子乳液聚合工艺,N -羟甲基丙烯酰胺(NMA)、丙烯酸羟乙酯(HEA)共聚改性传统丙烯酸树脂,合成了核-壳结构丙烯酸改性皮革填充剂。讨论了NMA的浓度、添加方式和交联时间等对改性树脂膜性能的影响,并利用玻璃化温度(Tg)和凝胶渗透色谱(GPC)进行了表征。     

Quantum与Premium PLC在钢坯加热炉上的综合应用设计

设计了Quantum与Premium PLC同时应用于同一项目的控制中,通过以太网和MB+网实现Quantum与Premium及Quantum与Modicon E984 PLC之间的信息交换。采用Unity Pro XL作为PLC的编辑软件,利用Vijeo Look 2.6制作监控画面,制造了稳定可靠、省时高效,集过程控制与界面操作、监控等多功能于一体的自动化控制系统。