Impact of regulatory rules on economic performance of PV power plants

The rapid growth of Renewable Energy Sources (RES) power plants connected to the grid has introduced new problems related to the safe and reliable operation of the electricity network from transmission to distribution sectors. New regulatory rules can promote RES producers to make a commitment on the energy amount that is likely to be supplied to the network. The present paper concerns the analysis of the energy production of a PV power plant from the economic point of view, with reference to the presence of regulatory rules. Costs of penalty and value of energy are compared, in order to evaluate the economic efficiency of the plant. Use of auxiliary energy storage devices is investigated, with the aim to determine the relevant dimensions that increase the economic efficiency of the PV plant. A software instrument that implements these algorithms is described and applied to a case study.     

被动区土体加固技术在福州软土地区深基坑中的应用

本文针对被动区加固技术在福州软土地区的应用,结合福州市民服务中心工程的工程实际情况,通过分析研究被动区加固技术的作用原理,对水泥土搅拌工艺技术进行总结和改进。     

土层锚杆在深基坑支护中的应用研究

针对土层锚杆在深基坑支护中的应用,提出一种适用于实际工程支护设计的数学方法。通过对土层锚杆支护理论及受力机理进行研究分析,结合锚杆支护在地铁深基坑工程中的应用实例,基于锚杆抗拔承载力试验及锚杆轴力的监测数据,采用统计归纳的数学分析方法,对几种设计理论与实测结果之间的关系进行分析,提出了采用粘结强度影响系数法对土层锚杆在深基坑支护工程中的应用进行设计的数学描述,给出了相应的数学表达式。     

用土力学的新概念解读和修正经典饱和土力学

论述了应该用有效应力的新概念代替经典有效应力原理。总应力压缩模量与渗流水等效压缩模量的曲线相似;有效应力压缩模量起加劲作用,而不是起决定性作用。土的压缩变形计算中应用有效应力原理是错误的。对于起始水力坡降,引入饱和粘性土的自由水压力衰减概念。在饱和粘性土中,自由水通道率折减不大,相对自由水压力通过一定厚度后衰减为零。所以,新概念土力学的算法接近我国规范:"对粘性土宜按水土合算计算"。还解读了地下室浮力折减、流沙陷阱等等。     

A Moisture Transfer Model for Isothermal Drying of Plant Cellular Materials Based on the Pore Network Approach

Plant materials with cellular structure, like fruits and vegetables, are often viewed as porous media in terms of model building of the drying process, on the basis of a hypothesis that all of the moisture of a plant tissue is trapped in a continuous and connected pore network system. However, most of the moisture in the plant tissue is contained naturally in enclosed cells. In the course of drying, the trapped moisture has to cross the cell membranes and then migrates in the extracellular space. Based on this concept, a pore network model for isothermal drying of plant materials was developed in which two stages of moisture movement—transmembrane transfer and extracellular transfer in the pore network—were considered. Finally, the isothermal convective air-drying processes of a potato slice were simulated. The calculated results were validated by the experiments conducted under the simulation conditions.     

芳纶标准回潮率测试方法的改进

针对现有GB/T 6503—2008测试纤维回潮率的缺陷,提出测试芳纶标准回潮率的改进方法:采用烘箱法先将纤维试样在烘箱中烘至恒重,然后将烘至恒重的试样在标准大气条件下调湿至平衡状态,最后将调湿平衡的试样在烘箱中烘至恒重,测试芳纶的标准回潮率。结果表明:该方法中起初的预烘干处理消除了芳纶表面的油剂等对测试有干扰的因素,测得的标准回潮率更准确,标准回潮率的相对标准偏差为0.64%,方法的重复性好。     

高强度硅烷化聚氨酯(SPU)密封胶的研究

综述了硅烷化聚氨酯(SPU)密封胶的性能优势和特点,研究硅烷化聚氨酯、填料和黏附促进剂三者对高强度硅烷化聚氨酯密封胶性能的影响。结果表明:中模量的SPUR1、SPUR2树脂和高模量的SPUR3以1∶6的质量比例进行复配使用时,密封胶的强度和断裂伸长率都能满足应用要求;偶联剂A-1100和A-1120进行等量混合使用后,密封胶的固化速率和力学性能都能取得相对较佳效果;在纳米碳酸钙用量占总配方量的50%~60%时,密封胶的补强性及工艺操作性取得最佳平衡。最后介绍了高强度硅烷化聚氨酯密封胶的应用前景。     

第三代煤调湿技术在生产实践中的应用

介绍了第三代煤调湿技术在生产实际应用中对炼焦和煤气净化系统生产带来的不利影响以及在节能方面的效果,同时进行原因分析并提出建议。     

植物修复铬污染土壤的研究进展

铬污染土壤的植物修复技术以其经济、高效和生态友好等优点成了众多修复技术中的佼佼者。文章归纳总结了土壤铬污染的来源及危害、铬污染土壤的植物修复以及植物与微生物的联合修复的最新进展,探讨了植物修复铬污染土壤存在的问题,展望了其发展趋势。     

土壤和沉积物中磷素释放过程的影响因子分析

磷素是水体富营养化的限制性因子,土壤和底泥沉积物中磷素的释放和水体中磷素的迁移转化,都会对水体富营养化产生影响。磷素的最终释放量是物理、化学及生物因素共同作用的结果。文章从影响磷素释放的影响因子入手,系统分析影响磷素释放的关键因子,研究其在磷素释放过程中所起的作用,为研究磷素在水-土介质及水-沉积物界面中的迁移转化提供依据。