新型堵漏材料在西港电厂项目的运用实践

燃煤电厂的地下煤斗及煤廊为承受荷载的地下结构,常规的注浆方法无法用于其防渗堵漏.为此,采用强堵-堵排结合-刚柔相济的原则,并以新型堵漏材料,成功地堵住了地下廊道的压力水,为电厂的顺利投产提供了保障.     

混凝土早期强度推算法及实用分析

本文对＂成熟度法＂、＂等温强度龄期曲线法＂及＂等效龄期法＂介绍了其实际应用方法。通过实例对比计算发现三者有很大差距，并对差距产生的原因进行了初步分析，对其今后的使用提供了参考数据。     

Enhanced sound absorption properties of porous ceramics modified by graphene oxide films

Under the condition of constant thickness, improving the low-frequency sound absorption performance of conventional sound-absorbing materials is a challenging research topic. To address this issue, a new reduced graphene oxide/polyvinyl alcohol (RGO/PVA) porous composite ceramic was fabricated using freeze-drying and optimized by redesigning the internal connecting pores of porous ceramic matrixes with a reticular microstructure using RGO and PVA. The as-prepared porous structure showed significant enhancement in the low-frequency sound absorption band compared with pristine porous ceramics. In addition, the hybrid porous ceramics exhibited low thermal conductivity. These favorable properties indicate that the hybrid sound-absorbing ceramics have potential application prospects for noise reduction in the fields of construction and electrical and mechanical devices.     

A Comparative Study on Open Circuit Voltage Models for Lithium-ion Batteries

The current research of state of charge(SoC) online estimation of lithium-ion battery(LiB) in electric vehicles(EVs)mainly focuses on adopting or improving of battery models and estimation filters. However, little attention has been paid to the accuracy of various open circuit voltage(OCV) models for correcting the SoC with aid of the ampere-hour counting method. This paper presents a comprehensive comparison study on eighteen OCV models which cover the majority of models used in literature. The low-current OCV tests are conducted on the typical commercial LiFePO_4/graphite(LFP) and LiNiMnCoO_2/graphite(NMC) cells to obtain the experimental OCV-SoC curves at different ambient temperature and aging stages. With selected OCV and SoC points from experimental OCV-SoC curves, the parameters of each OCV model are determined by curve fitting toolbox of MATLAB 2013. Then the fitting OCV-SoC curves based on diversified OCV models are also obtained. The indicator of root-mean-square error(RMSE) between the experimental data and fitted data is selected to evaluate the adaptabilities of these OCV models for their main features, advantages,and limitations. The sensitivities of OCV models to ambient temperatures, aging stages, numbers of data points,and SoC regions are studied for both NMC and LFP cells. Furthermore, the influences of these models on SoC estimation are discussed. Through a comprehensive comparison and analysis on OCV models, some recommendations in selecting OCV models for both NMC and LFP cells are given.     

多功能结构在固体火箭上的应用分析

为实现固体火箭轻质化设计,采用传统机械结构优化的方法能力十分有限。多功能结构优化设计方法,由于采用机、电、热一体化的系统工程级设计思路,为提升火箭整体性能开辟了一个全新的方向。介绍多功能结构设计方法及思路,结合一种新型箭载记录设备原型样机的研制,对多功能结构在固体火箭领域应用的前景进行深入探讨。     

As-cast microstructure of Al-Zn-Mg-Cu-Zr alloy containing trace amount of Sc

It has been reported that the element scandium(Sc) is the most effective modificator which can significantly refine the grain size, prohibit recrystallization process and increase the strength. Adding trace of Sc in 7000 series aluminum alloys is considered to be an effective way to modify its micros tructure and promote mechanical properties. In order to study the effect of Sc element on ascast microstructure of Al-Zn-Mg-Cu-Zr alloy, ingots containing different amounts of Sc were prepared by ferrous-mold cast. Microstructures were characterized by means of differential scanning calorimeter(DSC), X-ray diffraction(XRD), optical microscope(OM) and scanning electrical microscope(SEM). The results indicate that when the Sc level exceeds a critical concentration,Al_3(Sc,Zr) primary phase would form in the melt and act as an efficient nucleant, resulting in very refined grain and an equiaxed grain structure. Sc element reduces the number of eutectic phases formed during solidification,coupled with an increase in the concentration of major alloying elements retained in the solute. This behavior suggests possible benefits in improving the integrated properties of terminal products.     

山岳型森林公园规划探索--以山西省乌金山国家森林公园总体规划为例

本文针对山岳型森林公园这一特殊类型,研究其基本概念特征及规划的理论基础,并以山西省乌金山国家森林公园总体规划的具体案例为支撑,从多角度探讨规划设计的具体方法,旨在以此为基础,为森林公园的规划研究发展提供思路。     

回龙阁水库大坝除险加固方案浅析

本文针对当前国内病险水库大坝存在的主要问题结合湖北省回龙阁水库这一典型工程,提出了一套技术可行、经济适用的加处理设计方案,为今后类似工程进行除险加固建设提供了重要的参考。     

超声波辅助提取黄秋葵多酚和多糖的工艺研究

以黄秋葵为原料,对超声波辅助水提黄秋葵多酚和多糖的提取工艺进行了研究。通过单因素确定超声时间、超声温度、料液比和超声功率对黄秋葵多酚和多糖的影响,并在单因素实验的基础上利用正交实验确定最佳工艺条件。结果表明多酚和多糖的最佳提取条件为超声时间90min,超声温度45℃,料液比1∶45,超声功率84W。在此条件下,黄秋葵多酚和多糖的含量分别为4.207、2.671mg/g。