水利建设工程施工质量项目划分

判定水利工程施工质量是否合格,要通过数据、资料统计、分析来判断。首先要进行工程项目划分,依据项目划分的框架构造从单元工程开始,逐步评定到分部工程、单位工程,最后得到整个工程项目的施工质量。介绍了水利建设工程项目划分的一般原则和方法,结合工作经验和具体事例,提出了划分注意事项。     

薄壁U形钢板加固受火后钢筋混凝土梁受力性能研究

采用外套薄壁U形钢板、内灌无收缩灌浆料加固受火后钢筋混凝土梁,该加固技术能有效避免灌浆材料脱落,具有长效的加固功能。为验证该加固方法的有效性,进行了14根混凝土梁的静载试验,研究了U形钢板厚度和受火时间对加固RC梁受弯性能的影响,以及U形钢板厚度和剪跨比对加固RC梁受剪性能的影响。借鉴常温下组合梁承载力的计算方法,给出了薄壁U形钢板加固受火后RC梁受弯和受剪承载力的计算公式。结果表明：受火1.0、1.5h后混凝土梁的受弯承载力分别降低了9.4%、10.4%,剪跨比为1.74、2.58的混凝土梁受火1.5h后受剪承载力分别降低了19.5%、10.6%。薄壁U形钢板加固受火后RC梁的受弯、受剪承载力相比未受火RC梁分别提高了127.4%~151.7%、21.3%~56.7%。在薄壁U形钢板内侧和上翼缘焊接角钢形成的内隔环能保证薄壁U形钢板和混凝土共同工作,加固后试件可作为完全剪切连接的组合梁。加固试件发生受弯破坏时内隔环承受的纵向剪力较大,而发生受剪破坏时内隔环承受的纵向剪力较小。     

岩溶区流域月、季尺度降雨变化特征及其与台风相关性分析

研究采用相对变化率、集中度和集中期分析降雨的年内分布规律,然后采用线性趋势和Mann-Kendall等研究降雨的年际变化规律,最后采用Pearson相关分析和灰色相关分析方法探讨降雨与台风的相关性特征.结果显示,各月降雨相对变化率达到30％以上,降雨趋于集中化,主要集中在7月份;月平均降雨量相对稳定,春、夏季降雨减少,...     

Wide-Temperature,Long-Cycling,and High-Loading Pyrite All-Solid-State Batteries Enabled by Argyrodite Thioarsenate Superionic Conductor

Rechargeable FeS₂ battery has been regarded as a promising energy storage device, due to its potentially high energy density and ultralow cost. However, the short lifespan associated with the shuttle effect of polysulfides, large volume change, agglomeration of Fe⁰ nanoparticles, narrow operating temperature range, and sluggish reaction kinetics, greatly impede the application of rechargeable FeS₂ lithium-ion batteries. Herein, an all-solid-state battery (ASSB) coupling commercialized FeS₂ is proposed with a novel superionic conductor Li_6.8Si_0.8As_0.2S₅I (LASI-80Si) to overcome these challenges. The shuttle effect of polysulfides and volume change of FeS₂ are suppressed or completely eliminated in ASSB, due to solid-solid conversion of Li₂S/S and large stacking pressure, respectively. Furthermore, the operating temperature range (−60–60 °C) is significantly expanded by the ultra-high and temperature-insensitive ionic conductivity of LASI-80Si (E_a = 0.20 eV), along with the superior FeS₂/LASI-80Si interface stability. Thanks to the extra Li⁺ provided by Li₂S and LiI functional phases, the “bridge” effect of LiI on facile interfacial Li-ion conduction, and the enhanced reaction kinetics of LASI-80Si (${\sigma }_{L{i}^{+}}=$ 10.4 mS cm⁻¹), ASSBs with LASI-80Si deliver long cycle life (244 cycles at 0.1 C and 600 cycles at 1 C), superior rate capability (20 C), high areal mass loading (13.37 mg cm⁻²), and ultrahigh areal capacity (9.05 mAh cm⁻²). These inspiring results demonstrate the enormous potential of LASI-80Si and FeS₂ combination for practical application of wide-temperature and large-capacity ASSBs.