贵州某高速公路弃土场边坡稳定性分析

随着交通工程逐渐往山区延伸,越来越多的工程设施受限于地形条件.隧道开挖后形成的弃土场若不进行合理的布置,将为桥梁、道路工程的修建造成工程隐患.通过对某隧道出口弃土场边坡进行的工程地质调查,分析了拟建桥梁与边坡的相互作用关系,完成了岩土体力学参数取值.选取典型断面在天然工况和暴雨工况下进行了数值计算,使用了sigma/w和slope/w两个模块进行了数值计算,揭示了边坡的变形机理与稳定性状况和发展趋势,结果显示:若不采取合理的治理措施,在不利工况下,边坡将失稳,因此提出了设置抗滑桩的处置措施.     

动车组自动断电过分相车体瞬态过电压优化研究

高速动车组车载自动断电过分相时,瞬态电压会通过车顶高压电缆缆芯与屏蔽层间的耦合注入各节车体,合理的保护接地方式可快速泄放车体瞬态电压,保证各车体电位相等.基于此,介绍了动车组过分相的暂态过程,运用MATLAB/Simulink建立了各暂态过程的等效电路模型,经过仿真分析接地电感与电容对车体瞬态电压的影响规律,提出了并联电容器的保护接地方案,对动车组高效运行具有一定参考价值与指导意义.     

高强度开采双巷布置巷道围岩差异化控制研究

相邻工作面2条相邻的回采平巷留设一定煤柱同时掘进(双巷布置)是高强度开采发展趋势之一,两巷围岩的长期稳定性至关重要.本文结合现场钻孔成像研究巷道围岩变形破坏特征;采用数值模拟研究双巷布置时2条巷道围岩受采动影响的应力、变形破坏的分区差异化特征;提出以帮锚索+底角锚杆为基础的双巷差异化控制技术,选取湾图沟煤矿13406工作面作为试验地点,进行现场工业性试验,验证了所提出的巷道控制技术及参数设计合理性.     

中国城镇化的绿色转型与发展

改革开放40年以来,中国实现了全球规模最大的城镇化,成绩斐然.但在资源能源紧约束的条件下,我国城镇化高资源消耗、高能源消耗、高碳排放的"三高"问题值得关注,"双碳"目标也面临着城镇化水平提高、经济稳健发展和现代化建设的多重挑战.在生态文明建设背景下,中国已经进入了绿色城镇化发展的新阶段,这是城镇化"下半场"转型发展的必然选择.因而要结合能源、工业、交通、建筑、农业和土地利用等碳排放五大领域的研究,将"减碳"和"增汇"作为技术主线,从城镇格局、交通出行、绿色建筑、基础设施、城市运营这五个方面,探索绿色城镇化的规划技术体系和与之匹配的制度创新.     

"砼"趣 ——记清水混凝土建筑荣成青少年活动中心设计施工点滴

从清水混凝土材料特点、空间适用性、肌理、细节和工艺等方面总结了荣成青少年活动中心复杂异形清水混凝土工程从设计到建造的全过程,展现了本土设计理念和地域环境的融合、创新型施工工艺的成功应用及项目最终呈现的高品质完成度.     

Evaluation of hydrogen metabolism by Escherichia coli strains possessing only a single hydrogenase in the genome

The four hydrogenase isozymes; hydrogenase 1 (Hyd-1), hydrogenase 2 (Hyd-2), hydrogenase 3 (Hyd-3) and hydrogenase 4 (Hyd-4) of Escherichia coli have been reported for their crucial functions in the hydrogen metabolism; however, their distinctive roles could not be completely understood. In this study, four ideal hydrogenase operon mutants, Δhyb hyc hyf, Δhya hyc hyf, Δhya hyb hyf, and Δhya hyb hyc, in which only a single hydrogenase is intact in the genome, were constructed as well as one quadruple mutant (Δhya hyb hyc hyf) that all four hydrogenase operons were deleted. First, single operon mutants and single-gene mutants for each hydrogenase showed different hydrogen productivity and growth in the anaerobic fermentation, indicating that bacterial phenotype regarding the hydrogen metabolism via the deletion of each operon is different with that of each single gene. Then, 4 triple hydrogenase operon mutants and one quadruple mutant were investigated to evaluate the hydrogen metabolism (hydrogen production and uptake) using glucose or glycerol as a substrate of hydrogen fermentation. With both the carbon sources, only Hyd-2 and Hyd-3 were able to produce hydrogen. Furthermore, all the hydrogenases showed hydrogen uptake activity. In addition, no hydrogen production and hydrogen uptake were detected in the quadruple mutant which does not have all 4 hydrogenases. Hydrogen production from Hyd-2 and Hyd-3 was further confirmed by complementing their operons in the cloning vector pBR322.     

The dispersed SiO2 microspheres supported Ru catalyst with enhanced activity for ammonia decomposition

Ru nanoparticles supported on SiO₂ microspheres (Ru/SiO₂-GUS) were prepared by the glucose-urea-metallic salt method and applied in the decomposition of ammonia. In the glucose-urea-metallic salt method, glucose as the carbon template plays a significant role in the formation of diffusion-beneficial structural properties of Ru/SiO₂-GUS, and also induceds the modification of the electronic state of Ru. Ru/SiO₂-GUS exhibited higher catalytic activity compared with the catalyst prepared with the impregnation method. The catalytic performance of Ru/SiO₂-GUS was further enhanced with the addition of either K or Cs——the addition order and amount strongly affecting the catalytic performance. When the ratio of K/Cs to Ru is 2, the alkali metal (KOH/CsOH) solution is added in the homogeneous solution of glucose, urea, RuCl₃ and the colloidal silica, the promotion effect of K/Cs is the strongest, particularly under lower reaction temperatures. However, the promotion effects of K and Cs are different as reveled by the combined results of H₂-TPR, XPS and NH₃-TPSR. More NH₃ can be absorbed on K–Ru/SiO₂-GUS and the electron density of Ru decreased. By contrast, more metallic Ru formed on Cs–Ru/SiO₂-GUS, facilitating N₂ recombination.     

智能管控系统在城市更新调查中的应用

城市更新基础数据调查是一项复杂的工程,以智能信息化促进城市更新管理创新,带动管理的科学化、规范化、精细化.通过建设城市更新智能管控系统,构建"一户一档"基础信息库,建立业务标准化机制和财务费用管理机制,为城市更新决策提供实时、准确、科学的支撑信息,实现城市更新全过程精准化、智能化管理.     

映秀湾电站水轮机转轮沙水流动数值模拟

为了研究映秀湾水电站水轮机内部沙水流动特性,对水轮机进行沙水流动数值模拟,分析水轮机转轮部分沙水流动情况。研究结果表明,转轮内叶片进水边及出水边靠下环处是泥沙分布的主要区域。研究结果对水轮机泥沙磨损的研究具有指导意义。     

袁河新泉乡段梯级溢流堰水动力模拟及侵蚀分析

为了分析梯级溢流堰对袁河新泉乡段河道行洪及河床抗冲的影响,优化河道治理工程中溢流堰布置,建立了将拦河溢流堰作为闭边界条件的二维水动力数值模型,采用非结构化网格的有限体积法,对比分析了十年一遇洪水情况下梯级溢流堰建设前后河道水动力、河道水位、流场沿程变化特征,讨论了溢流堰布置对河道防洪及冲刷的影响。结果表明,在十年一遇洪水情况下溢流堰会抬升河道水位,平均增加0.49 m,满足河道行洪要求;梯级溢流堰使河道整体形成人工“阶梯深潭”体系,河道流速在空间上发生明显的异质性,堰上流速下降幅度较堰下流速大;水流发生急流与缓流之间交替,水流紊动强烈,加剧了水流能量损失,有效降低流速,减轻了河道冲刷,有利于稳定河岸结构。