摘要：Evapotranspiration(ET)is of great significance for the ecological environment and water resource utilization in arid and semi-arid *** Mongolian Plateau,owing to drought,low rainfall,and extremely uneven distribution of water resources,has a typical temperate continental climate.A refined understanding of the spatiotemporal distribution of ET in this region will help in establishing regulatory strategies for climate change responses,regional livestock regulation,and grassland degradation *** this study,meteorological station data,precipitation data,and the Penman-Monteith model were used to study the temporal and spatial distribution characteristics of actual ET over the Mongolian Plateau from 2011 to *** found that:(1)The spatial distribution of ET in the Mongolian Plateau showed a high trend in the north and east and a low trend in the middle and *** was a significant difference in the regional annual ET,with the highest ET reaching over 500 mm and the lowest being only approximately 70 mm.(2)The annual ET values in 2013,2018,and 2019 were relatively large,varying between 80 and 500 mm,and the overall ET of the Mongolian Plateau first decreased,then increased,and then decreased.(3)The temporal distribution exhibits a unimodal trend of increasing and then decreasing,with July being the turning ***-September was a period of high ET,with the highest ET exceeding 100 *** vegetation coverage was high,precipitation was abundant,and the vegetation ET effect was *** was a period of low ET,with a maximum ET of approximately 10 mm in January and December;the ET for the month with the lowest value was approximately *** quantitative inversion method proposed in this study can provide method and data support for north and central Asia,and other large arid and semi-arid areas.

摘要：钢木混合结构是一种主要由钢框架、内填轻型木剪力墙和钢木混合楼盖组成的新型结构体系。分别对普通螺栓连接和高强螺栓连接的单榀钢木混合墙体进行了往复加载试验,对比了两种连接下墙体的破坏模式和荷载-位移关系。试验发现,与普通螺栓连接的墙体试件相比,高强螺栓连接的墙体试件受力性能较好,可以充分传递钢框架和木剪力墙间的剪力,保证两者协同工作。设计了72个不同参数的高强螺栓连接的钢木混合墙体模型,采用有限元软件OpenSees对模型进行往复加载的数值模拟,结果显示,在相同延性水平下,木剪力墙与钢框架初始刚度比大的钢木混合墙体较刚度比小的墙体具有更小的滞回阻尼比。对模拟结果进行统计回归分析,进而给出了估算钢木混合结构体系的滞回阻尼比的算式。基于研究成果,提出了钢木混合结构基于性能的抗震设计方法。

摘要：目的:压缩指数是软土工程领域的关键参数。本文旨在提出一个基于进化多项式回归和实编码遗传算法(EPR-RCGA)的回归分析方法,将压缩指数与物理特性建立相关关系并应用于工程实践。创新点:结合EPR和RCGA方法,将中国沿海21个不同区域的黏土的压缩性指数与天然含水率和液塑限之间建立相关关系,并采用均方根误差(RMSE)、赤池信息量准则(AIC)和贝叶斯信息准则(BIC)对所建立的不同回归模型进行优选。方法:1.从文献中收集中国沿海21个地区的黏土的压缩指数和常见的基本物理性质,并对数据进行整理和分类。2.进行压缩指数和天然含水量及液塑限之间的EPR回归关系分析,并采用新近提出的RCGA优化方法来提高回归关系的精度。3.采用RMSE、AIC和BIC对不同组合下的回归关系进行优选,并确定最佳回归关系。4.将得到的关系式应用到有限元路堤计算来验证所得关系式的实用性和准确性。结论:1.本文提出的压缩指数关系式比现有的经验公式更好,预测得到的压缩指数更为精确。2.采用所提出的压缩指数回归模型预测了东南沿海一路堤下不同土层的压缩指数,并应用所得数据和有限元方法对路堤的沉降进行了模拟分析,验证了所提方法的可靠性。3.所有结果表明,结合基于EPR和RCGA的回归分析方法以及基于RMSE、AIC和BIC的模型选择方法对分析压缩指数与黏土的物理性质的相关关系是切实可行的,可以更好地服务于中国沿海地区的工程设计。

摘要：目的:功能梯度准晶材料有助于减缓层合板界面处的应力集中现象,提高层间粘接强度,从而提升层合板表面的耐磨性。本文旨在建立功能梯度压电准晶层合板的力学模型,并研究功能梯度变化和叠放顺序对层合板的影响。创新点:1.首次将状态向量法推广到功能梯度压电准晶板的分析中;2.假设功能梯度函数的变化形式为幂函数和指数函数;3.在准晶层中观察到声子场应力和电势的不敏感点。方法:1.通过联立三大基本方程,推导出准晶板的状态方程,并求解该微分方程,得到单层准晶板的解析解;2.通过引入功能梯度函数,使解析解中的描述各材料特性的值能够沿厚度方向呈现梯度变化;3.采用传递矩阵法,求出多层准晶板的解析解;4.通过仿真模拟,将所得结果与已有文献进行对比,验证所提方法的可行性和有效性。结论:1.准晶层合板中的功能梯度效应随着梯度参数的增加而增大,且材料参数的变化对声子场、相位子场以及电场的响应均产生影响。2.在功能梯度效应下,从准晶层中观察到了声子场应力和电势的不敏感点。3.与准晶作为中间层相比,准晶作为表层时机械载荷引起的位移响应更小。研究结果可以为压电准晶元器件的设计提供理论参考。

摘要：Soft rock surrounding deep roadway has poor stability and long-term rheological effect. More and larger deformation problems of surrounding rock occur due to adverse supporting measures for such roadways, which not only affects the engineering safety critically but also improves the maintenance costs. This paper takes the main rail roadway with severely deformation in China＇s Zaoquan coal mine as an example to study the long-term deformation tendency and damage zone by means of in-situ deformation monitoring and acoustic wave testing technique. A three-dimensional finite element model reflecting the engineering geological condition and initial design scheme is established by ABAQUS. Then, on the basis of field monitoring deformation data, the surrounding rock geotechnical and theological parameters of the roadway are obtained by back analysis. A combined supporting technology with U-shaped steel support and anchor-grouting is proposed for the surrounding soft rock. The numerical simulation of the combined supporting technology and in-situ deformation monitoring results show that the soft rock surrounding the roadway has been held effectively.

摘要：Alloyed nanoparticles with core-shell structures provide a favorable model to modulate interfacial interaction and surface structures at the atomic level,which is important for designing electrocatalysts with high activity and ***,core-shell structured Pd3M@Pt/C nanoparticles with binary PdM alloy cores(M=Fe,Ni,and Co)and a monolayer Pt shell were successfully synthesized with diverse *** these,Pd3Fe@Pt/C exhibited the best oxygen reduction reaction catalytic performance,roughly 5.4 times more than that of the commercial Pt/C catalyst used as *** significantly enhanced activity is attributed to the combined effects of strain engineering,interfacial electron transfer,and improved Pt *** functional theory simulations and extended X-ray absorption fine structure analysis revealed that engineering the alloy core with moderate lattice mismatch and alloy composition(Pd3Fe)optimizes the surface oxygen adsorption energy,thereby rendering excellent electrocatalytic *** researches may use this study as a guide on the construction of highly effective core-shell electrocatalysts for various energy conversions and other applications.

摘要：中巴公路沿线活跃的地质构造运动、陡峭的地形地貌与冰川气候造成泥石流广泛发育,威胁中巴公路扩建与建成后的运营。分布在中巴公路北段冰川泥石流对该公路的威胁最为严重。根据2008-2011年期间雨季前后泥石流的活动状况,采用沿线普查与重点详查的研究方式,总结中巴公路沿线泥石流灾害的主要危害类型;并结合设计图纸,对2009年以前原中巴公路防治工程进行简要的损毁评估;通过分析中巴公路的防治现状提出相应的防治对策,最终针对典型的病害提出具有代表性的改进措施,以期为高海拔区公路灾害的防治提供一定的参考。研究表明:中巴公路泥石流的危害类型有5种,即淤积、侵蚀、冲击、漫流改道与堵江;损毁评估结果显示原有小型泥石流防治工程基本失效;原大型桥梁工程配套防治工程需要新建或加固;而新建桥梁工程运行良好;泥石流防治工程应考虑以下5个现状:援建工程的性质、不良工程地质条件、公路短期安全与灾害发展趋势的统一、主动工程被动防治及建立灾害管理与公路养护机构;鉴于中巴公路防治工程所面临的"技术经济性"问题,典型防治工程应根据泥石流的分布特征、性质特点与公路的交汇关系,采取因地制宜的防治方案。

摘要：巴基斯坦喀喇昆仑山的Ghulkin冰川是距离中国-巴基斯坦喀喇昆仑公路最近的典型冰川之一,其冰川的进退变化影响着喀喇昆仑公路改建工程的线路设计与工程施工.为了追溯Ghulkin冰川的活动历史和查明近期进退变化,对过去200a的相关文献和记录进行统计分析,并开展了2008-2011年野外定点观测,总结与分析了Ghulkin冰川冰舌的活动历史与近期变化.研究表明:Ghulkin冰川在1885-1980年近百年间经历了3次前进和3次后退,在此期间冰川波动了625m;1913-1925年冰川处于显著的前进状态,1966-1978年冰川有小段距离的前进;2008-2011年K676+660处泥石流沟道逐年抬升,2011年南坡冰川融水由K676+660改道至K676+450;2010年的南坡冰舌较1994年后退了300余米,2011年的南坡冰舌较2010年后退了15.066m,可见在2010-2011年期间冰川处于局部短期后退状态.中巴公路冰川泥石流等灾害不但受区域气候的影响,而且还受冰川变化的影响.未来气候变暖将会导致冰川的强烈消融和后退,冰川融水携带大量冰碛体,形成大型的冰川泥石流,对公路的安全运营造成严重威胁.