摘要：In this study,a method for control of reticulated shells is proposed and its practicality is *** control is implemented by replacing selected bars of the shell with passive viscoelastic *** applying the eigenvalue perturbation technique and the earthquake spectrum concept,the sensitivities of various topologies of the shell are analyzed,and the optimal topology is determined by taking their symmetries into *** results of this research show that common damper topologies are not effective for all types of responses and recorded *** optimal topology identifi ed requires a minimal number of dampers for each type of earthquake *** displacement control effect of the dynamic responses of the optimal topology is 10% – 20%; the acceleration control effect is also about 10% – 20%; and the axial force control effect is as much as 30% – 45%.Furthermore,the incremental dynamic analysis(IDA) method is used to investigate the stability of the controlled *** results show that the dynamic stability of the controlled shell is well preserved when it is vibrated under vibration and is better than the uncontrolled *** ultimate load increased by 10% and the elements entered into the plastic stage when the peak acceleration reached 580 Gal,which is 200 Gal larger than the uncontrolled shell.

摘要：Pit limit design has,up to date,focused mainly on maximization of economic profit alone,with environmental and social issues largely *** paper focuses on incorporating both environmental and social issues in the pit limit design process and provides an approach to pit limit optimization that is in compliance with sustainable *** case study demonstrates that ecological costs have a substantial down-sizing effect and social benefits have a substantial up-sizing effect on the optimal pit *** the ecological costs are factored in,the optimal pit limit is 37.5%smaller than the economically optimal pit ***,when the social benefits are factored in,the optimal pit limit is 48.3%larger than the economically optimal *** overall optimal pit limit,with the economic profit,ecological costs and social benefits simultaneously considered,is a result of balancing conflicting goals of maximizing economic profit,minimizing ecological cost,and maximizing social benefit.

摘要：The extreme temperature has more outstanding impact on ecology and water resources in arid regions than the average *** the downscaled daily temperature data from 21 Coupled Model Inter-comparison Project(CMIP)models of NASA Earth Exchange Global Daily Downscaled Projections(NEX-GDDP)and the observation data,this paper analyzed the changes in temporal and spatiotemporal variation of temperature extremes,i.e.,the maximum temperature(Tmax)and minimum temperature(Tmin),in the Kaidu-Kongqi River basin in Northwest China over the period 2020–2050 based on the evaluation of preferred Multi-Model Ensemble(MME).Results showed that the Partial Least Square ensemble mean participated by Preferred Models(PM-PLS)was better representing the temporal change and spatial distribution of temperature extremes during 1961–2005 and was chosen to project the future *** 2020–2050,the increasing rate of Tmax(Tmin)under RCP(Representative Concentration Pathway)8.5 will be 2.0(1.6)times that under RCP4.5,and that of Tmin will be larger than that of Tmax under each corresponding *** will keep contributing more to global warming than *** spatial distribution characteristics of Tmax and Tmin under the two RCPs will overall the same;but compared to the baseline period(1986–2005),the increments of Tmax and Tmin in plain area will be larger than those in mountainous *** the emission concentration increased,however,the response of Tmax in mountainous area will be more sensitive than that in plain area,and that of Tmin will be equivalently sensitive in mountainous area and plain *** impacts induced by Tmin will be universal and *** of spatiotemporal variation of temperature extremes indicate that large increases in the magnitude of warming in the basin may occur in the *** projections can provide the scientific basis for water and land plan management and disaster prevention and mitigation in the inland river basin.

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：Physical model test is an effective way to unveil the dynamic response of a slope under seismic *** similarity design is the key of physical model *** isolated similarity design method for shaking table tests was proposed and verified in this *** this method,the relevant physical quantities were divided into several subsystems and subcharacteristic equations for each subsystem were then established based on the Buckingham similarity ***-scale shaking table tests on a reinforced slope were adopted herein to illustrate the application of the proposed isolated similarity design *** similarity system for the studied slope was divided into four parts in the process of similarity *** geometrical dimension L,densityρand gravity g were selected as fundamental quantities for the similarity design,and four subcharacteristic equations were established for each *** dynamic responses of the recorded acceleration and axis force show that the seismic waves propagate well in the model *** proposed isolated similarity design method solves the conflict between the similarity requirement for all relevant physical quantities and the difficulty of test model fabrication to satisfy all similarity relations.

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。