摘要：中巴经济走廊是“一带一路倡议”的先试区和重点项目区,拟建中巴铁路是其重要组成部分,但铁路行经的喀喇昆仑山脉为全球山谷冰川最发育的区域,我国尚无在冰川区修建铁路的经验。鉴此,以中巴经济走廊Gilgit至Khunjerb段为研究区,研究沿线大陆性冰川、海洋性冰川和跃动冰川的分布以及各类冰川的活动性特点,定义冰川直接作用区和间接作用区且分析相应的成灾模式,并据此提出选线要点;最后针对中巴铁路沿线四大冰川群,分别提出选线设计建议。研究成果对冰川区铁路选线设计具有普适性指导意义。

摘要：Maize(Zea mays L.) stands prominently as one of the major cereal crops in China as well as in the rest of the ***,predicting the growth and yield of maize for large areas through yield components under high-yielding environments will help in understanding the process of yield formation and yield potential under different environmental *** accurate early assessment of yield requires accuracy in the formation process of yield components as *** order to formulate the quantitative design for high yields of maize in China,yield performance parameters of quantitative design for high grain yields were evaluated in this study,by utilizing the yield performance equation with normalization of planting *** density was evaluated by parameters including the maximum leaf area index and the maximum leaf area per *** showed that the variation of the maximum leaf area per plant with varying plant density conformed to the Reciprocal Model,which proved to have excellent prediction with root mean square error(RMSE) value of 5.95%.Yield model estimation depicted that the best optimal maximum leaf area per plant was 0.63 times the potential maximum leaf area per plant of *** performance parameters for different yield levels were quantitatively designed based on the yield performance *** validation of the yield performance model by simulating high yields of spring maize in the Inner Mongolia Autonomous Region and Jilin Province,China,and summer maize in Shandong Province,the yield performance equation showed excellent prediction with the satisfactory mean RMSE value(7.72%) of all the *** present study provides theoretical support for the formulation of quantitative design for sustainable high yield of maize in China,through consideration of planting density normalization in the yield prediction process,providing there is no water and nutrient limitation.

摘要：研究目的:市域铁路对城市和区域发展起着重要的支撑和带动作用,多个城市已建或正建。道岔是轨道线路的薄弱环节,是影响列车安全平稳通过的关键因素。为保障高密度运营和减少日常维修,市域铁路轨下基础以无砟轨道为主,但配套的无砟道岔较少,有必要为正线设计60 kg/m钢轨12号可动心轨无砟道岔。研究结论:(1)通过采用复曲线道岔平面线型,提升了列车侧向通行的平顺性;(2)通过优化尖端结构,延长了曲线尖轨服役寿命;(3)通过采用可动心轨辙叉,解决了轮轨噪声扰民问题;(4)通过设置防跳机构,避免了列车高速过岔时尖轨、心轨跳动;(5)通过研究尖轨和辙叉跟端传力机构,保障了岔区无缝线路的实现;(6)通过优化滑床板和护轨垫板结构,增强了钢轨扣压稳定性;(7)通过研发三元乙丙橡胶扣件系统,满足了无砟道床低刚度要求;(8)本文研究成果对铁路科研单位及道岔制造厂家在市域铁路道岔设计研究方面具有参考作用。

摘要：The buckling resisting brace(BRB)is an efficient system against lateral loads that enjoy high seismic energy absorption *** desirable behavior of BRBs has been confirmed,the stiffness of the system is not desirable that it can be compensated by changing the configuration of BRB *** so doing,the configuration in the form of double K(DK)is investigated to achieve more favorable ***,the required mathematical formulas were proposed to design the *** of DK system with other conventional BRB showed that the DK system has a better structural performance and is more economical(due to needing less core area)than other conventional *** results indicated that the DK system increases the lateral ultimate strength,lateral nonlinear stiffness,and energy ***,the DK configuration reduces the axial forces created in columns in the nonlinear *** material demand,created forces in the main frame,and also increasing of nonlinear stiffens by DK improve the structure’s safety.

摘要：In this paper a numerical investigation has been presented on the stall mechanism of a highly loaded Single Stage Low Speed Fan designed for the research test facility to be installed at North Western Polytechnic University (NWPU) Xi’an, China. The results presented are for the design point, near stall and just stall operating conditions at design speed. Design point studies have been found to be an indicative of stall area. Unsteady method of domain scaling has been used to compute the results at near stall and just stall conditions. It has been found that unlike the conventional tip leakage flow of the rotor, stator hub section is mainly responsible for the stall of the fan. The flow mechanism has been discussed with correlation to the design variables and previous investigations. Commercial CFD code NUMECA FINE/Turbo has been used for computations; results have been compared with results obtained from commercial CFD code ANSYS-CFX. The loss prediction of latter code is conservative than the former. The stall mechanism predicted by both codes is analogous.

摘要：In the present paper, two models based on artificial neural networks and genetic programming for predicting split tensile strength and percentage of water absorption of concretes containing Cr2O3 nanoparticles have been developed at different ages of curing. For purpose of building these models, training and testing using experimental results for 144 specimens produced with 16 different mixture proportions were conducted. The data used in the multilayer feed forward neural networks models and input variables of genetic programming models are arranged in a format of 8 input parameters that cover the cement content, nanoparticle content, aggregate type, water content, the amount of superplasticizer, the type of curing medium, age of curing and number of testing try. According to these input parameters, in the neural networks and genetic programming models the split tensile strength and percentage of water absorption values of concretes containing Cr2O3 nanoparticles were predicted. The training and testing results in the neural network and genetic programming models have shown that every two models have strong potential for predicting the split tensile strength and percentage of water absorption values of concretes containing Cr2O3 nanoparticles. It has been found that NN and GEP models will be valid within the ranges of variables. In neural networks model, as the training and testing ended when minimum error norm of network was gained, the best results were obtained and in genetic programming model, when 4 genes were selected to construct the model, the best results were acquired. Although neural network has predicted better results, genetic programming is able to predict reasonable values with a simpler method rather than neural network.

摘要：IntroductionA rapidly increasing need for organ transplantation and short list of donated organs have led to the development of new materials and technologies for organ manufacturing. Although some simple organs, such as skin and cartilage, have been successfully fabricated and commercialized, it is still difficult to make tissues and organs with high complexity. Engineered tissues have other biomedical applications, such as drug screening models and bio-actuators. Threedimensional （3D） bioprinting has become a great tool to fabricate tissue constructs on demand for transplantation and other biomedical applications.

摘要：Control system design packages like MATLAB, MATRIXX, Control C, SIMNON, etc. have become essential ingredients of both undergraduate and graduate courses in the fields of systems and controls. The use of MATLAB and its companion toolboxes in teaching graduate and undergraduate courses was reported by many educators in the past. The experience with the use of SIMULINK and MATLAB in Intelligent Control Course is introduced which is offered to graduate students at Beijing University of Aeronautics and Astronautics （BUAA）. The use of SIMULINK for simulation of intelligent control of their behavior is emphasized. The MATLAB features useful in this course are presented. How SIMULINK and MATLAB help in enhancing the students＇ understanding of the material and reducing the amount of time spent in performing computational homework assignments is discussed.

摘要：2022年1月,荣获上海国际电影节最佳影片奖的电影《东北虎》登陆全国院线,以其独特的艺术风格、缓慢的叙事节奏与克制的镜像氛围等引发观众热议。影片围绕男人出轨、寻狗复仇、追讨欠款三个故事与鹤岗的地域景观相互编织,指向动物园被囚困的东北虎这个独特意象符号。继以往的几部影片之后,耿军再一次将目光投向家乡,对准鹤岗的深处和边缘,精心营构后工业社会背景下东北底层市民的生活图景.

摘要：利用已有瞬时荷载作用下未打穿竖井地基固结模型,根据线性偏微分方程的叠加原理,将变荷载作用问题分解为瞬时荷载作用问题,给出了变荷载作用下未打穿竖井地基固结解答。利用该求解方法,对一未打穿竖井地基在单级线性加载和多级加载情况下的孔压消散进行了分析。分析表明,受加载历时影响,竖井打设区平均固结度减小幅度大于下卧层,但下卧层受影响时间要长得多。另外,在粗略设计中,可以将多级加载简化为单级线性加载,这样对后期平均固结度的影响不大。