摘要：青藏高原南缘是崩塌滑坡堵江形成堰塞湖灾害链的高风险区,而我国铁路缺乏应对堰塞湖灾害的经验。铁路灾后改建工程线路优化设计将产生直接减灾效益,而新建铁路在选线阶段就采取一些主动减灾策略,也是风险调控的重要手段。为此,以中巴经济走廊中拟建哈维连至喀什铁路Attabad堰塞湖段为研究对象,根据堰塞湖灾害特点,通过将改建工程分段设计,并对不同改建线路方案进行技术经济指标比较,完成该段改建线路设计。基于上述工作,提出以有利地形控制溢流口开挖深度、宜尽量利用既有工程、在离开湖区后集中展线尽快与既有线联接、有条件时可提高限制坡度等灾后绕湖铁路选线设计要点与高位选线、酌情预留提高限坡措施的条件、尽量不跨河等新建铁路减灾选线设计策略,希望为铁路应对崩塌滑坡堵江堰塞湖灾害链提供参考。

摘要：The flight control system designer is increasingly concerned with the problem of providing adequate stability of the elastic modes of the flight vehicle. The problem of stabilizing bending modes can be solved by the use of different bending filters. But continuously changing behavior of the elastic modes frequencies makes it impossible to suppress the elastic modes. In this paper, adaptive tracking filter is used to solve this problem. Where it can track the frequency of predominant oscillatory component of its input signal and automatically adjust the shaping characteristics as a function of this frequency. Simulation results are presented to show the frequency tracking accuracy and response of the flight launch vehicle, which are based on the assumption that, only first bending mode is selected at a time. Comparison with the second order band pass filter is carried out in order to emphasis the effectiveness of this design methodology.

摘要：This article proposes a multidisciplinary design and optimization （MDO） strategy for the conceptual design of a multistage ground-based interceptor （GBI） using hybrid optimization algorithm, which associates genetic algorithm （GA） as a global optimizer with sequential quadratic programming （SQP） as a local optimizer. The interceptor is comprised of a three-stage solid propulsion system for an exoatmospheric boost phase intercept （BPI）. The interceptor＇s duty is to deliver a kinetic kill vehicle （KKV） to the optimal position in space to accomplish the mission of intercept. The modules for propulsion, aerodynamics, mass properties and flight dynamics are integrated to produce a high fidelity model of the entire vehicle. The propulsion module com- prises of solid rocket motor （SRM） grain design, nozzle geometry design and performance prediction analysis. Internal ballistics and performance prediction parameters are calculated by using lumped parameter method. The design objective is to minimize the gross lift off mass （GLOM） of the interceptor under the mission constraints and performance objectives. The proposed design and optimization methodology provide designers with an efficient and powerful approach in computation during designing interceptor systems.

摘要：为模拟内燃机缸套-活塞环运动,设计适用于缸套-活塞环的往复式摩擦性能试验台,由传动系统、加热系统、加载系统组成。根据系统中悬臂梁和活塞环专用夹具不同的使用要求,分别进行结构设计和有限元分析。结果表明,当实验条件达到预设极限值(加热温度130℃,摩擦力500 N)时悬臂梁和活塞环专用夹具均能满足使用要求。试验台使用二维力测力传感器,通过特殊装配设计,可同时测量摩擦力和法向负载。通过摩擦性能实验验证,缸套-活塞环在较低负荷(61.7、92.6、123.4 N)条件下,摩擦因数随转速的增大而急剧减小;在较高负荷(250.8、322.5 N)条件下,摩擦因数随转速的增大有所减小并逐渐趋于稳定状态。

摘要：This paper covers the detailed version of the potential raw material deposits at Darukhula and the adjacent areas of Nizampur, the manufacturing of high-strength Portland cement samples from the same material and comparison of the physical and chemical parameters for resulting cement with British and Pakistan standard specifications, which include compressive strength, setting time, consistency, lechatelier expansion, Blaine and insoluble residue. It was found that the raw material available in the study area meets the standard specifications and the area is feasible for the cement plant installation. The area can provide raw material which is quite sufficient for the running of a cement plant.

摘要：用铁尾矿陶粒替代普通混凝土天然粗骨料,根据《轻骨料混凝土技术规程》(JGJ/T 12—2019)设计配合比,制备LC30~LC40的铁尾矿陶粒混凝土。测定和计算其力学性能、耐久性、经济性,并与普通混凝土作对比。结果表明,铁尾矿陶粒混凝土能够满足《轻骨料混凝土技术规程》(JGJ/T 12—2019)中LC30配制强度,其强度与水胶比的相关性较普通混凝土弱,抗折强度和弹性模量分别仅有普通混凝土的60%和65%左右,但抗氯离子渗透能力和抗冻性能显著优于普通混凝土。本文研究了铁尾矿陶粒用于制备轻骨料混凝土的可行性和其混凝土的综合性能,为下一步装配式构件设计提供数据支撑,间接解决了陕南地区铁尾矿循环利用的问题。

摘要：研究了常规欠驱动船舶编队路径跟踪的一致性控制问题,设计了一个分散式控制器.结合反步法、虚拟结构法及李雅普诺夫理论,使设计的控制器不仅形式简单,而且具有良好的稳定性和全局收敛性,能有效实现欠驱动状态下船舶横向速度及位移的快速镇定.在此基础上引入一致性控制的思想,解决在输入量饱和情况下编队队形失效的问题,达到协调各船保持期望队形的目的.通过三艘船的仿真,对所设计控制器的正确性及有效性进行了验证.

摘要：The aerodynamic design of a strategic weapon is of interest, especially when the radar signatures are included in the conceptual design phase. The basics of stealth configurations and stealth mechanisms for missiles are reviewed. The Radar Cross Sections （RCS） of some generic missiles are predicted and compared to analyze the trade-offs involved between low RCS and aerodynamic performance. The consideration of RCS prediction in the conceptual design phase gives a quick insight into the stealth performance prior to detailed design.

摘要：Coal waste(CW)could be used for soil stabilization due to the pozzolanic elements it *** hasn’t been much investigation into how different fibers affect the mechanical qualities of stabilized sand,although adding fibers of any kind to soils may improve the soil because of fiber characteristics like *** this reason,several tests were carried out on sand that contained 6%cement(by dry weight of used sand),5 wt%CW,0 wt%,0.25 wt%,and 0.50 wt%fiber,as well as the unconfined compressive strength(UCS)test,indirect tensile strength(ITS)test,unconsolidated undrained(UU)triaxial test,scanning electron microscope(SEM)test and ultrasonic pulse velocity(UPV)*** results showed that in comparison to other fiber reinforced mix designs,the specimen reinforced with 0.5%fibers and the mix design of 0.25 wt%glass and 0.25 wt%polypropylene(PP)fibers exhibited the maximum *** the impact of fiber type found that glass fibers influence PP strength more favorably than other fiber *** use of PP fibers is an excellent solution for the problem of large strains in design processes,while adding glass fibers is considered a suitable treatment for issues related to small strains.

摘要：自动扶梯设计和运行的主要目标是能够把乘客从一个楼层运送到另一个楼层。但目前却缺乏有关乘客在自动扶梯上的信息和研究。由于对此方面知识的不足使笔者对乘客行为和自动扶梯设计参数之间的了解知之甚少。这里就增加梯级深度对于自动扶梯，特别是重型自动扶梯的运输能力的影响进行分析。