摘要：Hydraulic erecting systems are widely used in missile and rocket launchers because of their high power *** double-acting telescopic hydraulic cylinder(DATHC)plays a decisive role in the safe and proper operation of such *** particular,improper design of effective areas of a DATHC could potentially lead to an overspeed descent with severe damage for the erecting ***,there is no design constraint for DATHC to prevent ***,in this paper,a simplified and practical design constraint is *** on a developed mathematical model of a typical erecting system,we simulated and analyzed not only six cases meeting and not meeting the design constraint,but also the effectiveness of the design constraint under different *** were then carried out under four *** and experimental results validate the simplified design constraint,a constraint inequation guiding the design of diameters of effective areas for a DATHC.

摘要：This paper presents a new approach for designing the tool paths in the machining of sculptured surfaces for computer nu- merical controlled end milling. In the proposed method, the tool paths are determined so that the scallop height formed by two adja- cent machining paths is maintained constant across the machined surface. Unlike previous work on iso-scallop height milling, the present work considers the true 3D configuration of the milling procedure and can be used to generate better results, which is shown by examoles.

摘要：In this study,we report the design and simulation of an electrostatic ion lens system consisting of 22 round metal *** opening of the extractor plate is covered withmetal mesh,which is for shielding the interaction region of the lens system from the high DC voltages applied to all other plates than the repeller and extractor *** Simion simulation shows that both velocity-mapping and time focusing can be achieved simultaneously when appropriate voltages are applied to each of the *** makes the ion lens system be able to focus large ionic volumes in all three dimensions,which is an essential requirement for crossed ion-molecule scattering studies.A three-dimensional ion velocity measurement system with multi-hit and potential multi-mass capability is built,which consists of a microchannel plate(MCP),a P47 phosphor screen,a CMOS camera,a fast photomultiplier tube(PMT),and a high-speed *** two velocity components perpendicular to the flight axis are measured by the CMOS camera,and the time-of-flight,from which the velocity component along the flight axis can be deduced,is measured by the PMT.A Labview program is written to combine the two measurements for building the full three-dimensional ion velocity in real time on a frame-by-frame *** multi-hit capability comes from the fact that multiple ions from the camera and PMT in the same frame can be correlated with each other based on their various *** demonstrate this by using the photodissociation of CH31 at 304 nm.

摘要：本研究分析了闽江福州段河岸带20种优势草本植物根茎叶和根际土壤的Cd、Cr、Cu、Ni、Pb和Zn含量,评估了该区域土壤重金属污染状况以及植物的重金属富集能力,并比较了植物不同器官对重金属富集和转运的差异。结果显示:(1)研究区域土壤除Pb含量低于背景值,其余元素均超背景值1.05~1.5倍,Cd是主要危害元素;(2)20种植物对Cd和Cu的富集能力较强,对Pb的富集能力最弱;(3)根和叶对重金属的富集能力强于茎,叶对重金属的转运能力强于茎;(4)白花鬼针草(Bidens pilosa L.)、紫茎泽兰(Ageratina adenophora ***&***)和龙葵(Solanum nigrum L.)的重金属综合富集能力排名前三,重金属生物富集系数分别为0.686、0.662和0.470,而苍耳(Xanthium strumarium L.)对土壤重金属的规避性较强。

摘要：为设计满足特定目标并具有近似自然形态的多孔隙结构,同时实现对结构内部连通性的控制,提出一种基于样本学习的多孔隙结构设计方法.首先以多孔介质的孔隙率和连通性作为设计指标,以6-邻接体素结构建立参数化设计单元,通过手工标记方式建立设计单元样本库;在此基础上,利用随机决策树森林(RDF)学习样本结构与设计目标之间的关联模型,生成设计规则;最后将整个设计方法集成于一个可扩展的多孔隙建模框架中.实验结果表明,RDF的泛化能力能够对样本库之外的结构进行正确的判定,可以在满足设计目标的同时得到更加自然的多孔隙结构.

摘要：A number of conventional interpolation techniques have been proposed. However, it seems that there do not exist good criteria for the design of optimal linear interpolators. Also, such an interpolator can hardly provide a satisfactory solution for interpolating noisy images. In this paper, the novelty of this research is that a universal approach is proposed to design an image interpolator with any one image smoothing filter, thereby not only interpolating a down-sampled image but also preserving the characteristics of the performing filtering.

摘要：本论文阐述了中国古典木作家具装饰的定义和种类,按照家具发展史的线索梳理了中国古典木作家具的装饰部位和内容,突出立体装饰对于现代家具设计的重要性。总结了中国古典木作家具的装饰主题和艺术特征,并对中国古典木作家具装饰文化进行现代传承提出指导性建议。

摘要：宋代宦官人数不多,能量很大,是一支有较高文化素质的精英群体。他们普遍识字读书,不少宦官在文学、科技方面颇有成就,有作品流传于当世,甚至制定《权衡法》等法规,世界最早的船坞也是宋代宦官发明的。还涌现出一批著名画家,是北宋绘画史上一支不可忽视的画家群体。为宋代历史和文化繁荣贡献出了自己的聪明才智,其发明创意和文化产品促进了社会发展,在宋代文化史、科技史上应有一席之地。

摘要：目的旨在通过新媒体形式下的响应式网站平台设计实践将经典家具设计呈现在公众视野,使展示的产品能与受众产生互动,为用户提供最直观的展示方式、趣味性设计和独具特色的空间,通过将互联网与经典家具设计文化相结合,以期经典家具设计文化能够更好地推广、传承。方法前期采用文献调查法进行理论梳理,采用问卷调研定量法确定用户需求,构建交互系统、完成界面等相关设计后,运用HTML5、CSS3、JavaScript等技术实现设计,并进行响应式调试与发布。结果让用户产生愉悦感和获得更舒适的用户体验,受众群体由传统的参观者变成能亲自参与的体验者。结论通过相关研究及设计实践普及经典家具设计的文化内涵,从而使更多人去关注、了解中外经典家具设计,同时可以辅助相关教学和科学研究。

摘要："隧道效应"是艺术创作的重要理论,它借火车穿越山洞时人们的所见和所感来阐释"整体性"原则,对于理解艺术作品中"虚"和"实"的关系大有裨益。小说《飘》是美国女作家玛格丽特·米切尔的经典之作,作品一经出版即风靡全球,而其中的女主角郝思嘉的形象更是深入人心。将"隧道效应"应用于分析米切尔在描写郝思嘉的三次婚姻时对材料所作的"虚""实"处理,可以更好地洞悉小说的魅力之源和节奏之美。