探讨档案修裱用纸

一、档案修裱及用纸原则中国档案修裱技术历史悠久,正如唐朝初期的张彦远在《历代名画记》一书中所阐述的:“自晋代以前,装褙不佳,宋时范晔始能装褙”由此可见,装裱技术在中国至少已有1500多年了。它起源于魏晋,成熟于隋唐,鼎盛于宋,发展于明清,作为一项独特的技术一直流传至今,是档案界和书画界的一大瑰宝,享誉世界。公元前三世纪至公元三世纪的两汉时期造纸术兴起,纸张的出现为档案修裱技术的产生提供了极其重要的物质条件,并且随着纸张成为档案载体材料,档案修裱技术日益发展起来。魏晋南北朝时期,据《太平御览》引《桓玄伪事》称,在东晋…     

敦煌石窟本生故事画的形式——以睒子本生图为中心

啖子本生图盛行于北朝时期,莫高窟与西千佛洞保存着诸多图例。啖子故事以孝道为主题与中国传统伦理道德思想十分吻合,特别是北周至隋代十分流行。本文主要分析啖子本生图,对其构图形式,即横幅多场景画卷形式的展开与样式上的发展进行探讨;并与印度、犍陀罗、克孜尔及麦积山、云冈石窟的例证进行比较,详细验证敦煌壁画中啖子本生的画卷形式、连环画形式及异时同图法等,认为敦煌壁画中的睒子本生并非汉代传统形式的延续,而是在印度·犍陀罗的影响之下所形成的。     

修裱胶粘剂对纸质档案耐久性影响的初步研究

以宣纸为载体,市售浆糊、小麦淀粉浆糊和羧甲基纤维素（CMC）三种修裱胶粘剂为研究对象,分别从粘接前后试样的耐折强度、色差变化以及耐酸碱、防霉性能等方面初步研究了修裱胶粘剂与纸质档案耐久性的关系.结果表明,羧甲基纤维素更有利于纸质档案的耐久保存,小麦淀粉浆糊次之.     

Hierarchical planning for a surface mounting machine placement

For a surface mounting machine(SMM)in printed circuit board(PCB)assembly line,there are four problems,e.g. CAD data conversion,nozzle selection,feeder assignment and placement sequence determination. A hierarchical planning for them to maximize the throughput rate of an SMM is presented here. To minimize set-up time,a CAD data conversion system was first applied that could automatically generate the data for machine placement from CAD design data files. Then an effective nozzle selection approach was implemented to minimize the time of nozzle changing. And then,to minimize picking time,an algorithm for feeder assignment was used to make picking multiple components simultaneously as much as possible. Finally,in order to shorten pick-and-place time,a heuristic algorithm was used to determine optimal component placement sequence according to the decided feeder positions. Experiments were conducted on a four head SMM.The experimental results were used to analyse the assembly line performance.     

The “Hands Together” method of nonsterile scalpel blade mounting and removal

Scalpels are utilized by many different user groups for such purposes as medical procedures and dissection. Injuries caused by scalpels are a potential risk for scalpel users, and include injuries that may occur while mounting and removing the scalpel blade. Between 10% and 20% of all scalpel injuries in education and healthcare settings are reported to occur while scalpel blades are being mounted or removed. At present there are few published or “best practice” demonstrations of safe technique for scalpel blade mounting and removal. This brief article outlines a variation of the procedure for scalpel blade mounting and removal. It includes strategies developed to minimize risk or injury for the scalpel user, including providing a stable base for the hands and arms so as to prevent unnecessary large amplitude movements that may lead to injury of the scalpel user or a third party. Such a technique may promote scalpel safety, contribute to the development of “best practice” scalpel use, and help decrease injuries that may be caused while mounting or removing scalpel blades. Anat Sci Educ 7: 161–166. © 2013 American Association of Anatomists.     

FSAE赛车车架刚度特性分析

车架刚度及发动机悬置安装点动刚度是影响FSAE赛车振动性能的重要因素,通过建立某FSAE赛车车架有限元模型,进行车架扭转刚度及悬置安装点动刚度分析,研究车架静态与动态刚度性能。结果表明：增大车架驾驶舱段截面可有效提高扭转刚度;悬置安装点各向动刚度值以纵向最大,横向最小。结合模态振型及加速度响应曲线能够较好地反映发动机舱的振动特性。