oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 22 )

2018 ( 617 )

2017 ( 676 )

2016 ( 731 )

Custom range...

Search Results: 1 - 10 of 42389 matches for " 谭沅良 "
All listed articles are free for downloading (OA Articles)
Page 1 /42389
Display every page Item
激光增材制造用SiC粉末制备及成形工艺探索
王江,刘凯,孙华君,,吴添,马成飞,武娜
- , 2018, DOI: 10.11951/j.issn.1005-0299.20170092
Abstract: 为制备高强度复杂形状SiC陶瓷零件, 以酚醛树脂(PF)为粘接剂, 分别采用机械混合法(SPM)和搅拌蒸发法(SPC)制备两种SiC复合粉末, 并对两种粉末进行了SEM电镜扫描、SLS成形、碳化和渗硅反应烧结处理.研究表明, 在激光功率10 W, 分层厚度0.1 mm, 扫描速2 000 mm/s, 扫描间距0.2 mm时, SLS坯体密度大(1.259 g/cm3), 生产效率高.利用SPC粉末制得的SLS坯体内部孔隙更多, 碳化和渗硅烧结后坯体密度明显增加.采用SPC粉末所制零件最终力学性能更好, 更适于生产.在最优工艺条件下, 制备了复杂形状的高性能SiC零件.
To fabricate SiC parts with high performance and complex structure, Phenol-formaldehyde resin(PF) was applied as adhesive, SiC-PF mixing powder (SPM) and SiC-PF Coating powder(SPC) were prepared by mechanical mixing and stirring evaporation method.SEM analysis, Selective Laser Sintering (SLS), carbonization and siliconizing process were carried out to characterize the formation of these two materials.The results indicated that the powder fabricated by SLS had high body density and production efficiency when the laser power, layer thinkness, scanning speed and hatch spacing were respectively set at 10 W, 0.1 mm, 2 000 mm/s and 0.2 mm.It was found that the body formed by SPC powder had more micro pores and the body density increased apparently after carbonization and siliconizing process.SPC parts have higher density and it is more suitable for production.Complex ceramic parts were fabricated under the optimum process conditions.
OpenSSL Engine安全平台下的Engine对象分析

四川师范大学学报(自然科学版) , 2004,
Abstract: OpenSSLEngine安全平台的主要目的是替换OpenSSL的底层加密机制.介绍了OpenSSLEngine安全平台的原理,分析OpenSSLEngine安全平台下Engine对象的关键技术,剖析了OpenSSLEngine安全平台的不足并提出了相应的解决方案,对Engine对象的开发有指导意义.更多还原
“抛体运动实验”CAI课件

四川师范大学学报(自然科学版) , 1999,
Abstract: 介绍了抛体运动演示实验计算机辅助教学软件的设计思想和设计方法该软件用图形方式模拟了抛体运动的三种运动过程及状态参数的动态显示,并提供了友好的用户界面,操做简单方便它对开发其它实验课件有一定的启发作用更多还原
可信操作系统中可信客体的研究

计算机应用 , 2008,
Abstract: ?分析了操作系统中客体的类型,将客体分为静态客体和动态客体,然后总结了安全操作系统中对客体的处理存在的问题。在此基础路上,提出可信静态客体、可信动态客体和可信客体的概念,并分析了可信客体的特点以及与安全客体的关系。最后提出了在可信操作系统客体的可信需求。为下一步将要开展的工作奠定基础。
鄱阳湖入湖径流和水资源变化特征分析
Characteristic Analysis of Inflow and Water Resources in the Poyang Lake Basin
 [PDF]

喻中文, , 李国文
Journal of Water Resources Research (JWRR) , 2014, DOI: 10.12677/JWRR.2014.36057
Abstract:
鄱阳湖流域占江西省国土总面积的97.2%,占长江控制流域面积的9%,鄱阳湖流域水资源变化对长江流域有着显著影响。本文通过分析鄱阳湖流域降水、径流等水文水资源要素,得出了各要素的年际、年内及地域空间上的变化规律。同时,采用Mann-Kendall (MK)方法,分析鄱阳湖流域隆水量以及各站年入湖径流的变化趋势。
Poyang Lake basin accounts for 97.2% of total land area in Jiangxi Province and 9% of Yangtze River basin, and the change of water resources in the Poyang Lake significantly affects Yangtze River drainage area. In this study, the inter-annual, intra-annual and regional variation rules of each element were obtained through analyzing precipitation, runoff and other elements of hydrology and water resources in the Poyang Lake basin. Meanwhile, the Mann-Kendall (MK) method was used to analyze the precipitation of the Poyang Lake basin and the significance level of variation trend of annual inflow in each station.
单轴压缩下干燥和饱水岩石中超声P波的衰减
刘祖,胡毓,陈颙
地球物理学报 , 1984,
Abstract: 根据脉冲传播和频谱比方法的基本原理建立了一套超声波衰减和波速测量系统。研究了单轴压缩下超声P波在干燥和饱水的小浪底砂岩和房山大理岩中的衰减和速度。常压下,水饱和样品的Q_P值低于干燥样品。初始加载时,在大多数情况下,Q_p值明显增加即衰减减小;当应力水平达破裂强度50—60%后,岩石开始膨胀,Q_p减小即衰减增加;临近破裂Q_p减至最小。Q_p的变化量达一个数量级。单轴压缩下,在干燥和饱水的砂岩、大理岩中,V_p分别增加为27%和28%,44%和11%。径向Q_p和V_p随单轴压力的变化比轴向小得多,呈现明显各向异性。在本实验条件下,波在裂纹表面的摩擦耗散是主要的衰减机制,水的作用主要是潮湿和润滑裂纹表面,促进滑动,增加衰减。
fy-2卫星s-vissr数据几何纠正研究
,,范登科,徐琪
武汉大学学报(信息科学版) , 2012,
Abstract: ?提出了一种简单高效的fy-2卫星s-vissr数据的几何纠正方法。该方法以fy-2标称投影图像(nom)经纬度对照表作为参考图像,fy-2卫星s-vissr数据作为输入图像,首先利用s-vissr数据提供的简化格网数据在两幅图像间获取同名点,然后根据同名点寻找两幅图像间的几何变换模型,最后对s-vissr数据进行几何纠正。实验表明,利用该方法能够快速地完成对fy-2e和fy-2d卫星s-vissr数据的几何纠正,其精度达到了1个像素左右。
利用hj-1a/1bccd数据进行黄河凌汛监测
,徐琪,周正,
武汉大学学报(信息科学版) , 2012,
Abstract: ?利用hj-1a/1b卫星ccd数据进行黄河凌汛监测,提出了基于主成分分析和决策树的冰凌提取方法。实验结果显示,利用hj-1a/1b卫星ccd数据能有效地提取出黄河的冰凌范围,对黄河凌汛监测具有较大的应用潜力。
Research of trusted operating system
可信操作系统研究*

,周明天
计算机应用研究 , 2007,
Abstract: :The developing history of the SOS(security operating system) was reviewed in brief, some problems in the SOS were pointed out. Moreover, the conception of the trusted operating system(TOS) was put forward, and the characters, the connotation of the TOS and the relationship between the TOS and the SOS were addressed. Finally, presented and discussed some requirements for the TOS, which needed to be resolved.
动物胃肠道微生态理论与实践

应用生态学报 , 2003,
Abstract: 重点论述了动物胃肠道内与微生物群落密切相关的微生态学理论,介绍了动物胃肠道微生物群落的种类、特点和作用及其机制,并着重阐述了动物胃肠道微生态学理论与饲用微生物添加剂的关系及其微生物添加剂在畜牧业生产中的实际应用效果.
Page 1 /42389
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.