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1.
A bibliometric analysis of agricultural literature published in Malaysia between 1981–1990 was undertaken. The analysis shed light on the key journals that published agricultural literature; on the forms of publications which are resorted to in the communication of research results; on the subject areas which are well written on and those that have been neglected; on the nature of contributions made by Malaysian authors; on the publishing practice of corporate bodies and on the number of publications produced each year.  相似文献   

2.
Vulnerability to flooding: health and social dimensions   总被引:3,自引:0,他引:3  
This paper presents research results on the impacts that floods can have on the people affected, thus complementing the existing data on the monetary losses liable to occur in flood events. Both datasets should be used when deciding on investment in flood defence measures. We report on research on the vulnerability of flood-affected communities to adverse health effects, and the development of an index of community vulnerability based on extensive focus-group research and secondary-source census data.  相似文献   

3.
在硅和铁基底上同时进行CVD 金刚石的沉积,利用硅基底上的金刚石成核感应金刚石在铁基底上直接成核。研究表明,硅和铁基底上不同的沉积过程导致了铁基底上碳原子表面扩散的加强,从而促成了CVD 金刚石在铁基底上的直接成核。表面扩散对CVD 金刚石成核有重要影响。  相似文献   

4.
二元正态分布函数(Coons曲面法)插值研究   总被引:1,自引:0,他引:1  
根据Coons曲面生成原理,给出了二元正态(Gauss)分布的插值方法。对于二元正态分布密度函数,仅需给定插值区域边界上的值,即可插值出该区域上任意一点密度函数值;对于二元正态分布函数,仅需给定插值区域两边的双边界值,即可得到该区域上任意一点分布函数值。该方法无需知道也无需计算出Gauss分布函数的各项参数,便于应用,插值结果精确,绝对误差为O(10^-9),相对误差为O(10^-11)。  相似文献   

5.
The maximum thermal stress and stress concentration zones of iron/TiC cermet joint during cooling were studied inthis paper. The results showed that the shear stress on iron/TiC cermet joint concentrates on the interface tip andthe maximum shear stress appears on the left tip of iron/TiZrNiCu interface. Positive tensile stress on TiC cermetundersurface concentrates on both sides of TiC cermet and its value decreases during cooling. Negative tensile stresson TiC cermet undersurface concentrates on the center of TiC cermet and its value increases during cooling. Brazingtemperature has little effect on the development and maximum thermal stress.  相似文献   

6.
产品创新设计理论与方法综述   总被引:9,自引:7,他引:2  
蒋雯 《包装工程》2010,31(2):130-134
从工业设计和工程设计两个方面分析和归纳了当前产品创新设计理论与设计方法的发展现状,说明工业设计理论研究主要表现为设计思想、设计风格的研究,工业设计方法的研究主要面向设计思维本身和思维对象,中心是设计本身;工程设计理论研究主要表现为对设计过程的建模,工程设计方法的研究主要面向设计思维的模拟,中心是设计的手段。  相似文献   

7.
采用落锤法对复合材料加筋板进行了低速冲击损伤(LVI)试验,根据复合材料加筋板构型,设计了冲击支持支架,研究了支持支架的间距对冲击结果的影响;用相同的冲击能量对复合材料加筋板结构中3处典型位置进行冲击,得到不同位置的损伤形貌;分别对完好件和损伤试验件进行压缩试验,将试验结果进行对比,分析不同位置的冲击损伤对结构压缩性能的影响。试验结果表明:在相同的冲击能量下,支持支架间距越小,所造成的冲击损伤越严重;在50 J冲击能量下,筋条区蒙皮处的冲击所造成的损伤不易观察,筋条间蒙皮处的冲击所造成的损伤最为明显,而筋条边缘蒙皮处的冲击可以导致筋条边缘的脱粘;冲击损伤会使加筋板屈曲载荷轻微下降,筋条间蒙皮和筋条区蒙皮冲击损伤对压缩结果影响相对较小,筋条边缘处的冲击会引起损伤处蒙皮的子层屈曲,并影响结构破坏形式,使结构压缩承载能力有较为明显的下降。  相似文献   

8.
Despite their growing popularity in North America, little research has been conducted on understanding the effects of roadside memorials on drivers’ behaviour. In this study, we examined the short-term effects of roadside memorials on traffic speed and headways on a high speed intercity freeway as well as its long-term effect on traffic speed on a high speed urban freeway. Our study found that the placement of roadside memorials did not have any significant effect on traffic speeds or headways, either in the short or long term. Therefore, concerns about the negative effects on driver behaviour were not supported by this research, at least with regards to speeding and following too closely. However, no positive effects on safety were found either.  相似文献   

9.
The effect of integrated manufacturing on non-financial manufacturing performance and return on investment is studied. Technology-use data from over 1000 manufacturing plants in the USA were used to test empirically the relationships between variables integrated manufacturing, non-financial manufacturing performance and return on investment. Notable findings were (1) integrated manufacturing shows a strong effect on non-financial manufacturing performance and (2) non-financial manufacturing performance has a statistically significant direct effect on return on investment. It is recommended that the justification of investments in manufacturing technologies that contribute to integrated manufacturing must be based on non-financial manufacturing criteria as well as on return on investment. Using two different models, it is shown that the causal model developed in the study is robust.  相似文献   

10.
李易蔚  陈广学 《包装工程》2016,37(3):160-164
目的探究荧光增白剂对纸张印刷色彩管理的影响。方法选择2种300 g/m2定量的日本富士施乐彩激纸,一种含有荧光增白剂,一种不含荧光增白剂,使用KONICA MINOLTA C6000打印机输出色块,测量色彩管理前后2种纸张输入和输出色块之间的色差。对比2种条件下输出色块与输入色块的色差,分析荧光增白剂对不同阶调和墨层厚度的色块的输出影响,并探讨UV-cut滤镜对荧光增白剂的校正效果。结果在D50光源下,含有荧光增白剂的纸张较不含荧光增白剂的纸张输出颜色的色差大。荧光增白剂对中间调颜色的影响大于亮调和暗调颜色,对颜色的影响程度与亮度值呈正比,与墨层厚度呈反比。荧光增白剂对亮调颜色b值的影响大于暗调颜色,荧光增白剂对颜色的a值影响不大。结论含有荧光增白剂的纸张上输出的色域体积要小于不含荧光增白剂的纸张,对颜色的控制也较不含荧光增白剂的纸张差。使用UV-cut滤镜对荧光增白剂进行校正后纸张上输出色块的色差减小,对准确在纸张上进行颜色再现具有重要意义。  相似文献   

11.
在Navier-Stokes方程基础上,配合适当边界条件,借助计算流体力学软件CFD-ACE实现了单侧分布矩形微结构、梯形微结构和双侧分布矩形微结构零件模型的流场仿真,得到了三种零件的速度场和剪切速率场.结果表明,单侧矩形微结构零件各微结构截面的速度和剪切速率都有较大差异;单侧梯形微结构零件各微结构截面的剪切速率分布一致,速度分布不一致;双侧矩形微结构零件三个微结构截面的速度和剪切速率都一致.单侧分布梯形微结构零件流场均匀性好于单侧分布矩形微结构零件流场均匀性,双侧分布的微结构零件流场均匀性好于单侧布置的微结构零件流场均匀性.  相似文献   

12.
高速客车蛇行运动Hopf分叉的研究   总被引:2,自引:1,他引:1  
刘宏友  曾京  吕可维 《工程力学》2005,22(6):224-228
建立了高速客车非线性系统数学模型,模型中考虑了轨道的整体弹性和阻尼。基于常微分方程的一次近似理论和Hopf分叉理论,研究了高速客车在直线和大半径曲线轨道上蛇行运动的Hopf分叉情况。借助于DEPAR延续算法解决了圆曲线上车辆系统平衡位置难以确定的难题,分析了轨道整体刚度和阻尼、圆曲线半径和外轨超高及转向架悬挂参数等因素对高速客车Hopf分叉速度的影响。研究表明,高速客车在大半径曲线上也有可能出现Hopf分叉现象,并且曲线半径越大、外轨超高越大,车辆的Hopf分叉速度越高,但最大值不会超过车辆系统在直线上运行时的Hopf分叉速度。车辆系统在弹性轨道条件下的Hopf分叉速度高于刚性轨道条件下车辆系统对应的Hopf分叉速度。不论是刚性轨道还是弹性轨道,转向架悬挂参数对车辆系统Hopf分叉速度的影响趋势是一致的。  相似文献   

13.
聚氯乙烯瓶盖垫蒸发残渣的检测与分析   总被引:2,自引:2,他引:0  
以质量法和面积法为基准,对聚氯乙烯(PVC)瓶盖垫蒸发残渣量测定方法进行了研究和分析,探讨了样品形状和用量对PVC瓶盖垫蒸发残渣量的影响。结果表明:采用面积法测试蒸发残渣的量大于质量法测试的,且测试样品制成垫圈形式时,测试的蒸发残渣量比制成垫片形式的样品蒸发残渣量大;样品用量对基于质量法的蒸发残渣测试结果影响很大,但对基于面积法的测试结果影响不明显。  相似文献   

14.
虚拟现实条件下网上购物环境设计的工程心理学分析   总被引:3,自引:0,他引:3  
网上商店的界面设计一直是影响网上零售业发展的重要因素之一。初步研究发现,虚拟现实方式将对网上消费者的购物行为产生很大的积极影响,但现实中关于网上商店界面设计的系统研究却很少。文章从信息活动角度,分析网上购物的虚拟现实表征形式的工程心理学意义及其影响因素。  相似文献   

15.
韩宁  顾明 《振动与冲击》2009,28(12):188-192
对两个串列方柱在0°风向角下进行了其中之一的受扰方柱风压测量的风洞试验。根据试验结果,分析了施扰模型高度和位置变化对受扰方柱局部脉动风压的影响。结果显示,当施扰模型和受扰方柱等高时,随着间距比的增大,受扰方柱迎风面脉动风压增大,特殊的情况是在间距比小于4时,迎风面棱边和接近屋顶的部位脉动风压显著放大而中间部位其值则减小;当施扰模型位置固定时,随着高度比的增大,受扰方柱迎风面棱边和屋顶角部脉动风压相应增大,而迎风面中间部位则先增大后减小。  相似文献   

16.
Accept on zero and accept on one sampling plans are two common approaches to determine if a manufacturing lot can be accepted or rejected. Accept on zero plans inspect fewer items than the accept on one plans. On the other hand, accept on one plans have a higher probability of accepting a lot when the defect rate is between the Acceptable and Rejectable Quality Levels. This article proposes a double sampling plan whose probability of accepting a lot resembles an accept on one plan yet inspects considerably fewer items on average.  相似文献   

17.
剪切流场对塑料发泡成核行为的影响   总被引:1,自引:0,他引:1  
本文着重讨论了剪切流场对成核行为的影响,对宏观规律进行微观分析。通过剪切流场对高聚物熔体中分子取向排列的影响,在熔体中形成大量均匀分布的成核点,这不仅为开发优质泡体提供了理论依据,也是为国外正在加紧开发的微孔发泡技术提供参考。  相似文献   

18.
This study estimates the safety effect of road lighting on accidents in darkness on Dutch roads, using data from an interactive database containing 763,000 injury accidents and 3.3 million property damage accidents covering the period 1987-2006. Two estimators of effect are used, and the results are combined by applying techniques of meta-analysis. Injury accidents are reduced by 50%. This effect is larger than the effects found in most of the earlier studies. The effect on fatal accidents is slightly larger than the effect on injury accidents. The effect during twilight is about 2/3 of the effect in darkness. The effect of road lighting is significantly smaller during adverse weather and road surface conditions than during fine conditions. The effects on pedestrian, bicycle and moped accidents are significantly larger than the effects on automobile and motorcycle accidents. The risk of injury accidents was found to increase in darkness. The average increase in risk was estimated to 17% on lit rural roads and 145% on unlit rural roads. The average increase in risk during rainy conditions is about 50% on lit rural roads and about 190% on unlit rural roads. The average increase in risk with respect to pedestrian accidents is about 140% on lit rural roads and about 360% on unlit rural roads.  相似文献   

19.
Main Responsibilities of SAC 1.To draft and revise the state laws and regulations on standardization, to formulate and implement the policies on standardization; to formulate the national administrative rules on standardization and develop relevant systems; to organize the implementation of laws, rules and systems on standardization; 2.To be responsible for formulating the development programs on standardization of China; to organize, coordinate and draft the programs on the development and revision of national standards;  相似文献   

20.
综述了钛合金微弧氧化膜的摩擦学性能研究以及提高膜层耐磨性能和润滑性能所采用的方法,旨在对改善钛合金微弧氧化膜摩擦学性能的研究现状有一个系统全面的认识,并在此基础上展望了未来钛合金微弧氧化膜摩擦学研究的发展趋势和方向。  相似文献   

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