Experimental Investigation of Convective Heat Transfer Coefficient of Various Agricultural Products Under Open Sun Drying

Abstract

In this article, the convective heat transfer coefficients of various agricultural products were investigated under open sun drying conditions. Data obtained from open sun drying experiments for eight agricultural products, namely, mulberry, strawberry, apple, garlic, potato, pumpkin, eggplant, and onion were used to determine values of convective heat transfer coefficient. The value of convective heat transfer coefficient was determined as 1.861 W/m²°C for mulberry, 6.691 W/m²°C for strawberry, 11.323 W/m²°C for apple, 1.136 W/m²°C for garlic, 8.224 W/m²°C for potato, 8.613 W/m²°C for pumpkin, 6.981 W/m²°C for eggplant, and 6.767 W/m²°C for onion. The experimental error in terms of percent uncertainty was also calculated.     

倒葫芦张开状零件成形模具的设计

此文对倒葫芦张开状零件成形模具的设计进行了分析和计算,结论是所采用的模具结构成形类似零件是可行的。     

Amniotic fluid acetylcholinesterase measurements: Comparing immunochemical and polyacrylamide gel techniques

In the present study, a recently reported immunochemical technique for measuring acetylcholinesterase (AChE) in amniotic fluid utilizing the 4F19 antibody was compared with the widely utilized polyacrylamide gel technique to determine whether the immunochemical assay provided an advantage in separating unaffected pregnancies from those associated with open spina bifida (OSB) and open ventral wall defects (OVWD). The study included (1) 73 amniotic fluid samples from unaffected pregnancies [alpha-fetoprotein (AFP) < 2 MoM] with no visible gel AChE band, (2) nine bloodstained samples from unaffected pregnancies (AFP 2·2–4·0 MoM) with visible gel AChE bands, (3) 18 samples associated with OSB (AFP 2·2–7·0 MoM) with visible gel AChE bands, and (4) 20 samples associated with OVWD (AFP 3·2–53·5 MoM) with visible gel AChE bands. The immunochemical assay produced ranges of measurements in the four respective categories as follows: (1) 2–60 arbitrary units (AU): (2) 14–69 AU, (3) 61–593 AU, and (4)22–476 AU. Eight of the nine unaffected pregnancies with visible gel AChE bands had immunochemical measurements below the highest measurement for the samples with no visible AChE band (60 AU), as did five out of 20 OVWD pregnancies. Two of the OSB cases had values of 61 and 62 AU. These data indicate that the 4F19 specific monoclonal antibody to AChE is capable of distinguishing unaffected from affected pregnancies with reasonable reliability but that more work needs to be done to establish the extent of overlap between the unaffected and affected populations.     

基于UG的标题栏和明细表自动生成技术的研究

介绍了UG/OpenAPI的基本概念和特点,研究了标题栏和明细表自动生成的一些关键技术和方法。并用VC++6.0编制出标题栏和明细表自动生成程序,弥补了UG的不足。     

安太堡露天煤矿土场刺槐生长状况研究

安太堡露天煤矿１９９３－１９９８年土地复垦试验结果表明，在排土场逆境条件下，刺槐可以正常生长。坡度、坡向、地表物质组成和植物配置模式是影响其生长的主要因子。在阳向坡、避风处生长良好。黄土母质有利于１年生刺板的生长，岩土混排则更有利于２年生以上刺槐的生长、刺槐与草混交抑制刺槐生长。     

Did you say reference conditions? Ecological and socio-economic perspectives on the European Water Framework Directive

Reference conditions are a key concept in the European Water Framework Directive (WFD). The WFD stipulates that the ecological status of a given water body shall be assessed by quantifying the deviation from a set of reference conditions that represent the stable state of an ecosystem in the absence of significant human disturbance. This concept is subject to criticism from several authors, particularly because underlying ecological concepts are weak and the distinction between natural variability and the effects of anthropogenic activities on ecosystem function will become increasingly artificial. In this paper, a sociologist and an aquatic ecologist examine the origin, successes and limits of the reference conditions concept and raise important questions about applying this concept in practice. We argue that this concept fitted specific needs from different institutions and stakeholders which promoted the WFD. Monitoring practices using this concept require some adaptations. Setting goals for restoration based on reference conditions is more problematic. A more adaptive management approach would be wiser.     

香樟枝叶挥发物对小白鼠自发行为影响

采用小白鼠旷场分析试验,观察分析昆明种小白鼠在不同浓度香樟（Cinnamomum camphora）枝叶挥发气味环境中行为指标的变化,研究香樟枝叶挥发物对小鼠自发行为的影响,以此来客观评价香樟枝叶挥发物的保健功能。结果表明,（1）从小白鼠运动总路程来看,低浓度处理组〉空白对照组〉高浓度处理组,表明小白鼠对香樟枝叶挥发物的浓度有一定的承受阈值,超过一定的浓度对小白鼠的兴奋性产生抑制作用。（2）中央格运动总路程、站立次数这2项指标,表现出高浓度处理组一直显著低于空白组和低浓度处理组,低浓度处理组与空白组的差异不显著,但变化幅度比空白组大,说明高浓度香樟枝叶挥发物不仅降低了小白鼠的兴奋性,而且还降低了其认知和探索能力,低浓度没有表现出来这个方面的副作用。（3）从粪便粒数和体质量这2项指标来看,高浓度处理组和低浓度处理组体质量和空白组相比较,增长缓慢,中间处理过程中甚至出现平均体质量下降趋势,并且高浓度处理组的小白鼠粪便粒数一直高于对照组,说明香樟枝叶挥发物气味环境降低了小白鼠的食欲,且越高的浓度环境下相对紧张程度越高。     

Free or low-cost geoinformatics for disaster management: Uses and availability issues

The disaster management applications of geographical information systems and remote sensing are examined relative to the disaster cycle, in pre-disaster, crisis and post-disaster contexts. We focus on the uses and limitations of free or low-cost data and software. A wide range of geospatial datasets are currently freely available, from digital elevation models (DEMs) and thematic digital maps, to multispectral satellite imagery and virtual globes, such as Bing Maps. Maps of hazardous terrain and vulnerable features can be derived from sets of satellite data such as shuttle radar topography mission DEMs and Landsat imagery. The derived maps are particularly useful for district scale (1:25 to 1:100 K) disaster management in low-income countries. Detailed maps (i.e. better than 1:25 K scale) of hazardous terrain and vulnerable features generally require expensive high-resolution satellite imagery or aerial photography.

Although the Internet allows the distribution of free or low-cost geospatial data, software and training materials, there are still some countries with limited Internet access. Data integration, spatial/temporal analysis and map production are also limited by the frequently high price of geoinformatic software, making it a priority to develop suitable Free and Open-Source Software.     

基于断裂力学的受压容器安全评定方法

以断裂力学为基础,对在役含缺陷受压容器的评定方法与评定步骤进行了介绍,规范了缺陷简化及等效裂纹尺寸,并进行缺陷的脆断评定。它能对在役压力容器的现在和未来状况进行评估和预测,判断其是否能够继续使用及安全度如何,并能在安全的前提下使压力容器的潜能得到充分发挥,从而在最大程度上减少危害与损失。     

Planning for green cities: some emerging principles

There are a number of reasons why planners should take a more positive approach towards the natural economy of the city, and this paper rehearses the arguments in favour. The author takes the view that much publicly owned land is manicured and excessively stocked with exotic species so that they are relatively poor in wildlife. An alternative to the generally held view that dormant land in urban areas is unsightly and encourages vandalism, is that such sites offer opportunities for visual interest, education and recreation. The paper concludes by outlining a number of courses of action which, it is suggested, may come to dominate environmental planning.