罐顶对罐壁应力的影响     

陈湘球 《油气储运》1994,(4)

在大型油罐设计中采用线性理论的方法,分析论述了罐顶对罐壁是否产生影响这一问题。通过对拱顶油罐、浮顶油罐的罐壁边界条件、罐顶边界条件的分析计算,求出各层壁板挠度方程中的待定系数,便可得出其应力。从线性方程中,可看出影响罐壁应力的主要因素是挠度方程中的待定系数。待定系数除受储罐尺寸、液位高度的影响外,还受罐顶重量、罐顶剪力和弯矩的影响。以10万m~3浮顶油罐和拱顶油罐为例,进一步证明,液位是罐壁应力的控制因素,而罐顶重量、罐顶剪力和弯矩对罐壁应力的影响可以忽略不计。  相似文献   

湖北省土壤各级颗粒的磁化率     

余红家 《湖北农学院学报》1990,(1)

本试验对湖北省六种土壤五个粒级(>1,1-0.5,0.5-0.25,0.25-0.15.0.15-0.1mm)的磁化率进行了测定。结果表明:红壤、棕红壤、潮土和黄棕壤表土层磁化率大于母质层磁化率,而紫色土和黄褐土表土层磁化率小于下部土层的磁化率。棕红壤表土层磁化率小于淀积层磁化率。红壤、棕红壤、黄棕壤和黄褐土母质层磁化率随颗粒变细而明显增加,但这一现象在潮土、紫色土的母质层确不明显。0.25-0.15mm粒级是黄棕壤、红壤、棕红壤、潮土、紫色土磁化率随颗料大小变化的一个转折点。  相似文献   

固支矩形底扁球壳的边界几何缺陷     

蔡松柏  王选民 《湖南农业大学学报(自然科学版)》1991,18(3)

In this paper, concept of boundary geometrical imperfection during postbuckling process for shallow spherical shell is first presented. The effects of the declination of the rectangular boundary on postbuckling process are also studied by integrated metho  相似文献   

福禄考属植物及其主要栽培种的园艺学研究进展   总被引：2，自引：1，他引：2  

李红伟  张金政  张启翔 《园艺学报》2005,32(5):954-959

 简述了福禄考属植物的种质资源分布以及研究进展, 并对主要种———宿根福禄考的引种、育种、栽培以及繁殖方式等园艺学研究进展进行了归纳分析, 旨在推动以宿根福禄考为代表的宿根花卉在我国的研究与栽培应用。  相似文献   

粗山羊草抗条锈 (CYR32) 性状的遗传分析   总被引：8，自引：1，他引：8  

杨烈  杨武云  张新全  魏会廷  李俊 《草业学报》2005,14(4):102-105

12份粗山羊草材料成株期对中国条锈病新小种CYR32为免疫-高抗,1份为高感.为探讨抗病性遗传规律,组配成抗×感、抗×抗杂交组合.通过对抗×感以及杂交组合的F1、F2群体对CYR32条锈菌抗性表型的分析,结果显示,所有抗源亲本对条锈病抗性呈完全显性遗传, F2群体抗感分离比例为3∶1,条锈病的抗性受1对显性基因控制.抗×抗杂交组合F2均呈抗病性,推测12个抗病粗山羊草材料的抗病基因可能为同一对显性基因.  相似文献   

鸡蛋消毒方法的对比研究   总被引：3，自引：1，他引：3  

刘会珍  李刚  孙瑞国  高振江 《中国家禽》2005,9(Z1):170-173

采用5种消毒方法对鸡蛋蛋壳表面细菌进行杀菌效果试验,结果表明,各处理组之间抑菌效果差异显著(P＜0.05),杀菌效果优劣依次为开水浸烫＞甲醛熏蒸＞过氧乙酸熏蒸＞高锰酸钾浸泡＞过氧乙酸浸泡,开水浸烫操作技术难度较大,容易引起蛋壳破裂,适宜实际生产的消毒方法为过氧乙酸熏蒸和甲醛熏蒸.将消毒处理后的鸡蛋在温度25℃,相对湿度60%～80%贮存20天,开水浸烫处理组鸡蛋仍保持较鲜的品质,其余各组鸡蛋品质较差.结果表明,常规消毒方法(除开水浸烫法)只能抑制蛋壳表面微生物的生长繁殖,不能延缓鸡蛋品质下降达到保鲜鸡蛋的作用.  相似文献   

Assessing exterior egg quality indicators using machine vision     

A. V. Vasileva  E. V. Gorbunova  A. S. Vasilev  V. S. Peretyagin  A. N. Chertov  V. V. Korotaev 《British poultry science》2018,59(6):636-645

ABSTRACT

1. The objective of this study was to develop a machine vision method for analysing exterior parameters of chicken eggs to automate the stage of primary sorting.

2. The developed algorithm based on predetermined thresholds calculated egg quality indicators, including geometric dimensions, shape index and the mottling grade. The algorithm was implemented with an experimental setup that combined the image-based and the candling methods. A total of 400 egg samples were analysed.

3. Comparison of results of the algorithm with those obtained using the traditional manual method showed that mean value of radii values difference was 0.095 ± 0.058 mm for the sharp and 0.080 ± 0.047 mm for the blunt end of the egg, with standard deviations of 0.58 mm and 0.49 mm, respectively.

4. The correlation coefficient between the shape index values determined by the two methods was 0.93; the standard deviation of absolute differences between corresponding values was 1.05%.

5. The results of mottling grade estimation were compared using F-measure and confusion matrix.

6. The results allow the possibility to perform the assessment of egg exterior quality factors in an automatic mode, independent of the expertise of a grader.  相似文献   

基于茶籽壳代替木屑栽培茶树菇配方筛选试验     

魏云辉  李菁  胡中娥  王洪秀  熊小文 《中国食用菌》2014,(5):30-32

不同比例的茶籽壳和木屑组合成5个试验配方,比较不同配方对菌丝生长、子实体经济性状和生物转化率的影响。试验结果表明,在供试的5个配方中,配方4（棉籽壳50%、茶籽壳15%、木屑5%、麦麸20%、玉米粉7%、石膏1%、磷肥1%、石灰1%）为优选配方。  相似文献   

Effects of Oyster Shell Soil Amendmenton Fruit Auality and Soil Chemical Properties in Greenhouse Tomato Acidic Soils     

《农业科学与技术》2016,(9)

[Objective]The aim was to explore the feasibility of applying oyster shell soil amendment for tomato production in order to determine proper quantity of the soil conditional.[Method]Field tests were performed to research effects of the soil conditioner on tomato yield,quality and soil p H.[Result]The results showed that tomato yield increased in the treatment groups with oyster shell soil amendment.The group SC50 increased the most by 16.5%than the control group.Based on normal fertilization,tomato growth was promoted by the soil amendment,and per tomato weight and lycopene content both improved during peak-fruiting period.Besides,soil p H value was enhanced by the soil amendment also.[Conclusion]It can be concluded that the effect was the best when soil conditioner was applied at 750 kg/hm2.  相似文献   

我国橡子资源的开发利用   总被引：1，自引：0，他引：1  

张玥  谢文霁  杨可心  李德海  杨冰雨  林岩 《中国林副特产》2014,(4):85-88

橡子营养丰富，而且具有多种功能特性，广泛应用在食品和其它工业中。对橡子仁、橡子皮质和橡子壳的成分、功能和应用等研究情况进行了综述，并介绍了橡子资源在食品及其它工业领域的应用进展，以及提出了橡子资源开发与研究过程中遇到的问题和解决方案。  相似文献