墨吉对虾体长与体重关系的计算及其在生产中的应用     

黄鸿基  吴琴瑟  蒋静南 《广东海洋大学学报》1990,(1)

本文研究墨吉对虾(Penaeus merguiensis)体长(L)与体重(W)的关系,经回归分析得其关系式。根据此关系式计算得体长和体重换算表,对指导生产具有现实意义。  相似文献   

Examination of Daytime Length''''s Influence on Phytoplankton Growth in Jiaozhou Bay, China   总被引：4，自引：0，他引：4  

杨东方  高振会  张经  崔文林  石强 《中国海洋湖沼学报》2004,22(1)

1　INTRODUCTIONSystematicstudyisusefulforhumanvisualizationandcomprehensionofanetworkofcomplicatedcompo nentsandprocessesinvolvingfrequentenergyflow ,consideringenergyasthebasisofbothstructureandprocess (Automa ,1 993) .Energylanguageisaconceptfordepictingasysteminwhichallphenomenaareac companiedbyenergytransformation .Thefunctionoftheecosystemovertheworlddependsontheenergyfixationbymarineplantphotosynthesis ,mostofthemarefixedbymicrophytoplanktonnearseasurfaceexposedtosunlight (Niebaken …  相似文献   

Measuring the flow resistance of submerged grass     

C. A. M. E. Wilson  M. S. Horritt 《水文研究》2002,16(13):2589-2598

Through laboratory experiments conducted in a grass‐lined flume, the hydraulic resistance of grass is measured and quantified. For the grass examined, it is found that Manning's n value is greater than those recommended in well‐established texts such as Chow (1959. Open Channel Flow. McGraw‐Hill: Singapore), relatively lower than those predicted by n‐UR methods, but corresponds well with the value found from calibration studies of two‐ and three‐dimensional numerical models. The assumption of a uniform Manning's n value with flow depth, which is often made in numerical modelling, may be invalid depending on the relative submergence of the vegetation. Drag coefficients are evaluated for a method applicable to three‐dimensional numerical models. Further detailed experimental investigation and application of these approaches within a numerical modelling framework is now recommended. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   

滚动轴承内外圈滚道的磁力研磨研究     

张世亮 《广东海洋大学学报》1994,(1)

采用直流励磁装置、磁性磨料及工件共同构成磁加工系统。磁性磨料在磁场的作用下，对轴承内、外圈滚道以磁刷的形式进行研磨。由于磨料的可流动性，加工时既能满足对被加工表面粗糙度的加工要求，又能较好地保持工件原有的形位精度；且加工后在被加工表面形成一定的压应力，使工件的抗疲劳强度提高，使用寿命延长。  相似文献   

太阳表面米粒结构观测对比度分析     

饶长辉  姜文汉  凌宁 《天文学报》2001,42(2):134-139

分析以观测系统焦面上和探测器测到的太阳表面米粒结构的对比度与观测系统口径，大气湍流相干长度以及系统探测灵敏度的关系，给出了不同口径，不同大气湍流相干长度以及不同系统探测灵敏度时的米粒结构对比值计算结果，此外还给出了实验结果。  相似文献   

美洲斑潜蝇在湛江市的发生与防治     

张宜仲  刘蜀南  黄朝贵 《广东海洋大学学报》1997,(1)

调查了潜蝇在湛江市的发生与为害情况，结果表明，美洲斑潜蝇（LiriomyzaSatiuaeBlanchard）是为害作物潜蝇的优势种，包括有6个科18种，年间发生有6个为害高峰期。应用绿潜宝、乐果、巴丹等药剂在发生为害高峰期的峰前、中、后三次用药，防治效果维持70％以上。  相似文献   

被断裂破坏的盖层封闭能力评价方法及其应用   总被引：3，自引：0，他引：3       下载免费PDF全文

吕延防  万军  沙子萱  付晓飞  付广 《地质科学》2008,43(1):162-174

断层对盖层的破坏主要表现为两个方面:一是减小了盖层的连续封盖面积,二是减小了盖层的厚度。盖层被断层破坏的主要影响因素有断层的断距、倾角和盖层厚度。通过对影响因素研究,提出了盖层有效断接厚度的新概念和计算方法。根据我国部分与断层有关的大-中型气田气柱高度资料,发现了有效断接厚度与所能封闭的最大气柱高度的对数线性关系,并由此提出了评价被断层破坏的盖层封闭能力的新方法。通过对库车坳陷库姆格列木群膏泥岩盖层的应用研究,所得结论与勘探实践完全吻合,证明所提出的评价方法是可行的。  相似文献   

Influence of Structural Non-Stationarity of Surface Roughness on Morphological Characterization and Mechanical Deformation of Rock Joints   总被引：2，自引：2，他引：0  

N. Fardin 《Rock Mechanics and Rock Engineering》2008,41(2):267-297

Summary Structural non-stationarity of surface roughness affects accurate morphological characterization as well as mechanical behaviour of rock joints at the laboratory scale using samples with a size below the stationarity threshold. In this paper, the effect of structural non-stationarity of surface roughness is investigated by studying the scale dependence of surface roughness and mechanical behaviour of rock joints. The results show that the structural non-stationarity mainly affects the accurate characterization of the surface roughness of the fracture samples. It also controls the amount and location of the contact areas during shear tests, which in turn affects the mechanical properties and asperity degradation of the samples. It is concluded that for accurate determination of the morphological and mechanical properties of rock joints at laboratory and field scales, samples with size equal to or larger than the stationarity threshold are required. Author’s address: Nader Fardin, Rock Mechanics Group, Department of Mining Engineering, Faculty of Engineering, University of Tehran, P.O. Box: 11365/4563, Tehran, Iran  相似文献   

利用钻芯孔检测灌注桩钢筋笼长度的方法     

樊敬亮  董平  叶景艳  李明  朱国伟 《物探与化探》2008,32(3):335-337

根据充电法原理,结合模型桩试验,分析了钢筋笼周围的充电电场特征,结果表明钢筋笼的底端对应于电位梯度曲线的极小值点及电位曲线的拐点。以此研究结果为基础,提出了利用钻芯孔来检测成桩后钢筋笼长度的方法。某桥的应用表明,该方法简便、实用、可靠。  相似文献   

城市坐标系的建立与申报     

李玉平 《测绘与空间地理信息》2017,(2):220-221

为了满足城市建设对测绘基准的要求,需建立相对独立的平面坐标系,我国测绘法等相关法律法规对独立平面坐标系的建立及管理有着明确的要求,本文结合新疆某县城相对独立平面坐标系的建立技术方案、申报材料准备、申报组织以及发布等方面进行了详细论述,希望能为测绘同行和测绘管理单位建立城市相对独立平面坐标系起到一定的参考作用。  相似文献