北部湾野生长毛明对虾(Fenneropenaeus penicillatus)体重和形态性状的关系   总被引：1，自引：0，他引：1  

孙成波  李镇泉  黄海立  王平  徐安敏  陈科光 《广东海洋大学学报》2008,28(6)

测量北部湾86尾野生长毛明对虾体长、头胸甲长、胸高、胸宽、第一腹节宽、第一腹节高、第三腹节高、额剑上刺数、额剑下刺数和体重等10个性状,采用逐步回归法分析9个性状和体重的关系。结果表明:体长、头胸甲长、胸高、第一腹节宽、第三腹节高和额剑下刺数6个性状与体重的相关系数达到了极显著水平(P<0.01),在单独的决定系数中:头胸甲长对体重的决定系数(14.44%)最大,共同决定系数中,体长与头胸甲长最大为21.13%。通过分析,建立长毛明对虾的体长、头胸甲长、胸高、第一腹节宽、第三腹节高、额剑下刺数对体重的最优理想回归方程,为长毛明对虾选育种和保种提供理想的测度指标。  相似文献   

AM-LSTM网络的北京平原东部地面沉降模拟     

曹鑫宇  朱琳  宫辉力  郭琳  尉毓姣  郭涛  陈蓓蓓  王海刚  李蕙君 《遥感学报》2022,26(7):1302-1314

基于传统数值方法构建的地面沉降模拟预测模型需要大量的水文地质数据和实测数据,对于地质条件复杂地区的形变模拟预测难度大。本文基于PS-InSAR技术获取的北京平原东部地区的地面沉降信息,综合考虑不同层位地下水水位对沉降的影响,采用基于注意力机制的长短时记忆网络（AM-LSTM）对不同沉降发育地区典型位置处的地面沉降进行模拟。结果表明：（1）研究区地面沉降空间差异性明显,2010年11月—2016年8月最大沉降速率约153 mm/a,累计沉降量达到1063 mm,位于朝阳区三间房乡附近;（2）基于AM-LSTM模型的模拟精度优于传统LSTM模型,本次模拟精度最高提升了22%;(3) AM-LSTM模型注意力权重表明,第二承压含水层水位对地面沉降贡献最大。本次研究能够为地面沉降防控提供可靠的技术支撑。  相似文献   

Quantitative assessment of impacts of climate and economic-technical factors on grain yield in Jilin Province from 1980 to 2008     

Zuofang Yao  Fei Yang  Xingtu Liu  Minhua Yan  Jun Meng 《中国地理科学(英文版)》2011,21(5):543-553

Climate change is one of the most important challenges threatening agricultural grain yield and food security. Determining the factors influencing grain yield in Jilin Province and the weights of their contribution are a very important task, because Jilin Province is an important agriculture base in China. In this study, the accumulation factor sequence evaluating data method was used to analyze the climate and economic-technical factor contribution weights to grain yield and grain yield changes in each city of Jilin Province. Climate yield was also estimated to study the climate effect on the grain yield, and it was calculated in two ways:an improved algorithm and a traditional quadratic method. The results show that the climate and economic-technical factors have different contribution weights to grain yield in different cities in Jilin Province. The contribution weight of the climate factor to grain yield was 0.212-0.349, while that the economic-technical factor was 0.651-0.788. Furthermore, the changes of the climate factor contributing to grain yield changes accounted for 0.296-0.546, and the changes of the economic-technical factor accounted for 0.454-0.704. The weights of climate and economic-technical factor contributing to grain yield are very different between the eastern and western cities in Jilin Province, but their weights contributing to the grain yield change are similar in these cities. In general, the amount of fertilizer used per hectare (FUPH) is the main factor affecting grain yields and yield changes from 1980 to 2008. It is noted that when the FUPH growth rate stabilized after 1995, the effects of the climate factor on the grain yield become more obvious than before. The improved algorithm is effective for estimating climate yield in Jilin Province, and the climate yields were mostly between-500 kg/ha and 500 kg/ha, and showed a slightly rising trend in most cities.  相似文献   

矿石体重不同分析方法的对比探讨——以长山锌金多金属矿床为例          下载免费PDF全文

黄建  黄家龙  赵坦 《地质找矿论丛》2021,36(3):378-387

矿石体重的准确获取,对降低矿床储量计算误差十分重要.文章以长山锌金多金属矿为例,建立矿石体重与Cu、Pb、Zn、S等元素之间的数学模型.首先探讨矿石体重和元素之间的数学关系,并证明当矿石中有多种硫化物建立回归模型时,不需要对全硫进行扣减;在此基础上,分别建立2种多元线性回归模型和1种神经网络模型,并对3种模型拟合精度进...  相似文献   

抚仙湖近60年来沉水植物群落变化趋势分析     

高弋明  殷春雨  刘霞  赵钰  陈非洲  陈新芳  关保华 《湖泊科学》2021,33(4):1209-1219

自1960s以来,抚仙湖沿岸带沉水植物群落发展迅速,而监测频率相对不足.为了解抚仙湖沉水植物群落现状及过去60年内的变化趋势,于2016年7月,对抚仙湖全湖沉水植物进行调查,并结合以往多次调查数据进行趋势分析.本次调查设置了36条样带共41个样点.在实测数据验证后,使用卫星多光谱相机数据基于归一化植被指数(NDVI)计...  相似文献   

升温对丛生盔形珊瑚两种形态型代谢和共生藻光合生理的影响     

何茜  俞晓磊  梁宇娴  张喆  黄晖  周伟华  袁翔城 《热带海洋学报》2022,41(5):133-140

文章研究了温度升高对一种造礁石珊瑚——丛生盔形珊瑚(Galaxea fascicularis)的两种形态型(H和S型)代谢和共生藻光合生理的影响。研究显示H型和S型对升温的生理响应差异明显:在虫黄藻水平上, H型丢失了大量的虫黄藻,减轻了共生体呼吸代谢的负荷; S型中虫黄藻数目尚可维持共生体呼吸代谢的需求,同时提高叶绿素b含量增强光的吸收。在宿主水平上,H型充分利用虫黄藻输送的营养物质,并通过异养摄食补偿能量消耗;S型宿主所储存的营养物质可以协助共生体适应热环境。结果表明,丛生盔形珊瑚两种形态型通过不同的能量利用方式适应环境的变化, H型倾向于维持共生体的代谢平衡,而S型倾向于提高共生藻的能量分配。  相似文献   

Dynamics of carbon and nitrogen during the decomposition of detritus derived from estuarine macrophytes   总被引：2，自引：0，他引：2  

Donald L. Rice  Kenneth R. Tenore 《Estuarine, Coastal and Shelf Science》1981,13(6):681-690

  相似文献   

不同饵料对两种帘蛤科贝类生长性能的影响研究     

冯森磊  梁夏菲  徐晔  严维鑫  葛红星  董志国 《海洋科学》2021,45(12):47-54

为探讨不同饵料对青蛤(Cyclina sinensis)与文蛤(Meretrix meretrix)生长和存活的影响,本实验选用紫菜(Pyropia)、浒苔(Enteromorpha prolifera)、海带(Laminaria japonica)、小球藻(Chlorella vulgaris)和人工配合饲料5种饵料,采用单一饵料投喂方式进行饲养.结果表明:小球藻组中特定生长率、存活率及饲料转换率与各饵料组均有显著性差异(P<0.05),青蛤的增质量率显著低于紫菜组、海带组及人工配合饲料组(P>0.05).在人工配合饲料组中青蛤与文蛤的特定生长率与各饵料组均有显著性差异(P<0.05),青蛤的增质量率与各饵料组无显著性差异(P>0.05),文蛤的增质量率显著高于紫菜组、浒苔组及人工配合饲料组(P<0.05).在3组大型藻中,海带组中青蛤的特定生长率为0.07％,增质量率为4.59％,饵料转换率为7.09％,存活率为74％;文蛤的特定生长率0.13％,增质量率为8.36％,饵料转换率为1.41％,存活率为55.6％.综上,小球藻和人工配合饲料有利于青蛤和文蛤的生长,在3组大型藻中,投喂海带有利于文蛤和青蛤的生长和存活.  相似文献   

Stability of some New Zealand coastal inlets   总被引：1，自引：1，他引：0  

R. A. Heath 《新西兰海洋与淡水研究杂志》2013,47(4):449-457

The relation of tidal compartments to entrance cross‐sectional areas is examined for 20 coastal inlets. Sixteen inlets conform to a linear relationship, which is consistent with stable entrances the sizes of which are determined by the ability of the tidal flow to transport sediment. Based on this criterion deposition should be taking place at the entrances of the other four inlets: Wellington, Lyttelton, and Akaroa harbours, and Paterson Inlet. Available data confirm this for Wellington and Lyttelton Harbours.  相似文献   

Formation and functional significance of storage products in cyanobacteria     

Jacco Kromkamp 《新西兰海洋与淡水研究杂志》2013,47(3):457-465

The most common storage products of cyanobacteria are polyphosphate as a phosphorus storage compound, cyanophycin or phycobilin protein pigment as nitrogen storage products, and glycogen as a storage product of both carbon and energy. Nutrient uptake kinetics are regulated by the storage pools, and the patterns of regulation have a feedback effect on the amount of accumulated nutrient in the cells. Besides having a storage function the nutrient storage products are likely to act as metabolic sinks during conditions of energy stress. Regulation of storage products is especially strict in light‐limited cultures. By increasing the rate of polysaccharide formation during growth with short photoperiods, cyanobacteria are able to sustain relatively high growth rates. This effect is enhanced by keeping respiratory losses very low.  相似文献