Interannual variability in the biochemical composition of newly hatched larvae of the spider crab Maja brachydactyla (Decapoda,Majidae)     

Guiomar Rotllant  Carles G. Simeó  Guillermo Guerao  Marta Sastre  Daniel F. R. Cleary  Ricardo Calado  Alicia Estévez 《Marine Ecology》2014,35(3):298-307

The spider crab Maja brachydactyla is an important commercial species in Europe and supports intensive fisheries in the NE Atlantic. A field survey was performed to assess long‐term and consecutive interannual (2005–2010) variation of the biochemical composition of newly hatched larvae of M. brachydactyla. Larval biochemical profiles differed significantly among years, with pronounced differences being recorded in 2010. Differences among batches of newly hatched larvae were mainly explained by the contribution of triacylglycerols and, to a lesser degree, by protein and lipid content. The use of different nutrition indices is discussed. The biochemical composition of newly hatched larvae from M. brachydactyla was highly variable, even though surveyed broodstock was obtained from the same local population and was always sampled during the same season. The unpredictable biochemical profiles of newly hatched larvae may condition their survival and recruitment. This largely overlooked aspect of larval variability should be considered in future fisheries management strategies and captive production of marine organisms that still rely on wild seeds.  相似文献   

基于三维荧光光谱-平行因子技术联用的浮游藻化学分类学技术研究     

陈小娜  苏荣国  白莹  石晓勇  杨茹君 《海洋学报(英文版)》2014,33(12):192-205

An in vivo three-dimensional fluorescence method for the determination of algae community structure was developed by parallel factor analysis(PARAFAC) and CHEMTAX. The PARAFAC model was applied to fluorescence excitation-emission matrix(EEM) of 60 algae species belonging to five divisions and 11 fluorescent components were identified according to the residual sum of squares and specificity of the composition profiles of fluorescent. By the 11 fluorescent components, the algae species at different growth stages were classified correctly at the division level using Bayesian discriminant analysis(BDA). Then the reference fluorescent component ratio matrix was constructed for CHEMTAX, and the EEM–PARAFAC–CHEMTAX method was developed to differentiate algae taxonomic groups. The correct discrimination ratios(CDRs) when the fluorometric method was used for single-species samples were 100% at the division level, except for Bacillariophyta with a CDR of 95.6%. The CDRs for the mixtures were above 94.0% for the dominant algae species and above 87.0% for the subdominant algae species. However, the CDRs of the subdominant algae species were too low to be unreliable when the relative abundance estimated was less than 15.0%. The fluorometric method was tested using the samples from the Jiaozhou Bay and the mesocosm experiments in the Xiaomai Island Bay in August 2007. The discrimination results of the dominant algae groups agreed with microscopy cell counts, as well as the subdominant algae groups of which the estimated relative abundance was above 15.0%. This technique would be of great aid when low-cost and rapid analysis is needed for samples in a large batch. The fluorometric technique has the ability to correctly identify dominant species with proper abundance both in vivo and in situ.  相似文献   

广东江门水稻品质与地质地球化学关系研究   总被引：2，自引：0，他引：2  

朱鑫 《江苏地质》2014,38(2):302-308

重点开展了江门水稻种植区的生态地球化学调查。系统采集了全区表层土壤、稻谷及配套根系土样品,实测了营养、有益元素以及大米营养品质含量。通过开展生态地球化学评价,查明了影响水稻品质的主要地质地球化学因素,建立了特色农产品地质地球化学模型,开展了农产品适宜性评价和区划。  相似文献   

熔融制样波长色散X射线荧光光谱法测定白云石中钙镁硅铁铝   总被引：4，自引：3，他引：1  

褚宁  李卫刚  蒋晓光  张彦甫  毕孝瑞 《岩矿测试》2014,33(6):834-838

白云石属碳酸盐矿物,应用熔融制样X射线荧光光谱法测定其中主次量组分钙、镁、硅、铁、铝时,由于白云石灼烧减量大,在试料片制备过程中,如果以干基试料制备试料片,除灼烧减量外还有少量其他组分被分解出的大量CO₂带走,导致试料损失,测定结果偏低;如果以灼烧基试料制备试料片,由于灼烧后的试料极易吸收空气中的水分和CO₂,同样使测定结果偏低。基于质量守恒原理,本文直接以灼烧减量测量后的灼烧基试料质量作为试料量(即灼烧减量测定所称量的干基试料量扣除灼烧减量的量),以四硼酸锂为熔剂,5%碘化铵溶液为脱模剂,试料与熔剂的稀释比为1:10,于1050℃熔融15 min以上制备的试料片透彻、玻璃化程度高。以白云石标准物质和标准样品作为标准试料,制作各组分的标准曲线的相关系数在0.9940~0.9994之间;方法检出限为0.011%~0.48%;标准物质和标准样品的测定值与认定值基本一致,各组分的相对标准偏差(RSD,n=11)在0.5%~1.7%之间,方法具有较好的重现性。本方法以1050℃灼烧后的试样作为试料制备XRF分析样片,最大限度地降低了灼烧减量因素(空气中的水分和CO₂)对测定结果的影响,适用于白云石及其煅烧物中钙、镁、硅、铁、铝等组分的同时测定。  相似文献   

山东金亭岭金矿矿床地球化学异常分带模型   总被引：1，自引：0，他引：1  

卢月玲  陈远荣  林立保  罗亦城  刘晓明  李军州  张冠清  廖德好 《矿产与地质》2014,(1):66-71

通过对山东金亭岭金矿各类微量元素和烃类组分在该矿床不同中段的含量变化以及在纵向上的异常展布和富集规律进行分析和总结,建立了该矿床的地球化学叠加异常分带理想模型,得出矿床地球化学异常轴向分带序列确定为:甲烷、乙烷、丙烷、正丁烷、异丁烷、乙烯、丙烯、Sb(前缘晕)→As、Hg(矿头晕)→Au、Ag、Pb、Zn、Cu、Mn(矿中晕)→Co、Ni、Mo、Bi(矿尾晕),并总结了找矿预测标志,为其深部找矿预测提供了一定的科学借鉴依据。  相似文献   

基于SWH模型的青藏高原高寒草甸蒸散发及其组分变化分析          下载免费PDF全文

梅静  孙美平  李霖 《干旱区地理》2022,45(6):1740-1751

基于Shuttleworth-Wallace Hu（SWH）双源蒸散模型对青藏高原那曲、纳木错、藏东南站蒸散发进行估算,在结果验证良好基础上,对青藏高原蒸散发变化特征及各站主要影响因素进行了分析。结果表明：SWH模型在青藏高原3个草甸站适用性良好;年蒸散发介于388~732 mm之间,年内分布呈先增大后减小特征;3站蒸散发组分差异较大,那曲站和纳木错站土壤蒸发对蒸散总量的贡献分别为53%和56%,藏东南站蒸散发则几乎全部由植被蒸腾贡献,占比高达95%;植被叶面积指数为3站蒸散发最主要的影响因素,饱和水汽压差对藏东南站蒸散发影响也较大。研究结果可对青藏高原蒸散发及其组分时空格局与水循环过程研究提供科学依据。  相似文献   

航空矢量重力测量水平分量的带限直接地形影响     

周波阳  罗志才  宁津生  钟波 《测绘学报》2014,43(10):1019-1024

基于第二类Helmert凝聚法的级数展开式,独立推导了航空矢量重力测量水平分量带限直接地形影响的计算公式。在中国西部山区选取了两条沿纬圈方向4000m航线高度上的航线,采用 的数字高程模型基于解析核计算了水平分量的直接地形影响,经低通滤波后与基于带限公式计算的地形影响进行了比较。数值计算结果表明,二者吻合较好,本文给出的带限地形影响公式可用于航空矢量重力测量水平分量的地形归算。  相似文献   

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方川  高井祥  王坚  胡洪 《大地测量与地球动力学》2014,34(4):135-139

???й?????????IGS????,??????FES2004????????NAO99b?????????????????????????????????λ?????????????????????????????????λ????????cm??????????????U????????????????????????3~4????????????????????????????????mm????????????????????????С????????????????GPS????????????????10^-8??????????????????????????????????С??mm?????????????????????????????1 cm??  相似文献   

Complex component analysis of shear-wave splitting: theory   总被引：2，自引：0，他引：2  

Xiang-Yang Li  Stuart Crampin 《Geophysical Journal International》1991,107(3):597-604

  相似文献   

A graphic expression of salinization and pollution of groundwater The case of Israel's groundwater     

A. Melloul  B. Azmon 《Environmental Geology》1997,30(1-2):126-136

 Anthropogenic activities create various contaminated leachate, which can migrate downward from the vadose zone to groundwater, transferring contaminants, including some hazardous ones. When these various sources of contamination influence the groundwater aquifer simultaneously, the effects of contamination are enhanced. The major concern of this study has been to determine whether the shape of a groundwater chlorograph might be the result of such deterministic effects as accumulation of one or more particular processes of groundwater contamination, and how this might relate to specific hydrological situations. This study proposes a classification of groundwater contamination on the basis of properties of the main components of groundwater quality graphs and the corresponding hydrogeological/environmental situation. The study further suggests that contamination of groundwater in any hydrogeological situation (e.g. sea water) may be graphically expressed. A variety of chlorographs and nitrographs, representative of various groundwater aquifers sampled from a number of wells throughout Israel attest to this. The study thus indicates that groundwater quality graphs may be considered as a complementary tool for groundwater quality control and better understanding aquifer situations.  相似文献