嘉庚蛸(Octopus tankahkeei)基础生物学特征的研究   总被引：1，自引：0，他引：1       下载免费PDF全文

焦海峰  尤仲杰  王一农 《海洋学报》2008,30(5):88-93

从2003年1月到2003年12月对浙江省象山港内嘉庚蛸的生物学指标进行了测量,共获取样品408头,分析了其基础生物学的周年变化规律和主要体型特征。结果表明,嘉庚蛸长度分布频率具有明显的季节变化,6,7月份长度分布较其他月份广,6月份分布比较均匀具两个峰值(240和360 mm,所占比例分别为13.3%和16.7%);冬季生长缓慢,3,4月份为快速生长期,体长、体重等指标增长明显,4月底即进入了繁殖季节,在6,7月份可采捕到当年孵化的幼体。嘉庚蛸体长与体重以幂函数拟合最佳,而各体征指标与全长、体重和体积的相关关系也较为显著,但相关方程在雌雄间存在着差异。雌体在体型上明显比雄体粗壮,全长/胴长、全长/胴宽以及全长/体积经统计检验发现雌雄间存在着显著差异,主要表现为若全长相等的情况下,雌体的胴长、胴宽和体积明显大于雄体,自然种群的雌体比雄体更强壮、更丰满。  相似文献   

一种基于GTP的复杂地质体真3维建模方法:岩柱体分区法     

车德福  吴立新  殷作如 《地理信息世界》2008,6(1):34-38

在总结分析现有复杂断层及倒转褶皱3维建模方法的基础上,提出一种基于广义三棱柱(GTP)的3维交互建模方法(岩柱体分区RPBP建模法)。文中定义了岩柱体、界限三角形两个重要概念,RPBP法可以通过构建断层界限三角形,将复杂断层系转化为多个简单断层系,然后采用构建简单断层系模型的方法来实现复杂断层系的3维建模;而对于倒转褶皱,RPBP法则通过构建褶皱轴界限三角形避免数据局部重复和冲突,使GTP建模过程得以顺利进行。实验表明,该方法能便捷可靠地实现含多断层相互切割、倒转褶皱等复杂地质体的真3维建模。  相似文献   

Effect of dietary phosphorus on the growth and body components of juvenile Synechogobius hasta     

Zhi Luo  Xiaodong Li  Shiyuan Gong  Wenqiu Xi  Yali Li 《中国海洋大学学报(英文版)》2009,8(1):65-70

The effect of dietary phosphorus on the growth and body components of juvenile Synechogobius hasta was determined. Different percentages of dietary phosphorus (0.63, 0.77, 0.93, 1.06, 1.22 and 1.36) were tested by feeding the fish (body weight, 15.81 g ± 0.32 g; 20 individuals each group; 3 groups each percentage) at a surplus of 5%–10% above satiation for 35 d. Dietary phosphorus did not significantly affect the specific growth rate, feed intake, feed conversion ratio and protein efficiency rate. Nitrogen retention was found to be the highest in fish fed the diet containing 1.06% of phosphorus; however, this was not significantly different from other diets. Fish fed the diet containing 0.93% of phosphorus showed the highest phosphorus retention; similar phosphorus retention rates were found in fish fed the diets containing 0.77% and 1.06% of phosphorus. Fish fed the diet containing the highest percentage of dietary phosphorus were found to contain the least whole body lipid, lower than fish fed other diets (P<0.05). The protein content increased from 18.59% to 19.55% (although not significant) with the decrease of body lipid content (P>0.05). The contents of the whole body ash, whole body phosphorus and vertebrae phosphorus increased with dietary phosphorus percentage up to 1.06 (P<0.05), reaching a plateau after that. Dietary phosphorus did not significantly influence the muscle components (protein, lipid and moisture). Condition factor and hepatosomatic index were the highest in fish fed the diet containing 0.63% of dietary phosphorus; however, this was not significantly different from those of other diets. The second-order polynomial regression of phosphorus retention against dietary phosphorus identified a breakpoint at 0.88% of dietary phosphorus. However, the dietary requirement of phosphorus for maintaining maximum phosphorus storage determined by broken-line analysis of the contents of whole body phosphorus, and ash and vertebrae phosphorus was 1.06% of the diet.  相似文献   

Spatio-temporal patterns of abundance,size structure and body condition of Atherina boyeri (Pisces: Atherinidae) in a small non-tidal Mediterranean lagoon     

S. Maci  A. Basset 《Estuarine, Coastal and Shelf Science》2010

Sand smelt, Atherina boyeri, is a very abundant, widespread, locally harvested species, able to successfully survive and reproduce over a wide range of abiotic conditions and aquatic ecosystem types. In the North Sea and in the Mediterranean Sea transitional ecosystems its life history is well known, but very little information is available about the influence of intra-ecosystemic abiotic gradients on micro-scale patterns of distribution, body size and condition of individuals. In a small non-tidal Mediterranean lagoon, the cohorts' structure and evolution of sand smelt was described and the temporal and spatial variability of abundance, size structure and body condition was addressed. The study was carried out at the Acquatina lagoon (Lecce, Italy) where four stations, situated in two habitat types along a confinement gradient, were sampled twice per month for one year with fyke nets. The abundance of collected individuals was very high throughout the sampling period, with a peak in Summer and a constant decrease afterwards. Measured Standard Length ranged from 20 to 90 mm and the majority of individuals were estimated to be within 2 years old. The confined station resulted more abundantly colonized, especially by smaller size classes, and characterized by a narrower size frequency distribution. Also relative body condition showed significant spatial variations, with larger individuals having a better condition than smaller ones where optimal temperature and dissolved oxygen levels were available. Size-specific temporal patterns of body condition followed the seasonal climatic oscillations and the species' cycle of growth and reproduction, with larger individuals reaching higher fatness than smaller ones during Autumn and Winter, thus having more chances to survive and contribute to the reproductive effort. The results of the present study emphasised that, even at a very small scale, the presence of strong environmental gradients can drive movements, habitat preference and condition of individuals and thus promote an intra-ecosystemic spatial heterogeneity comparable to that observed between ecosystems at the land–ocean or geographical scale.  相似文献   

辽南庄河斜哨岩体LA-ICP-MS锆石U-Pb年龄及岩石地球化学特征          下载免费PDF全文

刘文彬 《地质找矿论丛》2022,37(1):76-83

斜哨岩体分布于辽宁南部庄河市木盂山至斜哨一带,岩性主要为中细粒石英闪长岩.岩石LA-ICP-MS锆石U-Pb测年206Pb/238 U年龄加权平均值为125.54 Ma士0.39 Ma,形成时代为早白垩世.岩石地球化学特征显示,w(Na2O+K2O)=4.3％～5.6％,里特曼指数σ平均值为 1.75,属钙碱系列;铝饱...  相似文献   

A reappraisal of the metamorphic history of the Tehuitzingo chromitite,Puebla state,Mexico     

《International Geology Review》2012,54(14):1706-1727

ABSTRACT

The Tehuitzingo ultramafic body (Acatlán Complex, southern Mexico) is a strongly serpentinized harburgitic body that encloses chromitite bodies and blocks of eclogitic rocks. Hydrous retrograde metamorphism on chromitite bodies resulted in the formation of: i) partly altered chromite characterized by unaltered cores surrounded by Fe²⁺-rich and Al-depleted porous chromite containing chlorite; ii) porous chromite corresponding to a chromite that was entirely transformed to Fe²⁺-rich and Al-depleted porous chromite; and iii) zoned chromite formed by modified cores surrounded by Fe³⁺-rich non-porous chromite and magnetite rims. The content of minor and trace elements (Ga, Ti, Ni, Zn, Co, Mn, V, Sc) in the cores of partly altered chromite preserves the magmatic fingerprint of back-arc-bearing chromitites, while the cores of zoned chromite are enriched in Zn, Co and Mn but depleted in Ga, Ti, Ni and Sc, and display a metamorphic signature. P-T pseudosections performed in the system CrMFASH allow us to constrain the temperature of formation of Fe²⁺-rich chromite by reaction of magmatic chromite with olivine between 584 and 449 °C; while the new thermodynamic calculations performed in the FMASH system shows that the Fe³⁺-rich non-porous chromite and magnetite rims in zoned chromites were formed at lower temperatures (i.e. 270–340 ºC and < 20 kbar). Temperatures of alteration obtained using our new thermodynamic model are in agreement with the qualitative estimation that use minor and trace elements in Fe²⁺-rich chromite (i.e. 560–700 ºC). These temperatures are more restricted than those estimated for chlorite hosted in partly altered (193–481 ºC) and porous chromite (158–255 ºC), and those reported in host serpentinite and associated eclogitic rocks (210–399 ºC). A comparison of P-T conditions estimated by our new thermodynamic models and the distribution of minor and trace elements in the different zones of chromites allow us to infer that the alteration took place during the hydrous retrograde metamorphism, and that the high-pressure metamorphism did not modify the composition of chromites. Thus, the microstructural zoning displayed by chromite grains was formed during the exhumation of a segment of a back-arc-related oceanic lithosphere, at similar temperature conditions than the Tehuitzingo serpentinite.  相似文献   

利用LaBr3（Ce）伽马谱仪直接测定铀矿体中铀含量的方法     

吴永鹏  汤彬  程建平  梁永顺  王哲 《物探与化探》2012,36(3):414-417

LaBr3（Ce）闪烁体是一种综合性能优良的新型伽马射线探测器。然而,以它的能量分辨性能还不能获得含铀矿体精细伽马谱,其仪器谱反映不出与铀含量直接相关的特征峰,在这种情况下,探索一种直接获取含铀矿体铀含量的方法。采用国产LaBr3（Ce）探头对系列硬岩型放射性矿体进行测量,通过234Pam之1.001 MeV伽马特征能量以能量窗结合线性回归的相对分析法直接求取铀等目标核素的含量,获得了良好效果,对硬岩型铀矿含铀99×10^-6以上相对误差不超过10.0%,对矿体中其他主要核素的定量分析误差也在8.5%以内。  相似文献   

大功率多道密集排列滚动方式三极测深在地灾隐患勘查中的应用          下载免费PDF全文

朱向泰  刘亚军  韩艳军 《地质找矿论丛》2012,27(2):251-259

大功率多道密集排列滚动方式三极测深是在传统电测深法基础上经过装置变换、改进而来的新型实用测深技术,相比常规的高密度直流电法,具有探测深度大、横向分辨率高、提供信息丰富(可同时提供视电阻率、充电率)、抗干扰能力强等特点,近几年广泛应用于多金属矿勘查、地质隐患调查、工程地质探查等领域,文章介绍了该方法的装置特点和工作流程,...  相似文献   

板状体MT倾子响应的二维有限元模拟与定性分析     

柳建新  甘佳雄  童孝忠  曹创华  籍炜 《物探化探计算技术》2012,34(5):541-547

在二维地电模型中,大地电磁测深倾子资料可以很好地反映地电构造的水平非均匀性,特别是在解释垂直或者倾斜板状体的空间分布情况时,可以起到十分重要的作用,在实际应用中可以用来寻找断裂,判断其走向、倾向、埋深和规模。应用有限单元法分别对水平、垂直和倾斜的板状模型进行正演模拟,该算法采用矩形网格内进一步三角形细化的方式剖分模型,通过三角形网格提高了对倾斜接触面的近似程度,同时增加计算量不明显,然后计算出倾子的实部、虚部和振幅的资料。研究结果表明:倾子响应对介质电性水平不均匀反映十分灵敏,特别是对横向低阻异常体,同时对异常体的位置和埋深也有清楚的显示。  相似文献   

大庙式铁矿的找矿远景和方向     

赵桂秋  纪广俭  刘小滨 《吉林地质》2012,(3):53-56,130

大庙式铁矿的成矿和找矿远景有两个方面,其一是在大庙岩体的内部,其二是在岩体之外的尚义—平泉断裂带沿线的深部。根据岩体的地表形态呈南宽北窄的似三角形,且南部边界平直并有平行的断层,推测岩体是由主侵体和溢流体组成的直立状勾手形综合体,南面相当直立的手掌,构成主侵体,北面相当于平放的并拢五指,组成溢流体。由于南面的主侵体可以一直向下延深,具有很大深度,有充足成矿物质来源,因而具有很大的成矿和赋矿远景,是找矿的重点部位。在大庙岩体的外围,沿尚义—平泉大断裂带两侧,西起崇礼,东到平泉200多千米长的地段内,有众多基性、超基性岩体发育,其内有较多的富磁铁矿岩石,构成超贫级铁矿,这些基性、超基性岩体可能属于隐伏在深部的大型基性、超基性岩体的浅部标志,具有较大的成矿和找矿远景。  相似文献