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1.
刘公岛水域内叶绿素—a含量和初级生产力   总被引:1,自引:0,他引:1  
据1990年11月至1991年8月间调查资料,提出刘公岛水域内叶绿素-a含量的时空分布和初级生产力的分布与变化。指出此分布与该水域温度和营养盐含量密切相关。叶绿素-a含量以春季最高,冬季次之,秋季稍低,夏季最低。年变幅为0.21 ̄2.45mg/m^3,年平均值为1.02mg/m^3。初级生产力以夏季最高,春季次之,秋季略低,冬季最低,年变幅为33.40 ̄512.72mg·c/m^2·d,年平均值为  相似文献   

2.
2011年5月(春季)、8月(夏季)、11月(秋季)和2012年2月(冬季)对南黄海辐射沙脊群进行了四个季节浮游动物调查,共鉴定浮游动物42种,夏季(30种)春季(25种)秋季(16种)冬季(14种).总平均丰度和总平均生物量分别为70.03ind·m-3和54mg·m-3,四季丰度由大到小依次为春季(144.61ind·m-3)冬季(51.76ind·m-3)秋季(46.28ind·m-3)夏季(37.47ind·m-3);生物量依次为春季(72mg·m-3)夏季(56mg·m-3)冬季(55mg·m-3)秋季(34mg·m-3).春季丰度和生物量的分布规律不明显,夏季向东北增加,秋季向东南增加,冬季整体分布较均匀.真刺唇角水蚤(Labidocera euchaeta)和中华哲水蚤(Calanus sinicus)是该海域的主要优势种,四个季节唯一的共同优势种是真刺唇角水蚤,数量大,分布广,春季中华哲水蚤对总丰度贡献最大,夏季由于水温的升高数量大幅减少,冬季又成为该海域的优势种.浮游动物多样性指数(H′)年均值为1.70,夏季(2.43)春季(1.97)秋季(1.31)冬季(1.08),该海区浮游动物整体群落结构较简单.对比发现该海域与邻近海域浮游动物种类组成和季节变化规律基本一致,但丰度和生物量较低.  相似文献   

3.
天河机场夏季鸣类生态研究   总被引:6,自引:1,他引:5  
通过对天河机场附近5种生境的11条样带考察,记录夏季鸟类59种,分属13日32科,东洋种31种、广布种12种,古北种16种、夏候鸟25种、留鸟24种、旅鸟10种,最重要鸟类为普通燕鸥和棕背伯劳;广性分布的有池鹭,普能燕鸥,黑卷尾等22种,种间遇见率为0.838。  相似文献   

4.
廉州湾海水温度盐度及pH值分析   总被引:2,自引:0,他引:2  
根据1998年和1999年的春夏秋冬季节的4次调查资料,分析廉州湾海水温度、盐度及pH值的季节变化和分布特征。结果表明:廉州湾海水温度(平均值),春季22.7℃,夏季35.6℃,秋季27.0℃,冬季18.3℃,变化特征与气温的季节变化相同,空间分布为春夏季河口区水温略高于湾口区,秋冬季则相反;海水盐度(平均值),春季25.6,夏季21.2,秋季26,3,冬季30.3,表现为冬季>秋季>春季>夏季,各季节空间分布的高低差值则刚好相反;海水PH值(平均值),春季8.03,夏季8.32,秋季8.18,冬季8.18,空间分布春夏季高低差值较大,秋冬季高低差值不断减小。廉州湾海水比较适宜开展对虾、文蛤等广温广盐性品种的人工养殖。  相似文献   

5.
为研究大连西中岛潮间带大型底栖经济海藻的生态学特征,共布设了4个采样断面,于2011年7月、2012年4月、2012年10月和2013年1月进行了采样调查,研究了大型底栖经济海藻的群落结构、季节变化和多样性.共鉴定出大型底栖经济海藻44种,隶属于4门21属,其中绿藻门12种,褐藻门9种,蓝藻门1种,红藻门22种.经济藻类种类和数量的季节性变化研究表明,藻类种类数呈现春季>夏季>冬季>秋季的特点,各季节红藻门种类数最多,其次为褐藻门和绿藻门,蓝藻门最少.优势度分析表明,角叉菜为主要优势物种,随着季节变化,优势种组成有所不同.各采样断面生物量的分布特征体现为夏季>春季>秋季>冬季.群落的水平结构特征表现为各断面的经济海藻种类在不同季节具有一定差异性;垂直结构特征表现为低潮带分布的经济藻类种类最多,以红藻为主;其次为中潮带,以褐藻为主;高潮带分布的藻类最少,以绿藻为主.多样性分析结果表明,春、夏季物种多样性、均匀度和丰富度指数均高于秋、冬季,且各采样断面的物种多样性呈现出一定差异.  相似文献   

6.
厦门海域渔业资源现存量评析   总被引:5,自引:0,他引:5  
2006—2007年夏季(2006年8月)、冬季(2007年1月)、春季(2007年4月)和秋季(2007年10月)在厦门海域利用底拖网渔船开展渔业资源调查.根据调查资料,对厦门海域(约2 713 km2)的渔业资源现状进行了评析.研究结果表明,4个季节渔业资源平均密度为981.97 kg/km2,其中秋季居首位,约为1 261.39 kg/km2;冬季和夏季次之,分别为951.31 kg/km2和936.93 kg/km2;而春季资源密度最低,约为778.24 kg/km2.各个季节的资源密度,鱼类均居首位,甲壳类次之,头足类最低.各季节鱼类优势种分别为:春季鱼类优势种有6种,以二长棘鲷(Parargyrops edita)幼鱼和短吻鲾(Leiognathus brevirostris)分别为第一和第二优势种;夏季有7种,以中华海鲶(Arius sinensis)和叫姑鱼(Johnius belengerii)分别为第一和第二优势种;秋季也有7种,以龙头鱼(Harpadon nehereus)、叫姑鱼和中华海鲶为主要优势种;冬季有4种,以叫姑鱼为最主要优势种.4个季节的平均渔业资源现存量约为1 694.71 t;渔业潜在可捕量约10 523 t.渔业资源分布与水温、水深及盐度关系较密切.该海域渔业资源已经明显衰退,急需加强渔业资源的管理和保护.  相似文献   

7.
通过对山口对林保护区昆虫春季(4月25日-30日)、夏季(7月14日-19日)、秋季(10月5日-8日) 季的4次调查,结果表明昆虫物种组成较丰富,1年内共有194种昆虫在该地区出现。同时其季节变化也很明显,春季、夏季、秋季和冬季的昆虫物种数为:69、166、94和33,春季的昆虫以双齿多刺蚁、淡紫异色粉等占优势,夏季以黄柑蚁、竹木蜂、等占优势,秋季以黄柑蚁、白逅中泰亚种等占优势,冬季则以小红标虫  相似文献   

8.
天河机场夏季鸟类生态研究   总被引:17,自引:1,他引:16  
通过对天河机场附近5 种生境的11 条样带考察,记录到夏季鸟类59 种,分属13 目32科.东洋种31种(52.5% )、广布种12 种(20.3% )、古北种16 种(27.2% );夏候鸟25 种(42.4% )、留鸟24 种(40.7% )、旅鸟10 种(16.9% ).最重要鸟类为普通燕鸥(1.367 只/hm 2)、池鹭(0.484 只/hm 2)和棕背伯劳(0.338 只/hm 2);广性分布的有池鹭、普通燕鸥、黑卷尾等22 种;种间遇见率为0.838.  相似文献   

9.
根据2006年8月和2007年1月、4月、10月福建沿岸海域底拖网调查结果,对福建沿岸海域蟹类的种类组成、数量分布及时空变化做了定量分析.结果表明:在福建沿岸海域调查海区中蟹类有43种,隶属10科、21属,其中以梭子蟹科种类最多.蟹类优势种的时空分布差异明显,春季有2种优势种,夏季有3种,秋季有5种,冬季有2种;双斑全...  相似文献   

10.
2016年11月6日在内蒙古乌兰察布凉城县岱海进行全国秋季迁徙水鸟的同步调查时记录到一种大型鸥类,根据观察和查阅有关文献确定该鸟为灰翅鸥Larus glaucescens,为内蒙古鸟类物种新纪录.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

13.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

14.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

18.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

19.
20.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

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