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1.
廉州湾近岸的海水理化要素含量的变化特征   总被引:1,自引:0,他引:1       下载免费PDF全文
根据2003年7月至2004年6月廉州湾近岸水质监测资料,以DIN、PO4-P、COD为富营养化评价指标,分析廉州湾近岸海水理化要素测值的变化特征。结果表明,廉州湾内河口区海水富营养化程度分布较高,湾口区相对较低;水温季节变化不大,盐度春夏季低秋冬高,pH值季节变化不明显,COD夏季明显高于春季,活性硅酸盐冬季较低,DIN春季高于冬季,PO4-P春季大于冬季,廉州湾沿岸水质变化的主要原因与河口径流、沿岸河水、水产养殖排放物有关。  相似文献   

2.
深圳湾福田红树林湿地腺带刺沙蚕分布的生态响应   总被引:3,自引:0,他引:3  
根据2005年3月至2008年1月在深圳湾福田红树林湿地3个断面10个取样站进行大型底栖动物12个季度监测获得的腺带刺沙蚕(Neanthes glandicincta)密度和生物量数据,阐述了腺带刺沙蚕数量的年际变化、季节变化和空间分布,分析了其栖息密度、生物量与部分环境因子的关系.结果表明,深圳湾福田红树林湿地腺带刺沙蚕密度和生物量的年均值大小顺序均是:2005年>2006年>2007年.季节均值大小顺序是:春季>冬季>秋季>夏季;而生物量的季节均值大小顺序是:春季>冬季>夏季>秋季.深圳湾福田红树林湿地腺带刺沙蚕的空间分布不均匀,不同断面或取样站之间数量差别很大,没有红树林的光滩取样站密度高,红树林内的取样站几乎很少采到.相关分析表明,腺带刺沙蚕密度时间分布与总有机质、气温、季度降水量、日照时数之间存在显著负相关,与盐度、相对湿度之间不存在显著相关.在空间分布上,腺带刺沙蚕的密度与总有机质和硫化物之间存在显著负相关,而与盐度、粘土等环境因子间无显著相关.  相似文献   

3.
对笼养黑琴鸡(Lyrurus tetrix baikallensis)四季静止代谢率(RMR)的研究结果表明:不同季节,RMR与环境温度(Ta,单位为℃)之间的关系可以用“RMR=a b1Ta b2T^2a”很好地拟合,且相关关数均达到了显著水平(P<0.05)。利用回归关系式求导,可以得到不同季节RMR的极小值(RMRmin)及其相对应的特定温度(ST,单位为℃),黑琴鸡RMRmin,ST产表现出明显的季节波动,夏季RMRmin最高4.58w/kg,分别为春,秋及冬季RMRmin的1.29倍和1.41倍,夏季ST值最高(27.3℃),分别比春,秋及冬季高2.2℃,1.4℃和4.8℃,黑琴鸡RMR季节变化明显,夏季显著高于其他季节,在20-30℃条件下春,秋和冬季RMR差异不显著,而在15℃以下,春季>春季>冬季。  相似文献   

4.
北海湾悬浮颗粒物的分布及其与环境因子间的关系   总被引:2,自引:0,他引:2  
在北海湾近岸内湾,设9个测站,选取4个有代表性的季度月,即1998年10月(秋季)和1999年1月(冬季)、4月(春季)、8月(夏季),采集海水样品分析测定悬浮颗粒物(SS),同时还同步测定水温、盐度、pH值、化学需氧量(COD)、透明度、叶绿素a及5种不同形态的氮、磷和溶解性硅,研究北海湾悬浮颗粒物的分布特征及其与环境因子之间的关系.结果表明,北海湾悬浮颗粒物含量具有春季较高,秋季次之,冬夏季较低的分布特点.在陆源影响较小的秋冬季节,悬浮颗粒物与环境因子之间的关系均不显著;而在陆源影响较大的春夏季节,悬浮颗粒物在与盐度、透明度呈显著负相关的同时,与COD和不同形态的氮、磷亦具有显著的正相关关系.  相似文献   

5.
廉州湾海域水化学要素含量的分布特征   总被引:2,自引:0,他引:2  
根据1998年1月、4月、8月、10月4个航次的调查资料,分析廉州湾海域水化学要素含量的变化及特点。结果表明,该湾水化学要素含量具有河口区特征,pH值和DO含量为冬季高于夏季,COD含量为夏季高于冬季,NO3-N、NO2-N、NH3-N的含量为春夏季高于秋冬季,PO4-P、SiO3-Si含量为夏季高于冬季。各含量变化的主要影响因素均为河流径流及各种污水的注入所致。  相似文献   

6.
为了解胶州湾表层沉积物中甲藻孢囊分布特征与环境因素之间的关系,于2015年7月采集分析了胶州湾12个站位的沉积物甲藻孢囊样品,同时与海湾夏季、冬季的水温、盐度、水深及沉积物粒度等因素进行了相关分析。结果显示,胶州湾水深介于4.5~24.7m之间,从湾内向湾外深度逐渐加大。海水温度的季节变化较显著,夏季高冬季低,夏季呈湾内高湾外低、而冬季为湾内低而湾外较高的分布特点。海水盐度的季节变化不显著,夏、冬季的盐度均由湾内向湾外逐渐升高。沉积物主要以砂、粉砂和黏土为主,其中大部分为细颗粒的粉砂质淤泥。甲藻孢囊共记录39种(含2个未定种),优势种为膝沟藻类(Gonyaulax spp.)孢囊。胶州湾甲藻孢囊群落呈显著的空间分布特征,表现为湾口及湾外丰度较高、而湾内较低的特点。聚类分析将孢囊类群分为4组,分别为湾口湾外组及湾内3个组(湾北部组、湾西部组及湾东部组),差异度主要贡献种类为具刺膝沟藻(G.spinifera)、多边舌甲藻(Lingulodinium polyedra)和原多甲藻(Protoperidinium sp.)孢囊。相关分析表明胶州湾甲藻孢囊的丰度与夏季温度呈显著负相关(P 0.05),与冬季温度、夏季盐度及海水深度呈显著正相关(P 0.01),而与沉积物粒度相关性不显著;表明温度和盐度对胶州湾甲藻孢囊的萌发与形成具有显著影响,而其分布受到多种环境因素的综合调控。  相似文献   

7.
史华明  王翔  马玉  蔡钰灿  许欣 《广西科学》2023,30(4):663-671
近海营养盐浓度显著受到人类活动和自然条件等因素影响,且会对海洋生态系统造成一定程度的干扰。本文根据2017-2018年北部湾东北部海湾秋季、冬季、春季和夏季4个季节的溶解态营养盐及其他环境参数数据,分析调查海域溶解态营养盐的时空分布、结构特征和变化趋势,并讨论该海域的营养盐限制因子。研究结果表明:溶解态营养盐分布表现为近岸高、远岸低的特点,高值区主要集中在铁山港、英罗港以及安铺港湾口。溶解无机氮 (DIN) 浓度为1.50-28.63 μmol/L,夏季浓度最高。磷酸盐 (SRP) 及硅酸盐(DSi)平均浓度均以秋季最高,全年SRP浓度为0.02-0.94 μmol/L,DSi浓度为1.03-18.19 μmol/L。调查海域的DIN、DSi受陆源输入的影响较大;夏季SRP的消耗速度大于输入速度,导致夏季SRP浓度较低。调查海域氮磷化(N/P)、硅磷比(Si/P)值均高于Redfield比值,其中夏季N/P平均值达175.3±94.5,SRP是该海域的主要营养盐限制因子。调查海域DIN季节平均浓度均低于钦州湾、珍珠湾和廉州湾3个海湾相应季节的DIN浓度,夏季SRP平均浓度低于廉州湾、钦州湾和珍珠湾,自20世纪80年代以来铁山港营养盐浓度呈现先升后降的趋势。  相似文献   

8.
利用河池气象站气温、降水量、日照时数观测数据,文章分析了44 年来河池市区气候变化的趋势和特征,并对未来的变化趋势作了预测. 44 年来河池市区气候变化的趋势主要有:年、夏季和秋季均温上升趋势显著,春、冬季均温呈上升趋势;年降水量和春、夏、秋季降水量呈减少趋势,冬季降水量呈增加趋势;年、夏季、冬季日照时数呈减少趋势,春、秋季日照时数呈增加趋势. 气候变化存在周期性特征:年、春季、夏季、秋季和冬季气温均存在23 年的变化主周期,年、春季、夏季、秋季和冬季降水量变化主周期分别为23 年、21 年、21 年、26 年和23 年,年、春季、夏季、秋季和冬季日照时数存在22~23 年的变化主周期. 过去44 年期间,气候变化的突变特征是:年、春季、夏季、秋季和冬季气温均发生显著的突变增加;年和夏季降水量未发生明显突变,春、秋、冬季降水量发生显著的突变减少;年、夏季、秋季和冬季日照时数未发生明显突变,春季日照时数发生显著的突变增加. 通过R/S 分析,对未来的气候变化趋势作出预测:年、春季、夏季、秋季和冬季气温和降水量未来变化趋势与过去44 年变化趋势一致;年、春季、夏季和秋季日照时数未来变化趋势与过去44 年变化趋势一致,而冬季则相反.  相似文献   

9.
赤枝栲的蒸腾特性与生态因子相关性   总被引:5,自引:1,他引:5  
在福建小湖赤枝栲林中定点定位观测,研究赤枝栲林的蒸腾强度日变化,季节变化及影响蒸腾强度的生态因子.得出了赤枝栲的蒸腾系数为123.72g,年蒸腾耗水量965.73mm;赤枝栲蒸腾速率日变化为单峰,双峰形曲线,季节变化为夏季>秋季>春季>冬季,与环境因子相关性显著.  相似文献   

10.
迄今为止,互花米草(Sporobolus alterniflorus(Loisel.) P.M.PetersonSaarela)虽被列入外来入侵植物,但就其生态环境效应仍在学界颇有争议。以福建省泉州湾洛阳江河口湿地的互花米草种群为研究对象,分别于2017年6月(夏)、9月(秋)、12月(冬)和2018年3月(春)进行采样,测定互花米草在不同潮位的密度、株高、丛径、鲜重和干重等指标。研究结果表明:季节变化对互花米草的密度、株高、丛径、鲜重与干重差异均有显著影响(P0.05)。三个潮区互花米草密度都呈现夏季秋季春季冬季,且不同潮区四个季节之间互花米草密度差异显著;株高在四个季度中呈现秋季夏季冬季春季,秋季显著高于其他季节;丛径随季节变化差异均显著,在夏季达到最大值;鲜重与干重在四个季度中均呈现秋季夏季冬季春季,且鲜重随季节变化差异均显著,干重表现为秋季和夏季显著高于冬季和春季。  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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