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1.
采用室内生态实验法研究了军曹鱼(Rachycentron canadum)幼鱼(初始体重(17.43±0.85) g分别饥饿0(对照组),2,4,6,8 d后的补偿生长规律,探讨军曹鱼幼鱼补偿生长的生物能量学机制.结果表明:随着饥饿时间的延长,幼鱼的能量及体重损失率显著升高;恢复生长过程中,饥饿处理组幼鱼的平均日摄食率(能量指标)均高于对照组,其中以饥饿8 d组幼鱼的平均日摄食率最高(17.20%);幼鱼在恢复生长过程中的能量、湿重及干重特定生长率均随着饥饿时间的延长而呈上升趋势;军曹鱼幼鱼在饥饿后的恢复生长过程中通过提高摄食率来实现其完全补偿生长能力;军曹鱼幼鱼在饱食条件下的能量收支方程为100.00C = 38.33G + 15.06F + 7.22U + 39.39R,同化能分配式为100.00A = 49.32G + 50.68R.  相似文献   

2.
饥饿状态下大黄鱼幼鱼能量收支的研究   总被引:2,自引:0,他引:2  
研究了饥饿状态下黄鱼幼鱼的能量收支。结果表明,其排汇能及代谢能与体质量均成指数关系,排泄能与温度正相关,代谢能与温度之间为二次函数关系,体质量以饥饿状态下的能量分配模式没有显著影响,其平均能量收支方程为:30.23U+69.77R-100G=0,能量分配模式随温度的变化而呈显著的变化。  相似文献   

3.
饥饿对鲇鱼幼鱼静止代谢率的影响   总被引:1,自引:0,他引:1  
本实验在25℃条件下对鲇鱼幼鱼(29.41~44.45 g)进行了60 d的饥饿处理,每天测定3次耗氧率。结果显示:鲇鱼幼鱼在饥饿60 d后,其静止代谢率由63.19±3.68降至22.38±1.36 mgO2kg-1h-1,下降了64.58%;通过对静止代谢率变化的分析,发现存在有3个相对稳定期:其代谢水平分别为41.62±0.34、34.72±0.55和27.59±0.52 mgO2kg-1h-1(P<0.05),持续时间分别为10、14和27 d。实验结果表明:鲇鱼幼鱼采用降低代谢水平的方式来适应饥饿环境;静止代谢率越低,则相对稳定期历时越长。  相似文献   

4.
设置养殖水体温度为22℃、24℃、26℃、28℃和30℃5个试验组,饲养平均体质量为1.25±0.01 g的大黄鱼幼鱼40 d,研究温度对大黄鱼幼鱼生长和养殖水质的影响.研究结果表明,温度对大黄鱼幼鱼的生长有显著影响(P<0.05),温度对大黄鱼幼鱼的存活率没有显著影响(P>0.05).大黄鱼幼鱼的最适生长温度约28℃,在该温度下,大黄鱼幼鱼的质量相对增加率、特定生长率和饲料效率都达到最高,分别为118.40±2.15%、1.98±0.02%·d-1和82.48±3.05%;水体NH4+-N和NO2--N在试验后期都下降.  相似文献   

5.
为了研究急性降温对鱼类的行为及代谢的影响,本实验设置25℃→25℃,25℃→15℃,15℃→15℃(驯化温度→实验温度)3个温度组,采用自制鱼类能量游泳装置测定了青鱼(体长8.87±0.75cm,体重11.86±3.60g)临界游泳速度(Ucrit)、耗氧率(MO2)以及疲劳后的恢复耗氧率.研究结果表明:青鱼在3个温度组Ucrit分别是11.32±0.29BL/s、8.04±0.38BL/s和7.73±0.25BL/s,急性降温(25℃→15℃)组的Ucrit是15℃→15℃组的96.2%,降低了3.8%,差异性不显著(P0.05),急性降温在短时间内抑制青鱼幼鱼游泳速度,影响不显著;MO2随着流速的增加而增大,耗氧率与流速关系分别为25℃→25℃:MO2=49.138U+365.990,R2=0.995;15℃→15℃:MO2=42.886U+315.002,R2=0.972;25℃→15℃:MO2=37.265U+259.987,R2=0.973;随着温度升高,耗氧率增大,急性降温对鱼类的耗氧率有抑制作用;疲劳后继续测定耗氧状况,90min内恢复耗氧率均呈先降低后逐渐趋于平稳,恢复耗氧率分别为25℃→25℃:73.14 mgO2/kg,25℃→15℃:102.47mgO2/kg,15℃→15℃,89.38mgO2/kg.研究表明:急性降温对青鱼幼鱼游泳特性具有显著的影响,并且对其行为产生胁迫作用,研究有利于为鱼道的建设提供数据资料,对鱼类的保护具有重要的意义.  相似文献   

6.
斜带石斑鱼仔稚鱼生长和摄食的研究   总被引:10,自引:0,他引:10  
于2003~2004年对人工培育的斜带石斑鱼(Epinephelus coioides)仔鱼、稚鱼和幼鱼的生长和摄食进行了研究.在水温28.5~31.0℃,盐度31.4~34.3条件下,初孵仔鱼经39 d培育变态为幼鱼.全长(L/mm)与日龄(D/d)的关系式为L=2.039 8e0.076 7D;体质量(M/mg)与日龄(D/d)的关系式为M=0.065 8e0.252 8D;全长(L/mm)和体质量(M/mg)的关系式为M=0.006 5L3.267 3.对170尾仔、稚、幼鱼的解剖观察结果表明,摄食率达95.88%,饱食率达77.65%.饱食量(F/mg)与体质量(M/mg)呈直线相关,F=0.043 3M-0.003 9,大多数仔稚鱼在30 min内可以饱食.仔鱼对轮虫的消化时间为1~2 h,稚鱼对卤虫无节幼体和桡足类的消化时间分别为1.5~3 h和2~4 h.斜带石斑鱼仔稚鱼的摄食强度具有明显的昼夜节律性,仔鱼白天摄食、晚上不摄食,前期仔鱼在8:00和18:00摄食量较大,后期仔鱼在8:00和16:00摄食量较大,稚鱼昼夜均摄食,摄食高峰期出现在中午12:00.  相似文献   

7.
亚硝酸钠对三疣梭子蟹幼体的急性毒性   总被引:1,自引:1,他引:1  
以三疣梭子蟹各期幼体为实验对象,以发育次日为实验起点,对其进行了亚硝酸氮的急性毒性实验。结果表明:亚硝酸盐对三疣梭子蟹Z1期幼体饥饿和饱食两种状态下72 h半致死浓(LC50)分别为为2.282mg/L和2.736 mg/L,Z2期幼体分别为9.955 mg/L和11.541mg/L,Z3期幼体分别为19.487mg/L和30.336mg/L,Z4期幼体分别为14.243 mg/L和15.568 mg/L,M期幼体分别为69.110 mg/L和126.020 mg/L;饥饿与饱食状态下72 h半致死浓度无显著差异;三疣梭子蟹育苗池亚硝酸盐含量应控制在0.228mg/L以下。最后就亚硝酸盐对三疣梭子蟹幼体的急性毒性效应和急性致毒机理进行了分析与探讨。  相似文献   

8.
鱼类活动代谢的研究进展   总被引:1,自引:0,他引:1  
鱼类生物能量学主要研究鱼类个体或种群内能量收支各组分间的定量模式及其与生态因子之间的关系.Warren&Davis(1967)提出了鱼类生物能量学的基本方程: C=G+F+U+Ms+SDA+Ma M=Ms+SDA+Ma 式中C指摄入食物能;G指鱼体生长能;F和U分别指粪便和排泄物损失能;Ms指标准代谢;SDA指营养物质在体内消化和转化的耗能;Ma指活动代谢;M指日总代谢. 活动代谢(activity metabolism)是指鱼类自发游泳活动的能量支出,它是能量收支基本方程中变异  相似文献   

9.
氨氮和亚硝态氮对大黄鱼幼鱼的急性毒性效应   总被引:2,自引:0,他引:2       下载免费PDF全文
在水温(23±1)℃,盐度20,pH值7.4~7.5,溶解氧大于5.0 mg/L的条件下研究了氨氮和亚硝态氮对体质量为(31.54±0.99)g的大黄鱼幼鱼的急性毒性效应.试验结果表明,氨氮对大黄鱼幼鱼的24、48、72和96 h的半致死浓度LC50及安全浓度SC分别为37.34、20.97、17.59、12.45及1.25 mg/L,对应的非离子氨的半致死浓度LC50及安全浓度SC分别为0.46、0.25、0.21、0.15及0.015 mg/L,亚硝态氮对大黄鱼幼鱼的24、48、72和96 h的半致死浓度LC50及安全浓度SC分别为137.45、94.02、72.81、50.06及5.01 mg/L.  相似文献   

10.
4种重金属离子对黑鲷幼鱼的急性毒性研究   总被引:1,自引:0,他引:1  
以体长(5.09±0.71)cm、体质量(2.09±0.66)g的黑鲷幼鱼为实验动物,采用静水停食试验法,在水温(28.8±1.6)℃,pH 8.24条件下,开展了Zn2+、Cr6+、Cu2+、Hg2+4种重金属离子对黑鲷幼鱼的急性毒性试验。结果表明,Zn2+对黑鲷幼鱼的24h、48 h、72 h、96 h LC50分别为11.53 mg/L、10.15 mg/L、6.56 mg/L、6.09 mg/L;Cr6+对黑鲷幼鱼的24 h、48 h、72 h、96 h LC50分别为31.48 mg/L、24.31 mg/L、23.01 mg/L、23.01 mg/L;Cu2+对黑鲷幼鱼的24 h、48 h、72 h、96 h LC50分别为2.75 mg/L、1.55 mg/L、1.30 mg/L、1.06 mg/L;Hg2+对黑鲷幼鱼的24 h、48 h、72 h、96 h LC50分别为0.098 8 mg/L、0.098 1 mg/L、0.089 2 mg/L,0.0742 mg/L。4种重金属离子对黑鲷幼鱼的毒性强度由高到低依次为Hg2+、Cu2+、Zn2+、Cr6+。最后还就重金属离子对黑鲷幼鱼的致毒特征、对黑鲷幼鱼早期发育的影响,以及水环境中重金属离子的毒性评价与控制进行了探讨。  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.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

14.
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   

15.
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   

16.
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   

17.
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   

18.
19.
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   

20.
Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with  相似文献   

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