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1.
温度和pH对驼背鲈消化酶活力的影响   总被引:2,自引:0,他引:2  
采用酶学分析方法研究了温度和pH对驼背鲈3种主要消化酶(蛋白酶、脂肪酶、淀粉酶)活力的影响。结果表明:在设定的温度和pH范围内,驼背鲈消化酶活力均随着温度和pH的升高呈先升后降的趋势。其中,胃蛋白酶的最适温度为40~45℃,肠、幽门盲囊、肝蛋白酶的最适温度均为40℃;胃脂肪酶的最适温度为35℃,幽门盲囊的最适温度为40~45℃,其他部位均为40℃;胃淀粉酶的最适温度为40℃,其他部位均为35℃。胃蛋白酶的最适pH为3.2,肠、幽门盲囊、肝的最适pH均为8.2;胃、肝脂肪酶的最适pH分别为7.2、8.2,其他部位均为6.2;胃淀粉酶的最适pH为7.2~8.2,其他器官的最适pH均为7.2。各部位在最适温度和pH下,脂肪酶酶活力顺序为肠胃肝幽门盲囊,淀粉酶酶活力顺序为肠幽门盲囊胃肝;蛋白酶在最适温度和pH下的酶活力顺序分别为肠胃肝幽门盲囊、肠胃幽门盲囊肝。  相似文献   

2.
目的:在室内控制条件下,研究不同海水盐度对全长为(13.70±0.91)cm,体质量为(9.74±0.85)g的军曹鱼幼鱼存活和生长的影响.方法:将30 d 70%存活率的盐度作为适宜存活临界盐度,将增长率为最佳增长率70%时所对应的盐度作为适宜生长临界盐度,最适存活盐度、最适生长盐度范围则为多重比较无统计学差异且存活率、日生长率最高的几个实验组所对应的盐度范围.结果:在水温为26.5~28℃,溶解氧大于6 mg/L的条件下,军曹鱼幼鱼的适宜存活盐度范围为3.68~37.43,最适存活盐度范围为10~34;适宜生长盐度范围为5.91~37.15,最适生长盐度范围为22~31.结论:军曹鱼作为广盐性鱼类,对盐度有较强的适应性,当盐度变化超出最适范围时,养殖军曹鱼幼鱼对高盐更为敏感.  相似文献   

3.
大口黑鲈主要消化器官淀粉酶活力的研究   总被引:3,自引:0,他引:3  
试验从酶学分析角度研究了大口黑鲈各消化道内淀粉酶的活力分布,以及不同温度、pH和底物浓度条件下其肝脏、幽门盲囊、胃、肠中淀粉酶的活力变化。结果表明,淀粉酶活力在消化道内活性强度存在明显差异,由高到低依次为肝脏、幽门盲囊、肠、胃。淀粉酶的活力随温度和pH变化呈现一定规律性变化,存在最适温度和pH,依次为:肝脏(40℃,7.2)、幽门盲囊(30℃,8.0)、肠(40℃,8.4)、胃(35℃,6.4)。幽门盲囊和肠淀粉酶在碱性环境下活力最大,肝胰脏和胃淀粉酶在中性或酸性条件下活力充分发挥。淀粉酶的活力大小与底物浓度有关,底物淀粉最适浓度依次为肝脏1%、幽门盲囊4%、肠2%、胃2%。本研究旨在为大口黑鲈人工饲料的研究与开发提供基础数据。  相似文献   

4.
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   

5.
在广东阳江闸坡网箱养殖区,采集不同生长阶段的斜带石斑鱼样品,体重20~500 g。采用酶学分析方法研究了斜带石斑鱼胃,幽门盲囊、肠、肝胰脏蛋白酶和淀粉酶的活力。结果表明,30℃养殖水温下,各部分蛋白酶活力为幽门盲囊>胃>肠>肝胰脏,淀粉酶活力为肝胰脏>幽门盲囊>肠>胃。在斜带石斑鱼发育进程中,300 g前蛋白酶活力呈上升趋势,350 g前淀粉酶活力呈上升趋势。胃、幽门盲囊、肠、肝胰脏蛋白酶活力的最适温度和pH依次为40℃和3.0,40℃和8.0,50℃和8.0,50℃和7.0,胃、幽门盲囊、肠、肝胰脏淀粉酶活力的最适温度和pH依次为40℃和5.0,40℃和8.0,50℃和8.0,50℃和7.0。  相似文献   

6.
pH对真鲷蛋白酶和淀粉酶活力的影响   总被引:2,自引:0,他引:2  
应用酶学分析研究不同pH度条件下真鲷成鱼胃、肠、肝胰脏和幽门盲囊4个部位蛋白酶和淀粉酶活力的变化.结果表明,真鲷成鱼胃、肠、肝胰脏和幽门盲囊蛋白酶的最适pH分别为6.4,7.2,7.6和8.4,淀粉酶的最适pH分别为6.4,8.0,8.0和7.6.  相似文献   

7.
饥饿胁迫对卵形鲳鲹幼鱼消化器官组织学的影响   总被引:1,自引:0,他引:1  
 将375 尾卵形鲳鲹Trachinotus ovatus幼鱼分别饥饿0、3、6 、9和12 d,利用形态学和连续组织切片技术,观察和研究了饥饿胁迫对卵形鲳鲹幼鱼食道、胃、幽门盲囊、肠和肝胰脏等消化器官组织结构的影响,了解其在饥饿状态下的形态和组织学结构变化及耐受饥饿的能力。3 d以内的短时间饥饿对消化器官组织结构的影响不明显,随着饥饿时间延长,消化器官开始出现损伤,饥饿6~9 d对消化器官的损伤程度较轻,饥饿12 d消化器官损伤严重,出现消化道管腔变窄、变薄,黏膜上皮细胞界限变得模糊,上皮逐渐脱落、断裂,分泌细胞变小等。食道组织结构受饥饿胁迫的损伤程度较其他消化器官轻,胃、幽门盲囊和肠道的组织结构受饥饿的影响相似,肝胰脏受饥饿的影响最严重。结果表明,饥饿胁迫使卵形鲳鲹幼鱼的消化器官发生了不同程度的变化,不同的饥饿胁迫时间对不同消化器官的影响程度也不同。  相似文献   

8.
通过对鮸鱼仔稚鱼各发育阶段消化器官的观察,描述了口裂、齿、鳃耙、胃和肠的形态发育特征。研究结果表明:在水温17.3~24.9℃的条件下,1日龄(体长2.90 mm)时,肠出现;4日龄(3.00 mm)时,肠发生弯曲,呈弧形;13~19日龄(4.60~4.70 mm),肠前部膨大形成胃,上鳃骨和角鳃骨上出现鳃耙6(1 5)枚,粗短,粒状;29日龄(7.70 mm),鳃耙大多数由粒状发育成细长状;35日龄(8.10 mm)时,胃和肠的交接处出现幽门盲囊,肠褶皱增多;进入稚鱼期(41日龄)后,鳃耙数、幽门盲囊数和肠的卷曲(2个弯曲)已与成鱼相符。消化器官发育在弯曲期和后弯曲期阶段最为迅速,其中肠的发育明显分为2个阶段:第一阶段为体长2.90~6.00 mm时,肠长与体长之比由16%快速增加到45%;第二阶段为体长达到6.00 mm后,肠长与体长之比保持在45%~50%。比较了石首鱼科鱼类仔鱼消化器官的发育,得出鮸鱼仔稚鱼消化器官的发育相对较快。在人工育苗中,需要结合消化器官的发育而及时转换饵料。  相似文献   

9.
盐度影响真鲷幼鱼消化酶活力的研究   总被引:30,自引:0,他引:30  
报告了海水盐度对真鲷幼鱼消化酶活性的影响.41日龄的真鲷幼鱼的蛋白酶、α-淀粉酶和脂肪酶的比活力均在盐度25时达最高值,随着盐度的上升或下降,消化酶的比活力下降.从3种酶的相对比活力来看,盐度对消化酶的活性影响较大,其中对脂肪酶的活性影响更大.这对于真鲷的人工育苗和养殖有参考价值.  相似文献   

10.
寄生线虫是鱼类的重要病原,会严重影响鱼类健康.采用形态分类学方法对采自美国南卡罗来纳州海域军曹鱼Rachycentron canadum(Linnaeus)(Perciformes:Rachycentridae)肠内的寄生线虫进行了准确的物种鉴定.研究发现,该线虫体表具有发达的环带,唇前缘无角质齿,间唇较小,排泄孔位于神经环略后端,胃盲囊明显长于肠盲囊,左交合刺长3.05~4.17 mm,右交合刺长3.50~4.43 mm,尾乳突37~38对,阴门距头端7.71~13.2 mm,尾具指状尾突等特征,根据形态特征将其鉴定为军曹带蛔线虫Iheringascaris inquies(Linton, 1901).此外,通过与采自我国福建厦门海域军曹鱼体内的长刺海豹蛔线虫Phocascaris longispiculum Wang&Wu, 1991进行形态特征比较,发现二者非常相似,研究认为长刺海豹蛔线虫P.longispiculum应是军曹带蛔线虫I.inquies的同物异名.  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.
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   

13.
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   

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.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  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.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

19.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

20.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

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