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1.
为研究不同pH处理时间对刺参Apostichopus japonicus Selenka生长、摄食及消化酶活性的影响,本实验以平均体重为(20.32±0.15)g的刺参为研究对象,以自然海水(pH=8.1±0.3)为对照组,设计pH=7.3,8.9两个梯度,在这两种pH条件下每日分别处理1,3,6,9,12h,随后换水并恢复正常pH,养殖实验周期为30d。研究结果表明,当养殖水pH为7.3时,刺参的特定生长率(SGR)、食物转化率(FCR)和摄食率(FR)随着处理时间的增加均呈现先上升后下降的变化趋势,当处理时间为6h时,各项指标达到峰值,显著高于对照组(P0.05);而当养殖水pH为8.9时,刺参的SGR、FCR和FR随着处理时间的增加而逐渐下降,但与对照组差异不显著(P0.05)。在养殖水pH为7.3时,刺参蛋白酶和淀粉酶活性随着pH处理时间的增加而先上升后下降,其高活性拐点出现每日6h处理组;而在养殖水pH为8.9时,蛋白酶和淀粉酶活性随着pH处理时间的增加而下降。实验结果表明,短时间的pH波动在一定程度上可促进刺参的生长和消化能力,但pH波动持续时间较长时则会抑制刺参的生长和消化。 相似文献
2.
同一养殖池塘不同规格刺参的非特异性免疫活性为:小规格刺参的体腔细胞数和体腔液的溶细胞活性显著大于大规格刺参(P< 0.05);随着刺参的生长,小规格刺参的溶菌酶活性逐渐增加,但与中、大规格的刺参没有显著性差异;其他免疫指标包括吞噬杀伤、COP、ACP及NOS活性等都与体重呈正相关,但差异不显著.结果表明,不同规格刺参的非特异性免疫活性虽有差别,但并不影响其生长. 相似文献
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《青海师范大学学报(自然科学版)》2013,(4):F0003-F0003
青海湖高寒湿地生态系统观测试验地处青藏高原东北部的青海湖,目前主要有两个野外观测站——小泊湖观测站和瓦颜山观测站。小泊湖观测站位于青海湖东岸,距共和县湖东种羊场西北约6公里,地理坐标北纬36°41′734″~36°42′256″,东经100°46′85″~100°47′21″,站区地形开阔,海拔3216~3221m,面积约14.8km~2,是青海湖水位下降遗留下来的沼泽草甸湿地。瓦颜山观测站位于青海湖北岸,距刚察县西北52公里瓦颜山河源处,地理坐标北纬37°43′38.03″-37°46′20″,东经100°01′58.87″~100°05′04.17″,海拔3720~3850m,面积约11.03 km~2,地势开阔,是沙柳河上游支流——瓦颜曲的河源湿地。 相似文献
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夏眠期间仿刺参生长、肠体比以及RNA/DNA比值变化的研究 总被引:1,自引:0,他引:1
为了深入了解夏眠期间仿刺参(Apostichopus japonicus Selenka)的生长和生理变化,研究了夏眠仿刺参的体质量、肠体比以及RNA/DNA(简称R/D)比值.实验期间,夏眠组水温以每周5℃(0.7℃/d)由16℃缓慢升至26℃,然后在26℃后保持5周;对照组水温在16℃维持7周.期间每周称量仿刺参体质量并取样,测定仿刺参的肠体比比值以及肠、呼吸树和体壁中的R/D比值.实验结果显示,夏眠组仿刺参体质量和肠体比缓慢下降,当进入夏眠阶段后,夏眠组肠体比比值显著低于对照组.夏眠组仿刺参肠、呼吸树和体壁中R/D比值均表现出先升高后降低的趋势,其中夏眠初期的R/D比值显著高于对照组.这说明夏眠过程中仿刺参肠道严重退化,R/D比值可以用于反映夏眠阶段仿刺参的生长特征.本研究丰富了仿刺参的基础研究,对于夏季仿刺参养殖生产有一定的理论指导意义. 相似文献
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刘晓兰 《中国新技术新产品精选》2012,(3):206-206
伊春红山水电站是汤旺河干流梯级规划中首批开发的水电站,位于汤旺河上游梯级电站的最后一级。红山水电站枢纽工程位于黑龙江省伊春市上甘岭区火车站北东约1.0km处,地理坐标为东经130°53′50″、北纬44°00′45″,坝址以上流域面积4541km2,占汤旺河流域面积的22%。水库正常蓄水位266.5m,总库容2670×104m3,以发电为主,兼顾供水、水产养殖、提供保障森林防火水源及发展旅游业等的综合利用水利枢纽工程。本次评价针对项目建设前后评价区自然生态系统现状进行评价,并对项目建设后对项目区生态完整性进行预测,评价项目建设对生态系统的影响程度。 相似文献
6.
一、前言本文所指南京地区,位于北纬31°38’—32°37′东经118°20′—119°16′之间,地处长江下游,宁镇弧形山脉西段,大体包括南京市及其所辖江宁,江浦、六合三县。面积约为4717平方公 相似文献
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周秀佳 《华东师范大学学报(自然科学版)》1986,(1)
上海位于北纬30°23′~31°37′,东经120°50′~121°45′。西北邻江苏省,西南邻浙江省。土地面积约6000 km~2。根据上海植被的地理分布特点、不同植被类型组合和植物区系成分,将上海植被划分为2个植被地带,即中亚热带常绿阔叶林和北亚热带常绿、落叶阔叶混交林,4个植被区,12个植被片。 相似文献
8.
采用实验生态学模拟方法,研究了经40d处理后温度与盐度对刺参生长的影响,以特定生长率(SGR)与净增重为参数反映生长状况。结果不同温度与盐度处理对刺参生长的影响均呈先升高后降低趋势。刺参SGR在温度为17℃时达最大值,为2.031±2.772%.d-1,体重净增长量达最大值9.247±12.179g;在盐度为30时达最大值3.067±2.069%.d-1,净增长量12.668±12.717g。根据回归曲线得出刺参最快生长温度是16.8℃,盐度是31。 相似文献
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东海剑尖枪乌贼的数量分布和生长特性研究 总被引:5,自引:0,他引:5
根据1994-1996年和2004-2006年东海大陆架25°30′-33°30′N,128°00′E以西海域调查资料,对剑尖枪乌贼的数量分布和生长特性进行研究,结果表明:剑尖枪乌贼渔获量高峰期出现在夏季,其资源密度指数达到20.3kg/h,其次是春、秋季,均为5.1kg/h,冬季最低。中心渔场在27°00′-28°30′N,122°30′-124°30′E和28°00′-30°30′N,124°00′-126°30′E。渔场表、底层水温分别为28-29℃和18-21℃,表、底层盐度分别为32-34和34-34.5。该种生命周期为1年,5月份出现性成熟个体,6-10月性成熟个体出现率较高,性成熟度Ⅳ期和Ⅴ期达到41.3-63.5%,有春生群、夏生群和秋生群之分,夏秋季出生的群体,经过越冬后,翌年春夏季长大进行繁殖,并与春生群、夏生群一起,成为夏秋季的主要捕捞对象。为合理利用该资源,宜在夏季渔获量高峰期发展光诱作业或鱿钓作业,以提高其利用效益。 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.
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.
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
14.
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
15.
Miao Maosheng 《华南师范大学学报(自然科学版)》2014,(6)
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
16.
Yang Weitao 《华南师范大学学报(自然科学版)》2014,46(6):137-138
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
17.
Bernard Kirtman 《华南师范大学学报(自然科学版)》2014,(6)
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that 相似文献
18.
《上海师范大学学报(自然科学版)》2014,(5):550
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with 相似文献
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《吉林大学学报(理学版)》2014,(5):1105
<正>"Journal of Jilin University(Science Edition)"is a comprehensive academic journal in the fields of science sponsored by Jilin University and administrated by the Ministry of Education of the Peoples Republic of China.The journal started publication in 1955.The original name at starting publication was"Journal of Natural Science of Northeast People University",which was changed into"Acta Scientiarum Naturalium Universitatis Jilinensis"in 1958 owing to the name change of the university.The present journal name has 相似文献