共查询到20条相似文献,搜索用时 62 毫秒
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黎振昌 《华南师范大学学报(自然科学版)》1998,(2):1-43
广东省阳山秤架自然保护区鱼类初步调查黎振昌杨文斌华南师范大学生物系广州510631关键词阳山县;自然保护区;鱼类中图分类号Q959.4广东省秤架自然保护区位于阳山秤架林场范围内.1994年7月30日至1994年8月2日和1995年7月25日至7月30... 相似文献
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《大众科学.科学研究与实践》2017,(12)
<正>水西海子群位于贵州省毕节市黔西县,由大海子、榨孔塘海子、柯家海子、龚家海子、哆啰坝海子、黑石头海子等组成。所谓"海子",其实是对高原上湖泊的统称。比起其它湿地,水西海子群显得尤为弥足珍贵——其所处位置位于喀斯特高原地区,土壤成分主要为石灰岩,会在雨水的冲刷下逐渐瓦解,很难锁住地表水,其地形地貌很难发育成湿地。然而,这些海子竟然能连片分布,并形成天然湿地而非人为使然,只能归因于大 相似文献
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菜子湖鱼类区系变动及其驱动力分析 总被引:1,自引:0,他引:1
2007~2008年对菜子湖鱼类多样性和渔业方式进行了调查,采集到鱼类8目18科68种,包括3种新记录.历史记录的13种洄游性鱼类本次仅见2种野生群,湖区野生洄游性鱼类经济绝灭.养殖鱼类产量占渔业总产的91.4%,成为渔业主体.杂食性鱼类物种丰富但产量甚微,相反人工放流的鲢、鳙等滤食性鱼类产量达鱼类总产的68.6%,为绝对优势种.湖区鱼类区系组成的特征变化与江湖阻隔和渔业养殖模式变革密切相关,因此江湖关系变动及渔业养殖当为菜子湖鱼类区系变动的关键驱动因子. 相似文献
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春季舟山渔场鱼类种类组成研究 总被引:3,自引:0,他引:3
根据2011年3月和4月的渔业生物资料,研究报道了春季不同月份舟山渔场鱼类种类组成、区系组成和优势种组成,比较了春季不同月份出现种类组成,优势种变化。结果表明,春季舟山渔场鱼类种类共有70种,隶属于14目46科,其中暖水种共有46种,暖温种共有24种;3月份鱼类出现种类58种,其中优势种有虻鲉、小黄鱼和日本鳀3种,4月份鱼类出现种类62种,优势种有虻鲉、七星底灯鱼、小黄鱼和龙头鱼4种。 相似文献
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麻阳河自然保护区鱼类资源调查初报 总被引:1,自引:0,他引:1
本文报道了麻阳河鱼类48种,隶属4目10科,占贵州鱼类种数202种的23.8%。除鳗鲡为降河性洞游鱼类外,余皆为纯淡水鱼类。区系组成:鲤形日4科35种,其中鲤科鱼类为最大的一个类群,有28种,是麻阳河鱼类区系的主体,胭脂鱼是国家二类保护鱼类,为重要经济鱼种。 相似文献
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台湾海峡经济鱼类感染寄生线虫幼虫的调查 总被引:13,自引:1,他引:12
罗大民 《厦门大学学报(自然科学版)》1999,38(4):604-610
自1996年4月至1998年1月间,对台湾海峡常见80多种经济鱼类作为中间宿主感染寄生线虫幼虫的情况进行了调查.报道了该海域中常见的8种鱼类寄生线虫幼虫及它们在鱼类中的感染状况.结果表明约59.26%的鱼类感染了线虫幼虫.可感染6种线虫幼虫的鱼类有灰海鳗、蓝圆鱼参和大带鱼等;绝大多数鱼类仅感染2~3种.优势种幼虫之一的Contracaecumsp.2约感染54.32%的受检鱼类.感染鱼类较多还有Contracaecummuraenesoxi和Anisakissimplex幼虫,它们的感染率分别是32.10%和21.16%.感染强度较大的3种幼虫分别是Contracaecumsp.2、Anisakissimplex和Raphidascaristrichiuri(YinetZhang,1983),它们的平均感染强度分别为46.25、47.14和28.78条/尾.本海域另一个优势种线虫幼虫是Raphidascaristrichiuri(YinetZhang,1983). 相似文献
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采集华南12个自然保护区的鱼类91种,分别隶属6目18科55属;以老第三纪原始鱼类类群后裔及南亚暖水性鱼类为主.详细研究了12个保护区鱼类起源、分布、区系组成.比较了12个保护区鱼类组成。 相似文献
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1997年4月下旬至5月中旬,应用PFU法收集东昌湖原生动物类群,对群落的种类组成、多样性指数和污生指数等进行了测定,共检出原生动物107种,其中23种为污染指示种 相似文献
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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
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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
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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
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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
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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
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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
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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
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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
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《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