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1.
江西省婺源县黄喉噪鹛调查初报   总被引:4,自引:0,他引:4  
在德国和英国鸟类保护组织的资助下 ,“江西省婺源县自然保护小区主要植物和鸟类调查”历时 3年 ,截至 2 0 0 0年 7月 1 4日 ,共查出鸟类 2 1 6种 ,树木、药材80 0余种。在鸟类中 ,发现了黄喉噪鹛 (Garrulaxgal banus)两个群体 ,分别为 6 0余只和 30余只 ,二者相距约 4 0km。该鸟是世界稀有、分布地域狭小的鸟种之一。据有关资料 ,仅分布于印度阿萨姆邦与缅甸交界处、中国江西省婺源和云南省思茅等 3处。计有南方、思茅两个亚种。自 1 874年采到第一只标本至今 ,人们对它的生态习性尚未作深入研究 ,知之甚少。 2 0 0 0年6…  相似文献   

2.
爱护鸟类 保护环境郑光美  1 982  0 3  0 5谈谈鸟耳李福来  1 982  0 3  0 7鸟类呼吸系统的微细结构与呼吸机制葛荫榕  1 982  0 2  2 0鸟类食性与消化道的特点李福来  1 984  0 2  2 4褐马鸡赖荣兴  1 984  0 2  60藏雀宋榆钧  1 984  0 3  1 2我国的几种珍稀濒危鸟类许维枢  1 985  0 2  1 6珍禽的驯养和繁殖甘声芸  1 985  0 2  1 9鸟类环志杨若莉  1 985  0 2  2 2鹌鹑消化系统的解剖刘佐桢等  1 985  0 3  0 9江南珍禽——草侯广梯  1 985  0 3  1 1四声杜鹃的观察晏安厚  1 985  0 3  1 3鸟…  相似文献   

3.
郑光美 《动物学研究》2004,25(5):377-378
《云南鸟类志·上卷·非雀形目》 (杨岚等编著 )、《云南鸟类志·下卷·雀形目》 (杨岚、杨晓君等编著 )已分别于 1994年 12月和 2 0 0 4年 8月由云南科技出版社出版。这是中国鸟类分类和区系研究的一项重要进展 ,对于推动我国鸟类学的发展和促进国内外交流具有重要意义。全书记述了云南省有分布记录的非雀形目鸟类 18目 4 1科 340种 ,雀形目鸟类 2 8科 5 0 8种 ,共计 84 8种 (10 74种和亚种 )。所记录和描述的云南鸟类种数 ,比彭燕章等 (1987)《云南鸟类名录》增加 75种。所记录鸟类种数 ,占中国鸟类种数 12 5 3(郑作新 ,2 0 0 0 )的 6 7 6…  相似文献   

4.
2005-2006年的1月、4月、7月和10月,利用样带法对广州市新垦红树林湿地和周边农田进行鸟类物种多样性研究。利用Shannon-Wiener指数分析了生境类型的鸟类群落种数、数量、物种多样性、均匀性指数等特征。结果表明,新垦红树林湿地1月鸟类种数高于周边农田湿地2倍,鸟类群落个体数量高于农田湿地9倍;红树林湿地4月和7月鸟类种数高于周边农田湿地1.5倍,鸟类群落个体数量高于农田湿地4倍;红树林湿地10月鸟类种数高于周边农田湿地1.5倍,鸟类群落个体数量高于农田湿地6.8倍;新垦红树林湿地和周边农田湿地鸟类物种多样性表现出明显的季节性变化。  相似文献   

5.
第 2 3届国际鸟类学大会于 2 0 0 2年 7月 1 2~ 1 7日在北京召开。来自世界各国的近千名鸟类学家围绕当前国际鸟类学的前沿、热点问题展开了讨论和交流。我国学者也首次在大会报告中介绍了我国古鸟类研究的最新进展。本届大会组委会主席由中国鸟类学会理事长郑光美教授担任。国际鸟类大会是较早开展的科学会议之一 ,1 884年首次在奥地利的维也纳召开。从1 92 6年的哥本哈根会议开始每 4年召开 1次 ,主要由欧美国家主办 ,本次会议是第一次在亚洲地区召开。本次会议提交的论文、报告共计 80 0多篇 ,其中包括 1 0篇大会报告。会议还就 4 0个专…  相似文献   

6.
拉萨拉鲁湿地夏季鸟类调查初报   总被引:5,自引:3,他引:2  
20 0 4年 8月采用样线法调查了拉萨市拉鲁湿地夏季鸟类的种类和数量 ,共记录到 2 6种鸟。鸟类群落中以灰沙燕 (Ripariariparia)、红脚鹬 (Tringatotanus)为优势种 ,优势度明显 (D =0 . 40 8) ,但群落多样性不高 (H′=1 . 5 3 1 )。拉鲁湿地夏季鸟类群落中涉禽和草甸鸟类占主导地位 ,标示着湿地表面水位下降、趋向于草原化的环境变化特点  相似文献   

7.
徐中辉 《四川动物》2001,20(1):35-36
1 自然概况广元市位于四川盆地北部周缘 ,东经 1 0 5°1 2′~1 0 6°1 7′ ,北纬 31°53′~ 32°52′。地势由北向南逐步降低 ,海拔多为 60 0~ 90 0m ,以林、草覆盖为主 ,间有部分耕地的浅丘地带 ,市区内有嘉陵江及其支流南河、白龙江及清江河。市区北部属秦巴区北亚热带湿润季风气候。市区南部属四川盆地中亚热带湿润季风气候。区内四季分明 ,雨量充沛。 7、8月最高气温 38 6℃ ,1月份最低气温零下 5℃ ,年平均 1 6 1℃ ,无霜期 2 63天。降水主要集中在 6~ 9月份 ,年降雨量 972 6mm。2 自然环境与鸟类数量分布的历史变迁2 0世纪 …  相似文献   

8.
1999年 10月~ 2 0 0 0年 4月在对云南丽江拉市海高原湿地自然保护区的越冬水禽进行调查的过程中 ,于 1999年 11月连续 3日观察到 1只白腰杓鹬 (Numeniusarquata)在湖边草地觅食 ;1999年 12月至 2 0 0 0年 3月观察到 1只国家Ⅰ级重点保护鸟类白头鹤 (Grusmonacha)与 5 0余只灰鹤混群活动。这 2种鸟类均为云南鸟类种的新纪录。云南发现白头鹤和白腰构鹬@权锐昌$中国科学院昆明动物研究所!650223 @文贤继$中国科学院昆明动物研究所!650223…  相似文献   

9.
内蒙古草原繁殖鸟类群聚组成之比较   总被引:9,自引:2,他引:7  
颜重威  邢莲莲  杨贵生 《生态学报》2000,20(6):992-1001
利用 5月份温带草原鸟类繁殖期 ,在荒漠草原、草原、湿地、沙地和山地等植被 ,选取 1 1个面积 1 0 0 hm2 ( 50 0 m×2 0 0 0 m)同样大小的样区 ,由 3人各隔 1 50 m作平行的穿越线调查 ,并记录所见鸟类的种类与数量。同时 ,也在每一样区任取面积 1 m2 之植被样方 ,记载样方内植物的种类、垂直高度、覆盖度和植物鲜重。调查结果显示草原繁殖鸟类的种类不多 ,在无树的荒漠草原植被是 4~ 6种 ,草原植被在 5~ 8种之间 ,湿地植被 1 5种 ;在有树的沙地植被是 9~ 1 2种 ,山地植被 6种。鸟种多样性和丰富度指数不大 ,由大而小依序是沙地植被、湿地植被、山地植被、草原植被、荒漠草原植被 ;密度也不高 ,由大而小依序是无树草原的湿地植被、草原植被、荒漠草原植被 ,而后是有树草原的沙地植被、山地植被。鸟类食性分布方面 ,荒漠草原和草原植被以食杂性鸟类为优势 ;湿地植被以食虫性鸟类为多 ;沙地植被以食杂与食肉性鸟类为胜 ;山地植被以食虫和食杂性鸟类较多 ,并增加一些食肉性鸟类。  相似文献   

10.
武汉桂子山地区冬季鸟类群落结构及多样性研究   总被引:1,自引:0,他引:1  
田丽  邓军  易兰  万红霞  刘家武 《四川动物》2007,26(1):157-160
2005年11月~2006年3月,对武汉桂子山地区冬季鸟类群落进行了调查,共记录鸟类44种,隶属10目22科。有国家Ⅱ级保护鸟类2种,湖北省重点保护鸟类16种;留鸟32种,冬候鸟11种,旅鸟1种,留鸟构成了冬季鸟类的主体;该地区冬季鸟类密度为4.30只/hm^2,物种多样性指数为2.6477,均匀性指数为0.6997。居民点、乔灌林、绿地和水域生境中,乔灌林鸟类多样性最高,数量最多。  相似文献   

11.
Ectogenesis, or the use of an artificial womb to allow a foetus to develop, will likely become a reality within a few decades, and could significantly affect the abortion debate. We first examine the implications for Judith Jarvis Thomson’s violinist analogy, which argues for a woman’s right to withdraw life support from the foetus and so terminate her pregnancy, even if the foetus is granted full moral status. We show that on Thomson’s reasoning, there is no right to the death of the foetus, and abortion is not permissible if ectogenesis is available, provided it is safe and inexpensive. This raises the question of whether there are persuasive reasons for the right to the death of the foetus that could be exercised in the context of ectogenesis. Eric Mathison and Jeremy Davis have examined several arguments for this right, doubting that it exists, while Joona Räsänen has recently criticized their reasoning. We respond to Räsänen’s analysis, concluding that his arguments are unsuccessful, and that there is no right to the death of the foetus in these circumstances.  相似文献   

12.
Methods of amperometry and potentiometric titration were used to follow dark respiration (DR) and apparent photosynthesis (AP) in the fucoids Ascophyllum nodosum (L.) Le Jol, Fucus vesiculosus L., and F. serratus L. from the Barents Sea littoral by the end of the 40-day-long polar night. The macroalgae were shown to manifest species-specific low rates of photosynthesis and respiration. However, in spite of their low photosynthetic status due to the effects of subzero temperature and prolonged low or zero illumination, the macroalgae have been able to restore DR and AP to the initial level already by the day 9; the ability to restore AP depended on the level of illumination. The study of the changes in the carbonate–bicarbonate system in the light and darkness demonstrated that the macroalgae grown in darkness, in contrast to those grown in twilight, could absorb bicarbonate in darkness; however, they lost this capacity after two-day-long illumination at an irradiance of 7 mol/(m2 s). Bicarbonate uptake in darkness and the capacity to restore the systems of photosynthesis and respiration in fucoid cells are discussed in the context of algal energy metabolism under the polar night conditions.  相似文献   

13.
日光温室采光面三效率计算模式及其优化选择研究   总被引:7,自引:0,他引:7  
本文针对日光温室常见的3种采光面(圆弧面、椭圆和抛物面),给出了各自采光效率、土地使用率和保温效率(简称三效率)的理论计算模式,并通过分析得出,各个高效采光面上的采光效率均随纬度增加而降低,随距冬至的日数而增加,随作物高度而降低,随高跨比增加而增加。在三种采光面中,无论时间、地点、高跨比和种植高度怎样变化,均以圆弧面的采光效率为最高,椭圆面次之,抛物面最低。另一方面,从土地使用效率来看,椭圆面最高,但它的保温效率最低。因此,采光面形状的选择应因使用对象而宜,本文给出了最佳选择建议。  相似文献   

14.
Summary The choriocapillaris is a fenestrated capillary bed located posterior to the retinal pigment epithelium. It serves as the main source of supply to the photoreceptors, retinal pigment epithelium, and other cells of the outer retina. The permeability of these capillaries to intravenously injected ferritin (MW — approx. 480,000; mol. diam. 11 nm) was examined in the mouse, rabbit, and guinea pig, each of which is characterized by a different type of retinal vascularization. In all three species, the bulk of the ferritin remained in the capillary lumina, where it appeared to be blocked at the level of the diaphragmed fenestrae. Some ferritin was present in endothelial cell vacuoles. The results confirm previous work on the rat choriocapillaris and indicate that the barrier function of the choriocapillary endothelium is present even among species in which the retinal circulation differs significantly.Supported by NIH grant EY03418  相似文献   

15.
We illuminated bacteriorhodopsin crystals at 210K to produce, in a photostationary state with 60% occupancy, the earliest M intermediate (M1) of the photocycle. The crystal structure of this state was then determined from X-ray diffraction to 1.43 A resolution. When the refined model is placed after the recently determined structure for the K intermediate but before the reported structures for two later M states, a sequence of structural changes becomes evident in which movements of protein atoms and bound water are coordinated with relaxation of the initially strained photoisomerized 13-cis,15-anti retinal. In the K state only retinal atoms are displaced, but in M1 water 402 moves also, nearly 1A away from the unprotonated retinal Schiff base nitrogen. This breaks the hydrogen bond that bridges them, and initiates rearrangements of the hydrogen-bonded network of the extracellular region that develop more fully in the intermediates that follow. In the M1 to M2 transition, relaxation of the C14-C15 and C15=NZ torsion angles to near 180 degrees reorients the retinylidene nitrogen atom from the extracellular to the cytoplasmic direction, water 402 becomes undetectable, and the side-chain of Arg82 is displaced strongly toward Glu194 and Glu204. Finally, in the M2 to M2' transition, correlated with release of a proton to the extracellular surface, the retinal assumes a virtually fully relaxed bent shape, and the 13-methyl group thrusts against the indole ring of Trp182 which tilts in the cytoplasmic direction. Comparison of the structures of M1 and M2 reveals the principal switch in the photocycle: the change of the angle of the C15=NZ-CE plane breaks the connection of the unprotonated Schiff base to the extracellular side and establishes its connection to the cytoplasmic side.  相似文献   

16.
Summary 1. The material for this study is drawn from two sources, (a) investigations of the fish fauna in the inner Oslofjord between 1897 and 1967, (b) fish landing statistics available since 1872 at the Oslo fish market.2. The investigations of the fish fauna reveal that 4 species of fish — 2 sharks and 2 arctic bullheads — have disappeared from the deep waters of the Oslofjord where they were known to exist in 1897. We assume that unfavourable conditions, great changes in temperature or lack of oxygen in the stagnant deep water to which these species belonged have been injurious to their propagation and survival.3. The annual fluctuations in the landed quantities of fish are great, but nevertheless there exists a marked decreasing trend since about 1930; total landings in recent years are less than 1/10 of what they were 30 or 40 years ago.4. The fluctuations in the landings of cod, herring and mackerel are studied in some detail. Three periods (of 20 to 22 years' duration) from 1872 to 1932 show increasing average landings of cod: 44, 57, and 74 tons respectively; in the period 1933 to 1955 landings decreased to an average of 16 tons per year. The effect of fluctuating year classes is discussed.5. The landings of herring and mackerel were very good between 1911 and 1919 or 1920 with a maximum of 1500 tons of herring and 800 tons of mackerel. In the following years there was a trend of decrease with a few years of moderately good landings. Mature mackerels are immigrating into the fjord for feeding and spawning, while mature herrings, to a major extent, are supposed to belong to a local stock. The highest landings of both species are due to extremely great catches of young fish, and the success of the fishery in any one year, therefore, dependent of a successful spawning and hatching one ort two years before.6. In conclusion, the attention is drawn to the fact that there are reasons to believe that the profuse growth of bacteria in the polluted waters seems to be injurious to the hatching of fish eggs and to the survival of fish larvae (Dannevig 1945,Oppenheimer 1955).
Veränderungen der Fischfauna und der Fischerei des Oslofjords seit der Jahrhundertwende
Kurzfassung Das Material zu dieser Untersuchung stammt aus zwei Quellen: (a) vier Untersuchungen über die Fischfauna des Oslofjords im Zeitraum zwischen 1897 und 1967, und (b) Statistiken für den Zeitraum von 1872 bis 1964 über die Fischmengen, die im inneren Oslofjord gefangen und an die Fischhalle in Oslo geliefert worden sind. Ein Vergleich der Resultate mit den vier Untersuchungen über die Fischfauna zeigt, daß vier Arten von Tiefwasserfischen aus dem inneren Oslofjord völlig verschwunden sind, nämlichEtmopterus spinax, Somniosus microcephalus, Artediellus uncinatus undIcelus bicornis, die beiden zuletzt genannten wahrscheinlich schon vor 1930. Eine Anzahl anderer Arten, die früher häufig waren, sind jetzt selten. Statistische Erhebungen über die im Oslofjord gefangenen Fische lassen erkennen, daß die Erträge seit den zwanziger und dreißiger Jahren stark zurückgegangen sind. Gleichzeitig hat die Zahl der Fischer abgenommen. Es wird die Schlußfolgerung gezogen, daß die Veränderungen des Oslofjords sich besonders in den letzten 30 Jahren für mehrere Fischarten als schädigend erwiesen haben. Diese Auffassung wird unterstützt durch die Untersuchungen vonDannevig (1945) undOppenheimer (1955), die gezeigt haben, daß die reiche Bakterienflora des Oslofjords für die Entwicklung der pelagischen Fischeier schädlich ist.
  相似文献   

17.
The visual system is beautifully crafted to transmit information of the external world to visual processing and cognitive centers in the brain. For visual information to be relayed to the brain, a series of axon pathfinding events must take place to ensure that the axons of retinal ganglion cells, the only neuronal cell type in the retina that sends axons out of the retina, find their way out of the eye to connect with targets in the brain. In the past few decades, the power of molecular and genetic tools, including the generation of genetically manipulated mouse lines, have multiplied our knowledge about the molecular mechanisms involved in the sculpting of the visual system. Here, we review major advances in our understanding of the mechanisms controlling the differentiation of RGCs, guidance of their axons from the retina to the primary visual centers, and the refinement processes essential for the establishment of topographic maps and eye-specific axon segregation. Human disorders, such as albinism and achiasmia, that impair RGC axon growth and guidance and, thus, the establishment of a fully functioning visual system will also be discussed.  相似文献   

18.
Abstract

In contrast to the huge amount of research on Turkish migration and migrants, the diasporic politics of the Turkish Kemalist state constitutes a neglected research subject in the scholarship on Turkish diaspora. How does the Turkish state reach out to its nationals and expatriates abroad? In what ways does the Turkish Republic seek to make Islam (as it does in Turkey) into an instrument legitimizing its politicizing and mobilizing enterprises? To explore these questions, this article investigates the long-distance Kemalism engaged in by the Turkish state to Turkify and secularize its nationals in the diaspora, using its activities in Australia as its case study. In sketching out trans-Kemalism's dimensions, the analysis directs attention to the intimate relationship between the political and religious fields of transnationalism manufactured by the state. The paper concludes that the intense political polarization in Turkey in the present makes the future of trans-Kemalism abroad somewhat uncertain.  相似文献   

19.
The time has come to proceed from forms of givenness of the word to forms of the word as such. They can, if you like, be called external and inner structures. Humboldt, however, preferred to speak of the external and inner forms of the language. Shpet adopted precisely this distinction. Why did this problem interest Shpet? Already in [Appearance and sense], he had set the task of returning to the source of pretheoretical, living science. Shpet wrote that the outer cover of words and logical expressions obscure the objectified meaning and that it was necessary to remove another cover from the objectified sign so as to grasp a certain genuine intimacy, and in it the fullness of being (Shpet, 1914. Pp. 5-6). We shall keep in mind this major undertaking posed by this scientist. The existence of the inner form of words should not come as a surprise. That same year (1914) Ortega y Gasset wrote that material objects have a third dimension. However, we cannot see or touch it: "For just as depth needs a surface beneath which to be concealed, the surface, or outer cover, in order to be so, needs something over which to spread, covering it" (Ortega y Gasset, 2000. Pp. 62-63).  相似文献   

20.
On the diversity of the Cladocera in the tropics   总被引:20,自引:13,他引:7  
The mythical concept of an impoverished tropical cladoceran fauna is refuted. On a planetary scale, around half of the cladoceran species presently known occur exclusively in the tropics-subtropics, often with considerable restriction to particular geographical subzones. On a regional (political) scale, the situation is often unclear because of the continued fragmentary nature of studies, and because political units are not a good basis for biogeographical comparisons. At the finest level of resolution (lake-perlake comparisons), there appears to be an upper limit of c. 50 cladoceran species per individual lake. No significant difference between lakes in the temperate zone and in the tropics could be established here. Daphnia is largely absent from the tropics, but is replaced by more Sidids, Moinids, and Bosminids, such that the average cladoceran community in the limnetic zone of a tropical lake is not characterized by less species but rather by lower population densities. This, in turn, is considered a consequence of higher prevalent predation levels in the tropics.  相似文献   

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