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Symposia and congresses (and similarly named conferences) provide a specific medium for scientific communication that should complement, not duplicate, published or circularized reporting. The total expenditure for presentation of results at a session of the International Geological Congress is at least in the region of 8 million dollars, and there are hundreds of smaller geological meetings every year. Progress in finding rational forms for meetings is slow, and elementary deficiencies in meeting organization are incessantly repeated. The fact that meetings have established themselves as a very viable institution in science provides no excuse for not watching and reviewing their structure and economy as vigilantly as, for example, publications.  相似文献   
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In the present study 241 shells from snails belonging to theBulinus africanus-group in West Africa, were examined in a morphometricanalysis including ten characters. Principal component analysisand stepwise discriminant function analysis were used for analysisof the data. It was shown that Bulinus umbilicatus, B. jousseaumeiand B. globosus are clearly distinct on morphometric shell characters.Besides a general differentiation between the three species,the characters necessary for differentiation between them twoby two are found. The knowledge of the geographic distributionof B. umbilicatus and B. jousseaumei is significantly improved. (Received 18 March 1988; accepted 4 May 1988)  相似文献   
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The two large organizations in international geology, the permanent International Union of Geological Sciences (IUGS) and the long-term International Geological Correlation Programme (IGCP), are strongly stratified units and victims of platform sedimentation. Their National Committees and corresponding bodies are often useless as channels of the active scientists' initiative and influence. Their constituent and affiliated scientific bodies are deprived of all influence on the management of the organizations, in favour of managements bureaucratically and autocratically recruited according to a pattern of equitable geographical distribution. The IGCP is wasting effort in hunting for programme gaps, whilst both organizations are campaigning against regional concentrations of interest and consequent influence. Both organizations are in bad need of activating their national members and opening up their management to influence from their scientific bodies. For this purpose important changes in their constitutions are needed. Only then can their formal strength become real and their many challenging tasks be efficiently tackled.  相似文献   
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Eleven new genera and 17 species are described, with one exception parasites on echinoderms: Trochostilifer gen. n. with T. domus sp.n. (type species) (Philippines) on Stylocidaris efftuens, T. mortenseni sp.n. (New Caledonia) on Prionocidaris australis and T. slriatus (Hedley) on P. baculosa annulifera; Ophioarachnicola biformis gen. et sp.n. (Solomon Is.) on Ophio-arachna incrassata; Hemiliostraca sloani sp.n. (Aldabra I.) on Ophiomyxa australis; Robil-lardia solida sp.n. (Loyalty Is.), host unknown. Ersilia Monterosato is transferred from Lacunidae to Eulimidae, E. stancyki sp.n. (Florida) is a parasite of Ophiolepis elegans. Hyper-mastus echinodisci sp.n. and H. sauliae sp.n. (both Borneo) are parasitic on Echinodiscus bisperforatus; Monogamus parasaleniae sp.n. (Tonga I.) on Parasalenia gratiosa. Scalari-balcis gen.n. is erected for Mucronalia angulata Mandahl-Barth. Concavibalcis scalaris gen. et sp.n. is described from the Philippines, host unknown. Echiuroidicola cicatricosa gen. et sp.n. (Malaysia) is a parasite on the echiuroid Ochetostoma erythrogrammon. Peasistilifer gen.n. (type species Mucronalia nitidula Pease) is erected for a group of holothurian parasites. Prostilifer gen.n. is erected for Eulima subpellucida Pease, parasitic on Pacific holo-thurians. Paramegadenus scutellicola sp.n. (Pacific) is parasitic on Stellaster incei, P. incerta sp.n. on an Australian starfish. Asterolamia hians gen. et sp.n. is described from Astropecten indicus and A. cingulata from Craspidaster hesperus , both Pacific. Microstilifer gen.n. is erected for Stilifer auricula Hedley. Vitreobalcis gen.n. is erected for Apicalia holdsworthi H. Adams, a parasite of Mespilia globulus and V. laevis sp.n. (from Synaptula purpurea , Australia) is provisionally placed here. Luetzenia asthenosomae gen. et sp.n. (Australia) and L. toki Habe are both parasites on Asthenosoma.  相似文献   
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The structure and late development of the flowers of the South‐East Asian bee‐pollinated palm Licuala peltata are described with special focus on the architecture of the unusual labyrinthine nectaries. The nectaries are derived from septal nectaries by extensive convolution of the carpel flank surfaces below the ovary throughout the inner floral base, thus also encompassing the inner surface of the corolla–androecium tube. A comparison with septal nectaries elsewhere in Arecaceae and with labyrinthine nectaries in other monocots shows that labyrinthine nectaries situated below the ovary, as described here, are not known from any other palms, but are similar to those of a few Bromeliaceae and, less strongly convoluted, some Haemodoraceae and Xanthorrhoeaceae. In addition, the substantial participation of parts other than the gynoecium in the nectary architecture of Licuala appears unique at the level of monocots. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 161 , 66–77.  相似文献   
49.
Storms can cause Europe-wide reduction in forest carbon sink   总被引:1,自引:0,他引:1  
Disturbance of ecosystems is a major factor in regional carbon budgets, and it is believed to be partly responsible for the large inter-annual variability of the terrestrial part of the carbon balance. Forest fires have so far been considered as the most important disturbance but also other forms of disturbance such as insect outbreaks or wind-throw might contribute significantly to the largely unexplained inter-annual variability, at least in specific regions. The effect of wind-throw has not yet been estimated because of lack of data on how carbon fluxes are affected. The Gudrun storm, which hit Sweden in January 2005, resulted in ca. 66 million m3 of wind-thrown stem wood on an area of ca. 272 000 ha. Using a model (BIOME-BGC) calibrated to CO2 flux measurements at two sites, the annual net ecosystem productivity during the first year after the storm was estimated to be in the range −897 to −1259 g C m−2 yr−1. This is a much higher loss compared with harvested (clear-cut) forests in Europe, which ranged between ca. −420 and −100 g m−2 yr−1. The reduction in the carbon sink scaled to the whole wind-thrown area was estimated at ca. 3 million tons C during the first year. By historical data on wind-throw in Europe combined with modelling, we estimated that the large Lothar storm in 1999 reduced the European carbon balance by ca. 16 million tons C, this is ca. 30% of the net biome production in Europe. We conclude that the impact of increased forest damage by more frequent storms in future climate change scenarios must be considered and that intermittent large wind-throw events may explain a part of the large inter-annual variability in the terrestrial carbon sink.  相似文献   
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