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George A. Antonelis Jr. Mark S. Lowry Douglas P. DeMaster Clifford H. Fiscus 《Marine Mammal Science》1987,3(4):308-322
Stomach lavaging was used to study the feeding habits of northern elephant seals ( Mirounga angustirostris ) found on San Miguel Island, California, during the spring of 1984. Fifty-nine elephant seals were chemically immobilized with an intramuscular injection of ketamine hydrochloride. Once immobilized, an animal's stomach was intubated, filled with 3–4 liters of water to create a slurry of the undigested food items, and evacuated into a collection device. The stomachs of 57 (96.6%) of the animals lavaged contained identifiable parts of prey. Twenty-nine different food items were identified, 12 of which have not been previously reported as prey of the northern elephant seal: two teleost fish, Coryphaenoides acrolepis (Pacific rattail) and another unidentified macrourid; two crustaceans, Pasiphaea pacifica (glass shrimp) and Euphausia sp.; six squid, Abraliopsis felis, Gonatus berryi, Histioteuthis dofleini, Cranchia scabra, Taonius pavo, and Galiteuthis sp. and two octopi, Octopus dofleini and Octopus rubescens. 相似文献
3.
Johannes H. P. Hackstein Theo A. van Alen 《Evolution; international journal of organic evolution》1996,50(2):559-572
It has been assumed that the feeding habits of vertebrates predispose the variety of intestinal differentiations and the composition of the microbial biota living in their intestinal tracts. Consequently, the presence of methanogenic bacteria in the various differentiations of the large intestine and the foregut of herbivorous vertebrates had been attributed primarily to the existence of anaerobic habitats and the availability of carbon dioxide and hydrogen originating from the fermentative microbial digestion of plant-based diets. However, Australian ratites, many murids, and several New World primates lack methanogens, despite their intestinal differentiations and their vegetarian feeding habits. Crocodiles, giant snakes, aardvarks, and ant-eaters on the other hand release significant amounts of methane. A determination of methane emissions by 253 vertebrate species confirmed that competence for intestinal methanogenic bacteria is shared by related species and higher taxa, irrespective of different feeding habits. In “methanogenic” branches of the evolutionary tree, a variety of differentiations of the large intestine evolved and, in some cases, differentiations of the foregut. In contrast, the lack of competence for methanogens in chiropterans/insectivores and carnivores apparently has precluded the evolution of specialized fermenting differentiations of the digestive tract. Our observations reveal that the presence of intestinal methanogenic bacteria is under phylogenetic rather than dietary control: competence for intestinal methanogenic bacteria is a plesiomorphic (primitive-shared) character among reptiles, birds, and mammals. This competence for methanogenic bacteria has been crucial for the evolution of the amniotes. 相似文献
4.
Food habits of sika deer on the Boso Peninsula,central japan 总被引:6,自引:0,他引:6
The rumen contents of sika deer (Cervus nippon Temminck) on the Boso Peninsula, central Japan, were analyzed to identify local, sexual and age-specific differences in food
habits. Graminoids and woody plants were the primary foods throughout the year. In winter, the use of evergreen broad leaves
increased. The food habits of sika deer on Boso Peninsula were intermediate between those of populations inhabiting northern
and southern Japan. Acorns, mainlyLithocarpus edulis Nakai, were consumed in fall and winter with a peak in October. Since the availability of acorns is not influenced by foraging
in previous years, it can be regarded as a stable food supply and hence may be important for deer on the Boso Peninsula. The
local difference between the Amatsukominato (AT) area, having a large plantation ofLithocarpus producing acrons, and the Kamogawa-Katsuura (KK) area, having a small plantation ofLithocarpus, was recognized; seeds and fruit were consumed more in AT than in KK in fall and winter. Males consumed more seeds and fruit
than females at both sites in fall. This can be attributed to sexual differences in nutritional requirement. 相似文献
5.
The food habits of the Iriomote catFelis iriomotensis were studied by analyzing 177 feces collected monthly from 1987 to 1988. A total of 26 food items were identified. The frequency
of lizards and frogs in the feces was higher than those of mammals and birds. The food habits changed greatly seasonally.Eumeces skinks were fed on most frequently, and found in the feces with a similar high frequency occurrence in March–April and July–September,
while their proportion to the total number of food items was larger in March–April than in July–September. The cats fed on
larg-sized skinks, adultEumeces kishinouyei, more in March–April than in other seasons. The number of skinks sighted in the course of a road census was greater from
March to August, and large-sized skinks were sighted more in March–April than in July–August. The cats fed selectively on
large-sized skinks in every season. Therefore, changes in the food habits depended on the food availability. Characteristics
of food habits in the Iriomote cat are discussed in comparison with the food habits of other felids in temperate and tropical
regions. 相似文献
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本研究于2021年3~9月,采用目标观察和全事件记录法,对广西防城港市钦州湾八路水湿地黑翅长脚鹬(Himantopus himantopus)的繁殖习性进行全过程观察记录。黑翅长脚鹬的栖息生境主要在盐田、虾塘和鱼塘,而巢主要分布在盐田生境。共发现39巢,雌雄共同营巢,按照主要巢材将其巢分为干草巢、碎石巢、泥皮巢和牛毛毡草巢4种;巢材包括禾本科(Gramineae)和莎草科(Cyperaceae)植物以及碎石、贝壳等;巢外径为(23.3±10.7)cm,巢内径为(11.2±1.9)cm,巢深为(1.6±0.5)cm,巢高为(6.5±4.3)cm(n=39);筑巢需(3±2)d(n=6)。窝卵数2~4枚,1~2 d产1枚卵,7 d内产完满窝卵(n=6)。雌雄均参与孵卵,雄性孵卵时间比雌性长,但二者差异不显著(P> 0.05),雄性(8 550±245.9)min,雌性(7 530±263.3)min,孵卵期为(25±2)d(n=6)。育雏期(26±3)d(n=6),雌雄轮流育雏,育雏前、中期(雏鸟1~20d日龄),雌性育雏时间比雄性长,是雄性的2倍,育雏后期(雏鸟大于20 d日龄),... 相似文献
8.
Richard D. Olson Abba J. Kastin Thomas K. von Almen David H. Coy Gayle A. Olson 《Peptides》1980,1(4):383-385
Twenty-four male albino rats were given daily intraperitoneal injections of vasoactive intestinal polypeptide (VIP), motilin, human gastrin I (1–17) or the diluent control vehicle at a dose of 100 μg/kg for four consecutive days and food intake, water intake, body weight, and running wheel activity were determined every 24 hours. Animals injected with motilin or human gastrin I (1–17) exhibited decreased food intake relative to those injected with VIP or diluent, which did not differ from each other, although food intake increased reliably over days. The mean water consumption followed the same pattern as that of food intake. As expected from the above results, VIP produced weight gains as compared with rats injected with motilin or gastrin but not reliably more than after diluent. A reliable effect of trials for weight gain was the greatest on day three. Running wheel activity was not affected by injections of human gastrin I (1–17), motilin, or diluent but was reliably decreased by VIP. No significant differences existed across days. Although the results indicate that GI peptides may affect behavior when injected systemically and that like other peptides they have multiple effects, caution is urged in the interpretation of behavioral results at this time. 相似文献
9.
Abundances of white sucker, 100–500 mm FL, were not significantly different among the epilimnia, metalimnia and portions of the hypolimnia shallower than 20 m in each of two lakes. However, small suckers < 200 mm were captured most frequently in the epilimnion and no white suckers were captured in the deepest region, 20–38 m, of the two lakes. White suckers consumed prey from all three temperature zones in each lake. Prominent food items were Hyalella azteca and the chironomid larvae Heterotrissocladius, Djalmabatista and Procladius. Despite differences in relative densities of benthic invertebrates among thermal zones of the two lakes, suckers in neither lake foraged exclusively on prey of epilimnetic origin. Suckers captured in the metalimnia foraged on invertebrates that were common to all three thermal zones. And, only 0–4% of the suckers captured in the hypolimnia of the two lakes contained prey that were unique to the epilimnia. Suckers caught in the hypolimnia mainly consumed deep water invertebrates; 83% of the suckers foraged in the metalimnion and hypolimnion of Islets Lake and 45% foraged in the hypolimnion in Burnt Island Lake. Consequently there was little evidence of a massive inshore feeding migration followed by a post-feeding return to the hypolimnion. Northern pike and lake trout rarely fed on white suckers in these lakes and thus piscivory was an unlikely factor in the observed distribution of suckers. 相似文献
10.
A year-round study was conducted to examine feeding habits and food resources of the filter-feeding Trichoptera Arctopsyche grandis and Brachycentrus occidentalis along a regulated mountain stream gradient. There was a well defined longitudinal species replacement with A. grandis reaching maximum densities 2.3 kilometers below the impoundment, and concomitant with its decline downstream was an increase in B. occidentalis. At all sampling sites the < 75 µm organic seston fraction usually consisted primarily of diatoms (>70%, by areal estimate on microscope slides), whereas the 75–250 µm and > 250 µm seston fractions were predominantly composed of detritus (> 80 %). B. occidentalis larvae consumed primarily detritus and diatoms (> 70 % of the diet), while A. grandis ingested a variety of materials with animals, detritus and/or filamentous algae often constituting > 80% of the diet. Animal material was over-represented in the diets of both species when compared with amounts in the seston. Feeding habits provided partial explanations for the distinct longitudinal distribution patterns of filter-feeding Trichoptera observed in the regulated river. 相似文献