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441.
442.
REBECCA L. BOULTON JULIE L. LOCKWOOD MICHELLE J. DAVIS ARTUR PEDZIWILK KELLY A. BOADWAY JOSHUA J. T. BOADWAY DAVID OKINES STUART L. PIMM 《The Journal of wildlife management》2009,73(4):530-537
ABSTRACT We investigated survival for male, female, and first-year Cape Sable seaside sparrows (Ammodramus maritimus mirabilis, hereafter sparrows), a federally endangered bird restricted to the Florida Everglades, USA. Accurate estimates of survival are critical to improve management decisions and population estimates for this and other threatened species. We used Program MARK to evaluate effects of age, sex, population membership, temporal variation, and ground-water levels on annual survival from mark-recapture data collected across 3 sparrow populations from 1997 to 2007. We found little evidence that annual survival rates differed between the populations or across ground-water levels, but we found high variability between years for both adult and juvenile survival. Our results revealed female sparrows experienced 14–19% lower survival than males. Sparrows experienced much lower survival during their first year of life and were short-lived (2–3 yr). Our results highlight sparrows' susceptibility to population declines and suggest that management actions aimed at increasing survival may be effective for this species' management. 相似文献
443.
A colony of moths recently studied and published for control of Schinus terebinthifolia is found not to be Oxydia vesulia (Cramer) but instead a possibly undescribed species. Three species were originally collected. The unknown species is diagnosed by morphology and COI and compared to congeners. 相似文献
444.
Min B. Rayamajhi Thai K. Van Paul D. Pratt Ted D. Center 《Wetlands Ecology and Management》2006,14(4):303-316
Melaleuca quinquenervia dominates large areas of the Florida Everglades in the southeastern USA where it has transformed sedge-dominated marshes
into melaleuca forests. Despite its prevalence, very little is known about the ecology and stand dynamics of this invasive
tree. We delineated large-, intermediate-, and small-tree stands in non-flooded, seasonally flooded and permanently flooded
areas of Florida in 1997, measured their biological attributes, and then quantified litterfall components for 3–4 year periods.
Melaleuca wood components and mature seed-capsules comprised the largest and the smallest portions of aboveground biomass,
respectively, while leaves, fine stems, mature fruits, bud scales, floral structures, and residues represented decreasingly
smaller fractions of the litter during the succeeding year. Dry weight proportion of leaves in litter was greatest (80.9%)
in non-flooded and least (69.1%) in permanently flooded habitats. It was also greatest in small (85.6%) and least in large
(64.7%) tree stands. Reproductive structures and mature-fruit fractions in litter were highest in large-tree stands whereas
the bud-scale fraction showed no relationship to tree size. Seasonally flooded habitats had the most litterfall, wherein small-,
intermediate-, and large-tree stands generated 0.662, 0.882, and 1.128 kg m−2 yr−1, respectively. Dry weight of stems, leaves, bud–scales, floral structures, and mature fruit fractions in litter increased
as the predominant size of the trees in the stand increased. Total annual litter production was highest during 1999–2000.
Leaf fall occurred year-round with maximal amount during April, July, and October. Highest amounts of bud scales and floral
structures fell during October–January, which corresponded with flushes of vegetative growth and major flowering events. Overall,
melaleuca alone accounted for nearly 99% of the total litterfall dry weight in all habitats and months sampled. The amount
of non-melaleuca litter was greater in small-tree stands than in intermediate- or large-tree stands. Litterfall data of this
nature will be helpful in detecting changes occurring in melaleuca canopies in response to biological control impact and in
prescribing site-specific management strategies. 相似文献
445.
446.
The cellular electrophysiology of left ventricular preparations from guinea pig hearts was studied 1 hour, 24 hours, and 4-6 weeks after myocardial infarction produced by 6-8 single ties of the distal left coronary artery system or after sham operation. Microelectrode recordings were used to monitor cells from the endocardial surface of each preparation in tissue bath. All coronary ligated preparations displayed accelerated spontaneous activity compared to normal and sham operated preparations. Single and multiple premature ventricular depolarizations occurred frequently in coronary ligated and rarely in normal and sham operated preparations. Premature stimuli delivered to areas overlying and bordering the area of infarction, induced short bursts of self-terminating rapid repetitive ventricular activity in 4 of 8 (50%) acute (1-hour), 5 of 9 (55%) subacute (24-hour), and 14 of 20 (70%) healed (4-6-week) infarcted preparations. Such activity could not be induced in normal and sham operated preparations. The preparations with healed infarction were unique in that they demonstrated runs of self-terminating repetitive ventricular activity which occurred spontaneously or was inducible with premature stimulation. Recordings from multiple sites in acute, subacute, and healed preparations revealed a variety of transmembrane action potential abnormalities (i.e., reduced action potential amplitude and resting potential, decreased and increased action potential duration, and depressed maximum rates of phase 0 depolarization) in cells overlying and bordering areas of infarction. Only Purkinje fiber action potentials were recorded over the healed infarcts. These data demonstrate that a spectrum of electrophysiological alterations occur in response to ischemic injury and persist after healing of the injury in this new model of myocardial infarction utilizing the guinea pig. 相似文献
447.
A method is presented for the precolumn derivatization and subsequent high-pressure liquid chromatographic separation of 3-methylhistidine from urine and plasma. The solvent system is 10 mm sodium phosphate (pH 7.5) and acetonitrile. The elution can be performed isocratically and requires less than 10 min. Both fluorescent and ultraviolet detection may be utilized. This method is at least 103 times more sensitive than conventional ion-exchange chromatography using ninhydrin. 3-Methylhistidine determinations performed on plasma and urine samples from normal volunteers correlated well with published literature values. 相似文献
448.
A patient with severe disabling recurrent aphthous stomatitis (RAS) was treated with four different preparations of oral human transfer factor (TF), as well as placebo, following a double-blind protocol. Two of the TF preparations had a significant effect upon the course of the patient's illness by prolonging the interval between attacks and decreasing the severity of attacks. No side effects attributable to any of the preparations were noted by the patient. Thus, some but not all preparations of human transfer factor given orally are an effective therapy for RAS. 相似文献
449.
Abstract. The commercial development that threatens the biodiversity of coastal habitats is particularly severe along the sandy shores of subtropical Florida. The objective of our study was to test the applicability of the equilibrium theory of island biogeography to Cayo-Costa Island, the largest protected barrier island remaining in peninsular Florida. Our null hypothesis was that there would be no change in the number and composition of native vascular plant species on Cayo-Costa 15 years after the first inventory of the island's flora. Our reinventory documents a total of 230 native species in 1990–92 compared to 255 native species in 1975–77. Immigrants were represented by twenty-eight new species, while extinctions totalled fifty-three species. These results indicate a turnover rate of approximately 2.7 species yr-1 with an extinction rate of 3.5 species yr-1 and an immigration rate of 1.9 species yr-1 . The net loss of 1.6 species yr-1 suggests a non-equilibrium condition that is not readily explained by changes in habitat diversity associated with the documented patterns of shoreline erosion and deposition. Cayo-Costa's net loss of twenty-five native species (including one tree species and four shrub species) was localized mainly in those habitats where there had been a significant increase in the relative abundance of the naturalized weedy exotic species Schinus terebinthifolius and Casuarina equisetifolia . We conclude that the spread of naturalized weedy species limits the applicability of the equilibrium theory of island biogeography to species-rich subtropical barrier islands, even in cases where the islands are protected from human disturbance. 相似文献
450.
The relative importance of input from chemoreceptors on the medial versus the lateral antennular flagellae of the spiny lobster, Panulirus argus, in olfactory orientation is examined. Ablation experiments show that input from the lateral filament, specifically the aesthetase tuft of the lateral filament, is necessary and sufficient to trigger searching behaviour in this organism when stimulated with a gradient of dilute shrimp extract. P. argus locates the odour source by using this lateral filament input in both tropotactic and klinotactic comparisons of odour intensities. 相似文献