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101.
Shogo Moriya Shunpei Sato Moongeun Yoon Tomonori Azumaya Shigehiko Urawa Akihisa Urano Syuiti Abe 《Fisheries Science》2009,75(2):359-367
More than 1,000 age-identified chum salmon Oncorhynchus keta collected at 23 stations in the Bering Sea and the North Pacific Ocean in June to July 2003 were used to estimate their origin
of stocks using a DNA microarray developed for analyzing the mitochondrial (mt)DNA haplotypes. The observed haplotype distribution
was nearly the same as that reported previously for fish collected in September 2002 and 2003 in the present surveyed areas.
A conditional maximum-likelihood method for estimation of stock compositions indicated that the Japanese stocks mainly distributed
in north central Bering Sea, whereas the Russian stocks were mainly in western Bering Sea. The North American stocks were
abundant in eastern Bering Sea and around the Aleutian Islands. Such an area-specific stock composition was not significantly
different between mature and immature fish. Thus, the combined results of 2 years suggest that the distribution of chum salmon
is nonrandom in the surveyed areas in summer and autumn, and that fish of the same origin migrate together to the same area
irrespective of age. 相似文献
102.
The spawning grounds of the chub mackerel (Scomber japonicus) and spotted mackerel (Scomber australasicus) in the East China Sea were estimated based on catch statistics of the Japanese large- and medium-type purse seine fishery
from 1992 to 2006. Biometric data were obtained from specimens caught by purse seiners in the East China Sea from 1998 to
2006. Gonadosomatic index (GSI) at 50% sexual maturity of chub mackerel and spotted mackerel females was 2.5 and 2.6, respectively.
Using this criterion for GSI, chub mackerel larger than 275 mm and spotted mackerel larger than 310 mm in fork length were
considered to be mature. Mature chub mackerel was observed in the area of 15–22°C sea surface temperature (SST), and mature
spotted mackerel was observed in the area of 17–25°C SST. The spawning period of chub mackerel ranged from February to June,
and that of spotted mackerel ranged from February to May in the East China Sea. The spawning grounds were estimated from the
distributions of catch per unit effort (CPUE) of spawners and SST. As a result, the spawning ground of chub mackerel was estimated
to be in the central and southern part of the East China Sea and the area west of Kyushu in February, March, and April, and
in the central part of the East China Sea, the area west of Kyushu and Tsushima Straight in May, and in Tsushima Straight
and western part of the Sea of Japan in June. The spawning ground of spotted mackerel was estimated to be in the central and
southern part of the East China Sea and southern coastal area of Kyushu in February, March, and April, and the central and
southern part of the East China Sea and the area west of Kyushu in May. 相似文献
103.
We examined the ability of salmon growth hormone (sGH) in sodium alginate (SA) gel to accelerate the somatic growth of juvenile
abalone, Haliotis discus hannai, by feeding. After the feeding of sGH at 50 μg or 100 μg in 350 mg SA gel, immunoreactivity to sGH in body fluid was maximal
after 12 h, and was still detectable at 24 h. No immunoreactivity was observed in the control group. Following the feeding
of sGH at 0.5 mg or 5 mg/8 g of SA gel at 7- and 14-day intervals, there was a greater increase in shell length and body weight
than in the control. In abalone, sGH can be transported from food into the circulatory system and subsequently improve somatic
growth. 相似文献
104.
Todd David Sink Sathyanand Kumaran Rebecca T. Lochmann 《Fish physiology and biochemistry》2007,33(3):189-193
Baitfish such as golden shiners are subjected to stress during harvesting, grading, and transport. Their small size makes
it difficult to measure the stress response with the biological indicator cortisol using conventional assay methods for plasma.
This paper examines the development and validation of methods for whole-body cortisol extraction from individual baitfish.
Three types of extracts were tested: (1) an ethyl ether unaltered extract (UA); (2) an extract reconstituted in phosphate
buffered saline (PBS); (3) an extract that had been increased in volume by the addition of food-grade vegetable oil (VO).
These extracts were evaluated using validation tests with radioimmunoassays (RIA) and enzyme-linked immunosorbent assays (ELISA).
The UA extract produced inadequate volumes of extract for multiple assays and could not be used for the determination of cortisol
in a single fish. The PBS reconstitution method failed the precision recovery of serial dilutions (62.3%), linearity (R
2: 0.7864), and parallelism validation tests. The VO volume-boosting method passed all validation tests [intra-assay coefficent
of variation (%CV): 16.3 for ELISA and 5.9 for RIA; inter-assay %CV: 10.3; spiked recovery: 102.0%; dilution recovery: 93.0%;
linearity R
2: 0.9435; log of serial dilutions was parallel] and provided enough extract for multiple assays from an individual baitfish.
Based on these results, we conclude that the VO volume-boosting method presents a means for determining cortisol from individual
baitfish using either RIA or ELISA assays. 相似文献
105.
Increased abundances of a number of seabird species have been found in areas of mussel longline aquaculture (compared to control
sites) in a recent study at Bantry Bay, southwest Ireland. The aim of this study was to investigate whether this form of mussel
aquaculture also affects the activity budgets and foraging behaviour of these seabirds. Scan-sampling was used to compare
seabird activity budgets between three areas of mussel longline aquaculture and three control sites. Foraging activities of
Great-Northern Divers Gavia immer, an Annex 1 species under the Euopean Union's Birds Directive, were also compared between sites using focal sampling. The
behaviour of gulls (Larus sp.), Cormorants Phalacrocorax carbo, Shags Phalacrocorax aristotelis and Great-Northern Divers (but not auks, Alcidae) differed significantly between areas of mussel aquaculture and control
sites in this study. Mussel suspension buoys were heavily utilized by gulls, cormorants and shags as safe perching platforms
for preening activities. Gulls also fed extensively on epifauna attached to the buoys. Great-Northern Divers spent more time
snorkelling (head submerged in search of food) in mussel sites than in the control sites, however dive duration and visible
foraging success rates did not differ significantly between sites. Overall, the environmental impact of mussel suspension
culture appears to be positive or neutral on marine bird species occurring at this study site. 相似文献
106.
107.
This study was carried out to investigate the influences of feeding frequency of extruded pellet and moist pellet on growth
and body composition of juvenile flounder (initial mean weight 6.3 g) in sub optimal water temperatures. A 2 (diets: extruded
pellet and moist pellet)×2 (feeding frequencies: two and three times daily)×2 (water temperatures: 12 and 17°C) factorial
design with three replications was used. After 60 days of feeding, the feeding frequency did not significantly affect growth
performance of fish. Weight gain, daily feed intake, feed efficiency and protein efficiency ratio were significantly (P<0.05) higher for fish reared at the higher water temperature. At the same water temperature, weight gain, feed efficiency,
and protein efficiency ratio were significantly (P<0.05) higher for fish fed the extruded pellet than moist pellet. The results of this study indicate that feeding frequency
of two times daily is sufficient for optimal growth of juvenile flounder when reared in suboptimal water temperatures, and
an increase in water temperature from 12 to 17°C improved growth and feed efficiency. 相似文献
108.
Masatomi Hosoi Chuya Shinzato Masaya Takagi Shoko Hosoi-Tanabe Hideki Sawada Eri Terasawa Haruhiko Toyohara 《Fisheries Science》2007,73(2):385-394
ABSTRACT: Taurine is the primary osmolyte in marine molluscs, whose cellular osmo-conforming process is vital for environmental adaptation because of a lack of osmotic homeostasis. Here, cDNA cloning and expression, and functional analyses of taurine transporter (TAUT) from the giant Pacific oyster are reported on. The deduced amino-acid sequence of oyster TAUT (oyTAUT) showed 47–51% identity to those of vertebrate TAUT, whereas identity among the vertebrates is 78–95%. Functional analysis of oyTAUT expressed in Xenopus oocytes revealed that oyTAUT has a lower affinity and specificity for taurine and a requirement for higher NaCl concentration, compared with vertebrate TAUT. Taken together with similar functional properties of TAUT from mussel, indicated by our previous study, it is possible that these functional features reflect the internal environment of the molluscs (i.e. higher taurine and NaCl concentrations). Oyster taurine transporter mRNA expression was induced by not only hyper-osmotic stress, similar to other TAUT, but also hypo-osmotic stress. It is speculated that the expression in response to hypo-osmotic stress was induced by a substantial decrease in tissue taurine content following the decrease in the internal osmolality. 相似文献
109.
Recording cerebellar neuron activities in swimming goldfish 总被引:1,自引:0,他引:1
ABSTRACT: Neuronal activities were investigated in the cerebellum of immobilized and swimming goldfish Carassius auratus . Extracellularly recorded neural activities of the cerebellum in immobilized goldfish were characterized and classified into five types. Based on the waveforms and recording depths, these five neural activity types were estimated to originate from three identified classes of cerebellar neurons: Purkinje cells, eurydendroid cells, and granule cells. Chronic recording of cerebellar neuron activities in unrestrained goldfish was performed for more than 100 h. During the chronic recordings, a submersible amplifier attached to the goldfish head, and a multielectrode array developed for the present study were used. Neuronal activities in the cerebellum of free-swimming fish could also be classified into five types as in the immobilized condition. Firing patterns of two neurons identified as Purkinje cells and eurydendroid cells were analyzed during turning movements of the goldfish. The firing patterns of these neurons changed in relation to turning movements. Although some improvements are required, the chronic recording method developed in the present study can be applied to further investigations concerning the direct relationship between brain neural activities and certain behavior. 相似文献
110.