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951.
We investigated the origin of dissolved free amino acids (DFAA) in stream water focusing on biofilms in the river bed by means
of incubation experiments in the laboratory. Stones were placed in the Toyohira River, Hokkaido, Japan, for 3 months, allowing
formation of biofilms, and then incubated for 24 h in the laboratory at stream water temperature. After incubation, the composition
and concentrations of DFAA in the incubation solution and total hydrolyzed amino acids (THAA) in biofilms were measured by
high-performance liquid chromatography. The amount of chlorophyll a (Chl. a) and the number of bacteria were also measured. The DFAA concentration increased greatly in the biofilm incubation solution,
but the DFAA composition (mol %) did not change relative to the inception of incubation, where it was similar to stream water.
There was no correlation between the increase in DFAA concentration and the THAA concentration, Chl. a amount, or the number of bacteria in biofilms. These results suggest that biofilms are one of the major sources of DFAA in
stream water. 相似文献
952.
Yoichi Miyake Shingo Kimura Tomohiko Kawamura Takashi Kitagawa Motoyuki Hara Hiroshi Hoshikawa 《Fisheries Science》2010,76(4):561-570
Most juveniles of Haliotis discus hannai have been found to be descendants of wild individuals, although most adults were artificially produced (released) individuals
as a result of restocking inside the refugium located near the head of Oshoro Bay, Hokkaido, Japan. To estimate the larval
supply from released and wild individuals into the refugium and to compare the suitability of locations as larval sources,
we simulated larval dispersal using a coupled hydrodynamic and particle-tracking model. The simulation results indicated that
more larvae may be supplied from the wild adults inside the bay to the refugium than from the released adults. These results
are consistent with the observed high abundance of wild juveniles in the refugium. Most larvae from the refugium were predicted
to disperse out of the bay. We found that larval retention in the bay was at least one order of magnitude higher than that
in the refugium. Thus, it may be more effective in terms of self-replenishment and reproduction if the refugium were to be
expanded to the bay scale. There were only minor differences among the compared sites at the head of the bay in terms of their
suitability as larval sources. Consequently, the establishment of new refugia in this area could be expected to provide an
effectiveness equal to that of the current refugium. 相似文献
953.
Vu Minh DUC Rina KAKIUCHI Takeshi OBI Hiroshi ASAKURA Takehisa CHUMA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2022,84(3):414
This study aimed to analyze the incidence of Campylobacter in a small-scale chicken meat processing plant producing “chicken-sashimi”, and determine the effectiveness of surface burning as a treatment during processing. The most probable number (MPN) method was used to analyze the load of Campylobacter in 48 samples from four different processing steps (de-feathering, chilling, surface burning, and final-products; 12 samples each). We found the highest load of isolated bacteria in chicken skin after de-feathering. Campylobacter was not detected after the surface burning step despite a large load of bacteria present in the cecum content. Campylobacter was absent in the final products. Adequate surface burning can avoid Campylobacter contamination of chicken sashimi in the processing plant by applying the external stripping method. 相似文献
954.
955.
Evaluation of aroma compounds contributing to muskmelon flavor in Porapak Q extracts by aroma extract dilution analysis 总被引:1,自引:0,他引:1
Hayata Y Sakamoto T Maneerat C Li X Kozuka H Sakamoto K 《Journal of agricultural and food chemistry》2003,51(11):3415-3418
The flavor of the Miyabi variety of Japanese muskmelon was extracted according to the Porapak Q column method (PQM) and evaluated by using aroma extract dilution analysis (AEDA) method. The overall odor of the PQM extracts was perceived as having a natural muskmelon-like odor, suggesting that the PQM was able to extract volatile compounds in muskmelon fruit without degradation of original flavor. Forty-six odorant compounds [Kovats index (KI), 961 < or = KI < or = 2605] were found by GC-sniffing in PQM extracts, confirming the effectiveness of PQM in trapping a wide range of volatile compounds in muskmelon flavor. The 46 odorants could be divided into three groups on the basis of their odor attributes: fruity note (KI < 1300); green, grassy, or cucumber-like note (1300 < KI < 2020); and sweet note (KI > 2020). When the original extracts were diluted in AEDA analysis, seven odorants could still be detected by GC-sniffing at a flavor diluation (FD) factor of 128 or above: one had a fruity note (compound 3); four had a cucumber-like, green, or grassy note (compounds 12, 17, 21, and 23); and two had a sweet note (caramel-like or yakitori-like) (compounds 32 and 34). 相似文献
956.
957.
Toshiyuki Takano Tomomi Murakami Hiroshi Kamitakahara Fumiaki Nakatsubo 《Journal of Wood Science》2008,54(4):332-336
Formaldehyde adsorption and release tests of karamatsu (Larix leptolepis) bark and bark ingredients were performed. Karamatsu bark had good formaldehyde adsorption ability that was better than microcrystalline
cellulose. An acetone-soluble fraction from karamatsu bark, which might contain bark tannin, had excellent formaldehyde adsorption
ability, and was found to release a trace amount of the adsorbed formaldehyde, suggesting that its formaldehyde adsorption
was predominantly due to chemical adsorption. It was confi rmed that the acetone-soluble fraction played an important part
in formaldehyde adsorption by karamatsu bark. An acetone-insoluble fraction from karamatsu bark had good formaldehyde adsorption
ability as well as the bark, in spite of the residue after the removal of the acetone-soluble fraction. 相似文献
958.
959.
Mechanism of formaldehyde adsorption of (+)-catechin 总被引:1,自引:1,他引:0
Toshiyuki Takano Tomomi Murakami Hiroshi Kamitakahara Fumiaki Nakatsubo 《Journal of Wood Science》2008,54(4):329-331
The reaction of (+)-catechin with formaldehyde vapor was investigated as a model reaction of formaldehyde adsorption of (+)-catechin.
It was found by H nuclear magnetic resonance spectroscopy, matrix-assisted laser desorption/ionization time-of-flight mass
spectrometry, and gel permeation chromatography of the product that the vapor reaction of (+)-catechin with formaldehyde without
a solvent or a catalyst proceeds via methylolation, condensation, and polymerization. This is the same as the reaction in
a solvent in the presence of an acid or a base. The formation of polyoxymethylenes such as paraformaldehyde was not confirmed. 相似文献
960.