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971.
Shin Deguchi Sunao Uozumi Keitaro Tawaraya Hidenori Kawamoto Osamu Tanaka 《Soil Science and Plant Nutrition》2005,51(4):573-576
We examined the effect of a living mulch with white clover on the growth of maize in an Andisol. Maize was grown using a living mulch without fertilizer application, or by conventional cultivation with or without fertilizer application. Although the living mulch did not affect the amount of available phosphate in soil, the phosphorus concentration of maize shoots increased due to the living mulch compared with conventional cultivation without fertilizer application. Arbuscular mycorrhizal (AM) colonization of maize roots was higher with the living mulch than with conventional cultivation. These results suggested that a living mulch with white clover enhanced the phosphorus uptake by maize through AM colonization. 相似文献
972.
Direct Quantitative Analysis of Particulate Aluminum Suspended in Water Using Laser-Induced Breakdown Spectroscopy 总被引:1,自引:0,他引:1
Noriko Yamaguchi Hiroyasu Hotokezaka Shinya Nagasaki Satoru Tanaka 《Soil Science and Plant Nutrition》2005,51(6):911-916
Laser-induced breakdown spectroscopy (LIBS) has been developed as a rapid and easy in situ technique for the analysis of inorganic elements. Qualitative and quantitative determinations of an inorganic element can be achieved by analyzing the wavelength and intensity of the light emitted from the excited atoms arising from breakdown phenomena. Because the energy threshold of breakdown phenomena increases in the order of solid相似文献
973.
974.
The first success of glass eel production in the world: basic biology on fish reproduction advances new applied technology in aquaculture 总被引:1,自引:0,他引:1
Hirohiko Kagawa Hideki Tanaka Hiromi Ohta Tatsuya Unuma Kazuharu Nomura 《Fish physiology and biochemistry》2005,31(2-3):193-199
The eel has long been esteemed as an important food fish in the world, especially in Japan, and has been used as an experimental
fish for many fields of fish physiology. However, the decreases in eel resources have been a serious concern in recent years.
The catches of glass eels as seedlings for aquaculture have shown a long-term decrease in both Europe and East Asia. To increase
eel resources, the development of techniques for artificial induction of maturation and spawning and rearing their larvae
have been eagerly desired. Recent progress of reproductive physiology of fish, especially mechanisms of oocyte maturation
and ovulation in female and of spermatozoa maturation in male, facilitate to establish techniques for hormonal induction of
maturation and spawning in sexually immature eels. With persistent effort to development of rearing techniques of larvae,
we have first succeeded to produce glass eel. These applied techniques are may contribute to understand the basic reproductive
physiology of the eel. 相似文献
975.
Taizo Nishikawa Masato Aritaki Daisuke Shimizu Toshihiro Wada Masaru Tanaka Masatomo Tagawa 《Fisheries Science》2010,76(5):827-831
The mechanism underlying malformation during flatfish metamorphosis is not clear. Here, the relationship between growth before
metamorphosis and the occurrence of malformation after metamorphosis was examined in individuals reared in a single tank.
Otoliths of starry flounder Platichthys stellatus larvae were labeled with alizarin complexone before metamorphosis [12 days after hatching (DAH)]. The positive linear regression
between the lapillus otolith diameter and body length at 12 DAH enabled the estimation of individual larval size after completion
of metamorphosis. At 12 DAH, the average body length of the typical pseudoalbino juveniles was significantly greater (5.37 mm)
than that of the normal juveniles (5.13 mm) (P < 0.01, n = 100). In addition, of the larvae that were estimated to measure less than 4.8 mm at 12 DAH, approximately 80% metamorphosed
into normal juveniles, whereas more than 60% of the larvae that measured more than 5.4 mm became pseudoalbino juveniles. These
results indicate that the larvae that grow rapidly during the first 12 days are more likely to become pseudoalbino individuals
after metamorphosis. 相似文献
976.
Kazufumi Osako Hiroaki Saito Wuyin Weng Koichi Kuwahara Munehiko Tanaka 《Fisheries Science》2009,75(4):1055-1066
To characterize the 22:6 n-3 (docosahexaenoic acid, DHA) levels of the oriental bonito Sarda orientalis, a coastal migratory tuna species, total lipids (TL) of white muscle, dark muscle, liver, pyloric cecum, gonad, and other
viscera were separated into lipid classes, the constituents of TL were quantified, and the fatty acid composition of TL, triacylglycerols
(TAG), phosphatidylethanolamine, and phosphatidylcholine was analyzed. The crude lipid contents of muscle and other organs
were 0.8–3.2% and 2.3–9.1%, respectively. DHA was found in TL of various organs at levels ranging from 19.2% to 27.6% in muscle
and 16.3% to 28.5% in other organs. The levels of DHA in muscle TAG (8.2–16.0%) were lower than or comparable to those in
visceral TAG (6.9–24.0%). These findings did not coincide with those observed in active-migratory tuna species, which accumulate
DHA in their muscle TAG during migration. These findings suggest that the DHA distribution of S. orientalis is different from that observed in active-migratory tuna species, and that the differences may be due to migration type of
the fish. 相似文献
977.
Akihiro Okamura Yoshiaki Yamada Noriyuki Horie Naomi Mikawa Satoru Tanaka Hideki Kobayashi Katsumi Tsukamoto 《Aquaculture Research》2013,44(10):1531-1538
Usual diets for rearing leptocephalus larvae of Japanese eel Anguilla japonica include eggs of the endangered spiny dogfish Squalus acanthias (SE). We investigated the effects of alternative food materials, hen egg yolk (HEY) and exoskeleton‐free (skinned) Antarctic krill (SAK), on the growth and survival of eel larvae. We found that feed comprising whole krill including exoskeleton (WAK) containing higher levels of fluoride (37.89 mg kg?1) was acutely toxic to eel larvae exposed to this alone. In contrast, extract from SAK containing lower concentrations of fluoride (4.25 mg kg?1) showed no apparent adverse effects. Growth of larvae fed a mixture of SE and SAK in a feed trial of 58 days [mean body weight (BW), 6.0 mg] was about twofold higher than that of larvae fed a mixture of SE and WAK (3.2 mg) (P < 0.01). A mixture of HEY and SAK also had some dietary benefits for eel larvae, enabling them to survive for up to 58 days and to grow significantly (mean BW, 2.4 mg), compared with their initial weight (mean BW, 0.2 mg) (P < 0.001). Although additional nutritional improvements are needed, the present results suggest that combination diet HEY and SAK may be a good alternative to SE as an effective diet for eel larvae. 相似文献
978.
Artificial intravaginal insemination using fresh semen in cats 总被引:1,自引:0,他引:1
Tanaka A Takagi Y Nakagawa K Fujimoto Y Hori T Tsutsui T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2000,62(11):1163-1167
To clarify the sperm count required for fertilization by artificial intravaginal insemination (AIVI), twenty-nine female cats were examined. Six male cats aged 2-12 years with normal semen quality, copulation capability, and fertility were used. In AIVI, animals received administration of 250 iu hCG once or 100 iu twice on days 2-4 of estrus to induce ovulation, and were inseminated 15, 20, or 30 hr after the initial hCG administration. The success of ovulation was judged by elevation of the peripheral progesterone level after hCG administration. AIVI was investigated at three sperm counts, 20 x 10(6) (Experiment 1), 40 x 10(6) (Experiment 2), and 80 x 10(6) (Experiment 3), with semen collected by the artificial vagina method. Semen was infused in the vagina under general anesthesia by advancing a 9 cm-long nylon probe with 1.5 mm diameter connected to a 1 ml syringe in the vagina for 3-4 cm. Ovulation was induced in 43 of 45 animals (95.6%). One of 16 animals was fertilized (conception rate: 6.6%) by AIVI in Experiment 1. In Experiments 2 and 3, conception was obtained in six of 18 animals (33.3%) and seven of nine animals (77.8%), respectively, and the mean numbers of kits were 4.0 +/- 0.4 and 3.3 +/- 0.5, respectively, and the mean numbers of kits were 4.0 +/- 0.4 (SE) and 3.3 +/- 0.5, respectively, showing no significant difference. There were no differences in the time of insemination after hCG administration and the conception rate among these groups. Our findings showed that the number of sperm required for fertilization by AIVI of fresh semen in cats was 80 x 10(6). 相似文献
979.
Aluminum has been reported as the active factor of acid soils which is deleterious to plant growth (3, 4, 6, 7). Aluminum in the soil becomes more soluble at low pH and a high concentration of aluminum in the soil solution may be toxic to plants. 相似文献
980.
The purpose of this study was to investigate the causes of changes in acoustic emission (AE) signals corresponding to changes
in grain orientation in routing. Both the AE signals and the state of cutting process were recorded on high-speed video cameras
in an attempt to clarify the relationships between them. Based on the results, it appeared that generated AE was closely related
to the state of cutting, as well as the surface finish. The greater the AE, the more severe the cutting performance for inclination
angles. The greatest AE was generated when machining failures – fuzzy grains – were produced. Concerning the annual ring angle,
the AE count rate, lowest at 0 degrees, slightly increased until 75 degrees, and then rapidly reached its maximum at 90 degrees.
Changes in the slope angle had also an effect on the AE signal. The AE count rate, highest at the 0 degrees, gradually decreased
until 75–105 degrees, and then increased to reach its maximum at 180 degrees. Moreover, there were correlations between the
AE count rate and surface roughness. Therefore, acoustic emission has shown promise for the monitoring of the surface roughness
including various cutting conditions.
Received 23 September 1998 相似文献