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141.
Maki Ishiki Hideaki Sakihama Seizen Agata Akira Tokuyama 《Water, air, and soil pollution》2009,198(1-4):111-124
The chemical characteristics of the Urauchi River water in Iriomote Island National park, Okinawa, Japan have been studied. Concentrations of PO4 3?, NO2 ?, and NH4 + were barely detectable. We compared the concentration ratios of Mg2+/Na+, HCO3 ?/Na+, and Ca2+/Na+ in the Urauchi River to those of 60 large rivers in the world and indicated that the chemical composition of the river is most likely formed by the binary mixing of sea salt components and silicate rock weathering components. Although rock weathering in the catchments area is driven by both H2CO3 and H2SO4, the role of H2CO3 is dominant. The percentages of the concentration of each cation in the river water are almost the same as those of other rivers with drainage areas consisting of silicate rock and sandstone. Thus, the Urauchi River shows the typical chemical characteristics of a river in a silicate rock area that includes sandstone. 相似文献
142.
Viliame Waqalevu Akinobu Honda Hideaki Matsui Kazuhiro Shiozaki Tomonari Kotani 《Fisheries Science》2018,84(6):1037-1049
Two common live feeds, the Brachionus plicatilis species complex SS-type and L-type were used to assess whether there were any differences in protein hydrolysis and digestive trypsin activity in first feeding Japanese flounder. There were no significant differences in hydrolysis activity at 2, 3 and 7 days after hatching (DAH). At 5 DAH, hydrolysis activity was significantly higher in larvae fed SS-type (p?<?0.05) at 50 kDa in 1.5- and 3-h incubation whereas L-type treatment had not completely hydrolyzed the proteins after 3 h at the same molecular weight. Larvae fed SS-type had significantly higher (p?<?0.05) trypsin activity at 3, 5, 6, 7 DAH. Contribution of live prey to trypsin fraction in larvae showed significantly higher (p?<?0.05) fraction for SS-type at 5 DAH (2.18?±?0.44%) and 6 DAH (2.04?±?0.29%) and the effect of exogenous trypsin from live prey was relatively low when compared to the total trypsin activity in larvae. This study discusses the differences in ability to digest proteins in Japanese flounder when fed different rotifer morphotypes and highlights the adaptability of this species to alternative rotifer morphotypes during its early developmental stages. 相似文献
143.
Kurata Y Katsuta O Doi T Kawasuso T Hiratsuka H Tsuchitani M Umemura T 《The Japanese journal of veterinary research》2003,50(4):175-183
In an attempt to establish a primate model of chronic cadmium (Cd) toxicosis, we ovariectomized cynomolgus monkeys and treated with CdCl2 by repeated intravenous injections for 13 to 15 months. The animals showed an increase in blood glucose from Month 10 and a decrease in blood insulin at Month 11of the Cd-treatment. Histopathological examination of the Cd-treated animals revealed islet atrophy with reduction in islet number and vacuolation of the islet cells, whereas there was no remarkable change in the acinar cells of the exocrine pancreas. In histomorphometrical examination, insulin-positive areas in the islets were significantly decreased, accompanying a relative increase of glucagon-positive areas. Large amounts of Cd accumulated in the pancreas, and metallothionein (MT), a Cd binding protein, was localized in the islets of Cd-treated animals. The present study demonstrated that the chronic intravenous injection of Cd to cynomolgus monkeys induced the accumulation of the metal in the pancreas, degeneration of islet B cells and the diabetic clinical signs. Therefore the islet B cell is one of the major targets of the chronic Cd poisoning in monkeys. 相似文献
144.
Expression of mRNA for sodium-glucose transporter 1 and fatty acid translocase in the ruminant gastrointestinal tract before and after weaning 总被引:1,自引:0,他引:1
Hideaki HAYASHI Tomo YONEZAWA Takeshi KANETANI Fuminori TERADA Kazuo KATOH Yoshiaki OBARA 《Animal Science Journal》2005,76(4):339-344
The mRNA expression of sodium‐glucose transporter 1 (SGLT1) and fatty acid translocase (CD36) in the gastrointestinal tract of Holstein cattle and Saanen goats before and after weaning was investigated. Before weaning, the expression of both SGLT1 and CD36 was highest in the jejunum, relative to the other parts of the gastrointestinal tract in both species. The expression of SGLT1 and CD36 in the duodenum was second highest in the goats. After weaning, SGLT1 and CD36 expression in the small intestine significantly decreased in both species. The expression of both types of transporters was also detected in the forestomach. From these results, it was concluded that the jejunum is probably the major absorption site for glucose and long‐chain fatty acids before weaning, and that the expression of both types of transporters decreases after weaning in cattle and goats. 相似文献
145.
Oyamada T Tanaka H Park CH Ueki H Komiya T Arai S 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2007,69(11):1155-1161
Of 197 cases of canine oral malignant melanoma, 29 cases with myxoid, cartilage, and osteoid formation were studied pathologically and immunohistochemically. Tumor tissues were classified into spindle cell type (13 cases), epithelioid cell type (1 case), and mixed type (15 cases). Myxoid matrixes (29 tumors) were formed mainly in the tissues of spindle cell type and were positive for Alcian blue (pH 2.5). Cartilaginous matrixes (12 tumors) were formed in the myxoid tumor tissues. The morphology of atrophied neoplastic cells, which were embedded in the cartilage cavities, significantly differed from that of spindle cells proliferating in surroundings. There were reticular areas in the process of transitioning from myxoid to cartilaginous matrixes. Osteoid matrixes were not continuous with myxoid or cartilaginous matrixes, and arose as eosinophilic trabeculae in the dense collagenous connective tissues. A calcified bone trabecula was present among the osteoid trabeculae in a case. Melanin-producing melanocytes were proliferating in the collagenous matrixes, while amelanotic cells were in the osteoid matrixes. Immunohistochemistry demonstrated proliferating neoplastic cells as melanocytes. All cells in/out of these three matrixes were positive for Melan-A, S-100 protein, NSE, and vimentin. From these results, it is suggested that cartilage and osteoid matrixes are produced by dedifferentiated melanocytes. 相似文献
146.
Yuuki Kawabata Kimio Asami Masato Kobayashi Taku Sato Koichi Okuzawa Hideaki Yamada Kenzo Yoseda Nobuaki Arai 《Fisheries Science》2011,77(3):345-355
In this study, the effect of shelter acclimation on the post-release movement and putative predation mortality of hatchery-reared
black-spot tuskfish Choerodon schoenleinii was examined using acoustic telemetry. We acclimated four 1-year-old fish to shelters in cages before release and compared
their movements with six nonacclimated fish. Since it was not possible to compare the behavioral pattern between the former
and the latter fish due to the short periods the latter fish were available to be monitored, we also compared their movements
with those of large nonacclimated fish that were less likely to be preyed upon. Sixty-seven percent of the nonacclimated fish
showed atypical movements before the signals ceased to be detected, a pattern that suggested a predation event had occurred,
whereas none of the acclimated and large nonacclimated fish showed the atypical movements. In addition, the probability of
detection cessation was about 13 times lower in the acclimated than nonacclimated fish. The signal detection patterns suggest
that the acclimated fish utilized night-time shelters from the first night after release, while the large nonacclimated fish
started to utilize shelters several days after release. Therefore, it is likely that the shelter acclimation enhanced the
shelter utilization by tuskfish, possibly decreasing post-release predation mortality. 相似文献
147.
The brain nanopeptide arginine vasotocin (AVT) and its mammalian homolog arginine vasopressin are involved in the regulation
of social and reproductive behavior. We investigated the relationship between social rank formation and the brain AVT system
in the false clown anemonefish (Amphiprion ocellaris), which forms a social rank that leads to sex differentiation in higher-ranked individuals. Tanks of three sexually immature
fish were kept for 90 days and each fish’s behavior was observed once a month. The social rank of each individual was distinguishable
by behavior, but gonadosomatic index (GSI) did not differ significantly. The number of AVT neurons in the magnocellular layer
in the preoptic area (POA) increased in subordinate individuals and declined with increasing hierarchical dominance. These
results suggest that social rank formation modulates AVT production in the brain of the clown anemonefish and may influence
their later sex differentiation. 相似文献
148.
Machiko Kirikae Ryusuke Hatano Hideaki Shibata Yumiko Tanaka 《Water, air, and soil pollution》2001,130(1-4):697-702
We determined proton budgets of surface soils in a deciduous forest (Df) and a coniferous forest (Cf) of Volcanogenous Regosols in Tomakomai, Hokkaido of northern Japan. The total H+ source was 12.9 and 11.6 kmolc ha?1 y?1 at Df and Cf respectively, and the external H+ was 1% at Df and 2% at Cf. The primary H+ sources were vegetation uptake of base cations and nitrification, while the major H+ sinks were release of base cations and NO3 + uptake by vegetation. Leaching incubation experiments using A horizon soils including Df and Cf with NH4 + solutions (5.3, 15.9 mg N L?1) showed that H+ from nitrification was generally higher in the Df soil than Cf soil, and nitrification of Tomakomai Df soil was the highest in both treatments. Results of multiple regression analyses suggested that pHkCl and exchangeable Ca2+ contributed to the H+ generation via nitrification. Leaching experiments with dilute HCl (pH 3.3) revealed that cation release (mainly Ca2+) occurred, and the proportion of release by decrease of exchangeable cations was higher than that by mineral weathering. Mineral weathering in the Tomakomai soil was higher than the other soils. 相似文献
149.
Yuichi?YamaokaEmail author Hayato?Masuya Nobuaki?Ohtaka Hideaki?Goto Shigeru?Kaneko Yoshio?Kuroda 《Journal of Forest Research》2004,9(1):67-74
Ophiostoma species were isolated from bark beetles and Abies mariesii, A. veitchii and A. homolepis attacked by the beetles in Nikko, Tochigi, central Honshu, Japan. One to two Ophiostoma species were frequently isolated from each species of bark beetle. Ophiostoma subalpinum was the most common associate of Cryphalus montanus. Ophiostoma sp. B as well as O. subalpinum was a common fungus associated with Polygraphus proximus. Ophiostoma europhioides was isolated from Dryocoetes hectographus and D. autographus as one of the common associates. Ophiostoma sp. J and Ophiostoma sp. S were frequently isolated from D. autographus and D. striatus, respectively. These fungi seem to have specific relationships with particular bark beetles. Ophiostoma sp. B, Ophiostoma sp. J and Ophiostoma sp. S have unique morphological characteristics and appear to be new species. Five trees of A. veitchii, approximately 43 years old, were inoculated with five Ophiostoma species to assess the relative virulence of the fungi. Ophiostoma subalpinum, Ophiostoma sp. B, and O. europhioides had relatively higher virulence than the other species studied. 相似文献
150.
亚热带常绿阔叶林结构、树种多样性和土壤特性的研究(英文) 总被引:1,自引:0,他引:1
采用样地调查法,对日本冲绳岛北部的亚热带常绿阔叶林的林分结构,树种组成以及土壤特性等进行了调查分析。结果表明,该亚热带林具有林冠低矮、小径木多等特点。林分的平均林冠高度仅10m,平均立木密度达5400株·hm2(≥3.0cmDBH),其中胸径小于10cm的立木占64%。林分胸高断面积为54.4m2·hm-2。30个调查样地共出现树种数(≥3.0cmDBH)达80种,分属31个科。根据树种的重要值,Castanopsis sieboldii和Schima wallichii分别为优势树种和亚优势树种。树种多样性指数(H’)平均达3.63,均衡度指数(J’)为0.71,丰富度指数(S’)为4.72。这些多样性指数都随着优势树种重要值的增加而显著降低。土壤养分测定结果表明,该森林的土壤肥力低,异质性大,并可能存在Al毒害。由相关分析知,林分密度和优势树高均与土壤pH值呈显著正相关关系;多样性指数则与土壤交换性K ,Ca2 以及Ca2 /Al3 比呈显著的正相关,而与土壤有机碳,全氮和磷呈显著的负相关。这些结果说明土壤性质是影响冲绳亚热带常绿阔叶林林分结构和树种组成多样性的重要因素。图3表4参38。 相似文献