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排序方式: 共有153条查询结果,搜索用时 390 毫秒
81.
Shinji Kaneko Noriko Akieda Fumiya Naito Koji Tamai Yasuhiro Hirano 《Journal of Forest Research》2007,12(1):38-44
Rehabilitated forests established about 100 years ago on denuded lands in a hilly granitic area are widespread in the Kyoto–Osaka
area, the second largest megalopolis in Japan. From 2001 to 2003, we monitored the annual nitrogen (N) budget of a rehabilitated
forest watershed dominated by Quercus serrata and Ilex pedunculosa. The ion concentrations of bulk rain in the watershed were similar to those of other watersheds in Japan. The annual bulk
rain input of N ranged from 5.1 to 6.3 kg N ha−1 year−1, and the N deposition from throughfall and stem-flow ranged from 7.5 to 8.2 kg N ha−1 year−1. Estimated annual outputs of N from the stream ranged from 3.3 to 10.6 kg N ha−1 year−1. These results indicate that the amount of N deposition in this area is less than that in urban Tokyo (>10 kg N ha−1 year−1), but the N output of the watershed is comparable with that of the Tokyo area. We discuss the characteristics of N dynamics
in rehabilitated forests, focusing on the biogeochemical processes of this watershed. 相似文献
82.
Md. Nazrul Islam Keisuke Ando Hidefumi Yamauchi Yoshinori Kobayashi Nobuaki Hattori 《Journal of Wood Science》2007,53(5):436-441
Square lumber specimens of laser-incised Douglas fir (Pseudotsuga menziesii Franco) were treated with steam before dipping. Two types of steam (saturated steam and superheated steam), three steam-injection
times (5, 10, and 20 min), four different time intervals (moving time) between steam treatment and dipping (immediate, 3,
10, and 30 min), and four different dipping times (0.5, 1, 3, and 12 h) were used in the study. The maximum absorption was
480 kg/m3 when saturated steam was injected for 20 min and the specimen was immediately dipped into liquid for 12 h. Samples treated
with this condition not only absorbed the maximum amount of liquid but also penetrated over 83.4% and 87.3% of the total area
along and across the grain, respectively. The optimum conditions were then applied to laser-incised sugi (Cryptomeria japonica D. Don) and Japanese larch (Larix leptolepis Gordon) where the absorption of liquid was 415 and 187 kg/m3, respectively. It was shown that initial moisture content below the fiber saturation point was good for passive impregnation.
The absorption of liquid and its distribution in wood indicates that it can be a good preservative treatment method for impermeable
woods. 相似文献
83.
Shoji?HashimotoEmail author Nobuaki?Tanaka Masakazu?Suzuki Ayako?Inoue Hideki?Takizawa Izumi?Kosaka Katsunori?Tanaka Chatchai?Tantasirin Nipon?Tangtham 《Journal of Forest Research》2004,9(1):75-79
Soil respiration and soil carbon dioxide (CO2) concentration were investigated in a tropical monsoon forest in northern Thailand, from 1998 to 2000. Soil respiration was relatively high during the rainy season and low during the dry season, although interannual fluctuations were large. Soil moisture was widely different between the dry and wet seasons, while soil temperature changed little throughout the year. As a result, the rate of soil respiration is determined predominantly by soil moisture, not by soil temperature. The roughly estimated annual soil respiration rate was 2560gCm–2year–1. The soil CO2 concentration also increased in the rainy season and decreased in the dry season, and showed clearer seasonality than soil respiration did. 相似文献
84.
Mino M Nakamura J Nakamuta N Morioka H Morikawa Y Okada T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2007,69(3):247-252
Effects of low protein intake on the development of the remaining kidney in subtotally (5/6) nephrectomized immature rats were examined. Three week-old weaning rats were kept on a diet containing either 12% (Lp rats) or 18% (Np rats) protein for 4 or 8 weeks after subtotal nephrectomy. Blood urea nitrogen (BUN) concentration was determined at 2, 4, 6, and 8 weeks after 5/6 nephrectomy. At 4 or 8 weeks after the operation, glomerular sclerosis and tubulointerstitial damage were assessed by a standard semiquantitative analysis and were expressed as the glomerular sclerosis index (GSI) and interstitial fibrosis score (IFS), respectively. The localization of DNA fragmented cells in the kidney was examined by the terminal deoxynucleotidyl transferase (TdT) -mediated d-UTP-biotin nick end labeling (TUNEL) method and the localization of the epidermal growth factor (EGF) by immunohistochemical methods. BUN concentration was significantly lower in the Lp rats compared with that in the Np rats. Both 4 and 8 weeks after subtotal nephrectomy, GSI and incidence of TUNEL positive cells in the distal tubules were significantly lower in the Lp rats than in the Np rats. Four weeks after the operation, IFS was significantly lower in the Lp rats than in the Np rats. Four and 8 weeks after the operation, EGF positive cells in the distal tubules were more observed in the Lp rats than in the Np rats. These findings reveal that protein restriction is effective in preventing renal tubular scarring in immature rats and that EGF is involved in the process of this prevention. 相似文献
85.
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
86.
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
87.
88.
Minoru Terazawa Sakae Horisawa Yutaka Tamai Kenzo Yamashita 《Journal of Wood Science》1999,45(4):354-358
A system for effective garbage decomposition using sawdust and aerobic soil bacteria was examined. The machinery used in this process, the garbage automatic decomposer-extinguisher (GADS), is composed of a container with an automatic mechanical mixer and a drain for liquid formed by the decomposition of garbage. The aerobic soil bacteria, cultivated in sawdust, degrades garbage within the container. The GADE machine, containing 4kg of sawdust, totally decomposed 59.75 kg of garbage within 3 months (0.66 kg/day). Constant temperature, pH level, and moisture content of the matrix throughout the experimental period suggested stable degrading action. The residual sawdust and drainage water from the GADE machine were converted to fertilizers or soil conditioners (GADE compost) by the garbage decomposition process. Neither inhibited germination or growth of three test crops: komatsuna, Chinese cabbage (Brassica campestris), hatsukadaikon, radish (Raphanus sativus L. var.radicula), and bisai (Raphanus sp.).Some of the results of this paper were presented at IUFRO, Nancy, France, 1992 相似文献
89.
Nobuhito Sekiya Motonori Tomitaka Nobuaki Oizumi Adam Gabriel Pyuza Richard James Shayo Anne Niediwe Assenga Takayoshi Iemoto Kenji Ishido Yasunori Saiki Kenji Tamura Takahiro Nakamura 《Paddy and Water Environment》2017,15(4):847-859
The productivity of irrigated rice is low in Tanzania. We hypothesized that this is caused by the absence of a packaged application of basic cultivation techniques. A baseline survey of 31 rice irrigation schemes across the country revealed that a large proportion of fields were cultivated without a technical package. Thus, a package was introduced to each of the 31 schemes through a farmer-to-farmer (FTF) extension approach. First, selected key farmers (KFs) were trained with the basic cultivation techniques at agricultural training institutes. Second, the KFs transferred their knowledge to intermediate farmers (IFs) by working together at a demo-field established in each scheme. Third, the KFs and IFs exhibited the rice performance to other farmers (OFs). The paddy yield across the 31 schemes greatly increased from the pre-training level of 2.4 t ha?1 to 3.6 t ha?1after the FTF extension. However, the farmer interviews in the four selected schemes suggested that the technical package was not adopted by all farmers owing to the time-consuming nature of the FTF extension. It was inferred from our study that the low productivity of irrigated rice is caused by the absence of basic cultivation techniques in Tanzania. However, the post-training yield remained relatively low compared with high-yields (4.3–8.4 t ha?1) recorded in cultivar selection trials and high-performing schemes in the county. This “yield gap” could be partly ascribed to the insufficient technical diffusion and the technique-dependent adoption among OFs. 相似文献
90.
Hiromichi Mitamura Nobuaki Arai Yukiko Yamagishi Yuuki Kawabata Yasushi Mitsunaga Metha Khachaphichat Thavee Viputhanumas 《Fisheries Science》2009,75(1):175-182
The horizontal and vertical movements of eight immature hatchery-reared (F2) Mekong giant catfish Pangasianodon gigas were monitored using acoustic telemetry in the Mae Peum reservoir, Thailand, from September to December 2005. All tagged
fish were successfully monitored throughout the study period. All fish moved throughout the reservoir for approximately 1 month
after release. Subsequently, their utilized areas became small, and the fish utilized deep areas of the reservoir. The fish
displayed diel spatial movement patterns between deep areas in the day and shallow areas in the night. The vertical movements
of the fish were related to the environment declination such as existence of hypoxic water and thermocline. Our results suggest
that the establishment of a protected area in addition to conventional fisheries regulations may sustain the fish population
in this reservoir. 相似文献