全文获取类型
收费全文 | 153篇 |
免费 | 5篇 |
国内免费 | 1篇 |
专业分类
林业 | 11篇 |
农学 | 4篇 |
36篇 | |
综合类 | 14篇 |
农作物 | 7篇 |
水产渔业 | 28篇 |
畜牧兽医 | 50篇 |
园艺 | 1篇 |
植物保护 | 8篇 |
出版年
2023年 | 1篇 |
2022年 | 4篇 |
2021年 | 5篇 |
2020年 | 5篇 |
2019年 | 3篇 |
2018年 | 2篇 |
2016年 | 5篇 |
2015年 | 3篇 |
2014年 | 9篇 |
2013年 | 9篇 |
2012年 | 5篇 |
2011年 | 8篇 |
2010年 | 4篇 |
2009年 | 7篇 |
2008年 | 10篇 |
2007年 | 5篇 |
2006年 | 7篇 |
2005年 | 12篇 |
2004年 | 6篇 |
2003年 | 5篇 |
2002年 | 3篇 |
2001年 | 10篇 |
2000年 | 5篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1968年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有159条查询结果,搜索用时 62 毫秒
21.
Amal Biswas Biswajit K. Biswas Junichi Ito Osamu Takaoka Norishige Yagi Syunsuke Itoh Kenji Takii 《Fisheries Science》2011,77(4):615-621
This study was carried out to investigate whether expensive enzyme-treated fish meal (EFM) can be partially replaced by soybean
meal (SM) or enzyme-treated SM (ESM) without compromising the growth of captive-raised Pacific bluefin tuna (PBT) juveniles.
Five fish diets were tested: EFM (control) and EFM in which 10 or 20% of the EFM was replaced with either ESM or SM (ESM10, ESM20, SM10 and SM20, respectively). The respective diets were provided to 28-day-old PBT juveniles (mean body weight approx. 0.38 g) stocked
randomly in 15-m3 tanks (276 juveniles per tank; two tanks per treatment) for 12 days. The final mean body weight of PBT juveniles on diets
EFM, SM10, and SM20 was significantly higher than that of juveniles on diet ESM20. Although daily feeding rate was significantly higher in the ESM and SM groups, feed efficiency (FE) was significantly higher
in the EFM group; there was no significant difference between juveniles fed diets EFM and SM10. Protein and phosphorus retention efficiency were significantly lower in the ESM20, and ESM20 and EFM groups, respectively. Phosphorus discharge was significantly lower in the SM groups. The results demonstrate that
10% SM (11% EFM replacement) can be included in EFM without compromising the growth performance of PBT juveniles. 相似文献
22.
Seko Takuya Imamura Shintaro Ishihara Kenji Yamashita Yumiko Yamashita Michiaki 《Fisheries Science》2020,86(1):171-179
Fisheries Science - The novel organic selenium compound, selenoneine, is found in the blood of tuna and has metal-binding activity. In this report, selenoneine displays tyrosinase inhibitory... 相似文献
23.
Yutaro Sakai Nobuyuki Yagi Masahiko Ariji Atsushi Takahara Hisashi Kurokura 《Fisheries Science》2009,75(5):1079-1087
A demand system analysis was conducted to examine the substitute relationships between tuna and skipjack tuna in the Japanese
market. Data from the Annual Report on Family Income and Expenditure Survey from 1965 to 2006 were used for the analysis using
the almost ideal demand system (AIDS). Results suggest that skipjack tuna can be a strong substitute for tuna, while other
fish groups are not a clear substitute. Our analysis of substitute relationships among fish species in a market indicates
that this is a factor that should be considered for better fisheries resource management. For instance, even under a situation
where one fish species is underexploited, proper attention to its fishery management is necessary if the fish is a strong
substitute for another popular fish species in the market. 相似文献
24.
Tomoko Suzuki Shougo Nishimura Kazuhiro Yagi Ryousuke Nakamura Yoshihiro Takikawa Yoshinori Matsuda Koji Kakutani Teruo Nonomura 《Phytoparasitica》2018,46(1):31-43
The lengths of conidiophores in fungal colonies of the melon powdery mildew pathogen Podosphaera xanthii Pollacci KMP-6 N cultured under greenhouse (natural) conditions differed markedly from those cultured in a growth chamber. We hypothesized that light wavelength was responsible for the differences in conidiophore length. In this study, we examined the effects of light-emitting diode (LED) irradiation (purple, blue, green, orange, and red light) and white light on colony development and conidiophore formation in KMP-6 N using a stereomicroscope and a high-fidelity digital microscope. Colonies on leaves were flat under greenhouse conditions and under red LED light irradiation but were stacked under growth chamber conditions and under purple, blue, green, and orange LED light irradiation. In addition, KMP-6 N formed catenated conidia comprising six conidia per conidiophore under greenhouse conditions and red light but more than seven conidia per conidiophore under growth chamber conditions and purple, blue, green, and orange light. Furthermore, almost none of the conidia on top of the conidiophores grown under blue light were fully constricted. Therefore, these fungi could not scatter their conidia and spread infection. This is the first report of the effects of LED lights on conidiophore formation in the melon powdery mildew fungus P. xanthii. The results provide insight into the mechanisms underlying the responses of conidiophores to light of specific wavelengths and conidial scatter from conidiophores of melon powdery mildew fungi. 相似文献
25.
Atsushi Hayakawa Hiroko Akiyama Shigeto Sudo Kazuyuki Yagi 《Soil biology & biochemistry》2009,41(3):521-529
Animal manures from intensive livestock operations can be pelleted to improve handlings and recyclings of embodied nutrients. The aim of this study was to evaluate the influence of pelleted poultry manure on N2O and NO fluxes from an Andisol field. In autumn 2006 and summer 2007, poultry manure (PM), pelleted poultry manure (PP), and chemical fertilizer (CF) were applied at a rate of 120 kg N ha−1 in each cultivation period to Komatsuna (Brassica rapa var. peruviridis). Nitrous oxide and NO fluxes were measured using an automated monitoring system. A soil incubation experiment was also conducted to determine the influence of intact and ground pelleted manure on N2O, NO, and CO2 production with a water-filled pore space (WFPS) of 30 or 50%. In the field measurements, N2O emission rates from the organic fertilizer treatments were larger than that from the CF treatment, possibly because organic C stimulated denitrification. The highest N2O flux was observed from the PP treatment after a rainfall following fertilization, and the cumulative emission rate (2.72 ± 0.22 kg N ha−1 y−1) was 3.9 and 7.1 times that from the PM and CF treatments, respectively. In contrast, NO emission rates were highest from the CF treatment. The NO/N2O flux ratio indicated that nitrification was the dominant process for NO and N2O production from the CF treatment. Cumulative N2O emission rates from all treatments were generally higher during the wetter cultivation period (autumn 2006) than during the drier cultivation period (summer 2007). In contrast, NO emission rates were higher in the drier than in the wetter cultivation period. The incubation experiment results showed a synergistic effect of soil moisture and the pelleted manure form on N2O emission rates. The intact pelleted manure with the 50% WFPS treatment produced the highest N2O and CO2 fluxes and resulted in the lowest soil NO3− content after the incubation. These results indicate that anaerobic conditions inside the pellets, caused by rainfall and heterotrophic microbial activities, led to denitrification, resulting in high N2O fluxes. Controlling the timing of N application by avoiding wet conditions might be one mitigation option to reduce N2O emission rates from the PP treatment in this study field. 相似文献
26.
We demonstrated that the inorganic phosphate (P(i)) requirement for growth of Japanese red pine (Pinus densiflora Sieb. & Zucc.) seedlings is increased by elevated CO(2) concentration ([CO(2)]) and that responses of the ectomycorrhizal fungus Pisolithus tinctorius (Pers.) Coker & Couch to P(i) supply are also altered. To investigate the growth response of non-mycorrhizal seedlings to P(i) supply in elevated [CO(2)], non-mycorrhizal seedlings were grown for 73 days in ambient or elevated [CO(2)] (350 or 700 micromol mol(-1)) with nutrient solutions containing one of seven phosphate concentrations (0, 0.02, 0.04, 0.06, 0.08, 0.10 and 0.20 mM). In ambient [CO(2)], the growth response to P(i) was saturated at about 0.1 mM P(i), whereas in elevated [CO(2)], the growth response to P(i) supply did not saturate, even at the highest P(i) supply (0.2 mM), indicating that the P(i) requirement is higher in elevated [CO(2)] than in ambient [CO(2)]. The increased requirement was due mainly to an altered shoot growth response to P(i) supply. The enhanced P(i) requirement in elevated [CO(2)] was not associated with a change in photosynthetic response to P(i) or a change in leaf phosphorus (P) status. We investigated the effect of P(i) supply (0.04, 0.08 and 0.20 mM) on the ectomycorrhizal fungus P. tinctorius in mycorrhizal seedlings grown in ambient or elevated [CO(2)]. Root ergosterol concentration (an indicator of fungal biomass) decreased with increasing P(i) supply in ambient [CO(2)], but the decrease was far less in elevated [CO(2)]. In ambient [CO(2)] the ratio of extramatrical mycelium to root biomass decreased with increasing P(i) supply but did not change in elevated [CO(2)]. We conclude that, because elevated [CO(2)] increased the P(i) requirement for shoot growth, the significance of the ectomycorrhizal association was also increased in elevated [CO(2)]. 相似文献
27.
Ken Touhata Atsushi Namikoshi Tamami Suzuki Jun Iguchi Nanami Mizusawa Tatsuro Hara Shintaro Imamura Takeshi Yabu Yumiko Yamashita Michiaki Yamashita 《Fisheries Science》2013,79(5):865-875
Nucleotide sequences in internal transcribed spacer (ITS)-1 region derived from dried nori products produced in Japan, China, and the Republic of Korea were compared. Thalli contained in the Japanese products were genetically homogenous, and their nucleotide sequences in ITS-1 were identical to those of the reference strains of Pyropia yezoensis f. narawaensis. In Chinese products, the thalli were related to P. yezoensis strain Minomiasakusa. In contrast, the thalli in the Korean products were genetically heterogeneous, and several different P. yezoensis strains and other Pyropia spp. were used for dried nori products. In some thalli produced in both China and Korea, the DNA sequences of the ITS-1 region were identical with that of Japan, suggesting that the cultivar strains might have been transplanted from Japan to China in recent years. The 432-bp-long nucleotide sequences in the ITS-1 region of thalli derived from Japanese origin were cleaved to two restriction fragments at 154 and 278 bp by cleavage of PCR-amplified products using MspI. Conversely, almost all of the corresponding sequences derived from China and Korea were lacking MspI or other restriction patterns, except for nori products from some areas that cultivate a closely related strain to the Japanese cultivar. 相似文献
28.
Arai Y Ohgane J Yagi S Ito R Iwasaki Y Saito K Akutsu K Takatori S Ishii R Hayashi R Izumi S Sugino N Kondo F Horie M Nakazawa H Makino T Shiota K 《The Journal of reproduction and development》2011,57(4):507-517
Epigenetic alteration is an emerging paradigm underlying the long-term effects of chemicals on gene functions. Various chemicals, including organophosphate insecticides and heavy metals, have been detected in the human fetal environment. Epigenetics by DNA methylation and histone modifications, through dynamic chromatin remodeling, is a mechanism for genome stability and gene functions. To investigate whether such environmental chemicals may cause epigenetic alterations, we studied the effects of selected chemicals on morphological changes in heterochromatin and DNA methylation status in mouse ES cells (ESCs). Twenty-five chemicals, including organophosphate insecticides, heavy metals and their metabolites, were assessed for their effect on the epigenetic status of mouse ESCs by monitoring heterochromatin stained with 4¢,6-diamino-2-phenylindole (DAPI). The cells were surveyed after 48 or 96 h of exposure to the chemicals at the serum concentrations of cord blood. The candidates for epigenetic mutagens were examined for the effect on DNA methylation at genic regions. Of the 25 chemicals, five chemicals (diethyl phosphate (DEP), mercury (Hg), cotinine, selenium (Se) and octachlorodipropyl ether (S-421)) caused alterations in nuclear staining, suggesting that they affected heterochromatin conditions. Hg and Se caused aberrant DNA methylation at gene loci. Furthermore, DEP at 0.1 ppb caused irreversible heterochromatin changes in ESCs, and DEP-, Hg- and S-421-exposed cells also exhibited impaired formation of the embryoid body (EB), which is an in vitro model for early embryos. We established a system for assessment of epigenetic mutagens. We identified environmental chemicals that could have effects on the human fetus epigenetic status. 相似文献
29.
We have estimated methane (CH4) emission from total rice (Oryza sativa L.) paddies in Japan by means of a process-based biogeochemistry model, DeNitrification-DeComposition(DNDC)-Rice, combined with a geographic information system (GIS) database of climate, soil and farming practices. In the GIS database, 2 million ha of rice paddies were divided into 17,408 units according to 136 climate areas, 16 soil types, four classes of drainage rate and two classes of groundwater level, to simulate CH4 flux from each of the units applying the DNDC-Rice model. As a result, the national-scale CH4 emission in 1990 was estimated to be 216 Gg carbon (C), 13% lower than a previous inventory estimated by the Tier 2 method. By our Tier 3 approach, a relatively higher CH4 flux was estimated from eastern regions than from western regions of Japan, presumably due to the differences in climate and water management. Sensitivity analysis and uncertainty assessment indicated that it is important to account for the heterogeneity in soil properties such as field water capacity, iron (Fe) concentration and drainage rate, in order to reduce the uncertainty in regional estimates. 相似文献
30.
Farmers in some parts of the Indochina Peninsula have been using earthen weirs to supply water to their rice fields, and the
use of such weirs is especially prevalent in Northeast Thailand. Although now a typical rain-fed rice cultivation area, a
significant percentage of rice fields in Northeast Thailand used earthen weirs before the extensive expansion of rain-fed
rice fields that occurred in the early 20th century. In this study, we clarified some of the historical changes associated
with the construction and use of earthen weirs and their effects on rice production. In particular, we investigated some of
the topographic effects, such as terrain, catchment size, and slope grade, on water delivery. In addition, water delivery
methods, construction periods, and the discontinued use of earthen weirs were examined with respect to regional influences
and topography. Earthen weirs were found to be most suitable in areas that exhibited complementarity between the riverbed
slope and the water catchment. The type of earthen weir was dependent on the magnitude of the riverbed slope. Earthen weirs
have been constructed continuously on steeper upstream slopes of rivers for more than a century, while weir construction on
lower riverbeds with larger catchments appears to be more recent.
相似文献
Keisuke HoshikawaEmail: |