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排序方式: 共有143条查询结果,搜索用时 31 毫秒
51.
Yoshikazu Hashimoto Yoshika Sekine Zhi-Min Yang Kanji Yoshioka 《Water, air, and soil pollution》2001,130(1-4):1849-1854
15 years ago an interim report for an intense environmental program was compiled concerning the location of the islands of Japan at the meteorological down stream of the East Asian Countries. Parts of sulfur dioxide and other air pollutants, those supposed to cause acid deposition are emitted from the eastern parts of the Asian continent, especially in China. The air pollutants flow down to the east to spread over these islands. This acid deposition is projected to cause damage to forest resources of Japan in the future by increasing air pollutants emanating from the continent. A long term project by a research group at Keio University commenced in 1985 to identify ways of preventing this damage to the forests. The group formed the JACK Air Surveillance Network in China and South Korea in order to collect the first precise air pollution data in this region, as well as to identify a reliable partner for the project. On the completion of the JACK project, a highly cooperative group was formed between the researchers of Keio University and those in Chengdu, Sichuan province of China and has effectively worked since 1991. The goal of the project is the formation of an Inland Environmental Information Center in inland China to be accomplished by 2005. To launch a 10 year project by the center, a nation wide campaign is planned to raise the awareness of the population, specifically the lower socio-economic group on the effect of environmental issues. It is suggested that this education campaign take effect in inland China no later than 2025 for the preservation of the forests on the Islands of Japan. 相似文献
52.
Yuki Okamoto Anh T. Nguyen Motohiro Yoshioka Julio C.M. Iehisa Shigeo Takumi 《Breeding Science》2013,63(4):423-429
Synthetic hexaploid wheat is an effective genetic resource for transferring agronomically important genes from Aegilops tauschii to common wheat. Wide variation in grain size and shape, one of the main targets for wheat breeding, has been observed among Ae. tauschii accessions. To identify the quantitative trait loci (QTLs) responsible for grain size and shape variation in the wheat D genome under a hexaploid genetic background, six parameters related to grain size and shape were measured using SmartGrain digital image software and QTL analysis was conducted using four F2 mapping populations of wheat synthetic hexaploids. In total, 18 QTLs for the six parameters were found on five of the seven D-genome chromosomes. The identified QTLs significantly contributed to the variation in grain size and shape among the synthetic wheat lines, implying that the D-genome QTLs might be at least partly functional in hexaploid wheat. Thus, synthetic wheat lines with diverse D genomes from Ae. tauschii are useful resources for the identification of agronomically important loci that function in hexaploid wheat. 相似文献
53.
Color changes in cephalopods are generated by the expansion or retraction of chromatophores located under the dermis. The behavior of the chromatophores is regulated by neurotransmitters; l-glutamate (l-Glu) is an excitatory transmitter that causes the chromatophores to expand. To date, serotonin [5-hydroxytryptamine (5-HT)] is the only neurotransmitter known to stimulate retraction of chromatophores. We found that the chromatophores in the Japanese squid Todarodes pacificus were regulated by γ-aminobutyric acid (GABA), an inhibitory neurotransmitter, and that GABA caused expanded chromatophores to retract. We also found that adenosine 5′-triphosphate (ATP) concentrations in skin samples remained stable at their initial values for more than 24 h after the death of each squid; therefore, the chromatophores could respond to both l-Glu and GABA during that period. Furthermore, we attempted to reduce the levels of ATP by storing skin sample in sodium azide solution. The chromatophores in sodium azide-treated skin samples were induced to expand by l-Glu, but these expanded chromatophores could not be induced to retract by GABA. Based on these observations, we conclude that ATP is essential for retraction, but not expansion, of chromatophores. 相似文献
54.
Hiroshi Shiotani Terutaka Yoshioka Masashi Yamamoto Ryoji Matsumoto 《Journal of General Plant Pathology》2008,74(2):133-137
Susceptibility to Xanthomonas
axonopodis pv. citri of a citrus cybrid, in which the nuclear and cytoplasmic genomes were derived from Citrus
sinensis and C. unshiu, respectively, was evaluated. Bacterial growth in the leaves of the cybrid was similar to that in C. sinensis after pin-prick inoculation throughout the experiment, whereas growth was greater than that in C. unshiu from 8 days after inoculation. Lesion expansion and pustules that later developed from the lesions on the cybrid and on C. sinensis also appeared to be greater than those on C. unshiu. The incidence of citrus canker disease caused by the bacteria on the cybrid trees was in the field was equivalent to that
on C. sinensis but was severer than on C. unshiu. These results indicate that the nuclear genome of the cybrid plays a critical role in susceptibility to citrus canker disease.
However, the pathogenicity gene pthA of the bacteria is not likely to be involved in the difference in susceptibility to the bacteria between C. unshiu and C. sinensis because their susceptibility to a pthA-deficient mutant of the bacteria also differs. 相似文献
55.
Ryunosuke Tateno Keitaro Fukushima Reiji Fujimaki Tetsuya Shimamura Masami Ohgi Hirotsugu Arai Nobuhito Ohte Naoko Tokuchi Takahito Yoshioka 《Journal of Forest Research》2009,14(5):276-285
We investigated soil net nitrogen mineralization rate, above- and belowground biomass allocation, and nitrogen use in a Cryptomeria japonica plantation chronosequence. Total biomass accumulation showed an asymptotic accretion pattern, and the peak total biomass
accumulation rate occurred approximately 30 years after afforestation. Soil net nitrogen mineralization rate was lowest 30 years
after afforestation. Between years 30 and 88, net nitrogen mineralization increased again. These results indicate that an
imbalance in soil nitrogen supply and plant nitrogen demand occurred approximately 30 years after afforestation. Furthermore,
leaf nitrogen concentration, which was used as an index of plant nitrogen status, was lower in mature forest than in young
forest, suggesting that mature stands did not take up nitrogen as successfully. If soil resources such as nitrogen limit plant
growth, plants may increase biomass allocation to fine root structure; however, fine root biomass was not higher in 30- and
88-year-old stands than in younger stands, suggesting that changes in biomass allocation may not be effective against nitrogen
deficiency in a C. japonica plantation chronosequence. 相似文献
56.
Hiroko Hayama Miho Tatsuki Hirohito Yoshioka Yuri Nakamura 《Postharvest Biology and Technology》2008,50(2-3):231-232
Controlling the rate of fruit softening in melting-flesh peaches is a primary goal of the fruit industry. Stony hard (SH) peach varieties lack the ability to synthesize 1-aminocyclopropane-1-carboxylic acid (ACC), the precursor of ethylene, which is required for fruit maturation. SH peaches thus have crisp flesh that remains firm during ripening. In this study, we developed a simple technique to stimulate fruit softening by a single spray application of ACC at a concentration of 10–20 mM, which was sufficient to allow ethylene synthesis and fruit softening. Higher concentrations of ACC increased ethylene production, and made the fruit softer. Ethylene synthesis was limited to the first 2–3 d after ACC treatment, after which fruit ceased softening and retained its remaining firmness. These results indicate that a single application of ACC solution can be used to regulate the process of fruit softening in SH peaches. 相似文献
57.
Yosuke Yoshioka Koichiro Shimomura Mitsuhiro Sugiyama 《Genetic Resources and Crop Evolution》2018,65(1):91-101
In melon (Cucumis melo L.), the amount of fertile pollen decreases at low temperature during winter and early spring and thereby restricts fertilization. A promising way to overcome this problem is to develop parthenocarpic cultivars. Parthenocarpic cucumber and squash, but not melon cultivars are available. In this study, we explored 172 accessions from an East Asian melon collection and identified accessions that exhibited strong parthenocarpic ability throughout the year. Crosses between parthenocarpic accessions and a non-parthenocarpic cultivar, and among parthenocarpic accessions indicated that parthenocarpy may be inherited in a recessive manner and is likely controlled by the same gene or genes in these accessions. The parthenocarpic indices, such as the size and number of parthenocarpic fruits, differed among the cultivation periods, indicating the importance of environmental factors for parthenocarpic fruit development. We conclude that it is possible to breed new cultivars with stable parthenocarpic ability throughout the year by using the identified accessions. 相似文献
58.
Keigo Inami Chizu Yoshioka Yasushi Hirano Masato Kawabe Seiya Tsushima Tohru Teraoka Tsutomu Arie 《Journal of General Plant Pathology》2010,76(2):116-121
Five primer/probe sets to identify the tomato wilt pathogen, Fusarium oxysporum f. sp. lycopersici (FOL), and its three races selectively were designed based on the rDNA-intergenic spacer and avirulence genes. Real-time PCR using
genomic DNA from mycelia and soil DNA with the primer/probe sets allowed the successful identification of FOL and its races. 相似文献
59.
60.
The cell proliferation activity of proliferating bile ducts produced by bile duct ligation (BDL) in rats was examined histologically, immunohistochemically, and ultrastructurally. Proliferating bile ducts, which were similar to normal bile ducts, increased with time after BDL. The cell proliferation activity of proliferating bile ducts, measured using proliferating-cell nuclear antigen and 5-bromo-2'-deoxyuridine antibodies, tended to be high at 1 and 3 days after BDL and decreased progressively at 2 to 4 weeks after BDL. On the other hand, alpha-smooth muscle actin-positive myofibroblast-like cells increased continuously after BDL. These findings indicate that there is a negative correlation between the cell proliferation activity of proliferating bile ducts and that of myofibroblast-like cells. 相似文献