全文获取类型
收费全文 | 119篇 |
免费 | 2篇 |
专业分类
林业 | 10篇 |
农学 | 1篇 |
基础科学 | 2篇 |
11篇 | |
综合类 | 17篇 |
农作物 | 5篇 |
水产渔业 | 10篇 |
畜牧兽医 | 44篇 |
园艺 | 2篇 |
植物保护 | 19篇 |
出版年
2022年 | 5篇 |
2021年 | 2篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2017年 | 2篇 |
2016年 | 4篇 |
2015年 | 2篇 |
2014年 | 1篇 |
2013年 | 6篇 |
2012年 | 3篇 |
2011年 | 8篇 |
2010年 | 3篇 |
2009年 | 11篇 |
2008年 | 6篇 |
2007年 | 9篇 |
2006年 | 2篇 |
2005年 | 5篇 |
2004年 | 7篇 |
2003年 | 4篇 |
2002年 | 2篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1999年 | 3篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1994年 | 1篇 |
1992年 | 1篇 |
1991年 | 3篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1982年 | 1篇 |
1972年 | 1篇 |
1969年 | 1篇 |
1917年 | 1篇 |
1916年 | 1篇 |
1915年 | 1篇 |
1906年 | 1篇 |
1902年 | 1篇 |
1901年 | 1篇 |
1900年 | 1篇 |
1899年 | 1篇 |
1893年 | 1篇 |
1891年 | 1篇 |
1890年 | 1篇 |
排序方式: 共有121条查询结果,搜索用时 15 毫秒
71.
Several forms of carboxylesterase were observed in a malathion-resistant small brown planthopper, Laodelphax striatellus Fallén, by isoelectrofocusing. To study the mechanisms of increased esterase activity, esterases were purified and their biochemical characteristics were investigated in five active esterase isozymes of two resistant strains. These esterases have polymorphic characteristics and their molecular weights ranged from 66 to 70 kDa, due to variations in glycosylation. The pI values of these esterases ranged from 5.3 to 4.7. These esterases were immunologically related and NH2-terminal amino acids were identical in all isozymes regardless of pI or molecular weight. No differences have been found in kinetic parameters (Km and Vmax) to α-naphthylacetate and specific activity toward α-naphthylacetate and malathion as a substrate in all isozymes. Resistant individuals showed high ali- and malathion carboxylesterase activities and these enhancements were caused by quantitative differences of carboxylesterases with several different pI. 相似文献
72.
Teruaki Hagiwara Takamasa Numano Tomomi Hara Taiki Sugiyama Yukinori Mera Seiko Tamano Hiroto Miyata 《Journal of toxicologic pathology》2022,35(4):321
In subcutaneous tumor models, changes in the tumor microenvironment can lead to differences in therapeutic treatment responses between the subcutaneous and parent tumors. Accordingly, we generated a lung carcinogenesis model that combines genetically modified mice (Tg-rasH2 mice) with two-stage chemical carcinogenesis as an alternative to the subcutaneous tumor model. In this model, Tg-rasH2 mice were treated with 1-ethyl-1-nitrosourea, followed by butylhydroxytoluene. Mice developed lung adenomas five weeks after treatment initiation. Subsequently, anti-mouse PD-1 antibody (α-mPD-1) or isotype control was administered intraperitoneally twice a week for 4 weeks. Tumor growth was examined by measuring the relative tumor area in serially sliced lung histopathological specimens. No statistically significant differences were observed in the relative lung tumor areas between treated and control groups. A second experiment then examined the antitumor efficacy of α-mPD-1 combined with gemcitabine in a mouse model. Mice were treated identically as in Experiment 1, except that the treated group received once-weekly intraperitoneal injections of 10 mg/kg gemcitabine. In contrast to Experiment 1, the combined treatment significantly reduced the relative tumor areas in the lungs. This result also resembles that of a phase III clinical trial (ORIENT-12), showing that patients with non-small-cell lung carcinoma benefited from combination treatment with gemcitabine and the anti-human PD-1 antibody sintilimab. Thus, this mouse model could be a feasible means to preclinically evaluate the antitumor efficacy of different immunotherapy and chemotherapy drug combinations. 相似文献
73.
Yasuko Mizoguchi Akira Miyata Yoshikazu Ohtani Ryuichi Hirata Satoko Yuta 《Journal of Forest Research》2009,14(1):1-9
Aggregating and sharing the metadata of flux observation sites results in a strong collaboration among various fields of study.
Such data sharing will also be a part of the future design of a tower flux observation network in Asia. The aim of this review
is to comprehend the state of tower flux observation sites in Asia. There are 109 tower flux observation sites in Asia including
51 forest sites. There are more new sites under construction in Asia than in America and Europe. These sites range from the
taiga in Siberia to the rainforest in Southeast Asia, and from the equatorial to polar Koeppen climate zones. There are many
highly humid areas in Asia, not only at low latitudes but also at middle latitudes. This climate condition has developed unique
vegetation such as lucidophyllous (evergreen broadleaf) forest, which is distributed in warm areas with high precipitation
in the growing season. However, there are only a few observations taking place in lucidophyllous forest. Rice paddy fields
are also unique land cover in Asia. It is important to accumulate long-term data for rice fields with their management records,
because plant activity depends highly on both climate conditions and land-use management. Flux data, especially net ecosystem
exchange and related elements, are used for widespread studies not only within the flux-research community but also in other
fields of study, for example remote sensing. At present, however, both the quantity and quality of the data are not sufficient
for these studies. Regarding the quantity, there are many recently established sites that have not published data yet; regarding
quality, flux data include uncertainties caused by methodological problems. Flux researchers are required not only to obtain
flux data but also to improve their quality. Meanwhile, data users must understand there are still uncertainties in flux data.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
74.
Raphael A. Stern Amir Raz Steve Applebaum Ami Meiri Martin Goldway 《Scientia Horticulturae》2009,122(3):417-420
Small fruit size is one of the limiting factors in marketing cherries (Prunus avium L.). Several techniques have been used to improve fruit size; among them, blossom and fruit thinning in order to reduce crop load have proved effective. Unfortunately, hand thinning is very costly, and chemical thinning has proved ineffective. In the present study, carried out in two consecutive years (2006–2007), application of uniconazole (E-1-(4-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-1-yl-1-penten-3-ol)) at 100–125 mg l−1, in the form of 0.2–0.25% Magic™, at 30% full bloom, reduced the fruit set of ‘Bing’ cherry fruit. As a result time spent in hand thinning was reduced by about 50% and the crop load by about 40%, and there was a considerable shift to larger fruit size (>26 mm), provided the crop load was not too low. No negative effects were observed on the return bloom and yield in the following year. 相似文献
75.
Insecticide toxicity and synergism by enzyme inhibitors in 18 species of pest insect and natural enemies in crucifer vegetable crops 总被引:1,自引:0,他引:1
The toxicities of three enzyme inhibitors and their synergistic effects on four insecticides were studied by using the dry film method on field populations of 18 species of insects collected in Jianxin and Shanjie, China, from 2003 to 2005. Meanwhile, the inhibitory effects of these enzyme inhibitors on the activities of acetylcholinesterases (AChE), carboxyesterases (CarE) and glutathione-S-transferases (GST), in vivo, were also studied. In general, triphenyl phosphate (TPP) and diethyl maleate (DEM) showed low toxicities to six herbivorous pest insects, four ladybirds and eight parasitoids. Piperonyl butoxide (PB) exhibited low toxicities to the herbivorous pest insects and ladybirds, but high toxicities to the eight parasitoids. The tolerance to the insecticides in 11 pest insects and natural enemies was mainly associated with the tolerance to PB. PB showed the highest synergism on methamidophos, fenvalerate, fipronil and avermectin in nine species of pest insects and natural enemies. In general, TPP and DEM showed significant synergisms to these four insecticides in four parasitoid species. However, in contrast to their effects on the parasitoids, the synergistic effects of TPP and DEM on the four insecticides by TPP and DEM against four pest insects and one ladybird varied depending on the insect species and enzyme inhibitor. Activity of AChE, CarE or GST could be strongly inhibited, in vivo, by PB, TPP or DEM, depending on the insect species and enzyme inhibitors. From the results obtained in this study, mixed-function oxidase (MFO) was thought to play the most critical role in insect tolerances to the tested insecticides in the field. Low competition existed in the evolution of insecticide resistance in the field populations of parasitoids, as compared with herbivorous pest insects and ladybirds. Possible causes of the high synergistic effects of PB on the four classes of insecticides, based on multiattack on the activity of CarE, GST or AChE in the insect species, are also discussed. 相似文献
76.
The contributions and relationships of erosion by splash and overland flow over a steep slope in a Japanese beech forest in plots with different percentages of ground cover were examined. Three erosion plots (2 m wide × 5 m long) with average understory coverage of 1%, 45%, and 94% were installed. Sediment transported by rain splash and by overland flow was sampled separately. For the plots with sparse, moderate, and high understory coverage, the average proportions of splash soil to total soil erosion during the monitoring period were 16%, 32%, and 18%, respectively. A significant correlation between the amount of splash soil and precipitation was found in the plots with 1% and 45% understory coverage, whereas no statistical relationship was identified for the plot with high understory coverage. At the sparse ground cover plot showing the largest sediment movement, the contribution of splash transport decreased with increasing precipitation. The amount of sheetwash erosion was significantly correlated with the amount of splash soil under the condition of sparse ground cover. This relationship was more pronounced during high precipitation events and the rainy season. Splash contribution to the sediment transport was in the range of 0.8%–76.7%, 2.8%–81% and 2.1%–60.8% for plot with high, moderate and low ground cover, respectively. The sparse ground cover showed the largest variation of splash and sheetwash contribution in soil erosion. This variability was due to variation in ground cover and soil surface wetness condition which led to a variation of detachment and non-linear relationship of sheetwash splash. 相似文献
77.
Shii T Tanaka T Watarumi S Matsuo Y Miyata Y Tamaya K Tamaru S Tanaka K Matsui T Kouno I 《Journal of agricultural and food chemistry》2011,59(13):7253-7260
Phenolic constituents of a new functional fermented tea produced by tea-rolling processing of a mixture (9:1) of tea leaves and loquat leaves were examined in detail. The similarity of the phenolic composition to that of black tea was indicated by high-performance liquid chromatography comparison with other tea products. Twenty-five compounds, including three new catechin oxidation products, were isolated, and the structures of the new compounds were determined to be (2R)-2-hydroxy-3-(2,4,6-trihydroxyphenyl)-1-(3,4,5-trihydroxyphenyl)-1-propanone 2-O-gallate, dehydrotheasinensin H, and acetonyl theacitrin A by spectroscopic methods. In addition, theacitrinin A and theasinensin H were obtained for the first time from commercial tea products. Isolation of these new and known compounds confirms that reactions previously demonstrated by in vitro model experiments actually occur when fresh tea leaves are mechanically distorted and bruised during the production process. 相似文献
78.
Interleukin-2 receptor beta chain gene: generation of three receptor forms by cloned human alpha and beta chain cDNA's 总被引:101,自引:0,他引:101
M Hatakeyama M Tsudo S Minamoto T Kono T Doi T Miyata M Miyasaka T Taniguchi 《Science (New York, N.Y.)》1989,244(4904):551-556
Interleukin-2 (IL-2) binds to two distinct receptor molecules, the IL-2 receptor alpha (IL-2R alpha, p55) chain and the newly identified IL-2 receptor beta (IL-2R beta, p70-75) chain. The cDNA encoding the human IL-2R beta chain has now been isolated. The overall primary structure of the IL-2R beta chain shows no apparent homology to other known receptors. Unlike the IL-2R alpha chain, the IL-2R beta chain has a large cytoplasmic region in which a functional domain (or domains) mediating an intracellular signal transduction pathway (or pathways) may be embodied. The cDNA-encoded beta chain binds and internalizes IL-2 when expressed on T lymphoid cells but not fibroblast cells. Furthermore, the cDNA gives rise to the generation of high-affinity IL-2 receptor when co-expressed with the IL-2R alpha chain cDNA. 相似文献
79.
80.
Bakare Archibold G. Cawaki Panapasa Ledua Ilaitia Kour Gurdeep Jimenez Vingelle Sharma Ami Tamani Eroni 《Tropical animal health and production》2020,52(5):2481-2489
Tropical Animal Health and Production - This study evaluated the effect of feeding cassava leaf meal–based diets on feeding behavioural patterns, growth performance parameters and nutritional... 相似文献