全文获取类型
收费全文 | 370篇 |
免费 | 8篇 |
专业分类
林业 | 15篇 |
农学 | 15篇 |
基础科学 | 1篇 |
86篇 | |
综合类 | 19篇 |
农作物 | 14篇 |
水产渔业 | 40篇 |
畜牧兽医 | 120篇 |
园艺 | 4篇 |
植物保护 | 64篇 |
出版年
2023年 | 1篇 |
2022年 | 4篇 |
2021年 | 12篇 |
2020年 | 4篇 |
2019年 | 5篇 |
2018年 | 3篇 |
2017年 | 6篇 |
2016年 | 13篇 |
2015年 | 9篇 |
2014年 | 7篇 |
2013年 | 34篇 |
2012年 | 29篇 |
2011年 | 26篇 |
2010年 | 10篇 |
2009年 | 10篇 |
2008年 | 28篇 |
2007年 | 26篇 |
2006年 | 26篇 |
2005年 | 24篇 |
2004年 | 24篇 |
2003年 | 22篇 |
2002年 | 21篇 |
2001年 | 18篇 |
2000年 | 8篇 |
1999年 | 3篇 |
1998年 | 1篇 |
1992年 | 1篇 |
1986年 | 1篇 |
1982年 | 1篇 |
1975年 | 1篇 |
排序方式: 共有378条查询结果,搜索用时 15 毫秒
91.
Yuri Ichinose Tomohiro Nishigaki Makoto Shibata Method Kilasara Hitoshi Shinjo Shinya Funakawa 《Soil Use and Management》2023,39(3):1155-1171
Sustainable land management of smallholder farms is crucial for ensuring food security in sub-Saharan Africa. However, little is known about the nutrient dynamics of smallholder farming systems at the farm level based on primary data. In this study, carbon (C) and nutrient budgets of the home garden system in the Kilimanjaro highlands, where Andosols predominate, were quantified at the farmer's field. We evaluated (1) the soil C and nutrient flow in the main three land-use blocks (banana (Musa spp.) garden, maize (Zea mays L.) field and grassland) in one representative home garden and (2) the internal flow between farmland and livestock and the external nutrient flow across the inside and outside of the six home gardens. Intensive applications of livestock dung to the banana trees resulted in a positive C budget (7.2 Mg C ha−1 year−1) in the banana garden. Nitrogen loss through the harvesting of feed and crops was almost balanced with the livestock dung application, while nitrogen loss through leaching only accounted for 3% of that applied. Banana productivity has been maintained despite a negative potassium budget (−241 kg K ha−1 year−1), probably owing to the replenished exchangeable potassium from Andosols. In the maize field, the C budget was negative (−1.7 Mg C ha−1 year−1) owing to high organic matter decomposition. Carbon and nutrient budgets in the grassland were all negative. Our results revealed that the village average livestock density (4.4 TLU ha−1: TLU means tropical livestock unit) was sufficient for P, Ca and Mg balance in the home garden, whereas it was not sufficient for N and K balance. Increasing livestock density improved the nutrient balance of the system. However, it is noteworthy that 33%–47% of the feed supplied as C and nutrients was collected from outside the home gardens, suggesting a high reliance on external inflow to fulfil feed demands. In conclusion, intensive livestock dung application to banana cultivation was fundamental for maintaining agricultural productivity to replenish the nutrients lost from the system. At the same time, this system was sustained not only by C and nutrient cycling within the system, but also by transporting resources from the external environment into the system. 相似文献
92.
Half a century of genetic interaction between farmed and wild Atlantic salmon: Status of knowledge and unanswered questions 下载免费PDF全文
93.
Improved physical control of glyphosate‐resistant Italian ryegrass (Lolium multiflorum) on rice paddy levees in Japan 下载免费PDF全文
Valentina Dwi Suci Handayani Yuki Tanno Masayuki Yamashita Hiroyuki Tobina Minoru Ichihara Yoshiki Ishida Hitoshi Sawada 《Weed Biology and Management》2017,17(2):77-83
Italian ryegrass ( Lolium multiflorum Lam.) is a non‐native annual winter grass that has seriously infested rice paddy levees and wheat fields in Japan. Recently, glyphosate‐resistant Italian ryegrass was found on paddy levees in central Japan, thereby making control of the grass by using glyphosate less effective. In this study, physical control methods were tested that combined the timing and frequency of mowing in order to more effectively control glyphosate‐resistant Italian ryegrass on rice paddy levees. A 3 year field experiment was conducted from 2012 to 2014 in a western region of Shizuoka Prefecture, where glyphosate‐resistant Italian ryegrass has become dominant. Five treatments were tested: (i) mowing once before the flowering of the grass (i.e. conventional mowing measure); (ii) mowing once during flowering; (iii) mowing twice during flowering; (iv) glyphosate application before flowering (i.e. one of the conventional mowing measures); and (v) no treatment. The above‐ground biomass, seed production, soil seed bank and seedling occurrence of Italian ryegrass were measured to determine the effectiveness of these treatments. Mowing during the flowering period resulted in reduced above‐ground biomass, seed production and soil seed bank when compared with the other treatments. Additionally, mowing twice during the flowering period resulted in a lower seedling density than mowing once. The results suggest that, in this region, physical control by mowing during the flowering period would be more effective than conventional measures for controlling glyphosate‐resistant Italian ryegrass. 相似文献
94.
Tadashi Oikawa Toshiya Matsui Yasunori Matsuda Teruko Takayama Hitoshi Niinuma Yasuyo Nishida Kazuo Hoshi Mitsuyoshi Yatagai 《Journal of Wood Science》2006,52(2):140-146
Volatile organic compounds (VOCs) from wood and their effects on artifacts are of intense interest to museum staff who must
strictly manage the preservation environment. In this study, the causal substances of deterioration were inferred by comparison
with laser Raman (LR) spectra of deterioration products. The artifact samples were deteriorated using VOCs from woods (WV
test), and using specific substances that occur in wood VOCs (SV test). The deteriorated samples were analyzed by LR spectroscopy
and the results of the WV and SV tests were compared.
Hinokitiol and acetic acid were found to be two of the main causal substances of deterioration in western red cedar. Deterioration
of iron and copper by spruce did not appear to be caused by acetic acid, as is generally assumed, but by some other unknown
compound(s). Sensitivity to wood-based VOC components depended on the type of artifact. In western red cedar, mitsudasou (litharge) was very sensitive to acetic acid, while other artifacts were sensitive to hinokitiol. The LR method used in this
study is very useful for the inference of causal substances of deterioration based on the detection of small amounts of deteriorated
products such as those generated by deterioration due to wood VOCs.
Part of this article was presented at the 25th Annual Meeting of the Japan Society for the Conservation of Cultural Property,
Kyoto, June 2003 相似文献
95.
Takasu M Shirota K Uchida N Iguchi T Nishii N Ohba Y Maeda S Miyazawa K Murase T Kitagawa H 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2006,68(5):519-521
We encountered an extremely rare tumor, a pericardial mesothelioma, in a neonatal calf. The patient calf showed severe abdominal distention, and died immediately after birth. The thoracic cavity was contained a huge heart with a large amount of pericardial fluid. A number of granular and cobblestone-like nodules were dispersed over the epicardium and pericardium. The nodules consisted of papillary proliferations of neoplastic cells, and the neoplasm occasionally showed mesenchymal proliferations. Immunohistochemistry revealed that they had the characteristics of mesothelial cells (cytokeratin-and vimentin-positive), and the neoplasm was diagnosed as mesothelioma. 相似文献
96.
97.
Maiko Sato Ashraf M Ahmed Ayako Noda Hitoshi Watanabe Yukio Fukumoto Tadashi Shimamoto 《Acta veterinaria Scandinavica》2009,51(1):46
Imported animals, especially those from developing countries, may constitute a potential hazard to native animals and to public health. In this study, a new flock of lesser flamingos imported from Tanzania to Hiroshima Zoological Park were screened for multidrug-resistant Gram-negative bacteria, integrons and antimicrobial resistance genes. Thirty-seven Gram-negative bacterial isolates were obtained from the flamingos. Seven isolates (18.9%) showed multidrug resistance phenotypes, the most common being against: ampicillin, streptomycin, tetracycline, trimethoprim/sulfamethoxazole and nalidixic acid. Molecular analyses identified class 1 and class 2 integrons, β-lactamase-encoding genes, blaTEM-1 and blaCTX-M-2 and the plasmid-mediated quinolone resistance genes, qnrS and qnrB. This study highlights the role of animal importation in the dissemination of multidrug-resistant bacteria, integrons and antimicrobial resistance genes from one country to another. 相似文献
98.
Kazuo Azuma Toshitsugu Ishihara Hiroyuki Nakamoto Takao Amaha Tomohiro Osaki Takeshi Tsuka Tomohiro Imagawa Saburo Minami Osamu Takashima Shinsuke Ifuku Minoru Morimoto Hiroyuki Saimoto Hitoshi Kawamoto Yoshiharu Okamoto 《Marine drugs》2012,10(10):2337-2348
We evaluated the anti-tumor activities of the oral administration of fucoidan extracted from Cladosiphon okamuranus using a tumor (colon 26)-bearing mouse model. The materials used included low-molecular-weight fucoidan (LMWF: 6.5–40 kDa), intermediate-molecular-weight fucoidan (IMWF: 110–138 kDa) and high-molecular-weight fucoidan (HMWF: 300–330 kDa). The IMWF group showed significantly suppressed tumor growth. The LMWF and HMWF groups showed significantly increased survival times compared with that observed in the control group (mice fed a fucoidan-free diet). The median survival times in the control, LMWF, IMWF and HMWF groups were 23, 46, 40 and 43 days, respectively. It was also found that oral administration of fucoidan increased the population of natural killer cells in the spleen. Furthermore, from the results of the experiment using Myd-88 knockout mice, it was found that these effects are related to gut immunity. These results suggest that fucoidan is a candidate anti-tumor functional food. 相似文献
99.
100.
Wulansari R Wijaya A Ano H Horii Y Makimura S 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2003,65(5):579-584
This study was carried out to clarify the role of lymphocyte subpopulations and Babesia-specific antibody on the treatment of clindamycin in dogs infected with B. gibsoni. Ten beagle dogs were divided into two groups: an untreated group (5 dogs) and a clindamycin-treated group (5 dogs), which was administered clindamycin at 25 mg/ kg body weight, per os, q 12 hr from 7 days to 21 days post-infection (PI). On the acute stage of infection, clindamycin treatment resolved anaemia and other clinical findings. There were no significant differences between treated and untreated dogs either in parasitemia levels or Babesial IgG antibody levels. However, morphological changes that indicated degeneration in the majority of parasites were observed. The numbers of CD4(+) showed a significant increase in treated dogs, especially after treatment. On the chronic stage, CD4(+) cells maintained high level both of the treated and untreated dogs. Although parasitemia maintained low level, their relapses were occurred on the 49th day PI in treated dogs and on the 42nd and 63rd PI in untreated dogs. A rapid humoral antibody response was observed in treated dogs, however, lower humoral antibody responses in untreated dogs after relapses. The antibody levels of treated dogs were significantly higher than those of untreated dogs. These results suggested that clindamycin might not eliminate rapidly parasites from peripheral blood, but damage parasites, which might stimulate efficiently humoral and cellular immunity against Babesia infection, and result in an improvement of clinical conditions. 相似文献