全文获取类型
收费全文 | 111篇 |
免费 | 4篇 |
专业分类
林业 | 25篇 |
农学 | 7篇 |
14篇 | |
综合类 | 11篇 |
农作物 | 4篇 |
水产渔业 | 17篇 |
畜牧兽医 | 25篇 |
园艺 | 1篇 |
植物保护 | 11篇 |
出版年
2021年 | 3篇 |
2019年 | 2篇 |
2018年 | 2篇 |
2017年 | 1篇 |
2016年 | 3篇 |
2015年 | 4篇 |
2014年 | 3篇 |
2013年 | 5篇 |
2012年 | 4篇 |
2011年 | 6篇 |
2010年 | 3篇 |
2009年 | 3篇 |
2008年 | 6篇 |
2007年 | 5篇 |
2006年 | 7篇 |
2005年 | 11篇 |
2004年 | 13篇 |
2003年 | 4篇 |
2002年 | 6篇 |
2001年 | 10篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1995年 | 1篇 |
1993年 | 1篇 |
1989年 | 1篇 |
1983年 | 1篇 |
1980年 | 1篇 |
1975年 | 1篇 |
1970年 | 1篇 |
1967年 | 1篇 |
1964年 | 1篇 |
排序方式: 共有115条查询结果,搜索用时 15 毫秒
41.
Using the same fish with different rules: A science‐based approach for improving management of recreational fisheries in a biodiversity hotspot of the Western South Atlantic
下载免费PDF全文
![点击此处可从《Fisheries Management and Ecology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Domingos Garrone‐Neto Eduardo Antonio Sanches Felippe Alexandre Lisboa de Miranda Daros Cleber Mikio Rosa Imanobu Pietro Simon Moro 《Fisheries Management and Ecology》2018,25(4):253-260
In this study we tested the hypothesis that Centropomus parallelus Poey moves between areas where fishing tourism is important, but the management rules for recreational fisheries are different. Fieldwork was conducted from May 2014 to June 2017 in an estuary located in the border between the states of São Paulo and Paraná, South‐Southeastern Brazil. Through a mark and recapture experiment, 2.000 individuals were tagged, of which 42 were recaptured. Among these, six fish were recaptured in Paraná, after being tagged in São Paulo, and a fish was recaptured in São Paulo, after being tagged in Paraná. These results support the hypothesis tested and indicate an uneven use of C. parallelus by anglers in both states. Thus, the use of the species and the recreational fisheries regulations need to be reviewed in the study area, taking into account the ability of C. parallelus to move across political boundaries and the importance of a fish‐oriented fisheries management regime. 相似文献
42.
43.
44.
45.
Michihisa Iida Donghyeon Kang Mitsuru Taniwaki Mutsumi Tanaka Mikio Umeda 《Computers and Electronics in Agriculture》2008,63(1):73-robotics
A hexapod robot was developed to explore an agricultural field and gather agronomical information such as soil nutrients and plant growth. In addition, a sensor device for the robot to track a gas source was developed. The sensor device consisted of a CO2 gas sensor and an anemoscope. The gas sensor detected the concentration of CO2 in the surroundings, and the anemoscope indicated the upwind direction from the robot. An indoor test was conducted during which the hexapod robot tracked windward direction using the sensor device. According to the results, the hexapod robot with the sensor device successfully localized a CO2 source that was in the upwind direction. The robot paused on the spot under windless conditions, and walked windward as soon as the wind started blowing again. 相似文献
46.
Nakazawa T Kasahara K Ikezaki S Yamaguchi Y Edamoto H Nishimura N Yahata M Tamura K Kamata E Ema M Hasegawa R 《Journal of toxicologic pathology》2009,22(2):125-131
In this study, we investigated the sequential changes in the development of renal tubular cysts in newborn rats treated with p-cumylphenol (PCP). Fifteen animals per sex were treated orally with 300 mg/kg/day of PCP for up to 18 days from postnatal day (PND) 4 and were sacrificed on PNDs 8, 12, 19 and 22 and after a 7 day recovery period. On PNDs 8 and 12, slight dilatation of the collecting ducts was frequently observed in the medulla and slight papillary necrosis was also noted in some cases. These dilated collecting ducts were lined with slightly hyperplastic epithelial cells. On PNDs 19 and 22, multiple large cystic changes arising from the collecting ducts in the outer medulla were seen. These cystically dilated ducts were also lined with hyperplastic epithelial cells. During the dosing period, the labeling index of proliferating cell nuclear antigen in the collecting duct epithelium was higher in the PCP-treated group than in the control group at all time points. After a 7 day recovery period, the cystic change still remained, although the cell density was decreased and the epithelial cells became flattened. On the other hand, basophilic tubules with peritubular lymphoid cell infiltration were multifocally observed in the cortex. In conclusion, PCP induced multiple renal cysts that developed in the collecting ducts of the outer medulla in neonatal rats, and it is suggested that epithelial cell proliferation may play some roles in the induction of cystic lesions. 相似文献
47.
A sharp peak of the zero-temperature penetration depth at optimal composition in BaFe2(As(1-x)P(x))2
Hashimoto K Cho K Shibauchi T Kasahara S Mizukami Y Katsumata R Tsuruhara Y Terashima T Ikeda H Tanatar MA Kitano H Salovich N Giannetta RW Walmsley P Carrington A Prozorov R Matsuda Y 《Science (New York, N.Y.)》2012,336(6088):1554-1557
In a superconductor, the ratio of the carrier density, n, to its effective mass, m*, is a fundamental property directly reflecting the length scale of the superfluid flow, the London penetration depth, λ(L). In two-dimensional systems, this ratio n/m* (~1/λ(L)(2)) determines the effective Fermi temperature, T(F). We report a sharp peak in the x-dependence of λ(L) at zero temperature in clean samples of BaFe(2)(As(1)(-x)P(x))(2) at the optimum composition x = 0.30, where the superconducting transition temperature T(c) reaches a maximum of 30 kelvin. This structure may arise from quantum fluctuations associated with a quantum critical point. The ratio of T(c)/T(F) at x = 0.30 is enhanced, implying a possible crossover toward the Bose-Einstein condensate limit driven by quantum criticality. 相似文献
48.
Mikio Shiraishi 《Euphytica》1993,71(1-2):99-106
49.
Inhibitory effects of lignans on the activity of human matrix metalloproteinase 7 (matrilysin) 总被引:1,自引:0,他引:1
Muta Y Oyama S Umezawa T Shimada M Inouye K 《Journal of agricultural and food chemistry》2004,52(19):5888-5894
Inhibitory effects of nine dibenzylbutyrolactone lignans on a human matrix metalloproteinase, matrilysin, were examined. All of the lignans examined inhibited matrilysin with the IC(50) values ranging from 50 to >280 microM. Matairesinol, which has the basic structure of the other lignans, showed the weakest inhibition. Lignans with methylenedioxy ring(s) or a hydroxyl group at the C5-position inhibited matrilysin more strongly than matairesinol. 5-Hydroxypluviatolide, which has both a methylenedioxy ring and a hydroxyl group at the C5-position, was the most potent inhibitor (IC(50) = 50 microM), suggesting that the introduction of these two elements might enhance synergistically the inhibitory activity of lignans. 5-Hydroxypluviatolide inhibited matrilysin in a competitive manner, and its inhibitory effect was greatly suppressed by the presence of another competitive inhibitor, dimethyl sulfoxide. The precursors of matairesinol, coniferyl alcohol and secoisolariciresinol, had no inhibitory activity, indicating that the dibenzylbutyrolactone structure is essential for the inhibition. It has been shown that lignans have the potential to inhibit matrilysin, and the knowledge of their structure-activity relationship might be beneficial to developing selective inhibitors for matrix metalloproteinases. 相似文献
50.
Sato H Hirata N Koketsu K Okaya D Abe S Kobayashi R Matsubara M Iwasaki T Ito T Ikawa T Kawanaka T Kasahara K Harder S 《Science (New York, N.Y.)》2005,309(5733):462-464
Devastating earthquakes occur on a megathrust fault that underlies the Tokyo metropolitan region. We identify this fault with use of deep seismic reflection profiling to be the upper surface of the Philippine Sea plate. The depth to the top of this plate, 4 to 26 kilometers, is much shallower than previous estimates based on the distribution of seismicity. This shallower plate geometry changes the location of maximum finite slip of the 1923 Kanto earthquake and will affect estimations of strong ground motion for seismic hazards analysis within the Tokyo region. 相似文献