全文获取类型
收费全文 | 417篇 |
免费 | 18篇 |
专业分类
林业 | 23篇 |
农学 | 11篇 |
42篇 | |
综合类 | 26篇 |
农作物 | 15篇 |
水产渔业 | 17篇 |
畜牧兽医 | 246篇 |
园艺 | 2篇 |
植物保护 | 53篇 |
出版年
2022年 | 7篇 |
2021年 | 15篇 |
2020年 | 7篇 |
2019年 | 9篇 |
2018年 | 16篇 |
2017年 | 9篇 |
2016年 | 5篇 |
2015年 | 16篇 |
2014年 | 15篇 |
2013年 | 21篇 |
2012年 | 19篇 |
2011年 | 15篇 |
2010年 | 10篇 |
2009年 | 7篇 |
2008年 | 18篇 |
2007年 | 15篇 |
2006年 | 29篇 |
2005年 | 26篇 |
2004年 | 18篇 |
2003年 | 21篇 |
2002年 | 16篇 |
2001年 | 25篇 |
2000年 | 19篇 |
1999年 | 18篇 |
1998年 | 5篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1992年 | 9篇 |
1991年 | 6篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 3篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1980年 | 2篇 |
1978年 | 1篇 |
1977年 | 3篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1971年 | 1篇 |
1969年 | 1篇 |
1966年 | 1篇 |
1964年 | 1篇 |
排序方式: 共有435条查询结果,搜索用时 0 毫秒
151.
152.
Kato Chihiro Sasaki Choichi Endo Akira Matsuyama Nobuhiko Nishimura Taku 《Paddy and Water Environment》2019,17(2):55-61
Paddy and Water Environment - Crops adapt to variable soil moisture by varying the distribution of their roots and patterns of water absorption. Meanwhile, proper numerical model for predicting... 相似文献
153.
Ryohei Suzuki Hirotaka Matsumoto Takahiro Teshima Hidekazu Koyama 《Journal of Veterinary Cardiology》2013,15(1):41-49
ObjectiveThe objective of this study was to clinically assess myocardial deformations in dogs with chronic mitral valve insufficiency (CMVI) using two-dimensional speckle-tracking echocardiography (2D-STE).Animals87 dogs with CMVI.MethodsDogs were placed into 1 of 3 classes, based on the International Small Animal Cardiac Health Council classification. In addition, 20 weight- and age-matched healthy dogs were enrolled as controls. The dogs were examined for myocardial deformations using 2D-STE, and strain and strain rate in the longitudinal, circumferential, and radial directions were evaluated.ResultsClass II and III dogs had higher circumferential strain than class I dogs (P = 0.002 and P = 0.001, respectively) and controls (P < 0.001 and P < 0.001, respectively). Class III dogs had higher radial strain than class I dogs (P = 0.001) and controls (P < 0.001). Class III dogs had higher radial strain rate than class I dogs (P = 0.006) and controls (P = 0.001). Other deformations, including longitudinal deformations, were not significantly different between classes of CMVI or between CMVI dogs and controls.ConclusionsIn the clinical progression of CMVI in dogs, myocardial deformations, as assessed by 2D-STE, differed according to myocardial contractile direction. Thus, assessments of multidirectional myocardial deformations may be important for better assessment of clinical cardiac function in dogs with CMVI. 相似文献
154.
Progesterone stimulation by LH involves the phospholipase-C pathway in bovine luteal cells 总被引:2,自引:0,他引:2
Nishimura R Shibaya M Skarzynski DJ Okuda K 《The Journal of reproduction and development》2004,50(2):257-261
Luteinizing hormone (LH)-stimulated steroidogenesis in luteal cells is known to be mediated through the activation of cyclic AMP (cAMP)-dependent protein kinase, and to be also modulated by calcium-dependent mechanisms. In the present study, we tested the hypothesis that LH stimulates progesterone (P4) production in bovine luteal cells through activation of phospholipase (PL) C by using a cell culture system. Bovine mid-luteal cells (Days 8-12 of the estrous cycle) were cultured for 24 h and then exposed to a PLC inhibitor (U-73122; 10 microM) with or without LH (10 ng/ml) for 4 h. U-73122 blocked LH-stimulated P4 production without affecting cAMP accumulation. Moreover, exposure of luteal cells to PLC increased P4 production in a dose-dependent manner. These results support the hypothesis that the luteotropic action of LH in bovine luteal cells is mediated not only by activation of adenylate cyclase but also by activation of PLC. 相似文献
155.
ABSTRACT: The synergetic effects of an immobilized cell system in an oleophilic polyurethane foam (PUF) and use of a thermotolerant strain on degradation of hydrocarbons by colorless green microalga Prototheca zopfii are reported. Two strains of P. zopfii , i.e. thermotolerant RND16 and non-thermotolerant ATCC30253, were immobilized in PUF to compare their abilities to biodegrade a mixed hydrocarbon substrate (MHS) containing aliphatic and polycyclic aromatic hydrocarbons (PAHs), as a function of temperature. The thermotolerant strain RND16 degraded MHS at 35°C, while ATCC30253 did not degrade hydrocarbons at temperatures higher than 30°C. Immobilization of P. zopfii in PUF resulted in shortened lag for growth-associated biodegradation of n -alkanes in MHS, the effect of which was most significant in cultures of RND16 at 25°C. Nevertheless, the decrease in the amount of degraded PAHs was caused by PUF immobilization and the level of this decrease was marked in the cultures of RND16, in which rate and extent of n -alkane degradation were higher than for ATCC30253. 相似文献
156.
Hidetoshi?UrakawaEmail author Tsutomu?Yoshida Masahiko?Nishimura Kouichi?Ohwada 《Fisheries Science》2005,71(1):174-182
ABSTRACT: Respiratory quinone compositions were analyzed by a high-performance liquid chromatography to characterize the depth-related changes and site-specific differences of microbial communities in marine sediments. Two deep-sea sediment samples and one coastal sediment sample were investigated from three sites on the coast of Japan, Sagami Bay, Suruga Bay and Tokyo Bay. Although depth-related changes in microbial community structures were observed, site-specific differences appeared to have greater influence on overall community structures. A variety of quinone homologs was commonly identified at all sampling sites and depths examined, but a few minor quinone fractions, mainly derived from Actinobacteria , were detected only at specific sampling sites. Methylmenaquinone-7 (MMK-7) was the major component throughout the examined depths in Sagami Bay and Tokyo Bay. Most abundant quinone homologs changed with each depth in Suruga Bay. Menaquinone-6 (MK-6) predominated in the 0 to 2-cm layer (19%). Below 0–2 cm, the most abundant homolog in each sampling depth was phylloquinone (K1 ; 13%, 4–6 cm), MK-8 (19%, 8–10 cm) and MK-7 (13%, 16–18 cm). The microbial respiratory quinone profiling method shown here, successfully demonstrates the usefulness of this approach to characterize microbial communities in marine sediments. 相似文献
157.
Tamon?YamashitaEmail author Nobuhiko?Kasuya Sen?Nishimura Hiroshi?Takeda 《Journal of Forest Research》2004,9(4):333-340
The effects of root exclusion and planted tree species on soil nitrogen (N) dynamics were examined at two plantations, one
planted with Japanese cedar and the other with Japanese cypress. We set up ten 1 × 1 × 0.2-m-deep trenched sites and ten untrenched
control sites at each plantation. We measured the pool size and leaching of inorganic N at each site for 2 years and the net
N mineralization 1 and 2 years after trenching. Despite similar soil conditions, the cedar plantation showed higher net N
mineralization than the cypress plantation. Stopped tree uptake of N was expected to cause an increased pool size and leaching
of inorganic N at the trenched sites. Nevertheless, we found no significant increase in those variables at both plantations.
The trenched cypress sites showed no decrease in the net N mineralization during the 2 years after trenching. However, the
net nitrification at the trenched cypress sites increased remarkably at the deeper horizons in comparison with that at the
control sites. Enhanced nitrification might result from improved ammonium availability through root exclusion. Net N mineralization
at the trenched cedar sites decreased more than 60% compared with that at the control sites 2 years after trenching. Higher
nitrification potential at the cedar plantation and enhanced nitrification potential at the trenched cypress sites never resulted
in increased leaching of N, due to added fine root litter which acted as an immobilization agent for excess N, thus preventing
N loss. 相似文献
158.
Wei Gao Yoko Kanahara Ryohei Tatsuno Kiyoshi Soyano Gregory N. Nishihara Chisato Urata Tomohiro Takatani Osamu Arakawa 《Fisheries Science》2018,84(4):723-732
To clarify the maturation-associated accumulation profile of tetrodotoxin (TTX) in the female pufferfish Takifugu pardalis, specimens collected from Omura Bay, Nagasaki Prefecture, Japan, from November through December, 2014, were separated based on the histology of ovarian sections into four groups: yolk vesicle stage (Yv), yolk globule stage (Yg)-1, Yg-2, and Yg-3. TTX quantification in each tissue in each group by liquid chromatography–mass spectrometry revealed that the TTX concentration [mouse unit (MU)/g] in the ovary increased from Yv to Yg-1, and the TTX amount (MU/individual) in the ovary increased from Yg-1 through Yg-3. In Yv, TTX in the skin accounted for 86% of the total TTX in the body, whereas from Yg-1 through Yg-3, ovarian TTX accounted for 53–76% of the total. In female specimens collected from the same bay from February to May 2015, the TTX amount in the ovary markedly decreased after spawning, and the TTX amount in the liver increased. Immunohistochemical observation of the ovarian sections indicated that TTX localized mainly in the nucleus of immature oocytes, but then distributes to the yolk vesicles and yolk globules as maturation advances, and is partly transferred to the egg membrane as spawning approaches. 相似文献
159.
ABSTRACT: The recruitment abundance index of Pacific bluefin tuna Thunnus orientalis was estimated from 1980 to 2003 fishing year by using the troll fishery data in Nagasaki Prefecture, western Japan. It has been shown that the troll fishery in Nagasaki Prefecture operates with good time–area coverage of the species habitat, and that the fishing power slightly changed during the period analyzed, based on fisheries statistics, published information, and interviews with the fishers. Average catch per unit effort (CPUEs) were standardized by a generalized linear model (GLM) considering the effects of fishing year, season and landing area. Standardized CPUE of age-0 bluefin tuna showed larger fluctuations year by year than the nominal CPUE combined for all ages. High CPUEs in fishing years of 1981, 1994, 1996 and 1999 were observed. Data from these years agreed with the higher recruitments estimated by virtual population analysis (VPA) or higher catch of age-0 fish reported for the Pacific side. The age-specific standardized CPUE of age-0 bluefin tuna in this study was judged to be a useful indicator of recruitment. 相似文献
160.
Mohammad M. Monir Kohzy Hiramatsu Sachiko Matsumoto Kei Nishimura Chihiro Takemoto Tomomi Shioji Takafumi Watanabe Kazumi Kita Shinichi Yonekura Sang Gun Roh 《Animal Science Journal》2014,85(5):581-587
Influences of a specific dietary nutrient on glucagon‐like peptide (GLP)‐1‐containing cells in the chicken intestine are not yet clear. Significance of dietary protein level on GLP‐1‐containing cells in the chicken ileum was investigated. Chickens fed control or experimental diets of varying protein levels were examined using immunohistochemical and morphometrical techniques. We show that the protein ingestion had an impact on the activities of GLP‐1‐immunoreactive cells in the chicken ileum. Weight gains declined with decreasing dietary crude protein (CP) levels, but no significant differences were detected in the daily feed intake and villous height. GLP‐1‐immunoreactive cells with a round or oval shape were frequently observed in the lower CP level groups (4.5% and 0%). Frequencies of occurrence of GLP‐1‐immunoreactive cells were 41.1 ± 4.1, 38.5 ± 4, 34.8 ± 3.1 and 34.3 ± 3.7 (cells/mm2, mean ± SD) for dietary CP level of 18%, 9%, 4.5% and 0% groups, respectively and significant differences were recognized between the control and lower CP level groups (P < 0.05). Multiple regression analysis indicated a significant correlation between the daily protein intake and frequencies of occurrence of GLP‐1‐immunoreactive cells. The protein ingestion is one of the signals that influence GLP‐1‐containing cells in the chicken small intestine. 相似文献