全文获取类型
收费全文 | 349篇 |
免费 | 15篇 |
专业分类
林业 | 26篇 |
农学 | 11篇 |
70篇 | |
综合类 | 21篇 |
农作物 | 16篇 |
水产渔业 | 39篇 |
畜牧兽医 | 141篇 |
园艺 | 5篇 |
植物保护 | 35篇 |
出版年
2023年 | 2篇 |
2022年 | 4篇 |
2021年 | 9篇 |
2020年 | 6篇 |
2019年 | 8篇 |
2018年 | 6篇 |
2017年 | 8篇 |
2016年 | 17篇 |
2015年 | 18篇 |
2014年 | 13篇 |
2013年 | 20篇 |
2012年 | 25篇 |
2011年 | 29篇 |
2010年 | 15篇 |
2009年 | 10篇 |
2008年 | 22篇 |
2007年 | 22篇 |
2006年 | 28篇 |
2005年 | 22篇 |
2004年 | 23篇 |
2003年 | 24篇 |
2002年 | 16篇 |
2001年 | 6篇 |
2000年 | 6篇 |
1999年 | 1篇 |
1998年 | 2篇 |
1985年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有364条查询结果,搜索用时 31 毫秒
41.
Ogawa H Chahota R Hagino T Ohya K Yamaguchi T Fukushi H 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2006,68(7):743-745
Although birds infected with avian polyomavirus (APV) subclinically could be a source of infection, no epidemiological studies of APV in psittacine birds have been reported in Japan. In the present study, we investigated subclinical morbidity rate of APV in imported and domestically bred psittacine birds by polymerase chain reaction (PCR). Of 402 live birds from which blood or feather samples were taken between April, 2003 and March, 2004, 11 (2.7%) were found to be APV positive. The DNA sequences of the APV t/T antigen region were determined for five APV-positive randomly selected samples and were found to be conserved. 相似文献
42.
We present direct evidence for complex p-wave order parameter symmetry and the presence of dynamical chiral order parameter domains of the form px +/- ipy in the ruthenate superconductor Sr2RuO4. The domain structure creates differences in the magnetic field modulation of the critical current of Josephson junctions fabricated on orthogonal faces of Sr2RuO4 single crystals. Transitions between the chiral states of a domain or the motion of domain walls separating them generates telegraph noise in the critical current as a function of magnetic field or time and is responsible for hysteresis observed in field sweeps of the critical current. The presence of such domains confirms the p-wave triplet spin and complex (broken time-reversal symmetry) nature of the superconducting pairing state in Sr2RuO4. 相似文献
43.
M. I. Tajul Takayuki Motoyama Akikazu Hatanaka M. Sariah Hiroyuki Osada 《European journal of plant pathology / European Foundation for Plant Pathology》2012,132(1):91-100
Four green-odour compounds—trans-2-hexenal, cis-3-hexenol, n-hexanal, and cis-3-hexenal—were applied (0.85 μg ml−1 as vapour) to rice plants in laboratory conditions to observe their biological activity against the phytopathogenic fungus
Maganporthe oryzae, which causes rice blast disease worldwide. Two compounds, trans-2-hexenal and cis-3-hexenal, showed remarkable disease suppression efficacy (99.7% and 100% suppression, respectively), while n-hexanal had moderate (86.5%) and cis-3-hexenol had weak (20.8%) disease-suppressing effects. Pre-application and post-application of trans-2-hexenal or cis-3-hexenal had slight effects on blast incidence, suggesting that these compounds had direct effects to suppress M. oryzae infection. In fact, trans-2-hexenal and cis-3-hexenal exhibited a growth suppression effect on M. oryzae. Interestingly, these two compounds inhibited appressorium formation at lower concentrations than the growth suppression.
Studies on the hypersensitive response (HR)-like reaction and plant β-1,3-glucanase activity in rice plant confirmed that
induced resistance was not the major factor involved in the disease suppression mechanism. Results of this study conclusively
showed that trans-2-hexenal and cis-3-hexenal possess potent inhibitory activities against the growth and the appressorium formation of M. oryzae and could be used as antifungal agents to significantly reduce M. oryzae infections in rice. 相似文献
44.
Using two sets of chromosome segment substitution lines (CSSLs) of crosses between cvs. ‘Koshihikari’ and ‘Kasalath’ (Ko/Ka) and between ‘Koshihikari’ and ‘Nona Bokra’ (Ko/NB), respectively, we have identified alleles for ten traits related to productivity (e.g., harvest index and biomass) in rice (Oryza sativa L.). A total of 43 chromosome regions affecting traits (CRATs) in Ko/Ka CSSLs and 40 in Ko/NB CSSLs were detected. Among them, ten and 18 CRATs in Ko/Ka and Ko/NB CSSLs, respectively, had positive effects. A CRAT for harvest index (HI) with a positive allele from ‘Kasalath’ on chromosome 6 (tentatively named HI6) increased the HI by 25 % relative to ‘Koshihikari’, raising it to the theoretical upper limit in rice (0.6). Functional analysis using CSSLs with HI6 indicated that HI6 reduced the size of the lower parts of the plant, which is not important for production, while maintaining the size of the other organs related to production (e.g., flag leaf and panicle), resulting in improved nitrogen (N) use efficiency. These results suggest an ‘ideal plant type’ with improved N use efficiency that can sustain higher yields. A CRAT for the SPAD (soil plant analysis development) value, which is a chlorophyll meter value commonly used as an indicator of leaf N content and strongly associated with the source ability of a leaf, with a ‘Nona Bokra’ allele on chromosome 4 increased the value by 13 % relative to ‘Koshihikari’ with no loss of leaf area. These CRATs can be used for the improvement of rice productivity. 相似文献
45.
Okawa T Kurio Y Morimoto M Hayashi T Nakagawa T Sasaki N Okuda M Mizuno T 《Research in veterinary science》2012,92(1):80-91
This is the first report describing the expression of canine calreticulin (cCRT) in canine mammary gland tumour (MGT). Using cDNA subtraction method, it is found that mRNAs of CRT, cathepsin A, ovostatin, and lactotransferrin were differentially expressed in mammary adenocarcinoma as compared to hyperplasia, both of which were obtained from the dog. Furthermore, the mRNA expression levels of CRT and cathepsin A were significantly higher in canine MGT samples than in nontumour samples. In contrast, immunohistochemical studies have indicated that the expression of cCRT protein found to be detected in most of mammary gland tissues and was not correlated to the types of canine MGTs. Furthermore, cCRT was molecularly cloned, and the amino acid sequence of cCRT was found to be very similar to those of other species. Further studies are required to elucidate additional roles of cCRT in canine MGT. 相似文献
46.
Significance of tumor-infiltrating immune cells in spontaneous canine mammary gland tumor: 140 cases
Saeki K Endo Y Uchida K Nishimura R Sasaki N Nakagawa T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2012,74(2):227-230
The numbers of tumor infiltrating T lymphocytes, B lymphocytes and antigen presenting cells were evaluated in an immunohistochemical manner in 140 canine spontaneous mammary gland tumor (MGT) tissues. As a result, we found a statistically significant increase in the number of intratumoral T lymphocytes (23.2 ± 23.8) in the malignant MGT group (n=51) compared with the benign MGT group (14.0 ± 16.0, n=89; P<0.05). Moreover, the high T lymphocyte infiltration in the malignant group correlated with poor prognosis in multivariate analysis (P<0.05). This study indicated the relationship between increased infiltrating T lymphocytes and canine MGT malignancy. 相似文献
47.
WULIJIDELIGEN Takayuki ASAHINA Kazushi HARA Kensuke ARAKAWA Hiroyuki NAKANO Taku MIYAMOTO 《Animal Science Journal》2012,83(10):704-711
The purification and characterization of a bacteriocin produced by Leuconostoc mesenteroides strain 406 that was isolated from traditional Mongolian fermented mare's milk, airag, were carried out. Leuconostoc mesenteroides strain 406 was identified on the basis of its morphological and biochemical characteristics and carbohydrate fermentation profile and by API 50 CH kit and 16S ribosomal DNA analyses. The neutral‐pH cell‐free supernatant of this bacterium inhibited the growth of several lactic acid bacteria and food spoilage and pathogenic organisms, including Listeria monocytogenes and Clostridium botulinum. The bacteriocin was heat‐stable and not sensitive to acid and alkaline conditions, but was sensitive to several proteolytic enzymes such as pepsin, pronase E, proteinase K, trypsin, and α‐chymotrypsin, but not catalase. Optimum bacteriocin production (4000 activity units/mL) was achieved when the strain was cultured at 25°C for 24–36 h in Man Rogosa Sharpe medium. The bacteriocin was partially purified by ammonium sulfate precipitation (80% saturation), dialysis (cut‐off MW: 1000), and gel filtration chromatography. Sodium dodecyl sulfate‐polyacrylamide gel electrophoresis revealed that the bacteriocin had a molecular weight of approximately 3.3 kDa. To our knowledge, this is the first report of the isolation of a bacteriocin‐producing Leuconostoc strain from airag. An application to fermented milks would be desired. 相似文献
48.
Takeo Sakaigaichi Yoshifumi Terajima Makoto Matsuoka Shin Irei Seiji Fukuhara Takayuki Mitsunaga 《Plant Production Science》2013,16(2):327-332
ABSTRACT Sugarcane smut, caused by Sporisorium scitamineum, is one of the most important sugarcane diseases in Japan. Wild sugarcane, Saccharum spontaneum, is known to be a key breeding material to obtain high-yielding clones. In this study, we sought to identify Japanese wild sugarcane accessions with high resistance to smut. Thirty wild sugarcanes and three sugarcane cultivars were tested by the pinprick method. The results of the inoculation tests aided in identifying wild sugarcanes with high resistance to smut disease, namely JW90, Iriomote8, and Iriomote15. After screening the germplasm, progeny distribution of smut resistance from the inoculation test and dry matter productivity in the smut disease-free field were compared. The highly resistant wild sugarcane accession had a much better impact on progeny distribution of smut resistance compared with the susceptible accession. No relationship was found between smut resistance and dry matter productivity in both populations. 相似文献
49.
Estimates of genetic parameters were obtained for body measurement traits of 648 animals at 4 months of age, of 545 at 8 months and carcass traits of 14 972 animals with the use of an animal model by the restricted maximum likelihood procedure. The estimated heritabilities for carcass traits were high (0.41 to 0.54). At 4 months the estimated direct heritabilities for body measurement traits were moderate to high (0.28 to 0.64), except for chest width (0.19); at 8 months they were also moderate to high (0.23 to 0.49), except for chest depth and chest width (0.18 and 0.06, respectively). Maternal heritabilities for all body measurement traits were low at both ages. The results indicate that because of their moderate direct genetic correlations with body measurement traits, carcass weight, rib thickness and subcutaneous fat thickness can be improved; however, rib eye area and beef marbling standard show little such possibility considering their correlation with body measurement traits. 相似文献
50.
The green fraction of humic acid (Pg) and the chloroform-extractable green fraction (CEGF) are characteristic soil organic matter (SOM) components. These alkaline solutions are green-colored due to the presence of 4,9-dihydroxyperylene-3,10-quinone (DHPQ) chromophore. While both of which are potential indicators for the effect of land use and paleoclimatic environment in the fields of soil science as well as geochemistry, CEGF as well as its relationship with Pg in soils are not yet fully documented. In this study, we firstly investigated the chemical properties of soil CEGF fractions by ultraviolet–visible (UV–Vis) and infrared (IR) method. Two CEGF components were separated by sequential liquid-liquid extraction using aqueous ammonium hydroxide (NH4OH) followed by aqueous sodium hydroxide (NaOH). Results showed that the UV–Vis spectral shape of NH4OH-extractable component is very similar to that of DHPQ, except that it is red-shifted. The solubility and UV–Vis spectrum of the NaOH-extractable fraction were completely identical with those of synthesized DHPQ. Their IR spectral shapes were also almost the same. Subsequently, the distribution of CEGF in humic acid (HA), fulvic acid (FA) and humin (HN) from Japanese Andosols and Cambisol was quantitatively evaluated by sequential extraction. Most of CEGF was detected in the HA (60–78%) and HN (22–40%), but not in the FA. While the UV–Vis spectral shape of CEGF extracted from Andosols HAs showed a relatively higher proportion of DHPQ than its derivative, the opposite was observed in Cambisol HA, whose CEGF is similar to that of sclerotium grain (one of the possible origin of CEGF). These results suggest the diversity of CEGF-producing soil fungi. Quantitative data also indicated that 35–49% of Pg consisted of a chloroform-soluble fraction (i.e., CEGF) and the remaining 51–65% of Pg was chloroform-insoluble. Based on these results, we propose that CEGF is composed of DHPQ and DHPQ-derivatives and that CEGF is one of the major fractions of Pg. 相似文献