全文获取类型
收费全文 | 1018篇 |
免费 | 34篇 |
国内免费 | 3篇 |
专业分类
林业 | 137篇 |
农学 | 50篇 |
基础科学 | 1篇 |
192篇 | |
综合类 | 55篇 |
农作物 | 40篇 |
水产渔业 | 101篇 |
畜牧兽医 | 371篇 |
园艺 | 13篇 |
植物保护 | 95篇 |
出版年
2023年 | 4篇 |
2022年 | 7篇 |
2021年 | 31篇 |
2020年 | 13篇 |
2019年 | 13篇 |
2018年 | 20篇 |
2017年 | 15篇 |
2016年 | 23篇 |
2015年 | 32篇 |
2014年 | 29篇 |
2013年 | 103篇 |
2012年 | 46篇 |
2011年 | 70篇 |
2010年 | 37篇 |
2009年 | 47篇 |
2008年 | 68篇 |
2007年 | 57篇 |
2006年 | 76篇 |
2005年 | 61篇 |
2004年 | 50篇 |
2003年 | 42篇 |
2002年 | 32篇 |
2001年 | 26篇 |
2000年 | 28篇 |
1999年 | 18篇 |
1998年 | 15篇 |
1997年 | 7篇 |
1996年 | 5篇 |
1995年 | 2篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1992年 | 4篇 |
1991年 | 8篇 |
1990年 | 3篇 |
1989年 | 4篇 |
1988年 | 3篇 |
1987年 | 4篇 |
1986年 | 10篇 |
1985年 | 7篇 |
1984年 | 2篇 |
1979年 | 2篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1972年 | 2篇 |
1970年 | 3篇 |
1967年 | 3篇 |
1966年 | 1篇 |
1964年 | 2篇 |
1962年 | 1篇 |
排序方式: 共有1055条查询结果,搜索用时 515 毫秒
1.
Kunio Shirakihara Masahiko Yoshida Machiko Nishino Yoshimi Takao Kouichi Sawada 《Fisheries Science》2001,67(3):430-435
SUMMARY: The vertical distribution of dwarf ayu Plecoglossus altivelis altivelis in the pelagic waters of Lake Biwa was evaluated from June to September in 1995–97 from eight acoustic surveys using a quantitative echosounder. In each survey, echoes from a depth range of 3 m to the sea bottom were collected at a station every 2.7 s for 24 h together with measurements of vertical profiles of water temperature and chlorophyll-a. The ayu's echoes were identified using an underwater video camera. The ayu were observed near the maximum chlorophyll-a depth and above the thermocline. Their density was highest at depths of 4–11 m with 2–4 individuals/m 3 and was almost zero below 20 m. Echo signs were recorded as having a frequent duration of more than 1 h at night, whereas were of a shorter duration in the day. The fish stay in the epilimnion during the day without any clear vertical migration, but are distributed more uniformly at night. The advantages of remaining in the epilimnion are discussed in terms of food availability and predator avoidance. 相似文献
2.
3.
Kouichi Suzaki Ken-ichi Ikeda Atsuko Sasaki Satoko Kanematsu Naoyuki Matsumoto Kouji Yoshida 《Journal of General Plant Pathology》2005,71(3):161-168
Monokaryotic strains of Helicobasidium mompa were used as vectors of a mycovirus between various H. mompa isolates to examine the transmissibility of one of the mycoviruses, totivirus (HmTV1–17 virus) in the hypovirulent isolate V17 of H. mompa. The isolates that acquired HmTV1–17 virus were also examined for any alteration in the virulence. Twelve dikaryotic isolates of H. mompa, belonging to 11 mycelial compatibility groups (MCGs) and being mycelially incompatible with isolate V17, were used as recipients of HmTV1–17 virus. Two monokaryotic isolates that were mycelially incompatible with isolate V17 and all of the recipients were also used as vectors of HmTV1-17 virus between isolate V17 and the recipients. When isolate V17 and recipients were directly paired on plate media, HmTV1-17 virus was transmitted from isolate V17 into 2 of the 12 recipients (i.e., 2 of the 11 MCGs). Two monokaryotic strains were paired with isolate V17, and the monokaryotic strains that acquired HmTV1-17 virus were then used as new virus donors. When the monokaryotic strains containing HmTV1-17 virus were paired with the 12 recipients, HmTV1-17 virus was transmitted into 7 of the 12 recipients from the monokaryotic strains (i.e., 7 of 11 MCGs). Based on these results, we concluded that monokaryotic strains could act as vectors to transmit HmTV1-17 virus into H. mompa isolates. When four of the H. mompa isolates that acquired HmTV1-17 virus were used to inoculate apple rootstock Malus prunifolia, the virulence of all of the isolates was attenuated from that of their parental isolates. Moreover, because the DNA fingerprints of the fungal isolates that acquired HmTV1-17 virus were the same as those of their parental isolates, the infection with HmTV1-17 virus is considered the cause of virulence attenuation of H. mompa. 相似文献
4.
5.
Minimal Set of Metabolic Pathways Suggested from the Genome of Onion Yellows Phytoplasma 总被引:1,自引:0,他引:1
6.
Competitive enzyme-linked immunosorbent assay for the detection of the antibodies specific to akabane virus. 总被引:5,自引:0,他引:5
Tomoyuki Tsuda Kazuo Yoshida Tohru Yanase Seiichi Ohashi Makoto Yamakawa 《Journal of veterinary diagnostic investigation》2004,16(6):571-576
A competitive enzyme-linked immunosorbent assay (C-ELISA) using neutralizing monoclonal antibodies (MAbs) against Akabane virus (AKAV) was developed to detect antibodies to AKAV in cattle sera. The performance of the test using 7 different competitor MAbs was evaluated in sequential serum samples and sera from cattle infected with various bovine arboviruses. The dynamics of the antibody response expressed by percentage of inhibition (PI) in C-ELISA coincided with those of neutralizing antibody titers in sequential serum samples from 2 cattle experimentally infected with AKAV. The value of PI in C-ELISA for convalescent sera from cattle infected with arboviruses correlated with the neutralizing antibody titer to AKAV but was unaffected by the antibodies to other arboviruses. In the validation experiment of C-ELISA using 286 bovine sera previously examined for the AKAV antibody by serum neutralization (SN) test, the relative specificity of C-ELISA was more than 98%, whereas the relative sensitivities of individual MAbs ranged from 49% to 82.2%. Overall agreement between C-ELISA and the SN test varied from 72% to 90% depending on the MAb. These results suggest that the C-ELISA is acceptable as a rapid and specific method for detecting antibodies to AKAV and is a potential alternative to the SN test. 相似文献
7.
Yoshida Koshi Srisutham Mallika Sritumboon Supranee Suanburi Desell Janjirauttikul Naruekamon 《Paddy and Water Environment》2019,17(3):341-349
Paddy and Water Environment - In Thailand, climate change has a direct effect on the export of food and agricultural products, which is one of the main revenue sources of the country. Furthermore,... 相似文献
8.
9.
Tsutomu Ohkoda Katsunori Yoshida Daichi Ijiri Akira Ohtsuka 《Animal Science Journal》2021,92(1):e13655
We investigated the effect of mixed rearing of barrows and gilts on the backfat thickness and the serum metabolite profiles of Kagoshima-Kurobuta (Berkshire) pigs. A total of 149 pigs with an average body weight of 35 kg were divided into the following groups: 100%, 90%, 70%, 50%, 30%, 10%, and 0% groups consisting of 10 barrows (1 pen), 9 barrows + 1 gilt (3 pens), 7 barrows + 3 gilts (2 pens), 5 barrows + 5 gilts (3 pens), 3 barrows + 7 gilts (2 pens), 1 barrow + 9 gilts (3 pens), and 9 gilts (1 pen), respectively. All pigs were raised to a shipping weight of 120 kg. Mixed rearing significantly reduced (p < 0.001) backfat thickness, and the optimum mixing ratio of barrows and gilts was 7:3 (the 70% group). Four types of circulating sex steroids were found in both the barrows and gilts in the 50% group but were not detected in barrows from the 100% group. These results indicated that mixed rearing of barrows and gilts was effective for reducing the backfat thickness of barrows, and induced sex steroid hormones may influence the backfat thickness of barrows in mixed-reared groups. 相似文献
10.
Immunogenic properties of Landrace pigs selected for resistance to mycoplasma pneumonia of swine 下载免费PDF全文
Liushiqi Borjigin Tomoyuki Shimazu Yuki Katayama Meihua Li Takumi Satoh Kouichi Watanabe Haruki Kitazawa Sang‐gun Roh Hisashi Aso Kazuo Katoh Takafumi Uchida Yoshihito Suda Akiko Sakuma Mituru Nakajo Keiichi Suzuki 《Animal Science Journal》2016,87(3):321-329
Mycoplasma pneumonia of swine (MPS) lung lesions and immunogenic properties were compared between a Landrace line that was genetically selected for reduced incidence of pulmonary MPS lesions, and a non‐selected Landrace line. The MPS‐selected Landrace line showed significantly lower degrees of pulmonary MPS lesions compared with the non‐selected Landrace line. When changes in immunity before and after vaccination were compared, the percentage of B cells in the peripheral blood of the MPS‐selected Landrace line was significantly lower than that of the non‐selected line. Furthermore, the concentration of growth hormone and the mitogen activity of peripheral blood mononuclear cells in the MPS‐selected Landrace line showed significantly (P < 0.05) lower increases after vaccination than the non‐selected line. Conversely, the concentration of peripheral blood interferon (IFN)‐γ and salivary immunoglobulin A (IgA) after Mycoplasma hyopneumoniae vaccination was significantly higher in the MPS‐selected Landrace line than in the non‐selected line. Gene expression of toll‐like receptor (TLR)2 and TLR4 was significantly higher in the MPS‐selected Landrace line in immune tissues, with the exception of the hilar lymph nodes. The present results suggest that peripheral blood IFN‐γ, salivary IgA TLR2, and TLR4 are important immunological factors influencing the development of MPS lesions. 相似文献