全文获取类型
收费全文 | 80篇 |
免费 | 9篇 |
专业分类
林业 | 1篇 |
综合类 | 17篇 |
畜牧兽医 | 70篇 |
植物保护 | 1篇 |
出版年
2018年 | 3篇 |
2017年 | 1篇 |
2016年 | 3篇 |
2015年 | 2篇 |
2014年 | 3篇 |
2013年 | 11篇 |
2012年 | 2篇 |
2010年 | 3篇 |
2009年 | 1篇 |
2007年 | 1篇 |
2002年 | 1篇 |
2001年 | 1篇 |
1999年 | 1篇 |
1998年 | 11篇 |
1997年 | 1篇 |
1996年 | 3篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 6篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1988年 | 5篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1975年 | 1篇 |
1973年 | 3篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1906年 | 1篇 |
排序方式: 共有89条查询结果,搜索用时 0 毫秒
71.
Canine tick‐borne pathogens and associated risk factors in dogs presenting with and without clinical signs consistent with tick‐borne diseases in northern Australia 下载免费PDF全文
72.
S Chen RS Ingram MJ Hostetler JJ Pietron RW Murray TG Schaaff JT Khoury MM Alvarez RL Whetten 《Science (New York, N.Y.)》1998,280(5372):2098-2101
A transition from metal-like double-layer capacitive charging to redox-like charging was observed in electrochemical ensemble Coulomb staircase experiments on solutions of gold nanoparticles of varied core size. The monodisperse gold nanoparticles are stabilized by short-chain alkanethiolate monolayers and have 8 to 38 kilodaltons core mass (1.1 to 1.9 nanometers in diameter). Larger cores display Coulomb staircase responses consistent with double-layer charging of metal-electrolyte interfaces, whereas smaller core nanoparticles exhibit redox chemical character, including a large central gap. The change in behavior is consistent with new near-infrared spectroscopic data showing an emerging gap between the highest occupied and lowest unoccupied orbitals of 0.4 to 0.9 electron volt. 相似文献
73.
Detection and isolation of Toxoplasma gondii from fresh semen of naturally infected dogs in Southern Brazil 下载免费PDF全文
MO Koch RR Weiss AA Cruz VT Soccol KA Gonçalves MAF Bertol OC Beltrame RL Dittrich 《Reproduction in domestic animals》2016,51(4):550-554
The aim of this study was to isolate Toxoplasma gondii and determine the viability of the parasite in fresh semen samples of clinically healthy adult dogs naturally infected. Eleven seropositive dogs with T. gondii IgG antibodies from southern Brazil were selected to confirm the presence and viability of T. gondii in fresh semen samples using in vitro isolation in Vero cell culture, polymerase chain reaction (PCR) and sequencing analysis. The presence of viable T. gondii was confirmed by in vitro isolation and PCR in five semen samples. The ITS1 region of the isolated protozoa (TG S4) was amplified and sequenced. The nucleotide sequence obtained was 99% compatible with the T. gondii DNA sequences stored in the GenBank. It has been shown that T. gondii tachyzoites may be isolated in vitro from fresh semen samples of clinically healthy dogs seropositive for T. gondii. 相似文献
74.
DH Sandweiss H McInnis RL Burger A Cano B Ojeda R Paredes MC Sandweiss MD Glascock 《Science (New York, N.Y.)》1998,281(5384):1830-1832
Excavations at Quebrada Jaguay 280 (QJ-280) (16 degrees30'S) in south coastal Peru demonstrated that Paleoindian-age people of the Terminal Pleistocene (about 11,100 to 10,000 carbon-14 years before the present or about 13,000 to 11,000 calibrated years before the present) in South America relied on marine resources while resident on the coast, which extends the South American record of maritime exploitation by a millennium. This site supports recent evidence that Paleoindian-age people had diverse subsistence systems. The presence of obsidian at QJ-280 shows that the inhabitants had contact with the adjacent Andean highlands during the Terminal Pleistocene. 相似文献
75.
Supergene chalcocite enrichment during weathering is an economically vital natural process that may lead to severalfold increases in the copper content of sulfide deposits. A scanning electron microscope study of chalcocite (Cu2S) from major enriched copper deposits in northern Chile revealed myriad bacterioform bodies in original growth positions near replacement interfaces with remnant hypogene sulfide grains. These minute (0.03 to 0.2 micrometers) chalcocite bodies are interpreted as fossilized and metallized nannobacteria that promoted the fixation of mobilized copper ions. Bacterial activity may thus be a fundamental factor in supergene enrichment of copper deposits. 相似文献
76.
CB Riley JT McClure S Low‐Ying BK Dolenko RL Somorjai RA Shaw 《Australian veterinary journal》2012,90(10):387-391
77.
It is shown that lagged correlations for and cross-correlations between observed hemispheric-mean temperature data differ markedly from those for unforced (control-run) climate model simulations. The differences can be explained adequately by assuming that the observed data contain a significant externally forced component involving both natural (solar) and anthropogenic influences and that the global climate sensitivity is in the commonly accepted range. Solar forcing alone cannot reconcile the differences in autocorrelation structure between observations and model control-run data. 相似文献
78.
The Canadian Basin of the Arctic Ocean, largely ice covered and isolated from deep contact with the more dynamic Eurasian Basin by the Lomonosov Ridge, has historically been considered an area of low productivity and particle flux and sluggish circulation. High-sensitivity mass-spectrometric measurements of the naturally occurring radionuclides protactinium-231 and thorium-230 in the deep Canada Basin and on the adjacent shelf indicate high particle fluxes and scavenging rates in this region. The thorium-232 data suggest that offshore advection of particulate material from the shelves contributes to scavenging of reactive materials in areas of permanent ice cover. 相似文献
79.
We combined two protein-marking enzyme-linked immunosorbent assays (ELISA) with a predator gut content ELISA to monitor the movement and feeding activity of commercially-purchased Hippodamia convergens Guèrin-Mèneville (Coleoptera: Coccinellidae) under realistic field conditions during two field seasons in central Arizona. The protein-marking ELISAs were used to differentiate released H. convergens from the native beetles. Commercially purchased beetles marked with rabbit immunoglobulin G (IgG) were released into cotton fields and chicken IgG marked beetles were released into adjacent cantaloupe fields. Results showed that the total native beetle abundance in each crop was about the same size. The recovery rates after 15 days for the released beetles were less than 1.0% over all the releases, indicating that they dispersed readily from the release site. Of the recaptured beetles containing rabbit IgG (cotton), 82.2% were recovered in cotton and 11.8% moved to cantaloupe. Of those containing chicken IgG (cantaloupe), 66.5% were recovered in cantaloupe and 33.5% moved to cotton. A predator gut content ELISA was used to determine if there were differences in the frequency of predation of released versus indigenous H. convergens on the silverleaf whitefly, Bemisia argentifolii Bellows &; Perring (Homoptera: Aleyrodidae). The proportion of beetles containing whitefly antigens was always higher for the released beetles than for their native counterparts. Our results demonstrate an approach to combine protein marking and predator gut content ELISAs that allows the simultaneous comparison of feeding and intercrop movement of native and commercially-obtained biological control agents. 相似文献
80.
鉴别丁香假单胞菌丁香致病变种和豌豆致病变种的 DNA 探针的制备 总被引:1,自引:0,他引:1
把引起豌豆枯萎病的丁香假单胞菌丁香致病变种 Pseudomonas syringae pv.syringae 菌株3319和丁香假单胞菌豌豆致病变种 P.syringae pv.pisi 的模式菌株2452的染色体 DNA 分别用限制性核酸内切酶 HindⅢ完全消化,再用 T_4DNA 连接酶把消化好的 DNA 片段连接到用HindⅢ内切酶消化的质粒载体 pUC19上,然后把重组的质粒载体转化到大肠杆菌(E.coli RR1)中去克隆.把菌株3319和2452的 DNA 用 p~(32)标记做成探针,分别与克隆菌落杂交,筛选出只对菌株3319的 DNA 有特异性的1个重组 DNA 的克隆和对菌株2452的 DNA 有特异性的2个重组 DNA 克隆.再把这3个重组质粒 DNA 分别用 P~(32)标记做成探针,与菌株3319和2452的 DNA 杂交,也显示只对各自 DNA 来源的菌株具有特异性.这3个重组质粒中,有2个携带有菌株2452的 DNA 片段,1个为0.82 kb。另1个略小于0.58 kb,还有1个质粒携带有菌株3319的 DNA 片段,为0.85 kb. 相似文献