全文获取类型
收费全文 | 284篇 |
免费 | 12篇 |
专业分类
林业 | 12篇 |
农学 | 16篇 |
基础科学 | 1篇 |
55篇 | |
综合类 | 39篇 |
农作物 | 20篇 |
水产渔业 | 9篇 |
畜牧兽医 | 97篇 |
园艺 | 9篇 |
植物保护 | 38篇 |
出版年
2023年 | 2篇 |
2022年 | 3篇 |
2021年 | 7篇 |
2020年 | 4篇 |
2019年 | 9篇 |
2018年 | 3篇 |
2017年 | 14篇 |
2016年 | 9篇 |
2015年 | 6篇 |
2014年 | 15篇 |
2013年 | 22篇 |
2012年 | 17篇 |
2011年 | 9篇 |
2010年 | 7篇 |
2009年 | 11篇 |
2008年 | 17篇 |
2007年 | 13篇 |
2006年 | 9篇 |
2005年 | 8篇 |
2004年 | 8篇 |
2003年 | 11篇 |
2002年 | 10篇 |
2001年 | 8篇 |
2000年 | 4篇 |
1999年 | 6篇 |
1998年 | 6篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1994年 | 4篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1990年 | 3篇 |
1989年 | 5篇 |
1988年 | 3篇 |
1987年 | 2篇 |
1986年 | 5篇 |
1985年 | 5篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1979年 | 1篇 |
1978年 | 5篇 |
1975年 | 1篇 |
1973年 | 2篇 |
1970年 | 1篇 |
1953年 | 1篇 |
1936年 | 2篇 |
排序方式: 共有296条查询结果,搜索用时 296 毫秒
31.
Gressel J Michaeli D Kampel V Amsellem Z Warshawsky A 《Journal of agricultural and food chemistry》2002,50(22):6353-6360
Infection by many fungi activates a variety of calcium dependent defenses in the hosts, slowing or suppressing the attacker and limiting the efficacy of mycoherbicides. The calcium requirement for fungal growth is so low that it could only be implied based on fungi containing calcium-dependent signaling enzymes. Analytical grade media contain <2 microM calcium, and the addition of specific chelators does not affect fungal growth. Hydrophobic derivatives of the calcium-specific chelator BAPTA designed to traverse plant cuticles were synthesized in order to chelate calcium internally during fungal attack. Some chelators as well as calcium precipitating oxalate and channel blocker verapamil were applied with a weakly mycoherbicidal Colletotrichum coccodes to cotyledons of compatible Abutilon threophrasti. They suppressed calcium dependent callose biosynthesis in the weed and increased virulence but may have affected other calcium-dependent processes that facilitate virulence. The low calcium requirement of fungi, and their high affinity for calcium, allows the application of calcium-regulating agents as synergists for mycoherbicides where the weed uses calcium-dependent defenses. 相似文献
32.
There is continuing concern over the health threat posed by theinhalation of ambient, transition-metal-containing particulatematter. Here, we report on the collection of two types ofanthropogenic, airborne particles, composed of iron with vanadiumand chromium (FeVCr) and iron with the rare earth metals ceriumand lanthanum (FeCeLa), respectively. Bi-weekly deposition platesamples were collected on indoor window sills of residentiallocations in inner-city Syracuse, NY. Sampling was continuous ateach location for two months during the spring of 1999. Themetal-bearing particles were identified, analyzed, and sizedin situ on each deposition plate using computer controlledscanning electron microscopy (CCSEM). Approximately 17% of thoseanalyzed by CCSEM fell into the inhalable size fraction. Particle loading varied between locations and changed over time.This was probably a function of various factors affectingparticle deposition rates. Notwithstanding, the plate loadingsfor the FeVCr-bearing particles tended to peak during the middleof the sampling period, suggesting that a single source/processwas operating to produce the FeVCr particles. The large sizeattained by some of these particles (greater than 50 μm inaggregates) suggest that long range transport was probably notinvolved. 相似文献
33.
Summary An outbreak of disease characterised by fever, ocular and nasal discharge, coughing and sneezing, oral necrosis, diarrhoea, enteritis and pneumonia in goats was shown by the use of specific cDNA probes to have been peste des petits ruminants, confirmed for the first time in Ethiopia. Both morbidity and mortality rates were high in goats but sheep were not affected.
Peste De Pequeños Rumiantes En Caprinos En Etiopia
Resumen Se presentó por vez primera en Etiopía, un brote de peste de pequeños rumiantes, la que fue detectada mediante el uso de de sondas cADN especificas. La enfermedad se caracterizó por fiebre, descargas ocular y nasal, tos, estornudos necrosis oral, diarrea, enteritis y neumonia. Tanto la morbilidad como la mortalidad fueron altas en caprinos pero no en ovinos.
Peste Des Petits Ruminants Chez Des Chevres Ethiopiennes
Résumé Une maladie caractérisée par de la fièvre, des écoulements nasal et oculaire, de la toux et des éternuements, une nécrose orale, de la diarrhée, de l'entérite et une pneumonie est apparue chez des chèvres. L'utilisation de sondes à ADNc spécifiques a montré qu'il s'agissait de la peste des petits ruminants, confirmée pour la première fois en Ethiopie. Les taux de morbidité étaient élevés chez les chèvres mais les moutons n'étaient pas affectés.相似文献
34.
A number of commercial fungicides and dinitrophenolic compounds were tested for their ability to suppress further sporulation of established infections of the apple mildew fungus Podosphaera leucotricha on seedlings in the greenhouse. Although they did not kill the fungus, two organophosphorus and two benzimidazole-type compounds gave powerful suppression for at least 18 days. Other fungicides known to control apple mildew in the field had a less marked effect. Sporulation occurred on subsequent untreated growth to the same extent as on control seedlings, except where either of two substituted dinitrophenols had been used. 相似文献
35.
36.
Four- and six-week-old turkeys were vaccinated subcutaneously using avian influenza virus (AIV) A/Duck/613/MN/79 (H4N2) killed oil-emulsion vaccine. Sequential serological tests using agar gel precipitin (AGP), hemagglutination inhibition (HI), and enzyme-linked immunosorbent assay (ELISA) for measuring antibodies to AIV were performed up to 4 weeks postvaccination, when birds were challenged intranasally using A/Turkey/MN/80 (H4N2) live AIV. The ELISA was 25 to 1600 times more sensitive than the HI test and was able to detect antibody production earlier than the HI test. All turkeys with an ELISA titer of greater than or equal to 800 were protected against homologous challenge, as measured by virus recovery 3 days postchallenge. Four turkeys out of 20 serologically negative by AGP and HI tests but ELISA-positive were protected. 相似文献
37.
ABSTRACT We studied the effect of water salinity on the incidence and severity of crown and root rot disease of tomato, as well as on the pathogen and on the plant's response to the pathogen. Irrigation with saline water significantly increased disease severity in tomato transplants inoculated with Fusarium oxysporum f. sp. radicis-lycopersici, and mineral fertilization further increased it. In one field experiment, disease incidence in plots irrigated with saline water (electrical conductivity [EC] = 3.2 +/- 0.1 dS m(-1)) and in those irrigated with fresh water (EC = 0.4 +/- 0.1 dS m(-1)) was 75 and 38%, respectively. Disease onset was earlier and yield was lower in plots irrigated with saline water. In a second field experiment, final disease incidence 250 days after planting, was 12% in plants which had been irrigated with saline water (EC = 4.6 +/- 0.1 dS m(-1)) and 4% in those irrigated with fresh water (EC = 1.2 +/- 0.1 dS m(-1)). Irrigation of tomato transplants with 20 mM NaCl did not inhibit plant development, but partial inhibition was observed at higher NaCl concentrations. Growth of the pathogen in culture or survival of conidia added to soil were not affected by saline water. Plants which were preirrigated with saline water were more severely diseased than those preirrigated with tap water. It was concluded that disease increases effected by saline water are associated with the latter's effect on plant response. 相似文献
38.
Sonnenberg GF Monticelli LA Alenghat T Fung TC Hutnick NA Kunisawa J Shibata N Grunberg S Sinha R Zahm AM Tardif MR Sathaliyawala T Kubota M Farber DL Collman RG Shaked A Fouser LA Weiner DB Tessier PA Friedman JR Kiyono H Bushman FD Chang KM Artis D 《Science (New York, N.Y.)》2012,336(6086):1321-1325
The mammalian intestinal tract is colonized by trillions of beneficial commensal bacteria that are anatomically restricted to specific niches. However, the mechanisms that regulate anatomical containment remain unclear. Here, we show that interleukin-22 (IL-22)-producing innate lymphoid cells (ILCs) are present in intestinal tissues of healthy mammals. Depletion of ILCs resulted in peripheral dissemination of commensal bacteria and systemic inflammation, which was prevented by administration of IL-22. Disseminating bacteria were identified as Alcaligenes species originating from host lymphoid tissues. Alcaligenes was sufficient to promote systemic inflammation after ILC depletion in mice, and Alcaligenes-specific systemic immune responses were associated with Crohn's disease and progressive hepatitis C virus infection in patients. Collectively, these data indicate that ILCs regulate selective containment of lymphoid-resident bacteria to prevent systemic inflammation associated with chronic diseases. 相似文献
39.
40.
Rawther SS Saseendranath MR Nair GP Tresamol PV Pillai UN Abraham J Senthilkumar TM Nagalakshmy S Nimisha KK 《Tropical animal health and production》2012,44(4):911-914
In the present study efficacy of single intradermal Johnin test, acid fast staining of faecal smear and IS 900 faecal polymerase chain reaction tests was evaluated in 200 goats for detection of Mycobacterium avium subsp paratuberculosis. Two hundred goats comprising 150 goats from an organised farm in Trichur district and 50 goats reared under field condition
at farmers premise from Malappuram district of Kerala state formed the study population. Faecal smear from all the 200 goats
was stained by Ziehl–Neelsen acid fast stain and faecal polymerase chain reaction (PCR) specific for M. avium subsp paratuberculosis (MAP); IS 900 was performed on all samples. All the animals were subjected to single intradermal Johnin test. Out of 200 goats screened
for paratuberculosis, six goats (3%), 11 goats (5.5%) and 42 goats (21%) were found positive by Ziehl–Neelsen acid fast staining
of faecal smear, single intradermal Johnin test and IS 900 PCR respectively. Results of the present study indicate that amplification of IS 900 insertion element was the most specific and sensitive diagnostic detection method. Single intradermal Johnin test and Ziehl–Neelsen
acid fast staining did not show any significant difference. 相似文献