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排序方式: 共有274条查询结果,搜索用时 15 毫秒
91.
EJM Teo H Russell T Lambert R Webster A Yappa P McDonagh G Harper D Barker SC Barker 《Australian veterinary journal》2023,101(12):479-489
We studied over 222,000 cases of emergency veterinary consultations in four regions along the eastern coast of Australia. We found that cases of tick paralysis (TP) caused by the eastern paralysis tick, Ixodes holocyclus, accounted for 7.5% of these cases: >16,000 cases. The season of TP and the number (prevalence) of TP cases varied among regions and over the years. Our study of the association between weather and (i) the start of the season of TP, and (ii) the number of TP cases revealed much about the intricate relationship between the weather and I. holocyclus. We studied the effect of the hypothetical availability of isoxazoline-containing tick-preventative medicines and found that an increase in the availability of these medicines had significantly contributed to the decrease in TP cases. We found that the weather in winter accounted for the time of the year the season of TP starts whereas the weather in summer accounted for the number of TP cases in the TP season. Last, through a study of the effects of shifts in the climate under four hypothetical scenarios (warmer/cooler and drier/wetter than average), we propose that the start of the season of TP depends on how soon the weather in winter becomes suitable for the activity (e.g. host-seeking) and the development of I. holocyclus nymphs, and that the number of TP cases during the TP season depends on how many engorged female ticks and their eggs survive during summer. 相似文献
92.
G M Shaw M E Harper B H Hahn L G Epstein D C Gajdusek R W Price B A Navia C K Petito C J O'Hara J E Groopman 《Science (New York, N.Y.)》1985,227(4683):177-182
Unexplained debilitating dementia or encephalopathy occurs frequently in adults and children with the acquired immune deficiency syndrome (AIDS). Brains from 15 individuals with AIDS and encephalopathy were examined by Southern analysis and in situ hybridization for the presence of human T-cell leukemia (lymphotropic) virus type III (HTLV-III), the virus believed to be the causative agent of AIDS. HTLV-III DNA was detected in the brains of five patients, and viral-specific RNA was detected in four of these. In view of these findings and the recent demonstration of morphologic and genetic relatedness between HTLV-III and visna virus, a lentivirus that causes a chronic degenerative neurologic disease in sheep, HTLV-III should be evaluated further as a possible cause of AIDS encephalopathy. 相似文献
93.
Low rates of acetylene reduction to ethylene in water samples from two dystrophic lakes indicate the presence of nitrogenase and in situ nitrogen fixation. Highest rates were found in anoxic water from the aphotic zone. Environmental conditions in these lakes suggest the agents of fixation were bacteria. 相似文献
94.
Kremen C Cameron A Moilanen A Phillips SJ Thomas CD Beentje H Dransfield J Fisher BL Glaw F Good TC Harper GJ Hijmans RJ Lees DC Louis E Nussbaum RA Raxworthy CJ Razafimpahanana A Schatz GE Vences M Vieites DR Wright PC Zjhra ML 《Science (New York, N.Y.)》2008,320(5873):222-226
Globally, priority areas for biodiversity are relatively well known, yet few detailed plans exist to direct conservation action within them, despite urgent need. Madagascar, like other globally recognized biodiversity hot spots, has complex spatial patterns of endemism that differ among taxonomic groups, creating challenges for the selection of within-country priorities. We show, in an analysis of wide taxonomic and geographic breadth and high spatial resolution, that multitaxonomic rather than single-taxon approaches are critical for identifying areas likely to promote the persistence of most species. Our conservation prioritization, facilitated by newly available techniques, identifies optimal expansion sites for the Madagascar government's current goal of tripling the land area under protection. Our findings further suggest that high-resolution multitaxonomic approaches to prioritization may be necessary to ensure protection for biodiversity in other global hot spots. 相似文献
95.
The abundance of hollow-bearing trees in urban dry sclerophyll forest and the effect of wind on hollow development 总被引:1,自引:0,他引:1
Anthropogenic change, particularly in urban landscapes, has resulted in the fragmentation of indigenous vegetation into often small isolated ‘remnants’. The persistence of arboreal fauna in small urban remnants in part depends on the distribution and abundance of habitat resources within the remnant. We surveyed 44 small (<2.5 ha) eucalypt remnants located within the south-eastern suburbs of metropolitan Melbourne to ascertain the abundance of hollow-bearing trees, an important ecological resource. The probability of a live or dead tree containing a hollow was investigated in relation to site variables that influenced exposure to wind, a factor thought to increase the propensity of hollow formation in eucalypt trees. A total of 2678 live and 224 dead eucalypt trees were surveyed, of which 350 live (12%) and 70 dead (31%) trees were hollow-bearing. The probability of a tree being hollow-bearing was strongly positively associated with the diameter of the tree, however, past management practices have lead to a paucity of large (>80 cm DBH) trees in small urban remnants. We found that variables that measured exposure to wind were correlated with the chance that a live tree will be hollow-bearing while reducing the chance that a dead tree will be hollow-bearing. Although highly variable, the number of hollow-bearing trees contained within small urban remnants (mean of 5.8 ha−1) fell well below that contained in areas of un-logged non-urban forest. Our results indicated that large numbers of hollow-bearing tree are unlikely to be recruited into urban remnants for a significant time-span and as such there is an increased importance placed on maintaining the current inventory of hollow-bearing trees for the maintenance of biodiversity in urban areas. 相似文献
96.
Summary A fertilizer experiment on potatoes in which mechanical damage was followed by infection with grey mould (Botrytis cinera Pers. ex Fr.) provided the opportunity to make some observations on the incidence of the disease upon plants having different
levels of mineral nutrition. It is suggested that the application of potash increases the resistance to infection by decreasing
the host susceptibility to damage. The response to nitrogen may be governed by the pathogen's requirement for both nitrogen
and carbohydrate. 相似文献
97.
James W. Woodhall Ian P. Adams Jeff C. Peters Glyn Harper Neil Boonham 《European journal of plant pathology / European Foundation for Plant Pathology》2013,136(2):273-280
Rhizoctonia solani is an important pathogen of potatoes causing stem canker and black scurf. The fungus is a species complex comprised of 13 known anastomosis groups (AGs). AG3-PT is the anastomosis group frequently associated with disease in potatoes. A real-time PCR assay was designed to the rDNA ITS region of AG3-PT isolates to enable the pathogen to be detected directly in tuber and soil samples. The resulting assay was highly specific for AG3-PT, and did not amplify DNA from isolates from other AGs or subgroups of AG3. Using a bulk DNA extraction method capable of extracting from up to 250 g of soil, the assay could detect one individual sclerotium of AG3-PT (weighing 200 μg) in 250 g of soil. The AG3-PT assay was used, with assays for AG2-1, AG5 and AG8 to determine the prevalence of those AGs in UK potato soils and tubers. AG2-1 and AG3-PT were the predominant groups in tubers and soils, although AG3-PT was more frequently isolated from tubers, highlighting its importance as a potato pathogen. AG3-PT was also detected in more than half of the tuber samples tested suggesting the importance of seed borne inoculum. 相似文献
98.
Leedom Larson KR Wagstrom EA Donham KJ Harper AL Hanson BM Male MJ Smith TC 《Journal of agricultural safety and health》2012,18(1):5-9
Methicillin-resistant Staphylococcus aureus (MRSA) nasal colonization has been documented in swine and swine workers. MRSA has also been found in the shower facilities of conventional swine farms. We previously conducted a review of the literature to identify measures used to reduce MRSA prevalence in athletic facilities. In this study, we evaluated those measures for adaptability to the pork production environment. A best practices protocol was developed to reduce MRSA levels in pork production shower facilities and implemented in two conventional swine production systems. 相似文献
99.
The effect of post‐harvest storage conditions on the development of black dot (Colletotrichum coccodes) on potato in crops grown for different durations
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J. C. Peters G. Harper J. L. Brierley A. K. Lees S. J. Wale A. J. Hilton P. Gladders N. Boonham A. C. Cunnington 《Plant pathology》2016,65(9):1484-1491
The effects of post‐harvest curing and storage temperature on severity of black dot, caused by Colletotrichum coccodes, were investigated for potato crops grown for different crop durations (days from 50% emergence to harvest) in soils that posed a low, medium and high risk of disease. In field trials over four growing seasons (2005–8), black dot severity at harvest increased with increasing crop duration, within the range 103–146 days from 50% emergence to harvest (P < 0.05). In field trials over three growing seasons (2006–8), black dot severity on tubers at harvest increased significantly with increasing soil inoculum in each year, within the range 43–4787 pg C. coccodes DNA/g soil (P < 0.05). Storage trials were conducted to measure the influence of accumulated post‐harvest temperature on black dot. In 2005, no difference in black dot severity was observed on tubers stored for 20 weeks at 2.5 and 3.5 °C. In 2006 (but not 2007), increasing the duration of curing after harvest from 4 to 14 days increased black dot severity on tubers from 8.9 to 11.2% (P < 0.01) in long duration crops (>131 days after 50% emergence) grown under high (>1000 pg C. coccodes DNA/g soil) soil inoculum. The number of days of curing did not affect disease severity for shorter duration crops grown at high soil inoculum, or on crops grown at medium or low (100–1000 and <100 pg C. coccodes DNA/g soil, respectively) soil inoculum concentrations. Soil inoculum and crop duration together provided a reasonable prediction of black dot severity at harvest and after a 20‐week storage period. 相似文献
100.
Raymond Cowley David J. Luckett Gavin J. Ash John D.I. Harper Cina A. Vipin Harsh Raman Simon Ellwood 《Breeding Science》2014,64(1):83-89
Phomopsis blight in Lupinus albus is caused by a fungal pathogen, Diaporthe toxica. It can invade all plant parts, leading to plant material becoming toxic to grazing animals, and potentially resulting in lupinosis. Identifying sources of resistance and breeding for resistance remains the best strategy for controlling Phomopsis and reducing lupinosis risks. However, loci associated with resistance to Phomopsis blight have not yet been identified. In this study, quantitative trait locus (QTL) analysis identified genomic regions associated with resistance to Phomopsis pod blight (PPB) using a linkage map of L. albus constructed previously from an F8 recombinant inbred line population derived from a cross between Kiev-Mutant (susceptible to PPB) and (resistant to PPB). Phenotyping was undertaken using a detached pod assay. In total, we identified eight QTLs for resistance to PPB on linkage group (LG) 3, LG6, LG10, LG12, LG17 and LG27 from different phenotyping environments. However, at least one QTL, QTL-5 on LG10 was consistently detected in both phenotyping environments and accounted for up to 28.2% of the total phenotypic variance. The results of this study showed that the QTL-2 on LG3 interacts epistatically with QTL-5 and QTL-6, which map on LG10 and LG12, respectively. P27174相似文献