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S. I. Warwick R. K. Gugel T. McDonald K. C. Falk 《Genetic Resources and Crop Evolution》2006,53(2):297-312
Information on genetic diversity and genetic relationships among genotypes of Brassica carinata is currently limited. The objectives of this study were to evaluate patterns and levels of genetic diversity in B. carinata based on amplified fragment length polymorphisms (AFLP) as compared with Brassica juncea and Brassica nigra, and to evaluate agronomic and seed quality data for plants grown in the field in western Canada. A total of 296 AFLP bands
were generated from four primer pair combinations and scored for presence/absence in 66, 20 and 7 accessions of B. carinata, B. juncea and B. nigra, respectively. B. carinata was less genetically diverse than the other two species. Differences in diversity were evident in the proportion of polymorphic
loci within each species: 23, 35 and 50% for B. carinata, B. nigra and B. juncea, respectively. Pair-wise similarity measures based on the Jaccard coefficient were highest among accessions of B. carinata and showed the narrowest range: 0.911 (0.810–0.981) compared to B. nigra: 0.569 (0.438–0.660) and B. juncea: 0.715 (0.345–0.951). AFLP-based genetic distance information can be used by plant breeders to select diverse genotypes.
AFLPs are also useful for fingerprinting cultivars and two primer pair combinations were sufficient to uniquely identify all
the accessions of B. carinata. More variation among accessions was identified in the agronomic trial than had previously been described in studies of B. carinata in western Canada, but the data were too limited to draw conclusions regarding specific accessions. Overall, the findings
were in agreement with other published work describing the favourable agronomic potential of this species. 相似文献
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As part of the Shenandoah National Park: Fish in Sensitive Habitats (SNP: FISH) project, movements of blacknose dace (Rhinichthys atratulus) and brook char (Salvelinus fontinalis) were examined during exposure to artificial acidification in paired channels of a laboratory stream. The objective of this study was to determine the ability of the fish to avoid depressions in the ambient pH and recognize and use a neutral-pH microhabitat refuge during acute reductions. Fish preference for a particular channel was statistically predictable based on the delivery of food. We tested fish avoidance behavior by manipulating food and the delivery of a pulse of acidified water. Both blacknose dace and brook char avoided the acid pulse (ambient pH reduced from 7.2 to 5.1) by sheltering in the pH-neutral refuge. Extensive field sampling in refuge microhabitats before and during episodic acidification is needed to determine changes in the distributional patterns of these species associated with acid precipitation events. 相似文献
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K.E. Moseby 《Biological conservation》2006,127(4):429-437
Pen and field trials were used to test the effectiveness and cost-efficiency of wire netting and electric fence designs as barriers to feral cats, foxes and rabbits in northern South Australia. A 180 cm high wire netting fence with foot apron and a curved ‘floppy’ overhang effectively contained most rabbits, feral cats and foxes during pen trials and proved effective with intensively monitored paddock-scale exclosures. A reduced height fence of 115 cm did not reduce effectiveness of the fence during fence trials but paddock-scale trials are yet to be completed. Conventional 40 mm diameter hexagonal “rabbit netting” was not an effective barrier against young independent rabbits and it is recommended that 30 mm hexagonal netting should be used. A 60 cm wide external netting overhang, curved in an arc and supported by lengths of heavy gauge wire, effectively precluded more feral cats and foxes than a 30 cm wide overhang angled upwards. The 30 cm foot apron was augmented in erosion-prone dunes and watercourses by the addition of wider netting or rubber matting to prevent incursions. Posts, and particularly corners, were targeted by feral cats and foxes and the efficacy of the fence was improved by using steel, rather than timber posts. Electric wires offset from the netting at heights of 120 and 150 cm provided a shock to animals exploring the base of the overhang and further improved the fence efficacy. PVC conduit rollers on the top wire were not effective.Material costs ranged from AUD $8814 per km for the 115 cm high fence to AUD $12,432 per km for the 180 cm high fence with two electric wires. The non-standard 30 mm hexagonal netting accounted for 57% of the material costs of the low netting fence. Increased demand for this netting may reduce the expense of rabbit exclusion. Expenses could also be reduced where existing stock fences are modified by the addition of netting. 相似文献
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利用DTOPSIS对参加国家甘蔗品种第六轮区试的13个品种,在云南瑞丽点两年新植1年宿根的品比结果,进行了综合分析,结果:闽糖95-261、福农99-20169、粤甘18号、福农02-3924、闽糖96-6016、桂引6号、粤甘16号、桂辐98-296、云蔗99-91九个品种的综合表现优于双对照ROC16(CK1)和粤糖93-159(CK2),适宜在湿热生态型蔗区推广应用;Rb76-5418的综合表现优于ROC16(CK1)。评价结果与糖产量排序基本一致,与甘蔗品种在云南瑞丽蔗区的实际表现吻合。 相似文献
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在美国学习和考察期间,充分体验了生物安全三级实验室的建筑设计、管理理念和运行情况,初步了解了美国生物安全三级实验室的运行管理模式,对今后我国兽医实验室的生物安全管理有了新的启发. 相似文献