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961.
提出了实现大熊猫保护方针和目标所需采取的具体措施,分析所取得的成果,并指出了大熊猫保护所面临的主要问题:栖息地破碎化严重,人为干扰依然严重,迁地保护任务紧迫,保护和管理资金匮乏,管理体制不顺、队伍力量薄弱,栖息地保护和恢复建设滞后、潜在栖息地未受到重视,汶川大地震的影响等。 相似文献
962.
【目的】基于微卫星标记特点,采用计算机模拟技术,探讨畜禽保种群遗传多样性的变化过程。【方法】选择30个均匀分布于基因组、具有4—10个等位基因的标记位点,位点间无相互作用;模拟产生的畜禽保种群公母比例为1﹕5、随机交配、各家系随机等量留种、群体规模保持世代恒定,世代间无重叠,群体有效大小分别为Ne=10、20、50、100和200,保种繁殖50个世代,1 000次重复。采用多态性位点数(num-p)、平均等位基因数(Na)、有效等位基因数(Ae)、观测基因杂合度(Ho)、期望杂合度(He)、稀有等位基因数(RA)、缺乏丰富位点数(NRP)作为遗传多样性度量指标。【结果】保种群体的遗传多样性总体趋势随保种世代而逐渐降低,不同群体规模遗传多样性的降低速度差异显著,相比基础群,Ne值越大,num-p、Na、Ae、Ho、He和 RA的下降速率越慢,且当Ne=100和200时,num-p基本维持50个世代不变,RA则分别增加0.86%和2.49倍;而Ne值越大,NRP的增加速率越慢。【结论】遗传漂变导致了群体内遗传多样性的丢失。小群体中遗传漂变导致的遗传多样性丢失速度比大群体更高,发生在闭锁群体水平上的有效群体规模的减少将加快基因漂变速度,从而降低保种群体内的遗传多样性。 相似文献
963.
964.
为科学评价河南省野生葡萄属植物资源,根据资源调查数据结合资料报道,以"濒危系数"和"优先保护值"为指标,制定了河南省野生葡萄属植物资源优先护存等级定量评价指标体系,并进行了优先保护排序,为野生葡萄属植物的保护、开发利用提供了理论依据。 相似文献
965.
“中国野生动物之乡”命名活动 总被引:1,自引:0,他引:1
野生动物是自然生态系统的重要组成部分,在促进人与自然和谐发展、维护生态平衡等方面发挥着重要作用。为了加强野生动物资源的保护,调动野生动物栖息地地区公众保护鸟类的积极性,提高公众野生动物保护的意识,促进人口、资源、环境和经济的协调发展,中国野生动物保护协会自2004年起在全国组织开展了“中国野生动物之乡”命名活动,受到了社会各界的广泛欢迎。截止2011年8月,中国野生动物保护协会共在全国23个省(区、市)命名了50个“中国野生动物之乡”。作为野生动物保护宣传的新模式,“中国野生动物之乡”对于加大提高公众的保护意识,树立地方的生态品牌,调动社会各界的保护积极性起到了促进作用。 相似文献
966.
采用EnviroSMART土壤水分定位监测系统于2008-05-14至2008-10-11及2009-05-05至2009-08-05对晋西黄土区刺槐人工林、油松人工林(水平条整地)、天然次生林0~150cm土层的土壤水分进行实时监测。以这些监测数据为基础,分析SWUF模型参数的敏感性,进行参数率定,验证SWUF模型在晋西黄土高原水土保持林地的适用性。结果表明:SWUF模型中的蒸发参数、产流参数、非饱和水流参数属于高度敏感性参数,使用SWUF时必须对这些参数进行率定;SWUF模型对刺槐人工林20~150cm各土层、油松人工林和次生林0~150cm各土层土壤水分动态模拟效果较好,模拟值与实测值相对误差在20%以内;SWUF适用于模拟油松人工林和天然次生林各土层每日土壤含水量,也能够比较充分地模拟3种林地不同深度土壤层土壤水分的日变化趋势,但在模拟耗水量大的刺槐林表层土壤水分方面还需要改进。 相似文献
967.
Rendo F Iriondo M Manzano C Estonba A 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2012,129(3):234-243
Here, we present the results of a genetic analysis of 463 Pottoka ponies corresponding to four generations, using 17 microsatellite markers. Ten years after the beginning of the Pottoka conservation programme, the values for the genetic diversity of the breed are still high and stable, indicating the success of the programme. We found null alleles in Pottoka for the ASB23, HMS3 and HTG10 microsatellites. Together with information obtained from other pony breeds from the Iberian Peninsula, this finding indicates that these microsatellites should not be used for phylogenetic analyses or parentage tests, at least for these breeds. The high heterozygosity exhibited by this breed in comparison to other ponies, together with its genetic proximity to the centroid of the allele frequencies, suggest that Pottoka allele frequencies are close to those initially exhibited by the ancestors of current European ponies. The results obtained in the current work, together with results from previous studies of ponies and horses from the Iberian Peninsula, corroborate the idea of a unique origin of all ponies from the European Atlantic Area. In contrast, our results do not corroborate the idea that these are derived from a domestication event in the Iberian Peninsula, nor that they have incorporated ancient Iberian horse genes into their genetic pool to a larger extent than other horse breeds. 相似文献
968.
《Scandinavian Journal of Forest Research》2012,27(3):235-242
Forest residue left after clear-cutting is increasingly being used as biofuel in Sweden. Deadwood is an important habitat for many species and a crucial resource for forest biodiversity. On eight clear-cuts in eastern central Sweden, the amount of Picea abies (L.) Karst. deadwood left on the ground was compared with the amount collected in piles for fuelwood extraction. It was found that 65% of the volume, 77% of the surface area and 84% of the pieces of slash were to be extracted. In another study on 23 clear-cuts in the same region, it was found that 36% of the logs left outside piles after clear-cutting were later removed. These studies indicate that a considerable amount of potential substrate is lost during slash extraction. 相似文献
969.
《Scandinavian Journal of Forest Research》2012,27(5):369-374
Abstract Variation in budburst, height increment and growth cessation within and among five Norwegian Ulmus glabra (Huds.) populations was recorded in an experimental trial during the fourth and fifth growing seasons. Budburst occurred first in inland populations and last in coastal populations, and latitude of origin was less important for timing of budburst than distance from the coast. Height increment and date of growth cessation were correlated to latitude, height increment decreased with increasing latitude of origin, whereas growth cessation occurred first in northern populations and later with increasing southern origin. Thus, the phenological traits vary in accordance with the climate from where the populations have been derived. There was a general large within-population variation in phenological traits. The results are discussed in relation to conservation of adaptive trait variation of the species. 相似文献
970.
Understanding habitat requirements and identifying landscape linkages are essential for the survival of isolated populations of endangered species. Currently, some of the giant panda populations are isolated, which threatens their long-term survival, particularly in the Xiaoxiangling mountains. In the present study, we quantified niche requirements and then identified potential linkages of giant panda subpopulations in the most isolated region, using ecological niche factor analysis and a least-cost path model. Giant pandas preferred habitat with conifer forest and gentle slopes (>20 to ≤30°). Based on spatial distribution of suitable habitat, linkages were identified for the Yele subpopulation to 4 other subpopulations (Liziping, Matou, Xinmin and Wanba). Their lengths ranged from 15 to 54 km. The accumulated cost ranged from 693 to 3166 and conifer forest covered over 31%. However, a variety of features (e.g. major roads, human settlements and large unforested areas) might act as barriers along the linkages for giant panda dispersal. Our analysis quantified giant panda subpopulation connectivity to ensure long-term survival. 相似文献