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81.
82.
为了解食蚊鱼Gambusia affinis对华南地区水生昆虫多样性的影响,在实验室条件下,以食蚊鱼栖境中有代表性的3种水生昆虫为猎物,研究食蚊鱼的捕食选择性.结果表明,在单捕食者-多种猎物作用系统中,当猎物密度较低时,食蚊鱼对不同猎物的捕食选择性差异不显著.但随猎物密度的增加,食蚊鱼对白纹伊蚊Aedes albopictus幼虫和蛹的捕食量明显增加,对摇蚊Chironomus kiiensis幼虫和蜉蝣Cloeon bengalense稚虫的捕食量下降.在单捕食者-2种猎物的作用系统中,在猎物比例相同的情况下,食蚊鱼更喜欢捕食白纹伊蚊幼虫;但是在猎物总数不变的情况下,改变猎物比例,对食蚊鱼总的捕食量影响不大.说明食蚊鱼喜欢捕食漂浮于水面上、会动的活体猎物,对死的或不动的猎物不敏感,且对蚊子幼虫具有明显的嗜好性. 相似文献
83.
[目的]研究基于ACO-SVM的粮虫特征提取,探讨粮虫特征提取的可行性。[方法]通过分析储粮害虫图像识别系统中的1个关键环节——特征提取,提出把支持向量机(Support vector machine,简称SVM)算法中交叉验证训练模型的识别率作为储粮害虫特征提取评价准则的1个重要因子,将蚁群优化算法(Ant Colony Optimization,简称ACO)应用于粮虫特征的自动提取。[结果]该算法从粮虫的17维形态学特征中自动提取出面积、周长等7个特征的最优特征子空间,采用参数优化之后的SVM分类器对90个粮虫样本进行分类,识别率达到95%以上。[结论]该研究表明蚁群优化算法在粮虫特征提取中的应用是可行的。 相似文献
84.
Insects respond to changes in microhabitat caused by canopy disturbance, and thus can be used to examine the ecological impacts of harvesting. Single-tree selection harvesting is the most common silvicultural system used to emulate local small-scale natural disturbance and maintain uneven-aged forest structure in temperate forests. Here, we test for differences in richness, abundance, and composition of hymenopteran and saproxylic insect assemblages at four different taxon levels (selected insect orders; and all hymenopteran families, and braconid subfamilies and morphospecies) between the canopy and understory of unharvested and single-tree selection harvested sites in a northern temperate forest from central Canada. Harvesting had no effect on insect assemblage richness, composition or abundance at the three highest taxon levels (order, family and subfamily). Similarly, richness and abundance at the lowest-taxon level (braconid morphospecies) were similar, although composition differed slightly between unharvested and harvested stands. Insect assemblages were vertically stratified, with generally higher abundance (for Diptera, Hymenoptera, some hymenopteran families and braconid subfamilies) and richness (for braconid morphospecies) in the understory than the canopy. In particular, composition of the braconid morphospecies assemblage showed relatively low similarity between the understory and canopy. Single-tree selection harvesting appears to influ-ence wood-associated insect taxa only subtly through small changes in community composition at the lowest taxon level, and thus is recommended as a conservative approach for managing these northern temperate forests. 相似文献
85.
电子鼻在储粮害虫检测中的应用研究 总被引:9,自引:0,他引:9
通过采用法国生产的Alpha MOS Fox3000电子鼻和自行设计的实验系统,分别对含有活的储粮害虫气体样本、含有死虫的气体样本和标准空气样本进行了检测与比较,并应用主元素分析法进行了模式识别.结果表明,无论虫量多少、虫子死活,它们的气体样本与标准气体样本都有明显的差异,从而能快速检测出粮食是否受到害虫的侵蚀. 相似文献
86.
87.
Julien Cucherousset 《Biological conservation》2008,141(12):2984-2992
We studied the patterns of commonness and rarity for one vertebrate (fish) and four freshwater insect taxa (Ephemeroptera, Plecoptera, Trichoptera and Coleoptera) in southwestern France (57,000 km2), and we analysed the relationships between the location of sites and the contribution of commonness and rarity to species richness within a large stream system. Richness patterns in fish and aquatic insects were related to the location of sites within the stream system. The number of common and rare fish species increased from up- to downstream areas as a result of downstream additions of species. The number of common insect species peaked in the intermediate section of the river continuum, whereas rarity increased with decreasing elevation. In all taxa, common species gave a closer approximation to overall patterns of species richness than did rare ones. The biodiversity patterns of river animals emerged from convergence in the distributions of common and rare species (fish), or mostly from the distribution of common species (insects). However, in fish, Ephemeroptera and Plecoptera, the rarer species became almost equally, or more strongly correlated with overall species richness when increasing information along the common-to-rare and rare-to-common sequences. These patterns suggested that rarer species show a similar or stronger affinity, on a species-for-species basis, for high richness areas than do the commoner species. These schemes have implications for biodiversity assessments, as studies using common species richness to target important areas for monitoring or conservation efforts within stream systems will not necessarily identify areas important for rare species, and vice versa. 相似文献
88.
89.
该文报道采自甘肃、江苏、浙江、广西等省的5种跳小蜂,即绒蚧艾菲跳小蜂AphycuseriocociTimberlake、五斑佳丽跳小蜂CalipteromaquinquegutataMotsch、毛角尖梗跳小蜂Cerapteroceruspilicornis、混淆莱曼跳小蜂Lamennaisiaambigua、三色丽突跳小蜂Leptomastideaabnormis。这5种跳小蜂在我国属首次报道,主要寄生各种介壳虫,其中除艾菲跳小蜂属Aphycus外,其余4个属是中国分布新记录属。 相似文献
90.
云南省森林昆虫病毒资源及其开发研究 总被引:3,自引:0,他引:3
在回顾我国,我省昆虫病毒研究历史的基础上,对云南省森林昆虫病毒资源,松毛虫病毒资源及其生物防治的研究,应用,病毒杀虫剂的产业化与开发利用前景等方面作了综合详尽的分析,就存在问题和解决途径也作了有益的讨论。 相似文献