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91.
黄胸蓟马对香蕉的危害及其防治 总被引:8,自引:0,他引:8
1996~1997年在香蕉花期调查结果表明,黄胸蓟马在广州地区香蕉园中普遍存在,香蕉花感虫率达100%,平均每花苞感虫82.8头。感虫数与花苞着生高度有关,以高度120~140cm的花苞感虫数最高,以后随高度的增加剧减。黄胸蓟马只危害稍开和已开的第1至第4苞片内花段,且虫口数由外向里递减。园中杂草有助于蓟马对香蕉花的危害,平均每花苞虫口数多杂草蕉园比管理精细的无杂草园多3.6倍。室内药效试验结果表明,毒死蜱、乐果、丁基克百威和灭多威对黄胸蓟马有很好的毒杀效果,氯氰菊酯和顺式氯氰菊酯效果不理想。 相似文献
92.
93.
张海英 《湖南农业大学学报(自然科学版)》2008,(4)
简化字已推行了五十多年,但被简化了的繁体字、异体字却频频出现在各种简体版的出版物特别是学术期刊中,导致期刊用字极不规范。以随机抽取的数种期刊为例,具体分析了其中被错误使用的繁体字、异体字,并简单讨论了错误使用的原因,提出了改变这种繁简乱用的混乱状况的建议。 相似文献
94.
高明玉 《安徽农业大学学报》2008,(2):118-121
翻译原本的选择主要受一定时期的主流意识形态的影响, 其中最主要的是统治阶级的政治需要、社会转型期的社会需求以及译者的价值取向。中国历史上大规模的翻译活动可以分为四次: 早期的佛经翻译、明末清初的科技翻译、清末民初的小说翻译及五四运动以来的翻译活动。每一次翻译活动中翻译原本的选择都和那一特定时期的意识形态有着密切的关系。 相似文献
95.
云南红河地区香蕉产业现状、存在问题及发展建议 总被引:1,自引:0,他引:1
简述红河州香蕉产业现状,分析了存在问题,提出了发展思路与建议。 相似文献
96.
Fruit characteristics of the disease-resistant bluggoe-type (ABB) cooking bananas (Musa × paradisiaca L.) ‘Saba’ and ‘Pelipita’ were compared with those of the susceptible ‘Currare’ (‘Horn’). Yields of ‘Saba’ and ‘Pelipita’ were similar to those of ‘Currare’; however, ‘Saba’ and ‘Pelipita’ yielded fewer hands with a greater number of small fruit when compared with ‘Currare’. Shoot-tip cultures of both clones were readily initiated on a modified Murashige and Skoog (MS) basal medium supplemented with N6-benzyladenine (BA) in combination with indole-3-acetic acid (IAA). Propagation cultures were initiated by splitting shoot tips along their longitudinal axis and re-culturing the individual pieces to basal medium supplemented with 5 mg l?1 BA. Transfer of axillary shoots to hormone-free medium resulted in rapid and extensive root formation. Plantlet survival after transfer to methyl bromide-treated soil exceeded 90%. Establishment in the field was achieved following procedures normally used for vegetative propagation of this crop. Trial plantings of in vitro propagated ‘Saba’ and ‘Pelipita’ were established in various provinces of Costa Rica for grower evaluation and for future comparison of growth and reproductive development with plants of these and other cultivars propagated from corms. 相似文献
97.
98.
依据野外调查资料和室内化学分析,组建了阜平表壳岩的填图单元,单元分为阜平表壳岩上部和阜平表壳岩下部岩石。上部岩石原岩为沉积岩,属角闪岩相,无紫苏辉石,具有变余沉积层理和韵律构造,塑性变形差,从下到上可见片麻岩、浅粒岩、大理岩、斜长角闪岩的大韵律,角闪岩中还见小韵律;上部表壳岩的斜长角闪岩中SiO2、CaO、Mg0的含量均高于下部1%左右。下部岩石原岩为火山岩,见变余火山杏仁状构造和枕状构造,为麻粒岩相,含紫苏辉石,塑性变形强烈,原岩构造保留较少。上下岩石无直接接触关系,从下部岩石中测得Rb-Sr全岩同位素年龄为2700~2900Ma,属太古代岩石。 相似文献
99.
采用整体分析和单因子分析相结合的方法,探讨余甘子二龄结果母枝强修剪处理对一龄结果母枝特性的影响。整体分析表明,强修剪处理对选取的五因子在整体上有极显著影响(Λ<Λ_(0.01))。单因子方差分析由Λ统计量转换而成,转换结果表明,二龄结果母枝强修剪处理对一龄结果母枝长、一龄结果母枝粗、一龄结果母枝结果枝数有极显著影响,对结果枝长有显著影响,对结果枝叶数无显著影响。强修剪处理使穗条(一龄结果母枝)在数量上增加,质量提高。这项研究为余甘子优树繁殖,结果、采穗两用果园的建立及树体生长、生殖平衡控制,提供了依据;提出了区间重叠度概念,并探讨了重叠度与处理有效性的关系;同时探讨了单因子显著性与因子组合显著性之间的关系。 相似文献
100.
Xiqun Wang Lüyi Ma Baoxiang Guo Shenhou Fan Jianxi Tan 《Frontiers of Forestry in China》2006,1(3):285-291
Lichuan, located at the foot of the Wuling Mountain in southwest Hubei Province of central China, is well known in the world
for the discovery of the living fossil Metasequoia glyptostroboides Hu & Cheng in the 1940s. Its natural habitat has been well protected by the Chinese government. In order to provide a scientific
foundation for the protection of the Metasequoia resource, it has become necessary to analyze the changes in the original,
natural Metasequoia mother trees (ONMMT) and their environment from 1948 to 2003. The results and countermeasures are as follows:
First, the distribution areas have little changed, involving four towns/farmland, 45 villages, 5,746 individual trees in 1983
and 5,388 trees in 2003, covering nearly 600 km2, with an average density of less than 0.1 tree/hm2. The Metasequoia distribution consists of two main types: a scattered distribution type found mainly at the foothills or
near houses, roads, villages and rivers while the population distribution type is found mainly at the mountains and valleys
with a minority at low elevations in the mountains and basins. The largest Metasequoia populations have 105 and 123 trees.
Second, in the past, attention was only paid to the protection of individual trees while the protection of the Metasequoia
population and environment was neglected. This led to a shift from the past mixed forests to pure Metasequoia forests, with
a simpler structure, reduced biodiversity and conditions non-conducive for natural renewal. From 1983 to 2003, 386 original
Metasequoia mother trees died. So it is vital to enhance the protection of the only original Metasequoia population in the
world and its habitat. Third, modern ecological means should be taken to protect the original Metasequoia population and its
habitat. Research on the restoration and rehabilitation of Metasequoia vegetation should be carried out. Restoration and rehabilitation
should be put into practice in the Xiaohe Valley, where the highest concentration of Metasequoia is found. Fourth, efficient
measures should be taken to stop human activities that are harmful to Metasequoia and to improve the environment of ONMMT
in order to promote the protection of the ONMMT population and its ecosystem. Eco-emigration and the return of marginal agricultural
land to forestry can be practiced.
__________
Translated from Acta Ecologica Sinica, 2005, 25(5): 972–977 [译自: 生态学报, 2005, 25(5): 972–977] 相似文献