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991.
992.
[Objective] The experiment aimed to study the difference of water physiology of male and female Ginkgo biloba L. for discussing the strategy of water utilization as well as the important role of this difference during evolution process. [Method] The stem sap flow, stomatal conductance(Gs), transpiration rate(Tr) and water use efficiency (WUE) of male and female Ginkgo biloba L. were comparatively studied. [Result] The day-night processes of flow on male and female Ginkgo biloba L. were similar. The flow on male and female Ginkgo biloba L. in day were almost same while the flow at night on male Ginkgo biloba L. was bigger than that on female Ginkgo biloba L. The Tr and Gs of male and female Ginkgo biloba L. were high in morning and at night but low at noon ,while Tr and Gs of female Ginkgo biloba L. in morning and at night were higher than these of male Ginkgo biloba L. at the same time point. However, these indexes of female plant were lower than these of male plant from 11:00 to 14:00. WUE changing trends of male and female Ginkgo biloba L. were similar, while average water utilization rate of female Ginkgo biloba L. was slightly lower than that of male Ginkgo biloba L. [Conclusion] Compared with other companion plants, water physiology of male and female Ginkgo biloba L. had strong homoplasy. The phenomenon might be a survival strategy of dioecious plants under long term evolutionary pressure. 相似文献
993.
994.
Effects of Nitrogen Application on Chlorophyll Fluorescence Parameters and Leaf Gas Exchange in Naked Oat 总被引:2,自引:0,他引:2
LIN Ye-chun HU Yue-gao REN Chang-zhong GUO Lai-chun WANG Chun-long JIANG Ying WANG Xue-jiao Phendukani Hlatshwayo ZENG Zhao-hai 《中国农业科学(英文版)》2013,(12):2164-2171
Naked oat(Avena nuda L.) was originated from China,where soil nitrogen(N) is low availability.The responses of chlorophyll(Chl.) fluorescence parameters and leaf gas exchange to N application were analysed in this study.After the N application rate ranged from 60 to 120 kg ha-1,variable fluorescence(F v),the maximal fluorescence(F m),the maximal photochemical efficiency(F v /F m),quantum yield(Φ PS II) of the photosynthetic system II(PS II),electron transport rate(ETR),and photochemical quenching coefficient(qP) increased with N application level,however,non-photochemical quenching coefficient(qN) decreased.Moreover,there was no difference in initial fluorescence(F o) with further more N enhancement.The maximum net photosynthetic rate(P max),apparent dark respiration rate(R d) and light saturation point(LSP) were improved with 40-56 kg N ha-1as basal fertilizer and 24-40 kg N ha-1as top dressing fertilizer applied at jointing stage.Initial quantum yield(α) was decreased with 24 kg N ha-1as basal fertilizer and 56 kg N ha-1as top dressing fertilizer.Flag-leaf net photosynthetic rate(P n) was significantly enhanced at the jointing and heading stages with 40-56 kg N ha-1as basal fertilizer; in addition,increased at grain filling stage of naked oat with 40-56 kg N ha-1as top dressing fertilizer.90 kg N ha-1(50-70% as basal fertilizer and 30-50% as top dressing fertilizer) application is recommended to alleviate photodamage of photosystem and improve the photosynthetic rate in naked oat. 相似文献
995.
常德市地被植物应用现状调查 总被引:1,自引:0,他引:1
为了配合常德市的生态园林城市建设,通过对常德市城区园林绿地中地被植物的应用情况进行实地调查、归纳统计,从地被植物种类、生长状况、多样性、群落结构等方面进行了详细的比较分析.结果显示,常德市应用的地被植物类型丰富、栽培形式多样、群落结构合理、注重应用乡土地被植物;并且认真地分析了园林应用中存在的问题,针对这些问题提出了加大乡土地被植物资源开发、科学引入外地地被植物、改善分布的均衡性、合理搭配乔木灌木、充分利用生态习性、提高养护管理水平的建议. 相似文献
996.
The Control Efficiency of Plant Alcohol Extracts on the Laboratory Populations of Myzus persicae (Sulzer)and Lipaphis erysimi (Kaltenbach) 总被引:6,自引:0,他引:6
The effects of semiochemicals extracted from 63 species of plants, on peach aphid (Myzus persicae) and mustard aphid (Lipaphis erysimi), were studied in laboratory. The deterrent rate, reproduction deterrent index and the interferential index of population control (ⅡPC) was used to evaluate the efficiency of semiochemicals on population control of the two target aphids. The results showed that the extracts of 34 species of common plants have noticeable effect on both aphid populations, especially, Xanthium sibiricum Petr.Et Widd. and Syngonium podophyllum Schott. These plant extracts could be used to construct the plant protectant to protect crops. 相似文献
997.
998.
QIN Ke HUANG Xiang ZENG Jian-hua WANG Chen SUN Guan-jie SONG De-qing CHEN Yao-sheng LIU Xiao-hong HE Zu-yong 《中国畜牧兽医》2017,44(3):773-781
In order to assess the purity of Luchuan pig populations, four South Chinese local pig breeds including Putian Black pig, Yuedong Black pig, Dahuabai pig, Bama miniature pig and three foreign pig breeds including Duroc pig, Yorkshire pig and Landrace pig were studied as controls by sequencing of PCR products, MC1R and KIT genotypes in 56 Luchuan pigs were analyzed in this study. Sequencing results indicated that a splicing mutation (G>A) was presented in the first base in intron 17 of KIT gene in both Yorkshire pig and Landrace pig, in contrast, the wildtype GG of KIT gene was presented in Luchuan pig, four south Chinese local pig breeds and Duroc pig.Compared with Hainan wild boar, South Chinese local pig breeds had two missense mutations 95Val > Met and 102Leu > Pro in the coding region of MC1R gene;Compared with Yorkshire pig, Landrace pig and Duroc pig, South Chinese local pig breeds had 5 to 6 SNPs in MC1R gene 5'UTR, and in addtion, an A base deletion in MC1R gene 3'UTR. Furthermore, we found one litter of Luchuan pig with abnormal coat color.The results showed that the presentation of two distinct MC1R genotypes ED1 and Ep in both litters and the sow,but only ED1 in the boar. Considering Ep was derived from Pietrain pig, we preliminarily considered that the genome of the sow might be infiltrated with foreign pig breeds. In summary, we detected the genotypes of the coat color genes KIT and MC1R in eight pig breeds, confirmed the molecular differences of coat color between Chinese local pig breeds and foreign pig breeds, which could be useful for the further investigation of the molecular mechanism of pig coat color. 相似文献
999.
目的 以马尾松人工纯林为对象,分析其近自然化改造后森林质量变化和树种发育情况,为此类人工纯林的近自然化经营提供参考和决策依据。 方法 2007年在广西凭祥中国林科院热带林业实验中心对马尾松纯林开展近自然改造试验并设置样地20块,其中经营样地16块、对照样地4块;于2007年第一次全面调查获得本底数据之后,冬季执行目标树抚育择伐;2008年春执行6个阔叶树种4种组合的林下补植作业;2016年实施第二次目标树抚育伐;2007年后,每2年执行1次样地复测调查,共获取了7期数据。对7期监测数据的重要值指数、平均胸径和纯生长量等指标进行统计,从树种组成、林分结构、林分生长等方面对马尾松人工林近自然化改造效果进行分析和评价。 结果 近自然化改造的马尾松人工纯林经过13 a后,林分逐步过渡到异龄复层混交林结构。林下补植的6个树种的重要值均处于前10名,林分中出现了安息香、油桐等树种的天然更新。近自然化改造的马尾松林的林木从5 cm起测径阶到55 cm径阶范围内均有分布,呈现出经营措施促进下快速形成混交异龄林格局的发展动态;而未作处理的对照林分依然呈同龄纯林的径级分布。就生长而言,近自然化改造林分生长量显著高于对照林分,并且林分生长量主要集中于较大径阶林木,实现了林分价值的显著提升。 结论 人工纯林近自然化改造中,调整树种组成是最关键的经营措施;扩大径级结构分布范围是针叶纯林近自然化改造的基本指标;近自然化改造显著提高了森林的生长量和蓄积量;同时促进了土壤微生物发育,改善了森林土壤和生态系统整体质量。 相似文献
1000.