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251.
中国苍术属一新亚种   总被引:8,自引:0,他引:8  
罗田苍术 新亚种 图1Atractylodeslancea(Thunb.)DC.subsp.luotianensisS.L.HuetX.F.Feng,subsp.nov.Fig.1Asubspecietypicafoliolismajoribus,5~13cmlongis,1.5~5cmlatis,capitulismajoribus,(1.5)2~4cmdiam.,achaeniisobovoideis,5.5~10mmlongisdiffert.China.Hubei(湖北):Loutian(罗田),JiuziheTown(九资河镇),Tia…  相似文献   
252.
凤丫蕨孢子壁的结构和发育研究   总被引:3,自引:0,他引:3  
利用光镜、扫描电镜和透射电镜对裸子蕨科(Hemionitidaceae)凤丫蕨(Coniogramme japonica(Thunb.) Diels)孢壁的结构和发育进行了研究。结果表明,凤丫蕨孢子外壁表面光滑,由2层构成,即薄的内层和厚的外层。周壁分为周壁内层和周壁外层两部分,周壁内层中上部具辐射状排列的小柱状成分,周壁外层由鳞片和小球体疏松交织成平面或立体网状,由两层周壁共同构成孢子表面皱状纹饰的轮廓。探讨了凤丫蕨孢子周壁的来源,为孢粉学和蕨类植物系统演化研究提供基础资料。  相似文献   
253.
It has been suggested that diploid Potentilla argentea, hoary cinquefoil, is a facultative apomict. We have investigated the way such plants produce seeds under natural conditions in two populations from southern Sweden. About one hundred plants were studied cytometrically to ascertain their ploidy level. A standard population investigation based on two informative isozyme loci was then performed on the diploid plants. Finally, seeds were taken from heterozygous plants to determine the genetic constitution of their offspring. From the offspring analysis it followed that apomixis did not occur, at least not to any noticeable degree. From the population investigation it could be deduced that most seeds were produced by selfing.  相似文献   
254.
二氢杨梅素和杨梅素是拐枣种子中的重要成分。通过超声辅助法从拐枣种子中提取二氢杨梅素,采用单因素法考察乙醇体积分数、超声辐照功率、提取温度、液料比和超声辐照时间影响参数的基础上,并选用Box-Behnken响应面设计法分析建立了超声辐照功率、超声辐照时间和液料比的二次多项式模型,优化提取工艺。结果得到超声辅助法提取拐枣种子中二氢杨梅素的最佳工艺参数为:乙醇体积分数为60%、超声辐照功率140 W、超声辐照时间30 min、液料比20.5 mL·g-1,提取温度40℃。在此最佳条件下,二氢杨梅素得率为2.14±0.09 mg·g-1。本提取方法简单快速,效率高,有利于拐枣资源的综合加工利用。  相似文献   
255.
F. H Dawson 《Hydrobiologia》1996,340(1-3):241-245
The high resistance to control by herbicides of stands of the aggressively-invasive water plant Crassula helmsii (Australian swamp stone crop or New Zealand Pygmy Weed, also sold as Tillaea recurva) was shown during a series of tank and field trials aimed at:firstly, selecting the most appropriate UK-approved herbicide showed that diquat, either directly or in alginate form was effective on submerged plants particularly at low biomass, whereas for emergent stands, although glyphosate was initially selected as effective, diquat was subsequently recommended;secondly, the efficacy of the herbicides selected under a range of conditions of biomass, season of application and, particularly, field conditions showed that whilst low biomasses could be controlled and the plant could probably be eliminated, elevated or multiple applications would be necessary at the very high biomasses (up to 45 kg fresh weight per m2) achieved by this plant, unless the bulk of the biomass could be physically reduced prior to herbicide application; further trials were considered necessary to meet legal current constraints.  相似文献   
256.
The purpose of this study was to investigate the pharmacological effect of fraction of Atractylodes lancea (Thunb.) DC. (A. lancea) extract. In this study, we isolated different polarity fractions, including petroleum ether (PE), ethyl acetate, n-butanol, and the remaining H2O fractions from the water extract of A. lancea. The antigastric cancer properties of the different fractions in BGC-823 and SGC-7901 cells were evaluated. Apoptotic cells were treated with PE fraction and stained with Hoechst 33342 and 5,5,6,6-tetrachloro-1,1,3,3-tetraethylbenzimidazolylcarbocyanine iodide. The cell cycle was analyzed via flow cytometry. The main compounds of PE fraction were determined by HPLC–ESI–MS. Results of this study showed that the PE fraction of A. lancea inhibited the growth of BGC-823 and SGC-7901 cells in a dose- and time-dependent manner. The morphological and mitochondrial transmembrane potential changes suggested that the cells showed preliminary apoptosis characteristics after treatment with the three different polarities. The main compounds of PE fraction include two sesquiterpene compounds: eudesm-4(15),7-diene-9α,11-diol and eudesm-4(15)-ene-7a,11-diol; three sesquiterpene lactone compounds: atractylenolid I, atractylenolid III and 3-β-acetyl-atractylenolid III and one polyacetylenic compound: 4,6,12-tetradecatriene-8,10-diyne-1,3,14-triol.  相似文献   
257.
258.
以4年生忍冬为试验材料,采用盆栽和叶面喷施方式,设置不同质量浓度的铜肥(10,30,50 mg/L Cu2+,分别表示为Cu10、Cu30、Cu50)和硼肥(20,40,60 mg/L B4O2-7,分别表示为B20、B40、B60)及其配施组合处理,测定忍冬叶片的光合参数以及茎藤的营养物质、药效成分含量、矿质离子含量,探究施铜和硼肥对忍冬光合生理、营养物质、矿质离子及其茎藤品质的影响,为优化忍冬栽培技术和提高其药材品质提供理论参考。结果表明:(1)喷施一定质量浓度的铜硼肥有助于提高忍冬叶片的净光合速率,尤以B40Cu50配施处理最佳;适宜质量浓度的铜硼肥有利于增加总叶绿素含量,高质量浓度的铜硼肥则起抑制作用。(2)配施铜硼肥对忍冬藤中营养物质及药效成分含量的影响比单施铜、硼肥更显著,其中B40Cu50处理可显著提高忍冬藤中可溶性蛋白、淀粉、还原糖含量,B20Cu10处理可显著提高可溶性糖含量;有利于忍冬藤中绿原酸和马钱苷积累的最佳配施处理分别是B60Cu50和B20Cu30。(3)喷施铜硼肥对忍冬藤矿质离子的含量也具有显著的影响,单施与配施铜硼肥处理忍冬藤矿质离子含量均有增加,且配施铜硼肥比单施铜硼肥增加效果显著,尤以B20Cu10、B20Cu30、B20Cu50处理最佳。综合考虑,B40Cu50配施处理可有效增加忍冬藤的营养与药用指标成分含量,是忍冬叶面喷施铜和硼肥的最佳比例。  相似文献   
259.
Abstract Genetic variations among selected Frankia isolates from nitrogen-fixing root nodules harvested from an individual actinorhizal plant ( Elaeagnus angustifolia L. or Shepherdia argentea Nutt.) were estimated by restriction fragment analysis of their total genomic DNA. The presence of plasmids and their restriction enzyme patterns were used as additional criteria. Certain isolates from separate nodules on the same plant were found indistinguishable, being probably clones of the same strain. An endophytic passage of a strain isolated from S. argentea on another host plant, Hippophaë rhamnoides L., did not modify the structural characteristics of the genome in the reisolates obtained. However, in some cases, especially when restriction endonucleases cleaving Frankia DNA into relatively small fragments were used, multiple infection of the actinorhizal plants with different Frankia strains and the presence of more than one strain in a nodule were demonstrated. Some aspects of variability in natural populations of Frankia are discussed.  相似文献   
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