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371.
水杨酸对马铃薯试管微薯形成的影响研究   总被引:12,自引:1,他引:11  
研究了不同浓度水杨酸(SA)对马铃薯脱毒试管苗生长,分化及试管微薯诱导和发育的 浓度SA显著抑帛式管苗主茎和根的生长,促进侧枝和匍匐茎分化。高浓度(0.1-1.0mmol/L)SA能诱导试管微薯形成并显著提高结薯率。SA浓度为0.5mmol/L时,结薯率最高,且成薯集中,薯块大小整齐一致。  相似文献   
372.
黄荆挥发油化学成分的研究   总被引:12,自引:0,他引:12  
采用气相色谱-质谱联用仪对产于秦岭略阳的黄荆叶的挥发油成分进行了分析鉴定,共确定出了35种成分。主要成分为石竹烯(33.01%)、桉树脑(13.30%)、β-水芹烯(13.23)、别-香树烯(6.58%)和β-法呢烯(5.56%)。  相似文献   
373.
培养球茎甘蓝( Brassica caulorapa)的带有花托、花柄和子房的外植体。在附加 B A 和 G A3 的培养基上,花托部位直接出芽;在附加不同浓度 B A 的培养基和附加 B A 和 G A3 的培养基上均诱导花柄切口直接出芽,在附加 B A 和 N A A 的培养基上,花托花柄切口剧烈增生愈伤组织。组织细胞学观察了芽的发生过程,结果表明:花托芽是由靠近维管束的多个皮层薄壁细胞恢复分裂能力形成,并与母体建立维管联系;花柄切口出芽是由皮层几个相靠近的薄壁细胞恢复分裂能力共同形成,与母体没有维管联系;花托增生愈伤组织也是皮层薄壁细胞剧烈分裂的结果。  相似文献   
374.
晚播小麦叶片衰老代谢和粒重变化的比较研究   总被引:3,自引:1,他引:2  
对7个小麦品种在晚播条件下的叶片衰老生理特性和粒重变化进行了比较研究。根据小麦叶片的衰老特征相差差异,将7个小麦品种区分为3个类型;后健型、早衰型和中间型。在小麦旗叶的衰老过程中,后健型小麦品种旗叶叶绿素和类胡萝卜素含量显著高于早衰型,脂质过氧化产物MDA含量显著低于早衰型,小麦粒重降幅依次为早衰型〉中间型〉后健型,并讨论了活性氧代谢在小麦叶片衰老过程中可能作用。  相似文献   
375.
黄运平  尹祖棠 《植物研究》1994,14(4):395-400
本文报道了风毛菊属28种植物瘦果表皮纹饰的扫描电镜观察。结果表明风毛菊属果皮纹饰有四种类型:即条纹型(有隔条纹亚型和无隔条纹亚型)、孔纹型、网纹型、复合型。果皮纹饰显示出明显的差异性,可作为划分组成或亚属的标准,与传统分类结果基本一致。也可为某些种间界限不清的种类提供有用的证据,但对于大多数种类来说,果皮纹饰在种的划分上还有待进一步研究。  相似文献   
376.
For real-time monitoring of the longitudinal position of the Bragg-peak during an ion therapy treatment, a novel non-invasive technique has been recently proposed that exploits the detection of prompt γ-rays issued from nuclear fragmentation. Two series of experiments have been performed at the GANIL and GSI facilities with 95 and 305 MeV/u 12C6+ ion beams stopped in PMMA and water phantoms. In both experiments, a clear correlation was obtained between the carbon ion range and the prompt photon profile. Additionally, an extensive study has been performed to investigate whether a prompt neutron component may be correlated with the carbon ion range. No such correlation was found. The present paper demonstrates that a collimated set-up can be used to detect single photons by means of time-of-flight measurements, at those high energies typical for ion therapy. Moreover, the applicability of the technique both at cyclotron and at synchrotron facilities is shown. It is concluded that the detected photon count rates provide sufficiently high statistics to allow real-time control of the longitudinal position of the Bragg-peak under clinical conditions.  相似文献   
377.
Emodin has antioxidative activities. Here, we investigated the effects of emodin on cigarette smoke (CS)‐induced acute lung inflammation. Mice (C57BL/6) were exposed to CS. Emodin was administrated with intraperitoneal bolus injection of emodin (20 or 40 mg/kg) daily 1 h before CS exposure. Emodin inhibited CS‐induced inflammatory cells infiltration in mouse lungs, especially at 40 mg/kg. Moreover, emodin resulted in significant reductions in total bronchoalveolar lavage fluid (BALF) cells, as compared with air exposure control, coupled with decreases in BALF cytokines. The activities of superoxide dismutase, catalase, and glutathione peroxidase were remarkably enhanced by emodin in CS‐exposed mice. Emodin enhanced CS‐induced expression of heme oxygenase‐1 and nuclear factor‐erythroid 2‐related factor‐2 (both are antioxidative genes) at both mRNA and protein levels, and profoundly promoted their activities in CS‐treated mice. Collectively, our results suggested that emodin protects mouse lung from CS‐induced lung inflammation and oxidative damage, most likely through its antioxidant activity.  相似文献   
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Oesophageal cancer (OC) is one of the most fatal malignancies in the world, and chemoresistance restricts the therapeutic outcome of OC. Long noncoding RNA (lncRNA) was reported to play roles in multiple cancer types. Yet, the function of lncRNA in chemoresistance of OC has not been reported. A lncRNA gene, PCAT‐1, showed higher expression in OC tissues, especially higher in secondary OC compared with normal mucosa tissues. Overexpression of PCAT‐1 increased the proliferation rate and growth of OC cells. Inhibition of PCAT‐1 decreased proliferation and growth of OC cells, and increased cisplatin chemosensitivity. In a mouse OC xenograft model, PCAT‐1 inhibition repressed OC growth in vivo. Therefore, PCAT‐1 may potentially serve as a therapeutic target for treating OC. PCAT‐1 promotes development of OC and represses the chemoresistance of OC to cisplatin, and silencing of PCAT‐1 may be a therapeutic strategy for treating OC.  相似文献   
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