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21.
本文报道广东地区小煤炱科(Meliolaceae)的2个新种及4个国内新纪录。2个新种是:寄生藤生小煤炱(Meliola dendrotrophicola H.Hu et J.C. Yang, sp.nov.);南五味子生小光壳炱(Asteridiella kadsuricola H.Hu et J.C.Yang,sp.nov.),并附有种的检索表。 相似文献
22.
本工作应用心钠素放射免疫测定和分子杂交技术首次发现,吗啡耐受大鼠血浆心钠素水平显著降低,心房内心钠素含量明显升高,同时心房内心钠素特异性mRNA水平也相应提高,提示在吗啡耐受时大鼠心房内心钠素的合成和贮存增加,释放减少。 相似文献
23.
正常情况下处于S期的CFU-S比例低于10%。氨甲酰胆碱(Cach 10~(-13)—10~(-9)mol/L)和Impromidine(Impro 10~(-9)—10~(-4)mol/L)在体外与小鼠骨髓细胞短时培育后,增加了CFU-S对细胞毒剂羟基脲的敏感性。反应最大时,9d和13dCFU-S的减少率分别是32.8和60.6%(Cach)以及38.4和49.5%(Impro)。这种效应可分别被胆碱能N受体阻断剂筒箭毒(10~(-6)mol/L)和组胺H_2受体阻断剂甲氰咪呱(10~(-6)mol/L)所阻断,表明9d和13d CFU-S表面胆碱能N受体和组胺H_2受体的密度或活性存在差别,再次证实了CFU-S是一个不均一的细胞群。 相似文献
24.
广东小煤炱科研究初报Ⅰ. 总被引:1,自引:0,他引:1
本文报告广东小煤炱属28个分类单位,其中红苞木生小煤炱 Meliola rhodolei-icola H.Hu、银鹃树生小煤炱 Meliola tapisciicola H.Hu 为新种,其余26个为我国新纪录种。 相似文献
25.
26.
丝裂素活化蛋白激酶参与内皮素刺激的兔主动脉平滑肌细胞增生 总被引:11,自引:1,他引:10
内皮素(endothelin,ET)是已知的体内活性最强的缩血管物质,其缩血管作用由G蛋白偶联受体所介导。但ET强大的促血管平滑肌细胞(VSMC)增生效应的机理尚未完全阐明。本研究选用培养的兔胸主动脉VSMC,探讨丝裂素活化蛋白激酶(MAPK)在ET促细胞增生中的作用。结果表明:ET-1呈时间和浓度依赖性地促进细胞摄取 ̄3H-TdR和激活MAPK,此作用可被蛋白激酶C(proteinkinaseC,PKC)抑制剂Staurosporine(STP),H-7和ET_A受体拮抗剂BQ123所抑制,但不被酪氨酸激酶抑制剂HerbimycinA(Herb)所抑制,用PKC激动剂PMA(Phorbolmyristateacetate)预处理VSMC,使其PKC活性下调,可显著减弱ET-1对MAPK的激活能力。本结果提示:(1)MAPK参与ET-1所致的VSMC增生;(2)ET-1促细胞增生与激活MAPK的作用是由ET_A受体和PKC介导的。 相似文献
27.
Phloem Mobility of Boron is Species Dependent: Evidence for Phloem Mobility in Sorbitol-rich Species 总被引:14,自引:1,他引:13
Boron is generally considered to be phloem immobile or to haveonly limited phloem mobility in higher plants. Evidence suggests,however, that B may be mobile in some species within thePyrus,Malus andPrunusgenera. These genera utilize sorbitol as a primarytranslocated photosynthate and it has been clearly demonstratedthat B forms stable complexes with sorbitolin vitro.In the researchpresented here we demonstrate, further, that B is freely phloemmobile inPyrus, MalusandPrunusspecies and suggest that thisis mediated by the formation and transport of B-sorbitol complexes. The pattern of B distribution within shoot organs and the translocationof foliar-applied, isotopically-enriched10B was studied in sixtree species. Results demonstrate that in species in which sorbitolis a major sugar (sorbitol-rich), B is freely mobile while inspecies that produce little or no sorbitol (sorbitol-poor) Bis largely immobile. The sorbitol-rich species used here werealmond [Prunus amygdalusB. syn.P. dulcis(Mill.)], apple (MalusdomesticaB.) and nectarine (Prunus persicaL. B. var.nectarinaM.),sorbitol-poor species included fig (Ficus caricaL.), pistachio(Pistacia veraL.) and walnut (Juglans regiaL.). In sorbitol-richspecies foliar applied10B was transported from the treated leavesto adjacent fruit and specifically to the fruit tissues (hull,shell or kernel) that developed during the experimental period.Whereas, foliar-applied10B was rapidly translocated out of leaves,only a small percentage of the11B present in the leaf at thetime of foliar application was retranslocated. In sorbitol-richspecies, B concentrations differed only slightly between oldand young leaves while fruit tissue had significantly greaterB concentrations than leaves. In contrast, sorbitol-poor specieshad significantly higher B concentrations in older leaves thanyoung leaves while fruit tissue had the lowest B concentration.This occurred irrespective the source of plant B (soil, solutionor foliar-applied). In a subsequent experiment the growth ofapple trees in solutions free of applied B was maintained solelyby foliar applications of B to mature leaves. These resultsindicate that B is mobile in species that produce significantamounts of sorbitol. We propose that the mobility of B in thesespecies is mediated by the formation of B-sorbitol complexes. Almond; Prunus amygdalus ; apple; Malus domestica; nectarine; Prunus persica; fig; Ficus carica; pistachio; Pistacia vera; walnut; Juglans regia; boron; phloem mobility; deficiency; toxicity; inductively coupled plasma-mass; spectrometer 相似文献
28.
小檗科鬼臼亚科植物的核型研究 总被引:10,自引:2,他引:8
本文首次报道了中华山荷叶与川八角莲的核型,分别为K(2n)=12=8m(4SAT)+2st+2t及K(2n)=12=4m(2SAT)十4sm+2st(2SAT)+2t,核型类型均为ZA型。本文报道的桃儿七及八角莲的核型与前人的结果有一定差异,前者为:K(2n)=12=6m(4SAT)+2sm+2st+2t,2B型,后者为K(2n)=12=8m(2SAT)+2st(2SAT)+2t,为2A型。本文分析了小檗科鬼臼亚科4个属共7种植物的核型,结果是该类植物的核型极为相似,染色体数目均为2n=12,由8条m或sm,2条st以及2条t染色体组成。核型的相似性反映了这类植物的亲缘关系,这4个属的植物是一个自然类群。但随着系统发育,核型的不对称性有所增加,其中以山荷叶属最为对称,八角莲属居中,桃儿七属与足叶草属最不对称。笔者认为,核型上的高度相似是该类植物在系统发育上不发达,属内种类稀少,通常为寡种属或单种属的重要原因。 相似文献
29.
Wen Yen Li Dhruba J. Chatterjee Bhasker V. Shetty Ellen Y. Wu Franco Muggia Robert T. Koda 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1995,673(2)
AG 331 is a novel thymidylate synthase inhibitor currently in Phase I clinical trial. To determine the pharmacokinetic parameters of AG 331 in human subjects, a suitable analytical method was developed using high-performance liquid chromatography. Serum and urine samples were prepared using both solid-phase extraction and solvent extraction. Either 4,4′-diaminodiphenyl sulfone or benz[cd]indole-2(1H)-one were used as internal standards for the method. A reversed-phase C18 analytical column completely resolved the drug and internal standard peaks from non-specific substances present in biological matrix. The method was validated for precision, accuracy, and reproducibility in serum and was linear over a concentration range of 50–2000 ng/ml, with a limit of detection of 20.0 ng/ml and a quantifiable limit of 50 ng/ml. 相似文献
30.
This paper describes an approach to seek for mouse c-Myc/Myn proteins-bound specific sequences among genomic DNA.cDNA fragment of myn gene was obtained through RT-PCR technique from RNA of NIH3T3 cells.DNA fragments encoding BR/HLH/LZ structure of Myc and Myn proteins were cloned in frame into pGEX-2T vector respectively.Fusion GST-Myc and GST-Myn synthesized in E.coli hosts showed affinity to CACGTG E-box DNA and subsequently interacted with genomic fragments prepared through whole-genome-PCR.A PCR-assisted procedure which combines protein-DNA interaction and affinity chromatography was designed to enrich Myc/Myn bound DNA.At least two genomic DNA fragments obtained exhibit specifical binding capacity to Myc/Myn complex but not to GST alone.Significance of the work and of the technique itself as well asidentification of the DNAs are discussed. 相似文献