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41.
王科  蔡磊 《菌物学报》2023,42(1):50-62
我国菌物分类学研究始于20世纪初,经过百余年的不断探索和发展,取得了丰硕的成果,并逐渐走进世界前列。本研究通过对世界菌物名称信息库Fungal Names进行数据统计,对发现自中国的菌物新物种和中国学者发表菌物新分类单元等数据开展分析,从中揭示中国菌物分类学的历史和发展趋势。过去,一共有2 214位中国学者参与发表了15 626个菌物新分类单元,包括 3个新纲、27个新目及亚目、117个新科及亚科、769个新属及亚属、11 100个新种、322个新种下单元和3 288个新组合。在全球已知的菌物物种中,自中国发现的新物种有10 233种,隶属于 3界13门44纲174目572科2 379属,占全球已知物种多样性的6.84%,居世界第二位。地理分布上,我国西南地区(云南、四川、贵州、西藏)和低纬度的热带、亚热带地区(中国台湾、广东)发现的新物种最多。根据每年发现的新分类单元数量趋势和命名作者的构成,可将中国菌物分类学的发展历史分为五个阶段:外人在华采菌及研究(1750s-1929)、中国菌物分类学起步(1930-1949)、新中国菌物分类学早期发展(1950-1977)、全国性菌物标本采集与研究(1978-2010)、走进世界前列(2011至今)。本研究对每个发展时期的分类学概况和重要历史事件进行了总结和回顾,通过上述综述性研究,有助于系统地了解中国菌物分类学不同阶段的发展趋势和研究概况,为学科当下和未来的发展提供参考。  相似文献   
42.
Disjunct distribution is a key issue in biogeography and ecology, but it is often difficult to determine the relative roles of dispersal vs. vicariance in disjunctions. We studied the phylogeographic pattern of the monotypic Conandron ramondioides (Gesneriaceae), which shows Sino-Japanese disjunctions, with ddRAD sequencing based on a comprehensive sampling of 11 populations from mainland China, Taiwan Island, and Japan. We found a very high degree of genetic differentiation among these three regions, with very limited gene flow and a clear Isolation by Distance pattern. Mainland China and Japan clades diverged first from a widespread ancestral population in the middle Miocene, followed by a later divergence between mainland China and Taiwan Island clades in the early Pliocene. Three current groups have survived in various glacial refugia during the Last Glacial Maximum, and experienced contraction and/or bottlenecks since their divergence during Quaternary glacial cycles, with strong niche divergence between mainland China + Japan and Taiwan Island ranges. Thus, we verified a predominant role of vicariance in the current disjunction of the monotypic genus Conandron. The sharp phylogenetic separation, ecological niche divergence among these three groups, and the great number of private alleles in all populations sampled indicated a considerable time of independent evolution, and suggests the need for a taxonomic survey to detect potentially overlooked taxa.  相似文献   
43.
黄芪有效成分对氧自由基清除作用的ESR研究   总被引:81,自引:0,他引:81  
用电子自旋共振技术研究了黄芪总黄酮(TFA)、黄芪总皂甙(TSA)和黄芪总多糖(TPA)对次黄嘌呤/黄嘌呤氧化酶体系产生的超氧阴离子自由基和H2O2-Fe2+体系产生的羟自由基的清除作用.结果表明,这3种成分均有清除氧自由基的作用;对超氧阴离子自由基的清除效能大于对羟自由基的清除作用;其作用强度依次为TFA>TSA>TPA.结果提示清除氧自由基可能是黄芪抗衰老的主要机理之一,TFA和TSA是黄芪抗氧化作用的主要药理活性成分.  相似文献   
44.
Despite the same mean volumetric power input of 19 and 47 W/m 3 , the specific oxygen uptake rate (OUR S ) of strawberry ( Fragaria ananassa) cell suspensions was higher in bioreactors equipped with a Rushton Turbine (4.4 and 6.2 3 10 -5 mol O 2 /kg.s) than with an anchor stirrer (2.5 and 4.6 3 10 -5 mol O 2kg.s). The increase in OUR S was caused by stress-activated respiration and appeared to be correlated with the locally dissipated power input. OUR S was corrected for the increase in surface through aggregate break-up and reached a maximum of 6.0 3 10 -5 mol O 2kg.s when agitating with approximately 200 kW/m 3 locally dissipated power input.  相似文献   
45.
The soybean cyst nematode, Heterodera glycines, is one of the most economically important pathogens of soybean. Effective management of the nematode is often dependent on the planting of resistant soybean cultivars. During the past 40 years, more than 60 soybean genotypes and plant introductions (PI) have been reported as resistant to H. glycines. About 130 modern soybean cultivars registered in the United States are resistant to certain races of H. glycines. Several resistance genes have been identified and genetically mapped; however, resistance levels in many soybean cultivars are not durable. Some older cultivars are no longer resistant to certain H. glycines populations in many production areas, especially if a soybean monoculture has been practiced. Past soybean registration reports show that all resistant cultivars developed in public institutions from the mid-1960s to the present have been derived from five PIs. This narrow genetic background is fragile. To further complicate the issue, soybean-H. glycines genetic interactions are complex and poorly understood. Studies to identify soybean resistance genes sometimes have overlapped, and the same genes may have been reported several times and designated by different names. Nevertheless, many potential resistance genes in existing germplasm resources have not yet been characterized. Clearly, it is necessary to identify new resistance genes, develop more precise selection methods, and integrate these resistance genes into new cultivars. Rational deployment of resistant cultivars is critical to future sustained soybean production.  相似文献   
46.
对喀喇昆仑、昆仑山地区87种植物21个元素含量及区域分异的研究表明,Ca、Cr、Cd、Fe、V含量比高等植物含量偏高,Ph、P的含量偏低。同种植物在不同地点元素含量有差异。盐柴荒漠植物中Na、K、Mg、P含量较高;高山草甸、冰缘植被植物Ba、Ca、Fe、V、Ti含量较高。各植被类型植物元素含量Na/K差异最大,Ca/Mg较小,Fe/Al差异最小。其变异系数分别为153.5、20.5和15.9.%  相似文献   
47.
H.Y. Nakatani  B. Ke  E. Dolan  C.J. Arntzen 《BBA》1984,765(3):347-352
A Photosystem-II (PS-II)-enriched chloroplast submembrane fraction has been subjected to non-denaturing gel-electrophoresis. Two chlorophyll a (Chl a)-binding proteins associated with the core complex were isolated and spectrally characterized. The Chl protein with apparent apoprotein mass of 47 kDa (CP47) displayed a 695 nm fluorescence emission maximum (77 K) and light-induced absorption characteristics indicating the presence of the reaction center Chl, P-680, and its primary electron acceptor, pheophytin. A Chl protein of apparent apoprotein mass of 43 kDa (CP43) displayed a fluorescence emission maximum at 685 nm. We conclude that CP43 serves as an antenna Chl protein and the PS II reaction center is located in CP47.  相似文献   
48.
Two independent relaxation kinetics methods were used to study samples of α-hemocyanin kindly furnished to us by members of the Biochemical Laboratory of the University of Groningen. A Durrum-Gibson stopped-flow apparatus was used to obtain concentration-jump data in the light-scattering mode. A recently developed pressurejump light-scattering apparatus was used to obtain completely independent data. The studies were made in 0.1 m acetate buffer at pH 5.7 containing 0.4 m NaCl, conditions under which equilibrium light-scattering studies had been reported by Engelborghs and Lontie (1973, J. Mol. Biol., 77, 577–587). In the companion paper (Kegeles, 1977, Arch. Biochem. Biophys., 180, 530–536), a model is proposed, consisting of a system containing a mixture of reactive and unreactive whole molecules, from which data are derived for the formation constant of whole molecules from halves and the fraction of material which is capable of undergoing reaction. The present study uses this estimate of this fraction of reactive material to permit the evaluation of overall rate constants and equilibrium constants. When the estimate of 65% of reactive material derived without making nonideality corrections is applied to the kinetics data, very satisfactory agreement is obtained between the equilibrium constant acquired from equilibrium data and the equilibrium constants derived from the kinetics data.  相似文献   
49.
基于11个内陆居群和32个岛屿居群的252份标本,采用ISSR分子标记技术对真藓(Bryum argenteum Hedw.)的遗传多样性进行了研究。结果显示:岛屿与内陆居群间的遗传多样性差异显著,岛屿居群间的分化程度(Gst=0.453)大于内陆居群(Gst=0.387),岛屿居群的遗传分化与地理来源间存在极显著相关性(r=0.478,n=175,P<0.001)。地理隔离效应是导致岛屿居群间遗传分化的重要因素。岛内居群间的遗传分化水平较低,仅有29.4%~29.7%的遗传多样性存在于居群间。聚类分析表明,43个居群可划分为10大类群,真藓遗传关系受地理因素和生境异质性的影响,水域隔离影响了真藓繁殖体在岛屿间的传播。  相似文献   
50.
唐凤鸾  赵健  赵志国  夏科  仇硕 《植物学报》1983,54(3):378-384
以走马胎(Ardisia gigantifolia)幼嫩茎段为外植体, 通过腋芽增殖的方式进行组织培养和快速繁殖研究。结果表明, 培养基MS+1.0 mg·L -1 6-BA+0.2 mg·L -1NAA和MS+0.5 mg·L -1 ZT均可用于腋芽的诱导和前期继代培养, 诱导率分别为89.3%和85.7%; 芽增殖最佳培养基为MS+0.5 mg·L -16-BA+0.1 mg·L -1ZT+0.1 mg·L -1NAA, 增殖系数为4.3倍; 根诱导最佳培养基为1/2MS+1.5 mg·L -1 IAA+1.0 mg·L -1 NAA, 生根率达92.3%, 且根系发达, 植株健壮; 生根苗在混合基质园土:泥炭:珍珠岩=3:1:1 (v/v/v )中移栽成活率为82%。该研究建立了走马胎种苗的组织培养快速繁殖技术体系, 且可应用于规模化生产。  相似文献   
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