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161.
<正>短尾鼩(Anourosorex squamipes Milne-Edwards,1872)隶属鼩形目(Soricomorpha)鼩鼱科(Soricidae)鼩鼱亚科(Soricinae)短尾鼩属,其模式产地为中国四川宝兴(Milne-Edwards,1872)。短尾鼩属的物种分布于亚洲中南部,共有4种,即A.assamensis、A.schmidi、A.squamipes和A.yamashinai(Wilson and Reeder,2005)。短尾鼩  相似文献   
162.
Polyphenol oxidases (PPOs) catalyzing the oxygen dependent oxidation of phenols to quinones are ubiquitously distributed in plants and are assumed to be involved in plant defense against pests and pathogens. A protein with high PPO activity was identified in Satsuma mandarine, extracted with Tris–HCl buffer, purified by salt precipitation and column chromatography, and characterized by mass spectrometry as germin-like protein (GLP), which belongs to pathogenesis related protein (PR) family. In the present study, the structure and enzymatic properties of GLP were characterized using spectroscopy methods. Based on native PAGE analysis, the molecular weight of GLP was estimated to be 108 kDa and GLP was identified as a pentamer containing five subunits of 22 kDa. The optimum pH and temperature for PPO catalyzing activity of GLP was 6.5 and 65 °C, respectively. Kinetic constants were 0.0365 M and 0.0196 M with the substrates catechol and pyrogallol, respectively. The structural characterization of GLP provided better insights into the regions responsible for its PPO activity.  相似文献   
163.
The vertical distribution of Tubifex tubifex, Limnodrilus hoffmeisteri and L. udekemianus, in a riverine mud was studied over a year. Distribution was dependent upon species identity, season and locality. The size structure of the population, and hence species life history, was of fundamental importance in determining temporal patterns of vertical distribution. A positive correlation between worm length and depth of penetration was clearly demonstrated for all three species. However, the mid-stream populations of the three species were closer to the mud surface during the summer and autumn than were the near-bank populations, although the size structures of the populations were not significantly different. Thus, another factor, possibly the distribution of food, also influenced the vertical distribution of the worms. Cocoon distribution was similar to that of the adult worms. Cocoons of the larger species, L. udekemianus, occurred deeper in the mud than those of T. tubifex. A comparison between the vertical distributions of tubificids in cores sectioned in situ, on the stream bank, and 30 mins later, showed there to be no significant change in distribution with time.  相似文献   
164.
Diphyllobothrium nihonkaiense was first described by Yamane in 1986 but the taxonomical features have been obscure due to lack of critical morphologic criteria in its larval and adult stages. In Korea, this tapeworm had long been known as Diphyllobothrium latum. In this study, we observed 62 specimens collected from Korean residents and analyzed them by morphological features and nucleotide sequences of mitochondrial cox1 gene as well as the ITS1 region. Adult tapeworms were examined after carmine or trichrome stain. Longitudinal sections of the gravid proglottids showed an obtuse angle of about 150 degree between the cirrus sac and seminal vesicle. This angle is known as a major differential point compared with that of D. latum. Nucleotide sequence differences between D. latum and the specimens from Koreans represented 17.3% in mitochondrial DNA cox1 gene. Sequence divergence of ITS1 among 4 Korean isolates was 0.3% and similarity was 99.7% with D. nihonkaiense and D. klebanovskii. All of the Korean specimens analyzed in this study were identified as being D. nihonkaiense (n = 62). We propose its Korean name as "Dong-hae-gin-chon-chung" which means ''long tapeworm of the East Sea'' for this newly analyzed diphyllobothriid tapeworm in Korea.  相似文献   
165.
通过对安徽省6家不同所有制、不同规模、不同经营方式的药品流通企业的实地调研,了解药品流通企业及药品配送工作的基本情况,剖析了药品招标配送中存在的问题,对实施药品集中招标采购配送工作提出政策建议。  相似文献   
166.
荔枝蝽田间种群消长动态及空间分布型研究   总被引:2,自引:0,他引:2  
对海南省儋州地区荔枝园中荔枝蝽Tessaratoma papillosa(Drury)种群动态及空间分布进行了系统调查与分析。结果表明,在2005—2006与2008—2009年期间,荔枝蝽的产卵高峰期分别为4月与2月,若虫高峰期为3月,成虫高峰期分别为4月及7月;分析表明荔枝蝽各虫态在荔枝园中均为聚集分布,且成虫个体间相互排斥。  相似文献   
167.
氮胁迫对水曲柳幼苗养分吸收、利用和生物量分配的影响   总被引:8,自引:2,他引:8  
树木受到环境胁迫时发生形态和生理上的改变,以便获取对其生长发育限制最严重的资源.在东北林区凋落物因受温度影响分解速度和有机物矿质化过程缓慢,森林树木常受到氮营养胁迫.通过温室栽培试验,对氮胁迫下水曲柳幼苗生长的生理学和形态学指标进行了研究.结果表明,在氮胁迫下,水曲柳幼苗的净氮吸收速率和净磷吸收速率都会减少,但在生长前期氮利用效率和磷利用效率高于氮供给充足(8mmol·L^-1)和过量(16mmol·L^-1)时的氮利用效率和磷利用效率.当氮供给浓度不足时,叶重比减少,而特定叶面积和根重比增加.相对生长速率随氮供给浓度增加而增加.在氮胁迫下净同化速率下降,导致总生物量下降.在幼苗生长前期,水曲柳幼苗处于氮胁迫时根/茎比显著大于氮供给充足或过量时的根/茎比。而在生长后期。根/茎比没有显著差别.  相似文献   
168.
Tarek M. Galal 《Flora》2011,206(7):638-645
The population structure of 10 common woody perennials was investigated in terms of size distribution, height, diameter and density in Wadi Gimal along the Red Sea coast of Egypt. It was attempted to assess the effect of elevation on the size, distribution and density of the studied species. These species are: five trees (Acacia tortilis subsp. raddiana, Acacia tortilis subsp. tortilis, Balanites aegyptiaca, Tamarix aphylla, and Tamarix nilotica), two shrubs (Leptadenia pyrotechnica and Nitraria retusa) and three shrublets (Pulicaria undulata, Zilla spinosa, and Zygophyllum coccineum). The size estimations were then used to classify population into six size classes: 20-80 cm for shrublets, 100-500 cm for shrubs, and 2-10 m for trees. The absolute and relative frequency of individuals and mean height, diameter and height to diameter ratio per individual in each size class were determined. Density of occurrence of most species, except B. aegyptiaca, decreased as elevation increased. The height-to-diameter ratio was less than unity for most of the recorded species except T. nilotica. Several forms - including, positively and negatively skewed, inverse J-shaped, bell shaped and more or less J-shaped distributions - were recognized along the different elevations. The size structure of some species was positively related with soil variables, such as T. nilotica with sulphate, while some others were negatively significant related to the substrate characteristics, such as Z. spinosa with salinity.  相似文献   
169.
170.
Summary The seasonal occurrence ofAtyaephyra desmaresti in The Netherlands has been studied by sampling the cooling-water filtering screens of power stations situated along the rivers Rhine and Meuse. The shrimps were only found in large numbers at the two power stations with vegetation in the cooling-water intake areas. Fluctuations in the seasonal occurrence showed great similarity for these two localities. Highest numbers of shrimps were impinged in November. High numbers also occurred in September, while a lower peak in numbers was found in May.Changes in the numbers of records during the last 30 years in The Netherlands were compared with climatological fluctuations (severe or mild winters), indicating that this mainly southern-European species is living here at the limits of its ecological and geographical range.The distribution in The Netherlands reveals thatAtyaephyra desmaresti mainly occurs in freshwater habitats, although it tolerates higher chlorinities.  相似文献   
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