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51.
蛋白酪氨酸磷酸酶SHP-2在乳腺癌细胞移动及粘附中的作用   总被引:2,自引:0,他引:2  
探讨蛋白酪氨酸磷酸酶SHP 2在乳腺癌细胞MCF 7的移动及粘附中的作用 .利用基因重组技术分别将野生型SHP 2与突变型SHP 2与绿色荧光蛋白GFP的基因片段构成重组质粒 (SHP 2 GFP、SHP 2C >S GFP) .脂质体转染法分别转入MCF 7中 ,表达成功后筛选并建立SHP 2 GFP和SHP 2C >S GFP细胞株 .荧光显微镜观察细胞移动情况 ,免疫印迹法检测粘附分子E 钙粘蛋白和金属蛋白酶MMP 1及MMP 9的表达 .实验后建立SHP 2 GFP及SHP 2C >S GFP细胞株 ,同时观察到SHP 2C >S GFP细胞的形态发生明显改变 :从梭形状态变成圆形状态 .荧光显微镜发现 ,MCF 7细胞和SHP 2 GFP、SHP 2C >S GFP转染的细胞在 3h、6h、9h的移动情况分别是MCF 7为 10 %、2 3%、5 4% ,SHP 2 GFP为 15 %、4 9%、98% ,SHP 2C >S GFP为 4 %、11%、30 % .免疫印迹结果表明 ,SHP 2C >S GFP细胞的E 钙粘蛋白表达比SHP 2 GFP细胞明显升高 (P <0 0 5 ) .MMP 1及MMP 9的表达量在SHP 2 GFP细胞中有所增强 (P <0 0 5 ) .实验表明 ,SHP 2可能通过调节粘附分子和基质金属磷酸酶而在细胞移动、粘附中发挥重要作用  相似文献   
52.
纤维素衍生物在固定酶和药物中的应用   总被引:1,自引:0,他引:1  
本文综述了纤维素衍生物在固定酶和药物中的应用。  相似文献   
53.
Rice LTRPK1, which encodes a member of the casein kinase I family, has been reported to be involved in root development, hormone response, and metabolic processes. Here we further show that LTRPK1 participates in stress resistance by regulating cytoskeleton rearrangement and formation of cold tolerance and adaptation. Semiquantitative RT-PCR analysis revealed enhanced expression of LTRPK1 in plants subject to low-temperature stress at 4 °C, suggesting a role in low-temperature-related cell responses and signal transduction pathways. Further analysis of LTRPK1-deficient transgenic plants showed that under low-temperature treatment, the growth rate of transgenic plant primary roots, which is commonly used as an indicator for cold stress response abilities, was less inhibited than that of control plants. Moreover, damage to the plasma membrane of root cells in LTRPK1-deficient plants was greater than that of controls as measured by relative electrical conductivity (REC). The malondialdehyde (MDA) content of LTRPK1-deficient plants also increased over that of the control, indicating increased plasma membrane permeability. Further immunofluorescence localization observations indicated that microtubules of transgenic plants subject to low temperature disassembled more rapidly, whereas the control plant microtubules in most cells of the root elongation zone kept their normal habitus, which suggested that LTRPK1-deficient plants had reduced capacity to resist low-temperature stress through regulation of microtubule assembly. These results demonstrate involvement of LTRPK1 in low-temperature stress and provide new insight for rice breeding and germplasm innovation to improve crop cold tolerance.  相似文献   
54.
Animal migration is one of the great wonders of nature, but the factors that determine how far migrants travel remain poorly understood. We present a new quantitative model of animal migration and use it to describe the maximum migration distance of walking, swimming and flying migrants. The model combines biomechanics and metabolic scaling to show how maximum migration distance is constrained by body size for each mode of travel. The model also indicates that the number of body lengths travelled by walking and swimming migrants should be approximately invariant of body size. Data from over 200 species of migratory birds, mammals, fish, and invertebrates support the central conclusion of the model - that body size drives variation in maximum migration distance among species through its effects on metabolism and the cost of locomotion. The model provides a new tool to enhance general understanding of the ecology and evolution of migration.  相似文献   
55.
56.
宁夏蝗虫地理分布格局的聚类分析   总被引:10,自引:1,他引:10  
根据宁夏的自然环境和行政区划将宁夏分为22个分布区域。为方便聚类分析,根据分布范围将宁夏蝗虫分为全布种(22个区域有分布)、多布种(2~21区域有分布)和独布种(只分布在1个区域)3类。在以分布区域为特征做聚类分析的基础上,把多布种分组并确定重叠的分布格局,共分为14个组。各组蝗虫在宁夏的自然分布作为其分布格局。结果表明:宁夏蝗虫的多布种多呈不连续分布;分布格局与国内外基本相似;贺兰山是宁夏蝗虫分布的热点。不连续的环境是造成宁夏蝗虫多布种不连续分布的主要原因。  相似文献   
57.
Phenolic composition and radical scavenging activity in the shochu distillery by-products of sweetpotato (Ipomoea batatas L.) treated with koji (Aspergillus awamori mut.) and cellulase (Cellulosin T2) were investigated to develop new uses. Koji and Cellulosin T2 treatment of shochu distillery by-products from sweetpotatoes, rice, and barley increased phenolic content. Caffeic acid was identified as a dominant phenolic component in the shochu distillery by-products of the sweetpotato. Adding koji and/or Cellulosin T2 to the shochu distillery by-product indicated that koji was involved in caffeic acid production. Caffeic acid was not detected in raw or steamed roots of "Koganesengan", the material of sweetpotato for shochu production, suggesting that it is produced during shochu fermentation. The phenolic content and radical scavenging activity the shochu distillery by-product treated with koji and Cellulosin T2 were superior to those of commercial vinegar. These results suggest that koji treatment of sweetpotato-derived shochu distillery by-products has potential for food materials with physiological functions. Further koji treatment of sweetpotato shochu-distillery by-products may be applicable to mass production of caffeic acid.  相似文献   
58.
The proteolipid subunit of H+-ATPase was labeled by [14C]N,N-dicyclohexylcarbodiimide in bovine heart mitochondria. The radioactive labeling was followed using various systems of sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE). When using discontinuous SDS-PAGE (Laemmli, U.K., 1970,Nature (London)227, 680–685) a monomeric (Mr 7600±1500) and a dimeric form (Mr 17,800±1200) of the proteolipid were detected, while only the monomeric form was found on urea (8 M) containing gels (SDS-PAGE according to Laemmli; or Swank, R. T., and Munkers, K. D., 1971,Anal. Biochem. 39, 462–477). When using SDS-PAGE with Na-Pi buffer (Weber, K., and Osborn, M., 1969,J. Biol. Chem. 244, 4406–4442), only a dimeric form of the proteolipid (Mr 15,000±1000) was detected. Experimental data indicate that the different patterns of proteolipid separation are related to the presence of the two distinct proteolipid conformations in the SDS solution.  相似文献   
59.
Effects of fertigation scheme on N uptake and N use efficiency in cotton   总被引:7,自引:0,他引:7  
While fertigation can increase fertilizer use efficiency, there is an uncertainly as to whether the fertilizer should be introduced at the beginning of the irrigation or at the end, or introduced during irrigation. Our objective was to determine the effect of different fertigation schemes on nitrogen (N) uptake and N use efficiency (NUE) in cotton plants. A pot experiment was conducted under greenhouse conditions in year 2004 and 2005. According to the application timing of nitrogen (N) fertilizer solution and water (W) involved in an irrigation cycle, four nitrogen fertigation schemes [nitrogen applied at the beginning of the irrigation cycle (N–W), nitrogen applied at the end of the irrigation cycle (W–N), nitrogen applied in the middle of the irrigation cycle (W–N–W) and nitrogen applied throughout the irrigation cycle (N&W)] were employed in a completely randomized design with four replications. Cotton was grown in plastic containers with a volume of 84 l, which were filled with a clay loam soil and fertilized with 6.4 g of N per pot as unlabeled and 15N-labeled urea for 2004 and 2005, respectively. Plant total dry matter (DM) and N content in N–W was significantly higher than in N&W in both seasons, but these were not consistent for W–N and W–N–W treatments. In year 2005, a significantly higher nitrogen derived from fertilizer (NDFF) for the whole plant was found in W–N and N–W than that in W–N–W and N&W. Fertigation scheme had a consistent effect on total NUE: N–W had the highest NUE for the whole plant, but this was not significantly different from W–N. Treatments W–N and W–N–W had similar total NUE, and N&W had the lowest total NUE. After harvesting, the total residual fertilizer N in the soil was highest in W–N, lowest in N–W, but this was not significantly different from N&W and W–N–W treatments. Total residual NO3–N in the soil in N&W and W–N treatments was 20.7 and 21.2% higher than that in N–W, respectively. The total 15N recovery was not statistically significant between the four fertigation schemes. In this study, the fertigation scheme N–W (nitrogen applied at the beginning of an irrigation cycle) increased DM accumulation, N uptake and NUE of cotton. This study indicates that Nitrogen application at the beginning of an irrigation cycle has an advantage on N uptake and NUE of cotton. Therefore, NUE could be enhanced by optimizing fertilization schemes with drip irrigation.  相似文献   
60.
本课题合成四个氮基三乙酸单酰苯胺(IDA)类及其类似物肝胆显像螯合物。(1)用家兔做了肝胆显像扫描实验,其显像效果较好。(2)~(3)为未见报道的化合物。  相似文献   
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