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981.
采用反相高效液相色谱法测定了相对标准偏差为二十五味大汤散中没食子酸的含量.用十八烷基硅烷键合硅胶做填充剂,甲醇-水做流动相,检测波长为274 nm.结果表明:线性范围为0.020 6~0.247 2μg,平均回收率为98.8%,相对标准偏差为1.1%.  相似文献   
982.
In this study, recognition of 4 recombinant viral proteins (GST?NHA1) by the antibodies induced by multi?epitope vaccine was testified. Inhibitory activities of these antibodies were also investigated in vitro against four heterologous influenza A viruses (H3N2). Three epitope?specific antibodies purified by affinity chromatography could reduce the plaque formation. Interestingly, the three neutralizing antibodies in combination showed obvious enhancement of inhibitory activity, suggesting that the development of recombinant multi?epitope vaccine might be an effective way against viral mutation.  相似文献   
983.
目的:建立反相高效液相色谱法测定盐酸乙胺丁醇的含量.方法:采用ZORBAX SB-C18(4.6mm×150mm,5μm)色谱柱,流动相为A(乙酸铵和乙酸铜的缓冲液用冰醋酸调节pH=5.0):B(甲醇)=83:17;柱温25℃;检测波长270nm;流速1.0ml·min-1;进样体积10μl.结果:盐酸乙胺丁醇浓度在14.40~720.0μg·ml-1范围内,线性关系良好(r=0.999 9 n=6),平均回收率98.88%,s为1.57%.结论:该法准确,灵敏,快速,适用于盐酸乙胺丁醇片含量的控制.  相似文献   
984.
Receptor-like kinase participates in the early events of plant signal transduction pathways. Previously, we screened the receptor-like kinase genes in rice and performed phylogenetic analyses. In this study, we isolated a receptor-like kinase gene, OsSI-RLK2, from rice. Expression of OsSI-RLK2 was induced by ABA treatment. In vitro analysis indicates that OsSI-RLK2 has Mn2 dependent autophosphorylation activity, but does not have this activity in the presence of Ca2 and Mg2 . Transgenic rice with over-expressed OsSI-RLK2 displayed shortened internodes resulting in a dwarf phenotype. Taken together, these results suggest that OsSI-RLK2 may represent a new type of functional RLK in rice that can inhibit the elongation of the internode.  相似文献   
985.
【目的】寻找一种准确有效的脂肪酶活力测定中的终止反应方法,以进行脂肪酶酶学性质研究。【方法】比较分析前人研究脂肪酶常用的终止方法(无水乙醇法、EDTA法、三氯乙酸法、碳酸钠法、沸水浴法)对酶活力的抑制效果和吸光值的稳定性。【结果】无水乙醇法对酶活的抑制率为97.56%,终止反应后5min内净吸光值减少5%;EDTA法对酶活抑制率为32.94%,终止反应后10min内净吸光值增加5%;三氯乙酸法对酶活的抑制率为99.46%,终止反应后10min内净吸光值增加了0.47%;碳酸钠法对酶活抑制率为76.44%,终止反应后10min内净吸光值增加了0.53%;沸水浴法对酶活抑制率为99.51%,终止反应后10min内净吸光值减少0.77%,但沸水浴会导致剩余底物的大量分解。【结论】三氯乙酸法是一种准确有效的终止脂肪酶活力测定反应的方法,可用于脂肪酶酶学性质的研究。  相似文献   
986.
The cannabinoid receptor 2 (CB2 receptor) has attracted considerable interest, mainly due to its potential as a target for therapeutics for treating various diseases that have a neuroinflammatory or neurodegenerative component while avoiding the adverse psychotropic effects that accompany CB1 receptor-based therapies. With the appreciation that CB2-selective ligands show marked functional selectivity, there is a renewed opportunity to explore this promising area of research from both a mechanistic as well as a therapeutic perspective. In this research, we are interested in the discovery of new chemotypes as highly selective CB2 modulators, which may serve as good starting points for further optimization towards the development of CB2 therapeutics. In search of new chemotypes as CB2 selective agents, we screened a series of triazole derivatives with interesting bioactive scaffolds, which led to the discovery of two novel and highly selective ligands for CB2 receptors. Compounds 6 and 11 produced a concentration-dependent inhibition of specific [3H]-CP55,940 (CB2) binding with Ki ± SEM values of 105.3 ± 22.6 and 116.4 ± 19.5 nM, respectively, while no binding affinity towards CB1 receptors or opioid receptors was observed. The CB2 functional activity of 6 and 11, as measured by a GPCR Tango assay (G-protein independent β-arrestin translocation assay), revealed that these compounds act as CB2 agonists with EC50 values ± SEM of 1.83 ± 0.16 and 1.14 ± 0.52 µM, respectively. Molecular modeling results showed that both compounds fit well into the active site of the CB2 receptor and showed strong hydrophobic interactions with key residues. In conclusion, the new triazole derivatives (6 and 11) showed promising activity towards CB2 receptors and have great potential to be developed into therapeutically useful CB2 agonists through hit-to-lead optimization.  相似文献   
987.
《印度化学会志》2022,99(11):100776
Crude Sophorolipid extract obtained from fermentation broth contains both acidic and lactonic forms of Sophorolipid with different degrees of acetylation and varying lengths of the fatty acid chains. Carboxylic end in the acidic form of the fatty acid is free, whereas in the lactonic form, it is internally esterified. Sophorolipid show different physicochemical properties with wide range of applications for each structural compound. This work represents the separation and purification strategies of acidic and lactonic Sophorolipid obtained from crude extract. Depending on structure of Sophorolipid molecule different resin were selected for screening based on % binding per ml of resin, % elution and % assay purity of the product obtained.Based on binding study, uptake kinetic, adsorption isotherm and Simchrome software results, macroporous adsorbent SEPABEADS SP 825L was selected as the choice of resin for preparative separation. Breakthrough capacity of the resin was calculated to be 37.8 and 2.801 mg/mL for lactonic and acidic SL respectively. Column study was performed to justify the previous results and 10 g of crude product was processed to obtain 4.2 and 3.9 g of acidic and lactonic SL having the assay purity of more than 90%.  相似文献   
988.
用放射配体结合实验方法确定钩藤提取物是否能与阿片受体发生相互作用,具体以3H-diprenorphine为标记配体,反应体系及反应条件同饱和结合实验,选用不同浓度的吗啡(10-10~10-5nmol/L)或钩藤提取物(0.125~4mg/mL)为竞争药物,考察钩藤提取物与转染阿片受体的结合水平.结果表明,钩藤提取物(0.125~4 mg/mL)浓度依赖地竞争3H-diprenorphine(1nmol/L)与μ、δ、κ3种阿片受体的结合,其IC50值分别为(1.27±0.86)mg/mL(n=3)(、0.59±0.21)mg/mL(n=4)和(1.20±0.24)mg/mL(n=3),其Ki值分别为(0.41±0.27)mg/mL(n=3)、(0.26±0.09)mg/mL(n=4)和(0.38±0.08)mg/mL(n=3),说明钩藤提取物非选择性地与μ、δ、κ三种阿片受体结合.  相似文献   
989.
为研究2种石松属植物化学成分的抗炎活性,筛选具有较强抗炎活性的化合物,用LPS诱导RAW264.7细胞建立了体外炎症模型,采用MTT法检测了化合物对小鼠巨噬细胞株RAW264.7细胞增殖的影响.在安全浓度范围内(细胞存活率大于80%)给予药物干预,用Griess法检测了培养上清液中一氧化氮(NO)水平,以各化合物抑制NO释放的能力为筛选指标,评价了化合物的抗炎活性.结果表明:乙酰基二氢石松生物碱(16)、对香豆酸甲酯(21)、豆甾烷-3-酮-21-酸(22)具有较好的NO抑制率,并呈一定剂量依赖关系,提示它们具有一定的抗炎活性.  相似文献   
990.
Chitosan is a linear polysaccharide and non-toxic bioactive polymer with a wide variety of applications due to its functional properties such as ease of modification, and biodegradability. In this study, a green protocol for supporting of Cu(II) on chitosan-encapsulated magnetic Fe3O4 nanoparticles is described. The morphological and physicochemical features of the material were determined using several advanced techniques like fourier transformed infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), inductively coupled plasma (ICP), vibrating sample magnetometer (VSM) and X-ray photoelectron spectroscopy (XPS). The average diameter of the NPs was approximately 15–25 nm. In addition, the Fe3O/CS/Cu(II) nanocomposite was engaged in biological assays like study of anti-oxidant properties by DPPH mediated free radical scavenging test using BHT as a reference molecule. Thereafter, on having a significant IC50 value in radical scavenging assay, we extended the bio-application of the desired nanocomposite in anticancer study of lung well-differentiated bronchogenic adenocarcinoma, lung moderately differentiated adenocarcinoma, and lung poorly differentiated adenocarcinoma of human lung in-vitro conditions. In the cytotoxicity and anti-human lung studies, the nanocomposite was treated to lung cancer lung well-differentiated bronchogenic adenocarcinoma (HLC-1), lung moderately differentiated adenocarcinoma (LC-2/ad), and lung poorly differentiated adenocarcinoma (PC-14) cell line following MTT assay. The cell viability of malignant lung cell line reduced dose-dependently in the presence of Fe3O/CS/Cu(II) nanocomposite. The recent results suggest that Fe3O/CS/Cu(II) nanocomposite have a suitable anticancer activity against lung cell lines.  相似文献   
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