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排序方式: 共有83条查询结果,搜索用时 15 毫秒
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LC/MS/MS determination and pharmacokinetic study of iridoid glycosides monotropein and deacetylasperulosidic acid isomers in rat plasma after oral administration of Morinda officinalis extract 下载免费PDF全文
Morinda officinalis is a famous traditional Chinese medicine containing iridoid glycoside compounds, such as monotropein and deacetylasperulosidic acid. The aim of the study was to develop a novel and sensitive liquid chromatography–tandem mass spectrometry (LC/MS/MS) method for the simultaneous determination of the two isomeric iridoid glycosides and then evaluate their pharmacokinetic properties in rats. Selected‐reaction monitoring mode was employed for quantification of two analytes in rat plasma. The calibration curves were linear over their respective concentration range with correlation coefficient >0.995 for both analytes. Precision for monotropein and deacetylasperulosidic acid ranged from 2.5 to 11.9% relative standard deviation, and the accuracy of two analytes was ?2.0–3.7 and ?6.4–10.7% relative error, respectively. This method was successfully applied in pharmacokinetic study after oral administration of M. officinalis extract in rats. The results provided a basis for further research on the bioactivity of M. officinalis. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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氯化钙在10X分子筛上的微波强化分散及其氨吸附的研究 总被引:3,自引:0,他引:3
利用干混法将氯化钙担载于10X分子筛上,通过微波法强化分散,研究了不同条件下样品的XRD图和氨吸附量,并与同样氯化钙担载量的焙烧法样品进行了比较.结果表明,微波法能显著提高CaCl2的分散度,且对应样品的氨吸附量显著提高.CaCl2在10X分子筛上的单层分散阈值在0.4 g/g~0.5 g/g之间,担载量为0.5 g/g的样品的氨吸附量最大,在35℃时达到0.575 g/g.在85 ℃时样品的吸附量都很小,这对利用低温余热脱附很有利.样品的适宜微波处理时间在10 min~20 min之间.同时,利用比表面分析和红外光谱分析证明微波法可以强化分散且不改变分子筛结构. 相似文献
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采用量子化学的密度泛函理论(DFT),在B3LYP/6 31G*水平上研究了(4 溴甲基双环[4. 4. 1] 1, 3, 5,7, 9 十一碳五烯基3 )甲醇环氧化反应机理,在对反应物和产物几何结构优化的基础上,搜索优化了反应的过渡态结构,通过振动分析和内禀反应坐标(IRC)跟踪方法对过渡态及其所处的反应路径进行了确认,并用电荷密度拓扑分析方法考察了反应过程中旧键断裂和新键形成的细节.计算结果表明,该反应中的消除反应和成环反应是协同进行的,溴化氢消除反应中的氢来自与O( 22 )相连的羟基氢,反应的活化势垒为139. 2kJ/mol,反应放热25. 1kJ/mol. 相似文献
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Technology of preparing anode films and the effect of co-sensitization in dye-sensitized solar cells 总被引:2,自引:0,他引:2
Jingchang Zhang Zhenhai Fu qian lv Xiuying Yang Weiliang Cao 《Journal of Sol-Gel Science and Technology》2012,63(3):554-562
Nanocrystalline N–Zn/TiO2 anode films were prepared by doping element N and Zn. These element-doped films have a better performance in dye-sensitized solar cell than the non-doped film. The test shows that the best thickness of N–Zn/TiO2 anode film is 13.5 μm. UV–Visible measurements show that there is a complementarity in ultraviolet–visible absorbance range between P3OT and N719, both are used as dyes in this study, the former is prepared and the latter is commercially available. SEM shows a significant mass increase of anode film after treated with TiCl4. Solar cells based on N–Zn/TiO2 anode film with TiCl4 treatment was firstly co-sensitized by N719/P3OT. A solar-to-electric energy conversion efficiency of 3.54 % was obtained. Compared with the traditional dye-sensitized solar cell, the photoelectric conversion efficiency, V oc and J sc have been increased. 相似文献
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Jingchang Zhang Zhiyue Han Xiuying Yang 《Journal of Physics and Chemistry of Solids》2010,71(9):1316-1323
A conducting polymer composite poly(3-dodecylthiophene)/titanium dioxide (P3DDT/TiO2) nanocomposite was first synthesized through the ultrasonic method. The results from X-ray diffraction (XRD) and infrared spectroscopy (IR) show that there is chemical interaction in the composite. Transmission electron microscope (TEM) and scanning electron microscope (SEM) depict the morphology of the samples, defining that TiO2 was successfully coated by poly(3-dodecylthiophene) molecules. The energy gap of the poly(3-dodecylthiophene)/titanium dioxide composite is lower to 0.76 eV compare with poly(3-dodecylthiophene) and titanium dioxide separately, and it also shows that the optical performance of the new material is far superior than P3DDT or TiO2 separately by ultraviolet-visible spectra (UV) and fluorescence spectroscopy (PL). Solar cell was sensitized by P3DDT/TiO2. A solar-to-electric energy conversion efficiency of 0.188% was attained with the system. 相似文献
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ZnO:N thin films were deposited on sapphire substrate by metal organic chemical vapor deposition with NH3 as N-doping sources. The reproducible p-type ZnO:N film with hole concentration of ∼1017 cm−3 was successfully achieved by subsequent in situ thermal annealing in N2O plasma protective ambient, while only weak p-type ZnO:N film with remarkably lower hole concentration of ∼1015 cm−3 was obtained by annealing in O2 ambient. To understand the mechanism of the p-type doping behavior of ZnO:N film, X-ray photoelectron spectroscopy (XPS) and soft X-ray absorption near-edge spectroscopy (XANES) measurements have been applied to investigate the local electronic structure and chemical states of nitrogen atoms in ZnO:N films. 相似文献
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