全文获取类型
收费全文 | 100篇 |
免费 | 12篇 |
国内免费 | 13篇 |
专业分类
化学 | 88篇 |
力学 | 2篇 |
综合类 | 1篇 |
数学 | 13篇 |
物理学 | 21篇 |
出版年
2023年 | 2篇 |
2022年 | 4篇 |
2021年 | 3篇 |
2020年 | 10篇 |
2019年 | 3篇 |
2018年 | 3篇 |
2017年 | 1篇 |
2016年 | 5篇 |
2015年 | 5篇 |
2014年 | 3篇 |
2013年 | 3篇 |
2012年 | 6篇 |
2011年 | 7篇 |
2010年 | 4篇 |
2009年 | 8篇 |
2008年 | 6篇 |
2007年 | 6篇 |
2006年 | 5篇 |
2005年 | 2篇 |
2004年 | 4篇 |
2003年 | 4篇 |
2002年 | 4篇 |
2001年 | 1篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1998年 | 3篇 |
1997年 | 5篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1992年 | 3篇 |
1991年 | 1篇 |
1989年 | 2篇 |
1984年 | 2篇 |
1940年 | 1篇 |
排序方式: 共有125条查询结果,搜索用时 0 毫秒
91.
92.
Kai Bin Liew Long Chiau Ming Bey-Hing Goh Kok Khiang Peh 《Molecules (Basel, Switzerland)》2022,27(10)
A fast melt tablet (FMT) is well regarded as an alternative delivery system that might help resolve a patient’s non-compliance issue. The main objective of this study was to develop a cocoa butter-based FMT. Additives, namely 5–15% of PEG 6000, beeswax, paraffin wax, and corn starch, were incorporated into the cocoa butter-based FMT to study the effects of these additives with the physical characteristic of a cocoa butter FMT. An optimum-based formulation was chosen according to the desired hardness and disintegration time and the taste masking property achieved with the model drug—dapoxetine. The analysis demonstrated that incorporating beeswax (15%) and paraffin wax (15%) could prolong the disintegration time by at least two-fold. On the contrary, the presence of corn starch was found to cause an increase in the hardness and reduction of the disintegration time. The disintegration mechanism might be presumed due to the synergistic effect of starch swelling and cocoa butter melting. The hardness value and in vitro disintegration time of the optimum formulation were recorded at 2.93 ± 0.22 kg and 151.67 ± 6.98 s. In terms of dissolution, 80% of dapoxetine was released within 30 min and the dissolution profile was comparable to the innovator product. The formulation was palatable and stable for at least 1 year. The exposure of the FMT formulation at 30 °C for 12 months was reported to be stable. Along with the sound palatability profile and high drug load capacity, the current formulation possesses the desired characteristics to be scaled up and marketed. 相似文献
93.
94.
Guang‐Rong Peh Eric Assen B. Kantchev Dr. Jun‐Cheng Er Jackie Y. Ying Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(13):4010-4017
As less attention has been focussed on the design of highly efficient palladium precatalysts to ensure the smooth formation of the active catalyst for metal‐mediated cross coupling reactions, we herein demonstrate that combining the bulky N‐heterocyclic carbene (NHC) 1,3‐bis(2,6‐diisopropylphenyl)imidazol‐2‐ylidene (IPr) with cyclopalladated acetanilide as the optimal palladium precatalyst leads to superior catalytic activity compared with the state‐of‐the‐art NHC–Pd catalysts. The complex was discovered through the evaluation of a small, rationally designed library of NHC–palladacycles prepared by a novel, practical and atom‐economic method, the direct reaction of IPr?HCl with palladacycle acetate dimers. 相似文献
95.
A series of La2O3-promoted precipitated iron catalysts (100Fe/2.8Si/nLa, n = 0, 0.5, 1, 2, and 4, atomic ratio) were prepared and characterized by in situ X-ray diffraction, CO temperature-programmed reduction, and N2 adsorption-desorption. The catalytic performance for Fischer-Tropsch synthesis was studied in a fixed-bed reactor. It was found that the addition of a small amount of La2O3 (La/Fe ≤ 0.01) gave a large decrease in the particle size of Fe2O3, which increased the specific surface area and dispersion of the catalysts. This also favored the formation of iron carbides, which gave a high catalytic activity in Fischer-Tropsch synthesis. With increasing La2O3 content (La/Fe ≥ 0.02), a high La2O3 coverage and the formation of a LaFeO3 compound decreased the formation of iron carbides, and the reaction activity decreased. The optimum La2O3 content was La/Fe = 0.01. The addition of La2O3 increased the selectivity for methane and suppressed the formation of C5+ hydrocarbons. 相似文献
96.
Gabriel Onn Kit Loh Emily Yii Ling Wong Yvonne Tze Fung Tan Siew Chyee Heng Mardiana Saaid Kit Yee Cheah Nurul Diyana Mohd Sali Nair Damenthi Sharon Shi Min Ng Long Chiau Ming Kok Khiang Peh 《Molecules (Basel, Switzerland)》2022,27(17)
Etoricoxib is a non-steroidal anti-inflammatory drug (NSAID) used to treat pain and inflammation. The objective of the current study was to develop a sensitive, fast and high-throughput HPLC-ESI-MS/MS method to measure etoricoxib levels in human plasma using a one-step methanol protein precipitation technique. A tandem mass spectrometer equipped with an electrospray ionization (ESI) source operated in a positive mode and multiple reaction monitoring (MRM) were used for data collection. The quantitative MRM transition ions were m/z 359.15 > 279.10 and m/z 363.10 > 282.10 for etoricoxib and IS. The linear range was from 10.00 to 4000.39 ng/mL and the validation parameters were within the acceptance limits of the European Medicine Agency (EMA) and Food and Drug Analysis (FDA) guidelines. The present method was sensitive (10.00 ng/mL with S/N > 40), simple, selective (K prime > 2), and fast (short run time of 2 min), with negligible matrix effect and consistent recovery, suitable for high throughput analysis. The method was used to quantitate etoricoxib plasma concentrations in a bioequivalence study of two 120 mg etoricoxib formulations. Incurred sample reanalysis results further supported that the method was robust and reproducible. 相似文献
97.
98.
99.
Jinqiao Dong Yutong Pan Heng Wang Kuiwei Yang Lingmei Liu Zhiwei Qiao Yi Di Yuan Shing Bo Peh Jian Zhang Leilei Shi Hong Liang Yu Han Xiaopeng Li Jianwen Jiang Bin Liu Dan Zhao 《Angewandte Chemie (International ed. in English)》2020,59(25):10151-10159
The self‐assembly of highly stable zirconium(IV)‐based coordination cages with aggregation induced emission (AIE) molecular rotors for in vitro bio‐imaging is reported. The two coordination cages, NUS‐100 and NUS‐101, are assembled from the highly stable trinuclear zirconium vertices and two flexible carboxyl‐decorated tetraphenylethylene (TPE) spacers. Extensive experimental and theoretical results show that the emissive intensity of the coordination cages can be controlled by restricting the dynamics of AIE‐active molecular rotors though multiple external stimuli. Because the two coordination cages have excellent chemical stability in aqueous solutions (pH stability: 2–10) and impressive AIE characteristics contributed by the molecular rotors, they can be employed as novel biological fluorescent probes for in vitro live‐cell imaging. 相似文献
100.
对碘酚对鲁米诺化学发光增强的试验研究 总被引:1,自引:0,他引:1
本文报道了由过氧化物酶催化鲁米诺与过氧化氢发光反应的增强发光研究。合成了增强剂对碘酚,并用对碘酚对鲁米诺与过氧化氢发光反应的光增强作用进行了试验,已经证实增强发光反应可将过氧化物酶的最低检测浓度降低到10-12~10-13mol/L水平。 相似文献