全文获取类型
收费全文 | 415篇 |
免费 | 15篇 |
专业分类
化学 | 324篇 |
晶体学 | 1篇 |
力学 | 1篇 |
数学 | 42篇 |
物理学 | 62篇 |
出版年
2023年 | 5篇 |
2022年 | 18篇 |
2021年 | 15篇 |
2020年 | 11篇 |
2019年 | 21篇 |
2018年 | 19篇 |
2017年 | 20篇 |
2016年 | 25篇 |
2015年 | 17篇 |
2014年 | 26篇 |
2013年 | 37篇 |
2012年 | 27篇 |
2011年 | 35篇 |
2010年 | 19篇 |
2009年 | 11篇 |
2008年 | 15篇 |
2007年 | 29篇 |
2006年 | 14篇 |
2005年 | 19篇 |
2004年 | 13篇 |
2003年 | 11篇 |
2002年 | 10篇 |
2001年 | 2篇 |
2000年 | 3篇 |
1998年 | 3篇 |
1997年 | 1篇 |
1991年 | 2篇 |
1983年 | 1篇 |
1979年 | 1篇 |
排序方式: 共有430条查询结果,搜索用时 31 毫秒
421.
Takaši Kusano Jelena V. Manojlovi? 《Applied mathematics and computation》2012,218(12):6684-6701
The fourth order nonlinear differential equations
(A) 相似文献
422.
Whole-genome DNA amplification (WGA) is a promising method that generates large amounts of DNA from samples of limited quantity. We investigated the accuracy of a multiplex PCR approach to WGA over STR loci. The amplification bias within a locus and over all analyzed loci was investigated in relation to the amount of template in the WGA reaction, the specific STR locus, and allele length. We observed reproducible error-free STR profiles with 10 ng down to 1 ng of DNA template. The amplification deviation at a locus and between loci was within the intra-method reproducibility. WGA is the method of choice for amplifying nanogram amounts of genomic DNA for different applications. We detected unbalanced STR amplifications at one locus and between loci, allelic drop-outs, and additional alleles after WGA of low-copy-number DNA. We found that the high number of drop-outs and drop-ins could be eradicated using pooled DNA from separate WGA reactions even with as little as 100 pg of starting template. Nevertheless, the quality of the results was still not sufficient for use in routine chimerism analysis of limited specific cell populations after allogeneic stem cell transplantation. 相似文献
423.
Velicković S Djordjević V Cvetićanin J Djustebek J Veljković M Nesković O 《Rapid communications in mass spectrometry : RCM》2006,20(20):3151-3153
Molecules of Li(n)X (n = 2, 3; X = Cl, Br, I) were examined with a magnetic sector mass spectrometer by surface ionization using a triple rhenium filament impregnated with fullerene (C60). The ionization energies obtained for Li(2)Cl, Li(2)Br and Li(2)I molecules are 3.8 +/- 0.1, 3.9 +/- 0.1 and 4.0 +/- 0.1 eV, respectively. The first ionization energy of Li(2)Cl is documented, while there are no literature data for the ionization energies of Li(2)Br and Li(2)I. The molecules of Li(3)Cl, Li(3)Br and Li(3)I were detected experimentally for the first time with ionization energies of 4.0 +/- 0.1, 4.1 +/- 0.1 and 4.1 +/- 0.1 eV, respectively. The ionization energies of Li(n)X (n = 2, 3; X = Cl, Br, I) are in correlation with the theoretical prediction of their hyperlithiated configurations. 相似文献
424.
Maja C. Pagnacco Jelena P. Maksimovi Nenad T. Nikoli Danica V. Bajuk Bogdanovi Milan M. Kragovi Marija D. Stojmenovi Stevan N. Blagojevi Jelena V. Senanski 《Molecules (Basel, Switzerland)》2022,27(15)
Indigo carmine is a commonly used industrial blue dye. To determine its concentration in a commercially available food dye composed of a mixture of indigo carmine and D-glucose, this paper characterizes it through (ATR, KBr) FTIR micro-Raman as well as UV/Vis and clock: Briggs–Rauscher (BR) oscillatory reaction methods. The indigo carmine was detected in the bulk food dye only by applying micro-Raman spectroscopy, indicating a low percentage of the indigo carmine present. This research provides an improvement in the deviations from the experimental Raman spectrum as calculated by the B97D/cc-pVTZ level of theory one, resulting in a better geometrical optimization of the indigo carmine molecule compared to data within the literature. The analytical curves used to determine indigo carmine concentrations (and quantities) in an aqueous solution of food dye were applied by means of UV/Vis and BR methods. BR yielded significantly better analytical parameters: 100 times lower LOD and LOQ compared to commonly used UV/Vis. The remarkable sensitivity of the BR reaction towards indigo carmine suggests that not only does indigo carmine react in an oscillatory reaction but also its decomposition products, meaning that the multiple oxidation reactions have an important role in the BR’s indigo carmine mechanism. The novelty of this research is the investigation of indigo carmine using a clock BR reaction, opening new possibilities to determine indigo carmine in other complex samples (pharmaceutical, food, etc.). 相似文献
425.
Stefan Mijatovic Jelena Antic Stankovic Ivana Colovic Calovski Eleonora Dubljanin Dejan Pljevljakusic Dubravka Bigovic Aleksandar Dzamic 《Molecules (Basel, Switzerland)》2022,27(19)
The aim of our study was to determine the susceptibility of 15 Candida albicans sputum isolates on fluconazole and caspofungin, as well as the antifungal potential of Lavandula angustifolia essential oil (LAEO). The commercial LAEO was analyzed using gas chromatography-mass spectrometry. The antifungal activity was evaluated using EUCAST protocol. A killing assay was performed to evaluate kinetics of 2% LAEO within 30 min treatment. LAEO with major constituents’ linalool (33.4%) and linalyl acetate (30.5%) effective inhibited grows of C. albicans in concentration range 0.5–2%. Fluconazole activity was noted in 67% of the isolates with MICs in range 0.06–1 µg/mL. Surprisingly, 40% of isolates were non-wild-type (non-WT), while MICs for WT ranged between 0.125–0.25 µg/mL. There were no significant differences in the LAEO MICs among fluconazole-resistant and fluconazole-susceptible sputum strains (p = 0.31) and neither among caspofungin non-WT and WT isolates (p = 0.79). The 2% LAEO rapidly achieved 50% growth reduction in all tested strains between 0.2 and 3.5 min. Within 30 min, the same LAEO concentration exhibited a 99.9% reduction in 27% isolates. This study demonstrated that 2% solution of LAEO showed a significant antifungal activity which is equally effective against fluconazole and caspofungin susceptible and less-susceptible strains. 相似文献
426.
Snežana Radisavljević Ana Kesić Dušan Ćoćić Vladimir Marković Jelena Milovanović Biljana Petrović Ana Rilak Simović 《应用有机金属化学》2023,37(1):e6922
In this work we synthesized new monofunctional gold(III) complex [Au(Cl-Ph-tpy)Cl]Cl2 (Cl-Ph-tpy = 4′-[4-chlorophenyl]-2,2′:6′, 2″-terpyridine). This complex was characterized by UV–Vis, NMR, IR, and ESI-MS spectrometry. The kinetic study of the substitution reactions of the Au-Cl-Ph-tpy complex with biomolecules showed that the rate constants depend on the nature of the entering nucleophile. Based on the calculated values of entropy (∆H≠ > 0) and enthalpy (∆S≠ < 0) the proposed substitution mechanism is associative. Additionally, the relative stability and thermodynamic properties of Au-Cl-Ph-tpy complex were compared with the analogue Au-tpy complex by the B3LYP/def2-svp method. DNA/BSA binding studies showed that Au-Cl-Ph-tpy complex interacts with CT DNA through the intercalation and moderately quenches the fluorescence of tryptophan residues in serum albumin (BSA). Molecular docking confirmed results obtained by spectroscopic experiments and suggested site I (subdomain IIA) for binding of Au complex to BSA. We demonstrated that the Au chlorophenyl terpyridine complex possessed significant in vitro cytotoxic activity against human oral squamous carcinoma cells (CAL-27), induced apoptosis, inhibited proliferation of CAL-27 cells, and induced cell cycle disturbance. Treatment of CAL-27 cells with the Au complex enhanced expression of cyclin-dependent kinase inhibitors p21 and p27, resulting in cell cycle arrest in the G1 phase, reduced the percentage of CAL-27 cells in S phase and decreased expression of Ki-67. Additionally, Au complex reduced expression of phosphorylated STAT3 and downstream regulated molecules associated with cancer stemness, NANOG, and Sox2 protein. 相似文献
427.
Nikolić Nebojša D. Lović Jelena D. Maksimović Vesna M. 《Journal of Solid State Electrochemistry》2023,27(7):1889-1900
Journal of Solid State Electrochemistry - The influence of chronopotentiometry response on the morphology and structure of galvanostatically synthesized tin dendritic particles has been... 相似文献
428.
Simović Andjela Stevanović Sanja Milovanović Branislav Etinski Mihajlo Bajat Jelena B. 《Journal of Solid State Electrochemistry》2023,27(7):1821-1834
Journal of Solid State Electrochemistry - In this work, six groups of non-toxic compounds were tested as inhibitors for mild steel in 1 M HCl solution: glycine (Gly), glutamic acid (Glu),... 相似文献
429.
Ciglenečki Irena Orlović-Leko Palma Vidović Kristijan Simonović Niki Marguš Marija Dautović Jelena Mateša Sarah Galić Ivo 《Journal of Solid State Electrochemistry》2023,27(7):1781-1793
Journal of Solid State Electrochemistry - This paper describes the application of a methodology, which primarily involves low-cost voltammetry, to rapidly track the reactivity (i.e. surfactant... 相似文献
430.
Dr. Matko Mužević Assoc. Prof. Dr. Igor Lukačević Ivan Kovač Dr. Davor Gracin Andreja Žužić Prof. Dr. Jelena Macan Asst. Prof. Dr. Maja Varga Pajtler 《Chemphyschem》2023,24(9):e202200837
Inorganic perovskite CaMnO was proposed as a substitution for the TiO anatase in electron transport layers of solar cells containing the hybrid perovskite CH NH PbI based on increased mobility of electrons and better optical matching. Due to a suitable band gap concerning the absorption of sunlight, we investigate the potential of CaMnO and similar manganite perovskites, where Ca is replaced by either Sr, Ba or La, as an absorber layer in inorganic perovskite solar cells. In this study, we have used optical measurements on the synthesized AMnO (A=Ca, Sr, Ba, La) samples to aid density functional theory calculations (DFT) in order to accurately simulate the electronic and optical properties of AMnO compounds and gauge their potential for the role of absorber layer. Both experimental measurements and theoretical calculations show suitable band gap of 1.1-1.5 eV, depending on the compound, and absorption coefficients of the order of cm in the visible part of the spectrum. 相似文献