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Diego Fontana de Andrade Louise Jank Vitor Breda Rego Roberto Minozzo Marcus Vinícius Burgel Sfoggia Álvaro Bavaresco Fabiano Barreto 《Biomedical chromatography : BMC》2020,34(9):e4873
Saponins from Quillaja saponaria have been commonly used as immunomodulatory adjuvants in foot-and-mouth disease vaccines (FMDVs). However, due to the lack of consensus over the possible exacerbation of local inflammatory responses in cattle and its economic impacts, their use has been discouraged by Brazilian authorities. A qualitative method intended to determine the presence of saponins from Q. saponaria bark extracts in FMDVs was developed and validated. Instrumental analysis was performed using an liquid chromatography (LC) coupled to a quadrupole–time-of-flight–mass spectrometry (TOF-MS) system. The method was validated according to the International Conference on Harmonization Harmonized Tripartite Guideline Q2 (R1) and Brazilian Ministry of Agriculture, Livestock and Food Supply Analytical Quality Assurance Guidelines. Validation parameters were determined and considered suitable to the established criteria. The validated method has been applied in routine analysis in the National Agricultural Laboratory at Rio Grande do Sul (LANAGRO-RS). All results obtained were in agreement with the vaccine's composition described by the manufacturer. The method is easy and adequate for analysis in routine laboratories. To the best of the authors' knowledge, this is the first report of a method which intends to investigate the presence of saponins from Q. saponaria bark extracts in veterinary vaccines. 相似文献
34.
Olefin Cyclopropanation by Radical Carbene Transfer Reactions Promoted by Cobalt(II)/Porphyrinates: Active‐Metal‐Template Synthesis of [2]Rotaxanes 下载免费PDF全文
Arthur F. P. Alcântara Liniquer A. Fontana Vitor H. Rigolin Yuri F. S. Andrade Dr. Marcos A. Ribeiro Prof. Wdeson P. Barros Prof. Catia Ornelas Prof. Jackson D. Megiatto Jr. 《Angewandte Chemie (International ed. in English)》2018,57(29):8979-8983
A CoII/porphyrinate‐based macrocycle in the presence of a 3,5‐diphenylpyridine axial ligand functions as an endotopic ligand to direct the assembly of [2]rotaxanes from diazo and styrene half‐threads, by radical‐carbene‐transfer reactions, in excellent 95 % yield. The method reported herein applies the active‐metal‐template strategy to include radical‐type activation of ligands by the metal‐template ion during the organometallic process which ultimately yields the mechanical bond. A careful quantitative analysis of the product distribution afforded from the rotaxane self‐assembly reaction shows that the CoII/porphyrinate subunit is still active after formation of the mechanical bond and, upon coordination of an additional diazo half‐thread derivative, promotes a novel intercomponent C?H insertion reaction to yield a new rotaxane‐like species. This unexpected intercomponent C?H insertion illustrates the distinct reactivity brought to the CoII/porphyrinate catalyst by the mechanical bond. 相似文献
35.
Ng KY Felix V Santos SM Rees NH Beer PD 《Chemical communications (Cambridge, England)》2008,(11):1281-1283
The first example of a catenane capable of performing circumrotation via an anion switching methodology is described; of particular interest is a conformational locking mechanism which results from chloride coordination in the catenane binding cavity. 相似文献
36.
Vitor Rosa Teresa Avilés Pedro T. Gomes Richard Welter M. Rosário Ribeiro 《Journal of organometallic chemistry》2008,693(4):769-775
A series of cobalt(II) compounds of the type [CoX2(α-diimine)] were synthesised by direct reaction of anhydrous CoCl2 or CoI2 and the corresponding α-diimine ligand, in CH2Cl2: [CoI2(o,o′,p-Me3C6H2-DAB)] (1), [CoI2(o,o′-iPr2C6H3-DAB)] (2), (where Ar-DAB = 1,4-bis(aryl)-2,3-dimethyl-1,4-diaza-1,3-butadiene), and [CoCl2(o,o′,p-Me3C6H2-BIAN)] (3), [CoCl2(o,o′-iPr2C6H3-BIAN)] (4), and [CoI2(o,o′-iPr2C6H3-BIAN)] (5) (where Ar-BIAN = bis(aryl)acenaphthenequinonediimine). All compounds were characterised by elemental analyses, IR, mass spectrometry, and X-ray diffraction whenever possible. The crystal structures of compounds 2-4 showed, in all cases, distorted tetrahedral geometries about the Co, built by two halogen atoms and two nitrogen atoms of the α-diimine ligand. Compounds 3 and 4, as well as [CoCl2(o,o′,p-Me3C6H2-DAB)] (1a), and [CoCl2(o,o′-iPr2C6H3-DAB)] (2a), were activated by methylaluminoxane (MAO) and tested as catalysts for ethylene polymerisation, showing low catalytic activities. Selected polyethylene (PE) samples were characterised by 1H and 13C NMR and FT-IR spectroscopies, and by differential scanning calorimetry (DSC), revealing branching microstructures (2.5-5.5%). 相似文献
37.
da Silva Júnior EN de Souza MC Pinto AV Pinto Mdo C Nogueira CM Ferreira VF Azeredo RB 《Magnetic resonance in chemistry : MRC》2008,46(12):1158-1162
Six new nor-beta-lapachones have been synthesized from reaction of 3-bromo-nor-beta-lapachone with arylamines. These derivatives have potent anticancer properties against several cell lines. Here, we report complete unambiguous assignments of (1)H and (13)C chemical shifts of the new compounds. The assignments were made using a combination of one- and two-dimensional NMR techniques ((1)H, (13)C, (1)H-(1)H COSY, (1)H-(13)C HSQC, and (1)H-(13)C HMBC). 相似文献
38.
Heart rate variability analysis by chaotic global techniques in children with attention deficit hyperactivity disorder 下载免费PDF全文
Rubens Wajnsztejn Tatiana Dias De Carvalho David M. Garner Luiz Carlos Marques Vanderlei Moacir Fernandes Godoy Rodrigo Daminello Raimundo Celso Ferreira Vitor E. Valenti Luiz Carlos De Abreu 《Complexity》2016,21(6):412-419
Attention deficit hyperactivity disorder (ADHD) is characterized by decreased attention span, impulsiveness, and hyperactivity. Autonomic nervous system imbalance was previously described in this population. We aim to compare the autonomic function of children with ADHD and controls by analyzing heart rate variability (HRV). Children with ADHD (22 boys, mean age 9.964 years) and 28 controls (15 boys, mean age 9.857 years) rested in supine position with spontaneous breathing for 20 min. Heart rate was recorded beat by beat. HRV analysis was performed by use of chaotic global techniques. ADHD promoted an increase in the chaotic forward parameter. The algorithm which applied all three chaotic global parameters was only the second optimum statistically measured by Kruskal–Wallis (P < 0.0001) and low standard deviations. It was also highly influential by principal component analysis with almost all variation covered by the first two components. The third algorithm which lacked the (high spectral Detrended Fluctuation Analysis) parameter performed best statistically. However, we chose the algorithm which applied all three chaotic globals due to previous studies mentioned in the text—forward and inverse problems. Comparison of the autonomic function by analyzing HRV with chaotic global techniques suggests an increase in chaotic activity in children with ADHD in relation to the control group. © 2015 Wiley Periodicals, Inc. Complexity 21: 412–419, 2016 相似文献
39.
Diketopyrrolo[3,4-c]pyrroles (DPP) are high-performance organic optoelectronic materials. They have applications in solar cells, fluorescent probes, bioimaging, photodynamic/photothermal therapy, and in many other areas. This article reports a convenient two-step synthesis of various DPP dyes from Pigment Red 254, an inexpensive commercial pigment. The synthesis includes a Suzuki–Miyaura cross-coupling reaction of a bis(4-chlorophenyl)DPP derivative with aryl and hetaryl boronic acids under mild reaction conditions. The new dyes show large Stokes shifts and high fluorescence quantum yields, important features for their potential use in technical and biological applications. 相似文献
40.
Pinto V Norberto F Pamplona T Fernandez MT Duarte MF 《Rapid communications in mass spectrometry : RCM》2006,20(15):2309-2316
Electron ionisation mass spectrometry studies were performed previously for p-diphenyl carbonate and some monosubstituted diphenyl carbonates. In this work, p-diphenyl carbonate and p-methoxyphenylphenyl carbonate are re-examined, and p-chlorophenyl phenyl carbonate and two disubstituted diphenyl carbonates, bis (p-chlorophenyl) carbonate and p-methoxyphenyl-p-fluorophenyl carbonate, are studied for the first time. The previously established fragmentation routes were observed for all compounds investigated. Some other different sequences were observed, and a fragmentation path, other than decarboxylation, of the molecular ion is proposed. In the fast-atom bombardment study it was observed that the M(+*)/[MH](+) ion abundance ratio increased from 0.44 for compound 1 to 2.95 for compound 5. [MH](+) is not a dominant ion in most of compounds studied, in spite of the presence of a carbonyl group, a strong proton acceptor. The presence of two oxygen atoms bonded to the carbonyl group appears to induce delocalisation of the electron pairs, thus deactivating the carbonyl site for protonation. In addition, m-nitrobenzyl alcohol (NBA) being a relatively aprotic/hydrophobic matrix reinforces the deactivation for protonation. Because the carbonate group and NBA are common features to the study, the contributions of the substituents were taken into account to explain the different behaviour of the five compounds with respect to protonation. 相似文献