全文获取类型
收费全文 | 126篇 |
免费 | 2篇 |
国内免费 | 2篇 |
专业分类
化学 | 80篇 |
晶体学 | 1篇 |
力学 | 2篇 |
数学 | 24篇 |
物理学 | 23篇 |
出版年
2023年 | 1篇 |
2022年 | 3篇 |
2021年 | 4篇 |
2020年 | 3篇 |
2019年 | 2篇 |
2018年 | 5篇 |
2017年 | 2篇 |
2016年 | 6篇 |
2015年 | 1篇 |
2014年 | 6篇 |
2013年 | 12篇 |
2012年 | 10篇 |
2011年 | 8篇 |
2010年 | 10篇 |
2009年 | 5篇 |
2008年 | 2篇 |
2007年 | 14篇 |
2006年 | 5篇 |
2005年 | 5篇 |
2004年 | 6篇 |
2003年 | 5篇 |
2002年 | 2篇 |
2000年 | 2篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1993年 | 2篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1982年 | 2篇 |
1975年 | 1篇 |
排序方式: 共有130条查询结果,搜索用时 15 毫秒
81.
82.
83.
The preparation of several amides and hydrazides from the reaction of the title compounds with different nitrogen nucleophiles is shown to be a general high-yield conversion of synthetic utility. 相似文献
84.
Adamová G Gardas RL Rebelo LP Robertson AJ Seddon KR 《Dalton transactions (Cambridge, England : 2003)》2011,40(47):12750-12764
A series of alkyltrioctylphosphonium chloride ionic liquids, prepared from trioctylphosphine, and the respective 1-chloroalkane (C(n)H(2n+1)Cl), where n = 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12 or 14, is presented. The cynosure of this work is the manner in which the variable chain length impacts the physical properties, such as melting points/glass transitions, thermal stability, density and viscosity. Experimental density and viscosity data were interpreted using QPSR correlations and group contribution methods. We present the first example of an empirical alternation effect for ionic liquids. 相似文献
85.
Josephine Blersch Vitor Francisco Catarina Rebelo Adrian Jimnez‐Balsa Helena Antunes Carlo Gonzato Sandra Pinto Susana Simes Klaus Liedl Karsten Haupt Lino Ferreira 《Angewandte Chemie (International ed. in English)》2020,59(5):1985-1991
RNA‐based therapies offer a wide range of therapeutic interventions including the treatment of skin diseases; however, the strategies to efficiently deliver these biomolecules are still limited due to obstacles related to the cellular uptake and cytoplasmic delivery. Herein, we report the synthesis of a triggerable polymeric nanoparticle (NP) library composed of 160 formulations, presenting physico‐chemical diversity and differential responsiveness to light. Six formulations were more efficient (up to 500 %) than commercially available lipofectamine in gene‐knockdown activity. These formulations showed differential internalization by skin cells and the endosomal escape was rapid (minutes range). The NPs were effective in the release of siRNA and miRNA. Acute skin wounds treated with the top hit NP complexed with miRNA‐150‐5p healed faster than wounds treated with scrambled miRNA. Light‐activatable NPs offer a new strategy to topically deliver non‐coding RNAs. 相似文献
86.
Sara Martínez de Salinas Jesús Sanjos‐Orduna Carlota Odena Sergio Barranco Jordi Benet‐Buchholz Mnica H. Prez‐Temprano 《Angewandte Chemie (International ed. in English)》2020,59(15):6239-6243
Herein, we disclose the synthesis of metallacyclic Cp*CoIII complexes containing weakly chelating functional groups. We have employed these compounds not only as an exceptional platform for accessing some of the most widely invoked transient intermediates in C?H functionalization processes but also as competent catalysts in different Cp*Co‐catalyzed transformations, including a benchmark coupling reaction. 相似文献
87.
The top quark mass and the flavour mixing are studied in the context of a seesaw model of quark masses based on the gauge group SU(2)L × SU(2)R × U(1). Six isosinglet quarks are introduced to give rise to the mass hierarchy of ordinary quarks. In this scheme, we reexamine a mechanism for the generation of the top quark mass. It is shown that, in order to prevent the seesaw mechanism to act for the top quark, the mass parameter of its isosinglet partner must be much smaller than the breaking scale of SU(2)R. As a result the fourth lightest up quark must have a mass of the order of the breaking scale of SU(2)R, and a large mixing between the right-handed top quark and its singlet partner occurs. We also show that this mechanism is compatible with the mass spectrum of light quarks and their flavour mixing. 相似文献
88.
Jos Antonio Pinto Renato Jos Corso Ana Cludia Rocha Guilherme Sílvia Rebelo Pinho Monica de Oliveira Nbrega 《Journal of voice》2004,18(1):90-96
Dysprosody also known as pseudo-foreign dialect, is the rarest neurological speech disorder. It is characterized by alterations in intensity, in the timing of utterance segments, and in rhythm, cadency, and intonation of words. The terms refers to changes as to duration, fundamental frequency, and intensity of tonic and atonic syllables of the sentences spoken, which deprive an individual's particular speech of its characteristics. The cause of this disease is usually associated with neurological pathologies such as brain vascular accidents, cranioencephalic traumatisms, and brain tumors. The authors report a case of dysprosody attended to at the Núcleo de Otorrinolaringologia e Cirurgia de Cabe?a e Pesco?o de S?o Paulo (NOSP). It is about a female patient with bilateral III degree Reinke's edema and normal neurological examinations that started presenting characteristics of the German dialect following a larynx microsurgery. 相似文献
89.
Trindade JR Visak ZP Blesic M Marrucho IM Coutinho JA Lopes JN Rebelo LP 《The journal of physical chemistry. B》2007,111(18):4737-4741
The effects of the addition of three inorganic salts, namely, NaCl, Na(2)SO(4), and Na(3)PO(4), on the liquid-liquid (L-L) phase diagram of aqueous solutions containing the model ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate, [bmim][BF(4)], were investigated. All three inorganic salts trigger salting-out effects, leading to significant upward shifts of the L-L demixing temperatures of the systems. The magnitude of the shifts depends on both the water-structuring nature of the salt and its concentration; that is, the effects are correlated with the ionic strength of the solution and the Gibbs free energy of hydration of the inorganic salt. The pH effect and the occurrence of salt precipitation in concentrated solutions are also discussed. 相似文献
90.
Leal JP Esperança JM da Piedade ME Lopes JN Rebelo LP Seddon KR 《The journal of physical chemistry. A》2007,111(28):6176-6182
Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) experiments showed that when aprotic ionic liquids vaporize under pressure and temperature conditions similar to those of a reduced-pressure distillation, the gas phase is composed of discrete anion-cation pairs. The evolution of the mass spectrometric signals recorded during fractional distillations of binary ionic liquid mixtures allowed us to monitor the changes of the gas-phase composition and the relative volatility of the components. In addition, we have studied a protic ionic liquid, and demonstrated that it exists as separated neutral molecules in the gas phase. 相似文献