全文获取类型
收费全文 | 115篇 |
免费 | 2篇 |
专业分类
化学 | 97篇 |
力学 | 2篇 |
数学 | 12篇 |
物理学 | 6篇 |
出版年
2023年 | 1篇 |
2022年 | 3篇 |
2021年 | 2篇 |
2020年 | 5篇 |
2019年 | 6篇 |
2018年 | 2篇 |
2017年 | 1篇 |
2016年 | 3篇 |
2015年 | 1篇 |
2014年 | 3篇 |
2013年 | 5篇 |
2012年 | 5篇 |
2011年 | 2篇 |
2010年 | 2篇 |
2009年 | 5篇 |
2008年 | 9篇 |
2007年 | 9篇 |
2006年 | 11篇 |
2005年 | 3篇 |
2004年 | 4篇 |
2003年 | 5篇 |
2002年 | 3篇 |
2001年 | 2篇 |
2000年 | 3篇 |
1999年 | 1篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 3篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1981年 | 1篇 |
1916年 | 2篇 |
排序方式: 共有117条查询结果,搜索用时 15 毫秒
51.
On the search for glycated lipoprotein ApoA-I in the plasma of diabetic and nephropathic patients 总被引:1,自引:0,他引:1
Lapolla A Brioschi M Banfi C Tremoli E Bonfante L Cristoni S Seraglia R Traldi P 《Journal of mass spectrometry : JMS》2008,43(1):74-81
The analysis of plasma samples from healthy, diabetic and nephropathic subjects was carried out by 2D gel electrophoresis. This approach shows clear differences among the three classes of subjects. In the case of diabetic and nephropathic patients intense spots appear. Their enzymatic digestion followed by matrix assisted laser desorption ionization/mass spectrometry (MALDI/MS) analysis shows that an overexpression of unglycated and glycated ApoA-I is present in both pathological states. Interestingly, this trend is also observed for the retinol-binding protein (RBP). The data obtained can be relevant to assess possible risks associated either with the glycation level of ApoA-I or with the overexpression of RBP. In fact, in the former case possibly a different functionality of the glycated protein is to be expected, reflecting a different efficiency in cholesterol transport. In the latter case, the increase of RBP level can be related to the overweight of the diabetic subjects under investigation: it is known that obesity leads to RBP overexpression. In the case of nephropathic patients, the RBP level increases in parallel with serum creatinin. 相似文献
52.
Mild Friedel–Crafts Reactions inside a Hexameric Resorcinarene Capsule: C−Cl Bond Activation through Hydrogen Bonding to Bridging Water Molecules 下载免费PDF全文
Pellegrino La Manna Dr. Carmen Talotta Giuseppe Floresta Dr. Margherita De Rosa Prof. Dr. Annunziata Soriente Prof. Dr. Antonio Rescifina Prof. Dr. Carmine Gaeta Prof. Dr. Placido Neri 《Angewandte Chemie (International ed. in English)》2018,57(19):5423-5428
A novel catalytic feature of a hexameric resorcinarene capsule is highlighted. The self‐assembled cage was exploited to promote the Friedel–Crafts benzylation of several arenes and heteroarenes with benzyl chloride under mild conditions. Calculations showed that there are catalytically relevant hydrogen‐bonding interactions between the bridging water molecules of the capsule and benzyl chloride, which is fundamental for the activation of the C?Cl bond. The capsule controls the reaction outcome. Inside the inner cavity of the capsule, N‐methylpyrrole is preferentially benzylated in the unusual β‐position while mesitylene reacts faster than 1,3‐dimethoxybenzene despite the greater π‐nucleophilicity of the latter compound. 相似文献
53.
54.
In the framework of the extended irreversible thermodynamics we examine the coupling between the magnetic field and the thermal field and their influence on the evolution of a heat conducting relativistic magnetizable fluid. 相似文献
55.
Lim J Pavan GM Annunziata O Simanek EE 《Journal of the American Chemical Society》2012,134(4):1942-1945
The synthesis, characterization, and host-guest chemistry of high-generation triazine dendrimers are described. With pyrene and camptothecin as guests, experiments revealed that the guest capacity of odd-generation triazine dendrimers increased until generation 7 but decreased at generation 9. Molecular dynamics simulations conducted in explicit solvent showed a useful fingerprint for this behavior in radial distribution functions of water molecules penetrating the interior of the dendrimers. A linear relationship between the guest capacity of dendrimers measured experimentally and the number of water molecules within the interior determined computationally was observed. 相似文献
56.
Rayleigh interferometry is a precise macroscopic gradient technique that has been utilized for the determination of multicomponent diffusion coefficients. Because concentration gradients in multicomponent systems drive a diffusion-based partial separation of different solutes, this interferometric technique may be potentially used for the determination of solute concentrations. We have therefore theoretically examined how Rayleigh interferometry can be applied for the determination of composition of ternary aqueous mixtures. The effect of cross-term diffusion coefficients on the accuracy of this method is also discussed. Furthermore, since the poly(vinyl)alcohol+poly(ethylene)glycol+water system undergoes liquid–liquid phase separation (LLPS), we have experimentally characterized its LLPS boundary at 25 °C. The corresponding tie-lines were characterized by determining the composition of the two coexisting liquid phases using Rayleigh interferometry. 相似文献
57.
Seryio Saris Sanduni T. Dona Valerie Niemann Anna Loiudice Raffaella Buonsanti 《Helvetica chimica acta》2020,103(6):e2000055
Encapsulation methods have shown to be effective in imparting improved stability to metal-halide perovskite nanocrystals (NCs). Atomic layer deposition (ALD) of metal oxides is one of the promising approaches for such encapsulation, yet better control on the process parameters are required to achieve viable lifetimes for several optoelectronic and photocatalytic applications. Herein, we optimize the ALD process of amorphous aluminum oxide (AlOx) as an encapsulating layer for CsPbBr3 NC thin films by using oxygen (O2) as a molecular diffusion probe to assess the uniformity of the deposited AlOx layer. When O2 reaches the NC surface, it extracts the photogenerated electrons, thus quenching the PL of the CsPbBr3 NCs. As the quality of the ALD layer improves, less quenching is expected. We compare three different ALD deposition modes. We find that the low temperature/high temperature and the exposure modes improve the quality of the alumina as a gas barrier when compared with the low temperature mode. We attribute this result to a better diffusion of the ALD precursor throughout the NC film. We propose the low temperature/high temperature as the most suitable mode for future implementation of multilayered coatings. 相似文献
58.
Summary A previos thermal model for the heat treatment of a little metal ribbon, moving under a broad laser beam with Gaussian intensity
distribution, is elaborated in order to apply it also in the opposite experimental condition, namely for sample width higher
than the laser spot. The temperature valuevs. the distance from the symmetry axis of the treated zone is determined as a function of both the sample displacement rate
and the laser power. When structural and magnetic-property modulation is produced in the transverse direction of a glassy
metal ribbon, the experimental results, concerning both reduced magnetization as a function of the temperature and structure
changes, are in agreement with the thermal-model predictions. 相似文献
59.
Rita Annunziata Maurizio Benaglia Marinella Caporale Laura Raimondi 《Tetrahedron: Asymmetry》2002,13(24):2727-2734
The inter- and intramolecular coupling of imines promoted by samarium diiodide and Lewis acids or by Zn/MsOH was extensively studied. The intramolecular reaction of chiral, enantiomerically pure bis-imines was also considered, and allowed the efficient, stereoselective synthesis of 1,2-diamines with C2-symmetry. 相似文献
60.
Addition reactions between Rawal’s diene and different carbonyl compounds are rapidly and efficiently promoted by water. No catalyst or any other additive, water as an eco-friendly medium, clean reaction conditions, a simple work-up, and short reaction times are the salient features in this procedure. The protocol is general, proceeding well with moderate to good yields for various aldehydes and activated ketones. Based on the experimental 1H NMR results, a Mukaiyama aldol mechanism was proposed as the reaction pathway, affording open chain products. 相似文献