全文获取类型
收费全文 | 346篇 |
免费 | 20篇 |
专业分类
电工技术 | 4篇 |
化学工业 | 148篇 |
机械仪表 | 9篇 |
建筑科学 | 7篇 |
能源动力 | 7篇 |
轻工业 | 55篇 |
石油天然气 | 1篇 |
无线电 | 9篇 |
一般工业技术 | 44篇 |
冶金工业 | 28篇 |
原子能技术 | 1篇 |
自动化技术 | 53篇 |
出版年
2023年 | 7篇 |
2022年 | 39篇 |
2021年 | 36篇 |
2020年 | 9篇 |
2019年 | 9篇 |
2018年 | 17篇 |
2017年 | 4篇 |
2016年 | 15篇 |
2015年 | 8篇 |
2014年 | 13篇 |
2013年 | 22篇 |
2012年 | 25篇 |
2011年 | 21篇 |
2010年 | 13篇 |
2009年 | 17篇 |
2008年 | 5篇 |
2007年 | 12篇 |
2006年 | 14篇 |
2005年 | 9篇 |
2004年 | 4篇 |
2003年 | 5篇 |
2002年 | 10篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1999年 | 4篇 |
1998年 | 4篇 |
1997年 | 9篇 |
1996年 | 7篇 |
1995年 | 3篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1985年 | 2篇 |
1984年 | 3篇 |
1983年 | 1篇 |
1981年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 3篇 |
1975年 | 1篇 |
排序方式: 共有366条查询结果,搜索用时 0 毫秒
31.
Bokyung Kim Young Ho Ko Massimiliano Runfola Simona Rapposelli Gabriella Ortore Grazia Chiellini Jin Hae Kim 《International journal of molecular sciences》2021,22(7)
Thyromimetics, whose physicochemical characteristics are analog to thyroid hormones (THs) and their derivatives, are promising candidates as novel therapeutics for neurodegenerative and metabolic pathologies. In particular, sobetirome (GC-1), one of the initial halogen-free thyromimetics, and newly synthesized IS25 and TG68, with optimized ADME-Tox profile, have recently attracted attention owing to their superior therapeutic benefits, selectivity, and enhanced permeability. Here, we further explored the functional capabilities of these thyromimetics to inhibit transthyretin (TTR) amyloidosis. TTR is a homotetrameric transporter protein for THs, yet it is also responsible for severe amyloid fibril formation, which is facilitated by tetramer dissociation into non-native monomers. By combining nuclear magnetic resonance (NMR) spectroscopy, computational simulation, and biochemical assays, we found that GC-1 and newly designed diphenyl-methane-based thyromimetics, namely IS25 and TG68, are TTR stabilizers and efficient suppressors of TTR aggregation. Based on these observations, we propose the novel potential of thyromimetics as a multi-functional therapeutic molecule for TTR-related pathologies, including neurodegenerative diseases. 相似文献
32.
Margherita Durso Cristian Bettini Alberto Zanelli Massimo Gazzano M. Grazia Lobello Filippo De Angelis Viviana Biondo Denis Gentili Raffaella Capelli Massimiliano Cavallini Stefano Toffanin Michele Muccini Manuela Melucci 《Organic Electronics》2013,14(11):3089-3097
The synthesis of two new thieno(bis)imide (TBI, N) end functionalized oligothiophene semiconductors is reported. In particular, trimer (NT3N) and pentamer (NT5N) have been synthesized and characterized. Two different synthetic approaches for their preparation were tested and compared namely conventional Stille cross coupling and direct arylation reaction via C–H activation. Theoretical calculations, optical and electrochemical characterization allowed us to assess the role of the π-conjugation extent, i.e., of the oligomer size on the optoelectronic properties of these materials. In both TBI ended compounds, due to the strong localization of the LUMO orbital on the TBI unit, the LUMO energy is almost insensitive to the oligomer size, this being crucial for the fine-tailoring of the energy and the distribution of the frontier orbitals. Surprisingly, despite its short size and contrarily to comparable TBI-free analogues, NT3N shows electron charge transport with mobility up to μN = 10−4 cm2 V−1 s−1, while increasing the oligomer size to NT5N promotes ambipolar behavior and electroluminescence properties with mobility up to μN = 0.14 cm2 V−1 s−1 and to μP = 10−5 cm2 V−1 s−1. 相似文献
33.
Maria Grazia Calabrese Gianfranco Mamone Simonetta Caira Pasquale Ferranti Francesco Addeo 《Food chemistry》2009
The unnatural amino acid lysinoalanine (LAL) has been identified in milk and cheese products by liquid chromatography mass spectrometry (LC/ESI/MS) with selective ion monitoring (SIM) of the 9-fluorenyl-methylchloro-formate (FMOC) derivative. LAL is not present in raw milk or derived from Mozzarella cheese; however, high amounts of LAL are found in calcium caseinate and milk powder. As expected, milk fortified with caseinate or whey protein powder produces cheese with higher LAL content. Our analytical procedure is based on the simultaneous detection of specific ion masses of the FMOC–LAL derivative and the N-ε-methyl-lysine internal standard. A linear relationship was observed within the 0.2–20 ppm concentration range, in addition to a high correlation coefficient and ∼3% relative standard deviation. 相似文献
34.
35.
Nicolette Czarnievicz Dr. Maria Grazia Rubanu Maialen Iturralde Dr. Jesús Albarran-Velo Dr. Eleftheria Diamanti Prof. Vicente Gotor-Fernandez Dr. Maciej Skolimowski Prof. Fernando López-Gallego 《Chembiochem : a European journal of chemical biology》2023,24(2):e202200614
The development of methods to engineer and immobilize amine transaminases (ATAs) to improve their functionality and operational stability is gaining momentum. The quest for robust, fast, and easy-to-use methods to screen the activity of large collections of transaminases, is essential. This work presents a novel and multiplex fluorescence-based kinetic assay to assess ATA activity using 4-dimethylamino-1-naphthaldehyde as an amine acceptor. The developed assay allowed us to screen a battery of amine donors using free and immobilized ATAs from different microbial sources as biocatalysts. As a result, using chromatographic methods, 4-hydroxybenzylamine was identified as the best amine donor for the amination of 5-(hydroxymethyl)furfural. Finally, we adapted this method to determine the apparent Michaelis-Menten parameters of a model immobilized ATA at the microscopic (single-particle) level. Our studies promote the use of this multiplex, multidimensional assay to screen ATAs for further improvement. 相似文献
36.
Luigi Bianchi Lucia Rita Quitadamo Girolamo Garreffa Gian Carlo Cardarilli Maria Grazia Marciani 《IEEE transactions on neural systems and rehabilitation engineering》2007,15(2):207-216
The evaluation of the performances of brain-computer interface (BCI) systems could be difficult as a standard procedure does not exist. In fact, every research team creates its own experimental protocol (different input signals, different trial structure, different output devices, etc.) and this makes systems comparison difficult. Moreover, the great question is whether these experiments can be extrapolated to real world applications or not. To overcome some intrinsic limitations of the most used criteria a new efficiency indicator will be described and used. Its main advantages are that it can predict with a high accuracy the performances of a whole system, a fact that can be used to successfully improve its behavior. Finally, simulations were performed to illustrate that the best system is built by tuning the transducer (TR) and the control interface (CI), which are the two main components of a BCI system, so that the best TR and the best CI do not exist but just the best combination of them. 相似文献
37.
Roberta Di Benedetto Renzo Alfini Martina Carducci Maria Grazia Aruta Luisa Lanzilao Alessandra Acquaviva Elena Palmieri Carlo Giannelli Francesca Necchi Allan Saul Francesca Micoli 《International journal of molecular sciences》2021,22(19)
Outer Membrane Vesicles (OMV) constitute a promising platform for the development of efficient vaccines. OMV can be decorated with heterologous antigens (proteins or polysaccharides), becoming attractive novel carriers for the development of multicomponent vaccines. Chemical conjugation represents a tool for linking antigens, also from phylogenetically distant pathogens, to OMV. Here we develop two simple and widely applicable conjugation chemistries targeting proteins or lipopolysaccharides on the surface of Generalized Modules for Membrane Antigens (GMMA), OMV spontaneously released from Gram-negative bacteria mutated to increase vesicle yield and reduce potential reactogenicity. A Design of Experiment approach was used to identify optimal conditions for GMMA activation before conjugation, resulting in consistent processes and ensuring conjugation efficiency. Conjugates produced by both chemistries induced strong humoral response against the heterologous antigen and GMMA. Additionally, the use of the two orthogonal chemistries allowed to control the linkage of two different antigens on the same GMMA particle. This work supports the further advancement of this novel platform with great potential for the design of effective vaccines. 相似文献
38.
Elisabetta Coppi Ilaria Dettori Federica Cherchi Irene Bulli Martina Venturini Daniele Lana Maria Grazia Giovannini Felicita Pedata Anna Maria Pugliese 《International journal of molecular sciences》2020,21(24)
Adenosine is a signaling molecule, which, by activating its receptors, acts as an important player after cerebral ischemia. Here, we review data in the literature describing A2BR-mediated effects in models of cerebral ischemia obtained in vivo by the occlusion of the middle cerebral artery (MCAo) or in vitro by oxygen-glucose deprivation (OGD) in hippocampal slices. Adenosine plays an apparently contradictory role in this receptor subtype depending on whether it is activated on neuro-glial cells or peripheral blood vessels and/or inflammatory cells after ischemia. Indeed, A2BRs participate in the early glutamate-mediated excitotoxicity responsible for neuronal and synaptic loss in the CA1 hippocampus. On the contrary, later after ischemia, the same receptors have a protective role in tissue damage and functional impairments, reducing inflammatory cell infiltration and neuroinflammation by central and/or peripheral mechanisms. Of note, demyelination following brain ischemia, or autoimmune neuroinflammatory reactions, are also profoundly affected by A2BRs since they are expressed by oligodendroglia where their activation inhibits cell maturation and expression of myelin-related proteins. In conclusion, data in the literature indicate the A2BRs as putative therapeutic targets for the still unmet treatment of stroke or demyelinating diseases. 相似文献
39.
Claudia Archetti M. Grazia Speranza Dennis Weyland 《International Transactions in Operational Research》2018,25(4):1137-1161
In this paper we present the results of a simulation study aimed at assessing an on‐demand transportation system. The on‐demand system uses minibuses that have neither fixed itineraries nor fixed stops. The minibuses are dynamically routed to accommodate the requests received by the users. To use the on‐demand service, users communicate, close to their desired departure time, the origin and destination of the trip. They accept the service if the estimated arrival time at destination fulfills their service level threshold. In the simulation users may decide whether to walk, to use a standard bus, to call the on‐demand service, and, if none of these options is satisfactory, to use a private car. We consider different scenarios to assess the potential benefits of the introduction of an on‐demand service. We also analyze the scalability and responsiveness of the service. The results suggest that an on‐demand system may be able to satisfy a large portion of user transportation requests and may be put beside standard transportation systems in order to provide a better transportation service to the users and substantially reduce the use of private cars. 相似文献
40.
Claudia Archetti Dominique Feillet Alain Hertz M. Grazia Speranza 《Computers & Operations Research》2010,37(11):1860-1869
A profit and a demand are associated with each edge of a set of profitable edges of a given graph. A travel time is associated with each edge of the graph. A fleet of capacitated vehicles is given to serve the profitable edges. A maximum duration of the route of each vehicle is also given. The profit of an edge can be collected by one vehicle only that also serves the demand of the edge. The objective of this problem, which is called the undirected capacitated arc routing problem with profits (UCARPP), is to find a set of routes that satisfy the constraints on the duration of the route and on the capacity of the vehicle and maximize the total collected profit. We propose a branch-and-price algorithm and several heuristics. We can solve exactly instances with up to 97 profitable edges. The best heuristics find the optimal solution on most of instances where it is available. 相似文献