全文获取类型
| 收费全文 | 3273篇 |
| 免费 | 175篇 |
| 国内免费 | 14篇 |
专业分类
| 化学 | 2256篇 |
| 晶体学 | 28篇 |
| 力学 | 64篇 |
| 数学 | 457篇 |
| 物理学 | 657篇 |
出版年
| 2024年 | 13篇 |
| 2023年 | 73篇 |
| 2022年 | 96篇 |
| 2021年 | 159篇 |
| 2020年 | 202篇 |
| 2019年 | 248篇 |
| 2018年 | 88篇 |
| 2017年 | 75篇 |
| 2016年 | 214篇 |
| 2015年 | 155篇 |
| 2014年 | 169篇 |
| 2013年 | 201篇 |
| 2012年 | 286篇 |
| 2011年 | 280篇 |
| 2010年 | 158篇 |
| 2009年 | 133篇 |
| 2008年 | 194篇 |
| 2007年 | 156篇 |
| 2006年 | 148篇 |
| 2005年 | 98篇 |
| 2004年 | 59篇 |
| 2003年 | 32篇 |
| 2002年 | 29篇 |
| 2001年 | 25篇 |
| 2000年 | 17篇 |
| 1999年 | 14篇 |
| 1998年 | 15篇 |
| 1997年 | 5篇 |
| 1996年 | 9篇 |
| 1995年 | 10篇 |
| 1994年 | 10篇 |
| 1993年 | 5篇 |
| 1992年 | 10篇 |
| 1991年 | 6篇 |
| 1990年 | 4篇 |
| 1988年 | 3篇 |
| 1987年 | 8篇 |
| 1986年 | 5篇 |
| 1983年 | 4篇 |
| 1982年 | 2篇 |
| 1981年 | 6篇 |
| 1980年 | 2篇 |
| 1979年 | 4篇 |
| 1978年 | 5篇 |
| 1975年 | 2篇 |
| 1974年 | 2篇 |
| 1973年 | 3篇 |
| 1938年 | 2篇 |
| 1934年 | 3篇 |
| 1932年 | 3篇 |
排序方式： 共有3462条查询结果，搜索用时 15 毫秒
991.
992.
Luca Laraia Guillaume Garivet Daniel J. Foley Nadine Kaiser Sebastian Müller Sarah Zinken Thomas Pinkert Julian Wilke Dale Corkery Axel Pahl Sonja Sievers Petra Janning Christoph Arenz Yaowen Wu Raphaël Rodriguez Herbert Waldmann 《Angewandte Chemie (International ed. in English)》2020,59(14):5721-5729
Chemical proteomics is widely applied in small‐molecule target identification. However, in general it does not identify non‐protein small‐molecule targets, and thus, alternative methods for target identification are in high demand. We report the discovery of the autophagy inhibitor autoquin and the identification of its molecular mode of action using image‐based morphological profiling in the cell painting assay. A compound‐induced fingerprint representing changes in 579 cellular parameters revealed that autoquin accumulates in lysosomes and inhibits their fusion with autophagosomes. In addition, autoquin sequesters Fe2+ in lysosomes, resulting in an increase of lysosomal reactive oxygen species and ultimately cell death. Such a mechanism of action would have been challenging to unravel by current methods. This work demonstrates the potential of the cell painting assay to deconvolute modes of action of small molecules, warranting wider application in chemical biology. 相似文献
993.
The combination of density functional theory and Monte Carlo simulations is a powerful approach for the atomistic modeling of defect transport in solid electrolytes. The present contribution introduces the MOCASSIN software (Monte Carlo for Solid State Ionics) for kinetic and Metropolis Monte Carlo simulations of crystalline materials. MOCASSIN combines model building, visualization, and simulation, aiming to provide accessible MC for end users. Developed for the investigation of solid electrolytes, MOCASSIN is ideal for screening common variation parameters, such as temperature and doping fraction. The input effort is minimized using space groups for processing symmetry. The graphical interface for model building allows complex model input, including multiple mobile species, multiple migration paths, small polaron hopping, vehicle movements, multiple complex migration mechanisms, and custom interaction clusters. The software is provided free of charge for noncommercial usage. 相似文献
994.
Mostafa Ahmadi Sebastian Seiffert 《Journal of polymer science. Part A, Polymer chemistry》2020,58(2):330-342
Hybrid polymer networks emerge between chemical and physical crosslinking, where two different modes of chain connectivity control the material behavior. However, rational relations between their microstructural characteristics, supramolecular kinetics, and the resulting network mechanics and dynamics are not well developed. To address this shortcoming, this study introduces a material platform based on a model dual-network hydrogel, comprising independently tunable chemical and physical crosslinks. The idea is realized by a click reaction between a tetra-PEG and a linear-PEG precursor, whereby the linear block also carries a terpyridine ligand at each end that can form additional physical crosslinks by metal ion–bis(terpyridine) complexation. We change the number of chemical crosslinks by varying the molar mass of the tetra-PEG, and we independently tune the metallo-supramolecular bonds by using different metal ions, Mn2+, Zn2+, Co2+, and Ni2+. Based on that modular approach, we study the rheological behavior and the diffusivity of fluorescent polymeric tracers. The dissociation of the metallo-supramolecular bonds provides a relaxation step, whose timescale and intensity are quantified by a sticky Rouse model. These two characteristics differ not only depending on the metal ion but also according to the chemical network mesh size, which highlights an interplay between the chemical and physical crosslinks. © 2020 The Authors. Journal of Polymer Science Part A: Polymer Chemistry published by Wiley Periodicals, Inc. J. Polym. Sci. 2020 , 58, 330–342 相似文献
995.
Stefan Mattsson Gene Senges Prof. Dr. Sebastian Riedel Prof. Dr. Beate Paulus 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(47):10781-10786
The Simons process, otherwise known as the electrochemical fluorination (ECF) method, is widely used in industry to electrolytically synthesize chemicals for various purposes. Even to this day, the exact mechanism of the ECF reaction remains unknown, but is believed to involve the formation of an anodic nickel fluoride film with highly oxidized nickel centers. In this study, experiments and density functional theory calculations are combined to characterize the initial anodic peak occurring at potentials typically required in an ECF cell. NiF2 is believed to form a passivating layer at low potentials. The calculations show that a potential of +3.1 V is required to oxidize surface Ni2+ centers to Ni3+. This is in good agreement with the measured anodic peak at +3.57 V. 相似文献
996.
Aleksandra Kawczyk-Krupka Dorota Bartusik-Aebisher Wojciech Latos Grzegorz Cieślar Karolina Sieroń Sebastian Kwiatek Piotr Oleś Beata Kwiatek David Aebisher Magdalena Krupka Rafał Wiench Dariusz Skaba Marcin Olek Jacek Kasperski Zenon Czuba Aleksander Sieroń 《Photochemistry and photobiology》2020,96(3):539-549
The purpose of this review is to present an overview of the development of photodiagnostic and photodynamic therapy (PDD and PDT) techniques in Poland. The paper discusses the principles of PDD, including fluorescent techniques in determining precancerous conditions and cancers of the skin, digestive tract, bladder and respiratory tract. Methods of PDT of cancer will be discussed and the current state of knowledge as well as future trends in the development of photodynamic techniques will be presented, including the possibility of using photodynamic antimicrobial therapy. Research pioneers in photodynamic medicine such as Thomas Dougherty are an inspiration for the development of methods of PDD and PDT in our Clinic. The Center for Laser Diagnostics and Therapy in Bytom, Poland, promotes the propagation of PDD and PDT through the training of clinicians and raising awareness among students in training and the general public. Physicians at the Center are engaged in photomedical research aimed at clinical implementation and exploration of new avenues in photomedicine while optimizing existing modalities. The Center promotes dissemination of clinical results from a wide range of topics in PDD and PDT and serving as representative authorities of photodynamic medicine in Poland and Europe. 相似文献
997.
998.
Dr. Weijin Li Song Xue Sebastian Watzele Shujin Hou Johannes Fichtner A. Lisa Semrau Prof. Liujiang Zhou Dr. Alexander Welle Prof. Aliaksandr S. Bandarenka Prof. Roland A. Fischer 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(14):5886-5892
Metal–organic frameworks (MOFs) and their derivatives are considered as promising catalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), which are important for many energy provision technologies, such as electrolyzers, fuel cells and some types of advanced batteries. In this work, a “strain modulation” approach has been applied through the use of surface-mounted NiFe-MOFs in order to design an advanced bifunctional ORR/OER electrocatalyst. The material exhibits an excellent OER activity in alkaline media, reaching an industrially relevant current density of 200 mA cm−2 at an overpotential of only ≈210 mV. It demonstrates operational long-term stability even at a high current density of 500 mA cm−2 and exhibits the so far narrowest “overpotential window” ΔEORR-OER of 0.69 V in 0.1 m KOH with a mass loading being two orders of magnitude lower than that of benchmark electrocatalysts. 相似文献
999.
Susanne Schröder Kristin Rammelkamp Franziska Hanke Iris Weber David Sebastian Vogt Sven Frohmann Simon Kubitza Ute Böttger Heinz-Wilhelm Hübers 《Journal of Raman spectroscopy : JRS》2020,51(9):1667-1681
Laser-induced breakdown spectroscopy (LIBS) and Raman spectroscopy have a high potential for in situ geochemical and mineralogical analyses for planetary exploration, in particular in combination. The SuperCam instrument onboard NASA's Mars 2020 rover will use both techniques together on another planet for the first time. The high-power pulsed LIBS laser ablates material, and a small luminous plasma is produced for spectral analysis. The laser–matter interaction and the plasma shock wave can alter the sample surface, and new molecules can be produced, which deposit close to the LIBS ablation crater. Subsequent Raman analysis might then not sample the original structure. Here, we investigated pure metals (Fe, Ni, and Ti), the iron-containing oxides hematite and ilmenite, and a fragment of the Gibeon meteorite in terrestrial ambient conditions, in simulated Martian atmospheric conditions, and in vacuum. LIBS ablation craters and their close proximity were studied with subsequent Raman analysis. Our analysis shows that Earth and Mars atmosphere provide enough oxygen in the LIBS plasma to produce oxides with metals from the sample. These can then be observed in the Raman data. Also, carbon was seen in some of the Raman data from the sample after the LIBS measurement. On hematite, a reduction of the mineral, that is, the presence of magnetite, was observed inside the LIBS crater for terrestrial and Martian atmospheric conditions and in vacuum. For the analysis and correct interpretation of Raman data it is important to be aware that alteration could have occurred by a preceding LIBS measurement. Raman analysis of several positions close to the LIBS ablation crater can help to infer the original and a possibly altered structure. 相似文献
1000.