全文获取类型
收费全文 | 594篇 |
免费 | 54篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 4篇 |
综合类 | 2篇 |
化学工业 | 204篇 |
金属工艺 | 11篇 |
机械仪表 | 16篇 |
建筑科学 | 61篇 |
矿业工程 | 2篇 |
能源动力 | 14篇 |
轻工业 | 76篇 |
水利工程 | 1篇 |
石油天然气 | 1篇 |
无线电 | 33篇 |
一般工业技术 | 126篇 |
冶金工业 | 29篇 |
原子能技术 | 4篇 |
自动化技术 | 66篇 |
出版年
2023年 | 11篇 |
2022年 | 26篇 |
2021年 | 37篇 |
2020年 | 17篇 |
2019年 | 16篇 |
2018年 | 14篇 |
2017年 | 14篇 |
2016年 | 34篇 |
2015年 | 31篇 |
2014年 | 24篇 |
2013年 | 46篇 |
2012年 | 38篇 |
2011年 | 29篇 |
2010年 | 41篇 |
2009年 | 27篇 |
2008年 | 35篇 |
2007年 | 40篇 |
2006年 | 28篇 |
2005年 | 25篇 |
2004年 | 12篇 |
2003年 | 14篇 |
2002年 | 11篇 |
2001年 | 6篇 |
2000年 | 5篇 |
1999年 | 4篇 |
1998年 | 8篇 |
1997年 | 11篇 |
1996年 | 10篇 |
1995年 | 3篇 |
1994年 | 1篇 |
1993年 | 7篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 5篇 |
1988年 | 2篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1976年 | 3篇 |
1975年 | 1篇 |
1971年 | 1篇 |
1912年 | 1篇 |
排序方式: 共有650条查询结果,搜索用时 31 毫秒
91.
Tommaso Marchesi D'Alvise Sean Harvey Lisa Hueske Jolanta Szelwicka Lothar Veith Tuomas P. J. Knowles Dennis Kubiczek Carolin Flaig Fabian Port Kay‐E. Gottschalk Frank Rosenau Bartlomiej Graczykowski George Fytas Francesco S. Ruggeri Katrin Wunderlich Tanja Weil 《Advanced functional materials》2020,30(21)
Cellular membranes have long served as an inspiration for nanomaterial research. The preparation of ultrathin polydopamine (PDA) films with integrated protein pores containing phospholipids and an embedded domain of a membrane protein glycophorin A as simplified cell membrane mimics is reported. Large area, ultrathin PDA films are obtained by electropolymerization on gold surfaces with 10–18 nm thickness and dimensions of up to 2.5 cm2. The films are transferred from gold to various other substrates such as nylon mesh, silicon, or substrates containing holes in the micrometer range, and they remain intact even after transfer. The novel transfer technique gives access to freestanding PDA films that remain stable even at the air interfaces with elastic moduli of ≈6–12 GPa, which are higher than any other PDA films reported before. As the PDA film thickness is within the range of cellular membranes, monodisperse protein nanopores, so‐called “nanodiscs,” are integrated as functional entities. These nanodisc‐containing PDA films can serve as semi‐permeable films, in which the embedded pores control material transport. In the future, these simplified cell membrane mimics may offer structural investigations of the embedded membrane proteins to receive an improved understanding of protein‐mediated transport processes in cellular membranes. 相似文献
92.
Katrin Ortstein Sebastian Hutsch Alexander Hinderhofer Jrn Vahland Martin Schwarze Sebastian Schellhammer Martin Hodas Thomas Geiger Hans Kleemann Holger F. Bettinger Frank Schreiber Frank Ortmann Karl Leo 《Advanced functional materials》2020,30(32)
In modern electronics, it is essential to adapt band structures by adjusting energy levels and band gaps. At first sight, this “band structure engineering” seems impossible in organic semiconductors, which usually exhibit localized electronic states instead of Bloch bands. However, the strong Coulomb interaction in organic semiconductors allows for a continuous shift of the ionization energy (IE) over a wide range by mixing molecules with halogenated derivatives that exhibit different quadrupole moments. Here, this effect of energy level engineering on blends of pentacene and two fluorinated derivatives, in which the position but not the number of fluorine atoms differ, is studied. Structural investigations confirm that pentacene forms intermixed phases in blends with the fluorinated species. The investigation of electronic properties and simulations reveals a much larger shift of the ionization energy (1.5 eV) than in previous studies, allowing to test this model in a range not investigated so far, and emphasizing the role of the position of the halogen atoms. The tuning effect is preserved in electronic devices such as field‐effect transistors and significantly influences device characteristics. 相似文献
93.
J. Tuominen H. Pajukoski P. Vuoristo S. Thieme S. Nowotny J. Näkki 《Materialwissenschaft und Werkstofftechnik》2018,49(10):1263-1277
Laser coatings are frequently used in applications where they slide against various elastomeric and polymeric seals or guide bands in different environments. Examples of such applications include hydraulics, maritime propulsion systems and components in pulp & paper industry. In this study highly corrosion resistant Inconel 625 (DIN Mat. No. 2.4856) and Thermanit 2509 super duplex stainless steel (~1.4501) coatings manufactured by novel coaxial hot‐wire laser cladding technique are tested in dry conditions at room temperature against various composite polytetrafluoroethylene (PTFE) seals. Despite only small difference in coating surface hardness, ~1.4501 and 2.4856 show significant differences in wear and friction performance against various seals. For instance, ~1.4501 is superior to 2.4856 against glass fiber and MoS2 reinforced PTFE in terms of wear resistance and friction characteristics, whereas 2.4856 performs better against bronze reinforced PTFE seal. The reference Stellite laser coating, which is the hardest counter surface in this study, exhibits the best wear behavior against all the seal materials tested. The differences in wear performances are explained by cohesive and adhesive wear mechanisms. 相似文献
94.
Ann‐Katrin U. Michel Andreas Heßler Sebastian Meyer Julian Pries Yuan Yu Thomas Kalix Martin Lewin Julian Hanss Angela De Rose Tobias W. W. Maß Matthias Wuttig Dmitry N. Chigrin Thomas Taubner 《Advanced materials (Deerfield Beach, Fla.)》2019,31(29)
Nanometer‐thick active metasurfaces (MSs) based on phase‐change materials (PCMs) enable compact photonic components, offering adjustable functionalities for the manipulation of light, such as polarization filtering, lensing, and beam steering. Commonly, they feature multiple operation states by switching the whole PCM fully between two states of drastically different optical properties. Intermediate states of the PCM are also exploited to obtain gradual resonance shifts, which are usually uniform over the whole MS and described by effective medium response. For programmable MSs, however, the ability to selectively address and switch the PCM in individual meta‐atoms is required. Here, simultaneous control of size, position, and crystallization depth of the switched phase‐change material (PCM) volume within each meta‐atom in a proof‐of‐principle MS consisting of a PCM‐covered Al–nanorod antenna array is demonstrated. By modifying optical properties locally, amplitude and light phase can be programmed at the meta‐atom scale. As this goes beyond previous effective medium concepts, it will enable small adaptive corrections to external aberrations and fabrication errors or multiple complex functionalities programmable on the same MS. 相似文献
95.
Maximilian Hrner Katrin Raute Barbara Hummel Josef Madl Guido Creusen Oliver S. Thomas Erik H. Christen Natascha Hotz Raphael J. Gübeli Raphael Engesser Balder Rebmann Jasmin Lauer Bernd Rolauffs Jens Timmer Wolfgang W. A. Schamel Jan Pruszak Winfried Rmer Matias D. Zurbriggen Christian Friedrich Andreas Walther Susana Minguet Ritwick Sawarkar Wilfried Weber 《Advanced materials (Deerfield Beach, Fla.)》2019,31(12)
96.
Maximilian Hrner Katrin Raute Barbara Hummel Josef Madl Guido Creusen Oliver S. Thomas Erik H. Christen Natascha Hotz Raphael J. Gübeli Raphael Engesser Balder Rebmann Jasmin Lauer Bernd Rolauffs Jens Timmer Wolfgang W. A. Schamel Jan Pruszak Winfried Rmer Matias D. Zurbriggen Christian Friedrich Andreas Walther Susana Minguet Ritwick Sawarkar Wilfried Weber 《Advanced materials (Deerfield Beach, Fla.)》2019,31(12)
Interrogation and control of cellular fate and function using optogenetics is providing revolutionary insights into biology. Optogenetic control of cells is achieved by coupling genetically encoded photoreceptors to cellular effectors and enables unprecedented spatiotemporal control of signaling processes. Here, a fast and reversibly switchable photoreceptor is used to tune the mechanical properties of polymer materials in a fully reversible, wavelength‐specific, and dose‐ and space‐controlled manner. By integrating engineered cyanobacterial phytochrome 1 into a poly(ethylene glycol) matrix, hydrogel materials responsive to light in the cell‐compatible red/far‐red spectrum are synthesized. These materials are applied to study in human mesenchymal stem cells how different mechanosignaling pathways respond to changing mechanical environments and to control the migration of primary immune cells in 3D. This optogenetics‐inspired matrix allows fundamental questions of how cells react to dynamic mechanical environments to be addressed. Further, remote control of such matrices can create new opportunities for tissue engineering or provide a basis for optically stimulated drug depots. 相似文献
97.
We report the use of superresolution fluorescence microscopy for studying the nanoscale distribution of protein colocalization in living mammalian cells. Nanoscale imaging is attained both by a targeted and a stochastic fluorescence on-off switching superresolution method, namely by stimulated emission depletion (STED) and ground state depletion microscopy followed by individual molecular return (GSDIM), respectively. Analysis of protein colocalization is performed by bimolecular fluorescence complementation (BiFC). Specifically, a nonfluorescent fragment of the yellow fluorescent protein Citrine is fused to tubulin while a counterpart nonfluorescent fragment is fused to the microtubulin-associated protein MAP2 such that fluorescence is reconstituted on contact of the fragment-carrying proteins. Images with resolution down to 65 nm prove a powerful new way for studying protein colocalization in living cells at the nanoscale. 相似文献
98.
Jadran Vrabec Martin Bernreuther Hans‐Joachim Bungartz Wei‐Lin Chen Wilfried Cordes Robin Fingerhut Colin W. Glass Jürgen Gmehling René Hamburger Manfred Heilig Matthias Heinen Martin T. Horsch Chieh‐Ming Hsieh Marco Hülsmann Philip Jäger Peter Klein Sandra Knauer Thorsten Köddermann Andreas Köster Kai Langenbach Shiang‐Tai Lin Philipp Neumann Jürgen Rarey Dirk Reith Gábor Rutkai Michael Schappals Martin Schenk Andre Schedemann Mandes Schönherr Steffen Seckler Simon Stephan Katrin Stöbener Nikola Tchipev Amer Wafai Stephan Werth Hans Hasse 《化学,工程师,技术》2018,90(3):295-306
This article outlines advances in molecular modeling and simulation using massively parallel high‐performance computers (HPC). In the SkaSim project, partners from the HPC community collaborated with users from science and industry. The aim was to optimize the prediction of thermodynamic property data in terms of efficiency, quality and reliability using HPC methods. In this context, various topics were dealt with: atomistic simulation of homogeneous gas bubble formation, surface tension of classical fluids and ionic liquids, multicriteria optimization of molecular models, the development of the molecular simulation codes ls1 mardyn and ms2, atomistic simulation of gas separation processes, molecular membrane structure generators, transport resistors and the evaluation of predictive property data models based on specific mixture types. 相似文献
99.
Brockmann MA Ulmer S Lamszus K Giese A Petersen D 《Microscopy research and technique》2004,63(5):306-309
Image analysis systems are an essential tool in measurements of size of intraparenchymal tumors or lesions in experimental small animal models. Conventional image analysis systems are relatively expensive. We therefore compared the performance of a professional image analysis system with an inexpensive setup by evaluating tumor size in an orthotopic glioma mouse model. The maximum cross-sectional tumor area of H&E stained brain-slides of two groups of mice (treatment and control group) was measured by two independent investigators using a professional image analysis system (Leica DM IRB microscope) with the Leica Quantimet 500c software, and a low-cost-system (Intel QX3 microscope) with a non-commercial image analysis software. Mean tumor volumes were calculated and the results from each of the image analysis systems, investigators, and treatment effects were compared. The tumor volumes as measured with the low-cost and the professional system differed between -3.7 and +7.5% (P = 0.69-0.99). Measurements made by investigator A and B differed between -7.0 and +3.9% (P = 0.69-0.88). Treatment in all cases significantly reduced the tumor volume between 58.4 and 62.7% (P = 0.0002 or 0.0003), regardless of the investigator or the used image analysis system. We therefore conclude that the QX3 low-cost microscope in combination with a non-commercial image-analysis software represents an inexpensive solution to reliably analyze the size of regions of interest, if they provide a sufficient contrast. However, the low-cost setup due to its low resolution definitely limits a detailed analysis of histologic features. 相似文献
100.
Esterification of Kraft lignin as a method to improve structural and mechanical properties of lignin‐polyethylene blends
下载免费PDF全文
![点击此处可从《应用聚合物科学杂志》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Lignin is a promising candidate for blends with thermoplastic polymers. Still, this endeavour is a challenge due to poor compatibility between both components. In this article, the effect of lignin esterification on the improvement of the compatibility between hardwood Kraft lignin and high‐density polyethylene (PE‐HD) is investigated. For this purpose, lignin was esterified with acetic, propionic, and butyric anhydride; its amount in the blends varied from 10 to 40%. Light microscopic images of blends show a reduction in particle size and a more homogeneous distribution with increasing length of the ester carbon chains (C2 to C4). Modification of lignin enhances the moduli and strength characteristics of the blends. Butyrated lignin performs best, as tensile strength of blends can be retained near that of pure PE‐HD with up to 40% lignin content. An additional investigation of unmodified lignin with reduced particle size confirms that modification is the decisive factor to enhance blend properties; a sole reduction of particle size is insufficient. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44582. 相似文献