全文获取类型
收费全文 | 439篇 |
免费 | 36篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 12篇 |
综合类 | 3篇 |
化学工业 | 141篇 |
金属工艺 | 9篇 |
机械仪表 | 5篇 |
建筑科学 | 18篇 |
矿业工程 | 1篇 |
能源动力 | 22篇 |
轻工业 | 57篇 |
水利工程 | 1篇 |
无线电 | 39篇 |
一般工业技术 | 93篇 |
冶金工业 | 11篇 |
自动化技术 | 64篇 |
出版年
2023年 | 27篇 |
2022年 | 29篇 |
2021年 | 44篇 |
2020年 | 29篇 |
2019年 | 38篇 |
2018年 | 19篇 |
2017年 | 17篇 |
2016年 | 26篇 |
2015年 | 12篇 |
2014年 | 14篇 |
2013年 | 22篇 |
2012年 | 22篇 |
2011年 | 21篇 |
2010年 | 13篇 |
2009年 | 20篇 |
2008年 | 12篇 |
2007年 | 8篇 |
2006年 | 3篇 |
2005年 | 6篇 |
2004年 | 5篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1997年 | 8篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1981年 | 2篇 |
1980年 | 6篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1974年 | 2篇 |
1928年 | 2篇 |
1927年 | 5篇 |
1926年 | 3篇 |
1924年 | 2篇 |
1923年 | 1篇 |
1922年 | 4篇 |
1921年 | 2篇 |
1920年 | 4篇 |
1918年 | 2篇 |
1916年 | 1篇 |
1915年 | 1篇 |
1913年 | 1篇 |
1912年 | 3篇 |
1911年 | 1篇 |
1910年 | 1篇 |
1909年 | 3篇 |
1907年 | 2篇 |
排序方式: 共有476条查询结果,搜索用时 343 毫秒
51.
Stephan Altmann Jürgen Mut Natalia Wolf Jutta Meißner-Weigl Maximilian Rudert Franz Jakob Marcus Gutmann Tessa Lühmann Jürgen Seibel Regina Ebert 《International journal of molecular sciences》2021,22(6)
Metabolic glycoengineering enables a directed modification of cell surfaces by introducing target molecules to surface proteins displaying new features. Biochemical pathways involving glycans differ in dependence on the cell type; therefore, this technique should be tailored for the best results. We characterized metabolic glycoengineering in telomerase-immortalized human mesenchymal stromal cells (hMSC-TERT) as a model for primary hMSC, to investigate its applicability in TERT-modified cell lines. The metabolic incorporation of N-azidoacetylmannosamine (Ac4ManNAz) and N-alkyneacetylmannosamine (Ac4ManNAl) into the glycocalyx as a first step in the glycoengineering process revealed no adverse effects on cell viability or gene expression, and the in vitro multipotency (osteogenic and adipogenic differentiation potential) was maintained under these adapted culture conditions. In the second step, glycoengineered cells were modified with fluorescent dyes using Cu-mediated click chemistry. In these analyses, the two mannose derivatives showed superior incorporation efficiencies compared to glucose and galactose isomers. In time-dependent experiments, the incorporation of Ac4ManNAz was detectable for up to six days while Ac4ManNAl-derived metabolites were absent after two days. Taken together, these findings demonstrate the successful metabolic glycoengineering of immortalized hMSC resulting in transient cell surface modifications, and thus present a useful model to address different scientific questions regarding glycosylation processes in skeletal precursors. 相似文献
52.
Maximilian Dyga Andreas Keller Hans Hasse 《American Institute of Chemical Engineers》2022,68(4):e17573
Formaldehyde is an important chemical that is mostly handled in aqueous solutions, which generally also contain methanol; furthermore, also solutions of formaldehyde in other alcohols are used. The density of these solutions is an important thermophysical property. The available models of the density of formaldehyde-containing solutions, however, all have shortcomings, such as a poor accuracy or a limited range of applicability. Therefore, in the present work, a new model of the density in systems of the type (formaldehyde + water + alcohol) was developed. The alcohols that are presently included in the new model are methanol, 1-propanol, and isoprenol; an extension to other alcohols is straightforward. The model was developed using literature data and extensive new density data measured in this work covering binary, ternary, and quarternary solutions of formaldehyde in water, methanol, 1-propanol, and isoprenol at temperatures of K and formaldehyde concentrations of 0.06 − 0.30 g g−1. 相似文献
53.
Jonas Maximilian Müller Nicolas Rozo Lopez Enzo Alexander Klein Christian Hopmann 《Polymer Engineering and Science》2020,60(6):1324-1332
For fiber-reinforced plastics, the strain-rate dependent response is governed by the matrix behavior. In this work, the Goldberg model is considered for the epoxy matrix constitutive material model. Moreover, the strain-rate dependency is achieved by direct influence on the elastic modulus, the inelastic strain, and the material strain to failure. In addition, an anisotropic damage response is implemented and extended through a strain-rate dependent definition. Since the constitutive model relies on nonphysical parameters, a parameter study is further performed. Additional numerical investigations using a micro-mechanical model are performed. Tension and shear loading conditions are evaluated and the influence of different strain rates is explored. Furthermore, the implemented anisotropic damage model is compared and discussed against an isotropic damage model. 相似文献
54.
Gastl Mareike Peereboom Sophie M. Fuetterer Maximilian Boenner Florian Kelm Malte Manka Robert Kozerke Sebastian 《Magma (New York, N.Y.)》2019,32(2):259-268
Magnetic Resonance Materials in Physics, Biology and Medicine - To study inter-individual differences of the relation between diaphragm and heart motion, the objective of the present study was to... 相似文献
55.
Ronen Gottesman Angang Song Igal Levine Maximilian Krause A. T. M. Nazmul Islam Daniel Abou‐Ras Thomas Dittrich Roel van de Krol Abdelkrim Chemseddine 《Advanced functional materials》2020,30(21)
A new method for enhancing the charge separation and photo‐electrochemical stability of CuBi2O4 photoelectrodes by sequentially depositing Bi2O3 and CuO layers on fluorine‐doped tin oxide substrates with pulsed laser deposition (PLD), followed by rapid thermal processing (RTP), resulting in phase‐pure, highly crystalline films after 10 min at 650 °C, is reported. Conventional furnace annealing of similar films for 72 h at 500 °C do not result in phase‐pure CuBi2O4. The combined PLD and RTP approach allow excellent control of the Bi:Cu stoichiometry and results in photoelectrodes with superior electronic properties compared to photoelectrodes fabricated through spray pyrolysis. The low photocurrents of the CuBi2O4 photocathodes fabricated through PLD/RTP in this study are primarily attributed to their low specific surface area, lack of CuO impurities, and limited, slow charge transport in the undoped films. Bare (without protection layers) CuBi2O4 photoelectrodes made with PLD/RTP shows a photocurrent decrease of only 26% after 5 h, which represents the highest stability reported to date for this material. The PLD/RTP fabrication approach offers new possibilities of fabricating complex metal oxides photoelectrodes with a high degree of crystallinity and good electronic properties at higher temperatures than the thermal stability of glass‐based transparent conductive substrates would allow. 相似文献
56.
Maximilian Michel Sandro Cocuzza Martin Biendl Frank Peifer Sebastian Hans Yvonne Methner Friedrich Pehl Werner Back Fritz Jacob Mathias Hutzler 《Journal of the Institute of Brewing》2020,126(4):354-361
Beer spoiling lactic acid bacteria are a major reason for quality complaints in breweries around the world. Spoilage by a variety of these bacteria can result in haze, sediment, slime, off-flavours and acidity. As these bacteria occur frequently in the brewing environment, using certain hop products that inhibit the growth of these spoilers could be a solution to prevent problems. To investigate the impact of seven different hop compounds (α-acids, iso-α-acids, tetrahydro-iso-α-acids, rho-iso-α-acids, xanthohumol, iso-xanthohumol and humulinones) on the growth of six major beer spoilage bacteria (Lactobacillus brevis. L. backi, L. coryniformis, L. lindneri, L. buchneri, Pediococcus damnosous), two concentrations (10 and 25 mg/L) of each hop substance were added to unhopped beer. The potential growth of the spoilage bacteria was investigated over 56 consecutive days. A comparison of the results shows a strong inhibition of growth of all spoilage bacteria at 25 mg/L of tetrahydro-iso-α-acids closely followed by α-acids as the second most inhibitory substance. The results showed a high resistance of L. brevis to all hop compounds as well as an inhibition of L. coryniformis and L. buchneri at low concentrations of most hop components. In comparison with the control sample, L. lindneri showed increased growth in the presence of some hop compounds (rho-iso-α-acids, xanthohumol, iso-xanthohumol, humulinones). © 2020 The Authors. Journal of the Institute of Brewing published by John Wiley & Sons Ltd on behalf of The Institute of Brewing & Distilling 相似文献
57.
Andre Gross Jonas Schoendube Stefan Zimmermann Maximilian Steeb Roland Zengerle Peter Koltay 《International journal of molecular sciences》2015,16(8):16897-16919
The handling of single cells is of great importance in applications such as cell line development or single-cell analysis, e.g., for cancer research or for emerging diagnostic methods. This review provides an overview of technologies that are currently used or in development to isolate single cells for subsequent single-cell analysis. Data from a dedicated online market survey conducted to identify the most relevant technologies, presented here for the first time, shows that FACS (fluorescence activated cell sorting) respectively Flow cytometry (33% usage), laser microdissection (17%), manual cell picking (17%), random seeding/dilution (15%), and microfluidics/lab-on-a-chip devices (12%) are currently the most frequently used technologies. These most prominent technologies are described in detail and key performance factors are discussed. The survey data indicates a further increasing interest in single-cell isolation tools for the coming years. Additionally, a worldwide patent search was performed to screen for emerging technologies that might become relevant in the future. In total 179 patents were found, out of which 25 were evaluated by screening the title and abstract to be relevant to the field. 相似文献
58.
Dr. Zsofia Lengyel-Zhand Dr. Liam R. Marshall Maximilian Jung Megha Jayachandran Dr. Min-Chul Kim Austin Kriews Prof. Dr. Olga V. Makhlynets Dr. H. Christopher Fry Prof. Dr. Armin Geyer Prof. Dr. Ivan V. Korendovych 《Chembiochem : a European journal of chemical biology》2021,22(3):585-591
The self-assembly of short peptides into catalytic amyloid-like nanomaterials has proven to be a powerful tool in both understanding the evolution of early proteins and identifying new catalysts for practically useful chemical reactions. Here we demonstrate that both parallel and antiparallel arrangements of β-sheets can accommodate metal ions in catalytically productive coordination environments. Moreover, synergistic relationships, identified in catalytic amyloid mixtures, can be captured in macrocyclic and sheet-loop-sheet species, that offer faster rates of assembly and provide more complex asymmetric arrangements of functional groups, thus paving the way for future designs of amyloid-like catalytic proteins. Our findings show how initial catalytic activity in amyloid assemblies can be propagated and improved in more-complex molecules, providing another link in a complex evolutionary chain between short, potentially abiotically produced peptides and modern-day enzymes. 相似文献
59.
Jacobsen V Tätte T Branscheid R Mäeorg U Saal K Kink I Lõhmus A Kreiter M 《Ultramicroscopy》2005,104(1):39-45
We demonstrate that an optically transparent and electrically conductive antimon-doped tin-oxide tip that is prepared in a sol-gel process can be used as a probe for scanning tunnelling microscopy (STM), yielding atomic vertical and nanometre lateral resolution. Emission of visible light from the tunnelling junction between gold particles and the tip is observed for bias voltages above 7 V. In contrast to the metallic tips generally used in STM, this tip does not significantly perturb the local optical response. Therefore, the tunnelling induced light can be used to map the optical near-field of surface structures with the tunnel gap acting as highly localised light source for the investigation of near-field enhancement in complex metal structures. 相似文献
60.
Jesse Ross-Jones Maximilian Gaedtke Sebastian Sonnick Matthias Rädle Hermann Nirschl Mathias J. Krause 《Computers & Mathematics with Applications》2019,77(1):209-221
Due to reduced thermal conductivity, vacuum insulation panels (VIPs) provide significant thermal insulation performance. Our novel vacuum panels operate at reduced pressure and are filled with a powder of precipitated silicic acid to further hinder convection and provide static stability against atmospheric pressure. To obtain an in depth understanding of heat transfer mechanisms, their interactions and their dependencies inside VIPs, detailed microscale simulations are conducted.Particle characteristics for silica are used with a discrete element method (DEM) simulation, using open source software Yade-DEM, to generate a periodic compressed packing of precipitated silicic acid particles. This aggregate packing is then imported into OpenLB (openlb.net) as a fully resolved geometry, and used to study the effects on heat transfer at the microscale. A three dimensional Lattice Boltzmann method (LBM) for conjugated heat transfer is implemented with open source software OpenLB, which is extended to include radiative heat transport. The infrared intensity distribution is solved and coupled with the temperature through the emissivity, absorption and scattering of the studied media using the radiative transfer equation by means of LBM. This new holistic approach provides a distinct advantage over similar porous media approaches by providing direct control and tuning of particle packing characteristics such as aggregate size, shape and pore size distributions and studying their influence directly on conduction and radiation independently. Our aim is to generate one holistic tool which can be used to generate silica geometry and then simulate automatically the thermal conductivity through the generated geometry. 相似文献