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排序方式: 共有1264条查询结果,搜索用时 15 毫秒
981.
Thomas Töppel Holger Lausch Michael Brand Eric Hensel Michael Arnold Christian Rotsch 《JOM Journal of the Minerals, Metals and Materials Society》2018,70(3):321-327
Laser beam melting (LBM), an additive laser powder bed fusion technology, enables the structural integration of temperature-sensitive sensors and actuators in complex monolithic metallic structures. The objective is to embed a functional component inside a metal part without losing its functionality by overheating. The first part of this paper addresses the development of a new process chain for bonded embedding of temperature-sensitive sensor/actuator systems by LBM. These systems are modularly built and coated by a multi-material/multi-layer thermal protection system of ceramic and metallic compounds. The characteristic of low global heat input in LBM is utilized for the functional embedding. In the second part, the specific functional design and optimization for tailored smart components with embedded functionalities are addressed. Numerical and experimental validated results are demonstrated on a smart femoral hip stem. 相似文献
982.
Dr. Mathew Sutherland Alice Li Anissa Kaghad Dimitrios Panagopoulos Dr. Fengling Li Dr. Magdalena Szewczyk Dr. David Smil Dr. Cora Scholten Dr. Léa Bouché Dr. Timo Stellfeld Dr. Cheryl H. Arrowsmith Dr. Dalia Barsyte Dr. Masoud Vedadi Dr. Ingo V. Hartung Dr. Holger Steuber Dr. Robert Britton Dr. Vijayaratnam Santhakumar 《ChemMedChem》2021,16(7):1116-1125
Protein arginine N-methyl transferase 4 (PRMT4) asymmetrically dimethylates the arginine residues of histone H3 and nonhistone proteins. The overexpression of PRMT4 in several cancers has stimulated interest in the discovery of inhibitors as biological tools and, potentially, therapeutics. Although several PRMT4 inhibitors have been reported, most display poor selectivity against other members of the PRMT family of methyl transferases. Herein, we report the structure-based design of a new class of alanine-containing 3-arylindoles as potent and selective PRMT4 inhibitors, and describe key structure–activity relationships for this class of compounds. 相似文献
983.
Dr. Marco Lelle Maik Otte Michele Bonus Prof. Dr. Holger Gohlke Prof. Dr. Klaus Benndorf 《Chembiochem : a European journal of chemical biology》2020,21(16):2311-2320
High-affinity fluorescent derivatives of cyclic adenosine and guanosine monophosphate are powerful tools for investigating their natural targets. Cyclic nucleotide-regulated ion channels belong to these targets and are vital for many signal transduction processes, such as vision and olfaction. The relation of ligand binding to activation gating is still challenging, and there is a need for fluorescent probes that enable the process to be broken down to the single-molecule level. This inspired us to prepare fluorophore-labeled cyclic nucleotides, which are composed of a bright dye and a nucleotide derivative with a thiophenol motif at position 8 that has already been shown to enable superior binding affinity. These bioconjugates were prepared by a novel cross-linking strategy that involves substitution of the nucleobase with a modified thiophenolate in good yield. Both fluorescent nucleotides are potent activators of different cyclic nucleotide-regulated ion channels with respect to the natural ligand and previously reported substances. Molecular docking of the probes excluding the fluorophore reveals that the high potency can be attributed to additional hydrophobic and cation-π interactions between the ligand and the protein. Moreover, the introduced substances have the potential to investigate related target proteins, such as cAMP- and cGMP-dependent protein kinases, exchange proteins directly activated by cAMP or phosphodiesterases. 相似文献
984.
Jan Folke Huiqing Song Julian Schittkowski Robert Schlögl Holger Ruland 《化学,工程师,技术》2020,92(10):1567-1573
The influence of oxygen poisoning on a state-of-the-art multipromoted iron-based industrial catalyst for ammonia synthesis as well as the effectivity of different gas purification methods to prevent oxygen poisoning for experiments on laboratory scale were studied in detail. Additionally, the observed results were compared to a common oxygen poisoning test from literature, which on the one hand confirmed its usability in a wide range of conditions, but on the other hand also demonstrated the limitations of this test. 相似文献
985.
The Carbon2Chem® project aims to convert exhaust gases from the steel industry into chemicals such as methanol to reduce CO2 emissions. Here, H2 is required for the conversion of CO2 into methanol. Although much effort is put to produce H2 from renewables, the use of fossil fuels, especially natural gas, seems to be fundamental in the short term. For this reason, the development of clean technologies for the processing of natural gas with a low environmental impact has become a topic of utmost importance. In this context, methane pyrolysis has received special attention to produce CO2-free H2. 相似文献
986.
987.
Ziyaad Mohamed Venkata D.B.C. Dasireddy Sooboo Singh Holger B. Friedrich 《International Journal of Hydrogen Energy》2018,43(49):22291-22302
CO oxidation and methanation over Ru-TiO2 and Ru-ZrO2 catalysts were investigated for CO removal for applications in proton exchange membrane fuel cells. The catalysts were synthesised by the deposition precipitation method at a pH of 7–7.5 for better interactions between the support and the active Ru metal. Various characterization experiments such as TPR, XPS, FTIR-CO, CO chemisorption and HRTEM were conducted to better understand the physio-chemical properties of Ru on the supports. Both catalysts showed excellent activity for the total oxidation of CO, however, with the addition of H2, the catalysts activity to CO oxidation decreased significantly. Higher temperatures for the preferential oxidation reaction indicated that the Ru catalysts not only oxidize CO, but hydrogenate it as well. Furthermore, H2 oxidation was favoured over the catalysts. Hydrogenation of CO over these catalysts gave high CO conversion and selectivity towards CH4. Both the catalysts showed similar activity across the temperature range screened and gave maximum CO conversions of 99.9% from 240 °C onwards, with 99.9% selectivity towards CH4. The catalysts also showed good stability in the reaction and the similarities in the catalytic activity of these were attributed to the well-dispersed Ru metal over the supports. The Ru catalysts effectively reduced CO concentrations in the reformate gas to less than 10 ppm, as is required for practical applications. 相似文献
988.
AbstractSignificant energy resources are needed for traditional and nontraditional water utilization in China. Yet the interlinkages between water and energy have not received adequate attention in the country. To address this gap, this article disaggregates and quantifies the magnitude and direction of energy and water flows in China at the national level through Sankey diagrams. Spatial distributions of energy use by different components of the water supply were further mapped at the provincial level to discern regional differences. The results of this study show that the total energy consumption by water abstraction, treatment and distribution, as well as waste treatment and reuse, amounts to 193.5 TWh of electricity, or about 4% of the total national electricity usage. The outcome of this study offers important policy implications for integrated water and energy planning and management and will contribute to achieving the goal of low-energy water utilization in the future. 相似文献
989.
Thomas Krampitz Mareen Zöllner Holger Lieberwirth Andre Kamptner Jens Friedrich 《化学,工程师,技术》2020,92(4):476-484
The comminution of carbon fiber reinforced plastics (CFRP) is a central process step for almost all recycling processes. Size reduction creates a specific surface that serves as a measure in particular of the size reduction success of fines. The article shows the comminution from 1 m edge length in the feed material down to a target product size of less than 100 µm by means of three-stage comminution. The challenges of granulometric characterization of the comminution products and the associated evaluation of the comminution success are specifically addressed. 相似文献
990.
Joost Duvigneau Stijn Cornelissen Núria Bardají Valls Holger Schönherr G. Julius Vancso 《Advanced functional materials》2010,20(3):460-468
Here, reactive imprint lithography (RIL) is introduced as a new, one‐step lithographic tool for the fabrication of large‐area topographically patterned, chemically activated polymer platforms. Films of polystyrene‐block‐poly(tert‐butyl acrylate) (PS‐b‐PtBA) are imprinted with PDMS master stamps at temperatures above the corresponding glass transition and chemical deprotection temperatures to yield structured films with exposed carboxylic acid and anhydride groups. Faithful pattern transfer is confirmed by AFM analyses. Transmission‐mode FTIR spectra shows a conversion of over 95% of the tert‐butyl ester groups after RIL at 230 °C for 5 minutes and a significantly reduced conversion to anhydride compared to thermolysis of neat films with free surfaces in air or nitrogen. An enrichment of the surface layer in PS is detected by angle‐resolved X‐ray photoelectron spectroscopy (XPS). In order to demonstrate application potentials of the activated platforms, a 7 nm ± 1 nm thick NH2‐terminated PEG layer (grafting density of 0.9 chains nm?2) is covalently grafted to RIL‐activated substrates. This layer reduces the non‐specific adsorption (NSA) of bovine serum albumin by 95% to a residual mass coverage of 9.1 ± 2.9 ng cm?2. As shown by these examples, RIL comprises an attractive complementary approach to produce bio‐reactive polymer surfaces with topographic patterns in a one‐step process. 相似文献