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排序方式: 共有4215条查询结果,搜索用时 15 毫秒
1.
Gross Jürgen Peter Malzbender Jürgen Schwaiger Ruth 《Journal of Materials Science》2022,57(15):7481-7490
Journal of Materials Science - The application of ceramics in advanced functional applications often requires thicknesses below a few hundred micrometers, rendering an assessment of the... 相似文献
2.
Ib Holzmeister Jan Weichhold Jürgen Groll Hala Zreiqat Uwe Gbureck 《Journal of the American Ceramic Society》2021,104(7):3554-3561
In this study, the hydraulic reactivity and cement formation of baghdadite (Ca3ZrSi2O9) was investigated. The material was synthesized by sintering a mixture of CaCO3, SiO2, and ZrO2 and then mechanically activated using a planetary mill. This leads to a decrease in particle and crystallite size and a partial amorphization of baghdadite as shown by X-ray powder diffraction (XRD) and laser diffraction measurements. Baghdadite cements were formed by the addition of water at a powder to liquid ratio of 2.0 g/ml. Maximum compressive strengths were found to be ~2 MPa after 3-day setting for a 24-h ground material. Inductively coupled plasma mass spectrometry (ICP-MS) measurements showed an incongruent dissolution profile of set cements with a preferred dissolution of calcium and only marginal release of zirconium ions. Cement formation occurs under alkaline conditions, whereas the unground raw powder leads to a pH of 11.9 during setting, while prolonged grinding increased pH values to approximately 12.3. 相似文献
3.
Gang Yan Jürgen Malzbender Shuo Fu Jürgen Peter Gross Shicheng Yu Rüdiger-A. Eichel Ruth Schwaiger 《Journal of the European Ceramic Society》2021,41(10):5240-5247
The NASICON type solid electrolyte LATP is a promising candidate for all-solid-state Li-ion batteries considering energy density and safety aspects. To ensure the performance and reliability of batteries, crack initiation and propagation within the electrolyte need to be suppressed, which requires knowledge of the fracture characteristics. In the current work, micro-pillar splitting was applied to determine the fracture toughness of LATP material for different grain orientations. The results are compared with data obtained using a conventional Vickers indentation fracture (VIF) approach. The fracture toughness obtained via micro-pillar splitting test is 0.89 ± 0.13 MPa?m1/2, which is comparable to the VIF result, and grain orientation has no significant effect on the intrinsic fracture toughness. Being a brittle ceramic material, the effect of pre-existing defects on the toughness needs to be considered. 相似文献
4.
The corrosion resistance of aluminium surfaces is closely linked to the surface state after a grinding process. For years, iron-containing abrasive materials were suspected to lead to increased corrosion susceptibility after processing of aluminium surfaces. To prove a possible correlation between the iron content of an abrasive and the corrosion behaviour of aluminium components, scientific investigations and experimentally practical corrosion tests are necessary. For the current investigation, specimens of a technical Al-Si alloy from the same batch were used. The test specimens were mechanically ground with various resin-bonded model abrasives containing different iron contents. The performed corrosion tests did not reveal a negative influence of the different iron-containing abrasives on the corrosion behaviour of the Al–Si alloy. However, the most sensitive measuring method (electrochemical noise) showed differences in the surface activity depending on the type of abrasive. 相似文献
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6.
Kasper T. Møller Mathias Jørgensen Jacob G. Andreasen Jørgen Skibsted Zbigniew Łodziana Yaroslav Filinchuk Torben R. Jensen 《International Journal of Hydrogen Energy》2018,43(1):311-321
A new potassium tetraamidoboranealuminate, K[Al(NH2BH3)4], has been synthesized by a mechanochemical reaction between KAlH4 and NH3BH3. The compound, K[Al(NH2BH3)4], crystallizes in a triclinic unit cell with space group symmetry P?1. The crystal structure consists of [K(NH2BH3)6]5? octahedra which facilitate the bridging between K+ in 1D chains, while also bridging K+ to Al3+ to connect the 1D chains in a 3D network. Thermal analysis reveals that K[Al(NH2BH3)4] decomposes in two exothermic steps at T ~ 94 and 138 °C and releases primarily hydrogen. The total gas release amounts to ~6.0 wt% H2. The decomposition products are investigated ex situ by powder X-ray diffraction, infrared spectroscopy, and 11B and 27Al NMR and identified as KBH4 and amorphous phases, possibly BN3, N2BH, and/or NBH2 whereas aluminum is found in four-, five-, and six-fold coordination. Unfortunately, the decomposed sample shows no hydrogen absorption at T = 260 °C and p(H2) = 110 bar. 相似文献
7.
8.
Dr. Tianqiang Liu Dr. Ping Song Anders Märcher Prof. Dr. Jørgen Kjems Dr. Chuanxu Yang Prof. Dr. Kurt V. Gothelf 《Chembiochem : a European journal of chemical biology》2019,20(8):1014-1018
Doxorubicin is a hydrophobic anticancer drug that has poor selectivity, due to the lack of active targeting capability. Here, learning lessons from the success of antibody–drug conjugates, we have designed a new doxorubicin delivery system without conjugating doxorubicin to antibody directly. In this setup, cetuximab, an antibody that targets the epidermal growth factor receptor (EGFR) in cancer cells, was conjugated to a single-stranded DNA with a carefully designed sequence in a site-selective manner by using the DNA-templated protein conjugation (DTPC) method. The DNA duplex in the conjugates serves as a carrier of doxorubicin through noncovalent intercalation, and cetuximab functions as the targeting agent; this could drastically decrease systemic toxicity and potentially avoid under- or overdosing. The size of conjugates loaded with doxorubicin was about 8.77 or 16.61 nm when characterized by dynamic light scattering and atomic force microscopy, respectively. In vitro cytotoxicity and selective cancer cell killing was investigated against two EGFR+ cell lines (KB and MDA-MB-231) and one EGFR− cell line (NIH-3T3). Cytotoxicity and flow cytometry data showed that doxorubicin loaded in cetuximab–DNA conjugates was more potent in terms of cell cytotoxicity than free doxorubicin in EGFR-overexpressed cell lines, thus suggesting that the conjugates were more selectively and easily taken up into cells, followed by rapid release of doxorubicin from the system into the cytoplasm from endosomes. 相似文献
9.
Chenhui Ding Marion Breunig Jana Timm Roland Marschall Jürgen Senker Seema Agarwal 《Advanced functional materials》2021,31(49):2106507
Covalent organic frameworks (COFs) show advantageous characteristics, such as an ordered pore structure and a large surface area for gas storage and separation, energy storage, catalysis, and molecular separation. However, COFs usually exist as difficult-to-process powders, and preparing continuous, robust, flexible, foldable, and rollable COF membranes is still a challenge. Herein, such COF membranes with fiber morphology for the first time prepared via a newly introduced template-assisted framework process are reported. This method uses electrospun porous polymer membranes as a sacrificial large dimension template for making self-standing COF membranes. The porous COF fiber membranes, besides having high crystallinity, also show a large surface area (1153 m2 g−1), good mechanical stability, excellent thermal stability, and flexibility. This study opens up the possibility of preparation of large dimension COF membranes and their derivatives in a simple way and hence shows promise in technical applications in separation, catalysis, and energy in the future. 相似文献
10.
Preparative protein crystallization can possibly replace one or more chromatographic steps in downstream processing. The development of such crystallization processes is demanding: first, promising principal crystallization conditions must be identified; second, details about the process must be defined; and third, the crystals have to be separated from the mother liquor without putting harm of their crystalline integrity. State‐of‐the‐art about these three steps is developing fast by (i) employing new screening methods which are based on fundamental understanding of the interaction of the protein molecules, (ii) application of existing concepts of technical bulk crystallization of small molecules to preparative protein crystallization, and (iii) making available specific gentle separation machinery. 相似文献