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1.
Jinshuang Wang Luyao Chen Mengdi Chen Yuyang Wu Yinghui Wang Yongsheng Yu Junbin Sun Bing Liu Qiangshan Jing 《Ceramics International》2021,47(16):22965-22975
In this study, the destabilization resistance of Sc2O3 and CeO2 co-stabilized ZrO2 (SCZ) ceramics was tested in Na2SO4 + V2O5 molten salts at 750°C–1100 °C. The phase structure and microstructure evolution of the samples during the hot corrosion testing were analyzed with X-ray diffraction (XRD), Raman spectra, scanning electron microscopy (SEM), energy dispersive X-ray spectrum (EDS), and X-ray photoelectron spectroscopy (XPS). Results showed that the destabilization of SCZ ceramics at 750 °C was the result of the chemical reaction with V2O5 to produce m-ZrO2 and CeVO4, and little ScVO4 was detected in the Sc2O3-rich SCZ ceramics. The primary corrosion products at 900 °C and 1100 °C were CeO2 and m-ZrO2 due to the mineralization effect. The Sc2O3-rich SCZ ceramics exhibited excellent degradation resistance and phase stability owing to the enhanced bond strength and the decreased size misfit between Zr4+ and Sc3+. The destabilization mechanism of SCZ ceramic under hot corrosion was also discussed. 相似文献
2.
An important criterium in selecting species for alley cropping is themineralization pattern of their prunings. This study determined effects of 5years of hedgerow pruning applications on soil organic C and total N at threelocations in Haiti and mineralization patterns from soil amended with theprunings during an incubation using micro-lysimeters. Soils (0–5cm) under 5 hedgerows were collected at each site and analyzed fororganic C and total N. In the laboratory, ground leaves and stems (<1cm diameter) of the hedgerow species were mixed with soil at ratesof 3 and 1.5 Mg ha–1, respectively, andaerobically incubated in the dark at 25 °C. A non-amended soilwas used as control. Soils were leached to determine mineral N at 1, 3, 7, 14,28, 42, 84 and 120 days of incubation. Evolved CO2 was measuredfollowing each leaching procedure. At the calcareous site, application ofprunings from Leucaena leucocephala (Lam.) De Wit andDelonix regia (Boj. ex Hook. Raf.) resulted in 23 and 13%higher soil N than the control, respectively, after 5 years. There were nodifferences in total N at the other sites but soil N was highest underLeucaena hybrid and Acaciaangustissima (Mill.) Kuntze, respectively at the basaltic and highelevation sites. Soils under D. regia (calcareous) andA. angustissima and Leucaena hybrid(high elevation) had higher organic C than the respective controls. Carbon andNmineralization and C turnover were highest when soils were amended with leavesof Leucaena diversifolia (Schlecht.) Benth (calcareous andbasaltic soils) and A. angustissima (high elevation) andlowest in non-amended control soils. Stem-amended soils showed differences in Cmineralization for calcareous and high elevation soils whereas N mineralizationwas similar among treatments within sites. Carbon and N mineralization (highelevation soil) correlated positively with N concentrations of leaf prunings.Amendments with leaf prunings increased soil C and N mineralization andturnoverrates, suggesting greater nutrient availability for the crop during a shortperiod than in non-amended control soils. 相似文献
3.
Soil organic matter dynamics are essential for terrestrial ecosystem functions as they affect biogeochemical cycles and, thus, the provision of plant nutrients or the release of greenhouse gases to the atmosphere. Most of the involved processes are driven by microorganisms. To investigate and understand these processes, individual-based models allow analyzing complex microbial systems' behavior based on rules and conditions for individual entities within these systems, taking into account local interactions and individual variations. Here, we present a streamlined, user-friendly and open version of the individual-based model INDISIM-SOM, which describes the mineralization of soil carbon and nitrogen. It was implemented in NetLogo, a widely used and easily accessible software platform especially designed for individual-based simulation models. Including powerful means to observe the model behavior and a standardized documentation, this increases INDISIM-SOM's range of potential uses and users, and facilitates the exchange among soil scientists as well as between different modeling approaches. 相似文献
4.
Aqueous interfaces are of paramount importance in the study of biological systems as well as in the biomedical sciences. To study these interfaces at the nanometer level it is of interest to develop methods that allow their observation with cryogenic transmission electron microscopy (cryo-TEM). Prevention of dehydration to preserve the "native" state during sample preparation prior to vitrification is often one of the most important parameters to control in cryo-TEM experiments. For the preparation of these types of samples, we felt the need for an extended workspace with temperature and humidity control; a 'glove-box' that seamlessly connects to the vitrification instrument, the Vitrobot. In this paper we describe the use of the glove-box in the 2D and 3D cryo-TEM study of DNA adsorption and calcium carbonate mineralization to Langmuir films. The data presented illustrates the necessity of a humidity-controlled environment to preserve the original "native" state of the monolayer system. 相似文献
5.
6.
永平铜硫矿床位于嵩山-侯家倒转背斜的东翼,虽然矿化与矽卡岩化关系密切,成矿地质条件和成矿模式等都有别于一般的矽卡岩型矿床。鉴于矿床类型比较独特,专家和业内人士将矿床冠名为“永平式”铜硫矿床。嵩山-侯家倒转背斜的西翼,与永平铜硫矿床相比,具有相似的成矿地质环境,是寻找“永平式”铜硫矿床的重要“靶区”,找矿前景良好。 相似文献
7.
东乡铜矿区构造特征与成矿的关系 总被引:2,自引:0,他引:2
本文针对东乡铜矿区构造特征的分析,尤其是对矿区北东向断层,含矿破碎带及横跨褶皱的深入探讨,结合地史背景阐明构造的产生、演化及对成矿的关系,并指出其找矿意义。 相似文献
8.
《Ceramics International》2017,43(18):16238-16247
Results obtained during in-vitro experiments concerning human osteoblasts cultivated on the surface of dense samples produced by Spark Plasma Sintering from three types of hydroxyapatite powders are described and discussed. The sintered products display diverse composition and microstructures which are found to significantly influence the biological response of the cells. Osteoblasts adhesion, viability and proliferation are quantitatively comparable for the three classes of bioceramics, whereas matrix mineralization occurs only in products exclusively consisting of hydroxyapatite. Correspondingly, a calcium-phosphate layer exhibiting a trabecular-like microstructure is deposited on the materials surface. Matrix mineralization is favored when the substrate is composed of submicrometer-sized apatite grains. On the other hand, the latter phenomena is markedly suppressed, and so does the formation of the new apatite phase, when cells are seeded on sintered disks composed of β-Tri-Calcium Phosphate, which was formed during the sintering process from the decomposition of initial apatite. 相似文献
9.
Shijian Yang Hongping He Daqing Wu Dong Chen Xiaoliang Liang Zonghua Qin Mingde Fan Jianxi Zhu Peng Yuan 《Applied catalysis. B, Environmental》2009,89(3-4):527-535
In this work, a series of Fe3−xTixO4 (0 ≤ x ≤ 0.78) was synthesized using a new soft chemical method. The synthetic Fe3−xTixO4 were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Mössbauer spectroscopy, thermogravimetric and differential scanning calorimetry (TG–DSC) analyses. The results showed that they were spinel structures and Ti was introduced into their structures.Then, decolorization of methylene blue (MB) by Fe3−xTixO4 in the presence of H2O2 at neutral pH values was studied using UV–vis spectra, dissolved organic carbon (DOC) and element C analyses. Furthermore, the degradation products remained in reaction solution after the decolorization were identified using ionic chromatography (IC), 13C nuclear magnetic resonance spectra (NMR), liquid chromatography and mass spectrometry (LC–MS). Although small amounts of MB were mineralized, the aromatic rings in MB were destroyed completely after the decolorization. Decolorization of MB by Fe3−xTixO4 in the presence of H2O2 was promoted remarkably with the increase of Ti content in Fe3−xTixO4 due to the enhancement of both adsorption and degradation of MB on Fe3−xTixO4. 相似文献
10.
The heterogeneous photocatalytic degradation of reactive blue 4 dye (RB4) solutions under Fenton reagent and TiO(2) assisted by concentrated solar light irradiation using a Fresnel lens has been studied. Multivariate experimental design was applied to study the kinetic process. The efficiency of photocatalytic degradation was determined from the analysis of color and total organic carbon (TOC) removal. Factorial experimental design allowed to determine the influence of four parameters (pH and initial concentrations of TiO(2), Fe(II) and H(2)O(2)) on the value of the decoloration kinetic rate constant. Experimental data were fitted using neural networks (NNs). The mathematical model reproduces experimental data within 86% of confidence and allows the simulation of the process for any value of parameters in the experimental range studied. Also, a measure of the saliency of the input variables was made based upon the connection weights of the neural networks, allowing the analysis of the relative relevance of each variable with respect to the others. Results showed that acidic pHs (pH=3.6) are preferred for the complete dye decoloration. The optimum catalyst concentration is 1.2g TiO(2)/l. The use of a low cost catalyst and its activation using a Fresnel lens to concentrate solar energy significantly accelerates the degradation process when compared with direct solar radiation alone and can offer an economical and practical alternative for the destruction of environmental organic compounds. 相似文献