检索结果-南通市图书馆

A Comparison of Hydrothermal Aging, SO₂ and Propene Poisoning Effects on NH₃-SCR over Cu-ZSM-5 and Cu-SAPO-34 Catalysts

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science and Chemical Engineering 2024年第5期12卷 10-28页

作者： Kouadio Brou Albert Koffi Konan Martin Zran van Eric-simon Horo Kone Unité de Formation et de Recherche des Sciences et de Technologies (UFR ST) Universit&#233 Alassane Ouattara Bouak&#233 C&#244te d&#8217Ivoire Unité de Formation et de Recherche Environnement (UFR E) Universit&#233 Jean Lorougnon Gu&#233d&#233 Daloa C&#244te d&#8217Ivoire Unité de Formation et de Recherche des Sciences des Structures de la Mati&#232re et de Technologie (UFR SSMT) Abidjan C&#244te d&#8217Ivoire

This study was aimed to investigate the effects of hydrothermal aging, propene and SO2 poisoning on the ammonia-selective catalytic reduction (NH3-SCR) performance of both Cu-SAPO-34 and Cu-ZSM-5. The catalytic activities of fresh, aged and poisoned samples were tested in ammonia-selective catalytic reduction (NH3-SCR) of NOx conditions. The XRD, TG and N2-desorption results showed that the structures of the Cu-SAPO-34 and Cu-ZSM-5 remained intact after 750˚C hydrothermally aged, SO2 and propene poisoned. After hydrothermal aging at 750˚C for 12 h, the NO reduction performance of Cu-ZSM-5 was significantly reduced at lower temperatures, while that of Cu-SAPO-34 was less affected. Moreover, Cu-SAPO-34 catalyst showed high NO conversion with SO2 or propene compared to Cu-ZSM-5. However, Cu-ZSM-5 showed a larger drop in catalytic activity with SO2 or propene compared to Cu-SAPO-34 catalyst. The H2-TPR results showed that Cu2 ions could be reduced to Cu and Cu0 for Cu-ZSM-5, while no significant transformation of copper species was observed for Cu-SAPO-34. Meanwhile, the UV-vis DRS results showed that CuO species were formed in Cu-ZSM-5, while little changes were observed for the Cu-SAPO-34. Cu-SAPO-34 showed high sulfur and hydrocarbon poison resistance compared to Cu-ZSM-5. In summary, Cu-SAPO-34 with small-pore zeolite showed higher hydrothermal stability and better hydrocarbon and sulfur poison resistant than Cu-ZSM-5 with medium-pore.

关键词： Hydrothermal Aging Propene and SO2Poisoning Ammonia-Selective Catalytic Reduction(NH3-SCR) Cu-SAPO-34 Cu-ZSM-5

Deciphering fluid inclusions in high-grade rocks

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Geoscience Frontiers 2014年第5期5卷 683-695页

作者： Alfons van den Kerkhof Andreas Kronz Klaus simon Geowissenschaftliches Zentrum der Universitat Gottingen Goldschmidtstr.1-3 D 37073 GottingenGermany

The study of fluid inclusions in high-grade rocks is especially challenging as the host minerals have been normally subjected to deformation, recrystallization and fluid-rock interaction so that primary in- clusions, formed at the peak of metamorphism are rare. The larger part of the fluid inclusions found in metamorphic minerals is typically modified during uplift. These late processes may strongly disguise the characteristics of the ＂original＂ peak metamorphic fluid. A detailed microstructural analysis of the host minerals, notably quartz, is therefore indispensable for a proper interpretation of fluid inclusions. Cathodoluminescence （CL） techniques combined with trace element analysis of quartz （EPMA, LA- [CPMS） have shown to be very helpful in deciphering the rock-fluid evolution. Whereas high-grade metamorphic quartz may have relatively high contents of trace elements like Ti and A1, low- temperature re-equilibrated quartz typically shows reduced trace element concentrations. The result- ing microstructures in CL can be basically distinguished in diffusion patterns （along microfractures and grain boundaries）, and secondary quartz formed by dissolution-reprecipitation. Most of these textures are formed during retrograde fluid-controlled processes between ca. 220 and 500 ℃, i.e. the range of semi-brittle deformation （greenschist-facies） and can be correlated with the fluid inclusions. In this way modified and re-trapped fluids can be identified, even when there are no optical features observed under the microscope.

关键词： Fluid inclusionsGranuliteCharnockiteCathodoluminescenceLA-ICPMSQuartz

Video capsule endoscopy:Perspectives of a revolutionary technique

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2014年第46期20卷 17330-17344页

作者： simon Bouchard Mostafa Ibrahim Andre van Gossum Department of Gastroenterology Hepatopancreatology and Digestive OncologyErasme HospitalULB1070 BrusselsBelgium Gastroenterology Department Theodor Bilahrz Research InstituteCairo 12411Egypt

Video capsule endoscopy (VCE) was launched in 2000 and has revolutionized direct endoscopic imaging of the gut. VCE is now a first-line procedure for exploring the small bowel in cases of obscure digestive bleeding and is also indicated in some patients with Crohn’s disease, celiac disease, and polyposis syndrome. A video capsule has also been designed for visualizing the esophagus in order to detect Barrett’s esophagus or esophageal varices. Different capsules are now available and differ with regard to dimensions, image acquisition rate, battery life, field of view, and possible optical enhancements. More recently, the use of VCE has been extended to exploring the colon. Within the last 5 years, tremendous developments have been made toward increasing the capabilities of the colon capsule. Although colon capsule cannot be proposed as a first-line colorectal cancer screening procedure, colon capsule may be used in patients with incomplete colonoscopy or in patients who are unwilling to undergo colonoscopy. In the near future, new technological developments will improve the diagnostic yield of VCE and broaden its therapeutic capabilities.

关键词： Video capsule endoscopy Esophagus Small bowel Colon Obscure digestive bleeding Polyp

Regulation of Plant Vitamin Metabolism:Backbone of Biofortification for the Alleviation of Hidden Hunger

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Molecular Plant 2021年第3期14卷 40-60页

作者： Ling Jiang simon Strobbe Dominique van Der Straeten Chunyi Zhang Biotechnology Research Institute Chinese Academy of Agricultural SciencesBeijing 100081P.R.China Laboratory of Functional Plant Biology Ghent UniversityK.L.Ledeganckstraat 359000 GhentBelgium These authors contributed equally to this work

Micronutrient deficiencies include shortages of vitamins and *** affect billions of people and are associated with long-range effects on health,learning ability,and huge economic *** of multiple micronutrients can play an important role in combating *** challenge,however,is to balance plant growth with nutrient requirements for ***,we summarize the major progress about vitamin biosynthesis and its response to the changing *** discuss the interactions among vitamins as well as possible strategies for vitamin ***,we propose to integrate new breeding technologies with metabolic pathway modification to facilitate the biofortification of crops,thereby alleviating the hidden hunger of target populations.

关键词： vitamins biosynthesis regulatory mechanisms biofortification hidden hunger

Machine learning potentials for metal-organic frameworks using an incremental learning approach

在线全文

学校读者我要写书评

暂无评论

npj Computational Materials 2023年第1期9卷 2147-2154页

作者： Sander vandenhaute Maarten Cools-Ceuppens simon DeKeyser Toon Verstraelen Veronique van Speybroeck Center for Molecular Modeling Ghent UniversityTechnologiepark 469052 ZwijnaardeBelgium

Computational modeling of physical processes in metal-organic frameworks(MOFs)is highly challenging due to the presence of spatial heterogeneities and complex operating conditions which affect their *** functional theory(DFT)may describe interatomic interactions at the quantum mechanical level,but is computationally too expensive for systems beyond the nanometer and picosecond ***,we propose an incremental learning scheme to construct accurate and data-efficient machine learning potentials for *** scheme builds on the power of equivariant neural network potentials in combination with parallelized enhanced sampling and on-the-fly training to simultaneously explore and learn the phase space in an iterative *** only a few hundred single-point DFT evaluations per material,accurate and transferable potentials are obtained,even for flexible frameworks with multiple structurally different *** incremental learning scheme is universally applicable and may pave the way to model framework materials in larger spatiotemporal windows with higher accuracy.

关键词： framework incremental neural

Large-scale transportation and storage of wood pellets:Investigation of the change in physical properties

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2021年第4期19卷 146-156页

作者： Hamid Gilvari Coen H.H.van Battum simon A.van Dijk Wiebren de Jong Dingena L.Schott Section of Transport Engineering and Logistics Department of Maritime and Transport TechnologyFaculty of MechanicalMaritime and Materials EngineeringDelft University of TechnologyThe Netherlands Chemical Services Uniper Benelux NVThe Netherlands Section of Large Scale Energy Storage Department of Process&EnergyFaculty of MechanicalMaritime and Materials EngineeringDelft University of TechnologyThe Netherlands

The change in physical properties of wood pellets,with a focus on particle size distributions due to pellet breakage and attrition,was studied in a large-scale(∼450 ton/h)transportation *** locations with a high probability of breakage through the whole transportation system were chosen and sampled to study the effect of transportation system design and operation on the mechanical properties of *** density,mechanical durability,moisture content,and particle size distribution of pellets were characterized for each *** of variance showed that there were significant differences between the percentages of small particles(<5.6 mm)in the samples taken at different locations,especially at one with a vertical free fall of 7.8 *** average,this relatively long drop increased the proportion of particles<5.6 mm in the samples from 8.73%to 14.09%,and that of particles<3.15 mm from 4.82%to 9.01%.Moreover,the measurements showed a wide deviation in the mechanical durability values,between a minimum of 90.8%and a maximum of 98.7%,which were not correlated to the sampling points but related to pellet *** can be concluded that pellet transportation systems require more dedicated design strategies to prevent breakage and attrition.

关键词： Wood pellets Large-scale transportation Durability Fines and dust Breakage Mechanical degradation

Insights into the radial water jet drilling technology-Application in a quarry

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2018年第2期10卷 236-248页

作者： Thomas Reinsch Bob Paap simon Hahn Volker Wittig Sidney van den Berg GFZ German Research Centre for Geosciences Telegrafenberg14473 PotsdamGermany TNO Sustainable Geo EnergyUtrechtThe Netherlands International Geothermal Centre-GZB Lennershofstr.14044801 BochumGermany Well Services Group Phileas Foggstraat 65NL-7825 AL EmmenThe Netherlands

In this context, we applied the radial water jet drilling(RJD) technology to drill five horizontal holes into a quarry wall of the Gildehaus quarry close to Bad Bntheim, Germany. For testing the state-of-the-art jetting technology, a jetting experiment was performed to investigate the influence of geological heterogeneity on the jetting performance and the hole geometry, the influence of nozzle geometry and jetting pressure on the rate of penetration, and the possibility of localising the jetting nozzle utilizing acoustic activity. It is observed that the jetted holes can intersect fractures under varying angles, and the jetted holes do not follow a straight path when jetting at ambient surface condition. Cuttings from the jetting process retrieved from the holes can be used to estimate the reservoir rock permeability. Within the quarry, we did not observe a change in the rate of penetration due to jetting pressure *** monitoring was partially successful in estimating the nozzle location. Although the experiments were performed at ambient surface conditions, the results can give recommendations for a downhole application in deep wells.

关键词： Acoustic monitoring Drilling performance Trajectory Permeability Rock properties Radial water jet drilling(RJD)

No association between brain size and male sexual behavior in the guppy

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Current Zoology 2015年第2期61卷 265-273页

作者： Alberto CORRAL-LOPEZ simon ECKERSTROM-LIEDHOLM Wouter van DER BIJL Alexander KOTRSCHAL Niclas KOLM Department of Zoology/Ethology Stockholm University Svante Arrhenius v~ig 18B. SE-10691 Stockholm Sweden

Animal behavior is remarkably variable at all taxonomic levels. Over the last decades, research on animal behavior has focused on understanding ultimate processes. Yet, it has progressively become more evident that to fully understand beha- vioral variation, ultimate explanations need to be complemented with proximate ones. In particular, the mechanisms generating variation in sexual behavior remain an open question. Variation in aspects of brain morphology has been suggested as a plausible mechanism underlying this variation. However, our knowledge of this potential association is based almost exclusively on com- parative analyses. Experimental studies are needed to establish causality and bridge the gap between micro- and macroevolutio- nary mechanisms concerning the link between brain and sexual behavior. We used male guppies that had been artificially selected for large or small relative brain size to study this association. We paired males with females and scored the full known set of male and female sexual behaviors described in guppies. We found several previously demonstrated associations between male traits, male behavior and female behavior. Females responded more strongly towards males that courted more and males with more orange coloration. Also, larger males and males with less conspicuous coloration attempted more coerced copulations. However, courting, frequency of coerced copulation attempts, total intensity of sexual behavior, and female response did not differ between large- and small-brained males. Our data suggest that relative brain size is an unlikely mechanism underlying variation in sexual behavior of the male guppy. We discuss these findings in the context of the conditions under which relative brain size might affect male sexual behavior .

关键词： Brain size Brain morphology Sexual behavior Guppy Artificial selection Behavioral mechanisms

Fabrication of on-chip probes for double-tip scanning tunneling microscopy

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Microsystems & Nanoengineering 2020年第1期6卷 212-220页

作者： Maarten Leeuwenhoek Freek Groenewoud Kees van Oosten Tjerk Benschop Milan P.Allan simon Groblacher Kavli Institute of Nanoscience Department of Quantum NanoscienceDelft University of TechnologyLorentzweg 12628CJ DelftThe Netherlands Leiden Institute of Physics Leiden UniversityNiels Bohrweg 22333CA LeidenThe Netherlands

A reduction of the interprobe distance in multiprobe and double-tip scanning tunneling microscopy to the nanometer scale has been a longstanding and technically difficult *** multiprobe systems have allowed for significant progress by achieving distances of~30 nm using two individually driven,traditional metal wire *** situations where simple alignment and fixed separation can be advantageous,we present the fabrication of on-chip double-tip devices that incorporate two mechanically fixed gold tips with a tip separation of only *** utilize the excellent mechanical,insulating and dielectric properties of high-quality SiN as a base material to realize easy-to-implement,lithographically defined and mechanically stable *** their large contact pads and adjustable footprint,these novel tips can be easily integrated with most existing commercial combined STM/AFM systems.

关键词： tunneling double separation