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Layer-like FAU-type zeolites:A comparative view on different preparation routes

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Frontiers of Chemical Science and Engineering 2020年第2期14卷 127-142页

作者： Bastian Reiprich Tobias Weissenberger Wilhelm Schwieger alexandra Inayat Institute of Chemical Reaction Engineering Friedrich-Alexander University Erlangen-NumbergErlangen 91058Germany

The creation of intergrown layer-like zeolite crystals is one route to form hierarchical ***-type(FAU-type)zeolites are among the industrially most important zeolites and the implementation of hierarchical porosity is a promising way to optimise their catalytic and adsorptive *** a short general survey into routes for the preparation of hierarchical pore systems in FAU,we will review the currently existing strategies for the synthesis of FAU with layer-like *** strategies are mainly based on the presence of morphology modifying agents in the synthesis ***,a very recent approach is the synthesis of layer-like FAU-type zeolite crystals assembled in an intergrown manner in the absence of such additives,just by finely adjusting the crystallization *** additive-free preparation route for layer-like FAU,which appears very attractive from an ecological as well as economic point of view,is highlighted in this ***,a comparison,including powder X-ray diffraction,scanning and transmission electron microscopy,nitrogen physisorption and elemental analysis,between conventional FAU and three layer-like FAU obtained by different synthesis routes was carried out to show the structural,morphological and textural differences and similarities of these materials.

关键词： FAU hierarchical zeolite layer-like morphology

Optimisation of zeolite LTA synthesis from alum sludge and the influence of the sludge source

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Journal of Environmental Sciences 2021年第1期33卷 130-142页

作者： alexandra Rozhkovskaya Jay Rajapakse Graeme J.Millar School of Civil and Enuironmental Engineering Science and Engineering FacultyQueensland University oTechnologyBrisbaneQueensland 4000Australia Institute for Future Environments and School of Mechanical Medical and Process EngineeringQueensland Uniuersity of TechnologyBrisbaneQueensland 4000Australia

Generation of alum sludge(AS)at drinking water treatment plants represents an environmental liability and adds to the cost of water ***,this study explored the feasibility of using low and high carbon containing alum sludge from two water treatment plants to synthesize zeolite *** hypothesis was that zeolite LTA synthesis was dependant upon alum sludge source and that a range of strategies may be required to optimize zeolite *** characteristics such as morphology,phase composition,crystallinity,and particle size distribution were recorded."One pot"hydrothermal synthesis of precursor gel with molar composition 4.2 Na2O:Al2O3:1.2 SiO_(2):168 H2O at 80℃ for 3 hr resulted in 25 and 46 wt.%zeolite LTA from high and low carbonaceous sludge,*** to hydrothermal reaction stage it was discovered that ageing of the gel,addition of zeolite LTA seeds,ultrasonic treatment and calcination all promoted zeolite LTA *** of the alum sludge at 700℃ for 2 hr before hydrothermal synthesis resulted in particle size reduction and the highest amount of crystalline zeolite LTA:79 wt.%from low carbon sludge and 65 wt.%from high carbon ***,the zeolite crystallinity reported in this study was the higher than previous studies on this *** outlined approach may allow value adding of alum waste and produce a commodity which could be used locally by the water treatment plant as a water softener.

关键词： Alum sludge Zeolite LTA Ultrasonic Ageing Waste conversion

Laparoscopic ultrasonography as an alternative to intraoperative cholangiography during laparoscopic cholecystectomy

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World Journal of Gastroenterology 2017年第29期23卷 5438-5450页

作者： alexandra Dili Claude Bertrand Unit of Digestive Endocrine and General Surgery Department of Surgery University Hospital - Godinne Université catholique de Louvain

To assess the role of laparoscopic ultrasound (LUS) as a substitute for intraoperative cholangiography (IOC) during cholecystectomy. METHODSWe present a MEDLINE and PubMed literature search, having used the key-words “laparoscopic intraoperative ultrasound” and “laparoscopic cholecystectomy”. All relevant English language publications from 2000 to 2016 were identified, with data extracted for the role of LUS in the anatomical delineation of the biliary tract, detection of common bile duct stones (CBDS), prevention or early detection of biliary duct injury (BDI), and incidental findings during laparoscopic cholecystectomy. Data for the role of LUS vs IOC in complex situations (i.e., inflammatory disease/fibrosis) were specifically analyzed. RESULTSWe report data from eighteen reports, 13 prospective non-randomized trials, 5 retrospective trials, and two meta-analyses assessing diagnostic accuracy, with one analysis also assessing costs, duration of the examination, and anatomical mapping. Overall, LUS was shown to provide highly sensitive mapping of the extra-pancreatic biliary anatomy in 92%-100% of patients, with more difficulty encountered in delineation of the intra-pancreatic segment of the biliary tract (73.8%-98%). Identification of vascular and biliary variations has been documented in two studies. Although inflammatory disease hampered accuracy, LUS was still advantageous vs IOC in patients with obscured anatomy. LUS can be performed before any dissection and repeated at will to guide the surgeon especially when hilar mapping is difficult due to fibrosis and inflammation. In two studies LUS prevented conversion in 91% of patients with difficult scenarios. Considering CBDS detection, LUS sensitivity and specificity were 76%-100% and 96.2%-100%, respectively. LUS allowed the diagnosis/treatment of incidental findings of adjacent organs. No valuable data for BDI prevention or detection could be retrieved, even if no BDI was documented in the reports analyzed. L

关键词： Intraoperative ultrasound Laparoscopic cholecystectomy Bile duct injury Choledocolithiasis Biliary anomalies

Calculating densities and viscosities of natural gas with a high content of C_(2+) to predict two-phase liquid-gas flow pattern

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Petroleum 2023年第4期9卷 579-591页

作者： Yekaterina Moisseyeva alexandra Saitova Sergey Strokin Peter the Great St.Petersburg Polytechnic University Russian Federation

The paper is devoted to the two-phase flow *** gas-condensate mixture flow in a horizontal pipe under high pressure is *** influence of the equation of state(EOS)choice for mixture properties modelling on the flow regime calculation results is studied for gas with high content of methane *** analytical overview of the methods to predict the flow pattern is *** on this analysis,two techniques are *** these techniques,values of density and viscosity for each phase are *** calculation for the gas phase is performed with Van der Waals based *** propriate EOS is selected based on studies of calculation errors for test *** of liquid phase density is done by means of Patela-Teja and Guo-Du equations,two different models are considered for viscosity *** flow patterns of gas-condensate mixture in a range of temperatures and pressures are calculated and verified via probability *** results of study allow to recommend the Brusilovsky EOS for calculation of densities for similar gas mixtures and make more rigorous flow regime *** probability map shows that for the chosen composition and parameters of media the flow pattern is mostly transitional between segregated and annular independent from EOS.

关键词： Two-phase flow Flow pattern Natural gas Wet gas High content of C_(2+) High pressure

Parallel patterns and trends in functional structures in extinct island mammals

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Integrative Zoology 2014年第2期9卷 167-182页

作者： alexandra A.E.VAN DER GEER Naturalis Netherlands Biodiversity Center LeidenNetherlands

Endemic mammalian species on islands are generally known to have followed a different evolutionary pathway than their mainland relatives. General patterns, such as body size trends, have been described regularly. How-ever, most island mammal species are unique and each of them is adapted to a specific local niche as part of an equally specific ecological assemblage. Therefore, comparing island species across taxa, islands and time is in-herently dangerous without understanding the adaptational value of the studied feature in the compared taxa and without taking the ecological setting of the taxa into account. In this contribution, general and recurring patterns are described per taxon. Some features, like body mass change and sturdy limbs, are relatively general, where-as most features, like bone fusions and change of orbital axis, occur only in a very few taxa. Some features are even contradictory, such as brain size and degree of hypsodonty, with each taxon having its own particular de-sign. In conclusion, general patterns are more often than not just trends and need to be applied with caution.

关键词： body proportions fossil record island rule paleo-insular mammals Pleistocene

Adjusted macroeconomic indicators to account for ecosystem degradation:an illustrative example

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Ecosystem Health and Sustainability 2019年第1期5卷 133-143,I0003页

作者： Alessandra La Notte alexandra Marques European Commission Joint Research Centre(JRC)IspraItaly

Adjusting macroeconomic indicators to account for the depletion and degradation of natural capital has long been viewed as a way to show the linkages between nature and the economy and foster more sustainable paths of ***,we show how the System of Environmental Economic Accounting(SEEA)Experimental Ecosystem Accounting(EEA)can be used to develop environmentally adjusted macroeconomic *** specifically,we show how an enlargement of the production boundary to include the consideration of ecosystems as institutional units allows the development of a net value added metric that reflects depreciation and degradation of the natural capital *** measurement could be useful for policymaking:the linkage of ecosystem services to economic activities allows us to account for loss,repair and substitution of natural capital,and thus helps us to formulate and monitor environmental policies.

关键词： Ecosystem services natural capital ecosystem accounting sustainability degradation

Post-dispersal seed predation of three grassland species in a plant diversity experiment

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Journal of Plant Ecology 2013年第6期6卷 468-479页

作者： Gesine Pufal alexandra-Maria Klein Institute of Ecology Leuphana UniversityScharnhorststr.121335 LüneburgGermany

Aims Post-dispersal seed predation is an important ecosystem process because it can influence the seed’s fate after the initial dispersal from the mother plant and subsequently transform *** at small scales,post-dispersal seed predation can vary greatly depending on seed identity,granivorous taxa or microhabitat ***,little is known about the role of plant species richness and functional group richness in post-dispersal seed *** overall aim of this study was to test whether increasing plant species richness or plant functional group richness affects the rate and variability of post-dispersal seed *** additionally investigated the influence of vegetation structure and seed species identity on the rate and variability of post-dispersal seed predation and whether the influence of different granivorous taxa changed with increasing plant species *** We conducted seed removal experiments along a long-term experimental plant diversity gradient,comprising plots with monocultures to 60 species mixtures of common grassland species in Jena,Germany,in August *** studied seeds of Onobrychis viciifolia,Pastinaca sativa and Trifolium pratense in exclusion experiments(seed cafeterias),an experimental setup that allowed access either for arthropods or slugs or for all granivorous ***,seeds removed from seed cafeterias were classified as consumed but we used traceable fluorescent-coloured seeds to obtain more accurate predation rates by subtracting recovered seeds from overall removed *** effect of multiple vegetation variables on mean and variability of seed predation rates was analysed using generalized mixed-effect models and linear regressions,*** Findings Rates of recovered seeds were low but contributed to significant differences between seed predation rates and removal rates of seeds in some *** predation rates were not directly correlated with increasing plant spe

关键词： arthropods cafeteria-style experiments ecosystem functions granivorous taxa slugs

Engineering mesenchymal stromal/stem cell-derived extracellular vesicles with improved targeting and therapeutic efficiency for the treatment of central nervous system disorders

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Neural Regeneration Research 2020年第12期15卷 2235-2236页

作者： alexandra M.Iavorovschi Aijun Wang Surgical Bioengineering Laboratory Department of SurgerySchool of MedicineUniversity of California-DavisInstitute for Pediatric Regenerative MedicineShriners Hospitals for Children-Northern CaliforniaSacramentoCAUSA Department of Biomedical Engineering University of CaliforniaDavis School of EngineeringDavisCAUSA

Treatment for central nervous system(CNS)disorders is known to be limited by the low regenerative potential of neurons,and thus neurodegenerative insults became known as nearly irreversible *** recovery for acquired CNS disorders,such as spinal cord injury(SCI),traumatic brain injury,ischemic stroke,Alzheimer’s disease,Parkinson’s disease,multiple sclerosis(MS),and for congenital CNS abnormalities,such as spina bifida,is not spontaneous and effective treatments are limited to *** in the past decades has proven the regenerative potential of stem cells,especially that of mesenchymal stromal/stem cells(MSCs)from various origins,such as bone marrow,placenta,and adipose tissue.

关键词： disorders treatment Alzheimer

Where Did the Wood Go？ Rethinking the Problematic Role of Wood in Wood-Like Mimicry

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Frontiers of History in China 2015年第2期10卷 188-221页

作者： alexandra Harrer School of Architecture Tsinghua University Beijing 100084 China

This paper explores fangmugou （＂imitating the mode of building with wood＂）, a comprehensive and longstanding architectural leitmotif reflective of the socio-cultural environment of China. Whether carved in stone, molded in clay, or cast in metal fangmugou continuously serves to visually confn＇m and ratify the significance of wood as the primary building material in Chinese architectural history. By peeling offthe successive layers of distortion between model and replica, this paper uncovers the traces of wood embedded infangmugou, and deciphers the visual and symbolic language that evolved out of the physical properties of wood, even as the final product transcends materiality by adapting to new media.

关键词： fangmugou wood symbolic language of mimicry distortion,Chinese traditional architecture