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International Journal of Minerals,Metallurgy and Materials 2016年第2期23卷 127-136页

作者： Gustavo Urbano Isabel Lázaro Israel Rodríguez Juan Luis Reyes Roxana Larios roel cruz Instituto de Metalurgia Universidad Autonotrla de San Luis PotosiAvSierra Leona 550Lomas 2a SeccionSan Luis PotosiS.L.P.78210Mexico Industrial Minera Mexico S.A.de C.V. San Luis PotosiS.L.P.Mexico Centro Universitario de Ciencias Exactas e Ingenierias Universidad de GuadalajaraGuadalajaraJaliscoMexico

Comparative voltammetry and differential double-layer capacitance studies were performed to evaluate interfacial interactions between cnalcopyrite（CuFeS2） and n-isopropyl xanthate（X） in the presence of ammonium bisulfite/39wt%SO2 and caustic starch at different pH *** spectroscopy,Fourier transform infrared（FTIR） spectroscopy,contact angle measurements,and microflotation tests were used to establish the type and extent of xanthate adsorption as well as the species involved under different mineral surface conditions in this *** results demonstrate that the species that favor a greater hydrophobicity of chalcopyrite are primarily CuX and S^0,whereas oxides and hydroxides of Cu and Fe as well as an excess of starch decrease the hydrophobicity.A conditioning of the mineral surface with ammonium bisulfite/39wt%SO2 at pH 6 promotes the activation of surface and enhances the xanthate ***,this effect is diminished at pH ≥ 8,when an excess of starch is added during the preconditioning step.

关键词： sulfide minerals chalcopyrite xanthates flotation interfacial reactions electrochemistry spectroscopy

Is a catalyst always beneficial in plasma catalysis? Insights from the many physical and chemical interactions

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Journal of Energy Chemistry 2023年第10期85卷 501-533,I0013页

作者： Björn Loenders roel Michiels Annemie Bogaerts Research group PLASMANT Department of ChemistryUniversity of AntwerpUniversiteitsplein 1B-2610 Wilrijk-AntwerpBelgium

Plasma-catalytic dry reforming of CH_(4)(DRM) is promising to convert the greenhouse gasses CH_(4) and CO_(2) into value-added chemicals, thus simultaneously providing an alternative to fossil resources as feedstock for the chemical industry. However, while many experiments have been dedicated to plasma-catalytic DRM, there is no consensus yet in literature on the optimal choice of catalyst for targeted products,because the underlying mechanisms are far from understood. Indeed, plasma catalysis is very complex,as it encompasses various chemical and physical interactions between plasma and catalyst, which depend on many parameters. This complexity hampers the comparison of experimental results from different studies, which, in our opinion, is an important bottleneck in the further development of this promising research field. Hence, in this perspective paper, we describe the important physical and chemical effects that should be accounted for when designing plasma-catalytic experiments in general, high-lighting the need for standardized experimental setups, as well as careful documentation of packing properties and reaction conditions, to further advance this research field. On the other hand, many parameters also create many windows of opportunity for further optimizing plasma-catalytic ***, various experiments also reveal the lack of improvement in plasma catalysis compared to plasma-only, specifically for DRM, but the underlying mechanisms are unclear. Therefore, we present our newly developed coupled plasma-surface kinetics model for DRM, to provide more insight in the underlying reasons. Our model illustrates that transition metal catalysts can adversely affect plasmacatalytic DRM, if radicals dominate the plasma-catalyst interactions. Thus, we demonstrate that a good understanding of the plasma-catalyst interactions is crucial to avoiding conditions at which these interactions negatively affect the results, and we provide some recommendations for im

关键词： Plasma catalysis Dry reforming of methane Discharges Reaction kinetics Modelling

Do birds in flight respond to(ultra)violet lighting?

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Avian Research 2017年第4期8卷 192-201页

作者： roel May Jens Astrom Oyvind Hamre Espen Lie Dahl Terrestrial Ecology Department Norwegian Institute for Nature Research(NINA)TrondheimNorway Steinoysund SmolaNorway.

Background: Concerns for bird collisions with wind turbines affect the deployment of onshore and offshore windpower *** avoid delays in consenting processes and to streamline the construction and operation phase,functional mitigation measures are required which efficiently reduces bird *** is the primary sensory system in birds,which for a number of species also includes the ultraviolet *** bird species that are known to collide with offshore wind turbines are sensitive in the violet or ultraviolet *** species that are mainly active at lower ambient light levels,lighting may deter birds from the lit ***(ultra)violet lights may in addition not disturb ***,we do not know whether UV-sensitive birds in flight actually respond behaviourally to UV ***: We therefore tested the efficacy of two types of lights within the violet(400 nm) and ultraviolet(365 nm) spectrum to deter birds from the lit *** lights were placed vertically and monitored continuously between dusk and dawn using an avian radar ***: Relative to control nights,bird flight activity(abundance) was 27% lower when the ultraviolet light was *** light resulted in a 12% decrease in overall abundance,and in addition,a vertical displacement was seen,increasing the average flight altitude by 7 *** temporal changes occurred,this effect persisted over the season below 40 m above sea ***: Although the results from this pilot study are promising,we argue there still is a long way to go before a potentially functional design to mitigate collisions that has proven to be effective in situ may be in place.

关键词： Avian radar Displacement Habituation Mitigation Seabirds Ultraviolet Wind turbine

Sino-European Space Cooperation——A Comparative Analysis of Galileo and Double Star

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Sino-European Space Cooperation——A Comparative Analysis of...

作者： roel Gremmen 上海交通大学

学位级别：硕士

The solution of many international challenges,like climate change and ozone depletion,depends on effective international scientific and technological（S＆T）***,numerous international security concerns depend on *** China and the EU emphasise the development of space science and technology,and the process of institution-building has been paving the way for the further development of bilateral ***,history suggests that space technology often originates from military defence,and then spreads to the field of civilian ***,space S ＆ T has an important significance both on a security level as well as on a commercial *** S ＆ T is highly advanced technology,vital for national security and often top-secret,and it has been regarded as a competitive and closed *** is it possible for China and Europe to cooperate in a strategic field? Which vital factors drive the cooperative motivation of both actors? Are they looking for a balance of power,pursuing common interests,or operating on mutual trust? Why do some joint programmes advance smoothly,such as the Double Star programme,and do some programmes,such as the Galileo cooperation,fail? Two in-depth case studies are presented in this *** making a comparative analysis between the successful Double Star Project and the unsuccessful Galileo project to determine which factors contributed to the ultimate outcome of the programmes.I argue that the EU is motivated by its goal to move away from dependence on US technology,and the idea of utilizing space solely for maximisation of security,rather than treating it as a common good that can be *** on its turn is mainly looking to further develop and modernise its space technology and partnered with Europe to circumvent the restrictions of the ***,scientific institutions encourage cooperation for the sake of science ***,those institutions are currently the main way through wh

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Insights on Chemical and Natech Risk Management in Japan and South Korea:A Review of Current Practices

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International Journal of Disaster Risk Science 2022年第3期13卷 359-371页

作者： Hyejeong Park Ana Maria cruz Disaster Prevention Research Institute Kyoto UniversityKyoto611-0011Japan

A growing number of natural hazard-triggered technological accidents(Natech)has been reported by several researchers,and this trend is expected to continue due to climate *** a result,some governments have initiated direct efforts to manage Natech risks,particularly in the United States and ***,two surveys conducted by the Organisation for Economic Co-operation and Development(OECD)in 2009 and 2017 found that there was a lack of proper risk management and risk governance for Natech among OECD member states,including Japan and South *** study aimed to identify relevant regulations and practical considerations for chemical and Natech risk management from government perspectives in Japan and South *** article provides a review of the current state of risk management,emergency response,and risk communication on chemical and Natech risk management in the two countries,and concludes with a discussion of some of the issues that require improvement of the current chemical risk *** practices for chemical risk management in Japan and South Korea point to the possibility of improvements in dealing with the Natech *** practical lessons will be valuable for improving the capacity for dealing with challenges in chemical and Natech risk management.

关键词： Chemical accidents Government perspectives Japan Natech Risk governance Risk management South Korea

Equipartitioning is not sufficient for Green's function extraction

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Earthquake Science 2010年第5期23卷 403-415页

作者： roel Snieder Yuanzhong Fan Evert Slob Kees Wapenaar Center for Wave Phenomena Colorado School of Mines Golden CO 80401 USA Faculty of Civil Engineering and Geosciences Delft University of Technology 2600 GA Delft Netherlands

The extraction of the Earth＇s Green＇s function from field fluctuations is a rapidly growing area of research. The principle of Green＇s function extraction is often related to the requirement of equipartitioning, which stipulates that the energy of field fluctuations is distributed evenly in some sense. We show the meaning of equipartitioning for a variety of different formulations for Green＇s function retrieval. We show that equipartitioning is not a sufficient condition, and provide several examples that illustrate this point. We discuss the implications of lack of equipartitioning for various schemes for the reconstruction of the Green＇s function in seismology. The theory for Green＇s function extraction is usually based on a statistical theory that relies on ensemble averages. Since there is only one Earth, one usually replaces the ensemble average with a time average. We show that such a replacement only makes sense when attenuation is taken into account, and show how the theory for Green＇s function extraction for oscillating systems can be extended to incorporate attenuation.

关键词： seismic interferometry Green's function retrieval equipartitioning

Global stability for multi-species Lotka-Volterra cooperative systems： One hyper-connected mutualistic-species

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International Journal of Biomathematics 2015年第3期8卷 215-223页

作者： cruz Vargas-De-Leon Unidad de Medicina Experimental Hospital General de Mexico"Dr. Eduardo Liceaga" DF 06726 Mexico

We propose two models of one hyper-connected mutualistic-species described by delay differential equations of Lotka-Volterra type. An hyper-connected model comprises a central species interacting with a number of peripheral species around it, that is to say, one animal species （pollinators or dispersers） that interacts with several plant species （flowering plants or fruit trees）, or several animal species that interact with one plant species. We derive a necessary and sufficient condition for the global asymptotic stability of the unique coexisting steady state of hyper-connected systems by means of novel Lyapunov functionals.

关键词： Lotka Volterra cooperative system discrete delays distributed delays Lyapunov functional global stability.

Utilizing a novel fiber optic technology to capture the axial responses of fully grouted rock bolts

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Journal of Rock Mechanics and Geotechnical Engineering 2018年第2期10卷 222-235页

作者： Nicholas Vlachopoulos Daniel cruz Bradley Forbes Department of Civil Engineering Royal Military College of Canada Department of Geological Sciences and Geological Engineering Queen's UniversityKingston

Rock bolts are one of the primary support systems utilized in underground excavations within the civil and mining engineering industries. Rock bolts support the weakened rock mass adjacent to the opening of an excavation by fastening to the more stable, undisturbed formations further from the excavation. The overall response of such a support element has been determined under varying loading conditions in the laboratory and in situ experiments in the past four decades; however, due to the limitations with conventional monitoring methods of capturing strain, there still exists a gap in knowledge associated with an understanding of the geomechanical responses of rock bolts at the microscale. In this paper, we try to address this current gap in scientific knowledge by utilizing a newly developed distributed optical strain sensing(DOS) technology that provides an exceptional spatial resolution of 0.65 mm to capture the strain along the rock bolt. This DOS technology utilizes Rayleigh optical frequency domain reflectometry(ROFDR) which provides unprecedented insight into various mechanisms associated with axially loaded rebar specimens of different embedment lengths, grouting materials, borehole annulus conditions, and borehole diameters. The embedment length of the specimens was found to be the factor that significantly affected the loading of the rebar. The critical embedment length for the fully grouted rock bolts(FGRBs) was systematically determined to be430 mm. The results herein highlight the effects of the variation of these individual parameters on the geomechanical responses FGRBs.

关键词： Fiber optic technology Fully grouted rock bolts Load transfer Stress distribution

Extracting Natech Reports from Large Databases: Development of a Semi-Intelligent Natech Identification Framework

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International Journal of Disaster Risk Science 2020年第6期11卷 735-750页

作者： Xiaolong Luo Ana Maria cruz Dimitrios Tzioutzios Department of Urban Management Graduate School of EngineeringKyoto UniversityKyoto 615-8540Japan Disaster Prevention Research Institute Kyoto UniversityKyoto 611-0011Japan

Natural hazard-triggered technological accidents(Natechs)refer to accidents involving releases of hazardous materials(hazmat)triggered by natural *** economic losses,as well as human health and environmental problems are caused by *** this regard,learning from previous Natechs is critical for risk ***,due to data scarcity and high uncertainty concerning such hazards,it becomes a serious challenge for risk managers to detect Natechs from large databases,such as the National Response Center(NRC)*** the largest database of hazmat release incidents,the NRC database receives hazmat release reports from citizens in the United ***,callers often have incomplete details about the incidents they are *** results in many records having incomplete ***,it is quite difficult to identify and extract Natechs accurately and *** this study,we introduce machine learning theory into the Natech retrieving research,and a Semi-Intelligent Natech Identification Framework(SINIF)is proposed in order to solve the *** tested the suitability of two supervised machine learning algorithms,namely the Long ShortTerm Memory(LSTM)and the Convolutional Neural Network(CNN),and selected the former for the development of the *** to the results,the SINIF is efficient(a total number of 826,078 records were analyzed)and accurate(the accuracy is over 0.90),while 32,841 Natech reports between 1990 and 2017 were extracted from the NRC ***,the majority of those Natech reports(97.85%)were related to meteorological phenomena,with hurricanes(24.41%),heavy rains(19.27%),and storms(18.29%)as the main causes of these reported ***,this study suggests that risk managers can benefit immensely from SINIF in analyzing Natech data from large databases efficiently.

关键词： Data extraction method Machine learning Natechs Natural hazards NRC database

Transanal total mesorectal excision:a valid option for rectal cancer?

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World Journal of Gastroenterology 2015年第41期21卷 11700-11708页

作者： Nicolas C Buchs Gary A Nicholson Frederic Ris Neil J Mortensen roel Hompes Department of Colorectal Surgery Churchill Hospital Oxford University Hospitals Division of Visceral Surgery Department of Surgery University Hospitals of Geneva Nuffield Department of Surgical Science University of Oxford John Radcliffe Hospital

Low anterior resection can be a challenging operation, especially in obese male patients and in particular after radiotherapy. Transanal total mesorectal excision(Ta TME) might offer technical advantages over laparoscopic or open approaches particularly for tumors in the distal third of the rectum. The aim of this article is to review the current experience with Ta TME. The limits and future developments are also explored. Although the experience with Ta TME is still limited, it might be a promising alternative to laparoscopic TME, especially for difficult cases where laparoscopy is too demanding. The preliminary data on complications and short-term oncological outcomes are good, but also emphasize the importance of careful patient selection. Finally, there is a need for large-scale trials focusing on long-term outcomes and oncological safety before widespread adoption can be recommended.

关键词： Transanal Bottom up Transanal minimally invasive s