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Twenty years of population dynamics in European beech-oak forest at their rear range margin anticipate changes in its structure and composition

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Forest Ecosystems 2024年第3期11卷 358-370页

作者： álvaro Rubio-Cuadrado Iciar Alberdi Isabel Canellas Fernando Montes Jesús Rodríguez-Calcerrada Rosana López Guillermo G.Gordaliza María Valbuena-Carabana Nikos Nanos Ramón Perea Luis Gil Departamento de dinamica y gestion forestal Instituto de Ciencias Forestales(ICIFOR-INIA)CSICCtra.La Coruna km 7.528040MadridSpain Departamento de Sistemas y Recursos Naturales Escuela Tecnica Superior de Ingeniería de MontesForestal y del Medio NaturalUniversidad Politecnica de Madrid.Ciudad Universitaria s/n28040MadridSpain School of Forestry and Natural Environment Aristotle University of ThessalonikiUniversity Campus54124ThessalonikiGreece

There is an increasing interest in restoring degraded forests,which occupy half of the forest areas.Among the forms of restoration,passive restoration,which involves the elimination of degrading factors and the free evolution of natural dynamics by applying minimal or no management,is gaining attention.Natural dynamics is difficult to predict due to the influence of multiple interacting factors such as climatic and edaphic conditions,composition and abundance of species,and the successional character of these species.Here,we study the natural dynamics of a mixed forest located in central Spain,which maintained an open forest structure,due to intensive use,until grazing and cutting were banned in the 1960s.The most frequent woody species in this forest are Fagus sylvatica,Quercus petraea,Quercus pyrenaica,Ilex aquifolium,Sorbus aucuparia,Sorbus aria and Prunus avium,with contrasting shade and drought tolerance.These species are common in temperate European deciduous forest and are found here near their southern distribution limit,except for Q.pyrenaica.In order to analyze forest dynamics and composition,three inventories were carried out in 1994,2005 and 2015.Our results show that,despite the Mediterranean influence,the natural dynamics of this forest has been mainly determined by different levels of shade tolerance.After the abandonment of grazing and cutting,Q.pyrenaica expanded rapidly due to its lower shade tolerance,whereas after canopy closure and forest densification,shade-tolerant species gained ground,particularly F.sylvatica,despite its lower drought and late-frost tolerance.If the current dynamics continue,F.sylvatica will overtake the rest of the species,which will be relegated to sites with shallow soils and steep slopes.Simultaneously,all the multi-centennial beech trees,which are undergoing a rapid mortality and decline process,will disappear.

关键词： Forest succession Secondary forest Woodland Mixed forest Competition Recruitment

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Assessment of compressive strength of jet grouting by machine learning

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第1期16卷 102-111页

作者： Esteban Diaz Edgar Leonardo Salamanca-Medina Roberto Tomas Departamento de ingeniería Civil Escuela Politécnica SuperiorUniversidad de AlicanteP.O.Box 99E-03080AlicanteSpain

Jet grouting is one of the most popular soil improvement techniques,but its design usually involves great uncertainties that can lead to economic cost overruns in construction projects.The high dispersion in the properties of the improved material leads to designers assuming a conservative,arbitrary and unjustified strength,which is even sometimes subjected to the results of the test fields.The present paper presents an approach for prediction of the uniaxial compressive strength(UCS)of jet grouting columns based on the analysis of several machine learning algorithms on a database of 854 results mainly collected from different research papers.The selected machine learning model(extremely randomized trees)relates the soil type and various parameters of the technique to the value of the compressive strength.Despite the complex mechanism that surrounds the jet grouting process,evidenced by the high dispersion and low correlation of the variables studied,the trained model allows to optimally predict the values of compressive strength with a significant improvement with respect to the existing works.Consequently,this work proposes for the first time a reliable and easily applicable approach for estimation of the compressive strength of jet grouting columns.

关键词： Jet grouting Ground improvement Compressive strength Machine learning

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Recent progress in carbonaceous materials based Z-scheme and Sscheme heterojunctions for photocatalytic clean energy generation

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新型炭材料(中英文) 2024年

作者： Sahil Rana Amit Kumar Wang Tong-tong Gaurav Sharma Pooja Dhiman Alberto García-Penas Interdisciplinary and Innovate Research Xi'an University of Architecture and Technology Departamento de Ciencia e ingeniería de Materiales e ingeniería Química (IAAB) Universidad Carlos III de Madrid International Research Centre of Nanotechnology for Himalayan Sustainability (IRCNHS) Shoolini University

Carbonaceous materials including carbon nanotubes/nanofibers, graphene, graphene oxide, reduced graphene oxide,graphyne, graphdiyne, carbon quantum dots and fullerenes have gained considerable attention in the recent years for their unique properties such as high conductivity, excellent stability and biocompatibility. The integration of these carbonaceous materials into Zscheme and S-scheme heterojunctions has emerged as a transformative strategy to enhance the photocatalytic efficiency for energy conversion applications. This review delves into the fundamental principles of clean energy generation such as photocatalytic H2generation and CO2reduction, elucidating their respective mechanisms and advantages. Furthermore, various types of carbonaceous materials, their synthesis and construction of Z-scheme and S-scheme heterojunctions are discussed emphasizing their role in promoting charge separation, reducing recombination losses and extending the spectral response range. With the focus on solar fuel production,the recent advancements in carbonaceous based Z-scheme and S-scheme heterojunctions are discussed and summarized for photocatalytic H2generation and CO2reduction. Lastly, the current bottlenecks and challenges in the field of carbonaceous based photocatalysts are discussed with the valuable insights for future development in this particular field.

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Tribologically induced nanostructural evolution of carbon materials: A new perspective

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Friction 2024年第1期12卷 144-163页

作者： Guilherme Oliveira NEVES Nicolás ARAYA Diego Berti SALVARO Thiago de Souza LAMIM Renan Oss GIACOMELLI Cristiano BINDER Aloisio Nelmo KLEIN JoséDaniel Biasoli de MELLO Laboratório de Materiais Universidade Federal de Santa CatarinaSanta Catarina 88040-900Brazil Departamento de ingeniería Mecánica Facultad de IngenieríaUniversidad del Bío-BíoConcepcion 4070-386Chile Universidad de Concepción Concepcion 4070-386Chile SENAI Innovation Institute for Laser Processing Santa Catarina 89218-153Brazil Universidade Federal de Uberlândia Minas Gerais 38408-100Brazil

Carbon-based solid lubricants are excellent options to reduce friction and wear,especially with the carbon capability to adopt different allotropes forms.On the macroscale,these materials are sheared on the contact along with debris and contaminants to form tribolayers that govern the tribosystem performance.Using a recently developed advanced Raman analysis on the tribolayers,it was possible to quantify the contactinduced defects in the crystalline structure of a wide range of allotropes of carbon-based solid lubricants,from graphite and carbide-derived carbon particles to multi-layer graphene and carbon nanotubes.In addition,these materials were tested under various dry sliding conditions,with different geometries,topographies,and solid-lubricant application strategies.Regardless of the initial tribosystem conditions and allotrope level of atomic ordering,there is a remarkable trend of increasing the point and line defects density until a specific saturation limit in the same order of magnitude for all the materials tested.

关键词： carbon nanostructures tribology Raman spectroscopy defects quantification tribolayer solid lubrication

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Optimal Design of Hybrid Microgrid in Isolated Communities of Ecuador

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Journal of Modern Power Systems and Clean Energy 2024年第2期12卷 488-499页

作者： Luis A.Pesantes Ruben Hidalgo-León Johnny Rengifo Miguel Torres Jorge Aragundi JoséCordova-Garcia Luis F.Ugarte Facultad de ingeniería en Electricidad y Computación of Escuela Superior Politécnica del Litoral(ESPOL)University GuayaquilEcuador Department of Electrical Engineering at Universidad Técnica Federico Santa María SantiagoChile IEEE

In rural territories, the communities use energy sources based on fossil fuels to supply themselves with electricity, which may address two main problems: greenhouse gas emissions and high fuel prices. Hence, there is an opportunity to include renewable resources in the energy mix. This paper develops an optimization model to determine the optimal sizing, the total annual investment cost in renewable generation, and other operating costs of the components of a hybrid microgrid. By running a k-means clustering algorithm on a meteorological dataset of the community under study, the hourly representative values become input parameters in the proposed optimization model. The method for the optimal design of hybrid microgrid is analyzed in six operating scenarios considering:(1) 24-hour continuous power supply;(2) load shedding percentage;(3) diesel power generator(genset) curtailment;(4) the worst meteorological conditions;(5) the use of renewable energy sources including battery energy storage systems(BESSs);and(6) the use of genset. A mathematical programming language(AMPL) tool is used to find solutions of the proposed optimization model. Results show that the total costs of microgrid in the scenarios that cover 100% of the load demand(without considering the scenario with 100% renewables) increase by over 16% compared with the scenario with genset operation limitation. For the designs with power supply restrictions, the total cost of microgrid in the scenario with load shedding is reduced by over 27% compared with that without load shedding.

关键词： Battery energy storage system(BESS) isolated community microgrid renewable energy optimization

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Experimental and Numerical Analysis of a PCM-Integrated Roof for Higher Thermal Performance of Buildings

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Journal of Thermal Science 2024年第2期33卷 522-536页

作者： SIMON François RUIZ-VALERO Letzai GIRARD Aymeric GALLEGUILLOS Hector Centro de Desarrollo Urbano Sustentable(CEDEUS) Pontificia Universidad Católica de Chile7500000SantiagoChile Facultad de Ciencias e ingeniería Pontificia Universidad Católica Madre y Maestra(PUCMM)10103Santo DomingoDominican Republic LMGC IMT Mines AlesUniv MontpellierCNRS30100AlèsFrance Facultad de ingeniería y Ciencias Universidad Adolfo Ibañez2520000Viña del MarChile Centro de Desarrollo Energético Antofagasta(CDEA) Universidad de Antofagasta1240000AntofagastaChile

Phase change materials(PCMs) designate materials able to store latent heat.PCMs change state from solid to liquid over a defined temperature range.This process is reversible and can be used for thermo-technical purposes.The present paper aims to study the thermal performance of an inorganic eutectic PCM integrated into the rooftop slab of a test room and analyze its potential for building thermal management.The experiment is conducted in two test rooms in Antofagasta(Chile) during summer,fall,and winter.The PCM is integrated into the rooftop of the first test room,while the roof panel of the second room is a sealed air cavity.The work introduces a numerical model,which is built using the finite difference method and used to simulate the rooms' thermal behavior.Several thermal simulations of the PCM room are performed for other Chilean locations to evaluate and compare the capability of the PCM panel to store latent heat thermal energy in different climates.Results show that the indoor temperature of the PCM room in Antofagasta varies only 21.1℃±10.6℃,while the one of the air-panel room varies 28.3℃±18.5℃.Under the experiment's conditions,the PCM room's indoor temperature observes smoother diurnal fluctuations,with lower maximum and higher minimum indoor temperatures than that of the air-panel room.Thermal simulations in other cities show that the PCM panel has a better thermal performance during winter,as it helps to maintain or increase the room temperature by some degrees to reach comfort temperatures.This demonstrates that the implementation of such PCM in the building envelope can effectively reduce space heating and cooling needs,and improve indoor thermal comfort in different climates of Chile.

关键词： phase change material thermal energy storage building space heating and cooling energy efficiency designbuilder

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Output feedback adaptive super twisting sliding mode control for quadrotor UAVs

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Control Theory and Technology 2024年第1期22卷 92-105页

作者： Oscar Salas-Peña Jesus DeLeón-Morales Susana V.Gutiérrez-Martínez École Centrale de Nantes-LS2N UMR 6004 CNRS44300NantesFrance Facultad de ingeniería Mecánica y Eléctrica Universidad Autónoma de Nuevo León66451San Nicolás de Los GarzaMexico

In this paper, a sliding mode control with adaptive gain combined with a high-order sliding mode observer to solve the tracking problem for a quadrotor UAV is addressed, in presence of bounded external disturbances and parametric uncertainties. The high order sliding mode observer is designed for estimating the linear and angular speed in order to implement the proposed scheme. Furthermore, a Lyapunov function is introduced to design the controller with the adaptation law, whereas an analysis of finite time convergence towards to zero is provided, where sufficient conditions are obtained. Regarding previous works from literature, one important advantage of proposed strategy is that the gains of control are parameterized in terms of only one adaptive parameter, which reduces the control effort by avoiding gain overestimation. Numerical simulations for tracking control of the quadrotor are given to show the performance of proposed adaptive control–observer scheme.

关键词： Adaptive super twisting controller High-order sliding modes observer UAV

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碳基材料的Z型和S型异质结光催化清洁能源综述

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新型炭材料（中英文） 2024年第3期39卷 458-482页

作者： Sahil Rana Amit Kumar WANG Tong-tong Gaurav Sharma Pooja Dhiman Alberto García-Penas International Research Centre of Nanotechnology for Himalayan Sustainability(IRCNHS) Shoolini UniversitySolan173229India 西安建筑科技大学交叉创新研究院西安710055 Departamento de Ciencia e ingeniería de Materiales e ingeniería Química(IAAB) Universidad Carlos Ⅲ de MadridLegan'es28911Spain

碳纳米管/纳米纤维、石墨烯、氧化石墨烯、还原氧化石墨烯、石墨炔、碳量子点和富勒烯等炭材料因具有高导电性、优异的稳定性和生物相容性等独特性能,近年来受到广泛关注。在炭材料中构建Z型和S型异质结已成为在能量转换应用中提高光催... 详细信息

碳纳米管/纳米纤维、石墨烯、氧化石墨烯、还原氧化石墨烯、石墨炔、碳量子点和富勒烯等炭材料因具有高导电性、优异的稳定性和生物相容性等独特性能,近年来受到广泛关注。在炭材料中构建Z型和S型异质结已成为在能量转换应用中提高光催化效率的一种有效策略。本文综述了光催化制氢和CO_(2)还原等清洁能源的基本原理,阐述了它们各自的机理和优势。此外,还讨论了不同类型的炭材料以及其中Z型和S型异质结的合成和构建,强调了它们在促进电荷分离、减少光生载流子复合损失和扩大光谱响应范围方面的作用。以太阳能燃料生产为重点,讨论和总结了碳基Z型和S型异质结在光催化制氢和还原CO_(2)方面的最新进展。最后,讨论了目前碳基光催化剂领域的瓶颈和挑战,并对该领域的未来发展提出了有价值的见解。

关键词：炭材料异质结 Z型 S型光催化氢能材料

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Developments and characteristics of craft beer production processes

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Food Bioscience 2022年第1期45卷 232-248页

作者： Salvador Villacreces Carlos A.Blanco Isabel Caballero Dpto de ingeniería Agrícola forestal ETS de Ingenierías AgrariasUniversidad de Valladolid34004Palencia.Spain

Beer is a popular drink and represents the most widely consumed alcoholic beverage in the world.In recent years,there has been a significant growth of independent craft breweries,even in countries without a brewing tradition.A craft brewery is usually defined as a small,independent and traditional brewery.Nowadays,consumers are looking for genuine,singular,different and high-quality products.Craft beer manufacturers have responded to this with the introduction of a novel combination of raw or malted cereals and have modified the beer flavours and taste with the addition of fruit,spices,etc.This work presents an analysis of the different aspects related to craft beer.Its characteristics and brewing singularities are analyzed.The quality and safety standards used are examined and future trends of craft beer are also discussed.

关键词： Craft beer Ingredients Craft beer quality By-products Microbiological safety

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Porphyrins,phthalocyanines,and related covalent-organic frameworks in the photochemical and electrochemical water splitting:A review

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Particuology 2024年第7期90卷 236-265页

作者： Oxana V.Kharissova Yolanda Peña Méndez Boris I.Kharisov Aleksandr LNikolaev Edith Luévano-Hipólito Lucy T.González Universidad Autónoma de Nuevo León Ave.Universidad s/nSan Nicolás de los GarzaNuevo León66455Mexico Department of Chemistry Moscow State UniversityVorobievy HillsMoscowRussia CONACYT-Universidad Autónoma de Nuevo León Facultad de Ingeniería Civil-Departamento de Ecomateriales y EnergíaCd.UniversitariaC.P.66455San Nicolás de los GarzaNLMexico Tecnologico de Monterrey Escuela de IngenieríaCienciasMonterreyNuevo León 64890Mexico Tecnologico de Monterrey Centro del AguaMonterreyNuevo León 64890Mexico

In this review,the possibilities of photochemical and electrochemical water splitting(WS)using porphyrins,phthalocyanines,related macrocycles,and their metal complexes are discussed.Significant efforts are being carried out in order to develop novel and cheap methods for water decomposition to generate inexhaustible greener energy sources(molecular hydrogen)instead of oil and gas.The processes of WS in heterogeneous and homogeneous media require novel photo-and electrocatalysts,in particular those on macrocycle basis.A high WS efficiency has been observed for porphyrins and phthalocyanines,showing their suitability both for HER and OER processes are available using these relative compounds for WS purposes.Porphyrins can be used in photocatalytic and electrocatalytic WS processes both in their free forms or as metal porphyrins/porphyrinates,mainly loaded on various inorganic materials,such as Au NPs,C_(3)N_(4),GaP,KTaO_(3),GaP,and so on,as part of porphyrin-containing polymers or on electrode surface as modifying coatings,being sometimes better than commercial catalysts,such as Pt/C.Photocatalytic H2 evolution can be considerably depended on the shape of porphyrin particles;in particular,porphyrin nanowires can yield up to 20 times more H2 than its powder.In certain cases,both HER and OER can be driven in the same electrolyte using metal porphyrins.The capacity of metal porphyrins to generate ROS(in particular,singlet oxygen 1O_(2))under ultrasonic treatment is known and can be successfully used for H_(2)O_(2) and O_(2) generation.Phthalocyanines can be used in similar processes in free form or as composites with inorganic or organic counterparts,being immobilized on nanocarbons,metal oxides and salts,or simply dissolved in water acting in a homogeneous medium.An additional use of ultrasound can lead to better results due to the synergistic effect of the sonochemical treatment and light.Covalent-organic frameworks are also applied for WS purposes and are mainly based on a variety of N-containing ligands,such as tr

关键词： Porphyrins Phthalocyanines COFs Water splitting Photocatalysis Electrocatalysis

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