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Friction 2024年第3期12卷 522-538页

作者： Marta OSTOLAZA Alaitz ZABALA jon inaki arrizubieta Iñigo LLAVORI Nagore OTEGI Aitzol LAMIKIZ Department of Mechanical Engineering University of the Basque Country UPV/EHUPlaza Torres Quevedo 1Bilbo 48013Spain Faculty of Engineering Mechanics and Industrial ProductionMondragon UnibertsitateaLoramendi 4Mondragon 20500Spain

Wear-driven tool failure is one of the main hurdles in the industry.This issue can be addressed through surface coating with ceramic-reinforced metal matrix composites.However,the maximum ceramic content is limited by cracking.In this work,the tribological behaviour of the functionally graded WC-ceramic-particlereinforced Stellite 6 coatings is studied.To that end,the wear resistance at room temperature and 400°C is investigated.Moreover,the tribological analysis is supported by crack sensitivity and hardness evaluation,which is of utmost importance in the processing of composite materials with ceramic-particle-reinforcement.Results indicate that functionally graded materials can be employed to increase the maximum admissible WC content,hence improving the tribological behaviour,most notably at high temperatures.Additionally,a shift from abrasive to oxidative wear is observed in high-temperature wear testing.

关键词： friction coating metal matrix composite functionally graded materials high temperature laserdirected energy deposition

Implications for brainstem recovery from studies in primates after sensory loss from arm

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Neural Regeneration Research 2024年第3期19卷 479-480页

作者： Jamie L.Reed Hui-Xin Qi jon H.Kaas Department of Psychology Vanderbilt UniversityNashvilleTNUSA

For decades,researchers have known that when neurons lose their activating inputs,they can atrophy and even die.For example,removing sensory nerve inputs from the arm to the spinal cord after amputation or cutting the spinal nerves can shrink the post-synaptic target zones(e.g.,Woods et al.,2000).From touch receptors for the hand and arm,primary nerve afferents enter the spinal cord,and axons travel in the dorsal columns to target the cuneate nucleus(Cu)of the brainstem on the same side of the body(Figure 1).When sensory loss is unilateral,the overwhelming result is for the associated primary target zone to shrink in total size(cross-sectional area),as compared to the size of the opposite side.

关键词： brainstem shrink removing

Technical efficiency of cocoa farms at varying elevation levels in Davao City, Philippines: implications to sustainable upland farming systems

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Journal of Mountain Science 2024年第1期21卷 33-48页

作者： Francis Levi A.DURANO jon Marx SARMIENTO Larry N.DIGAL Pedro A.ALVIOLA IV School of Management University of the Philippines MindanaoDavao City 8000Philippines

Elevation is one of many components that influence agriculture, and this in turn affects the level of both inputs and outputs of farmers. This article focuses on the productivity and technical efficiency of 100 cocoa farms using cross-sectional data from areas ranging from 190 to 1021 m above sea level which were classified as low, medium, and high elevation in Davao City, considered as the chocolate capital of the Philippines. Using stochastic frontier analysis, the results showed that the cost of inputs per ha and the number of cocoa trees per ha significantly increase yield. Farms at high elevations were less technically efficient, as this entails lower temperatures and increased rainfall, and cocoa farming in those areas and conditions can be more challenging, especially with changes in farming practices, terrain, and distance to markets. Other significant variables were age of cocoa farms, married farmers, and age of the farmers. Older farms may be more developed, farmers who are married benefit from their spouses being able to readily contribute as farm labor, and lastly, older farmers' inefficiency may likely stem from nonadaptation of newer farming practices. With an average technical efficiency of 0.61, 0.63, and 0.26 in low, medium, and high elevation areas, respectively, farmers therefore have an incentive to improve farm practices and consider topographical variations found in high elevation areas. Recommendations for the improvement of technical efficiency of cocoa farms are better connectivity to markets, enhancing farm practices, and continuation and improvement of government programs on cocoa with an added emphasis on research. For farmers in high elevation areas, mitigating solutions such as sustainable agriculture practices and ecolabelling are key to improving efficiency and minimizing the potential negative impact on upland farming systems. Moreover, such adaptation measures may also contribute to sustainability of cocoa farming in high elevation areas.

关键词： Cocoa farms Cobb-Douglas production function Elevation Philippines Stochastic frontier analysis Technical efficiency

Enhancement of the CO_(2)adsorption and hydrogenation to CH_(4)capacity of Ru–Na–Ca/γ–Al_(2)O_(3)dual function material by controlling the Ru calcination atmosphere

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Journal of Environmental Sciences 2024年第6期140卷 292-305页

作者： Alejandro Bermejo-López Beñat Pereda-Ayo jon A.Onrubia-Calvo JoséA.González-Marcos Juan R.González-Velasco Department of Chemical Engineering Faculty of Science and TechnologyUniversidad del País Vasco UPV/EHUBarrio Sarrienas/n48940 LeioaBizkaiaSpain

Integrated CO_(2)capture and utilization(ICCU)technology requires dual functional materials(DFMs)to carry out the process in a single reaction system.The influence of the calcination atmosphere on efficiency of 4%Ru-8%Na_(2)CO_(3)-8%CaO/γ-Al_(2)O_(3)DFM is studied.The adsorbent precursors are first co-impregnated onto alumina and calcined in air.Then,Ru precursor is impregnated and four aliquotes are subjected to different calcination protocols:static air in muffle or under different mixtures(10%H_(2)/N_(2),50%H_(2)/N_(2)and N_(2))streams.Samples are characterized by XRD,N_(2)adsorption-desorption,H_(2)chemisorption,TEM,XPS,H_(2)-TPD,H_(2)-TPR,CO_(2)-TPD and TPSR.The catalytic behavior is evaluated,in cycles of CO_(2)adsorption and hydrogenation to CH_(4),and temporal evolution of reactants and products concentrations is analyzed.The calcination atmosphere influences the physicochemical properties and,ultimately,activity of DFMs.Characterization data and catalytic performance discover the acccomodation of Ru nanoparticles disposition and basic sites is mostly influencing the catalytic activity.DFM calcined under N_(2)flow(RuNaCa-N_(2))shows the highest CH_(4)production(449μmol/g at 370℃),because a well-controlled decomposition of precursors which favors the better accomodation of adsorbent and Ru phases,maximizing the specific surface area,the Ru-basic sites interface and the participation of different basic sites in the CO_(2)methanation reaction.Thus,the calcination in a N_(2)flow is revealed as the optimal calcination protocol to achieve highly efficient DFM for integrated CO_(2)adsorption and hydrogenation applications.

关键词： CO_(2)methanation Integrated CO_(2)capture and utilization(ICCU) Dual functional material(DFM) Ru calcination atmosphere

两种富含甘氨酸的RNA结合蛋白参与选择性剪接实现对水稻耐热性的昼夜节律调控

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Science Bulletin 2024年第1期69卷 59-71页

作者：杨闯罗安妮芦海平 Seth jon Davis 刘建祥 State Key Laboratory of Plant Environmental Resilience College of Life SciencesZhejiang UniversityHangzhou 310027China Department of Biology University of YorkYork YO105DDUK

Rice(Oryza sativa L.)production is threatened by global warming associated with extreme high temperatures,and rice heat sensitivity is differed when stress occurs between daytime and nighttime.However,the underlying molecular mechanism are largely unknown.We show here that two glycine-rich RNA binding proteins,Os GRP3 and Os GRP162,are required for thermotolerance in rice,especially at nighttime.The rhythmic expression of Os GRP3/Os GRP162 peaks at midnight,and at these coincident times,is increased by heat stress.This is largely dependent on the evening complex component Os ELF3-2.We next found that the double mutant of Os GRP3/Os GRP162 is strikingly more sensitive to heat stress in terms of survival rate and seed setting rate when comparing to the wild-type plants.Interestingly,the defect in thermotolerance is more evident when heat stress occurred in nighttime than that in daytime.Upon heat stress,the double mutant of Os GRP3/Os GRP162 displays globally reduced expression of heat-stress responsive genes,and increases of m RNA alternative splicing dominated by exon-skipping.This study thus reveals the important role of Os GRP3/Os GRP162 in thermotolerance in rice,and unravels the mechanism on how Os GRP3/Os GRP162 regulate thermotolerance in a diurnal manner.

关键词： Alternative splicing Diurnal regulation Glycine-rich protein Oryza sativa L. Thermotolerance

Are gender inclusiveness and rural transformation interlinked?The case of Bangladesh

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Journal of Integrative Agriculture 2024年第6期23卷 2112-2126页

作者： Maria Fay Rola-Rubzen Mohammad Jahangir Alam jon Marx Sarmiento Ismat Ara Begum Al Amin Al Abbasi Subrata Saha UWA School of Agriculture and Environment The University of Western AustraliaPerth 6009Australia Department of Agribusiness and Marketing Bangladesh Agricultural UniversityMymensingh-2202Bangladesh Department of Agricultural Economics Bangladesh Agricultural UniversityMymensingh-2202Bangladesh

Gender inclusiveness is important in the rural transformation process of Bangladesh as rural women play key roles in both agricultural and non-agricultural sectors.Gender inclusiveness also leads to gender equity.We empirically evaluate relationships between rural transformation and gender inclusiveness in Bangladesh.We consider three rural transformation indicators:high-value commodities’share in agricultural output values,non-farm employment’s share in rural labor employment,and non-agricultural GDP’s share in total GDP.Indicators capturing gender inclusiveness include the per capita rural income of males and females,ratio of investments into gender programs,female access to education,access to healthcare,employment participation,land ownership,and asset ownership.We test the effect of the difference in per capita rural income of males and females and the ratio of their incomes and check for the robustness of the gender variables across different model specifications.Analyzing 128 district-level observations from 32 districts of Bangladesh across four time periods(2000,2005,2010 and 2016),we use both ordinary least squares and fixed effects panel regression models.We find that female land and asset ownership and access to education and healthcare are robust determinants of various stages of rural transformation.Thus,our results suggest that improving women’s ownership of land and assets and investing in women’s education and healthcare will likely contribute to a more inclusive rural transformation.

关键词： rural transformation Bangladesh gender inclusiveness investments on women

Investigation of Hexavalent Chromium Reduction in Strong Saline and Acidic Nitro-Phosphate Solutions

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Journal of Analytical Sciences, Methods and Instrumentation 2024年第1期14卷 1-13页

作者： Deniz Avsar Niels Højmark Andersen Dag Øistein Eriksen jon Petter Omtvedt Department of Chemistry University of Oslo Oslo Norway

Phosphorus fertilizers from less pure sedimentary sources become increasingly important, due to depletion of phosphorus from igneous rock of high quality. Consequently, robust methods with potential to remove various types of hazardous elements are required. Among such impurities, hexavalent chromium (Cr(VI)) is very likely to become a future challenge. Different industrial ways to treat phosphate rock are currently being practised, and we have here studied how chromium behaves when using the nitro-phosphate process. The reduction mechanism of Cr (VI) in nitric acid and phosphoric acid solutions was investigated by measuring redox potential and UV-VIS spectra. The results show that Cr (VI) is not stable in strong nitric acid solutions. Reduction of Cr (VI) species decreased with decreasing temperature, NO2 concentration, ionic strength and absence of light. These findings support the proposed reduction reaction:The reduction rate was observed proportional to the nitric acid decomposition: .

关键词： Nitro-Phosphate Fertilizers Chromium (VI) Reduction Chromium Speciation Ultraviolet-Visible Spectroscopy

从分析的马克思主义到情感理论——美国社会科学哲学家乔恩·埃尔斯特访谈

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哲学分析 2024年第1期15卷 186-195页

作者： [美]乔恩·埃尔斯特陈伟美国哥伦比亚大学复旦大学哲学学院

乔恩·埃尔斯特(jon Elster,1940—),美国著名的政治理论家,哥伦比亚大学罗伯特·默顿社会科学讲席教授,曾在巴黎大学、奥斯陆大学和芝加哥大学任教。他是分析的马克思主义(Analytical Marxism)的创始人之一,对分析的马克思主义有开创... 详细信息

乔恩·埃尔斯特(jon Elster,1940—),美国著名的政治理论家,哥伦比亚大学罗伯特·默顿社会科学讲席教授,曾在巴黎大学、奥斯陆大学和芝加哥大学任教。他是分析的马克思主义(Analytical Marxism)的创始人之一,对分析的马克思主义有开创性贡献;是当代理性选择理论的代表性人物,在社会科学哲学领域有重要学术影响,出版《逻辑与社会》《理解马克思》《酸葡萄》《政治心理学》《心灵炼金术》等20多本专著,发表200余篇论文。

关键词：巴黎大学哥伦比亚大学芝加哥大学政治心理学政治理论家埃尔斯特理性选择理论社会科学哲学

Heterogeneous tunable Ⅲ-Ⅴ-on-silicon-nitride mode-locked laser emitting wide optical spectra

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Photonics Research 2024年第3期12卷 I0021-I0027页

作者： MAXIMILIEN BILLET STIJN CUYVERS STIJN POELMAN ARTUR HERMANS SANDEEP SEEMA SASEENDRA TASUKU NAKAMURA SHINYA OKAMOTO YASUHISA INADA KAZUYA HISADA TAKU HIRASAWA JOAN RAMIREZ DELPHINE NÉEL NICOLAS VAISSIÈRE JEAN DECOBERT PHILIPPE SOUSSAN XAVIER ROTTENBERG GUNTHER ROELKENS jonØ.KJELLMAN BART KUYKEN Photonics Research Group Department of Information TechnologyGhent University-imec9052 GhentBelgium imec 3001 LeuvenBelgium Technology Division Panasonic Holdings CorporationMoriguchi-CityOsakaJapan Ⅲ-Ⅴ Lab F91767 PalaiseauFrance

We demonstrate a Ⅲ-Ⅴ-on-silicon-nitride mode-locked laser through the heterogeneous integration of a semiconductor optical amplifier on a passive silicon-nitride cavity using the technique of micro-transfer printing. In the initial phase of our study, we focus on optimizing the lasing wavelength to be centered at 1550 nm. This optimization is achieved by conducting experiments with 27 mode-locked lasers, each incorporating optical amplifiers featuring distinct multiple-quantum-well photoluminescence values. Subsequently we present a comprehensive study investigating the behavior of the mode-locking regime when the electrical driving parameters are varied. Specifically, we explore the impact of the gain voltage and saturable absorber current on the locking stability of a tunable mode-locked laser. By manipulating these parameters, we demonstrate the precise control of the optical spectrum across a wide range of wavelengths spanning from 1530 to 1580 nm. Furthermore, we implement an optimization approach based on a Monte Carlo analysis aimed at enhancing the mode overlap within the gain region. This adjustment enables the achievement of a laser emitting a 23-nm-wide spectrum while maintaining a defined 10 dB bandwidth for a pulse repetition rate of 3 GHz.

关键词： tunable amplifier mode

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在线学习环境:隐喻问题与系统改进

开放学习研究 2024年第1期29卷 1-14,62页

作者： [加]乔恩·德龙肖俊洪(译) 阿萨巴斯卡大学计算机与信息系统学院加拿大阿萨巴斯卡T9S 3A3 不详

在线教育中,教师经常沿用面授教学方法,学校则复制针对面授教学而设置的各种制度和结构,虽然这些制度和结构的原本唯一目的是解决物理空间环境下教学所产生的问题。与此同时,学习技术的开发和使用主要是为了建设旨在复制具备校园学习环... 详细信息

在线教育中,教师经常沿用面授教学方法,学校则复制针对面授教学而设置的各种制度和结构,虽然这些制度和结构的原本唯一目的是解决物理空间环境下教学所产生的问题。与此同时,学习技术的开发和使用主要是为了建设旨在复制具备校园学习环境特点的虚拟学习环境,结果复制的是面授教师在物理环境下不得不解决的问题,而且复制得很蹩脚。这是一个制造问题和解决问题的恶性循环,对谁都没有好处。把我们为了支持学习而建设的在线学习系统比喻为“环境”有误导之嫌,因为这种认识限制了我们在教学方法上的选择和借助技术解决问题的能力。本文采用基础设施和服务这个比喻,以便能够使用更能体现灵活性、学习者驱动和数字原生的方法设计支持学习的系统(包括工具、教学方法和结构)。

关键词：在线学习学习环境学习管理系统下一代数字学习环境个人学习环境学习基础设施