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Phase-field modelling of discontinuous structures in geomaterials
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作者 WANG Yunteng WANG Yadong +2 位作者 LIU Jiaxin KANG Xuan WU Wei 《地质力学学报》 北大核心 2025年第5期869-885,共17页
[Objective]This study aims to develop a thermodynamically consistent phase-field framework for modeling the initiation and evolution of discontinuous structures in geomaterials.[Methods]Our model introduces crack driv... [Objective]This study aims to develop a thermodynamically consistent phase-field framework for modeling the initiation and evolution of discontinuous structures in geomaterials.[Methods]Our model introduces crack driving forces derived from the volumetric-deviatoric strain decomposition strategy,incorporating distinct tension,compression,and shear degradation mechanisms.Inertia effects capture compaction-band formation driven by wave-like disturbances,grain crushing,and frictional rearrangement.A monolithic algorithm ensures numerical stability and rapid convergence.[Results]The framework reproduces tensile,shear,mixed tensile-shear,and compressive-shear failures using the Benzeggagh-Kenane criterion.Validation against benchmark simulations-including uniaxial compression of rock-like and triaxial compression of V-notched sandstone specimens-demonstrates accurate predictions of crack initiation stress,localization orientation,and energy dissipation.[Conclusions]The framework provides a unified and robust numerical tool for analyzing the spatiotemporal evolution of strain localization and fracture in geomaterials.[Significance]By linking microscale fracture dynamics with macroscale failure within a thermodynamically consistent scheme,this study advances predictive modeling of rock stability,slope failure,and subsurface energy systems,contributing to safer and more sustainable geotechnical practice. 展开更多
关键词 rock cracks localized deformation bands multiscale characteristics phase-field model numerical simulations
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How to determine the leaf area index(LAI)of forests:A comparison of forest inventory versus satellite-driven estimates
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作者 Muhammed Sinan Hubert Hasenauer 《Forest Ecosystems》 2025年第4期750-759,共10页
Leaf area index(LAI)is a key measure of forest stand physiology and biomass production,and is essential within ecosystem modeling.There are two common approaches to obtaining LAI:(i)terrestrial forest inventory-based... Leaf area index(LAI)is a key measure of forest stand physiology and biomass production,and is essential within ecosystem modeling.There are two common approaches to obtaining LAI:(i)terrestrial forest inventory-based“bottom-up”,and(ii)satellite-based“top-down”techniques.The purpose of this study is to compare terrestrial LAI from allometric functions applied to more than 30,000 trees of the Austrian National Forest Inventory(NFI)vs.satellite-based LAI estimates obtained from moderate resolution imaging spectroradiometer(MODIS)and Sentinel(Sentinel-3 TOC reflectance and PROBA-V)data across Austrian forests.We analyzed a satellite pixelto-plot aggregation and obtained the full inventory data set for the LAI comparison.The results suggest that terrestrial vs.satellite(MODIS and Sentinel)driven LAI estimates are consistent,but(i)the variation of the terrestrial forest inventory LAI is larger vs.the pixel average LAI from satellite data,and(ii)any satellite LAI estimation needs a forest stand density correction if the crown competition factor(CCF),a measure for stand density,is<250 to avoid an overestimation in LAI. 展开更多
关键词 ALLOMETRY Moderate resolution imaging spectroradiometer(MODIS) SENTINEL Forest management Stand density Ecosystem modeling Remote sensing
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Identifying suitable areas for plenter forest management
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作者 Mathias Leiter Christoph Pucher +4 位作者 Michael Kessler Ferdinand Honigsberger Manfred J.Lexer Harald Vacik Hubert Hasenauer 《Forest Ecosystems》 2025年第1期83-92,共10页
Plenter forests,also known as uneven-aged or continuous cover forests enhance forest resilience and resistance against disturbances compared to even-aged forests.They are considered as an adaptation option to mitigate... Plenter forests,also known as uneven-aged or continuous cover forests enhance forest resilience and resistance against disturbances compared to even-aged forests.They are considered as an adaptation option to mitigate climate change effects.In this study,we present a conceptual approach to determine the potentially suitable area for plenter forest management within central European mixed species forests and apply our approach to the case study area in Styria,the south-eastern Province of Austria.The concept is based on ecological and technicaleconomic constraints and considers expected future climate conditions and its impact on plenter forest management.For each 1 ha forest pixel,we assess the ecological conditions for plenter forest management according to the autecological growth conditions of silver fir,and at least one additional shade tolerant tree species.The technical-economic constraints are defined by slope(≤30%)and distance to the next forest road(≤100 m)to ensure cost-efficient harvesting.The results show that under current climate conditions 28.1%or 305,349 ha of the forests in Styria are potentially suitable for plenter forest management.For the years 2071–2100 and under the climate change scenario RCP 4.5,the potential area decreases to 286,098 ha(26.3%of the total forest area)and for the scenario RCP 8.5 to 208,421 ha(19.1%of the total forest area).The main reason for these changes is the unfavourable growing conditions for silver fir in the lowlands,while in the higher elevations silver fir is likely to expand.Our results may serve forest managers to identify areas suitable for plenter forests and assist in the transformation of even-aged pure forests to uneven-aged forests to increase resistance,resilience,and biodiversity under climate change. 展开更多
关键词 Plenter forest Uneven-aged forest management Tree species suitability Tree harvesting Transformation
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A general methodological framework for hazard assessment in remote mountain areas combining geomorphological mapping with UAV survey
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作者 Elena GAROVA Bogdan CHADROMTSEV +6 位作者 Alexander PEDANOV Pavel GREBENNIKOV Igor ILTUGANOV Pavel LOBANOV Pavel PONOMARJOVS Felix DRAESNER Sven FUCHS 《Journal of Mountain Science》 2025年第3期763-775,共13页
This paper presents a standardised workflow for conducting hazard assessments of mass wasting processes in remote mountain areas with limited data.The methodology integrates geomorphological mapping and remote sensing... This paper presents a standardised workflow for conducting hazard assessments of mass wasting processes in remote mountain areas with limited data.The methodology integrates geomorphological mapping and remote sensing techniques and is adaptable to different national standards,thus ensuring its applicability in a variety of contexts.The principal objective is to guarantee the safety of mountainous regions,particularly in the vicinity of essential infrastructure,where the scope for implementing structural measures is restricted.The framework commences with comprehensive geomorphological mapping,which facilitates the identification of past hazardous processes and potential future hazards.New technologies,such as uncrewed aerial vehicles(UAVs),are employed to create high-resolution DEMs,which are particularly beneficial in regions with limited data availability.These models facilitate the assessment of potential hazards and inform decisions regarding protective measures.The utilisation of UAVs enhances the accuracy and efficiency of data collection,particularly in remote mountainous regions where alternative remotely sensed information may be unavailable.The integration of modern approaches into traditional hazard assessment methods allows for a comprehensive analysis of the spatial distribution of factors driving mass wasting processes.This workflow provides valuable insights that assist in the prioritisation of interventions and the optimisation of risk reduction in high mountainous areas. 展开更多
关键词 Geomorphological mapping Hazard assessment UAV Remote mountain areas Mitigation planning
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Body size and condition,not allochrony,affect temporal reproductive patterns in a prolonged breeding anuran
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作者 Stephan Burgstaller Andras Horvath +4 位作者 Marie-Luise Aiglsperger Bernhard Kapeller Magdalena Spießberger Martina Staufer Lukas Landler 《Current Zoology》 2025年第4期482-491,共10页
Individual phenological life-history variations in the context of seasonal conditions are well documented in fshes and birds.However,amphibians,a group heavily affected by habitat loss and fragmentation,have received ... Individual phenological life-history variations in the context of seasonal conditions are well documented in fshes and birds.However,amphibians,a group heavily affected by habitat loss and fragmentation,have received relatively little attention regarding research on life-history adaptations.Here we present 3 years of data on the timing of reproductive activity in a suburban European green toad(Bufotes viridis)population.We found annually consistent patterns of reproductive activity and investigated whether these were caused by allochrony or individual attributes.Body size(a proxy for age),body condition,and sex signifcantly affected the timing of reproductive activity.However,most individuals showed considerable overlap in their reproductive timeframe,refuting the existence of allochronic subpopulations.Our fndings may indicate life-history adaptations in the direction of a faster lifestyle in response to hazardous environments.We propose to focus further research efforts on phenological variations in the context of environmental conditions,and that phenological variations should be considered more strongly in amphibian conservation efforts. 展开更多
关键词 AMPHIBIANS LIFE-HISTORY PHENOLOGY reproductive timing scaled mass index
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Ecological Models Reveal a Weakened Population Structure, and Distribution Drivers of Osyris lanceolata (Santalaceae) in the Karamoja Sub-Region, Uganda
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作者 Ben Belden Mugula Samuel Kuria Kiboi +6 位作者 James Ireri Kanya Harald Meimberg Manuel Curto Paul Okullo Anthony Egeru Jenipher Biira Salamula Stephen F. Omondi 《Open Journal of Ecology》 2025年第2期153-173,共21页
Osyris lanceolata is heavily and illegally exploited in East Africa for its essential oils, yet little is known about its population status and ecological requirements. This study examined its population structure and... Osyris lanceolata is heavily and illegally exploited in East Africa for its essential oils, yet little is known about its population status and ecological requirements. This study examined its population structure and environmental factors influencing its distribution in the semi-arid Karamoja sub-region, Uganda. We surveyed 388 plots (5 m radius) at different altitudes, recording life stages, stem diameters, and regeneration patterns, and analyzed soil samples. Multivariate analyses, including Canonical Correspondence Analysis (CCA), Detrended Correspondence Analysis (DCA), Non-metric Multidimensional Scaling (NMDS), and Multiple Regression Modeling (MRM), identified key environmental factors affecting its distribution. Findings show that O. lanceolata populations in Moroto, Nakapiripirit, and Amudat districts are severely degraded due to overexploitation. The species is primarily regenerating through coppicing rather than seedlings, with an exploitation intensity of 56.6%. Population densities are low, distribution is irregular, and sustainable harvesting is not viable. Soil properties, particularly Ca2+, N, P, K+, Na+, and organic matter, significantly influence its abundance. Conservation efforts should focus on identifying suitable provenances for genetic preservation and plantation establishment. Areas with at least 9 trees per hectare in Moroto, Nakapiripirit, and Amudat could serve as potential sites for ex-situ plantations. Further research should explore how biotic interactions, genetic diversity, and morphology affect oil yield and quality to support restoration, breeding, and domestication initiatives. 展开更多
关键词 Plant Ecology Hemiparasites Edaphic Drivers Ecological Modelling Multivariate Analysis Essential Oils “R”
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Optimal integration of forest inventory data and aerial image-based canopy height models for forest stand management
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作者 Ardalan Daryaei Zoran Trailovic +3 位作者 Hormoz Sohrabi Clement Atzberger Eduard Hochbichler Markus Immitzer 《Forest Ecosystems》 2025年第3期443-453,共11页
Accurate,reliable,and regularly updated information is necessary for targeted management of forest stands.This information is usually obtained from sample-based field inventory data.Due to the time-consuming and costl... Accurate,reliable,and regularly updated information is necessary for targeted management of forest stands.This information is usually obtained from sample-based field inventory data.Due to the time-consuming and costly procedure of forest inventory,it is imperative to generate and use the resulting data optimally.Integrating field inventory information with remote sensing data increases the value of field approaches,such as national forest inventories.This study investigated the optimal integration of forest inventory data with aerial image-based canopy height models(CHM)for forest growing stock estimation.For this purpose,fixed-area and angle-count plots from a forest area in Austria were used to assess which type of inventory system is more suitable when the field data is integrated with aerial image analysis.Although a higher correlation was observed between remotely predicted growing stocks and field inventory values for fixed-area plots,the paired t-test results revealed no statistical difference between the two methods.The R2 increased by 0.08 points and the RMSE decreased by 7.7 percentage points(24.8m^(3)·ha^(−1))using fixed-area plots.Since tree height is the most critical variable essential for modeling forest growing stock using aerial images,we also compared the tree heights obtained from CHM to those from the typical field inventory approach.The result shows a high correlation(R^(2)=0.781)between the tree heights extracted from the CHM and those measured in the field.However,the correlation decreased by 0.113 points and the RMSE increased by 4.2 percentage points(1.04m)when the allometrically derived tree heights were analyzed.Moreover,the results of the paired t-test revealed that there is no significant statistical difference between the tree heights extracted from CHM and those measured in the field,but there is a significant statistical difference when the CHM-derived and the allometrically-derived heights were compared.This proved that image-based CHM can obtain more accurate tree height information than field inventory estimations.Overall,the results of this study demonstrated that image-based CHM can be integrated into the forest inventory data at large scales and provide reliable information on forest growing stock.The produced maps reflect the variability of growth conditions and developmental stages of different forest stands.This information is required to characterize the status and changes,e.g.,in forest structure diversity,parameters for volume,and can be used for forest aboveground biomass estimation,which plays an important role in managing and controlling forest resources in mid-term forest management.This is of particular interest to forest managers and forest ecologists. 展开更多
关键词 Forest inventory Growing stock Fixed-area plot Angle-count plot Aerial imagery Tree height Random forest regression
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Global projections of future landslide susceptibility under climate change
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作者 Yu Duan Mingtao Ding +5 位作者 Yufeng He Hao Zheng Ricardo Delgado-Téllez Sergey Sokratov Francisco Dourado Sven Fuchs 《Geoscience Frontiers》 2025年第4期373-386,共14页
Landslides pose a significant threat to both human society and environmental sustainability,yet,their spatiotemporal evolution and impacts on global scales in the context of a warming climate remain poorly understood.... Landslides pose a significant threat to both human society and environmental sustainability,yet,their spatiotemporal evolution and impacts on global scales in the context of a warming climate remain poorly understood.In this study,we projected global landslide susceptibility under four shared socioeconomic pathways(SSPs)from 2021 to 2100,utilizing multiple machine learning models based on precipitation data from the Coupled Model Intercomparison Project Phase 6(CMIP6)Global Climate Models(GCMs)and static metrics.Our results indicate an overall upward trend in global landslide susceptibility under the SSPs compared to the baseline period(2001–2020),with the most significant increase of about 1%in the very far future(2081–2100)under the high emissions scenario(SSP5-8.5).Currently,approximately 13%of the world’s land area is at very high risk of landslide,mainly in the Cordillera of the Americas and the Andes in South America,the Alps in Europe,the Ethiopian Highlands in Africa,the Himalayas in Asia,and the countries of East and South-East Asia.Notably,India is the country most adversely affected by climate change,particularly during 2081–2100 under SSP3-7.0,with approximately 590 million people—23 times the global average—living in areas categorized as having very high susceptibility. 展开更多
关键词 Landslide susceptibility CMIP6 Climate change Spatiotemporal analysis Ensemble modeling
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Detoxification of coumarins by rumen anaerobic fungi:insights into microbial degradation pathways and agricultural applications
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作者 Yuqi Li Jian Gao +6 位作者 Yaxiong Cao Xinming Cheng Zhanying Sun Jiyu Zhang Weiyun Zhu Martin Gierus Yanfen Cheng 《Journal of Animal Science and Biotechnology》 2025年第4期1804-1819,共16页
Background Coumarins are toxic phytochemicals found in a variety of plants and are known to limit microbial degradation and interfere with nutrient cycling.While the degradation of coumarins by fungi has been studied ... Background Coumarins are toxic phytochemicals found in a variety of plants and are known to limit microbial degradation and interfere with nutrient cycling.While the degradation of coumarins by fungi has been studied in an environmental context,little is known about their degradation in the gastrointestinal system of herbivores after ingestion.Results In this study,we investigated in vitro fermentation by microbial enrichment,transcriptome sequencing,and high-resolution mass spectrometry to evaluate the ability of rumen anaerobic fungi to degrade coumarins.The results showed that despite the low abundance of anaerobic fungi in the rumen microbiota,they were able to effectively degrade coumarins.Specifically,Pecoramyces ruminantium F1 could tolerate coumarin concentrations up to 3 mmol/L and degrade it efficiently via metabolic pathways involving alpha/beta hydrolases and NAD(P)H oxidoreductases within the late growth phase.The fungus metabolized coumarin to less toxic compounds,including o-coumaric acid and melilotic acid,highlighting the detoxification potential of anaerobic fungi.Conclusions This study is the first to demonstrate the ability of rumen anaerobic fungi to degrade coumarin,providing new insights into the use of anaerobic fungi in sustainable agricultural practices and environmental detoxification strategies. 展开更多
关键词 Anaerobic fungi COUMARIN DETOXICATION Melilotus officinalis Microbial degradation
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An Evaluation on Physical Characteristics of Konjac Polysaccharides-Based Film Coating and Its Application for Strawberries Preservation
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作者 Desy Nurliasari Awaly Ilham Dewantoro +7 位作者 Muhammad Adly Rahandi Lubis Roni Kastaman Mohamad Djali Efri Mardawati Devi Maulida Rahmah Siti Nurhasanah Akbar Hanif Dawam Abdullah Lukmanul Hakim Zaini 《Journal of Renewable Materials》 2025年第1期181-197,共17页
Konjac is an ideal candidate for edible coatings on fruits due to its hydrophilic properties,film-forming ability,barrier properties,safety,and biodegradability.Meanwhile,the high market demand for strawberries necessi... Konjac is an ideal candidate for edible coatings on fruits due to its hydrophilic properties,film-forming ability,barrier properties,safety,and biodegradability.Meanwhile,the high market demand for strawberries necessitates post-harvest treatment to extend their shelf life and preserve their quality,as strawberries are known for their fragile skin and soft texture.To fully utilize konjac and develop high-quality coatingfilms,native konjacflour(NKF)and konjac glucomannan(KGM)were extracted from its corm and used as a coatingfilm for strawberries in the present study.Therefore,this study aimed to compare the physical properties of thefilm coatings between NKF and KGM,and evaluate their effects on strawberries preservation over 7 days of storage.A multistage extrac-tion process was employed to isolate NKF and KGM,after which the glucomannan content was measured.NKF yield was 31.81%,exceeding KGM yield of 26.42%,and the glucomannan content obtained of NKF(25.93%)was higher than KGM(21.41%).Nuclear magnetic resonance spectroscopy confirmed that both NKF and KGM con-tain glucomannan in their structure.Furthermore,both NKF and KGM were combined with carboxymethyl cel-lulose(CMC)and glycerol to produce eight thin-layerfilms to assess their physical and mechanical properties.Compared to the KGM variant,the NKF variant generally exhibited higher moisture content,water vapor trans-mission rate,and tensile strength.However,NKF was less effective than KGM in extending strawberry storage life,leading to faster color changes and greater weight loss,despite maintaining similar hardness values.Nonetheless,konjac-based coatings were generally effective at maintaining the freshness and quality of strawberries compared to uncoated samples.Konjac shows promise as an edible coating,improving fresh produce shelf life and appeal,aligning with consumer preferences for natural and sustainable products. 展开更多
关键词 Amorphophalus oncophyllus coating performances ediblefilm strawberry preservation
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孕期传统和新兴真菌毒素暴露的胚胎发育毒性及其生物监测的研究现状 被引量:1
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作者 韩小敏 叶金 +6 位作者 纪剑 徐文静 吴宇 叶永丽 Rudolf KRSKA 孙秀兰 白莉 《粮油食品科技》 CAS CSCD 北大核心 2024年第4期16-23,共8页
真菌毒素是某些真菌菌种在特定条件下产生的有毒次级代谢产物。研究发现多种真菌毒素的联合暴露可引起胎儿发育迟缓、胚胎停育甚至流产等胚胎发育毒性。目前,尚没有关于孕期真菌毒素暴露对宫内胎儿胚胎发育毒性的影响和生物监测情况的... 真菌毒素是某些真菌菌种在特定条件下产生的有毒次级代谢产物。研究发现多种真菌毒素的联合暴露可引起胎儿发育迟缓、胚胎停育甚至流产等胚胎发育毒性。目前,尚没有关于孕期真菌毒素暴露对宫内胎儿胚胎发育毒性的影响和生物监测情况的系统报道。因此,为预防和降低孕期真菌毒素暴露带来的危害,本文梳理了孕期传统真菌毒素如黄曲霉毒素、脱氧雪腐镰刀菌烯醇、玉米赤霉烯酮和新兴真菌毒素如交链孢毒素、白僵菌素和恩镰孢菌素等暴露引起的胚胎发育毒性,以及以生物标志物如暴露标志物和效应标志物为基础的生物监测技术的研究现状。 展开更多
关键词 孕期 传统和新兴真菌毒素 胚胎发育毒性 生物监测
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从欧洲视角探究食物中天然毒素对健康的潜在长期风险(中英文) 被引量:1
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作者 Rudolf KRSKA Christoph BUESCHL +1 位作者 Mari ESKOLA Chris ELLIOTT 《粮油食品科技》 CAS CSCD 北大核心 2024年第4期1-15,共15页
食品中完全无毒素的理念往往更接近于一种理想化的幻想而非现实。为辨别并优先处理长期摄入食品累积的有害物质,特别是天然毒素带来的健康风险,我们开展了一项针对性研究。通过审查100多项主要由欧洲食品安全局(EFSA)开展的欧洲层面的... 食品中完全无毒素的理念往往更接近于一种理想化的幻想而非现实。为辨别并优先处理长期摄入食品累积的有害物质,特别是天然毒素带来的健康风险,我们开展了一项针对性研究。通过审查100多项主要由欧洲食品安全局(EFSA)开展的欧洲层面的风险评估研究来评估食品供应的安全性。深入探讨了欧洲消费者长期接触的食品中潜在天然毒素对健康的影响,以及关于特定毒素的研究发现。此外,尝试对长期接触与公众健康有关的食品化学污染物所构成的风险进行排名。黄曲霉毒素被列为食品中第三大重要的化学污染物,因其具有很强的致癌能力,会导致人类患肝癌,加之欧洲谷物类食品消费量高,导致了高风险。虽然吡啶碱类物质具有基因毒性和致癌性,但由于人类接触这类植物毒素的来源有限——例如通过茶、蜂蜜或草药,它们在榜单中仅排第五。 展开更多
关键词 欧洲视角 天然毒素 食品供应 安全性 风险评估
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考虑物态变化的粗粒土亚塑性本构模型 被引量:7
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作者 张嘎 张建民 吴伟 《岩土力学》 EI CAS CSCD 北大核心 2008年第6期1530-1534,共5页
建立了可描述粗粒土单调和循环力学特性的一个亚塑性本构模型。基于亚塑性理论的基本框架,引入临界状态参数,建立了一个新的粗粒土亚塑性模型,给出了数学公式及参数确定方法。采用该模型对粗粒土单调和循环加载试验进行了模拟和预测。... 建立了可描述粗粒土单调和循环力学特性的一个亚塑性本构模型。基于亚塑性理论的基本框架,引入临界状态参数,建立了一个新的粗粒土亚塑性模型,给出了数学公式及参数确定方法。采用该模型对粗粒土单调和循环加载试验进行了模拟和预测。该模型无需判断加卸载、参数较少、易于三维化,能够较全面地描述单调和循环荷载作用下粗粒土的主要力学特性,如强度与围压的非线性关系,胀缩规律与围压相关、卸载体缩、体变随加载过程累积等主要体变特性等。 展开更多
关键词 粗粒土 模型 亚塑性 临界状态 物态
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Resin infiltration of deproteinised natural occlusal subsurface lesions improves initial quality of fissure sealing 被引量:5
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作者 Andrej M Kielbassa Ina Ulrich +3 位作者 Rita Schmidl Christoph Schuller Wilhelm Frank Vanessa D Werth 《International Journal of Oral Science》 SCIE CAS CSCD 2017年第2期117-124,共8页
The aim of this ex vivo study was to evaluate the infiltration capability and rate of microleakage of a low-viscous resin infiltrant combined with a flowable composite resin(RI/CR) when used with deproteinised and etc... The aim of this ex vivo study was to evaluate the infiltration capability and rate of microleakage of a low-viscous resin infiltrant combined with a flowable composite resin(RI/CR) when used with deproteinised and etched occlusal subsurface lesions(International Caries Detection and Assessment System code 2). This combined treatment procedure was compared with the exclusive use of flowable composite resin(CR) for fissure sealing. Twenty premolars and 20 molars revealing non-cavitated occlusal carious lesions were randomly divided into two groups and were meticulously cleaned and deproteinised using Na OCl(2%). After etching with HCl(15%), 10 premolar and 10 molar lesions were infiltrated(Icon/DMG; rhodamine B isothiocyanate(RITC)-labelled) followed by fissure sealing(G-?nial Flo/GC; experimental group, RI/CR). In the control group(CR), the carious fissures were only sealed. Specimens were cut perpendicular to the occlusal surface and through the area of the highest demineralisation(DIAGNOdent pen, Ka Vo). Using confocal laser-scanning microscopy, the specimens were assessed with regard to the percentage of caries infiltration, marginal adaption and internal integrity. Within the CR group, the carious lesions were not infiltrated. Both premolar(57.9% ± 23.1%) and molar lesions(35.3% ± 22.1%) of the RI/CR group were uniformly infiltrated to a substantial extent, albeit with significant differences(P = 0.034). Moreover, microleakage(n = 1) and the occurrence of voids(n = 2) were reduced in the RI/CR group compared with the CR group(5 and 17 specimens,respectively). The RI/CR approach increases the initial quality of fissure sealing and is recommended for the clinical control of occlusal caries. 展开更多
关键词 aprismatic enamel fissure sealing occlusal caries resin infiltration sodium hypochlorite
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Balancing development and conservation needs of stakeholders in the Tusheti Protected Landscape 被引量:1
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作者 SVAJDA Juraj MALAC Lukas KHARTISVILI Lela 《Journal of Mountain Science》 SCIE CSCD 2020年第3期709-723,共15页
Public governance and civil society play an important role in the preservation of the environmental and cultural values of the specific region of Tusheti. This area is an interesting study object also due to its uniqu... Public governance and civil society play an important role in the preservation of the environmental and cultural values of the specific region of Tusheti. This area is an interesting study object also due to its unique governing model and different management issues including the historical background of the region and the current growth of tourism. In the region, where there is a significant number of initiatives supported by donors, a management plan for the protected landscape was prepared and put into practice and selected measures were implemented. Our evaluation of the activities was focused on relevance, efficiency, effectiveness,impacts and sustainability of outcomes. On the basis of the formulated conclusions, a few recommendations related to process and system nature, implementation and replicability of approaches are suggested. The results show an increase in tourism in the region,which leads to an improvement in the quality of life of the local population. On the other hand, it represents a threat to natural and cultural values, historical identity and uniqueness. The Management Plan is an excellent platform for stakeholder cooperation and implementation of specific measures to protect this exceptional territory. 展开更多
关键词 Protected LANDSCAPE Management plan GOVERNANCE BIODIVERSITY Tourism
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Impregnated Paper-Based Decorative Laminates Prepared from Lignin-Substituted Phenolic Resins 被引量:2
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作者 Marion Thébault Ya Li +4 位作者 Christopher Beuc Stephan Frömel-Frybort Edith-Martha Zikulnig-Rusch Larysa Kutuzova Andreas Kandelbauer 《Journal of Renewable Materials》 SCIE EI 2020年第10期1181-1198,共18页
High Pressure Laminates(HPL)panels consist of stacks of self-gluing paper sheets soaked with phenol-formaldehyde(PF)resins.An important requirement for such PFs is that they must rapidly penetrate and saturate the pap... High Pressure Laminates(HPL)panels consist of stacks of self-gluing paper sheets soaked with phenol-formaldehyde(PF)resins.An important requirement for such PFs is that they must rapidly penetrate and saturate the paper pores.Partially substituting phenol with bio-based phenolic chemicals like lignin changes the physico-chemical properties of the resin and affects its ability to penetrate the paper.In this study,PF formulations containing different proportions of lignosulfonate and kraft lignin were used to prepare paper-based laminates.The penetration of a Kraft paper sheet was characterized by a recently introduced,new device measuring the conductivity between both sides of the paper sheet after a drop of resin was placed on the surface and allowed to penetrate the sheet.The main target value measured was the time required for a specific resin to completely penetrate the defined paper sample(“penetration time”).This penetration time generally depends on the molecular weight distribution,the flow behavior and the polarity of the resin which in turn are dependent on the manufacturing conditions of the resin.In the present study,the influences of the three process factors:(1)type of lignin material used for substitution,(2)lignin modification by phenolation and(3)degree of phenol substitution on the penetration times of various lignin-phenolic hybrid impregnation resins were studied using a complete twolevel three-factorial experimental design.Thin laminates made with the resins diluted in methanol were mechanically tested in terms of tensile and flexural strains,and their cross-sections were studied by light microscopy. 展开更多
关键词 LIGNIN phenol-formaldehyde resin(PF) decorative laminate impregnated paper
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Innovation and Technical Efficiency in the Smallholder Dairy Production System in Ethiopia 被引量:1
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作者 Amlaku Asres Johann Solkner Maria Wurzinger 《Journal of Agricultural Science and Technology(A)》 2013年第2期151-164,共14页
This study provides estimates of smallholder household's production efficiency and its determinants, and separately analyses the technical efficiency of dairy technology adopting and non-adopting farmers using data f... This study provides estimates of smallholder household's production efficiency and its determinants, and separately analyses the technical efficiency of dairy technology adopting and non-adopting farmers using data from Ethiopia. Cobb-Douglas stochastic frontier production function was modeled in the context of local level agricultural innovation systems framework and estimated using 2011 milk production data on 304 dairy farmers. Results show that the mean level of technical efficiency among the sampled farmers was about 26%. This result suggests that there is room for significant increases of production through reallocation of existing resources. Despite significant variation among farmers, these results also indicate only 19% of farmers have mean efficiency scores (_〉 50%), implying a need to focus on creating innovation capacity that pushes the production frontier outward in the dairy production system. It is also revealed that individual farm households' efficiency varied widely across dairy technology adoption status, gender and districts. The significant gamma (g) statistic, of 0.9985 in the analysis indicates that about 99.85% variation in the output of milk production would be attributed to technical inefficiency effects (those under farmer's control) while only 0.0015% would be due to random effects, i.e., beyond the farmers control and hence calling for a focus on efficiency enhancing investments. Education, farm size, extension visit and off-farm income opportunity were found to be efficiency enhancing. The study recommends that different components of an agricultural innovation system have to interact to improve the innovation capacity of different actors and thereby improve the estimated technical inefficiencies. 展开更多
关键词 Agricultural innovation systems DAIRY Ethiopia stochastic frontier analysis technical inefficiency.
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Performance of Hydra Probe and MPS-1 Soil Water Sensors in Topsoil Tested in Lab and Field 被引量:1
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作者 Gerhard Kammerer Reinhard Nolz +1 位作者 Marek Rodny Willibald Loiskandl 《Journal of Water Resource and Protection》 2014年第13期1207-1219,共13页
Soil water sensors are commonly used to monitor water content and matric potential in order to study hydrological processes such as evaporation. Finding a proper sensor is sometimes difficult, especially for measureme... Soil water sensors are commonly used to monitor water content and matric potential in order to study hydrological processes such as evaporation. Finding a proper sensor is sometimes difficult, especially for measurements in topsoil, where changes of temperature and soil water dynamics occur generally with greater intensity compared to deeper soil layers. We assessed the perfor-mance of Hydra Probe water content sensors and MPS-1 matric potential sensors in topsoil in the laboratory and in the field. A common soil-specific calibration function was determined for the Hydra Probes. Measurement accuracy and sensor-to-sensor variation were within the manufacturer specification of ±0.03 m3·m-3. Hydra Probes can operate from dry to saturated conditions. Sensor-specific calibrations from a previous study were used to reduce sensor-to-sensor variation of MPS-1. Measurement accuracy can be expressed by a mean relative error of 10%. According to the manufacturer, the application range of matric potential readings is from -10 kPa to -500 kPa. MPS-1 delivered also values beyond this range, but they were not reliable. Sensor electronics of the MPS-1 were sensitive to ambient temperature changes. Beyond instrument effects, field measurements showed substantial temperature-driven fluctuations of soil water content and matric potential, which complicated data interpretation. 展开更多
关键词 Water CONTENT Matric Potential Temperature
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Determination of Selected Toxic Elements in Apples from Organic Farming 被引量:1
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作者 Michaela Zeiner Iva Juranovic Cindric +1 位作者 Ivona Krizman Gerhard Stingeder 《Journal of Chemistry and Chemical Engineering》 2011年第7期577-582,共6页
Due to the elevated ecological awareness nowadays the consumption of products of organic agriculture is increasing. Organic farming means excluding the use of synthetic inputs, such as synthetic fertilizers and pestic... Due to the elevated ecological awareness nowadays the consumption of products of organic agriculture is increasing. Organic farming means excluding the use of synthetic inputs, such as synthetic fertilizers and pesticides or genetically modified organisms, but there are only a few regulations regarding heavy metal concentrations in soils. Thus a not negligible uptake of metals from the soil where the apple trees are grown may occur. Furthermore inorganic copper compounds being traditional fertilizers for apple trees are not considered as synthetic fertilizers, thus they are still used in organic apple farming for soil or foliar application. Thus also apples produced by organic agriculture may contain toxic elements, such as cadmium, chromium, copper, and lead. The concentrations of these elements were determined in whole apples, as well as in the flesh and peel in order to estimate the possible risk for human health. Prior to analysis using ICP-AES samples underwent a microwave assisted digestion. The LODs obtained are below the recommended maximum levels in vegetables/fruits by WHO. In all samples no Cu, Cr, and Pb could be detected. Only Ca was found in the peel of about a third of samples investigated in concentrations between LOD and LOQ (1-3 μg/g). 展开更多
关键词 Apples CADMIUM CHROMIUM copper LEAD organic farming.
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尼日利亚纳萨拉瓦州市售灌木芒果、腰果、秋葵、芝麻和高粱的真菌毒素污染情况研究 被引量:1
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作者 Isaac M Ogara Michael Sulyok +8 位作者 Anthony Negedu Kolawole I Ayeni Zega M Zebedee John D Mamman Abiodun Adedokun Janet I Ogara Eunice A Adgidzi Chibundu N Ezekiel Rudolf Krska 《粮油食品科技》 2021年第6期71-92,共22页
采用LC-MS/MS真菌毒素检测法,对尼日利亚纳萨拉瓦州市场出售的食物作物(灌木芒果(n=12)、烤腰果(n=12)、干秋葵(n=12)、芝麻(n=35)、高粱(n=36))进行了分析研究。结果显示具致肝癌性黄曲霉毒素B1在灌木芒果、干秋葵和高粱样品中检出率... 采用LC-MS/MS真菌毒素检测法,对尼日利亚纳萨拉瓦州市场出售的食物作物(灌木芒果(n=12)、烤腰果(n=12)、干秋葵(n=12)、芝麻(n=35)、高粱(n=36))进行了分析研究。结果显示具致肝癌性黄曲霉毒素B1在灌木芒果、干秋葵和高粱样品中检出率分别为42%、25%和19%,其平均浓度分别为19.2、8.27和4.75μg/kg,伏马毒素B1污染了9%的芝麻样品(平均浓度为12.5μg/kg)和47%的高粱样品(平均浓度为461μg/kg);同时受到黄曲霉毒素B1和伏马毒素B1污染的高粱样本至少有19%。灌木芒果、高粱和干秋葵中检测到了具致肾毒性的赭曲霉毒素A,这是首次在干秋葵中报道检测到该毒素。可见,当地市场出售的这些食物作物受到真菌毒素的污染,可能威胁消费者的健康,需要采取积极措施防控污染。 展开更多
关键词 黄曲霉毒素B1 谷物 坚果 油籽 食品安全 真菌毒素 公共卫生 蔬菜
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