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Investigation of the Fermentation Mode of Rice Husk for the Stabilization of Earth Plaster
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作者 Nafissatou Savadogo Yasmine Binta Traore +2 位作者 Nathael Lankoande Philbert Nshimiyimana Adamah Messan 《Journal of Minerals and Materials Characterization and Engineering》 2024年第1期17-36,共20页
Despite its low resistance to humidity, adobe remains the most widely used material for housing construction, particularly in developing countries. The present study aims to assess different modes of use of fermented ... Despite its low resistance to humidity, adobe remains the most widely used material for housing construction, particularly in developing countries. The present study aims to assess different modes of use of fermented RH and to evaluate their influence on the behavior of raw earth for application in plaster. The influences of two types of RH are evaluated: granular rice husk (RHg) and powdered RH (RHp). The clay mainly consists of clay (40%), silt (22%), and sand (38.4%), with a small proportion of gravel (0.24%). Its liquidity limit is 40% and the plasticity index is 26.5%. The mixtures were designed using earth and each of the two rice husks at the volumetric content of 10%, 15% and 20% of the total volume mixed with water 36.5%, 38.5% and 40.3% and fermented for three weeks. Each fermented mixture was added to the soil to form the paste, and 40 × 40 × 160 mm<sup>3</sup> test speciments were made for characterization. The results generally show an improvement in the physico-mechanical properties and water resistance of the mortars containing fermented RH, with an optimal content between 10% and 15%. The powdered RH improved the performance of the mortar better than granular RH. 展开更多
关键词 earth Plaster Rice Husk CLAY FERMENTATION ADOBE
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Note on:“Ballistic model for the prediction of penetration depth and residual velocity in adobe:A new interpretation of the ballistic resistance of earthen masonry”
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作者 Andreas Heine Matthias Wickert 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第1期607-609,共3页
A recently published modeling approach for the penetration into adobe and previous approaches implicitly criticized are reviewed and discussed.This article contains a note on the paper titled“Ballistic model for the ... A recently published modeling approach for the penetration into adobe and previous approaches implicitly criticized are reviewed and discussed.This article contains a note on the paper titled“Ballistic model for the prediction of penetration depth and residual velocity in adobe:A new interpretation of the ballistic resistance of earthen masonry”(DOI:https://doi.org/10.1016/j.dt.2018.07.017).Reply to the Note from Li Piani et al is linked to this article. 展开更多
关键词 ADOBE PREDICTION earth
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Ecological environmental quality evaluation and driving factor analysis of the Lijiang River Basin,based on Google Earth Engine
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作者 WEI Xi YANG Dazhi +2 位作者 CAI Xiangwen SHAO Ya TANG Xiangling 《中国生态农业学报(中英文)》 CAS CSCD 北大核心 2024年第9期1592-1608,共17页
For regional ecological management,it is important to evaluate the quality of ecosystems and analyze the underlying causes of ecological changes.Using the Google Earth Engine(GEE)platform,the remote sensing ecological... For regional ecological management,it is important to evaluate the quality of ecosystems and analyze the underlying causes of ecological changes.Using the Google Earth Engine(GEE)platform,the remote sensing ecological index(RSEI)was calculated for the Lijiang River Basin in Guangxi Zhuang Autonomous Region for 1991,2001,2011,and 2021.Spatial autocorrelation analysis was employed to investigate spatiotemporal variations in the ecological environmental quality of the Lijiang River Basin.Furthermore,geographic detectors were used to quantitatively analyze influencing factors and their interaction effects on ecological environmental quality.The results verified that:1)From 1991 to 2021,the ecological environmental quality of the Lijiang River Basin demonstrated significant improvement.The area with good and excellent ecological environmental quality in proportion increased by 19.69%(3406.57 km^(2)),while the area with fair and poor ecological environmental quality in proportion decreased by 10.76%(1860.36 km^(2)).2)Spatially,the ecological environmental quality of the Lijiang River Basin exhibited a pattern of low quality in the central region and high quality in the periphery.Specifically,poor ecological environmental quality characterized the Guilin urban area,Pingle County,and Lingchuan County.3)From 1991 to 2021,a significant positive spatial correlation was observed in ecological environmental quality of the Lijiang River Basin.Areas with high-high agglomeration were predominantly forests and grasslands,indicating good ecological environmental quality,whereas areas with low-low agglomeration were dominated by cultivated land and construction land,indicating poor ecological environmental quality.4)Annual average precipitation and temperature exerted the most significant influence on the ecological environmental quality of the basin,and their interactions with other factors had the great influence.This study aimed to enhance understanding of the evolution of the ecological environment in the Lijiang River Basin of Guangxi Zhuang Autonomous Region and provide scientific guidance for decision-making and management related to ecology in the region. 展开更多
关键词 Ecological environmental quality Remote sensing ecological index Driving factor Google earth Engine Lijiang River Basin
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Higher Grain-Filling Rate in Inferior Spikelets of Tolerant Rice Genotype Offset Grain Yield Loss under Post-Anthesis High Night Temperatures
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作者 Nitin SHARMA Bhupinder SINGH +6 位作者 Subbaiyan Gopala KRISHNAN Haritha BOLLINEDI Pranab Kumar MANDAL Milan Kumar LAL Prakash Kumar JHA P.V.Vara PRASAD Anjali ANAND 《Rice science》 SCIE CSCD 2024年第5期572-586,I0059-I0061,共18页
Increased nighttime respiratory losses decrease the amount of photoassimilates available for plant growth and yield. We hypothesized that the increased respiratory carbon loss under high night temperatures(HNT) could ... Increased nighttime respiratory losses decrease the amount of photoassimilates available for plant growth and yield. We hypothesized that the increased respiratory carbon loss under high night temperatures(HNT) could be compensated for by increased photosynthesis during the day following HNT exposure. Two rice genotypes, Vandana(HNT-sensitive) and Nagina 22(HNT-tolerant), were exposed to HNT(4 ℃ above the control) from flowering to physiological maturity. They were assessed for alterations in the carbon balance of the source(flag leaf) and its subsequent impact on grain filling dynamics and the quality of spatially differentiated sinks(superior and inferior spikelets). Both genotypes exhibited significantly higher night respiration rates. However, only Nagina 22 compensated for the high respiration rates with an increased photosynthetic rate, resulting in a steady production of total dry matter under HNT. Nagina 22 also recorded a higher grain-filling rate, particularly at 5 and 10 d after flowering, with 1.5- and 4.0-fold increases in the translocation of ^(14)C sugars to the superior and inferior spikelets, respectively. The ratio of photosynthetic rate to respiratory rate on a leaf area basis was negatively correlated with spikelet sterility, resulting in a higher filled spikelet number and grain weight per plant, particularly for inferior grains in Nagina 22. Grain quality parameters such as head rice recovery, high-density grains, and gelatinization temperature were maintained in Nagina 22. An increase in the rheological properties of rice flour starch in Nagina 22 under HNT indicated the stability of starch and its ability to reorganize during the cooling process of product formation. Thus, our study showed that sink adjustments between superior and inferior spikelets favored the growth of inferior spikelets, which helped to offset the reduction in grain weight under HNT in the tolerant genotype Nagina 22. 展开更多
关键词 high night temperature inferior grain pasting property radiolabeled sugar superior grain
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Effects of Desalination Processes on the Water Circulation and Earth System
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作者 Jae-Woo Choi 《Journal of Environmental Protection》 2024年第3期338-342,共5页
Desalination is emerging as a promising alternative among various technologies to resolve water shortage. However, desalination requires a sufficient energy and cooling device and therefore poses limitations for its i... Desalination is emerging as a promising alternative among various technologies to resolve water shortage. However, desalination requires a sufficient energy and cooling device and therefore poses limitations for its installation and application. In particular, many countries suffering water deficits are economically underdeveloped and cannot afford the technology. As this technology, which changes seawater into freshwater, has little environmental impact, developed countries will need to assist less developed countries to introduce this technology as a humanitarian effort. This will help reduce the number of countries that have experienced difficulty with development. 展开更多
关键词 DESALINATION earth System Humanitarian Effort Water Shortage
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Interrelationships between Length of the Day, Moon Distance, Phanerozoic Geodynamic Cycles, Tidal Dissipation and Earth’s Core: Review and Analysis
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作者 Heinz-Jürgen Brink 《International Journal of Geosciences》 CAS 2024年第5期396-415,共20页
The rotation of the Earth and the related length of the day (LOD) are predominantly affected by tidal dissipation through the Moon and the growth of the Earth’s core. Due to the increased concentration of mass around... The rotation of the Earth and the related length of the day (LOD) are predominantly affected by tidal dissipation through the Moon and the growth of the Earth’s core. Due to the increased concentration of mass around the rotation axis of the spinning Earth during the growth of the core the rotation should have been accelerated. Controversially the tidal dissipation by the Moon, which is mainly dependent on the availability of open shallow seas and the kind of Moon escape from a nearby position, acts towards a deceleration of the rotating Earth. Measurements of LOD for Phanerozoic and Precambrian times open ways to solve questions concerning the geodynamical history of the Earth. These measurements encompass investigations of growth patterns in fossils and depositional patterns in sediments (Cyclostratigraphy, Tidalites, Stromatolites, Rhythmites). These patterns contain information on the LOD and on the changing distance between Earth and Moon and can be used as well for a discussion about the growth of the Earth’s core. By updating an older paper with its simple approach as well as incorporating newly published results provided by the geoscientific community, a moderate to fast growth of the core in a hot early Earth will be favored controversially to the assumption of a delayed development of the core in an originally cold Earth. Core development with acceleration of Earth’s rotation and the contemporaneous slowing down due to tidal dissipation during the filling of the ocean may significantly interrelate. 展开更多
关键词 Length of the Day Moon Distance Phanerozoic Geodynamic Cycles Tidal Dissipation earth’s Core
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Control of Earth system evolution on the formation and enrichment of marine ultra-deep petroleum in China
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作者 ZHANG Shuichang WANG Huajian +3 位作者 SU Jin WANG Xiaomei HE Kun LIU Yuke 《Petroleum Exploration and Development》 SCIE 2024年第4期870-885,共16页
Taking the Paleozoic of the Sichuan and Tarim basins in China as example,the controlling effects of the Earth system evolution and multi-spherical interactions on the formation and enrichment of marine ultra-deep petr... Taking the Paleozoic of the Sichuan and Tarim basins in China as example,the controlling effects of the Earth system evolution and multi-spherical interactions on the formation and enrichment of marine ultra-deep petroleum in China have been elaborated.By discussing the development of“source-reservoir-seal”controlled by the breakup and assembly of supercontinents and regional tectonic movements,and the mechanisms of petroleum generation and accumulation controlled by temperature-pressure system and fault conduit system,Both the South China and Tarim blocks passed through the intertropical convergence zone(ITCZ)of the low-latitude Hadley Cell twice during their drifts,and formed hydrocarbon source rocks with high quality.It is proposed that deep tectonic activities and surface climate evolution jointly controlled the types and stratigraphic positions of ultra-deep hydrocarbon source rocks,reservoirs,and seals in the Sichuan and Tarim basins,forming multiple petroleum systems in the Ediacaran-Cambrian,Cambrian-Ordovician,Cambrian-Permian and Permian-Triassic strata.The matching degree of source-reservoir-seal,the type of organic matter in source rocks,the deep thermal regime of basin,and the burial-uplift process across tectonic periods collectively control the entire process from the generation to the accumulation of oil and gas.Three types of oil and gas enrichment models are formed,including near-source accumulation in platform marginal zones,distant-source accumulation in high-energy beaches through faults,and three-dimensional accumulation in strike-slip fault zones,which ultimately result in the multi-layered natural gas enrichment in ultra-deep layers of the Sichuan Basin and co-enrichment of oil and gas in the ultra-deep layers of the Tarim Basin. 展开更多
关键词 evolution of earth system multi-spherical interaction Paleozoic marine ultra-deep petroleum Tarim Basin Sichuan Basin
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Improvement strategy on thermophysical properties of A_(2)B_(2)O_(7)-type rare earth zirconates for thermal barrier coatings applications:A review
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作者 Zijian Peng Yuhao Wang +8 位作者 Shuqi Wang Junteng Yao Qingyuan Zhao Enyu Xie Guoliang Chen Zhigang Wang Zhanguo Liu Yaming Wang Jiahu Ouyang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第5期1147-1165,共19页
The A_(2)B_(2)O_(7)-type rare earth zirconate compounds have been considered as promising candidates for thermal barrier coating(TBC) materials because of their low sintering rate,improved phase stability,and reduced ... The A_(2)B_(2)O_(7)-type rare earth zirconate compounds have been considered as promising candidates for thermal barrier coating(TBC) materials because of their low sintering rate,improved phase stability,and reduced thermal conductivity in contrast with the currently used yttria-partially stabilized zirconia (YSZ) in high operating temperature environments.This review summarizes the recent progress on rare earth zirconates for TBCs that insulate high-temperature gas from hot-section components in gas turbines.Based on the first principles,molecular dynamics,and new data-driven calculation approaches,doping and high-entropy strategies have now been adopted in advanced TBC materials design.In this paper,the solid-state heat transfer mechanism of TBCs is explained from two aspects,including heat conduction over the full operating temperature range and thermal radiation at medium and high temperature.This paper also provides new insights into design considerations of adaptive TBC materials,and the challenges and potential breakthroughs are further highlighted for extreme environmental applications.Strategies for improving thermophysical performance are proposed in two approaches:defect engineering and material compositing. 展开更多
关键词 rare earth zirconates thermal barrier coatings defect engineering doping and compositing thermal conductivity thermal expansion
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Wetting front migration model of ion-adsorption rare earth during the multi-hole unsaturated liquid injection
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作者 Yu Wang Xiaojun Wang +8 位作者 Yuchen Qiu Hao Wang Gang Li Kaijian Hu Wen Zhong Zhongqun Guo Bing Li Chunlei Zhang Guangxiang Ye 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第2期483-496,共14页
In the process of ion-adsorption rare earth ore leaching,the migration characteristics of the wetting front in multi-hole injection holes and the influence of wetting front intersection effect on the migration distanc... In the process of ion-adsorption rare earth ore leaching,the migration characteristics of the wetting front in multi-hole injection holes and the influence of wetting front intersection effect on the migration distance of wetting fronts are still unclear.Besides,wetting front migration distance and leaching time are usually required to optimize the leaching process.In this study,wetting front migration tests of ionadsorption rare earth ores during the multi-hole fluid injection(the spacing between injection holes was 10 cm,12 cm and 14 cm)and single-hole fluid injection were completed under the constant water head height.At the pre-intersection stage,the wetting front migration laws of ion-adsorption rare earth ores during the multi-hole fluid injection and single-hole fluid injection were identical.At the postintersection stage,the intersection accelerated the wetting front migration.By using the Darcy’s law,the intersection effect of wetting fronts during the multi-hole liquid injection was transformed into the water head height directly above the intersection.Finally,based on the Green-Ampt model,a wetting front migration model of ion-adsorption rare earth ores during the multi-hole unsaturated liquid injection was established.Error analysis results showed that the proposed model can accurately simulate the infiltration process under experimental conditions.The research results enrich the infiltration law and theory of ion-adsorption rare earth ores during the multi-hole liquid injection,and this study provides a scientific basis for optimizing the liquid injection well pattern parameters of ion-adsorption rare earth in situ leaching in the future. 展开更多
关键词 Ion-adsorption rare earth ore Multi-hole unsaturated liquid injection In situ leaching Intersection effect Calculation model
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Probing signals of atmospheric gravity waves excited by the July 29,2021 M_(W)8.2 Alaska earthquake
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作者 Geng Zhang Jianqiao Xu +2 位作者 Xiaodong Chen Heping Sun Lizhuo Gong 《Geodesy and Geodynamics》 EI CSCD 2024年第3期219-229,共11页
It is commonly believed that the atmosphere is decoupled from the solid Earth.Thus,it is difficult for the seismic wave energy inside the Earth to propagate into the atmosphere,and atmospheric pressure wave signals ex... It is commonly believed that the atmosphere is decoupled from the solid Earth.Thus,it is difficult for the seismic wave energy inside the Earth to propagate into the atmosphere,and atmospheric pressure wave signals excited by earthquakes are unlikely to exist in atmospheric observations.An increasing number of studies have shown that earthquakes,volcanoes,and tsunamis can perturb the Earth's atmosphere due to various coupling effects.However,the observations mainly focus on acoustic waves with periods of less than 10 min and inertial gravity waves with periods of greater than 1 h.There are almost no clear observations of gravity waves that coincide with observations of low-frequency signals of the Earth's free oscillation frequency band within 1 h.This paper investigates atmospheric gravity wave signals within1 h of surface-atmosphere observations using the periodogram method based on seismometer and microbarometer observations from the global seismic network before and after the July 29,2021 M_(w)8.2 Alaska earthquake in the United States.The numerical results show that the atmospheric gravity wave signals with frequencies similar to those of the Earth's free oscillations _(0)S_(2) and _(0)T_(2) can be detected in the microbaro meter observations.The results con firm the existence of atmospheric gravity waves,indicating that the atmosphere and the solid Earth are not decoupled within this frequency band and that seismic wave energy excited by earthquakes can propagate from the interior of the Earth to the atmosphere and enhance the atmospheric gravity wave signals within 1 h. 展开更多
关键词 Atmospheric gravity modes Atmospheric gravity waves Alaska earthquake Normal modes Coupling of solid earth and atmosphere
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High-quality Development of the Pearl River Night Tour in the Context of Deep Integration of Culture and Tourism
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作者 Juan JIANG Lianrong PANG 《Meteorological and Environmental Research》 2024年第1期38-45,共8页
Urban night tourism is a new form of urban tourism development and an important driving force for the prosperity of urban night economy.As the most prestigious business card among many night tour projects in Guangzhou... Urban night tourism is a new form of urban tourism development and an important driving force for the prosperity of urban night economy.As the most prestigious business card among many night tour projects in Guangzhou,the Pearl River water night tour has contributed to the development of Guangzhou s night economy,which cannot be underestimated.However,in the process of rapid development,there are also problems such as diversified operators,insufficient integration of intangible cultural elements,excessive commercial attributes,issues of tourism facilities and service facilities.Under the new stage of integrated development of culture and tourism,how to use mutual promotion of culture and tourism in the Pearl River night tour to seek innovative paths for high-quality development in the future is the main problem expected to be solved in this paper.Therefore,based on the perspective of culture and tourism integration,this paper analyzes the general situation and development status of the Pearl River night tour,and proposes five development strategies:the overall planning of culture and tourism integration,the deep integration of intangible cultural elements,the balance of commercial attributes and tourism attributes,the high integration of culture,business,tourism and education,and the creation of tourism atmosphere,in order to provide inspiration for the healthy,orderly and high-quality development of the Pearl River night tour. 展开更多
关键词 Integration of culture and tourism the Pearl River night tour High-quality development Intangible cultural elements
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Physical and Thermo-Mechanical Properties of Composite Materials Based on Raw Earth and Crushed Palm Leaf Fibers (Borassus aethiopum)
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作者 Mouhamadou Nabi Kane Mapathe Ndiaye +1 位作者 Pape Moussa Touré Adama Dione 《Materials Sciences and Applications》 2024年第9期358-377,共20页
The objective of this study is to seek solutions to reduce the impact of buildings on climate change and to promote the use of local bio-sourced or geo-sourced materials for sustainable construction. Different samples... The objective of this study is to seek solutions to reduce the impact of buildings on climate change and to promote the use of local bio-sourced or geo-sourced materials for sustainable construction. Different samples of raw earth from 3 sites were taken in the commune of Mlomp. Geotechnical tests showed that the raw earth samples from sites 2 and 3 have more clay fraction while site 1 contains more sand. The fact of integrating fibers from crushed palm leaves (Borassus aethiopum) (2%, 4% and 6%) into the 3 raw earth samples reduced the mechanical resistance to compression and traction of the 3 raw earths. The experimental results of thermal tests on samples of earth mixtures with crushed Palma leaf fibers show a decrease in thermal conductivity as well as thermal effusivity as the percentages increase (2%, 4% and 6%) of fibers in raw earth for the 3 sites. This shows that this renewable composite material can help improve the thermal insulation of building envelopes. 展开更多
关键词 Raw earth Palma Leaf Fibers Ecological Composite Materials PHYSICAL thermo-Mechanical thermal Conductivity thermal Effusivity
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Optimisation of Thermal Comfort of Building in a Hot and Dry Tropical Climate: A Comparative Approach between Compressed Earth/Concrete Block Envelopes
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作者 Arnaud Louis Sountong-Noma Ouedraogo Césaire Hema +2 位作者 Sjoerd Moustapha N’guiro Philbert Nshimiyimana Adamah Messan 《Journal of Minerals and Materials Characterization and Engineering》 2024年第1期1-16,共16页
Compressed earth blocks (CEB) are an alternative to cement blocks in the construction of wall masonry. However, the optimal architectural construction methods for adequate thermal comfort for occupants in hot and arid... Compressed earth blocks (CEB) are an alternative to cement blocks in the construction of wall masonry. However, the optimal architectural construction methods for adequate thermal comfort for occupants in hot and arid environments are not mastered. This article evaluates the influence of architectural and constructive modes of buildings made of CEB walls and concrete block walls, to optimize and compare their thermal comfort in the hot and dry tropical climate of Ouagadougou, Burkina Faso. Two identical pilot buildings whose envelopes are made of CEB and concrete blocks were monitored for this study. The thermal models of the pilot buildings were implemented in the SketchUp software using an extension of EnergyPlus. The models were empirically validated after calibration against measured thermal data from the buildings. The models were used to do a parametric analysis for optimization of the thermal performances by simulating plaster coatings on the exterior of walls, airtight openings and natural ventilation depending on external weather conditions. The results show that the CEB building displays 7016 hours of discomfort, equivalent to 80.1% of the time, and the concrete building displays 6948 hours of discomfort, equivalent to 79.3% of the time. The optimization by modifications reduced the discomfort to 2918 and 3125 hours respectively;i.e. equivalent to only 33.3% for the CEB building and 35.7% for the concrete building. More study should evaluate thermal optimizations in buildings in real time of usage such as residential buildings commonly used by the local middle class. The use of CEB as a construction material and passive means of improving thermal comfort is a suitable ecological and economical option to replace cementitious material. 展开更多
关键词 Compressed earth Blocks Hot and Dry Climate thermal Comfort Architectural Optimization of thermal Models Cement Blocks Empirical Validation
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Aspirations on the Bright Side of Humanity: It is Time to Translate Aspirations Into Actions With Establishing the Government of Earth
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作者 Nandor Ludvig 《Philosophy Study》 2024年第1期1-8,共8页
The thesis of this paper is that the digital noosphere of the World Wide Web and its users,the borderless move of virtually all resources of the planet,and the consequent globalization of most aspects of national poli... The thesis of this paper is that the digital noosphere of the World Wide Web and its users,the borderless move of virtually all resources of the planet,and the consequent globalization of most aspects of national politics,economy,and culture,along with the increasing difficulty of controlling the related high-tech military conflicts,human-made environmental crises,and the abnormal migrations of abused people now make it inevitable to leave behind the competitive international chaos rooted in humankind’s animal past and turn to the cooperative social spirit recommended by Aristotle,Lao Tzu,Jesus,Dante,H.G.Wells,Martin Luther King Jr.,John Lennon,Nicholas Hagger,and others to finally translate their aspirations into actions via establishing the Government of Earth for the decent and free.The paper presents a five-step,15-year,~$25B plan to start this process.That this plan has nothing to do with the Godless work of secret societies,the authoritarian urges of renewed fascism or the political absurdities of Marxism-Leninism it is relayed by the envisioned Intercontinental Education System of the outlined Government of Earth to teach every child on the planet-via a new community of digitally linked extraordinary teachers-for the beauty of lifelong learning,tolerance,duty,honor,free cooperation,and artful communication for divine missions. 展开更多
关键词 humankind Soul of Multiverse cosmological neuroscience Government of earth
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基于GoogleEarthEngine的黄土高原植被覆盖度时空变化特征分析 被引量:3
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作者 姚楠 董国涛 薛华柱 《水土保持研究》 CSCD 北大核心 2024年第1期260-268,共9页
[目的]探究黄土高原植被覆盖度变化的时空特征,揭示植被对气候因子变化的时滞效应,进而为地区生态保护与高质量发展提供数据支撑。[方法]基于2001年至2020年的黄土高原地区NDVI数据、气温和降水数据,利用像元二分法、一元线性回归和时... [目的]探究黄土高原植被覆盖度变化的时空特征,揭示植被对气候因子变化的时滞效应,进而为地区生态保护与高质量发展提供数据支撑。[方法]基于2001年至2020年的黄土高原地区NDVI数据、气温和降水数据,利用像元二分法、一元线性回归和时滞偏相关分析等方法,开展地区植被与气候因子变化关系的研究。[结果]过去20年间,黄土高原植被覆盖度以0.076/10 a的速率增加,在空间上主要呈现极显著增加,但占总面积38.29%的区域植被覆盖变化波动较大。黄土高原月植被覆盖度与气温和降水呈现显著正相关关系,其中降水是影响植被变化的主要因素。植被对降水的响应滞后时间主要集中在3个月,而气温的滞后时间在空间上存在较大差异,东南部植被主要滞后0至1个月,而西北部植被主要滞后2至3个月。[结论]黄土高原植被变化主要受降水影响,20年间植被恢复情况良好,但变化波动较大,未来应继续生态保护工作进行巩固。 展开更多
关键词 植被覆盖度 GEE 时滞相关 气候变化 黄土高原
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On the apparent line-of-sight alignment of the peak X-ray intensity of the magnetosheath and the tangent to the magnetopause,as viewed by SMILE-SXI 被引量:2
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作者 Andrew Read 《Earth and Planetary Physics》 EI CSCD 2024年第1期155-172,共18页
The Soft X-ray Imager(SXI)on board the Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)spacecraft will be able to view the Earth’s magnetosheath in soft X-rays.Simulated images of the X-ray emission visible f... The Soft X-ray Imager(SXI)on board the Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)spacecraft will be able to view the Earth’s magnetosheath in soft X-rays.Simulated images of the X-ray emission visible from the position of SMILE are created for a range of solar wind densities by using 3 years of the SMILE mission orbit,together with models of the expected X-ray emissivity from the Earth’s magnetosheath.Results from global magnetohydrodynamic simulations and a simple model for exospheric neutral densities are used to compare the locations of the lines of sight along which integrated soft X-ray intensities peak with the lines of sight lying tangent to surfaces(defined here to be the magnetopause)along which local soft X-ray intensities peak or exhibit their strongest gradients,or both,for strongly southward interplanetary magnetic field conditions when no depletion or low-latitude boundary layers are expected.Where,in the parameter space of the various times and seasons,orbital phases,solar wind conditions,and magnetopause models,the alignment of the X-ray emission peak with the magnetopause tangent is good,or is not,is presented.The main results are as follows.The spacecraft needs to be positioned well outside the magnetopause;low-altitude times near perigee are not good.In addition,there are seasonal aspects:dayside-apogee orbits are generally very good because the spacecraft travels out sunward at high altitude,but nightside-apogee orbits,behind the Earth,are bad because the spacecraft only rarely leaves the magnetopause.Dusk-apogee and dawnapogee orbits are intermediate.Dayside-apogee orbits worsen slightly over the first three mission years,whereas nightside-apogee orbits improve slightly.Additionally,many more times of good agreement with the peak-to-tangent hypothesis occur when the solar wind is in a high-density state,as opposed to a low-density state.In a high-density state,the magnetopause is compressed,and the spacecraft is more often a good distance outside the magnetopause. 展开更多
关键词 X-rays MAGNETOSPHERE MAGNETOSHEATH MAGNETOPAUSE Solar wind Magnetosphere Ionosphere Link Explorer(SMILE) earth solar wind charge exchange
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Erratum to:A review of the wave gradiometry method for seismic imaging
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作者 Chuntao Liang Feihuang Cao +1 位作者 Zhijin Liu Yingna Chang 《Earthquake Science》 2024年第1期91-91,共1页
Earthq Sci 2023(36):254-281 Doi:10.1016/j.eqs.2023.04.002 In the original version of this article,the important funding source was inadvertently omitted in Acknowledgement section.The corrected one is as follows.
关键词 SEISMIC earth SOURCE
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Crystal growth, magnetic and electrical transport properties of the kagome magnet RCr_(6)Ge_(6)(R= Gd–Tm)
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作者 杨星宇 曾庆祺 +3 位作者 何苗 许锡童 杜海峰 屈哲 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第7期569-575,共7页
Kagome magnets have attracted considerable research attention due to the interplay between topology,magnetism and electronic correlations.In this study we report single-crystal synthesis of a series of the kagome magn... Kagome magnets have attracted considerable research attention due to the interplay between topology,magnetism and electronic correlations.In this study we report single-crystal synthesis of a series of the kagome magnets.RCr_(6)Ge_(6)(R=Gd-Tm) that possess defect-free Cr kagome lattices and systematically study their magnetic and electrical transport properties.The transition from a canted ferrimagnetic to a paramagnetic state in GdCr_(6)Ge_(6),TbCr_(6)Ge_(6),DyCr_(6)Ge_(6),HoCr_(6)Ge_(6),ErCr_(6)Ge_(6) and TmCr_(6)Ge_(6) occurs at 11.3 K,10.8 K,4.3 K,2.5 K,3.3 K and below 2 K,respectively,due to R-R interactions within the compounds.Magnetization measurements reveal highly anisotropic magnetism with canted magnetic moments in these compounds.In electrical transport,both negative and positive magnetoresistances at different magnetic fields and temperatures have been observed due to the competition between different scattering mechanisms.This work enriches our understanding of the Cr-based kagome magnets and paves the way to search for possible topological responses in this family. 展开更多
关键词 kagome lattice MAGNETISM rare earth
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The Mechanism of Changes in Mantle Volume
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作者 Daoxiong Hu 《International Journal of Geosciences》 CAS 2024年第8期549-556,共8页
The crust floats above the mantle, and the volume change of the mantle is the driving force of crustal movement. The increase in mantle volume leads to crustal extensional movement, resulting in continental crust rupt... The crust floats above the mantle, and the volume change of the mantle is the driving force of crustal movement. The increase in mantle volume leads to crustal extensional movement, resulting in continental crust rupture and oceanic crust expansion. The decrease in mantle volume leads to crustal compression movement, resulting in continental crust superposition, folding, and oceanic crust subduction. The factors that contribute to the increase in mantle volume include a change in material state, where solid material in the mantle melts into liquid material. The factors leading to a decrease in mantle volume include: oceanic crust uplift, crustal crystallization, volcanic eruptions, magma intrusion, and hydrothermal upwelling. The change in mantle volume dominates the evolution pattern of the crust. When the mantle volume increases unidirectionally, the crust only has horizontally crystallized continental crust. When the volume of the mantle changes in both directions, blocky layered oceanic crust is formed. The expansion and subduction of oceanic crust, as well as the stretching and compression of continental crust, are the supporting mechanisms for changes in Earth’s surface area caused by changes in mantle volume. 展开更多
关键词 earth Formation Mantle Volume Crustal Movement
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Assessing the Influence of Dykes on the Drainage Network of the Shivan River in North Maharashtra
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作者 Sandeep B. Bhise Tushar P. Raut +1 位作者 Suchitra S. Pardeshi Sudhakar D. Pardeshi 《International Journal of Geosciences》 CAS 2024年第8期582-589,共8页
The prominent linear dyke ridges outcropped in the Narmada-Tapi dykes’ swarm represent an intrusion in the Deccan Traps. Understanding the relationship among the underlying geological structures, the strike of the dy... The prominent linear dyke ridges outcropped in the Narmada-Tapi dykes’ swarm represent an intrusion in the Deccan Traps. Understanding the relationship among the underlying geological structures, the strike of the dykes, and the channel patterns is essential. Dykes act as obstructions to stream flow, causing diversions, and their geometry and patterns significantly impact the rivers and streams that drain and cross the dyke swarm zone. For this study, Google Earth images, LISS III images, and Cartosat DEM were used to delineate the Shivan basin and extract dyke features. The Shivan River basin is a sixth-order drainage system that reflects superimposed drainage systems within the Tapi dyke swarm zone. About 65% (169 km2) of its area is controlled by dyke orientation. The dyke ridges align predominantly in an East-West (E-W) direction, a pattern mainly followed by lower-order streams, which have developed an insequent, transverse drainage network within the dyke swarm zone. In the lower parts of the Shivan basin, where the number of dykes decreases, the drainage network follows the general slope and is oriented in a North-South direction. The Shivan River and its tributaries have partially adjusted to the dyke orientation, resulting in a transverse drainage pattern in areas characterized by parallel dyke ridges. 展开更多
关键词 Deccan Traps Narmada-Tapi Dyke Swarm Google earth LISS III Cartosat DEM
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