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Unexpected texture transition induced by grain growth during static annealing of a dilute Mg-1Al alloy 被引量:1
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作者 Meng-Na Zhang Hai-Long Jia +3 位作者 Xiao Ma Lei Zhao Zhi-Gang Li Min Zha 《Journal of Magnesium and Alloys》 2025年第3期1133-1148,共16页
Conventional rolled Mg-Al alloy sheets typically exhibit strong basal textures that remain and may even strengthen after recrystallization annealing due to the preferential growth of basal-oriented grains,resulting in... Conventional rolled Mg-Al alloy sheets typically exhibit strong basal textures that remain and may even strengthen after recrystallization annealing due to the preferential growth of basal-oriented grains,resulting in poor formability at room temperature.Therefore,the knowledge of recrystallization and grain growth is critical for modifying textures of Mg-Al alloy sheets.The static recrystallization and texture evolution in a cold-rolled dilute Mg-1Al(wt.%)alloy during various annealed temperatures ranging from 300℃ to 450℃,have been investigated using the quasi in-situ electron backscatter diffraction(EBSD)method.The as-rolled Mg-1Al alloy shows a dominant basal texture,which weakens and broadens in the rolling direction(RD)during the subsequent annealing,accompanied by the formation of{1010}texture component.Particularly,the {1010} texture component is more pronounced after annealing at high temperatures.The quasi in-situ EBSD results show that recrystallized grains are mainly induced by shear bands,which exhibit a wide spectrum of orientations with c-axis tilt angles ranging 20°-45°from the normal direction(ND).Orientations of shear band-induced recrystallized grains are retained during the entire recrystallization process,resulting in a reduction in the texture intensity.Moreover,recrystallized grains belonging to the {1010}texture component grow preferentially compared to those with other orientations,which is attributed to low energy grain boundaries,especially grain boundaries with∼30°misorientation angles.Furthermore,the high temperature annealing facilitates the rapid growth of grain boundaries having a 30°misorientation angle,leading to the occurrence of distinct {1010} texture after annealing at 450℃ for 1 h.The results provide insights for texture modification of rare earth-free low-alloyed Mg alloys by controlling annealing parameters. 展开更多
关键词 Magnesium alloy Static recrystallization TEXTURE Preferential growth Grain boundary
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Terminating interfacial hydrogen-bond networks via preferential coordination for stable zinc metal anode
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作者 Bowen Zhang Tianyue Qian +7 位作者 Ruimin Li Jianping Chen Xin Zhang Wanyu Zhao Jinlei Zhang Yuxin Yuan Zi-Feng Ma Xiaowei Yang 《Journal of Energy Chemistry》 2025年第8期1-8,共8页
Aqueous zinc-ion batteries have emerged as promising candidates in next-generation energy storage sys-tems.However,their practical implementation is significantly hindered by interfacial side reactions,par-ticularly t... Aqueous zinc-ion batteries have emerged as promising candidates in next-generation energy storage sys-tems.However,their practical implementation is significantly hindered by interfacial side reactions,par-ticularly the hydrogen evolution reaction(HER)at the Zn metal anode interface.Herein,this study presents an innovative approach to address this challenge through the construction of an interfacial pref-erential coordination layer on the Zn anode surface.The proposed layer effectively terminates the conti-nuity of interfacial hydrogen-bond networks and blocks proton transport,thereby mitigating the HER.Specifically,2-phenylbenzimidazole-5-sulfonic acid(PBSA)with zincophilic groups was introduced as an electrolyte additive,which would be preferentially and selectively anchored on the Zn surface through its zincophilic nitrogen and sulfonic acid,forming the interfacial coordination layer.This coordination layer serves as a protective barrier,repelling water molecules from the Zn electrode surface and alleviat-ing water decomposition.Crucially,the interfacial coordination layer features stronger hydrogen-bonding interactions with interfacial water molecules,terminates the hydrogen-bonding network between water molecules,hinders the transportation and electro-reduction of proton,and ultimately inhibits HER at the interface.As a result,the Zn symmetric cell with PBSA/ZnSO_(4)delivered higher cycling stability of 2500 h at 1 mA cm^(-2)and Zn/NH_(4)V_(4)O_(10)full cells with PBSA/ZnSO_(4)possessed enhanced capac-ity retention.This interfacial hydrogen-bond regulation strategy provided valuable insight for designing HER-free interfacial protective layer in high-performance aqueous batteries. 展开更多
关键词 Aqueous zinc ion batteries Zinc metal anode Hydrogen evolution Interfacial hydrogen-bond networks Preferential coordination
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Soil water sources and transport modes based on stable isotope tracing in Northeastern Qinghai-Tibet Plateau
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作者 GUI Juan YUAN Youjing +2 位作者 LI Zongxing FENG Qi DU Fa 《Journal of Mountain Science》 2025年第9期3227-3241,共15页
A thorough understanding of the source and infiltration mechanism of soil water is of great significance to the stable supply of regional water resources and the protection of ecological environment.To solve this cruc... A thorough understanding of the source and infiltration mechanism of soil water is of great significance to the stable supply of regional water resources and the protection of ecological environment.To solve this crucial scientific problem,a total of 1980 samples of various water bodies in Qilian Mountains were collected in early,heavy and end ablation period in 2012-2019 to determine the source of soil water with endmember mixing analysis.Double isotope mass balance was used to calculate the relative contribution of piston flow and preferred flow to groundwater.The results of the study show that precipitation dominated the soil water in the study region,and it contributes 78%,89%and 91%of soil water in early,heavy and end ablation periods,respectively.Ground ice meltwater is also an important source of soil water,its contribution was 16%,11%and 7%in early,heavy and end ablation period,respectively.Snowmelt contributed to soil water only during the early(6%)and late(2%)ablation periods.Groundwater is replenished through the combined effects of preferential flow and piston flow.According to double isotope mass balance,the contribution of priority flow to shallow groundwater is 34%,45%and 34%,respectively in early,heavy and end ablation periods.This study identified the sources of soil water and water transport mechanisms in the Qilian Mountains,providing scientific and technological support for water resource conservation and sustainable utilization in cold regions. 展开更多
关键词 Soil water Preferential flow Qilian mountains
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Synergetic regulation of bulk reconstruction and preferential orientation realizing long-lifespan thin Li anodes for high-energy-density lithium metal batteries
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作者 Xu Chu Feilong Dong +2 位作者 Ying Jiang Qianmai Qiao Haiming Xie 《Journal of Energy Chemistry》 2025年第6期418-426,I0010,共10页
Li plating behavior of the Li metal anode and its compatibility with electrolytes play a decisive role in the electrochemical performance of the Li metal batteries(LMBs),while the intrinsic highly reactive Li would in... Li plating behavior of the Li metal anode and its compatibility with electrolytes play a decisive role in the electrochemical performance of the Li metal batteries(LMBs),while the intrinsic highly reactive Li would induce serious results especially under deep Li plating/stripping depth and with lean electrolytes.Herein,we propose an innovative strategy to simultaneously regulate the bulk construction and the preferential orientation of Li deposition by introducing Li22Sn5/Li-Mg alloys to realize ultra-stable thin Li anodes with long lifespan.The alloys can form a continuous framework with high lithiophilicity and fast ion-diffusion to enable homogenous Li flux,and meanwhile tune the preferential orientation of Li from the conventional(110)plane to(200)to lower the Li reactivity with electrolytes and optimize Li deposition.Therefore,the thin Li-Sn-Mg alloy anode showcases ultra-stable cycling without volume changes and dendrites under a deep Li plating/stripping depth of 89.1%(5 mAh cm^(-2))for over 1200 h in commercial carbonate electrolytes.Moreover,a multilayered NCM811pouch cell with a high energy density of403.6 Wh kg^(-1)is achieved under the harsh conditions of low N/P ratio(0.769)and lean electrolytes(~2.1 g Ah^(-1)).Synchronously,the thin alloy anode shows improved air stability which benefits the manufacturing process and performance of LMBs,displaying the great application potential of these alloy anodes. 展开更多
关键词 Li metal anodes Continuous alloy framework Preferential orientation Long lifespan High energy density
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Effect of long-term thermal aging on lead-bismuth eutectic corrosion behavior of 9Cr ferritic/martensitic steel
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作者 Yanyun Zhao Shiao Ding +2 位作者 Yanyan Du Kunjie Yang Shaojun Liu 《Journal of Materials Science & Technology》 2025年第7期299-311,共13页
In lead-cooled fast reactor(LFR)systems,the liquid lead-bismuth eutectic(LBE)coolant provides a cor-rosive environment that damages the steel components during high-temperature operation.This study investigated the mi... In lead-cooled fast reactor(LFR)systems,the liquid lead-bismuth eutectic(LBE)coolant provides a cor-rosive environment that damages the steel components during high-temperature operation.This study investigated the microstructural deterioration of 9Cr ferritic/martensitic(F/M)steel under thermal aging at 550℃for 2,000,10,000,or 20,000 h and its effect on oxidation corrosion in an LBE environment using multiscale characterization techniques.The results indicated that the thickness of the internal oxidation zone(IOZ)increased significantly with extended thermal aging,whereas that of the spinel layer remained relatively constant.The abundant subgrain boundaries that emerged during extensive thermal aging facil-itated Fe diffusion,and the enlarged Cr-rich M23C6 carbides contributed to the formation of preferential oxidation regions,accelerating IOZ layer growth.The spinel layer formed from the IOZ was influenced by microstructural defects within the IOZ.A theoretical model describing the accelerated oxide layer growth due to thermal aging was developed.These findings support the advancement of LFR technology. 展开更多
关键词 Thermal aging treatment Lead-bismuth eutectic Internal oxidation zone Preferential oxidation region
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Synergistic catalytic sites in platinum-rare earth alloys to modulate competitive activation of multiple reactants for preferential CO oxidation
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作者 Yue Jiang Haorun Li +7 位作者 Kunming Hou Ze Liu Lina Li Yang Liu Heng Zhang Yanheng Hao Ying Liu Shanghong Zeng 《Journal of Energy Chemistry》 2025年第6期427-438,I0010,共13页
Intercalation of rare-earth(RE)into Pt offers an option to optimize the electronic structure of Pt-based catalysts by interaction effect,in which the synergistic catalytic sites are of great significance,yet the under... Intercalation of rare-earth(RE)into Pt offers an option to optimize the electronic structure of Pt-based catalysts by interaction effect,in which the synergistic catalytic sites are of great significance,yet the underpinning mechanism remains elusive.Herein,the introduction of silanol nests enables the alloy formation on the SiO_(2)surface.The amination modification is disclosed to induce the electron transfer from RE to Pt and weaken the adsorption of CO on electron-rich Pt species.In situ/operando spectroscopic analyses in conjunction with density functional theory calculations demonstrate the electronic couple of Pt atoms and adjacent Ce atoms concurrently achieves the enhancement of CO oxidation and suppression of H_(2)oxidation.Additionally,CO_(2)is readily desorbed from the Pt_(5)Ce(111)surface to enhance intrinsic activity and longevity.These findings provide an atomic-level insight into the synergistic catalytic sites on regulating the electronic state of the Pt-RE alloy catalysts toward highly selective oxidation reactions. 展开更多
关键词 Platinum-rare earth alloys Amination modification Synergistic catalytic sites Pt_(5)Ce Preferential CO oxidation
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Zokor activity promotes soil water infiltration in the Mu Us sandy land of northern Shaanxi,China 被引量:1
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作者 Miao GAN Xuchao ZHU +7 位作者 Xueqin YANG Xiaorong WEI Qingyin ZHANG Tongchuan LI Ming'an SHAO Meixia MI Xi YANG Mingyu CHEN 《Pedosphere》 SCIE CAS CSCD 2024年第1期136-145,共10页
Zokors are common subterranean rodents that inhabit agricultural fields, shrublands, and grasslands in the arid and semi-arid regions of China. Zokor burrowing activities can alter soil structure and affect soil hydro... Zokors are common subterranean rodents that inhabit agricultural fields, shrublands, and grasslands in the arid and semi-arid regions of China. Zokor burrowing activities can alter soil structure and affect soil hydrological processes;however, there are few studies regarding their effects on soil preferential flow in the Mu Us sandy land. An evaluation of the effects of zokor disturbance on their habitat and soil water is important for understanding the ecological role of zokors in the soil ecosystem of the Mu Us sandy land. A field dye-tracing experiment was conducted in the Gechougou watershed on the southeastern edge of the Mu Us sandy land to investigate the effect of zokor burrowing activity on soil preferential flow characteristics. Our results showed that the density of zokor tunnels was the highest(0.40–0.46 m m^(-2)) under 30%–50% vegetation coverage and that the tunnels were approximately 3 cm from the surface.Both stained area ratio and stained path number were higher at sites with zokors than without zokors. Stained path widths were 10–80 and > 80 mm at zokor-harboring sites exhibiting homogeneous flow and heterogeneous finger flow, respectively. In the absence of zokors, homogeneous flow and highly interacted macropore flow were predominant. Soil water content below the zokor tunnels was higher than that above the tunnels. Moderate disturbance of soil structure by zokor activity facilitated soil water infiltration. These results enabled a better understanding of the effect of soil fauna on soil structure and hydrological processes and provided recommendations for ecological construction and renovation in arid and semi-arid regions. 展开更多
关键词 eld dye-tracing experiment preferential flow soil fauna stained area ratio stained path number stained path width subterranean rodent surface tortoise crack
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Internal erosion characteristics and microstructure effects of undisturbed loess
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作者 ZHANG Buping ZHU Xinghua +1 位作者 CHENG Yuxiang Aamir ASGHAR 《Journal of Mountain Science》 SCIE CSCD 2024年第11期3630-3649,共20页
Loess internal erosion caused by preferential flow often leads to serious loess ground collapse,shallow loess landslides,and other geological disasters.However,there is a lack of quantitative evaluation of the interna... Loess internal erosion caused by preferential flow often leads to serious loess ground collapse,shallow loess landslides,and other geological disasters.However,there is a lack of quantitative evaluation of the internal erodibility of undisturbed loess under the action of preferential flow,and little is known about the correlation between the internal erodibility of loess and its microstructure.In this study,we carried out a series of hole erosion tests(HET)on undisturbed loess samples from 4 typical locations on China's Loess Plateau.The internal erodibility of loess was quantitatively evaluated through an improved HET method,and its association with initial water content,clay content,and initial water head difference was investigated.On the microscopic scale,the microstructure of loess with different clay content was measured by scanning electron microscopy(SEM).The correlation between pore and particle microstructure parameters and loess internal erosion parameters was established based on grey correlation theory.When the initial water content increased from 10%to 36%,the erodibility index increased from 1 to 2.5.When the clay content increased from 8%to 27.95%,the erodibility index increased 3.5 times.The increase of initial water head difference has a positive linear effect on the internal erodibility of loess.The microstructure analysis shows that with the increase of clay content,the microstructure of undisturbed loess changes from a mosaic structure to a cementation structure,which creates favourable conditions for controlling the internal erosion of loess.Through grey correlation analysis,it has been determined that the microstructure of undisturbed loess has a significant correlation with the critical shear stress,and the loess microstructure morphology strongly correlates with the erosion rate.Under normal circumstances,the higher the clay content,the better the erosion resistance,the better the mechanical stability,and the easier to form a stable cave in loess.This study can provide a reference for revealing the cave formation mechanism in the loess area in the future. 展开更多
关键词 Undisturbed loess Preferential flow Internal erosion Hole erosion test Microstructure effect Loess Plateau
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Evolution model and failure mechanisms of rainfall-induced cracked red clay slopes:insights from Xinshao County,China
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作者 JIAO Weizhi ZHANG Ming +4 位作者 LI Peng XIE Junjin PANG Haisong LIU Fuxing YANG Long 《Journal of Mountain Science》 SCIE CSCD 2024年第3期867-881,共15页
Red clay landslides are widely distributed worldwide,resulting in severe loss of life and property.Although rainfall-induced red clay slopes have received extensive attention,the role of cracks in the evolutionary pro... Red clay landslides are widely distributed worldwide,resulting in severe loss of life and property.Although rainfall-induced red clay slopes have received extensive attention,the role of cracks in the evolutionary process of red clay slopes and their connection to failure mechanisms is still poorly understood.A comprehensive approach integrating field investigation,laboratory tests,and numerical simulations was conducted to study the 168 red clay landslides in Xinshao County,China.The results show that red clay is prone to forming cracks at high moisture content due to its low swelling and high shrinkage properties.The failure mode of red clay slopes can be summarized in three stages:crack generation,slope excavation,and slope failure.Furthermore,the retrospective analysis and numerical simulations of the typical landslide in Guanchong indicated that intense rainfall primarily impacts the shallow layer of soil within approximately 0.5 m on the intact slope.However,cracks change the pattern of rainfall infiltration in the slope.Rainwater infiltrates rapidly through the preferential channels induced by the cracks rather than uniformly and slowly from the slope surface.This results in a significant increase in both the depth of infiltration and the saturated zone area of the cracked slope,reaching 3.8 m and 36.2 m^(2),respectively.Consequently,the factor of safety of the slope decreases by 13.4%compared to the intact slope,ultimately triggering landslides.This study can provide valuable insights into understanding the failure mechanisms of red clay slopes in China and other regions with similar geological settings. 展开更多
关键词 Red clay slopes Cracks Preferential flow Failure mechanism
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Investigation of Solvent Effect on the Structural Morphological and Optical Properties of ZnO Doped Mg Elaborated by Sol-Gel Method
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作者 Asmaa El Hamidi Ahmed El Hichou Abdelmajid Almaggoussi 《Journal of Materials Science and Chemical Engineering》 2024年第12期67-79,共13页
This work aims to study the solvent’s effect on the structural, morphological, and optical properties of Mg-doped zinc oxide (MZO) thin films. The results of the XRD analysis revealed that the 2-methoxyethanol solven... This work aims to study the solvent’s effect on the structural, morphological, and optical properties of Mg-doped zinc oxide (MZO) thin films. The results of the XRD analysis revealed that the 2-methoxyethanol solvent imparts a preferential orientation to the MZO samples, following the (002) plane, with a maximum value observed at 2% Mg. In contrast, the samples prepared using methanol show no preferential orientation. SEM analysis corroborated that the use of 2-methoxyethanol results in an orderly distribution of MZO crystallites. The optical characterization indicated that the transmittance of MZO thin films reached a maximum value of 90% for Mg concentrations ranging from 2% to 3%. At the same time, the refractive index showed its lowest value of 1.46. In contrast, the use of methanol as a solvent resulted in a maximum transmittance of 80% at 4% Mg, accompanied by a minimum refractive index value of 1.96. 展开更多
关键词 ZNO ZnO Doped Mg METHANOL 2-Methoxyethanol Preferential Orientation Optical Properties Sol-Gel
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Landslide monitoring in southwestern China via time-lapse electrical resistivity tomography 被引量:14
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作者 徐冬 胡祥云 +1 位作者 单春玲 李睿恒 《Applied Geophysics》 SCIE CSCD 2016年第1期1-12,217,共13页
The dynamic monitoring of landslides in engineering geology has focused on the correlation among landslide stability,rainwater infiltration,and subsurface hydrogeology.However,the understanding of this complicated cor... The dynamic monitoring of landslides in engineering geology has focused on the correlation among landslide stability,rainwater infiltration,and subsurface hydrogeology.However,the understanding of this complicated correlation is still poor and inadequate.Thus,in this study,we investigated a typical landslide in southwestern China via time-lapse electrical resistivity tomography(TLERT) in November 2013 and August 2014.We studied landslide mechanisms based on the spatiotemporal characteristics of surface water infiltration and flow within the landslide body.Combined with borehole data,inverted resistivity models accurately defined the interface between Quaternary sediments and bedrock.Preferential flow pathways attributed to fracture zones and fissures were also delineated.In addition,we found that surface water permeates through these pathways into the slipping mass and drains away as fissure water in the fractured bedrock,probably causing the weakly weathered layer to gradually soften and erode,eventually leading to a landslide.Clearly,TLERT dynamic monitoring can provide precursory information of critical sliding and can be used in landslide stability analysis and prediction. 展开更多
关键词 time-lapse electrical resistivity tomography LANDSLIDE HYDROGEOPHYSICS MONITORING preferential flow
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Gravity and magnetic anomalies field characteristics in the South China Sea and its application for interpretation of igneous rocks 被引量:8
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作者 李淑玲 孟小红 +3 位作者 郭良辉 姚长利 陈召曦 李和群 《Applied Geophysics》 SCIE CSCD 2010年第4期295-305,399,共12页
Igneous rocks in the South China Sea have broad prospects for oil and gas exploration.Integrated geophysical methods are important approaches to study the distribution of igneous rocks and to determine and identify ig... Igneous rocks in the South China Sea have broad prospects for oil and gas exploration.Integrated geophysical methods are important approaches to study the distribution of igneous rocks and to determine and identify igneous rock bodies.Aimed at the characteristics of gravity and magnetic fields in the South China Sea,several potential field processing methods are preferentially selected.Reduction to the pole by variable inclinations in the area of low magnetic latitudes is used to perform reduction processing on magnetic anomalies.The preferential continuation method is used to separate gravity and magnetic anomalies and extract the gravity and magnetic anomaly information of igneous rocks in the shallow part of the South China Sea.The 3D spatial equivalent distribution of igneous rocks in South China Sea is illustrated by the 3 D correlation imaging of magnetic anomalies.Since the local anomaly boundaries are highlighted gravity and magnetic gradients,the distribution characters of different igneous rocks are roughly outlined by gravity and magnetic correlation analysis weighted by gradient.The results show the distribution of igneous rocks is controlled and influenced by deep crustal structure and faulting. 展开更多
关键词 South China Sea gravity and magnetic fields reduction to the pole at low latitudes preferential continuation igneous rock distribution
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Gas-solid catalytic reactions over ruthenium-based catalysts 被引量:4
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作者 施文博 刘霄龙 +3 位作者 曾俊淋 王健 魏耀东 朱廷钰 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2016年第8期1181-1192,共12页
Ruthenium (Ru)‐based catalysts are widely employed in several types of gas‐solid reactions because of their high catalytic activities. This review provides theoretical research on Ru‐based catalysts and an analys... Ruthenium (Ru)‐based catalysts are widely employed in several types of gas‐solid reactions because of their high catalytic activities. This review provides theoretical research on Ru‐based catalysts and an analysis of their basic properties and oxidation behavior. There is particular emphasis on Ru‐catalyzed gas‐solid catalytic reactions, including the catalytic oxidation of VOCs, preferential oxidation of CO, synthesis of ammonia, oxidation of HCl and partial oxidation of CH4. Recent litera‐ture on catalysis is summarized and compared. Finally, we describe current challenges in the field and propose approaches for future development of Ru‐based catalysts. 展开更多
关键词 Gas-solid catalytic reaction RUTHENIUM Volatile organic compound Catalytic oxidation Preferential CO oxidation HCl oxidation
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Vanadium recovery from stone coal through roasting and flotation 被引量:6
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作者 刘春 张一敏 包申旭 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2017年第1期197-203,共7页
A new process for vanadium recovery from stone coal by roasting-flotation was investigated based on the mineralogy. The process comprised four key steps: decarburization, preferential grinding, desliming and flotatio... A new process for vanadium recovery from stone coal by roasting-flotation was investigated based on the mineralogy. The process comprised four key steps: decarburization, preferential grinding, desliming and flotation. In the decarburization stage, roasting at 550 ℃ effectively avoided the negative effect of the carbonaceous materials in raw ore and generation of free CaO from calcite decomposition during roasting. Through preferential grinding, the high acid-consuming minerals were enriched in the middle fractions, while mica was enriched in the fine and coarse fractions. Through flotation, the final concentrate can be obtained with V2O5 grade of 1.07% and recovery of 83.30%. Moreover, the vanadium leaching rate of the final concentrate increased 13.53% compared to that of the feed. The results reveal that the decarburization by roasting at 550 ℃ is feasible and has little negative impact on mica flotation, and vanadium recovery from stone coal is conducive to reducing handling quantity, acid consumption and production cost. 展开更多
关键词 vanadium-bearing stone coal roasting decarburization MINERALOGY preferential grinding FLOTATION
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New Recognized Intellect for Prospecting Large-superlarge Mineral Deposits 被引量:3
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作者 PEI Rongfu MEI Yanxiong +1 位作者 WANG Haolin QU Hongying 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2012年第3期539-546,共8页
Based on the data base of 1285 mineral deposits of 22 commodities in 121 countries of 6 continents of the world, the authors use the linear trend analysis for their reserves to determine the cut-off limited order of r... Based on the data base of 1285 mineral deposits of 22 commodities in 121 countries of 6 continents of the world, the authors use the linear trend analysis for their reserves to determine the cut-off limited order of reserves to select 36 exceptional superlarge (as peak mineral), 95 superlarge and 314 large deposits as new recognized intellect for their quantitative change. We have projected above 445 large-superlarge deposits on (1:5 M) global tectonic background map and divided 4 metallogenic domains, 21 metallogenic belts. Global metallogeny of large-superlarge deposits are: unity by endogenic, exogenic metamorphic and epigenetic in origin; speciality in different metallogenic domains and belts; preferentiality to ore-forming elements of Cu, Au, Fe, Ag, Cr, Mn, Zn, Pb, Sb, Hg, to continental margins or plate convergent belts, to Intra-continental tectono-magmatic complex belts and Large ductile shear zones; abnormality by the global oxyatmversion (excess oxygen atmospheric event) in Archean, redoxyatmversion (lack oxygen atmospheric event) in Proterozoic-Paleozoic, and tectonosphere thermal erosion (great amount of tectonic magmatic event) in Mesozoic-Cenozoic. 展开更多
关键词 new recognized intellect large-superlarge deposits metallogenic unity SPECIALITY preferentiality abnormality
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Variations in tidal currents and suspended sediment concentration of the upper part of the North Channel of Changjiang Estuary over the past 10 years 被引量:1
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作者 刘高伟 程和琴 +3 位作者 计娜 乔远英 胡浩 王冬梅 《Marine Science Bulletin》 CAS 2015年第2期9-24,共16页
The tidal current duration (TCD) and velocity (TCV) and suspended sediment concentration (SSC) were measured in the dry season in December, 2011 and in the flood season in June, 2012 at the upper part of the Nor... The tidal current duration (TCD) and velocity (TCV) and suspended sediment concentration (SSC) were measured in the dry season in December, 2011 and in the flood season in June, 2012 at the upper part of the North Channel of Changjiang Estuary. They were assimilated with the measured data in 2003, 2004, 2006 and 2007, using the tidal range's proportion conversion. Variations in TCD and TCV, preferential flow and SSC have been calculated. Influences of typical engineering projects such as Qingcaosha fresh water reservoir, Yangtze River Bridge, and land reclamation on the ebb and flood TCD, TCV and SSC in the North Channel for the last 10 years are discussed. The results show that: (1) currently, in the upper part of North Channel, the ebb tide dominates; after the construction of the typical projects, ebb TCD and TCV tends to be larger and the vertical average ebb and flood SSC decrease during the flood season while SSC increases during the dry season; (2) changes in the vertical average TCV are mainly contributed by seasonal runoff variation during the flood season, which is larger in the flood season than that in the dry season; the controlling parameters of increasing ebb TCD and TCV are those large-scale engineering projects in the North Channel; variation in SSC may result mainly from the reduction of basin annual sediment loads, large-scale nearshore projects and so on. 展开更多
关键词 changes in tidal currents and suspended sediment concentration preferential flow data assimilation large-scale engineering projects Changjiang Estuary
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无尺度网络中的统计力学特征 被引量:3
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作者 唐芙蓉 蔡绍洪 李朝辉 《贵州大学学报(自然科学版)》 2005年第1期13-17,共5页
从统计力学的角度分析和考察了无尺度网络(scale freenetworks)的基本特征,介绍了无尺度网络(scale freenetworks)的最常用的动力学模型——Barabasi Albert模型,总结求解度分布的理论方法,分析此动力学模型自身的不足,并据此提出新的... 从统计力学的角度分析和考察了无尺度网络(scale freenetworks)的基本特征,介绍了无尺度网络(scale freenetworks)的最常用的动力学模型——Barabasi Albert模型,总结求解度分布的理论方法,分析此动力学模型自身的不足,并据此提出新的研究问题。 展开更多
关键词 无尺度网络(scale—free networks) 度分布 Barabasi—Albert模型 连接偏好(preferential attachment)
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Solvatochromic Parameters and Preferential Solvation Behavior for Binary Mixtures of 1,3-Dialkylimidazolium Ionic Liquids with Water
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作者 丁珊 魏立纲 +1 位作者 李坤兰 马英冲 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2016年第4期497-507,I0002,共12页
Binary mixtures of 1,3-dialkylimidazolium based ionic liquids (ILs) and water were selected as solvent systems to investigate the solute-solvent and solvent-solvent interactions on the preferential solvation of solv... Binary mixtures of 1,3-dialkylimidazolium based ionic liquids (ILs) and water were selected as solvent systems to investigate the solute-solvent and solvent-solvent interactions on the preferential solvation of solvatochromic indicators at 25 ℃. Empirical solvatochromic pa- rameters, dipolarity/polarizability (π^*), hydrogen-bond donor acidity (α), hydrogen-bond acceptor basicity (β), and Reichardt's polarity parameters (ET^N) were measured from the ultraviolet-visible spectral shifts of 4-nitroaniline, 4-nitroanisole, and Reichardt's dye. The solvent properties of the IL-water mixtures were found to be influenced by IL type and IL mole fraction (XIL). All these studied systems showed the non-ideal behavior. The max- imum deviation to ideality for the solvatochromic parameters can be obtained in the XIL range from 0.i to 0.3. For most of the binary mixtures, the π^* values showed the synergistic effects instead of the ETN, α and β values. The observed synergy extent was dependent on the studied systems, such as the dye indicator and IL type. A preferential solvation model was utilized to gather information on the molecular interactions in the mixtures. The dye indicator was preferentially solvated on the following trend: IL〉IL-water complex〉water. 展开更多
关键词 Solvatochromic parameters Preferential solvation Ionic liquid WATER
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Enhanced catalytic activities and selectivities in preferential oxidation of CO over ceria-promoted Au/Al_2O_3 catalysts 被引量:4
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作者 苗雨欣 王静 李文翠 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2016年第10期1721-1728,共8页
The preferential oxidation of CO (CO‐PROX) is a hot topic because of its importance in pro‐ton‐exchange membrane fuel cells (PEMFCs). Au catalysts are highly active in CO oxidation. Howev‐er, their activities ... The preferential oxidation of CO (CO‐PROX) is a hot topic because of its importance in pro‐ton‐exchange membrane fuel cells (PEMFCs). Au catalysts are highly active in CO oxidation. Howev‐er, their activities still need to be improved at the PEMFC operating temperatures of 80–120 &#176;C. In the present study, Au nanoparticles of average size 2.6 nm supported on ceria‐modified Al2O3 were synthesized and characterized using powder X‐ray diffraction, nitrogen physisorption, transmission electron and scanning transmission electron microscopies, temperature‐programmed hydrogen reduction (H2‐TPR), Raman spectroscopy, and in situ diffuse‐reflectance infrared Fourier‐transform spectroscopy. Highly dispersed Au nanoparticles and strong structures formed by Au–support in‐teractions were the main active species on the ceria surface. The Raman and H2‐TPR results show that the improved catalytic performance of the Au catalysts can be attributed to enhanced strong metal–support interactions and the reducibility caused by ceria doping. The formation of oxygen vacancies on the catalysts increased their activities in CO‐PROX. The synthesized Au catalysts gave excellent catalytic performances with high CO conversions (&gt;97%) and CO2 selectivities (&gt;50%) in the temperature range 80–150 &#176;C. 展开更多
关键词 Gold catalysis CERIA ALUMINA Preferential oxidation of carbon monoxide DEPOSITION-PRECIPITATION
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