检索结果-内蒙古大学图书馆

Using radium isotopes to quantify submarine groundwater discharge at different scales in the Huanghe River Estuary,China

引用

Acta Oceanologica Sinica 2023年第8期42卷 32-39页

作者： Haowei Xu Disong Yang Xiaoyi Guo Maosheng Gao Guangquan Chen Diansheng Ji Shengtao Chen Huaming Yu Bochao Xu Frontiers Science Center for Deep Ocean Multispheres and Earth System/Key Laboratory of Marine Chemistry Theory and Technology of Ministry of Education Ocean University of ChinaQingdao 266100China Laboratory for Marine Ecology and Environmental Science Qingdao National Laboratory for Marine Science and TechnologyQingdao 266071China College of Chemistry and Chemical Engineering Ocean University of ChinaQingdao 266100China North China Sea Environmental Monitoring Center of State Oceanic Administration/Key Laboratory of Ecological Prewarning and Protection of Bohai Sea Ministry of Natural ResourcesQingdao 266033China Shandong Provincial Key Laboratory of Marine Ecological Environment and Disaster Prevention and Mitigation Qingdao 266033China Qingdao Institute of Marine Geology Qingdao 266071China Key Laboratory of Marine Sedimentology and Environmental Geology First Institute of OceanographyMinistry of Natural ResourcesQingdao 266061China Laboratory for Marine Geology Qingdao National Laboratory for Marine Science and TechnologyQingdao 266237China Yantai Marine Center Ministry of Natural ResourcesYantai 264003China North China Sea Ecological Center Ministry of Natural ResourcesQingdao 266033China Key Laboratory of Ecological Prewarning and Protection of Bohai Sea Ministry of Natural ResourcesQingdao 266033China College of Oceanic and Atmospheric Sciences Ocean University of ChinaQingdao 266100China Sanya Oceanographic Institution Ocean University of ChinaSanya 572000China

As an important land-ocean interaction process,submarine groundwater discharge(SGD)is composed of multiple dynamical processes at different scales and plays an important role in the study of coastal ocean geochemical ***,most of the existing studies focus on the quantification of the total groundwater discharge,few studies are about the differentiation and quantification of groundwater discharge processes at different scales(i.e.,short-scale SGD and long-scale SGD).As a world-class river,the Huanghe River is highly turbid and heavily regulated by *** natural and anthropogenic factors have a significant impact on groundwater discharge processes in the Huanghe River Estuary(HRE).In this study,the distribution patterns of the natural geochemical tracer radium isotopes(^(224)Ra and^(223)Ra)and other hydrological parameters in the HRE were investigated during four *** solving the mass balance of^(224)Ra and^(223)Ra in the HRE,the long-scale SGD flux was quantified as 0.01−0.19 m/d,and the short-scale SGD flux was 0.03−0.04 m/*** rate of short-scale SGD remained essentially constant among seasons,while the rate of long-scale SGD varied considerably at different periods and showed a synchronous trend with the variation of river *** results of this study are significant for understanding the SGD dynamics in the HRE and the contribution of SGD to the ocean geochemical budgets.

关键词： radium isotopes submarine groundwater discharge Huanghe River Estuary

来源：评论

学校读者我要写书评

暂无评论

The Review of γ-ray Astronomical Observing Techniques

引用

Chinese Astronomy and Astrophysics 2021年第3期45卷 281-300页

作者： Si-liang, F.E.N.G. Peng, F.A.N. Yi-fan, H.U. Tian-yu, M.A. Yan, X.I.A. Beijing Institute of Spacecraft Environment Engineering Beijing 100094 National Key Laboratory of Science and Technology on Reliability and Environmental Engineering Beijing 100094 Department of Engineering Physics Tsinghua University Beijing 100084 Key Laboratory of Particle & Radiation Imaging (Tsinghua University) Ministry of Education Beijing 100084

γ-ray is a unique probe for extreme events in the universe. Detecting the γ-ray provides an important opportunity to understand the composition of universe, the evolution of stars, the origin of cosmic rays, etc. γ-ray astronomy involves in various frontier scientific issues, and the observed energy spectrum spans over a wide range from a few hundreds of keV to a few hundreds of TeV. Different γ-ray telescopes are in need for different scientific goals and spectral bands. In this work, 5 kinds of space- and ground-based γ-ray observing techniques were summarized, including the Coded-aperture telescopes, Compton telescopes, Pair-production telescopes, Imaging Atmospheric Cherenkov Telescopes, and Extensive Air Shower Arrays. The progress in γ-ray astronomy in the past 70 years, motivated by the observation capability, was reviewed. Great achievements have been made in the high-energy domain and very-high-energy domain, while because of the limited missions conducted, as well as a lower sensitivity comparing with other domains, discoveries in low- and medium-energy are few, and due to the high observation difficulty, as well as the late start, relevant scientific yields in ultra- and extremely-high energy are limited. Moreover, the future planned missions and capabilities of the γ-ray telescopes and their possible scientific outputs were discussed. Among these missions, low- and medium-energy space telescopes e-ASTROGAM (enhanced-ASTROGAM), AMEGO (All-sky Medium Energy Gamma-ray Observatory), and very-high-energy ground-based arrays LHAASO (Large High Altitude Air Shower Observatory) and CTA (Cherenkov Telescope Array) greatly improve sensitivity than their corresponding last generation, thus expect very likely to further expand our knowledge on the γ-universe. © 2021

关键词： gamma rays: general Instrumentation: detectors Telescopes

来源：评论

学校读者我要写书评

暂无评论

Multi-Scale Modelling And Micromechanical Properties Of Semi-Crystalline Polymers

引用

Procedia Structural Integrity 2024年 52卷 63-71页

作者： Chenxu Jiang Jia Zhou Peng Jiang Changqing Miao National Key Laboratory of Science and Technology on Advanced Composites in Special Environment Harbin Institute of Technology Harbin 150001 China School of Water Conservancy & Civil Engineering Northeast Agricultural University Harbin 150006 China

This work proposed multi-scale modelling to predict the micromechanical properties of semi-crystalline polymers. Semi-crystalline polymers are usually spherulitic crystal structure, which is, however, not completely radially symmetric. In the initial stage of spherulite growth, its structure is manifested as multilayer wafers with a certain orientation namely sheaf structure. The size and orientation of sheaf structure are affected by various processing parameters. Previous research considered spherulite as completely radially symmetric structures, ignoring the effects of structures anisotropy on mechanical properties. In this work, the microstructure of single spherulite was first modelled with different initial orientations. The crystal plasticity constitutive model together with the Arruda-Boyce model was used to describe the micromechanical behaviors of the crystalline lamellae and amorphous lamellae, respectively. Based on the deformation behaviors of single spherulite, the Voronoi tessellation was then used to characterize the multi-spherulites, the evolution of inhomogeneous plastic deformation and inter-lamellae deformation was observed under tension. Achieving the cross-scale analysis from micro-modeling to meso-modeling. The results shown by this work improve the understanding of the micromechanical properties of semi-crystalline polymers, which, in turn, provides theoretical guides to improve their fracture resistance in manufacturing.

关键词： Spherulite Microstructure Micro-mechanics Semi-crystalline polymers

来源：评论

学校读者我要写书评

暂无评论

Effect of ions on conductivity and permittivity in the Polar Mesosphere Summer Echoes region

引用

Earth and Planetary Physics 2021年第2期5卷 196-204页

作者： Safi Ullah HaiLong Li Abdur Rauf Lin Meng Bin Wang ShuCan Ge MaoYan Wang School of Electronic Science and Engineering University of Electronic Science and Technology of ChinaChengdu 610054China Terahertz Science and Technology Key Laboratory of Sichuan Province Chengdu 610054China National Key Laboratory of Electromagnetic Environment China Research Institute of Radiowave PropagationQingdao 266107China School of Physics University of Electronic Science and Technology of ChinaChengdu 610054China

For the first time,the effect of ions on complex conductivity and permittivity of dusty plasma at Polar Mesosphere Summer Echoes(PMSE)altitude is *** of ions higher mass and smaller thermal velocity,generally,their effects are not considered in the study of electromagnetic properties of dusty *** this study,we modified the equations of conductivity and permittivity by adding the effect of *** the PMSE altitude region between 80 and 90 km,a local reduction in electron density(i.e.,an electron biteout),is produced by electron absorption onto dust *** bite-out condition contains high dust density and smaller electron *** simulation results in comparatively strong bite-out conditions,we found that the ion effects on conductivity become significant with smaller dust size,lower electron temperature,and lower neutral *** comparatively weak bite-out conditions,the ion effects on conductivity become significant with larger dust size,higher electron temperature,and higher neutral *** the other hand,for different dust sizes,electron temperatures and neutral density,the ion effects on complex permittivity become significant only in very strong bite-out *** on these simulation results,we conclude that,in the absence of electron bite-out conditions,the effect of ions on complex conductivity and permittivity is not significant and can be ***,during bite-out conditions,the effect of ions becomes significant and cannot be ignored because it significantly changes the conductivity and permittivity of dusty plasmas.

关键词： PMSE electromagnetic waves collision and charging effect conductivity and permittivity

来源：评论

学校读者我要写书评

暂无评论

Energy absorption evaluation of multiple fabrics under hypervelocity impact loading

引用

Procedia Structural Integrity 2024年 52卷 52-62页

作者： Huadong Xu Jia Zhou Xu Cao Wenxiang Liu Changqing Miao National Key Laboratory of Science and Technology on Advanced Composites in Special Environment Harbin Institute of Technology Harbin 150001 China School of Water Conservancy & Civil Engineering Northeast Agricultural University Harbin 150001 China

In this work, the energy absorption capability of multiple fabrics was evaluated by hypervelocity impact (HVI) experiments. Six distinct high-performance fabrics, Aluminum (Al) mesh, and 5A06 Al plates were considered as experimental samples, and the areal density were kept constant for all shielding configuration. HVI experiments were carried out by the two-stage light gas gun capable of accelerating 3.97 mm diameter Al projectiles to 4.0 ∼ 4.2 km/s. An evaluation methodology of absorbed energy was proposed to analysis the energy absorption of multiple fabrics in HVI experiments, which based on initial velocity of projectiles, penetrated layers in fabric targets, the depth and volume of the impact crater on witness plate. It was found that UHMWPE and aramid fabric targets were not penetrated, and had a higher energy absorption capacity, exhibiting excellent shielding performance compared to other materials of the same area density.

关键词： Hypervelocity impact Space debris Multiple fabrics. Shielding performance Energy absorption

来源：评论

学校读者我要写书评

暂无评论

Ultrahigh pressure shock compression of platinum up to 1.1 TPa: Melting and ionization

引用

Physical Review B 2024年第14期109卷 144109-144109页

作者： Zhiguo Li Long Hao Xiang Wang Guojun Li Yong Hou Qingsong Wang Lei Liu Huayun Geng Yuying Yu Chengda Dai Qiang Wu Jianbo Hu National Key Laboratory for Shock Wave and Detonation Physics Institute of Fluid Physics China Academy of Engineering Physics Mianyang Sichuan 621900 China Department of Physics National University of Defense Technology Changsha 410073 China State Key Laboratory for Environment-Friendly Energy Materials Southwest University of Science and Technology Mianyang 621010 China

Shock compression experiments on platinum (Pt) were carried out by combining a two-stage gas gun with the unique high-Z three-stage gas gun launcher technique. The shock Hugoniot of Pt was determined in a wide pressure range of 0.2–1.1 TPa. These data fill the gap between the two-stage gas gun and magnetically driven shock experiments, and thereby we observe a clear softening behavior of the Pt Hugoniot at the beginning of ∼1.1 TPa. Ab initio molecular dynamics simulations were also performed to reveal the response of Pt under ultrahigh pressure compressions. The simulation results show that the melting of Pt under shock compression occurs at ∼570 GPa, and a sudden increase in conductivity and free electron number density emerges at the beginning of the Hugoniot softening. The further electronic structure calculations indicate that the Hugoniot softening may arise from the thermal excitation (ionization) of the 5d electrons and the localized 6s electrons in Pt under extreme shock compression. This work has gained further insight into the ionization behaviors of high-Z metal elements with complex electronic structures under ultrahigh pressure compressions, which is of significance for understanding the partial ionization effect in the transition region from condensed matter to warm dense matter.

关键词： Equations of state First-principles calculations Shock waves Warm-dense matter

来源：评论

学校读者我要写书评

暂无评论

New insights into the interactions between Pb(II) and fruit waste biosorbent

引用

CHEMOSPHERE 2022年第Part1期303卷 135048页

作者： Wang, Qian Wang, Yunlong Tang, Junjie Yang, Zi Zhang, Li Huang, Xiaowu [a]Department of Physics Chemistry and Pharmacy University of Southern Denmark 5230 Odense M Denmark [b]Key Laboratory of Protected Horticulture Engineering in Northwest Ministry of Agriculture College of Horticulture Northwest A&F University Yangling Shaanxi 712100 China [c]Environmental Science and Engineering Program Guangdong Technion-Israel Institute of Technology 241 Daxue Road Shantou Guangdong 515063 China [d]State Key Laboratory of Crop Stress Biology in Arid Areas College of Life Sciences Northwest A&F University Yangling Shaanxi 712100 China [e]National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering Beijing University of Technology Beijing 100124 China

Fruit waste is a sustainable biosorbent for heavy metal removal from wastewater. Elucidation of adsorption mechanism is imperative for the process control and development of effective adsorbents. In this study, watermelon rind (WR) exhibited selective and efficient Pb(II) adsorption with a maximum uptake of 230.5 mg/g at pH 5.0. The WR-packed bed column showed high Pb(II) uptake and robust durability over 10 adsorption desorption cycles with long breakthrough time of 8-13 h (89-144 bed volume), and 95% of sequestered Pb (II) was rapidly desorbed in 1-2 h by 0.05 M HCl. Spectroscopic characterization by FTIR and XPS identified hydroxyl, carboxyl, amine, and ether groups as the binding sites for Pb(II) via the binding force of complexation. Physicochemical analysis showed that ion exchange with Mg2+ and Ca2+ accounted for 19% of Pb(II) adsorption by WR;electrostatic attraction and microprecipitation jointly contributed. Quantum chemistry simulation verified the interactions between Pb(II) and binding sites and revealed carboxyl was the preferential functional group. The findings corroborate the applicability of WR in scale-up Pb(II) removal/recovery from wastewater and elaborate the mechanisms of Pb(II) adsorption by the WR biosorbent. This also provides insights into the behavior of heavy metals in other liquid/solid interfaces.

关键词： Fruit waste Heavy metal Adsorption mechanism Column study Circular economy

来源：评论

学校读者我要写书评

暂无评论

Spintronic terahertz emitter with integrated electromagnetic control

引用

Chinese Optics Letters 2022年第4期20卷 77-81页

作者： Yunqing Jiang Xiaoqiang Zhang Yongshan Liu Pierre Vallobra Sylvain Eimer Fan Zhang Yinchang Du Fengguang Liu Yong Xu Weisheng Zhao School of Integrated Circuit Science and Engineering Hefei Innovation Research InsitituteBeihang UniversityBeijing 100191China Anhui High Reliability Chips Engineering Laboratory Hefei 230013China Key Laboratory of Geospace Environment University of Science and Technology of ChinaHefei 230026China

Spintronic thin films are considered as one of the promising terahertz(THz)source candidates,owing to their high performance and low *** effort has been made to achieve spintronic THz sources with broadband and high conversion ***,the development of spintronic THz emitters with good compatibility,low cost,and miniaturized technology still faces many ***,it is urgent to extend commercial and portable spintronic THz emitters to satisfy many practical ***,we design a new generation of spintronic THz emitters composed of an alter-nating electromagnet and a miniaturized electronic *** only can this new type of spintronic THz emitter largely simplify the ancillary equipment for spintronic sources,it also has a twice larger THz signal compared to the traditional THz time-domain spectroscopy systems with a mechanical *** results and theoretical calculations for electromagnetic coils show that our design can stably generate THz signals that are independent of the frequency and magnetic field of alternating *** the spin thin film is optimized,a magnetic field as low as 75 G satisfies the require-ment for high performance THz ***,not only is the efficiency of the pump power enhanced,but also the driving current in the electromagnet is *** believe that it has a wide range of applications and profound implications in THz technology based on spintronic emitters in the future.

关键词： spintronic THz emitters trilayer heterostructure electromagnet electrically driven control

来源：评论

学校读者我要写书评

暂无评论

Water budgets in an arid and alpine permafrost basin:Observations from the High Mountain Asia

引用

Advances in Climate Change Research 2024年第5期15卷 830-844页

作者： Qing-Feng WANG Hui-Jun JIN Dong-Liang LUO Yu SHENG Jun WEN Chien-Lu PING Mark H.CLARK Qiang MA Xiao-Ying JIN Ji-Chun WU Yu-Zhong YANG Qiang LI Raul D.SERBAN Daqing YANG Victor F.BENSE Qing-Bai WU Key Laboratory of Cryospheric Science and Frozen Soil Engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China Qinghai-Beiluhe Plateau Frozen Soil Engineering Safety National Oseration and Research Station Norhwes Institute of Eco-Environment and Resources Chinese Academy of Sciences Lanzhou 730000China School of Civil Engineering and Transportation China-Russia Joint Laboratory of Cold Regions Engineering and Environmentand Permafrost InstituteNortheast Forestry UniversityHarbin 150040 China College of Atmospheric Science Plateau Atmosphere and Environment Key Laboratory of Sichuan ProvinceChengdu University of Information Technology Chengdu 610225China Agricultural and Forestry Experiment Station University of Alaska FairbanksPalmer Research CenterPalmer 99645USA USDA-Natural Resources Conservation Service Palmer 99645USA College of Water Conservancy and Hydropower Engineering Gansu Agricultural UniversityLanzhou 730070China Institute for Alpine Environment Eurac ResearchBolzano 39100Italy Faculty of Agricultural Environmental and Food SciencesFree University of Bozen-BolzanoBolzano 39100Italy Watershed Hydrology and Ecology Division Environment and Climate Change CanadaVictoria V8S 3V3Canada Institute of Tibetan Plateau Research Chinese Academy of SciencesBeijing 100101China Hydrology and Quantiative Water Management Group Department of Environmental SciencesWageningen UniversityWageningen 6700The Netherlands

Ground freeze-thaw processes have significant impacts on infiltration,runoff and ***,there are still critical knowledge gaps in understanding of hydrological processes in permafrost regions,especially of the interactions among permafrost,ecology,and *** this study,an alpine permafrost basin on the northeastern Qinghai-Tibet Plateau was selected to conduct hydrological and meteorological *** analyzed the annual variations in runoff,precipitation,evapotranspiration,and changes in water storage,as well as the mechanisms for runoff gen-eration in the basin from May 2014 to December *** annual flow curve in the basin exhibited peaks both in spring and autumn *** high ratio of evapotranspiration to annual precipitation(>1.O)in the investigated wetland is mainly due to the considerably underestimated‘observed'precipitation caused by the wind-induced instrumental error and the neglect of snow *** stream flow from early May to late October probably came from the lateral discharge of subsurface flow in alpine *** study can provide data support and validation for hydrological model simulation and prediction,as well as water resource assessment,in the upper Yellow River Basin,especially for the headwater *** results also provide case support for permafrost hydrology modeling in ungauged or poorly gauged watersheds in the High Mountain Asia.

关键词： Water budget Runoff Freeze-thaw processes Active layer Permafrost basin Alpine wetland

来源：评论

学校读者我要写书评

暂无评论

Fabrication of novel thin-film composite membrane based on ultrathin metal-organic framework interlayer for enhancing forward osmosis performance

引用

Chinese Chemical Letters 2023年第12期34卷 305-309页

作者： Hao Liu Bo Li Pin Zhao Rongming Xu Chuyang Y.Tang Weilong Song Zunaira Habib Xinhua Wang Jiangsu Key Laboratory of Anaerobic Biotechnology School of Environmental and Civil EngineeringJiangnan UniversityWuxi 214122China Shenergy Environmental Technology Co. Ltd.Hangzhou 31100China State Key Laboratory of Pollution Control and Resource Reuse School of the EnvironmentNanjing UniversityNanjing 210023China Department of Civil Engineering The University of Hong KongHong Kong SAR 999077China Institute of Environmental Sciences and Engineering School of Civil and Environmental EngineeringNational University of Sciences and TechnologyIslamabad44000Pakistan Department of Chemistry Rawalpindi Women UniversityRawalpindi 46300Pakistan Jjiangsu Collaborative Innovation Center of Technology and Material of Water Treatment Suzhou University of Science and TechnologySuzhou 215009China

To improve operation efficiency,an interlayered thin-film composite forward osmosis(iTFC-FO)membrane was designed by introducing an ultrathin and porous interlayer based on aluminum tetra-(4-carboxyphenyl)porphyrin(a stable metal-organic framework nanosheet,Al-MOF).Surface characterization results revealed that Al-MoF spread evenly in the macro-porous substrate,and provided a flat and smooth reaction interface with moderate hydrophilicity and uniform small *** resultant polyamide(PA)layer had a thin base(without intrusion into substrate)and crumpled surface(with abundant leaves).The leaves size and cross-linking degree of PA layer firstly increased and then decreased with the Al-MOF *** to the original membrane,the iTFC-FO showed an enhanced water permeability and a reduced reverse sodium flux in both modes of active layer facing feed solution(ALFS)and active layer facing draw solution(AL-DS).To be specific,the specific reverse sodium flux(reverse sodium flux/pure water flux)decreased from 0.27 g/L to 0.04 g/L in the AL-FS mode,while from 1.36 g/L to 0.23 g/L in the AL-DS mode with 2 mol/L NaCl as ***,the iTFC-FO maintained high stability and high permeability under high-salinity and contaminated *** study offers a new possibility for the rational fabrication of high-performance TFC-FO membranes.

关键词： Thin-film composite embrane Forward osmosis 2Dmetal-organic ramework Porous interlayer Membrane prformance

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：