检索结果-南通市图书馆

The regional difference in engineering-control and tillage factors of Chinese Soil Loss Equation

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2021年第3期18卷 658-670页

作者： chen Rui-yin YAN Dong-chun WEN An-bang SHI Zhong-lin chen Jia-cun liU Yuan chen tai-li Key Laboratory of Mountain Surface Processes and Ecological Regulation Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu 610041China University of Chinese Academy of Sciences Beijing 100049China

Accurate assessment of soil erosion is an important prerequisite for controlling soil *** engineering-control(E)and tillage(T)factors are the keys for Chinese Soil Loss Equation(CSLE)to accurately evaluate water erosion in ***,the E and T factors can reflect the water and soil conservation effects of engineering-control and tillage *** in the current full coverage of soil erosion surveys in China(such as soil erosion dynamic monitoring),for the same practice,the E or T factors are assigned the same value across the *** selected 469 E and T factors data based on runoff plots from 73 publications,and they came from six soil and water conservation *** analysis,regression analysis,and nonparametric tests were used to determine the comparability of the data,and it was proved that the runoff plots dimensions are consistent with the local *** results of one-way ANOVA and nonparametric tests for E and T factors in different regions showed that the engineering-control practices have good soil and water conservation effects and weaken the regional differences of other environmental factors,so there were no significant differences in E factors between different ***,there were significant differences in T factors between different regions,and the geodetector was applied to explore the intrinsic driving force of the spatial distribution of T *** results of the geodetector showed that the dominant driving forces of the spatial distribution of different types of tillage practices were not completely the *** using CSLE to calculate water erosion,the E factor of the same practice can be used uniformly throughout the country,and the T factor needs to be considered and selected according to regional *** the same time,when choosing tillage practices in each water and soil conservation region,practices with better sediment reduction benefits should also be selected according to the regiona

关键词： Engineering-control factor Tillage factor Runoff plot Soil and water conservation regions Geodetector

Multifractal characteristics and spatial variability of soil particle-size distribution in different land use patterns in a small catchment of the Three Gorges Reservoir Region,China

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2021年第1期18卷 111-125页

作者： chen tai-li SHI Zhong-lin WEN An-bang YAN Dong-chun GUO Jin chen Jia-cun liU Yuan chen Rui-yin Key Laboratory of Mountain Surface Processes and Ecological Regulation Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu 610041China University of Chinese Academy of Sciences Beijing 100049China Department of Resources and Environmental Engineering Sichuan Water Conservancy Vocational CollegeChengdu 611231China

Characterizing soil particle-size distribution is a key measure towards soil *** purpose of this study was to evaluate the multifractal characteristics of soil particle-size distribution among different land-use from a purple soil catchment and to generalize the spatial variation trend of multifractal parameters across the catchment.A total of 84 soil samples were collected from four kinds of land use patterns(dry land,orchard,paddy,and forest)in an agricultural catchment in the Three Gorges Reservoir Region,*** multifractal analysis method was applied to quantitatively characterize the soil particle size *** soil particle size distribution(PSD)multifractal parameters(D(0),D(1),D(2),(35)a(q),(35)f[a(q)],α(0))were ***,a geostatistical analysis was employed to reveal the spatial differentiation and map the spatial distribution of these *** multifractal characteristics were *** trend of generalized dimension spectrum of four land use patterns was basically consistent with the range of 0.8 to ***,orchard showed the largest monotonic decline,while the forest demonstrated the smallest decrease.D(0)of the four land use patterns were ranked as:dry land

关键词： Land use patterns Purple soil Multifractal characteristics Particle size distribution Geostatistics Spatial variability

Mental retardation,seizures and language delay caused by new SETD1B mutations:Three case reports

在线全文

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2024年第2期12卷 383-391页

作者： Le Ding li-Wan Wei tai-Song li Jing chen Department of Neurology Children’s Hospital of Nanjing Medical UniversityNanjing 210000Jiangsu ProvinceChina Chigene(Beijing)Translational Medical Research Center Co.Ltd.Beijing 101111China

BACKGROUND The SETD1B gene is instrumental in human intelligence and nerve *** in the SETD1B gene have been linked in recent studies to neurodevelopmental disorders,seizures,and language *** SUMMARY This study aimed to analyze the clinical manifestations and treatment of three patients suffering from mental retardation,epilepsy,and language delay resulting from a new mutation in the SETD1B *** individuals with these symptoms were selected,and their clinical symptoms,gene test results,and treatment were *** article discusses the impact of the SETD1B gene mutation on patients and outlines the treatment *** the three patients(two females and one male,aged 8,4,and 1,respectively),all exhibited psychomotor retardation,attention deficit,and hyperactivity disorder,and two had *** treatment with sodium tripolyvalproate halted the seizures in the affected child,although mental development remained somewhat *** exome sequencing revealed new mutations in the SETD1B gene for all patients,specifically with c.5473C>T(***1825trp),c.4120C>T(***1374*,593),c.14_15insC(***5Hisfs*33).CONCLUSION Possessing the SETD1B gene mutation may cause mental retardation accompanied by seizures and language *** the exact mechanism is not fully understood,interventions such as drug therapy,rehabilitation training,and family support can assist patients in managing their symptoms and enhancing their quality of ***,genetic testing supplies healthcare providers with more precise diagnostic and therapeutic guidance,informs families about genetic disease risks,and contributes to understanding disease pathogenesis and drug research and development.

关键词： Neurodevelopmental disorder Seizure SETD1B gene Whole-exome sequencing New mutation Case report

Underdetermined direction of arrival estimation with nonuniform linear motion sampling based on a small unmanned aerial vehicle platform

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第3期33卷 352-363页

作者： Xinwei Wang Xiaopeng Yan tai An Qile chen Dingkun Huang Science and Technology on Electromechanical Dynamic Control Laboratory School of Mechatronical EngineeringBeijing Institute of TechnologyBeijing 100081China

Uniform linear array(ULA)radars are widely used in the collision-avoidance radar systems of small unmanned aerial vehicles(UAVs).In practice,a ULA's multi-target direction of arrival(DOA)estimation performance suffers from significant performance degradation owing to the limited number of physical *** improve the underdetermined DOA estimation performance of a ULA radar mounted on a small UAV platform,we propose a nonuniform linear motion sampling underdetermined DOA estimation *** the motion of the UAV platform,the echo signal is sampled at different ***,according to the concept of difference co-array,a virtual ULA with multiple array elements and a large aperture is synthesized to increase the degrees of freedom(DOFs).Through position analysis of the original and motion arrays,we propose a nonuniform linear motion sampling method based on ULA for determining the optimal *** the condition of no increase in the aperture of the physical array,the proposed method obtains a high DOF with fewer sampling runs and greatly improves the underdetermined DOA estimation performance of *** results of numerical simulations conducted herein verify the superior performance of the proposed method.

关键词： Unmanned aerial vehicle(UAV) Uniform linear array(ULA) Direction of arrival(DOA) Difference co-array Nonuniform linear motion sampling method

Effect of Reclamation on the Groundwater-Lake Water Interaction in chen Lake

在线全文

学校读者我要写书评

暂无评论

Journal of Earth Science 2024年第3期35卷 1083-1086页

作者： Kun Lei Teng Ma liuzhu chen Zhenxing li Yu chen School of Environmental Studies State Key Laboratory of Biogeology and Environmental GeologyChina University of GeosciencesWuhan 430078China

0 INTRODUCTION To relieve the short supply of suitable land for residing,cultivating,and commerce,it is accepted to reclaim land from lakes,river estuaries,and coastal regions in many countries(Mancini et al.,2020).The large-scale reclamation activities have an irreversible effect on the mico-geomorphology and hydrodynamic system of seasonally flooded areas(Zhang et al.,2019;Yu et al.,2018).For example,coastal regions reclaimed extended the groundwater flow paths,as well as created groundwater level rise,resulting in water-logging in the reclaimed area(Hu et al.,2008).Similar changes in groundwater flow systems may alter groundwater-lake water interactions,and it can ultimately affect the water cycle in the lake ***,such detailed studies are presently *** addition,natural exchanges between the lake and groundwater systems can be strongly affected by physical hydrological processes(Javadzadeh et al.,2020),chemical properties(Kamtchueng et al.,2015),and bioto behavior(Hancock et al.,2005).

关键词： groundwater coastal logging

Flexible interdigitated layered framework with multiple accessible active sites for high-performance CH_(3)I capture

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第5期67卷 1569-1577页

作者： Bo tai Baoyu li linwei He Zhonglin Ma Shujing lin Mingxing Zhang Junchang chen Fuqi Wu Long chen Xing Dai Fuyin Ma Zhifang Chai Shuao Wang State Key Laboratory of Radiation Medicine and Protection School for Radiological and interdisciplinary Sciences(RAD-X)and Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education InstitutionsSoochow UniversitySuzhou 215123China

The development of adsorbent materials for effective capture of radioactive iodomethane(CH_(3)I) from the off-gas of used nuclear fuel reprocessing, remains a significant and challenging line of research because currently state-of-art adsorbents still suffer from low binding affinity with CH_(3)I. Here, we proposed a brand-new adsorption topological structure by developing a 2D interdigitated layered framework, named SCU-20, featuring slide-like channel with multiple active sites for CH_(3)I capture. The responsive rotating-adaptive aperture of SCU-20 enables the optimal utilization of all active sites within the pore for highly selective recognition and capture of CH_(3)I. A record-breaking CH_(3)I uptake capacity of 1.84 g/g was achieved under static sorption conditions with saturated CH_(3)I vapor. Both experimental and theoretical findings demonstrated that the exceptional uptake of SCU-20 towards CH_(3)I can be attributed to the confined physical electrostatic adsorption of F sites, coupled with the chemical nitrogen methylation reaction with uncoordinated N atoms of pyrazine. Moreover, dynamic CH_(3)I uptake capacity potentially allows for the capture of CH_(3)I in simulated real-world off gas reprocessing conditions. This study highlights the potential of SCU-20 as a promising candidate for efficient capture of iodine species and contributes to the development of effective solutions for radioactive iodine remediation.

关键词： 2D interdigitated layered framework iodomethane dual-sites electrostatic interaction physisorption and chemisorption

Sedimentary paleoenvironment and its control on organic matter enrichment in the Mesoproterozoic hydrocarbon source rocks in the Ordos Basin, southern margin of the North China Craton

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2024年第4期21卷 2257-2272页

作者： Zhi-chen Wu Ju-Ye Shi tai-liang Fan Ming Jiang School of Energy Resources China University of Geosciences (Beijing) Key Laboratory of Marine Reservoir Evolution and Hydrocarbon Enrichment Mechanism Ministry of Education China University of Geosciences (Beijing)

The black shale of the Mesoproterozoic Cuizhuang Formation in the Changcheng System in Yongji city,North China Craton, is a potential source rock. Understanding the organic matter enrichment mechanism is crucial for evaluating source rock resources and understanding oil and gas accumulation *** this study, we evaluated the sedimentary paleoenvironment and organic matter enrichment mechanisms of shale using thin section observations, mineral composition analysis, organic geochemistry, and elemental geochemistry. We found significant differences in the sedimentary paleoenvironment and organic matter enrichment mechanisms between the lower Cuizhuang Formation and the Beidajian Formation shale. The Cuizhuang Formation was deposited in a late-stage, restricted basin environment during the rift phase, and elemental and geochemical indicators showed that the Cuizhuang Formation was in a suboxic-anoxic water environment, that was influenced by a warm and humid paleoclimate and submarine hydrothermal activities, which promoted the accumulation of organic matter. However, the enrichment of organic matter in the Cuizhuang Formation was mainly controlled by redox *** formation of suboxic-anoxic water environments may be closely related to the warm and humid paleoclimate and submarine hydrothermal activities. Warm conditions promote continental weathering and increase marine productivity, thereby consuming oxygen in the bottom water. Moreover, acidic hydrothermal activity also helps to establish an anoxic environment. Our results reveal the effects controlling various coupled mechanisms dominated by redox conditions, which may explain the development of source rocks in the Cuizhuang Formation.

关键词： Cuizhuang formation Paleoproterozoic source rocks Marine productivity Paleoenvironments Submarine hydrothermal activity Organic matter enrichment

Low-Carbon Dispatching for Virtual Power Plant with Aggregated Distributed Energy Storage Considering Spatiotemporal Distribution of Cleanness Value

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Modern Power Systems and Clean Energy 2024年第2期12卷 346-358页

作者： Hongchao Gao tai Jin Guanxiong Wang Qixin chen Chongqing Kang Jingkai Zhu State Key Laboratory of Power System Operation and Control Department of Electrical EngineeringTsinghua UniversityBeijing 100084China Sichuan Energy Internet Research Institute Tsinghua University Chengdu 200016China Power Dispatching and Control Center of Shanghai Municipal Electric Power Company Shanghai 200122China IEEE

The scale of distributed energy resources is increasing,but imperfect business models and value transmission mechanisms lead to low utilization ratio and poor *** address this issue,the concept of cleanness value of distributed energy storage(DES)is proposed,and the spatiotemporal distribution mechanism is discussed from the perspectives of electrical energy and *** on this,an evaluation system for the environmental benefits of DES is constructed to balance the interests between the aggregator and the power system ***,an optimal low-carbon dispatching for a virtual power plant(VPP)with aggregated DES is constructed,where-in energy value and cleanness value are both *** achieve the goal,a green attribute labeling method is used to establish a correlation constraint between the nodal carbon potential of the distribution network(DN)and DES behavior,but as a cost,it brings multiple nonlinear ***,a solution method based on the convex envelope(CE)linear re-construction method is proposed for the multivariate nonlinear programming problem,thereby improving solution efficiency and ***,the simulation verification based on the IEEE 33-bus DN is *** simulation results show that the multidimensional value recognition of DES motivates the willingness of resource users to ***,resolving the impact of DES on the nodal carbon potential can effectively alleviate overcompensation of the cleanness value.

关键词： Distributed energy storage virtual power plant(VPP) spatiotemporal distribution low-carbon dispatching

Formation and growth of nanophase iron particles on the surface of Mercury revealed by experimental study

在线全文

学校读者我要写书评

暂无评论

Acta Geochimica 2024年第4期43卷 774-784页

作者： Ronghua Pang Yang li chen li Pengfei Zhang Zhuang Guo Sizhe Zhao Han Yu li Wang chenxi Zhu Shuangyu Wang Kairui tai Qinwei Zhang Yuanyun Wen Rui li Center for Lunar and Planetary Sciences Institute of GeochemistryChinese Academy of SciencesGuiyangChina University of Chinese Academy of Sciences BeijingChina Center for Excellence in Comparative Planetology Chinese Academy of SciencesHefeiChina Institute of Remote Sensing and Geographical Information System School of Earth and Space SciencesPeking UniversityBeijingChina State Key Laboratory of Lunar and Planetary Sciences Macao University of Science and TechnologyMacaoChina Faculty of Metallurgical and Energy Engineering Kunming University of Science and TechnologyKunmingChina State Key Laboratory of High Performance Ceramics and Superfi ne Microstructures Shanghai Institute of CeramicsChinese Academy of SciencesShanghaiChina Laboratory for Space Environment and Physical Sciences Harbin Institute of TechnologyHarbinChina Research Center for Planetary Science College of Earth ScienceChengdu University of TechnologyChengduChina Key Laboratory of Planetary Sciences Purple Mountain ObservatoryChinese Academy of SciencesNanjingChina

Space weathering is a primary factor in altering the composition and spectral characteristics of surface materials on airless ***,current research on space weathering focuses mainly on the Moon and certain types of *** particular,the impacts of meteoroids and micrometeoroids,radiation from solar wind/solar flares/cosmic rays,and thermal fatigue due to temperature variations are being *** weathering produces various transformation products such as melted glass,amorphous layers,iron particles,vesicles,and solar wind *** in turn lead to soil maturation,changes in visible and near-infrared reflectance spectra(weakening of characteristic absorption peaks,decreased reflectance,increased near-infrared slope),and alterations in magnetism(related to small iron particles),collectively termed the“lunar model”of space weathering *** to the Moon and asteroids,Mercury has unique spatial environmental characteristics,including more intense meteoroid impacts and solar thermal radiation,as well as a weaker particle radiation environment due to the global distribution of its magnetic ***,the lunar model of space weathering may not apply to *** studies have extensively explored the eff ects of micrometeoroid ***,this work focuses on the eff ects of solar-wind particle radiation in global magnetic-field distribution and on the weathering transformation of surface materials on Mercury under prolonged intense solar *** the utilization of highvalence state,heavy ion implantation,and vacuum heating simulation experiments,this paper primarily investigates the weathering transformation characteristics of the major mineral components such as anorthite,pyroxene,and olivine on Mercury’s surface and compares them to the weathering transformation model of the *** experimental results indicate that ion implantation at room temperature is insufficient to generate np-Fe^(0)directly but

关键词： Mercury Space weathering Np-Fe^(0) Solar thermal radiation Solar wind