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Recovery of thorium and rare earths from leachate of ion-absorbed rare earth radioactive residues with N1923 and Cyanex■572

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Journal of Rare Earths 2021年第10期39卷 1273-1281,I0004页

作者： Jia Su Xiangguang Guo Yun Gao shan wu Ruigao Xu Xiaoqi Sun CAS Key Laboratory of Design and Assembly of Functional Nanostructures And Fujian Key Laboratory of NanomaterialsFujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China Xiamen Institute of Rare Earth Materials Haixi InstituteChinese Academy of SciencesXiamen 361021China University of Chinese Academy of Sciences Beijing 100039China Longnan County Nanyu Rare Earth Resources Comprehensive Utilization Co. Ltd.Ganzhou 341000China Ganzhou Rare Earth Group Co. Ltd.Ganzhou 341000China

Ion-absorbed rare earth ores radioactive residues(IREORR)are a class of waste residue from the production of rare earth elements(REEs).Because of its radioactive dose,IREORR are usually stored in waste *** are difficult to be disposed ***,it contains relatively high concentrations of REEs,which can be considered as a valuable secondary *** this paper,a novel process is developed for the separation of thorium(Th)and recovery of REEs from IREORR hydrochloric acid leachate with primary amine N1923 and Cyanex?572,*** effects of sulfate concentration,extractant concentration and pH on N1923 extraction in hydrochloric acid solution were investigated in *** results show that the extraction capacity of N1923 can be improved by adding sulfate to the solution and increasing the concentration of *** has little effect on the extraction of Th when pH is higher than *** for the stripping,REEs are more easily stripped from loaded organic phase than Th,and nitric acid is a better stripping agent than hydrochloric *** with the extraction of Cyanex■572 for REEs,a fractional extraction experiment for separating Th and enriching of REEs was *** yield of Th is higher than 99.9%and the concentration of REEs is enriched to 183.84 g/L.

关键词： Radioactive residues Rare earth Thorium Primary amine N1923 Cyanex?572

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Dreamlet:A New Representation and Migration of Seismic Wavefield in Full Local Domains

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Communications in Computational Physics 2020年第6期28卷 111-127页

作者： Bangyu wu Ru-shan wu Xiudi Jiang Wenbo Sun Jinghuai Gao School of Mathematics and Statistics Xi’an Jiaotong UniversityXi’an 710049P.R.China Department of Earth and Planetary Sciences University of California Santa CruzSanta Cruz 95064USA CNOOC Research Institute Co. Ltd.Beijing 100028P.R.China

Seismic events have limited time duration,vary with space/traveltime and interact with the local subsurface medium during *** is a valu-able strategy for nonstationary seismic data analysis,processing and wave *** has the potential for sparse data representation,flexible data operation and highly accurate local wave *** local transforms are powerful tools for seismic data segmentation and *** this paper,a detailed description of a multi-dimensional local harmonic transformed domain wave propagation and imaging method is *** a tensor product of a Local Exponential Frame(LEF)vector as the time-frequency atom(a drumbeat)and a Local Cosine Basis(LCB)function as the space-wavenumber atom(a beamlet),we construct a time-frequency-space-wavenumber local atom-dreamlet,which is a combination of drumbeat and *** dreamlet atoms have limited spatial extension and temporal duration and constitute a complete set of frames,termed as dreamlet frames,to decompose and represent the *** dreamlet transform first partitions the wavefields using time-space supporting functions and then the data in each time-space blocks is repre-sented by local harmonic *** transformed wavefield is downward-continued by the dreamlet propagator,which is the dreamlet atom evolution weightings deduced from the phase-shift one-way *** dreamlet imaging method is formulated with a local background propagator for large-scale medium propagation and com-bined with a local phase-screen correction for small-scale *** features of dreamlet migration and imaging include sparse seismic data representation,accurate wave propagation and the flexibility of localized time operations during *** tests using Sigsbee 2A synthetic data set and real marine seismic data demonstrate the validity and accuracy of this *** time-domain localization being involved,the dreamlet method can also be

关键词： Seismic imaging wave equation local harmonic transform seismic migration dreamlet transform

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富水岩溶隧道注浆处理及工艺优化

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公路工程 2024年第2期49卷 39-45页

作者：张瑞平邱伟超唐宇巫山中交路桥华北工程有限公司北京101100 中南大学资源与安全工程学院湖南长沙410083

为了提高隧道富水岩溶区的注浆加固效果,依托某隧道工程,采用多种超前探测手段对隧道富水岩溶区进行全面探测。在此基础上,采用数值模拟方法,分析不同注浆厚度下隧道位移变化和涌水的变化规律,并采用3种注浆技术相结合的方法对隧道富水... 详细信息

为了提高隧道富水岩溶区的注浆加固效果,依托某隧道工程,采用多种超前探测手段对隧道富水岩溶区进行全面探测。在此基础上,采用数值模拟方法,分析不同注浆厚度下隧道位移变化和涌水的变化规律,并采用3种注浆技术相结合的方法对隧道富水岩溶区进行了注浆加固。研究结果表明:帷幕注浆厚度主要体现在减少涌水量上,当注浆厚度超过5 m以后,隧道的止水效果几乎不再增长;选择5 m的注浆厚度和25 m的注浆长度作为工程的注浆范围。在注浆过程中,3种注浆技术相结合,可以有效解决高水位涌动和成孔困难的问题。勘探和注浆结合的方法,可为后续注浆方案提供动态反馈和优化。注浆结束后,现场施工情况表明,注浆效果良好。

关键词：隧道工程注浆参数现场试验帷幕注浆数值模拟

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中国式现代化进程中就业质量对充分就业影响研究

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调研世界 2024年第9期 3-16页

作者：吴珊郭航张也驰张壬壬国家统计局人口和就业统计司

本文构建了我国就业质量指标体系,并使用Dagum基尼系数分解法分析就业质量区域差异和演变趋势,结果显示我国就业质量总体水平逐年提高,但区域不平衡程度加深。通过空间计量模型发现,就业质量提升对充分就业总体有促进作用,且这种促进作... 详细信息

本文构建了我国就业质量指标体系,并使用Dagum基尼系数分解法分析就业质量区域差异和演变趋势,结果显示我国就业质量总体水平逐年提高,但区域不平衡程度加深。通过空间计量模型发现,就业质量提升对充分就业总体有促进作用,且这种促进作用呈倒U型,在中等分位点有较强促进作用,在高、低分位点的促进作用较弱。

关键词：就业质量指标体系 Dagum基尼系数

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多工序机床自动上下料控制系统设计

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锻压装备与制造技术 2024年第4期59卷 74-76页

作者：陈尔含郝晓庆刘坤武珊济南和拓自动化科技有限公司山东济南250000

随着科技的发展,机器人因其装卸精度高、免维护、可连续不间断工作等特点在工业生产中得到快速普及应用。本文针对多工位机床上料控制系统的硬件、软件实现进行简要介绍,并对某些功能实现进行了改进优化。

关键词：工业机器人自动上下料控制系统铁屑冲洗

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Diversity and vertical distributions of sediment bacteria in an urban river contaminated by nutrients and heavy metals

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Frontiers of Environmental Science & Engineering 2013年第6期7卷 851-859页

作者： Xunan YANG shan HUANG Qunhe wu Renduo ZHANG Guangli LIU Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology School of Environmental Science and Engineering Sun Yat-sen University Guangzhou 510275 China

The aim of this study was to investigate the benthic bacterial communities in different depths of an urban river sediment accumulated with high concentrations of nutrients and metals. Vertical distributions of bacterial operational taxonomic units （OTUs） and chemical para- meters （nutrients： NH4＋, NO3, dissolved organic carbon, and acid volatile sulfur; metals： Fe, Zn, and Cu） were characterized in 30 cm sediment cores. The bacterial OTUs were measured using the terminal restriction fragment length polymorphism analysis. Biodiversity indexes and multivariate statistical analyses were used to characterize the spatial distributions of microbial diversity in response to the environmental parameters. Results showed that concentrations of the nutrients and metals in this river sediment were higher than those in similar studies. Furthermore, high microbial richness and diversity appeared in the sediment. The diversity did not vary obviously in the whole sediment profile. The change of the diversity indexes and the affiliations of the OTUs showed that the top layer had different bacterial community structure from deeper layers due to the hydrological disturbance and redox change in the surface sediment. The dominant bacterial OTUs ubiquitously existed in the deeper sediment layers （5-27 cm） corresponding to the distributions of the nutrients and metals. With much higher diversity than the dominant OTUs, the minor bacterial assemblages varied with depths, which might be affected by the sedimentation process and the environmental competition pressure.

关键词： heavy metals nutrients sediment profile,terminal restriction fragment length polymorphism

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Second organic aerosol formation by irradiation of α-pinene-NO_x-H_2O in an indoor smog chamber for atmospheric chemistry and physics

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Chinese Science Bulletin 2008年第21期53卷 3294-3300页

作者： ZHAO Zhe HAO JiMing LI JunHua wu shan Department of Environmental Science and Engineering Tsinghua University Beijing 100084 China

Ozone(O3) and secondary organic aerosol(SOA) are considered to be the most serious secondary air pollutants of concern in most metropolitan areas,as well as for *** this study,O3 and SOA for-mation potential of α-pinene,the most abundant biogenic VOCs,is investigated at Tsinghua Indoor Chamber *** experiments were conducted under atmospheric relevant HCs/NOx ratios in both presence and absence of ammonia sulfate seed aerosol.A Scanning Mobility Particle Sizer system(3936,TSI) and a Condensation Particle Counter(3010,TSI) were used to study the SOA formation and a gas chromatograph(GC) equipped with a DB-5 column and a flame ionization detector(FID) was used to measure α-pinene *** results show that the presence of ammonia sulfate seed aerosol did not change the formation trend of O3,but significantly contribute to SOA formation.A strong linear relationship(r2 = 0.90) between SOA yield enhancement(△Y*) and surface concentration of seed aerosol(PMi,s)has been found,denoting that the PMi,s is the control factor for SOA yield *** the possible reason for the enhancement is acid-catalyzed heterogeneous reactions.

关键词：种子微粒物气溶胶照射 a-蒎烯-NOx-H2O 化学

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Corrosion behavior and corrosion products of a low-alloy weathering steel in Qingdao and Wanning

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International Journal of Minerals,Metallurgy and Materials 2009年第1期16卷 58-64页

作者： Shu-tao Wang shan-wu Yang Ke-wei Gao Xin-lai He School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China

A newly developed low-alloy weathering steel has been exposed in two coastal sites （Qingdao in the north, Wanning in the south） in China for one year. The samples in Wanning corroded far more seriously than those in Qingdao. The rust layer formed on the steel was analyzed by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, N2 adsorption approach, polarization curves, and electrochemical impedance spectroscopy （EIS）. The rust formed in Qingdao contains more X-ray amorphous compounds and is more compact than that formed in Wanning. Cr and Cu are enriched in the rust layer near the steel matrix, and the phenomenon is more obvious in Qingdao than in Wanning. The rust layer formed in Qingdao suppresses the anodic and cathodic reaction more remarkably than that formed in Wanning does. The rust layer formed in Qingdao possesses a higher ability to block the permeation of chloride ions than that formed in Wanning does.

关键词： low-alloy steel weathering steel atmospheric corrosion marine environment subtropical environment

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Boosting the Activity and Stability with Dual-Metal-N Couplings for Li–O_(2)Battery

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Energy & Environmental Materials 2022年第3期5卷 918-927页

作者： shan wu Di wu Dawei Zhang Wenhong Liu Hao Luo Jianbo He Qingchun Yang Zhiwei Li Ruiping Liu School of Chemistry and Chemical Engineering Hefei University of TechnologyHeifei Anhui 230009China Department of Materials Science and Engineering China University of Mining and Technology-Beijing CampusBeijing 100083China

Electrocatalysts with high efficiency are crucial for improving the storage capacity and electrochemical stability of lithium–oxygen batteries(LOBs).In this work,through a facile hydrothermal method,cobalt–nitrogen-doped carbon nanocubes(Co–N/C),the calcination products of zeolitic imidazolate framework(ZIF–67)are encapsulated by ultrathin C–MoS_(2) nanosheets to obtain Co–N/C@C–MoS_(2) composites which are used as host materials for the oxygen *** synergistic effect between Co–N_(x) active sites and Mo–N coupling centers effectively promotes the formation and decomposition of Li_(2)O_(2) during repeated discharge and charge *** mesoporous C–MoS_(2) nanosheets with delicately designed morphology facilitate charge transfer and account for improved reaction kinetics and more importantly,suppressed side reactions between the carbon materials and the *** oxygen cathode with the Co–N/C@C–MoS_(2)host shows a high initial discharge specific capacity of 21197 mAh g^(-1)and a long operation life of 332 *** calculation provides in-depth explanation for the reaction mechanism and offers insights for the rational design of electrocatalysts for LOBs.

关键词： carbon-based electrocatalyst cobalt and nitrogen doping electrochemical stability Li–O_(2)batteries molybdenum disulfide

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新安江水库流域降水时间演变特征

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水电能源科学 2024年第9期42卷 17-20,16页

作者：赵新华杨登宇谢意乐李强吴善锋国网新源集团有限公司新安江水力发电厂浙江杭州310000 国电南瑞科技股份有限公司江苏南京211106

为了解新安江水库流域降水的长期演变特征,利用2006~2022年GPM降水数据、GLDAS土壤含水率数据和典型站点的降水量与水位数据,结合HYSPLIT、PSCF、CWT模式,分析了降水量和水位的时间演变特征、不同降水气团的差异和降水的潜在来源。结果... 详细信息

为了解新安江水库流域降水的长期演变特征,利用2006~2022年GPM降水数据、GLDAS土壤含水率数据和典型站点的降水量与水位数据,结合HYSPLIT、PSCF、CWT模式,分析了降水量和水位的时间演变特征、不同降水气团的差异和降水的潜在来源。结果表明,干流单一站点的降水量可用于代表新安江水库流域的降水量变化特征。降水量、0~200 cm土壤含水率和水位存在明显月际变化,降水量在6月最高,土壤含水率和水位在7月最高。2006~2022年新安江流域的降水气团共分为六类:1型西南内陆远距离气团(31.8%)、2型西北内陆气团(7.2%)、3型局地气团(19.7%)、4型西南内陆近距离气团(15.7%)、5型东部海洋气团(3.8%)和6型西部内陆气团(21.8%)。不同类型气团降水的时间分布特征存在显著差异。新安江流域降水的PSCF分布与CWT分布类似,高值区均位于其西南方向。新安江流域的降水潜在来源贡献主要是江西全省和湖南省的东部地区,在对其降水过程预报时应多关注该区域的降水气团变化。研究结果可为新安江水库防汛和水力发电提供理论依据。

关键词：新安江水库流域降水量水位时间演变气团聚类潜在来源

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