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Precise separation and efficient recovery of Pd(Ⅱ) from high-level liquid waste by XAD-based adsorbents

Rare Metals 2024年第10期43卷 5372-5390页

作者： Hao-Ran Dong Shun-Yan Ning zeng-yuan li Si-Zhi Xu Feng-Tao Hu Feng Gao You-Bin Wang li-Feng Chen Xiang-Biao Yin Toyohisa Fujita Mohammed F.Hamza Yue-Zhou Wei School of Resources Environment and MaterialsGuangxi University School of Nuclear Science and Technology University of South China

Efficient separation of palladium (Pd（II）) from high-level liquid waste （HLLW） not only helps the safe disposal of nuclear waste,but also is a vital importan supplement to Pd（II） ***,16 kinds of nove Amberlite XAD resins-based adsorbents were prepared by vacuum impregnation method for the separation of Pd（II）from simulated HLLW,and the MMBT/XAD7HP prepared using 4-methyl-2-mercaptobenzothiazole （MMBT） as ligand and Amberlite XAD7HP resin （XAD7HP） as the carrier was selected as the optimal research *** analysis experiments proved the successful preparation of MMBT/XAD7HP,which exhibited ultrahigh adsorption selectivity for Pd（II）(distribution coefficient （Kd）≥12584.5 ml·g-1,separation factor (SFPd/M)≥2818.4) and superior adsorption capacity(Q≥130.1 mg·g-1).The adsorption kinetics and adsorption isotherms for Pd（II） matched with pseudo-secondorder （PSO） kinetics model and Langmuir model,indicating that the adsorption mode for Pd（II） by MMBT/XAD7 HP was monolayer chemical *** dynamic column experiments showed that MMBT/XAD7 HP achieved efficiently separation of Pd（II） from simulated HLLW,and the recovery rate was nearly 100% The adsorption mechanism was analyzed by Fourier transform infrared spectroscopy （FTIR）,X-ray photoelectron spectroscopy （XPS） and density functional theory（DFT）,and the ultrahigh selectivity of MMBT/XAD7 HP is attributed to the preferred affinity of the soft-N,S donor atoms in MMBT for Pd（II）.MMBT has the shortest frontline molecular orbital energy band gap （HOMO–LUMO） among the four ligands,which makes it easier to become an electron donor to attract Pd2+to participate in ***3-participates in the adsorption to keep charge *** summary,MMBT/XAD7 HP has broad application prospects for the treatment of Pd（II） in HLLW

关键词： Adsorption Column experiments HLLW Palladium XAD

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活性碳负载纳米金属氧化物对AP热分解的催化性能

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火炸药学报 2024年第5期47卷 475-484,I0006页

作者：石小兵谢五喜李洋黄海涛胥会祥李勇宏曾丽媛庞维强西安近代化学研究所陕西西安710065

采用水热法制备了两种纳米金属氧化物(纳米CuO和纳米Fe_(2)O_(3)颗粒),将纳米CuO和纳米Fe_(2)O_(3)负载在活性碳上,制备成CuO@C、Fe_(2)O_(3)@C复合材料,并将其作为催化剂与高氯酸铵(AP)混合制备成混合物样品AP/CuO、AP/CuO@C、AP/Fe_(2... 详细信息

采用水热法制备了两种纳米金属氧化物(纳米CuO和纳米Fe_(2)O_(3)颗粒),将纳米CuO和纳米Fe_(2)O_(3)负载在活性碳上,制备成CuO@C、Fe_(2)O_(3)@C复合材料,并将其作为催化剂与高氯酸铵(AP)混合制备成混合物样品AP/CuO、AP/CuO@C、AP/Fe_(2)O_(3)、AP/Fe_(2)O_(3)@C;通过扫描电子显微镜(SEM)、差示扫描量热仪(DSC)、热重-微分热重分析(TG-DTG)和热重-红外光谱(TG-FTIR)联用等技术研究了4种催化剂对AP热分解的催化机理及分解动力学特性。结果表明,4种催化剂均将AP的两步分解反应催化为单放热峰,在5 K/min升温速率下,AP的分解峰温较纯AP分别提前90.1、73.4、65.4和69℃;AP/CuO@C分解主要气相产物有HCl、CO_(2)、N_(2)O、HNO_(3)和NO_(2),其中NO_(2)含量最高;AP/Fe_(2)O_(3)@C分解主要气相产物中CO_(2)含量显著提升,NO_(2)含量稍有降低。

关键词：物理化学水热法催化性能 AP 分解动力学气相产物金属氧化物活性炭燃烧催化剂

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小应变土体硬化模型参数的敏感性分析及确定方法

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科学技术与工程 2024年第15期24卷 6366-6376页

作者：董鑫周峰朱锐王旭东曾丽媛南京工业大学交通运输工程学院南京211816

小应变土体硬化(hardening soil model with small strain stiffness,HSS)模型能够反映土体小应变阶段的非线性特性和应力相关性,在深基坑工程领域已被广泛应用。但由于模型参数众多,目前对参数确定方法尚缺乏系统研究。分析了HSS模型... 详细信息

小应变土体硬化(hardening soil model with small strain stiffness,HSS)模型能够反映土体小应变阶段的非线性特性和应力相关性,在深基坑工程领域已被广泛应用。但由于模型参数众多,目前对参数确定方法尚缺乏系统研究。分析了HSS模型各参数的意义及常规确定方法,采用数值模拟方法开展了HSS模型参数的敏感性分析,基于统计的大量研究成果,建立了土体参数与孔隙比之间的非线性关系,进一步通过2处深基坑工程的变形分析进行验证。结果表明:在基坑数值分析中,参考动剪切模量G_(0)^(ref)的敏感性最高,参考切线模量E_(oed)^(ref)的敏感性最低,建立的非线性关系能够较好地反映土体模量与孔隙比的相关性,围护结构侧移的计算值及实测值较为吻合,验证了提出的参数确定方法的适用性,可为相关工程提供参考。

关键词：基坑工程 HSS模型小应变特性敏感性分析参数确定

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Estimating Stem Volume Using QuickBird Imagery and Allometric Relationships for Open Populus xiaohei Plantations

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Journal of Integrative Plant Biology 2007年第9期49卷 1304-1312页

作者： Xiao-Qing Wang zeng-yuan li Xing-E liu Guang Deng Ze-Hui Jiang Research Institute of Wood Industry Chinese Academy of Forestry Beijing 100091 China Research Institute of Forest Resource Information Techniques Chinese Academy of Forestry Beijing 100091 China Intemational Centre for Bamboo and Rattan Beijing 100102 China)

There has been a great deal of interest in studying the crown of trees using remote sensing data. In this study, crown width was extracted from high-resolution QuickBird images for open Populus xiaohei plantations. Regression models for predicting the individual stem volumes of Populus xiaohei were established using extracted crown width, as well as estimated tree parameters （i.e. diameter at breast height [DBH] and tree height） as predictors. Our results indicated that crown width could be accurately extracted from QuickBird images using a multi-scale segmentation approach with a mean relative error of 5.74%, especially for wide-spacing stands. Using either extracted crown width alone or with estimated DBH and tree height can successfully estimate individual stem volume of Populus xiaohei with the R2 value ranging from 0.87 to 0.92 depending on different model forms. In particular, the two second-order polynomial models （model 2 and model 6）, based on QuickBird image-derived crown widths and estimated DBH and tree heights, respectively, were the best at describing the relationship between stem volume and tree characteristics.

关键词： diameter at breast height Populus xiaohei QuickBird image stem volume tree crown tree height.

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Migration and distribution characteristics of soil heavy metal(loid)s at a lead smelting site

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Journal of Environmental Sciences 2024年第1期135卷 600-609页

作者： Chuxuan li Mu li Jiaqing zeng Shanxin yuan Xinghua Luo Chuan Wu Shengguo Xue School of Metallurgy and Environment Central South UniversityChangsha 410083China Chinese National Engineering Research Center for Control and Treatment of Heavy Metal Pollution Central South UniversityChangsha 410083China

Heavy metal(loid)s contamination is a constant issue at smelting *** is essential to investigate the spatial distribution and migration characteristics of heavy metal(loid)s in the soil for environmental management and remediation strategies of non-ferrous smelting *** this study,203 soil samples from 57 sites were collected in a typical lead smelting *** findings demonstrated that there were significant Pb,Zn,Cd,and As contamination in soil *** spatial distribution of heavy metal(loid)s showed strong spatial heterogeneity,the contaminated soil areas of Pb,As,Cd,and Zn were 99.5%,98.9%,85.3%,and 72.4%,***,Cd,and As contamination of the soil reached a depth of 5 m,which migrated from the surface to deep soil *** leaching contents of Zn,Pb,and As decreased obviously in 3-4 m soil layer,but the leaching content of Cd was still high,which indicated the high migration of *** the increase of depth,the proportion of acid soluble fraction of heavy metal(loid)s decreased,and the residual fraction *** acid soluble fraction of Cd accounted for a higher proportion,and As mainly existed in reducible and residual fractions in *** to the calculation of the migration factor,the migration of heavy metal(loid)s in soils were ordered as Cd>Zn>Pb>*** outcomes are advantageous for risk reduction and site remediation for non-ferrous metal smelting sites.

关键词： Smelting sites Heavy metal(loid)s Spatial distribution Chemical speciation Migration characteristics

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The origin and evolution of Earth's nitrogen

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National Science Review 2024年第6期11卷 56-75页

作者： yuan li State Key Laboratory of Isotope Geochemistry Guangzhou Institute of GeochemistryChinese Academy of Sciences Bayerisches Geoinstitut Universit?t Bayreuth

Nitrogen is a vital element for life on Earth. Its cycling between the surface(atmosphere + crust) and the mantle has a profound influence on the atmosphere and climate. However, our understanding of the origin and evolution of Earth's nitrogen is still incomplete. This review presents an overview of the current understanding of Earth's nitrogen budget and the isotope composition of different reservoirs, laboratory constraints on deep nitrogen geochemistry, and our understanding of the origin of Earth's nitrogen and the deep nitrogen cycle through plate subduction and volcanism. The Earth may have acquired its nitrogen heterogeneously during the main accretion phase, initially from reduced, enstatite-chondrite-like impactors,and subsequently from increasingly oxidized impactors and minimal CI-chondrite-like materials. like Earth's surface, the mantle and core are also significant nitrogen reservoirs. The nitrogen abundance and isotope composition of these three reservoirs may have been fundamentally established during the main accretion phase and have been insignificantly modified afterwards by the deep nitrogen cycle, although there is a net nitrogen ingassing into Earth's mantle in modern subduction zones. However, it is estimated that the early atmosphere of Earth may have contained ～1.4 times the present-day atmospheric nitrogen(PAN),with ～0.4 PAN being sequestered into the crust via biotic nitrogen fixation. In order to gain a better understanding of the origin and evolution of Earth's nitrogen, directions for future research are suggested.

关键词： nitrogen isotopes silicate Earth atmosphere magma ocean

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Comparative study on interaction between rare earth oxide refractories and rare earth treated steel

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Journal of Iron and Steel Research International 2024年第6期31卷 1493-1501页

作者： Ze Meng Guang-qiang li Cheng yuan Yi-jiang Zhao Qing Zheng Bin zeng Yu liu The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan430081HubeiChina Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan430081HubeiChina Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steelmaking Wuhan University of Science and TechnologyWuhan430081HubeiChina Technical Center Lianyuan Iron and Steel Co.Ltd.Loudi417009HunanChina

Refractories have an important effect on the cleanliness of molten *** interaction between CeAlO_(3) refractories and Ce treated steel was explored and compared with that between Al_(2)O_(3) refractories and Ce treated *** results show that the Ce content in steel decreases sharply after contact with Al_(2)O_(3) refractories and the pick-up of dissolved Al *** with the test of Al_(2)O_(3) refractories,the loss of Ce content is less in the test of CeAlO_(3) refractory,and the total oxygen content and dissolved Al content in steel increase *** dense and continuous Ce_(2)O_(2)S interface layer is observed at the CeAlO_(3) refractories/steel interface,which can serve as the metallurgical isolation layer and hinder the further interaction between refractories and ***,the higher steel cleanliness and less penetration of refractories by molten steel are obtained in the test of CeAlO_(3) *** CeAlO_(3) refractories show a promising prospect in the production of clean Ce treated steel.

关键词： CeAlO_(3)refractory Steel Cleanliness Interaction Rare earth

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Evolution of interfacial heat transfer,contact behavior and microstructure during sub-rapid solidification of molten steel with different hydrogen contents

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Journal of Iron and Steel Research International 2024年第1期31卷 215-223页

作者： Cheng Lu Wan-lin Wang Chen-yang Zhu Jie zeng Xin-yuan liu Hua-long li School of Metallurgy and Environment Central South UniversityChangsha410083HunanChina National Center for International Research of Clean Metallurgy Central South UniversityChangsha410083HunanChina Institute of Research of Iron and Steel ShasteelZhangjiagang215625JiangsuChina

Typical Q235 low-carbon steel samples with different hydrogen contents(0.0004,0.0008,and 0.0013 wt.%)were prepared by adjusting the environment humidity and *** effects of hydrogen on interfacial heat transfer,contact behavior,and microstructure evolution were investigated using a novel droplet solidification *** results revealed that when the hydrogen content increases from 0.0004 to 0.0013 wt.%,the maximum heat flux between the molten steel and cooling substrate decreases from 8.01 to 6.19 MW/m^(2),and the total heat removed in the initial 2 s reduces from 10.30 to 8.27 MJ/m^(2).Moreover,the final contact angle between the molten steel and substrate increases from 103.741°to 113.697°,and the number of pores on the droplet bottom surface increases significantly from 21 to 210 with the increase in *** surface roughness of the droplet bottom surface increases from 20.902 to 49.181 *** addition,the average grain size of the droplet increases from 14.778 to 33.548 pm with the increase in the hydrogen *** interfacial contact condition becomes worse due to the escape of hydrogen from the steel matrix during the cooling process,which leads to the reduction in the interfacial heat transfer and the increase in the grain size.

关键词： Strip casting Hydrogen content Interfacial heat transfer behavior Contact behavior Microstructure evolution

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A chiral fluorescent probe for molecular recognition of basic amino acids in solutions and cells

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Chinese Chemical Letters 2024年第10期35卷 364-369页

作者： Chuan-Zhi Ni Ruo-Ming li Fang-Qi Zhang Qu-Ao-Wei li yuan-yuan Zhu Jie zeng Shuang-Xi Gu School of Chemistry and Environmental Engineering School of Chemical Engineering&PharmacyPharmaceutical Research InstituteHubei Key Laboratory of Novel Reactor and Green Chemical TechnologyWuhan Institute of TechnologyWuhan 430205China Nanjing Pusheng Biomedical Co. Ltd.Nanjing 210033China

A novel and readily available binaphthyl-based fluorescent probe(S)-1 was designed and synthesized.(S)-1 can be used to not only chemoselectively discriminate 3 basic amino acids out of common amino acids,but also enantioselectively recognize ***,enantioselective imaging of histidine in cells was achieved for the first time by the probe(S)-*** performances endowed it potential application in the chiral analysis of basic amino acids in asymmetric synthesis and cell imaging for diagnosis of diseases caused by racemization of *** magnetic resonance(NMR)and mass spectrometry investigations suggested that different reaction extent of(S)-1 with L/D-histidine and different product structures generated the observed enantioselective fluorescent *** molecular structures and thermodynamic stability of the complexes,formed from(S)-1+Zn2+and enantiomers of histidine,were calculated by Gaussian 16 based on density functional theory(DFT)to validate the above action mechanism.

关键词： Fluorescent probe Chiral recognition Enantioselectivity Chemoselectivity Basic amino acids Cell imaging

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Degree of shade tolerance shapes seasonality of chlorophyll, nitrogen and phosphorus levels of trees and herbs in a temperate deciduous forest

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Journal of Forestry Research 2024年第4期35卷 60-72页

作者： Jiajia zeng Fan liu yuan Zhu Jiayi li Ying Ruan Xiankui Quan Chuankuan Wang Xingchang Wang Aulin College Northeast Forestry UniversityHarbin 150040People’s Republic of China Center for Ecological Research Northeast Forestry UniversityHarbin 150040People’s Republic of China Key Laboratory of Agricultural Water Resources Center for Agricultural Resources ResearchInstitute of Genetics and Developmental BiologyChinese Academy of SciencesShijiazhuang 050021People’s Republic of China Institute of Applied Ecology Chinese Academy of SciencesShenyang 110016People’s Republic of China Key Laboratory of Sustainable Forest Ecosystem Management Ministry of EducationNortheast Forestry UniversityHarbin 150040People’s Republic of China

Forest productivity is closely linked to seasonal variations and vertical differentiation in leaf ***,leaf structural and chemical traits variation among co-existing species,and plant functional types within the canopy are poorly *** this study,the seasonality of leaf chlorophyll,nitrogen(N),and phosphorus(P)were quantified vertically along the canopy of four major tree species and two types of herbs in a temperate deciduous *** role of shade tolerance in shaping the seasonal variation and vertical differentiation was *** the entire season,chlorophyll content showed a distinct asymmetric unimodal pattern for all species,with greater chlorophyll levels in autumn than in spring,and the timing of peak chlorophyll per leaf area gradually decreased as shade tolerance *** a:b ratios gradually decreased with increasing shade *** N and P contents sharply declined during leaf expansion,remained steady in the mature stage and decreased again during leaf *** the seasons,the lower canopy layer had significantly higher chlorophyll per leaf mass but not chlorophyll per leaf area than the upper canopy layer regardless of degree of shade ***,N and P per leaf area of intermediate shade-tolerant and fully shade-tolerant tree species were significantly higher in the upper canopy than in the *** variations in N:P ratios suggest changes in N or P *** findings indicate that shade tolerance is a key feature shaping inter-specific differences in leaf chlorophyll,N,and P contents as well as their seasonality in temperate deciduous forests,which have significant implications for modeling leaf photosynthesis and ecosystem production.

关键词： Leaf traits Leaf nutrients Seasonal variations Chlorophyll Nitrogen Phosphorus Shade tolerance Canopy layers

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