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Heterobimetallic lanthanide tetrahedral cages:Synthesis,design and application for potential multimodal imaging contrast agent

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Journal of Rare Earths 2024年第2期42卷 278-285,I0002页

作者： yongxiu li Feng Guo Siwei Wei Duofu li Jun Zhang Kai Xu Dongping li Department of Chemistry Nanchang UniversityNanchang330031China Key Laboratory of Functional Molecule Design and Interface Process Anhui Jianzhu UniversityHefei230601China Department of Otolaryngology Head and Neck SurgeryThe Second Affiliated Hospital of Nanchang UniversityNanchang330006China

The construction and functionalization of lanthanide-organic cages have been a research hotspot in coordination *** from the unique luminescent and magnetic properties of lanthanide ions,the potential applications of lanthanide-organic cages in biological imaging applications are promising,but only a few corresponding explorations have been *** rein,we introduced a series of lanthanide tetrahedral cages,(Eu_(n)Gd_(4-n)L_(4))(sol)_8(n=0,1,2,3 and 4,where L=(4,4',4"-tris(4,4,4-trifluoro-1,3-dioxobutyl)-triphenylamine,and sol=dimethyl sulfoxide and methanol),with potential applications in biological *** the good luminescent and magnetic properties of Eu^(3+) and Gd^(3+) ions,Eu_(4)L_(4) and Gd_(4)L_(4) complexes show a high luminescence quantum yield of 29% in DMSO and large longitudinal relaxivity(r_(1)) of 11.4(mmol/L)^(-1)/s at 0.5 T in water containing 1 vol% DMSO,*** heterobimetallic Eu-Gd complexes achieve a dual imaging mode by combining luminescent and magnetic centers in one *** the Gd:Eu ratio increases from 1:3 to 3:1,the r_(1) values increases from 5.33 to 8.64(mmoI/L)^(-1)/s,higher than that of commercial contrast agent Gd-DOTA(3.23(mmol/L)^(-1)/s).Owing to their low toxicity and good cell imaging ability toward ECA 109 cells,the selfassembled Eu-Gd heterobimetallic tetrahedral cages could be potential candidates for the multimodal imaging contrast agent.

关键词： Lanthanide organic cage Luminescence Cell imaging Contrast agents Rare earths

Tuning thermal decomposition of ammonium perchlorate by nanoporous Gd2O3 for improved safety and enhanced propellant efficiency

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Journal of Rare Earths 2020年第1期38卷 108-112页

作者： Xuezhen Zhou Chunyan Hu Xiaojun liu Weifan Chen Qun Tang yongxiu li Research Center for Rare Earths&Nano/micro Functional Materials Nanchang UniversityNanchang 330047China Jiangxi Agricultural University Nanchang 330045China

Nanoporous Gd2O3 powders(NGPs) with different specific surface areas were prepared by a nonaqueous sol-gel method and utilized to tune the exothermal decomposition of ammonium perchlorate(AP) for enhanced propellant efficiency and improved *** is found that with the increasing dosage of NGPs into AP,the two exothermal peaks of AP merge into one intense exothermal peak,indicating that an "energy stacking" has been ***,the unique delay of the first exothermal peak of AP is conducive to the safety of AP in application ***,the dependence of decomposition heat of AP on dosage and calcination temperature is more evident than on the surface areas of NGPs,suggesting that the promotion effect of NGPs on the thermal decomposition of AP does not only rely on the surface ***,an electron transfer mechanism is proposed to illustrate the decomposition process of AP tuned by NGPs.

关键词： Nanoporous Gd2O3 powders Thermal decomposition Ammonium perchlorate Electron transfer mechanism Rare earths

Leaching ion adsorption rare earth by aluminum sulfate for increasing efficiency and lowering the environmental impact

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Journal of Rare Earths 2019年第4期37卷 429-436页

作者： lifen Yang Cuicui li Dashan Wang Fengyang li Yanzhu liu Xuezhen Zhou Mingbiao liu Xiufeng Wang yongxiu li Research Center for Rare Earths & Nano/Micro Functional Materials Nanchang University Qiandong Rare Earth Croup Co. Ltd.

The leaching efficiency(LE) of ion adsorption rare earth(IARE) by the sulfate and chloride of ammonium,magnesium and aluminum were comparatively determined using column leaching method. It is found that at equal equivalent concentration of cation, the LE of IARE by aluminum sulfate is the highest, and the zeta potential of clay mineral particles in the tailing is near to zero, which means a lower risk of landslide and pollutant emission. Furthermore, the optimum concentration of aluminum sulfate is determined to be0.02 mol/L, which is much lower than that of ammonium sulfate and magnesium sulfate. To reduce the production cost and environmental impact, we proposed a multi-stage leaching process, which was firstly leaching with ammonium sulfate and then with aluminum sulfate, following by water washing and lime neutralizing. With the ratio of ammonium sulfate to aluminum sulfate varying from 1:0 to 0.5:0.5, the residual ammonium in tailing decreases from 11.2% to 0.6%, however, the LE of RE shows an optimum value at 0.8:0.2. By neutralizing the pH of tailing with lime water to over 6, the ion concentration in water rinsing solution can meet the requirement for water discharge. At the same time, the zeta potential of clay particles is found to be around-5 mV, means a relatively lower risk of landslide. These facts indicate that the LE of IARE can be increased and the danger caused by tailings landslides and pollutant emissions can be reduced by replacing ammonium sulfate with aluminum sulfate as leaching reagent.

关键词： Ion adsorption rare earth Aluminium sulfate Leaching efficiency Environmental protection

Evaluating the fractionation of ion-adsorption rare earths for in-situ leaching and metallogenic mechanism

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Journal of Rare Earths 2018年第12期36卷 1333-1341页

作者： Qiuhua Xu lifeng Yang Dashan Wang Xiao Hou Yuanyuan Sun Xuezhen Zhou Xinmu Zhou yongxiu li Research Center for Rare Earths Micro/Nano-Functional Materials Nanchang University College of Environmental and Chemical Engineering Nanchang Hangkong University

The fractionation of ion adsorption rare earths(IAREs) along the depth in a shaft of a deposit at Dajishan,Jiangxi, China was comparatively evaluated using the partition values(PVs) and relative fractionation values(RFVs) of the leached rare earths(REs). It is found that both PVs and RFVs can objectively reflect the migration and fractionation of REs, but RE content and abrasion pH could not. However, the RFVs can provide more information to quantitatively evaluating the migration and fractionation characteristics of REs along the selected direction and region than PVs could, which is of significance for designing the optimal procedures of in-situ leaching based on the determined flow direction of injecting solution. It is demonstrated that the migration of Ce, Pr, and Nd along the depth direction is inert, and that of REs post Sm and Y is active. Meanwhile, the migration of La shows region characteristics which is active in the upper and inert in lower region. More interesting, the dependence of RFVs on atomic number of REs displays a tetrad group variation trend. However, the fractionation of REs among clay minerals with different particle sizes is not evident, especially for the clay in the bottom region. These results indicate that the migration and fractionation of REs not only are dominated by the adsorption of their hydrated ions, but also rely on their hydrolysis tendency, which provide information for understanding the metallogenic mechanism of IAREs.

关键词： Ion-adsorption rare earth In-situ leaching Fractionation Metallogenic

Preparation of Compound Ultrafine CeO2 by Wet-Solid-Phase Mechanochemical Modification

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Journal of Rare Earths 2004年第Z1期22卷 42-45页

作者： Gu Ziyin Chen Weifan（China National Special Superfine Powder Engineering Research Center, Nanjing University of Science & Technology, Nanjing 10094, China） Hu Pinggui li yongxiu Engineering Research Center for Rare Earth Nanchang UniversityNanchang 330047 China 　　 Engineering Research Center for Rare Earth Nanchang UniversityNanchang 330047 China Engineering Research Center for Rare Earth Nanchang UniversityNanchang 330047 China

To satisfy practical requirements from industrial applications, an alternate route for synthesis compound ultrafine CeO2 powders by wet-solid-phase mechanochemical modification using industrial grade hydrated cerium carbonate as raw material was *** effect of modifier reaction percentage, reaction time, calcining temperature and modifier amount on particle size, density, suspensibility, and hardness of compound CeO2 powder was *** phase evolutions of preparation process were characterized by *** micrograph of the final product shows that compound CeO2 powders obtained are well-dispersed, spherically-shaped, uniformly-sized and submicron-sized *** method is readily available in raw material, low in cost, simple in process, and has great potential for *** compound CeO2 powders of different physical properties can be synthesized by controlling the above-mentioned influence factors in preparation process.

关键词： ultrafine compound CeO2 powder mechanochemical modification preparation rare earths

Correlation Evaluation of Ion Adsorption-Based Rare Earth Leaching Performance Based on Zeta Potential Drop Leaching

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Journal of Materials Science and Chemical Engineering 2023年第11期11卷 28-47页

作者： Xunhe li Zhengxiong Ding Sengbiao Zeng Yanzhu liu Dongping li yongxiu li School of Chemistry and Chemical Engineering Nanchang University Nanchang China

Rare earth elements are indispensable raw materials for advanced aero-engines, special optical materials, and high-performance electronic products. With the development of the social economy, the global demand for rare earth resources is increasing, and rare earths have become a key metal for the development of new industries and frontier technologies that are highly valued both at home and abroad. Ion-adsorbed rare earth ores are an important source of rare earths, so the efficient green leaching of ion-adsorbed rare earths is important. Researchers found that the selection of an efficient green leaching agent for ion-adsorbed rare earths is based on the zeta potential of tailing clay minerals in addition to leaching efficiency, and both zeta potential and leaching ion concentration are related to mineral acidity and alkalinity, and the pH of tailing water suspension is a direct indicator of environmental water quality requirements. Therefore, the efficiency of the leaching process is closely integrated with the environmental evaluation, and the characteristics and correlation of the changes in zeta potential, pH, conductivity and pollutant concentration of the pulp of clay mineral content during the leaching process of ore leaching and tailings aqueous electrolyte solution leaching are studied by evaluating the leaching system, and a set of correlation leaching efficiency and environmental impact evaluation method is established based on the results of the above analysis, which is of scientific development of ion adsorption rare earth resources. It has important theoretical significance and practical application value.

关键词： Ion Adsorption Rare Earth Ph Value Zeta Potential the Leaching Efficiency

THE COORDINATION BETWEEN SILVER NITRATE AND OPEN CHAIN POLYETHER

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中国有色金属学会会刊：英文版 1993年第1期3卷 38-41页

作者： li, yongxiu Ni, Zhaoai Jiangxi University, Nanchang 330047, China Hangzhou University, Hangzhou 310028, China

A complex of silver nitrate with 1.8-bis（8’-quinolyloxy）-3.6-dioxaoctane （noted as ligand L） was synthesized. The results of element analysis show that it consists of the calculated values of [Ag4L3]（NO3）4. It is clear from the IR, UV and ’HNMR spectra that the ligand L coordinated to Ag+ ion with its N and 0 atoms which connected with the terminal quinolyloxy group.

关键词： open chain polyether silver nitrate coordination

Controlling preparation of single crystalline cerium carbonate with high-purity for precursor of polishing material by triammonium citrate

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Controlling preparation of single crystalline cerium carbona...

中国化学会第十届全国无机化学学术会议

作者： Zhu Minxuan li Jing Zhou Xuezhen li yongxiu School of chemistry Nanchang University

In order to meet the demand of chip polishing, the synthesis conditions of crystalline cerium carbonate(CCC) with high purity[1] for precursor of polishing material were discussed. The crystallization process of CCC from cerium chloride via ammonium bicarbonate precipitation were investigated with regarding to the chloride content[2,3]. The morphology and structure of CCC obtained under different feeding ratios of ammonium bicarbonate to cerium ion(FR of HCO/Ce) and adding different amount of triammonium citrate(TAC) were observed by SEM and XRD. It was found that the chloride content in CCC prepared with low FR of HCO/Ce is high, and decreased with the increase of FR of HCO/Ce. Furthermore, the addition of TAC can slow the crystallization of CCC, and lower the chloride content as shown in Fig 1. In addition, the SEM in Fig. 2 shows that the obtained CCC looks like sheet-structure with fine crystals.

关键词： chip polishing precursor cerium carbonate ammonium bicarbonate low chloride

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试论广西粤剧剧目创作与创新发展

广西民族大学学报（哲学社会科学版） 2020年第4期42卷 78-84页

作者：李永秀广西职业师范学院外国语与国际教育学院广西南宁530007

广西粤剧的发展史就是自身的一部守正创新史。如今在壮乡肥沃土壤的滋养下,广西粤剧剧目创作呈现出鲜明的地域民族特点:创作题材"本土化",传达的是"广西精神",展现的是广西民族民间文化。其地域民族特色是广西粤剧剧目的优势所在、艺术... 详细信息

广西粤剧的发展史就是自身的一部守正创新史。如今在壮乡肥沃土壤的滋养下,广西粤剧剧目创作呈现出鲜明的地域民族特点:创作题材"本土化",传达的是"广西精神",展现的是广西民族民间文化。其地域民族特色是广西粤剧剧目的优势所在、艺术特色所在、艺术个性所在。但是,在新时代下,人们的审美渴望不断提高,广西粤剧的剧目创作也应如岭南经济发展般大步踏前,大胆创新:守正与创新和谐统一,地域性、民族性与时代性和谐统一,人性与诗性和谐统一,使广西粤剧能引领地方戏剧潮流文化,再创时代经典。

关键词：广西粤剧民族文化剧目创新戏剧人类学