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Synthesis of highly concentrated,carrier free ^(188)Re-mercaptoacetyltriglycine

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Nuclear Science and Techniques 2002年第4期13卷 237-243页

作者： ZHANG Xiu-li, WANG yong-xian, li Jun-ling, ZHANG Chun-Fu, WANG li-Hua,YIN Duan-Zhi(Shanghai Institute of Nuclear Research, the Chinese Academy of Sciences, Shanghai 201800) Shanghai Institute of Nuclear Research the Chinese Academy of Sciences 201800

Chelation of 188Re to compounds such as MAG3 will further reduce the radiation dose to the patient in case of balloon rupture through the rapid excretion from the body. In order to prepare highly concentrated, carrier free 188Re-MAG3, Sbenzoyl mercaptoacetyltriglycine (S-Bz-MAG3) was synthesized, labeled with carrier free 188Re. The overall yield of S-Bz-MAG3 is higher than those published in theliterature. Dependence of the labeling yield of 1ssRe-MAG3 upon concentrations of reducing agent, pH, reaction time, etc. was examined and optimum conditions were confirmed. The concentration procedure was succeeded with Sep-Pak C18 cartridge to obtain highly concentrated 1s8Re-MAG3. In the case of optimun conditions, the labeling yield of 188Re-MAG3 was more than 98%. Radiochemical purity of 188ReMAG3 was more than 92% after 24 hour storage at room temperature.

关键词：放射同位素 ^188Re 放射免疫疗法

Synthesis of Planar-Chiral[2.2]Paracyclophane-Based Oxazole-Pyrimidine ligands and Application in Nickel-Catalyzed 1,2-Reduction ofα,β-Unsaturated Ketones

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Chinese Journal of Chemistry 2024年第7期42卷 705-710页

作者： Juan Wang Qing-xian Xie xiang li Chang-Bin Yu yong-Gui Zhou School of Chemistry Dalian University of Technology2 Linggong RoadDalianLiaoning 116024China State Key Laboratory of Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalianLiaoning 116023China

The planar-chiral ligands have been widely applied as a class of unique and significant ligands in asymmetric *** them,chiral[2.2]paracycyclophane has emerged as a privileged type of planar-chiral framework and has been utilized as an important toolbox due to their structural ***,we design and synthesize[2.2]paracyclophane-derived oxazole-pyrimidine ligands(abberviated as PYMCOX).These N,N-ligands with stable properties,rigid structure and large steric hindrance performed successfully in nickel-catalyzed asymmetric 1,2-reduction ofα,β-unsaturated ketones,affording the chiral allylic alcohols with up to 99%yield and 99%***,this reduction reaction could be conducted on gram-scale without loss of activity and enantioselectivity,and the chiral ligand could be conveniently recovered with high yield.

关键词： Oxazole-pyrimidine ligands Planar chirality Nickel Hydroboration Asymmetric synthesis

Different mechanisms underlie similar species-area relationships in two tropical archipelagoes

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Plant Diversity 2024年第2期46卷 238-246页

作者： Shengchun li Tieyao Tu Shaopeng li xian Yang yong Zheng liang-Dong Guo Dianxiang Zhang lin Jiang Key Laboratory of Plant Resources Conservation and Sustainable Utilization South China Botanical GardenChinese Academy of SciencesGuangzhou 510650China ECNU-Alberta Joint Lab for Biodiversity Study Tiantong Forest Ecosystem National Observation and Research StationSchool of Ecological and Environmental SciencesEast China Normal UniversityShanghai 200241China School of Biological Sciences Georgia Institute of TechnologyAtlantaGA 30332USA Jiangxi Academy of Forestry Nanchang 330032China Institute of Eco-Chongming(IEC) Shanghai 202162China State Key Laboratory of Biocontrol School of EcologySun Yat-sen UniversityGuangzhou 510275China School of Geographical Sciences Fujian Normal UniversityFuzhou 350007China State Key Laboratory of Mycology Institute of MicrobiologyChinese Academy of SciencesBeijing 100101China

Despite much research in the field of island biogeography,mechanisms regulating insular diversity remain ***,we aim to explore mechanisms underlying plant species-area relationships in two tropical archipelagoes in the South China *** found positive plant species-area relationships for both coral and continental ***,our results showed that different mechanisms contributed to similar plant species-area relationships between the two *** coral islands,soil nutrients and spatial distance among communities played major roles in shaping plant community structure and species *** contrast,the direct effect of island area,and to a lesser extent,soil nutrients determined plant species richness on continental ***,increasing soil nutrients availability(N,P,K)had opposite effects on plant diversity between the two *** summary,the habitat quality effect and dispersal limitation are important for regulating plant diversity on coral islands,whereas the passive sampling effect,and to a lesser extent,the habitat quality effect are important for regulating plant diversity on continental *** generally,our findings indicate that island plant species-area relationships are outcomes of the interplay of both niche and neutral processes,but the driving mechanisms behind these relationships depends on the type of islands.

关键词： Coral and continental islands Plant diversity Soil nutrients Species-area relationships The sampling effect

Three-stage niobium mineralization at Bayan Obo, China

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National Science Review 2024年第4期11卷 102-110页

作者： Yan Yu Yang li Yu liu Xiao-Xiao ling li-Guang Wu li Yang Lan Yang Bo Yang yong-Gang Zhao xian-Hua li State Key Laboratory of lithospheric Evolution Institute of Geology and Geophysics Chinese Academy of Sciences College of Earth and Planetary Science University of Chinese Academy of Sciences Ministry of Education Key Laboratory of Orogenic Belts and Crustal Evolution School of Earth and Space SciencesPeking University Mining Research Institute Baotou Iron and Steel(Group) Co.LTD State Key Laboratory of Baiyunobo Rare Earth Resource Research and Comprehensive Utilization

The Chinese Bayan Obo deposit is a world-class rare earth element(REE) deposit with considerable niobium(Nb) and iron(Fe) resources. A complete genetic understanding on all metals is fundamental for establishing genetic models at Bayan Obo. With extensive research being focused on REE enrichment, the timing and controls of Nb enrichment remain unresolved at Bayan Obo, which is mainly due to the challenges in dating, i.e. multistage thermal events, fine-grained minerals with complex textures and the rare occurrence of uranium-enriched minerals with mature dating methods. Based on robust geological and petrographic frameworks, here we conducted ion probe uranium-lead(U-Pb) dating of ferrocolumbite to unravel the timing, hence the genesis of Nb mineralization. Three types of hydrothermal ferrocolumbites—key Nb-bearing minerals—are identified based on their textures and mineral assemblages. They yield U-Pb ages of 1312 ± 47 Ma(n = 99), 438 ± 7 Ma(n = 93), and 268 ± 5 Ma(n = 19), respectively. In line with deposit geology, we tentatively link the first, second and third stage Nb mineralization to Mesoproterozoic carbonatite magmatism, ubiquitous early Paleozoic hydrothermal activity, and Permian granitic magmatism, respectively. While quantifying the contribution of metal endowment from each stage requires further investigation, our new dates highlight that multi-stage mineralization is critical for Nb enrichment at Bayan Obo, which may also have implications for the enrichment mechanism of Nb in REE deposits in general.

关键词： niobium mineralization U-Pb dating ferrocolumbite Bayan Obo

Theoretical Design of Defects as a Driving Force for Ion Transport in li_(3)OBr Solid Electrolyte

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Energy & Environmental Materials 2024年第3期7卷 143-153页

作者： Xingyun Luo Yanlu li xian Zhao State Key Lab of Crystal Materials and Institute of Crystal Materials Shandong UniversityJinan 250100China Center for Optics Research and Engineering Shandong UniversityQingdao 266237China

Due to ever-increasing concerns about safety issues in using li ionic batteries,solid electrolytes have extensively *** li-rich antiperovskite li_(3)OBr has been considered as a promising solid electrolyte candidate,but it still suffers challenges to achieve a high ionic conductivity owing to the high intrinsic symmetry of the crystal ***,we presented a design strategy that introduces various point defects and grain boundaries to break the high lattice symmetry of li_(3)OBr crystal,and their effect and microscopic mechanism of promoting the migration of li-ion were explored *** has been found that li_(i)are the dominant defects responsible for the fast li-ion diffusion in bulk li_(3)OBr and its surface,but they are easily trapped by the grain boundaries,leading to the annihilating of the Frenkel defect pair V'_(li)+li_(i),and thus limits the V'_(li)diffusion at the grain *** V_(Br)defect near the grain boundaries can effectively drive V'_(li)across the grain boundary,thereby converting the carrier of li^(+)migration from li,in the bulk and surface to V'_(li)at the grain boundary,and thus improving the ionic conductivity in the whole li_(3)OBr *** work provides a comprehensive insight into the li^(+)transport and conduction mechanism in the li_(3)OBr *** opens a new way of improving the conductivity for all-solid-state li electrolyte material through the defect design.

关键词： defects density functional theory ionic migration solid electrolyte

Gas sensor array based on carbon-based thin-film transistor for selective detection of indoor harmful gases

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Rare Metals 2024年第9期43卷 4401-4411页

作者： Can liu Yu Sun Jia-Yi Guo Xiu-Lei li Lu Tao Jin-yong Hu Jue-xian Cao Ping-Hua Tang yong Zhang School of Electrical and Information Engineering Hunan Institute of EngineeringXiangtan 411104China Physics and Optoelectronics&Hunan Institute of Advanced Sensing and Information Technology Xiangtan UniversityXiangtan 411105China

The identification of indoor harmful gases is imperative due to their significant threats to human health and *** achieve accurate identification,an effective strategy of constructing a sensor array combined with the pattern recognition algorithm is ***-based thin-film transistors are selected as the sensor array unit,with semiconductor carbon nanotubes(CNTs)within the TFT channels modified with different metals(Au,Cu and Ti)for selective responses to NH_(3),H_(2)S and HCHO,*** accurate gas species identification,an identification mode that combines linear discriminant analysis algorithms and logistic regression classifier is *** test results demonstrate that by preprocessing the sensor array’s sensing data with the LDA algorithm and subsequently employing the LR classifier for identification,a 100%recognition rate can be achieved for three target gases(NH3,H2S and HCHO).This work provides significant guidance for future applications of chip-level gas sensors in the realms of the Internet of Things and Artificial Intelligence.

关键词： Carbon-based thin-film transistors Gas sensor arrays Semiconductor carbon nanotubes Multi-gas detection linear discriminant analysis

Microstructure and water-swelling mechanism of red-bed mudstone in the Xining region,Northeastern Tibetan Plateau

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第7期16卷 2537-2551页

作者： Huan Guan yong Ren Sixiang ling Xiyong Wu Tao Yu xian li Sen Wang Chunwei Sun School of Civil Engineering Southwest Jiaotong UniversityChengdu610031China Faculty of Geosciences and Engineering Southwest Jiaotong UniversityChengdu611756China Moe Key Laboratory of High-speed Railway Engineering Southwest Jiaotong UniversityChengdu610031China Guangzhou Metro Design and Research Institute Co Ltd. Guangzhou510010China Chengdu City Construction Investment Group Co Ltd. Chengdu610036China

This paper examines the effect of the microstructure and electrical conductivity(EC)on the swelling ratio and pressure in red-bed mudstone sampled from arid areas in the Xining region in the northeastern Tibetan Plateau.A series of laboratory tests,including swelling experiments,X-ray diffraction(XRD),and scanning electron microscope(SEM),was carried out for mechanical and microstructural *** coupled influence of the EC and microstructural parameters on the expansion ratio and pressure was investigated,and the weight coefficients were discussed by the entropy weight *** results revealed an increasing exponential trend in EC,and the maximum swelling speed occurred at an EC of approximately 10 μS/*** addition,a method for predicting the expansion potential is proposed based on the microstructure,and its reliability is verified by comparing with swelling experimental *** addition,according to the image analysis results,the ranges of the change in the clay minerals content(CMC),the fractal dimension(FD),the average diameter(AD)of pores,and the plane porosity(PP)are 23.75%-53%,1.08-1.17,7.53-22.45 mm,and 0.62%-1.25%,***,mudstone swelling is negatively correlated with the plane porosity,fractal dimension and average diameter and is linearly correlated with the clay mineral ***,the weight values prove that the microstructural characteristics,including FD,AD,and PP,are the main factors influencing the expansion properties of red-bed mudstones in the Xining *** on the combination of macro and micro-analyses,a quantitative analysis of the swelling process of mudstones can provide a better reference for understanding the mechanism of expansion behavior.

关键词： Mudstones Microstructure Swelling characteristics Electrical conductivity(EC) Scanning electron microscope Water-swelling

Microstructure and magnetocaloric properties of melt-extracted SmGdDyCoAl high-entropy amorphous microwires

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Rare Metals 2024年第3期43卷 1234-1242页

作者： Shi-Jie Wei Hong-xian Shen Lun-yong Zhang lin Luo Xin-Xing Tang Jian-Fei Sun Xiao-Qing li School of Materials Science and Engineering Harbin Institute of TechnologyHarbin150001China Applied Materials Physics Department of Materials Science and EngineeringKTH-Royal Institute of Technology10044StockholmSweden

This paper presents a systematic investigation of the microstructure and magnetocaloric properties of melt-extracted Sm_(20)Gd_(20)Dy_(20)Co_(20)Al_(20)high-entropy *** fabricated wires exhibited an amorphous structure,and the temperature interval of the undercooled liquid AT was 45 *** microwires underwent a second-order magnetic transition from a ferromagnetic to a paramagnetic state near the Curie temperature(T_(C)=52 K),The maximum magnetic entropy change(-ΔS_M^(max)),the relative cooling power and the refrigeration capacity reached 6.34 J·kg^(-1)·K^(-1).422.09 J·kg^(-1)and 332.94 J·kg^(-1),respectively,under a magnetic field change of 5 *** addition,the temperature-averaged entropy changes with two temperature lifts(3 and 10 K)were 6.32 and 6.27 J·kg^(-1)·K^(-1),*** good magnetocalorie performance highlights the significant potential for the Sm_(20)Gd_(20)Dy_(20)Co_(20)Al_(20)microwires to be used as magnetic refrigerant materials in low-temperature region *** work will serve as a valuable reference for future investigations on low-temperature high-entropy magnetocaloric materials.

关键词： Melt-extraction High-entropy amorphous microwires Magnetocaloric effect Magnetic refrigeration

Evaluation of transmission risk of respiratory particles under different ventilation strategies in an elevator

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Building Simulation 2024年第5期17卷 771-784页

作者： liangyu Zhu xian li Bujin Feng Fan liu School of Civil Engineering and Architecture Linyi UniversityLinyi276000China College of Agriculture Shandong Agricultural UniversityTaian271018China School of Environment and Architecture University of Shanghai for Science and TechnologyShanghai200093China

People in elevators are at risk of respiratory infection because the elevator cabin is crowded and has poor *** exhaled particles may be inhaled by the susceptible person,deposited on the surface and suspended in the elevator,which can result in direct and indirect ***,whether the air vent designs adopted in the elevator can effectively reduce the transmission risk of respiratory particles remains *** this study,the dispersion of particles under four common ventilation strategies used in the commercial elevator was investigated by proven computational fluid dynamics(CFD)*** flow field was simulated with the RNG κ-ξ turbulence model and the Lagrangian method was adopted to track particle *** effects of air vent layout and airflow rate on particle transmission were *** found that more than 50% of exhaled particles(average value)were suspended in the cabin and difficult to discharge under the investigated ventilation *** deposited fraction of particles on the susceptible person reached up to 39.14% for infiltration ventilation,which led to a high risk of contact *** the ventilation rate could not significantly reduce the inhalation proportion of particles due to the poor airflow distribution inside the elevator.A more proper ventilation strategy should be explored for the elevator to control transmission risk.

关键词： particle dispersion transmission risk elevator ventilation strategy computational fluid dynamics(CFD)