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

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 sites.It 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 sites.In this study,203 soil samples from 57 sites were collected in a typical lead smelting site.The findings demonstrated that there were significant Pb,Zn,Cd,and As contamination in soil samples.The 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%,respectively.Pb,Cd,and As contamination of the soil reached a depth of 5 m,which migrated from the surface to deep soil layers.The 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 Cd.With the increase of depth,the proportion of acid soluble fraction of heavy metal(loid)s decreased,and the residual fraction increased.The acid soluble fraction of Cd accounted for a higher proportion,and As mainly existed in reducible and residual fractions in soil.According to the calculation of the migration factor,the migration of heavy metal(loid)s in soils were ordered as Cd>Zn>Pb>As.The 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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Geometric prior guided hybrid deep neural network for facial beauty analysis

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CAAI Transactions on Intelligence Technology 2024年第2期9卷 467-480页

作者： Tianhao Peng mu li Fangmei Chen Yong Xu David Zhang The School of Computer Science and Technology Guizhou UniversityGuiyangChina Department of Automation Moutai InstituteRenhuaiGuizhouChina The School of Computer Science and Technology Harbin Institute of TechnologyShenzhenShenzhenChina The Information and Communication Engineering Department Dalian Minzu UniversityDalianChina The School of Data Science The Chinese University of Hong KongShenzhenShenzhenChina

Facial beauty analysis is an important topic in human society.It may be used as a guidance for face beautification applications such as cosmetic surgery.Deep neural networks(DNNs)have recently been adopted for facial beauty analysis and have achieved remarkable performance.However,most existing DNN-based models regard facial beauty analysis as a normal classification task.They ignore important prior knowledge in traditional machine learning models which illustrate the significant contribution of the geometric features in facial beauty analysis.To be specific,landmarks of the whole face and facial organs are introduced to extract geometric features to make the decision.Inspired by this,we introduce a novel dual-branch network for facial beauty analysis:one branch takes the Swin Transformer as the backbone to model the full face and global patterns,and another branch focuses on the masked facial organs with the residual network to model the local patterns of certain facial parts.Additionally,the designed multi-scale feature fusion module can further facilitate our network to learn complementary semantic information between the two branches.In model optimisation,we propose a hybrid loss function,where especially geometric regulation is introduced by regressing the facial landmarks and it can force the extracted features to convey facial geometric features.Experiments performed on the SCUT-FBP5500 dataset and the SCUT-FBP dataset demonstrate that our model outperforms the state-of-the-art convolutional neural networks models,which proves the effectiveness of the proposed geometric regularisation and dual-branch structure with the hybrid network.To the best of our knowledge,this is the first study to introduce a Vision Transformer into the facial beauty analysis task.

关键词： deep neural networks face analysis face biometrics image analysis

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Design of advanced porous silver powder with high-sintering activity to improve silicon solar cells

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Nano Research 2024年第4期17卷 3189-3197页

作者： Yongsheng li Ziwei Chen Rui Zhou Wenguang Zhao mu li Jun Chen Zhongyuan Huang Jian liu Yuhang li Maolin Yang Minghan Yu Dong Zhou Yuan lin Feng Pan School of Advanced Materials Peking UniversityShenzhen Graduate SchoolShenzhen 518055China Institute of Advanced Science Facilities Shenzhen 518107China Institute of Zhejiang University-Quzhou Quzhou 324000China Key Laboratory of Photochemistry Institute of ChemistryChinese Academy of SciencesBeijing 100190China Institute of Materials Research(IMR) Tsinghua UniversityTsinghua Shenzhen International Graduate SchoolShenzhen 518055China School of Materials Science and Engineering Harbin Institute of Technology(Shenzhen)Shenzhen 518055China

Silver(Ag)paste is widely used in semiconductor metallization,especially in silicon solar cells.Ag powder is the material with the highest proportion in Ag paste.The morphology and structure of Ag powder are crucial which determine its characteristics,especially for the sintering activity.In this work,a simple method was developed to synthesize a type of microcrystalline spherical Ag particles(SP-A)with internal pores and the structural changes and sintering behavior were thoroughly studied by combining ultra-small-angle X-ray scattering(USAXS),small-angle X-ray scattering(SAXS),in-situ heating X-ray diffraction(XRD),focused ion beam(FIB),and thermal analysis measurement.Due to the unique internal pores,the grain size of SP-A is smaller,and the coefficient of thermal expansion(CTE)is higher than that of traditional solid Ag particles.As a result,the sintering activity of SP-A is excellent,which can form a denser sintered body and form silver nanoparticles at the Ag–Si interface to improve silver silicon contact.Polycrystalline silicon solar cell built with SP-A obtained a low series resistance(Rs)and a high photoelectric conversion efficiency(PCE)of 19.26%.These fill a gap in Ag particle structure research,which is significant for the development of high-performance electronic Ag particles and efficient semiconductor devices.

关键词： silver particles small angle X-ray scattering(SAXS) pore size distribution in-situ heating X-ray diffraction(XRD) sintering silicon solar cells

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Study of 26 Galactic Open Clusters with Extended Main-sequence Turnoffs

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Research in Astronomy and Astrophysics 2024年第6期24卷 30-39页

作者： Yang-Yang Deng Zhong-mu li Yunnan Observatories Chinese Academy of Sciences University of Chinese Academy of Sciences Institute of Astronomy and Information Dali University

Recent studies indicate that some Galactic open clusters(OCs) exhibit extended main-sequence turnoff(eMSTO)in their color–magnitude diagrams(CMDs). However, the number of Galactic OCs with eMSTO structures detected so far is limited, and the reasons for their formation are still unclear. This work identifies 26 Galactic OCs with undiscovered eMSTOs and investigates the causes of these features. Stellar population types and fundamental parameters of cluster samples are acquired using CMD fitting methods. Among them, the results of 11 OCs are reliable as the observed CMDs are well-reproduced. We propose the crucial role of stellar binarity and confirm the importance of stellar rotation in reproducing eMSTO morphologies. The results also show that the impact of age spread is important, as it can adequately explain the structure of young OCs and fit the observed CMDs of intermediate-age OCs better.

关键词： (Galaxy:) open clusters and associations: general (stars:) binaries: general (stars:) Hertzsprung-Russell and C-M-diagrams Galaxy: fundamental parameters

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BSEC Method for Unveiling Open Clusters and its Application to Gaia DR3:83 New Clusters

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Research in Astronomy and Astrophysics 2024年第5期24卷 169-184页

作者： Zhong-mu li Cai-Yan Mao Institute of Astronomy and Information Dali UniversityDali 671003China

Open clusters(OCs) are common in the Milky Way, but most of them remain undiscovered. There are numerous techniques, including some machine-learning algorithms, available for the exploration of OCs. However, each method has its limitations and therefore, different approaches to discovering OCs hold significant values. We develop a comprehensive approach method to automatically explore the data space and identify potential OC candidates with relatively reliable membership determination. This approach combines the techniques of Hierarchical Density-Based Spatial Clustering of Applications with Noise, Gaussian mixture model, and a novel cluster member identification technique, color excess constraint. The new method exhibits efficiency in detecting OCs while ensuring precise determination of cluster memberships. Because the main feature of this technique is to add an extra constraint(EC) for the members of cluster candidates using the homogeneity of color excess,compared to typical blind search codes, it is called Blind Search-Extra Constraint(BSEC) method. It is successfully applied to the Gaia Data Release 3, and 83 new OCs are found, whose color–magnitude diagrams(CMDs) are fitted well to the isochrones. In addition, this study reports 621 new OC candidates with discernible main sequence or red giant branch. It is shown that BSEC technique can discard some false negatives of previous works, which takes about three percentage of known clusters. It shows that as an EC, the color excess(or twocolor) constraint is useful for removing fake cluster member stars from the clusters that are identified from the positions and proper motions of stars, and getting more precise CMDs, when differential reddening of member stars of a cluster is not large(e.g., ΔE(GBP-GRP) < 0.5 mag). It makes the CMDs of 15% clusters clearer(in particular for the region near turnoff) and therefore is helpful for CMD and stellar population studies. Our result suggests that the color excess constraint is more appropriate for clusters with small di

关键词： Galaxy stellar content-(Galaxy:)open clusters and associations general-stars fundamental parameters

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multidisciplinary and multiscale nanoscience research roadmap based on large scientific facilities

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Science China Chemistry 2024年第8期67卷 2497-2523页

作者： Yuan Zeng Shuhan Zhang Yuecong Guo Yalin Cong Xu Ding Peihua li Yunxiang lin Wenzhi Ren Hui Su Weigang Sun liuxin Xu Guikai Zhang Shihua Chen Yu Chen Weiren Cheng Shengqi Chu Yong Guan Jinru Han Jie lin Hengjie liu Zheyi liu Pan Luo Fanchun Meng Sicong Qiao Zongyin Song Ying Wang Zhao Wu Chenyu Yang Meng Yang Shirui Yang Zi Yin Zhibin Yin Pengjun Zhang Hongyu Zhang Pingping Zheng Jia Zhou Wanlin Zhou Pengfei An He Cheng Chunhai Fan Xingjiu Huang Yong Lei lina li mu li Qinghua liu Shuming Peng li Song Zhihu Sun Yangchao Tian Fangjun Wang lihua Wang liming Wang Shiqiang Wei Aiguo Wu Chunlei Xiao Xueming Yang Panchao Yin Jing Zhang Mingxin Zhang Yaling Wang Chunying Chen Beijing Synchrotron Radiation Facility Institute of High Energy Physics Chinese Academy of Sciences CAS Key Laboratory of Separation Sciences for Analytical Chemistry Dalian Institute of Chemical Physics Chinese Academy of Sciences State Key Laboratory of Molecular Reaction Dynamics Dalian Institute of Chemical Physics Chinese Academy of Sciences Institute of Advanced Science Facilities State Key Laboratory of Coal Conversion Institute of Coal Chemistry Chinese Academy of Sciences State Key Laboratory of Particle Detection and Electronics Institute of High Energy Physics Chinese Academy of Sciences CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety Institute of High Energy Physics and National Center for Nanoscience and Technology of China Chinese Academy of Sciences Henan Institutes of Advanced Technology Zhengzhou University Institute of High Energy Physics Chinese Academy of Sciences Spallation Neutron Source Science Center CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety New Cornerstone Science Laboratory National Center for Nanoscience and Technology College of Chemistry and Chemical Engineering Shanghai Jiao Tong University The Palace museum Shanghai Synchrotron Radiation Facility Shanghai Advanced Research Institute Chinese Academy of Sciences Institute of Nuclear Physics and Chemistry China Academy of Engineering Physics Institute of Materiobiology College of Science Shanghai University School of Marine Science and Engineering School of Chemistry and Chemical Engineering Hainan University University of Chinese Academy of Sciences National Synchrotron Radiation Laboratory University of Science and Technology of China Institute of Solid State Physics Hefei Institutes of Physical Science Chinese Academy of Sciences Institutes of Physical Science and Information Technology Anhui University Ningbo Key Laboratory of Biomedical Imaging Probe Materials and Technology Zhejiang International Cooperation Base of Biomedical Materials Technol

With the advancement of modern science and technology, large scientific facilities are increasingly oriented toward demand and application, and can be used for basic research as well as serving multiple disciplines. Developing large scientific facilities and related analytical technologies enhances understanding of large scientific facilities and popularizes their application in research across multiple disciplines. The combination of light or neutron sources from large scientific facilities and advanced analytical technologies can be achieved for materials structure information, dynamics study of chemical reactions, high dissociation of biomolecules, 3D visualization of energy materials or biological samples, etc. We first introduce the progress of domestic large scientific facilities of synchrotron radiation(SR) and free electron lasers(FELs) with different wavelengths and neutron sources.We further discuss the comparison between Chinese and typical foreign facilities in X-ray radiation from X-ray tubes, synchrotrons, X-ray FELs, and neutron sources based on physical parameters of light and neutron sources. In addition, we focus on the technological progress and perspectives combined with advanced X-ray radiation and neutron sources of large scientific facilities in China, especially in the nanoscience fields of energy catalysis and biological science. We hope that this roadmap will provide references on technology and methods to experimental users, as well as prospects for future development of technologies based on large research infrastructure facilities. Comprehensive studies and guidelines for basic research to practical application in various disciplines can be made with the assistance of large scientific facilities.

关键词： chemical dynamics FEL light sources large scientific facilities neutron sources spectroscopic analysis methods structural information synchrotron radiation X-ray imaging techniques

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Performance measurement and evaluation of an ionic liquid electrospray thruster

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Chinese Journal of Aeronautics 2023年第3期36卷 1-15页

作者： Chengjin HUANG Jianling li mu li School of Power and Energy Northwestern Polytechnical UniversityXi’an 710072China Shenzhen Key Laboratory of Ultraintense Laser and Advanced Material Technology Center for Advanced Material Diagnostic Technologyand College of Engineering PhysicsShenzhen Technology UniversityShenzhen 518118China

As a novel micro-propulsion system for small satellites(from micro to nano),the ionic liquid electro spray propulsion system is a promising candidate.However,performance measurement and evaluation of the Ionic liquid Electrospray Thruster(ILET)is one of the most challenging issues for practical application,due to the difficulties in the development of a prototype and direct measurements of micro-thrust and small flow rate.To address this issue,a Modular Ionic liquid Electrospray Thruster(MILET)prototype is constructed,and a diagnostic system for thrust and mass flow rate is specially developed based on an analytical balance method.With the ionic liquid 1-ethyl-3-methylimidazolium tetrafluoroborate as the propellant,a series of experiments is carried out on the MILET prototype under a wide operating condition through changing the applied voltage to control the thrust.Under different applied voltages,the thrust and the mass flow rate of the propellant are directly measured.The propulsive performance parameters of the thruster,such as thrust,specific impulse,thrust-to-power ratio,thruster efficiency,etc.,are comprehensively analyzed.Then,a performance comparison is made between the MILET and other representative ILETs.With a relatively low applied voltage ranging from 1550 V to 2000 V,the MILET achieves a quasi-constant specific impulse of 1263 s with the averaged thrust-to-power ratio of 65.2μN/W and thruster efficiency of 40.7%.The performance of ILET is also compared with other typical electric propulsions.The results demonstrate that the ILET exhibits an excellent ability of minimalization with high specific impulse and thruster efficiency,which guarantees a great superiority in micro propulsions.Finally,the ways to further improve the performance of ILET are discussed,which further confirms the potential prospect of ILET.The present result helps to advance the development and application of ILET.

关键词： Electrospray thruster Ionic liquids Performance measurement Performance estimation Micro-propulsion

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Layered coordination polymer with two-dimensional covalent bismuth-organic networks:Semiconductor and lithium ion storage

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Nano Research 2024年第3期17卷 2181-2185页

作者： mu-Qing li Yulin Cao Lei Qin Hua Cheng Weimin Yang Zhouguang Lu School of Materials Science and Environmental Engineering Shenzhen Polytechnic UniversityShenzhen 518055China Industrial Training Center Shenzhen Polytechnic UniversityShenzhen 518055China Department of Materials Science and Engineering Southern University of Science and TechnologyShenzhen 518055China Department of Chemistry Southern University of Science and TechnologyShenzhen 518055China

Single crystals of a bismuth-based coordination polymer(CP)with carboxyl-thiol ligands,[Bi(C_(8)H_(2)O_(4)S_(2))(C2H8N)]n(Bi-DSBDC-DMA,DMBDC=2,5-disulfur-1,4-dicarboxylate,DMA=dimethylamine),have been successfully synthesized.X-ray diffraction analysis reveals that Bi-DSBDC-DMA possesses a layered structure,with two-dimensional(2D)Bi-DSBDC networks alternating with layers composed of dimethylamine ions.This material demonstrates semiconducting properties,featuring an optical bandgap of 2.2 eV and an electrical conductivity of 2×10^(-8) S/cm.Furthermore,electrodes based on this material exhibit a capacity of 250 mAh/g after 200 cycles for lithium-ion storage.

关键词： bismuth layer coordination polymer(CP) semiconductor lithium ion storage

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Splitting of the virtual class for genus one stable quasimaps

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Science China Mathematics 2024年

作者： Sanghyeon Lee mu-lin li Shanghai Center for Mathematical Sciences Fudan University School of Mathematics Hunan University

We analyze the local structure of the moduli space of genus one stable quasimaps. Combining it with the p-fields theory developed by Chang and li（2020）, we prove the splitting formula for the virtual cycle of stable...

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Clinical manifestations,diagnosis and long-term prognosis of adult autoimmune enteropathy:Experience from Peking Union Medical College Hospital

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World Journal of Gastroenterology 2024年第19期30卷 2523-2537页

作者： mu-Han li Ge-Chong Ruan Wei-Xun Zhou Xiao-Qing li Sheng-Yu Zhang Yang Chen Xiao-Yin Bai Hong Yang Yu-Jie Zhang Peng-Yu Zhao Ji li Jing-Nan li Department of Gastroenterology Chinese Academy of Medical Sciences&Peking Union Medical College HospitalBeijing 100730China Department of Pathology Chinese Academy of Medical Scinences&Peking Union Medical College HospitalBeijing 100730China Department of Pathology Tianjin First Central HospitalNankai UniversityTianjin 300192China Affairs Office Chinese Academy of Medical Sciences&Peking Union Medical College Hospital(West campus)Beijing 100032China

BACKGROUND Autoimmune enteropathy(AIE)is a rare disease whose diagnosis and long-term prognosis remain challenging,especially for adult AIE patients.AIM To improve overall understanding of this disease’s diagnosis and prognosis.METHODS We retrospectively analyzed the clinical,endoscopic and histopathological characteristics and prognoses of 16 adult AIE patients in our tertiary medical center between 2011 and 2023,whose diagnosis was based on the 2007 diagnostic criteria.RESULTS Diarrhea in AIE patients was characterized by secretory diarrhea.The common endoscopic manifestations were edema,villous blunting and mucosal hyperemia in the duodenum and ileum.Villous blunting(100%),deep crypt lymphocytic infiltration(67%),apoptotic bodies(50%),and mild intraepithelial lymphocytosis(69%)were observed in the duodenal biopsies.Moreover,there were other remarkable abnormalities,including reduced or absent goblet cells(duodenum 94%,ileum 62%),reduced or absent Paneth cells(duodenum 94%,ileum 69%)and neutrophil infiltration(duodenum 100%,ileum 69%).Our patients also fulfilled the 2018 diagnostic criteria but did not match the 2022 diagnostic criteria due to undetectable anti-enterocyte antibodies.All patients received glucocorticoid therapy as the initial medication,of which 14/16 patients achieved a clinical response in 5(IQR:3-20)days.Immunosuppressants were administered to 9 patients with indications of steroid dependence(6/9),steroid refractory status(2/9),or intensified maintenance medication(1/9).During the median of 20.5 months of followup,2 patients died from multiple organ failure,and 1 was diagnosed with non-Hodgkin’s lymphoma.The cumulative relapse-free survival rates were 62.5%,55.6%and 37.0%at 6 months,12 months and 48 months,respectively.CONCLUSION Certain histopathological findings,including a decrease or disappearance of goblet and Paneth cells in intestinal biopsies,might be potential diagnostic criteria for adult AIE.The long-term prognosis is still unsatisfactory despite corticosteroid and immunosuppressan

关键词： Autoimmune enteropathy Clinical manifestations Diagnostic criteria Pathological features Long-term prognosis

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