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A state-of-the-art review on delayed expansion of cemented paste backfill materials

Rare Metals 2024年第8期43卷 3475-3500页

作者： meng-yuan li li-Jie Guo Yue Zhao Lei Zhang Kai Yang Xiao-Peng Peng Andrew Pan BGRIMM Technology Group Beijing 100160China National Centre for International Research On Green Metal Mining Beijing102628China Department of Civil and Mineral Engineering University of TorontoTorontoON M5S 1A4Canada

Utilizing delayed expansion cemented paste backfill materials(DECPB) in mine backfill operations offers an effective solution to the challenge of achieving proper contact between the in-situ cemented backfill mass and the roof in mined-out areas(backfill-roof contact).This article presents recent progress in both theoretical and experimental research concerning *** types and mechanisms of expansive additives,including expansive agents,foaming agents,and expansive mineral materials relevant to DECPB,are explained,along with their impact on the expansive properties and mechanical characteristics of *** composition,material characteristics,preparation methods,and controlled release mechanisms of microcapsules are *** methods for measuring the volume change rate of paste backfill slurries are *** indicates that an appropriate content of expansive additives not only enhances the expansive properties of cemented paste backfill materials but also contributes to improving their mechanical *** foaming agents and bentonite are found to be more suitable for preparing DECPB compared to expansive *** delayed expansion of cemented paste backfill material is influenced by microcapsules,with their wall materials,preparation parameters,and the alkaline slurry environment affecting their controlled release *** and optimizing precise measurement devices and methods forfor the volume change rate of cemented paste backfill materials is essential requirement for studying the performance of *** delayed expansion technology with retarding techniques in cemented paste backfill materials can provide a reliable solution for achieving proper backfill-roof contact in the future.

关键词： Paste backfill Delayed expansion Mining with backfill Expansive additives Tailings

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Electropolishing technique of Hastelloy C-276 alloy

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Rare Metals 2017年第8期36卷 635-639页

作者： Qiang Jia Yi Wang Hong-li Suo Pan Wang meng-yuan li Qian-Yu Huo School of Materials Science and Engineering Beijing Universityof TechnologyBeijing 100022China

Preparing a highly textured,flawless YBa_（2-）Cu_3O_7（YBCO）layer by ion-beam-as sis ted deposition（IBAD）requires a substrate with a smooth *** this paper,smooth tapes of Hastelloy C-276,a common template alloy,were prepared by electrochemical polishing,and the surface roughness the tapes was investigating by atomic force microscopy and scanning electron *** analyzing these results,it was discussed how the processing parameters affect the surface roughness,and it is found the following optimized processing parameters：current density of 0.104 A·cm^（-2）,temperature of 50℃,plate spacing of 9 cm and time of 150 *** these optimized parameters,the substrate roughness decreases to less than 5 nm,meeting the requirements of IBAD.

关键词： Hastelloy C-276 Electro-chemical polishing Atomic force microscopy Current density

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Tailoring sulfur-doped and nitrogen-defective carbon nitride nanosheets for efficient photo-controlled radical polymerizations

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Science China Chemistry 2024年第7期67卷 2325-2334页

作者： Xue li meng Kai Xu yuan Huang Tao Cai Key Laboratory of Biomedical Polymers of Ministry of Education College of Chemistry and Molecular SciencesWuhan UniversityWuhan 430072China Wuhan University Shenzhen Research Institute Shenzhen 518057China

Despite the challenges that remain,the synergistic adjustment of various microstructures and photochemical parameters of graphitic carbon nitride(g-C_(3)N_(4))in photocatalytic reactions holds promises for improving catalytic efficiency and reducing energy ***,sulfur-doped and nitrogen-defective g-C_(3)N_(4)(n-SC_(3)N_(x))nanosheets were designed and elaborately *** resultant n-SC_(3)N_(x)possessed a precisely defined 2D layer structure with extensive porosity and incremental specific surface *** photoinduced electron transfer-reversible addition-fragmentation chain transfer(PET-RAFT)polymerization of vinyl monomers with low dispersity,excellent temporal control and high chain-end fidelity was achieved under mild blue light irradiation in a nondegassed *** to their ultrathin nanostructures with nitrogen defects and sulfur dopants,n-SC_(3)N_(x)was capable of catalyzing RAFT polymerization in aqueous solutions at significantly accelerated rates,which were nearly 8 times faster compared to bulk g-C_(3)N_(4).The ease of separation and efficient reusability in subsequent polymerizations was enabled by the heterogeneous nature of n-SC_(3)N_(x).The appeal of this approach was illustrated by the fact that utilizing a reusable and metal-free photocatalyst in aqueous environments allowed for the synthesis of polymers with molecular weight up to 300 kg mol^(-1) and a dispersity of 1.32.

关键词： graphitic carbon nitride nitrogen defects sulfur dopants PET-RAFT polymerization recyclability

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Design,synthesis and biological evaluation of O-linked indoles as VEGFR-2 kinase inhibitors(Ⅰ)

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Chinese Chemical Letters 2015年第9期26卷 1165-1168页

作者： Guo-Rui Gao meng-yuan li lin-Jiang Tong li-Xin Wei Jian Ding Hua Xie Wen-Hu Duan School of Pharmacy East China University of Science & Technology Division of Anti-tumor Pharmacology State Key Laboratory of Drug ResearchShanghai Institute of Materia MedicaChinese Academy of Sciences Pharmacology and Safety Evaluation Key Laboratory of Tibetan Medicine in Qinghai Province Northwest Institute of Plateau BiologyChinese Academy of Sciences Department of Medicinal Chemistry Shanghai Institute of Materia MedicaChinese Academy of Sciences

Inhibition of VEGFR-2 signaling pathway has already become one of the most promising approaches for the treatment of *** this study,we describe the design,synthesis,and biological evaluation of a series of O-linked indoles as potent inhibitors of *** these compounds,18 showed significant anti-angiogenesis activities via VEGFR-2 in enzymatic proliferation assays,with IC50 value of3.8 nmol/L Kinase selectivity profiling revealed that 18 was a multitargeted inhibitor,and it also exhibited good potency against VEGFR-1,PDCFR-α and β.

关键词： VEGFR-2 Inhibitor Indole

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Influence of nitrogen status on fermentation performances of non-Saccharomyces yeasts:a review

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Food Science and Human Wellness 2024年第2期13卷 556-567页

作者： Jinchen li mengmeng yuan Nan meng Hehe li Jinyuan Sun Baoguo Sun Key Laboratory of Brewing Molecular Engineering of China light Industry Beijing Key Laboratory of Flavor ChemistryBeijing Technology&Business UniversityBeijing 100048China

Nitrogen,one of the most crucial nutrients present in grapes and musts,plays a key role in yeast activities during alcoholic *** influences are imposed on yeast growth and fermentation performances including the formation of secondary *** cerevisiae,the main yeast responsible for fermentation,has been studied extensively regarding nitrogen *** the other hand,a similar study for non-Saccharomyces yeasts,whose contributions to winemaking have gradually been acknowledged,remains to be fully explored,with a few studies being *** review starts by discussing nitrogen impacts on non-Saccharomyces yeast growth and fermentation kinetics in different case scenarios,then proceeds to summarize the nitrogen preferences of individual yeast strains with regulation mechanisms elucidated by recent *** discussions on the influences on the production of volatile compounds and proposed pathways therein are made,followed by future work suggested as the final *** summarizing the nitrogen impacts on non-Saccharomyces yeasts throughout alcoholic fermentation,this review will be helpful in obtaining a more comprehensive view on these non-conventional wine yeasts in terms of nutrient requirements and corresponding volatile *** gaps will therefore be elucidated for future research.

关键词： Non-Saccharomyces yeasts Nitrogen Fermentation kinetics Nitrogen preference Wine aroma

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Tough Polymeric Hydrogels Based on Amino Acid Derivative Mediated Dynamic Metal Coordination Bonds

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Chinese Journal of Polymer Science 2024年第10期42卷 1578-1588,I0014页

作者： meng li meng-yuan Zhang Wu-Xuan Lei Zhu-Ting Lv Qing-Hua Shang Zheng Zhao Jiang-Tao li Yi-Long Cheng Engineering Research Center of Energy Storage Materials and Devices Ministry of EducationSchool of ChemistryXi’an Jiaotong UniversityXi’an710049China Polymer Materials&Engineering Department School of Materials Science&Engineering Chang’an UniversityXi’an710064China School of Electrical Engineering Xi’an Jiaotong UniversityXi’an710049China Department of Nuclear Medicine the First Affiliated Hospital of ChinaXi’an Jiaotong UniversityXi’an710049China

Abstract The development of physically crosslinked hydrogels with excellent mechanical and sensing properties is of importance for expanding the practical applications of intelligent soft hydrogel ***,after copolymerization of hydroxyl-containing amino acid derivative N-acryloyl serine(ASer)with acrylamide(AM),we introduce Zr4+through an immersion strategy to construct metal ion-toughened non-covalent crosslinked hydrogels(with tensile strength of up to 5.73 MPa).It is found that the synergistic coordination of hydroxyl and carboxyl groups with Zr^(4+)substantially increases the crosslinking density of the hydrogels,thereby imparting markedly superior mechanical properties compared to hydroxyl-free Zr^(4+)-crosslinked hydrogels,such as N-acryloyl alanine(AAla)copolymerized with AM hydrogels(with tensile strength of 2.98 MPa)Through the adjustment of the composition of the copolymer and the density of coordination bonds,the mechanical properties of the hydrogels can be modulated over a wide ***,due to the introduction of metal ions and the dynamic nature of coordination bonds,the hydrogels also exhibit excellent sensing performance and good self-recovery properties,paving the way for the development of flexible electronic substrates with outstanding comprehensive performances.

关键词： Hydrogel Amino acid Metal coordination Mechanical performance Flexible sensor

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Selective leaching of calcium from mechanically activated mixed rare earth concentrate

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Journal of Rare Earths 2024年第6期42卷 1149-1156,I0006页

作者： Jiang liu Bingxue Chen yuanqi Feng Yijun Cao Yukun Huang yuan Shi meng li Zhongyuan Critical Metals Laboratory School of Chemical EngineeringZhengzhou UniversityZhengzhou450001China State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals Lanzhou University of TechnologyLanzhou730050China

The loss of rare earths(REs)takes place during the pre-decalcification process of mixed rare earth *** an effort to reduce such RE loss,a novel idea to improve the leaching selectivity of Ca to REs by applying selective mechanical activation was ***,regarding the key minerals affecting the leaching selectivity of Ca to REs,the differences in the mechanical activation behaviors of CaF_(2) and REFCO_(3) were studied,and we find that the lattice strain of CaF_(2) increases from 0.21%to 0.42%,whereas that of REFCO_(3) increases from 0.31%to 0.40%.Notably,CaF_(2) demonstrates a larger lattice strain than REFCO_(3),indicating greater mechanical activation energy storage and higher leaching ***,the HCl leaching process was studied.A significant leaching selectivity of Ca to REs,from 21.6 to 35.1,is achieved through mechanical *** Ca leaching rate reaches 80.7%when the RE loss is 2.3%in the activated *** study provides an novel approach for achieving selective extraction of specific components via mechanical activation pretreatment.

关键词： Mixed rare earth concentrate Pre-decalcification Selective mechanical activation Selective leaching

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Quantum dot-enabled infrared hyperspectral imaging with single-pixel detection

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light(Science & Applications) 2024年第6期13卷 1112-1121页

作者： Heyan meng yuan Gao Xuhong Wang Xianye li lili Wang Xian Zhao Baoqing Sun School of Information Sciences and Engineering Shandong UniversityQingdaoChina Center for Optics Research and Engineering(CORE) Key Laboratory of Laser&Infrared System(Shandong University)Ministry of EducationShandong UniversityQingdaoChina School of Mechanical Electrical and Information EngineeringShandong UniversityWeihaiChina

Near-infrared(NIR)hyperspectral imaging is a powerful technique that enables the capture of three-dimensional(3D)spectra-spatial information within the NIR spectral range,offering a wide array of ***,the high cost associated with InGaAs focal plane array(FPA)has impeded the widespread adoption of NIR hyperspectral *** this challenge,in this study,we adopt an alternative approach—single-pixel detection for NIR hyperspectral *** investigation reveals that single-pixel detection outperforms conventional FPA,delivering a superior signal-to-noise ratio(SNR)for both spectral and imaging *** implement this strategy,we leverage self-assembled colloidal quantum dots(CQDs)and a digital micromirror device(DMD)for NIR spectral and spatial information multiplexing,complemented by single-pixel detection for simultaneous spectral and image *** experimental results demonstrate successful NIR hyperspectral imaging with a detection window about 600 nm and an average spectral resolution of 8.6 nm with a pixel resolution of 128×*** resulting spectral and spatial data align well with reference instruments,which validates the effectiveness of our *** circumventing the need for expensive and bulky FPA and wavelength selection components,our solution shows promise in advancing affordable and accessible NIR hyperspectral imaging technologies,thereby expanding the range of potential applications.

关键词： spectral Quantum mirror

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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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Simulation and reconstruction of particle trajectories in the CEPC drift chamber

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Nuclear Science and Techniques 2024年第8期35卷 9-22页

作者： meng‑Yao liu Wei‑Dong li Xing‑Tao Huang Yao Zhang Tao lin Ye yuan Institute of Frontier and Interdisciplinary Science Shandong UniversityQingdao 266237China Institute of High Energy Physics Beijing 100049China University of Chinese Academy of Sciences Beijing 100049China

The circular electron-positron collider(CEPC)is designed to precisely measure the properties of the Higgs boson,study electroweak interactions at the Z-boson peak,and search for new physics beyond the Standard *** a component of the 4th conceptual CEPC detector,the drift chamber facilitates the measurement of charged *** study implemented a Geant4-based simulation and track reconstruction for the drift *** the simulation,detector construction and response were implemented and added to the CEPC simulation *** development of track reconstruction involves track finding using the combinatorial Kalman filter method and track fitting using the tool of *** the simulated data,the tracking performance was *** results showed that both the reconstruction resolution and tracking efficiency satisfied the requirements of the CEPC experiment.

关键词： CEPC Drift chamber Detector simulation Track reconstruction

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