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Mechanistic insights into stepwise activation of malachite for enhancing surface reactivity and flotation performance

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International Journal of Minerals,Metallurgy and Materials 2024年第10期31卷 2159-2172页

作者： Qicheng feng Wanming Lu Han wang qian Zhang State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization Faculty of Land Resource EngineeringKunming University of Science and TechnologyKunming 650093China Yunnan Key Laboratory of Green Separation and Enrichment of Strategic Mineral Resources Kunming University of Science and TechnologyKunming 650093China

Malachite is a common copper oxide mineral that is often enriched using the sulfidization-xanthate flotation ***,the direct sulfidization method cannot yield copper concentrate ***,a new sulfidization flotation process was developed to promote the efficient recovery of *** this study,Cu^(2+) was used as an activator to interact with the sample surface and increase its reaction sites,thereby strengthening the mineral sulfidization process and *** to single copper ion activation,the flota-tion effect of malachite significantly increased after stepwise Cu^(2+) *** potential,X-ray photoelectron spectroscopy(XPS),time-of-flight secondary ion mass spectroscopy(ToF-SIMS),scanning electron microscopy and energy dispersive spectrometry(SEM-EDS),and atomic force microscopy(AFM)analysis results indicated that the adsorption of S species was significantly enhanced on the mineral surface due to the increase in active Cu sites after Cu^(2+) stepwise ***,the proportion of active Cu-S spe-cies also increased,further improving the reaction between the sample surface and subsequent ***-transform infrared spec-troscopy(FT-IR)and contact angle tests implied that the xanthate species were easily and stably adsorbed onto the mineral surface after Cu^(2+) stepwise activation,thereby improving the hydrophobicity of the mineral ***,the copper sites on the malachite sur-face after Cu^(2+) stepwise activation promote the reactivity of the mineral surface and enhance sulfidization flotation of malachite.

关键词： malachite copper ions stepwise activation flotation mechanism enhanced sulfidization

The Adjustment Analysis Method of the Active Surface Antenna Based on Convolutional Neural Network

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Research in Astronomy and Astrophysics 2024年第6期24卷 294-306页

作者： You Ban Shang Shi Na wang qian Xu Shufei feng School of Mechanical Engineering Xinjiang UniversityUrumqi 830017China Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China School of Mechanical Engineering Dongguan University of TechnologyDongguan 523808China

Active surface technique is one of the key technologies to ensure the reflector accuracy of the millimeter/submillimeter wave large reflector *** antenna is complex,large-scale,and high-precision equipment,and its active surfaces are affected by various factors that are difficult to comprehensively deal *** this paper,based on the advantage of the deep learning method that can be improved through data learning,we propose the active adjustment value analysis method of large reflector antenna based on deep *** method constructs a neural network model for antenna active adjustment analysis in view of the fact that a large reflector antenna consists of multiple panels spliced *** on the constraint that a single actuator has to support multiple panels(usually 4),an autonomously learned neural network emphasis layer module is designed to enhance the adaptability of the active adjustment neural network *** classical 8-meter antenna is used as a case study,the actuators have a mean adjustment error of 0.00252 mm,and the corresponding antenna surface error is0.00523 *** active adjustment result shows the effectiveness of the method in this paper.

关键词： techniques:radar astronomy telescopes methods:analytical methods:numerical

Spatial-temporal evolution of vegetation evapotranspiration in Hebei Province,China

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Journal of Integrative Agriculture 2018年第9期17卷 2107-2117页

作者： wang qian-feng TANG Jia ZENG Jing-yu QU Yan-ping ZHANG Qing SHUI Wei wang Wu-lin YI Lin LENG Song Fujian Provincial Key Laboratory of Remote Sensing of Soil Erosion and Disaster Protection/College of Environment and Resources Fuzhou UniversityFuzhou 350116P.R.China Research Center on Flood and Drought Disaster Reduction China Institute of Water Resources and Hydropower Reseat'chBeijing 100038P.R.China Key Laboratory of Digital Earth Science Institute of Remote Sensing and Digital EarthChinese Academy of ScienceBeijing 100094P.R.China Geospatial Information Center Shenzhen Institutes of Advanced TechnologyChinese Academy of SciencesShenzhen 518055P.R.China Climate Change Cluster University of Technology SydneyNew South Wales 2007Australia

Evapotranspiration （ET） is the sum of soil or water body evaporation and plant transpiration from the earth surface and ocean to the atmosphere, and thus plays a significant role in regulating carbon and water resource cycles. The time-series data set from the remote sensing MOLDS product （MOD16） was used to study the spatial-temporal evolution of vegetation evapotranspiration in salinized areas during 2000-2014 by analyzing the variability, spatial patterns and Mann-Kendall （MK） nonparametric trends for the time series. The results indicate that inter-annual and intra-annual variations of ET across various vegetated areas show seasonal changes, with the abnormal months identified. The Cultivated land displays a greater degree of spatial heterogeneity and the spatial pattern of ET in the area covered by broadleaved deciduous forests corresponds to a higher ET rate and increased water consumption. Awidespread decline of ET is observed only in cultivated areas. However, agricultural cultivation doesn＇t worsen water shortage and soil salinization problems in the region, and water shortage problems are worsening for other vegetated areas. This research provides a basis of reference for the reasonable allocation of water resources and restructuring of vegetation patterns in salinized areas.

关键词： evapotranspiration Hebei Province MODIS spatial pattern vegetation spatial-temporal evolution

Curation,nomenclature,and topological classification of receptor-like kinases from 528 plant species for novel domain discovery and functional inference

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Molecular Plant 2024年第4期17卷 658-671页

作者： qian Liu Qiong Fu Yujie Yan qian Jiang Longfei Mao Long wang feng Yu Heping Zheng State Key Laboratory of Chemo/Biosensing and Chemometrics Hunan University College of BiologyChangshaHunan 410082China Bioinformatics Center Hunan University College of BiologyChangshaHunan 410082China

Receptor-like kinases(RLKs)are the most numerous signal transduction components in plants and play important roles in determining how different plants adapt to their ecological *** on RLKs has focused mainly on a small number of typical RLK members in a few model *** is an urgent need to study the composition,distribution,and evolution of RLKs at the holistic level to increase our understanding of how RLKs assist in the ecological adaptations of different plant *** this study,we collected the genome assemblies of 528 plant species and constructed an RLK *** this dataset,we identified and characterized 524948 RLK family *** member underwent systematic topological classification and was assigned a gene ID based on a unified nomenclature ***,we identified two novel extracellular domains in some RLKs,designated Xiao and *** analysis of the RLK family revealed that the RLCK-XVII and RLCK-XII-2 classes were present exclusively in dicots,suggesting that diversification of RLKs between monocots and dicots may have led to differences in downstream cytoplasmic *** also used an interaction proteome to help empower data mining for inference of new RLK functions from a global perspective,with the ultimate goal of understanding how RLKs shape the adaptation of different plants to the environments/*** assembled RLK dataset,together with annotations and analytical tools,forms an integrated foundation of multiomics data that is publicly accessible via the metaRLK web portal(http://***).

关键词： RLK RLCK domain signaling pathway receptor-protein interactions

Airblast evolution initiated by wangjiayan landslides in the M_(s)8.0 Wenchuan earthquake and its destructive capacity analysis

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China Geology 2024年第2期7卷 237-247页

作者： Yu-feng wang qian-gong Cheng Qi Zhu Department of Geological Engineering Southwest Jiaotong UniversityChengdu 610031China Sichuan Highway Planning SurveyDesign and Research Institute LtdChengdu 610041China

Airblasts,as one common phenomenon accompanied by rapid movements of landslides or rock/snow avalanches,commonly result in catastrophic damages and are attracting more and more scientific *** quantitatively analyze the intensity of airblast initiated by landslides,the wangjiayan landslide,occurred in the Wenchuan earthquake,is selected here with the landslide propagation and airblast evolution being studied using FLUENT by introducing the Voellmy rheological *** results reveal that:(1)For the wangjiayan landslide,its whole travelling duration is only 12 s with its maximum velocity reaching 36 m/s at t=10 s;(2)corresponding to the landslide propagation,the maximum velocity,28 m/s,of the airblast initiated by the landslide also appears at t=10 s with its maximum pressure reaching594.8 Pa,which is equivalent to violent storm;(3)under the attack of airblast,the load suffered by buildings in the airblast zone increases to 1300 Pa at t=9.4 s and sharply decreased to-7000 Pa as the rapid decrease of the velocity of the sliding mass at t=10 s,which is seriously unfavorable for buildings and might be the key reason for the destructive collapse of buildings in the airblast zone of the wangjiayan landslide.

关键词： Landslide Voellmy rheological law 3D FLUENT simulation Airblast Intensity Building destructive collapse Wenchuan earthquake Geological hazards survey engineering

Core-rim structured MXene@SiO_(2)composites as oil-based additives for enhanced tribological properties

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Friction 2024年第8期12卷 1728-1740页

作者： Yuhong CUI Shenghua XUE Tiantian wang Shujuan LIU qian YE feng ZHOU Weimin LIU State Key Laboratory of Solidification Processing Center of Advanced Lubrication and Seal MaterialsSchool of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi'an 710072China State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China

Herein,we have prepared SiO_(2)particles uploaded MXene nanosheets via in-situ hydrolysis of *** to the large number of groups at the edges of MXene,SiO_(2)grows at the edges first,forming MXene@SiO_(2)composites with a unique core-rim *** tribological properties of MXene@SiO_(2)as lubricating additive in 500 SN are evaluated by *** results show that MXene@SiO_(2)can reduce the friction coefficient of 500 SN from 0.572 to 0.108,the wear volume is reduced by 73.7%,and the load capacity is increased to 800 *** superior lubricity of MXene@SiO_(2)is attributed to the synergistic effect of MXene and SiO_(2).The rolling friction caused by SiO_(2)not only improves the bearing capacity but also increases the interlayer distance of MXene,avoiding accumulation and making it more prone to interlayer ***@SiO_(2)is adsorbed on the friction interface to form a physical adsorption film and isolate the friction *** addition,the high temperature and high load induce the tribochemical reaction and form a chemical protection film during in the friction ***,the presence of these protective films results in MXene@SiO_(2)having good lubricating properties.

关键词： Ti3C2Tx MXene SiO_(2)nanoparticles lubricating additives protective film

In-situ formation of nitrogen doped microporous carbon nanospheres derived from polystyrene as lubricant additives for anti-wear and friction reduction

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Friction 2024年第3期12卷 439-451页

作者： Yixin wang Qi LU Huijie XIE Shujuan LIU qian YE feng ZHOU Weimin LIU State Key Laboratory of Solidification Processing Center of Advanced Lubrication and Seal MaterialsSchool of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi'an 710072China State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China

This study presents a nitrogen-doped microporous carbon nanospheres(N@MCNs)prepared by a facile polymerization–carbonization process using low-cost *** N element in situ introduces polystyrene(PS)nanospheres via emulsion polymerization of styrene with cyanuric chloride as crosslinking agent,and then carbonization obtains N@*** as-prepared carbon nanospheres possess the complete spherical structure and adjustable nitrogen amount by controlling the relative proportion of tetrachloromethane and cyanuric *** friction performance of N@MCNs as lubricating oil additives was surveyed utilizing the friction experiment of ball-disc *** results showed that N@MCNs exhibit superb reduction performance of friction and *** the addition of N@MCNs was 0.06 wt%,the friction coefficient of PAO-10 decreased from 0.188 to 0.105,and the wear volume reduced by 94.4%.The width and depth of wear marks of N@MCNs decreased by 49.2% and 94.5%,*** carrying capacity of load was rocketed from 100 to 400 N *** the analysis of the lubrication mechanism,the result manifested that the prepared N@MCNs enter clearance of the friction pair,transform the sliding friction into the mixed friction of sliding and rolling,and repair the contact surface through the repair ***,the tribochemical reaction between nanoparticles and friction pairs forms a protective film containing nitride and metal oxides,which can avert direct contact with the matrix and improve the tribological *** experiment showed that nitrogen-doped polystyrene-based carbon nanospheres prepared by in-situ doping are the promising materials for wear resistance and reducing *** preparing method can be ulteriorly expanded to multi-element co-permeable *** and boron co-doped carbon nanospheres(B,N@MCNs)were prepared by mixed carbonization of N-enriched PS and boric acid,and exhibited high load carrying capacity and good tribolog

关键词： lubricant additives hypercrosslinked polystyrene carbon nanospheres friction reduction anti-wear

Nanoscopic tribological characteristics of a cryogenically cycled Zr-based metallic glass

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Science China(Physics,Mechanics & Astronomy) 2024年第6期67卷 113-126页

作者： qian Jia Qiaosheng Xia Qing Zhou Yucheng wang Yue Ren Yu Meng Haifeng wang feng Zhou State Key Laboratory of Solidification Processing Center of Advanced Lubrication and Seal MaterialsNorthwestern Polytechnical UniversityXi’an 710072China Shaanxi Key Laboratory of Surface Engineering and Remanufacturing Xi’an UniversityXi’an 710065China State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China

Optimized macroscopic tribological behavior can be anticipated in metallic glasses(MGs)by cryogenic cycling treatment(CCT),which is attributed to enhanced ***,the intrinsic friction mechanisms of MGs induced by cryogenic rejuvenation are still poorly *** the present study,nanoscopic wear tests were conducted on the Zr-based MGs surface with different CCT cycles using atomic force microscopy(AFM).After CCT treatment with 100 cycles,the MG displays the highest adhesion and ploughing frictions,but significantly improved anti-wear *** tests and molecular dynamics simulations disclose that the increased adhesion is attributed to the dominance of liquid-like regions in the CCT-treated MGs,and the impact of reduced hardness and weak elastic recovery results in the deteriorated ploughing *** enhanced plasticity effectively dissipates the strain from the AFM tip through multiple shear bands and weakens the adhesion during deformation,giving rise to excellent wear *** study elucidates the promoting effect of CCT on the outstanding antiwear performance of MGs,and is helpful for the development of novel alloys.

关键词： metallic glasses cryogenic cycling treatment nanoscope wear friction mechanism

Structure Engineering of Layered Double Hydroxides(LDHs)for Heterogeneous Catalysis

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Chemical Research in Chinese Universities 2024年第4期40卷 590-610页

作者： GAO Zhexi MA Haoran wang qian LI Dianqing feng Junting DUAN Xue State Key Laboratory of Chemical Resource Engineering Beijing Engineering Center for Hierarchical CatalystsBeijing University of Chemical TechnologyBeijing100029P.R.China Quzhou Institute for Innovation in Resource Chemical Engineering Quzhou324000P.R.China

Layered double hydroxide(LDH)is regarded as an advanced platform material in catalysis and attracts vast attrition *** a kind of two-dimensional layered material,it exhibits great advantages including cation-tunability in layer,lattice limitation,topological transformation,ion exchange and intercalation *** also can be used as building blocks for composite catalytic *** 100 years,a large number of works have been accomplished and researchers made great progress on investigating the LDH-based catalytic *** this review,we summarize representative achievements and significant progress in recent years,which mainly include constructing high entropy catalytic material,high dispersion/stability and interfacial supported catalytic material,composite catalytic materials and nano-reactor based on ***,through collecting the excellent works,we conclude the future development potential of LDH and provide a perspective.

关键词： Layered double hydroxide(LDH)material Heterogeneous catalysis Structure engineering