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Achieving Negatively Charged Pt Single Atoms on Amorphous Ni(OH)_(2)Nanosheets with Promoted Hydrogen Absorption in Hydrogen Evolution

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Nano-Micro Letters 2024年第10期16卷 213-224页

作者： Yue Liu Gui Liu Xiangyu Chen Chuang Xue Mingke Sun Yifei Liu Jianxin Kang Xiujuan Sun Lin guo School of Chemistry Beijing Advanced Innovation Center for Biomedical EngineeringKey Laboratory of Bio-inspired Smart Interfacial Science and TechnologyBeihang UniversityBeijing 100191People's Republic of China School of Chemistry Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of EducationXiangtan UniversityXiangtan 411105HunanPeople'Republic of China

Single-atom(SA)catalysts with nearly 100%atom utilization have been widely employed in electrolysis for decades,due to the outperforming catalytic activity and ***,most of the reported SA catalysts are fixed through the strong bonding between the dispersed single metallic atoms with nonmetallic atoms of the substrates,which greatly limits the controllable regulation of electrocatalytic activity of SA *** this work,Pt-Ni bonded Pt SA catalyst with adjustable electronic states was successfully constructed through a controllable electrochemical reduction on the coordination unsaturated amorphous Ni(OH)_(2)nanosheet *** on the X-ray absorption fine structure analysis and first-principles calculations,Pt SA was bonded with Ni sites of amorphous Ni(OH)_(2),rather than conventional O sites,resulting in negatively charged Pt^(δ-).In situ Raman spectroscopy revealed that the changed configuration and electronic states greatly enhanced absorbability for activated hydrogen atoms,which were the essential intermediate for alkaline hydrogen evolution *** hydrogen spillover process was revealed from amorphous Ni(OH)_(2)that effectively cleave the H-O-H bond of H_(2)O and produce H atom to the Pt SA sites,leading to a low overpotential of 48 mV in alkaline electrolyte at-1000 mA cm^(-2)mg^(-1)_(Pt),evidently better than commercial Pt/C *** work provided new strategy for the control-lable modulation of the local structure of SA catalysts and the systematic regulation of the electronic states.

关键词： Hydrogen evolution reaction Amorphous Pt single atoms Hydrogen spillover

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Efficient and rapid capture of uranium(Ⅵ) in wastewater via multiamine modified β-cyclodextrin porous polymer

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Chinese Journal of Chemical Engineering 2024年第4期68卷 144-155页

作者： Xing Zhong Yubin Tan Siyuan Wu Caixia Hu Kai guo Yongchuan Wu Neng Yu Mingyang Ma Ying Dai School of Chemistry and Materials Science East China University of TechnologyNanchang 330013China

It is quite important to ensure the safety and sustainable development of nuclear energy for the treatment of radioactive wastewater. To treat radioactive wastewater efficiently and rapidly, two multi-amine β-cyclodextrin polymers(diethylenetriamine β-cyclodextrin polymer(DETA-TFCDP) and triethylenetetramine β-cyclodextrin polymer(TETA-TFCDP)) were prepared and applied to capture uranium. Results exhibited that DETA-TFCDP and TETA-TFCDP displayed the advantages of high adsorption amounts(612.2and 628.2 mg·g-1, respectively) and rapid adsorption rates, which can reach(88 ± 1)% of their equilibrium adsorption amounts in 10 min. Moreover, the adsorbent processes of DETA-TFCDP and TETATFCDP on uranium(Ⅵ) followed the Langmuir model and pseudo-second-order model, stating they were mainly chemisorption and self-endothermic. Besides, TETA-TFCDP also showed excellent selectivity in the presence of seven competing cations and could be effectively reused five times via Na2CO3as the desorption reagent. Meanwhile, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy illustrated that the enriched multi-amine groups and oxygen-containing functional groups on the surface of TETA-TFCDP were the main active sites for capturing uranium(Ⅵ). Hence, multi-amine β-cyclodextrin polymers are a highly efficient, rapid, and promising adsorbent for capturing uranium(Ⅵ)from radioactive wastewater.

关键词： Adsorption Waste water Pollution Uranium(VI) b-Cyclodextrin

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Role of tannin pretreatment in flotation separation of magnesite and dolomite

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International Journal of Minerals,Metallurgy and Materials 2024年第3期31卷 452-461页

作者： Xiufeng Gong Jin Yao Jun guo Bin Yang Haoran Sun Wanzhong Yin Yulian Wang Yafeng Fu School of Resources and Civil Engineering Northeastern UniversityShenyang 110819China Key Laboratory of Solid Waste Treatment and Resource Utilization of the Ministry of Education Southwest University of Science and TechnologyMianyang 621010China School of Chemical Engineering China University of Mining and TechnologyXuzhou 221116China School of Materials Science and Engineering Shenyang Ligong UniversityShenyang 110159China Ansteel Beijing Research Institute Co. Ltd.Beijing 102200China

Flotation separation of magnesite and its calcium-containing carbonate minerals is a difficult ***,new regulat-ors have been proposed for magnesite flotation decalcification,although traditional regulators such as tannin,water glass,sodium carbon-ate,and sodium hexametaphosphate are more widely used in ***,they are rarely used as the main regulators in research because they perform poorly in magnesite and dolomite single-mineral flotation *** by the limonite presedimentation method and the addition of a regulator to magnesite slurry mixing,we used a tannin pretreatment method for separating magnesite and *** experiments confirmed that the tannin pretreatment method selectively and largely reduces the flotation recovery rate of dolomite without affecting the flotation recovery rate of ***,the contact angles of the tannin-pretreated magnesite and dolomite increased and decreased,respectively,in the presence of *** potential and Fourier transform infrared analyses showed that the tannin pretreatment method efficiently hinders NaOl adsorption on the dolomite surface but does not affect NaOl adsorption on the magnesite surface.X-ray photoelectron spectroscopy and density functional theory calculations confirmed that tannin interacts more strongly with dolomite than with magnesite.

关键词： tannin pretreatment selective inhibition flotation separation magnesite dolomite

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Simple chemical synthesis and isotropic negative thermal expansion in MHfF_(6)(M=Ca,Mn,Fe,and Co)

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Nano Research 2024年第3期17卷 2195-2203页

作者： Yongqiang Qiao Sen Zhang Peixian Zhang Juan guo Andrea Sanson Xi Zhen Kaiyue Zhao Qilong Gao Jun Chen Key Laboratory of Materials Physics of Ministry of Education and School of Physics and MicroelectronicsZhengzhou UniversityZhengzhou 450052China Department of Physics and Astronomy University of PadovaPadova I-35131Italy Beijing Advanced Innovation Center for Materials Genome Engineering Department of Physical ChemistryUniversity of Science and Technology BeijingBeijing 100083China

The rapid progress of modern technologies has accelerated the prominence of thermal expansion mismatch between materials,and tunable thermal expansion materials will be a powerful safeguard against this ***,isotropic MHfF_(6)(M=Ca,Mn,Fe,and Co)compounds with tunable thermal expansion have been produced via a low-cost synthetic method and *** utilizing temperature dependent X-ray diffraction(XRD)and Raman spectroscopy,combined with first principles calculations,it was revealed that the transverse thermal vibrations of the F atoms are dominated by low-frequency phonons with negative Grüneisen parameters and are therefore the origin of the negative thermal expansion(NTE).Very interestingly,with the increase of the M atomic number,the metal…F atomic linkages become stiffer,reducing the number of vibrational modes with negative Grüneisen parameters,so that the strong NTE can be gradually adjusted to moderate NTE and to near zero thermal *** present study achieves the tunable thermal expansion in a new compound family and shed light on the internal mechanism from the perspective of lattice vibrational dynamics.

关键词： negative thermal expansion fluorides chemical synthesis nanosheet structure first principles calculations

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用粘结剂处理工艺制备高性能预混粉

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粉末冶金工业 2009年第1期19卷 1-5页

作者：郭瑞金王宝飞 Sylvain St-Laurent Claude Gelinas 魁北克金属粉末(苏州)有限公司 Quebec Metal Powders Ltd.

FLOMET工艺是一种用粘结剂处理预混粉的技术,是指用固态有机粘结剂将细小的石墨、金属添加剂及润滑剂颗粒粘结在较粗的铁粉颗粒上。和常规预混粉相比,粘结剂处理预混粉的主要好处是,流动性好,可提高生产率与零件的一致性,以及较小的扬... 详细信息

FLOMET工艺是一种用粘结剂处理预混粉的技术,是指用固态有机粘结剂将细小的石墨、金属添加剂及润滑剂颗粒粘结在较粗的铁粉颗粒上。和常规预混粉相比,粘结剂处理预混粉的主要好处是,流动性好,可提高生产率与零件的一致性,以及较小的扬尘与无偏析。这些特性都使粘结剂处理的预混粉适合于生产高性能粉末冶金制品,以及其他各种需要优异充填特性的预混粉的场合。QMP在20世纪90年代中期提出了一系列粘结剂处理的预混粉。此后,一直为改进这类预混粉的性能和开发能用于特殊用途的粘结剂处理预混粉进行不懈的努力。本文回顾了粘结剂处理材料的物理性能。特别关注的是这些材料的生产工艺特性。

关键词：粘结剂处理粘结剂预混粉铁基粉末

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Efficient removal of Cr(VI) by polydopamine-modified lignin from aqueous solution: Batch and XAFS studies

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Water Science and Engineering 2024年第1期17卷 51-61页

作者： Xiao-jie guo Wei-kang Fu Jing-yuan Ma Bo-jun Xi Chen Wang Meng-yao Guan College of Materials and Environmental Engineering Hangzhou Dianzi UniversityHangzhou 310018China College of Textile and Garment Shaoxing UniversityShaoxing 312000China Shanghai Synchrotron Radiation Facility Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201204China

Lignocellulose has the potential to become a bio-based adsorbent due to its biodegradability and *** this study,a novel polydopamine functionalized-lignin(lignin@PDA),prepared via self-polymerization of dopamine(PDA)on lignin,was used as a bio-based adsorbent for rapid scavenging of hexavalent chromium(Cr(VI)).The morphology,functional groups,crystalline structure,and chemical composition of lignin@PDA were characterized with a scanning electron microscope-energy dispersive spectrometer,Fourier transform infrared spectroscopy,X-ray diffraction,and X-ray photoelectron *** Cr(VI)adsorption process of lignin@PDA was studied using batch experiments as a function of pH,ionic strength,adsorbent dose,and contact time at room *** adsorption rate of lignin@PDA was five times greater than that of the unmodified lignin,with a maximum adsorption capacity of 102.6 mg/g in an acidic *** adsorption of Cr(VI)on lignin@PDA fit the pseudo-secondorder equation and the Freundlich model,indicating that the adsorption process was mainly dominated by chemisorption and surface *** thermodynamic parameters showed that adsorption of Cr(VI)on lignin@PDA was an endothermic and spontaneous *** X-ray absorption fine structure results showed that sorption and reduction of Cr(VI)into Cr(II)occurred simultaneously on ***,PDA coating not only improved the reactivity of lignin but also promoted the complete reduction of Cr(VI)by *** to these results,polydopamine functionalized-lignin is a promising bio-based adsorbent for immobilization of Cr(VI)from wastewater.

关键词： Lignin Polydopamine Hexavalent chromium EXAFS Adsorption mechanism

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Assessing structure of Mg_(3)Bi_(2-x)Sb_(x)(0≤x≤2)at pressures below 40 GPa

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Journal of Materiomics 2024年第4期10卷 837-844页

作者： Weiwei Dong Wei Xu Zhiying guo Weishu Liu Yu Pan Satishkumar Kulkarni Xiaodong Li Konstantin Glazyrin Beijing Synchrotron Radiation Facility(BSRF) Institute of High Energy PhysicsChinese Academy of Sciences100049BeijingChina Deutsches Elektronen-Synchrotron DESY Notkestr.8522607HamburgGermany International Centre for Material Science Superstripes RICMASSVia dei Sabelli 119A00185RomeItaly Department of Materials Science and Engineering Southern University of Science and Technology518055ShenzhenChina Max-Planck-Institute for Chemical Physics of Solids Nöthnitzer Straße 4001187DresdenGermany Centre for X-ray and Nanoscience CXNS Deutsches Elektronen Synchrotron DESYNotkestr.8522607HamburgGermany

Mg_(3)Bi_(2-x)Sb_(x)(0≤x≤2)have gained significant attention due to their potential in thermoelectric(TE)***,there has been much debating regarding their structural properties and phase diagram as a function of pressure,which is crucial for understanding of their TE ***,we investigate a unified phase diagram of Mg_(3)(Bi,Sb)_(2) materials up to 40 GPa at room temperature using high-pressure X-ray *** high-pressure phases with the structural transition succession of P3m1→C2/m→P21/n are observed,which is valid for all Mg_(3)Bi_(2-x)Sb_(x)(0≤x≤2)*** further explore the low-pressure phase P3m1 and report that alloying does not change the quasi-isotropic compression of the unit lattice parameters nor has effect on the anisotropic bond compressibility,as recently reported for the *** study presents a comprehensive picture of Mg3Bi2–xSbx as a function of pressure and chemical composition providing a solid foundation for the future experimental and theoretical studies searching for the most efficient TE compound in Mg_(3)(Bi,Sb)_(2).

关键词： Mg_(3)Bi_(2-x)Sb_(x)(0≤x≤2) Thermoelectric High-pressure Structural evolution

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Squeeze and Excitation Convolution with Shortcut for Complex Plasma Image Recognition

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Computers, Materials & Continua 2024年第8期80卷 2221-2236页

作者： Baoxia Li Wenzhuo Chen Xiaojiang Tang Shaohuang Bian Yang Liu Junwei guo Dan Zhang Feng Huang College of Information and Electrical Engineering China Agricultural UniversityBeijing100083China College of Science China Agricultural UniversityBeijing100083China

Complex plasma widely exists in thin film deposition,material surface modification,and waste gas treatment in industrial plasma *** complex plasma discharge,the configuration,distribution,and size of particles,as well as the discharge glow,strongly depend on discharge ***,traditional manual diagnosis methods for recognizing discharge parameters from discharge images are complicated to operate with low accuracy,time-consuming and high requirement of *** solve these problems,by combining the two mechanisms of attention mechanism(strengthening the extraction of the channel feature)and shortcut connection(enabling the input information to be directly transmitted to deep networks and avoiding the disappearance or explosion of gradients),the network of squeeze and excitation convolution with shortcut(SECS)for complex plasma image recognition is proposed to effectively improve the model *** results show that the accuracy,precision,recall and F1-Score of our model are superior to other models in complex plasma image recognition,and the recognition accuracy reaches 97.38%.Moreover,the recognition accuracy for the Flowers and Chest X-ray publicly available data sets reaches 97.85%and 98.65%,respectively,and our model has *** study shows that the proposed model provides a new method for the diagnosis of complex plasma images and also provides technical support for the application of plasma in industrial production.

关键词： Image recognition complex plasmas deep learning

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Zero thermal expansion in Cs_(2)W_(3)O_(10)

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Chinese Chemical Letters 2024年第7期35卷 538-541页

作者： Juan guo Mingyuan Fang Qingsong Liu Xiao Ren Yongqiang Qiao Mingju Chao Erjun Liang Qilong Gao School of Physics&Microelectronics Key Laboratory of Materials Physics of Ministry of Education of ChinaZhengzhou UniversityZhengzhou 450052China

Zero thermal expansion materials are important for the practical applications due to their shape stability as changing *** reported concept of average atomic volume is an available method to hunt new zero thermal expansion ***,according to this concept,a tetragonal tungstate Cs_(2)W_(3)O_(10)with zero expansion has been *** is no structure phase transition as increasing temperature from 150 K to 573 *** coefficient of thermal expansion of axes and volume areαa=0.0074×10^(-6)K^(-1),αc=1.63×10^(-6)K^(-1),andαV=1.60×10^(-6)K^(-1),respectively,in the temperature range of 150~573 *** temperature-and pressure-dependent Raman spectra reveal that the vibrations of WO6octahedra libration modes with positive total anharmonicity and W-O-W bending mode with negative Grüneisen parameter are possibly the origin of zero thermal expansion in Cs_(2)W_(3)O_(10).

关键词： Zero thermal expansion Cesium tungstate Raman spectra Average atomic volume Temperature-dependent X-ray diffraction

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Combined use of fly ash and silica to prevent the long-term strength retrogression of oil well cement set and cured at HPHT conditions

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Petroleum Science 2024年第2期21卷 1122-1134页

作者： guo-Dong Cheng Xue-Yu Pang Jin-Sheng Sun Zheng-Song Qiu Chuang-Chuang Wang Jian-Kun Qin Ning Li School of Petroleum Engineering China University of Petroleum(East China)Qingdao266580ShandongChina National Key Laboratory of Deep Oil and Gas China University of Petroleum(East China)Qingdao266580ShandongChina Oil and Gas Engineering Research Institute(Tarim Oilfield Company) China National Petroleum CorporationTarim841000XinjiangChina

The long-term strength retrogression of silica-enriched oil well cement poses a significant threat to wellbore integrity in deep and ultra-deep wells, which is a major obstacle for deep petroleum and geothermal energy development. Previous attempts to address this problem has been unsatisfactory because they can only reduce the strength decline rate. This study presents a new solution to this problem by incorporating fly ash to the traditional silica-cement systems. The influences of fly ash and silica on the strength retrogression behavior of oil well cement systems directly set and cured under the condition of 200°C and 50 MPa are investigated. Test results indicate that the slurries containing only silica or fly ash experience severe strength retrogression from 2 to 30 d curing, while the slurries containing both fly ash and silica experience strength enhancement from 2 to 90 d. The strength test results are corroborated by further evidences from permeability tests as well as microstructure analysis of set cement. Composition of set cement evaluated by quantitative X-ray diffraction analyses with partial or no known crystal structure(PONKCS) method and thermogravimetry analyses revealed that the conversion of amorphous C-(A)-S-H to crystalline phases is the primary cause of long-term strength *** addition of fly ash can reduce the initial amount of C-(A)-S-H in the set cement, and its combined use with silica can prevent the crystallization of C-(A)-S-H, which is believed to be the working mechanism of this new admixture in improving long-term strength stability of oil well cement systems.

关键词： Fly ash Long-term strength retrogression High temperature Quantitative X-ray diffraction(QXRD) Partial or no known crystal structure(PONKCS)

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