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SAPO-34 facilitates the formation of benzene,toluene and xylenes in direct syngas conversion over MnCrO_(x)-SAPO-34-ZSM-5

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Science China Chemistry 2024年第2期67卷 732-740页

作者： Shuchi Zhang Dengyun Miao Yi Ding Mengyuan Li Shujing Guo Yujuan Zhang Xiulian Pan xinhe Bao State Key Laboratory of Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian116023China University of Chinese Academy of Sciences Beijing100049China Shaanxi Yanchang Petroleum(Group)Co. Ltd.&Dalian Institute of Chemical Physics Xi’an Clean Energy(Chemical Industry)Research InstituteXi’an710000China

Direct conversion of syngas to aromatics over metal oxide and zeolite(OXZEO) composite catalysts is ***,the selectivity of more valuable products such as benzene,toluene and xylenes(BTX) is limited due to undesired secondary methylation of ***,we report that the introduction of SAPO-34 into MnCrO_(x)-ZSM-5 catalyst enhances significantly the formation of BTX without sacrificing the aromatics *** optimized conditions,the fraction of BTX in aromatics reaches 64.7% versus 28.9% over the catalyst without SAPO-34.A number of model reaction tests and characterizations reveal that SAPO-34 consumes partially the intermediates such as ketene,by converting them to light ***,the methylation of BTX by ketene to heavy aromatics is inhibited over the external acid sites of ZSM-5,leading to an enhanced BTX selectivity in the *** hybrid catalyst provides an efficient method for highly selective synthesis of BTX from syngas.

关键词： selective syngas conversion OXZEO aromatics BTX multi-functional catalysts

Effect of Low pH on Forming Process of Desulfurization Gypsum Composite Boards Strengthened by Melamine-formaldehyde Resin

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Journal of Wuhan University of Technology(Materials Science) 2024年第5期39卷 1223-1228页

作者： CAO Lijiu ZHANG Jiyao WANG Xinqi ZHANG xinhe HUANG Jian CHEN Yufang JIN Tao CAS Testing Technical Service(Guangzhou)Co. Ltd.Guangzhou 510650China Xuefeng Innovation(Beijing)Technology Co. Ltd.Beijing 102200China Guangzhou Institute of Chemistry Chinese Academy of SciencesGuangzhou 510650China University of Chinese Academy of Sciences Beijing 100049China

Through exploring the effects of low pH on the composite system of desulfurization gypsum(DG)enhanced by melamine-formaldehyde resin(MF),it is found that the inducing of sulfate-ion,in contrast to chloride and oxalate ions,favors the longitudinal growth of the crystalline form of the hydration product,which was relatively simple and had the highest length to width(L/D)*** the same time,MF can also improve L/D ratio of gypsum hydration products,which favors the formation of hydrated ***,in a composite system composed of hemihydrate gypsum,MF,and glass fibers,when dilute sulfuric acid was used to regulate pH=3-4,the tight binding formed among the components of the composite system compared to pH=*** hydration product of gypsum adheres tightly to glass fiber surface and produces a good cross-linking and binding effect with *** flexural strength,compressive strength,elastic modulus,and water absorption of the desulphurized gypsum composite board is 22.7 MPa,39.8 MPa,5608 MPa,and 1.8%,respectively.

关键词： MF-reinforced desulphurized gypsum board composite forming system low pH condition hydration process aspect ratio synergistic effect

Upgrading ethylene via renewable energy-driven electrocatalysis

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Science China Chemistry 2024年

作者： Hanyu Wang Dunfeng Gao Guoxiong Wang xinhe Bao State Key Laboratory of Catalysis Dalian National Laboratory for Clean Energy iChEM (Collaborative Innovation Center of Chemistry for Energy Materials) Dalian Institute of Chemical Physics Chinese Academy of Sciences University of Chinese Academy of Sciences

Ethylene oxide （EO） and ethylene glycol （EG） are two important commodity chemicals and are industrially produced from petroleum-derived ethylene via thermocatalytic processes. The overoxidation of ethylene and the implementation of high temperature and pressure lead to substantial CO2emission. Renewable energy-driven electrocatalysis provides a low-carbon route for upgrading ethylene under mild conditions, especially when it couples with ethylene electrosynthesis from CO2. In this minireview, we summarize recent achievements in the selective electrocatalytic oxidation of ethylene to EO and EG. Three main reaction routes including direct electrocatalytic oxidation with water, indirect electrocatalytic oxidation with halide mediators,and tandem electrocatalytic and thermocatalytic oxidation with hydrogen peroxide intermediate, are discussed. Some representative catalyst systems and reactor designs are exemplified. We discuss the existing scientific and technical challenges of electrocatalytic ethylene upgrading in terms of reaction rate, selectivity, and long-term stability, and propose future research directions and opportunities for pushing the process towards practical application.

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Anthrax lethal toxin and tumor necrosis factor-a synergize on intestinal epithelia to induce mouse death

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Protein & Cell 2024年第2期15卷 135-148页

作者： xinhe Gao Teng Teng Yifei Liu Tingting Ai Rui Zhao Yilong Fu Peipei Zhang Jiahuai Han Yingying Zhang State Key Laboratory of Cellular Stress Biology School of Life SciencesFaculty of Medicine and Life SciencesXiamen UniversityXiamen 361102China Research Unit of Cellular Stress of CAMS Xiang'an Hospital of Xiamen UniversityCancer Research Center of Xiamen UniversitySchool of MedicineFaculty of Medicine and Life SciencesXiamen UniversityXiamen 361102China Laboratory Animal Center Faculty of Medicine and Life SciencesXiamen UniversityXiamen 361102China

Bacillus anthracis lethal toxin(LT)is a determinant of lethal *** function in myeloid cells is required for bacterial dissemination,and LT itself can directly trigger dysfunction of the cardiovascular *** interplay between LT and the host responses is important in the pathogenesis,but our knowledge on this interplay remains *** necrosis factor-a(TNF-a)is a pleiotropic pro-inflammatory cytokine induced by bacterial *** LT accumulates and cytokines,predominantly TNF,amass during *** infection,co-treatment of TNF+LT in mice was used to mimic in vivo conditions for LT to function in inflamed *** marrow transplantation and genetically engineered mice showed unexpectedly that the death of intestinal epithelial cells(IECs)rather than that of hematopoietic cells led to LT+TNF-induced *** of p38a mitogen-activated protein kinase(MAPK)signaling by LT in IECs promoted TNF-induced apoptosis and necroptosis of IECs,leading to intestinal damage and mouse ***,p38a inhibition by LT enhanced TNF-mediated cell death in human colon epithelial HT-29 *** intestinal damage is one of the leading causes of lethality in anthrax patients,the IEC damage caused by LT+TNF would most likely be a mechanism underneath this clinical manifestation and could be a target for interventions.

关键词： lethal toxin TNF p38a intestinal epithelial cell cell death

Yeast-Controlled Double-Shelled CacO_(3)/CaF_(2)Hollow Nanospheres with Hierarchically Porous for Sustained pH-Sensitive Drug Release

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Chinese Journal of Chemistry 2024年第15期42卷 1713-1720页

作者： xinhe Liu Yi Chang Guanglei Ma Tingting Liu Penghui Song Heng Yu Xueqing Ren Yuming Guo Xiaoming Ma School of Chemistry and Chemical Engineering Henan Normal UniversityXinxiangHenan 453007China Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals Key Laboratory of Green Chemical Media and ReactionsMinistryof EducationHenan Normal UniversityXinxiangHenan 453007China

Hierarchically porous materials(HP materials)are believed one of the most hopeful matrix materials because of their distinctive multimodal pore structures and tremendous application potentials in the field of ***,green and facile synthesis of hierarchically porous nanomaterials with beneficial water dispersibility and biocompatibility is still a great ***,a novel biomimetic strategy is proposed to prepare the cell-tailored double-shelled HPCaCO_(3)/CaF_(2) hollow nanospheres under the mediation of yeast *** biomolecules derived from the secretion of yeast cells are used as conditioning and stabilizing agents to control the biosynthesis of the HPCaCO_(3)/CaF_(2) materials,which exhibit excellent water dispersibility and favorable *** double-shelled CaCO_(3)/CaF_(2) nanospheres hold hierarchically porous structure and have abundant pore channel and large specific surface area,showing high drug-loading and a prolonged drug sustainable release profile by the pore-by-pore diffusion pattern of the hierarchical ***,the HPCaCO_(3) with pH-sensitivity could controllably release drug doxorubicin hydrochloride(DOX)at the acidic tumor *** in vitro and in vivo results demonstrate that HPCaCO_(3)/CaF_(2) has the sustainable pH-sensitive drug release property,showing an enhanced therapeutic ***,this study provides a biomimetic strategy to synthesize the hierarchically porous double-shelled hollow nanomaterials for applying in sustainable drug delivery system.

关键词： Biomimetic synthesis Hierarchically porous Sustained pH-sensitive drug release Antitumor agents Drug delivery Calcium Cancer therapy/Hollow structures

A low-frequency and broadband wave-insulating vibration isolator based on plate-shaped metastructures

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Applied Mathematics and Mechanics(English Edition) 2024年第7期45卷 1171-1188页

作者： wei wei Feng GUAN Xin FANG College of Intelligent Science National University of Defense TechnologyChangsha410073China Naval Research Academy Beijing100161China

A metamaterial vibration isolator,termed as wave-insulating isolator,is proposed,which preserves enough load-bearing capability and offers ultra-low and broad bandgaps for greatly enhanced wave *** consists of plate-shaped metacells,whose symmetric and antisymmetric local resonant modes offer several low and broad mode bandgaps although the complete bandgap remains high and *** bandgap mechanisms,vibration isolation properties,effects of key parameters,and robustness to complex conditions are *** experimentally demonstrated,the wave-insulating isolator can improve the vibration insulation in the ranges of[50 Hz,180 Hz]and[260 Hz,400 Hz]by 15 dB and 25 dB,respectively,in contrast to the conventional isolator with the same first resonant frequency.

关键词： metamaterial and metastructure vibration isolation bandgap wave insulation plate

Confined Mn^(2+) enables effective aerobic oxidation catalysis

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Science China Chemistry 2024年第5期67卷 1545-1553页

作者： Desheng Yuan Sicong Ma Xiao Kong Chi Zhang Lin Chen Chengsheng Yang Lihua Wang Zhen Liu Lin Ye Yongmei Liu Rui Ma Zhi-Pan Liu Yifeng Zhu Yong Cao xinhe Bao Department of Chemical Physics University of Science and Technology of ChinaHefei 230026China Department of Chemistry Shanghai Key Laboratory of Molecular Catalysis and Innovative MaterialsCollaborative Innovation Center of Chemistry for Energy MaterialsFudan UniversityShanghai 200438China Key Laboratory of Synthetic and Self-Assembly Chemistry for Organic Functional Molecules Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China School of Materials and Chemistry University of Shanghai for Science and TechnologyShanghai 200093China Shanghai Synchrotron Radiation Facility Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201204China Institute of Advanced Fluorine-Containing Materials Zhejiang Normal UniversityJinhua 321004China State Key Laboratory of Catalysis National Laboratory for Clean EnergyCollaborative Innovation Center of Chemistry for Energy MaterialsDalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China

Effective and mild activation of O_(2) is essential but challenging for aerobic oxidation. In heterogeneous catalysis, high-valence manganese oxide(e.g., +4) is known to be active for the oxidation, whereas divalent MnO is ineffective due to its limited capacity to supply surface oxygen and its thermodynamically unstable structure when binding O_(2) in reaction conditions. Inspired by natural enzymes that rely on divalent Mn^(2+), we discovered that confining Mn^(2+) onto the Mn_(2)O_(3) surface through a dedicated calcination process creates highly active catalysts for the aerobic oxidation of 5-hydroxymethylfurfural, benzyl alcohol, and *** Mn_(2)O_(3)-confined Mn^(2+) is undercoordinated and efficiently mediates O_(2) activation, resulting in 2–3 orders of magnitude higher activity than Mn_(2)O_(3) alone. Through low-temperature infrared spectroscopy, we distinguished low-content Mn^(2+) sites at Mn_(2)O_(3) surface, which are difficult to be differentiated by X-ray photoelectron spectroscopy. The combination of in-situ energydispersive X-ray absorption spectroscopy and X-ray diffraction further provides insights into the formation of the newly identified active Mn^(2+) sites. By optimizing the calcination step, we were able to increase the catalytic activity threefold *** finding offers promising frontiers for exploring active oxidation catalysts by utilizing the confinement of Mn^(2+)and oftenignored calcination skills.

关键词： confinement catalysis manganese oxide aerobic oxidation divalent Mn^(2+) operando spectroscopies

The lithology and composition of lunar mantle modifi ed by ilmenite bearing cumulate: A thermodynamic model

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Acta Geochimica 2024年第05期43卷 856-875页

作者： wei Huang wei Du State Key Laboratory of Ore Deposit Geochemistry Institute of GeochemistryChinese Academy of Sciences University of Chinese Academy of Sciences Center for Excellence in Comparative Planetology Chinese Academy of Sciences

Due to their high density,the ilmenite-bearing cumulates (IBC)(with or without KREEP) formed during the late-stage lunar magma ocean solidifi cation are thought to sink into the underlying lunar mantle and trigger lunar mantle *** evidence implied that IBC may descend deep inside the Moon and remain as a partially molten layer at the core-mantle boundary (CMB).However,partial melting may have occurred on the mixed mantle cumulates during the sinking of IBC/KREEP and the silicate melt may be positively buoyant,thus preventing the IBC/KREEP layer from sinking to the ***,we perform thermodynamic simulation on the stability of lunar mantle cumulates at diff erent depths mixed with diff erent amounts of IBC/KREEP from an updated LMO *** modeling results suggest that the sinking of IBC/KREEP will cause at least 5 wt%partial melting in the shallow (～120 km) and a much larger degree of partial melting in the deep lunar mantle (～420 km).Due to the density contrast with the surrounding mantle,IBC/KREEP-bearing melts could potentially decouple under certain *** modifi ed lunar mantle by sinking of IBC/KREEP can better explain the formation of diff erent kinds of lunar basaltic magma than the primary lunar mantle formed through diff erentiation of lunar magma *** of IBC/KREEP back into the lunar mantle may introduce plagioclase,clinopyroxene,garnet,and incompatible radioactive elements into the deep lunar mantle,which will further aff ect the thermal and chemical evolution of the lunar interior.

关键词： Ilmenite-bearing cumulate KREEP Lunar mantle overturn Partial melting pMELTS

Task-specific Part Discovery for Fine-grained Few-shot Classification

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Machine Intelligence Research 2024年第5期21卷 954-965页

作者： Yongxian wei Xiu-Shen wei School of Computer Science and Technology Nanjing University of Science and TechnologyNanjing210094China

Localizing discriminative object parts(e.g.,bird head)is crucial for fine-grained classification tasks,especially for the more challenging fine-grained few-shot *** work always relies on the learned object parts in a unified manner,where they attend the same object parts(even with common attention weights)for different few-shot episodic *** this paper,we propose that it should adaptively capture the task-specific object parts that require attention for each few-shot task,since the parts that can distinguish different tasks are naturally *** for a few-shot task,after obtaining part-level deep features,we learn a task-specific part-based dictionary for both aligning and reweighting part features in an ***,part-level categorical prototypes are generated based on the part features of support data,which are later employed by calculating distances to classify query data for *** retain the discriminative ability of the part-level representations(i.e.,part features and part prototypes),we design an optimal transport solution that also utilizes query data in a transductive way to optimize the aforementioned distance calculation for the final *** experiments on five fine-grained benchmarks show the superiority of our method,especially for the 1-shot setting,gaining 0.12%,8.56%and 5.87%improvements over state-of-the-art methods on CUB,Stanford Dogs,and Stanford Cars,respectively.

关键词： Fine-grained image recognition few-shot learning transductive learning visual dictionary part feature discovery