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Precise immobilization of metal single atoms into a porphyrinic metal-organic framework for an efficient alkene hydrosilylation

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Nano Research 2024年第7期17卷 5914-5921页

作者： Chun-Ying Chen Qi-Jie mo Fu-Zhen li Hai-li Song li Zhang mOE Laboratory of Bioinorganic and Synthetic Chemistry Lehn Institute of Functional MaterialsSchool of ChemistrySun Yat-Sen UniversityGuangzhou 510006China

Alkene hydrosilylation is one of the most concise and atom-economical methods to synthesize organosilicon ***,we reported the precise immobilization of metal single atoms(m-SAs;m=Ru,Rh,Ir,Pd,Pt,and Au)into a porphyrinic metalorganic framework(mOF)of PCN-222(PCN=porous coordination network),and then applied the resultant mOF composites of m-SAs@PCN-222 to alkene *** solvent-free conditions,Pt-SAs@PCN-222 displayed an especially high catalytic efficiency with the turnover frequency up to 119 s−1 and the maximum turnover number of 906,250 at room *** and theoretical studies revealed that there existed strong interactions between Pt-SAs@PCN-222 and the substrates,which helped to condense the substrates in the cavities of the porous *** density functional theory calculations and molecular dynamics simulations disclosed that PCN-222 could transfer electrons to Pt-SAs to enhance the silane oxidative addition and drive the reaction to proceed smoothly via Chalk–Harrod pathway.

关键词： alkene hydrosilylation single atom catalysts metal-organic frameworks precision chemistry synergistic catalysis

The component-activity interrelationship of cobalt-based bifunctional electrocatalysts for overall water splitting:Strategies and performance

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Journal of Energy Chemistry 2024年第4期91卷 453-474页

作者： mingjie Sun Riyue Ge Sean li liming Dai Yiran li Bin liu Wenxian li School of materials Science and Engineering Shanghai UniversityShanghai 200444China Institute of Textiles and Clothing The Hong Kong Polytechnic UniversityHong Kong SAR 999077China School of materials Science and Engineering University of New South WalesSydneyNew South Wales 2052Australia UNSW materials&manufacturing Futures Institute UNSW SydneyNew South Wales 2052Australia School of Chemical Engineering University of New South WalesSydneyNew South Wales 2052Australia

Cobalt-based electrocatalysts take advantage of potentially harmonizable microstructure and flexible coupling effects compared to commercial noble metal-based catalytic ***,conventional water electrolysis systems based on cobalt-based monofunctional hydrogen evolution reaction(HER)or oxygen evolution reaction(OER)catalysts have certain shortcomings in terms of resource utilization and *** contrast,cobalt-based bifunctional catalysts(CBCs)have attracted much attention in recent years for overall water splitting systems because of their practicality and reduced preparation cost of *** review aims to address the latest development in CBCs for total *** main modification strategies of CBCs are systematically classified in water electrolysis to provide an overview of how to regulate their morphology and electronic ***,the catalytic performance of CBCs in total-hydrolysis is summarized according to the types of cobalt-based phosphides,sulfides and oxides,and the mechanism of strengthened electrocatalytic ability is emphasized through combining experiments and theoretical *** efforts are finally suggested to focus on exploring the dynamic conversion of reaction intermediates and building near-industrial CBCs,designing advanced CBC materials through micro-modulation,and addressing commercial applications.

关键词： Cobalt Bifunctional electrocatalysis Water splitting modification strategies Electrocatalytic performances

Unveiling three-dimensional sea surface signatures caused by internal solitary waves:insights from the surface water ocean topography mission

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Journal of Oceanology and limnology 2024年第3期42卷 709-714页

作者： Xudong ZHANG Xiaofeng li Key Laboratory of Ocean Observation and Forecasting Key Laboratory of Ocean Circulation and WavesInstitute of OceanologyChinese Academy of SciencesQingdao 266071China

Internal solitary waves(ISW),characterized by large amplitude and long propagation distance,are widespread in global *** remote sensing images have played an essential role in studying ISWs,they mainly exploit two-dimensional image ***,with the launch of the surface water ocean topography(SWOT)satellite on December 16,2022,a unique opportunity has emerged to capture wide-swath three-dimensional ISW-induced sea surface *** this study,we examine ISWs in the Andaman Sea using data from the Ka-band Radar Interferometer(KaRIN),a crucial sensor onboard *** not only provides backscattering satellite images but also employs synthetic aperture interferometry techniques to retrieve wide-swath two-dimensional sea surface height *** observations in the Andaman Sea revealed the presence of ISWs characterized by dark-bright strips and surface elevation *** surface soliton has an amplitude of 0.32 m,resulting in an estimation of ISW amplitude of approximately 60 *** contrast to traditional two-dimensional satellite images or nadir-looking altimetry data,the SWOT mission’s capability to capture threedimensional sea surface information represents a significant *** breakthrough holds substantial promise for ISW studies,particularly in the context of ISW amplitude inversion.

关键词： internal solitary wave(ISW) surface water ocean topography(SWOT) altimeter

Investigations of Water Flow Behaviors Induced by Local Temperature Variations through a Single Rough Fracture for the Enhanced Geothermal Systems

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Journal of Thermal Science 2024年第3期33卷 1055-1064页

作者： li Jiawei YE lin Department of Energy and Power Engineering Tsinghua UniversityBeijing100084China School of Power and Energy Northwestern Polytechnical UniversityXi’an710072China

In recent years,Enhanced Geothermal System(EGS)technologies have been applied to the geothermal resources production in the Hot Dry Rock(HDR).The core of EGS technologies is to adopt hydraulic fracturing in the reservoir to create a connected network of discrete fractures with the consideration of water as a working fluid for hydraulic fracturing and heat *** paper investigates the characteristics of water flow behaviors through a single rough fracture under different temperature and pressure conditions.A single fracture model with rough fracture surfaces is constructed and then characterized,and influences of the anisotropic factor on the average tortuosity and frictional resistance coefficient of water flow through a single fracture with rough surfaces have been compared and *** consideration of other impacting factors(temperature,pressure,fracture roughness),the impact of mass flow rate has also been *** simulation results present that changes of average tortuosity for water flow through a single rough facture are mainly affected by *** can be observed that higher temperature leads to larger average tortuosity but the frictional resistance coefficient shows an opposite *** for pressure conditions,it is found that effects of pressure on average tortuosity and frictional resistance coefficient is very small,which can be neglected under high pressure ***,the average tortuosity shows a progressively linear relationship with the mass flow *** the contrary,the frictional resistance coefficient has a negative relationship with the mass flow *** is revealed that when the mass flow rate reaches a critical point,the influences of temperature on the frictional resistance coefficient will be *** of single rough fractures with different anisotropic factors show that values of average tortuosity and frictional resistance coefficient have positive relationships with the increase

关键词： single rough fracture tortuosity frictional resistance enhanced geothermal system

Hydrographic Characteristics and Oceanic Heat Flux in the Upper Arctic Ocean over the Alpha Ridge Observed by the DTOP Platform in 2018 and 2021

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Journal of Ocean University of China 2024年第2期23卷 304-316页

作者： WANG Yongjun li Tao College of Oceanic and Atmospheric Sciences Ocean University of ChinaQingdao 266100China Frontier Science Center for Deep Ocean multispheres and Earth System(FDOmES) and Physical Oceanography Laboratory Ocean University of ChinaQingdao 266100China Laoshan Laboratory Qingdao 266237China

In 2018 and 2021,the Drift-Towing Ocean Profilers(DTOP)provided extensive temperature and salinity data on the upper 120m ocean through their drifts over the Alpha Ridge north of the Canada *** thickness and temperature maximum of Alaska Coastal Water(ACW)ranged from 20m to 40m and-1.5℃to-0.8℃,respectively,and the salinity generally maintained from 30.2 to *** with World Ocean Atlas 2018’s climatology manifested a 40m-thick and warm ACW roughly ex-ceeding the temperature maximum by 0.4–0.5℃in June–August *** anomalously warm ACW was highly related to the ex-pansion of the Beaufort Gyre in the negative Arctic Oscillation *** summer,the under-ice oceanic heat flux F_(w)^(OHF)was elevated,with a maximum value of above 25Wm^(-2).F_(w)^(OHF)was typically low in the freezing season,with an average value of 1.2Wm^(-2).The estimates of upward heat flux contributed by ACW to the sea ice bottom F_(w)^(OHF)were in the range of 3–4Wm^(-2)in June–August 2021,when ACW contained a heat content of more than 80mJm^(-2).The heat loss over this period was driven by a weak stratification upon the ACW layer associated with a surface mixed layer(SmL)approaching the ACW *** autumn,F_(w)^(OHF)was reduced(m^(-2))except during rare events when it elevated F_(w)^(OHF)*** addition,the intensive and widespread Ekman suction,which created a violent upwelling north of the Canada Basin,was largely responsible for the substantial cooling and thinning of the ACW layer in the summer of 2021.

关键词： Arctic Ocean oceanic heat flux Alaska Coastal Water Alpha Ridge

Transcriptome Analysis of Heterosis in Survival in the Hybrid Progenies of‘Haida No.1’and Orange-Shelled lines of the Pacific Oyster Crassostrea gigas

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Journal of Ocean University of China 2024年第1期23卷 199-208页

作者： YANG Hang li Qi Key Laboratory of mariculture Ministry of EducationOcean University of ChinaQingdao 266003China

Heterosis has been exploited to enhance the yield and adaptability in various shellfish species;however,the molecular basis of it remains *** Pacific oyster Crassostrea gigas is one of the most economically important aquaculture species,and its productive traits can be improved by ***,an intraspecific cross between orange shell(O,10th generation)and‘Haida No.1’(H,13th generation)of *** was performed to assess the heterosis of survival *** rates of hybrid family(OH)and inbred families(HH and OO)were compared at larval stage,and eyed-pediveliger larvae of three families were subjected to transcriptome *** analysis results of best-parent heterosis and mid-parent heterosis showed that the hybrid family exhi-bited a high heterosis in survival relative to the parental *** OH-m(OH ***)and OH-P(OH ***)had 425 and 512 dif-ferentially expressed genes(DEGs),*** enrichment analysis of these DEGs revealed that the significantly enrich-ed genes function in virion binding,C-type lectin receptor signaling pathway,cellular defense response and other immune-related pro-cesses,which involves perlucin-like protein,CD209 antigen-like protein,ZNFX1,caspase-3 and acan *** differentially ex-pressed genes in OH-m and OH-P,together with the immune-related processes mentioned above may play an important role in the larval survival of *** addition,three genes(CYP450,fucolectin and perlucin-like)are associated with the orange shell and low survival of maternal oyster *** findings provide support for the application of hybrid with superior survival and will facilitate the understanding of heterosis formation in the Pacific oyster.

关键词： Crassostrea gigas survival rate heterosis transcriptome

Hierarchical porous(Ta_(0.2)Nb_(0.2)Ti_(0.2)Zr_(0.2)Hf_(0.2))C high-entropy ceramics prepared by a self-foaming method for thermal insulation

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Journal of Advanced Ceramics 2024年第7期13卷 956-966页

作者： Cuiyan li Ruinan Gao Haibo Ouyang Tianzhan Shen Zihao Chen Yanlei li Key Laboratory for Green manufacturing&Functional Application of Inorganic materials School of Materials Science and EngineeringShaanxi University of Science and TechnologyXi’an 710021China

To meet the emerging demands for thermal protection materials for hypersonic aircraft,developing porous ultrahigh-temperature ceramics with both robust mechanical properties and superior thermal insulation performance is a critical ***,we report novel porous(Ta_(0.2)Nb_(0.2)Ti_(0.2)Zr_(0.2)Hf_(0.2))C high-entropy carbide(PHEC)ceramics fabricated by a self-foaming method using commercially available metal chloride and furfuryl alcohol(FA)as *** PHEC ceramics are constructed of microspheres with a size of 2µm,leading to a high porosity of 91.3%and an interconnected *** microspheres consist of high-entropy carbide grains(20 nm),resulting in abundant interfaces and nanosized pores in the PHEC *** to its unique hierarchical structure,the prepared PHEC ceramics have outstanding compressive strength(28.1±2 mPa)and exceptionally low thermal conductivity(κT,0.046 W·m^(-1)·K^(-1))at room *** makes it a promising thermal insulation materials for ultrahigh temperature *** work provides a cost-effective and facile strategy for producing porous ultrahigh-temperature ceramics.

关键词： porous ceramics high-entropy carbides hierarchical structure thermal insulation self-foaming

Hydrodechlorination of trifluoro-trichloroethane to chlorotrifluoroethylene:Revealing the deactivation mechanism and regeneration strategy of Pd-Cu/AC catalyst

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Chinese Journal of Chemical Engineering 2024年第6期70卷 261-268页

作者： Song Tian Yicheng Chen Xiaoyu Wen Bingcheng li Jian Lu Zile li Feng Feng Qingtao Wang Qunfeng Zhang Xiaonian li State Key Laboratory Breeding Base of Green Chemistry Synthesis Technology Institute of Industrial Catalysis of Zhejiang University of TechnologyHangzhou 310014China State Key Laboratory of Fluorine&Nitrogen Chemicals Xi'an Modern Chemistry Research InstituteXi'an 710065China

Chlorotrifluoroethylene(CTFE)is a vital fluorinated olefinic monomer produced through the catalytic hydrodechlorination of trichlorotrifluoroethane(CFC-113),an eco-friendly ***,hydrodechlorination catalysts for olefin production often suffer from poor *** Pd/AC catalyst and Pd-Cu/AC catalyst prepared by co-impregnation method exhibited poor stability,Pd-Cu/AC catalyst with CFC-113 conversion dropping to around 37%after 50 h of hydrodechlorination ***-Emmett-Teller,transmission electron microscopy,X-ray photoelectron spectroscopy,and X-ray diffraction of fresh and deactivated Pd/AC catalysts indicate that the deactivation of Pd/AC catalysts is due to high-temperature agglomeration of *** analysis of fresh and deactivated Pd-Cu/AC catalysts using Brunauer-Emmett-Teller,transmission electron microscopy,and thermogravimetric analysis techniques revealed decreased dispersion of active sites,reduced surface area,catalyst aggregation deactivation,and a significant decrease in Cu ***,the results of NH3-TPD revealed that the acid sites of the catalyst increased significantly.X-ray diffraction spectra indicated the formation of new species,basic copper chloride(Cu_(2)(OH)_(3)Cl),during the *** the reaction progressed,these new species agglomerated,leading to a gradual loss of catalyst ***,the deactivated catalyst was successfully reactivated using a simple alkaline washing method.

关键词： CFC-113 Hydrodechlorination Chlorotrifluoroethylene Catalyst deactivation

In situ plasmonic & electrochemical fiber-optic sensor for multi-metal-ions detection

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Science China(Information Sciences) 2024年第1期67卷 292-302页

作者： Xiaoling PENG Zhiyong YANG Bo PENG Zhi li Zhicong REN Xicheng WANG Jiahai li Zhencheng li liang CHEN Daotong YOU Kaiwei li Jianqing li Tuan GUO Institute of Photonics Technology Jinan University School of Computer Science and Engineering Macau University of Science and Technology Institute for Environmental and Climate Research Jinan University Key Laboratory of Bionic Engineering of ministry of Education Jilin University

High precision and high throughput detection of heavy metal ions is essential for water quality monitoring and ***,we propose a plasmonic & electrochemical dual-mode fiber sensing probe for label-free and real-time detection of multiple ions(Pb2+and Cu2+as examples).This sensor comprises a multimode fiber-single mode fiber reflection probe,the outer surface of which is coated with a gold nanofilm to excite the surface plasmon resonance(SPR) optically and simultaneously serves as an electrochemical working *** traditional electrochemical detection,the enrichment of ions cannot be detected in ***,by utilizing the plasmonic & electrochemical dual-mode detection method,various kinds of metal ions can be deposited onto the gold nanofilm and selectively oxidized during forward potential scanning,and the entire electrochemical process can be monitored by SPR *** experimentally demonstrate that the sensor can simultaneously detect Pb2+and Cu2+in a mixed solution in real-time,providing a linear response over the ion concentration range from 10-12to 10-7m and offering an excellent detection limit(1.69×10-14–5.49×10-13m).The proposed dual-mode fiber sensor has the benefits of remote sensing,compact footprint,and cost-effectiveness and shows excellent potential for water quality risk management in difficult-to-reach environments.

关键词： optical fiber sensor surface plasmon resonance electrochemical measurement ions detection water pollution