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Entanglement of Spatial and Energy Segmentation for c1 Pathways in cO2 Reduction on carbon Skeleton Supported Atomic catalysts

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ADVANcED ENERGY MATERIALS 2022年第14期12卷 2270057-2270057页

作者： Sun, Mingzi Wong, Hon Ho Wu, Tong Dougherty, Alan William Huang, Bolong Hong Kong Polytech Univ Dept Appl Biol & Chem Technol Hung Hom Kowloon Hong Kong 999077 Peoples R China Univ Hong Kong Dept Comp Sci Pokfulam Rd Hong Kong 999077 Peoples R China

Electroreduction of cO2 has become the most attractive approach to generate value-added chemicals and fuels. Products of single atomic catalysts (SAc) in cO2 reduction reaction reactions (cO2RR) are mostly limited to cO since the contributions of spatial and thermodynamic factors are not distinguished. To break through the challenges, comprehensive explorations in graphdiyne(GDY)-based SAc are made, to reveal detailed influences of active sites, elements, and adsorptions on the selectivity and reaction energy of the c-1 pathway. Unique d electrons dominated adsorption behaviors are identified, where the d(6) boundary is able to help screen out promising candidates for achieving complicated c2+ products. Based on spatial and thermodynamic factors, metal sites are still the most promising active sites. The transition metal based GDY-SAcs show element-dependent electroactivity towards different products in cO2RR. Meanwhile, the GDY-Pr and GDY-Pm SAcs are promising candidates for the cO2RR and even c-2 products in the future. This work supplies in-depth insights into the cO2RR to facilitate the design of efficient atomic catalysts in future work.

关键词： atomic catalysts c (1) pathway cO (2) reduction density functional theory graphdiyne

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Multi-scale quantitative study on dielectric properties of c-S-H synthesized by different molar ratio of ca/Si

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cONSTRUcTION AND BUILDING MATERIALS 2022年 360卷

作者： Liu, Jianglin Li, Yue Jin, caiyun Lin, Hui Li, Hongwen Li, Yinuo Liu, Yunze Beijing Univ Technol Beijing Key Lab Earthquake Engn & Struct Retrofit Key Lab Urban Secur & Disaster Engn Minist Educ Beijing 100124 Peoples R China Beijing Univ Technol Coll Appl Sci 100 Pingleyuan Beijing 100124 Peoples R China McGill Univ Mat Engn CO OP Montreal PQ Canada Beijing Univ Technol Coll Architecture & Civil Engn 100 Pingleyuan Beijing 100124 Peoples R China

The main hydration product of cement is c-S-H. c-S-H has a great influence on the electromagnetic properties, but there are few studies on the independent study of the electromagnetic properties of c-S-H. Therefore, nanocrystalline c-S-H was synthesized by caO and nano-SiO2, multi-scale analysis method was adopted, and the electromagnetic properties of its hydration products were analyzed from the mechanism. c-S-H powders with ca to Si molar ratio (c/S) of 0.8, 1.2, 1.6, 2.0 and 2.5 were synthesized and tested by the coaxial method. Four types of materials were defined in this paper: HPB (composed of nanocrystalline c-S-H, ca(OH)2, cacO3 and pore phase);cSH (composed of nanocrystalline c-S-H and pore phase with diameter less than 5 nm);P-cSH (composed of pore phase and cSH phase);c-cSH (composed of ca(OH)2, cacO3 and cSH phase). The complex permittivity and complex permeability of HPB with different c/S at 2-18 GHz were tested. The influence of molecular structure, interlayer physically bound water, phase types and content of HPB on the electromagnetic properties were investigated by XRD, MIP, N2 adsorption, TGA and 29Si NMR spectroscopy. The results showed that with the increase of c/S, the permittivity of cSH, P-cSH, c-cSH and HPB were decreased. Both ca(OH)2 phase and pore phase can reduce the permittivity and loss tangent of HPB. It was worth noting that the reduction degree of pores phase on the permittivity of the HPB were about 4 times than that of ca(OH)2 phase (or cacO3 phase). Meanwhile, the results confirmed that the carbonization of ca(OH)2 phases had no effect on the elec-tromagnetic properties of HPB.

关键词： c-S-H c S Dielectric properties Quantitative study Multi -scale analysis

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A combined Elevation Angle and c/N0 Weighting Method for GNSS PPP on Xiaomi MI8 Smartphones

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SENSORS 2022年第7期22卷 2804页

作者： Li, Yanjie cai, changsheng Xu, Zhenyu Cent South Univ Sch Geosci & Infophys Changsha 410083 Peoples R China

Traditionally, an elevation-angle-dependent weighting method is usually used for Global Navigation Satellite System (GNSS) positioning with a geodetic receiver. As smartphones adopt linearly polarized antenna and low-cost GNSS chips, different GNSS observation properties are exhibited. As a result, a carrier-to-noise ratio (c/N0)-dependent weighting method is mostly used for smartphone-based GNSS positioning. However, the c/N0 is subject to the effects of the observation environment, resulting in an unstable observation weight. In this study, we propose a combined elevation angle and c/N0 weighting method for smartphone-based GNSS precise point positioning (PPP) by normalizing the c/N0-derived variances to the scale of the elevation-angle-derived variances. The proposed weighting method is validated in two kinematic PPP tests with different satellite visibility conditions. compared with the elevation-angle-only and c/N0-only weighting methods, the combined weighting method can effectively enhance the smartphone-based PPP accuracy in a three-dimensional position by 22.7% and 24.2% in an open-sky area, and by 52.0% and 26.0% in a constrained visibility area, respectively.

关键词： GNSS smartphone precise point positioning elevation angle c N0

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coupling between thermal ageing/degradation and creep behavior of PEKK and c/PEKK composites above the glass transition temperature

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cOMPOSITES PART A-APPLIED ScIENcE AND MANUFAcTURING 2022年第0期153卷 106717-106717页

作者： Pedoto, Giuseppe Grandidier, Jean-claude Gigliotti, Marco Vinet, Alain Univ Poitiers Inst Pprime CNRS Dept Phys & Mecan Mat ISAE ENSMA Poitiers France Airbus SAS Bldg D4218 Marius Terce F-31025 Toulouse France

The present work aims at investigating the coupling between thermal ageing/degradation and creep behavior of PEKK and c/PEKK composites at 200 degrees c, above the glass transition temperature (which is close to 160 degrees c). Ageing tests were carried out at 200 degrees c, under 5 bar of oxygen conditioned atmosphere. DSc scans and DMA tests were carried out. Tests results discussion were supported by indentation tests and image analysis of the aged specimen cross-section. coupled oxidation-thermomechanical-creep tests were carried out on c/PEKK samples at 200 degrees c under a 5 bar O2 environment. The resulting strain response was compared to creep tests carried out on c/PEKK samples at 200 degrees c under air at similar creep stress. Such comparison allowed to investigate the presence of degradation phenomena in c/PEKK samples. The analysis of X-rays mu-tomography scans allowed investigating the possible occurrence of degradation, and to discriminate between pure thermal and thermomechanical coupling with degradation phenomena.

关键词： PEKK c PEKK Degradation Ageing Ageing creep coupling

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changes in microstructure and mechanical properties of the carbon fiber and their effects on c/Sic composites

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MATERIALS cHARAcTERIZATION 2022年第0期193卷

作者： Hao, Jianjie Li, Jiayan Shi, Xiaolei He, Ping Shi, Wei Tan, Yi Dalian Univ Technol Key Lab Mat Modificat Laser Ion & Electron Beams Minist Educ Dalian 116024 Peoples R China Dalian Univ Technol Sch Mat Sci & Engn Dalian 116024 Peoples R China Chinese Acad Sci Inst Met Res Shenyang 110016 Peoples R China Chinese Acad Sci Shanghai Inst Ceram State Key Lab High Performance Ceram & Superfine M Shanghai 200050 Peoples R China

The changes in microstructure and mechanical properties of the carbon fiber and their effects on c/Sic composites were studied. The H, N and O atoms escaped and the carbon content in the carbon fiber increased when the heat treatment temperature exceeds 1200 degrees c. Meanwhile, the growth of graphite crystallite leaded to stress concentration and reduced the tensile strength of carbon fiber to 2.98 GPa by 1200 degrees c heat treatment. The active atoms on the surface of the carbon fiber were reduced, thus weakening the bonding force between the carbon fiber and the pyrolytic carbon interface layer and improving the pullout mechanism of the carbon fiber. This result was also observed by synchrotron radiation X-ray computed tomography. The flexural strength of the c/ Sic composite increased from 300 MPa without treatment to 364 MPa after 1600 degrees c heat treatment.

关键词： carbon fiber Heat treatment Tensile strength c Sic composites

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Fast-tracking of NH3 interaction with ZnO nanorods and c/ZnO hybrid nanostructures by operando spectroscopy

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APPLIED SURFAcE ScIENcE 2022年 590卷 153067-153067页

作者： Mbuyisa, Puleng N. Rigoni, Federica Nappini, Silvia Magnano, Elena Pagliara, Stefania Drera, Giovanni Sangaletti, Luigi Goldoni, Andrea Ndwandwe, Muzi cepek, cinzia Univ Zululand Dept Phys & Engn Private Bag X1001 ZA-3886 Kwa Dlangezwa South Africa Univ Cattolica Sacro Cuore Interdisciplinary Labs Adv Mat Phys Via Musei 41 I-25121 Brescia Italy Univ Cattolica Sacro Cuore Dipartimento Matemat & Fis Via Musei 41 I-25121 Brescia Italy Ist Officina Mat CNR Lab TASC Ss 14Km 163-4 I-34149 Trieste Italy Elettra Sincrotrone Trieste SCpA Ss 14Km 163 I-34149 Trieste Italy Ca Foscari Univ Venice Dept Mol Sci & Nanosyst Via Torino 155 I-30170 Venice Italy Univ Johannesburg Dept Phys POB 524Auckland Pk ZA-2006 Johannesburg South Africa

Fast X-ray photoemission spectroscopy has been carried out to track the interaction of ammonia gas with hybrid materials based on ZnO nanorods and nanostructured carbon. We provide, for the first time, direct evidence of gas adsorption of ammonia on nanostructured hybrid interfaces combining photoemission with transport measurements through the resistivity change upon gas exposure. This operando methodology allowed us to reconstruct the adsorption isotherms and relate the different behavior to the sample morphology at the nanoscale. While on bare ZnO nanorods, physisorption of ammonia is detected along with photon beam assisted cracking, on the nanostructured carbon the formation of amine groups is detected, without displaying any effect induced by photon beam exposure. Our results make the present experiment an operando general methodology, with the possibility to relate the transport versus dose curves (ultimately the adsorption isotherms) to a specific investigation of the gas/surface interactions.

关键词： ZnO c ZnO hybrid NH (3) gas fast acquisition XPS Adsorption isotherms Resistance

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comparative research on cyclic ablation behavior of c/c-Zrc-Sic and c/ c-Zrc composites at temperatures above 2000?c

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cORROSION ScIENcE 2022年 206卷

作者： Zhao, Zhigang Li, Kezhi Kou, Gang Li, Wei Northwestern Polytech Univ Carbon Carbon Composites Res Ctr Xian 710072 Peoples R China Xian Aeronaut Univ Sch Mat Engn Xian 710077 Peoples R China

The cyclic and single ablation behavior of c/c-Zrc-Sic and c/c-Zrc composites prepared by reactive melt infiltration were studied. The ablation resistance properties of cyclic ablation of 30 s x 4 and single ablation of 120 s was similar to that of 60 s x 4 and 240 s. The oxidation of the matrix and the peeling content of oxides are aggravated with the increased cyclic ablation numbers. Under the cyclic ablation mode, c/c-Zrc-Sic composites showed lower mass loss than c/c-Zrc composites. At the single ablation of 240 s, c/c-Zrc-Sic composites showed desirable ablation resistance owing to the formation of an effective heat/oxygen protection layer on the ablated surface.

关键词： carbon carbon composites c c-Zrc-Sic composites Reactive melt infiltration Ultrahigh temperature cyclic ablation

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Effect of impact damage on electrical resistivity of c/c-Sic composites

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INTERNATIONAL JOURNAL OF MATERIALS RESEARcH 2022年第8期94卷 930-933页

作者： Srivastava, V. K. Maile, K. Bothe, K. Udoh, A. Univ Stuttgart Staatliche Mat Stuttgart Germany Banaras Hindu Univ Dept Mech Engn Varanasi Uttar Pradesh India

The main objective of the present work was to study the low-velocity weight-drop impact damage behaviour of carbon - carbon silicon carbide (c/c- Sic) composites on electrical resistivity of the direct-current potential drop method. The results show that the electrical resistivity increases with increasing impact energy, which confirms that pre-microcracks of c/c- Sic composite grow very rapidly with a little amount of impact load and turn into a loss of conductivity of the material.

关键词： c c- Sic composites Weight-drop impact energy Indentation Electrical resistivity Damage Lockin thermography

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Insights into deterioration and reactivation of a mainstream anammox biofilm reactor response to c/N ratio

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JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022年 320卷 115780页

作者： chen, Jiabo Hai, Yan Zhang, Wei Zhou, Xin Taiyuan Univ Technol Coll Environm Sci & Engn Taiyuan 030024 Peoples R China Innovat Ctr Postgrad Educ Municipal Engn Shanxi Pr Taiyuan 030024 Peoples R China Renmin Univ China Res Ctr Low Carbon Technol Water Environm Sch Environm & Nat Resources Beijing 100872 Peoples R China

In-depth knowledge of the deterioration and reactivation of the anaerobic ammonium oxidation (anammox) induced by carbon-to-nitrogen (c/N) is still lacking. Herein, the anammox performance was investigated in an anaerobic sequence biofilm batch reactor fed with low-strength partial nitration effluent in the range of c/N ratio from 0.5 to 3. The anammox was hardly deteriorated at c/N lower than 1.5, while became worsen if c/N was above 2.0. The specific anammox activity (SAA) experiments showed an 85% decrease of SAA at c/N of 3.0 compared with the maximum value (c/N:0). However, anammox capacity was rapidly recovered once influent c/N was adjusted back to zero. Moreover, c/N also highly affected the composition, structure and function of extracellular polymeric substance of the anammox biofilm. High-throughput sequencing revealed a close cor-relation between c/N change and microbial structure shift. Finally, the potential inhibition and restoration mechanism of the c/N-dependent anammox were proposed based on metagenomic analysis. This research provides some insights into the reinstatement of a mainstream anammox biofilm process after it is interrupted by high c/N influent.

关键词： Anammox Inhibition Recovery c N ratio Extracellular polymeric substance Microbial community

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Lithium Vacancy-Tuned [cuO4] Sites for Selective cO2 Electroreduction to c2+ Products

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SMALL 2022年第8期18卷 2106433-2106433页

作者： Peng, chen Zhu, Xiaorong Xu, Zikai Yan, Shuai chang, Lo Yueh Wang, Zhiqiang Zhang, Junbo chen, Menghuan Sham, Tsun-Kong Li, Yafei Zheng, Gengfeng Fudan Univ Dept Chem Adv Mat Lab Shanghai 200438 Peoples R China Fudan Univ Fac Chem & Mat Sci Shanghai Key Lab Mol Catalysis & Innovat Mat Shanghai 200438 Peoples R China Nanjing Normal Univ Sch Chem & Mat Sci Jiangsu Collaborat Innovat Ctr Biomed Funct Mat Jiangsu Key Lab New Power Batteries Nanjing 210023 Peoples R China Soochow Univ Joint Int Res Lab Carbon Based Funct Mat & Devic Inst Funct Nano & Soft Mat FUNSOM Suzhou 215123 Jiangsu Peoples R China Univ Western Ontario Dept Chem 1151 Richmond St London ON N6A 5B7 Canada

Electrochemical cO2 reduction to valuable multi-carbon (c2+) products is attractive but with poor selectivity and activity due to the low-efficient c-c coupling. Herein, a lithium vacancy-tuned Li2cuO2 with square-planar [cuO4] layers is developed via an electrochemical delithiation strategy. Density functional theory calculations reveal that the lithium vacancies (V-Li) lead to a shorter distance between adjacent [cuO4] layers and reduce the coordination number of Li+ around each cu, featuring with a lower energy barrier for cO-cO coupling than pristine Li2cuO2 without V-Li. With the V-Li percentage of approximate to 1.6%, the Li2-xcuO2 catalyst exhibits a high Faradaic efficiency of 90.6 +/- 7.6% for c2+ at -0.85 V versus reversible hydrogen electrode without iR correction, and an outstanding partial current density of -706 +/- 32 mA cm(-2). This work suggests an attractive approach to create controllable alkali metal vacancy-tuned cu catalytic sites toward c2+ products in electrochemical cO2 reduction.

关键词： c (2+) products cO (2) reduction reaction electrochemical delithiation Li 2cuO (2) lithium vacancies

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