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Effect of valence and spin state on ethane dehydrogenation in Fe-S-1 catalyst

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Journal of Energy Chemistry 2024年第10期97卷 677-686页

作者： Liusai huang Yumeng Fo peng Zhang Shaojia Song Xinxin Zhang Xueqiu Wu Saeed Soltanali jian Liu Weiyu Song State Key Laboratory of Heavy Oil Processing China University of Petroleum (Beijing) China Petrochemical Research Institute PetroChina Company Limited Catalysis Technologies Development Division Research Institute of Petroleum Industry (RIPI)

Light alkanes non-oxidative dehydrogenation is an attractive non-oil route for olefins *** alkane dehydrogenation reaction is limited by thermodynamic equilibrium,and the C-H bond cleavage is commonly considered as the rate-determined *** valence state of metal sites in catalysts will influence the stabilization of the vital intermediate(i.e.,CxHy...Mδ+...H) during the C-H bond cleavage process,which in turn affects the catalytic ***,we explicitly investigated the effect of different valence states of framework-Fe in silicate-1 zeolite on ethane dehydrogenation reaction through the combination of experimental and theoretical ***（Ⅱ）-S-1 and Fe（Ⅲ）-S-1 catalysts are successfully synthesized by ligand-assisted in situ crystallization method,In-situ C2H6-FTIR shows the higher coverage of hydrocarbon intermediates on Fe（Ⅱ）-S-1,Under the same evaluation co nditio n,Fe（Ⅱ）-S-1 exhibits a higher space time yield of *** functional theory（DFT） results reveal that the more coordinate-unsaturated and electron-enriched Fe（Ⅱ） sites boost the first C-H bond activation by slight deformation and efficient electron donation with C2H5****,the second C-H bond cleavage on Fe（Ⅱ）-S-1 undergoes a spin-crossing process from quintet state to triplet state,which involves a two-electro n-two-orbital interaction,further promoting the formation of *** analysis is consistent with the experimental and DFT *** work could provide methodology for elucidating the effect of metal valence states on catalytic performance as well as offer guidance for designing more efficient Fe-zeolite catalysts.

关键词： DFT Electron-enriched Ethane dehydrogenation Iron Spin crossover

Gria:an efficient deterministic concurrency control protocol

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Frontiers of Computer Science 2024年第4期18卷 25-37页

作者： Xinyuan WANG Yun peng Hejiao huang School of Computer Science and Technology Harbin Institute of TechnologyShenzhen 518055China Institute of Artificial Intelligence and Blockchain Guangzhou UniversityGuangzhou 510006China

Deterministic databases are able to reduce coordination costs in a *** property has fostered a significant interest in the design of efficient deterministic concurrency control ***,the state-of-the-art deterministic concurrency control protocol Aria has three ***,it is impractical to configure a suitable batch size when the read-write set is ***,Aria running in low-concurrency scenarios,e.g.,a single-thread scenario,suffers from the same conflicts as running in high-concurrency ***,the single-version schema brings write-after-write *** address these issues,we propose Gria,an efficient deterministic concurrency control *** has the following ***,the batch size of Gria is ***,Gria’s conflict probability in low-concurrency scenarios is lower than that in high-concurrency ***,Gria has no write-after-write conflicts by adopting a multi-version *** further reduce conflicts,we propose two optimizations:a reordering mechanism as well as a rechecking *** evaluation result on two popular benchmarks shows that Gria outperforms Aria by 13x.

关键词： deterministic concurrency control transaction processing

Identification and characterization of camptothecin tailoring enzymes in Nothapodytes tomentosa

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Journal of Integrative Plant Biology 2024年第6期66卷 1158-1169页

作者： Yin Chen jian-Ping huang Yong-jiang Wang Meng-Ling Tu Junheng Li Bingyan Xu Guoqing peng Jing Yang Sheng-Xiong huang State Key Laboratory of Phytochemistry and Plant Resources in West China and Yunnan Key Laboratory of Natural Medicinal Chemistry Kunming Institute of BotanyChinese Academy of SciencesKunming 650201China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory for Economic Plants and Biotechnology Kunming Institute of BotanyChinese Academy of SciencesKunming 650201China

Camptothecin is a complex monoterpenoid indole alkaloid with remarkable antitumor *** that two C-10 modified camptothecin derivatives,topotecan and irinotecan,have been approved as potent anticancer agents,there is a critical need for methods to access other aromatic ringfunctionalized congeners(e.g.,C-9,C-10,etc.).However,contemporary methods for chemical oxidation are generally harsh and low-yielding when applied to the camptothecin scaffold,thereby limiting the development of modified *** herein,we have identified four tailoring enzymes responsible for C-9 modifications of camptothecin from Nothapodytes tomentosa,via metabolomic and transcriptomic *** consist of a cytochrome P450(Nt CPT9H)which catalyzes the regioselective oxidation of camptothecin to 9-hydroxycamptothecin,as well as two methyltransferases(Nt OMT1/2,converting 9-hydroxycamptothecin to 9-methoxycamptothecin),and a uridine diphosphate-glycosyltransferase(Nt UGT5,decorating 9-hydroxycamptothecin to9-β-D-glucosyloxycamptothecin).Importantly,the critical residues that contribute to the specific catalytic activity of Nt CPT9H have been elucidated through molecular docking and mutagenesis *** work provides a genetic basis for producing camptothecin derivatives through metabolic *** will hasten the discovery of novel C-9 modified camptothecin derivatives,with profound implications for pharmaceutical manufacture.

关键词： camptothecin biosynthesis enzymatic assay Nothapodytes tomentosa tailoring enzyme transcriptomic analysis

Preparation, Crystallization and Mechanical Properties of Potassium Aluminosilicate Glass-ceramics

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Journal of Wuhan University of Technology(Materials Science) 2024年第3期39卷 587-595页

作者：郑伟宏黄猛 GAO Zipeng ZHANG Hang YUAN jian TIAN Peijing peng Zhigang State Key Laboratory of Silicate Materials for Architectures Wuhan University of TechnologyWuhan 430070China Shahe Research Institute of Glass Technology Shahe 054100China

In this study,transparent K_(2)O-Al_(2)O_(3)-SiO_(2)(KAS)glass-ceramics with leucite as the main crystalline phase were prepared by melting-quench method and two-step heat *** effects of SiO_(2)/Al_(2)O_(3) ratio and heat treatment on crystallization and mechanical properties were *** crystallization kinetics and X-Ray Diffraction(XRD)results showed that SiO_(2)/Al_(2)O_(3) ratio and heat treatment system had a direct impact on the crystallization behavior of potassium aluminosilicate *** heat-treated at 680℃/2 h and 780℃/1 h,cracks generated on the surface of the sample with the addition of SiO_(2)/Al_(2)O_(3)=4.8(in mol)due to the huge difference in the coefficient of thermal expansion between glass matrix and *** the addition of SiO_(2)/Al_(2)O_(3)(in mol)was 4,the sample with leucite as the main crystalline phase showed an excellent fracture toughness(1.46 MPa·m^(0.5))after the heat treatment of 680℃/2 h and 780℃/5 *** there was a phase transformation from kaliophilite to *** crystalline phases of the sample heat-treated at 680℃/8 h and 780℃/1 h were leucite and kaliophilite,which resulted in the visible light transmittance of 63%and the fracture toughness of 0.91 MPa·m^(0.5).Furthermore,after the heat treatment of 680℃/2 h and 780℃/5 h,the main crystalline phase of the sample with SiO_(2)/Al_(2)O_(3)=3.2(in mol)was still *** leucite only grows on the surface of the sample and is hard to grow inward,it is hard to achieve the bulk crystallization of leucite in the sample with SiO_(2)/Al_(2)O_(3)=3.2(in mol).

关键词： leucite glass-ceramic kaliophilite crystallization kinetics

Universal architecture and defect engineering dual strategy for hierarchical antimony phosphate composite toward fast and durable sodium storage

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Journal of Energy Chemistry 2024年第3期90卷 110-119,I0004页

作者： Jiawei Wu Gaoyu Wang Wei Zhang Lixiang Wang jian peng Qinghua Li Zhixin Liang Wenbo Fan Jiazhao Wang Shaoming huang School of Materials and Energy Guangzhou Key Laboratory of Low-Dimensional Materials and Energy Storage DevicesGuangdong University of TechnologyGuangzhou 510006GuangdongChina School of Mechanical and Electrical Engineering Jiaxing Nanhu UniversityJiaxing 314001ZhejiangChina Institute for Superconducting and Electronic Materials Australian Institute for Innovative MaterialsUniversity of WollongongInnovation CampusSquires WayNorth WollongongNSW2522Australia

Antimony(Sb)-ba sed anode materials are feasible candidates for sodium-ion batteries(SIBs) due to their high theoretical specific capacity and excellent electrical ***,they still suffer from volume distortion,structural collapse,and ionic conduction interruption upon ***,a hierarchical array-like nanofiber structure was designed to address these limitations by combining architecture engineering and anion tuning strategy,in which SbPO_(4-x) with oxygen vacancy nanosheet arrays are anchored on the surface of interwoven carbon nanofibers(SbPO_(4-x)@CNFs).In particular,bulky PO_(4)^(3-) anions mitigate the large volume distortion and generate Na_(3)PO_(4) with high ionic conductivity,collectively improving cyclic stability and ionic transport *** abundant oxygen vacancies substantially boost the intrinsic electronic conductivity of SbPO_4,further accelerating the reaction *** addition,hierarchical fibrous structures provide abundant active sites,construct efficient conducting networks,and enhance the electron/ion transport *** from the advanced structural design,the SbPO_(4-x)@CNFs electrodes exhibit outstanding cycling stability(1000 cycles at 1.0 A g^(-1) with capacity decay of 0.05% per cycle) and rapid sodium storage performance(293.8 mA h g^(-1) at 5.0 A g^(-1)).Importantly,systematic in-/ex-situ techniques have revealed the "multi-step conversion-alloying" reaction process and the "battery-capacitor dual-mode" sodium-storage *** work provides valuable insights into the design of anode materials for advanced SIBs with elevated stability and superior rate performance.

关键词： SbPO_(4) anodes Hierarchical nanostructures Oxygen vacancy Stress dispersion Sodium-ion batteries

Simulation of RFI Cancellation Using Subspace Projection Algorithm for PAF Receiver

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Research in Astronomy and Astrophysics 2024年第1期24卷 237-244页

作者： peng Wu jian Li Mao-Zheng Chen Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China University of Chinese Academy of Sciences Beijing 100049China Xinjiang Key Laboratory of Microwave Technology Urumqi 830011China

The simulation of radio frequency interference(RFI) cancellation by applying a spatial filtering technique for phased array feed(PAF) is presented. In order to better reflect the characteristics of PAF, a new signal model is to add the coupling coefficient among elements of PAF to the conventional array signal model. Then the subspace projection(SP) algorithm is used to cancel RFI from the correlation matrix of the signal, and finally, the 2D power image is drawn. The power variation of signal-of-interest direction and RFI direction before and after using the SP algorithm is analyzed. The new signal model and simulation strategy can be used to test and verify the beamformer.

关键词： methods:analytical techniques:radar astronomy telescopes

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Tsinghua Science and Technology 2024年第4期29卷 971-984页

作者： Yuze peng Shengjun Xu Qingkun Chen Wenjin huang Yihua huang School of Electronics and Information Technology Sun Yat-sen UniversityGuangzhou 510006China Guangdong Provincial Key Laboratory of Optoelectronic Information Processing Chips and Systems Sun Yat-sen UniversityGuangzhou 510006Chinaand Southern Marine Science and Engineering Guangdong LaboratoryZhuhai 519080China

Popularity plays a significant role in the recommendation system. Traditional popularity is only defined as a static ratio or metric (e.g., a ratio of users who have rated the item and the box office of a movie) regardless of the previous trends of this ratio or metric and the attribute diversity of items. To solve this problem and reach accurate popularity, we creatively propose to extract the popularity of an item according to the Proportional Integral Differential (PID) idea. Specifically, Integral (I) integrates a physical quantity over a time window, which agrees with the fact that determining the attributes of items also requires a long-term observation. The Differential (D) emphasizes an incremental change of a physical quantity over time, which coincidentally caters to a trend. Moreover, in the Session-Based Recommendation (SBR) community, many methods extract session interests without considering the impact of popularity on interest, leading to suboptimal recommendation results. To further improve recommendation performance, we propose a novel strategy that leverages popularity to enhance the session interest (popularity-aware interest). The proposed popularity by PID is further used to construct the popularity-aware interest, which consistently improves the recommendation performance of the main models in the SBR community. For STAMP, SRGNN, GCSAN, and TAGNN, on Yoochoose1/64, the metric P@20 is relatively improved by 0.93%, 1.84%, 2.02%, and 2.53%, respectively, and MRR@20 is relatively improved by 3.74%, 1.23%, 2.72%, and 3.48%, respectively. On Movieslen-1m, the relative improvements of P@20 are 7.41%, 15.52%, 8.20%, and 20.12%, respectively, and that of MRR@20 are 2.34%, 12.41%, 20.34%, and 19.21%, respectively.

关键词： popularity Proportional Integral Differential(PID) algorithm session-based recommendation user’s interests

Efficacy and safety of single microneedle radiofrequency *** therapy on moderate-to-severe acne vulgaris:A prospective,randomized,controlled study

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Chinese Medical Journal 2024年第8期137卷 1006-1008页

作者： Chuchu huang Mengping Mao Yiran peng Ben Wang Yuxuan Deng Hongfu Xie Dan jian Department of Dermatology Xiangya HospitalCentral South UniversityChangshaHunan 410008China National Clinical Research Center for Geriatric Disorders Xiangya HospitalCentral South UniversityChangshaHunan 410008China Hunan Key Laboratory of Aging Biology Xiangya HospitalCentral South UniversityChangshaHunan 410008China Department of Dermatology and Allergy and Christine Kühne-Center for Allergy Research and EducationUniversity Hospital of BonnD-53127BonnGermany

To the Editor:Acne vulgaris is a prevalent skin disorder affecting both physical and psychosocial health.[1]Although photodynamic therapy(PDT)exists for moderate-to-severe acne,due to its adverse reactions,we are still looking forward to a novel therapeutic option with fewer side ***,radiofrequency has been used to treat moderate acne.[2]In this study,we aimed to evaluate the efcacy and safety of moderate-to-severe acne treatment based on a single microneedle with radiofrequency(MRF)*** during three consecutive sessions through a prospective,randomized,and controlled trial study.

关键词： needle prospective randomized

In-situ powder mixing for laser-based directed energy deposition of functionally graded materials

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Advances in Manufacturing 2024年第1期12卷 150-166页

作者： Ji-peng Chen Shou-Chun Xie He huang School of Mechanical and Electronic Engineering Nanjing Forestry UniversityNanjing210037People’s Republic of China Nanjing Huirui Photoelectric Technology Co. LtdNanjing211121People’s Republic of China

The mixing of powders is a highly relevant field under additive manufacturing,however,it has attracted limited interest to *** in-situ mixing of various powders remains a significant *** paper proposes a new method utilizing a static mixer for the in-situ mixing of multiple powders through the laser-based directed energy deposition(DED)of functionally graded ***,a powder-mixing experimental platform was established;WC and 316L powders were selected for the mixing ***,scanning electron microscopy,energy dispersive spectroscopy,and image processing were used to visually evaluate the homogeneity and proportion of the in-situ mixed ***,powder-mixing simulations were conducted to determine the powder-mixing *** the simulations,a powder carrier gas flow field and particle mixing were ***,a WC/316L metal matrix composite sample was produced using laser-based DED to verify the application potential of the static *** was found that the static mixer could adjust the powder ratio online,and a response time of 1–2 s should be considered when adjusting the ratio of the mixed powder.A feasible approach for in-situ powder mixing for laser-based DED was demonstrated and investigated,creating the basis for functionally graded materials.

关键词： Laser Deposition Static mixer Powder mixing Functionally graded materials