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The effect of Al3+ coordination structure on the propane dehydrogenation activity of Pt/Ga/Al2O3 catalysts

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Journal of Energy Chemistry 2020年第2期29卷 93-99页

作者： Qinqin yu tie yu Hongyu Chen Guangzong Fang Xiulian Pan Xinhe Bao State Key Laboratory of Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023LiaoningChina

The effect of the Al2O3 structure on the performance of Pt/Ga/Al2O3 catalysts is investigated for the direct dehydrogenation of propane. The study unveils that the structure of Al3+determines the bulk structure of catalysts, particularly a high content of coordinatively unsaturated Al3+sites(penta-coordinated Al3+,denoted as Al3+penta) could lead to a remarkably improved dehydrogenation activity of the catalyst. The bulk characterization reveals that the sufficient amount of Al3+pentain Al2O3 benefit the dispersion of Pt and Ga2O3 on the Al2O3 support. At the same time, TPR results reveal that the presence of Pt facilitates the reduction of Ga2O3, likely due to the hydrogen spillover between the well dispersed Pt and Ga2O3,which consequently enhances the synergistic function between Pt and Ga2O3 in the dehydrogenation of propane. Recyclability tests demonstrate that the dehydrogenation activity stabilizes after three cycles over the Pt/Ga/Al2O3 catalyst.

关键词： Dehydrogenation Ga2O3 Al2O3 Coordinatively unsaturated

Annotation of miRNAs in the COVID-19 Novel Coronavirus

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Journal of Electronic Science and Technology 2021年第1期19卷 6-13页

作者： tie-Ying yu Min Chen Chun-De Wang the Department of Yantai Institute of Coastal Zone Research and Center for Ocean Mega-Science Chinese Academy of SciencesYantai 264003 the College of Life Sciences Shandong Agricultural UniversityTai’an 271018 the School of Marine Science and Engineering Qingdao Agricultural UniversityQingdao 266109

The coronavirus disease 2019(COVID-19)coronavirus is a new strain of coronavirus that had not been previously detected in *** its severe pathogenicity is concerned,it is important to study it thoroughly to aid in the discovery of a *** this study,the microRNAs(miRNAs)of COVID-19 were annotated to provide a powerful tool for the study of this novel *** obtained 16 novel coronavirus genome sequences and the mature sequences of all viruses in the microRNA database(miRbase),and then used the miRNA matures sequences of the virus to perform the Basic Local Alignment Search Tool(BLAST)analysis in the coronavirus genome,extending the matched regions of approximately 20 bp to two segments by 200 *** sequences were obtained after deleting redundant ***,the hairpin structures of the mature miRNAs were determined using *** mature sequence on one hairpin arm was selected into a total of 4 sequences,and finally the relevant miRNA precursor prediction tools were used to verify whether the selected sequences are miRNA precursor sequences of the novel *** miRNAs of the novel coronavirus were annotated by our newly developed method,which will lay the foundation for further study of this virus.

关键词： microRNA(miRNAs)annotation novel coronavirus nucleotide Basic Local Alignment Search Tool(BLASTN) RNAfold

Temperature and thermodynamic deformation analysis of the rotors on a twin screw multiphase pump with high gas volume fractions

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第9期12卷 720-730页

作者： tie-yu GAO Dong-fang YANG Feng CAO Jin-cheng JIAO School of Energy and Power Engineering Xi'an Jiaotong University Xi'an 710049 China

The pressure increasing process within a twin screw multiphase pump, under the condition of high gas volume fractions (GVFs), induces large temperature and pressure changes that cause the rotors to deform. Rotor deformations heavily influence the backflow of the multiphase fluid through clearances within the twin screw multiphase pump and these deformations may even lead to pump failures. An accurate temperature and pressure distribution on the screw rotors need be obtained before the deformation analysis can be carried out. By means of small temperature and pressure sensors embedded into the groove at the root of the rotors, the temperatures of 12 points on the rotors and the pressure distributions of a twin screw multiphase pump under high GVFs conditions were recorded. Temperature test results were adopted to perform a heat transfer analysis for determining the temperature distribution on the screw rotors. Then deformation analyses, including thermal deformation, force deformation, and total deformation, were conducted according to the pressure and temperature distributions. Deformation analysis for different materials was also conducted under the same boundary conditions. A material was suggested for the manufacturing of rotors in a twin screw multiphase pump under the condition of high gas volume fractions.

关键词： Multiphase pump Twin screw rotor Thermal deformation Finite element analysis

Enhanced hydrogen evolution reaction over molybdenum carbide nanoparticles confined inside single-walled carbon nanotubes

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Journal of Energy Chemistry 2019年第1期28卷 123-127页

作者： Tingting Cui Jinhu Dong Xiulian Pan tie yu Qiang Fu Xinhe Bao State Key Laboratory of Catalysis Dalian Institute of Chemical Physics Chinese Academy of Sciences University of Chinese Academy of Sciences

Carbon nanotubes(CNTs) have shown as unique nanoreactors to tune the catalytic activity of confined nano-catalysts. Here we report that the catalytic performance of molybdenum carbide nanoparticles(MoC_x NPs) for the hydrogen evolution reaction(HER) process can be enhanced by encapsulation within single-walled carbon nanotubes(SWNTs) with a diameter of 1–2 nm. The catalyst with MoC_x NPs located on the interior surface of SWNTs(MoCx@SWNTs) exhibits a lower onset over-potential and a smaller Tafel slope than the one with MoC_x NPs attached on the exterior surface(MoCx/SWNTs). This is likely attributed to the much smaller particle size and the more reduced states of the confined MoC_x NPs, as well as the larger specific surface area of MoCx@SWNTs compared with Mo Cx/SWNTs. In addition, the electronic structure of the confined MoC_x NPs might be modified by the confinement effects of SWNTs, and hence the adsorption free energy of H atoms on the confined MoC_x NPs, which could also contribute to their higher performance. These results suggest that the SWNTs can be further explored for constructing novel catalysts with beneficial catalytic performance.

关键词： Single-walled carbon nanotubes Confined catalysis Molybdenum carbide Nanoparticles Hydrogen evolution reaction

Exploration of relationships between phytoplankton biomass and related environmental variables using multivariate statistic analysis in a eutrophic shallow lake:A 5-year study

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Journal of Environmental Sciences 2007年第8期19卷 920-927页

作者： WANG Xiao-long LU Yong-long HE Gui-zhen HAN Jing-yi WANG tie-yu State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 Chin Graduate School of the Chinese Academy of Sciences Beijing 100039 China Environmental Policy Group Wageningen University 6706 KN Wageningen the Netherlands

Understanding the process of the changing phytoplankton patterns can be particularly useful in water quality improvement and management decisions. However, it is generally not easy to illustrate the interactions between phytoplankton biomass and related environmental variables given their high spatial and temporal heterogeneity. To elucidate relationships between them, in a eutrophic shallow lake, Taihu Lake, relative long-term data set of biotic and abiotic parameters of water quality in the lake were conducted using multivariate statistical analysis within seasonal periodicity. The results indicate that water temperature and total phosphorus （TP） played governing roles in phytoplankton dynamics in most seasons （i.e. temperature in winter, spring and summer; TP in spring, summer and autumn）; COD （chemical oxygen demand） and BOD （biological oxygen demand） presented significant positive relationships with phytoplankton biomass in spring, summer and autumn. However, a complex interplay was found between phytoplankton biomass and nitrogen considering significant positive relationships occurring between them in spring and autumn, and conversely negative ones in summer. As the predatory factor, zooplankton presented significant grazing-pressure on phytoplankton biomass during summer in view of negative relationship between them in the season. Significant feedback effects of phytoplankton development were identified in summer and autumn in view that significant relationships were obser,qed between phytoplankton biomass and pH, Trans （transparency of water） and DO. The results indicate that interactions between phyto：plankton biomass and related environmental variables are highly sensitive to seasonal periodicity, which improves understanding of different roles of biotic and abiotic variables upon phytoplankton variability, and hence, advances management methods for eutrophic lakes.

关键词： eutrophication phytoplankton zooplankton Taihu Lake

Facile synthesis of nitrogen-doped graphene aerogels functionalized with chitosan for supercapacitors with excellent electrochemical performance

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Chinese Chemical Letters 2017年第5期28卷 935-942页

作者： Yong Zhang Jia-Yi Zhu Hong-Bo Ren yu-tie Bi Lin Zhang Department of Physics University of Sdence and Technology of ChinaHefei 230026China Joint Laboratory for Extreme Conditions Matter Properties Southwest University of Science and Technology and Research Center of Laser FusionMianyang621010China Science and Technology on Plasma Physics Laboratory Research Center of Laser FusionChina Academy of Engineering PhysicsMianyang 621900China

Three-dimensional porous nitrogen-doped graphene aerogels（NGAs） were synthesized by using graphene oxide（GO） and chitosan via a self-assembly process by a rapid *** morphology and structure of the as-prepared aerogels were *** results showed that NGAs possesed the hierarchical pores with the wide size distribution ranging from mesopores to *** NGAs carbonized at different temperature all showed excellent electrochemical performance in 6 mol/L KOH electrolyte and the electrochemical performance of the NGA-900 was the *** working as a supercapacitor electrode,NGA-900 exhibited a high specific capacitance（244.4 F/g at a current density of 0.2 A/g）,superior rate capability（51.0% capacity retention） and excellent cycling life（96.2% capacitance retained after 5000 cycles）.

关键词： Nitrogen-doped graphene aerogels Hierarchical porous structure Carbonizing temperature Supercapacitors Energy storage and conversion

Identifying hidden charm pentaquark signal from non-resonant background in electron–proton scattering

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Chinese Physics C 2020年第8期44卷 125-131页

作者： Zhi Yang Xu Cao yu-tie Liang Jia-Jun Wu Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China School of Physical Sciences University of Chinese Academy of Sciences(UCAS)Beijing 100049China

In this study,we analyze the electroproduction of the LHCb pentaquark states with the assumption that they are resonant *** main concern is to investigate the final state distribution in the phase space to extract a feeble pentaquark signal from a large non-resonant *** results indicate that the signal to background ratio will increase significantly with a proper kinematic cut,which will be beneficial for future experimental analysis.

关键词： pentaquark electroproduction Pomeron electron-ion collider

Review of borophene and its potential applications

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Frontiers of physics 2019年第3期14卷 65-84页

作者： Zhi-Qiang Wang tie-yu Lu Hui-Qiong Wang yuan Ping Feng Jin-Cheng Zheng Department of Physics and Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices Xiamen University Xiamen 361005 China Department of Physics National University of Singapore Singapore 117542 Singapore Institute of Artificial Intelligence Xiamen University Malaysia 439000 Sepang Selangor Malaysia Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry Xiamen University Xiamen 361005 China

Since two-dimensional boron sheet (borophene) synthesized on Ag substrates in 2015, research on borophene has grown fast in the fields of condensed matter physics, chemistry, material science, and nanotechnology. Due to the unique physical and chemical properties, borophene has various potential applications. In this review, we summarize the progress on borophene with a particular emphasis on the recent advances. First, we introduce the phases of borophene by experimental synthesis and theoretical predictions. Then, the physical and chemical properties, such as mechanical, thermal, electronic, optical and superconducting properties are summarized. We also discuss in detail the utilization of the borophene for wide ranges of potential application among the alkali metal ion batteries, Li-S batteries, hydrogen storage, supercapacitor, sensor and catalytic in hydrogen evolution, oxygen reduction, oxygen evolution, and CO2 electroreduction reaction. Finally, the challenges and outlooks in this promising field are featured on the basis of its current development.

关键词： borophene structural diversity high anisotropy boron vacancy concentration

Production of hidden-charm and hidden-bottom pentaquark states in electron-proton collisions

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Chinese Physics C 2021年第4期45卷 107-113页

作者： Ya-Ping Xie Xu Cao yu-tie Liang Xurong Chen Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China Institute of Quantum Matter South China Normal UniversityGuangzhou 510006China

Electro-production of several pentaquark states is investigated in this *** eSTARlight package is adapted to study the electro-production of J/ψand γ(1S)via pentaquark P_(c)and P_(b)resonance channels in ep→eJ/ψp and ep→eγ(1S)p scattering processes at the proposed electron-ion colliders(EICs).The results obtained in this study are compared to those of non-resonance t-channels,which are described in the pomeron exchange model developed in our *** pseudo-rapidity and rapidity distributions of J/ψand γ(1S)are presented for the proposed EICs,including EicC and *** is found that EicC is a good platform to identify P_(b) states in the future.

关键词： electron-proton scattering exotic states vector meson production