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A water-stable metal-organic framework： serving as a chemical sensor of PO43– and a catalyst for CO2 conversion

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Science China Chemistry 2017年第10期60卷 1328-1333页

作者： Bin Zhai Hang xu Zhong-Yi Li chun-Shuai Cao Bin Zhao College of Chemistry and Chemical Engineering Shangqiu Normal University Shangqiu 476000 China Key Laboratory of Advanced Energy Material Chemistry Department of Chemistry Nankai University Tianjin 300071 China Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) Tianjin 300071 China

A new 2D Eu-BTB framework(1) with stratified gridding structure of about 14.6×16.9was synthesized and *** 1 displays excellent water stability with the pH 2–12. The luminescent investigations suggest that 1 could represent a chemical sensor of PO43. with high sensitivity and selectivity. Importantly, 1 as a sensor of PO_4^(3-) can be reused at least five *** the other hand, the catalytic investigations of 1 were carried out, indicating that 1 could be demonstrated as a recyclable catalyst for CO_2 conversion with epoxides.

关键词： MOFs water and pH stability luminescent detection CO_2 conversion

Calibrating Photometric Redshift Measurements with the Multi-channel Imager(MCI) of the China Space Station Telescope(CSST)

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Research in Astronomy and Astrophysics 2022年第2期22卷 204-214页

作者： Ye Cao Yan Gong Zhen-Ya Zheng chun xu Key Laboratory of Space Astronomy and Technology National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China School of Astronomy and Space Sciences University of Chinese Academy of SciencesBeijing 100049China Science Center for China Space Station Telescope National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China CAS Key Laboratory for Research in Galaxies and Cosmology Shanghai Astronomical ObservatoryShanghai 200030China Division of Optical Astronomical Technologies Shanghai Astronomical ObservatoryShanghai 200030China Joint Center of SHAO and SITP for Infrared Astronomical Instrumentation Shanghai Astronomical ObservatoryShanghai 200030China

The China Space Station Telescope(CSST) photometric survey aims to perform a high spatial resolution(~0.″ 15)photometric imaging for the targets that cover a large sky area(~17,500 deg^(2)) and wide wavelength range(from NUV to NIR). It expects to explore the properties of dark matter, dark energy, and other important cosmological and astronomical areas. In this work, we evaluate whether the filter design of the Multi-channel Imager(MCI), one of the five instruments of the CSST, can provide accurate photometric redshift(photoz) measurements with its nine medium-band filters to meet the relevant scientific objectives. We generate the mock data based on the COSMOS photometric redshift catalog with astrophysical and instrumental effects. The application of upper limit information of low signal-to-noise ratio data is adopted in the estimation of photoz. We investigate the dependency of photoz accuracy on the filter parameters, such as band position and width. We find that the current MCI filter design can achieve good photoz measurements with accuracy σ_(z)■ 0.017 and outlier fraction f_(c)■ 2.2%. It can effectively improve the photoz measurements of the main CSST survey using the Survey Camera to an accuracy σ_(z)■ 0.015 and outlier fraction f_(c)■ 1.5%. This indicates that the original MCI filters are proper for the photoz calibration.

关键词： cosmology:observations (cosmology:)large-scale structure of universe galaxies:distances and redshifts

An Immersive Virtual Reality System for Rodents in Behavioral and Neural Research

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International Journal of Automation and computing 2021年第5期18卷 838-848页

作者： Li Liu Zi-Yang Wang Yu Liu chun xu Institute of Automation Chinese Academy of SciencesBeijing 100190China Shanghai Center for Brain Science and Brain-inspired Intelligence Technology Shanghai 200031China Institute of Neuroscience Chinese Academy of SciencesShanghai 200031China

Context cognition involves abstractly deriving meaning from situational information in the world and is an important psychological function of higher cognition. However, due to the complexity of contextual information processing, along with the lack of relevant technical tools, little remains known about the neural mechanisms and behavioral regulation of context cognition. At present, behavioral training with rodents using virtual reality techniques is considered a potential key for uncovering the neurobiological mechanisms of context cognition. Although virtual reality technology has been preliminarily applied in the study of context cognition in recent years, there remains a lack of virtual scenario integration of multi-sensory information, along with a need for convenient experimental design platforms for researchers who have little programming experience. Therefore, in order to solve problems related to the authenticity, immersion, interaction, and flexibility of rodent virtual reality systems, an immersive virtual reality system based on visual programming was constructed in this study. The system had the ability to flexibly modulate rodent interactive 3 D dynamic experimental environments. The system included a central control unit, virtual perception unit, virtual motion unit, virtual vision unit, and video recording unit. The neural circuit mechanisms in various environments could be effectively studied by combining two-photon imaging and other neural activity recording methods. In addition, to verify the proposed system′s performance, licking experiments were conducted with experimental mice. The results demonstrated that the system could provide a new method and tool for analyzing the neural circuits of the higher cognitive functions in rodents.

关键词： Virtual space flexible control multi-sensory interactions visual programming context cognition

Heat transfer and plume statistics in turbulent thermal convection with sparse fractal roughness

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Journal of Hydrodynamics 2021年第5期33卷 1065-1077页

作者： Guang-chun xu Qi Wang Zhen-hua Wan De-jun Sun Department of Modern Mechanics University of Science and Technology of ChinaHefei 230027China

Rough-surface Rayleigh-Benard convection is investigated using direct numerical simulations in two-dimensional convection cells with aspect ratioГ=*** types of fractal roughness elements,which are marked as nl,n2 and n3,are constructed based on the Koch curve and sparsely mounted on both the plates,where n denotes the level of the *** considered Rayleigh numbers Ra range from 10^(7)to 10^(11)with Prandtl number Pr=*** regimes are identified for cases nl,*** Regime I,the scaling exponentsβin the effective Nusselt number Nu vs Ra scaling Nu~Ra^(β)reach up to about ***,when Ra is larger than a critical value Ra_(c),the flow enters RegimeⅡ,with p saturating back to a value close to the smooth-wall case(0.3).Rac is found to increase with increasing n,and for case n3,only Regime I is identified in the studied Ra *** extension of Regime I in case n3 is due to the fact that at high Ra,the smallest roughness elements can play a role to disrupt the thermal boundary *** thermal dissipation rate is studied and it is found that the increasedβin Regime I is related with enhanced thermal dissipation rate in the *** interesting finding is that no clear convection roll structures can be identified for the rough cases,which is different from the smooth case where well-organized convection rolls can be *** difference is further quantified by the detailed analysis of the plume statistics,and it is found that the horizontal profiles of plume density and velocity are relatively flattened due to the absence of clear convection rolls.

关键词： Thermal convection Rayleigh-Benard convection rough surface Introduction

Numerical investigation of the dynamics of flexible vegetations in turbulent open-channel flows

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Journal of Hydrodynamics 2022年第4期34卷 681-699页

作者： Dong xu Jia-ning Liu Yun-feng Wu chun-ning Ji State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin UniversityTianjin 300072China

Aquatic vegetations widely exist in natural rivers and play an essential role in the evolution of the water environment and ecosystem by changing the river’s hydrodynamic characteristics and transporting sediments and *** reality,most aquatic vegetations are highly flexible,which invalidates the“rigid-cylinder”assumption widely adopted in many *** explore the dynamics of submerged flexible vegetation in open-channel flows and its feedback to turbulent flow structures,numerical simulations are carried out using an in-house fluid-structure interaction(FSI)*** the simulations,the geometry of vegetation plants is grid-resolved,the turbulent flow is simulated using the large eddy simulation(LES),the dynamics of the flexible plants are solved using the vector form intrinsic finite element(VFIFE)method,and the turbulent flow and the plants are two-way coupled using the immersed boundary(IB)*** dynamic responses of the flexible vegetation with different plant flexibility,spacing,and submergence are *** results show that flexible plants are subjected to complex flow-induced vibrations(FIVs)rather than static *** FIV involves both streamwise and cross-flow motions driven by the small-scale vortex shedding around the plants and the large-scale Kelvin-Helmholtz(K-H)vortices developed in the vegetation canopy *** vegetations exhibit pulsive wave motion of different patterns in relatively long and narrow open *** with the open-channel flows with static plants with equivalent bending deformation,the dynamic responses of flexible plants may increase the turbulent Reynolds stress of the open-channel flow by 70%–100%and increase the invasion depth of the K-H vortices by 30%–50%.

关键词： Flexible vegetation dynamic responses flow-induced vibration(FIV) fluid-structure interaction(FSI)

A review on the structure-performance relationship of the catalysts during propane dehydrogenation reaction

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Petroleum Science 2022年第2期19卷 819-838页

作者： Bohan Feng Yue-Chang Wei Wei-Yu Song chun-Ming xu State Key Laboratory of Heavy Oil Processing College of ScienceChina University of PetroleumBeijing102249People's Republic of China

Dehydrogenation of propane(PDH)technology is one of the most promising on-purpose technologies to solve supply-demand unbalance of *** industrial catalysts for PDH,such as Pt-and Cr-based catalysts,still have their own limitation in expensive price and security ***,a deep understanding into the structure-performance relationship of the catalysts during PDH reaction is necessary to achieve innovation in advanced high-efficient *** this review,we focused on discussion of structure-performance relationship of catalysts in *** on analysis of reaction mechanism and nature of active sites,we detailed interaction mechanism between structure of active sites and catalytic performance in metal catalysts and oxide *** relationship between coke deposition,co-feeding gas,catalytic activity and nanostructure of the catalysts are also *** these discussions on the relationship between structure and performances,we try to provide the insights into microstructure of active sites in PDH and the rational guidance for future design and development of PDH catalysts.

关键词： Dehydrogenation of propane Metal catalysts Oxide catalysts Structure-performance relationship Active site Reaction mechanism

Oxygen transfer characteristics of bubbly jet in regular waves

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Journal of Hydrodynamics 2020年第5期32卷 879-887页

作者： Ze-gao Yin De-chun Liu Yuan Li Yan-xu Wang College of Engineering Ocean University of ChinaQingdao 266100China

The dissolved oxygen level is an important index of the water environment,and in this paper,the oxygen transfer of the bubbly jet in regular waves is investigated numerically and *** Reynolds-averaged Navier-Stokes equations,the re-normalisation group k-e equations,and the volume of fluid(VOF)technique are used along with a 2-D CFD model to simulate the wave and bubble motions as well as the turbulence,and a dissolved oxygen transport equation is used to model the oxygen transfer behavior both through the bubbly interface and the wave surface.A series of experiments are conducted to validate the mathematical model,with good *** addition,a group of dimensionless parameters are defined from the wave parameter and the aeration parameter,and their relationships with the total oxygen transfer coefficient are ***,the dimensional analysis and the least squares methods are used to derive simple prediction formulas for the total oxygen transfer coefficient,and they are validated with the related experimental data.

关键词： Bubbly jet regular wave mathematical model total oxygen transfer coefficient

Environmental Mn(Ⅱ) enhances the activity of dissimilatory arsenate-respiring prokaryotes from arsenic-contaminated soils

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Journal of Environmental Sciences 2023年第3期125卷 582-592页

作者： Yan Wu Weiwei Wu Yifan xu Yanxia Zuo Xian-chun Zeng State Key Laboratory of Biogeology and Environmental Geology&School of Environmental Studies China University of Geosciences(Wuhan)Wuhan 430074China Institute of Hydrobiology the Chinese Academy of SciencesWuhan 430072China

Many investigations suggest that dissimilatory arsenate-respiring prokaryotes (DARPs) play a key role in stimulating reductive mobilization of As from solid phase into groundwater,but it is not clear how environmental Mn(Ⅱ) affects the DARPs-mediated reductive mobilization of *** resolve this issue,we collected soil samples from a realgar tailingsaffected *** found that there were diverse arsenate-respiratory reductase (arr) genes in the *** microbial communities had high arsenate-respiring activity,and were able to efficiently stimulate the reductive mobilization of *** to the microcosms without Mn(Ⅱ),addition of 10 mmol/L Mn(Ⅱ) to the microcosms led to 23.99%-251.79% increases in the microbial mobilization of As,and led to 133.3%-239.2% increases in the abundances of arr *** further isolated a new cultivable DARP,Bacillus sp.F11,from the arseniccontaminated *** completely reduced 1 mmol/L As(V) in 5 days under the optimal reaction *** further found that it was able to efficiently catalyze the reductive mobilization and release of As from the solid phase;the addition of 2 mmol/L Mn(Ⅱ) led to 98.49%-248.78% increases in the F11 cells-mediated reductive mobilization of As,and70.6%-104.4% increases in the arr gene *** data suggest that environmental Mn(Ⅱ) markedly increased the DARPs-mediated reductive mobilization of As in arseniccontaminated *** work provided a new insight into the close association between the biogeochemical cycles of arsenic and manganese.

关键词： dissimilatory arsenate-respiring prokaryote Arsenic mobilization Arsenic-contaminated groundwater Arsenate reduction Mn(II)

Fabrication of a novel poly(dimethylsiloxane) microchips with two sharpened stretching tips

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Chinese Chemical Letters 2007年第2期18卷 221-224页

作者： chun Ye Liu xu xu Hong Jun Gao Jie Rong Chen School of Life Science and Technology Xi’an Jiaotong UniversityXi’an 710049China Shanghai Institute of Organic Chemistry Chinese Academy of SciencesShanghai 200032China

An integrated poly(dimethylsiloxane) (PDMS) microchip with two sharpened stretching has been presented. The sample was directly introduced into the separation channel through the stretching inlet tip without complicated power switching supplies and without injection cross-channel. Operations of running buffer refreshing or channel cleaning also becomes simple by vacuumed in one end and placed another tip into solution vial. The fabrication method can be easily applied in most analytical laboratories at low cost in the absence of soft lithography and plasma bonding equipments. Characteristics of the chips were tested and it can be used to separate fluorescence labeled molecules.

关键词： Poly(dimethylsiloxane) Microchip Electrophoresis Sample injection