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| 1 | Deterioration in Heat Transfer of Endothermal Hydrocarbon Fuel显示文摘Numerical studies under supercritical pressure are carried out to study the heat transfer characteristics in a single-root coolant channel of the active regenerative cooling system of the scramjet engine, using actual physical properties of pentane. The relationships between wall temperature and inlet temperature, mass flow rate, wall heat flux, inlet pressure, as well as center stream temperature are obtained. The results suggest that the heat transfer deterioration occurs when the fuel temperature approaches the pseudo-critical temperature, and the wall temperature increases rapidly and heat transfer coefficient decreases sharply. The decrease of wall heat flux, as well as the increase of mass flow rate and inlet pressure makes the starting point of the heat transfer deterioration and the peak point of the wall temperature move backward. The wall temperature increment induced by heat transfer deterioration decreases, which could reduce the severity of the heat transfer deterioration. The relational expression of the heat transfer deterioration critical heat flux derives from the relationship of the mass flow rate and the inlet pressure. | Weixing Zhou Wen Bao Jiang Qin Yunfeng Qu | 2011 | Journal of Thermal Science2011，20，2： | 10 |
| 2 | Highly efficient Cu/anatase TiO2 {001}-nanosheets catalysts for methanol synthesis from CO2显示文摘Anatase TiO_2 nanosheets(-ns-) with dominant exposed {001} facets were used as support to load copper,and the synthesized Cu/TiO_2-ns catalysts were evaluated for CO_2 hydrogenation to methanol. Under the reaction conditions, P = 3.0 MPa, T = 260 ℃, V(N_2):V(H_2):V(CO_2) = 8:69:23 and gas hourly space velocity(GHSV) = 3600 mL g^(-1)h^(-1), the methanol yield reached an appealing high value, 5.6%. Copper-loading amount, calcination temperature and reduction atmosphere have been investigated in this work, which significantly influence the particle sizes of copper and/or the defect concentration in TiO_2, then leading to different catalytic performance. Characterizations of XRD, EPR, CO_2-TPD and FTIR demonstrate that higher specific surface area of Cu is good for the hydrogenation of CO_2 and adequate amount of Ti^(3+) plays important roles in CO_2 activation. Both of them facilitate high turnover frequency(TOF) of methanol formation. | Yunfeng Bao Chunlei Huang Limin Chen Yu dong Zhang Long Liang Jinjun Wen Mingli Fu Junliang Wu Daiqi Ye | 2018 | Journal of Energy Chemistry2018，27，2： | 7 |
| 3 | Smooth fractal surfaces derived from bicubic rational fractal interpolation functions显示文摘Dear editor,Fractal geometry is an important and active branch of nonlinear science.It has attracted more and more attention[1,2].As an important research field of fractal geometry,fractal interpola- | Fangxun BAO Xunxiang YAO Qinghua SUN Yunfeng ZHANG Caiming ZHANG | 2018 | Science China(Information Sciences)2018，61，9： | 3 |
| 4 | Kernel-blending connection approximated by a neural network for image classification显示文摘This paper proposes a kernel-blending connection approximated by a neural network(KBNN)for image classification.A kernel mapping connection structure,guaranteed by the function approximation theorem,is devised to blend feature extraction and feature classification through neural network learning.First,a feature extractor learns features from the raw images.Next,an automatically constructed kernel mapping connection maps the feature vectors into a feature space.Finally,a linear classifier is used as an output layer of the neural network to provide classification results.Furthermore,a novel loss function involving a cross-entropy loss and a hinge loss is proposed to improve the generalizability of the neural network.Experimental results on three well-known image datasets illustrate that the proposed method has good classification accuracy and generalizability. | Xinxin Liu Yunfeng Zhang Fangxun Bao Kai Shao Ziyi Sun Caiming Zhang | 2020 | Computational Visual Media2020，6，4： | 2 |
| 5 | Super broadband absorbing hierarchical CoFe alloy/porous carbon@carbon nanotubes nanocomposites derived from metal-organic frameworks显示文摘The exploitation of electromagnetic wave absorption(EMA) materials has attracted ever-increasing attention,not only because electromagnetic wave(EMW) originated from overuse of electronic products has threatened human' health seriously,but also because EMA materials can effectively protect radar stealth from being detected.However,it is still a challenge to obtain broadband and efficient EMA materials to satisfy practical applications.In this work,we developed a series of hierarchical CoFe alloy/porous carbon@carbon nanotubes(CoFe/PC@CNTs) nanocomposites through revising the proportion of Fe^(2+) in the metal-organic frameworks(MOFs)(CoFe-ZIF) precursor and one-step simple pyrolysis process.The cross deposition between CoFe alloy,carbon nanotubes(CNTs),and porous carbon(PC) formed a double conductive network,favoring for achieving excellent EMA property.Surprisingly,when the filler mass ratio is only 10 wt%,the optimized CoFe/PC@CNTs nanocomposites display the best EMA capability,whose minimum reflection loss(RL_(min)) value is-68.94 dB at 13.69 GHz and the effective absorption band(EAB,<-10 dB) reaches up 9.14 GHz with a matching thickness of 2.63 mm.In addition,the largest EAB can achieve up to 11 GHz(3.35-14.35 GHz) during all matching thicknesses.The splendid EMA performance benefits the favorable dielectric loss provided by the double conductive network,the good magnetic loss benefited from the evenly distributed CoFe alloy,the excellent impedance matching,rich transmission paths,and multiple polarization.Therefore,such EMA materials with super broadband absorbing provide desirable candidates for lightweight and high-efficient microwave absorbers. | Siyao Guo Yunfeng Bao Ying Li Hailong Guan Dongyi Lei Tiejun Zhao Baomin Zhong Zhihong Li | 2022 | Journal of Materials Science & Technology2022，，23： | 2 |
| 6 | Atmospheric carbonyls in a heavy ozone pollution episode at a metropolis in Southwest China:Characteristics,health risk assessment,sources analysis显示文摘Ambient carbonyls were continuously observed in the field during a heavy ozone pollution episode in Chengdu, China from August 4 to August 19, 2019, and the pollution characteristics, atmospheric photochemical reactivity, human health risk, and sources of carbonyls were analyzed. Fifteen carbonyls were quantified with average total mixing ratios of 20.38 ppbv Formaldehyde(9.86 ppbv), acetone(4.41 ppbv), and acetaldehyde(3.57 ppbv) were the three most abundant carbonyls. During the heavy ozone pollution episode, the concentration of carbonyls was found to be higher on pollution days than on the clean days, and relatively higher in the daytime, especially at noon on the pollution days. This was influenced by the intensity of photochemical reactions and precipitation. The “weekend effect” with the concentration of carbonyls was higher on the weekends than on the weekdays was pointed out. Formaldehyde, acetaldehyde and hexaldehyde were the dominant oxidative species during the observation. The carcinogenic and non-carcinogenic risk values of formaldehyde and acetaldehyde were higher on pollution days than on clean days, and these values were higher compared with those of other cities in China and abroad. Long-term exposure to these compounds should therefore be avoided. Diagnostic ratios and correlation analysis together with backward trajectory analysis showed that primary emission and secondary formation accounted 66%-76% and 24%–34% of carbonyls in Chengdu, respectively, with primary emission being the main sources of carbonyls, and carbonyls from the surrounding cities and emission from natural sources also had a significant contribution to the carbonyls in Chengdu. | Jiemeng Bao Hong Li Zhenhai Wu Xin Zhang Hao Zhang Yunfeng Li Jun Qian Junhui Chen Liqun Deng | 2022 | Journal of Environmental Sciences2022，34，3： | 1 |
| 7 | Synthesis of perovskite BaTaO_(2)N with low defect by Zn doping for boosted photocatalytic water reduction显示文摘Perovskite BaTaO_(2) N(BTON) is one of the most promising photocatalysts for solar water splitting due to its wide visible-light absorption and suitable conduction/valence bands,but it still confronts the challenge of high defect density causing decreased charge separation as well as photocatalytic activity.In this work,we develop a simple zinc doping strategy to greatly suppress its defect density and promote its water reduction performance.It is found that the defect formation on the nitrided Ba(Zn_(1/3-x)Ta_(2/3))O_(3-y)N_z(denoted as BZTON hereafter) will be greatly inhibited when the Zn-doped Ba(Zn_(1/3)Ta_(2/3))O_(3)(BZTO) oxide is used as the nitridation precursor.The structural characterizations and discussion demonstrate that the effective inhibition of Ta^(5+)into Ta^(4+)defects in BZTON mainly results from the easy reduction of zinc ions into metal and further the evaporation of zinc metal under the thermal ammonia flow.Interestingly,this simply doping methodology can be easily extended into the synthesis of SrTaO_(2) N(STON) with extremely low defect density,demonstrating its generality.Benefiting from the successful control to the defect density,the as-obtained BZTON photocatalyst exhibits remarkably promoted charge separation as well as water reduction activity to produce hydrogen with respect to the pristine BTON.Our work may provide an alternative avenue to prepare oxynitride semiconductors with reduced defect density for promoted solar energy conversion. | Yunfeng Bao Hai Zou Nengcong Yang Gao Li Fuxiang Zhang | 2021 | Journal of Energy Chemistry2021，30，12： | 1 |
| 8 | Shape control of a bivariate interpolating spline surface 显示文摘 | Duan Qi Bao Fangxun Zhang Yunfeng | 2008 | International Journal of Computer Mathematics2008，85，5： | 1 |
| 9 | Reversed configuration of photocatalyst to exhibit improved properties of basic processes compared to conventional one显示文摘Performances of semiconductor photocatalysts are integrally determined by efficiencies of basic processes such as light absorption,charge separation and surface catalysis,but conventional configurations of photocatalysts normally suffers from the competition of light absorption originating from cocatalyst deposition and limited interface charge separation between the photocatalyst and cocatalyst.Herein we give the first proof-of-concept illustration that a reversed configuration of photocatalysts with a core/shell structure of microsized Mo2N cocatalysts and nanosized CdS photocatalysts,which exhibits superior solar hydrogen production to the conventional configuration with nanosized Mo2N cocatalysts deposited on the surface of CdS photocatalysts.It is revealed that the reversed configuration outperforms the conventional one in all areas of light absorption,charge separation and surface catalysis.Strikingly,the special core/shell structure introduced here can well avoid the competition of light absorption by cocatalysts and make an effective confinement effect to promote the surface catalysis of Mo2N.Our finding provides an alternative strategy to improve performances of photocatalysts. | Juhong Lian Yu Qi Yunfeng Bao Zixi Yin Yang Zhang Nengcong Yang Naijia Guan Shengye Jin Landong Li Fuxiang Zhang | 2020 | Science China Chemistry2020，63，6： | 1 |
| 10 | Efficient TurboID-based proximity labelling method for identifying terminal sialic acid glycosylation in living cells显示文摘TurboID,a proximity labelling method based on mutant biotin ligase,is an efficient new technique for recognizing protein-protein interactions and has been successfully applied to living cells.Sialic acid is typically the terminal monosaccharide attached to many glycoproteins and plays many important roles in many biological processes.However,the lack of enrichment methods for terminal sialic acid glycosylation in vivo hinders the identification and analysis of this glycosylation.Here,we introduce TurboID to identify terminal sialic acid glycosylation in living cells.SpCBM,the carbohydrate-binding domain of sialidase from Streptococcus pneumoniae,is fused with TurboID and overexpressed in HeLa cells.After streptavidin-based purification and detection by mass spectrometry,31 terminal sialic acid N-glycosylated sites and 1359 putative terminal sialic acid glycosylated proteins are identified,many of which are located in the cytoplasm and nucleus. | Wu Liu Yunfeng Long Yongfen Bao Yang Li Mengxue Deng Xiuyi Yang He Zhu Yanting Su | 2022 | Acta Biochimica et Biophysica Sinica2022，54，12： | 0 |
| 11 | Human exposure to a mixture of endocrine disruptors and serum levels of thyroid hormones:A cross-sectional study显示文摘Exposure to endocrine disruptors(EDCs) could disrupt thyroid hormone homeostasis. However, human epidemiological studies reported inconsistent observations, and scarce information on the effect of a mixture of chemicals. The aim of the present study was to examine the associations of multiple chemicals with thyroid hormones among adults from China. We measured serum levels of thyroid hormones and urinary levels of 11 EDCs, including six phthalate metabolites, bisphenol A(BPA), bisphenol F(BPF), bisphenol S(BPS), perchlorate, and thiocyanate among 177 healthy adults without occupational exposure. Associations of multiple urinary analytes with serum thyroid hormones were examined by performing general linear regression analysis and bayesian kernal machine regression analysis. These EDCs were detected in almost all samples. After adjusting for various covariates, we observed only BPF significantly associated with total thyroxin(TT4)(β=-0.27, 95% confidence interval(CI) [-0.41,-0.14]), total triiodothyronine(TT3)(β=-0.02 95% CI [-0.03,-0.01]), free T4(fT4)(β=-0.02, 95% CI [-0.03,-0.01]), and free T3(fT3)(β=-0.04, 95% CI [-0.07,-0.01]), and mono-(2-ethyl-5-oxohexyl) phthalate(MEOHP) and monoethyl phthalate(MEP) positively associated with TT4(β=0.24, 95% CI [0.01, 0.48]) and fT4(β=0.02, 95% CI [0.01, 0.04]), respectively. Moreover, we observed significant dose-response relationships between TT4 and the mixture of11 EDCs, and BPF was the main contributor to the mixture effect, suggesting the priority of potential effect of BPF on disrupting thyroid function under a real scenario of human exposure to multiple EDCs. Our findings supported the hypothesis that human exposure to low levels of EDCs could alter thyroid hormones homeostasis among non-occupational healthy adults. | Bing Yue Shangyong Ning Hongjian Miao Congrong Fang Jingguang Li Lei Zhang Yan Bao Sai Fan Yunfeng Zhao Yongning Wu | 2023 | Journal of Environmental Sciences2023，，3： | 0 |
| 12 | Strategies and Methods of Modulating Nitrogen-Incorporated Oxide Photocatalysts for Promoted Water Splitting显示文摘CONSPECTUS:The conversion of solar energy to chemicals and the storage of this energy is one of the most promising routes to realizing a“carbon zero”society,for which particulate photocatalytic water splitting to produce hydrogen has been considered to be a clean potential route.For this purpose,many d^(0)and d^(10)metal-based nitrogen-incorporated oxide(including nitrogen-doped oxide and oxynitride)semiconductor photocatalysts have been developed as good candidates to harvest major visible regions of solar light and to exhibit suitable energy levels to drive water splitting.Compared to the oxide-type photocatalysts,valence bands of the nitrogen-incorporated oxide can be upshifted in consideration of the lower electronegativity of nitrogen atoms concerning the oxygen atoms. | Yunfeng Bao Can Li Kazunari Domen Fuxiang Zhang | 2022 | Accounts of Materials Research2022，3，4： | 0 |
| 13 | Homogeneous nitrogen-doped(111)-type layered Sr5Nb4O15-xNx as a visible-light-responsive photocatalyst for water oxidation显示文摘The development of visible-light-responsive photocatalysts for promoting solar-driven oxygen(O2)production from water splitting is a potentially attractive but still a challenging scheme.In the present work,a(111)-type layered perovskite oxynitride,Sr5Nb4O15-xNx,was synthesized via the nitridation treatment of the disk-like oxide precursor under the ammonia flow,which was fabricated using a flux method.The homogeneous dispersion of nitrogen(N)dopant in N-doped Sr5Nb4O15 was ascertained by energy-dispersive X-ray spectroscopy characterization,and the Sr5Nb4O15-xNx was found to be a direct semiconductor with a light absorption edge of approximately 640 nm.Density functional theory investigation implies that the hybridization between the outmost N 2p orbitals and O 2p orbitals upshifts the original valence band maximum of Sr5Nb4O15 and endows its visible-light-responsive characteristics.Loading with cobalt oxide(CoOx)as cocatalyst,the as-prepared Sr5Nb4O15-xNx exhibited an enhanced photocatalytic O2 evolution activity from water splitting under visible-light illumination(λ>420 nm).Moreover,another homogeneous N-doped layered perovskite-type niobium(Nb)-based oxynitride,Ba5Nb4O15-xNx,was also developed and investigated for the visible-light-actuated O2 production,highlighting the versatility of the present approach for exploring novel visible-light-responsive photocatalysts. | Shiwen Du Hai Zou Yunfeng Bao Yu Qi Xueshang Xin Shuowen Wang Zhaochi Feng Fuxiang Zhang | 2022 | Nano Research2022，15，12： | 0 |
| 14 | Side Effects of Gamifying Environmental Education Activities in Chinese Kindergartens显示文摘Environmental education is an effective approach to addressing environmental issues,and incorporating environmental education into kindergarten through gamified activities aligns with the concept of gamifying teaching and provides the optimal pathway for implementing environmental education.The purpose of this study is to investigate the specific processes involved in determining the objectives,themes,and content of gamified environmental education activities,as well as the organization,implementation,and evaluation of these activities in kindergarten settings.Five classes from Class G in Xining City Kindergarten were selected as the observational subjects for this study.Interviews were conducted with the teaching staff and the head of the kindergarten.The data obtained from observations and interviews served as the primary data for this research.The results indicate that the activity objectives formulated by teachers lack scientific basis and operability,with limited incorporation of gaming elements.The activity themes and content are narrow in scope and primarily determined by teachers and kindergarten administrators.The organization and implementation of activities often neglect the playful experiences of children,and activity evaluation is not given sufficient attention. | Huanhuan Zhang Wanping Bao Xiaoshu Xu Yunfeng Zhang | 2023 | 教育技术与创新2023，5，4： | 0 |
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