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Comparison of dark energy models:A perspective from the latest observational data

中国科学：物理学、力学、天文学英文版 2010年第9期53卷 1631-1645页

作者： li miao1,2,li xiaodong2,3.& zhang xin1,4 {3. institute for theoretical physics China,chinese academy of sciences,beijing 100190,China 2Key Laboratory of Frontiers in theoretical physics,institute of theoretical physics,chinese academy of sciences,beijing 100190,China 3.nterdisciplinary Center for theoretical Study,University of Science and Technology of China,Hefei 23.026,China 4Department of physics,College of sciences,Northeastern University,Shenyang 110004,China kavli institute for theoretical {3. China Chinese Academy of Sciences Beijing China Key Laboratory of Frontiers in theoretical physics Institute of Theoretical Physics Chinese Academy of Sciences Beijing China Interdisciplinary Center for theoretical Study University of Science and Technology of China Hefei China Department of physics College of Sciences Northeastern University Shenyang China

We compare some popular dark energy models under the assumption of a flat universe by using the latest observational data including the type Ia supernovae Constitution compilation,the baryon acoustic oscillation measurement from the Sloan Digital Sky Survey,the cosmic microwave background measurement given by the seven-year Wilkinson Microwave Anisotropy Probe observations and the determination of H0 from the Hubble Space *** comparison statistics such as the Bayesian and Akaike information criteria are applied to assess the worth of the *** statistics favor models that give a good fit with fewer *** on this analysis,we find that the simplest cosmological constant model that has only one free parameter is still preferred by the current *** other dynamical dark energy models,we find that some of them,such as the αdark energy,constant w,generalized Chaplygin gas,Chevalliear-Polarski-linder parametrization,and holographic dark energy models,can provide good fits to the current data,and three of them,namely,the Ricci dark energy,agegraphic dark energy,and Dvali-Gabadadze-Porrati models,are clearly disfavored by the data.

关键词： dark energy models observational constraints model comparison information criteria

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Single-atom-mediated electron islands boost photocatalytic CO_(2)chemical fixation

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Science China Chemistry 2024年第7期67卷 2292-2299页

作者： Shu Shang Lei li xin He Hui Wang lirong Zheng Wei Shao {3. zhang Yi Xie Hefei National Research Center for Physical sciences at the Microscale University of Science and Technology of ChinaHefei 230026China institute of Energy Hefei Comprehensive National Science CenterHefei 230031China beijing Synchrotron Radiation Facility Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China School of Chemistry and Chemical Engineering Hefei Normal UniversityHefei 230031China

Photocatalytic cycloadditions of CO_(2)with epoxides are emerging as a significant platform for the green synthesis of valuable carbonates,where efficient catalytic systems with spatially separated charge carriers are ***,a single p-block metal atom is proposed to be a candidate for photogenerated electron localization on a metal oxide *** taking the Bi single-atom supported on ZnO nanosheet(Bi1/ZnO)as an example,we show that the Bi atom plays the role of an electron island in the sea of delocalized holes within ***,the as-formed electron island could readily promote the rate-determining ring-opening process of cycloaddition *** from the unique spatially separated electrons and holes,the Bi1/ZnO achieves a high yield of cyclic carbonates with almost 100%*** study provides a pioneering strategy for enhancing the performances of photocatalytic CO_(2)chemical fixation.

关键词： electron islands CO_(2)photofixation photogenerated charge carriers

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Fabrication of MXene-Bi_(2)WO_(6)heterojunction by Bi_(2)Ti_(2)O_(7)hinge for extraordinary LED-light-driven photocatalytic performance

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Nano Research 2024年第6期17卷 4729-4736页

作者： Zhiwen li liangliang Xu Zaheer Ud Din Babar Ali Raza Yifei zhang xinrui Gu Yu-xin miao Zhen Zhao Gao li institute of Catalysis for Energy and Environment College of Chemistry and Chemical EngineeringShenyang Normal UniversityShenyang 110034China State Key Laboratory of Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China Scuola Superiore Meridionale(SSM) University of Naples Federico IILargo S.Marcellino1080138Italy Department of Chemical and Biomolecular Engineering Korea Advanced Institute of Science and Technology(KAIST)Daejeon 34141Republic of Korea University of chinese academy of sciences Beijing 100049China

Heterojunction composites with intimate interfaces can shorten the diffusion distance,which leads to a shorter path for photogenerated carriers,thereby increasing photocatalytic ***,we report the fabrication of Ti_(3.C_(2)-Bi_(2)WO_(6)(TC-BW)heterojunctions hinged by Bi_(2)Ti_(2)O_(7)joints via an in situ hydrothermal reaction of Ti_(3.C_(2)in the presence of Na_(2)WO_(4)and Bi(NO_(3.)_(3..The TC-BW was characterized using X-ray diffraction(XRD),scanning transmission electron microscopy(STEM),and Raman ***-BW showed superior photocatalytic activity(productivity over 15TC-WB reaches up to 5.0 mmolreacted BA·gcat.^(−1)·h^(−1))in the oxidation of benzyl alcohol using light-emitting diode(LED)light,arising from the surface defects and intimate heterojunction interface between the Ti_(3.C_(2)MXene and Bi_(2)WO_(6)***-BW heterojunctions provide an enhanced separation efficiency of photogenerated charges,which in turn yields superior photocatalytic ***,it is well substantiated by density functional theory(DFT)*** summary,this study elucidates the preparation of heterojunction composites with intimate interfaces for highly efficient photooxidation.

关键词： MXene-Bi_(2)WO_(6) heterojunction LED-light-driven photocatalysis Bi_(2)Ti_(2)O_(7) photooxidation

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Predominant types of regional cold waves in North China and their historical changes

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Atmospheric and Oceanic Science Letters 2024年第4期17卷 46-51页

作者： xinyi Cheng Yiyi zhang Jiandong li xin Hao Center for Climate System Prediction Research/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters/Key Laboratory of Meteorological Disaster Ministry of EducationNanjing University of Information Science&TechnologyNanjingChina Nansen-Zhu International Research Centre Institute of Atmospheric PhysicsChinese Academy of SciencesBeijingChina Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment TechnologySchool of Environmental Science and EngineeringNanjing University of Information Science&TechnologyNanjingChina

寒潮事件对东亚地区的社会经济,生态系统和人体健康影响巨大.根据1980-2019年间10月至次年3.的每日寒潮记录和K-means聚类,本文识别出了中国两种不同类型的区域性寒潮(T1和T2). T1区域性寒潮主要影响东北地区,T2区域性寒潮则主要影响... 详细信息

寒潮事件对东亚地区的社会经济,生态系统和人体健康影响巨大.根据1980-2019年间10月至次年3.的每日寒潮记录和K-means聚类,本文识别出了中国两种不同类型的区域性寒潮(T1和T2). T1区域性寒潮主要影响东北地区,T2区域性寒潮则主要影响华北和东部地区.与T1区域性寒潮相比, T2区域性寒潮强度更强,持续时间更长,影响范围更广. 1980–2019年期间, T1区域性寒潮的频率显著增加,而T2区域性寒潮的频率则没有趋势变化. T1和T2区域性寒潮事件均与西伯利亚高压增强有关,然而与它们相关的对流层中层波列明显不同.在T1区域性寒潮事件发生期间,西伯利亚-蒙古上空出现负-正模态的500-hPa位势高度异常波列,削弱了东亚大槽,导致西伯利亚冷空气东移.T1区域寒潮频次增加趋势可能与全球变暖引起的500-hPa位势高度的线性趋势变化有关.与T2区域寒潮事件相关的波列则在乌拉尔山脉,蒙古和华北地区形成了脊-槽-脊环流异常,导致冷空气向东南方向入侵.本文得出结论,由于两类区域寒潮影响不同,西伯利亚高压增强和对流层中层波列模态在我国区域性寒潮事件的预报中应综合考虑.

关键词：寒潮 K-means聚类西伯利亚高压波列

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Operando measurement of lattice deformation profiles of synchrotron radiation monochromator

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Nuclear Science and Techniques 2024年第7期35卷 8-19页

作者： Yue zhang Zhong-liang li Shang-Yu Si lian Xue Hong-xin Luo Xiao-Wei zhang Jun Hu Shanghai Synchrotron Radiation Facility Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai201204China ShanghaiTech University Shanghai201210China University of the chinese academy of sciences Beijing100049China beijing Synchrotron Radiation Facility Institute of High Energy PhysicsChinese Academy of ScienceBeijing100049China

This study presents a new method for characterizing the thermal lattice deformation of a monochromator with high precision under service conditions and first reports the operando measurements of nanoscale thermal lattice deformation on a double-crystal monochromator at different incident *** nanoscale thermal lattice deformation of the monochromator first crystal was obtained by analyzing the intensity of the distorted DuMond *** diagrams of the 3.3.diffraction index,sensitive to lattice deformation,were obtained directly using a 2D detector and an analyzer crystal orthogonal to the *** increasing incident power and power density,the maximum height of the lattice deformation increased from 3.2 to 18.5 nm,and the deformation coefficient of the maximum height increased from 1.1 to 3.2 nm/*** maximum relative standard deviation was 4.2%,and the maximum standard deviation was 0.1 *** on the measured thermal deformations,the flux saturation phenomenon and critical point for the linear operation of the monochromator were predicted with increasing incident *** study provides a simple solution to the problem of the lower precision of synchrotron radiation monochromator characterizations compared to simulations.

关键词： Synchrotron radiation Monochromator Lattice deformation X-ray dynamic diffraction

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Estimating surface evapotranspiration using combined MODIS and CBERS-02 data

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Science China(Technological sciences) 2005年第S2期48卷 145-160页

作者： xin Xiaozhou1,2, liU Qinhuo1, TANG Yong1,3. TIAN Guoliang1, GU xingfa1, li Xiaowen1,2, ZHENG Hongsheng4 & CHEN Jiayi4 1. State Key Laboratory of Remote Sensing Science, institute of Remote Sensing Applications, chinese academy of sciences, beijing 100101, China 2. Research Center for Remote Sensing and GIS, Department of Geography, beijing Normal University, beijing 100875, China 3. Graduate University of chinese academy of sciences, beijing 10003., China 4. Department of Atmospheric {13., Peking University, beijing 100871, China State Key Laboratory of Remote Sensing Science Institute of Remote Sensing Applications Chinese Academy of Sciences Beijing 100101 China Research Center for Remote Sensing and GIS Department of Geography Beijing Normal University Beijing 100875 China Graduate University Chinese Academy of Sciences Beijing 100039 China Department of Atmospheric physics Peking University Beijing 100871 China

Spatial scale error is one of the most serious problems in the estimates of land surface heat fluxes of sensible and latent from satellite-borne data such as MODIS 1km resolution reflectance and emissive data. One of the feasible and economic ways to decrease the spatial scale error is to use high resolution land use class data together with the MODIS data. CBERS-02 data were used to produce land use class of Baiyangdian area, Hebei Province, China in the autumn of 2004. The area ratio of each class in MODIS pixel was calculated, and used to derive the heat fluxes of the mixed pixel. The results showed that the estimated heat fluxes of soil, sensible and latent have been changed remarkably after using the high resolution land class data. It could be concluded from the comparison between simulated and ground-measured fluxes as well as the theoretical analysis that high resolution land class data are useful to diminishing the scale error of heat fluxes estimated from low resolution satellite data.

关键词： surface evapotranspiration spatial scale error MODIS CBERS land class.

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Investigation into the rotational bands of ^(185)Pt with the particle-rotor model

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Science China(physics,Mechanics & Astronomy) 2011年第S1期54卷 114-118页

作者： li GuangShun1,2, ZHOU XiaoHong1,2, zhang ShuangQuan3. zhang YuHu1 & MENG Jie3.1 {3. of Modern {3., chinese academy of sciences, Lanzhou 73.000, China 2 Graduate University of chinese academy of sciences, beijing 100049, China 3.School of {3. and SK Laboratory of Nuclear {3. & Technology, Peking University, beijing 100871, China institute of Modern physics Chinese Academy of Sciences Lanzhou China Graduate University of chinese academy of sciences Beijing China School of physics and SK Laboratory of Nuclear physics & Technology Peking University Beijing China

theoretical calculations have been performed for the ν9/2+[624](i13.2) and ν7/2-[503.(f7/2) bands of 185Pt in the framework of particle-rotor model. The band properties of signature splitting and configuration mixing have been analyzed. The level energy and signature splitting before the band crossing can be well interpreted by introducing triaxiality. The positive-parity yrast band is pro posed to be dominated by the ν9/2+[624](i13.2) component, while the negative-parity band shows strong mixing of ν7/2-[503.(f7/2) and ν9/2-[505](h9/2) configurations.

关键词： High-spin states particle-rotor model signature splitting configuration mixing

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Pre-irradiation with low-dose ^(12)C^(6+) beam significantly enhances the efficacy of AdCMV-p53.gene therapy in human non-small lung cancer

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Science China(physics,Mechanics & Astronomy) 2007年第2期50卷 221-230页

作者： liU Bing1,2,zhang Hong1,li WenJian1,li Qiang1,ZHOU GuangMing1,XIE Yi1,2,HAO JiFang1,MIN Fengling1,2,ZHOU QingMing1,2 & DUAN xin1,21 institute of Modern {3.,chinese academy of sciences,Lanzhou 73.000,China 2 Graduate University of chinese academy of sciences,beijing 10003.,China institute of Modern physics Chinese Academy of Sciences Lanzhou China Graduate University of chinese academy of sciences Beijing China

The combination of ionizing radiation and gene therapy has been investigated. However, there are very few reports about the combination of heavy-ion irradiation and gene therapy. To determine if the pre-exposure to low-dose heavy ion beam enhances the suppression of AdCMV-p53.on non-small lung cancer (NSLC), the cells pre-irradiated or non-irradiated were infected with 20, 40 MOI of AdCMV-p53. Survival fraction and the relative biology effect (RBE) were determined by clonogenic assay. The results showed that the proportions of p53.positive cells in 12C6+ beam induced AdCMV-p53.infected cells were more than 90%, which were signifi-cantly more than those in γ-ray induced AdCMV-p53.infected cells. The pre-exposure to low-dose 12C6+ beam significantly prevented the G0/G1 arrest and activated G2/M checkpoints. The pre-exposure to 12C6+ beam significantly improved cell to apoptosis. RBEs for the 12C6+ + AdCMV-p53.infection groups were 3.%-60%, 20%-13.% and 3.%-70% more than those for the 12C6+-irradiated only, AdCMV-p53.infected only, and γ-irradiation induced AdCMVp53.infected groups, respectively. The data suggested that the pre-exposure to low-dose 12C6+ beam significantly promotes exogenous p53.expression in NSLC, and the suppression of AdCMV-p53.gene therapy on NSLC.

关键词： heavy-ion beam gene therapy p53 non-small lung cancer adenoviral vector low dose

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Enhancing Photovoltaic Performance of Nonfused-Ring Electron Acceptors via Asymmetric End-Group Engineering and Noncovalently Conformational Locks

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chinese Journal of Chemistry 2024年第5期42卷 485-490页

作者： Bo liu Congqi li Xiaobin Gu Yinghui Han Zhixiang Wei Yunhao Cai xin {3. Hui Huang Yanping Huo School of Chemical Engineering and light Industry Guangdong University of TechnologyGuangzhouGuangdong510006 China College of Materials Science and Opto-Electronic Technology & Center of Materials Science and Optoelectronics Engineering & CAS Center for Excellence in Topological Quantum Computation & CAS Key Laboratory of Vacuum physics University of Chinese Academy of SciencesBeijing100049 China College Resources and Environment University of Chinese Academy of SciencesBeijing100049 China Center for Excellence in Nanoscience (CAS) & Key Laboratory of Nanosystem and Hierarchical Fabrication (CAS) National Center for Nanoscience and TechnologyBeijing100190 China

By employing the asymmetric end-group engineering,an asymmetric nonfused-ring electron acceptor(NFREA)was designed and *** with the symmetric analogs(NoCA-17 and NoCA-18),NoCA-19 possesses broader light absorption range,more coplanarπ-conjugated backbone,and appropriate crystallinity according to the experimental and theoretical *** organic solar cells based on J52:NoCA-19 exhibited a power conversion efficiency as high as 12.26%,which is much higher than those of J52:NoCA-17(9.50%)and J52:NoCA-18(11.77%),mainly due to more efficient exciton dissociation,better and balanced charge mobility,suppressed recombination loss,shorter charge extraction time,longer charge carrier lifetimes,and more favorable blend film *** findings demonstrate the great potential of asymmetric end-group engineering in exploring low-cost and high-performance NFREAs.

关键词： Organic solar cells Nonfused-ring electron acceptors Asymmetric end-group engineering Noncovalently conformational locks Low-cost acceptors

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High-rate CH_(4)-to-C_(2)H_(6) photoconversion enabled by Au/ZnO porous nanosheets under oxygen-free system

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Science China Chemistry 2024年第3期67卷 869-875页

作者： Kai Zheng Xiaojing zhang Jun Hu Chengbin Xu Juncheng Zhu Jing li Mingyu Wu Shan Zhu li li Shumin Wang Yumei Lv xin He Ming Zuo Chengyuan liu Yang Pan Junfa Zhu Yongfu Sun Yi Xie Hefei National Laboratory for Physical sciences at Microscale National Synchrotron Radiation LaboratoryUniversity of Science and Technology of ChinaHefei 230026China Key Laboratory of Photochemical Conversion and Optoelectronic Materials Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing 100190China State Grid Anhui Electric Power Research institute Hefei 230601China

Photocatalytic CH_(4) coupling into high-valued C_(2)H_(6) is highly attractive,whereas the photosynthetic rate,especially under oxygen-free system,is still ***,we designed the negatively charged metal supported on metal oxide nanosheets to activate the inert C-H bond in CH_(4)and hence accelerate CH_(4) coupling *** an example,the synthetic Au/ZnO porous nanosheets exhibit the C_(2)H_(6) photosynthetic rate of 1,121.6μmol g^(-1)_(cat)h^(-1)and the CH_(4) conversion rate of 2,3.4.6μmol g^(-1)_(cat)h^(-1) under oxygen-free system,2 orders of magnitude higher than those of previously reported *** virtue of several in situ spectroscopic techniques,it is established that the generated Au^(δ-)and O^-species together polarized the C-H bond,while the Au^(δ-)and O^-species jointly stabilized the CH_(3. intermediates,which favored the coupling of CH_(3. intermediate to photosynthesize C_(2)H_(6) instead of overoxidation into CO_(x).Thus,the design of dual active species is beneficial for achieving high-efficient CH_(4)-to-C_(2)H_(6) photoconversion.

关键词： dual surface-active sites selective methane coupling ethane room temperature

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