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Multifractal Characteristics of Intermittent Turbulence in the Urban Canopy Layer

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Atmospheric and Oceanic Science Letters 2015年第2期8卷 72-77页

The multifractality of energy and thermal dissipation of fully developed intermittent turbulence is investigated in the urban canopy layer under unstable conditions by the singularity spectrum for the fractal dimensions of sets of singularities characterizing multifractals. In order to obtain high-order moment properties of smallscale turbulent dissipation in the inertial range, an ultrasonic anemometer with a high sampling frequency of 100 Hz was used. The authors found that the turbulent signal could be singular everywhere. Moreover, the singular exponents of energy and thermal dissipation rates are most frequently encountered at around 0.2, which is significantly smaller than the singular exponents for a wind tunnel at a moderate Reynolds number. The evidence indicates a higher intermittency of turbulence in the urban canopy layer at a high Reynolds number, which is demonstrated by the data with high temporal resolution. Furthermore, the temperature field is more intermittent than the velocity field. In addition, a large amount of samples could be used for verification of the results.

关键词： urban canopy layer intermittent turbulence turbulent dissipation multifractality singularity spectrum

Soil Carbon Sequestration Potential as Affected by Management Practices in Northern China:A Simulation Study

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Pedosphere 2014年第4期24卷 529-543页

作者： WANG Guo-Cheng WANG En-Li HUANG Yao xu jing-jing State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry(LAPC) Institute of Atmospheric PhysicsChinese Academy of Sciences CSIRO Land & Water Black MountainCanberraACT 2601(Australia) State Key Laboratory of Vegetation and Environmental Change(LVEC) Institute of BotanyChinese Academy of Sciences

Soil has been identified as a possible carbon （C） sink for sequestering atmospheric carbon dioxide （CO2）. However, soil organic carbon （SOC） dynamics in agro-ecosystems is affected by complex interactions of various factors including climate, soil and agricultural management practices, which hinders our understanding of the underlying mechanisms. The objectives of this study were to use the Agricultural Production Systems simulator （APSIM） model to simulate the long-term SOC dynamics under different management practices at four long-term experimental sites, Zhengzhou and xuzhou with double cropping systems and Gongzhuling and Urtimqi with single cropping systems, located in northern China. Firstly, the model was calibrated using information from the sites and literature, and its performance to predict crop growth and SOC dynamics was examined. The calibrated model was then used to assess the impacts of different management practices, including fertilizer application, irrigation, and residue retention, on C dynamics in the top 30 cm of the soil by scenario modelling. Results indicate a significant SOC sequestration potential through improved management practices of nitrogen （N） fertilizer application, stubble retention, and irrigation. Optimal N fertilization （Nopt） and 100% stubble retention （R100） increased SOC by about 11.2%, 208.29%, and 283.67% under irrigation at Gongzhuling, Zhengzhou, and xuzhou, respectively. Soil organic carbon decreased rapidly at lJriimqi under irrigation, which was due to the enhanced decomposition by increased soil moisture. Under rainfed condition, SOC remained at a higher level. The combination of Nopt and R100 increased SOC by about 0.46% under rainfed condition at /Jr/imqi. Generally, agricultural soils with double cropping systems （Zhengzhou and xuzhou） showed a greater potential to sequester C than those with single cropping systems （Gongzhuling and Urumqi）.

关键词： agro-ecosystems APSIM model fertilizer application irrigation residue retention scenario analysis soil organic carbon

On the scaling law of ramp structures in scalar turbulence

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Atmospheric and Oceanic Science Letters 2018年第4期11卷 372-377页

作者： CHEN Dong-Wei HU Fei xu jing-jing State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric Physics Chinese Academy of Sciences College of Earth Science University of Chinese Academy of Sciences

Ramp structures widely exist in scalar turbulence,such as temperature,water vapor,and carbon dioxide(CO2),which refer to the phenomenon that the physical quantity increases slowly with time and then suddenly *** structures lead to large gradients on a small scale and result in intermittency and anisotropy of turbulent *** this paper,wavelet analysis is used to analyze observed data from the beijing 325-m meteorological tower to extract ramp structures in temperature,water vapor,and CO2 *** structures in CO2 signals are different from those in temperature and water vapor in terms of the averaged temporal scale and normalized amplitude,and the ramp duration almost equals the cliff duration,which means ramp structures in CO2 signals are not easy to generate and different physical mechanisms may *** addition,both the ascending and descending part of ramp structures are linearly *** is found that a scaling law exists between the slope and duration in the ascending part in the three scalar *** corresponding power exponents are slightly ***,the same rule exists in the descending part of ramp structures,which indicates that self-similarity may be a universal law in scalar ***,the maxima of selected ramp structures show the same pattern,*** are ramp structures in the maximum sequence,which proves that small-scale ramp structures are superimposed on large-scale ramp structures.

关键词： Scalar turbulence ramp structure scaling law selfsimilarity

Introducing a drought index to a crop model can help to reduce the gap between the simulated and statistical yield

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Atmospheric and Oceanic Science Letters 2018年第4期11卷 307-313页

作者： WANG Guo-Cheng ZHANG Qing xu jing-jing LAPC Institute of Atmospheric Physics Chinese Academy of Sciences

A well-established and pre-calibrated crop model can normally represent the overall characteristics of crop growth and ***,it can hardly include all relevant factors that affect the yield,and usually overestimates the crop yield when extreme weather conditions *** this study,the authors first introduced a drought index(the Standardized Precipitation Evapotranspiration Index)into a process-based crop model(the Agro-C model).Then,the authors evaluated the model’s performance in simulating the historical crop yields in a double cropping system in the Huang-Huai-Hai Plain of China,by comparing the model simulations to the statistical *** results showed that the adjusted Agro-C model significantly improved its performance in simulating the yields of both maize and wheat as affected by drought events,compared with its original *** can be concluded that incorporating a drought index into a crop model is feasible and can facilitate closing the gap between simulated and statistical yields.

关键词： Agro-C model crop yield drought index

The Use of Zein and Shuanghuangbu for Periodontal Tissue Engineering

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International Journal of Oral Science 2010年第3期2卷 142-148页

作者： Yan-zhi xu jing-jing Wu Yan-ping Chen Jian Liu Na Li Feng-ying Yang Department of Stomatology the Fourth Hospital of Hebei Medical University Shijiazhuang China

Aim Tissue engineering is a promising area with a broad range of applications in the fields of regenerative medicine and human health. The emergence of periodontal tissue engineering for clinical treatment of periodontal disease has opened a new therapeutic avenue. The choice of scaffold is crucial. This study was conducted to prepare zein scaffold and explore the suitability of zein and Shuanghuangbu for periodontal tissue *** A zein scaffold was made using the solvent casting/particulate leaching method with sodium chloride （NaC1） particles as the porogen. The physical properties of the zein scaffold were evaluated by observing its shape and determining its pore structure and porosity. Cytotoxicity testing of the scaffold was carried out via in vitro cell culture experiments, including a liquid extraction experi- ment and the direct contact assay. Also, the Chinese medicine Shuanghuangbu, as a growth factor, was diluted by scaffold extract into different concentrations. This Shuanghuangbu-scaffold extract was then added to periodontal ligament cells （PDLCs） in order to determineits effect on cell proliferation. Results The zein scaffold displayed a sponge-like structure with a high porosity and sufficient thickness. The porosity and pore size of the zein scaffold can be controlled by changing the porogen particles dosage and size. The porosity was up to 64.1%-78.0%. The pores were well-distributed, interconnected, and porous. The toxicity of the zein scaffold was graded as 0-1. Furthermore, PDLCs displayed full stretching and vigorous growth under scanning electronic microscope （SEM）. Shuanghuangbu-scaffold extract could reinforce proliferation activity of PDLCs compared to the control group, especially at 100 μ***^-1 （P〈0.01）. Conclusion A zein scaffold with high porosity, open pore wall structure, and good biocompatibility is conducive to the growth of PDLCs. Zein could be used as scaffold to repair periodontal tissue defects. Also, Shuanghu

关键词： zein periodontal tissue engineering scaffold,periodontal ligament cells Shuanghuangbu

Bias Correction in Wind Direction Forecasting Using the Circular-Circular Regression Method

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Atmospheric and Oceanic Science Letters 2014年第2期7卷 87-91页

作者： xu jing-jing HU Fei XIAO Zi-Niu CHENG xue-Ling xu jing-jing XIAO Zi-Niu CHENG xue-Ling International Center for Climate and Environment Science (ICCES) Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry (LAPC) Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China China Meteorological Administration Training Centre Beijing 100081 China State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG) Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

Wind direction forecasting plays an important role in wind power prediction and air pollution management. Weather quantities such as temperature, precipitation, and wind speed are linear variables in which traditional model output statistics and bias correction methods are applied. However, wind direction is an angular variable; therefore, such traditional methods are ineffective for its evaluation. This paper proposes an effective bias correction technique for wind direction forecasting of turbine height from numerical weather prediction models, which is based on a circular-circular regression approach. The technique is applied to a 24-h forecast of 65-m wind directions observed at Yangmeishan wind farm, Yunnan Province, China, which consistently yields improvements in forecast performance parameters such as smaller absolute mean error and stronger similarity in wind rose diagram pattern.

关键词： wind direction forecast bias correction circular-circular regression numerical model wind power prediction

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Atmospheric and Oceanic Science Letters 2014年第4期7卷 320-323页

作者： SONG Zong-Peng HU Fei xu jing-jing CHENG xue-Ling State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric Physics Chinese Academy of Sciences University of Chinese Academy of Sciences

Time series of wind speed are composed of large and small ramp structures. Data analysis reveals a power law relation between the linear slope of ramp structures and the time scale. This suggests that these ramp structures of wind speed have a self-similar characteristic. The lower limit of the self-similar scale range was 2 s. The upper limit is unexpectedly large at 27 rain. Data are collected from grassland, city, and lake areas. Although these data have different underlying surfaces, all of them clearly show a power law relation, with slight differences in their power exponents.

关键词： ramp structure self-similarity power law time series of wind speed

Association of CDKN2B-AS1 Polymorphisms with Premature Triple-vessel Coronary Disease and Their Sex Specificity in the Chinese Population

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Biomedical and Environmental Sciences 2018年第11期31卷 787-796页

作者： xu jing jing JIANG Lin xu Lian Jun GAO Zhan ZHAO xue Yan ZHANG Yin SONG Ying LIU Ru SUN Kai GAO Run Lin xu Bo SONG Lei YUAN Jin Qing Department of cardiology Fuwai HospitalNational Center for Cardiovascular DiseasesChinese Academy of Medical Science and Peking Union Medical College State Key Laboratory of Cardiovascular Disease Fuwai HospitalNational Center for Cardiovascular DiseasesChinese Academy of Medical Science and Peking Union Medical College Department of Hypertension Fuwai HospitalNational Center for Cardiovascular DiseasesChinese Academy of Medical Science and Peking Union Medical College

Objective The aim of this study is to establish whether cyclin-dependent kinase inhibitor 2B antisense RNA 1(CDKN2 B-AS1) gene polymorphisms are associated with premature triple-vessel disease(PTVD). Methods Nine single-nucleotide polymorphisms(rs1063192, rs10757274, rs1333042, rs1333049, rs2285327, rs3217986, rs3217992, rs4977574, and rs9632884) were genotyped in 884 PTVD patients and 907 control subjects(males ≤ 50 years old and females ≤ 60 years old) using the improved multiplex ligase detection reaction method. Results The allele frequencies of rs10757274 G, rs1333049 C, rs4977574 G(all P < 0.001), and rs3217986 G(P = 0.040) were significantly higher in the PTVD group than in the control group, but those of rs1063192 A, rs1333042 G, and rs9632884 C(all P < 0.001) were significantly lower in the former than in the latter. Logistic regression analysis revealed that homozygote AA of rs1333042 is associated with decreased risk for PTVD(OR = 0.42, 95% CI: 0.22-0.82, P = 0.011). In addition, the allele frequencies observed differed between genders. The G allele of rs3217986 was associated with increased risk for PTVD in male patients only(OR = 2.94, 95% CI: 1.27-6.80, P = 0.012) in the dominant model, and no positively mutated allele was found in female patients. Conclusion Polymorphisms of the CDKN2 B-AS1 gene are associated with the incidence of PTVD in the Chinese population. Furthermore, the frequencies of mutated alleles differed between genders.

关键词： Premature triple-vessel disease Single-nucleotide polymorphism Risk

Association of α_(2A)-Adrenergic Receptor Genetic Variants with Platelet Reactivity in Chinese Patients on Dual Antiplatelet Therapy Undergoing Percutaneous Coronary Intervention

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Biomedical and Environmental Sciences 2017年第12期30卷 898-906页

作者： SONG Ying TANG Xiao Fang YAO Yi HE Chen xu jing jing WANG Huan Huan GAO Zhan WANG Miao YUAN Jin Qing Department of Cardiology Fuwai Hospital National Center for Cardiovascular Diseases Chinese Academy of Medical Sciences and Peking Union Medical College Beijing 10003 7 China

Objective The alpha 2A-adrenergic receptor gene （ADRA2A） polymorphism in individuals antiplatelet response to sympathetic stimulation. The aim of this study was to investigate ADRA2A variants on platelet reactivity in Chinese patients on dual antiplatelet therapy undergoing percutaneous coronary intervention （PCI）. modifies the the effect of （DAPT） after Methods From March 2011 to March 2013, 1,024 patients were enrolled in this prospective, single-center, observational study in China. Four single nucleotide polymorphisms （SNPs） of ADRA2A gene （rs11195419, rs3750625, rs13306146, and rs553668） and CYP2C19^＊2 were detected by ligase detection reaction （LDR）, and adenosine diphosphate （ADP） inhibition was detected by thromboelastography （TEG）. Results The minor allele frequencies of ADRA2A SNPs were common. Platelet ADP inhibition was significantly different among patients carrying rs11195419 （adjusted P = 0.022） and rs3750625 （adjusted P = 0.016）. The homozygous allele carriers had the lowest ADP inhibition. However, ADP inhibition was not significantly different in rs553668 and rs13306146. At the multivariate analysis, rs11195419 （P = 0.033）, rs3750625 （P = 0.020） and CYP2C19＂2 （P = 0.002） were independent predictors of ADP inhibition. Subgroups analysis based on sex showed rs11195419 （P = 0.003） and rs3750625 （P = 0.002） were significantly associated with ADP inhibition in males, but not in females. Conclusion ADRA2A genetic variations were associated with ADP-induced platelet aggregation during DAPT in Chinese patients undergoing PCI, and the effect was particularly more pronounced in males.

关键词： ADRA2A Platelet function Polymorphisms Dual antiplatelet therapy Percutaneouscoronary intervention