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An empirical approach to predict regional organic carbon in deep soils
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作者 Jingjing WANG Xiaorong WEI +4 位作者 Xiaoxu JIA Mingbin HUANG Zhipeng LIU Yufei YAO Ming’an SHAO 《Science China Earth Sciences》 SCIE EI CAS CSCD 2023年第3期583-593,共11页
Deep soil organic carbon(SOC)plays an important role in carbon cycling.Precisely predicting deep SOC at the regional scale is crucial for the accurate assessment of carbon sequestration potential in soils but has been... Deep soil organic carbon(SOC)plays an important role in carbon cycling.Precisely predicting deep SOC at the regional scale is crucial for the accurate assessment of carbon sequestration potential in soils but has been challenging for a century.Herein,we developed a depth distribution function-based empirical approach to predict SOC in deep soils at the regional scale.We validated this approach with a dataset from four regions of the world and examined the application of this approach in China’s Loess Plateau.We found that among the reported depth distribution functions describing vertical patterns of SOC,the negative exponential function performed best in fitting SOC along the soil profile in various regions.Moreover,the parameters(i.e.,Ceand k)of the negative exponential function were linearly correlated to surface SOC(0–20 cm)and the changing rates of SOC within the topsoil(0–40 cm).Based on the above relationships,the empirical equations for predicting the negative exponential parameters are established.The validation results from site-specific and regional dataset showed that combining the negative exponential function and such empirical equations can precisely predict SOC concentration in soils down to 500 cm depth.Our study provides a simple,rapid and accurate method for predicting deep soil SOC at the regional scale,which could simplify the assessment of deep soil SOC in various regions. 展开更多
关键词 Deep SOC empirical approach Negative exponential function Depth distribution Spatial pattern
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A new empirical chart for rockburst analysis in tunnelling:Tunnel rockburst classification(TRC) 被引量:4
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作者 Hadi Farhadian 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2021年第4期603-610,共8页
Rockburst is defined as a phenomenon with immediate dynamic instability under excavation unloading conditions of deep or high geostress areas.Inadequate knowledge and lack of characterizing information prevent enginee... Rockburst is defined as a phenomenon with immediate dynamic instability under excavation unloading conditions of deep or high geostress areas.Inadequate knowledge and lack of characterizing information prevent engineers and experts from achieving appropriate prediction results related to the rockburst behaviour.In this study,a data set including 220 rockburst instances was collected for rockburst classification via the geostatistical method.An update of the 2D graph,the tunnel rockburst classification(TRC)chart,was introduced based on analysing three indicators,namely,elastic energy index(Wet),tangential stress in rock mass(σ_(0)),and uniaxial compressive strength(σ_(c)).Distribution and correlation of data were drawn on 2D plot,and the boundaries of rockburst were distinguished according to the achieved interpolate points by kriging method.Hierarchically,the validation phase was performed using an additional set of 28 case histories obtained from several projects around the world.The results showed that the TRC chart with an average error percentage of 3.6%in the prediction of rockburst had a significant and effective implementation in comparison to the exiting heuristic systems.Despite the initial character of the prediction,the described chart may be a helpful tool in the first steps of design and construction. 展开更多
关键词 Prediction Tunnel rockburst Classification empirical approach TRC
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Reviewed Work:A Study of Liu Yong and His Lyrics,by Laifong Leung.Beijing:China Translation&Publishing House,2020.PP x+506.¥98.00(paper back).ISBN 978-7-5001-6326-8
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作者 YUAN Long-zhen DANG Zheng-sheng +1 位作者 WANG Xiao-long Laifong Leung 《Journal of Literature and Art Studies》 2022年第9期910-915,共6页
Laifong Leung,based on the literature and materials from Chinese,English and Japanese,by using empirical approach and closing reading,produced Chinese-English combined version A Study of Liu Yong and His Lyrics.The wo... Laifong Leung,based on the literature and materials from Chinese,English and Japanese,by using empirical approach and closing reading,produced Chinese-English combined version A Study of Liu Yong and His Lyrics.The work mainly probes into Liu Yong’s life story and closely analyzes the characteristics of his lyrics in the way of tune titles,thematic matters,images and diction,rhythm and structure,and his contributions to the establishment of Ci genre are dealt with.Therefore,it is rewarding to promote academic exchange and disseminate classical Chinese literature,and it is pioneering to provide a new angle in the study of Liu Yong and his lyrics by using quantitative analysis. 展开更多
关键词 writing techniques of Liu’s lyrics empirical approach academic translation
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Explicit diagnosis of the local ozone production rate and the ozone-NOx-VOC sensitivities 被引量:36
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作者 Zhaofeng Tan Keding Lu +10 位作者 Huabin Dong Min Hu Xin Li Yuhan Liu Sihua Lu Min Shao Rong Su Haichao Wang Yusheng Wu Andreas Wahner Yuanhang Zhang 《Science Bulletin》 SCIE EI CSCD 2018年第16期1067-1076,共10页
In the troposphere, ozone is a harmful gas compound to both human health and vegetation. Ozone is produced from the reaction of NO_x(@NO + NO_2) and VOCs(volatile organic compounds) with light. Due to the highly nonli... In the troposphere, ozone is a harmful gas compound to both human health and vegetation. Ozone is produced from the reaction of NO_x(@NO + NO_2) and VOCs(volatile organic compounds) with light. Due to the highly nonlinear relationships between ozone and its precursors, proper ozone mitigation relies on the knowledge of chemical mechanisms. In this study, an observation-based method is used to simulate ozone formation and elucidate its controlling factors for a rural site on the North China Plain. The instantaneous ozone production rate is calculated utilizing a box model using the dataset obtained from the Wangdu campaign. First, the model was operated in a time-dependent mode to calculate the ozone production rate at each time stamp. The calculated ozone formation rate showed a diurnal average maximum value of 17 ppbv/h(1-h diurnal averaged). The contribution of individual peroxy radicals to ozone production was analyzed. In addition, the functional dependence of calculated P(O_3) reveals that ozone production was in a NO_x-limited regime during the campaign. Furthermore, the missing peroxy radical source will further extend NO_x-limited conditions to earlier in the day, making NO_xlimitation dominate more of a day than the current chemical model predicts. Finally, a multiple scenarios mode,also known as EKMA(empirical kinetic modeling approach), was used to simulate the response of P(O_3) to the imaginary change in precursor concentrations. We found that ozone production was in the NO_x-limited region. However, the use of NO_2 measured by the molybdenum converter and/or the absence of a peroxy radical source in the current chemical model could over-emphasize the VOC-limited effect on ozone production. 展开更多
关键词 Observational-based model Instantaneous ozone production rate empirical kinetic modeling approach EKMA
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