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Global and regional soil organic carbon estimates:Magnitudes and uncertainties

Pedosphere 2024年第4期34卷 685-698页

作者： Ziqi LIN Yongjiu DAI Umakant MISHRA Guocheng WANG Wei shangguan Wen ZHANG Zhangcai QIN School of Atmospheric Sciences Guangdong Province Key Laboratory for Climate Change and Natural Disaster StudiesSun Yat-sen UniversityZhuhai 519082China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 519082China Computational Biology&Biophysics Sandia National LaboratoriesLivermore CA 94550USA Faculty of Geographical Science Beijing Normal UniversityBeijing 100875China State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China

Globally,soil is the largest terrestrial carbon(C)*** quantification of soil organic C(SOC)stocks in existing global observation-based estimates avails accurate predictions in carbon-climate feedbacks and future climate *** investigated the magnitudes and distributions of global and regional SOC estimates(i.e.,density and stocks)based on five widely used global gridded SOC datasets,a regional permafrost dataset developed in 2021(UM2021),and a global-scale soil profile database(World Soil Information Service)reporting measurements of a series of physical and chemical edaphic *** five global gridded SOC datasets were the Harmonized World Soil Database(HWSD),World Inventory of Soil Emission Potentials at 30 arc-second resolution(WISE30sec),Global Soil Dataset for Earth System Models(GSDE),Global Gridded Soil Information at 250-m resolution(SoilGrids250m),and Global Soil Organic Carbon Map(GSOCmap).Our analyses showed that the magnitude and distribution of SOC varied widely among datasets,with certain datasets showing region-specific *** the global scale,SOC stocks at the top 30 and 100 cm were estimated to be 828(range:577–1171)and 1873(range:1086–2678)Pg C,*** estimates from GSDE,GSOCmap,and WISE30sec were comparable,and those of SoilGrids250m and HWSD were at the upper and lower *** spatial SOC distribution varied greatly among datasets,especially in the northern circumpolar and Tibetan Plateau permafrost ***,UM2021 and WISE30sec performed well in the northern circumpolar permafrost regions,and GSDE performed well in *** estimates of SOC by different datasets also showed large variabilities across different soil layers and *** discrepancies were generally smaller for the 0–30 cm soil than the 0–100 cm *** datasets demonstrated relatively higher agreement in grasslands,croplands,and shrublands/savannas than in other biomes(e.g.,wetlands).The users should be mindful of the gaps b

关键词： biome carbon cycle Earth System Models permafrost region soil dataset soil map

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Enhanced photocatalytic water splitting with surface defective SrTiO_(3)nanocrystals

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Frontiers in Energy 2021年第3期15卷 700-709页

作者： Junying LIU Zhidong WEI Wenfeng shangguan Institute of Physical Chemistry University of HamburgGrindelallee 11720146 HamburgGermany Research Center for Combustion and Environment Technology Shanghai Jiao Tong UniversityShanghai 200240China

Surface reconstructed SrTiO_(3)nanocrystals were synthesized by a thermal treatment process in presence of NaBH_(4)and SrTiO_(3)*** surface reconstruction of SrTiO_(3)nanocrystals is attributed to the introduction of surface oxygen vacancies or Ti sites(such as Ti^(3+)and Ti^(2+))during the hydrogenation treatment *** light absorption and the charge transfer ability of SrTiO_(3)nanocrystals are simultaneously enhanced due to surface oxygen vacancies or Ti sites(such as Ti^(3+)and Ti^(2+)),which are beneficial to photocatalytic water ***,these defects also change the redox potential of the *** there existed a synergistic effect between the three,the ratio of hydrogen to oxygen production was also regulated.

关键词： SrTiO_(3) surface reconstruction oxygen vacancies photocatalytic water splitting

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Sample size adaptive strategy for time-dependent Monte Carlo particle transport simulation

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Nuclear Science and Techniques 2023年第4期34卷 127-134页

作者： Dan-Hua shangguan Wei-Hua Yan Jun-Xia Wei Zhi-Ming Gao Yi-Bing Chen Zhi-Cheng Ji Institute of Applied Physics and Computational Mathematics Beijing 100094China

When multiphysics coupling calculations contain time-dependent Monte Carlo particle transport simulations, these simulations often account for the largest part of the calculation time, which is insufferable in certain important cases. This study proposes an adaptive strategy for automatically adjusting the sample size to fulfil more reasonable simulations. This is realized based on an extension of the Shannon entropy concept and is essentially different from the popular methods in timeindependent Monte Carlo particle transport simulations, such as controlling the sample size according to the relative error of a target tally or by experience. The results of the two models show that this strategy can yield almost similar results while significantly reducing the calculation time. Considering the efficiency, the sample size should not be increased blindly if the efficiency cannot be enhanced further. The strategy proposed herein satisfies this requirement.

关键词： Time-dependent Monte Carlo particle transport simulation Shannon entropy Adaptive strategy

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Identification of Ice Elevation Change of the Shuiguan River No.4 Glacier in the Qilian Mountains,China

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Journal of Mountain Science 2010年第4期7卷 375-379页

作者： LI Jing LIU Shiyin shangguan donghui ZHANG Yinsong State Key Laboratory of Cryospheric Sciences Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China

GPS measurement,an effective method for surveying glacier surface topography,has been applied in some glaciers for many *** Shuiguan River No.4 glacier,a small glacier with its area of 1.84 km2 in 1972,located in the east of the Qilian Mountains,China,was selected to study its ice elevation change using GPS measurement in *** study was conducted on the ablation area with GPS-measured area 0.5 *** ice elevation change of the glacier was obtained by comparing the DEM obtained by a 1:50 000 topographic map made in 1972 with the DEM by GPS-measured data acquired in *** differences of the two DEMs showed the thinning condition of the glacier was *** mean thinning was 15±8 m with the mean thinning rate of 0.42±0.22 m a-1 for 1972-2007 in the measurement area,which equaled 0.38±0.20 m yr-1 in water equivalent(w.e.).The prominent thinning occurred on the south part of the glacier,which was the area near the glacier terminus with the maximum thinning of 41±8 *** the thinning value of 15±8 m for the glacier area below 4640 m a.s.l.,the wasting ice mass was calculated to be 6.4±3.2×10-3 km3 for 1972-2007,corresponding to 5.7±2.8×10-3 km3 w.e.,which meant that the montane runoff released by the glacier was at least 5.7±2.8×106 m3 between 1972-2007.

关键词： GPS RTK DEM Glacier mass balance Mountane runoff

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New Result for Synchronization of Chaotic Lur’e Systems with Time Delay Using Sampled-data Control 36

New Result for Synchronization of Chaotic Lur’e Systems wit...

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第36届中国控制会议

作者： shangguan Xingchen HE Yong ZHANG Chuanke WU Min School of Automation China University of Geosciences Hubei Key Laboratory of Advanced Control and Intelligent Automation for Complex Systems

ISBN: (纸本)9781538629185

This paper investigates synchronization problem of two identical chaotic Lur’e systems with time delay using sampleddata control. Firstly, a novel piecewise Lyapunov-Krasovskii function（LKF）, which considers fully useful information of the systems and their cross terms, is introduced. Secondly, a new synchronization criterion is developed in terms of linear matrix inequalities（LMIs） by discarding the positive definite constraint of the piecewise LKF. Then, maximal sampling interval and corresponding controller are obtained. At last, case study based on a typical Chua’s circuit is carried out to verify the effectiveness and advantages of the proposed method.

关键词： Chaotic Lur’e system Sampled-data control Synchronization Time delay Piecewise functional

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A review on nitrogen transformation and conversion during coal pyrolysis and combustion based on quantum chemical calculation and experimental study

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Chinese Journal of Chemical Engineering 2021年第7期34卷 107-123页

作者： Tingting Jiao huiling Fan Shoujun Liu Song Yang Wenguang Du Pengzheng Shi Chao Yang Yeshuang Wang Ju shangguan State Key Laboratory of Clean and Efficient Coal Utilization Taiyuan University of TechnologyTaiyuan 030024China Shanxi Engineering Central of Civil Clean Fuel Taiyuan University of TechnologyTaiyuan 030024China College of Chemistry and Chemical Engineering Taiyuan University of TechnologyTaiyuan 030000China Taiyuan Green Coke Energy Co. Ltd.Taiyuan 030006China

The emission of NOx during coal combustion contributes to the formation of acid rain and photochemical smog,which would seriously affect the quality of atmospheric ***,the decrease of NOx is of great importance for improving the efficient utilization of *** present review comprehensively summarized the influence factors and mechanisms of migration and transformation of nitrogen during the coal pyrolysis and combustion based on experimental study and quantum chemical ***,in the process of pyrolysis:the occurrence state and transformation of nitrogen were *** influence of temperature,atmosphere,heating rate and catalyst on formation of NOx precursor and nitrogen migration path at the molecular level were summarized;Secondly,during the process of combustion:the influence of temperature,ambient oxygen concentration,physical structure of coal char,catalyst on heterogeneous oxidation of char(N)were summarized;The effects of char surface properties,catalyst and ambient atmosphere on heterogeneous reduction of NOx were also *** on the quantum chemical calculation,the reaction path of heterogeneous oxidation of char-N and heterogeneous reduction of NOx were described in *** studies focus more on the generation of HCN and NH3,but in order to reduce the pollution of NOx from the source,it is necessary to further improve the process conditions and the optimal formula of producing more N2 during pyrolysis,as well as clarify the path of the generation of *** study and quantum chemistry calculation should be combined to complete the research of directional nitrogen reduction during pyrolysis and denitration during combustion.

关键词： Coal combustion Pyrolysis Environment Nitrogen oxides Quantum chemical calculation

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Relationships between distribution characteristics of ceramic fragments and anti-penetration performance of ceramic composite bulletproof insert plates

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Defence Technology（防务技术） 2023年第1期19卷 103-110页

作者： Wen-hao Yu Wei-ping Li Yi-fan shangguan Xin-yang Ji Tian Ma Guo-qing Wu School of Materials Science and Engineering Beihang UniversityBeijing100191China Institute of Quartermaster Engineering Technology of PLA Academy of Military Science Beijing100010China China Linyi High-tech Zone Shuanghang Material Technology Co. Ltd.Linyi276000China

Through quantitative statistics and morphological characterization of ceramic fragments for ceramic composite bulletproof insert plates(CCBIPs),distribution characteristics of ceramic fragments within a specific size range were analyzed for different Armor Piercing Incendiary(API)and shot *** quantitatively evaluate the effect of energy absorption for ceramic plates,a model of energy absorption during penetration for CCBIPs was established based on statistics of the size distribution of ceramic fragments(SDCF).Variation in the SDCF and its influence on energy absorption for CCBIPs were *** results indicate that the distribution feature of ceramic fragments in the range of 0.25-2.25 mm is Gaussian *** with Type 56 of API(56-API),ceramic fragments formed by 53-API with higher kinetic energy possess more quantity and more concentrated distribution,whose average equivalence size decreases by 6.5%,corresponding to increasing by 83.9%of estimated energy ***,the ability of CCBIPs to resist the third shot is significantly weakened,whose estimated energy absorption decreases by 58.8%compared with the first *** concentrated distribution and fewer fragments are formed after the third shot,the average equivalence size of ceramic fragments increases by 6.9%,which may attribute to the micro-cracks induced by the previous two shots.

关键词： Bulletproof insert plate Ceramic fragment Statistic Energy absorption Anti-penetration performance

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Advances in Electrostatic Plasma Methods for Purification of Airborne Pathogenic Microbial Aerosols:Mechanism,Modeling and Application

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Environment & Health 2024年第9期2卷 596-617页

作者： Shanlong Tao Yong Zhu Mingxia Chen Wenfeng shangguan Research Center for Combustion and Environmental Technology School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240PR China School of Mechanical and Power Engineering East China University of Science and TechnologyShanghai 200237PR China

The transmission of pathogenic airborne microorganisms significantly impacts public health and societal *** healthy indoor air quality in public spaces is *** various air purification technologies,electrostatic precipitation and atmospheric pressure nonthermal plasma are notable for their broad-spectrum effectiveness,high efficiency,cost-effectiveness,and *** review investigates the primary mechanisms by which these electrostatic methods collect and disinfect pathogenic *** also delves into recent advancements in enhancing their physical and chemical mechanisms for improve ***,a thorough summary of mathematical models related to the migration and deactivation of pathogenic aerosols in electrostatic purifiers is *** will help us to understand the behavior of aerosols in purification ***,the review discusses the current research on creating a comprehensive health protection system and addresses the challenges of balancing byproduct control with *** aim is to establish a foundation for future research and development in electrostatic aerosol purification and develop integrated air purification technologies that are both efficient and safe.

关键词： electrostatic microbial aerosols inactivation collection air purification

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Influence of Ni interlayer on interfacial microstructure and mechanical properties of Ti-6Al-4V/AZ91D bimetals fabricated by a solid–liquid compound casting process

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Journal of Magnesium and Alloys 2021年第4期9卷 1389-1402页

作者： Fulin Wen Jianhua Zhao Miaowang Yuan Jingfeng Wang Dengzhi Zheng Jinyong Zhang Ke He Jingjing shangguan Yu Guo College of Materials Science and Engineering Chongqing UniversityChongqing 400044China National Engineering Research Center for Magnesium Alloys Chongqing UniversityChongqing 400044China

The solid–liquid compound casting of Mg-AZ91D and Ti-TC4 alloys was developed by using pure Ni electro-deposited *** pouring temperatures of 660℃,690℃,720℃and 750℃were chosen to investigated the effects of casting temperatures on microstructural evolution,properties,and fracture behaviors of Ni-coated TC4/AZ91D bimetals by the solid–liquid compound casting(SLCC).The scanning electron microscopy(SEM)and the energy dispersive spectroscopy(EDS)results showed that the interfacial zone mainly composed of nickel,Mg_(2)Ni and Mg-Al-Ni in the bimetals cast at 660℃.As the pouring temperature was increased to 750℃,the width of the interface zone,which mainly composed ofδ(Mg),Mg_(2)Ni,Mg-Al-Ni,Mg_(3)TiNi_(2) and Al_(3)Ni,gradually *** microhardness tests showed that the micro-hardness of the interface zone was smaller than that of TC4 substrate but larger than that of the cast AZ91D *** the pouring temperature of 720℃,the Ni-coated TC4/AZ91D bimetals had the most typical homogeneous interface,which had granular Mg-Al-Ni ternary phase but no ribbon-like Al3Ni binary phase,and achieved the highest shear strength of ***,further fracture behavior analysis showed that most fracture failure of Ni-coated TC4/AZ91D bimetals occurred at the Mg_(2)Ni+δ(Mg)eutectic structure and Al_(3)Ni hard intermetallic.

关键词： Dissimilar materials Solid–liquid compound casting Interface Titanium alloy AZ91D Mg Intermetallic compound Mechanical property

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可见光响应光催化剂BiYWO_6的制备、表征及其完全分解水的研究

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高等学校化学学报 2008年第8期29卷 1603-1608页

作者：刘恢袁坚上官文峰上海交通大学燃烧与环境技术研究中心上海200240

制备了一种可见光响应的光催化剂BiYWO6,该体系是Bi2WO6-Y2WO6的伪二元固溶体,其禁带宽度为2.71eV.其负载了助催化剂后,可在紫外光和可见光下完全分解水生成氢气和氧气,其中负载RuO2助催化剂的BiYWO6具有最好的光催化活性.通过对光催化... 详细信息

制备了一种可见光响应的光催化剂BiYWO6,该体系是Bi2WO6-Y2WO6的伪二元固溶体,其禁带宽度为2.71eV.其负载了助催化剂后,可在紫外光和可见光下完全分解水生成氢气和氧气,其中负载RuO2助催化剂的BiYWO6具有最好的光催化活性.通过对光催化反应前后的BiYWO6和助催化剂的表面各元素的化学状态的研究证实了RuO2/BiYWO6体系的稳定性.比较分析了BiYWO6的能带结构,认为可见光完全分解水的性能可归因于Y和Bi在固溶体BiYWO中形成了合适的能带结构.

关键词：光催化固溶体完全分解水可见光金属氧化物

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