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| 1 | Spatial-temporal Changes of Vegetation Cover in Guizhou Province, Southern China显示文摘Guizhou Province is an important karst area in the world and a fragile ecological area in China. Ecological risk assessment is very necessary to be conducted in this region. This study investigates different characteristics of the spatial-temporal changes of vegetation cover in Guizhou Province of Southern China using the data set of SPOT VEGETATION(1999–2015) at spatial resolution of 1-km and temporal resolution of 10-day. The coefficient of variation, the Theil-Sen median trend analysis, and the Mann-Kendall test are used to investigate the spatial-temporal change of vegetation cover and its future trend. Results show that: 1) the spatial distribution pattern of vegetation cover in Guizhou Plateau is high in the east whereas low in the west. The average annual normalized difference vegetation index(NDVI) from west to east is higher than that from south to north. 2) Average annual NDVI improved obviously in the past 17 years. The growth rate of average annual NDVI is 0.028/10 yr, which is slower than that of vegetation in the country(0.048/10 yr) from 1998 to 2007. Average annual NDVI in karst area is lower than that in non-karst area. However, the growing rate of average annual NDVI in karst area(0.030/10 yr) is faster than that in non-karst area(0.023/10 yr), indicating that vegetation coverage increases more rapidly in karst area. 3) Vegetation coverage in the study area is stable overall, but fluctuates in the local scales. 4) Vegetation coverage presents a continuous increasing trend. The Hurst exponent of NDVI in different vegetation types has an obvious threshold in various elevations. 5) The proportion of vegetation cover with sustainable increase is higher than that of vegetation cover with sustainable decrease. The improvement in vegetation cover may expand to most parts of the study area. | TIAN Yichao BAI Xiaoyong WANG Shijie QIN Luoyi LI Yue | 2017 | Chinese Geographical Science2017，27，1： | 21 |
| 2 | Application of a ^(137)Cs fingerprinting technique for interpreting responses of sediment deposition of a karst depression to deforestation in the Guizhou Plateau,China显示文摘Deforestation to reclaim land often triggers severe soil erosion in the Guizhou Karst Plateau. 137Cs dating of the deposited sediments in the karst depression bottom was used to estimate soil losses by surface erosion since deforestation started in 1979 on hillslopes in the Shirenzhai catchment, Puding County, Guizhou Province. The catchment has a drainage area of 0.054 km2. The average 137Cs contents of the top and peak layers in five cores of the depression bottom (with an area of 2652 m2), collected in 2009, were 2.35 and 7.25 Bq kg-1, respectively. The medium depths in the depression (which ranged between 84 cm and 113.5 cm with a mean value of 92.1 cm) showed the presence of sediments deposited in 1979. The total volume and weight of the deposited sediments since 1979 were estimated to be 1965 m3 and 2496 t, respectively. The depression bottom can be treated as a temporary impoundment and its sediment trapping efficiency was estimated to be 0.7. The relevant average soil erosion rate on the hillslopes was 2315 t km-2 yr-1 since 1979. The mean 137Cs inventory of the five cores was 7693 Bq m-2, which was ~10 times the local reference inventory of 782 Bq m-2. The total 137Cs activity of the sediments in the bottom was 20.4×106 Bq, and the relevant 137Cs inventory loss from the hillslopes was 358 Bq m-2 (since 1954), which accounted for 45.8% of the reference inventory. As soil erosion was not severe before and after the period of deforestation and following cultivation in 1979-1990, the erosion rates on the hillslopes could potentially reach 7000 t km-2 yr-1. | ZHANG XinBao BAI XiaoYong LIU XiuMing | 2011 | Science China Earth Sciences2011，54，3： | 14 |
| 3 | Spatiotemporal evolution of carbon sequestration of limestone weathering in China显示文摘Carbonate carbon sequestration(CS) can aid in solving the problem of terrestrial residual carbon sinks and imbalances in the global carbon budget. Thus, complete understanding of the magnitude, spatiotemporal distribution, and evolution of this sequestration is highly desirable. On the basis of random forest regression and maximal potential dissolution model for carbonate, we estimated the CS of typical carbonate weathering in China from 2000 to 2014, that is, the sequestration of limestone weathering, using long-term ecologic, meteorological, hydrological raster data, and monitored data from 44 watersheds in China and surrounding regions. We extended our analyses by systematically exploring the spatiotemporal pattern and evolution trend of the flux and total sequestration. High levels of ionic activity coefficients of Ca^(2+) and HCO_3^- in limestone regions were observed to be mainly distributed in Northern and Northwestern China with a clear gradient from northwest to southeast. With a contrary spatial pattern, the annual average CS flux(CSF) of limestone weathering in China was estimated to be 4.28 t C km^(-2) yr^(-1), with high values mainly in the karst zones in Southeastern China. The mean CSF in different latitudes showed that Southern China(south of 28.14°N) was the region with the largest interannual fluctuation of flux and CSF increases as latitude decreases. The mean CSF in subtropical and tropical(TR) regions was the maximum of all major climate types, and for the frigid(F), mid-temperate(MTE), warm temperate(WTE), and temperate(TE) major climates; the CSF in the desert(D)subdivided climate was the minimum of these climates. By contrast, the values in grassland(G) and broad-leaved forest subdivided climate were the maximum. The pixel-based trend analysis indicated that the CSF of limestone weathering in China was slightly increasing in the period 2000–2014 with a rate of 0.036 t C km^(-2) yr^(-1). Furthermore, the annual total CS was estimated to be 7.07 Tg carbon per year(Tg C yr^(-1)) with high levels in 2002, 2008, and 2010, and the minimum appeared in 2011 with a slightly increasing trend of the total CS being observed with a rate of 0.06 Tg C yr^(-1). Tibet Autonomous Region was the administrative division with the largest total CS of limestone weathering(1.20 Tg C yr^(-1)) in China, and karst zones in Southeastern China had the largest total CS(4.95 Tg C yr^(-1)) which accounts for 70.01% of that in the three divided karst regions. On the basis of the diversity of rock chemical weathering carbon cycle mechanisms of different carbonate rock types, we estimated that the total CS of carbonate weathering in China may reach 11.37 Tg C yr^(-1)(the sink was approximately 5.02 t C km^(-2) yr^(-1)),which amounts to 16.20% of the total biomass CS in China, furthermore, the CSF of carbonate weathering in China can reach6.54 t C km^(-2) yr^(-1) if excluding the interference of the negative runoff. This finding indicates that CS of carbonate weathering is an indispensable part of China's terrestrial carbon sink system. The research pattern of this study was important for further improving the accuracy of the estimation for the global carbonate weathering carbon sink. | Huiwen LI Shijie WANG Xiaoyong BAI Yue CAO Luhua WU | 2019 | Science China Earth Sciences2019，62，6： | 7 |
| 4 | Investigation of seasonal variability of CDOM fluorescence in the southern Changjiang River Estuary by EEM-PARAFAC显示文摘The southern Changjiang River Estuary has attracted considerable attention from marine scientists because it is a highly biologically active area and is biogeochemically significant.Moreover,land-ocean interactions strongly impact the estuary,and harmful algal blooms(HABs) frequently occur in the area.In October 2010 and May 2011,water samples of chromophoric dissolved organic matter(CDOM) were collected from the southern Changjiang River Estuary.Parallel factor analysis(PARAFAC) was used to assess the samples' CDOM composition using excitation-emission matrix(EEM) spectroscopy.Four components were identified:three were humic-like(C1,C2 and C3) and one was protein-like(C4).Analysis based on spatial and seasonal distributions,as well as relationships with salinity,Chl a and apparent oxygen utilization(AOU),revealed that terrestrial inputs had the most significant effect on the three humic-like Components C1,C2 and C3 in autumn.In spring,microbial processes and phytoplankton blooms were also important factors that impacted the three components.The protein-like Component C4 had autochthonous and allochthonous origins and likely represented a biologically labile component.CDOM in the southern Changjiang River Estuary was mostly affected by terrestrial inputs.Microbial processes and phytoplankton blooms were also important sources of CDOM,especially in spring.The fluorescence intensities of the four components were significantly higher in spring than in autumn.On average,C1,C2,C3,C4 and the total fluorescence intensity(TFI) in the surface,middle and bottom layers increased by123%–242%,105%–195%,167%–665%,483%–567% and 184%–245% in spring than in autumn,respectively.This finding corresponded with a Chl a concentration that was 16–20 times higher in spring than in autumn and an AOU that was two to four times lower in spring than in autumn.The humification index(HIX) was lower in spring that in autumn,and the fluorescence index(FI) was higher in spring than in autumn.This result indicated that the CDOM was labile and the biological activity was intense in spring. | BAI Ying SU Rongguo HAN Xiurong ZHANG Chuansong SHI Xiaoyong | 2015 | Acta Oceanologica Sinica2015，34，10： | 3 |
| 5 | Characterization of chromophoric dissolved organic matter(CDOM) in the East China Sea in autumn using excitationemission matrix(EEM) fluorescence and parallel factor analysis(PARAFAC)显示文摘Samples of chromophoric dissolved organic matter(CDOM)in the East China Sea in autumn(October in 2011)were analyzed by excitation emission matrix(EEM)fluorescence spectroscopy combined with parallel factor analysis(PARAFAC).Three terrestrial humic-like components(C1,C2 and C3)and one protein-like component(C4)were identified.Based on spatial distributions,as well as relationships with salinity,the following assignments were made.The three humic-like components(C1,C2 and C3)showed conservative mixing behavior and came mainly from riverine input.The protein-like component(C4)was considered a combination of autochthonous production and terrestrial inputs and a biologically labile component.Path analysis of samples from the middle and bottom layers revealed that the causal effects on C1 were 78.46%for salinity,and 21.54%for apparent oxygen utilization(AOU);those on C2 were 76.43%for salinity,and 23.57%for AOU;those on C3 were70.49%for salinity,7.01%for Chl-a,and 22.50%for AOU;those on C4 were 55.54%for salinity,14.6%for Chl-a,and29.86%for AOU in middle layer;and those on C4 were 57.37%for salinity,29.02%for Chl-a,and 13.61%for AOU in bottom layer.Results indicated that CDOM in the East China Sea was mainly affected by terrestrial inputs,and microbial activities also played a key role in biogeochemical processes of CDOM.The application of the EEM-PARAFAC model presented a unique opportunity to observe compositional changes in CDOM in the East China Sea.In addition,the humification index(HIX)suggested that CDOM from the East China Sea was less stable and stayed shorter in the environment. | BAI Ying SU RongGuo YAN LiHong YAO Peng SHI XiaoYong WANG XiuLin | 2013 | Science China Chemistry2013，56，12： | 3 |
| 6 | Electron-phonon coupling-assisted universal red luminescence of o-phenylenediamine-based carbon dots显示文摘Due to the complex core-shell structure and variety of surface functional groups,the photoluminescence(PL)mechanism of carbon dots(CDs)remain unclear.o-Phenylenediamine(oPD),as one of the most common precursors for preparing red emissive CDs,has been extensively studied.Interestingly,most of the red emission CDs based on oPD have similar PL emission characteristics.Herein,we prepared six different oPD-based CDs and found that they had almost the same PL emission and absorption spectra after purifiication.Structural and spectral characterization indicated that they had similar carbon core structures but diffferent surface polymer shells.Furthermore,single-molecule PL spectroscopy confirmed that the multi-modal emission of those CDs originated from the transitions of different vibrational energy levels of the same PL center in the carbon core.In addition,the phenomenon of'spectral splitting'of single-particle CDs was observed at low temperature,which confirmed these oPD-based CDs were unique materials with properties of both organic molecules and quantum dots.Finally,theoretical calculations revealed their potential polymerization mode and carbon core structure.Moreover,we proposed the PL mechanism of red-emitting CDs based on oPD precursors;that is,the carbon core regulates the PL emission,and the polymer shell regulates the PL intensity.Our work resolves the controversy on the PL mechanism of oPD-based red CDs.These findings provide a general guide for the mechanism exploration and structural analysis of other types of CDs. | Boyang Wang Zhihong Wei Laizhi Sui Jingkun Yu Baowei Zhang Xiaoyong Wang Shengnan Feng Haoqiang Song Xue Yong Yuxi Tian Bai Yang Siyu Lu | 2022 | Light(Science & Applications)2022，11，7： | 2 |
| 7 | A New Indicator for Global Food Security Assessment: Harvested Area Rather Than Cropland Area显示文摘Cropland area has long been used as a key indicator of food security.However,grain yield is not solely controlled by the area of the cropland.Therefore,we proposed a new indicator to assess food security.Results show that from 1992 to 2004,the global cropland area increased by 840200 km^(2)(99.4%),but the grain yield increased only by 310 million t(29.1%);and from 2004 to 2015,the cropland area decreased by 39000 km^(2)(4.64%),but the grain yield increased by 370 million t(70.84%).This result showed that grain yield was not linearly correlated with cropland area,and delimiting the threshold of cropland protection may not guarantee food security.Combined with further correlation analysis,we found that the increase in the global grain yield was more closely related to the harvested area(R^(2)=0.94),which indicated that the harvested area is a more scientific and accurate indicator than cropland area in terms of guaranteeing food security.Therefore,if governments want to ensure the food security,they should choose a new and more accurate indicator:harvested area rather than cropland area. | SONG Fengjiao WANG Shijie BAI Xiaoyong WU Luhua WANG Jinfeng LI Chaojun CHEN Huan LUO Xuling XI Huipeng ZHANG Sirui LUO Guofeng YAN Mengqi ZHEN Qingqing | 2022 | Chinese Geographical Science2022，32，2： | 2 |
| 8 | Rapid estimation of soil heavy metal nickel content based on optimized screening of near-infrared spectral bands显示文摘In near-infrared spectroscopy,the traditional feature band extraction method has certain limitations.Therefore,a band extraction method named the three-step extraction method was proposed.This method combines characteristic absorption bands and correlation coefficients to select characteristic bands corresponding to various spectral forms and then uses stepwise regression to eliminate meaningless variables.Partial least squares regression(PLSR)and extreme learning machine(ELM)models were used to verify the effect of the band extraction method.Results show that the differential transformation of the spectrum can effectively improve the correlation between the spectrum and nickel(Ni)content.Most correlation coefficients were above 0.7 and approximately 20%higher than those of other transformation methods.The model effect established by the feature variable selection method based on comprehensive spectral transformation is only slightly affected by the spectral transformation form.Infive types of spectral transformation,the RPD values of the proposed method were all within the same level.The RPD values of the PLSR model were concentrated between 1.6 and 1.8,and those of the ELM model were between 2.5 and2.9,indicating that this method is beneficial for extracting more complete spectral features.The combination of the three-step extraction method and ELM algorithm can effectively retain important bands associated with the Ni content of the soil.The model based on the spectral band selected by the three-step extraction method has better prediction ability than the other models.The ELM model of the first-order differential transformation has the best prediction accuracy(RP^2=0.923,RPD=3.634).The research results provide some technical support for monitoring heavy metal content spectrum in local soils. | Qian Lu Shijie Wang Xiaoyong Bai Fang Liu Shiqi Tian Mingming Wang Jinfeng Wang | 2020 | Acta Geochimica2020，39，1： | 2 |
| 9 | Global patterns and changes of carbon emissions from land use during 1992e2015显示文摘Carbon emissions from land use(ELUC)are an important part of anthropogenic CO_(2) emissions,but its size and location remain uncertain,and our knowledge of the relationship between ELUC and GDP remains partial.We showed that the carbon emissions directly caused by land use change(direct ELUC)during 1992-2015 was 26.54 Pg C(1.15 Pg C yr^(-1)),with a decreased trend and a net reduction rate of0.15 Pg C yr^(-1).The areas that exhibited reductions were concentrated in South America,Central Africa,and Southeast Asia,and those with increments were scattered in Northwestern North America,Eastern South America,Central Africa,East Asia,and parts of Southeast Asia.For the indirect carbon emissions from the utilization of built-up land(indirect ELUC),it manifested an upward trend with a total emission of 27.51 Pg C(1.2 Pg C yr^(-1)).The total value resulted by global ELUC was $136.3×10^(9) US,and the value of annual was equivalent to 3.7 times the GDP of the Central African Republic in 2015($5.93×10^(9) US yr^(-1)).Among the 79 countries and regions considered in this study,54 represented the upward GDP with increased emissions,and only 25 experienced GDP growth with emission reductions.These findings highlight the pivotal role of land use change in the carbon cycle and the significance of coordinated development between GDP and carbon emissions. | Shiqi Tian Shijie Wang Xiaoyong Bai Guangjie Luo Qin Li Yujie Yang Zeyin Hu Chaojun Li Yuanhong Deng | 2021 | Environmental Science and Ecotechnology2021，，3： | 2 |
| 10 | A joint call for actions to advance taxonomy in China显示文摘Taxonomy plays an important role in understanding the origin, evolution, and ecological functionality of biodiversity. There are large number of unknown species yet to be described by taxonomists, which together with their ecosystem services cannot be effectively protected prior to description. Despite this, taxonomy has been increasingly underrated insufficient funds and permanent positions to retain young talents. Further, the impact factordriven evaluation systems in China exacerbate this downward trend, so alternative evaluation metrics are urgently necessary. When the current generation of outstanding taxonomists retires,there will be too few remaining taxonomists left to train the next generation. In light of these challenges, all co-authors worked together on this paper to analyze the current situation of taxonomy and put out a joint call for immediate actions to advance taxonomy in China. | Chaodong Zhu Arong Luo Ming Bai Michael COrr Zhonge Hou Siqin Ge Jun Chen Yibo Hu Xuming Zhou Gexia Qiao Hongzhi Kong Limin Lu Xiaohua Jin Lei Cai Xinli Wei Ruilin Zhao Wei Miao Qingfeng Wang Zhongli Sha Qiang Lin Meng Qu Jianping Jiang Jiatang Li Jing Che Xuelong Jiang Xiaoyong Chen Lianming Gao Zongxin Ren Chunlei Xiang Shixiao Luo Donghui Wu Dong Liu Yanqiong Peng Tao Su Chenyang Cai Tianqi Zhu Wanzhi Cai Xingyue Liu Hu Li Huaijun Xue Zhen Ye Xuexin Chen Pu Tang Shujun Wei Hong Pang Qiang Xie Feng Zhang Feng Zhang Xianjin Peng Aibing Zhang Taiping Gao Changfa Zhou Chen Shao Libin Ma Zhaoming Wei Yunxia Luan Ziwei Yin Wu Dai Cong Wei Xiaolei Huang Jingxian Liu Xiangsheng Chen Tianci Yi Zhisheng Zhang Zhulidezi Aishan Qin Li Hongying Hu | 2022 | Zoological Systematics2022，47，3： | 1 |
| 11 | The application of caesium-137 measurements to estimate recent sedimentation rates in a typical karst depression of Guizhou Plateau, China显示文摘The existing traditional methods of assessing the rates of soil loss have many limitations and are difficult to apply in the karst areas of Southwest China. Karst depressions comprise geomorphologically important sources and sinks for sediments and associated pollutants, yet the sedimentology of many depressions is not well understood. In this paper, the 137Cs technique was employed to investigate recent sedimentation rates in a Chinese polygonal karst depression. The results indicated that the sediment deposition rates ranged from 0.91 to 1.97 mm?a?1 in the period from 1963 to 2007, and the average sediment deposition rate and specific deposit yield of the catchment were estimated to be 1.47 mm?a?1 and 20 t?km?2?a?1, respectively. The results obtained were consistent with the local monitoring data of runoff plots, confirming the validity of the overall approach. It was shown that soil loss rates were very low in some karst areas of Southwest China. Above all, the approach appears to offer valuable potential to study surface erosion by estimating sediment deposition rates of karst depressions, rather than the assessment of complicated soil erosion in stony soils of carbonate rock slopes. In addition, the spacial distribution of surface soil and 137Cs inventories was affected remarkably by the inhomogeneous dissolution of limestone under the soil. It may be an important phenomenon which exists widely in the karst areas and is significantly different from other places. | BAI Xiaoyong ZHANG Xinbao WANG Shijie | 2011 | Chinese Journal Of Geochemistry2011，30，1： | 1 |
| 12 | A carbon-neutrality-capactiy index for evaluating carbon sink contributions显示文摘The accurate determination of the carbon-neutrality capacity(CNC)of a region is crucial for developing policies related to emissions and climate change.However,a systematic diagnostic method for determining the CNC that considers the rock chemical weathering carbon sink(RCS)is lacking.Moreover,it is challenging but indispensable to establish a fast and practical index model to determine the CNC.Here,we selected Guizhou as the study area,used the methods for different types of carbon sinks,and constructed a CNC index(CNCI)model.We found that:(1)the carbonate rock chemical weathering carbon sink flux was 30.3 t CO_(2)km^(-2)yr^(-1).Guizhou accounted for 1.8%of the land area and contributed 5.4%of the carbonate chemical weathering carbon sink;(2)the silicate rock chemical weathering carbon sink and its flux were 1.44×10^(3)t CO_(2)and 2.43 t CO_(2)km^(-2)yr^(-1),respectively;(3)the vegetation-soil ecosystem carbon sink and its flux were 1.37×10^(8)t CO_(2)and 831.70 t CO_(2)km^(-2)yr^(-1),respectively;(4)the carbon emissions(CEs)were 280 Tg CO_(2),about 2.8%of the total for China;and(5)the total carbon sinks in Guizhou were 160 Tg CO_(2),with a CNCI of 57%,which is 4.8 times of China and 2.1 times of the world.In summary,we conducted a systematic diagnosis of the CNC considering the RCS and established a CNCI model.The results of this study have a strong implication and significance for national and global CNC determination and gap analysis. | Xiaoyong Bai Sirui Zhang Chaojun Li Lian Xiong Fengjiao Song Chaochao Du Minghui Li Qing Luo Yingying Xue Shijie Wang | 2023 | Environmental Science and Ecotechnology2023，，3： | 1 |
| 13 | Soil creeping in the weathering crust of carbonate rocks and underground soil losses in the karst mountain areas of Southwest China显示文摘 | Zhang Xinbao Bai Xiaoyong He Xiubin | 2011 | Carbonates Evaporites2011，26，： | 1 |
| 14 | The relations between land use and karst rocky desertification in a typical karst area,China显示文摘 | Li Yangbing Shao Jingan Bai Xiaoyong | 2009 | Environmental Geology2009，57，3： | 1 |
| 15 | Discrimination of marine algal taxonomic groups based on fluorescence excitation emission matrix, parallel factor analysis and CHEMTAX显示文摘An in vivo three-dimensional fluorescence method for the determination of algae community structure was developed by parallel factor analysis(PARAFAC) and CHEMTAX. The PARAFAC model was applied to fluorescence excitation-emission matrix(EEM) of 60 algae species belonging to five divisions and 11 fluorescent components were identified according to the residual sum of squares and specificity of the composition profiles of fluorescent. By the 11 fluorescent components, the algae species at different growth stages were classified correctly at the division level using Bayesian discriminant analysis(BDA). Then the reference fluorescent component ratio matrix was constructed for CHEMTAX, and the EEM–PARAFAC–CHEMTAX method was developed to differentiate algae taxonomic groups. The correct discrimination ratios(CDRs) when the fluorometric method was used for single-species samples were 100% at the division level, except for Bacillariophyta with a CDR of 95.6%. The CDRs for the mixtures were above 94.0% for the dominant algae species and above 87.0% for the subdominant algae species. However, the CDRs of the subdominant algae species were too low to be unreliable when the relative abundance estimated was less than 15.0%. The fluorometric method was tested using the samples from the Jiaozhou Bay and the mesocosm experiments in the Xiaomai Island Bay in August 2007. The discrimination results of the dominant algae groups agreed with microscopy cell counts, as well as the subdominant algae groups of which the estimated relative abundance was above 15.0%. This technique would be of great aid when low-cost and rapid analysis is needed for samples in a large batch. The fluorometric technique has the ability to correctly identify dominant species with proper abundance both in vivo and in situ. | CHEN Xiaona SU Rongguo BAI Ying SHI Xiaoyong YANG Rujun | 2014 | Acta Oceanologica Sinica2014，33，12： | 0 |
| 16 | Storage, form, and influencing factors of karst inorganic carbon in a carbonate area in China显示文摘Carbonate rock chemical weathering carbon sinks reduce the rate of increase of the atmospheric CO_(2) concentration and global warming. However, uncertainty still exists in the estimation results of carbonate rock chemical weathering carbon sink fluxes(CCSF), and the contributions of climate change and ecological restoration to the CCSF are not clear. To this end, we compiled published site data on ion concentrations in different watersheds in China and used a classical thermodynamic dissolution model to reassess the potential and spatial and temporal patterns of the CCSF in China from 1991 to 2020. We quantified the contributions of temperature(MAT), precipitation(MAP), evapotranspiration(ET), soil water(SM), and the normalized difference vegetation index(NDVI) to the CCSF. The results revealed that(1) China's CCSF was 22.76 t CO_(2)km^(-2)yr^(-1), which was higher than the global average(15.77 t CO_(2)km^(-2)yr^(-1)). The total carbonate rock chemical weathering carbon sink(CCS) was 4772.67×10^(4)t CO_(2), contributing 14.91% of the global CCS through a carbonate rock area of 252.98×10^(4)km^(-2).(2) China's CCSF decreased gradually from southeast to northwest, with values of 33.14, 12.93, and7.27 t CO_(2)km^(-2)yr^(-1)in the southern karst, Qinghai-Tibetan karst, and northern karst regions, respectively.(3) The overall CCSF in China exhibited an increasing trend from 1991 to 2020, with a rate of increase of 0.16 t CO_(2)km^(-2)yr^(-1).(4) The contributions of the MAP, MAT, ET, SM, and NDVI to the CCSF were 63.3%, 3.02%, 27.5%, 3.1%, and 3.05%, respectively. Among them, the increase in precipitation was the main contributor to the increase in the CCSF in China over the last 30 years, while the enhancement of ET offset part of the positive contribution of the increase in precipitation to the CCSF. In conclusion, the results of this study provide a systematic quantification of the magnitude, the patterns, and the influencing factors of CCS over a long time series in China. The results are of great significance and provide a reference for the diagnosis and gap analysis of the national and global carbon neutrality capacities. | Chaochao DU Xiaoyong BAI Yangbing LI Qiu TAN Cuiwei ZHAO Guangjie LUO Luhua WU Fei CHEN Chaojun LI Chen RAN Sirui ZHANG Lian XIONG Fengjiao SONG Biqin XIAO Zilin LI Yingying XUE Mingkang LONG Qing LUO Xiaoyun ZHANG Minghui LI Xiaoqian SHEN Shu YANG | 2024 | Science China Earth Sciences2024，67，3： | 0 |
| 17 | Yangshan A-Type Granites in the Lower Yangtze River Belt Formed by Ridge Subduction:Radiogenic Ca and Nd Isotopic Constraints显示文摘The Early Cretaceous aluminous A-type granites in the Lower Yangtze River belt(LYRB)can provide important insights into the Mesozoic magmatism in eastern China,but their origin remains highly controversial.In this study,radiogenic Ca-Nd isotopic analysis was performed for syenite porphyry and alkali-feldspar granite porphyry of the Yangshan pluton,a typical aluminous A-type granitic intrusion in the LYRB,to constrain its source and geodynamic setting.The results show thatε_(Ca)(126 Ma),ε_(Nd)(126 Ma)and K/Ca_(source) of the syenite porphyry range from-0.24 to+0.96,-7.2 to-6.0,and 0.31 to 1.26,respectively.The corresponding values for the alkali-feldspar granite porphyry range from 0.26 to 0.84,-8.0 to-6.1,and 0.79 to 1.08,respectively.Binary mixing modeling indicates that they were originated from the same sources with different proportion,namely,a mixing of 50%to 75%Neoproterozoic crust and 50%to 25%asthenospheric mantle.Together with previous works,we propose that the Early Cretaceous subduction of the ridge between the Pacific and Izanagi plates was responsible for the formation of the aluminous A-type granites in the LYRB. | Jianghao Bai Mingxing Ling Xiaoyong Yang Fang Liu Huangling Gu Zebin Luo Xiaoyan Jiang Zhaofeng Zhang | 2022 | Journal of Earth Science2022，33，3： | 0 |
| 18 | Message from Editors显示文摘SPECIAL motor systems are high-efficiency and high-quality electromechanical energy conversion devices suitable for complex operating conditions.As key components,special motor systems are widely used in the fields of aerospace,energy,power,transportation,high-end manufacturing,etc.Innovations of fundamental theories and application technologies in special motor systems can promote the progress of related disciplines and fields,which has drawn great attentions from countries all over the world. | Ping Zheng Fengge Zhang Shoudao Huang Deliang Liang Bo Zhou Xiuhe Wang Wei Hua Wenxiang Zhao Xiaoyong Zhu Chengde Tong Jingang Bai Yi Sui Mingqiao Wang | 2022 | CES Transactions on Electrical Machines and Systems2022，6，1： | 0 |
| 19 | Hyperspectral estimation model of soil Pb content and its applicability in different soil types显示文摘In order to obtain Pb content in soil quickly and efficiently,a multivariate linear regression(MLR) and a principal component regression(PCR) Pb content estimation model were established on the basis of hyperspectral techniques,and their applicability in different soil types was evaluated.Results indicated that Pb exhibited strong spatial heterogeneity in the study area,and more than 82% of the samples exceeded the background value.In addition,the pollution range was large.Pb was sensitive in the nearinfrared band,and the correlation of absorbance(AB) was most significant of all the transformed forms.Both models achieved optimal stability and reliability when AB was used as an independent variable.Compared with the PCR model,the stability,fitting accuracy,and predictive power of the MLR model were superior with a coefficient of determination,root mean square error,and mean relative error of 0.724%,24.92%,and 28.22%,respectively.Both models could be applied to different soil types;however,MLR had better applicability compared with PCR.The PCR model that distinguished different soil types had better reliability than one that did not.Thus,the model established via hyperspectral techniques can achieve largearea,rapid,and efficient soil Pb content monitoring,which can provide technical support for the treatment of heavy metal pollution in soil. | Shiqi Tian Shijie Wang Xiaoyong Bai Dequan Zhou Qian Lu Mingming Wang Jinfeng Wang | 2020 | Acta Geochimica2020，39，3： | 0 |
| 20 | Oil droplet movement and micro-flow characteristics during interaction process between gas bubble and oil droplet in flotation显示文摘Flotation is an efficient pre-treatment technology for oily water.In this work,the interaction process between the moving oil droplet and the gas bubble was studied by high-speed camera and Bassset-Boussinesq-Oseen(BBO)theoretical model,and the experimental and simulation results of the oil droplet trajectory were compared.Moreover,the micro-particle image velocimetry system was utilized to observe the flow inside and outside of the moving oil droplet.The results show that the BBO model with the mobile bubble’s surface can reflect the velocity change trend of the oil droplet during the interaction process between the moving oil droplet and the gas bubble,but there are some significant differences between the experimental and simulation results.While the oil droplet is moving on the bubble’s surface,the velocity of the area near the contact point of oil droplet–gas bubble is less than that of the other areas inside the oil droplet.Meanwhile,the flow of water above the oil drop is more biased towards the gas bubble. | Shenglin Yan Yan Zhang Chong Peng Xiaoyong Yang Yuan Huang Zhishan Bai Xiao Xu | 2022 | Chinese Journal of Chemical Engineering2022，35，5： | 0 |
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