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| 1 | Direct synthesis of L10-FePt nanopartides from single-source bimetallic complex and their electrocatalytic applications in oxygen reduction and hydrogen evolution reactions显示文摘L10-FePt nan oparticles(NPs)with high chemical ordering represent effective electrocatalysts to reduce the cost and enhance theircatalytic performanee in fuel cells.A molecular strategy of preparing highly ordered FePt NPs was used by direct pyrolysis of a Fe,Pt-containing bimetallic complex.The resultant L10-FePt NPs had very high crystallinity as reflected by the obvious diffractionpatterns,clear lattice fringes and characteristic X-ray diffraction peaks,etc.Besides,the strong ferromagnetism with room temperaturecoercivity of 27 kOe further confirmed the face-centered tetrag on al(fet)phase in good agreement with the ordered nano structures.TheFePt NPs can be used as electrocatalysts to catalyze oxygen reduction reaction(ORR)in an O2·saturated 0.1 M HClO4 solution andhydrogen evolution reaction(HER)in the 0.5 M H2SO4 electrolyte with much better performance than commercial Pt/C,and showedquite high stability after 10,000 cycles.The strategy utilizing orga no metallic precursors to prepare metal alloy NPs was dem on strated tobe a reliable approach for improving the catalytic efficiency in fuel cells. | Zhengong Meng Fei Xiao Zhuoxun Wei Xuyun Guo Ye Zhu Yurong Liu Guijun Li Zhen-Qiang Yu Minhua Shao Wai-Yeung Wong | 2019 | Nano Research2019,12,12: | 5 |
| 2 | Temporal variability of vertical heat flux in the Makarov Basin during the ice camp observation in summer 2010显示文摘Based on hydrographic data obtained at an ice camp deployed in the Makarov Basin by the 4th Chinese Arctic Research Expedition in August of 2010, temporal variability of vertical heat flux in the upper ocean of the Makarov Basin is investigated together with its impacts on sea ice melt and evolution of heat content in the remnant of winter mixed layer(r WML). The upper ocean of the Makarov Basin under sea ice is vertically stratified. Oceanic heat flux from mixed layer(ML) to ice evolves in three stages as a response to air temperature changes, fluctuating from 12.4 W/m2 to the maximum 43.6 W/m2. The heat transferred upward from ML can support(0.7±0.3) cm/d ice melt rate on average, and daily variability of melt rate agrees well with the observed results. Downward heat flux from ML across the base of ML is much less, only 0.87 W/m2, due to enhanced stratification in the seasonal halocline under ML caused by sea ice melt, indicating that increasing solar heat entering summer ML is mainly used to melt sea ice, with a small proportion transferred downward and stored in the r WML. Heat flux from ML into r WML changes in two phases caused by abrupt air cooling with a day lag. Meanwhile, upward heat flux from Atlantic water(AW) across the base of r WML, even though obstructed by the cold halocline layer(CHL), reaches0.18 W/m2 on average with no obvious changing pattern and is also trapped by the r WML. Upward heat flux from deep AW is higher than generally supposed value near 0, as the existence of r WML enlarges the temperature gradient between surface water and CHL. Acting as a reservoir of heat transferred from both ML and AW, the increasing heat content of r WML can delay the onset of sea ice freezing. | GUO Guijun SHI Jiuxin JIAO Yutian | 2015 | Acta Oceanologica Sinica2015,34,11: | 1 |
| 3 | Summer freshwater content variability of the upper ocean in the Canada Basin during recent sea ice rapid retreat显示文摘Freshwater content (F W C) in the Arctic Ocean has changed rapidly in recent years, in response to significant decreases in sea ice extent. Research on freshwater content variability in the Canada Basin, the main storage area of fresh water is very important to understand the input-output freshwater in the Arctic Ocean. The F W C in the Canada Basin was calculated using data from the Chinese National Arctic Research Expeditions of 2003 and 2008, and from expeditions of the Canadian icebreaker Louis S. St-Laurent (LSSL) from 2004 to 2007. Results show that the upper ocean in the Canada Basin became continuously fresher from 2003 to 2008, except during 2006. The F W C increased at a rate of more than 1 m · a 1 , and the maximum increase, 7 m, was in the central basin compared between 2003 and 2008. Variability of the F W C was almost entirely limited to the layer above the winter Bering Sea Water (wBSW), below which the F W C remained around 3 m during the study period. Contributors to the F W C increase are generally considered to be net precipitation, runoff changes, Pacific water inflow through the Bering Strait, sea ice extent, and the Arctic Oscillation(AO). However, we determined that the first three contributors did not have apparent impact on the F W C changes. Therefore, this paper focuses on analysis of the latter two factors and the results indicate that they were the major contributors to the F W C variability in the basin. | GUO GuiJun SHI JiuXin ZHAO JinPing JIAO YuTian XU Dong | 2011 | Advances in Polar Science2011,22,3: | 1 |
| 4 | Deformation characteristics of rock salt with mudstone interbeds sur- rounding gas and oil storage cavern 显示文摘 | Guijun Wang Kangmei Guo Mark Christianson | 2011 | International Journal of Rock Mechanics and Mining Sciences2011,48,6: | 1 |
| 5 | The impact of COVID-19 on China’s regional economies and industries显示文摘Scientifically assessing the economic impact of major public health emergencies,containing their negative effects,and enhancing the resilience of an economy are important national strategic needs.The new coronavirus disease(COVID-19)has,to date,been effectively contained in China,but the threat of imported cases and local risks still exist.The systematic identification of the virus’s path of influence and intensity is significant for economic recovery.This study is based on a refined multi-regional general equilibrium analysis model,which measures the economic and industrial impacts at different epidemic risk levels in China and simulates development trends and the degree of damage to industries and the economy under changes to supplies of production materials and product demand.The results show that,at the macroeconomic level,China’s GDP will decline about 0.4%to 0.8%compared to normal in 2020,with an average drop of about 2%in short-term consumption,an average drop in employment of about 0.7%,and an average increase in prices of about 0.9%.At the industry level,the epidemic will have the greatest short-term impact on consumer and laborintensive industries.For example,the output value of the service industry will fall 6.3%compared to normal.Looking at the impact of the epidemic on the industrial system,the province most affected by the epidemic is Hubei,which is the only province in China in the level-1 risk category.As the disease spread outward from Hubei,there were clear differences in the main industries that were impacted in different regions.In addition,simulation results of recovery intensity of regional economies under the two epidemic response scenarios of resumption of work and production and active fiscal stimulus policies show that an increase in fiscal stimulus policies produces a 0.3%higher rate of gross regional product growth but it causes commodity prices to rise by about 1.8%.Measures to resume work and production offer a wider scope for industrial recovery. | WU Feng LIU Guijun GUO Naliang LI Zhihui DENG Xiangzheng | 2021 | Journal of Geographical Sciences2021,31,4: | 1 |
| 6 | Chinese investigation and research in Southern Ocean physical oceanography and meteorology during the Chinese Polar Programs 2011–2015显示文摘Within the context of developing a research presence in the Antarctic region, the first phase of the Chinese Polar Programs covered the period 2011–2015, which almost coincided with the 12 th Five-Year Plan(2011–2015). For the promotion of full understanding of the progress of Chinese expeditions and research in Antarctica, the observations and achievements of cruises during 2011–2015 are summarized in this paper. Four Antarctic cruises(28th–31st) were performed in the Prydz Bay and Antarctic Peninsula regions during the first phase of the Polar Programs. These cruises performed systemic collections of physical oceanographic and meteorological data to support further research on the ice–ocean–atmosphere interactions in Antarctica. Overall, 248 CTD/LADCP stations, 66 microstructure profiles, 507 XBT/XCTDs, 181 air sounding balloons, 58000 total gaseous mercury(TGM) concentrations, 452 aerosol samples, 294 atmospheric samples, 11 moorings, and 28 surface drifters were acquired or deployed during the four cruises. Using these extensive observations and other data, Chinese scientists have achieved new recognition in the fields of Southern Ocean physical oceanography and meteorology, as well as in other interdisciplinary subjects. These studies, which have been associated with scientific techniques, instrumentation, ocean circulation, water mass formation, energy transformation, and carbon uptake, have elucidated the dynamic mechanisms and potential effects of climate change in Antarctica. Finally, some observations based on experience gained during previous Chinese Antarctic Research and Expedition campaigns are summarized with advice for the improvement of future investigations in the Antarctic region. | GAO Libao WEI Zexun GUO Guijun SHI Jiuxin | 2016 | Advances in Polar Science2016,27,4: | 1 |
| 7 | Potential suitable sites for the calibration of Scientific Echo Sounder in the marginal seas around Antarctica显示文摘The in situ calibration of Scientific Echo Sounders(SESs)in the Southern Ocean is crucial for accurate assessments of Antarctic krill and fishery biomasses.Because of the occurrence of strong winds,waves,and sea ice coverage in most seasons,SES calibration is usually difficult to perform in the Southern Ocean.Accordingly,it is essential to identify potential sites suitable for SES calibration in the marginal seas around Antarctica to successfully calibrate SESs in the Southern Ocean.Using synthetic analyses of the wind,surface current,and sea ice concentration in the targeted seas,we found that the polynya in the southeast Prydz Bay,close to the Chinese Zhongshan Station,is an ideal location to calibrate SESs based on its weak wind and surface current and its ice-free coverage during Antarctic cruises.Calibrations of the SESs onboard the research vessels of Xuelong and Xuelong 2 during the 36th and 37th Chinese National Antarctic Research Expeditions indicate that this location is a potential suitable site for conducting SES calibration with the vessel in a drifting mode. | CHEN Qingman GUO Guijun LUO Guangfu HE Jianfeng | 2022 | Advances in Polar Science2022,33,1: | 1 |
| 8 | Turbulent mixing in the upper ocean of the northwestern Weddell Sea, Antarctica显示文摘Turbulent mixing in the upper ocean(30-200 m) of the northwestern Weddell Sea is investigated based on profiles of temperature,salinity and microstructure data obtained during February 2014.Vertical thermohaline structures are distinct due to geographic features and sea ice distribution,resulting in that turbulent dissipation rates(ε) and turbulent diffusivity(K) are vertically and spatially non-uniform.On the shelf north of Antarctic Peninsula and Philip Ridge,with a relatively homogeneous vertical structure of temperature and salinity through the entire water column in the upper 200 m,both ε and K show significantly enhanced values in the order of O(10^(-7))-O(10^(-6)) W/kg and O(10^(-3))-O(10^(-2)) m^2/s respectively,about two or three orders of magnitude higher than those in the open ocean.Mixing intensities tend to be mild due to strong stratification in the Powell Basin and South Orkney Plateau,where s decreases with depth from O(10^(-8)) to O(10^(-9)) W/kg,while K changes vertically in an inverse direction relative to s from O(10^(-6)) to O(10^(-5)) m^2/s.In the marginal ice zone,K is vertically stable with the order of10^(-4) m^2/s although both intense dissipation and strong stratification occur at depth of 50-100 m below a cold freshened mixed layer.Though previous studies indentify wind work and tides as the primary energy sources for turbulent mixing in coastal regions,our results indicate weak relationship between K and wind stress or tidal kinetic energy.Instead,intensified mixing occurs with large bottom roughness,demonstrating that only when internal waves generated by wind and tide impinge on steep topography can the energy dissipate to support mixing.In addition,geostrophic current flowing out of the Weddell Sea through the gap west of Philip Passage is another energy source contributing to the local intense mixing. | GUO Guijun SHI Jiuxin JIAO Yutian | 2016 | Acta Oceanologica Sinica2016,35,3: | 1 |
| 9 | Physical Activity,Sedentary Behavior,and the Risk of Cardiovascular Disease in Type 2 Diabetes Mellitus Patients:The MIDiab Study显示文摘The aim of this study was to explore the associations of moderate-to-vigorous-intensity physical activity(MVPA)time and sedentary(SED)time with a history of cardiovascular disease(CVD)and multifactorial(i.e.,blood pressure(BP),body mass index(BMI),low-density lipoprotein cholesterol(LDL-C),and glycated hemoglobin A1c(HbA1c))control status among type 2 diabetes mellitus(T2DM)patients in China.A cross-sectional analysis of 9152 people with type 2 diabetes from the Multifactorial Intervention on Type 2 Diabetes(MIDiab)study was performed.Patients were grouped according to their self-reported MVPA time(low,<150 min·week−1;moderate,150 to<450 min·week−1;high,≥450 min·week−1)and SED time(low,<4 h·d–1;moderate,4 to<8 h·d–1;high,≥8 h·d–1).Participants who self-reported a history of CVD were identified as having a CVD risk.Odds ratios(ORs)and 95%confidence intervals(CIs)of CVD risk and multifactorial control status associated with MVPA time and SED time were estimated using mixed-effect logistic regression models,adjusting for China’s geographical region characteristics.The participants had a mean±standard deviation(SD)age of(60.87±8.44)years,44.5%were women,and 25.1%had CVD.After adjustment for potential confounding factors,an inverse association between high MVPA time and CVD risk that was independent of SED time was found,whereas this association was not observed in the moderate-MVPA group.A higher MVPA time was more likely to have a positive effect on the control of BMI.Compared with the reference group(i.e.,those with MVPA time≥450 min·week−1 and SED time<4 h·d–1),CVD risk was higher in the low-MVPA group:The OR associated with an SED time<4 h·d–1 was 1.270(95%CI,1.040–1.553)and that associated with an SED time≥8 h·d–1 was 1.499(95%CI,1.149–1.955).We found that a high MVPA time(i.e.,≥450 min·week−1)was associated with lower odds of CVD risk regardless of SED time among patients with T2DM. | Yafei Wu Guijun Qin Guixia Wang Libin Liu Bing Chen Qingbo Guan Zhongshang Yuan Xu Hou Ling Gao Chao Xu Haiqing Zhang Xu Zhang Qiu Li Yongfeng Song Fei Jing Shizhan Ma Shanshan Shao Meng Zhao Qingling Guo Nanwei Tong Hongyan Zhao Xiaomin Xie Chao Liu Zhongyan Shan Zhifeng Cheng Xuefeng Yu Shulin Chen Tao Yang Yangang Wang Dongmei Li Zhaoli Yan Lixin Guo Qiuhe Ji Wenjuan Wang Jiajun Zhao | 2023 | Engineering2023,,1: | 1 |
| 10 | Turbulent mixing above the Atlantic Water around the Chukchi Borderland in 2014显示文摘This study presents an analysis of the CTD data and the turbulent microstructure data collected in 2014, the turbulent mixing environment above the Atlantic Water(AW) around the Chukchi Borderland region is studied.Surface wind becomes more efficient in driving the upper ocean movement along with the rapid decline of sea ice,thus results in a more restless interior of the Arctic Ocean. The turbulent dissipation rate is in the range of4.60×10^(–10)^(–3.31×10^(–9) W/kg with a mean value of 1.33×10^(–9) W/kg, while the diapycnal diffusivity is in the range of1.45×10^(–6)–1.46×10^(–5)m^2/s with a mean value of 4.84×10^(–6) m^2/s in 200–300 m(above the AW). After investigating on the traditional factors(i.e., wind, topography and tides) that may contribute to the turbulent dissipation rate, the results show that the tidal kinetic energy plays a dominating role in the vertical mixing above the AW. Besides, the swing of the Beaufort Gyre(BG) has an impact on the vertical shear of the geostrophic current and may contribute to the regional difference of turbulent mixing. The parameterized method for the double-diffusive convection flux above the AW is validated by the direct turbulent microstructure results. | ZHONG Wenli GUO Guijun ZHAO Jinping LI Tao WANG Xiaoyu MU Longjiang | 2018 | Acta Oceanologica Sinica2018,37,3: | 1 |
| 11 | Simulated Reflectance of Apple Trees in Canopy Level Based on the PROSAIL Model and HJ-1A-HSI Data显示文摘Using the PROSAIL radiation transfer model and HJ-1A-HSI data to simulate the canopy reflectivity of apple trees, this study lays the foundation for the inversion of canopy parameters. Taking Qixia City of Yantai City, Shandong Province as the research area, the apple tree was taken as the research object, and the hyperspectral reflectance, LAI and sample GPS of apple canopy were measured in the field. The parameters required for the PROSAIL model were obtained by experimental methods. The model simulates the reflectivity;the HSI image data is preprocessed, and the canopy reflectivity is extracted by GPS coordinates. The PROSAIL model and the HSI image simulated reflectance were fitted to the measured apple canopy reflectivity. The decisive factor (R2) of the simulated reflectance and the measured reflectance of the PROSAIL model was 0.9944, and the relative error (RE%)was 0.1845. The HSI data simulated reflectance and measured reflectance. The coefficient of determination is 0.9714 and the relative error is 0.6202. Both have achieved good fitting effects and can be used for inversion studies of apple canopy parameters. | Xiaoyan Guo Xicun Zhu Jingling Xiong Ruiyang Yu Xueyuan Bai Yuanmao Jiang Dongsheng Gao Guijun Yang | 2019 | 遥感科学(中英文版)2019,7,1: | 0 |
| 12 | Seasonal variation of mesoscale eddy intensity in the global ocean显示文摘Mesoscale eddies are a prominent oceanic phenomenon that plays an important role in oceanic mass transport and energy conversion.Characterizing by rotational speed,the eddy intensity is one of the most fundamental properties of an eddy.However,the seasonal spatiotemporal variation in eddy intensity has not been examined from a global ocean perspective.In this study,we unveil the seasonal spatiotemporal characteristics of eddy intensity in the global ocean by using the latest satellite-altimetry-derived eddy trajectory data set.The results suggest that the eddy intensity has a distinct seasonal variation,reaching a peak in spring while attaining a minimum in autumn in the Northern Hemisphere and the opposite in the Southern Hemisphere.The seasonal variation of eddy intensity is more intense in the tropical-subtropical transition zones within latitudinal bands between 15°and 30°in the western Pacific Ocean,the northwestern Atlantic Ocean,and the eastern Indian Ocean because baroclinic instability in these areas changes sharply.Further analysis found that the seasonal variation of baroclinic instability precedes the eddy intensity by a phase of 2–3 months due to the initial perturbations needing time to grow into mesoscale eddies. | Yongcan Zu Yue Fang Shuangwen Sun Libao Gao Yang Yang Guijun Guo | 2024 | Acta Oceanologica Sinica2024,43,1: | 0 |
| 13 | Characteristics of hydrogen/oxygen isotopes in water masses and implications for spatial distribution of freshwater in the Amundsen Sea,Southern Ocean显示文摘Antarctica’s marginal seas are of great importance to atmosphere-ocean-ice interactions and are sensitive to global climate change.Multiple factors account for the freshwater budget in these regions,including glacier melting,seasonal formation/decay of sea ice,and precipitation.Hydrogen(H)and oxygen(O)isotopes represent useful proxies for determining the distribution and migration of water masses.We analyzed the H and O isotopic compositions of 190 seawater samples collected from the Amundsen Sea during the 34th Chinese Antarctic Research Expedition in 2017/2018.The upper-oceanic structure(<400 m)and freshwater(meteoric water and sea ice melt)distribution in the Amundsen Sea were identified based on conductivity-temperature-depth data and the H and O isotopic composition.Antarctic Surface Water,characterized as cold and fresh with low H and O isotopic ratios,was found distributed mainly in the upper~150 m between the Antarctic Slope Front and Polar Front,where it had been affected considerably by upwelled Upper Circumpolar Deep Water(UCDW)between 68°S and 71°S.A three-endmember(meteoric water,sea ice melt,and Circumpolar Deep Water)mixing model indicated that waters with relatively high proportions(>3%)of freshwater generally lie in the upper~50 m and extend from Antarctica to~65°S in the meridional direction(anomalously low freshwater proportion occurred between 68°S and 71°S).Winter Water mainly occupied the layer between 50 and 150 m south of 71°S in the western Amundsen Sea.The water structure and spatial distribution of freshwater in the upper Amundsen Sea were found influenced mainly by the rates of basal and surficial melting of ice shelves,seasonal alternation of sea ice melt/formation,wind forcing,and regional bathymetry.Owing to the distance between heavy sea ice boundary(HSIB)and ice shelves is much shorter in the western HSIB than the east HSIB,the western part of the heavy sea ice boundary includes a higher proportion of freshwater than the eastern region.This study,which highlighted the distribution and extent of freshwater derived from ice(ice shelves and sea ice)melt,provides important evidence that the offshore drift pathway of cold and fresh Antarctic continental shelf water is likely interrupted by upwelled UCDW in the Amundsen Sea. | SHAO Hebin HE Jianfeng LUO Guangfu LAN Musheng YU Lejiang GUO Guijun LIAN Ergang | 2021 | Advances in Polar Science2021,32,3: | 0 |