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| 1 | The uptake diversity of soil nitrogen nutrients by main plant species in Kobresia humilis alpine meadow on the Qinghai-Tibet Plateau显示文摘We studied the uptake of ammonium,nitrate,and a variety of amino acids by alpine plant species in the Kobresia humilis alpine meadow ecosystem in situ.We examined the extent of niche separation in uptake of N source by different plant species in alpine communities,and investigated the contribution of symbiotically fixed N to the total N in alpine meadow.The results are(1) δ 15 N natural abundance values of 13 plant species lie between 2.680‰ and 5.169‰,and the scope is 7.849‰.(2) Leguminous plants,such as Trigonella ruthenica,Gueldenstaedtia diversiffolia,and Oxytyopis ochrocephala,and non-leguminous plant Gentiana straminea uptake low amounts of 15 N labeled ammonium,nitrate,glycine or aspartate in soil.(3) As far as the plant uptake of organic N is concerned,Kobresia humilis,Poa pratensis,and Gentiuna spathutifolta can effectively uptake organic nitrogen,and about 37%-40% of the nitrogen of these species comes from soil organic nitrogen sources(such as glycine and aspartate).Stipa aliena can effectively uptake nitrate,and 60% of its nitrogen comes from soil nitrate.Potentilla anserina,Poa pratensis,and Thalictrum alpinum can effectively absorb ammonium in comparason to other plant species in the meadow,and about 25%-27% of the nitrogen in these plants comes from soil ammonium.(4) The contribution of leguminous fixed N to total N is 7.48%-9.26% in Kobresia humilis alpine meadow.(5) These data show many plant species of alpine meadow may effectively utilize dissolved organic nitrogen such as amino acids,and these plants have diverse ways to uptake soil nitrogen in alpine meadows.Based on the results we can partly explain why there are abundant biodiversities and how plants at alpine habitat utilize the limited soil N sources. | WANG WenYing MA YongGui XU Jin WANG HuiChun ZHU JinFu ZHOU HuaKun | 2012 | Science China Earth Sciences2012，55，10： | 13 |
| 2 | QTL mapping for flour and noodle colour components and yellow pigment content in common wheat显示文摘 | Yelun Zhang Yunpeng Wu Yonggui Xiao Zhonghu He Yong Zhang Jun Yan Yan Zhang Xianchun Xia Chuanxi Ma | 2009 | Euphytica2009，，3： | 1 |
| 3 | Infl uence of sequential tropical cyclones on phytoplankton blooms in the northwestern South China Sea显示文摘Upper ocean responses to the passage of sequential tropical cyclones over the northwestern South China Sea(SCS)in 2011 were investigated using satellite remote sensing data,Argo reanalysis data,and an array of mooring data.We found that the sea surface low temperature region lasted for more than 38 days and two phytoplankton blooms occurred after the passage of sequential tropical cyclones.The upper ocean cooling reached 2–5°C with a right-side bias was observed along the typhoon track to about 200 km.The maintenance of low temperature region and the two phytoplankton blooms were mainly driven by upwelling and near-inertial turbulence mixing induced by the sequential tropical cyclones.The fi rst phytoplankton bloom appeared on the 7 th day after the passage of the three tropical cyclones,and the chlorophyll-a(chl-a)concentration increased by 226%,which may be mainly driven by typhoons induced upwelling.The second phytoplankton bloom occurred on the 30 th day,the chl-a concentration increased by 290%.Further analysis suggested that only the typhoons with similar characteristics as Nesat and Nalgae can induce strong near-inertial oscillation(NIO).Strong turbulent mixing associated with the near-inertial baroclinic shear instability lasted for 26 days.The measured mean eddy diff usivity in the upper ocean was above 10-4 m 2/s after typhoon Nesat.Enhancement of the turbulent mixing in the upper ocean helped to transport nutrient-rich cold waters from the deep layer to the euphotic layer,and is a major mechanism for the long-term maintenance of low temperature region as well as the second phytoplankton bloom. | Tongyu WANG Shuwen ZHANG Fajin CHEN Yonggui MA Chen JIANG Jie YU | 2021 | Journal of Oceanology and Limnology2021，39，1： | 1 |
| 4 | Two-dimen- sional volume of fluid simulation studies on single bubble formation and dynamics in bubble columns 显示文摘 | MA Dou LIU Mingyan ZU Yonggui | 2012 | Chemi- cal Engineering Science2012，72，： | 1 |
| 5 | Improving long-term temperature bias stability of an integrated optical gyroscope employing a Si_(3)N_(4)resonator显示文摘The presence of polarization noise generated by the waveguide resonator limits the performance of a resonant integrated optical gyroscope(RIOG).Using silicon nitride(Si_(3)N_(4))to fabricate a waveguide with an ultralowaspect-ratio can result in a resonator that only supports light transmission in a single-polarization state,suppressing polarization noise.We successfully fabricated a Si_(3)N_(4)resonator with a bending radius of 17.5 mm,a finesse(F)of 150,a quality factor(Q)of 1.54×10^(7),and a propagation loss of 1.2 d B/m.The Si_(3)N_(4)resonator was used to construct a double closed-loop RIOG that showed long-term bias stability(3600 s)of 13.2°/h at room temperature,14.8°/h at 40℃,21.2°/h at 50℃,and 23.6°/h at 60℃.We believe this to be the best performance reported to date for a Si_(3)N_(4)resonator-based RIOG.This advancement paves the way for the wider application of RIOGs. | CHANGKUN FENG YONGGUI ZHANG HONGHAO MA HUI LI LISHUANG FENG | 2022 | Photonics Research2022，10，7： | 0 |
| 6 | Upper ocean near-inertial response to the passage of two sequential typhoons in the northwestern South China Sea显示文摘Fifty-seven days of moored current records are examined, focusing on the sequential passage of Typhoons Nesat and Nalgae separated by 5 days in the northwestern South China Sea. Both typhoons generated strong near-inertial waves(NIW) as detected by a moored array, with the near-inertial velocity to the right of the typhoon path significantly larger than to the left. The estimated vertical phase and group velocities of the NIW induced by Typhoon Nesat are 0.2 cm s^(-1) and 0.85 m h^(-1), respectively,corresponding to a vertical wavelength of 350 m. Both the vertical phase and group velocities of the NIW induced by Typhoon Nalgae are lower than those of Typhoon Nesat, with the corresponding vertical wavelength only one-half that of Nesat. The threshold values of induced near-inertial kinetic energy(NIKE) of 5 J m^(-3) reach water depths of 300 and 200 m for Typhoons Nesat and Nalgae, respectively, illustrating that the NIKE induced by Typhoon Nesat dissipated less with depth. Obvious blueshifts in the induced NIW frequencies are also detected. The frequency of NIW induced by Typhoon Nesat significantly increases at water depths of 100–150 m because of Doppler shifting, but decreases significantly at water depths of 100–150 m for Nalgae because of the greater influence of the background vorticity during the passage of Typhoon Nalgae. | Yonggui MA Shuwen ZHANG Yiquan QI Zhiyou JING | 2019 | Science China Earth Sciences2019，62，5： | 0 |
| 7 | Alloying engineering for thermoelectric performance enhancement in p-type skutterudites with synergistic carrier concentration optimization and thermal conductivity reduction显示文摘The enhancements in thermoelectric(TE)performances of p-type skutterudites are usually limited due to the relatively low Seebeck coefficients owing to the higher carrier concentration and more impurity phases induced by inherent structural instability of a Fe-based skutterudite.As shown in this study,alloying engineering of Ni doping at Fe sites in a p-type CeFe_(3.8)Co_(0.2)Sb_(12)skutterudite can not only reduce the impurity phases with high thermal conductivity but also regulate the carrier concentration,and thus significantly increase the Seebeck coefficient.The thermal conductivity was largely suppressed due to the enhanced point defect phonon scattering and decreased hole concentration.As a result,a TE figure of merit ZT of the CeFe_(3.5)Ni_(0.3)Co_(0.2)Sb_(12)sample reached 0.8,which is approximately 50%higher than that of a Ni-free sample.Appropriate Ni doping can maintain a high ZT at a high temperature by controlling the reduction in a band gap.Therefore,a high average ZT close to 0.8 at 650–800 K for CeFe_(3.5)Ni_(0.3)Co_(0.2)Sb_(12)was obtained,which was comparable to or even higher than those of the reported Ce-filled Fe-based skutterudites due to the synergistic optimization of electrical and thermal performances.This study provides a strategy to synergistically optimize electrical–thermal performances of the p-type skutterudites by alloying engineering. | Zhiyuan Liu Yonggui Wang Ting Yang Zuju Ma Huiyan Zhang Hailing Li Ailin Xia | 2023 | Journal of Advanced Ceramics2023，12，3： | 0 |
| 8 | Factors contributing to the oxygen concentration over the Qinghai-Tibetan Plateau and its contribution rate calculation显示文摘A decline in atmospheric oxygen concentration is projected in the 21st century given the background of global warming.The Qinghai-Tibetan Plateau is located at a high altitude,and thus,it faces a hypoxia challenge;however,knowledge of the factors contributing to its atmospheric oxygen concentration is still lacking.Here,we conducted joint observations of ecosystem oxygen production and carbon sinks and near-surface atmospheric oxygen concentrations on the Qinghai-Tibetan Plateau and meteorological elements at Beijing Fangshan Station.Using seasonal differences and statistical methods,we calculated the relative contribution rates of vegetation to changes in atmospheric oxygen concentration.Our results indicate that solar radiation,atmospheric humidity,and ecosystem oxygen consumption and production have a significant impact on the atmospheric oxygen concentration,and the impact shows temporal and spatial differences.Vegetation significantly impacts the oxygen concentration,with a contribution rate of 16.7%–24.5%,which is underestimated in existing research.Our findings provide important insights into the factors that influence atmospheric oxygen concentration and highlight the contribution of vegetation.To better understand the oxygen dynamics of the Qinghai-Tibetan Plateau,we recommend further field observations of soil respiration and vegetation photosynthesis to clarify the contributions of carbon storage,carbon sinks and other factors to the near-surface atmospheric oxygen concentration. | Peijun SHI Ying ZHANG Yanqiang CHEN Wenquan ZHU Xiaokang HU Heyi YANG Lu JIANG Yonggui MA Haiping TANG | 2024 | Science China Earth Sciences2024，67，2： | 0 |
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