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8篇 您的检索式:作者名="MA Changkun"
    题名 作者 年代 出处 被引量
1Impact of climate change on the streamflow in the glacierized Chu River Basin, Central Asia显示文摘Catchments dominated by meltwater runoff are sensitive to climate change as changes in precipitation and temperature inevitably affect the characteristics of glaciermelt/snowmelt, hydrologic circle and water resources. This study simulated the impact of climate change on the runoff generation and streamflow of Chu River Basin(CRB), a glacierized basin in Central Asia using the enhanced Soil and Water Assessment Tool(SWAT). The model was calibrated and validated using the measured monthly streamflow data from three discharge gauge stations in CRB for the period 1961–1985 and was subsequently driven by downscaled future climate projections of five Global Circulation Models(GCMs) in Coupled Model Inter-comparison Project Phase 5(CMIP5) under three radiative forcing scenarios(RCP2.6, RCP4.5 and RCP8.5). In this study, the period 1966–1995 was used as the baseline period, while 2016–2045 and 2066–2095 as the near-future and far-future period, respectively. As projected, the climate would become warmer and drier under all scenarios in the future, and the future climate would be characterized by larger seasonal and annual variations under higher RCP. A general decreasing trend was identified in the average annual runoff in glacier(–26.6% to –1.0%), snow(–21.4% to +1.1%) and streamflow(–27.7% to –6.6%) for most of the future scenario periods. The projected maximum streamflow in each of the two future scenarios occurred one month earlier than that in the baseline period because of the reduced streamflow in summer months. Results of this study are expected to arouse the serious concern about water resource availability in the headwater region of CRB under the continuously warming climate. Changes in simulated hydrologic outputs underscored the significance of lowering the uncertainties in temperature and precipitation projection.MA Changkun SUN Lin LIU Shiyin SHAO Ming'an LUO Yi 2015Journal of Arid Land2015,7,4:8
2Cow, yak, and camel milk diets differentially modulated the systemic immunity and fecal microbiota of rats显示文摘Cow milk is most widely consumed; however,non-cattle milk has gained increasing interest because of added nutritive values. We compared the health effects of yak,cow,and camel milk in rats. By measuring several plasma immune factors,significantly more interferon-c was detected in the camel than the yak(P = 0.0020) or cow(P = 0.0062) milk group. Significantly more Ig M was detected in the yak milk than the control group(P = 0.0071). The control group had significantly less interleukin 6 than the yak(P = 0.0499)and cow(P = 0.0248) milk groups. The fecal microbiota of the 144 samples comprised mainly of the Firmicutes(76.70 ± 11.03%),Bacteroidetes(15.27 ± 7.79%),Proteobacteria(3.61 ± 4.34%),and Tenericutes(2.61 ± 2.53%) phyla. Multivariate analyses revealed a mild shift in the fecal microbiota along the milk treatment. We further identified the differential microbes across the four groups. At day 14,22 and 28 differential genera and species were identified(P = 0.0000–0.0462),while 8 and 11 differential genera and species(P = 0.0000–0.0013) were found at day 28. Some short-chain fatty acid and succinate producers increased,while certain health-concerned bacteria(Prevotella copri,Phascolarctobacterium faecium,and Bacteroides uniformis) decreased after 14 days of yak or camel milk treatment. We demonstrated that different animal milk could confer distinctive nutritive value to the host.Yongping Wen Qiuwen He Jia Ding Huiyan Wang Qiangchuan Hou Yi Zheng Changkun Li Yuzhu Ma Heping Zhang Lai-Yu Kwok 2017Science Bulletin2017,62,6:4
3Cross-sectional rainfall observation on the central-western Tibetan Plateau in the warm season:System design and preliminary results显示文摘The central and western Tibetan Plateau(CWTP)is characterized by harsh environment and strong interactions among the spheres of earth as well as significant changes in climate and water cycles over the past four decades.The lack of precipitation observations is a bottleneck for the study of land surface processes in this region.Over the past six years,we have designed and established two observation transects across the south-north and the west-east in this region to obtain hourly rainfall data during the warm season(May-September).The south-north transect extends from Yadong Valley on the southern slope of the Himalayas to Shuanghu County in the hinterland of the plateau,with a total of 31stations;the west-east transect extends from Shiquanhe in the west to Naqu in the central TP,with a total of 22 stations.The observation dataset has been applied to clarify the spatiotemporal characteristics of precipitation in the CWTP,to evaluate the quality of typical gridded precipitation products,to support the development of regional climate models,and to reveal the processes of summertime lake-air interactions.The observation dataset has been released in the National Tibetan Plateau Data Center.Kun YANG Yingying CHEN Lazhu Changhui ZHAN Xiaoyan LING Xu ZHOU Yaozhi JIANG Xiangnan YAO Hui LU Xiaogang MA Lin OUYANG Weihao PAN Yanghang REN Changkun SHAO Jiaxin TIAN Yan WANG Hua YANG Siyu YUE Ke ZHANG Dingchi ZHAO Long ZHAO Jianhong ZHOU Mijun ZOU 2023Science China Earth Sciences2023,66,5:0
4Improving 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 2022Photonics Research2022,10,7:0
5Fiber resonator using negative-curvature anti-resonant fiber with temperature stability显示文摘The coupling efficiency of hollow-core fiber changes with temperature,which leads to the decrease of the finesse(F)of fiber resonator and limits the performance of the resonant fiber optic gyroscope(R-FOG)system.Negative-curvature antiresonant fiber(ARF)can maintain single-mode characteristics under the condition of large mode field diameter,achieve efficient and stable fiber coupling,and significantly improve the consistency of the F of the spatial coupling resonator in variable temperature environment.A new type of ARF with a mode field diameter(MFD)of 25μm is used to fabricate a fiber resonator with a length of 5.14 m.In the range of 25℃-75℃,the average F is 31.45.The ARF resonator is used to construct an R-FOG system that shows long-term bias stability(3600 s)of3.1°/h at room temperature,4.6°/h at 75℃.To our knowledge,this is the best reported index of hollow-core fiber resonator and R-FOG system within the temperature variation range of 50℃ test.MA Honghao LI Hui FENG Changkun FENG Lishuang GAO Shoufei WANG Yingying WANG Pu 2022Journal of Systems Engineering and Electronics2022,33,6:0
6Bright semiconductor single-photon sources pumped by heterogeneously integrated micropillar lasers with electrical injections显示文摘The emerging hybrid integrated quantum photonics combines the advantages of different functional components into a single chip to meet the stringent requirements for quantum information processing.Despite the tremendous progress in hybrid integrations of III-V quantum emitters with silicon-based photonic circuits and superconducting single-photon detectors,on-chip optical excitations of quantum emitters via miniaturized lasers towards single-photon sources(SPSs)with low power consumptions,small device footprints,and excellent coherence properties is highly desirable yet illusive.In this work,we present realizations of bright semiconductor SPSs heterogeneously integrated with on-chip electrically-injected microlasers.Different from previous one-by-one transfer printing technique implemented in hybrid quantum dot(QD)photonic devices,multiple deterministically coupled QD-circular Bragg Grating(CBG)SPSs were integrated with electrically-injected micropillar lasers at one time via a potentially scalable transfer printing process assisted by the wide-field photoluminescence(PL)imaging technique.Optically pumped by electrically-injected microlasers,pure single photons are generated with a high-brightness of a count rate of 3.8 M/s and an extraction efficiency of 25.44%.Such a high-brightness is due to the enhancement by the cavity mode of the CBG,which is confirmed by a Purcell factor of 2.5.Our work provides a powerful tool for advancing hybrid integrated quantum photonics in general and boosts the developments for realizing highly-compact,energy-efficient and coherent SPSs in particular.Xueshi Li Shunfa Liu Yuming Wei Jiantao Ma Changkun Song Ying Yu Rongbin Su Wei Geng Haiqiao Ni Hanqing Liu Xiangbin Su Zhichuan Niu You-ling Chen Jin Liu 2023Light(Science & Applications)2023,12,3:0
7Estimation and testing of linkages between forest structure and rainfall interception characteristics of a Robinia pseudoacacia plantation on China’s Loess Plateau显示文摘Understanding the interaction between canopy structure and the parameters of interception loss is essential in predicting the variations in partitioning rainfall and water resources as affected by changes in canopy structure and in implementing water-based management in semiarid forest plantations.In this study,seasonal variations in rainfall interception loss and canopy storage capacity as driven by canopy structure were predicted and the linkages were tested using seasonal filed measurements.The study was conducted in nine 50 m×50 m Robinia pseudoacacia plots in the semiarid region of China’s Loess Plateau.Gross rain-fall,throughfall and stemflow were measured in seasons with and without leaves in 2015 and 2016.Results show that measured average interception loss for the nine plots were 17.9% and 9.4% of gross rainfall during periods with leaves (the growing season) and without leaves, respectively. Average canopy storage capacity estimated using an indirect method was 1.3 mm in the growing season and 0.2 mm in the leafless season. Correlations of relative interception loss and canopy storage capacity to canopy variables were highest for leaf/wood area index (LAI/WAI) and canopy cover, fol-lowed by bark area, basal area, tree height and stand density. Combined canopy cover, leaf/wood area index and bark area multiple regression models of interception loss and canopy storage capacity were established for the growing season and in the leafless season in 2015. It explained 97% and 96% of the variations in relative interception loss during seasons with and without leaves, respectively. It also explained 98% and 99% of the variations in canopy storage capacity during seasons with and without leaves, respectively. The empiri-cal regression models were validated using field data col-lected in 2016. The models satisfactorily predicted relative interception loss and canopy storage capacity during seasons with and without leaves. This study provides greater under-standing about the effects of changes in tree canopy structure (e.g., dieback or mortality) on hydrological processes.Changkun Ma Yi Luo Mingan Shao Xiaoxu Jia 2022Journal of Forestry Research2022,33,2:0
8Adjuvant chemotherapy versus adjuvant concurrent chemoradiotherapy after radical surgery for early-stage cervical cancer:a randomized,non-inferiority,multicenter trial显示文摘We conducted a prospective study to assess the non-inferiority of adjuvant chemotherapy alone versus adjuvant concurrent chemoradiotherapy (CCRT) as an alternative strategy for patients with early-stage (FIGO 2009 stage IB–IIA) cervical cancer having risk factors after surgery. The condition was assessed in terms of prognosis, adverse effects, and quality of life. This randomized trial involved nine centers across China. Eligible patients were randomized to receive adjuvant chemotherapy or CCRT after surgery. The primary end-point was progression-free survival (PFS). From December 2012 to December 2014, 337 patients were subjected to randomization. Final analysis included 329 patients, including 165 in the adjuvant chemotherapy group and 164 in the adjuvant CCRT group. The median follow-up was 72.1 months. The three-year PFS rates were both 91.9%, and the five-year OS was 90.6% versus 90.0% in adjuvant chemotherapy and CCRT groups, respectively. No significant differences were observed in the PFS or OS between groups. The adjusted HR for PFS was 0.854 (95% confidence interval 0.415–1.757;P = 0.667) favoring adjuvant chemotherapy, excluding the predefined non-inferiority boundary of 1.9. The chemotherapy group showed a tendency toward good quality of life. In comparison with post-operative adjuvant CCRT, adjuvant chemotherapy treatment showed non-inferior efficacy in patients with early-stage cervical cancer having pathological risk factors. Adjuvant chemotherapy alone is a favorable alternative post-operative treatment.Danhui Weng Huihua Xiong Changkun Zhu Xiaoyun Wan Yaxia Chen Xinyu Wang Youzhong Zhang Jie Jiang Xi Zhang Qinglei Gao Gang Chen Hui Xing Changyu Wang Kezhen Li Yaheng Chen Yuyan Mao Dongxiao Hu Zimin Pan Qingqin Chen Baoxia Cui Kun Song Cunjian Yi Guangcai Peng Xiaobing Han Ruifang An Liangsheng Fan Wei Wang Tingchuan Xiong Yile Chen Zhenzi Tang Lin Li Xingsheng Yang Xiaodong Cheng Weiguo Lu Hui Wang Beihua Kong Xing Xie Ding Ma 2023Frontiers of Medicine2023,17,1:0
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