维普中文期刊产品整合服务
4篇 您的检索式:作者名="Xiaping Li"
    题名 作者 年代 出处 被引量
1Remediation of saline–sodic soil with flue gas desulfurization gypsum in a reclaimed tidal flat of southeast China显示文摘Salinization and sodicity are obstacles for vegetation reconstruction of coastal tidal flat soils. A study was conducted with flue gas desulfurization(FGD)-gypsum applied at rates of 0, 15, 30, 45 and 60 Mg/ha to remediate tidal flat soils of the Yangtze River estuary.Exchangeable sodium percentage(ESP), exchangeable sodium(ExNa), p H, soluble salt concentration, and composition of soluble salts were measured in 10 cm increments from the surface to 30 cm depth after 6 and 18 months. The results indicated that the effect of FGD-gypsum is greatest in the 0–10 cm mixing soil layer and 60 Mg/ha was the optimal rate that can reduce the ESP to below 6% and decrease soil p H to neutral(7.0). The improvement effect was reached after 6 months, and remained after 18 months. The composition of soluble salts was transformed from sodic salt ions mainly containing Na^+, HCO_3^-+ CO_3^(2-)and Cl-to neutral salt ions mainly containing Ca^(2+)and SO_4^(2-). Non-halophyte plants were survived at 90%. The study demonstrates that the use of FGD-gypsum for remediating tidal flat soils is promising.Yumei Mao Xiaping Li Warren A.Dick Liming Chen 2016Journal of Environmental Sciences2016,28,7:14
2Transcriptional control by HNF-1:Emerging evidence showing its role in lipid metabolism and lipid metabolism disorders显示文摘The present review focuses on the roles and underlying mechanisms of action of hepatic nuclear factor-1(HNF-1)in lipid metabolism and the development of lipid metabolism disorders.HNF-1 is a transcriptional regulator that can form homodimers,and the HNF-1αand HNF-1βisomers can form heterodimers.Both homo-and heterodimers recognize and bind to specific cis-acting elements in gene promoters to transactivate transcription and to coordinate the expression of target lipid-related genes,thereby influencing the homeostasis of lipid metabolism.HNF-1 was shown to restrain lipid anabolism,including synthesis,absorption,and storage,by inhibiting the expression of lipogenesis-related genes,such as peroxisome proliferator-activated receptorγ(PPARγ)and sterol regulatory element-binding protein-1/2(SREBP-1/2).Moreover,HNF-1 enhances the expression of various genes,such as proprotein convertase subtilisin/kexin type 9(PCSK9),glutathione peroxidase 1(GPx1),and suppressor of cytokine signaling-3(SOCS-3)and negatively regulates signal transducer and activator of transcription(STAT)to facilitate lipid catabolism in hepatocytes.HNF-1 reduces hepatocellular lipid decomposition,which alleviates the progression of nonalcoholic fatty liver disease(NAFLD).HNF-1 impairs preadipocyte differentiation to reduce the number of adipocytes,stunting the development of obesity.Furthermore,HNF-1 reduces free cholesterol levels in the plasma to inhibit aortic lipid deposition and lipid plaque formation,relieving dyslipidemia and preventing the development of atherosclerotic cardiovascular disease(ASCVD).In summary,HNF-1 transcriptionally regulates lipid-related genes to manipulate intracorporeal balance of lipid metabolism and to suppress the development of lipid metabolism disorders.Fang Liu Xiao Zhu Xiaping Jiang Shan Li Yuncheng Lv 2022Genes & Diseases2022,9,5:3
3Evaluation of BDS and GPS RAIM availability based on data collected in June 2020显示文摘The satellite pseudo-range fault detection with the Receiver Autonomous Integrity Monitoring(RAIM)method is affected by several satellite observations and the geometric distribution of satellites.The poor geometry distribution of satellites will conceal the positioning errorcaused by the satellite pseudo-range fault,resulting in unreliable detection results.Therefore,the availability evaluation must be made before RAIM to ensure that the fault detection performance will not be affected.On June 23,2020,China successfully launched the 30 th(last)navigation satellite of BeiDou’s third-generation navigation satellite system(BDS-3),which is also the 55 th BeiDou navigation satellite.Combining all the available satellites of BDS-1,BDS-2 and BDS-3,the positioning performance of BDS can be greatly improved.In order to evaluate the RAIM availability of BeiDou Navigation Satellite System(BDS)and Global Positioning System(GPS)in China,this paper first deduces the mathematical models and their characteristics of the three RAIM availability evaluation methods.Then,the study area(N10°-70°,E60°-150°)is divided into 4536 grid points at intervals of 1°×1°in latitude and longitude,and the elevations of these grid points are taken from the global terrain data file.The Horizontal Protection Level(HPL)values of these grid points are calculated during 8-15 June 2020 using BDS and GPS ephemeris data.The RAIM availability differences between the two systems are compared and analysed.The analysis shows the Horizontal Protection Level method(HPLM)based on single-satellite pseudo-range fault is the most practical and convenient.During the 8-day observation period,the HPL values of BDS are significantly smaller than those of GPS in terms of geographic location and observation time,and the variation of HPL time series of BDS is also smaller than that of GPS,which indicates that the RAIM availability of GPS in China is not as good as that of BDS.Most importantly,in the four flight stages of the aircraft’s Oceanic/Continental lowdensity En-route,Continental En-route,Terminal En-route and Non-precision approach(NPA),BDS can completely satisfy its RAIM availability requirement,while GPS can only meet the availability requirement of the En-route(Oceanic/Continental low density)phase,and the availability of the other three phases can at least reach 99.714%.Xiaping Ma Kegen Yu Ershen Wang Xiaoxing He Tieding Lu Qinzhen Li 2021Geodesy and Geodynamics2021,12,3:0
4A 4H-SiC semi-super-junction shielded trench MOSFET: p-pillar is grounded to optimize the electric field characteristics显示文摘A 4H-SiC trench gate metal-oxide-semiconductor field-effect transistor(UMOSFET)with semi-super-junction shiel-ded structure(SS-UMOS)is proposed and compared with conventional trench MOSFET(CT-UMOS)in this work.The advantage of the proposed structure is given by comprehensive study of the mechanism of the local semi-super-junction structure at the bottom of the trench MOSFET.In particular,the influence of the bias condition of the p-pillar at the bottom of the trench on the static and dynamic performances of the device is compared and revealed.The on-resistance of SS-UMOS with grounded(G)and ungrounded(NG)p-pillar is reduced by 52%(G)and 71%(NG)compared to CT-UMOS,respectively.Additionally,gate ox-ide in the GSS-UMOS is fully protected by the p-shield layer as well as semi-super-junction structure under the trench and p-base regions.Thus,a reduced electric-field of 2 MV/cm can be achieved at the corner of the p-shield layer.However,the quasi-intrinsic protective layer cannot be formed in NGSS-UMOS due to the charge storage effect in the floating p-pillar,resulting in a large electric field of 2.7 MV/cm at the gate oxide layer.Moreover,the total switching loss of GSS-UMOS is 1.95 mJ/cm2 and is reduced by 18%compared with CT-UMOS.On the contrary,the NGSS-UMOS has the slowest overall switching speed due to the weakened shielding effect of the p-pillar and the largest gate-to-drain capacitance among the three.The proposed GSS-UMOS plays an important role in high-voltage and high-frequency applications,and will provide a valuable idea for device design and circuit applications.Xiaojie Wang Zhanwei Shen Guoliang Zhang Yuyang Miao Tiange Li Xiaogang Zhu Jiafa Cai Rongdun Hong Xiaping Chen Dingqu Lin Shaoxiong Wu Yuning Zhang Deyi Fu Zhengyun Wu Feng Zhang 2022Journal of Semiconductors2022,43,12:0
返回顶部 每页显示:
共1页 首页 上一页 第1页 下一页 末页 /1 跳转

网站首页 | 关于我们 | 联系我们 | 产品服务 | 客服中心 | 广告服务 | 版权声明 | 网站联盟 | 友情链接 | 售卡网点

版权所有© 渝B2-20050021-1 渝公网安备 50019002500403号 违法和不良信息举报中心

互联网出版许可证 新出网证(渝)字10号 全国400电话 - 免长途话费