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磷酸镁水泥加固低液限粉土的pH和电导率响应与孔隙特征研究

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材料导报 2024年第16期38卷 108-116页

作者：范旭涵王炳楠汤世豪辛星裴妍山东大学土建与水利学院济南250061

为了探究磷酸镁水泥(Magnesium phosphate cement,MPC)对黄河淤积低液限粉土的加固问题,本试验研究不同MPC占干土的掺量、镁磷比(m(M/P))及硼酸与氧化镁比(m(BA/M))对粉土初始pH、电导率的响应;探究选定m(M/P)、m(BA/M)下不同龄期和不同... 详细信息

为了探究磷酸镁水泥(Magnesium phosphate cement,MPC)对黄河淤积低液限粉土的加固问题,本试验研究不同MPC占干土的掺量、镁磷比(m(M/P))及硼酸与氧化镁比(m(BA/M))对粉土初始pH、电导率的响应;探究选定m(M/P)、m(BA/M)下不同龄期和不同MPC掺量固化土的无侧限抗压强度、pH、电导率与水化产物的变化规律,并基于CT扫描技术重构了三种不同MPC掺量下固化土的孔隙网络模型,结合XRD物相分析,揭示其固化机理。结果表明:随着MPC掺量的增加,m(M/P)较小时固化土的初始pH逐渐减小,而m(M/P)较大时pH先增大后减小。MPC掺量和m(M/P)一定时,随着m(BA/M)的增加,pH在m(BA/M)为某一值(2%)时降为最低,随后逐渐增大。考虑到低液限粉土的低用水量与促进后期水化需求,选择偏酸性配比(m(M/P)=1,m(BA/M)=2%)与低于15%MPC掺量较为合适。pH随着龄期和MPC掺量的增加而增加,电导率变化规律则与pH相反,二者呈负指数的关系,且能定性地表征水化情况。力学试验结果表明MPC能使粉土强度大幅提升,龄期与MPC掺量的增加均使固化土的强度增长。XRD与CT扫描结果表明,MPC固化机制为各龄期均出现的鸟粪石和MgO胶结在土粒之间形成交互结构,且随着MPC的掺量增加,土颗粒间的粘结更加紧密,形成的土骨架提升了宏观力学强度,同时扩大孔隙空间,增加了孔隙率,增强了孔隙间的连通性,导致渗透性增大,因此工程应用时可通过改善孔隙结构进一步提升固化性能。

关键词：低液限粉土磷酸镁水泥 pH和电导率无侧限抗压强度孔隙网络模型

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流域生态环境司法专门化:根基、守成与发展

南京工业大学学报（社会科学版） 2024年第1期23卷 82-95,114页

作者：肖爱汤世豪湘潭大学法学院湖南湘潭411105 湖南师范大学法学院湖南长沙410081

流域生态环境具有整体性和区域性、稳定性和动态性、共性与差异性等对立统一特性,这些特性既是自然的,也是社会和人文的,其成为流域生态环境司法专门化产生的制度根基。流域生态环境司法专门化目的在于通过司法保护流域生态环境整体性... 详细信息

流域生态环境具有整体性和区域性、稳定性和动态性、共性与差异性等对立统一特性,这些特性既是自然的,也是社会和人文的,其成为流域生态环境司法专门化产生的制度根基。流域生态环境司法专门化目的在于通过司法保护流域生态环境整体性和系统性,促进流域生态环境司法尺度一致性,提升流域生态环境司法质效。流域生态环境司法专门化应当在守成基础上求发展,全面总结和吸收实践经验,针对其现实不足,坚持系统观念系统思维,以必要性为原则谨慎设置流域生态环境司法专门机构,优化流域生态环境案件集中管辖制度,避免将其混同于“生态环境司法流域化”,实施“程序嵌合式”、有限的“多审合一”审理机制,将司法协作作为流域生态环境司法专门化机制的重要组成部分,不断优化流域生态环境司法专门化运行机制。

关键词：流域生态环境司法专门化集中管辖协作机制

Intraseasonal Variations of Summer Convection over the Tibetan Plateau Revealed by Geostationary Satellite FY-2E in 2010–14

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Journal of Meteorological Research 2019年第3期33卷 478-490页

作者： Bo LI Liu YANG shihao tang National Satellite Meteorological Center China Meteorological Administration Beijing 100081 Key Laboratory of Radiometric Calibration and Validation for Environmental Satellites China Meteorological Administration Beijing 100081 Meteorological Office of Longquanyi District of Chengdu Sichuan Province Chengdu 610100

Based on the infrared black body temperature (TBB) observed by the geostationary meteorological satellite FY-2E from 2010 to 2014, the seasonal migration, occurrence frequency, and intraseasonal variability of summer convection over the Tibetan Plateau (TP) and its surrounding areas are analyzed. The results show that in May, convection mainly occurs over the eastern edge of the TP;in June, following the onset of the Asian summer monsoon, the strongest (severe) convection occurs in the southeastern part of the TP;and in July-August, strong southwesterly winds transport abundant moisture to the eastern and central areas of the TP, leading to formation of an active convection belt over southeastern TP. The results also show that in the western TP, the area with convection frequency greater than 6% occupies the southern plateau around the 37th pentad, and gradually moves northward until the end of July;in the central plateau, convection (severe convection) becomes active since early (mid) June, and maintains through the entire late summer with three major northward movements until reaching 34°N;and in the eastern TP, the convection is relatively active since the beginning of May and its northward stretching is slightly later than that over the central plateau. Overall, summer convective activities are unevenly distributed over the TP, with frequency of convection decreasing from south to north;and they also exhibit considerable intraseasonal variability, the maximum of which is found over the middle reach of the Yarlung Zangbo River and the southeastern plateau. EOF analysis of summer convection frequency over the TP reveals two leading modes, with the first mode being a dipole variation pattern between the Indian monsoon region and the southeastern TP, and the second mode a tripole pattern over the western TP, the Indian continent west of 80°E, and the South Asian continent east of 80°E.

关键词： Tibetan Plateau black body temperature (TBB) severe convection intraseasonal variation

全球204个国家地区1990至2019年尘肺病发病率和患病率的趋势分析

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中华劳动卫生职业病杂志 2024年第2期42卷 123-128页

作者：唐侍豪崔佳欣陈育全麦秋苑张晋蔚王致广州市第十二人民医院广州市职业病防治院广州市第十二人民医院职业环境与健康重点实验室广州510620 中山大学公共卫生学院广州510080

目的分析全球尘肺病发病率和患病率的变化趋势,为卫生政策制定提供科学依据。方法于2022年6月,通过全球健康数据交换(GHDx)查询工具(http://***/gbd-results-tool)下载并整理尘肺病发病率和患病率数据。应用年估计变化百分比(EAPC)和年... 详细信息

目的分析全球尘肺病发病率和患病率的变化趋势,为卫生政策制定提供科学依据。方法于2022年6月,通过全球健康数据交换(GHDx)查询工具(http://***/gbd-results-tool)下载并整理尘肺病发病率和患病率数据。应用年估计变化百分比(EAPC)和年龄标化率(ASR)估算1990至2019年尘肺病的趋势变化。基于ASR应用线性回归模型估算EAPC。结果在1990至2019年间,全球尘肺病发病率和患病率的ASR均呈下降趋势,EAPC分别为-0.85%(95%CI:-1.11%~-0.60%)和-0.78%(95%CI:-1.08%~-0.49%)。1990至2019年,不同社会人口指数(SDI)地区尘肺病发病率和患病率均呈下降趋势,高SDI地区尘肺病发病率和患病率下降速度均最快,EAPC分别为-1.46%(95%CI:-1.76%~ -1.15%)和-1.99%(95%CI:-2.44%~-1.53%)。110个国家/地区的尘肺病年龄标化发病率(ASIR)呈上升趋势,伊朗和格鲁吉亚的ASIR呈上升趋势最明显,EAPC分别为5.32%(95%CI:4.43%~6.22%)和4.39%(95%CI:3.81%~4.97%)。125个国家/地区的尘肺病患病率ASR呈上升趋势,伊朗患病率上升速度最快(EAPC=6.40%,95%CI:5.33%~7.49%)。结论 1990至2019年间,全球尘肺病发病趋势有所下降,但一些中低收入国家地区尘肺病负担沉重,需要更有效的策略来预防和减轻尘肺病所带来的负担。

关键词：尘肺病全球疾病负担年估计变化百分比年龄标化率

Vegetation Products Derived from Fengyun-3D Medium Resolution Spectral Imager-Ⅱ

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Journal of Meteorological Research 2020年第4期34卷 775-785页

作者： Xiuzhen HAN Jun YANG shihao tang Yang HAN National Satellite Meteorological Center China Meteorological AdministrationBeijing 100081

The surface vegetation condition has been operationally monitored from space for many years by the Advanced Very High Resolution Radiometer(AVHRR) and the Moderate Resolution Imaging Spectroradiometer(MODIS) instruments. As these instruments are close to the end of their design life, the surface vegetation products are required by many users from the new satellite missions. The MEdium Resolution Spectral Imager-Ⅱ(MERSI-Ⅱ) onboard the Fengyun(FY) satellite(FY-3 series;FY-3 D) is used to retrieve surface vegetation parameters. First, MERSI-Ⅱ solar channel measurements at the red and near-infrared(NIR) bands at the top of atmosphere(TOA) are corrected to the surface reflectances at the top of canopy(TOC) by removing the contributions of scattering and absorption of molecules and aerosols. The normalized difference vegetation index(NDVI) at both the TOA and TOC is then produced by using the same algorithms as the MODIS and AVHRR. The MERSI-Ⅱ enhanced VI(EVI) at the TOC is also developed. The MODIS technique of compositing the NDVI at various timescales is applied to MERSI-Ⅱ to generate the gridded products at different resolutions. The MERSI-Ⅱ VI products are consistent with the MODIS data without systematic biases. Compared to the current MERSI-Ⅱ EVI generated from the ground operational system, the MERSI-Ⅱ EVI from this study has a much better agreement with MODIS after atmospheric correction.

关键词： MEdium Resolution Spectral Imager-Ⅱ(MERSI-Ⅱ) Fengyun(FY)satellite vegetation index(VI) atmospheric correction

Field validation of the GLASS land surface broadband emissivitydatabase using pseudo-invariant sand dune sites in northern China

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International Journal of Digital Earth 2013年第S01期6卷 96-112页

作者： Lixin Dong Juyang Hu shihao tang Min Min Key Laboratory of Radiometric Calibration and Validation for Environmental Satellites National Satellite Meteorological CenterBeijingChina

The land surface broadband emissivity (LSBE) is a key parameter for estimatingsurface radiation, and there have been many studies of the LSBE at global orlocal scales. However, few studies have validated the surface emissivity databasewith multi-point field measurement data using infrared radiometry, especially inChina. In this study, we focus on the validation of the emissivity product of theglobal land surface satellite (GLASS) LSBE database for northern China for theperiod from 2006 to 2011. Specifically, we have employed an eight-day averaged,gridded emissivity product in the 813.5 mm spectral range produced at a spatialresolution of 1000 m from the Moderate Resolution Imaging Spectrometeralbedo product using a new algorithm. The GLASS LSBE database was validatedover bare surfaces with field measurement data from sand samples collected atmany pseudo-invariant sand dune sites located in western and northwesternChina. By comparing measured emissivity for different land surface types atdifferent sites and different times, it was shown that the results were consistentand that the accuracy of the field measurements was reliable. The results of thevalidation of GLASS LSBE with these field emissivity data showed very goodagreement.

关键词： validation broadband emissivity field measurement emissivity GLASS northern China

An Operational Precipitable Water Vapor Retrieval Algorithm for Fengyun-2F/VISSR Using a Modified Three-Band Physical Split-Window Method

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Journal of Meteorological Research 2019年第2期33卷 276-288页

作者： Juyang HU shihao tang Hailei LIU Min MIN Key Laboratory of Radiometric Calibration and Validation for Environmental Satellites National Satellite Meteorological Center China Meteorological Administration Key Laboratory of Atmospheric Sounding Chengdu University of Information Technology

The Visible and Infrared Spin-Scan Radiometer(VISSR) onboard the Fengyun-2(FY-2) satellite can provide valuable thermal infrared observations to help create a precipitable water vapor(PWV) product with high spatial and temporal resolutions. The current FY-2/VISSR PWV product in operation is produced by using a traditional two-band physical split-window(PSW) method, which produces low quality results under dry atmospheric conditions. Based on the sensitivity characteristics of FY-2 F/VISSR water vapor channel and two split-window channels to atmospheric water vapor, this study developed a new, robust operational PWV retrieval algorithm for FY-2 F to improve the operational precision of the current PWV product. The algorithm uses a modified three-band PSW method, which adds a scale for the water vapor channel in the improved three-band PSW method. Integrated PWV products from the radiosonde data in 2016 are used here to validate the precision of the PWV retrieved by the modified three-band and traditional two-band PSW methods. The mean bias, root mean square error(RMSE), and correlation coefficient of the PWV retrieved by the modified three-band PSW method are 0.28 mm, 4.53 mm, and 0.969, respectively. The accuracy is much better than the PWV retrieved by the two-band method, whose mean bias, RMSE, and correlation coefficient are 12.67 mm, 29.35 mm, and 0.23. Especially, in mid-or high-latitude regions, the RMSE of the PWV is improved from 10 to 2 mm by changing the inversion in the two-band method to the modified three-band PSW method. Furthermore, the modified three-band PSW results show a better consistency with the radiosonde PWV at any zonal belt and season than the two-band PSW results. This new algorithm could significantly improve the quality of the current FY-2 F/VISSR PWV product, especially at sites where the actual PWV are lower than 15 mm.

关键词： physical split-window (PSW) method precipitable water vapor (PWV) FY-2F/VISSR thermal infrared

Influence of Near Real-Time Green Vegetation Fraction Data on Numerical Weather Prediction by WRF over North China

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Journal of Meteorological Research 2021年第3期35卷 505-520页

作者： Bing LU Jiqin ZHONG Wei WANG shihao tang Zhaojun ZHENG Institute of Urban Meteorology China Meteorological AdministrationBeijing 100089China National Center for Atmospheric Research BoulderCO 80301USA Key Laboratory of Radiometric Calibration and Validation for Environmental Satellites National Satellite Meteorological CenterChina Meteorological AdministrationBeijing 100089China

The green vegetation fraction(GVF)can greatly influence the partitioning of surface sensible and latent heat fluxes in numerical weather prediction(NWP)***,the multiyear averaged monthly GVF climatology—the most commonly used representation of the vegetation state in models—cannot capture the real-time vegetation state *** this study,a near real-time(NRT)GVF dataset generated from an 8-day composite of the normalized difference vegetation index is compared with the 10-yr averaged monthly GVF provided by the WRF *** annual variability of the GVF over North China is examined in *** differences between the two GVF datasets are found over dryland,grassland,and cropland/grassland mosaic *** experiments using different GVF datasets are performed to assess the impacts of GVF on forecasts of screen-level temperature and *** results show that using NRT GVF can lead to a widespread reduction of 2-m temperature forecast errors from April to *** against in-situ observations shows that the positive impact on 2-m temperature forecasts in the morning is more distinct than that in the *** study demonstrates that NRT GVF can provide a more realistic representation of the vegetation state,which in turn helps to improve short-range forecasts in arid and semiarid regions of North ***,our study shows that the negative effect of using NRT GVF is closely related to the initial soil moisture.

关键词： green vegetation fraction(GVF) near real-time(NRT) soil moisture 2-m temperature and humidity warm season

Impact factors of soil wind erosion in the center of Taklimakan Desert

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Journal of Arid Land 2011年第1期3卷 9-14页

作者： Qing HE XingHua YANG Ali Mamtimin shihao tang Istitute of Desert Meteorology China Meteorological Administration Urumqi 830002 China Desert Atmosphere and Environment Observation Experiment of Taklimakan Station Tazhong 841000 China National Satellite Meteorological Center China Meteorological Administration Beijing100081 China

The development and progress of soil wind erosion are influenced by the factors of climate, terrain, soil and vegetation, etc. This paper, taking Tazhong region, a town in the centre of the Taklimakan Desert, as an example and using comparative and quantitative methods, discussed the effects of climate, surface roughness （including vegetation cover） and surface soil properties on soil wind erosion. The results showed that the climate factor index C of annual wind erosion is 28.3, while the maximum of C is 13.9 in summer and it is only 0.7 in winter. The value of C has a very good exponential relationship with the wind speed. In Tazhong region, the surface roughness height is relatively small with a mean of 6.32 x 10 Sm, which is in favor of soil wind erosion. The wind erosion is further enhanced by its sandy soil types, soil particle size, lacking of vegetation and low soil moisture content. The present situation of soil wind erosion is the result of concurrent effects of climate, vegetation and surface soil properties.

关键词： Taklimakan Desert roughness particle size soil moisture content soil wind erosion