Generation of continuous surface soil moisture dataset using combined optical and thermal infrared images

Surface soil moisture (SSM) is a critical variable for understanding water and energy flux between the atmosphere and the Earth's surface. An easy to apply algorithm for deriving SSM time series that primarily uses temporal parameters derived from simulated and in situ datasets has recently been reported. This algorithm must be assessed for different biophysical and atmospheric conditions by using actual geostationary satellite images. In this study, two currently available coarse‐scale SSM datasets (microwave and reanalysis product) and aggregated in situ SSM measurements were implemented to calibrate the time‐invariable coefficients of the SSM retrieval algorithm for conditions in which conventional observations are rare. These coefficients were subsequently used to obtain SSM time series directly from Meteosat Second Generation (MSG) images over the study area of a well‐organized soil moisture network named REMEDHUS in Spain. The results show a high degree of consistency between the estimated and actual SSM time series values when using the three SSM dataset‐calibrated time‐invariable coefficients to retrieve SSM, with coefficients of determination (R²) varying from 0.304 to 0.534 and root mean square errors ranging from 0.020 m³/m³ to 0.029 m³/m³. Further evaluation with different land use types results in acceptable debiased root mean square errors between 0.021 m³/m³ and 0.048 m³/m³ when comparing the estimated MSG pixel‐scale SSM with in situ measurements. These results indicate that the investigated method is practical for deriving time‐invariable coefficients when using publicly accessed coarse‐scale SSM datasets, which is beneficial for generating continuous SSM dataset at the MSG pixel scale.     

贵州茂兰板寨水域水生植物δ~(13)C特征及光合作用固定HCO_3~-碳量估算

为研究水生植物光合作用对岩溶碳汇的贡献,选取板寨河水域为研究区,分冬季和夏季测定典型水生植物的生物量以及各采样点水生植物碳同位素组成(δ13 C值),并利用水生植物稳定碳同位素与碳酸酐酶间的关系建立的二端元模型,估算板寨河水生植物光合作用的固碳量。结果发现夏季生物量小于冬季生物量,水生植物的δ13 C值变化在-35.45‰~-24.62‰之间,其中挺水植物的δ13 C值最大,平均为-27.89‰,其次为沉水植物,平均为-29.96‰。浮水植物的δ13 C值最低,平均为-32‰,受流速、CO2浓度、光合途径等影响引起同种水生植物间同位素差异。水域水生植物固定下的HCO-3碳量为19.52tc/(a.km2),其利用HCO-3作为无机碳源进行光合作用的比例平均为47.84%,显示出巨大的固碳潜力,是全球岩溶碳汇的一个重要组成部分。     

基于原位双环、试坑浸水试验和数值模拟反演的Q3黄土饱和渗透系数对比研究

为准确获取原状Q3黄土的竖向和水平饱和渗透系数,进行了原位、室内试验测试以及数值模拟反演,并应用大型试坑浸水试验检验了所获饱和渗透系数的可靠性。进行了不同内径尺寸的原位双环入渗试验,获取了竖向饱和渗透系数,并应用室内试验测试了竖向和水平饱和渗透系数以及持水曲线;应用COMSOL软件对双环入渗试验进行数值模拟,检验了所测饱和渗透系数的可靠性,利用正交试验获得了最优的竖向和水平饱和渗透系数取值,并利用反演结果对试坑进行数值模拟,将其水分入渗情况与实测值对比。研究结果表明：在现场进行双环入渗试验时选取较大内径的双环获得的竖向饱和渗透系数更为合理。针对双环入渗试验,数值模拟反演所得最优饱和渗透系数在竖向上接近于原位试验所得竖向饱和渗透系数、水平向上接近室内所测水平向饱和渗透系数,竖向饱和渗透系数比水平向饱和渗透系数更加显著地影响水分入渗过程。通过对大型试坑水分入渗情况的验证,检验了反演所得最优饱和渗透系数的可靠性。     

Effect of chemical fertilizers on the fractionation of Cu,Cr and Ni in contaminated soil

Effect of chemical fertilizers (urea, NH₄Cl, Ca(NO₃)₂, KCl and KH₂PO₄) on the fractionation of Cu, Cr and Ni was studied by a 4-month incubation experiment. Using sequential extraction procedure, it was found that the application of fertilizers could change the distribution of Cu, Cr and Ni in the fractions of soil. Applying urea (CO(NH₂)₂) significantly decreased the concentrations of Cu, Cr and Ni in water soluble plus exchangeable (WE) fraction, but increased those in Fe–Mn oxides bound (FM) fraction (p < 0.01). However, application of NH₄Cl caused an increase in the WE fraction by 27.7% for Cu, 111.5% for Cr and 20.4% for Ni. The CO(NH₂)₂ raised the soil pH from 4.51 to 4.96, whereas NH₄Cl lowered the pH of soil by 0.44 units. The WE fraction of the three heavy metals was significantly increased, while the FM fraction was significantly decreased by adding KCl (p < 0.01). Moreover, the supply of KH₂PO₄ reduced the WE and carbonate bound (CB) fractions of Cu, Cr and Ni in the soil, however, it raised Cu and Ni in the residual (RS) fraction and Cr in the FM fraction. In addition, the mobility index indicated that KCl and NH₄Cl increased the mobility of Cu, Cr and Ni in the soil, whereas urea and KH₂PO₄ decreased the mobility of the three metals in the soil. These results suggest that applying chemical fertilizers does not only provide plant nutrients, but may also change the speciation and mobility of heavy metals in the soil.     

松辽盆地东南缘营城组地层序列的划分与区域对比

从营城组沿革分析入手,立足于九台市城子街镇斜尾巴沟-官马山-团结村营城组地表标准剖面的研究,综合运用岩性地层对比、生物地层对比、同位素年代对比和气候事件对比的综合性地层对比方法,对比了松辽盆地东南缘与盆地北部徐家围子断陷20个营城组典型剖面。营城组可划分为5个岩性段,结合地层序列特征和应用习惯,自下而上划分为下段（K₁y^下）,一段（K₁y¹）,二段（K₁y²）,三段（K₁y³）和四段（K₁y⁴）。下段以中基性火山岩夹碎屑岩和薄煤层为主,厚度60~478 m,以营城煤矿343孔为标准剖面;一段以厚层流纹岩夹珍珠岩、流纹质火山碎屑岩为主,偶夹复成分砾岩,厚度20~630 m;二段以碎屑岩为主,夹凝灰岩、偶夹流纹岩,含煤层,厚度92~640 m;三段以中基性火山岩、火山碎屑岩为主,顶部为中性、酸性火山岩互层,厚度85~346.5 m;斜尾巴沟－官马山－团结村剖面可作为一段至三段的标准剖面;四段以凝灰质砾岩为主,夹泥岩,仅发育在徐家围子断陷,厚度10~400 m,徐深1井可作为标准剖面。     

超高强混凝土短柱抗震性能的试验研究

通过对12根剪跨比λ=2．0的超高强混凝土短柱在低周反复荷载下抗震性能的试验研究,分析了其破坏形态,并研究了轴压比和配箍率对试件滞回特性和抗震延性的影响,提出了满足一定延性要求（μ△≥3．0）超高强混凝土短柱的轴压比限值和箍筋加密区的最小配箍特征值的建议值。该值可为现行规范的修订提供参考。     

防震减灾行业下一代IPv6信息网络发展研究

下一代网络(next generation network,缩写为NGN)是以高性能、可扩展、可运营、可管理、更安全的下一代电信网络为基础,实现高质晕流媒体应用、无线和移动应用、多样化终端没备、按需的传输质量控制和更高安全保障的新型网络,IPv6是下一代网络的关键支撑技术.IPv6网是F一代IP网,不等同于下一代网络,IPv6网只有在满足下一代网络的必要特征后才可成为下一代网络.     

Conditional nonlinear optimal perturbation: Applications to stability,sensitivity, and predictability

Conditional nonlinear optimal perturbation (CNOP) is a nonlinear generalization of linear singular vector (LSV) and features the largest nonlinear evolution at prediction time for the initial perturbations in a given constraint. It was proposed initially for predicting the limitation of predictability of weather or climate. Then CNOP has been applied to the studies of the problems related to predictability for weather and climate. In this paper, we focus on reviewing the recent advances of CNOP’s applications, which involves the ones of CNOP in problems of ENSO amplitude asymmetry, block onset, and the sensitivity analysis of ecosystem and ocean’s circulations, etc. Especially, CNOP has been primarily used to construct the initial perturbation fields of ensemble forecasting, and to determine the sensitive area of target observation for precipitations. These works extend CNOP’s applications to investigating the nonlinear dynamical behaviors of atmospheric or oceanic systems, even a coupled system, and studying the problem of the transition between the equilibrium states. These contributions not only attack the particular physical problems, but also show the superiority of CNOP to LSV in revealing the effect of nonlinear physical processes. Consequently, CNOP represents the optimal precursors for a weather or climate event; in predictability studies, CNOP stands for the initial error that has the largest negative effect on prediction; and in sensitivity analysis, CNOP is the most unstable (sensitive) mode. In multi-equilibrium state regime, CNOP is the initial perturbation that induces the transition between equilibriums most probably. Furthermore, CNOP has been used to construct ensemble perturbation fields in ensemble forecast studies and to identify sensitive area of target observation. CNOP theory has become more and more substantial. It is expected that CNOP also serves to improve the predictability of the realistic predictions for weather and climate events plays an increasingly important role in exploring the nonlinear dynamics of atmospheric, oceanic and coupled atmosphere-ocean system. Supported by National Basic Research Program of China (Grant Nos. 2006CB403606, 2007CB411800), National Natural Science Foundation of China (Grant Nos. 40830955, 40675030, 40505013), Institute of Atmospheric Physics, Chinese Academy of Sciences (Grant No. IAP07202), and LASG State Key Laboratory Special Fund     

对Nakai拟合法的改进及实际应用

本文对Nakai拟合法作了改进并应用于计算井水固体潮和气压系数。利用该方法还可以计算井水位对固体潮和气压响应的滞后时间。以鲁06井为例,用本文的方法计算出其井水位的固体潮和气压系数分别为16.9mm/10~(-3)和5.58mm/hPa,滞后时间分别为18.8和22.4分钟。校正后的中误差由8.5mm下降到6.1mm。     

河南平顶山平煤矿区天然地震、爆破、塌陷时频特征分析

选取2019年3月—8月河南平顶山市宝丰县平煤矿区发生的ML 2.0—2.9天然地震、爆破、塌陷等9次震动事件,在区域地质构造背景和波形特征分析基础上,采用短时傅里叶变换(STFT)方法开展时频波谱分析,提取不同类型事件的时频特征。结果显示:(1)天然地震频率成分丰富,且高、低频分布均匀,P波在约3 Hz和8 Hz处存在2个峰值,S波存在多个峰值;(2)爆破事件的时频谱相对集中,以低频为主,P波频率峰值约5Hz,信号主频随时间变化,大致呈线性降低至1—2 Hz;(3)塌陷事件频率成分以4 Hz以下的低频为主,P波无明显峰值且频率成分单一,主频出现在2 Hz左右的面波。本文结果可为今后该矿区震动事件类型判断提供参考依据。