Background and Research Prospect of Geo-ecological Survey and Monitor in the Critical Zone of Black Soil

正The American Science journal,on the occasion of its 125 publication anniversary,in 2016,released 125 of the most challenging scientific issues (Kennedy et al.,2005) to the world.According to the basics,breadth and the influence,25 of the issues which considered to be the most important were screened,including"How many people can the Earth carry?"(Stokstad,2005;Dailyg et al.,1992;Cohen,1995) and"How high will the greenhouse effect make the earth temperature?"These two     

Application of an error statistics estimation method to the PSAS forecast error covariance model

In atmospheric data assimilation systems, the forecast error covariance model is an important component. However, the paralneters required by a forecast error covariance model are difficult to obtain due to the absence of the truth. This study applies an error statistics estimation method to the Pfiysical-space Statistical Analysis System （PSAS） height-wind forecast error covariance model. This method consists of two components： the first component computes the error statistics by using the National Meteorological Center （NMC） method, which is a lagged-forecast difference approach, within the framework of the PSAS height-wind forecast error covariance model; the second obtains a calibration formula to rescale the error standard deviations provided by the NMC method. The calibration is against the error statistics estimated by using a maximum-likelihood estimation （MLE） with rawindsonde height observed-minus-forecast residuals. A complete set of formulas for estimating the error statistics and for the calibration is applied to a one-month-long dataset generated by a general circulation model of the Global Model and Assimilation Office （GMAO）, NASA. There is a clear constant relationship between the error statistics estimates of the NMC-method and MLE. The final product provides a full set of 6-hour error statistics required by the PSAS height-wind forecast error covariance model over the globe. The features of these error statistics are examined and discussed.     

能谱CT成像瞬时切换技术对于肺结节的临床价值

目前的研究已证实能谱CT成像技术可用于评价病灶性质的判断。对于肺结节,能谱CT成像技术有助于肺结节良恶性的鉴别;对于肺癌患者,能谱CT成像技术也可以提供有关定性、分期及疗效监测的信息。本文对目前肺结节的能谱CT成像技术的临床应用进行综述;包括肺结节的能谱CT成像扫描技术、肺结节的鉴别诊断、肺癌分期、与临床指标的相关性以及其在疗效监测等方面的应用。      

Comparison between ozonesonde measurements and satellite retrievals over Beijing,China

从2013年开始,作者团队使用自主研发电化学原理臭氧探空仪在华北平原北京地区进行每周一次观测.本研究首次使用2013-2019年期间北京地区臭氧探空数据评估Aqua卫星搭载大气红外探测仪(AIRS)和Aura卫星搭载微波临边探测器(MLS)反演垂直臭氧廓线,并对比臭氧探空,AIRS和Aura卫星搭载臭氧监测仪(OMI)臭氧柱总量结果.尽管臭氧探空与卫星反演垂直臭氧廓线在局部高度处差异较大,但整体来说两者较为接近(相对偏差大多<10%).臭氧探空,AIRS和OMI三种仪器测量臭氧柱总量的年变化特征较为一致,其年均臭氧柱总量分别为351.8±18.4 DU,348.8±19.5 DU和336.9±14.2 DU.后续对国内多站点观测数据分析将有助于进一步理解臭氧探空与卫星反演臭氧资料在不同区域的一致性.     

Development of periglacial landforms and soil formation in the Ilgaz Mountains and effect of climate(Western Black Sea Region-Türkiye)

The main aims of the current study are to determine the morphological features of the periglacial landforms(non-sorted step, mud circle, stony earth circle, thufur, and congeliturbation) located on the Ilgaz Mountains, examine the physicochemical and mineralogical properties with pedological processes of the soils, and assess of the effects of climatic conditions controlling the development of landforms. The Ilgaz Mountains(2587 m a.s.l.), located in the Western Black Sea Region, within the Anat...     

Direct use of peak ground motion parameters for the estimation of inelastic displacement ratio of SDOF systems subjected to repeated far fault ground motions

This study is aimed at developing statistical equations to estimate the inelastic displacement ratio of singledegree- of-freedom systems subjected to far fault repeated earthquakes. In the study, peak ground motion parameters are used to define the scatter of the original data. The ratio of peak ground acceleration to peak ground velocity, and peak ground velocity of the ground motion records and structural parameters such as period of vibration and lateral strength ratio are used in the proposed equations. For the development of the equations, nonlinear time history analyses of single-degree-offreedom systems are conducted. Then, the results are used in a multivariate regression procedure. The equations are verified by comparing the estimated results with the calculated results. The average error and coefficient of variation of the proposed equations are presented. The analyses results revealed that the direct use of peak ground motion parameters for the estimation of inelastic displacement ratio significantly reduced the scatter in the original data and yielded accurate results. From the comparative results it is also observed that results obtained using equations specific to peak ground velocity or peak ground acceleration to peak ground velocity ratio are similar.     

长江水下三角洲沉积物磁性特征空间差异及其冲淤指示意义

三角洲冲淤具有空间异质性,而沉积物的磁性特征可灵敏地反映物源、沉积动力特征以及早期成岩作用影响,是揭示空间异质性的有效方法。选取长江水下三角洲20~35 m水深的四个约2 m长的柱样进行磁学和碳、硫地球化学分析,结合粒度及年代资料,探讨了长江水下三角洲沉积物柱样磁性特征空间差异及其冲淤指示意义。研究结果显示,粒度表征的动力分选影响沉积物的磁性特征,这在年代较新（<350 a）的柱样中表现尤为明显,即细颗粒沉积物中富集亚铁磁性矿物,从而具有较高的磁化率。铁、碳、硫及硫同位素特征揭示了长江水下三角洲沉积物较弱的硫酸盐还原特征。沉积物年龄及沉积速率影响沉积物成岩改造强度,进而导致了磁性特征垂向变化的空间差异,整体上看,远离现代沉积中心的柱样,成岩改造特征更为明显。磁化率值的大小、成岩分带的完整性及其反映的铁还原带和硫酸盐还原带转换深度,一定程度上可以揭示三角洲的淤积和侵蚀特征。     

Research and Application of In‐seam Seismic Survey Technology for Disaster‐causing Potential Geology Anomalous Body in Coal Seam

In order to effectively detect potential geology anomalous bodies in coal bearing formation, such as coal seam thickness variation, small faults, goafs and collapse columns, and provide scientific guidance for safe and efficient mining, the SUMMIT-II EX explosion-proof seismic slot wave instrument, produced by German DMT Company, was used to detect the underground channel wave with the help of transmission method, reflection method and transflective method. Region area detection experiment in mining face had been carried out thanks to the advantage of channel wave, such as its great dispersion, abundant geology information, strong anti-interference ability and long-distance detecting. The experimental results showed that: (1) Coal seam thickness variation in extremely unstable coal seam has been quantitatively interpreted with an accuracy of more than 80% generally; (2) The faults, goafs and collapse columns could be detected and predicted accurately; (3) Experimental detection of gas enrichment areas, stress concentration regions and water inrush risk zone has been collated; (4) A research system of disaster-causing geology anomalous body detection by in-seam seismic survey has been built, valuable and innovative achievements have been got. Series of innovation obtained for the first time in this study indicated that it was more effective to detect disaster-causing potential geology anomalies by in-seam seismic survey than by ground seismic survey. It had significant scientific value and application prospect under complex coal seam conditions.     

Monitoring open water area changes in a small tarn using historical orthophotomaps and a historical bathymetric map: a case study of the Litworowy Staw lake,the High Tatras

According to scientific evidence in general, the disappearance of the Tatras tarns as a result of external geomorphological processes has been accepted since the long term analyses of lake sediments and peat bogs, geomorphological mapping, geophysical measurements(– all indirect methods). It is paradoxical that the direct cartographic evidence of such changes has not existed until now. In this paper, we evaluate shore line changes of the small mountain glacial lake in the High Tatras-Litworowy Staw lake using a multitemporal analysis of a series of historical orthophotomaps and a historical map. Over the last 100 years, the tarn has lost 46.4% of open water level area. Significant visual changes were caused by vegetation growth of Carex species(sedges) on the water's surface. The accumulation of fine sediments and dead plant residues in the tarn basin create suitable conditions for this process, all together causing the tarn to become more shallow.