Couple Effect of Joint Pore Pressure and Joint Orientations on Rock Strength Based on Numerical Modeling

Geotechnical and Geological Engineering - The joint pore pressure inside rock mass significantly affects groundwater bursting. To investigate the couple effect of joint pore pressure and joint...     

Ecosystem responses to climate change in a large on-river reservoir, Lake Paldang, Korea

The impact of climate change on a large river reservoir ecosystem was investigated. Long-term meteorological data showed that recent climate change, including warmer winters, increased precipitation intensity and extended dry periods, may have influenced the basin of Lake Paldang, the most downstream reservoir of a series of on-river reservoirs. Extreme hydrologic events and climate warming, acting independently and in combination, appear to be related to changes in the Lake Paldang ecosystem. A significant increase in chlorophyll a concentrations in early spring corresponded to the timing of ice break-up. An increase in winter temperatures, which resulted in a shorter time period of ice-cover and earlier ice break-up, appears to have stimulated phytoplankton growth in winter and early spring. Repeated intensive and extended influxes of turbid water, associated with more frequent extreme rainfall events, have increased concentration of suspended solids and may have influenced the biotic community structure of Lake Paldang. In the mid-2000s, the area vegetated by submerged hydrophytes, the abundance and biomass of the phylum Mollusca, as well as the abundance of fish from the subfamily Acheilognathinae, which spawn in the body of bivalve molluscs, was all smaller than in the late 1980s and early 1990s. Together, these results suggest that climate change may have contributed directly and indirectly to changes in each trophic level of the Lake Paldang ecosystem.     

A new calibration model for pointing a radio telescope that considers nonlinear errors in the azimuth axis ＊

A new calibration model of a radio telescope that includes pointing error is presented, which considers nonlinear errors in the azimuth axis. For a large radio telescope, in particular for a telescope with a turntable, it is difficult to correct pointing errors using a traditional linear calibration model, because errors produced by the wheel-on-rail or center bearing structures are generally nonlinear. Fourier expansion is made for the oblique error and parameters describing the inclination direction along the azimuth axis based on the linear calibration model, and a new calibration model for pointing is derived. The new pointing model is applied to the 40 m radio telescope administered by Yunnan Observatories, which is a telescope that uses a turntable. The results show that this model can significantly reduce the residual systematic errors due to nonlinearity in the azimuth axis compared with the linear model.     

STATUS AND DYNAMIC CHANGE OF REGIONAL MANLAND SYSTEM IN VIEW OF MICRO-LEVEL QUANTITATIVE ASPECT ——Case Study of Gongyi City of Henan Province

1INTRODUCTION Thequantitativestudyofregionalman-earthrelationship system can be traced back to a long time ago. Paul Vidal de la Blache, a human geographer from France, put for- ward the idea of man-earth relativity, which was further developed by his student named Jean Brunhen (BRUN- HEN, 1935). In the early 1980s, WU Chuan-jun, an aca- demician from Chinese Academy of Sciences, expanded the view of the man-earth areal system (WU, 1981), and he believed that onlythese qualitative …     

MULTI-DIMENSIONAL NUMERICAL STUDIES OF CONVECTION-RELATED STELLAR PROBLEMS

1　IntroductionManybottlenecksinthetheoreticalstudyofstellarevolutionarisefromthelackofunder standingofsomehighlycomplicatedprocessesthatcannotbetreatedwithanalyticaltech niques .Alargeportionoftheseprocessesisrelatedtohydrodynamics,particularlyconvec tion .Theapplicationofmultidimensionalnumericalcomputationstotheinvestigationofthesedifficultproblemshasmadegreatprogressinrecentyears .Here ,weprovideasurveyoftherecentnumericalstudiesofconvectionrelatedproblems.Theobjectiveistoassistthosewhoar…     

鲁西南8-9月份阴雨日数与前期大气环流关系

对鲁西南1979-2008年8-9月份阴雨日数进行统计分析,发现8-9月份阴雨日数总体呈上升趋势;与前期北半球500hPa月平均高度场进行相关分析,结果表明：8-9月份阴雨日数与北半球500hPa平均高度场存在显著的滞后相关性,共得出45个优势相关区,相关区具有明显的区域性,大多数优势相关区出现在60篘以南地区。阴雨日数与前期极涡位置及强弱有很好的对应关系。从优势相关区提取的预报因子具有明显的季节性,上一年秋冬季预报因子占6/9;建立预报方程,试用效果较好。     

The causality between the rapid rotation of a sunspot and an X3.4 flare

Using multi-wavelength data of Hinode, the rapid rotation of a sunspot in ac-tive region NOAA 10930 is studied in detail. We found extraordinary counterclockwise rotation of the sunspot with positive polarity before an X3.4 flare. From a series of vector magnetograms, it is found that magnetic force lines are highly sheared along the neu-tral line accompanying the sunspot rotation. Furthermore, it is also found that sheared loops and an inverse S-shaped magnetic loop in the corona formed gradually after the sunspot rotation. The X3.4 flare can be reasonably regarded as a result of this movement. A detailed analysis provides evidence that sunspot rotation leads to magnetic field linestwisting in the photosphere. The twist is then transported into the corona and triggers flares.     

基于数据挖掘探讨李佩芳治疗失眠的用药规律

目的：应用数据挖掘方法分析李佩芳主任医师治疗失眠的用药规律。方法：收集2019年1月至2021年1月李佩芳主任医师门诊治疗失眠的有效病例及首诊中药处方,使用Excel软件建立数据库,进行频次、频率等统计;运用IBM SPSS Modeler 18.0软件的关联规则分析常用药物组合;运用SPSS Statistics 23.0软件对频次较高的中药进行聚类分析。结果：共收集符合标准的病例112 例,纳入中药处方112个,涉及药物151味。其中使用频次≥30次的中药有23味,排名前8位的依次为夜交藤、茯苓、牡蛎、茯神、龙骨、煅磁石、川芎、炒酸枣仁;高频药物功效以养心安神、重镇安神、活血行气、健脾和胃为主。通过复杂网络和关联规则的组方规律分析,得出最常用的中药组合为夜交藤→煅磁石,茯苓→茯神,牡蛎→龙骨,川芎→酸枣仁。通过聚类分析,得出4个聚类组,主要功效分别为交通心肾、重镇安神,养血调肝、宁心安神,祛痰利窍、养心安神,健脾和胃。结论：李佩芳主任医师认为失眠病位主要在心,与脾胃、肝、肾密切相关,临证常运用通调三焦法治疗失眠,以酸枣仁汤、甘麦大枣汤合安神定志丸为主方,并在此基础上确立了交通心肾、疏肝理脾、重镇安神的治疗原则。     

Sedimentary records of the late Early Cretaceous compressional setting in the South China block: A case study of the Xingning Basin,Guangdong Province

Recently, some scholars have proposed that the South China Block (SCB) was controlled by a compressive tectonic regime in the middle–late Early Cretaceous, challenging the belief that the SCB was under an extensional setting during the Cretaceous. The Early Cretaceous tectonic setting constraint in the SCB can offer vital insight to clarify the Mesozoic subduction history of the Paleo-Pacific. Therefore, to determine the SCB tectonic regime during the Early Cretaceous, this study investigated sedimentary rocks from the Lower Cretaceous Heshui Formation in the Xingning Basin, a foreland basin located in the southeastern SCB. Provenance analysis was performed using sandstone modal analysis, sandstone geochemical characteristics, and detrital zircon geochronology. Based on the results, we discussed basin sediment sources and the SCB tectonic regime during the Early Cretaceous. The results showed that the maximum Heshui Formation depositional age was 103 Ma ± 1.6 Ma in the Early Cretaceous Albian. Detrital framework modes and geochemical characteristics of sandstone indicated that Heshui Formation's source rocks were granites and sedimentary rocks. The detrital zircon U–Pb ages could be classified into two major and four subordinate age populations. The Wuyi Terrane to the north and southeast coastal regions to the east were the primary potential Heshui Formation source areas. However, the lower and upper sandstones are different in the peak ages, ~437 and ~146 to 104 Ma, respectively, indicating that the major source area shifted from the Wuyi Terrane to the southeastern coastal regions during the late Early Cretaceous. The sandstone modal analysis results indicated that the source area comprised mainly collisional–orogenic material. The SCB was under a compressive tectonic regime during the late Early Cretaceous and this compression action continued until at least 103 Ma ± 1.6 Ma.