雷达发射机灯丝电源故障维修

灯丝电源是一个交流稳压电源,通过灯丝中间变压器和位于油箱中的脉冲变压器及灯丝变压器,为速调管灯丝供电.2011年7月18日,内蒙古气象局通辽天气雷达站的CINRAD/CB雷达发射机反复出现灯丝电源故障,且无法加高压导致雷达停机,经分析和排查故障原因,最终排除了雷达故障.就此次故障的出现,分析其原因,举一反三,对雷达台站在今后的工作中加强备件的管理和测试数据的管理有一定的启示.     

Research progress on behaviors and environmental effects of mercury in the cryosphere of the Tibetan Plateau:a critical review

The behavior and fates of environmental pollutants within the cryosphere and the associated environmental impacts are of increasing concerns in the context of global warming.The Tibetan Plateau(TP),also known as the"Third Pole",represents one of the most important cryospheric regions in the world.Mercury(Hg)is recognized as a global pollutant.Here,we summarize the current knowledge of Hg concentration levels,pools and spatio-temporal distribution in cryospheric environments(e.g.,glacier,permafrost),and its transfer and potential cycle in the TP cryospheric region.Transboundary transport of anthropogenic Hg from the surrounding heavily-polluted regions,such as South and Southeast Asia,provides significant sources of atmospheric Hg depositions onto the TP cryosphere.We concluded that the melting of the cryosphere on the TP represents an increasing source of Hg and brings a risk to the TP environment.In addition,global warming acts as an important catalyst accelerating the release of legacy Hg from the melting cryosphere,adversely impacting ecosystems and biological health.Furthermore,we emphasize on the remaining gaps and proposed issues needed to be addressed in future work,including enhancing our knowledge on some key release pathways and the related environmental effects of Hg in the cryospheric region,integrated observation and consideration of Hg distribution,migration and cycle processes at a key region,and uses of Hg isotopic technical and Hg models to improve the understanding of Hg cycling in the TP cryospheric region.     

长江中下游地区中生代“蝴蝶结”形态的构造成因研究：来自殷店—马垅剪切带的证据

殷店—马垅剪切带位于大别造山带南侧,它不仅是一条划分大别造山带南侧岩性界线的剪切带,更是长江中下游地区“蝴蝶结”几何学形态的西侧边界断裂。本文通过该剪切带几何学、运动学、年代学和动力学特征深入了解整个区域的演化过程和动力学背景。剪切带宏观与显微构造均指示其运动学特征为右行剪切。纵向上,越靠近剪切带,呈现出分形维数值越大的变化趋势,差异应力值σ和应变速率ε也表现出此规律。横向上,剪切带东段岩石有限应变R_XZ在1.91~2.46之间,大于剪切带西段的值。表明剪切带越靠近“蝴蝶结”结点部位时,构造作用力的影响越深,剪应力和应变强度越大。显微构造特征估算、角闪石单矿物温压计和黑云母单矿物压力计计算,获得其形成时温压条件为：T = 588 ℃~640 ℃,P = 0.45~0.52 GPa,属于中低角闪岩相变质范围。剪切带涡度值W_k远大于0.75,以简单剪切变形为主。构造应力场指示了以190°向180°~170°的转变,可能代表了华南华北板块碰撞后产生的南北向挤压应力场逐渐转变为受太平洋构造体制影响下的应力场。锆石U-Pb定年获得了剪切带在153.5±2.9 Ma存在剪切活动,属于中生代构造活动的一部分,结合前人研究成果,认为剪切带活动时间约从176 Ma开始,到130 Ma左右结束。中生代以来,受太平洋构造体制的影响,殷店—马垅剪切带与脉动式左行剪切的郯庐断裂带在几何学、运动学、年代学上十分吻合,共同构成了整个区域构造系统下的共轭剪切作用。二者的构造活动使得桐柏—大别造山带内物质由西向东深层次有序流动,运动方向转变为向南,在桐柏—大别造山带最南缘处成为理论上最佳的应力集中点,这种应力方式在与扬子板块相互挤压的共同作用下,可能造成了如今长江中下游地区表现为中间窄,两侧渐宽的“蝴蝶结”状几何学形态。

     

联合速度建模及其在反射波法隧道超前预报中的应用

We propose a combined migration velocity analysis and imaging method based on Kirchhoff integral migration and reverse time migration, using the residual curvature analysis and layer stripping strategy to build the velocity model. This method improves the image resolution of Kirchhoff integral migration and reduces the computations of the reverse time migration. It combines the advantages of efficiency and accuracy of the two migration methods. Its application in tunnel seismic prediction shows good results. Numerical experiments show that the imaging results of reverse time migration are better than the imaging results of Kirchhoff integral migration in many aspects of tunnel prediction. Field data show that this method has efficient computations and can establish a reasonable velocity model and a high quality imaging section. Combination with geological information can make an accurate prediction of the front of the tunnel geological structure.     

峨口铁矿高陡边坡稳定性三维模型试验研究

据计算, 峨口铁矿边坡如增加1坡角可减少剥离量5684万吨, 节约经费1.7亿元。在地质调查基础上, 应用三维物理模型对峨口铁矿边坡进行了设计最终边坡角开挖试验, 加陡边坡角以及陡帮强采试验研究, 以进一步验证矿山原设计最终边坡角的合理与否。     

恒压喷灌系统调压特性研究

分析了调压罐容积、调压罐内气体状态变化指数、管网阻力及田间综合阻力等对调压特征值的影响,分析表明调压罐容积及气体状态变化指数的大小均影响系统压力变化周期,而对系统的压力变幅值影响较小;输水管网阻力的大小既影响系统的压力变化周期,也影响系统的压力变幅值;田间综合阻力系数的大小影响系统的压力动态变化过程,存在最小运行周期。     

武汉上空大气密度温度的激光雷达探测

介绍了中国科学院武汉物理与数学研究所瑞利散射激光雷达的结构和性能,报道了该激光雷达观测所得到的我国武汉上空30～70 km范围内大气密度和30～60 km范围内温度廓线的反演结果。     

台风过程影响下的滨海湿地物理变量观测及湿地系统响应

如何研究台风等极端天气事件影响下的湿地系统响应过程,进而提出有效的生态完整性维护和管理方案,对关键区域的湿地管理及生态安全维护具有重要意义。本文于2021年9月“灿都”台风期间在南汇东滩南岸设置水动力观测点,采集表层沉积物、测量滩面高程并用无人机获得植被影像,运用ArcGIS空间分析,探讨了台风过程影响下的南汇东滩水动力、滩面沉积变化与植被分布面积响应。结果表明：台风中,观测点近底层平均流速为0.23 m/s,植被边缘平均有效波高和波能是台风前后的1.54倍和2.14倍,近底层1 m的滩面出现“高悬沙浓度层”（>10 g/L）且存在时长为8.13 h。台风后高程低于4 m的稀疏海三棱藨草和互花米草滩面侵蚀0～4.8 cm,高程高于4 m的茂盛互花米草和芦苇滩面淤积0～14.7 cm;研究区植被分布面积共减少1 827.67 m²,减少量占台风前植被总量的1.63%,其中侵蚀滩面植被分布面积减少31.9%,淤积滩面减少68.1%。对台风过程影响后的湿地管理,可以总结为：（1）湿地在台风过程后滩面基本表现为明显的侵蚀、淤积区域共存的特征;（2）对高程低于4 m的侵蚀滩面,建议确定植被适宜生长的高程,结合台风过程冲淤变化通过“微生物膜”和植被斑块移植的方法消浪、固滩和促淤,加速湿地在台风过程影响后的修复。     

塔里木盆地北部跃南断裂带的形成演化

跃南断裂带是塔里木盆地北部的一条形状奇特的断裂带,平面展布呈口袋状。在系统的地震资料解释的基础上,通过认真的断裂构造分析,认为跃南断裂带经历了二叠纪、二叠纪末—三叠纪和侏罗—白垩纪3期断裂作用的叠加。二叠纪大陆裂谷作用形成的一系列NE-SW和NW-SE走向的陡倾的正断层,组成一个共轭断裂系统。沿跃南断裂带的两组不同方向的正断层活动加强,并最终追踪、贯通,形成了口袋状的跃南断裂带。也就是说,跃南断裂带实际上是由NE-SW和NW-SE走向两组断层组合而成的。断裂带围限的地块相对抬升,形成一个大型的垒块。二叠纪末—三叠纪南天山碰撞造山作用引起的逆冲断层,叠加在二叠纪正断层之上,进一步强化了跃南断裂带,使之断距加大,围限的垒块进一步抬升。侏罗—白垩纪的正断层属于南天山造山后的伸展构造,见于跃南断裂带上方,规模不大,数量不多,对断裂带有一定的调整作用。     

Study on the Fracture of Hard and Thick Sandstone and the Distribution Characteristics of Microseismic Activity

The movement of hard and thick key stratum during underground coal extraction via longwall top coal caving differs from that of other types of overlying strata. Therefore, numerous problems such as roadway instability, rock burst and strong mining-induced mine seismicity will be encountered as a result of the fracture of a hard and thick key stratum. The key to controlling the behavior of strata is to understand the movement and fracture pattern of the hard and thick key stratum. Taking the 103_up02 working face of Baodian coal mine as a case study in this study, according to the in situ measured microseismic data, the rule of fracture of overlying hard and thick sandstone caused by working face mining is studied, and the mechanism of dynamic pressure impact induced by hard and thick strata fracture is explained. Finally, the dynamic pressure control technology is put forward. The research results are of great significance for coal mining under hard and thick strata, mastering the fracture rules of hard and thick strata and predicting dynamic disasters.