日照帆船比赛期间风的特征分析

利用日照1995-2004年8月和9月风向、风速的时值、日值、旬值及各风向频率以及日照水上运动基地加密自动气象站2006-2007年8-9月逐时风向、风速等资料,对日照8-9月尤其是帆船比赛期间风向、风速的平均状况及演变特征进行了统计分析.结果表明:日照帆船比赛期间日照站和水上运动基地加密自动站风速差别不大,且日变化特征一致,均呈现出夜间风速较小,白天风速较大特征;起风时间也一致,上午9:00风速开始增大到3.0m*s-1以上,平均最大风速时间段均出现在12:00-16:00之间;略有差别的是两个站8-9月各旬平均最大风速出现时间段的平均风速大小有所不同,8月上旬、中旬和9月中旬日照站的平均风速均大于水上运动基地,尤其是8月中旬平均风速大2.3m*s-1,但是8月下旬和9月上旬平均风速基本相同.≥20m*s-1的风速,出现几率很小,仅为0.99%.可为帆船比赛赛程安排提供有益参考.     

机载LiDAR技术应用于茂密植被山区地质灾害调查

我国茂密植被山区地质灾害具有高位、高隐蔽性的特点,传统地质灾害排查手段在有效解决隐患的早期识别方面存在一定困难.机载雷达技术不仅可获取地面反射的三维激光点云,同时能够提供高分辨率、高精度的地形地貌二维影像.机载雷达的多次回波技术可"穿透"地面植被,通过滤波算法能够有效去除地表植被的影响,获取真地面高程数据信息,从而可获...     

海底砂土中气体运移过程电阻率监测探针设计与实验

在浮力和动、静压力作用下,海底浅层气会在高渗透性土中发生垂直和水平方向的运移、聚集,诱发地层变形,甚至失稳破坏。为探索一种新型的气体运移过程原位监测技术,实现气致灾害实时监测预警,根据静电场测量原理,设计、制作了点状电极和环状电极两种形式电阻率探针。在分析了两种探针探测精度基础上,以砂土中气体扩散过程监测为例,利用其对3种速率气体运移过程进行连续监测实验。实验结果表明,两种探针电阻率测量误差均小于0.1%。点状电极探针测量灵敏度较高,可准确监测布设点含气量的变化、气体汇聚、消散过程及相应速率;环状电极探针测量灵敏度相对较低,但可监测气体在砂土中的时空运移过程。两种探针各有利弊,都可实现气体运移过程的有效监测。     

Spatio-temporal changes of ≥ 10°C accumulated temperature in northeastern China since 1961

The objective of this study was to provide reliable basis for decision making for national food security and layout and structure adjustment of grain production in the northeastern China. The data of mean daily air temperature of 1961-2009 from 106 meteorological stations in the northeastern China were chosen in this study. Using statistical methods and isoline method, the spatio-temporal changes of various decadal ≥ 10℃ accumulated temperature and the climatic means of ≥ 10℃ accumulated temperature were studied in this paper. The results showed that 1) The geo-graphical distribution of ≥ 10℃ accumulated temperature in the northeastern China could be influenced directly by the latitude, longitude and altitude. If latitude moved one degree northward, the average decrease amplitude of the climatic means was 101.9℃ in the study area. 2) The means of decadal ≥ 10℃ accumulated temperature rose since the 1980s, and their increase amplitudes became larger in the 1990s and the 2010s obviously. Compared with those of the 1980s, ≥ 10℃ accumulated temperature increased by about 100℃ in the mountainous and plain areas in the 1990s; compared with those of the 1990s, ≥ 10℃ accumulated temperature increased by about 200℃ in the Hulun Buir High Plain and the Songnen Plain, and 100℃ in the Sanjiang Plain and the Liaohe Plain in the 2010s. 3) The means of the decadal ≥ 10℃ accumulated temperature for 106 meteorological stations in the northeastern China increased with the rate of 145.57℃/10yr in 1961-2009. 4) The climatic means of ≥ 10℃ accumulated temperature increased from 1961-1990 to 1971-2000 and 1981-2009. Compared with the climatic mean of 1971-2000, that of 1981-2009 had increased by above 50℃ in most of the study area, even up to 156℃. Compared with the climatic mean of 1961-1990, that of 1981-2009 increased by above 100℃ in most parts of the study area, even up to 200℃. 5) The maximum northward shift, eastward and westward extension amplitudes of 3100℃, 3300℃ and 3500℃ isolines were larger among all isoli-nes for the climatic means of the three phases. Compared with the positions of the isolines of 1961-1990, those ampli-tudes of 3100℃ isoline of 1981-2009 were 145 km, 109 km and 64 km, respectively; those of 3300℃ isoline were 154 km, 54 km and 64 km, respectively; and the maximum northward shift of 3500℃ isoline was about 100 km.     

“天-空-地”协同滑坡监测技术进展

滑坡灾害是全球范围内发生频率最高、分布范围最广、造成损失最重的自然灾害之一,严重威胁着人类生命财产和重大工程设施的安全。科学监测是实现滑坡预警预报与主动防范的重要技术前提,经过多年的技术攻关,融合高分辨率光学遥感、卫星InSAR、无人机摄影测量、无线传感网络(WSN)等多种新技术方法,滑坡监测已从传统点式人工监测逐步发展到“天-空-地”多维协同监测,在我国地质灾害风险识别与监测预警方面取得显著成效。本文结合多年来对滑坡发生机理与变形破坏过程的研究认识,从天(光学遥感和InSAR)、空(无人机摄影测量)、地(全球导航卫星系统、裂缝计等专业监测)三维立体角度对我国滑坡监测技术的最新研究进展进行了系统总结,分析讨论了不同技术在工程实践中的技术优势和适用性,构建了滑坡变形破坏全过程的“天-空-地”协同监测技术体系,为滑坡地质灾害的科学防范提供一种新的思维范式和经验指导。     

A comparison of multiplatform wind products in the South China Sea during summer and autumn in 2019

Journal of Oceanology and Limnology - Sea surface wind (SSW) observations from a newly developed “Black Pearl” wave glider, the Chinese-French Oceanography Satellite (CFOSAT), the HY-2A...     

Characteristics of Channeling Flow in Cultivated Horizon of Saline Rice Soil

1 Introduction The preferential flow tends to result in the loss of irriga- tion water and nutrients. The formation of the preferen- tial flow was caused by various factors, such as soil structure, tillage, worm cavity and root channeling rup- ture (Pot et al., 2005). Besides, frozen rupture can not be ignored in the northeastern China where the lowest tem- perature reaches -40℃ (Wang et al., 1993). There are several types of preferential flow, such as bypass flow, channeling flow and macro…     

First Discovery and Zircon U‐Pb Dating of Early Ordovician Granitoids in Lincang Batholith,Western Yunnan: Implications for the Presence of Proto‐Tethyan Orogeny in the Sanjiang Region,SW China

正Objective The Lincang granitic batholith,extending over 370 km from north to south with an area of more than 10000 km~2,is the major part of the Sanjiang region in western Yunnan,SW China,and is one key area to study the evolution of the Tethys.Previous studies all agreed that the Lincang batholith was formed in the Triassic,and     

Review of the Seabed Sediment Resuspension by Internal Solitary Wave

Internal Solitary Waves (ISWs) are nonlinear, large amplitude motions of the interface between two fluids with different densities in the stratified ocean. Because of their strong vertical and horizontal current velocity, and the vortex, turbulent mixing caused by breaking, they affect marine environment, seabed sediment and man-made structures in the ocean. In the paper, we systematically analyzed and summarized the ISW-induced shoaling break mechanisms, models of suspension, and seabed dynamical response. Then, we discussed the ISW-induced sediment resuspension criteria, forming bottom and intermediate nepheloid layer and the capacity to suspend sediments in the seabed, and further put forward the unsolved problems based on the conducted work and related achievements. In shallow seas with complex terrain variations, shoaling can cause ISWs to deform, break, and split. Studies on the propagation of ISWs of depression over sloping topography have shown that an adverse pressure gradient causes the rotation of the flow separation, which produces vortices, and this results in global instability of the boundary layer and ISW burst. The separation vortices increase the bottom shear stress, vertical velocity, and near-bottom Reynolds stress, which leads to sediment resuspension and transport in the flow and vortex core. Although episodic, ISW-induced resuspension is hypothesized to be important enough to shape the topography. Shoaling ISWs may erode, resuspend and transport mud-like sediments, first towards shore by boluses, and subsequently offshore through the generation of intermediate nepheloid layers. Shoaling ISWs might be an important mechanism of muddy sediment dispersal along continental shelves. Furthermore, recent hypotheses suggest that sediment mobilization and transport caused by internal waves in general, and ISWs in particular, may be at the origin of some sedimentary structures found in the sedimentary rock record and also the hummocky-cross stratification. Observed on-shelf propagating frontal ISW most likely interacts with the sand waves, sediment waves or sand dunes. ISWs contribute to their generation, as they are trailed by considerable shear-induced turbulence and high-frequency internal waves close to the buoyancy frequency. This work is of great value for further understanding the process of ISW-induced sediment resuspension, transportation, and the capacity to suspend sediments in the seabed. It helps further study of the dynamic process of marine ecological environment dynamic process by ISW and the deep sea sedimentation process.     

坦桑尼亚姆贝亚Sangambi地区土壤地球化学特征

坦桑尼亚的Sangambi地区位于姆贝亚的东北部、卢帕金矿田的东部。通过1∶10 000土壤地球化学测量,圈定了6个Au,Cu,Cr,Ni元素的组合异常,其中ZH-1和ZH-6组合异常与金、铜的矿化关系密切,而ZH-3和ZH-4组合异常与铬、镍(铜)矿化有一定关系。在片麻状花岗岩、细晶闪长岩和花岗闪长岩中发育大量NW向的韧性剪切带和断裂构造,其中的石英脉中经常见有黄铁矿、黄铜矿和金的矿化,刻槽取样最高品位w(Au)=11.5×10-6。土壤测量的结果证实,在卢帕金矿田的东部依然存在金成矿的潜力。