矿脉雁列规律及其意义

在研究内生脉状矿床时,可见矿脉出现雁行状排列的形式(也称斜列、侧列、尖灭侧现等)。认识它们排列的规律,在理论上和实践上都是有意义的。本文根据实际材料,对充填于不同性质成矿断裂的各种雁列矿脉进行综合总结,并结合实验结果讨论其形成机制,最后阐述运用雁列规律在构造应力分析、指导找矿勘探、矿体预测及开采工作中的应用和意义。     

水下运动物体间相互作用力的计算探讨

本文首先用体内奇点分布法建立了水下多个运动回转体的数学模型,基此提出了一种新的计算多物体相互作用力的方法──等价拓展体法,达到考虑粘性、简化边界层计算的目的。以上方法都以两个运动回转体为例作了数值计算与比较。     

Integrating Uncertainty Theories with GIS for Modeling Coastal Hazards of Climate Change

Prediction of coastal hazards due to climate change is fraught with uncertainty that stems from complexity of coastal systems, estimation of sea level rise, and limitation of available data. In-depth research on coastal modeling is hampered by lack of techniques for handling uncertainty, and the available commercial geographical information systems (GIS) packages have only limited capability of handling uncertain information. Therefore, integrating uncertainty theory with GIS is of practical and theoretical significance. This article presents a GIS-based model that integrates an existing predictive model using a differential approach, random simulation, and fuzzy set theory for predicting geomorphic hazards subject to uncertainty. Coastal hazard is modeled as the combined effects of sea-level induced recession and storm erosion, using grid modeling techniques. The method is described with a case study of Fingal Bay Beach, SE Australia, for which predicted responses to an IPCC standard sea-level rise of 0.86 m and superimposed storm erosion averaged 12 m and 90 m, respectively, with analysis of uncertainty yielding maximum of 52 m and 120 m, respectively. Paradoxically, output uncertainty reduces slightly with simulated increase in random error in the digital elevation model (DEM). This trend implies that the magnitude of modeled uncertainty is not necessarily increased with the uncertainties in the input parameters. Built as a generic tool, the model can be used not only to predict different scenarios of coastal hazard under uncertainties for coastal management, but is also applicable to other fields that involve predictive modeling under uncertainty.     

黑潮及相邻海域表层砂壳纤毛虫分布模式:以夏季黄海、东海至西太平洋断面为例

2019年夏季对沿黄、东海至西太平洋跨越黑潮一个断面(122°E～145°E)的表层砂壳纤毛虫群落进行调查,研究了黑潮中砂壳纤毛虫与相邻水体的差异.根据水文环境及各站位所处的空间位置,我们将研究区域划分为大洋边缘区域、黑潮区域和大洋区域.各站位砂壳纤毛虫的丰度范围为3.95～31.94 ind·L–1,种丰富度范围为6...     

浙江省东部土壤元素地球化学特征及意义

为了研究土壤和稻米元素地球化学分布特征及影响稻米中重金属质量分数的主要因素,对浙江省东部农田根系土-稻谷样品进行了采集和分析。结果表明：各研究区均有重金属元素质量分数高于区域地球化学背景值,尤其是温州南郊地区的Hg、台州泽国地区Cd、绍兴北郊地区的Hg,其质量分数分别是背景值的6倍、5倍及9倍;7个研究区中,只有嘉兴新胜地区的As质量分数超过背景值。其原因是这些地区工业化进程迅速,人为活动频繁,污染较严重。绍兴北郊、嘉兴新丰、嘉兴新胜和桐乡崇福地区稻米中As、Cd、Cr、Hg、Se和Pb质量分数均未超过标准限值。稻米对重金属元素的吸收富集主要受土壤有机质、pH、土壤阳离子交换量和黏粒组成等土壤理化性质的影响：土壤有机碳越丰富越有利于稻米对As、Cd、Cr和Ni的吸收;稻米对As、Cd、Mn和Ni的富集系数随着pH上升而下降;土壤阳离子交换量和黏粒组成与水稻As、Cu、Hg、Mn、Pb、Se和Zn的富集系数呈显著负相关。     

The ecological distributions of N, P utilizing bacteria and heterotrophic bacteria in the moderate hypoxia zone of the Changjiang Estuary

The distributions of N utilizing bacteria (denitrifying bacteria and ammonifying bacteria), P utilizing bacteria (organic phosphobacteria and inorganic phosphobacteria) and heterotrophic bacteria in the Changjiang Estuary, and the roles of main environmental factors in distributing bacteria, are explored with observations from two cruises in June and August 2006. Comparisons between the two important periods of initial hypoxia phase (June) and developed hypoxia phase (August) show differences in both bacterial distributions and the associated main environmental factors. First, the primary group of ammonifying bacteria has larger magnitude with spatial maximum value in the hypoxic stations related to sediment in August. The phosphobacterial abundance and detection rates in August are much lower than those in June, but the denitrifying bacterial abundance becomes greater in August. However, the difference of heterotrophic bacterial abundance between June and August is not obvious. Second, main environmental factors influencing bacteria vary from initial hypoxia phase to developed hypoxia phase. Two parameters (salinity and NO₃ ^?) in surface water and five environmental parameters (pH, salinity, PO₄ ^3?, NO₃ ^? and temperature) in bottom water and surface sediment play major roles in the bacterial abundance in June, while different parameter combinations (salinity and PO₄ ^?) in surface water and different parameter combinations (DO, DOC, NO₃ ^?, PO₄ ^3? and pH) in bottom water and surface sediment play major roles in August. Moreover, the bottom bacteria distributions in area south of 31°N are related to the position of the Taiwan Warm Current in June. The bacterial abundance and distribution may respond to the environmental change in the hypoxia processes of initial phase and developed phase. During the hypoxia processes, the whole structure of bacterial functional groups probably turns to different states, causing the recycling of nutrient regeneration and aggravating hypoxia regionally.     

Vegetation cover variation in the Qilian Mountains and its response to climate change in 2000–2011

An understanding 0f variati0ns in vegetati0n c0ver in resp0nse t0 climate change is critical f0r predicting and managing future terrestrial ec0system dynamics. Because scientists anticipate that m0untain ec0systems will be m0re sensitive t0 future climate change c0mpared t0 0thers, 0ur 0bjectives were t0 investigate the impacts 0f climate change 0n variati0n in vegetati0n c0ver in the Qilian M0untains （QLM）, China, between 2000 and 2011. T0 acc0mplish this, we used linear regressi0n techniques 0n 250-m MODIS N0rmalized Difference Vegetati0n Index （NDVI） datasets and mete0r0l0gical rec0rds t0 determine spati0temp0ral variability in vegetati0n c0ver and climatic fact0rs （i.e. temperature and precipitati0n）. Our results sh0wed that temperatures and precipitati0n have increased in this regi0n during 0ur study peri0d. In additi0n, we f0und that gr0wing seas0n mean NDVI was mainly distributed in the vertical z0ne fr0m 2,700 m t0 3,600 m in elevati0n. In the study regi0n, we 0bserved significant p0sitive and negative trends in vegetati0n c0ver in 26.71% and 2.27% 0f the vegetated areas. C0rrelati0n analyses indicated that rising precipitati0n fr0m May t0 August was resp0nsible f0r increased vegetati0n c0ver in areas with p0sitive trends in gr0wing seas0n mean NDVI. H0wever, there was n0 similar significant c0rrelati0n between gr0wing seas0n mean NDVI and precipitati0n in regi0ns where vegetati0n c0ver declined thr0ugh0ut 0ur study peri0d. Using spatial statistics, we f0und that veeetati0n c0ver freauentlvdeclined in areas within the 2,500-3,100 m vertical z0ne, where it has steep sl0pe, and is 0n the sunny side 0f m0untains. Here, the p0sitive influences 0f increasing precipitati0n c0uld n0t 0ffset the drier c0nditi0ns that 0ccurred thr0ugh warming trends. In c0ntrast, in higher elevati0n z0nes （3,900-4,500 m） 0n the shaded side 0f the m0untains, rising temperatures and increasing precipitati0n impr0ved c0nditi0ns f0r vegetati0n gr0wth. Increased precipitati0n als0 facilitated vegetati0n gr0wth in areas experiencing warming trends at l0wer elevati0ns （2,000-2,400 m） and 0n l0wer sl0pes where water was m0re easily c0nserved. We suggest that spatial differences in variati0n in vegetati0n as the result 0f climate change depend 0n l0cal m0isture and thermal c0nditi0ns, which are mainly c0ntr0lled by t0p0graphy （e.g. elevati0n, aspect, and sl0pe）, and 0ther fact0rs, such as l0cal hydr0l0gy.     

Heavy metal pollution in sediments of a typical mariculture zone in South China

The heavy metal inventory and the ecological risk of the estuarine sediments in Hailing Bay, an important maricultural zone along the southern coast of China, were investigated. Results show that the surface sediments were mainly polluted by As (2.17-20.34 mg/kg), Ni (1.37-42.50mg/kg), Cu (1.21-58.84 mg/kg) and Zn (11.69-219.22 mg/kg). Furthermore, the aquafarming zone was significantly more polluted than the non-aquafarming zone, and cluster analysis suggested additional sources of heavy metal input in the aquafarming zone. As, Cr, Cu, Ni, Pb and Zn were mainly present in the non-bioavailable residual form in the surface sediments, whereas Cd was predominantly in the highly mobile acid soluble and reducible fractions. The ecological risk of the polluted sediments stemmed mainly from Cd, and from As, Cu and Pb to less degrees. The highest potential risks occurred near the aquaculture base, indicating the need to control heavy metal inputs from aquafarming activities.     

Vision-based system of AUV for an underwater pipeline tracker

This paper describes a new framework for detection and tracking of underwater pipeline,which includes software system and hardware system.It is designed for vision system of AUV based on monocular CCD camera.First,the real-time data flow from image capture card is pre-processed and pipeline features are extracted for navigation.The region saturation degree is advanced to remove false edge point group after Sobel operation.An appropriate way is proposed to clear the disturbance around the peak point in the process of Hough transform.Second,the continuity of pipeline layout is taken into account to improve the efficiency of line extraction.Once the line information has been obtained,the reference zone is predicted by Kalman filter.It denotes the possible appearance position of the pipeline in the image.Kalman filter is used to estimate this position in next frame so that the information of pipeline of each frame can be known in advance.Results obtained on real optic vision data in tank experiment are displayed and discussed.They show that the proposed system can detect and track the underwater pipeline online,and is effective and feasible.     

利用sPn震相计算九江-瑞昌地区地震的震源深度

近震震相sPn与Pn到时差与震中距无关,只与震源深度和地壳模型有关.应用此方法,计算了发生在九江-瑞昌地区两次地震的震源深度,结果表明,利用区域台网sPn-Pn的到时差确定地震震源深度较为可信.根据华南地区速度模型,建立了九江-瑞昌地区sPn与Pn到时差与震源深度便查表.