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111.
Thirty years(1984–2014) of groundwater science teaching and research in China: A dissertation-based bibliometric survey 下载免费PDF全文
ZHAI Yuan-zheng JIANG Shi-jie TENG Yan-guo WANG Jin-sheng GU Hong-biao XIE Liang YIN Zhi-hua 《地下水科学与工程》2015,3(3):222-237
In order to track the footprint of groundwater science teaching and research in China during the past years, a bibliometric analysis was conducted based on the database of China National Knowledge Infrastructure (CNKI), which covered the time span from 1984 to present and included more than 2.6 million master and doctoral dissertations from hundreds of institutions of Mainland China. The bibliometric analysis summarized output, geographical, and institutional patterns, as well as research directions and hotspots in groundwater studies in China in the period of 1984-2014. A total of 1 396 groundwater-related dissertations including 1 161 master dissertations and 235 doctoral dissertations, contributed by 128 institutions distributed in 53 cities nationwide, were searched out in the database. It can be seen obviously that, the groundwater science teaching and research in China has experienced a notable growth in the past three decades especially during 2000-2014. Groundwater modeling, resource, and exploitation were the top three major subject categories; China University of Geosciences (Beijing), Jilin University and Chang’an University were the top three productive institutions together accounting for more than one third of the total dissertations and 50% of the doctoral dissertations, which further prompted the cities (Beijing, Changchun, and Xi’an) to become the top three productive cities. The dissertations generally covered all the international research topics, which indicated that hydrogeologists in China have tracked the international frontier closely during the past decades. The keywords analysis revealed that, (1) numerical modeling was still the hottest topic and PHREEQC, MODFLOW, GMS, and FEFLOW were the four most used softwares; (2) the topics related with groundwater pollution and quality developed steadily and rapidly; (3) environmental isotopes and GIS were frequently used tools for hydrogeological condition analysis, and spatial data processing respectively; and (4) the unsaturated zone as an integral part of aquifers attracted more and more attentions from hydrogeologists focus on saturated zone. 相似文献
112.
Forecasting weather parameters such as temperature and pressure with a reasonable degree of accuracy three hours ahead of
the scheduled departure of an aircraft helps economic and efficient planning of aircraft operations. However, these two parameters
exhibit a high degree of persistency and have nonstationary mean and variance at sub-periods (i.e. at 0000, 0300, 0600,…,
2100UTC). Hence these series have been standardised (to have mean 0 and variance 1) and thereafter seasonal differenced (lag
8) to achieve almost near stationarity. An attempt has been made to fit the standardised and seasonal differenced series of
Chennai (a coastal station) and Trichy (an inland station) airport into an Auto Regressive (AR) process. The model coefficients
have been estimated based on adaptive filter algorithm which uses the method of convergence by the steepest descent. The models
were tested with an independent data set and diagnostic checks were made on the residual error series. An independent estimation
of fractal dimension has also been made in this study to conform the number parameters used in the AR processes. The models
contemplated in this study are parsimonious and can be used to forecast surface temperature and pressure. 相似文献
113.
海洋区域地质调查近年来逐渐得到重视,海洋地质调查技术的发展也为开展海洋区域地质调查奠定了基础。上海地区社会经济发展对地质工作的需求,为摸清上海市长江口及邻近海域的地质现状提出了必然要求。本文在系统整理长江口及邻近海域地质资料的基础上,重点分析了区内存在的重点地质问题和研究存在的问题,根据海洋地质调查的技术发展,结合国内相关地区的调查经验,对长江口及邻近海域内区域地质调查进行了展望,提出了采用综合物探技术、地质取样和测试分析进行综合地质环境调查的建议,并对具体采用的调查技术和调查内容进行了论述。 相似文献
114.
《Geoforum》2017
Climate change increases the complexity and uncertainty of regional natural resource management (NRM), calling into question the appropriateness of linear knowledge-transfer approaches. In this paper we reflect on knowledge practices among a partnership of researchers and NRM planners, under a federal program of NRM investment intended to ‘deliver information’ to regional NRM planners to support planning for climate change. We unpack ‘container’ and ‘conduit’ metaphors of linear, one-way communication invoked by the starting conditions, and explore whether more relational ways of communicating were achieved. A key theme emerged early in the research that NRM planners felt overwhelmed by the sheer volume of information available and discouraged by the irrelevance of much of it to their climate change planning. Our research-practice collaboration unfolded in this context and through ongoing face-to-face and virtual engagement over a period of two years. The collaborative approach featured joint identification of priority activities, co-design of planning approaches, and the iterative co-development of an online ‘information portal’, which acted as a boundary object. We report the emergence of a ‘knowing system’, resulting from these efforts to foster relationships and co-produce boundary objects in a particular geographic context. Our findings highlight the potential benefits of investing in the capacity of researchers and NRM practitioners to engage in collaborative research partnerships premised on the emergence of knowing systems. 相似文献
115.
我国南极固体地球科学研究的最新进展和主要成果 总被引:3,自引:0,他引:3
本文报道了近三年中国在南极地球科学研究上取得的主要进展和成果:编制了南极大陆地质图,完善了布兰斯菲尔德海峡地层层序和构造格架,揭示了拉斯曼丘陵泛非构造-热事件的地质含义,首次在南极发现硅硼镁铝矿,进一步研究了菲尔德斯半岛火山岩时代和陆地威德尔生物地理区,获得长城站地区地壳电性结构,建立了菲尔德斯半岛GPS卫星地壳形变监测网,成功地进行了拉斯曼丘陵地区小象幅航摄成图和卫星影象数字制图,论述了早期太阳星云化学分馏作用连续性的岩石化学证据。 相似文献
116.
117.
利用2021年2月28日机载探测资料, 结合欧洲中期天气预报中心ERA5再分析资料、陕西省延安站探空资料, 分析飞机发生严重积冰的天气背景和云的宏微观结构特征。此次严重积冰天气是受高空槽、低空切变线、低空急流和地面冷锋共同影响的结果。ERA5再分析资料表明:过冷水大值区主要分布于锋区前部暖侧的700 hPa至600 hPa高度。探空资料表明:飞机探测区环境温度为-9~-3℃, 温度露点差为0℃, 具有发生严重积冰的温度和湿度条件。飞机遭遇严重积冰期间环境温度为-8~-5℃, 云粒子探头观测的液态水含量平均为0.35 g·m-3, 最大为0.7 g·m-3;总水含量仪观测的液态水含量平均为0.5 g·m-3, 最大为0.85 g·m-3, 有11 min大于0.45 g·m-3;云粒子中值体积直径平均为20.3 μm, 云粒子数浓度平均为149.3 cm-3;云粒子数浓度由低层到高层呈增大趋势, 而云粒子中值体积直径变化趋势与之相反。计算表明:国王350飞机在穿云作业时, 云中过冷水含量分别高于0.04 g·m-3, 0.15 g·m-3和0.45 g·m-3时可能遭遇轻度积冰、中度积冰和严重积冰。 相似文献
118.
Microcracks in the Cretaceous Ryoke-type granite in Japan were investigated by using deep drilling core samples collected in the Mizunami Underground Research Project of the Japan Nuclear Cycle Development Institute (JNC). The granite body suffered brittle deformation associated with Tertiary thrust movement. Based on core-scale and microscopic deformation features, the drill core from a depth of 300 to 700 m is divided into four domains, i.e. (A) undeformed granite, (B) granite intruded by cataclastic seams, (C) fractured granite in the fault damage zone, and (D) foliated cataclasite at the fault center. To characterize microcrack geometries in each domain, we employed the impregnation method using a low-viscous acrylic resin doped with fluorescent agents and captured the microcrack images by confocal laser scanning microscopy (CLSM). The CLSM image in the fault damage zone revealed anisotropic development of microcrack networks related to the fault movement. Both CLSM observation and porosity measurements reveal a drastic increase of micro-pores in the foliated cataclasite, possibly caused by fragmentation, and granulation and crack sealing in the fault zone. 相似文献
119.
极震区岩体地震动力破坏是造成极震区严重的地震地质灾害和次生灾害的根本原因。汶川地震中因此而导致的交通工程结构损坏、中断和次生崩滑流、堰塞湖等地质灾害,不仅加剧了灾害损失,并给震后的灾区恢复重建和对外交通遗留了较多的安全隐患。从岩体稳定、山体稳定和区域稳定的层次,分别对有关极震区岩体地震动力破坏的主要研究成果进行了系统总结,分析了其现状和存在的问题。结合对研究思路和方法论的讨论,构建了极震区岩体地震动力破坏研究的体系框架,提出了极震区岩体地震动力破坏研究的主要内容和方向,以期明晰概念,理清思路,为有关问题的深入研究提供有益的参考。 相似文献
120.
中国位于全球三大成矿域的交汇部位,成矿条件优越.同时发育有几种独具特色的成矿系统,如西南大面积低温成矿域、峨眉山地幔柱成矿系统以及广泛分布在华北的前寒武纪条带状铁矿,引起国内外地质学界的广泛关注.对这3种特殊的成矿系统近年来的科研进展进行了综述性回顾,并提出今后需要加强研究的若干重要科学问题. 相似文献