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151.
Internet的迅速发展和WWW的面世给传统的GIS软件开发提出了新的挑战,本文通过对Java特点的阐述,论述了Java成为GIS软件开发的新工具的可能性和必然性,笔者认为在不久的将来,Java必将取代Visual Basic和Visual C++成为GIS软件开发的新工具。 相似文献
152.
主体功能区规划是我国正在施行的一项战略性空间规划制度,陆海统筹是其重要的规划原则,然而在陆域和海洋规划由不同部门主导、分别编制的工作思路下,陆海统筹难以得到切实保障。文章剖析了沿海地区陆域和海洋主体功能分区不协调的现实困境,以山东省主体功能区规划为例,从陆域和海洋主体功能分区不协调、规划保障措施不对接两方面分析了规划单元陆海分区无法衔接的原因,并提出了统筹沿海地区主体功能区划分、发挥海岸带规划的陆海统筹作用和推进陆海统筹的规划保障措施实施等对策建议,以期为我国国土空间规划工作中主体功能分区提供借鉴,促进沿海地区的人口、经济、资源环境与国土空间开发利用保护的充分协调。 相似文献
153.
Temporal changes in biological characteristics of small yellow croaker Larimichthys polyactis in the Yellow Sea were examined for the period of 1960–2008. The body size and age of small yellow croaker decreased substantially, in particular, average length of fish in 2008 was reduced by ~85% than those occurring in 1985, and at that time ~93% of the total catch was dominated by one-year-old individuals. Correspondingly, growth parameters also varied significantly over the years, i.e., k(growth coefficient) and t_0(zero-length age) gradually increased from 0.26 and –0.58 year in 1960 to 0.56 and –0.25 year in 2008, respectively. Although, L∞(body length)sharply decreased from 34.21 cm in 1960 to 24.06 cm in 2008, and t_r(inflexion age) decreased from 3.78 year in1960 to 1.61 year in 2008. There was a great increase both in natural mortality coefficient and fishing mortality coefficient. However, according to the gray correlation analysis, changes in the biological characteristics of small yellow croaker were induced by different stressors ranked as: fishing vessel powerfeeding gradesea surface temperature. This study suggests that the active fishery management measures for biological characters of fish populations should be considered. 相似文献
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目的:运用网络药理学和分子对接技术探讨麻黄附子细辛汤合肾四味汤治疗变应性鼻炎(AR)的作用机制。方法:利用TCMSP数据库,获取并筛选麻黄附子细辛汤合肾四味汤的活性成分和潜在靶点;通过多个数据库挖掘AR的相关靶点,并与麻黄附子细辛汤合肾四味汤的潜在靶点取交集,获得麻黄附子细辛汤合肾四味汤治疗AR的核心靶点,同时进行蛋白质-蛋白质相互作用(PPI)网络构建,利用R语言对核心靶点进行基因本体(GO)功能和京都基因与基因组百科全书(KEGG)通路富集分析;采用分子对接技术将主要活性成分与核心靶点进行分子对接。结果:麻黄附子细辛汤合肾四味汤中的67个有效成分可以通过白细胞介素-17受体通路、Toll样受体通路、低氧诱导因子受体通路(HIF-1 Signaling Pathway)等多种受体通路治疗AR。分子对接结果显示槲皮素与基质金属蛋白酶9(MMP9)、木犀草素与白细胞介素-6大分子蛋白有良好的结合性。结论:麻黄附子细辛汤合肾四味汤可以从多靶点、多通路治疗AR,为后续研究提供了新的方向。 相似文献
156.
Yintao Lu Xiwu Luan Boqing Shi Weimin Ran Fuliang Lü Xiujuan Wang Quanbin Cao Xiaoyong Xu Hui Sun Genshun Yao 《海洋学报(英文版)》2021,40(2):81-94
Analysis of 3 D seismic data and well log data from the Rovuma Basin in East Africa reveals the presence of a late Eocene channel-lobe complex on its slope. The first two channels, denoted as channel-1 and channel-2, are initiated within a topographic low on the slope but come to a premature end when they are blocked by a topographic high in the northwest region of the basin. New channels migrate southeastward from channel-1 to channel-6 due to the region's sufficient sediment supply and stripping caused by bottom currents. The primary factors controlling the development of the channel complex include its initial paleo-topographic of seafloor, the property of gravity flows, the direction of the bottom current, and the stacking and expansion of its levees. The transition zone from channel to lobe can also be clearly identified from seismic sections by its pond-shaped structure. At a certain point, thest systems record a transiton from erosive features to sedimentary features, and record a transition from a confined environment to an open environment. Channels and lobes can be differentiated by their morphologies: thick slump-debris flows are partly developed under channel sand sheets,whereas these slump-debris flows are not very well developed in lobes. Well log responses also record different characteristics between channels and lobes. The interpreted shale volume throughout the main channel records a box-shaped curve, thereby implying that confined channel complexes record high energy currents and abundant sand supply, whereas the interpreted shale volume throughout the lobe records an upward-fining shape curve,thereby indicating the presence of a reduced-energy current in a relatively open environment. Within the Rovuma Basin of East Africa, the average width of the Rovuma shelf is less than 10 km, the width of the slope is only approximately 40 km, and the slope gradient is 2°–4°. Due to this steep slope gradient, the sand-rich top sheet within the channel also likely contributes to the straight feature of the channel system. It is currently unclear whether the bottom current has any effect on its sinuosity. 相似文献
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158.
Xu Ning Wu Shiguo Shi Buqing Lu Bing Xue Liangqing Wang Xiujuan Jia Ying 《Marine and Petroleum Geology》2009,26(8):1413-1418
Many mud diapirs have been recognized in southern Okinawa Trough by a multi-channel seismic surveying on R/V KEXUE I in 2001. Gas hydrates have been identified, by the seismic reflection characteristics, the velocity analysis and the impedance inversion. Geothermal heat flow around the central of the mud diapir has been determined theoretically by the Bottom Simulating Reflectors (BSRs). Comparing the BSR derived and the measured heat flow values, we infer that the BSR immediately at the top of the mud diapirs indicate the base of the saturated gas hydrate formation zone (BSGHFZ), but not, as we ordinarily know, the base of the gas hydrate stability zone (BGHSZ), which could be explained by the abnormal regional background heat flow and free gas flux associated with mud diapirs. As a result, it helps us to better understand the generation mechanism of the gas hydrates associated with mud diapirs and to predict the gas hydrate potential in the southern Okinawa Trough. 相似文献
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提出了一种提取山脊线和山谷线的新方法。基于矢量等高线,以Mean Shift思路为全局步骤,以多因素流水模型为局部追踪依据,在提取特征点的同时完成山脊线、山谷线追踪。首先建立等高线间的拓扑关系,确立追踪起点;然后分割等高线弯曲,并依此建立虚拟扇形区域;最后,建立多因素流水模型,根据"流向最大概率"原则,追踪山脊、山谷线。实验结果表明,该方法能更加准确地提取地形特征点,增强抗噪性,并在特征点提取的同时完成山脊、山谷线的连接,大大减少运算量。 相似文献