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1.
Under the artificial condition the 59Fe morphology in sea water, its concentration in sediment and phytoplankton, its distribution and metabolism in tissue organs of marine animals were studied. The results showed that the morphology of 59Fe was in a particulate state in sea water. The adsorption rule of 59Fe by three kinds of sediments was similar. The concentration ability of 59Fe by phytoplankton was very strong. The critical concentration organs of S9Fe by marine animals were viscera. The gross radioactivity of 59Fe was mainly concentrated in protein. The concentration factor of 59Fe by DNA was the highest one. After excretion experiment, 59Fe of all the tissue organs was not detected. Small part of59Fe remained in the organic acid and protein state. There was a redistribution process in sediment for59Fe. 相似文献
2.
The impact of several chemical poisons on the Arca granosa absorbing 45Ca was studied. The results showed that the absorption of 45Ca in the blood and the soft tissue by Arca granosa was inhibited by the inorganic compounds of Cu, Zn, Pd, Cd, Hg and so on, among which the inhibition of Cd was the strongest, next was that of Cu and Hg. But the inhibition of the absorption of 45Ca in the shell of Arca granosa was little. The impact of three kinds of energy metabolism inhibitory substances on the absorption of 45Ca by the Area granosa showed that the absorption was an active transfer process. 相似文献
3.
Fulong Wu 《Transactions in GIS》2003,7(2):193-210
This research aims to understand the source of temporal fluctuations in real estate development through simulating a cellular automata model. In this cellular automata city, investment decisions are made according to the profitability measured in a local neighbourhood. If developers think there is enough of a profit margin in a particular site, i.e. a 'niche' of investment, they will increase investment at that site. However, by increasing investment at the site, new 'niches' might be created. Therefore, the action of converging towards an equilibrium state itself paves the way towards new fluctuations. This model demonstrates the potential of using simulation to increase our understanding of real estate dynamics. The experiments suggest that locally made 'rational' decisions can lead to temporal fluctuations because of non–linearity (discrete changes/densification and local bounded information). Interestingly, the fluctuations may show the property of a temporal fractal. This requires a sufficiently sensitive process of 'niche' formation compared with a relatively large impact of additional investment. The simulation suggests that the impact should be 4 to 20 times higher than the threshold over which a niche will be formed. This condition is satisfied in most cases of real estate investment, thus suggesting a self–organised criticality in complex real estate development. 相似文献
4.
Emerging Chinese Cities: Implications for Global Urban Studies 总被引:2,自引:0,他引:2
Fulong Wu 《The Professional geographer》2016,68(2):338-348
Chinese cities are emerging in multiple senses: They have created new physical spaces to accommodate the fast urbanization of the country but have also developed new properties and characteristics along with urban transformation. The novelty created by emerging cities in China is not easily covered by Western urban theory. This article examines the dynamism of Chinese urban transformation, especially political economic changes vis-à-vis so-called neoliberalism, and spatial outcomes as diverse and contrasting spaces of formality and informality. Finally, this article speculates on implications for global urban studies. 相似文献
5.
利用Pettitt非参数检验法和Mann-Kendall非参数趋势检验法,分析年最大洪峰流量序列的非一致性,确定序列的变异形式,采用“分解-合成”理论对其进行一致性修正,得到过去、现状两种条件下年最大洪峰流量序列,根据贝叶斯理论对序列一致性修正前后参数不确定性进行估计,并对其预报区间优良性进行评价。研究结果表明:年最大洪峰流量序列变异点发生在1993年,序列整体上升趋势不显著,在1957-1993年子序列呈显著下降趋势,而1994-2006年子序列变化趋势不显著,跳跃变异为序列主要变异形式;给出了实测、还原及还现序列参数后验分布估计值及95%置信区间,将其结合优化适线法进行P-Ⅲ型频率分析,得到修正前后设计频率年最大洪峰流量预报区间估计值;还原、还现序列与实测序列相比,预报区间覆盖率均提高24%,平均带宽分别减少39.59%、23.17%,平均偏移幅度分别减少28.45%、11.39%。通过对非一致性年最大洪峰流量序列还原/还现计算,可减小参数估计不确定性对其计算产生的影响,从而提高预报区间的可靠性。 相似文献
6.
随着互联网的飞速发展,医疗数据爆炸性增长,大量的医疗数据面临着安全共享问题.本文提出了一种基于医疗联盟链的数据安全保护方法,其中包括提出了一种安全认证与访问控制模型,并将查询逻辑分离存储技术引入该模型中,同时描述了基于医疗联盟链的认证凭据和访问权限数据的存储和访问.基于医疗联盟链的安全认证与访问控制模型包含了三个角色,第一角色是患者,第二角色是医护人员,第三角色是医疗联盟链.通过查询逻辑分离存储技术保护患者数据隐私,查询逻辑分离技术与医疗联盟链技术紧密结合,满足了不同医院之间医疗数据共享的需求,保障了患者的数据隐私和医护人员查阅数据的权限. 相似文献
7.
8.
基于非局部滤波的SAR强度RC合成变化检测法对小图斑、线型地物等动态监测灵敏,且对数据获取无时空基线要求,在多云多雨城市地表要素变化检测中具备潜力。本文研究以多时相SAR强度RC合成图为数据源,提出一种基于色彩空间变换的变化图斑半自动提取方法,即通过色彩空间转换、训练样本选取、监督分类影像分割、变化区域提取4步骤,可实现基于SAR强度图的城市建设用地动态监测与图斑高效更新。选取南京河西新城与江北新区为示范,以最优参数配置(3特征向量与10样本类别)进行试验,实现了优于88%的建设用地查准率指标。 相似文献
9.
转型期上海社会空间分异研究 总被引:75,自引:14,他引:61
采用2000年第五次全国人口普查数据库中居民委员会尺度的数据,对转型期上海城市空间重构与分异展开研究。存在6类社会区:计划经济时代建设的工人居住区、外来人口集中居住区、白领集中居住区、农民居住区、新建普通住宅居住区、离退休人员集中居住区。通过计算分异指数,发现当前上海存在严重的住房分异;但并不存在明显的以社会经济属性为基础的社会空间分异。造成这一现象的原因在于计划经济时代的历史以及仍然存在的大型企事业单位对住房的影响。中国城市目前的社会空间分异在程度上与西方城市还有根本的差异。 相似文献
10.
Cheng Zhiheng Liu Biao Zou Quanle Wang Xin Feng Jicheng Zhao Zhiyan Sun Fulong 《Natural Resources Research》2020,29(3):1601-1615
Natural Resources Research - Mining-induced fracture plays a key role in gas drainage for gas burst-prone underground coal mines, especially for closely multilayered coal seams. The layout and... 相似文献