基于边缘梯度投影图的航空影像初始视差确定     

袁修孝  许骥  谢酬 《武汉大学学报(信息科学版)》2005,30(9):762-765

通过对航空立体像对及其边缘影像的分析,提出了一种新的航空影像初始视差的确定方法。试验表明,该算法能准确地确定纹理单一、影像对比度小的航空立体影像对的初始视差,可明显提高影像匹配的精度和可靠性。  相似文献   

基于已知定向参数影像的光束法区域网平差   总被引：1，自引：1，他引：1  

袁修孝  季顺平  谢酬 《武汉大学学报(信息科学版)》2005,30(11):955-959

从自检校光束法区域网平差模型出发,建立了利用同一地区已知定向参数的影像解求新获取影像外方位元素并进行目标定位的数学模型。以此为基础,对来自某地区相隔两年的三期不同摄影比例尺航空影像两两组合地进行联合光束法区域网平差。结果表明,当两期影像比例尺相近时,所解求的新影像外方位元素和加密点坐标精度基本达到常规光束法区域网平差的精度;当两期影像比例尺不同时,利用已知定向参数的大比例尺影像解求出的小比例尺影像的外方位元素和加密点坐标可满足现行规范精度要求,利用已知定向参数的小比例尺影像去解求大比例尺影像的外方位元素和加密点坐标精度明显下降且不可用。本文的研究证实,就同一地区的多时相航摄影像而言,利用已知定向参数的影像进行新影像的定向方法是可行的。  相似文献   

Sulfates on Mars: A systematic Raman spectroscopic study of hydration states of magnesium sulfates     

Alian Wang  John J. Freeman  Bradley L. Jolliff  I-Ming Chou 《Geochimica et cosmochimica acta》2006,70(24):6118-6135

The martian orbital and landed surface missions, OMEGA on Mar Express and the two Mars Explorations Rovers, respectively, have yielded evidence pointing to the presence of magnesium sulfates on the martian surface. In situ identification of the hydration states of magnesium sulfates, as well as the hydration states of other Ca- and Fe- sulfates, will be crucial in future landed missions on Mars in order to advance our knowledge of the hydrologic history of Mars as well as the potential for hosting life on Mars. Raman spectroscopy is a technique well-suited for landed missions on the martian surface. In this paper, we report a systematic study of the Raman spectra of the hydrates of magnesium sulfate. Characteristic and distinct Raman spectral patterns were observed for each of the 11 distinct hydrates of magnesium sulfates, crystalline and non-crystalline. The unique Raman spectral features along with the general tendency of the shift of the position of the sulfate ν₁ band towards higher wavenumbers with a decrease in the degree of hydration allow in situ identification of these hydrated magnesium sulfates from the raw Raman spectra of mixtures. Using these Raman spectral features, we have started the study of the stability field of hydrated magnesium sulfates and the pathways of their transformations at various temperature and relative humidity conditions. In particular we report on the Raman spectrum of an amorphous hydrate of magnesium sulfate (MgSO₄·2H₂O) that may have specific relevance for the martian surface.  相似文献   

西藏朱诺斑岩型Cu-Mo矿床成矿斑岩金红石成因及找矿指示意义     

戴婕  倪师军  黄勇  丁俊  周义明 《地质学报》2018,92(6):1228-1239

西藏冈底斯成矿带南缘西段新发现的朱诺铜矿床是具有大型规模的斑岩铜钼矿床。金红石是斑岩铜矿床中最典型的副矿物之一,对其成分和结构特征的研究能反演成矿流体演化过程并确定斑岩铜矿的主矿体。在详细的野外地质观察的基础上,对钾化带成矿斑岩(黑云花岗闪长岩)中金红石的研究表明:金红石主要与磁铁矿(Ⅰ类)、赤铁矿共生(Ⅲ类),常形成固溶体分离结构并分布在黑云母裂隙及附近;其次呈板状(长10~80μm,宽3~10μm)、颗粒状(粒径10~40μm)、不规则状独立分布在石英硫化物脉中(Ⅱ类)。Ⅰ类金红石是由钛磁铁矿在富S条件下反应形成的;Ⅲ类金红石由钛铁矿在富氧条件下反应形成的;Ⅱ类金红石是由含Ti的热液结晶沉淀而来的。成矿斑岩全岩中TiO_2的含量为0.66%,为金红石的形成提供了丰富的物源。成矿斑岩金红石中的电子探针分析结果显示,其成分除含有约94%的TiO_2外,还含有V_2O_3,Nb_2O_5,FeO,WO_3,CaO,SiO_2,Al_2O_3,ZrO_2,几乎不含或很少含MgO和MgO。金红石中V_2O_3范围为0.20%~2.39%,平均为0.49%,Nb2O5的含量范围为0.20%~4.63%,平均1.25%,WO_3和FeO的平均含量分别为1.92%和1.81%,且有约0.05%的ZrO_2异常。利用金红石找矿方法开展朱诺矿床外围找矿时,首先必须考虑金红石中V_2O_3的含量(0.2%,Ⅱ类金红石0.5%),在此基础上考虑Nb的含量(0.2%,乙类金红石2.6%),同时考虑W,Fe偏高,Zr异常的特点。对Ⅱ类金红石还需要额外考虑其粒径大于10μm。  相似文献   

Optimization of landfill leachate treatment by microwave oxidation using the Taguchi method     

C.-J. Yeh  S.-L. Lo  J. Kuo  Y.-C. Chou 《International Journal of Environmental Science and Technology》2018,15(10):2075-2086

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Atmospheric teleconnection mechanisms of extratropical North Atlantic SST influence on Sahel rainfall   总被引：1，自引：0，他引：1  

Yuwei Liu  John C. H. Chiang  Chia Chou  Christina M. Patricola 《Climate Dynamics》2014,43(9-10):2797-2811

Extratropical North Atlantic cooling has been tied to droughts over the Sahel in both paleoclimate observations and modeling studies. This study, which uses an atmospheric general circulation model (GCM) coupled to a slab ocean model that simulates this connection, explores the hypothesis that the extratropical North Atlantic cooling causes the Sahel droughts via an atmospheric teleconnection mediated by tropospheric cooling. The drying is also produced in a regional climate model simulation of the Sahel when reductions in air temperature (and associated geopotential height and humidity changes) from the GCM simulation are imposed as the lateral boundary conditions. This latter simulation explicitly demonstrates the central role of tropospheric cooling in mediating the atmospheric teleconnection from extratropical North Atlantic cooling. Diagnostic analyses are applied to the GCM simulation to infer teleconnection mechanisms. An analysis of top of atmosphere radiative flux changes diagnosed with a radiative kernel technique shows that extratropical North Atlantic cooling is augmented by a positive low cloud feedback and advected downstream, cooling Europe and North Africa. The cooling over North Africa is further amplified by a reduced greenhouse effect from decreased atmospheric specific humidity. A moisture budget analysis shows that the direct moisture effect and monsoon weakening, both tied to the ambient cooling and resulting circulation changes, and feedbacks by vertical circulation and evaporation augment the rainfall reduction. Cooling over the Tropical North Atlantic in response to the prescribed extratropical cooling also augments the Sahel drying. Taken together, they suggest a thermodynamic pathway for the teleconnection. The teleconnection may also be applicable to understanding the North Atlantic influence on Sahel rainfall over the twentieth century.  相似文献   

Simulation analysis of the impact of excavation backfill on permafrost recovery in an opencast coal-mining pit   总被引：3，自引：0，他引：3  

Wei Cao  Yu Sheng  Jichun Wu  Jing Li  Jinping Li  Yaling Chou 《Environmental Earth Sciences》2016,75(9):837

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Success factors of enhanced disaster resilience in urban community     

Jui-Sheng Chou  Jia-Huei Wu 《Natural Hazards》2014,74(2):661-686

Due to its unique geographic environment, Taiwan is prone to natural disasters such as earthquakes and typhoons that can cause heavy casualties and huge property losses. The effects of global warming have also increased extreme climate events and the frequency and severity of natural disasters. Therefore, disaster prevention/mitigation and response is not only an important government policy issue, but also an important daily life issue. To increase the awareness of natural disasters and the importance of community safety, the Taiwan government actively promotes a community disaster prevention system. However, to avoid over-reliance on the government taskforce, the spontaneous participation and cooperation within communities can complete specific disaster preparedness and reinforce local resources for disaster prevention and response. Although the concept of disaster-resilient community (DRC) has been shaped for a long period of time, community residents cannot keep pace with the government, which may decrease the effectiveness of DRC development. Therefore, theoretical and practical studies of urban DRC become imperative. This qualitative case study used the participant observation method to collect relevant empirical data by performing action research with self-reflection. Particularly, this article is supplemented by service work experience of the researchers in DRC promotion. A qualitative analysis of case communities during training in disaster preparedness revealed the critical success factors (CSFs) affecting the level of community-based disaster prevention and protection works. Based on the literature and empirical data, the CSFs are discussed through three spindle constructs: coping strategy, operations management, and organizational behavior. Finally, the conclusions and suggestions are given for promoting sustainable DRC.  相似文献   

表碛型冰川的时序InSAR识别方法与形变监测研究     

黄淞波  常占强  谢酬  田帮森  杨箐 《测绘科学》2022,47(1)

为了对表碛覆盖型冰川边界进行识别并掌握其变化,以伦道夫(RGI6.0)冰川编目为基础,基于Sentinel-1数据运用时序InSAR技术对昆仑山东段表碛覆盖型冰川进行了形变监测。根据2014年10月至2020年9月表碛覆盖下冰川的时序形变情况,将InSAR形变与光学影像相结合验证冰川边界。结果表明:对昆仑山东段研究区域内280条冰川边界的研究中,探测到3处表碛覆盖型冰川,对边界进行调整后冰川面积分别增加0.19、0.1、0.18 km~2。根据时序形变,发现冰川表碛形变呈现明显的季节周期性,形变与温度、坡向显著相关。另外,表碛覆盖型冰川的变形幅度在(-5,5)cm范围内,暖季变形幅度最大,且地形对突变幅度造成影响。这表明时序InSAR技术可对表碛覆盖型冰川进行形变监测与识别研究。  相似文献   

A time series of mercury accumulation and improvement of dietary feed in net caged Atlantic salmon (Salmo salar)     

Chou CL 《Marine pollution bulletin》2007,54(6):720-725

The study was undertaken to investigate the uptake of mercury in salmon throughout the entire farming period at the net cage. Mercury concentrations in muscle, liver, kidney, and gill and responses to the various dietary mercury concentrations were determined. The accumulation of mercury is in the order of kidney>gill=liver>muscle. The highest mercury peak concentrations were observed for both kidney and gill at the parr-smolt period, while liver and muscle mercury peaked one month later after caging at the grow-out site. High dietary sodium and calcium fed to the salmon contributed to the elevation of mercury in kidney and gill during the smolting process. The mercury burden over the grow-out period increased sharply with a linear relationship of mercury uptake. The tissue mercury burden per gram of growth was calculated using the slope of mercury burden and the slope of growth over the period of each stage. The results showed dietary mercury loadings on marketable salmon were within tolerance limits of FDA and US EPA. Rapid growth of salmon and low dietary mercury progressively reduces the uptake of mercury in salmon. The time series of mercury monitoring showed that mercury concentrations in salmon were greater at the parr stage in freshwater than at the grow-out stage in salt water.  相似文献