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吉林省区域核心城市可持续发展能力的定量化研究 被引量:6
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作者 刘力 丁四保 《人文地理》 CSSCI 北大核心 2002年第4期59-62,共4页
本文选取吉林省 9个地区的核心城市 ,进行可持续发展能力的定量化研究。提出了针对吉林省核心城市的可持续发展能力评估的 5个方面 49个指标 ,分别采用指数化方法与因子分析法对吉林省区域核心城市可持续发展能力进行测度。经对比分析 ... 本文选取吉林省 9个地区的核心城市 ,进行可持续发展能力的定量化研究。提出了针对吉林省核心城市的可持续发展能力评估的 5个方面 49个指标 ,分别采用指数化方法与因子分析法对吉林省区域核心城市可持续发展能力进行测度。经对比分析 ,最后确定以指数化方法的研究结论作为吉林省区域核心城市可持续发展能力的测试结果 ,并对结论进行了定性分析。 展开更多
关键词 核心城市 可持续发展能力 指数化方 因子分析法
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Blow-up and Critical Fujita Exponents in a Degenerate Parabolic Equation
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作者 Takefumi Igarashi 《Journal of Mathematics and System Science》 2016年第7期276-283,共8页
In this paper, we consider the Cauchy problem of degenerate parabolic equation not in divergence form u, = uPAu + uq, p 〉 1, q 〉 1, and give the blow-up conditions and the critical Fujita exponents for the existenc... In this paper, we consider the Cauchy problem of degenerate parabolic equation not in divergence form u, = uPAu + uq, p 〉 1, q 〉 1, and give the blow-up conditions and the critical Fujita exponents for the existence of global and non-global solutions to the Cauchy problem. 展开更多
关键词 BLOW-UP global existence critical exponent degenerate parabolic equation.
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Identifying Scale-location Specific Control on Vegetation Distribution in Mountain-hill Region 被引量:3
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作者 QIU Bing-wen ZENG Can-ying +2 位作者 TANG Zheng-hong LI Wei-jiao Aaron HIRSH 《Journal of Mountain Science》 SCIE CSCD 2013年第4期541-552,共12页
vegetation continuous The scale-location specific control on distribution was investigated through wavelet transforms approaches in subtropical mountain-hill region, Fujian, China. The Normalized Difference Vegetatio... vegetation continuous The scale-location specific control on distribution was investigated through wavelet transforms approaches in subtropical mountain-hill region, Fujian, China. The Normalized Difference Vegetation Index (NDVI) was calculated as an indicator of vegetation greenness using Chinese Environmental Disaster Reduction Satellite images along latitudinal and longitudinal transects. Four scales of variations were identified from the local wavelet spectrum of NDVI, with much stronger wavelet variances observed at larger scales. The characteristic scale of vegetation distribution within mountainous and hilly regions in Southeast China was around 20 km. Significantly strong wavelet coherency was generally examined in regions with very diverse topography, typically characterized as small mountains and hills fractured by rivers and residents. The continuous wavelet based approaches provided valuable insight on the hierarchical structure and its corresponding characteristic scales of ecosystems, which might be applied in defining proper levels in multilevel models and optimal bandwidths in Geographically Weighted Regression. 展开更多
关键词 NDVI Continuous wavelet transform Characteristic scale Mountain-hill region Scale-location specific
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Chemometrics-aided Metabolic Fingerprint Method Applied in Bladder Cancer Stages Differentiating
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作者 You QIN Lin CHEN +2 位作者 Jian-Hu HUANG Shui-Han ZHANG Zuo-Wei XIAO 《Digital Chinese Medicine》 2018年第3期211-218,共8页
Objective To establish early detection and diagnosis for bladder cancer.Methods In the current study,a metabolomics strategy was used to profile bladder cancer urine metabolites in mice and to further characterize the... Objective To establish early detection and diagnosis for bladder cancer.Methods In the current study,a metabolomics strategy was used to profile bladder cancer urine metabolites in mice and to further characterize the disease status at different stages.In addition,some chemometrics algorithms were adopted to analyze the metabolites fingerprints,including baseline removal and retention time shift,to overcome variations in the experimental process.After processing,metabolites were qualitatively and quantitatively analyzed in each sample at different stages.Finally,a random forest algorithm was used to discriminate the differences among different groups.Results Four potential biomarkers,including glyceric acid,(R*,R*)-2,3-Dihydroxybutanoic acid,N-(1-oxohexyl)-glycine and D-Turanose,were discovered by exploring the characteristics of different groups.Conclusion These results suggest that combining chemometrics with the metabolites profile is an effective approach to aid in clinical diagnosis. 展开更多
关键词 Metabolic fingerprints Chemometrics approaches Data analysis Bladder cancer
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On the reconstruction of media inhomogeneity by inverse wave scattering model
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作者 ZHONG Min LIU JiJun 《Science China Mathematics》 SCIE CSCD 2017年第10期1825-1836,共12页
Consider the reconstruction of the complex refraction index of an object, which is immersed in a known homogeneous background, from the knowledge of scattered waves of the point sources outside of the object. We first... Consider the reconstruction of the complex refraction index of an object, which is immersed in a known homogeneous background, from the knowledge of scattered waves of the point sources outside of the object. We firstly establish the uniqueness for this inverse problem, which provides the theoretical basis for the reconstruction scheme. Then based on the contrast source inversion(CSI) method, we propose an algorithm determining the refraction index and the artificial wave sources alternately by a dynamic iterative scheme. The algorithm defines the iterates by solving a series of minimization problems with uniformly convex penalty terms, which are allowed to be non-smooth to include L1 and total variation like functionals, ensuring the reconstruction quality when the unknown refraction index has the special features such as sparsity and discontinuity. By choosing the regularizing parameter automatically, the algorithm is terminated in terms of discrepancy principle. The convergence property of the iterative sequence is rigorously proven. Numerical implementations demonstrate the validity of the proposed algorithm. 展开更多
关键词 inverse scattering integral equation alternating iteration TV regularization CONVERGENCE
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