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981.
982.
983.
晚清时期,新知识群体的崛起,现代印刷业的进步,报刊语言和文体的成型,都为民族主义的产生提供了现实的可能性.从天下到万国和世界,由历史循环论到历史进化论,晚清报刊的时空转换和时空想象同时也催生了民族观念和国家观念的形成.在办报办刊理念上,晚清报刊以通上下内外之情强国,以培育国民精神建立国家认同,以改良思想救国,以正确、适宜之独立言论报国,其根本目的都是为了建立现代民族国家.晚清报刊不仅为民族主义的产生提供现实基础和观念前提,更为想象中国进行舆论造势,成为民族主义思潮勃兴的引擎和载体.  相似文献   
984.
Aggregation convergecast scheduling in wireless sensor networks   总被引:3,自引:0,他引:3  
We consider the problem of scheduling in wireless sensor networks for the purposes of aggregation convergecast. We observe that existing schemes adopt essentially a two phase approach, consisting of, first, a tree construction and, second, a scheduling phase. Following a similar approach, we propose two new improvements, one to each of the two phases. Starting with a new lower bound on the schedule length, we make use of it in the tree construction phase. The tree construction phase consists of solutions to instances of bipartite graph semi-matchings. The scheduling phase is a weight-based priority scheme that obeys dependency (tree) and interference constraints. Our extensive experiments show that, overall, our proposed solution not only outperforms all previously proposed solutions in terms of schedule length, but it also significantly extends the network’s lifetime.  相似文献   
985.
The multi-granular switching concept defined in Generalized Multiprotocol Label Switching (GMPLS) is expected to be a future-proof solution for mitigating the Optical Crossconnet scalability problems associated with the skyrocketing growth of traffic in optical transport networks. In this paper, we address the problem of planning the GMPLS-based (or multi-granular) transport network with color (or label) conversion and signal regeneration capabilities. The objective of the problem is to minimize the total weighted port count in the transport network. The novelty of this problem lies in the incorporation of the following for the first time: (1) considering all traffic granularities defined in GMPLS; (2) allowing wavelength, waveband, and fiber conversions; (3) considering the optical-reach limitation of optical signals; and (4) customizing the optical reach of all-optical paths. Due to the computational complexity of the problem, we propose various efficient heuristics that are capable of solving large-sized problems in a reasonable amount of time. In order to achieve the best possible solution to the planning problem, a comprehensive evaluation of different heuristic variations through illustrative examples and simulations is conducted. The results also provide valuable insights into many issues that can contribute to further research and development in this area.  相似文献   
986.
In an optical network, the connections are generally bidirectional, but their QoS parameters in each direction may be not the same. In this paper, we propose an enhanced algorithm called Node Label Order First (NLOF), which can maintain asymmetrical information and guarantee availability of the compressed topology. Besides, a decoding algorithm to restore the compressed topology named Average Proportional point (AP) is also proposed, which not only retains the space complexity of the aggregation process but also improves the accuracy of the restored information. Simulation results show that combing NLOF with AP can balance the contradiction between space complexity of the aggregation algorithm and routing accuracy.  相似文献   
987.
A facile approach for the synthesis of gold nanoparticle-loaded carbon nanofiber(Au/CNF) composites was developed. When applied to electrochemistry, these composites showed attractive performances such as high conductivity and facile electron transfer kinetics. Under physiological conditions, the Au/CNF composite modified electrode exhibits highly electrocatalytic activity for the oxidation of dopamine, ascorbic acid and uric acid. Owing to the good selectivity for the simultaneous detection of these three species, the novel composites are promising for the development of effective electrochemical biosensors.  相似文献   
988.
The cutoff wavelength of dominant mode in unilateral finline is analyzed by finite element method. The cutoff wavelength can be changed by adjusting the thickness of metallic fins and dielectric constant of dielectric substrate. Numerical results provide in this paper have important values in practical applications.  相似文献   
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