2,920 research outputs found

    A New Base Station Receiver for Increasing Diversity Order in a CDMA Cellular System

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    The impact of clustering of DFI on urban economic development in China: the case of Qingdao development zones.

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    With the dramatic increase in direct foreign investment (DFI) in China over the past two decades, understanding the role of DFI in her economic development has become essential. This thesis focuses on the impact of the clustering of DFI on urban economic development through a case study of the Economic and Technological Development Zone (ETDZ) and High-tech Industrial Park (HTIP) in Qingdao, Shandong Province. The concept of 'cluster' has become an object of desire for many cities and regions, resting on the widely accepted assumption that increased specialisation and external economies in clusters may contribute to urban and regional economic development Little research has been conducted, however, as to the underlying role of DFI in fostering industrial clusters. This thesis attempts to fill this gap by examining the supplier-buyer linkages between foreign invested firms and local firms within the electrical and electronic sectors in development zones built by the Chinese government, hence investigating the mechanisms of how such a linkage may increase productivity and promote local economic development. The present research utilises 21 detailed firm case studies and describes the process and mechanisms of urban economic development through the interaction between foreign invested firms and local firms in development zones. In addition, with the help of quantitative methods, including regression, shift-share and location quotient (LQ) analyses, the thesis quantifies the macroeconomic impact of the clustering of DFI on local economic development. This thesis concludes that large domestic firms have played a pivotal role in forming the local industrial cluster, whereas foreign invested firms have played a supporting role. However, the foreign invested firms act as a bridge between large Chinese firms and their local suppliers by being both a main supplier (first-tier supplier) for large Chinese firms and a main buyer of raw materials and components for local suppliers (second-tier and third-tier suppliers). Through such a relationship, foreign invested firms, as innovators, enhance quality control management in local industries and facilitate the technology transfer for local suppliers. Thus, local suppliers and foreign invested firms provide the stable quality parts and components for the main domestic firms who play the leading role in forming clusters

    Spontaneous Formation of Gold Nanoparticles on Graphene by Galvanic Reaction through Graphene

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    We demonstrate an effective and facile method for the deposition of gold nanoparticles (AuNPs) on graphene by using spontaneous galvanic reaction. Despite the interest and importance of the hybrid structure of noble metal-deposited graphene has been considerably increased for its fundamental knowledge in chemical and physical sciences and for its various applications, the progress of this subject is very slow mainly because of the lack of synthetic methods for such structures, especially that are not free from chemical contamination and usage of complex and expensive equipment. Therefore, we developed a new method allowing chemically pure AuNPs/graphene hybrid structures employing galvanic reaction. The spontaneous galvanic reaction was derived from reductant/graphene/oxidant sandwich structures, such as Au ions/graphene/Ge wafer and Au ions/graphene/copper foil, by placing Au ion solution droplets on graphene transferred on a germanium wafer or as made graphene on Cu foil, respectively. According to scanning electron microscopy and atomic force microscopy results, it was confirmed that AuNPs were successfully formed on the graphene surface. This result implies two important points. One is that the formation of pure AuNPs on graphene is possible without using other chemicals frequently required for conventional NP preparation. The other one is that it was experimentally demonstrated that there are electronic communications between the oxidant and reductant that are separated by graphene, through which electrons can pass freely.11Ysciescopu

    Three-Dimensional Superconductivity in the Infinite-Layer Compound Sr_{0.9}La_{0.1}CuO_2 in Entire Region below TcT_c

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    The infinite-layer compound ACuO2_{2} (A == alkaline-earth ions) is regarded as the most suitable material for exploring the fundamental nature of the CuO2_2 plane because it does not contain a charge-reservoir block, such as a rock-salt or a fluorite like block. We report that superconductivity in the infinite-layer compound Sr0.9_{0.9}La0.1_{0.1}CuO2_2 is of a three-dimensional nature, in contrast to the quasi two-dimensional superconducting behavior of all other cuprates. The key observation is that the cc-axis coherence length is longer than the cc-axis lattice constant even at zero temperature. This means that the superconducting order parameter of one CuO2_{2} plane overlaps with those of neighboring CuO2_{2} planes all the temperatures below the TcT_c. Among all cuprates, only the infinite-layer superconductor shows such a feature.Comment: 4 pages and 4 figure

    Landscape Design for Improved Thermal Environment: An Optimized Tree Arrangement Design for Climate-Responsive Outdoor Spaces in Residential Buildings Complexes

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    The heat reduction effect of trees has been investigated through numerical simulations; however, there are still challenges to applying the scientific results to the planning process due to the model's complexity and the computational resources required. This study investigates a rapid spatial evaluation method for heat stress potential, measured by mean radiant temperature (MRT), by decomposing radiation into sub-radiation using a multilayer MRT model. This method also enables the reproduction of optimized layouts considering the effect of tree arrangement in residential buildings. Multi-objectives were achieved through an evolutionary algorithm, resulting in more effective design layouts combining tree types and arrangements, all within a standard budget. By adopting this study's approach, landscape designers can create climate-responsive tree layouts with reduced heat exposure and generate customized planting designs tailored to their preferences

    Synthesis and pinning properties of the infinite-layer superconductor Sr0.9La0.1CuO

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    We report the high-pressure synthesis of the electron-doped infinite-layer superconductor Sr0.9La0.1CuO2 and its superconducting properties. A Rietveld analysis of X-ray powder diffraction data showed that, within the resolution of the measurement, the sample had purely an infinite-layer structure without any discernible impurities. The superconducting volume fraction and the transition width were greatly improved compared to those in previous reports. The irreversibility field line and the intragranular critical current density were much higher than those of La1.85Sr0.15CuO4 and Nd1.85Ce0.15CuO4. The stronger pinning behaviors are consistent with the strong interlayer coupling due to the short distance between CuO2 planes.Comment: Physica C (in press) 5 pages, 4 figur

    Time and Amplitude of Afterpulse Measured with a Large Size Photomultiplier Tube

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    We have studied the afterpulse of a hemispherical photomultiplier tube for an upcoming reactor neutrino experiment. The timing, the amplitude, and the rate of the afterpulse for a 10 inch photomultiplier tube were measured with a 400 MHz FADC up to 16 \ms time window after the initial signal generated by an LED light pulse. The time and amplitude correlation of the afterpulse shows several distinctive groups. We describe the dependencies of the afterpulse on the applied high voltage and the amplitude of the main light pulse. The present data could shed light upon the general mechanism of the afterpulse.Comment: 11 figure
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