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STUDY ON BEIJING''''S EMERGING MOBILE COMMUNICATION INDUSTRIAL CLUSTER AND ITS POLICY IMPLICATIONS 总被引:1,自引:0,他引:1
1INTRODUCTIONClusters,definedasgeographicallyproximategroupsofinterconnectedcompaniesandassociatedinstitutionsinparticularfields,linkedbycommonalitiesandcomple-mentarities(PORTER,2000),havearousedanintenseinterestofurbanandregionalplanningresearchersandpolicymakersoverthepastdecades.Itiswidelyrecog-nizedthatclusterscanpromoteproductivityandinno-vation,developlocalcompetitiveadvantages.Popular-izedbyMichaelPORTERinhisbook“TheCompetitiveAdvantageofNationsin1990,theclusterisnotanewcon… 相似文献
3.
Xiaoan Zuo Halin Zhao Xueyong Zhao Yirui Guo Yulin Li Yayong Luo 《Environmental Geology》2008,54(5):1111-1120
A survey was conducted in an 11-year recovery mobile dune (RMD11) and a 20-year recovery mobile dune (RMD20), in Horqin Sandy
Land, Northern China, to determine plant distribution at the mobile dune scale and its relevance to soil properties and topographic
features. The results showed that (1) vegetation cover and species number increased from dune top to bottom in the restoration
process of mobile dune; (2) the average value of soil organic C, total N, pH, relative height of sampling site, very fine
sand content and soil water contents (40−60 and 60−80 cm) of RMD11 were less than that of RMD20, respectively, and there were
significant differences (P < 0.05) between the two dunes; (3) soil resources were redistributed by shrub restoration and relative height of sampling
site on dune. The distribution of sand pioneer plant, Agriophyllum squarrosum, was positively related to the relative height of sampling site and soil water content, while that of other herbaceous plants
was positively related to soil nutrients in the restoration process of mobile dune. These results suggest that at mobile dune
scale, plant distributions are determined by a combination of soil properties and topographic feature. Much effort should
be made to preserve the interdune lowland and to improve the level of soil nutrients on mobile dune. 相似文献
4.
This paper presents an example of application of the double solid reactant method (DSRM) of Accornero and Marini (Environmental
Geology, 2007a), an effective way for modeling the fate of several dissolved trace elements during water–rock interaction. The EQ3/6 software
package was used for simulating the irreversible water–rock mass transfer accompanying the generation of the groundwaters
of the Porto Plain shallow aquifer, starting from a degassed diluted crateric steam condensate. Reaction path modeling was
performed in reaction progress mode and under closed-system conditions. The simulations assumed: (1) bulk dissolution (i.e.,
without any constraint on the kinetics of dissolution/precipitation reactions) of a single solid phase, a leucite-latitic
glass, and (2) precipitation of amorphous silica, barite, alunite, jarosite, anhydrite, kaolinite, a solid mixture of smectites,
fluorite, a solid mixture of hydroxides, illite-K, a solid mixture of saponites, a solid mixture of trigonal carbonates and
a solid mixture of orthorhombic carbonates. Analytical concentrations of major chemical elements and several trace elements
(Cr, Mn, Fe, Ni, Cu, Zn, As, Sr and Ba) in groundwaters were satisfactorily reproduced. In addition to these simulations,
similar runs for a rhyolite, a latite and a trachyte permitted to calculate major oxide contents for the authigenic paragenesis
which are comparable, to a first approximation, with the corresponding data measured for local altered rocks belonging to
the silicic, advanced argillic and intermediate argillic alteration facies. The important role played by both the solid mixture
of trigonal carbonates as sequestrator of Mn, Zn, Cu and Ni and the solid mixture of orthorhombic carbonates as scavenger
of Sr and Ba is emphasized.
相似文献
Luigi Marini (Corresponding author)Email: |
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以1,4—苯二酚和不同的短链脂肪酸为基本原料,经溴代、加成、形成酰卤和酰化等反应,合成了六种新的溴化脂肪酸—2,3,5,6—四溴—1,4—苯二酯。通过对产物的碳、氢、溴等元素的定量分析,以及红外吸收光谱和氢核磁共振谱的研究,验证了化合物的结构。 相似文献
7.
半潜式超大浮体连接器动力特性的一种时间序列分析方法 总被引:1,自引:2,他引:1
根据刚性模块弹性连接器 (RMFC)假设研究由 3个模块连接而成的半潜式超大浮体MobileOffshoreBase(MOB)的波浪载荷动力响应。模块和连接器动力响应根据时间序列法计算 ,这种方法包括海况模拟 ,波浪载荷计算和结构响应计算三个主要部分。通过对结构的适当简化 ,根据Airy波理论 ,Morrison公式以及流体中的结构运动方程、弹性连接器变形方程 ,计算求得MOB在不规则海况下的动力响应 ,并将其与相关文献中的结果进行比较 ,表明该方法有良好的精确性 相似文献
8.
移动式海上基地(MOB)连接器动力响应试验研究 总被引:1,自引:0,他引:1
移动式海上基地(Mobile Offishore Base,MOB)是由若干半潜模块相连而成的超大型浮式结构物。在进行海上作业时,模块间的连接器将会产生巨大的载荷。用缩尺比为1:100的三模块MOB模型在实验室进行了连接器动力响应试验研究。文中对试验的关键问题,如连接器模型的设计、制作、安装、试验工况的确定和测试方法等作了较详细的介绍。 相似文献
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