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“121”服务万户千家周鸣(河南省气象台,郑州·45003)气象信息在国民经济建设和人民生活中起着重要作用。随着科学的进步和人民生活水平的提高,人们对各种气象信息越来越关注。电话的普及,使电话服务成为气象部门新的经济增长点。郑州市“121”于1996... 相似文献
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Commercial economic region (CER), or commercial geographical region, is the result of socialized production and development of commodity economy, characterized by system holisty, regional independence, interregional openness and relative steadiness. Commercial economic regionalization provides a scientific basis for organizing and building a commodity circulation network system with all directions, multifunction and openness, rational planning the direction of commodity flow. The principles of commercial economic regionalization are as follows: The principle taking a city business center as the core; the optimization principle of integrated function; the difference principle of physical geographical environment; the uniformity principle of human geographical environment; and the order principle of dissipative structure. According to the above-mentioned principles, China's CER can be divided into 4 1evels. 相似文献
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在吴官庄村下采煤实测资料的基础上,分析了地表变形与房层变形的关系,求得了房屋裂缝宽度预测的典型曲线模型。该预测模型的建立,可以对房屋裂缝的发育规律作出国为精确的定量预测,对房屋将出现的最大破坏程度有充分的估计,可保证村下采煤安全可靠。 相似文献