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灾害天气气象预报是气象预报人员经验、知识和推理思维的创造性应用。本文介绍了灾害天气气象预报专家系统的功能、推理模式可信度计算方法以及气象知识表达和数据库技术。 相似文献
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低温冷害气象预报是气象预报人员经验、知识和推理思维的创造性应用。通过讨论低温冷害气象预报专家系统的结构、功能、推理机制、可信度计算方法以及气象知识表达和数据库技术 ,指出专家系统在气象领域有着广阔的应用前景 相似文献
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浅析农业气象服务的现状和发展 总被引:4,自引:0,他引:4
通过农业气象业务、农业气象情报、农业气象预报、农业气候资源与区划、农业气象灾害监测评估和人工影响天气等方面对农业气象服务的现状做了叙述,分析了目前存在的问题,并对农业气象服务的未来发展作了一些展望。 相似文献
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目前,越来越多的企业以高价向私营气象信息公司购买更加精确的气象预报,使“天气生意”在日本成为一个新兴行业。每天下午3时,神奈川县茅崎市的自助商店经理就会向各柜台主任传送第二天的气象预报。他们根据气象预报估计出顾客人数并决定要订购的食品品种和数量。天气与顾客的相互关系是根据过去储存在电脑中的数据算出的。目前 相似文献
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实时气象信息处理在气象预报工作中具有重要意义,该系统为气象预报人员及时地提供各种气象数据,使气象预报人员准确地进行天气分析、预报以及各种气象图形、图象的显示和处理。本文介绍了系统的设计与实现思想,详细阐述了系统硬件配置、运行环境、实时气象信息接收和信息组织方式。 相似文献
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迅速崛起的日本新型社会服务业——气象预报服务行业目前,越来越多的企业以高价向私营气象信息公司购买更加精确的气象预报,使“天气生意”在日本成为一个新兴行业。每天下午3时,神奈川县茅崎市的自助商店经理就会向各柜台主任传送第二天的气象预报。他们根据气象预报... 相似文献
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气象预报人员面临的问题之一是如何准确有效地识别短时强降水天气.短时强降水是一种主要由强对流天气形成的气象灾害,产生原因与空气湿度、大气中的水分以及温湿等物理量参数有关,由此提出基于物理量参数和深度学习模型DBNs的短时强降水天气识别模型.首先,利用SMOTE算法人工合成短时强降水少数类(相对于非短时强降水天气类)样本,调整原始数据集不均衡分布问题;然后通过含有高斯玻耳兹曼机的深度学习模型对地面大气监测站逐小时加密的观测量,以及常用于天气预报分析的物理量等低层特征构造出抽象的高层特征,发现数据特征内在关系;最后实现了DBNs短时强降水的自动识别模型.结果表明,该方法能够较为准确地识别短时强降水,对于短时强降水的命中率、误警率和临界成功指数,都有着较好的表现. 相似文献
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Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness. 相似文献
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Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly. 相似文献
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Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well. 相似文献
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The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation. 相似文献
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理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。 相似文献
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As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death. 相似文献
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Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system. 相似文献
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以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性. 相似文献
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Miao Maosheng 《华南师范大学学报(自然科学版)》2014,(6)
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula- 相似文献
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Yang Weitao 《华南师范大学学报(自然科学版)》2014,46(6):137-138
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re- 相似文献