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221.
马迪  吕世华  鲍艳  奥银焕  韩博  赵林 《中国沙漠》2017,37(4):749-754
利用陆面过程模式BATS,引入地表发射率及两种大气发射率参数化方案,同时引入不同的地表粗糙度参数化方案,对比各种参数化方案对沙漠下垫面地面温度及能量收支的模拟状况。结果表明:采用Van Bavel等发展的地表发射率及Chung等发展的大气发射率方案可以明显改进地面温度及向上长波辐射的模拟,Chung等方案在夜间与正午的模拟效果更好,减小了1 ℃左右的地面温度模拟偏差,减小了10 W·m-2左右的向上长波辐射模拟偏差。晴天地面温度及向上长波辐射的模拟结果优于阴天。利用Zhang等发展的裸土粗糙度参数化方案也会提高模式对地表感热通量模拟的准确性。  相似文献   
222.
干热岩是一种新型清洁能源,其开发利用区的确定十分重要。笔者首先通过对松辽盆地热源、资源量、导热、聚热、地震活动5个方面资料的收集,提出了松辽盆地增强型地热系统开发选区适宜性评价方法;然后选取8项评价因子,利用ArcGIS 10.2平台将松辽盆地划分为26个评价单元,根据打分法和层次分析法(AHP)求取每个因子的权重;最后,对26个选区进行综合评价,将其分成适宜、较适宜、一般适宜、较不适宜和不适宜5个等级。结果表明:松辽盆地干热岩开发适宜区和较适宜区主要集中在盆地中部的大安—大庆一带,确定的适宜选区范围对今后干热岩开发工作具有一定指导作用。  相似文献   
223.
云南马关都龙锡锌多金属矿床位于滇东南老君山锡锌钨多金属成矿区南部,是我国三大锡石硫化物矿床之一,目前对其矿床成因认识存在较大分歧。本文采用ICP-MS对都龙矿床中闪锌矿微量元素及稀土元素组成进行分析,以探讨该矿床成矿作用,为甄别已有成因观点提供证据。结果表明,矿床中闪锌矿以富集Fe、Mn、In、Co、Sn和贫Cd、Ga、Ge、Ni等元素为特征,成矿温度属于中—高温,其微量元素组成与白牛厂矿床(与燕山晚期花岗岩有关的矽卡岩型矿床)中的闪锌矿非常相似,和远源矽卡岩型铅锌矿床(核桃坪和芦子园)中闪锌矿存在一定差异,明显有别于喷流沉积型铅锌矿床(云南澜沧老厂和广东大宝山)中闪锌矿。此外,该矿床闪锌矿稀土配分模式多为轻稀土元素富集中等的向右倾斜曲线,以LREE/HREE值高、Eu负异常明显和Ce异常不明显为特征,与矿区燕山晚期隐伏花岗岩稀土元素特征基本一致,成矿物质来源以矿区燕山晚期隐伏花岗岩为主。结合近期矿山开采和地质勘探所揭露的矿化和矽卡岩蚀变的垂向分带等矿床地质特征,认为云南马关都龙锡锌多金属矿床属于与燕山晚期花岗岩有关的矽卡岩型多金属矿床,其中层状矽卡岩的形成应为成矿流体顺层交代的结果,矿化类型和围岩蚀变的分带与隐伏岩体的距离有关。  相似文献   
224.
肖锋  侯岳  贾宝 《测绘通报》2016,(4):96-98,109
为满足移动互联网用户的个性化信息服务需求,引入用户兴趣模型匹配技术,提出了一种基于情境建模下的LBS智能信息推送服务模式,通过构建位置过滤模块、用户兴趣模型匹配及智能信息分类模块,实现了对推送信息的层层过滤,并同时结合反馈处理部分的修正功能实时改进推送模型的精度,从而提高了信息服务的质量和效率,使推荐的信息资源更加符合用户的实际需要。原型系统的实际应用表明了该方法的有效性。  相似文献   
225.
In this work, we apply the experimenting pressure field technique to the problem of the flow of two or more immiscible phases in porous media. In this technique, a set of predefined pressure fields are introduced to the governing partial differential equations. This implies that the velocity vector field and the divergence at each cell of the solution mesh can be determined. However, since none of these fields is the true pressure field entailed by the boundary conditions and/or the source terms, the divergence at each cell will not be the correct one. Rather the residue which is the difference between the true divergence and the calculated one is obtained. These fields are designed such that these residuals are used to construct the matrix of coefficients of the pressure equation and the right‐hand side. The experimenting pressure fields are generated in the solver routine and are fed to the different routines, which may be called physics routines, which return to the solver the elements of the matrix of coefficients. Therefore, this methodology separates the solver routines from the physics routines and therefore results in simpler, easy to construct, maintain, and update algorithms.  相似文献   
226.
227.
双宝  王力  孙英男 《吉林地质》2009,28(1):42-45
云南个旧锡铜多金属矿集区是中国最重要的锡、铜多金属矿集区之一,本文从多方面对该矿集区的资源潜力进行了分析,并指明了找矿方向。  相似文献   
228.
Assuming an intrinsic ‘Band’ shape spectrum and an intrinsic energy‐independent emission profile we have investigated the connection between the evolution of the rest‐frame spectral parameters and the spectral lags measured in gamma‐ray burst (GRB) pulses by using a pulse model. We first focus our attention on the evolution of the peak energy, E0,p, and neglect the effect of the curvature effect. It is found that the evolution of E0,p alone can produce the observed lags. When E0,p varies from hard to soft only the positive lags can be observed. The negative lags would occur in the case of E0,p varying from soft to hard. When the evolution of E0,p and the low‐energy spectral index α0 varying from soft to hard then to soft we can find the aforesaid two sorts of lags. We then examine the combined case of the spectral evolution and the curvature effect of fireball and find the observed spectral lags would increase. A sample including 15 single pulses whose spectral evolution follows hard to soft has been investigated. All the lags of these pulses are positive, which is in good agreement with our theoretical predictions. Our analysis shows that only the intrinsic spectral evolution can produce the spectral lags and the observed lags should be contributed by the intrinsic spectral evolution and the curvature effect. But it is still unclear what cause the spectral evolution (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   
229.
Eleutheronema rhadinum is a potential commercial fisheries species and is subject to intense exploitation in China. Knowledge on the population structure of E. rhadinum in Chinese coastal waters, which is important for sustainable exploitation and proper resource management, is lacking. In the present study, the genetic diversity and population structure of E. rhadinum were evaluated using a 564-base pair fragment of the mitochondrial cytochrome c oxidase subunit I (COl) gene. A total of 76 specimens were collected from three localities around the East (Qidong and Zhoushan) and South China Seas (Zhuhai). Among these individuals, nine polymorphic sites were detected and 1 l distinct haplotypes were defined. High levels ofhaplotype diversity (h=0.759i0.035) and low levels of nucleotide diversity (re=0.001 98i0.003 26) were observed in these populations, Hierarchical analysis of molecular variance (AMOVA) indicated that 96.72% of the genetic variation occurred within the populations, whereas 3.28% occurred among populations. No significant genealogical branches or clusters were recognized on the neighbor-joining tree. Intra-group variation among populations was significant (~0~t=0.032 85, P〈0.01). These results suggest that E. rhadinum populations in the East and South China Seas have developed divergent genetic structures. Tests of neutral evolution and mismatch distribution suggest that E. rhadinum may have experienced a population expansion. The present study provides basic information for the conservation and sustainable exploitation of this species.  相似文献   
230.
Using the defined sensitivity index, the sensitivity of streamflow, evapotranspiration and soil moisture to climate change was investigated in four catchments in the Haihe River basin. Climate change contained three parts: annual precipitation and temperature change and the change of the percentage of precipitation in the flood season (Pf). With satisfying monthly streamflow simulation using the variable infiltration capacity model, the sensitivity was estimated by the change of simulated hydrological variables with hypothetical climatic scenarios and observed climatic data. The results indicated that (i) the sensitivity of streamflow would increase as precipitation or Pf increased but would decrease as temperature increased; (ii) the sensitivity of evapotranspiration and soil moisture would decrease as precipitation or temperature increased, but it to Pf varied in different catchments; and (iii) hydrological variables were more sensitive to precipitation, followed by Pf, and then temperature. The nonlinear response of streamflow, evapotranspiration and soil moisture to climate change could provide a reference for water resources planning and management under future climate change scenarios in the Haihe River basin. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   
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