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1.
以概化的淮河入海水道为例研究复合模型的实现,通过对原型的总体分析确定复合边界的位置,对复合边界划分的两个部分分别建立物理模型和数学模型,为实现数,物模的耦合,数学模型采用菱形差分网格,为了提高耦合的精度,在数学模型中加入了复合边界处水位变化的预判断,对影响复合模型运动的一些因素进行了分析,强调复合模型实时耦合中参数的匹配问题,给出了模型的运行情况,其精度满足工程需要,实现了实时耦合的复合模型。  相似文献   

2.
通过计算机控制系统将物理模型和数学模型两部分耦合在一起。该控制系统有两条控制回路,即流量控制回路和水位控制回路,其中流量控制回路实现了物模和数模在耦合边界处水位和流量的交换;水位控制回路实现了入海口潮汐水位的模拟。同时根据采样和控制的高精度要求,分别在软件和硬件中采取滤波措施。试验结果表明,计算机控制系统实现了物理模型和数学模型的实时耦合,试验精度达到工程要求。  相似文献   

3.
李育真 《科技信息》2009,(33):333-334
随着科技进步,数字地面模型(DTM)在公路设计中得到广泛应用,地形原始数据是建立数模的基础数据,它直接影响到建模的合理性以及高程内插结果是否可靠,原始数据点的分布及密度是否与地形变化、数据采集设备和方法、数模类型、建模目的、数模精度以及所研究地区的地形特征等诸多因素相适应,通过对DTM地形数据采集方法的分析比较,尽可能做到以不太多的地形点表示出具有一定精度的地形表面。  相似文献   

4.
建立了多点连接主次结构耦合系统的数学模型,并利用模态截断技术求出各自的模态响应传递函数和位移响应,以主次结构系统的位移功率谱密度函数在整个频率域内的积分得到位移响应的均方根值并与精确解进行比较.算例表明。即使在只取主次结构前几阶模态的情况下,该方法仍具有很高的精度;将次结构视为MTMD(复合调频质量阻尼器)系统来控制主结构的位移均方响应,分析了主次结构的质量比、次结构的刚度质量比和模态阻尼比等因素对控制效果的影响,算例表明,次结构的刚度质量比是影响控制效果的关键因素.  相似文献   

5.
为了分析长周期光纤光栅的耦合机制和光栅特性,基于耦合模理论,对长周期光纤光栅中纤芯导模与包层模间的模式耦合进行了研究,推导出长周期光纤光栅的传输率、耦合系数等多个公式;基于Matlab软件编程,研究得到比较可行的长周期光纤光栅传输谱仿真模拟方法,模拟结果与实验观测相符。  相似文献   

6.
攀枝花市矿产资源丰富,采矿历史悠久,开采活动强度大,地质结构复杂,生态环境脆弱,矿山地质灾害频发.基于2019年的三江(怒江,澜沧江,金沙江)北段矿产开发环境遥感监测调查资料,在分析矿山地质灾害发育规律与影响因素关系的基础上,选取坡度、工程地质岩组、距断层的距离、降水量、植被覆盖度、距河流的距离以及距开采活动面的距离7个评价因子,借助ArcGIS软件平台,采用确定性系数(Certainty Factor,CF)模型、信息量模型以及CF与信息量耦合模型开展攀枝花市矿山地质灾害易发性评价研究.结果表明,工程地质岩组、植被覆盖度、距开采活动面的距离是影响矿山地质灾害分布的控制因子;经过ROC(Receiver Operating Characteristic Curve, ROC)曲线检验,CF与信息量耦合模型的AUC(Area Under the Curve, AUC)值高达0.909,表明耦合模型比单一模型的评价精度高,其精度为耦合模型>信息量模型>确定性系数模型;耦合模型的易发性分区为极高易发区(5.24%)、高易发区(11.67%)、中易发区(41.66%)和低易发区(4...  相似文献   

7.
随着全球变暖现象加剧,控制建筑业碳排放成为了重要研究课题,建筑施工现场碳排放的计算与监测问题成为重点。为了有效解决这一问题,梳理了现有碳排放计算方法,总结了各类方法的特点,提出了基于信息物理系统(CPS)技术的施工现场碳排放实时监测系统框架;针对施工现场碳排放计算边界及计算逻辑进行了定义,并从硬件系统与软件系统两部分实现了碳排放实时监测系统的开发。最后,通过无线传感器、服务器、数据库以及客户端的有效耦合,实现了对建筑施工现场的碳排放进行实时监测和数据分析。  相似文献   

8.
高程起伏对雷达景像匹配的影响及改正方法   总被引:2,自引:0,他引:2  
雷达景像匹配由于具有全天候的特征,在飞行器导航与定位中受到重视。针对实时雷达景像以及参考基准图像的成像方式,分析了地面高程起伏对实时雷达景像以及参考基准图像构像的影响,及合成孔径雷达(SAR)影像上因地形起伏产生的影像变形的改正;推导出实时雷达景像上,影像像点位移与地面高程起伏的关系式,以及由此产生的影像变形的改正方法和具体改正步骤,同时利用数字地面模型(DEM)对模拟实时雷达图像进行反纠正,在辐射特性一致的条件下,通过匹配试验分析因地形起伏产生的实时雷达景像变形对匹配精度的影响。  相似文献   

9.
文章通过构建旅游经济—生态环境评价指标体系,综合运用系统耦合协调模型、回归效应模型和障碍因子诊断模型,分析1995—2019年西北地区旅游经济—生态环境系统协调效应、影响因素及障碍因子。研究结果显示:(1)1995—2019年西北地区旅游经济—生态环境系统的耦合协调度呈现不断向好的发展态势。耦合协调度发展态势经历了“不协调发展(1995—2009年)→转型发展(2010-2014年)→协调发展(2015—2019年)”的演化阶段,耦合协调等级由“极度失调”演化为“中度协调”,形成旅游经济滞后和生态环境滞后两种发展类型;(2)1995—2019年西北地区旅游经济—生态环境系统耦合协调发展受旅游经济系统影响较大;旅游规模和旅游效益是影响系统耦合协调发展的驱动因素,生态环境压力和生态环境响应是影响系统耦合协调发展的重要因素;(3)1995—2019年旅游系统影响西北地区旅游经济—生态环境系统耦合协调发展前五位的障碍因子变动不大,主要以旅游规模和旅游效益为主;生态环境系统前五位的障碍因子因阶段不同而有所差异。  相似文献   

10.
证明了Virasoro超代数的不可分解模一定是下述模之一:i)一致有界模;ii)范畴 的模;iii)范畴 的模;iv)具有平凡模V(0)作为其复合因子的一类模.推广了文献[3]的结果.  相似文献   

11.
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   

12.
何延凌 《科技信息》2008,(4):258-258
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   

13.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

14.
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   

15.
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   

16.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

17.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

18.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

19.
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   

20.
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   

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