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1.
热力学边界热质传递过程的促进传递(Facilitated Transport)可以强化热力学系统与外界的物量传递,进而影响系统内部的物量变化.提出热力学边界热质传递过程的促进传递和促进因子等概念,拓展边界热质传递过程的内涵,即促进传递过程是在边界内伴有可逆化学反应的强化传递过程,通过多个过程的耦合作用实现;讨论边界促进传递的分类和机理,并以质量促进传递过程为例分析促进传递过程.在传热学和热力学领域对促进传递过程研究应从传递机理、分析模型和应用等方面进行.  相似文献   

2.
热力学系统通过边界实现与外界的热质传递,精确分析边界中热质传递过程,是研究系统内部参数变化规律的前提和基础.在热力学系统定量化模型及基本概念研究的基础上,讨论复杂边界分类、边界表达式、物量传递方式、物量传递过程分析、边界开放度熵判据、交换率熵判据等;作为应用,对麦克斯韦妖系统进行分析,提出热力学系统中"被动传递"、"促...  相似文献   

3.
热力学系统动态变化过程是由系统与外界的热质传递过程引起的,但传统热力学并不能完全对此作出判断.借鉴现代热力学和界壳理论,提出一种新的热力学系统模型,由系统内部、边界(界壳)和外界组成,其中边界(界壳)由界壁和界门组成,界壁是"绝缘"的;给出热力学系统边界开放度、边界交换率概念,讨论边界开放度与边界交换率关系;在新的热力...  相似文献   

4.
以“势场”为研究载体,提供注蒸气驱油过程动力为统一目标,将不可逆热力学中“流”与“力”的概念引入驱油过程,在研究驱油域势场动力学特征的基础上,注蒸气多场耦合的驱油机理可概括为动力势场之间、阻力势场之间及动力势场与阻力势场之间3个层次.尽管已在注蒸气驱油过程多场耦合的多层次描述与分析方面取得一些研究成果,仍需要开展探索性...  相似文献   

5.
文章对桂林市阳朔县月亮山地区地质、构造条件,地热地质特征、水热对流特征等方面进行分析,认为区内热源主要是大地热流,属于以中、低温热水型为主的断裂型地热系统,断裂传导热及地下水深循环是形成地热系统的主要因素。地热系统的水热对流传递主要有层间对流传递、通过隔水层单纯热传递、导水断层进行水热交换传递3种形式。  相似文献   

6.
地图概括中空间目标几何信息传递模型研究   总被引:1,自引:0,他引:1  
地图概括是实现多比例尺地图生产和更新的一种重要理论方法。目前,国际国内制图学界对地图概括的研究主要集中在发展地图概括算法方面,在地图概括的质量评价方面的研究还很少。为此,本文以信息论为理论基础,以地图概括中空间目标几何信息的传递问题为研究对象,以相应空间目标几何信息的传递效率来度量地图概括中单个空间目标的概括质量。首先,建立了地图概括的空间信息传递模型,描述不同比例尺地图之间空间信息的传递过程。进而提出了地图概括过程中空间目标(即:线和面目标)几何信息的传递模型,并且对地图概括中空间目标几何信息的传递状况进行了评估,给出了具体的计算和实现方法。最后,通过实验初步验证了地图概括中空间目标几何信息传递模型的可行性。  相似文献   

7.
“第二次全国海岛资源综合调查”项目即将全面展开,对海岛进行高程基准传递的方法研究亟需深化。该文从高程基准传递的发展历史入手,依据其发展现状,结合近年来对江苏省海岛的工作,综合利用JSCORS,GPS[CD*2]RTK,PPP和同步水准观测等技术方法,提出一种包含近岸、中等离岸距离和远岸三类组成的海岛高程基准传递方法。  相似文献   

8.
采用GFZ精密卫星轨道、钟差和MGEX测站观测数据,分析BDS载波相位时频传递性能。在KARR站BDS可视卫星数较多(平均为10.1颗)时,BDS时间传递精度为0.2 ns,与GPS、GLONASS相当;在PTVL站BDS可视卫星较少(平均为6.9颗)时,平均TDOP为3.5,大于GPS和GLONASS,其时间传递精度较低,仅为0.68 ns,差于GPS和GLONASS。目前,由于BDS全球跟踪站有限,MEO卫星较少,BDS收敛时间长于GPS和GLONASS。两测站三系统频率传递结果和频率稳定度结果基本相当,变化趋势一致。因测站KARR、PTVL未配备高稳定度的原子钟作为外接频标,得到的频率传递精度和频率稳定度较差。  相似文献   

9.
弹性岩石层、区域重力异常和上地幔小尺度对流   总被引:1,自引:0,他引:1  
在小尺度地幔对流模型的基础上 ,建立了顾及岩石层与地幔耦合的地幔对流模型。考虑到岩石层对上地幔小尺度对流的弹性响应 ,将上地幔视为一均匀的等粘滞系数的牛顿粘滞流体 ,其对流能量来源于下地幔 ,用热流体动力学基本方程得到的上地幔对流在壳幔边界处的垂向应力作为弹性板弯曲方程的垂直加载 ,来耦合弹性岩石层和可流动地幔。推导了两者耦合下区域重力异常和上地幔小尺度对流的相关方程 ,用以反演上地幔小尺度对流流场模式和岩石层底部拖曳力场格局。对比了有、无弹性岩石层影响的模型之间的差异 ,并对模型应用范围 ,特别是板块边界水平构造力可能产生的影响 ,作了进一步探讨。  相似文献   

10.
在多级滑坡的渐进破坏过程中, 滑带不同部位的屈服程度和破坏模式不同, 强度参数也不同。在强降雨条件下, 坡表产生的张拉裂缝充水, 会产生静水压力。当前广泛应用的传递系数法对滑带不同位置取同一强度参数, 也尚未考虑到静水压力作用。为此提出了一种考虑静水压力作用和滑带不同部位强度参数差异的改进传递系数法, 对降雨引起的西安市柳西村南部的牛角沟滑坡进行了计算。结果表明: 与不考虑静水压力和滑带不同部位强度参数差异的计算方法比, 改进传递系数法计算的抗滑力相对较小, 剩余下滑力计算结果相对较大, 各级滑坡稳定性系数分别减小了约33.26%、17.92%、24.95和16.94%;而改进前的稳定性系数偏高, 可能会导致支挡工程的安全储备不足。本研究提出的改进传递系数法可为多级滑坡处置提供更安全的参考。   相似文献   

11.
The wave Coriolis-Stokes-Force-modified ocean momentum equations are reviewed in this paper and the wave Stokes transport is pointed out to be part of the ocean circulations. Using the European Centre for Medium-Range Weather Forecasts 40-year reanalysis data (ERA-40 data) and the Simple Ocean Data Assimilation (SODA) version 2.2.4 data, the magnitude of this transport is compared with that of wind-driven Sverdrup transport and a 5-to-10-precent contribution by the wave Stokes transport is found. Both transports are stronger in boreal winter than in summers. The wave effect can be either contribution or cancellation in different seasons. Examination with Kuroshio transport verifies similar seasonal variations. The clarification of the efficient wave boundary condition helps to understand the role of waves in mass transport. It acts as surface wind stress and can be functional down to the bottom of the ageostrophic layer. The pumping velocities resulting from wave-induced stress are zonally distributed and are significant in relatively high latitudes. Further work will focus on the model performance of the wave-stress-changed-boundary and the role of swells in the eastern part of the oceans.  相似文献   

12.
This study investigates the Arctic Ocean warming episodes in the 20th century using both a high-resolution coupled global climate model and historical observations. The model, with no flux adjustment, reproduces well the Atlantic Water core temperature (AWCT) in the Arctic Ocean and shows that four largest decadalscale warming episodes occurred in the 1930s, 70s, 80s, and 90s, in agreement with the hydrographic observational data. The difference is that there was no pre-warming prior to the 1930s episode, while there were two pre-warming episodes in the 1970s and 80s prior to the 1990s, leading the 1990s into the largest and prolonged warming in the 20th century. Over the last century, the simulated heat transport via Fram Strait and the Barents Sea was estimated to be, on average, 31.32 TW and 14.82 TW, respectively, while the Bering Strait also provides 15.94 TW heat into the west- ern Arctic Ocean. Heat transport into the Arctic Ocean by the Atlantic Water via Fram Strait and the Barents Sea correlates significantly with AWCT ( C = 0.75 ) at 0- lag. The modeled North Atlantic Oscillation (NAO) index has a significant correlation with the heat transport ( C = 0.37 ). The observed AWCT has a significant correlation with both the modeled AWCT ( C =0.49) and the heat transport ( C =0.41 ). However, the modeled NAO index does not significantly correlate with either the observed AWCT ( C = 0.03 ) or modeled AWCT ( C = 0.16 ) at a zero-lag, indicating that the Arctic climate system is far more complex than expected.  相似文献   

13.
Thefastpaceofeconomicgrowth,urbanpopula-tiongrowthandfamily-incomeincreasesincel978hastriggeredaboomofcarownershipandusage.ThishasbeenaccompaniedbyincreasingtrafficdemandofGuangzhouandthetransportland-useincreasedac-cordingly.Atthesametime,duetoacceleratedurbanizationandsharpincreaseofresidential,businessandindustriallanduseaswellastheirexpansiontowardtheperipheryofthecity,theconflictbetweenlanduseandtraffcdemandhasbeenmoreandmoreevident,whichmakesthisstudymeaningful.lDEVELOPMENTANDPATT…  相似文献   

14.
1Introduction Theglobalclimatechangehasbeenoneoftheprob lemschallengingtheworldinrecentyears.TheweatherandclimateonEarthhasbeeninvariationontimescalesfromseasonaltomillennialorevenlonger.ResearchesonvariationsofweatherandclimateintheNorthernHemispherehave…  相似文献   

15.
In considering the vertical heat transport problems in the upper ocean, the flat upper boundary approximation for the free surface and the horizontal homogenous hypothesis are usually applied. However, due to the existence of the wave motion, the application of this approximation may result in some errors to the solar irradiation since it decays quickly in respect to the actual thickness of the water layer below the surface; on the other hand, due to the fluctuation of the water layer depth, it is improper to neglect the effects of the horizontal advection and turbulent diffusion since they also contribute to the vertical heat transport. A new model is constructed in this study to reflect these effects. The corresponding numerical simulations show that the wave motion may remarkably accelerate the vertical heat transferring process and the variation of the temperature in the wave affected layer appears in an oscillating manner. Supported by the National High Technology Research and Development Program of China (863 Program, No. 2006AA09A309); China Postdoctoral Science Foundation (No. 20070411111) and the Fund of Shandong Province for the Excellent Post-Doctors (No. 200603056)  相似文献   

16.
This study investigates the heat and mass transfer mechanism of a marine engine exhaust-powered adsorption refrigerating system by using irreversible thermodynamics. The equations of entropy-production rate and the linear phe-nomenological equations of thermodynamic flux and force are established. The conventional experimental facilities of unit tube are developed and the phenomenological coefficients are obtained by fitting the experimental data. It is concluded that the thermodynamic process in the adsorbent bed is determined by the coupling effect of the heat and mass transfer; furthermore, the mass transfer is determined by the heat transfer. Taking some measures to increase heat transfer can improve the performance of the adsorption refrigerating system. The conclusions presented in this paper may be of value to the engineering applications of the system.  相似文献   

17.
四川"9.3"大暴雨中的水汽输送分析   总被引:4,自引:0,他引:4  
利用NCEP/NCAR再分析资料对四川“9.3”大暴雨中水汽来源进行了讨论。结果表明,这次暴雨的水汽主要来源于南海、西太平洋地区;异常水汽输送在这次暴雨中占了较大的比例。暴雨日及前3天的异常水汽输送表明,造成此次川东暴雨的异常水汽来源于西太平洋经南海、东海、黄海的向北水汽输送和暴雨区北方的向南水汽输送,以及青藏高原的异常偏西风输送,孟加拉湾的水汽输送对异常强降水并没有明显的作用。大暴雨发生的前期,副高突然异常加强西伸。  相似文献   

18.
轨道是缓解城市交通问题的重要设施,增加出行者选择轨道出行的概率,有利于交通与土地利用协调和TOD可持续发展。本文提出站点客流潜力的概念,并根据复杂网络特征和出行模式构建站点客流潜力模型,通过协调潜力值与实际客流为TOD研究提供新视角。以北京市轨道站点POI数据构建Space-L模型,并依据站点客流潜力模型计算北京市364个站点的客流潜力。研究发现:① 本文提出的站点客流潜力具有吸引力和承载力两类内涵,能定量分析站点空间与站域客流的协调情况;② 北京市站点客流潜力值空间分布为“核心-边缘”模式,区间概率分布为等差数列分类的指数分布和等比数列分类的正态分布;③ 根据出行目的设置四类出行情景。不同情景下出行者选择轨道出行的概率具有差异,早高峰和晚高峰情景下轨道出行概率大,受潜力值影响小,非工作出行情景下轨道出行概率小,受潜力值影响大。实例分析表明相比于单独考虑复杂网络特征,潜力值具有更好的可解释性和科学性;④ 耦合度C <0.5时认定站点失调,其中标准化的实际客流与潜力值的比值Z >1,表示客流过饱和,如西二旗等,会造成站点拥堵,Z <1表示站点交通地理优势未充分发挥,如北运河西等。北京市轨道交通需协调优化以提升效率,实现TOD可持续发展。  相似文献   

19.
The"5.12"Wenchuan earthquake in 2008 triggered a large number of co-seismic landslides.The rear boundary or cracks of co-seismic landslide are generally located at the steep free surface of thin or thick mountains.Dynamic process of this kind of landslides could be divided into two parts:the seismic dynamic response of the slope and the movement process of rock mass.Taking the Laoyingyan rockslide as an example,the amplification effect was studied by single-degree-of-freedom system analysis method.Besides,the dynamic process of landslide under seismic loading was simulated by the finite difference method(FDM)and discrete element method(DEM).The amplification coefficient of the rockslide to seismic wave is 1.25.The results show that the critical sliding surface of the Laoyingyan rockslide was formed at the 23 th seconds under the action of seismic wave.At the same time,tension failure occurred at the rear edge of the sliding mass and shear failure occurred at the front edge.The maximum displacement was 0.81 m and the initial velocity was 2.78 m/s.During the initiation process of the rockslide,the rock mass firstly broke down along the joints which are along the dip of the rock stratum,and then collapsed bodily along the secondary structural planes.In the process of movement,the maximum velocity of rock mass was 38.24 m/s.After that,the rock mass underwent multiple collisions,including contact,deceleration to 0 and speed recovery after rebound.Finally,due to the constant loss of energy,the rocks stopped and accumulated loosely at the foot of the slope.The longest distance of movement was about 494 m.Besides,the smaller the damping ratio,the farther the rock mass moved.Compared with the results without considering the amplification factor,the movement distance of landslide by considering the amplification factor was more accurate.The study of the Laoyingyan rockslide is helpful to strengthen our field identification of potential co-seismic rockslides.At the same time,understanding its movement and accumulation process can help us better predict the hazard scope of the co-seismic rockslides,and provide a reference for the design of treatment projects.  相似文献   

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