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1.
三氟乙烷的气相音速测量与热力学性质研究   总被引:1,自引:0,他引:1  
采用球型腔体声学共振法测量了新型制冷剂三氟乙烷(HFC143a)的气相音速,得到了压力在200~800kPa范围内,温度分别为293.61、302.96、313.19和323.18K时的4条等温线共28个音速数据.根据实验数据,由热力学关系式得到了HFC143a的理想气体比定压热容和第二音速维里系数等热力学性质,同时根据现有的高精度实验数据拟合了HFC143a的理想气体比热方程.温度、压力和气体音速测量的不确定度分别为±14mK、2.0kPa和±0.0037%.  相似文献   

2.
293~347 K温度区间二甲醚饱和蒸气压的实验研究   总被引:4,自引:5,他引:4  
为了给二甲醚作为替代燃料和制冷剂的研究提供基本物性数据 ,对 2 93 7762~ 3 47 464 3K温度区间的二甲醚饱和蒸气压进行了测量 ,其中实验结果的温度不确定度小于± 2mK ,压力不确定度小于± 0 7kPa .同时 ,利用获得的实验数据拟合了一个新的Wagner型二甲醚饱和蒸气压方程 ,新方程与实验结果的平均偏差为 0 0 2 3 % ,最大偏差为 0 0 96% ,适用温度范围为 2 93~ 40 0K .  相似文献   

3.
高精度流体热物性测试实验系统的研制   总被引:9,自引:2,他引:9  
在分析各种流体热物性参数测量要求的基础上,借鉴前人研究经验,结合最新的温度、压力等参数测量与控制技术,完成了流体热物性测试用的温度测量系统、高精度控温油/水槽、高精度控温酒精槽、压力测量系统、真空及配气系统、配套的测试与控制软件等的研制与开发,最终形成了一套相对完整的测试实验系统平台.在实验系统的运行范围内,最佳的温度测量不确定度小于±1mK,恒温槽15min的温度波动度可优于±1mK,压力测量的准确度为量程的0 01%.大量的实际运行结果表明:新研制的流体热物性测试实验系统性能稳定,测试结果可靠,为目前正在进行的流体热物性测试自动化研究奠定了良好的基础.  相似文献   

4.
利用振动盘式粘度计对混合工质的气相粘度进行了实验测量.实验采用相对测量的方法,测量了真空下的对数衰减率;通过氮气的粘度测量获得了工作方程的修正项,并通过测量HCFC22的粘度对实验系统的准确性和可靠性进行了检验;然后对HFC152a/HCFC22(质量分数15%/25%)的气相粘度进行了测量,测量温度293~370 K,压力0.1~1.9 MPa,实验测量的不确定度为3%,并关联了粘度、温度和密度的经验公式.  相似文献   

5.
为了获得准确的流体黏度数据,基于振动弦理论,研制了一套高压振动弦黏度测量实验系统.该系统具有精度高、稳定可靠、测量范围大等特点,测量温度范围为243~400K,压力范围为0~40MPa.利用标准物质甲苯对实验系统进行了标定和检验,黏度测量的不确定度为±2.0%.此外,利用制冷剂R134a对实验系统进行了检验,并将实验结果与文献值进行了比较.结果表明,实验系统准确可靠,可以用于流体黏度的高精度测量.  相似文献   

6.
用球共鸣声学法测量了工质二氟乙烷(HFC152a)在温度分别为293.86、302.96、313.19和323.16 K时,压力为200~420 kPa的四条等温线共24个音速数据.根据实验数据,由热力学关系式得到了HFC152a在四个温度下的理想气体比热容和第二音速维里系数.同时根据现有的高精度实验数据拟合HFC152a的理想气体比热容方程.这些研究为HFC152a在工程上的应用提供了必需的热物理性质基础数据.  相似文献   

7.
建立了一套基于磁悬浮密度计的流体PVT测量系统,其温度测量范围203.15~423.15 K,标准不确定度为0.005 K,压力测量范围0~7 MPa,标准不确定度为700 Pa.通过对恒温系统的改进,缩短了实验本体达到热平衡的时间,提高了温度稳定性.利用该系统对高纯氮气在271~345 K,0~6 MPa范围内进行了密度测量,实验结果与NIST REFPROP9.0数据相比偏差在0.1%以内,并对由于拟合维里方程的不确定度、温度测量和压力测量不确定度引起的密度结果的不确定进行了分析.  相似文献   

8.
1,1,1,2,3,3,3-七氟丙烷的热力性质   总被引:1,自引:0,他引:1  
为获得不破坏臭氧层的环保工质的热物性数据 ,对HFC- 2 2 7ea的热力学性质进行了研究 ,精确测量了 2 43~375 K的饱和蒸气压 ,使用膨胀 -定容法测量了 2 78~ 377K,压力 0 .2 6~ 2 .6 MPa的 HFC- 2 2 7ea的气相 p VT性质 ,温度和压力测量的最大不确定度分别为± 10 m K和± 5 0 0 Pa。使用测量结果关联了 HFC- 2 2 7ea的蒸气压方程 ,导出了维里系数、饱和气相密度、饱和蒸发焓 ,并关联了截断维里型的状态方程用于再现 HFC- 2 2 7ea气相区的热力性质。  相似文献   

9.
研制了一套高精度制冷工质溶解度实验系统,由自行开发的测控软件进行计算机实时测控.实验系统包括高精度温度测量系统(在253.15~363.15 K范围内,测量的不确定度小于±14mK),高精度压力测量系统(在0~3.5 MPa范围内,测量的不确定度小于±1.6 kPa),高精度恒温水浴(293.15~363.15 K),高精度恒温酒精浴(253.15~293.15 K),真空及配气系统等.对283.15~348.15 K温度范围内HFC-134a的饱和蒸气压进行了测量,并与标准值进行了比较,测量的平均偏差为0.54%.用此装置对制冷剂R22在吸收剂N,N-二甲基甲酰胺中的溶解度进行了实验研究,并同文献提供的数据进行对比,结果表明该实验系统具有较高的精度.  相似文献   

10.
多相流体流量测量的采样分流方法   总被引:2,自引:0,他引:2  
借用数据采集中的采样概念,提出了一种多相流采样分流方法,以获得具有高度代表性的分流体,从而提高多相流体的流量测量精度.首先,以足够高的频率从被测多相流中采集流量数据(分流体),然后把采集到的分流体分离成单相流体,再分别用单相流量计测量其流量,最后根据采样关系确定被测多相流体的总流量.由于分流体只占总流量的很少一部分,因此所需分离器的体积可以大幅度缩小,基本接近普通单相流量计的大小.在油气水三相流实验回路上进行了实验研究,结果表明在实验范围内,采样机构运转平稳、可靠,获得的分流体具有足够高的代表性,测量结果与流型无关,干度偏差小于2%,总流量的测量不确定度小于3.82%.  相似文献   

11.
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   

12.
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   

13.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

14.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

15.
Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with  相似文献   

16.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

17.
18.
The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.  相似文献   

19.
R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).  相似文献   

20.
The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.  相似文献   

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