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1.
本文研究了平板膜式氧合器中不伴有氧合反应时氧在血液中的传质过程。根据氧在血液中传递特性建立了数学模型。通过解扩散微分方程,求得了氧在血液中的平均浓度,平均Sh(?)rwood数的理论表达式,并在硅胶平板膜式氧合器中进行了实验验证。在实验范围内(Re=0.8—25),还把Sherwood数关联成下列准数形式: (?)=0.055 Re~(0.59)Se~(0.33) 该式可供设计平板膜式氧合器时参考使用。  相似文献   

2.
液体初始分散对逆流旋转床内传质影响的研究   总被引:2,自引:0,他引:2  
探讨液体的初始分布对逆流旋转填充床流体力学特性和传质的影响。在逆流旋转填充床内,用水吸收空气中的氨,通过使用五种不同的液体分布器,研究操作条件(转速、气量、液量)对逆流旋转填充床气相压降和传质的影响。在相同操作条件下,不同液体分布器对旋转床气相压降影响表现为,旋转床气相压降随转速、气量的增加而增大,随液量的增大而减小,不同分布器对传质的影响不明显。气相总传质系数Kya随转速、气量、液量的增加而增大;旋转床内的传质主要发生在填料层内,从分布器到填料空腔内的传质约占整个旋转床内传质的10%以下。  相似文献   

3.
根据污水处理所用填料的技术特征,自行开发研制了一种新型组合填料,通过平行实验测定了亏氧清水中该组合填料和其他3种填料塔的氧液相体积传质系数,并进行了比较,结果表明该组合填料具有优良的氧传递性能,对实验结果进行回归分析,得到4种填料氧传质系数的计算式。其计算值与实测值基本吻合,最后对同种填料在相同操作条件下,对亏氧清水和餐厅污水中的氧传递实测结果进行了比较,结果表明餐厅污水中的氧传质系数小于亏氧清水中的氧传质系数。  相似文献   

4.
旋转填充床中两种填料压降特性与传质特性的对比   总被引:3,自引:0,他引:3  
利用空气-水-SO2 系统研究了逆流旋转床的气相压降及传质特性。结果表明, 填料A(普通丝网 )比填料B(RS钢波纹丝网)的气相压降大30%左右, 体积传质系数小15%左右, 即填料B比填料A的流体力学性能和传质性能好。  相似文献   

5.
逆流和并流操作时旋转床气相压降的对比   总被引:5,自引:0,他引:5  
对逆流和并流旋转床的气相压降进行了实验研究。结果表明:在并流和逆流操作条件下,旋转床的湿床压降小于干床压降;且随液量增大而略有减小,随气量增大而增大;当转速增大时,并流操作的压降减小,逆流操作的压降增大;拟合结果与实验结果吻合很好。  相似文献   

6.
超临界流体萃取塔传质性能的研究   总被引:2,自引:0,他引:2  
建立了描述连续逆流超临界流体萃取塔传质性能的数学模型。在直径为25mm连续逆流操作的超临界填料塔、筛板塔、喷淋塔中,应用超临界二氧化碳-异丙醇-水、超临界二氧化碳-乙醇-水两种实验体系对传质模型进行了实验验证,计算结果与本文实验数据符合较好。  相似文献   

7.
在旋转床(RPB)中,用氮气-系统,通过氧解吸过程对两种不同形状填料的传质过程进行实验研究,实测体积传质系数与转子转速、液体流率及气体流率的关系,进而揭示出旋转床内两种填料的传质特性。对这两种不同形状的填料表面传质特性进行比较,找出传质效果较好的填料。文中还进一步对填料比表面积对体积传质系数的影响进行了探讨,证实了液体在转子填料层中的连续微粒化所得到的大量液滴表面是旋转床传质强化的重要因素。基于对旋转床传质的实验结果,提出了平均体积传质系数的回归关系式。  相似文献   

8.
移动床生物膜反应器中两种填料氧传质性能的比较   总被引:2,自引:0,他引:2  
在移动床生物膜反应器中,填料是废水处理工艺的核心,也是加强传质的基本手段.笔者选用Mutag BiochipTM填料1,WD-F10-4型BioMTM聚乙烯填料2对比研究两种填料的氧传质性能.在相同操作工艺条件下,5%填料1和30%填料2的填充率可保证二者总比表面积相同,COD去除率相当;对比分析移动床生物膜反应器中两种填料在有无附着生物膜体系的氧传质性能受进水COD浓度变化的影响,结果显示,填料1体系的氧传质性能稳定并优于填料2体系.  相似文献   

9.
液滴粒径是影响旋转床中气液传质的重要因素。通过分析液滴的运动和气体的流场特性,构建液滴在单级雾化并流旋转床中的二维运动模型,探索液滴群粒径分布。根据液滴速率和粒径分布确定填料的径向间距,设计了发散型丝网填料。该填料增大了相界比表面积,对提高传热传质效率,优化旋转床脱硫工艺具有一定的意义。  相似文献   

10.
建立了气-液两相流二维CFD模型,运用FLUENT软件对板式蒸发式冷凝器板束中气-液两相逆流、并流两种操作进行了模拟,直观地表征了板束中喷淋水流量、风速及风向对水膜流动的影响,并用水蒸汽对两种操作进行了传热实验研究。模拟分析得出的结论与实验结果吻合甚好,表明了空气与水并流比逆流更有利于利用液体薄膜强化传热的特性。  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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