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1.
用极限扩散电流技术(LDCT)对竖直管内的液体单相流与气液两相流的传质特性进行了测量,经三传类比由测量结果获得了传热特性.实验在一内径为18mm的垂直有机玻璃管内进行,实验液体为K3Fe(CN)6-K4Fe(CN)6-NaOH溶液,气体为空气.实验结果与Dittus-Boelter式的计算值及两相流传热的文献值吻合较好.实验中对气液两相流瞬时极限电流信号进行了测量与分析,采用小波分析法对瞬时极限电流波动信号进行了6尺度分解与重构,深入认识了气液两相流的传递过程.对上升管中气弹运动对传热传质的影响提出了假设.  相似文献   

2.
根据溶液的pH值与CO2溶解量间的关系,测定了30t底吹电弧炉1:7水模型中溶液的气液总综合传质系数(k,A)与液体表面的气液综合传质系数(kLA)s由此计算了气泡区综合传质系数(kLA)B。结果表明,底吹CO2后气泡区与表面区均因发生吸气反应而使溶液pH值降低,综合传质系数(kLA),(kLA)B和(kLA)S均随气体流量增大而增大,且回归得到了(kLA)(kLA)s与气体流量Q之间的关系分别为  相似文献   

3.
在分析研究智能型功率模块的结构特点、技术性能的基础上,提出了该模块在设计使用中应注意的问题。给出了该模块在UPS(不间断电源)中的应用实例。结果表明,智能型功率模块的使用,大大提高了设备的自动化程度和工作可靠性,有效地克服了GTR(功率晶体管)、GTO(门极可关断晶闸管)、VDMOS(垂直双扩散场效应管)等分立器件在UPS中易损坏问题。  相似文献   

4.
气液两相接触传质过程与设备是化工中一个重要的问题,近年来在这方面有了不少发展,大大地提高了设备的生产能力与操作效率。本文先就气液两相接触的流体力学和传质的机理进行了讨论,并进而对气液两相接触传质塔设备方面的发展进行了评述。  相似文献   

5.
以多元传质的扩散方程为基础,提出化学反应,吸附对气液传质增强因子以及伴有化学反应、吸附的气液传质过程的多元传质系数的估算方法,用非平衡级模型及上述方法得到的传质系模拟脂肪酸甲酯化反应精馏过程,与实验结果吻合。  相似文献   

6.
利用液相体积传质系数研究了气升式内环流反应器中添加表面活性物质(叔丁醇、季戊四醇、乙醇及CaCl2)后的传质特性.实验结果表明,与空气-去离子水体系相比较,添加微量表面活性物质会显著增强氧的气-液传质性能,但这种强化作用仅发生在一定的浓度范围内,超过极限浓度后,液相体积传质系数会有所降低.另外,叔丁醇和季戊四醇的碳链尽管长于乙醇,但促进气-液传质效果不及乙醇,说明分子空间结构对脂肪醇抑制气泡的聚并有一定的影响.  相似文献   

7.
ALR中表面活性物质对氧气液传质影响   总被引:1,自引:1,他引:1  
在气升式内环流反应实验装置中,添加乙醇和乙酸异戊酯作为表面活性物质考察了氧的气液传质性能.结果表明,在纯水和添加表面活性物质的情况下,较大气速范围内,氧的气液体积传质系数随气速提高而增加.添加表面活性物质可强化气液传质.两种物质的浓度对体积传质系数也有一定影响,且其影响在气速较高的情况下更为显著.提出乙醇分子在界面形成单分子层从而形成电荷分布的观点,并以此观点对乙醇影响氧的气液传质性能进行了分析,同时对添加乙酸异戊酯时体积传质系数出现峰值的情况进行了讨论.  相似文献   

8.
气扫式膜蒸馏用于脱除水中氨的分离性能   总被引:2,自引:0,他引:2  
针对气扫式膜蒸馏脱除水中氨的过程,以传质基本理论为依据,导出了考虑水中氨解离的总传质系数表达式,并建立了利用实验结果计算总传质系数和选择性系数的方程。在气扫式膜蒸馏实验中测定了各种操作条件下氨浓度和跨膜通量随时间的变化关系,并利用导出的方程、由实验结果得出了相应的总传质系数和选择性系数。研究结果表明,升高料液温度能够提高氨的总传质系数,但却使选择性系数下降;料液的流速对氨的总传质系数和选择性系数均无重要影响,但提高吹扫气速能使两者都明显上升;总传质系数和选择性系数随料液浓度的升高而略有下降;提高料液的初始pH值能同时明显地增大总传质系数和选择性系数。  相似文献   

9.
实验研究了非压缩状态下第二类哑铃畴(ⅡD)畴壁中垂直布洛赫线(VBL)的温度稳定性,发现了与材料参量有关的两个重要温度(T)(ⅡD)与(T0)(ⅡD)当温度达到(T )(ⅡD)时,ⅡD畴壁中的VBL开始丢失;当温度达到(T0)(ⅡD)时,所有ⅡD畴壁中的VBL链全部解体。在(T  )(ⅡD)与(T0)(ⅡD)之间,温度越高,ⅡD畴壁中丢失的VBL数目越多。  相似文献   

10.
气-液-固三相体系颗粒完全离底悬浮的临界搅拌转速   总被引:1,自引:0,他引:1  
在机械搅拌槽中,使用翼形轴流桨(K4)、涡轮桨(DT)、6叶45°斜叶桨(6PTD、6PTU)(排出流向下、向上),对低粘度物系气-液-固三相体系的颗粒完全离底悬浮的临界搅拌转速N_(JSG)作了实验研究,阐明了不同搅拌桨结构下,悬浮液浓度及通气量对N_(JSG)的影响规律。实验得出在相同的悬浮液浓度及通气量下,K4的N_(JSG)最低。  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.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
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   

15.
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   

16.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

17.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

18.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

19.
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   

20.
Quality traits in wheat (Triticum aestirum L.) were studied by quantitative trait locus (QTL) analysis in a recombinant inbred line (RIL) population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross (ChSh). Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.  相似文献   

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