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1.
利用选择、配制出的两级相变材料体系,即:Ca(NO3)2·4H2O+4.7%碳酸盐成核剂+1.9%增调剂体系和Na2CO3·10H2O+6%硼酸盐成核剂+4.5%增稠剂体系作为第一、第二级隔热相变材料;设计、制作了单级相变材料复合体系和两级相变材料复合体系的实验装置.对单级与两级相变材料复合体系的隔热降温特性进行了探讨.实验证明,两级相变材料复合体系的隔热降温性能优于单级体系.  相似文献   

2.
单级和两级相变复合材料体系隔热降温特性的优劣取决于相变复合材料体系的输出功率大小,输出功率越大,说明其有效性大即隔热降温特性越好.在单级相变材料中存在着最佳相变温度,因而产生最大有效输出功率.通过实验及理论分析证明:采用两级相变体系的效率要比单级相变体系的效率提高59%.  相似文献   

3.
相变材料对砂浆热效应的影响   总被引:2,自引:0,他引:2  
研究了相变材料状态、掺量对砂浆热效应的影响;系统研究了有机相变材料(某多元醇)嵌入到导热系数较高的二氧化硅纳米层空间内,制备有机-无机纳米复合相变蓄热材料的工艺条件及其效果.结果表明:相变材料直接掺人砂浆中掺量达1%~3%(占砂浆胶凝材料质量分数),具有明显的蓄热降温效应,但在50℃环境下耐久性明显下降;复合相变材料较纯相变材料相变潜热提高1.66倍,50℃环境下耐久性明显提高.  相似文献   

4.
将纳米技术,尤其是纳米材料制备技术应用于相变储热领域,可以得到纳米胶囊相变材料、纳米复合相变材料以及纳米高温相变材料。纳米级相变材料的开发将拓宽相变储热技术的应用领域。本文综述了纳米胶囊相变材料、纳米复合相变材料和纳米高温相变材料的研究进展,介绍了纳米相变材料的应用。  相似文献   

5.
 冷却服能够为高温作业人员提供降温保护,提高人体微气候区的舒适度。分析了各种类型冷却服(气体冷却服、液体冷却服和相变冷却服)的降温方式、原理、特点及研究进展,着重阐述了相变冷却服的关键技术及发展方向:研究易塑性、耐腐蚀性的封装材料和相应的封装技术,解决液相相变材料存在的变形、泄露及水蚀问题;将纳米技术与相变材料微胶囊结合,研制作用时间长、散热良好的复合相变材料,提高相变材料的导热系数;将相变冷却技术与其他技术相结合,开发作用效果可调控的新型冷却服,同时研制可快速激活相变材料的设备或新型材料,使相变材料能够快速蓄冷。  相似文献   

6.
相变贮热材料是绿色材料,种类达4300多种,具有清洁和节能等优点。系统地介绍了相变贮热材料分类及其特点,讨论了相变贮热材料在太阳能热动力发电、航天器仪器仪表的恒温控制、舱外航天服方面的应用。  相似文献   

7.
定形相变材料的热性能   总被引:42,自引:0,他引:42  
定形相变材料在蓄热采暖领域有重要应用。分别用低密度聚乙烯和高密度聚乙烯为支撑材料制备了定形相变材料,分析了材料的均匀性和稳定性,讨论了材料中石蜡掺混比例的临界值,利用电子扫描显微镜、DSC2910差示扫描量热仪研究了其理化结构及热性能,并将定形相变材料与混凝土掺混,研究了其热性能。实验结果表明:高密度聚乙烯更适合做支撑封装材料,材料热性能和稳定性较好;定形相变材料和混凝土搀混后材料的单位体积蓄热量也有相当提高。  相似文献   

8.
相变材料的选择主要依据是相变温度.根据实验要实现的致冷目标,依次选定相变温度,再据相变温度选择相变材料.通过加入适当比例的成核剂和增稠剂,以解决无机相变材料的主要问题:过冷现象和分层现象.最终选择、配制出合适的两级相变材料体系,即:Ca(NO3)2·4H2O+4.7%碳酸盐成核剂+1.9%增稠剂体系,和Na2CO3·10H2O+6%硼酸盐成核剂+4.5%增稠剂体系.  相似文献   

9.
NPG-TAM/蒙脱土纳米复合贮能材料的研究   总被引:2,自引:0,他引:2  
研究了利用插层复合法将新戊二醇-三羟甲基氨基甲烷(NPG-TAM)二元体系多元醇混合物嵌插到蒙脱土的层间,制取NPG-TAM/蒙脱土复合贮能材料的方法。由实验确定了适宜的制备条件。用XRD、IR、DSC等方法对其结构及贮能性能进行了分析。实验结果表明:所得材料是一种纳米复合贮能材料,具有较适宜的相变温度和相转变焓,同时较好地解决了多元醇单独使用时存在的塑晶现象。  相似文献   

10.
MA-SA/蒙脱土复合相变贮能材料的制备   总被引:2,自引:1,他引:1  
用DSC法研究了豆蔻酸(MA)和硬脂酸(SA)二元混合物的热性能,确定了MA-SA二元低共熔物的组成为67.00:33.00,相变温度为43.13℃;在此基础上,研究了MA-SA二元低共熔物/蒙脱土复合贮能材料的制备方法,并用XRD、IR和DSC等方法对复合材料的结构和性能进行了表征与测试。研究结果表明:MA-SA被有效地包封在蒙脱土层间,制得复合材料的相变温度为41.86℃,相变焓为130.32J/g,贮能性能满足调温纺织品的要求。  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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