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1.
CaCl2/LiCl改性中孔硅胶的吸附/脱附性能   总被引:2,自引:1,他引:2  
使用不同的金属盐溶液对中孔硅胶进行改性,并采用间歇式吸附方法研究了水蒸气在硅胶上的吸附动力学实验,利用程序升温脱附技术测定了水在改性硅胶上的程序升温脱附(TPD)曲线并估算了水的脱附活化能,讨论了表面改性对硅胶吸湿性能以及水的脱附活化能的影响.实验结果表明:与C型中孔硅胶相比,经CaCl2或LiCl改性的中孔硅胶,孔容变小而平均孔径变大,在相对湿度(RH)小于80%的范围内,其吸湿性能明显增加,水的脱附活化能也增大;由于Ca^2+的极化势大于Li^+的极化势,水分子在经CaCl2改性的硅胶上的脱附活化能要大于其在经LiCl改性硅胶上的脱附活化能.  相似文献   

2.
复合干燥剂转轮性能测试及其应用   总被引:1,自引:0,他引:1  
测试了新型复合干燥剂和硅胶的平衡吸附性能.实验结果显示与常用硅胶干燥剂相比,前者的吸湿能力约是后者的2倍以上.为了进一步验证新型复合干燥剂优良的吸湿性能,设计了一台除湿机,测试了转速、再生温度对转轮除湿性能的影响,并且分析了在典型气候条件下,该除湿机在除湿冷却空调中的应用情况.结果表明,采用新型复合干燥剂的除湿冷却空调不仅出口空气的温湿度能够达到送风要求,而且系统性能系数(COP)能达到1.28,比采用硅胶干燥剂的系统COP提高了34.7%.  相似文献   

3.
不同吸湿官能团对高分子调湿材料吸湿和放湿性能的影响   总被引:1,自引:0,他引:1  
以甲基纤维素、甲基丙烯酸甲酯、甲基丙烯酸、丙烯酰胺及甲基丙烯磺酸钠等合成具有不同官能团的湿度控制材料,通过间歇式吸附/脱附进行吸湿动力学实验和恒温脱附实验;采用TG-DTA和FTIR表征改性复合材料的热稳定性及其结构。实验结果表明:CaCl2改性可以明显提高高分子复合调湿材料的吸湿性能,其吸湿量随单体所含亲水基团的极性的增强而增加;含强极性的离子基团(—COOH和—SO 3-)高分子调湿材料的吸湿能力明显大于含非离子基团(—CONH2,—OH及—COOCH3)材料的吸湿能力,尤其是CaCl2改性聚甲基丙烯酸及甲基丙烯磺酸钠材料在相对湿度为100%的最大湿容量可高达2 g/g,而含非离子性基团(—CONH2,—OH及—COOCH3)弱极性基团的复合材料则比较容易脱附,CaCl2改性聚甲基丙烯酸甲酯材料在80℃于20 min内可以脱附80%吸附水,且所有材料在300℃以下具有良好的热稳定性。  相似文献   

4.
吸附制冷用复合吸附剂的制备   总被引:2,自引:0,他引:2  
用静态法测定主要吸附材料和自制复合吸附剂对水的吸附量,用TG-DTA法对主要吸附材料的热稳定性和自制吸附剂对水的脱附峰端温度进行分析。对吸附剂原料复合比例、焙烧温度和扩孔剂种类等制备条件进行了实验研究。结果表明:自制复合吸附剂比单一吸附材料对水有着更大的吸附能力;DTA分析的脱水的峰端温度明显低于单一吸附材料;采用较高的焙烧温度和分段焙烧方法,可明显改善复合吸附剂的吸附性能及强度;对于用不同的吸附材料复合的吸附剂,需加入不同的扩孔剂,方可增加孔容和孔径,改善其吸附性能;自制复合吸附剂对水的吸附量显著高于13x和硅胶等传统吸附剂。其中,M1-9906和M1-9907复合吸附剂对水的吸附量大约是13x和硅胶的2-3倍。  相似文献   

5.
文中研究了碳纤维/乙烯基酯树脂(CF/VE)拉挤复合材料在65℃和95℃、质量分数为5%的H2SO4水溶液中的吸湿特性、以及材料的动态力学性能和静态力学性能的变化。结果表明,在5%H2SO4水溶液中,浸泡前期复合材料的吸湿与Fick扩散相似,但后期吸湿率略有下降;拉挤复合材料的力学损耗(tanδ)随浸泡时间的延长而增大,且温度越高影响越大;玻璃化转变温度(Tg)、储能模量(E′)以及弯曲强度和剪切强度随浸泡时间的延长而下降,且温度越高,下降幅度越大。  相似文献   

6.
研究了Na2SO4/SiO2复合储能材料的工艺性能.进行了成型压力、烧成温度和保温时间3因素3水平L9(33)正交实验.分析了这些因素对储能材料的致密度与高温强度的影响,从中获得了致密度和高温强度最佳时的工艺参数.对储能材料的蓄热性能进行了初步研究,结果表明Na2SO4/SiO2复合储能材料的蓄热密度是显热陶瓷蓄热料的2.7倍.  相似文献   

7.
赵莹 《天津科技》2014,(9):17-19
利用熔融挤出法研究了两种不同环氧值的环氧树脂(E20,E06)对PA6/CaCl2复合体系的结晶、力学、耐热性能的影响。结果表明,在相同环氧树脂含量下,PA6/CaCl2/E20复合材料的熔融温度、起始结晶温度、结晶峰温度、结晶度大体上低于PA6/CaCl2/E06复合材料的值,PA6的结晶受限程度也较大。当EP含量为9份时,PA6/CaCl2/E20与PA6/CaCl2/E06复合材料的拉伸强度均达到最大值(92.7,87.0 MPa),与PA6/CaCl2(47.0 MPa)相比提高了97%和85%。当E20,E06含量分别为3份、5份时,PA6/CaCl2/EP复合材料的冲击强度分别达到最大值8.7,8.7 kJ/m2,与PA6/CaCl2(6.0 kJ/m2)相比提高了45%。另外,加入适量E20,E06后,复合材料耐热性能均有显著提高,且热稳定性降幅不大。综合得知,加入适量的环氧值较高的E20可以得到力学性能优良、耐热性能较好的PA6/CaCl2/E20复合材料。  相似文献   

8.
环氧树脂/ZrW2O8封装材料的制备及其性能   总被引:4,自引:0,他引:4  
将负热膨胀材料ZrW2O8粉体按一定质量比例与E-51环氧树脂混合,制备电子封装材料.测定了不同比例下封装材料的线膨胀系数、玻璃化温度、抗拉与弯曲强度、吸湿率和耐腐蚀性能.研究结果表明:采用超声波处理,可使ZrW2O8粉体均匀分散在环氧树脂E-51基体中.随着ZrW2O8质量分数的增加,封装材料的线膨胀系数下降,玻璃化温度升高,拉伸、弯曲强度与抗吸湿性提高;当ω(E-51)∶ω(ZrW2O8)=3∶2时,封装材料的耐酸性腐蚀较好,而耐碱性腐蚀的能力较差.  相似文献   

9.
含可膨胀石墨复合吸附剂块制冷研究   总被引:1,自引:0,他引:1  
为提高颗粒状沸石分子筛传热效果,提出一种新型含可膨胀石墨、金属M的氢氧化物、硅胶等添加剂的复合吸附剂块,通过正交实验及在自行研制的模拟吸附制冷装置上进行制冷实验,确定了添加剂间的最佳配比,实验结果表明:可膨胀石墨是三因素中的主要影响因素;复合吸附剂块的导热系数为颗粒状沸石分子筛导热系数的6.2~8.6倍;吸附剂块经压制成型后,模拟吸附制冷系统的性能系数提高23.8%。  相似文献   

10.
三维编织炭纤维增强环氧树脂复合材料的吸湿特性   总被引:1,自引:0,他引:1  
为了研究三维编织复合材料的吸湿行为,利用树脂传递模塑(RTM)工艺制备了三维编织炭纤维增强环氧树脂(C3D/EP)复合材料.通过吸水实验,研究了该材料的吸湿规律、温度对吸湿的影响以及吸湿过程中复合材料力争陛能的变化.结果表明:C3D/EP复合材料吸湿初期符合Fick扩散定律,但整个吸湿行为可用Sigmoidal曲线来描述;温度可加速C3D/EP复合材料的吸湿速率,并使平衡吸湿量提高;在吸湿过程中,C3D/EP复合材料的弯曲强度随吸湿时间的延长而下降,先快后慢,与吸湿曲线相对应,而且温度越高,下降越明显,表明吸湿量的大小决定了力学性能的降低程度.  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.
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 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   

15.
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   

16.
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   

17.
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   

18.
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   

19.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

20.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

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