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1.
以无机陶瓷管为支撑体、热塑性酚醛树脂为原料,经高温炭化制备了炭分子筛膜.用低温N2吸附的方法测定了炭分子筛膜的比表面积,用扫描电子显微镜对膜的形貌和厚度进行了表征.考察了膜的气体透过率以及气体的理想选择性随温度的变化关系: H2、CO2、O2、N2和CH4的透过率随温度的升高而增大;理想选择性α(H2/N2)、α(CO2/N2)、α(CO2/CH4)随温度的升高而减小,而α(O2/N2)随温度的升高先增大后减小,在90℃左右气体选择性达到最大.最后由阿累尼乌斯公式计算了气体透过炭分子筛膜的活化能, 进一步说明气体透过机理为活化扩散.  相似文献   

2.
采用水热法制备全硅Deca-Dodecasil 3Rhombohedral(DD3R)沸石分子筛晶种, 并通过二次生长法在涂覆晶种的α-Al2O3片式支撑体上成功合成DD3R分子筛膜. 结合X线衍射仪(XRD)与电子扫描电镜(SEM), 考察晶种球磨处理对颗粒形貌、支撑体表面晶种涂覆以及膜的微结构的影响. 单组分气体H2、CO2和SF6的渗透实验表明:采用球磨的晶种所制得膜在500℃下, H2/SF6与H2/CO2的理想选择性分别为11.3和6.7.采用硅烷水解法修饰膜后, 在相同条件下所获得H2/SF6与H2/CO2的理想选择性分别为∞和45.8.  相似文献   

3.
使用混合结构导向剂,在摩尔配比为1.00 SiO2:0.10 Na2 O:0.01 Al2 O3:0.10 TMAdaOH:0.10 BTMAOH:80.00 H2 O的溶胶体系中,于大孔管状莫来石支撑体上通过一步水热过程制备了高性能的SSZ-13分子筛膜.膜制备具有很好的可重复性.考察了温度和压力对CO2和N2单气体渗透通过SSZ-13分子筛膜的渗透行为的影响,以及等摩尔CO2/N2气体的分离性能.在压差为0.2 MPa和温度为25℃的条件下,SSZ-13分子筛膜的平均CO2渗透速率和CO2/N2分离选择性分别为1.65×10-7 mol/( m2·s· Pa)和16.  相似文献   

4.
用一次浸渍和多次浸渍法制备出高活性、高选择性负载型镍催化剂 ,将其用于糠醇液相加氢制备四氢糠醇的反应中。试验结果表明 ,镍负载量在 2 0 %~ 6 0 %时 ,负载型镍催化剂对糠醇加氢反应的活性和选择性较高 ,采用多次浸渍法可显著地提高催化剂的加氢活性和选择性。在不使用溶剂和较缓和的反应条件下 (催化剂浓度为 10g/L ,温度为 170℃ ,压力为 5~ 6MPa ,停留时间为 4~ 4.5h ,搅拌速度为 10 0 0r/min) ,糠醇转化率达 10 0 % ,四氢糠醇收率为 95 %~ 96 % ,选择性大于 95 %。反应产物经减压蒸馏后四氢糠醇的纯度高达 99%以上。研究结果表明 ,采用多次浸渍法制备的负载型镍催化剂在四氢糠醇生产中具有良好的工业应用前景  相似文献   

5.
采用微波加热浸渍法制备生物炭负载的Ni催化剂,催化剂XRD、TEM和XPS对催化剂进行表征.10%Ni/CSC-Ⅱ催化剂在硝基苯选择性加氢制环己胺反应中表现出很好的活性,在200℃,2.0 MPa H_2,100 mg氢氧化锂的条件下,硝基苯的转化率为100%,目标产物环己胺选择性高达96.7%.结果表明微波加热有助于提高催化剂的活性.  相似文献   

6.
用一次浸渍和多次浸渍法制备出高活性、高选择性负载型镍催化剂,将其用于糠醇液相加氢制备四氢糠醇的反应中。试验结果表明,镍负载量在20%-60%时,负载型镍催化剂对糠醇加氢反应的活性和选择性较高,采用多次浸渍法可显著地提高催化剂的加氢活性和选择性。在不使用溶剂和较缓和的反应条件下(催化剂浓度为10g/L,温度为170℃,压力为5-6MPa,停留时间为4-4.5h,搅拌速度为1000r/min),糠醇转化率达100%,四氢糠醇收率为95%-96%,选择性大于95%。反应产物经减压蒸馏后四氢糠醇的纯度高达99%以上。研究结果表明,采用多次浸渍法制备的负载型镍催化剂在四氢糠醇生产中具有良好的工业应用前景。  相似文献   

7.
采用反应晶种法在片式多孔α-Al2O3支撑体表面制备金属有机骨架MIL-96膜.采用X线衍射仪(XRD)和扫描电子显微镜(SEM)对MIL-96膜进行相结构和形貌表征,并考察膜的热稳定性和化学稳定性.在不同的操作温度下,对MIL-96膜的单组分气体H2、CH4、N2和CO2的渗透行为进行详细研究.结果表明:随着操作温度的升高,气体的渗透性呈现出微弱的先下降后上升的趋势,在130℃时渗透性最小,这主要源于MIL-96骨架的柔性.温度升高导致分子热运动加剧,不利于气体渗透;但当温度高于130℃时,MIL-96的柔性骨架受温度影响引起晶格震动,膜的有效孔径增加,从而气体渗透性增加.同时,H2与CH4、H2与N2、H2与CO2的理想选择性都稍有增加.  相似文献   

8.
酚醛树脂基气体分离炭膜制备   总被引:5,自引:0,他引:5  
以热固性酚醛树脂为原料,利用浸渍法制备了气体分离用管状炭膜,考察了涂膜液浓度,涂膜次数对炭膜气体透过性和选择性的影响。结果表明:随着涂膜液浓度和涂膜次数的增加,H2、N2、CO2、CH4的涌透速率下降,H2/N2、H2/CO2、H2/CH4的分离因数增加,扫描电镜观察表明,炭膜由多孔结构的支撑体和其上覆盖的致密分离层组成、气体在炭膜内主要以努森扩散方式勇士, 随着粘性流存在。  相似文献   

9.
采用浸渍法制备出4种不同质量分数的Cu-Ce-O/-γA l2O3催化剂并用于富氢气体中CO的选择性氧化反应,研究发现以40%Cu-Ce-O/-γA l2O3催化剂活性较好.向其中掺杂钌的1%Ru-Cu-Ce-O/-γA l2O3催化剂的低温活性有很大提高,而掺杂铂的1.5%Pt-Cu-Ce-O/-γA l2O3催化剂的高温活性有了很大的改善.  相似文献   

10.
采用浸渍方法制备NiO(Clx)/CeO2系列样品,经还原后得到Ni(Clx)/CeO2催化剂,用于富氢气体中CO的选择甲烷化反应,考察Cl/Ce原子比(x)对CO选择甲烷化反应活性的影响. 结果表明,添加氯离子能够显著抑制CO2甲烷化反应,因而可使富氢气体中CO浓度降至10-5以下并且CO甲烷化反应选择性不低于50%,满足质子交换膜燃料电池对燃料的要求. 通过CO和CO2吸附实验、程序升温还原(TPR)测定以及物相组成和晶粒尺寸分析,揭示添加氯离子的作用.   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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