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1.
采用组合法制备了CsaFebHxPVMo11As0.4Oy系列Keggin型杂多化合物催化剂,用于异丁烷的选择性催化氧化。采用FFIR、TG—DTA等方法对催化剂进行了表征,探讨了杂多酸盐中Cs、Fe含量对其选择氧化异丁烷的影响。实验表明,反应温度为400℃,烷氧比为2/3时,CsaFebHxPVMo11As0.4Oy对异丁烷的催化性能最好,异丁烷的转化率达30.68%,选择性达32.33%。  相似文献   

2.
用β-环糊精和马来酸酐合成双(6-氧-丁烯二酸单酯)-β-环糊精(简称为化合物1),以化合物1与Fe^3 形成的配合物模拟乳酸脱氢酶催化乳酸的脱氢,用过氧化氢作为质子受体,生成的丙酮酸用2,4-二硝基苯肼检测,结果表明:化合物1与Fe^3 形成的配合物可以催化乳酸的脱氢反应。  相似文献   

3.
采用水热法和组合法制备了杂多化合物催化剂Cs2.0Fe0.1HxPVMo11As0.4Oy.采用FT-IR和TG-DTA对不同方法制备的催化剂结构进行了研究,对它们在连续流动固定床反应器中选择性催化氧化异丁烷的催化性能进行了比较研究.实验表明,在C4H10/O2/N2/H2O=2/3/6/1,GHSV为910 h-1的条件下,水热法和组合法制备的催化剂的催化性能均在380℃时达到最佳,但这两者的催化性能差别却很大,产物甲基丙烯酸的选择性分别为9.53%和32.33%.  相似文献   

4.
杂多化合物在C4催化中的应用   总被引:3,自引:0,他引:3  
概述杂多型催化剂的特性,回顾近些年来杂多化合物用于异丁烯的催化氧化,丁烷的催化异构,异丁烷的烷基化及催化氧化的进展,分析目前存在的一些问题和一些反应的机理。  相似文献   

5.
以MoO_3-SiO_2为主催化剂,研究了助剂Fe、Co的催化作用。Fe的加入,提高了催化剂对甲烷的脱氢能力,从而提高生成HCHO的选择性;Co的掺入与Mo形成CoMoO_4相,改善了MoO_3在含水气氛中的稳定性。考察了空气作氧化剂取代N_2O进行CH_4选择氧化的可能性。反应过程中水的加入抑制了深度氧化反应的进行,使生成HCHO选择性提高。  相似文献   

6.
考察Mo2V1M0.5Ox(M=Co,Zr,Nb,Bi,Ni,Fe,Mn,Al,Sb,P,Nd,Te)系列催化剂的丙烷氧化脱氢性能,其中,添加Co的催化剂表现出较好的催化活性和丙烯选择性.对催化剂的BET,XRD,H2-TPR和NH3-TPD表征结果表明,Co元素的添加,改变了催化剂的物相组成,氧化还原性和酸碱性质,从而提高了Mo2V1Co0.5Ox催化剂的丙烷氧化脱氢性能.  相似文献   

7.
通过合成的一系列溴代十六烷基吡啶修饰的过渡金属取代单缺位的Keggin型磷钨杂多化合物PW_(11)O_(39)M(II/III)(M=Fe、Co、Ni、Cu、Mn),并利用红外和X-射线光谱对其结构进行了表征.以其为相转移催化剂,评价了合成的杂多化合物对苯乙烯氧化反应的催化活性.通过观察反应温度、反应时间、催化剂用量和叔丁基过氧化氢用量对(Cpyr)_5PW_(11)Co催化苯乙烯氧化反应的影响,发现合成的过渡金属取代的单缺位Keggin结构磷钨杂多化合物,当反应温度为80℃,反应时间为8 h时,(Cpyr)_5PW_(11)Co具有最高的催化活性,反应物苯乙烯的转化率高达89.3%,目标产物环氧苯乙烷的选择性为78%,且催化剂的重复利用性较好.  相似文献   

8.
均相和非均相Fenton型催化剂催化氧化含酚废水   总被引:31,自引:4,他引:31  
研究了均相和非均相Penton型催化剂催化氧化含酚废水.对均相催化氧化反应进行正交试验和单因数试验,确定其氧化降解特定废水的最优化条件.在Fenton反应机理的基础上,探讨了Fe^3 在均相和非均相条件下的催化氧化机理;制备了Fe^3 /人造沸石和Fe^3 /活性炭催化剂;进行了非均相催化氧化降解高浓度含酚废水的试验;比较了均相和非均相催化氧化反应对苯酚降解率的影响.结果发现非均相反应能大大提高苯酚降解率,使用Fe^3 /活性炭为催化剂时可使苯酚的降解率达到93.02%.  相似文献   

9.
有机钴盐,在化工生产中被广泛地用作有机液相氧化反应的催化剂,特别是用于烷基芳香族、饱和烃类、不饱和甘油酯类等化合物的液相催化氧化反应。例如,甲苯氧化成苯甲酸,二甲苯氧化成甲基苯甲酸或苯二甲酸;环已烷氧化成环己酮或己二酸以及不饱和聚酯树酯的固化,油漆的干燥等过程中,都常常应用有机钴盐作催化剂或促进剂。  相似文献   

10.
低碳烷烃氧化脱氢是制备烯烃类基础化工原料的重要方式,相较于已工业化的直接脱氢过程具有不受热力学平衡限制、催化剂不易积碳失活等优势.低碳烷烃氧化脱氢应用的瓶颈在于反应易发生深度氧化而生成CO和CO_2.近年来,硼基催化剂(如氮化硼和氧化硼等)因在烷烃氧化脱氢反应中表现出高烯烃选择性和优异的抑制深度氧化能力而备受关注.本文系统总结了已报道的硼基催化剂在低碳烷烃氧化脱氢反应中的催化性能,以及目前对这些催化剂上的活性位和反应机理的认识及争议,并针对该类非金属催化剂的拓展应用和先进表征技术等进行了展望,以期为相关催化研究提供有益借鉴.  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.
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   

15.
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   

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.
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   

19.
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   

20.
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   

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