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1.
目的:通过工艺改进实现原料2-乙酰呋喃的完全转化,提高中间体2-甲氧亚氨基-2-呋喃乙酸的顺式结构的选择性,从而提高呋喃铵盐的收率,降低成本.方法:以2-乙酰呋喃为原料,通过氧化、肟化、成盐三步反应制备呋喃铵盐.结果:通过液相检测2-乙酰呋喃的氧化转化率提高到100%,2-甲氧亚氨基-2-呋喃乙酸的顺式选择性从82.55%提高到97%,产品收率达到85%.结论:该制备方法操作简便、工艺稳定、收率高.  相似文献   

2.
研究了在Pd/C催化下水合肼还原对硝基苯乙酸制备对氨基苯乙酸的方法.讨论了反应时间、反应温度、水合肼及催化剂用量对产物收率的影响,在优化条件下对氨基苯乙酸的收率达89.52%.经IR、MS和NMR证实了其结构.  相似文献   

3.
以NaOH溶液快速沉淀CuCl2和AlCl3的混合溶液制备了催化剂CuO-Al2O3.在20%NaOH水溶液中,以CuO-Al2O3催化水合肼还原邻硝基苯乙酸得到邻氨基苯乙酸,经重氮化和卤置换反应得到邻卤苯乙酸,收率65%~73%.总收率为40%~45%.  相似文献   

4.
相转移催化合成乙酸苄酯香料   总被引:1,自引:0,他引:1  
用氯化苄和乙酸钠为原料,以相转移催化法合成乙酸苄酯香料。提出了最佳工艺条件和反应过程中催化剂、过剩反应物料循环利用的可行性。结果表明,转化率高达99%,选择性为98%~100%;产品收率在90%~95%.工艺过程简单,副反应很少,是乙酸苄酯生产的一条高产、优质、低成本的有效途径。  相似文献   

5.
三乙基苄基氯化铵催化合成乙酸苄酯工艺研究   总被引:3,自引:0,他引:3  
文章利用相转移催化剂三乙基苄基氯化铵(TEBAC)催化合成乙酸苄酯,最佳反应条件如下:氯化苄∶乙酸钠=1∶1.4,催化剂用量为9%,反应温度为98℃~102℃,反应时间为3 h,酯收率达88.8%.实验证明,三乙基苄基氯化铵催化合成对该酯化反应是高效、低成本和实用的方法.  相似文献   

6.
采用热分解法制备含中间涂层IrO_2的Ir-Ta-Ti-Nb/Ti四元复合涂层钛阳极,对比考察了该四元复合涂层钛阳极及传统涂层钛阳极在电催化合成红矾钠过程中的槽电压、电流效率等工艺参数,并采用XRD和SEM方法分析四元复合涂层电催化前后组织结构特征和表面形貌。结果表明,该四元复合涂层钛阳极在电催化合成红矾钠的过程中槽电压约为3. 2 V、平均电流效率为94. 50%、平均转化率为95. 01%,相比于传统涂层钛阳极的工艺参数(槽电压约为3. 4 V、平均电流效率为92. 10%、平均转化率为92. 80%),其工艺参数更优异,且涂层电催化前后的主要物相和表面形貌未发生变化,说明制备的涂层钛阳极具有较好的稳定性和电催化性能。  相似文献   

7.
通过电解小试实验,研究甲酸、乙酸、柠檬酸、酒石酸、乌头酸、葡萄糖及蔗糖等有机物对锰电解电流效率(MECE)的影响.结果表明:甲酸、乙酸和柠檬酸等有机酸在一定质量分数范围内均可提高锰电解电流效率,达73%左右,最高可达77.9%,但有机酸质量分数过高,锰电解电流效率反而降低;葡萄糖和蔗糖粘度较高、质量分数过大,会阻碍电解液中离子的迁移,从而导致锰电解电流效率下降.  相似文献   

8.
用AC法处理高锑低银类铅阳极泥,其氯化浸出渣经转化脱氯、硅氟酸浸铅、氨水浸银和水合肼还原,得到含Ag大于95%的银粉,铅以硅氟酸铅溶液返回电解精炼.在V苏打溶液/m浸出渣=4mL/g,n苏打实=1.6n苏打理,转化时间为4h及温度为80℃的最佳转化条件下,铅、银、氯的平均转化率为91.42%;在V(H2SiF6)/m浸出渣=4mL/g,浸出时间为1h,温度为50~60℃的最佳浸铅条件下,硅氟酸浸铅率为85.74%~86.07%,硝酸浸铅率大于95%;在浸银过程中,银的浸出率约为94.0%,沉银率约为98.0%.在整个工艺中,银的直收率及总回收率分别为93.63%及98.80%,铅直收率为85.91%,总回收率98.99%.  相似文献   

9.
无水三氯化铝催化合成N,N-二甲氧基羰基乙基苯胺的研究   总被引:2,自引:0,他引:2  
报道了用无水三氯化铝作催化剂在低温下将苯胺和丙烯酸甲酯转化为N ,N -二甲氧基羰基乙基苯胺的新方法 ,其反应转化率达 95 %以上 ,产品收率高于 91% ,纯度高于96 % .  相似文献   

10.
乙酸异戊酯的合成研究   总被引:3,自引:0,他引:3  
研究了乙酸异戊酯的合成条件及工艺过程。用固体酸对氨基苯磺酸作催化剂,以异戊醇和冰乙酸直接酯化合成乙酸异戊酯。产物后处理简单,收率80%,催化剂可重复多次使用。  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.
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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