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1.
在常压CO2—H2O体系中,实现了铁粉选择还原硝基苯制备苯胺.在室温常压条件下,苯胺的选择性为100%,硝基苯的转化率可达100%.  相似文献   

2.
制备了两种PVP稳定的负载型稀土金属催化剂, 考察了其催化邻氯硝基苯(o-CNB)选择加氢制备邻氯苯胺(o-CAN)的催化性能. 所用氢气通过乙醇的液相催化重整产生并直接用于邻氯硝基苯的原位加氢. 评价了不同反应条件(温度、时间、Fe修饰剂等)对邻氯硝基苯的选择加氢的影响. 研究表明, PVP-La/γ-Al2O3催化剂比另一贵金属催化剂PVP-Pd/γ-Al2O3拥有更好的催化性能. 同时, 在优化的条件下, Fe修饰的PVP-La/γ-Al2O3催化剂催化的邻氯硝基苯选择加氢反应中, o-CNB的转化  相似文献   

3.
研究细菌合成纳米颗粒原位还原硝基苯类污染物,为废水中有机物的去除提供参考和思路.首先利用Staphylococcu. saprophyticus JJ-1还原氯钯酸钠合成生物钯纳米颗粒(Bio-Pd NPs),采用一系列表征技术对所合成的Bio-Pd纳米颗粒的形貌、尺寸、晶型进行分析.进一步,利用"S. saprophyticus JJ-1/Bio-Pd"复合体系,还原转化邻氯硝基苯(O-Chloronitrobenzene,2-CNB),利用气相色谱-质谱联用仪(GC-MS)和高效液相色谱仪(HPLC)对2-CNB的还原途径和还原产物进行分析.结果表明,S. saprophyticus JJ-1能够合成Bio-Pd NPs,并于所合成的Bio-Pd NPs协同作用催化邻氯硝基苯的还原. GC-MS分析显示,邻氯硝基苯的还原产物为邻氯苯胺、硝基苯以及苯胺,说明在此体系下既可以实现硝基还原又可以进行脱氯反应. HPLC对邻氯硝基苯及其还原产物的定量分析显示,邻氯苯胺、硝基苯为中间产物,苯胺为最终产物.此外,研究结果表明,为建立还原2-CNB的"S. saprophyticus JJ-1/Bio-Pd"复合体系,最适的氯钯酸钠浓度为0.2 mmol/L,邻氯硝基苯的浓度上限不应超过0.6 mmol/L. S. saprophyticus JJ-1能够快速的合成Bio-Pd NPs,并于所合成的Bio-Pd NPs构成协同体系,很好地催化邻氯硝基苯(2-CNB)的还原转化.  相似文献   

4.
研究了水/有机两相催化体系中,水溶性钌络合物催化剂AC—1催化卤代芳香硝基化合物中硝基的选择性加氢反应.以对—氯硝基苯为底物,考察了表面活性剂种类及浓度、反应温度、氢压、催化剂浓度和反应时间等对反应转化率和选择性的影响.实验结果表明,阳离子表面活性剂对反应有明显的影响,其中以添加十六烷基三甲基溴化铵(CTAB)效果最好.当反应条件为90℃,氢压4.0MPa时,反应5h,对-氯硝基苯转化率可达100%,生成对—氯苯胺的选择性可达99.9%.该催化体系对其它卤代芳香硝基化合物的选择性加氢也具有很高的活性和选择性。  相似文献   

5.
为控制多氯硝基苯加氢制备多氯苯胺的深度脱氯,在Pd/C催化剂制备中,考察了硝酸浓度、催化剂还原温度和时间对催化剂上Pd粒径及催化加氢活性和选择性的影响。结果表明:Pd粒径的增大导致催化剂对多氯硝基苯的催化活性下降,但多氯苯胺的选择性上升;随着硝酸浓度的增加,Pd的分散性和粒径先增大后减少,而还原温度和时间的增加可增大Pd的粒径;采用15%硝酸处理、200~250℃下氢气还原4~5 h可获得较理想的Pd粒径为16~20 nm的Pd/C催化剂;对五氯硝基苯加氢还原呈现较高的加氢活性和选择性,转化率可达99%以上,五氯苯胺选择性可达96%以上。  相似文献   

6.
采用异丙醇浸渍法制备了负载型Ru-Ir/γ-A l2O3双金属催化剂用于催化对氯硝基苯的选择加氢。系统考察了温度、压力、时间、溶剂的极性及底物浓度对于催化加氢反应的影响。实验结果表明,在Ru-Ir/γ-A l2O3双金属催化体系中,催化剂的活性和目标产物的选择性较好。在P(H2)=1.0 MPa,70℃,反应150 m in的条件下,双金属催化剂Ru-Ir/γ-A l2O3催化对氯硝基苯中硝基选择性加氢反应转化率达到100%,生成对氯苯胺选择性达95%。  相似文献   

7.
绿锈还原转化邻氯硝基苯实验研究   总被引:1,自引:0,他引:1  
合成2种含有结构态Fe(Ⅱ)的化合物——硫酸盐绿锈(GRSO4)和碳酸盐绿锈(GRCO3),研究了它们对邻氯硝基苯(CNB)的还原转化能力,并探讨了反应途径和还原产物.实验表明,2种绿锈都能使邻氯硝基苯发生快速的还原转化,绿锈中的结构态Fe(Ⅱ)是主要的还原活性组分,GRSO4的还原能力明显大于GRCO3.还原产物主要为邻氯苯胺,绿锈被氧化为磁铁矿、针铁矿等含铁矿物.pH值对绿锈还原能力有重要影响,pH值升高有利于绿锈对CNB的还原.  相似文献   

8.
以聚乙烯吡咯烷酮(PVP)为保护剂,乙醇为还原剂,乙醇-水为溶剂制备了PVP-2Ru/1Pt双金属胶体.以PVP-2Ru/1Pt催化间氯硝基苯(m-CNB)和对氯硝基苯(p-CNB)的催化氢化反应.考察了底物浓度、催化剂浓度和反应温度等因素的影响.当反应温度为30℃,氢气压力为0.1MPa时,反应速率分别可达0.0545(m-CNB)和0.0542(p-CNB)s^-1,转化率均可达到100%,间氯苯胺和对氯苯胺的选择性分别可达99.3%和〉99.9%.  相似文献   

9.
以苄基三丁基氯化铵做相转移催化剂,邻硝基氯苯、甲醇和氢氧化钠为原料,在常压下合成了邻硝基苯甲醚。并对原料配比、反应时间、催化剂的选择及用量对转化率的影响进行了讨论。在最佳反应条件下邻硝基氯苯的转化率>99%,邻硝基苯甲醚的收率为93%,凝固点≥9.8℃。  相似文献   

10.
本文研究了80℃常压CO2-H2O体系中,锌粉选择还原硝基苯生成苯基羟胺的反应.硝基苯的转化率随反应时间的延长而增加,同时苯基羟胺和苯胺的产率也增大,但苯基羟胺的选择性基本不变.通过实验证实苯胺是通过原料硝基苯和苯基羟胺还原而得到的.  相似文献   

11.
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   

12.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

13.
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   

14.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

15.
Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with  相似文献   

16.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

17.
18.
The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.  相似文献   

19.
R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).  相似文献   

20.
The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.  相似文献   

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