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1.
目的运用量子化学计算为苯乙烯基苯并咪唑染料分子的结构与性质关系,以及染料的设计及合成提供理论依据。方法采用PBE1PBE和B3LYP两种密度泛函理论(DFT)方法及6-31G*极化基组对染料分子进行量化计算。结果对α-甲基-2-取代苯乙烯基苯并咪唑染料系列进行了几何构型全优化,并采用含时密度泛函方法(TD-DFT)计算了分子第一激发态的电子跃迁,计算所得到的最大吸收波长λmax与实验值吻合得很好,在微观上解释了苯环上取代基CH3,OH,Cl,OCH3,N(CH3)2,NO2对分子电荷转移,前线轨道能量和电子光谱的影响规律。结论采用PBE1PBE/6-31G*方法可以计算并预测苯乙烯基苯并咪唑系列染料分子的几何构型和电子吸收光谱性质。  相似文献   

2.
采用密度泛函理论(DFT)的B3P86方法,在6-311G**基组水平上,优化出CH3自由基的稳定构型为双重态D3h构型,并得出基态的简正振动频率、转动常数.在此基础上,根据对称陀螺分子红外光谱跃迁定则,计算了谱线跃迁频率.使用以上数据,我们研究了不同温度下CH3自由基ν2平行谱带谱线强度,并分析了谱线强度随温度的变化规律.结果表明直到1600 K时,谱线强度计算值和实验结果符合很好.表明对CH3自由基在高温下谱线强度的计算方法是成功的.进而计算了CH3自由基在2000和3000 K时ν2谱带谱线强度及模  相似文献   

3.
基于Hartree-Fock和密度泛函理论,用几种不同水平的基组对CH3Br和CH3I分子价轨道电子动量分布进行了计算,并与Minchinton等人的实验和理论进行了比较.得到的计算结果有很大的改善,与Minchinton等人的实验符合较好.对CH3Br分子,计算结果的改善主要是使用了有极化、弥散函数的大基组.对于CH3I分子,则主要是来自考虑了相对论效应的LANL2DZ基组.  相似文献   

4.
采用量子化学密度泛函理论与从头算分子轨道理论研究了CH自由基与NO反应的机理,在B3LYP/6-311++G(d,p)水平上优化了反应过程中反应物、中间体、过渡态和产物的几何构型,并在G3水平上计算了它们的能量,同时对它们进行了振动分析,以确定中间体和过渡态的真实性.从对CH自由基与NO反应机理的研究结果看,CH自由基与NO反应为多通道反应.可能的产物是OH+CN、0+HCN、H+CNO、H+NCO、N+HCO、NH+CO,这些产物与实验检测到的结果相吻合.理论分析表明,反应通道CH+NO→IM6→TS8→IM7→TS9→N+HCO控制步骤的活化能最低(144.6kJ/mol),为主要反应通道.同时理论计算得到的各通道反应热与实验值一致,可以说明研究结果是比较可靠的.  相似文献   

5.
通过密度泛函理论(DFT)在6—311G*基组水平上对CH3+HCI<=>CH4+Cl反应进行研究,获得反应中间体,过渡态的最优化构型、能量及振动频率.对前驱化合物、过渡态、后继化合物的频率分析得出了其反应机理.HCl分子中的H进攻C原子,经前驱化合物形成过渡态,电子转移在前驱化合物中发生.  相似文献   

6.
用密度泛函理论在QCISD/6-311 G**//B3LYP/6-311G*水平上对星际分子CH3CN和NO 的反应机理和动力学进行了理论研究,得到了体系的势能面信息和可能的反应机理:CH3CN和NO 反应中共存在9个反应通道、4种中间体和11种过渡态,并得到CH2 CHN2O,CH2C N2OH,CH3NC NO 和CH3C N2O 4种产物;从能量变化角度考虑,CH3CN NO →CH3NC NO 应为主反应通道.  相似文献   

7.
CH3S, CH3SH, CH3SO, CH3SO2的标准摩尔生成焓的研究   总被引:1,自引:0,他引:1  
利用7种密度泛函(DFT)方法(B3LYP,BLYP,BHLYP,BP86,B3P86,BPW91,B3PW91),以DZP 为基函数对CH3S, CH3SH, CH3SO, CH3SO2的标准摩尔生成焓进行了理论计算.采用等键方程在BPW91水平下预测的结果为-23.56 kJ/mol(CH3S),115.85 kJ/mol (CH3SH), -106.16 kJ/mol(CH3SO)和-255.56 kJ/mol(CH3SO2),接近已有的实验结果.这表明,采用密度泛函方法只需要很少的计算量和中等大小的基组就能得到很好的结果,对于某些特殊例子(如CH3SO2),其预测结果甚至好于高水平的CCSD(T)/CBS方法.  相似文献   

8.
应用密度泛函理论在B3LYP/6-311+G(d)、M06-2X/6-311+G(d)、CAM-B3LYP/6-311+G(d)理论水平,分别计算12个不同取代基取代的六苯并蔻分子的电荷传输速率.研究结果显示,采用长程较正泛函CAMB3LYP更适合目标体系的电荷传输性能研究.在六苯并蔻环上,引入6个—CH3与—CN取代基,得到的六苯并蔻衍生物分子与母体六苯并蔻相比,空穴迁移率相对较大,分别为2.51、0.92 cm2·V-1·s-1,可设计为性能优良的p型有机半导体分子;引入6个—SH、—CH2SCH3及—COOCH3取代基,得到的3个分子与母体六苯并蔻相比,对分子的电荷传输速率改善较小;引入—SCH3、—OCH3、—OH、—NHCH3、—N(CH3)2等5个取代基,所得到的5个分子电子迁移速率为空穴迁移速率的1.7~18倍,有望设计成性能优良的n型有机半导体材料.  相似文献   

9.
采用密度泛函理论的B3LYP方法,用不同基组研究了CH2CF自由基与HNCS的微观反应机理,优化了反应过程中的反应物、中间体、过渡态和产物;振动分析结果和IRC分析结果证实了中间体和过渡态的真实性,用AIM计算所得的部分成键临界点电荷密度的变化也确认了反应过程向生成物方向进行.对于CH2CF自由基与HNCS反应,我们找到了五条反应通道.结果分析表明,反应通道CH2CF+HNCS→IMA1→TSA1→CH2CHF+NCS控制步骤活化能最低,是该反应的主要通道,有稳定的氢键复合物IMA1生成,表现为H原子迁  相似文献   

10.
采用密度泛函理论的B3LYP方法,在6-311++G(d,p)基组水平上研究了CH3CH2自由基与HNCO的微观反应机理,优化了反应过程中的反应物、中间体、过渡态和产物,为了获得更精确的能量信息,在QC ISD(T)/6-311++G(d,p)水平上计算体系在反应通道各驻点的能量.振动分析结果和IRC分析结果证实了中间体和过渡态的真实性,计算所得的成键临界点电荷密度变化也确认了反应过程.对于CH3CH2自由基与HNCO反应,找到了10条反应通道.对结果的分析表明,其中生成烷基酰亚胺稳定分子的反应通道的控制步骤活化能最低,因此为主要通道,在该反应体系中氢迁移反应已不是主要的反应过程,但其活化能不高,也是能发生的.  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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