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1.
在RHF/6-31G(d,p),RHF/6-6-31+G(d,p),MP2/6-31+G(d,p)和B3LYP/6-31+G(d,p)水平优化得到了桶烯和相关分子的平衡几何构型,进一步用MP2/6-31G(d,p)//RHF/6-31+G(d,p),MP2/6-31+G(d,p)//RHF/6-31G+(d,p)和B3LYP/6-31+G(d,p)//BLYP/6-31+G(d,p)水平计算桶稀、双环[2.2.2]-辛二稀和双环[2.2.2]-然的气相氢化热(△H^0(298K),气相氢化自由能(△G^0(298K)和同键反应芳香性稳定化能(HASE),计算结果指出桶烯有的G(sp^2)-C(sp^3)单链,小的∠C-C-=C键有和比较大的氢化热,同键反应芳香性稳定化能为正值,表明桶烯为反双环芳香性分子,实现了标合物反芳香性的几何、能量的判定。  相似文献   

2.
在B3LYP/6-311++G(d,p)、B3LYP/6-311++G(3df,2p)和B3P86/6-311++G(3df,2p)水平优化计算了锗亚按、磷杂烯、磷杂锗烯和砷杂硅烯以及标题物质子化正离子的平衡几何构型.用优化计算的平衡几何构型,在B3LYP/6-311++G(3df,2p)//B3LYP/6-311++G(3df,2p)计算了各标题物的旋转势垒.在B3LYP/6-311++G(d,p)//B3LYP/6-311++G(d,p),B3LYP/6-311++G(3df,2p)//B3LYP/6-311++G(3df,2p)和B3P86/6-311++G(3df,2p)//B3P86/6-311++G(3df,2p)计算了各标题物的质子亲和能,质子化反应自由能(ΔG 298)和质子化反应的焓变(ΔH 298).计算结果表明标题物有较强的π键和负值较大的质子亲和能、ΔG 298和ΔH 298,有稳定的质子质子化正离子产物.计算的旋转势垒标表标题物分子有比较强的π键,质子化正离子的π键比对应的中性分子强.  相似文献   

3.
采用DFT/B3LYP/6-311+G(d,p)、MP2/6-311+G(d,p)和MP2(full)/6-311+G(d,p)优化了氮方酸的几何构型,计算发现DFT/B3LYP/6-311+G(d,p)方法优化的几何构型较为合理.用TDDFT/B3LYP/6-311+G(d,p)和GIAO及SCRF方法对其NMR、IR、UV和FL光谱吸收光谱进行计算,发现溶剂对其光谱有影响,但溶剂介电性能对光谱影响较小.  相似文献   

4.
用量子化学密度泛函理论对路易斯酸Sn(OTf)2催化活化供电子-吸电子环丙烷的机理进行了量子化学研究.在B3LYP/6-31G计算水平全优化了反应势能面上所有驻点的几何结构,用自洽反应场极化连续介质模型分别在B3LYP/6-31G和B3LYP/6-311G(d,p)计算水平计算了单点溶剂化效应.结果表明,Sn(OTf)2催化活化D-A环丙烷是通过它们的配位作用增大C1-C(2)偶极矩和降低反键轨道σ*(C1-C2)的能量来实现的  相似文献   

5.
利用量子化学密度泛函理论(DFT)研究了B19H0/-2的结构和性质。利用不同杂化泛函包括PBE0、TPSSh、B3LYP和X3LYP在6-311+G(d,p)基组水平上,对富硼硼氢团簇B19H0/-2进行了构型优化,得到一系列能量较低的构型,确定了B19H0/-2的最稳定结构均为平面Cs对称构型而不是长条状的平面双链带状结构。虽然它们与B0/-19的全局极小结构明显不同,但是可以由B0/-19相应的次稳定结构加氢生成。通过氢化热ΔE和吉布斯自由能ΔG的计算表明,氢化反应B0/-19→B19H0/-→B19H0/-2为放热反应,且B19H0/-2在热力学上均可稳定存在。另外,CsB19H-2(1)的ΔEGap为3.10eV,接近于C2vB-19(b)的3.13eV,预期极有可能被实验观察到。正则分子轨道(CMO)分析表明,最稳定结构CsB19H-2的离域π轨道与[10]环轮烯D10hC10H10和C2vB-19(b)的离域π轨道存在着对应关系,但CsB19H-2不具有芳香性。本文中在PBE0/6-311+G(d,p)水平下计算了阴离子B19H-2的垂直剥离能(VDE)和绝热剥离能(ADE),模拟了B19H-2的光电子能谱图(PES),以便于实验进行观测。  相似文献   

6.
在B3LYP/6-311 G(d,p)、B3LYP/6-311 G(3df,2p)、B3P86/6-311 G(3df,2p)水平优化得到了亚胺、磷杂烯、硅亚胺和磷杂硅烯以及相应的质子化正离子的平衡几何构型.用优化的几何构型在B3LYP/6-311 G(d,p)//B3LYP/6-311 G(d,p)水平计算了标题物的旋转势垒.在B3LYP/6-311 G(d,p)//6-311 G(d,p),B3LYP/6-311 G(3df,2p)//B3LYP/6-311 G(3df,2p),B3P86/6-311 G(3df,2p)//B3P86/6-311 G(3df,2p)水平计算了标题物的质子亲和能(E)、质子化反应自由能增量(AG298^θ)和质子化反应的焓变(△H298^θ).计算结果表明标题物有强的π键和负值较大的质子亲和能、△G298^θ、△H298^θ,有稳定的质子化正离子产物.计算的旋转势垒说明标题物分了中Ⅰ的π键最强,Ⅲ的π键较弱.  相似文献   

7.
分别在B3LYP/6-31++G(d,p)、MP2/6-31++G(d,p)、MP2/aug-cc-pVDZ水平下,对OH-(H2O)n(n=1~8)团簇进行结构、二阶稳定化能、结合能等性质的研究,并进行电荷性质讨论,分析了上述稳定构象下的电荷分布和电荷转移.计算结果表明:对于氢氧根离子水团簇的结构、电荷转移、二阶稳定化能、结合能等性质,3种方法的计算结果多数比较接近,且氢氧根离子水团簇的结构、电荷转移、二阶稳定化能都与氢氧根离子的氧原子的配位数有关.OH-与第一壳层水分子形成的平均氢键长R-O…H,随着OH-氧的配位数的增加而增加.对于水分子数相同的团簇,第一壳层的平均角度θ-H…O…H、氢氧根离子总电荷与第一壳层水分子平均电荷的乘积qOH-×q-FW、氢氧根离子的电荷转移量的绝对值|ΔqOH-|以及第一壳层的平均二阶稳定化能E-ave(O…H)随配位数的增加而减小.  相似文献   

8.
对CH(X2Ⅱ)自由基与NH3的反应进行了量子化学研究.分别在B3LYP/6-311++G(d,p),B3LYP/6-311++G(3df,3pd),MP2/6-311++G(d,p)和MP2/6-311++G(3df,3pd)水平优化了反应势能面上各驻点的几何结构,并在QCISD(T)/6-311++G(3df,3pd)水平上计算了各驻点的能量.通过IRC计算确认了过渡态,确定了反应的机理.  相似文献   

9.
在RHF/6 31G ,MP2 /6 31G ,RHF/6 311G和MP2 /6 311G水平上 ,对水分子作为催化剂参与下 3 羟基 2 亚膦基吡啶的异构化反应进行了研究 .计算所得Ea(RHF/6 31G) ,Ea(MP2 /6 31G) ,Ea(RHF/6 311G)和Ea(MP2 /6 311G)分别为 153.982 8,12 8.0 0 2 7,156 .96 19和 134.3916kJ·mol- 1,可见水分子作为催化剂参与下目标反应有较高的活化能 .  相似文献   

10.
采用Gaussian 98从头算程序包,从理论上对反应CH3CN+OH→CH2CN+H2O的动力学进行了研究.反应物、产物和过渡态的几何优化分别在UMP2/6-311+G(d,p)和UB3LYP/6-311+G(d,p)水平下进行.用MP4(SDTQ)/6-311+G(d,p)和CCSD(T)/6-311G(3df,2p)方法对UMP2/6-311+G(d,p)优化的反应物、产物和过渡态进行了单点能校正,并计算出了反应在300~2 100 K温度范围的速率常数和谐振频率.  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.
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   

16.
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   

17.
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   

18.
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   

19.
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   

20.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

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