新型三重态硅烯的理论研究

应用密度泛函理论方法研究了8种新型含氮杂环卡宾单元的硅烯,在M06-2x/6-311+G(d,p)水平上计算了它们的单重态及三重态的结构,在QCISD/6-311++G(d,p)水平上计算了单点能量.结果表明,这些硅烯的三重态能量比单重态能量低,基态为三重态.引进氮杂环卡宾骨架能够提高三重态硅烯的稳定性.     

不同共轭桥的氮氧双自由基分子NLO性质的DFT研究

采用密度泛函理论(DFT)UB3LYP/6-31G(d,p)方法对不同共轭桥的氮氧双自由基分子4个体系的非线性光学(NLO)系数进行了计算.结果表明:所有体系单重态为稳定的基态,与自旋极化规则一致;4个体系的极化率在单重态时较大,三重态时较小;体系a,b和c在单重态与三重态的二阶超极化率与极化率规律相同,而具有垂直稳定构型的体系d,由于强的反铁磁性耦合体现出三重态时具有较大的二阶超极化率.     

四元环芳香体系N2S2的量子化学计算研究

在UB3L YP／6-311 G(d，P)、UB3L YP／6-311 G(3df，2p)、UB3L YP／AUG-CC-PVTZ，UQCISD／6-311 G(d，p)水平优化得到了N2S2单、三重态的平衡几何构型，发现单重态N2S2为能量最低的稳定分子。用优化的最稳定单重态N2S2结构在UB3L YP／6-311 G(d，p)／／UB3L YP／6-311 G(d，P)，UB3L YP／6-311 G(3df，2p)／／UB3L YP／6-311 G(3df，2p)计算同键反应芳香性稳定化能(HASE)。用基团加和法(group increment approach)在UB3L YP／6-311 G(d，P)／／UB3L YP／6-311 G(d，P)和UB3L YP／6-311 G(3df，2p)／／UB3L YP／6-311 G(3df，2p)水平计算磁化率增量(A)，计算结果表明N2S2分子的键长发生了平均化。同键反应芳香性稳定化能和磁化率增量均为负值．表明N2S2具有芳香性．实现了N2S2分子芳香性的几何、能量和磁性的判定．     

锗亚胺及其相关分子的密度泛函计算研究

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.     

有机小分子、离子芳香性的密度泛函研究Ⅱ.芳香性与磁性材料设计

在B3LYP水平、6－31＋G（d）基组上分别计算了单重态和三重态4nπ电子的有机轮烯离子C5H5^＋和C6H6^ 的芳香性和构型。根据几何、能量和磁性判据，发现4nπ电子轮烯单重态具有反芳香性，而三重态具有芳香性，且其三重态能量比单重态能量低。因此具有Dnh对称性的4nπ电子轮烯可以提供基态具有未成对电子的顺磁中心，用于分子基磁性材料的合成。     

RN3解离反应中交叉点构型及电子密度拓扑分析

采用CASSCF(10,8)/3-21G方法优化了CH3N3,CH3CH2N3,(CH3)2CHN3和(CH3)3CN3单重态和三重态解离过程中交叉点的几何构型.4个反应中的交叉点的几何构型参数比较接近.采用电子密度拓扑分析方法计算了交叉点的电子密度拓扑性质.研究发现:交叉点在单重态和三重态途径上N(2)-N(3)键的特性变化较大,在三重态反应途径上N(2)-N(3)键更容易断裂.     

含有dithiole-2-one的苯并噻吩基乙烯化合物光致变色反应的溶剂效应

采用B3LYP/6-311G方法及溶剂效应中的极化连续模型,对含有dithiole-2-one的二苯并噻吩基乙烯化合物(BTDO)进行了理论计算研究.并运用TD/B3LYP/6-311G方法计算了其电子吸收光谱,得到的最大吸收波长与气相中所得到的实验值相吻合;研究还发现第一激发三重态对应的是分子的HOMO→LUMO(π→π*)电子跃迁.通过分析其前线分子轨道,解释了不同溶剂下吸收光谱的差异.     

二氯卡宾与异硫氰酸反应机理的量子化学研究

用密度泛函理论B3LYP方法研究了单、三重态CCl2与HNCS的反应机理.在B3LYP/6-311＋＋G＊＊水平上对反应物、中间体和过渡态进行了全几何参数优化;通过频率分析和内禀反应坐标（IRC）方法确认了中间体和过渡态;并用CCSD（T）/6-311＋＋G＊＊//B3LYP/6-311＋＋G＊＊方法计算了各个驻点的单点能.结果表明,对于单、三重态CCl2与HNCS反应,共有4条可行的反应通道,且通道CCl2（S）＋HNCS→IM1→TS1→IM2→HCN＋CCl2S（P1）反应能垒最低,为该反应的主反应通道;单重态抽提亚氨基通道反应能垒也比较低,为主反应通道的竞争通道.可为进一步实验研究提供参考.     

均双核配合物Co(Ⅱ)-Co(Ⅱ)的密度泛函研究

用密度泛函方法,在ROB3LYP/SDD//ROB3LYP/LANL2MB水平上,对Co(Ⅱ)-Co(Ⅱ)均双核配合物进行了理论计算,优化得到了它的单、三重态的平衡几何构型,计算了它们的谐振动频率.结果表明:配合物分子的三重态比单重态稳定,电子自旋布居高度集中在两Co原子上,体系中存在较弱的自旋离域效应.配合物的磁轨道分析表明:体系的铁磁性耦合作用主要来自于d-π*-d反键的超交换作用.     

CH3C(O)O2+HO2反应机理的理论研究

用量子化学密度泛函方法,在B3LYP/6-31+G(d,p)和B3LYP/6-311++G(d,p)水平上研究了乙酰过氧自由基(CH3C(O)O2)和氢过氧自由基(HO2)的反应机理.研究表明,该反应是在单、三态势能面上的多通道反应.三重态的势能面低于单重态的势能面.各反应的通道入口存在以氢键结合的松散络合物.该反应体系的主要产物是过乙酸,它将进一步分解释放OH自由基.     

Markedness and its Interpretation in Language Use

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.     

Lower Paleozoic oil relationships within Williston Basin, Canada

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

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.     

Features of Women's language

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

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.     

Design and analysis of generic LBS application developing platform

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.     

橡胶颗粒沥青混合料低温抗裂性试验研究

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.     

低渗透非均质砂岩油藏启动压力梯度研究

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。     

Quantitative trait loci （QTLs） for quality traits related to protein and starch in wheat

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.     

On Tragic Consciousness In The Works By Ernest Hemingway

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.