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1.
该文在四氯化碳介质中考察了苯乙烯对丙酮肟和N,N-二甲基甲酰胺(DMF)1HNMR谱的溶剂效应,观察到丙酮肟、DMF和苯乙烯的化学位移随苯乙烯的摩尔分数增加而逐渐移向高场,丙酮肟和DMF分子中的两个甲基向高场移动的程度不同,而且两个甲基和苯乙烯分子中的苯基的化学位移与混合溶剂中苯乙烯的摩尔分数呈线性关系.  相似文献   

2.
本文测定了N,N—二甲基甲酰胺(DMF)在甲苯和四氯化碳混合溶剂申随甲苯摩尔分数变化的~1H NMR谱,观察到N,N—二甲基甲酰胺(DMF)分子中的两个甲基和混合溶剂中的甲苯共振吸收峰的化学位移随甲苯摩尔分数增加而逐渐移向高场,而且两个甲基向高场移动的程度不同。发现如果苯环上的氢被甲基取代,DMF分子中的甲基和溶剂分子中的苯基向高场移动的幅度递减,得到了所有化学位移与混合溶剂中甲苯的摩尔分数呈线性关系。  相似文献   

3.
本文通过质子宽带去耦(PBBD)和质子偏共振去耦(PORD)核磁共振技术;研究了新型手性衍生化试剂2-甲氧基-2-三氟甲基-2-苯基-乙胺(MTPEA)分子中^13C-^1H、^13C-^12F间的耦合作用。在此基础上,报导了MTPEA分子中各基团的化学位移和^13C-^19F间的一级、二级耦合常数(^1J和^2J)。  相似文献   

4.
研究二乙酰一肟在四氯化碳和苯混合溶剂中的1HNMR,观察到二乙酰一肟分子中两个甲基和混合溶剂中苯的共振吸收峰的化学位移随苯的摩尔分数增加而逐渐移向高场,而且两个甲基共振吸收峰向高场移动的程度不同,α甲基的Δδ值较β甲基的Δδ值为大。α甲基和混合溶剂中苯的化学位移与苯的摩尔分数呈线性关系,可用方程δ=Ax+B表示,式中x是混合溶剂中苯的摩尔分数,相关系数R接近于-1。  相似文献   

5.
利用分子动力学模拟方法研究了不同温度下甲醇缔合体系中氢键与弱氢键的缔合情况.通过模拟与核磁共振实验数据研究表明:(1)强氢键的缔合度与羟基的质子位移变化趋势一致,羟基质子的化学位移直接受缔合度的影响;(2)强氢键在低温下起着主要的作用,致使甲基质子位移处于高场,随着温度升高,强氢键很快减少;(3)在高温下弱氢键对溶液结构慢慢占据主要地位,它的作用是使得甲基质子移向低场,其数目同样随着温度升高而减少,但受温度的影响远小于强氢键。  相似文献   

6.
本文测定1-[5-(3-吡啶)-四唑-2-乙酰基]-4-芳基氨基硫脲及3-[5-(3-吡啶)-四唑-2-亚甲基]-4-芳基-1,2,4-三唑-5-硫酮等六种化合物的^13C-NMR谱。各种^13C-NMR化学位移,根据取代基效应,讯号强度以及同模型化合物化学位移对照而确认其归属。  相似文献   

7.
用2,6-二(咪唑甲基)-4-氯苯酚分别与邻、间、对-二(溴甲基)苯或2,6-二(溴甲基)吡啶反应,合成了一类新型的取代酚-咪唑Weng型环番。所有化合物均被MS,^1HNMR,IR和元素分析证实。  相似文献   

8.
研究了丙酮肟在四氯化碳和苯乙烯混合溶剂中随苯乙烯摩尔分数变化的^1HNMR,观察到丙酮肟分子中两个甲基共振峰的化学位移随苯乙烯摩尔分数增加而逐渐移向高场,而且两个甲基向高场移动的程度不同.ASIS值随苯乙烯摩尔分数增加而增加,两个甲基共振峰在四氯化碳中是一个单峰,而且当混合溶剂中苯乙烯的摩尔分数大于0.30时分裂为双峰.丙酮肟分子中两个甲基共振峰化学位移δ与混合溶剂中苯乙烯的摩尔分数呈良好的线性关系.  相似文献   

9.
本文测定了3-羟基-2.丁酮(acetoin)、二丙酮醇(DA)在四氯化碳、正庚烷、苯和1,2-二氯乙烷等中的红外光谱(3800—3100cm ̄(-1)).根据谱峰的强度和峰位的变化,证实了acetoin在溶液中能形成较稳定的五元环分子内缔合体,二丙酮醇可形成六元环分子内缔合体.另外,对甲醇、正了醇与acetoin在四氯化碳中相互作用的红外光谱也进行了研究,结果表明,acetoin分子中羰基和羟基的相互作用,使得自由基的吸收峰移向低频(△γ=20cm ̄(-1)),同时羰基醇中羰基接受质子的能力亦被增强.  相似文献   

10.
使用半径验分子轨道计算得到了化合物N-(2’4‘,5’-三氯)苯甘-2-羟基-3,5,6-三氯苯磺酰胺的一些电子性质,用分子力学程序MMP2得到了该化合物的分子几何构型和稳定构象。计算时参数取自对分子N-甲基甲基磺酸胺的abinitio计算研究和X-光晶体衍射结果。研究表明:原子S和N形成d-p配价键,通过此键,其电子进一步与两边的取代苯环共轭,d-p配价键对分子中的电子离域可能起着一个重要的桥梁  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.
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   

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