Friedmann时空自由粒子的Dirac方程

Parker在Friedmann宇宙内粒子的产生一文中讨论过K=0的Friedmann时空中自由粒子的Dirac方程,Ford在Einstein宇宙的量子真空能量一文中讨论过Einstein时空自由粒子的Dirac方程。Frolov等在研究Friedmann时空中标量粒子和旋量粒子的产生过程的差别时,讨论过K=1的Friedmann时空中自由粒子的Dirac方程,他们用的是(?)矩阵方法。本文用旋量零标架方法研究了K=1的Friedmann时空自由粒子的Dirac     

双指数势Cardassian宇宙模型

对存在通常物质与双指数势标量场的Cardassian宇宙模型进行了研究，并分析了它的动力学性质．Cardassian模型对Friedmann方程引入修正项以符合目前观测的宇宙加速膨胀现象．对修正后的Friedmann方程选取适当的无量纲化，使得两项不同性质的能量密度在不同能量标度的极限下，分别现显出前者主要影响支配宇宙的高能时期，而后者影响支配宇宙的低能时期．计算结果表明，双指数势将影响宇宙演化，最终由其中一个优势项决定演化方式．     

关于LTB宇宙模型中的Friedamann方程

Lema tre-Tolman-Bondi(LTB)宇宙模型是对超新星亮度变暗的观测事实的另一种解释,其优点在于不再需要引入神秘的暗能量.在特殊情形下,LTB宇宙模型能够约化到通常的Friedmann-Robertson-Walker(FRW)宇宙模型.对于一般的LTB宇宙模型,通常的Friedmann方程必须作出相应的推广.由于LTB宇宙模型是非均匀但各向同性的,因而推广的Friedmann方程应含有两个哈勃参数.但在LTB的相关文献中,所讨论的是单哈勃参数的Friedmann方程,它无法完备地描述宇宙的演化.仅从牛顿引力理论即可导出单哈勃参数Friedmann方程,还进一步定义了LTB宇宙模型中无量纲参数,给出了双哈勃参数Friedmann方程的另一种形式.     

高导数引力理论宇宙动力学方程

利用高导数引力理论研究宇宙的演化。在Friedmann宇宙模型中，由高导数场方程导出宇宙动力学方程。此方程为宇宙标度因子关于时间的三阶非线性微分方程，并由能量-动量守恒及物态方程导出能量密度和宇宙标度因子的关系，最后比较了高导数引力理论动力学方程和标准动力学方程。     

旋量场背景下宇宙弦引力场

考虑静质量为零的中微子背景,探讨了背景场对整体宇宙弦核外引力场的影响,采用通常的静态柱对称度规,运用共动Ｃａｒｔａｎ标架场方法求解弯曲时空中旋量场的Ｄｉｒａｃ方程进而求出旋量场的能动张量,将其能动张量与宇宙弦（核外）的能动张量叠加,求出了中微子场背景下整体宇宙弦为源的Ｅｉｎｓｔｅｉｎ方程的线性近似解,其度规为通常的结果加上旋量场的贡献,即在通常对数排斥势的基础上获得了一项附加的对数引力势的修正,对     

五维Brans-Dicke引力理论的宇宙膨胀

将Brans-Dicke(BD)引力理论扩展到五维Kaluza-Klein时空,在物质场和BD标量场是空间均匀分布的假设条件下,提出五维时空的Robertson-Walker度规,由五维BD标－张量引力场方程出发,导出宇宙动力学方程,建立以五维BD引力理论为基础的宇宙模型,求得标度因子为时间t的幂函数形式的宇宙膨胀解,对辐射为主和物质为主时期的[宇宙膨胀作出讨论。     

五维时空中宇宙视界对应的量子统计熵

把广义测不准关系引入宇宙视界对应的量了统计熵的计算, 采用由广义测不准关系得到的新的态密度方程, 研究了五维黑洞背景下Bose场与Fermi场的熵. 利用新的态密度方程后, 不通过紫外截断可以消除brick-wall 模型中无法克服的发散项, 并且同样可得到宇宙视界对应的量子统计熵与视界面积成正比的结论. 计算结果表明, 宇宙视界对应的量子统计熵是视界面上量子态的熵, 是一种量子效应, 是时空的内禀性质, 这使人们对宇宙视界对应的量子统计熵的认识有更进一步的理解. 在计算中直接应用量子统计的方法, 求五维黑洞背景下Bose场与Fermi场的配分函数, 避开了求解各种粒子波动方程的困难, 为研究高维时空宇宙视界对应的量子统计熵提供了一条途经.     

旋量-张量引力理论与宇宙学

"宇宙在加速膨胀"这一现象的发现要求对爱因斯坦的引力理论做出修改.使用新的方法,利用旋量一张量耦合模型来修改引力理论,并导出修正的friedmann方程.     

暴涨指数的随机理论

回顾了现代宇宙学的历史和现状,从Friedmann方程出发,将标量场的量子涨落作为Gaussian白噪声,建立了反映宇宙暴涨过程的Langevin方程,得到尺度因子的均值、自相关系数和方差;特别是详细计算了暴涨指数,发现用这种方法得到的暴涨指数与经典结果差异甚微.     

关于共形平坦时空间的理想流体源的爱因斯坦方程的解

本文对高度致密的宇宙,当ρ=3P 情况下,假设引力源为理想流体,以及魏尔张量为零,即g(?)=Ω~2η(?)时,求得了爱因斯坦方程的解。     

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.