首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
设φ(n)为Euler函数,探究一个系数为特殊勾股数的三元不定方程φ(abc)=3φ(a)+4φ(b)+5φ(c)的可解性.利用初等方法与技巧,对主要结论进行了完整的阐明,通过分析筛选后得到该不定方程共有40组正整数解.文中所用分类方法以及将系数选定为特殊勾股数的思想,为同类型方程的研究提供了新的思路.  相似文献   

2.
研究了二阶变时滞Emden-Fowler型阻尼差分方程Δ[Anφ(Δyn)]+Bnφ(Δyn)+Qnf(Φ(xσn))=0(n≥n0)的振动性,其中yn=xn+Png(xτn),φ(u)=|u|λ-1u,Φ(u)=|u|β-1u(这里λ〉0,β〉0为实常数). 利用广义的黎卡提变换,结合其它数学分析方法, 获得了该类方程的一系列新的振动准则,并给出了若干例子说明本文所得结果的有效性.  相似文献   

3.
多孔介质应力关系方程   总被引:9,自引:0,他引:9  
Terzaghi方程(σ=σG+P)是描述多孔介质应力关系的经典方程,由于方程同时定义了二个不可测量,因而是不实用的;方程没有引入反映多孔介质特性的最重要参数(φ),因而是不妥当的;鉴于方程存在的问题,本文对其进行了深入的研究,重新建立了多孔介质应力之间的关系方程:σ=φP+(1-φ)σG;由于φ的引入,新方程更全面、更合理地反映了多孔介质固有的力学特性.  相似文献   

4.
设p(t)、q(t)∈C^∞[0,+∞),若λ1、λ2是指标方程λ(λ-1) p(0)λ q(0)=0的根,Reλ1≥Reλ2,则方程t^2utt tp(t)ut 1(t)u=0在(0,+∞)内的任一解均可表示为(c1 c2hlnt)t^λ1φ(t) c2t^λ2φ(t),其中c1,c2是任意常数,φ(t)、φ(t)∈C^∞[0, ∞),φ(0)=φ(0)=1,h是一定值且当λ1-λ2≠0,1,2…时,h=0;当λ1=λ2时,h=1。  相似文献   

5.
讨论出现在吸引玻色-爱因斯坦凝聚中的一类阻尼Gross-Pitaevskii(GP)方程(在数学上又称为带调和势的阻尼非线性Schroedinger方程) iφ1+△φ-|x|^2φ+|φ|^2φ+iλφ=0, 其中t≥0,x∈R^2,λ是阻尼参数.这类方程已不再满足能量守恒定律,与不带阻尼的GP方程有很大的区别.对照玻色-爱因斯坦凝聚的物理性质,获得了其初值问题的整体稳定性的一个充分条件,且证明了该条件与一个非线性数量场方程的唯一正解相关.另外还获得了初值问题解坍塌的一个必要条件.  相似文献   

6.
设m,n是任意非零整数,且满足(m+n)(m-n)≠0, M是实或复数域F上的Hilbert空间上的一个因子von Neumann代数.利用代数分解方法证明了M上满足2mφ(AB)+2nφ(BA)=mφ(A)B+mAφ(B)+nφ(B)A+nBφ(A)的非线性映射φ为可加中心化子,并刻画出具体形式φ:A→λA(λ∈F, A∈M).  相似文献   

7.
讨论了几个有关Euler函数φ(n)与广义Euler函数φ_2(n)的二元定系数方程φ(xy)=k(φ_2(x)+φ_2(y))与二元变系数方程φ(xy)=k_1φ_2(x)+k_2φ_2(y)解的问题,结合Euler函数φ(n)与广义Euler函数φ_2(n)的性质,利用初等方法给出了所讨论的几个方程的解的情况.  相似文献   

8.
研究了一类带调和势的非线性Schrodinger方程iφt=-△φ+|x|^2φ+μ|φ|^2φ+λ|φ|^4φ,x∈R^N,t≥0其中μ〉0,λ〉0.采用T.Cazenave和P.L.Lions的方法以及一个紧性引理,得到了其所有驻波的存在性.进一步,证明了其所有驻波是轨道稳定的.  相似文献   

9.
研究了方程φ(abcd)=φ(a)+2φ(b)+3φ(c)+4φ(d)-6的可解性问题,φ(n)定义为欧拉函数。利用欧拉函数的性质和初等数论的方法,得到了该方程的所有正整数解。  相似文献   

10.
设φ(m)为Euler函数.本文探讨了方程φ(ab)=8(φ(a)+φ(b))的正整数解,利用初等方法给出了该方程的所有正整数解.根据方程φ(ab)=8(φ(a)+φ(b))正整数解的结论和已被讨论的相类似方程的正整数解的结论,证明了以下2个结论:对于任意正整数k,(a,b)=(2k,2k)是方程φ(ab)=k(φ(a)+φ(b))的1个整数解;对任意的正整数k,(a,b)=(~(2k+1),2~k×3)和(2~k×3,2~(k+1))是方程φ(ab)=2~k(φ(a)+φ(b))的2个正整数解.  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.
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   

15.
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   

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.
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   

19.
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   

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   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号