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1.
利用双线性函数给出了准伪正交基、伪正交变换、准对合变换与伪对称变换的概念,研究了它们的性质及其之间的联系,获得了许多新的结果,推广了伪欧氏空间的伪正交基与伪正交变换的概念。  相似文献   

2.
在矩阵代数中,非奇异矩阵是很重要的慨念,但它必须足方阵,这在应用上带来了很大不便,现在把非奇异矩阵的概念推广到列满秩矩阵之后,这不仅保持了非奇异矩阵的一些重要性质,而且能够灵活地应用到许多方面,特别是在处理许多矩阵问题有不少简便和巧妙的  相似文献   

3.
本文研究在相空间中的准坐标下非保守奇异系统的Noether对称性和守恒量。首先,将奇异性导致的内在约束按外在非完整约束等效处理,利用Euler-Lagrange方程变换得到准坐标下的约束Hamilton系统的正则方程;其次引进时间、准坐标和广义动量的无限小变换,得到系统Hamilton作用量在此变换下的Noether广义准对称性的定义、判据和定理,并研究了该系统的Noehter对称性逆问题。研究结果表明,准坐标下的约束力学系统比广义坐标下的约束力学系统更具有普遍性,准坐标可使奇异系统表达更简洁。  相似文献   

4.
将准对角矩阵F分布的定义推广到左球准对角矩阵分布中,给出了推广的准对角矩阵F分布变量的矩量表达、特征根分布及其关于对角非奇异矩阵变换的不变性.  相似文献   

5.
引入了线性空间的准循环子空间的概念,进而研究了准循环码与准循环子空间的关系,给出了准循环码的准循环子空间表示定理。  相似文献   

6.
研究准坐标下非完整奇异力学系统的Lie对称性与守恒量。首先,定义准坐标下非完整奇异力学系统的无限小变换生成元,利用微分方程在无限小变换下的不变性,建立系统的确定方程。其次,给出结构方程并求出相应的守恒量。最后,研究Lie对称性逆问题举例说明结果的应用。  相似文献   

7.
目前的基于多项式、正交多项式和加权正交多项式的图像配准方法是以误差平方和为度量标准的.此度量会导致图像配准结果出现过溢出现象,并且泛化能力差.根据结构风险最小化原则,重新定义误差函数,即在误差函数中引入系数惩罚项,提出了改进的多项式、正交多项式和加权正交多项式三种图像配准方法.实验结果表明,基于新的误差函数的图像配准方法较好地提高了图像配准的准确度。  相似文献   

8.
多径衰落信道下准正交时分复用的研究   总被引:2,自引:0,他引:2  
基于时频对偶原理,提出了一种准正交时分复用(QOTDM)系统.该系统利用频域具有升余弦性质的脉冲波形的平移准正交特性,采用自适应信道均衡方法,使发送滤波器、信道和接收滤波器的频域总特性具有升余弦性质,信道等效脉冲响应满足奈奎斯特采样点无失真准则.发送端利用上述信道进行时域波形准正交的离散信息符号序列传输;接收端根据信息符号波形的准正交特性,实现准正交分离.与正交频分复用(OFDM)系统相比,QOTDM系统在略微降低频带利用率的条件下,可以降低峰值平均功率比,并且当信噪比较高时具有更强的抗多径衰落能力.仿真结果表明,在准静态多径衰落信道下,采用正交幅度调制,在误比特率为10^-3时,QOTDM比OFDM的平均比特信噪比值约低3dB.  相似文献   

9.
一类二值谓词逻辑中公式的准真度理论   总被引:13,自引:0,他引:13  
在二值谓词逻辑中引入了一阶语言的一类特殊解释,该类解释中的解释域取为非空有限集.在此基础上基于有限均匀分布概率测度空间的可数无穷乘积引入了逻辑公式的相对真度与准真度概念,证明了关于准真度而言MP规则与HS规则成立,并基于准真度对全体谓词公式之集进行了分类.准真度理论虽然并不与逻辑有效公式以及矛盾式概念完全吻合,但可证明存在一类公式,对该类公式而言,逻辑有效性等价于准真度为1,矛盾性等价于准真度为0.所以准真度为1或0分别是逻辑有效公式或矛盾式概念的一种推广.  相似文献   

10.
实用的准晶     
准晶是令人十分感兴趣的一类材料,它们具有特殊的晶体结构、奇异的物理性质和可与金属合金相比的机械特性。这一方面促使人们更深人细致地去研究和了解准晶的基本性能,另一方面又推动人们去积极开拓其技术应用,现有的应用和潜在的应用大多是与节能有关。  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.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  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   

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