分数阶线性定常系统的能控性研究

介绍了分数阶线性定常系统的能控性定义以及状态方程解的一般表达式,给出了状态转移矩阵的概念,并 在此基础上提出并证明了分数阶线性定常系统能控性的格拉姆(Gram)矩阵判据,所得结论对分数阶控制系统的 分析与综合是有益的。     

线性系统Hamilton扩张系统的能控性和能观测性

利用控制系统的微分几何理论,研究了线性系统和它的Hamilton扩张系统的能控性之问的关系以及它们的能观测性之间的关系.通过计算线性系统的能控性矩阵和它的Hamilton扩张系统的能控性矩阵,证明了线性系统和它的Hamilton扩张系统的能控性是等价的.同时通过计算线性系统的能观测性矩阵和它的Hamilton扩张系统的能观测性矩阵,证明了线性系统和它的Hamilton扩张系统的能观测性也是等价的.证明了线性系统的Hamilton扩张系统是能控的当且仅当它是能观测的,原线性系统既是能控的,又是能观测的.     

具有多噪声的马尔科夫跳变随机系统的精确能观性

本文研究了具有多噪声的马尔科夫(Markov)跳变随机系统的精确能观性问题,利用H-表示和谱算子的方法以及伊藤公式,建立了马尔科夫跳变随机系统的系数矩阵和确定性系统的系数矩阵之间的关系,将随机系统的精确能观性转化为确定性系统的完全能观性,从而得到了离散时间马尔科夫跳变随机系统的精确能观性的格拉姆矩阵判据(Gramian matrix criterion)。     

线性随机控制系统的能控性

首先讨论了时变系数随机混合控制系统的精确能控性问题,给出了控制系统精确能控的等价判据.然后又研究了常系数的混合控制系统的精确能控性问题,用两种方法得到了相应的能控性的代数判据.     

格拉姆（Gram）矩阵的半正定性及其应用

本文给出格拉姆矩阵的半正定性的简单证明,讨论格拉姆行列式的几个重要结论,并应用于一类不等式的证明．     

量化网络控制系统的能控性与能观性

将网络引入控制系统不可避免地引起很多新的问题,传统意义下的系统能控性与能观性在应用到网络化系统时必须重新考虑.针对网络控制系统中普遍存在的信息量化问题,研究网络控制系统的基本问题.定义量化网络控制系统的能控性与能观性,给出系统能控和能观的充分条件,指出量化网络控制系统的能控性与能观性取决于量化阶距的选取.     

Banach空间上控制系统的能控性的一个注记

本文应用泛函分析方法,研究了Banach空间上有界线性控制系统(A,B)在连续时间和离散时间时的能控性,指出离散时间控制系统(A,B)_d精确能控的充要条件为连续时间控制系统(A,B)_c精确能控。     

Buck变换器混杂动态系统的能控性和能达性

尝试在Buck变换器的能控性和能达性研究中引入混杂动态系统和切换线性系统的概念．首先建立Buck变换器的切换线性系统模型;然后根据该模型的特点,给出系统矩阵定常、输入矩阵切换的切换线性系统的能控性和能达性定义和定理,并严格证明了Buck变换器的能控性和能达性;最后讨论了能控性和能达性与输出能控性的关系,指出能控性、能达性和输出能控性是一致的,同时对Buck变换器的能控性进行实验验证,结果表明,在负载阶跃变化的情况下,变换器的输出完全可以控制并且稳定在设计值,这和Buck变换器作为切换线性系统模型的能控性分析结果是一致的．本文的研究方法也可用于其他功率变换器的能控性和能达性的研究．     

输入矩阵定常的切换线性系统的能控性和能达性

针对一类具有不同系统矩阵和相同输入矩阵的切换线性系统,证明了系统能控性和能达性的充要条件,同时给出具有不同输入矩阵和相同系统矩阵的切换线性系统能控性和能达性的充要条件,指出两类切换线性系统能控性和能达性充要条件是对偶的．对于上述两类切换线性系统,分别给出一个例子,并分析系统的能控性和能达性．     

力伺服波浪补偿器控制研究及其性能优化

力伺服波浪补偿器广泛应用于海洋工程领域,研究力伺服波浪补偿器的控制系统具有重要意义。建立了其数学模型,运用前馈复合控制方法消除作用在液压马达输出轴的外负载力矩的扰动干扰。基于消去扰动干扰的系统的数学模型,分析了系统的稳定性、能观性、能控性,运用极点配置方法对系统的控制性能进行优化,得到反馈矩阵。通过仿真验证了优化后系统的控制性能达到了优化设计目标。     

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.     

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.     

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.     

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.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

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.