采用反馈的鲁棒系统设计方法

基于多变量系统鲁棒理论和反馈可以减小对象参数变化对输出影响的思想，本提出一种鲁棒系统设计方法和设计内反馈增益矩阵的算法。用该方法对一实际工业对象设计了鲁棒控制系统，结果令人满意。理论分析和实际系统设计结果表明，该方法设计的系统比串联补偿鲁棒设计的系统具有更好的鲁棒稳定性和鲁棒性能。     

一个“鲁棒”稳定性判据及其在控制系统设计中的应用

本文提出了受扰线性定常多变量系统“鲁棒”稳定性的一个充分和必要条件。它不仅可用于系统分析中作为“鲁棒”稳定性判据，而且也为“鲁棒”稳定系统的综合提供设计依据。它特别适用于参数变化范围较大的控制对象的综合设计。设计程序包括选择合适的名义设计参数，确定闭环系统的主极点以及检验高、低频稳定性等。     

一类线性系统的鲁棒稳定性分析

控制系统的稳定性问题一直被人们所关注,而系统的某些参数总是有某种变化的,所以对于控制系统的鲁棒稳定性研究更被人们所重视,本文通过对线性系统运动方程系数矩阵特征值的鲁棒性分析,分析了系统的鲁棒稳定性,同时给出了扰动矩阵稳定的充分条件。     

互质因子摄动系统的非脆弱控制

研究了被控对象和控制器均存在不确定时闭环系统鲁棒稳定性和非脆弱控制问题,分别讨论了左互质因子摄动和右互质因子摄动情况下反馈系统的非脆弱鲁棒稳定性和性能敏感性问题,并给出了相应条件下系统非脆弱鲁棒稳定的充分条件,最后给出了两种情况下系统非脆弱鲁棒稳定性之间的关系。     

对象族的鲁棒控制器设计

研究对象族的同时镇定问题,设计出同时镇定两个选定对象的含参数控制器.其基本思想是找到两个特殊对象:对象族的标称对象和"最坏点"对象,据此设计鲁棒镇定对象族的含参数控制器.由于引入了参数,使得通过已有的方法设计鲁棒控制器成为可能.根据对象族系统的稳定性理论确定控制器中的参数,把设计控制器的问题转化成稳定性检验问题,从而可求出同时镇定对象族的控制器及与之相应的被控对象的不确定参数的取值.     

中立型时滞微分系统的鲁棒稳定性

本文首先获得了中立型拟多项式包鲁棒稳定性分析的边界定理。依此，具有可公度时滞的中立型系统的鲁棒稳定性，归结为其特征拟多项式包所有边的Ｈｕｒｗｉｔｚ稳定性及其中立型项子包所有边的Ｓｃｈｕｒ稳定性的判定；同时给出了检验拟多项式包的边鲁棒稳定性的图解法。最后指出，其参数在超矩阵内变化的一维中立型拟多项式包的鲁棒稳定性等价于其所有顶点拟多项式的稳定性。     

多变量解耦鲁棒控制的遗传优化方法

提出一种基于遗传算法的鲁棒准优势化算法。该算法将鲁棒对角优势和遗传算法相结合,综合考虑各摄动系统的关联性,搜寻最优的鲁棒解耦控制器。用该算法对一参数不确定性工业对象进行了鲁棒系统设计,结果表明该设计方法比多模型加权准优势化算法具有更好的鲁棒稳定性和鲁棒性能,因而更适于实际工程应用。     

一类线性不确定时滞系统奇异摄动界

研究了一类常见的奇异摄动时否不确定线性系统的鲁棒稳定性问题，获得了参数H∞范数有界摄动时，系统时滞有关稳定的充分条件，给出了系统稳定时，时滞г及奇异摄动参数ε的上界。应用实例表明了奇异摄动时滞不确定系统鲁棒稳定性充分条件使用的方便性。     

一类带马尔科夫参数的不确定性系统鲁棒控制器设计

针对一类连续的带有马尔科夫参数的不确定性系统,进行鲁棒稳定性分析,利用李亚普诺夫定理,以不确定系统的名义系统作为研究对象,得到其鲁棒稳定性条件,对鲁棒控制器进行设计,将确定因素与不确定因素进行分离,通过Lyapunov函数和线性矩阵不等式定理得到系统控制器的线性矩阵不等式形式,并依据该形式进行仿真,得到算例的控制器参数.     

具有稳定摄动的反馈系统的鲁棒稳定性

研究了对象和控制器同时具有非结构不确定性时闭环系统的鲁棒稳定性问题。利用结构奇异值的概念和方法 ,给出了闭环系统鲁棒稳定性的充要条件。对于单变量 ,进一步给出了有关结论的解析表达式     

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.