一类离散不确定系统的状态反馈控制问题

研究了一类离散不确定系统的状态反馈控制问题．通过将系统的鲁棒控制器解存在的充分条件转化为一类极小极大的优化命题，给出了一种简便而有效的最优鲁棒控制器的设计方法．为了克服最优鲁棒控制器设计的保守性，还通过定义最小状态反馈系数矩阵将反馈控制器的系数矩阵的增益设计到最小的程度．     

一类离散不确定系统的状态反馈控制问题

研究了一类离散不确定系统的状态反馈控制问题。通过将系统的鲁棒控制器解存在的充分条件转化为一类极小极大的优化命题，给出了一种简便而有效的最优鲁棒控制器的设计方法。为了克服最优鲁棒控制器设计的保守性，还通过定义最小状态反馈系数矩阵将反馈控制器的系数矩阵的增益设计到最小的程度。     

基于无源性的感应电机最小磁场能量的效率优化控制

借鉴互联和阻尼分配的基于无源性控制器设计的基本思想和设计方法,依据最小磁场能量原则,设计了一种新的效率优化的感应电机转矩跟踪控制器.由于只针对分解后得到的电气子系统进行最小磁场能量优化和转矩跟踪控制器设计,得到的磁通优化律不受转子电阻的影响,且控制器不需要观测转子侧的状态变量,因此系统具有更强的参数鲁棒性.控制器方程是全局定义的,不存在发散奇点,能够跟踪快速变化的转矩和磁通给定,从而保证了系统的动静态性能.仿真实验结果证实,该控制器在保证系统具有良好的动、静态性能的同时,能有效地提高感应电机轻载时功率因数,并取得良好的节能效果.     

倒立摆的输出反馈控制

倒立摆是不稳定的非最小相位系统,其H∞输出反馈缺乏鲁棒性。用带宽设计的观点分析了不稳定非最小相位对象的控制难点,指出非最小相位的控制要求系统的带宽要窄,而不稳定对象的控制则要求带宽要宽。提出用一个宽带宽的回路对不稳定动态部分进行镇定,再对只具有非最小相位的回路设计一个窄带宽的控制器。通过仿真表明,这样的设计具有良好的鲁棒性。     

一种稳健的自校正控制器

本文基于Juky判据提出了一种稳健的自校正控制器的设计方法,并且,就一类新目标函数意义下稳健的自校正控制器的设计进行了讨论。大量仿真结果证明所给出的控制器是可行的,对于非最小相位及不稳定的系统也能稳定地工作。     

一种非最小相位系统的非线性控制器设计方法

为解决非线性系统状态反馈线性化过程中出现的非最小相位问题,设计了一种非线性控制器实现对非最小相位环节的有效控制;通过微分同胚映射将原非线性系统变换为线性化标准型形式,此标准型由线性子系统描述的外部动态和由非线性子系统描述的内部动态(即零动态)构成;基于极点配置和李雅普诺夫稳定性理论,给出了一种零动态不稳定系统(即非最小相位系统)非线性控制器设计方法。数值算例仿真结果表明,该方法所设计的控制器既能确保外部动态满足性能要求同时也能保证零动态稳定。     

一类中立型时滞系统的时滞依赖保性能控制

研究了一类含有不确定参数和非线性扰动的中立型时滞系统的时滞依赖保性能控制问题,所设计的控制器对于所允许的的参数不确定性和时滞,能保证闭环系统渐近稳定且闭环的性能函数值不超过给定上界.最后通过解优化问题得到性能指标的最小上界.数值例子证明了所设计控制器的有效性和较小保守性.     

搅拌机的分散鲁棒控制

基于鲁棒频域响应近似设计方法与序列控制器设计方法，提出了一种线性多变量系统分散鲁棒控制器的设计过程，在序列控制器设计的每一步，单个鲁棒控制器用鲁棒频域响应近似法获得，并使用频域响应近似法进行控制器降价，整个过程应用于非最小相应搅拌机系统的分散鲁棒控制器设计。     

一类统一混沌系统的简单控制器设计

提出了一类统一混沌系统的控制器简单设计新方法.应用最小相位系统理论针对系统线性子系统给出了单一控制器设计,并证明闭环系统具有渐近稳定性.仿真结果表明所提出控制器的有效性.     

基于least-squares算法的随机非线性系统自适应控制的模块化设计

线性系统中基于估计的模块化设计就是任意镇定的控制器能够和任意标准的辨识器结合在一起,将这种设计思想推广到不确定随机非线性系统的鲁棒自适应控制设计中,设计一个输入状态稳定控制器模块,该控制器具有很强的参数鲁棒稳定性.根据Swapping技术设计辨识器模块,它由两个滤波器组成,将动态参数模型转化为静态模型,基于最小二乘(least-squares,LS)算法设计参数自适应律,并与梯度算法的设计结果进行比较研究,仿真结果验证了该算法的有效性.     

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.