基于模糊控制的直流无刷伺服控制系统

主要研究了采用模糊算法且要求运行更快更精确的微机控制直流无刷伺服系统，分析了模糊控制器在伺服系统中稳态误差、调节时间和响应时间方面的性能。采用DSP数字处理器实现伺服控制，用MatLab语言仿真了模糊控制的响应，并且提出了PI控制加模糊控制的算法。     

考虑铁损时异步电机模糊PI控制的调速研究

随着工业的发展,控制系统复杂程度的不断加大,参数随机多变,传统PI速度控制器已经不能满足系统对性能的要求,在传统PI速度控制器基础上,根据模糊控制理论,设计了模糊PI控制器,利用MATLAB/Simulink进行传统PI控制器和模糊PI控制器的仿真,对比仿真结果说明模糊PI控制器具有更加好的稳定性和鲁棒性.     

一种用于机器人视觉伺服系统的参数自适应模糊控制器

提出了一种用于机器人视觉伺服系统的参数自适应模糊控制器,使得模糊控制规则可以得到实时在线的调整。仿真结果表明基于参数自适应模糊控制器的机器人视觉伺服系统的性能较一般模糊控制机器人视觉伺服系统有了较大的改善。     

基于模糊控制的交流伺服系统的设计

针对永磁同步电动机交流伺服系统,提出了模糊控制方案.在交流伺服系统的设计中,采用模糊控制器作为其位置调节器,采用电流快速跟踪控制方案设计电流调节器,对于速度调节器,按Ⅱ型系统设计,并选用PI型调节器,极大地提高了系统的性能.实验与仿真结果表明,基于模糊控制的交流伺服系统与常规PID控制的交流伺服系统相比,具有良好的动态、稳态性能以及较强的鲁棒性,从而证明了这种设计方法的合理性和优越性.     

有源电力滤波器直流侧电压新的控制策略

针对有源电力滤波器(APF)直流侧电压传统PI控制策略参数难以确定的问题,设计了一种基于模糊控制的参数自整定的模糊PI控制器.通过对APF的工作原理分析可知谐波电流补偿效果与直流侧电压稳定密切相关.以实际电压与给定电压的差值及其变化率为输入量建立模糊控制规则,实现PI参数自调节的目的.MATLAB仿真结果表明,在模糊PI控制策略下,直流侧电压更稳定,APF滤波效果也更好.     

液压缸位置伺服系统的模糊控制

以模糊集理论为基础，设计了一种可以实时地进行模糊运算和模糊揄的模糊控制器，在ＰＣ９８２１计算机上成功地实现了液压缸位置伺服系统的模糊控制，通过仿真和实验研究，将模糊控制器的动态性能和传统的ＰＩＤ控制器进行了比较，验证了模糊控制应用液压控制系统中的优越性。     

基于规则自校正模糊控制器的交流伺服系统

提出了一种规则自校正模糊控制器,并将其用于交流伺服系统的控制中,设计了一种在线的模糊推是算法,使得模糊控制规则可以得到实时在线的调整。仿真结果表明基于规则自校正模糊控制器的交流伺服系统的性能较一般模糊控制交流伺服系统有了较大的改善。     

无刷直流电机的模糊自适应控制

在分析无刷直流电机数学模型的基础上，将模糊控制和经典自适应控制相结合，设计了模糊自适应无刷直流电机速度控制器，并应用于调速伺服系统。仿真实验证明，该控制器具有优越的跟踪能力与控制性能。     

永磁同步电动机新型模糊PI控制器的设计

为提高永磁同步电动机控制系统的抗扰性能,设计了一种新型的模糊PI控制器.该控制器包括模糊控制器和PI控制器,采用模糊开关选择器根据系统的状态实现不同控制器之间的切换,实现简单.将该新型控制器用于永磁同步电机控制系统中,仿真结果表明:与传统PI控制永磁同步电机伺服系统相比,永磁同步电机模糊PI控制系统鲁棒性强、响应快、对被控对象参数变化具有较好的适应能力.     

连续型模糊PID复合控制器在直流位置伺服系统中的应用

为了实现直流位置伺服系统的高速和高精度位置控制,针对实际伺服系统中存在的非线性、强耦合等各种不确定因素,提出了一种连续型模糊控制算法,以抑制各种非线性因素对被控对象的影响,同时引入传统的PID控制器,进一步改善了系统的稳态性能.通过实际运用表明,该连续型模糊PID复合控制器可以明显地提高直流位置伺服系统的动态性能和稳态精度,同时系统具有较强的适应性和鲁棒性.     

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.     

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.