基于Labwindows／CVI和模糊PID算法的流化床温控系统设计

针对流化床加热炉传统控制方法落后,成本高,自动化程度低等问题,基于模糊PID控制算法对流化床加热炉的温度进行控制,实现了PID参数自整定,提高了控制精度、效率及过程的稳定性.同时,利用Labwindows/CVI设计了上位机的人机界面.实际运行表明,加热炉内温度稳定时的误差变化幅度小于0.3℃,满足一般流化床加热炉的要求.     

基于MEA的加热炉炉温控制器参数自整定

针对工业加热炉大惯性、纯滞后、参数非线性等特点,以及传统PID控制器参数不易调节的特点,提出一种基于思维进化算法和模糊神经网络的加热炉炉温PID控制器参数自整定方法.并通过MATLAB进行仿真研究,仿真结果表明,使用该方法得到的炉温控制器可以获得较好的控制效果.     

模糊控制算法在温度控制系统中的研究

本文结合电加热炉的控制特性,分析了传统PID算法控制器和模糊逻辑控制器的优缺点,并根据智能控制理论的前沿研究,选择了模糊PID复合控制(Fuzzy-PID)来实现对电加热炉这一数学模型为双输入双输出系统的智能控制。根据实际温控系统的要求,设计出一种PID控制与模糊控制相结合的智能控制系统,具备一定的自适应控制能力,因而特别适用于难于用精确数学模型描述的温度控制系统,有较强的稳定性和鲁棒性。     

自动加药系统中模糊自整定PID控制方法的研究

提出利用模糊自整定PID控制器实现自动加药的方法,将控制器和PID控制器结合在一起,利用模糊逻辑控制实现了PID控制器参数在线自调整,完善了传统PID控制器的性能,提高了系统的控制精度.并把MATLAB中的Fuzzy Toolbox和Simulink结合起来,方便实现了自整定模糊PID控制系统的计算机仿真.仿真结果表明模糊自整定PID对被控系统的适应性强,鲁棒性好,超调小,反应时间快,能很好地适应现实生产过程中的控制要求.     

基于电加热炉温度系统的自适应模糊PID-Smith控制方法研究

针对电加热炉温度控制系统,研究了自适应模糊PID-Smith控制方法.该控制方法利用Smith预估算法克服纯滞后,利用模糊控制来提高系统的鲁棒性,利用PID控制来提高稳态精度.通过Matlab仿真研究,表明该控制器具有良好的稳定性和鲁棒性,对于大时间滞后的电加热炉温控系统是一种实用而简便的控制方法.     

工业电加热炉非线性批量PID控制研究

在工业控制过程中,电加热炉温度控制系统是一个严重的非线性,大惯性,时变和纯滞后环节.由于传统PID的局限性,如果采用传统的PID对该系统进行控制很难在时变系统中达到良好的性能.基于对此问题的考虑,本文应用批量PID控制方法以及应用一种新的PID参数整定方法来解决在电加热炉控制过程中的一些实际问题.     

液压张力温轧实验轧机薄带在线加热温度控制

采用电阻加热的方法对试样施加低电压大电流实现在线加热.为保证薄板加热过程中的测温精度和温度均匀性,设计了接触式测温仪和双回路加热装置.温度控制器采用前馈控制器和反馈控制器相结合的方式,以薄板电阻加热时的热平衡方程为基础进行前馈控制器设计,反馈控制采用PID控制器,将前馈和反馈控制量叠加后作为温度控制器的总设定值.该技术能够满足试样加热速率和温度控制精度的要求,通过在轧制过程中持续补温,提高试样的温度均匀性.     

PID参数自整定模糊控制器的应用

针对电加热炉大惯性、纯滞后、参数时变的非线性对象的控制的特点,以及常规PID控制参数不易调节的特点,提出了一种PID参数自整定模糊控制方法,设计了PID参数自整定模糊控制器,并在炉温控制系统中应用。实验结果表明:PID参数自整定模糊控制消除了系统的稳态误差,没有超调和振荡,鲁棒性较强,而且简单易行,具有一定的实用价值。     

基于S7-200PLC的食品杀菌温度PID控制系统设计

针对食品杀菌过程中温度较难控制的问题,采用PLC中PID控制器进行解决,介绍了PID算法及S7-200PLC中PID回路指令的使用方法.说明了PID控制器在食品杀菌温度控制系统中的程序设计的全过程,该控制方法能满足实际生产需要.     

一种基于专家系统的变结构神经元自适应PID控制器的设计与实现

根据温度控制系统的具体特性提出一种变结构神经元自适应PID控制器算法,特别是在调整神经元控制器最敏感的参数K值时引入了专家经验.实验结果表明,利用这种控制器进行电加热炉温度控制具有调节时间短、稳定性能好、遇干扰回复能力强等优点.     

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.