汽车空调间歇制冷的原因和解决方法

夏季汽车行驶离不开空调系统提供冷风,然而随之而来的故障也越来越多,文中就典型故障—空调间歇制冷分析其原因以及提出相应的解决方法。     

排气分析仪用于汽车故障诊断

介绍了用排气分析仪监测汽车尾气排放污染物中的有害气体一氧化碳(CO)和碳氢化合物(HC)、以检测数值来确定汽车发动的故障原因及故障部位的方法。     

线性离散系统间歇故障的鲁棒检测方法

针对一类存在未知扰动、过程噪声和测量噪声的离散线性随机动态系统,研究了其鲁棒间歇故障检测问题.设计了降维未知输入观测器的输出,通过引入滑动时间窗口构造了截断残差信号,使得该残差信号对未知扰动解耦而对间歇故障敏感;针对间歇故障的发生时刻和消失时刻,分别提出了2个假设检验,在给定误报率和漏报率的情况下,分别定量确定了间歇故障发生时刻和消失时刻的检测阈值以满足检测性能要求,并在概率框架下分析了间歇故障的可检测性.同时,在某卫星模型上对所提出的方法进行了仿真验证.结果表明,所提出的方法能够快速、准确地检测出间歇故障的发生时刻和消失时刻.     

示波器在电控发动机故障诊断中的应用

汽车电子设备的有些信号变化速率非常快,许多故障信号是间歇的,时有时无,这就需要仪器的测试速度要高于故障信号的速度,数字示波器完全可以胜任这个速度,通过数字示波器可以观察到汽车电子系统是如何工作的,同时也呈现出某种变化规律,将这些规律总结出来进行波形分析,可以快速找到发动机故障部位甚至故障原因,充分体现示波器运用于发动机电子控制系统故障诊断中的实际意义。     

尾气分析仪在汽车检测与故障诊断中的应用

在许多汽车维修企业,尾气分析仪只是作为车辆年检前调整尾气、测试简单参数的普通仪器,并没有充分发挥出它在汽车故障诊断中的作用。其实,还可利用其检测尾气成分的结果,通过对其成分参数分析后,可对汽车故障的快速诊断会有一定帮助。     

基于AMWPSO-LSTM的多阶段间歇过程故障预测

过程安全对于间歇过程生产具有重要意义，为提高间歇过程生产安全性，提出一种基于改进粒子群算法(AMWPSO)优化长短期记忆网络(LSTM)的间歇过程故障预测模型AMWPSO-LSTM。针对LSTM中的神经元个数、迭代次数、学习率等参数需要人为设置的问题，采用AMWPSO对这些参数进行自动寻优。AMWPSO在原有粒子群优化算法(PSO)中融入了自适应变异和非线性递减惯性权重，提高了PSO的参数寻优能力。由于间歇过程具有多阶段性，因此先根据模糊C均值聚类(FCM)方法对间歇过程进行阶段划分，再利用Pearson相关系数对各阶段实验数据进行相关性分析，以降低系统变量的维数，并建立各阶段T²统计量控制限作为系统是否发生故障的指标。实验以青霉素发酵过程数据为例，建立基于AMWPSO-LSTM 的多阶段故障预测模型，并将该模型的预测结果与基于LSTM的多阶段预测模型、基于PSO-LSTM的多阶段预测模型的预测结果进行比较，结果表明，基于AMWPSO-LSTM 的多阶段故障预测模型可取得较高的预测准确度。     

基于分数阶混沌系统的风力机叶片微弱间歇故障幅值检测

针对风力发电机的特殊工况导致其叶片微弱间歇故障成长检测困难的问题,提出了一种基于分数阶混沌系统的微弱间歇故障幅值变化检测方法.给出了混沌系统相态判别方法,阐述了庞加莱密度峰值算法(PSDPA)原理和流程,构建了间歇故障成熟度函数(IFDF).采集了风机叶片径向和轴向轻微裂纹处的振动信号,并用PSDPA和IFDF分析了风机叶片径向和轴向微弱间歇故障的幅值变化.结果表明:通过PSDPA算法可以实现混沌系统的快速相态判别,采用IFDF曲线可以直观表征间歇故障成长趋势,揭示了一种微弱间歇故障成长为永久性故障的发展历程.     

通过尾气变化诊断发动机故障

本文针对目前汽车诊断维修中对尾气分析仪的使用价值认识不够,没有从机理上探明尾气参数变化能够反映的各种发动机故障现象。主要研究通过发动机尾气参数变化反推发动机燃烧质量的状况,从而判断出发动机外在表现的故障。尾气参数代表了发动机的综合性能,只要发动机带有故障,其尾气参数必然会引起变化。利用尾气参数变化诊断发动机故障,在汽车发动机诊断维修中的应用具有极其重要的现实意义。     

基于事件触发的间歇传感器故障主动容错控制

提出一种基于事件触发的线性离散系统间歇传感器故障估计和主动容错控制方法.首先,利用一种新的表达方式来描述不同模态下的间歇传感器故障,并针对该故障在传感器输出端引入事件触发机制,通过获取的非均匀采样信息设计故障观测器,实现系统状态和传感器间歇故障的联合估计.然后,根据观测器的估计信息设计容错控制器,通过求解不同故障模态下...     

汽车常见故障的诊断

汽车在行驶过程中难免要发生这样或那样的故障,致使汽车不能行驶,常见故障有: 一、发动机不能起动 1.若汽车行驶中突然熄火,不能重新起动是电气点火系故障所致,按下列方法检查:①观察电流表指针在"0"不动,按电喇叭按钮不响,开灯不亮,起动机不转动,一般是低压电路故障所引起的.检查保险盒是否跳开,蓄电池各桩头连线是否脱落或桩头损坏;②按电剌叭响,灯亮,电流表指针在"3～5A"不作间歇摆动,故障也在低压电路.检查点火开关接触工况,容电器是否击穿,点火开关至电流表、分电器、点火线圈等的连线是否牢靠或有搭铁之处.     

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.     

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.     

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。     

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.     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to