基于AMESim的某型航空发动机滑油供油系统故障模拟

为了更加方便、经济地获取航空发动机滑油供油系统的故障诊断数据,本文提出了一种基于AMESim进行滑油供油系统的故障仿真以获取故障数据的方法。首先对某型航空发动机的滑油供油系统的部件进行数学建模,然后以此为基础,在AMESim中搭建整体模型。最后对供油系统中的供油油滤与活门进行故障注入,得到了油滤堵塞、单向活门卡滞、旁通活门弹簧松弛、卸压活门预紧力不足这四类故障与其相应监测点的压力、流量之间的映射关系。     

航空发动机结构故障统计分析方法研究

针对航空发动机系统可靠性设计问题，建立故障时间分布的概率统计分析方法，编制故障时间数据处理计算机程序，该程序可用五种以上常用寿命分布函数拟合外场及实验室故障数据，进行分布函数的假设检验及拟合择度比较，可处理全样本或任意截尾样本的外场及实验室数据，并结合航空发动机典型机型结构系统的实际设计过程来验证算法。     

大数据方法在航空发动机性能监控中的应用

将大数据方法应用到航空发动机性能监控领域,克服了传统阀值监控的弊端,提高了监控的精度和效率。建立发动机性能参数与故障模式的知识库,以及性能参数与发动机剩余使用寿命的知识库。利用大数据理论模型,预测发动机性能参数的变化趋势,判断其性能状况。     

基于随机森林的航空发动机工作状态识别

为解决人工识别航空发动机工作状态中存在的误判和耗时费力等问题,提高识别准确率,提出了一种基于主成分分析(PCA)的特征提取方法和随机森林(RF)的智能识别方法。首先对飞参数据进行预处理,利用PCA将数据降维进行属性约简,并根据发动机工作状态将样本分组,用随机森林方法训练获得分类器;然后将几种分类方法的识别效果进行对比;最后采用该方法对某一架次的发动机工作状态进行识别。结果表明,该方法能够准确快速地识别航空发动机的稳定工作状态,识别准确率达到97.89%。可应用于发动机工作状态的相关研究。     

采用监督局部切空间排列算法的航空发动机磨损故障诊断

为解决传统特征提取技术难以处理具有非线性结构的复杂故障数据、影响故障诊断准确性的问题,将非线性维数约简技术——局部切空间排列引入航空发动机滑油光谱数据特征提取中,提出了一种基于监督局部切空间排列的发动机磨损故障诊断方法。该方法对非线性分布故障流形数据的内在几何特征进行捕捉,并将数据向低维故障特征空间进行非线性映射,完成故障特征的提取,最后在故障特征空间里构造分类器,完成磨损故障的识别诊断。采用某型发动机磨损故障滑油光谱数据开展实验,结果表明:与传统主元分析、线性鉴别分析特征提取方法相比,该方法能够更有效地提取出嵌入于故障数据中的非线性特征,提高了故障分类的准确率,并且只需采用简单的线性分类器就能具有很好的故障诊断性能。     

一种基于人工免疫理论的性能监控与故障诊断方法

本文针对航空发动机故障样本获取比较困难等问题，提出了一种基于人工免疫理论的航空发动机性能监控与故障诊断方法。利用免疫系统的反面选择机理，并结合人工神经网络，确定发动机性能偏离正常值的程度（异常度），实现发动机性能趋势的监控。该方法能够灵敏、准确地反映发动机整体性能的变化情况，提高发动机性能正常与否的识别率，并以此来发现发动机潜在早期故障，防止故障的扩大。通过对某型涡扇发动机进行监控，证明该方法确实有效。     

基于NFI直推式学习算法的故障诊断方法

在故障特征数据空间中,搜索输入数据最相邻的训练数据作为子训练数据集,用最速下降法对模型模糊规则参数进行优化。用Fisher's iris数据集仿真并同自适应神经模糊推理系统(ANFIS)比较,平均试验误差降低了15%,运算速度提高了约30%。将一组采自航空发动机实际试车故障特征数据输入到诊断模型中,模型能准确识别发动机存在的三类故障状态,说明了此算法对解决一些故障诊断问题的有效性。     

基于嵌入式的航空发动机监控模块设计

为了航空发动机安全可靠地运行,需要对其进行故障监控,及时消除故障;探讨了嵌入式操作系统的移植,并应用到航空发动机故障监控上;利用小波分析方法来实现对故障信号特征的提取.基于小波去噪原理,通过选取适当的小波函数,对故障信号进行分析和处理.通过对航空发动机喘振故障实际测量数据的分析,表明该模块可以监控喘振故障的发生.经过多组喘振故障数据试验证明试验结果满意,对航空发动机喘振故障的实时监控有重要意义,具有良好的应用前景.     

基于状态监控数据的航空活塞发动机故障诊断

针对某型航空活塞发动机空中功率迟滞和地面停车故障,提出一种通过飞行动态模型还原、数据推理和比较法相结合的故障诊断方法。以美国莱康明发动机和GARMIN 1000飞行数据为研究对象,利用Google Earth和FLIGHTDATA运用航段坐标和姿态数据还原飞机故障航段轨迹,结合EGVIEW发动机数据处理软件分析发动机运行中采集的各项数据,研究故障发动机典型数据特征,并基于故障时段发动机余气系数的计算结果判断故障发动机实际工况。结果表明：发动机故障发生时严重富油,通过对燃油调节器结构原理的剖析和地面测试台对其的性能测试,确定了两起发动机故障同源且均与飞行操纵、燃油调节器慢车性能参数超标和慢车活门结构设计有关,同时验证了利用状态监控数据进行故障诊断的有效性和准确性。     

基于支持向量机的滚动轴承早期故障诊断

针对航空发动机故障诊断过程缺乏大量实际故障数据的问题,提出了一种基于支持向量机和小波包相结合的滚动轴承的早期故障诊断方法.该方法利用有限的故障样本,以结构风险最小原理为基础,建立滚动轴承早期故障特征与其运行状态之间的对应函数关系,即故障分类器,并以该函数的输出判定轴承的早期故障类型.实验结果表明,小波包分析能够有效的提取滚动轴承中微弱的早期故障特征,支持向量机可以对这些早期故障特征进行准确识别.     

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.