壅塞可调固体火箭冲压发动机性能计算

综合给出了二维超声速进气道特性,并将其应用于壅塞可调固体火箭冲压发动机性能计算中,建立了壅塞可调固体火箭冲压发动机特性计算方法.通过调节燃气发生器喷管喉道面积保持给定空燃比不变.根据飞行速度/高度计算出了发动机非设计点性能和相应的燃气发生器喉道面积变化规律.结果表明,飞行速度/高度对燃气发生器喉道面积调节计划产生相当大的影响;当飞行高度低于设计高度时,高度变化明显改变进气道-发动机匹配工作点,高空低马赫数飞行时,进气道位于严重亚临界工作状态,明显降低了超声速进气道稳定工作范围.     

燃气挤压器式辅助动力源起竖装置建模及性能

为缩短车载导弹发射装置起竖时间,降低系统装机功率,提出一种基于燃气挤压器式辅助动力源的快速起竖方案.建立描述燃气挤压器式辅助动力源起竖过程的气、液、机多物理系统耦合数学模型.在Matlab/Simulink中搭建燃气发生器内弹道求解模块,在AMESim中构建挤压式油箱、液压元件和机械机构仿真模型,以燃气发生器喷管质量流量和挤压式油箱燃气腔压力为传递变量,实现联合仿真,并基于原理样机试验对燃气挤压器仿真模型的有效性进行了验证.分析了起竖装置的快速性和功率特性,并与传统泵式液压起竖装置进行了对比.研究结果表明:新型起竖装置可在34.5 s内实现快速起竖,起竖时间缩短了42.5%,总装机功率仅为11.6 kW,降低了38.9%,大幅提高了系统的起竖速度,显著降低了系统的装机功率.      

次高压、中压燃气压差发电实验研究

次高压、中压燃气在供给用户之前,需要经过调压装置调压,调压过程压力能损失较大,利用燃气调压过程压差发电将会有效回收这部分压力能损失。燃气压力能进行了热力学分析,燃气比由比温度和比压力组成,比压力远大于比温度。利用压缩空气模拟中压燃气,搭建了中压管道压差发电实验系统,实验研究了流量、压力比对压差发电的影响,通过实验数据拟合得到了发电功率(P)与流量(Q)、压力比(n)之间的关系式为P=16.10Qlnn。     

调压阀内流场数值模拟及动态特性分析

以研究调压阀内流场和动态特性为目的,建立了固体燃气发生器调压阀内流场三维模型,用动态网格技术对流场进行模拟并采用子程序计算阀芯的运动,以相关的冷气试验进行验证.分析了燃气阀内部收敛-扩张外型下的瞬态流动特性和波系变化情况,并分析了不同条件下阀芯运动的动态特性.阀芯的周期性振动导致流场以相同频率变化,较高入口压力和较小弹性系数使阀门能够较快稳定,但导致流量、阀芯位移等物理量峰值增大.     

气溶胶发生器负压发生装置数值模拟

为解决气溶胶发生器负压装置的效率低、易堵塞、对颗粒磨损大等问题,采用数值模拟的方法比较传统结构与多孔环形结构的性能.在Autodesk Inventor软件中创建出两种结构负压装置的三维模型,导入Autodesk Simulation CFD软件中进行有限元分析计算.分析在进口压力与流量一致的情况下,不同结构内的气体流动情况,将分析结果进行比较,发现多孔环形结构引入气体的流量较大,且流体流动顺畅.结果表明:多孔环形结构适合应用在气溶胶发生器的负压装置上.     

城市燃气管网的瞬态模拟研究

城市燃气管网节点的压力、流量和温度等参数直接影响整个输配系统的运行。结合燃气管网实际运行工况,建立了包含能量方程在内的城市燃气管网不稳定流数学模型,采用隐式中心有限差分法对方程组线性化,应用Newton-Rapshan法迭代求解,在此基础上采用VC++6.0编制了燃气管网动态仿真软件。对某管网进行计算,得到该管网各节点压力、流量的变化趋势以及各管段压力沿程的变化趋势。通过和国外相关软件的计算结果比较,计算偏差在2%左右。     

喷管管内流动参数的嵌入式智能测试系统

在原喷管试验台的基础上 ,引入嵌入式微控制器控制的实时智能测量系统 ,以AT89C5 2单片微控制器为主控芯片 ,集成了压力 (负压、差压 )、流量、温度、位移等高精度测量模块 ,增加了探针位移的自动调节和闭环控制 ,提高了测量精度和位移控制精度 测试结果表明 :该系统测试精度高、离散度小 ,不但能满足喷管管内流动参数实时、高精度测量的要求 ,有助于管内流动过程热力学状态参数基本变化规律的研究 ,也能应用于需要进行压力、温度、流量等测量的场合     

射流低频高声强发生器设计与实验研究

为解决现有低频高声强发生器声压低、装置复杂、声学性能可调性与重复性差等问题,设计了以压缩空气为能源、电机调谐的低频射流高声强发生器.按照气体动力学一维行波理论、守恒方程、伯努利方程与声学理论对其进行声学设计.按理想可压缩气体定常流流体动力学控制方程模型,采用三维结构化网格、压力耦合方程半隐式算法,计算得到流场的压力分布特性.为验证其声学特性,进行了现场发声测试试验.实验结果与设计值基本一致,验证了该低频高声强发生器具有50 Hz低声频、181dB高声强、声特性重复可调的特点,可以为噪声伤害、高声强声源工业应用及声学武器的研究提供实验基础与声源.     

yo-yo 运 动 的 振 荡 神 经 网 络 控 制

在分析简单的振荡网络基本构成基础上,提出了一种用振荡神经网络对yo yo运动实现闭环控制的具体构架.给出了系统中所采用的神经网振荡器——抑制性锁相环、开关信号发生器和机器臂参考信号发生器等环节的数学模型.建立了实现yo yo运动闭环控制的实时控制系统,并通过实验对该控制方法进行验证.结果表明,振荡神经网络实现yo yo运动闭环控制的方法是可行的.     

冷却恒压供水控制系统

恒压供水控制系统是采用电动机调速装置与可编程控制器(PLC)构成控制系统,根据泵出水压力来进行优化控制泵组的调速运行,并自动调整泵组的运行台数,完成供水压力的闭环控制,在管网流量变化时达到稳定供水压力和节约电能的目的。     

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.