T/R组件性能退化试验系统设计与实现

T/R组件是有源相控阵雷达装备的重要部件,其性能变化严重影响雷达技术、战术指标,通过试验系统进行T/R组件性能退化试验是分析T/R组件性能变化的重要途径。在分析T/R组件性能退化试验流程基础上,设计了T/R组件性能退化试验系统结构;设计了试验系统平台,解决了多个T/R组件自动测试与开关级联切换下的噪声系数测量问题;设计了自动测试软件,实现了T/R组件性能参数的自动测试、测量结果的自动存储。基于此试验系统,进行了某型T/R组件的性能退化试验,结果表明该试验系统能够自动完成多个T/R组件性能参数的自动测试,提高了测试效率,为T/R组件和有源相控阵雷达的性能分析提供了试验平台。     

HT46R系列单片机定时问题研究

随着HT46R系列单片机在各种测控系统上的实际应用,定时/计数器的作用也显得越来越重要.介绍了通过程序对HT46R系列单片机内部的可编程定时/计数器的定时方式和工作模式的设定和控制以确定定时时间,并提出了一种扩展定时/计数器定时范围的有效方法.最后,以该定时/计数器方法在全自动电饭煲控制系统中的应用为例,说明该方法使得定时/计数器的应用范围更加广泛,使用更加灵活.     

R448A和R455A在复叠制冷系统中替代R404A的性能分析

现阶段广泛使用的R404A制冷剂的GWP值（全球变暖潜能值）较高、对环境不友好,为了探究GWP值较低的新型替代制冷剂对制冷系统性能的影响,本文建立了复叠制冷系统的热力学模型,研究了R455A和R448A制冷剂在不同工况下的性能表现,并从低温级蒸发温度、高温级冷凝温度、中间温度,以及高、低温级过冷度等方面与R404A系统进行对比分析。结果表明,在不同工况下,R455A/R23系统的COP（制冷系数）始终最高,R404A/R23系统的COP最小。在相同蒸发温度下,R455A/R23和R448A/R23系统的最佳中间温度低于R404A/R23系统,最佳COP分别比R404A/R23系统高6.77%,5.25%。另外,高温级过冷度增加会使系统COP增大,其中,R404A/R23系统COP的增加幅度最大,R448A/R23系统COP的增加幅度最小,而低温级过冷度的增加则会使系统性能下降。     

GPC-气相色谱质谱法测定卷烟主流烟气中的苯并[a]芘

建立了用凝胶渗透色谱(GPC)联用GC-SIM-MS法测定卷烟主流烟气中苯并[a]芘的方法.卷烟烟气样品经环己烷超声萃取,GPC系统分离纯化后,经浓缩后用GC-SIM-MS分析测定.与经固相萃/R(SPE)分离纯化的样品相比,通过GPC系统处理后,卷烟烟气样品的干扰烽大大减小,样品谱图干净.该方法测定苯并[a]芘的线性范围为:10.00ng/mL～130.00ng/mL;相关系数R2为O.999 1,检出限为0.99ng/mL,加标回收率为91.70%-103.40%.GPC系统在处理卷烟烟气样品上有独特的优势,该方法适宜应用于卷烟主流烟气中苯并[a]芘含量检测.     

渐近周期竞争-竞争-互惠扩散系统的持续生存性

讨论如下渐近周期竞争-竞争-互惠系统｛u1t-d1△u1=g1u1(1-u1/a1-a2u2/1 a3u3),u2t-d2△u2=g2u2(1-b1u1-u2/b2), in()R , u3t-d3△u3=g3u3(1-u3/c1 c2u1),ui=0 on ()×R ,i=1,2,3 的解的全局渐近性态.证明在系数满足一定条件时该系统是持续生存的,而在系数满足另外的条件时该系统是部分绝灭的.     

直膨式太阳能热泵热水器不同工质的性能分析

为了研究直膨式太阳能热泵热水器,分别采用R22、R410A和R290作为工质的性能,建立了太阳能集热/蒸发器和冷凝器的分布参数均相流动模型、压缩机和膨胀阀的集中参数模型以及系统工质充注量模型,编制了直膨式太阳能热泵热水器系统性能模拟程序.比较发现,理论模型计算值与文献实验结果吻合较好.在不同环境参数和运行参数的工况下,对采用3种热泵工质的系统性能系数、集热器的集热效率和系统制热功率进行对比分析.结果表明:R290系统的性能系数明显高于R22和R410A系统,R410A系统的集热效率和制热功率略高于R22和R290系统;环境参数对R290系统的影响程度大于R22和R410A系统;压缩机转速的变化对R410A系统影响显著,而水箱水温的变化对R290系统影响较明显;R290和R410A系统的最佳工质充注量分别约为R22系统的46%和95%.     

R448A和R455A在复叠制冷系统中替代R404A的性能分析

现阶段广泛使用的R404A制冷剂的GWP值（全球变暖潜能值）较高、对环境不友好,为了探究GWP值较低的新型替代制冷剂对制冷系统性能的影响,本文建立了复叠制冷系统的热力学模型,研究了R455A和R448A制冷剂在不同工况下的性能表现,并从低温级蒸发温度、高温级冷凝温度、中间温度,以及高、低温级过冷度等方面与R404A系统进行对比分析。结果表明,在不同工况下,R455A/R23系统的COP（制冷系数）始终最高,R404A/R23系统的COP最小。在相同蒸发温度下,R455A/R23和R448A/R23系统的最佳中间温度低于R404A/R23系统,最佳COP分别比R404A/R23系统高6.77%,5.25%。另外,高温级过冷度增加会使系统COP增大,其中,R404A/R23系统COP的增加幅度最大,R448A/R23系统COP的增加幅度最小,而低温级过冷度的增加则会使系统性能下降。     

面向R语言的分布式流处理系统设计与实现

为了使得在数据分析领域广泛使用的R语言能够应用于大规模数据的分布式流处理计算,基于Spark Streaming框架,设计和实现了一个面向R语言的分布式流处理系统。系统提出了一套完备的R/Java跨语言交互模型,实现了R语言程序和Java程序的互相调用,从而使得R语言程序可以运行在Java平台上,改进了R语言在大规模数据处理和并发计算等方面的不足。系统也提供了Spark Streaming的R语言编程接口,提高了后者的易用性。通过实例验证了该系统的可行性和实用性。     

具有年龄结构和常数迁移率的SIR模型

建立了具有年龄结构和常数迁移率的SIR模型,并研究了该模型的有关性态.得到了基本再生数R0的表达式,证明了当R01时,系统存在唯一全局渐近稳定的无病平衡态;当R01时,系统存在地方病平衡态,并且在地方病平衡态处的线性化系统的特征方程无非负实根.     

熵能比存在上限吗?

一、Bekenstein猜想的提出 1981年,Bekenstein由黑洞热力学研究提出一个猜想:对于任意具有有效半径R的系统,其熵能比存在一个普遍的上限,其大小为2πRK_B/hc~(?).这里所说的有效半径指该系统的最大线度的一半L_(max)/2。这一猜想可用下列不等式表示: S/E≤2πRK_B/hc (1) 或S/E≤20πR (K_B=G=h=c=1) (2) 下面我们简略的介绍Bekenstein猜想提出的背景。1971年,S.W.Hawking在广     

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.     

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.     

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.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

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.     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-