数字射频贮频器多比特相位量化原理及影响寄生电平的因素

讨论数字射频存贮器 (DRFM)多比特相位量化的原理、实现方法和影响寄生电平的因素。通过计算机仿真 ,给出 4bit相位量化器正交下变频输出幅、相不平衡 ,及相加网络加权方法等对寄生电平的影响     

DRFM 采样过程的频谱分析及仿真

以一位量化DRFM为例，对DRFM中采样过程进行了分析，得出了经过量化和采样后的频谱含量及幅度的计算式，并对由此式计算出的结果进行了仿真验证，仿真结果同理论分析结果相吻合。可以用同样的方法来分析多位量化DRFM的频谱含量及幅度。     

基于TMS320C6711的幅度相位量化

比相法在雷达测向系统中具有高精度的特点．相位量化是比相测向系统中的重要组成部分，实现方法主要有极性相位量化法和幅度相位量化法．极性相位量化方法现在较为普遍，着重介绍了另一种量化方法的实现：基于TMS320C6711的幅度相位量化方法，并介绍了TTMS320C6711在设计应用中需要注意的事项．     

离散变量板壳结构拓扑优化设计及其应用

将包含两类变量的桁架结构拓扑优化设计的概念及求解离散优化的相对差商法进一步推广到由板壳单元组成的板壳结构的拓扑优化，建立了包含两类变量的板壳结构拓扑优化设计模型，并采用相对差商算法进行求解．最后给出了一个特种车起竖油缸支撑横梁拓扑优化的工程实例．     

基于密度法的热传导结构拓扑优化准则算法

热传导结构优化设计研究主要集中在形状及尺寸优化方面，这类方法由于结构初始估计构形带有经验性，通常并不是结构的最优拓扑，使设计具有局限性；为了有效求解热传导结构的最优拓扑，将结构力学中成熟的拓扑优化思想及其方法拓展到热传导结构的拓扑优化设计中，同时以最小热量传递势容耗散为优化目标，基于密度法建立热传导结构拓扑优化设计数学模型，并推导相应的优化准则；计算过程中应用基于卷积的滤波技术处理迭代密度场，消除数值计算不稳定性；不同条件下的数值算例验证了本文思想和算法的正确性、有效性，所得拓扑优化结果为后继的形状和尺寸优化提供了可靠的依据．     

纯电动汽车白车身拓扑优化设计及性能验证

基于变密度结构拓扑优化方法,以柔度最小化为目标建立了汽车白车身拓扑优化数学模型。对其白车身结构在静载荷、弯曲载荷,以及扭转载荷工况下分别进行拓扑优化设计,得到相应的最优拓扑结构。通过建立基于优化结果的白车身线框模型对其弯曲和扭转刚度进行验证。数值算例结果证明,拓扑优化方法能够得到具有工程实用价值的纯电动汽车白车身最优结构,在满足车身结构刚度要求的同时实现车身轻量化。     

包含两类变量的离散变量框架结构拓扑优化设计

将包含两类变量的桁架结构拓扑优化设计的概念及求解离散优化的相对差商法进一步推广到由梁单元组成的框架结构的拓扑优化，建立了包含两类变量的框架结构拓扑优化设计模型，构造了包含应力约束和位移约束的统一约束函数，发展了统一处理两类变量，求解包含两类变量的框架结构拓扑优化设计问题的算法，并给出了两个算例．     

渐进结构优化方法在联轴器优化设计中的应用

针对联轴器优化设计中普遍关注的结构轻量化和最大应力最小化问题,借助Hyperworks 有限元分析软件,采用渐进结构优化方法,对SSWZ330 型十字轴万向联轴器进行了结构拓扑优化设计。优化后,可使材料节省9． 17%,工作时最大静应变减少2． 3%,最大应力减少52． 1%,改善了结构性能,减轻了结构重量,拓展了Hyperworks 软件在机械部件结构拓扑优化设计领域的实际工程应用。     

一种优化延迟链结构的线性相位准正交数字滤波器组的算法

研究了线性相位准正交滤波器组的新优化设计算法．该设计算法对因子分解中的延迟环节数进行了优化，在新算法中，滤波器的长度将逐渐随级联的格型结构和延时链路而减少．滤波器长度和对称性的可能分布，可在设计过程中决定．文中给出设计算法以及７信道情况下的设计样例．     

桁架结构拓扑优化设计的模拟退火算法

研究了平面桁架结构拓扑优化设计的模拟退火算法．构造了一个双重控制Ｍｅｔｒｏｐｏｌｉｓ准则处理应力约束,提出了一个基于力平衡的启发式准则,以实现优化过程中单元的自动增删．算例表明,该方法能够克服桁架结构拓扑优化中因存在非凸星形可行域而造成的拓扑优化求解困难．     

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。     

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.