CDPD系统数据传输性能分析

蜂窝数字分组数据（ＣＤＰＤ）是利用现有的模拟蜂窝电话网来传输数据的一种新技术,它有两种信道分配方案,固定信道方案和跳频方案。立足于ＭＡＣ（ 媒质接入控制） 层,通过仿真和计算,对ＭＤＢＳ（ 移动数据基站） 和ＭＥＳ（ 移动终端系统） 之间的数据传输性能进行了分析,得到了数据吞吐量、平均时延以及由于传输数据而引起的话务量损失值     

乳腺组织的位相衬度成像

将位相村度成像用于乳腺肿瘤的结构研究后,发现:正常乳腺组织的吸收图像的清晰度比较高,原因是正常乳腺组织比较致密,对于对X射线的吸收相对较强。而位相衬度成像在分辨肿瘤组织内部结构方面的优势是比较明显的,能够清晰地显示出乳腺组织中的一些精细结构,并可以反映出正常组织、良性肿瘤组织和癌变组织结构的特异性。在位相衬度成像中,图像的村度是与样品到探测器的距离有关的,在不同样品到探测器的距离下,位相村度成像的分辨率是不同的。根据衬度传递函数(CTF),可以估计出乳腺癌组织中的钙化尺度在30μm左右。     

SoC处理器的时钟生成器：电路和体系结构

本书涵盖了面向SoC（System　on　Chip，片上系统）处理器的集成综合器电路设计的论题，采取了一种更为全局的设计观念来考察电路级和体系结构级的设计空间。书中的论述十分广泛，而且包括电路理论和锁相环反馈控制理论的综述。在电路级方面，讨论包括深亚微米数字CMOS过程的低功耗模拟设计、供电噪声效应、设备噪声；在体系结构级方面的论述，涵盖了连续时间和离散时间模型的锁相环分析，以及锁相行为的细节分析。还有一些章节对特定的时钟生成器模块做了电路级和系统结构级的深入描述，其中包括高供电噪声屏蔽的锁相环电路、体系结构和数字锁相环体系结构，考察了为离散时间模拟部件产生低失真采样时钟的方法。这里所说的锁相环包括希格马．代尔塔N分锁相环、直接数字综合（DDS、Direct　Digital　Synthesis）技术和锁相环的非常规应用。本书讨论的面向测试的设计（Dvr、Design　for　Test），其中包括锁相环的精确测量滤波器方法和嵌人式测试（BIST、Built—in—self-test）技术。     

Depositional history of the early part of the Jurassic succession on the Rajasthan Shelf, western India

Part of the lowermost deposits of the Triassic to Earlymid Jurassic (up to Bajocian) sedimentary succession spread across the Rajasthan shelf on the western part of the Indian craton is found in the Jaisalmer Basin east of Jaisalmer with the best exposed sections along the Jodhpur-Jaisalmer Highway. Based on lithostratigraphic characteristics, the succession is divided into four: Odania and Thaiat members, Lathi Formation; and Hamira and Joyan members, Jaisalmer Formation. Six facies are defined from microfacies, sedimentary structures, biotic components and depositional environments: (1) ferruginous, pebbly, cross-bedded sandstone—high-energy, fluvial; (2) cross-bedded, poorly sorted, fossil wood-bearing sandstone—highenergy, terrestrial, with high influx of sediment and warm and humid climate; (3) cross-bedded to rarely bioturbated, alternating silt to fine-grained sandstone—fluctuating sedimentation rates and energy—nearshore, mesohaline embayment to lagoonal; (4) partly bioturbated, storm-dominated, mixed siliciclastic-carbonate facies—fully marine; (5) low angle cross-laminated, silt to fine-grained sandstone—nearshore shallow water, above fair weather wave base; and (6) thick rudstones with mega-ripples and reworked coral heads-storm deposits representing the peak of first major marine transgression across the basin.     

纤维对PEI改性环氧树脂单向复合材料形态的影响

人们改善环氧树脂基复合材料的脆性通常只改善环氧树脂基体和增强纤维间的界面，提高环氧树脂韧性的另一种常用方法是添加初始相容性良好的热塑性树脂如聚醚酰亚胺，在某一转化率（取决于体系的组成和反应温度）时体系发生相转变，体系最终的形态由相转变速率和环氧树脂反应速度所控制。本文作者研究了两种增强纤维（玻璃纤维和碳纤维）对不同环氧树脂／聚醚酰亚爱体系形态形成的影响，结果发现体系中纤维的存在不会影响基体相分离过程，但会改变体系的最终形态；形态的变化与纤维的品种关系不大；基体中不同组分的粘度是影响复合材料形态形成的关键因素。     

Advances and applications of electrohydrodynamics

Electrohydrodynamics (EHD) has been applied in many areas, such as EHD enhanced heat transfer, EHD pump, electrospray mass spectrometry, electrospray nanotechnology, etc. The basic theories underlying these applications and a brief review of the EHD advances are presented in this paper. As electrospray is an important branch of EHD,the applications of electrospray are particularly discussed.Finally, this paper gives some suggestions for the future research and development.     

Design and fabrication of 1-D semiconductor nanomaterials for high-performance photovoltaics

To date, the cost-effective utilization of solar energy by photovoltaics for large-scale deployment remains challenging. Further cost minimization and efficiency maximization, through reduction of material consumption, simplification of device fabrication as well as optimization of device structure and geometry, are required. The usage of 1D nanomaterials is attractive due to the outstanding light coupling effect, the ease of fabrication, and integration with one-dimensional(1-D) semiconductor materials. The light absorption efficiency can be enhanced significantly, and the corresponding light-toelectricity conversion efficiency can be as high as their bulk counterparts. Also, the amount of active materials used can be reduced. This review summarizes the recent development of 1-D nanomaterials for photovoltaic applications, including the anti-reflection, the light absorption,the minority diffusion, and the semiconductor junction properties. With solid progress and prospect shown in the past 10 years, 1-D semiconductor nanomaterials are attractive and promising for the realization of high-efficiency and low-cost solar cells.     

1800mm虚拟轧机板形控制性能

定义了评价轧机板形控制性能的六项指标,包括承载辊缝凸度调节域、辊缝横向刚度、板形调控功效曲线、边缘降、辊间接触压力平均幅值和辊间接触压力分布不均匀度.建立了HC,CVC,PC和DSR系列轧机的有限元仿真模型,并从板形控制性能的六项指标方面分析了当前国际上流行的各种机型的特点.     

衰荡腔光谱技术检测混合气体中甲醛含量

利用光参量振荡技术产生2.2~3.97μm的宽调谐窄线宽中红外相干辐射.采用该中红外光源和衰荡腔光谱技术建立了一痕量气体成分光谱检测系统,并使用该系统对混合气体中的甲醛成分进行了测量,得到了72×10-9的检测灵敏度.整个光谱检测系统具有很好的光谱分辨率、选择性以及测量灵敏度,适用于大气中多种污染或温室效应气体成分的检测.     

云南保山盆地生物气源岩生物标志化合物特征

通过对保山盆地气源岩有机质饱和烃色谱、三环萜烷、四环萜烷、五环三萜烷及甾烷分布特征的研究,发现气源岩有机质碳数分布存在比较明显的奇碳优势,结合R.数据,认为该区气源岩成熟度很低;可溶有机质生物标志化合物中的三环萜烷、四环萜烷含量低,五环三萜烷中有含量十分丰富的生物藿烷,表明源岩成熟度低;还检测出与细菌作用有关的C<,3...