交织码在无线通信可靠性中的应用研究

在对无线通信可靠性要求较高的系统中，如何保证信息的无误接收是关键。本文讨论了交织码的纠错原理，给出了具体的编码设计，对可靠性的提高进行了定性和定量的分析，并在工程中得到了验证。     

二维三氧化钨纳米结构的合成及其在光电探测器中的应用

三氧化钨（WO₃）是制造晶体管和光电探测器的理想材料,虽然在WO₃纳米结构的生长方面已经完成了一些工作,但是制造足够长的理想型纳米线仍然是一个挑战。在众多的合成方法中,作者选择了化学气相沉积（CVD）方法合成WO₃纳米线,并对其在光电传感器中的应用进行了研究。影响WO₃纳米线成品率的主要因素是前体材料温度、基片位置、载气流速和生长持续时间。在合适的生长条件下生长的纳米线长度最长约为100 μm。这些WO₃纳米线可用来制造高性能的光电探测器,WO₃光电探测器具有灵敏度高、响应速度快、模块微型化等优良的器件性能,表明二维WO₃纳米线在光电探测器的制造中具有很大的优势。      

地基平板载荷试验中存在问题及探讨

根据目前地基平板载荷试验中存在的一些问题．提出一些建议供工程检测人员及规范制定单位参考．     

数字化核电厂班组SSA测度方法与实验研究

情景意识(SA)问题在数字化核电厂中更为突出。为识别班组共享情景意识（SSA）水平及行为形成因子（PSF）对班组SSA的影响,基于情景意识全面评估技术（SAGAT）建立一种班组SSA测量和计算方法并进行模拟机实验。结果表明,个体SA（ISA）水平与SSA水平有关,ISA级别越高,SSA级别越高;ISA和班组SSA都受到PSF的影响,PSF的状态水平越高,ISA和SSA的水平越高;对于不同的实验场景,操纵员的ISA水平和班组SSA水平不同,这表明风险场景的症状越明显及知识经验水平越好,ISA和SSA水平就越高。最后,通过被试的自评价识别当前PSF的状态水平,主要不良的PSF是班组沟通和合作水平、压力水平、人-机界面等。这些评估结果为提高数字化核电厂人因可靠性和安全水平提供了理论支持。     

Spin-resolved magnetic studies of focused ion beam etched nano-sized magnetic structures

Scanning ion microscopy with polarization analysis (SIMPA) is used to study the spin-resolved surface magnetic structure of nano-sized magnetic systems. SIMPA is utilized for in situ topographic and spin-resolved magnetic domain imaging as well as for focused ion beam (FIB) etching of desired structures in magnetic or non-magnetic systems. Ultra-thin Co films are deposited on surfaces of Si(1 0 0) substrates, and ultra-thin, tri-layered, bct Fe(1 0 0)/Mn/bct Fe(1 0 0) wedged magnetic structures are deposited on fcc Pd(1 0 0) substrates. SIMPA experiments clearly show that ion-induced electrons emitted from magnetic surfaces exhibit non-zero electron spin polarization (ESP), whereas electrons emitted from non-magnetic surfaces such as Si and Pd exhibit zero ESP, which can be used to calibrate sputtering rates in situ. We report on new, spin-resolved magnetic microstructures, such as magnetic “C” states and magnetic vortices, found at surfaces of FIB patterned magnetic elements. It is found that FIB milling has a negligible effect on surface magnetic domain and domain wall structures. It is demonstrated that SIMPA can evolve into an important and efficient tool to study magnetic domain, domain wall and other structures as well as to perform magnetic depth profiling of magnetic nano-systems to be used in ultra-high density magnetic recording and in magnetic sensors.     

RS(255,223)译码器的设计与FPGA实现

RS码是一种多进制分组循环码。检错和纠错能力强．尤其适合纠正突发错误，在通信系统中有着广泛的应用。本文所研究的RS(255，223)译码器采用修正的Euclid译码算法(MEA)，介绍了一种基于FPGA的RS译码器的设计和硬件电路实现方案。按照自顶向下的设计流程．划分模块．详细论述了各子模块的设计过程。     

Comments on “Wirtinger-based integral inequality: Application to time-delay systems [Automatica 49 (2013) 2860–2866]”

In a recent paper (Automatica 49 (2013) 2860–2866), the Wirtinger-based inequality has been introduced to derive tractable stability conditions for time-delay or sampled-data systems. We point out that there exist two errors in Theorem 8 for the stability analysis of sampled-data systems, and the correct theorem is presented.     

一种基于S2SH的Web应用框架及实现方法

Struts2采用WebWork2．2内核,在体系上与Strutsl差别很大,因而与Spring、Hibemate的整合是一项崭新的技术。论文提出一种以上三种轻量级框架整合的Web应用框架（简称为S2SH）,并给出详细的实现方法。S2SH充分发挥了这三种框架的优势,达到优势互补的效果,具有良好的应用前景。     

原位插层聚合法制备聚苯乙烯/海泡石纳米复合材料

采用十八烷基三甲基氯化铵(OTAC)作为有机插层剂对海泡石进行了有机化处理,该有机化的海泡石粒子在苯乙烯单体中很容易地均匀分散并形成稳定的胶体溶液.通过对分散有海泡石的苯乙烯进行原位插层聚合制备了聚苯乙烯/海泡石纳米复合材料.并用X射线衍射(XRD)、傅里叶变换红外光谱(FT-IR)、扫描电镜(SEM)和透射电镜(TEM)对聚苯乙烯/海泡石复合材料的结构进行了表征.研究表明聚苯乙烯的大分子链插入到海泡石片层间,形成了部分插层、部分剥离型纳米复合材料.     

Ultralow feeding gas flow guiding growth of large-scale horizontally aligned single-walled carbon nanotube arrays

On the basis of the rational analysis about the fluidic property of the system, an ultralow gas flow chemical vapor deposition (CVD) strategy was designed to prepare large-scale horizontally aligned ultralong single-walled carbon nanotube (SWNT) arrays. SWNT arrays could be well obtained under extremely low feeding flow of 1.5 sccm in a 1 in. quartz tube reactor. It was confirmed that the tubes grew floatingly and could cross microtrenches or climb over micro-obstacles in ultraslow gas flow. SWNTs arrays also could be formed no matter the substrate was placed vertically or upside down. The growth mechanism was discussed. Both the buoyancy effect induced by gas temperature/density difference and gas flow stability played dominant roles. More attractively, simultaneous batch-scale preparation of SWNT arrays was realized by the ultralow gas flow strategy. This new strategy turns to be more abstemious, efficient, promising, and flexible compared with the high gas flow rate fast-heating CVD processes.