一种改善Turbo乘积编码OFDM系统性能的新方法

本文提出一种利用对译码器软信息限幅来改善多径衰落信道中Turbo乘积编码OFDM(TPC-OFDM)系统性能的新方法。通过对不同多径衰落信道中QPSK映射和16QAM映射的TPC-OFDM系统性能的数值仿真，结果表明在10^-5误比特率下，这种新方法比传统的迭代译码大约有6～10dB的改进，对严重多径环境下TPC-OFDM系统的错误平底也有明显的改进。     

On regular drawn symbolic picture languages

Drawn symbolic pictures are an extension of drawn pictures obtained by associating a symbol from an alphabet to each point of the picture. In the paper we will address some new interesting issues derived from the introduction of the symbols and we will identify the conditions, which ensure the preservation of properties holding for drawn pictures in the setting of the proposed extension.     

1/3码的动态CMOS全自检电路的设计

自检测电路设计方法有多种多样,本文中介绍了TSC电路的概念,并采用1/3码的动态CMOS设计TSC电路,通过在Cadence环境下仿真,仿真结果表明本设计可行。     

计算机存储系统的9位字节单向错误检测码

本文介绍了一种计算机存储系统中的单向错误检测码，系统构成采用９位字节，其中８位数据位，１位校验位，并使用一个单独的附加奇偶校验字节。单向错误检测码有两类，一类每个字包含固定的奇偶校验位；另一类每个字节包含的检验位的构成方式是任意的。     

钠冷快堆中喷雾钠火的计算分析

根据钠冷快堆中喷雾钠火的特点建立了理论模型，编制了SSPRAY程序。该程序模拟钠喷雾燃料过程中钠滴的运动、钠和氧气的燃烧反应、热量传递和质量传递等瞬态过程。用该程序计算了气体和墙壁温度、气体压力、氧气摩尔份额、喷雾流燃烧速率和热量热递速率等主要参数。利用AI实验数据和美国SPRAY－3A的计算结果对程序进行了验证，结果符合较好。     

稳定同位素井间示踪技术在深层块状稠油油藏水驱特征研究的应用

经对冷43块深层块状普通稠油水驱注水5个试验井组开展的稳定同位素示踪测试，利用中子活化技术分析样品，采用先进的示踪剂定量分析与流动模拟相互结合的方法，以示踪数值模拟为手段，评价了油井连通、油层平面及纵向上的非均质性、隔层的封隔性等因素对水驱控制程度及动用状况的影响，通过优化注水推进方向及速度，强化动态调整措施，提高了稳产基础。     

苯乙烯类嵌段共聚物的生产及市场分析

介绍了苯乙烯类嵌段共聚物(SBC)的国内外生产和消费情况，分析了我国SBC的市场前景，提出了加大研发力度、提高SBC生产术、扩大生产规模、提高国内市场占有率，建设多功能装置等建议。     

线性分组码的神经网络译码

介绍了神经网络与线性分组码之间的关系，并在文献[1]的基础上证明了软判决译码与求解能量函数最大值之间的等价性，然后以(7，4，3)汉明码为例介绍了神经网络在循环码硬判决、软判决译码中的应用。     

Synthesis and characterization of poly(siloxane-urethane)s

A series of polyurethane block copolymers based on hydroxy-terminated polydimethylsiloxane and poly(propylene glycol) soft segments of molecular weights 1818 and 2000, respectively, were synthesized. The hard segments consisted of 4,4′-diphenylnethane diisocyanate and 1,4-butanediol as the chain extender. Samples with different molar ratios were prepared. We tried to synthesize polydimethylsiloxane-based polyurethanes (PDMS-PU) containing a hard block as major fraction and a soft block as minor fraction for preparing toughened rigid systems. After a study of the pure polydimethylsiloxane-based polyurethane and poly(propylene glycol)-based polyurethane (PPG-PU), (mixed polyol)-based block copolymers and blends of PDMS-PU and PPG-PU were synthesized, and characterized by means of differential scanning calorimetry, tensile testing and scanning electron microscopy. In (mixed polyol)-based copolymers and lower hard-segment content blends, macro-phase separation occurred, but blends with higher hard-segment contents showed significant reduction in amounts of phase separation.