Optimized LDPC differential-encoded 16QAM scheme for high-speed transmission systems

The 16-ary quadrature amplitude modulation （16QAM） is a high spectral efficient scheme for high-speed transmission systems. To remove the phase ambiguity in the coherent detection system, differential-encoded 16QAM （DE-16QAM） is usually used, however, it will cause performance degradation about 3 dB as compared to the conventional 16QAM. To overcome the performance loss, a serial concatenated system with outer low density parity check （LDPC） codes and inner DE-16QAM is proposed. At the receiver, joint iterative differential demodulation and decoding （ID） is carried out to approach the maximum likelihood performance. Moreover, a genetic evolution algorithm based on the extrinsic information transfer chart is proposed to optimize the degree distribution of the outer LDPC codes. Both theoretical analyses and simulation results indicate that this algorithm not only compensates the performance loss, but also obtains a significant performance gain, which is up to 1 dB as compared to the conventional non-DE-16QAM.     

Conceptual design and RCS performance research of shipborne early warning aircraft

In order to improve the survivability of the aircraft,conceptual design and radar cross section（RCS） performance research are done. The CATIA software is used to design the 3D digital model of the shipborne early warning aircraft, and some measures are taken to reduce the RCS characteristics of the early warning aircraft at the same time. Based on the physical optics method and the equivalent electromagnetic flow method,the aircraft＇s RCS characteristics and strength distribution characteristics are simulated numerically, and compared with the foreign advanced shipborne early warning aircraft. The simulation results show that under the X radar band, when the incident wave pitching angle is 0？, compared with the foreign advanced shipborne early warning aircraft, the forward RCS average value of the conceptual shipborne early warning aircraft is reduced to 24.49%, the lateral RCS average value is reduced to 5.04%, and the backward RCS average value is reduced to 39.26%. The research results of this paper are expected to provide theoretical basis and technical support for the conceptual design and the stealth design of the shipborne early warning aircraft.     

A2O生物脱氦法焦化废水处理的管理和控制

通过对A2O系统进水水质的管理和控制，保证了生物脱氮系统的稳定、高效运行，同时对各操作单元的工艺控制实现A2O处理效果的良性循环。     

可列个非负线性合成对策的解结构

给出了可列个非负线性合成对策，证明了可列个非负线性合成对策的几种解也可由其子对策相应的解来表达，从而解决了可列个非负线性合成对策解的结构问题．     

1,6-二芳酰基二硫脲衍生物的合成及其生物活性的研究

在固液相转移催化条件下，以聚乙二醇６００（简称ＰＥＧ６００）为催化剂，芳酰氯、硫氰酸铵与水合肼反应，以良好的产率获得１６二芳酰基二硫脲衍生物．初步生物活性试验表明，此类新化合物对小麦幼苗的生长具有显著的促进作用．     

一类推广的整数极小极大问题的求解算法

讨论了一类推广的整数极小极大问题，给出了问题最优解的充分必要条件，在此基础上给出了求解最优解的算法，最后，给出了一个数值例子。     

关于推广的线性规划问题的BP网络求解

推广的线性规划问题比常规线性规划问题有更广泛的实际应用背景．而求解线性规划问题的许多有效方法如单纯形法，Ｋａｒｍａｒｋａｒ’ｓ方法等却无法直接用于推广的线性规划问题的求解，注意到推广的线性规划问题等价于一个非线性映射，利用ＢＰ神经网络的本质并行性和高度非线性处理能力，该文提出了一类求解推广的线性规划问题的ＢＰ神经网络方法，它具有网络构建简单，求解精度高，计算量小等优点，实验结果表明其高效性．     

影响微生物絮凝剂产出的因素

通过测定不同培养条件下制备的微生物产生菌培养液对高岭土悬浊液的絮凝性能，探讨了培养基，培养时间和温度等因素对微生物絮凝剂产出的影响，研究表明察氏培养基比原用培养基更为经济实用的适宜培养时间在3－8d之间，适合温度为30度，与絮凝剂产生菌的生长相比，微生物絮凝剂的产生时间稍有些滞后。     

Demianski-Newman黑洞的热性质及广义Bekenstein-Smarr公式

对于Demianski-Newman(D-N）黑洞，同样存在在外观视界处温度为T＋的Hawking辐射和在内视界处温度为T－的Hawking吸收，其形式与Kerr-Nweman（K－N）黑洞相似，根据D－N黑洞中参数l的一些性质，得到了与参数l有关的广义Bekenstein-Smarr(B-S）公式，对比K－N黑洞的B－S公式，可以推测l－方面与转动效应有关，另一方面又有产生势场，可能是与自旋有关的某种荷。     

关于供暖系统运行管理问题的探讨

为了保证供暖系统的正常运行，除在设计中认真进行水力计算外，不应在施工中严格按规范进行操作，按程序进行交工验收，同时运行中要加强维护管理，只有三者有机结合才能提高供热质量。