Parity Nonconservation in of Multiply Dielectronic Recombination Charged Ions

A parity nonconserving （PNC） asymmetry in the cross section for dielectronic recombination of polarized electrons on multiply charged ions with Z≥40 is discussed. This effect is strongly enhanced for close doubly-excited states of opposite parity in the intermediate compound ion. Such states are known for He-like ions. However, these levels have large energy and large radiative widths which hampers observation of the PNC asymmetry. We argue that accidentally degenerate states of more complex ions may be more suitable for the coresponding experiment.     

〔23，12，7〕Golay码的改进译码算法

ＭａｒｉｏＢｌａｕｍ和ＪｅｈｏｓｈｕａＢｒｕｃｋ提出了一种基于［２３,１２,７］Ｇｏｌａｙ码校验矩阵＂设计＂特性的译码算法,和其它的Ｇｏｌａｙ码译码算法相比,这种译码算法的复杂度最小,但它不便于用集成器件实现和不便于完全集成化,作者对该算法进行了改进,使其易于集成实现;同时使［２３,１２,７］Ｇｏｌａｙ码译码算法进一步简化．对其复杂度分析证明,当误码率≤１０％时,作者所设计的译码算法优于其它译码算法。     

线性近似下的X-Y-Z模型-各向异性亚铁磁性Heisenberg系统的自旋波解

通过Holstein-Primakoff变换、点阵傅里叶变换、宇称变换、Shwinger角动量表象的转动变换、Bogoliubov变换、压缩变换等幺正变换，在线性近似下研究了X-Y-Z模型-各向异性亚铁磁性Heisenberg系统的基态、激发态的性质．     

块衰落信道中的迭代盲信道估计与译码

提出了衰落信道下的一种迭代盲信道估计与译码算法，推导了高阶调制下的MAP估计和ML估计表达式，并证明了在信噪比充分大或块衰落信道的块长充分大时。MAP与ML估计是等价的。通过仿真发现，在对迭代信道估计与译码算法的影响上，信噪比与衰落信道的块长之间存在着折中关系，并分析了块衰落信道的块长对迭代信道估计与译码算法的性能的影响。     

结合奇偶测试的大规模集成电路征兆测试

征兆测试是一种高效简捷的电路测试方法。该文提出一种适用于大规模集成电路的测试方法——组合征兆测试法。利用这种方法,测试者可以通过穷举输入组合,使奇偶测试和征兆测试相结合,共同解决对大规模集成电路故障测试的难题。主要思想是:首先通过被测电路的奇偶性判断该电路的征兆测试法的可测性,对征兆测试法不可测的电路,引入高阶征兆测试的思想,使其成为高阶征兆测试法可测电路。结果表明:该方法在提高可测性的同时,还提高了电路征兆测试的测试效率和故障覆盖率。通过对一些基准电路和常用电路的测试验证了该方法的实用性。     

Construction of protograph LDPC codes with circular generator matrices

The application of protograph low density parity check(LDPC) codes involves the encoding complexity problem.Since the generator matrices are dense,and if the positions of "1" s are irregularity,the encoder needs to store every "1" of the generator matrices by using huge chip area.In order to solve this problem,we need to design the protograph LDPC codes with circular generator matrices.A theorem concerning the circulating property of generator matrices of nonsingular protograph LDPC codes is proposed.The circulating property of generator matrix of nonsingular protograph LDPC codes can be obtained from the corresponding quasi-cyclic parity check matrix.This paper gives a scheme of constructing protograph LDPC codes with circulating generator matrices,and it reveals that the fast encoding algorithm of protograph LDPC codes has lower encoding complexity under the condition of the proposed theorem.Simulation results in additive white Gaussian noise(AWGN) channels show that the bit error rate(BER) performance of the designed codes based on the proposed theorem is much better than that of GB20600 LDPC codes and Tanner LDPC codes.     

Can purchasing power parity help forecast the dollar?

This paper examines the information on future exchange rate movements provided by the doctrine of purchasing power parity (PPP). Previous research has studied this issue by analyzing the time-series properties of period-by-period levels of, or changes in, exchange rates. In contrast, the present study focuses on the durations of periods in which exchange rates deviate from their PPP levels. If PPP provides information about future exchange rate movements, these durations should exhibit positive duration dependence. That is, the probability of returning to PPP levels should increase as the period of deviation increases. Parametric hazard functions estimated using data from eighteen countries provide no evidence of positive duration dependence. These results are robust to alternative definitions of PPP and to alternative functional specifications. While exchange rates take prolonged swings away from their PPP levels and then eventually return, these movements apparently constitute Monte Carlo cycles in which, at any point in time, the probability of moving back toward PPP is the same as the probability of moving farther away. Thus, PPP provides no useful information on future exchange rate changes, a result consistent with market efficiency.     

基于时间冗余的一致空间法在故障检测及隔离中的应用

研究基于时间冗余的一致空间法在线性时不变系统故障检测及隔离中的应用.指出系统在某一时刻某个故障在一致空间中位于固定方向.通过选取最优转换矩阵,将这一方向与其它因素在一致空间中所在方向相分离,提出一种故障隔离的方法.仿真实验表明,在传感器、执行器和元件均可能发生故障并且系统存在未知输入的情况下可实现故障检测及隔离.     

粒子弱荷的研究

为了研究有质量的中微子，在理论上引入了粒子（基本费米子、中间玻色子和强子）弱荷的新概念首次报道了弱荷守恒定律，并提出了检验弱荷是否存在的实验方案，根据弱荷的手征性，合理地解释了宇称不守恒的原因，根据弱荷的对称性扩展了标准模型，指出所有的中微子都是有质量的Dirac粒子，但是右手中微子和左手反中微子的弱荷为零，它们不参与弱相互作用，因而称为暗粒子。     

关于电偶极跃迁的普用选择定则的讨论

推导出电偶极跃迁的普用选择定则，以单电子（或单价）原子和多电子原子能级间跃迁为例，阐明了这些规律的实质。