Nonlinear network coding based on multiplication and exponentiation in GF（2^m）

This article proposes a novel nonlinear network code in the GF(2m) finite field. Different from previous linear network codes that linearly mix multiple input flows, the proposed nonlinear network code mixes input flows through both multiplication and exponentiation in the GF(2m). Three relevant rules for selecting proper parameters for the proposed nonlinear network code are discussed, and the relationship between the power parameter and the coding coefficient K is explored. Further analysis shows that the proposed nonlinear network code is equivalent to a linear network code with deterministic coefficients.     

Performance of degree distribution based HARQ scheme for LDPC-coded OFDM system

This article studies the degree distribution property of low density parity check (LDPC) codes by Gaussian approximation (GA) and presents an efficient hybrid automatic repeat quest (HARQ) scheme for LDPC-coded orthogonal frequency division multiplexing (OFDM) system. In the scheme, the important bits with large degrees have high retransmission priorities and are mapped to the sub-carriers with better channel quality indicator (CQI) levels in the OFDM system. The new scheme provides more protection to the bits with large degrees and thus contributes more to the decoding process by offering more transmission power. In this way the system performance would be improved. The statistics and simulation results also prove the new scheme.     

中科大潘建伟小组建成世界上首个光量子电话网

日前，中国科学技术大学潘建伟研究小组在实用化量子通信方面取得了重大进展。在合肥建成世界上首个光量子电话网，这标志着绝对安全的量子通信由实验室走进了日常生活。     

基于单总线网络的防盗报警系统

本文将信号线整合到电源线上,利用单总线同时实现系统供电与信号传输,相比传统传输方式,有效降低了成本设计还加入防拆、抗干扰和循环状态检测等功能,使系统工作更加稳定可靠.     

胶体量子点太阳能电池转化效率创新纪录

据物理学家组织网7月30日(北京时间)报道,加拿大多伦多大学和沙特阿拉伯阿卜杜拉国王科技大学的科研人员称,借助在胶体量子点(CQD)薄膜领域获得的突破,他们利用低价材料制成了迄今为止效率最高的胶体量子点太阳能电池,转化效率可达7%。这比此前同类电池的转化效率提升了37%,创造了新的世界纪录。相关研究报告发表在近期出版的《自然.纳米技术》杂志上。     

盛群推出红外线遥控编码IC

盛群发表一款高整合度的红外线遥控器编码IC—HT62104，与市场多家知名厂牌遥控Ic相容。HT62104内建OSC电路，不须外挂455kHzResonator及震荡电容；并内建IR驱动器，可直推IR发光二极管（LED），不须外接三极管，比同类似的Ic节省许多的外部零件和系统整体成本。     

Im Anfang was das Bewusstsin, und das Bewusstsein war bei Sich Selbst, und das Bewusstsein was Sich Selbst. An actress must never lose her ego without it she has no talent. --Tom Lehrer

据说量子物理和相对论是现代物理的两大支柱.不过,这两大支柱是建立在self-adjointness,eigenvalue（vec-tor）,proper time（length）,proper Lorentz group,self-interference等事关＂自己的＂概念碎石上的.没了自我,物理学似乎少了很多内容.     

“体验式编码”在教学类节日传播中的应席——“希望英语”新体验版块的实践与探索

“编码”是信息论的一个重要概念，其义是指用预先规定的方法将文字、数字或其他对象编成数码，或将信息、数据转换成规定的电脉冲信号。编码是信息从一种形式或格式转换为另一种形式的过程。本文将试图从“体验”的角度，结合中央电视台科教频道的相关栏目实践谈一谈体验式编码在教学类节目信息传播中的应用。     

Theoretical Study of Interesting Fine-Structure Splittings Based on a Scenario for Precise Calculations

Based on the multi-configuration Dirac-Fock self-consistent field method, a scenario has been presented to calculate the fine-structure energy levels of C^2＋ and Si^2＋ excited states （31 D2 and 33D1,2,3）. The Breit interactions and quantum electrodynamics corrections are added as perturbations. The present calculation results are found to be in excellent agreement with the experimental data. By means of the precise calculation procedure, we elucidate that four competitive mechanisms influence the interesting fine-structure splittings in C^2＋ and Si^2＋, such as spin-orbit interactions, relativistic corrections of exchange interactions, the Breit interactions and electron correlation effects. Furthermore, the mechanism of relativistic correction of exchange interactions has been studied clearly. We elucidate that the inner shell 2p1/2,3/2 orbitals are essential to relativistic corrections of exchange interactions which are crucial for the final anomalous fine-structure splittings.