Dependence of mechanical and tribological performance on the microstructure of (CrAlTiNbV)Nx high-entropy nitride coatings in aviation lubricant

The (CrAlTiNbV)N_x coatings are fabricated by controlling the substrate bias via magnetron sputtering method. Under low substrate bias, the coating tends to form a loose columnar crystal structure with (200) preferred orientation. However, when the substrate bias increases, the coating transforms into a dense nanocrystalline structure, and the (111) orientation is enhanced. As the substrate bias increases, the residual stress and hardness of the coating gradually increase, while the adhesion strength decreases slightly. Friction tests show that the coating possesses the lowest average friction coefficient (about 0.06) and wear rate (8.7 × 10^-9 mm³/N·m) in 4050# aviation lubricant, which is achieved under the substrate bias of -96 V and -126 V, respectively.     

北斗三星无源定位技术

介绍了北斗双星定位系统的特点、功能、系统组成和工作原理,说明了北斗有源定位方式在应用方面的局限性。针对北斗有源定位方式不能无线电静默,和人们对具有无线电隐蔽性的卫星定位的需求,详细介绍一种北斗三星无源定位技术:包括工作原理、实现方法、定位精度分析和目前达到的定位精度。阐述了北斗三星无源定位技术的优点和应用形势。     

2.4GHz动态CMOS分频器的设计

对现阶段的主流高速CMOS分频器进行分析和比较,在此基础上设计一种采用TSPC(truesingle phase clock)和E-TSPC(extended TSPC)技术的前置双模分频器电路.该分频器大大提高了工作频率,采用0.6μm CMOS工艺参数进行仿真的结果表明,在5V电源电压下,最高频率达到3GHz,功耗仅为8mW.     

关于Alcatel基站时钟同步的设置优化

本文就Alcatel基站的时钟同步的重要性进行阐述和分析,并根据工作的实际案例和维护经验,提出相应的解决办法.     

抗真菌蛋白Rs-AFP2基因定点突变及其对大肠杆菌中表达的影响

为了研究遗传密码子对表达调控的影响,利用PCR重叠延伸法,对萝卜抗真菌蛋白Rs-AFP2基因编码序列区的部分核苷酸进行沉默突变,构建突变体Rs-AFPm.序列分析表明,PCR产物全长240bp,有一个阅读框,编码的蛋白由29个氨基酸的信号肽和51个氨基酸的抗真菌蛋白组成.突变体与突变前的Rs-AFP2基因相比,在编码区第3号氨基酸Lys相差一个碱基(TTG→TTA),第5号氨基酸Gln相差一个碱基(CAG→CAA),第6号稀有密码子Arg相差两个碱基(CAG→CGA).重新合成引物,将切除信号肽的Rs-AFP2基因和Rs-AFPm基因与原核表达载体pET-21b(+)分别重组到大肠杆菌BL21菌株.IPTG诱导后,二者均得到了表达.软件分析显示,突变前pETAFPo表达产物占全菌蛋白的3%,突变后pETAFPm的表达产物占全菌蛋白含量的8%;表达蛋白主要以包涵体的形式存在,包涵体经超声波破碎后,蛋白质复性,抑菌结果表明,pETAFPm表达产物的抑菌半径大于pETAFP2表达产物的抑菌半径.这些都说明改造后的Rs-AFPm基因与Rs-AFP2基因相比,已有效地提高表达量.     

Life is pleasant--and memory helps to keep it that way!

People's recollections of the past are often positively biased. This bias has 2 causes. The 1st cause lies in people's perceptions of events. The authors review the results of several studies and present several new comparative analyses of these studies, all of which indicate that people perceive events in their lives to more often be pleasant than unpleasant. A 2nd cause is the fading affect bias: The affect associated with unpleasant events fades faster than the affect associated with pleasant events. The authors review the results of several studies documenting this bias and present evidence indicating that dysphoria (mild depression) disrupts such bias. Taken together, this evidence suggests that autobiographical memory represents an important exception to the theoretical claim that bad is stronger than good. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

一类Feistel密码的线性分析

该文提出一种新的求取分组密码线性偏差上界的方法，特别适用于密钥线性作用的Feistel密码．该分析方法的思路是，首先对密码体制线性偏差进行严格的数学描述，分别给出密码线性偏差与轮函数F及S盒的线性偏差的数学关系；然后通过求取线性方程组最小重量解，确定密码线性偏差的上界．     

Biases of Success Rate Differences Shown in Binomial Effect Size Displays.

The intent of a binomial effect size display (BESD) is to show "the [real-world] importance of [an] effect indexed by a correlation [r]" (R. Rosenthal, 1994, p. 242) by reexpressing this correlation as a success rate difference (SRD) (e.g., treatment group success rate - control group success rate). However, SRDs displayed in BESDs generally overestimate real-world SRDs implied by correlations of (a) dichotomous X and Y variables (φ coefficients), (b) dichotomous X and continuous Y variables (point-biserial coefficients [rphs]). and (c) continuous X and Y variables (rxys). Furthermore, overestimation biases are larger for rxys than for rphs. Differences in the sizes of biases linked to different correlations suggest that BESD SRDs reported for different correlations are not comparable. The stochastic difference index (N. Cliff, 1993: A. Vargha & H. D. Delaney, 2000) is recommended as an alternative to the BESD. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

PCM/FM遥测系统中用于去除多谱勒频率和载波频偏的新方法

本文首先分析了均匀采样二阶DPLL(Digital Phase-Locked Loop)误差传递函数的特性,并基于均匀采样二阶DPLL误差传递函数的高通特性提出了脉冲编码调制/调频(PCM/FM)遥测系统中用于去除多谱勒频率和载波频偏的新方法;然后给出了设计实例和相应的计算机仿真结果;最后给出了有效的实现方法。计算机仿真结果表明,基于均匀采样二阶DPLL误差传递函数的高通特性用于去除多谱勒频率和载波频偏的方法是可行的。