Weighted Superimposed Codes and Constrained Integer Compressed Sensing

We introduce a new family of codes, termed weighted superimposed codes (WSCs). This family generalizes the class of Euclidean superimposed codes (ESCs), used in multiuser identification systems. WSCs allow for discriminating all bounded, integer-valued linear combinations of real-valued codewords that satisfy prescribed norm and nonnegativity constraints. By design, WSCs are inherently noise tolerant. Therefore, these codes can be seen as special instances of robust compressed sensing schemes. The main results of the paper are lower and upper bounds on the largest achievable code rates of several classes of WSCs. These bounds suggest that, with the codeword and weighting vector constraints at hand, one can improve the code rates achievable by standard compressive sensing techniques.     

基于人机工程的汽车组合仪表设计研究

重点介绍了轿车内部组合仪表的布置及校核方法。通过以人机工程为依据,对组合仪表的位置、视野盲区、反光、眩目进行理论分析,同时结合工作经验,提出了一些设计经验,对新产品的设计开发具有指导意义。     

Fractionation and characterization of ɛ-poly-l-lysine from Streptomyces albulus CGMCC 1986

ɛ-Poly-l-lysine (ɛ-PLL) produced by Streptomyces albulus CGMCC 1986 was fractionated using ultra-filtration technique with 2 and 5 kDa cut-offs of membrane. The number-average molecular weight of each fraction was determined by ¹H nuclear magnetic resonance (NMR) method. The number-average molecular weights of the cutoffs of 5 and 2 kDa and the filtrate are 4,230.95, 3,687.80, and 1,900.82 Da, respectively. ¹H NMR indicates the chemical shifts of α-H, β-H, γ-H, δ-H, and ɛ-H are very similar to all the fractions. Fourier transform-infrared (FTIR) spectra showed that the ɛ-PLL solid samples obtained by freeze-drying at pH 5 with molecular weights higher than 2 kDa take on a β-turn conformation, however, the fraction with molecular weight smaller than 2 kDa adopts random coil structure. The antibacterial test proved that the fraction between 2 and 5 kDa of membranes behaves the highest antibacterial activity than other fractions for the test strains of Staphylococcus aureus, Micrococcus luteus, Bacillus subtilis, Escherichia coli, and Shigella.     

Antiproliferative and antioxidant properties of anthocyanin-rich extract from açai

An anthocyanin-rich extract, generated from açai (AEA), was investigated for its antioxidant properties and antiproliferative activity against C-6 rat brain glioma cells and MDA-468 human breast cancer cells. AEA has an ORAC value of 2589 μmoles trolox equivalents (TE)/g dried powder and a DPPH radical-scavenging activity of 1208 μmoles TE/g, suggesting that AEA is an exceptional source of natural antioxidants. In addition, AEA remarkably suppresses proliferation of C-6 rat brain glioma cells, but has no effect on the growth of MDA-468 human breast cancer cells. Further experiments demonstrated that the AEA treatment dose-dependently inhibited the growth of C-6 rat glioma cells with an IC₅₀ of 121 μg/ml. The DNA ladder fragmentation results indicated that AEA induced apoptosis of C-6 rat brain glioma cells. To compare açai with other anthocyanin-rich extracts, a number of berry extracts, including blueberry, strawberry, raspberry, blackberry and wolfberry, were assessed for potential antiproliferative activity against C-6 rat brain glioma cells. However, none of them showed suppressing effect. The results suggest that the active antiproliferative constituents in AEA are unlikely to be anthocyanins normally found in common berries.     

大型地下室混凝土墙裂缝分析及控制

结合某大型地下室工程实践和试验研究,从设计、材料、施工3个方面分析了地下室开裂和渗漏的原因,提出了关于地下室结构后浇带、钢筋、混凝土、外加剂等方面抗裂防渗的设计和构造,并阐述了抗裂防渗高性能混凝土的研究和配制原则,以及地下室抗裂防渗的关键施工技术。     

昆明新机场航站楼钢彩带贝雷架支撑系统设计与应用

昆明新机场航站楼钢彩带为双层群拱结构,施工时采用自行设计的贝雷架支撑系统,此系统主要由贝雷片和支撑架组合而成.根据群拱结构特点和吊装顺序,利用有限元软件SAP2000对吊装过程的胎架受力和变形进行了分析计算,计算结果表明自行设计的贝雷架支撑系统满足钢彩带施工要求.介绍了贝雷架的安装过程.采用全站仪对贝雷架卸载前后的变形进行了监测,发现卸载前后的胎架变形实测值与模拟值基本吻合.     

心脏病与高频心电研究

寻求心脏病的早期诊断方法是当务之急,高频心电除了具有较宽的通频带和较小信号幅度外,它比常规心电图具有更多的有关心脏活动状态的信息,可以观察到更多有关心脏主要部位病变的细节,能揭示出QRS综合波上某些部位的波形特征,所谓切迹(motch)和转折(slur)。本文重点研究高频心电的分析和识别方法及其技术实现。     

切削温度实验数据处理装置

介绍一种可对切削温度实验数据进行采集、处理并综合成指数公式打印出来的装置。     

可修串联系统退化工作的可靠性研究

某些多状态系统,可允许在多不同水平的功能状态下工作.为了正确评价系统在这些状态下的可靠性,本文探讨了可修系统退化工作的可靠性研究.避开了复杂的多状态系统分析问题,有效地解决了工业系统可靠性设计中的一个实际问题.首先,定义了部件的任务分担系数并给出其确定方法,以定量分析各部件失效对子系统的影响.其次,为了对大型复杂系统进行定量分析,定义了可修退化工作系统的等效单元及其失效率λ_(e)和μ_(eo).分析了由一类部件,两类部件乃至多类部件组成的可修退化工作系统的可靠性.最后,给出了系统退化工作的可靠性参数预计公式.     

船舶波浪增阻的近场和远场公式

本文给出船舶波浪增阻远场公式的一个简洁推导方法，大大简化了肥后靖和河文根在文［１］中给出的推导过程．