The time-delay digital tanlock loop: performance analysis in additive Gaussian noise

Recently, a new non-uniform sampling digital phase-locked loop, the time-delay digital tanlock loop (TDTL), has been proposed. We have analyzed in a previous work the first- and second-order TDTLs under noise-free conditions. In this work, we analyze the performance of the TDTL in the presence of additive Gaussian noise for different values of the loop parameters. It is shown that the expected value of the steady-state phase errors at the input and the output of the phase error detector are equal to the noise-free steady-state values, while the variance is significantly reduced when the signal-to-noise ratio is increased or the phase shift introduced by the time-delay approaches 90°. The locking ranges of the TDTL parameters under noise-free conditions are unchanged by the presence of noise.     

电导法测定HCI在水和甘露醇混合溶剂中的活度系数

应用电导法测定了HCl在水和甘露醇混合溶剂中的活度系数，讨论了电解质溶液活度系数与温度和浓度的关系．     

瑞香狼毒提取物作用于人肺癌细胞NCI-H446[H446]后端粒酶的定量表达

目的:通过端粒酶的数量变化来探讨瑞香狼毒提取物对肺癌细胞NCI-H446[H446]的抗肿瘤作用。方法:体外培养肺癌细胞NCI-H446[H446]细胞株,以不同浓度的瑞香狼毒提取物作用24h后,用荧光标记的方法定量检测端粒酶。结果:瑞香狼毒提取物作用人肺癌细胞提取物NCI-H446[H446]后,端粒酶的数量明显减少并呈现与剂量的正相关性。结论:瑞香狼毒提取物对肺癌细胞NCI-H446[H446]具有明显的抗肿瘤作用。     

Perceptual importance analysis for H.264/AVC bit allocation

The existing H.264/AVC rate control schemes rarely include the perceptual considerations. As a result, the improvements in visual quality are hardly comparable to those in peak signal-to-noise ratio （PSNR）. In this paper, we propose a perceptual importance analysis scheme to accurately abstract the spatial and temporal perceptual characteristics of video contents. Then we perform bit allocation at macroblock （MB） level by adopting a perceptual mode decision scheme, which adaptively updates the Lagrangian multiplier for mode decision according to the perceptual importance of each MB. Simulation results show that the proposed scheme can efficiently reduce bit rates without visual quality degradation.     

基于H.264/AVC的新三步搜索算法的设计与实现

针对传统三步搜索算法（TSS）的缺陷,提出十字-正方形模板运动估计快速算法（RSPS）。该算法利用运动矢量分布的中心偏置特性,结合起始运动矢量预测与零运动块预判断,有效提高运动估计搜索速度并保持较高的搜索精度。     

膜萼藤属——我国新记录属

The present paper reports the first record of the genus Hymenopyramis in China. H. cana is a new record on Hainan Island of Guangdong Province. It grows in deciduous mon- soon forests or shrubby savanna (western Hainan) at 50 to 150 m alt.     

How to allocate R&D (and other) subsidies: An experimentally tested policy recommendation

This paper evaluates the typically applied rules for awarding R&D subsidies. We identify two sources of inefficiency: the selection based on a ranking of individual projects, rather than complete allocations, and the failure to induce competition among applicants in order to extract and use information about the necessary funding. In order to correct these inefficiencies we propose mechanisms that include some form of an auction in which applicants bid for subsidies. Our proposals are tested in a simulation and in controlled lab experiments. The results suggest that adopting our proposals may considerably improve the allocation.     

H_6P_2W_(18)O_(62)/SiO_2催化合成环己酮1,2-丙二醇缩酮

以二氧化硅负载Dawson型磷钨酸H6P2W18O62/SiO2为催化剂,采用环己酮和1,2-丙二醇为原料合成环己酮1,2-丙二醇缩酮.探讨H6P2W18O62/SiO2对缩酮反应的催化活性,较系统地研究了各种因素对产物收率的影响.实验表明:H6P2W18O62/SiO2是合成环己酮1,2-丙二醇缩酮的良好催化剂,在n(环己酮)∶n(1,2-丙二醇)=1∶1.5,带水剂环己烷6 mL,催化剂用量占反应物料总质量的0.6%,反应时间60 min的优化条件下,环己酮1,2-丙二醇缩酮的收率可达85.4%.     

H3 PW12 O40／TiO2－SiO2催化合成3，4－二氢嘧啶－2（1H）－酮衍生物

以H3 PW12 O40／TiO2－SiO2为催化剂,取代苯甲醛、乙酰乙酸乙酯和尿素为原料,无水乙醇为溶剂合成3,4－二氢嘧啶－2（1H）－酮衍生物．探讨了原料物质的量比、反应温度、催化剂用量及反应时间对收率的影响．实验表明：固定取代苯甲醛的用量为0．04 mol和无水乙醇的量为15 mL的情况下,n（取代苯甲醛）∶n（乙酰乙酸乙酯）∶n（尿素）＝1∶1．0∶1．5,催化剂的用量占反应物料总质量的1．5％,反应温度为90℃,反应时间为75 min,分别以对羟基苯甲醛、对硝基苯甲醛、茴香醛、4－氯苯甲醛、对甲氧基苯甲醛分别代替苯甲醛,产品收率为35.0％－89.2％．催化剂和合成产品分别采用IR, XRD和1 H NMR, IR, MS手段进行表征．     

《查泰莱夫人的情人》中劳伦斯对工人阶级的偏见态度——身体叙述研究

本文在弗雷德里克·詹姆逊政治无意识理论的启发下,探讨劳伦斯《查泰莱夫人的情人》所体现的对劳动阶级所持有的偏见态度;然而,劳伦斯这种偏见态度是无意识的,成为他被压抑的意识形态在文本中的体现。本文以小说呈现的身体叙述为切入点,劳伦斯对工人的身体的叙述可分为三类：身体的阶级化;身体的异化;身体的未开化。通过区分上层阶级与工人阶级身体叙述的不同,来诠释他对工人阶级的偏见态度。