SDH系统E1接口定时的高质量恢复

SDH传输网中由指针调整带来的低频抖动和漂移已经成为SDH传输网与其它传输网互通的障碍.这一问题可以通过在SDH系统的边界支路输出口处采用极低带宽的锁相环对SDH网络指针调整带来的抖动和漂移进行平滑来得到改善和解决.本文介绍了一种捕捉速度快、带宽窄、适合于多支路大规模集成的用于SDH系统E1支路接口的二阶全数字锁相环路.     

CHARACTERIZATION OF STOMACH AND PYLORIC CAECA PROTEINASES OF TAMBAQUI (COLOSSOMA MACROPOMUM)

The effects of pH, temperature, inhibitors, and substrates on proteolytic activities of crude extracts from the stomach, liver, pyloric caeca, and intestines of Colossoma macropomum were investigated. The highest acid and alkaline proteolytic activities were found in stomach and pyloric caeca, respectively. The optimum pH for the acid and alkaline proteases were 1.8 and 7.0–9.0, respectively, while the optimum temperatures were 35C and 65C. This alkaline protease thermal stability remained unaltered after 90 min incubation at 55C. A pepsin‐like protease was responsible for most of the acidic proteolytic activity (Pepstatin A inhibited approximately 90%), whereas PMSF inhibited about 40% of the alkaline protease. The alkaline proteolytic activity has attractive thermal properties for industrial applications.     

JB／T 4730．2—2005与DL／T821-2002射线标准在电站锅炉检验中的应用比较

比较了JB／T4730．2—2005与DL／T821-2002射线检测标准在电站锅炉中的应用效果。分析了两标准中有关概念、小径管透照工艺和质量分级等的不同,对比了实际使用效果。说明了JB／T4730．2—2005标准的先进性,为有关单位和检验人员正确执行标准提供参考。     

光子晶体光纤的研究新进展

综述了光子晶体光纤（PCF）不同于传统光纤的各种性质,并详细讨论了光子晶体光纤在通信和光纤激光等领域的新发展。     

国产异丁司特缓释胶囊的人体相对生物利用度研究

目的 考察国产异丁司特缓释胶囊的人体相对生物利用度。方法 12 名男性健康受试者随机分为3组,分别口服单剂量日本产异丁司特缓释胶囊20 mg、国产异丁司特缓释胶囊20 mg、异丁司特原料药10mg,交叉自身对照。于服药后取静脉血,用HPLC 法测定血清异丁司特浓度。结果 三种制剂的Cm ax 分别为(54.9±9.7)、(60.7±9.1)、(62.2±11.5)μg · L^-1,t_max分别为(3.8±0.8)、(3.9±0.8)、(1.75±0.34)h,t_1/2(ke)为(11.5±1.4)、(12.1±1.0)、(3.5±0.5)h,AUC_(0~t)为(618.1±57.7)、(588.2±66.6)、(233.0±46.4)μg ·h·L^-1。以日本杏林公司产品作为参比制剂,国产异丁司特缓释胶囊的人体相对生物利用度为(95.6±11.0)%。结论 经双向单侧t检验,国产和进口缓释胶囊具有生物等效性,与原料药相比具有明显的缓释特性。     

红外测温技术在氧化锌避雷器故障诊断中的应用

发热是电力设备最典型的故障特征之一,借助红外测温技术能够有效诊断变电站内部电力设备的早期缺陷.近几年来,孝感供电公司将红外测温技术应用于设备的状态检修,效果显著,先后发现了多起设备的严重缺陷.重点介绍一起220 kV氧化锌避雷器(MOA)异常红外测温结果的详细处理情况.对该MOA的带电检测、停电试验以及解体检查与分析表明,通过红外测温与阻性电流测量可及时、准确发现MOA受潮故障,提高了MOA的工作可靠性.     

基于物理层信息加密的卫星隐蔽通信研究

为了增强卫星通信信号的隐蔽性和安全性,提出一种基于物理层信息加密的加权分数傅里叶变换（WFRFT）调制方式。结合WFRFT的低概率截获特性以及无线信道状态信息（CSI）的动态唯一性,在WFRFT系统中构造一个具有加密性质的酉矩阵,克服了传统WFRFT方法的不足,增加了信号处理的多样性。加密酉矩阵的生成利用了卫星通信系统的物理层信道特征,合法通信双方通过约定方式将合法信道的CSI转化为相位旋转因子,并以此为密钥完成对传输信号的加密和解调。仿真结果表明,经酉矩阵加密后的卫星信号在保持原WFRFT信号统计特性的基础上具有更复杂的星座分布,窃听者的误码率始终保持在0.5左右,有效保证了信息的安全传输。     

基于直流电抗电压的柔性直流配电网故障测距方法

故障测距是柔性直流配电网发展所需的关键技术之一,传统的高压直流输电系统故障测距方法在直流配电系统中适应性不好。因此在考虑线路配置直流电抗器的情况下,提出一种基于直流电抗电压的直流配电网双端故障测距方法。该方法从直流故障的电容放电阶段进行研究,利用线路两端直流电抗电压构建包含故障距离和过渡电阻的两个未知参数的时域微分方程,并利用最小二乘法进行求解。PSCAD仿真结果表明该方法能够有效地进行故障定位,并且能够计算出故障点过渡电阻,可以满足直流配电网的故障测距要求。     

基于测后模拟原理的半波长输电线路暂态量纵联保护

针对特高压半波长超长的输电距离带来的继电保护难题,提出基于测后模拟原理的半波长输电线路暂态量纵联保护方法.特高压半波长交流输电具有传输距离远、输送容量大、全线无功自平衡等优点,可以作为未来清洁能源电力输送的一种可选方案.通过分析现有输电线路保护方法对于半波长交流输电线路的不适用性,对特高压半波长输电线路在区内外故障情况...     

The cortisol response to psychological stress in temporomandibular dysfunction

Recombinant antibody fragments can be produced in large quantities using bacterial expression systems and could potentially be useful for the generation of biofilters for the selective removal of viral particles from fluids. A human single chain-Fv antibody library, derived from synthetic repertoires of germ line VH-gene segments rearranged in vitro and paired to a single light chain (Nissim et al., 1994, EMBO J., 13, 692-698), has recently been used to isolate hundreds of different binding specificities by panning with antigen. Antibodies from this library typically have affinities in the 10(6)-10(7) M-1 range. Occasionally, better binders are isolated but at other times the affinities recovered are poor. In the latter situation binding cannot be detected with soluble antibodies, but only by high-avidity display of multiple copies of antibodies on phage. By panning with human cytomegalovirus (HCMV)-coated immunotubes, we have isolated a number of antibody clones from this library that bound to the antigen only if displayed on the filamentous phage, but not in soluble form. One of these clones was selected for an affinity maturation procedure, achieved by combinatorial mutagenesis of the complementarity determining region 3 (CDR3) of the antibody light chain, followed by selection of the resulting library for HCMV binding. By this means, we were able to isolate a number of binders, some of which exhibited specific HCMV binding in soluble form. The clone that gave the strongest ELISA signal was expressed in bacteria, purified in solution, characterised using a novel capture methodology with surface plasmon resonance detection on a BIAcore instrument and used for the production of an immunofilter for the removal of HCMV form human serum. The filter removed more than 99% of applied HCMV in 10 min circulation time, while the amount of HCMV retained non-specifically in a cartridge derivatised with a non-specific antibody was less than 10% under similar conditions.