烟草中多酚氧化酶的生理生化特征及其活性控制的研究

对烟草叶中的多酚氧化酶(PPO)进行了部分纯化，对比了叶中PPO在苗期和田间的活性差异，研究了其活性变化规律，发现生长旺盛期PPO活性高于其他时期，研究了烟叶在不同水势条件下PPO活性变化规律，发现水势过高、过低，PPO活性均较低，在一872．78kPa水势条件下，PPO活性最高，所以细胞中的含水量是影响PPO活性的因素之一．研究了PPO在35℃、40℃、45℃、50℃、55℃、60℃、65℃、70℃和75℃等烘烤温度条件下的热敏感性，发现：酶的最适反应温度为35℃；温度由35℃升至75℃，活性逐渐下降，在每一温度下保持5min，活性趋于稳定，用回归法得出了烟叶中PPO的下降百分数与温度之间的关系式．用双倒数作图法比较了NaDiCa、EDTA、巯基乙醇和硫脲4种常用抑制剂对烟叶中PPO活性的抑制强度，结果表明：同一浓度下它们对PPO的抑制强度依次递减，而NaDiCa抑制效率明显高于其他3种抑制剂；CuCl2可以促进PPO活性，用回归法得出了活力增加百分数与二价铜离子浓度的关系式。     

一种新型的光纤曲率传感器

开发了一种新型的埋入式光纤曲率传感器 ,以结构的曲率变形对传感器的输出光强实现强度调制 .对传感器的静态和动态特性作了分析 ,提出了该传感器的传感机理 ,对传感器的结构作了改进 .将此传感器埋入树脂基复合材料板内部 ,测量板的弯曲变形 .可利用此曲率传感器组成准分布式传感系统检测智能结构的形状变化 .     

Short-range clutter suppression method combining oblique projection and interpolation in airborne CFA radar

The airborne conformal array(CFA)radar's clutter ridges are range-modulated,which result in a bias in the estimation of the clutter covariance matrix(CCM)of the cell under test(CUT),further,reducing the clutter suppression performance of the airborne CFA radar.The clutter ridges can be effectively compensated by the space-time separation interpolation(STSINT)method,which costs less computation than the space-time interpolation(STINT)method,but the performance of interpolation algorithms is seriously affected by the short-range clutter,especially near the platform height.Location distributions of CFA are free,which yields serious impact that range spaces of steering vector matrices are non-orthogonal complement and even no longer disjoint.Further,a new method is proposed that the shortrange clutter is pre-processed by oblique projection with the intersected range spaces(OPIRS),and then clutter data after being pre-processed are compensated to the desired range bin through the STSINT method.The OPIRS also has good compatibility and can be used in combination with many existing methods.At the same time,oblique projectors of OPIRS can be obtained in advance,so the proposed method has almost the same computational load as the traditional compensation method.In addition,the proposed method can perform well when the channel error exists.Computer simulation results verify the effectiveness of the proposed method.     

颗粒形状对裂缝封堵层细观结构稳定性的影响

裂缝封堵层结构与裂缝性地层封堵承压能力存在密切联系,并常常决定着钻井防漏堵漏作业的成败.为研究颗粒形状对裂缝封堵层细观结构稳定性的影响,选用5种不同形状的聚碳酸酯颗粒,模拟压力波动情况,开展裂缝封堵层剪切失稳的二维光弹实验,获得裂缝封堵层细观结构演化过程中的光弹图像,并运用Matlab处理光弹图像,析出强力链占比和强力...     

界面反应及界面张力对Sn-Zn-Bi焊料润湿性的影响

通过合金化的方式得到了Sn-Zn-Bi三元及Sn-Zn-Bi-Nd四元无铅焊料,采用润湿平衡法测量了其润湿力和润湿时间,并对润湿后的焊料/Cu界面组织进行了分析.结果表明:Bi元素不参与焊料/Cu界面的扩散反应,但能够通过吸附作用降低界面张力,从而提高焊料在Cu基底上的润湿力;Zn元素优先向焊料/Cu界面进行扩散形成Cu5Zn8金属间化合物,且扩散层随焊料中Zn含量的提高而增长,此时固-液界面张力方向发生改变,润湿力提高,但润湿时间延长;Nd元素的作用类似于Bi,既能提高焊料的润湿力,也能够缩短润湿时间,是一种改善Sn-Zn基焊料润湿性的有效元素.     

东营市利津县青少年头发九种微量元素含量初步调查

采用原子吸收光谱法对东营市利津县10～20岁50名青少年发样进行九种微量元素(Ca,Mg,Fe,Cu,Zn,Mn,Pb,Ni,Cr)测定,对测定数据进行统计分析。九种微量元素含量的平均值(μg/g)分别为:Ca:822,Mg:142,Fe:13.7,Cu:10.3,Zn:196,Mn:1.2,Pb:1.5,Ni:0.26,Cr;0.12.锌值的频率分布基本为正态分布,其算术平均值为196μg/g,标准偏差为24μg/g,由此提出该地区青少年头发微量锌的背景范围为172～220μg/g。     

Avoiding obstacles by using a proximity infrared sensor skin

Placement and wiring of vast amount of sensor elements on the 3-dimensionally configured robot surface to form soft sensor skin is very difficult with the traditional technology. In this paper we propose a new method to realize such a skin. By implanting infrared sensors array in an elastic body, we obtain an elastic and tough sensor skin that can be shaped freely. The developed sensor skin is a large-area, flexible array of infrared sensors with data processing capabilities. Depending on the skin electronics, it endows its carrier with an ability to sense its surroundings. The structure, the method of infrared sensor signal processing, and basic experiments of sensor skin are presented. The validity of the infrared sensor skin is investigated by preliminary obstacle avoidance trial.     

孤东油田上第三系馆陶组上段微量元素的分布特征及沉积环境分析

通过对孤东油田馆上段四日进109块岩样中的Ca,Mg,Sr,Cr.Cu,Fe,Mn,V,Ni等九种元素的分析,得出了孤东油田馆陶组上段微量元素含量及其比值与氧化还原、湖盆盐度、古气候等沉积条件的关系,从而提供了利用微量元素及其比值的变化分析沉积环境,划分微相类型及判断古盐度高低的一种新方法.     

TNF-RII and c-IAP1 mediate ubiquitination and degradation of TRAF2

Tumour necrosis factor-alpha (TNF-alpha) is a proinflammatory mediator that exerts its biological functions by binding two TNF receptors (TNF-RI and TNF-RII), which initiate biological responses by interacting with adaptor and signalling proteins. Among the signalling components that associate with TNF receptors are members of the TNF-R-associated factor (TRAF) family. TRAF2 is required for TNF-alpha-mediated activation of c-Jun N-terminal kinase (JNK), contributes to activation of NF-kappaB, and mediates anti-apoptotic signals,. TNF-RI and TNF-RII signalling complexes also contain the anti-apoptotic ('inhibitor of apoptosis') molecules c-IAP1 and c-IAP2 (refs 5, 6), which also have RING domain-dependent ubiquitin protein ligase (E3) activity. The function of IAPs in TNF-R signalling is unknown. Here we show that binding of TNF-alpha to TNF-RII induces ubiquitination and proteasomal degradation of TRAF2. Although c-IAP1 bound TRAF2 and TRAF1 in vitro, it ubiquitinated only TRAF2. Expression of wild-type c-IAP1, but not an E3-defective mutant, resulted in TRAF2 ubiquitination and degradation. Moreover, E3-defective c-IAP1 prevented TNF-alpha-induced TRAF2 degradation and inhibited apoptosis. These findings identify a physiologic role for c-IAP1 and define a mechanism by which TNF-RII-regulated ubiquitin protein ligase activity can potentiate TNF-induced apoptosis.     

图书馆在学校教育中的作用

作者以自身实践出发,从5个方面论述了学校图书馆在学校教育中的作用。