纤维素结合域的引入对角质酶在纤维素类纤维上吸附性能的影响

为了研究纤维素结合域（Cellulose-binding Domain,CBD）的引入对角质酶在纤维素类纤维上吸附能力的影响,本文选用漂白棉织物、粘胶纤维、醋酯纤维以及纯棉针织坯布这四种材质,对角质酶与CBD-角质酶进行吸附对比试验。研究表明：CBD结构的引入,可提高角质酶在纤维素纤维上的吸附量。但是当纤维素葡萄糖残基上羟基被部分酯化后,CBD结构的引入对吸附量造成的影响开始减弱,而当纤维素纤维表面被疏水性杂质覆盖时,CBD-角质酶对纤维素纤维的吸附能力反而降低。     

停车场远程视频监控系统的设计与开发

提出和实现了一种基于嵌入式设备的停车场视频监控和车位检测方案。在嵌入式Linux操作系统下,通过调用计算机视觉库OpenCV中的图像处理函数,实现多车位的检测,检测结果保存到嵌入式数据库中。通过嵌入式设备将车位信息发送给PC或手持设备,并以图像的形式显示,达到远程车位检测的目的。本系统还移植了Mjpgstreamer实现停车场的远程视频监控。车位状态的检测采用2种判据:一是车位范围内差影的均值;二是车位区域内的边缘点数。测试结果表明,该方案可以很好地运行在嵌入式平台,为停车诱导提供支持。     

规范收购程序维护农民利益--粮食收购部门收购中计量作弊一例

一年一度的夏粮（小麦）征购工作即将开始 ,一些粮食收购部门为单纯追求自身经济利益 ,置法律和企业、农民的利益于不顾 ,在等级、结算量方面作弊 ,牟取暴利。笔者在前两年的执法检查工作中 ,发现和掌握了个别粮食部门在收购过程中存在的问题 ,主要是一些粮食部门通过不明示量值的方法伪造数据进行计量作弊。具体情况如下 :粮食部门在农副产品收购时 ,按正常程序（农副产品上秤→司秤员称重→报毛重量→填秤码单→复称〈此环节基本不做〉→入仓→扣杂除皮→填写结算单）进行 ,司秤员如果伪造数据 ,很容易被发现和查处。为此 ,一些粮食收购部…     

插入n-AlGaN/GaN超晶格改善GaN基LED的droop效应

在GaN基LED的n-GaN和InGaN/GaN发光区之间插入n-AlGaN/GaN超晶格来改善其droop效应。注入电流低于100mA时,插入n-AlGaN/GaN超晶格的LED的流明效率低于没有插入层的LED。注入电流高于100mA时,插入n-AlGaN/GaN超晶格的LED的流明效率高于没有插入层的LED。插入n-AlGaN/GaN超晶格后,GaN基LED在-5V的反向电压下,漏电由2.568029μA减少到0.070543μA。人体模式下,插入n-AlGaN/GaN超晶格的LED在2000V的静电电压下的通过率从60%提高到了90%。LED droop效应的改善是因为n-AlGaN/GaN超晶格过滤了穿透位错并改善了电流扩展能力。     

Influence of growth conditions on the V-defects in InGaN/GaN MQWs

The influence of the growth temperature,TMIn/TEGa andⅤ/Ⅲratio on the V-defects of InGaN/GaN multi-quantum wells（MQWs） has been investigated and discussed.When the TMIn flow increases from 180 to 200 sccm,the density of V-defects increases from 2.72×10¹⁸ to 5.24×10¹⁸ cm^-2,and the V-defect width and depth increase too.The density also increases with the growth temperature.The densities are 2.05×10⁸,2.72×10¹⁸ and 4.23×10⁸ cm^-2,corresponding to a growth temperature of 748,753 and 758℃respectively.When the NH₃ flows are 5000,6600 and 8000 sccm,the densities of the V-defects of these samples are 6.34×10¹⁸,2.72×10¹⁸ and 4.13×10¹⁸ cm^-2,respectively.A properⅤ/Ⅲratio is needed to achieve step flow growth mode.We get the best quality of InGaN/GaN MQWs at a growth temperature of 753℃TMIn flow at 180 sccm,NH₃ flow at 6600 sccm,a flatter surface and less V-defects density.The depths of these V-defects are from 10 to 30 nm,and the widths are from 100 to 200 nm.In order to suppress the influence of V-defects on reverse current and electro-static discharge of LEDs,it is essential to grow thicker p-GaN to fill the V-defects.     

沉管施工的质量控制

本文结合广州市南沙自来水厂原水输水工程过河管道过鱼窝头涌段沉管施工成功经验，分析总结了沉管施工的质量控制。     

变电站PT保险熔断现象机理分析

在公司辖内的变电站中,电压互感器(PT)保险熔断现象时有发生,影响了电网的安全稳定运行。文章结合变电站现场发生的PT保险熔断现象,通过理论分析,对变电站PT保险熔断现象的根本原因做出解释,并提出解决此问题的方向。     

Improvement of the efficiency droop of GaN-LEDs using an AlGaN/GaN superlattice insertion layer

With an n-AlGaN(4 nm)/GaN(4 nm) superlattice(SL) inserted between an n-GaN and an InGaN/GaN multiquantum well active layer,the efficiency droop of GaN-based LEDs has been improved.When the injection current is lower than 100 mA,the lumen efficiency of the LED with an n-AlGaN/GaN SL is relatively small compared to that without an n-AlGaN/GaN SL.However,as the injection current increases more than 100 mA,the lumen efficiency of the LED with an n-AlGaN/GaN SL surpasses that of an LED without an n-AlGaN/GaN SL. The wall plug efficiency of an LED has the same trend as lumen efficiency.The improvement of the efficiency droop of LEDs with n-AlGaN/GaN SLs can be attributed to a decrease in electron leakage due to the enhanced current spreading ability and electron blocking effect at high current densities.The reverse current of LEDs at -5 V reverse voltage decreases from 0.2568029 to 0.0070543μA,and the electro-static discharge(ESD) pass yield of an LED at human body mode(HBM)-ESD impulses of 2000 V increases from 60%to 90%.     

基于伪微分算法的混合磁悬浮地球仪

为实现永磁电磁混合悬浮地球仪的稳定悬浮控制,采用伪微分反馈控制算法进行了力学和运动学分析,建立了系统数学模型,推导出控制对象及控制系统的传递函数,并对其稳态性能进行了理论分析.研究结果表明,伪微分反馈控制策略针对混合磁悬浮系统非线性和固有的不稳定性具有鲁棒性和控制精度高的特点.