双笼翻板施工升降机进楼层存在问题案例分析

施工升降机的布置是一项技术性较强的工作,吊笼进入楼层的方式有是否使用脚手架平台之异。以某住宅项目为例,分析了双笼翻板施工升降机构造与外脚手架类型、建筑物平面与立面造型、施工进度动态管理等方面遇到的问题,提出了缩短附着架长度、调整外脚手架杆件、变更施工方式等解决方案,为今后类似条件下的施工提供借鉴参考。     

智能超表面辅助低轨卫星通信技术综述

卫星通信能够提供超视距、大容量的通信服务,但在城市区域、峡谷森林等视线受遮蔽严重的区域,会出现视距衰落严重、多径效应显著等问题,影响通信质量。近年来出现的智能超表面(RIS)可以通过动态控制反射单元的电磁性质,构建可控电磁环境,为改善低轨(LEO)卫星通信质量提供新的思路。本文基于RIS基本原理与优势,对RIS用于LEO卫星通信中信道建模、信道估计、波束成形等关键技术进行探讨,最后分析了目前RIS在实际应用中面临的主要挑战,以期为LEO卫星场景下的RIS研究提供参考。     

Genome-Wide Identification of TaSAUR Gene Family Members in Hexaploid Wheat and Functional Characterization of TaSAUR66-5B in Improving Nitrogen Use Efficiency

Excessive input of nitrogen fertilizer not only causes a great waste of resources but brings about a series of ecological and environmental problems. Although Small Auxin Up-regulated RNAs (SAURs) participate in diverse biological processes, the function of SAURs in the nitrogen starvation response has not been well-studied. Here, we identified 308 TaSAURs in wheat and divided them into 10 subfamilies. The promoter regions of most TaSAURs contain hormone responsive elements, and their expression levels change under the treatment of different hormones, such as IAA, MeJA, and ABA. Interestingly, overexpression of one of the TaSAUR family members, a nitrogen starvation responsive gene, TaSAUR66-5B, can promote the growth of Arabidopsis and wheat roots. In addition, overexpression of TaSAUR66-5B in Arabidopsis up-regulates the expression levels of auxin biosynthesis related genes, suggesting that overexpression TaSAUR66-5B may promote root growth by increasing the biosynthesis of auxin. Furthermore, overexpression of TaSAUR66-5B in wheat can increase the biomass and grain yields of transgenic plants, as well as the nitrogen concentration and accumulation of both shoots and grains, especially under low nitrogen conditions. This study provides important genomic information of the TaSAUR gene family and lays a foundation for elucidating the functions of TaSAURs in improving nitrogen utilization efficiency in wheat.     

三槽丝锥中径的测量

本文介绍在没有专用量具、量仪的条件下,在双面啮合综合检查仪上用比较测量法,测出三槽丝锥的1/2M值,然后计算出中径d2的方法.     

Differences in lithospheric structures between two sides of Taihang Mountain obtained from the Zhucheng-Yichuan deep seismic sounding profile

A 2-D model of lithospheric velocity structures in the southern part of the North China Craton was obtained using data from the Zhucheng-Yichuan deep seismic sounding profile.Results show that there are great differences in lithospheric structures between two sides of Taihang Mountain.In the eastern region,the lithosphere is thinner,with a thickness of about 70-80 km,while in the western region,the thickness is 85-120 km.There is a jump of the lithospheric thickness across Taihang Mountain gravity anomaly b...     

一种宽调节范围高线性度压控振荡电路的设计

介绍了一种基于0.8μm CMOS工艺的宽调节范围高线性度压控锯齿波振荡电路,同时利用Candence仿真工具对电路进行了仿真模拟.结果表明,产生的锯齿波压控调节范围为1.1~1.9MHz,中间频段线型度很高,且频率稳定、精度较高,可广泛应用在稳压器以及各种相位频率锁定系统中.     

仿真嵌入实装的技术实现

随着通信对抗装备的复杂性增加和对其形成作战能力的要求不断提出,装备训练的问题日益突出。阐述了把仿真嵌入实装的需求层次和思路,并提出了相应的实现途径和总体框架。     

具有多台链功能的测距设备实现

机载设备已由针对单一地面台工作转变为可针对多地面台工作,如测得距3个地面台的斜距P,利用P-P-P定位方法,可进行定位和导航计算,这种多地面台扫描工作体制将成为DME发展的趋势。结果表明,该系统能够实现多台链工作,性能稳定可靠。     

江西信丰恐龙蛋化石碎片的显微喇曼光谱研究

本文分别采取两种激光波长激发(514.5nm和785nm),首次利用激光显微喇曼光谱对江西信丰的恐龙蛋化石碎片进行了研究。我们发现恐龙蛋化石的主要矿物成分是方解石。其次,某些样品中还含有少量的石英、α-石英和赤铁矿,其中石英晶体仅分布于蛋壳内表面。显微镜下观察到蛋壳内表面呈黑色的原生方解石以及银白色的次生方解石颗粒,另外,还观测到石英晶体颗粒。近红外激光激发下的喇曼光谱中出现了一些有机物的谱峰,它们分别位于1200cm-1、1300cm-1,和1500cm-1附近。该研究结果为揭示恐龙蛋石化过程中经历的地质环境提供了重要的依据。