基于低速光调相信号注入DFB-LD产生4～16倍频的40GHz和60GHz毫米波信号

提出一种基于低速光调相信号注入半导体分布反馈激光器(DFB-LD)产生最低4倍频,最高16倍频的40GHz和60GHz的毫米波调相信号。该方案利用注入光的N阶调相边带锁定DFB-LD的波长,同时DFB-LD放大此调相边带并与原注入光信号通过相干差拍作用在LD腔内形成毫米波调相信号。通过理论建模分析了工作原理,经系统实验验证了此方案的可行性。应用2.5,5和10GHz的光调相信号均得到40GHz或60GHz的毫米波信号,实现了最低4倍频,最高16倍频的毫米波信号产生,并通过单边带相位噪声的测量验证了毫米波的频率稳定度。     

同步辐射软X射线对单细胞的辐射损伤

应用国家同步辐射实验室软X射线显微术光束线的光学系统,搭建了适合软X射线单细胞辐照损伤效应研究的实验装置,选择氧元素K吸收边能量对Hela细胞进行单细胞辐照,运用单细胞凝胶电泳技术进行辐照损伤评价.实验结果表明,辐射损伤效应与辐射剂量有依赖性关系.     

建筑外墙反射隔热涂料节能效率探讨

选坐落于广州的一幢1梯2户6层为特定的参照建筑,用JGJ 75—2003《夏热冬暖地区居住建筑节能设计标准》的方法,计算该建筑物外装饰材料的太阳能辐射吸收率ρ与建筑物空调年耗电量指数(ECFc)的关系。结果表明:ρ值越低,建筑物ECFc越低,越节能;当ρ≤0.65时,ECFc≤0.5,即该建筑符合JGJ 75—2003的节能设计;证明反射隔热涂料的基本要求之一就是要降低涂料的ρ值。测量涂料的太阳能总反射比(TSR)结果表明:使用铬铁黑、铬铁红等颜料,在中等深度颜色到深颜色范围内,涂料的TSR能够提高10%～20%,节约空调年耗电量10%左右。     

钙钛矿复合氧化物的介孔化及用于CH4催化燃烧

利用有序介孔立方相(Ia3d)乙烯基三乙氧基硅烷(TEVS)为模扳,通过纳米组装法在硅基硬模板的介孔中填入La - Fe -柠檬酸络合物,经焙烧和碱洗去除硅基模板,制备具有有序介孔结构且高比表面积的LaFeO3钙钛矿(ABO3),并与软模板法和自燃烧法制备的LaFeO3钙钛矿催化荆作对比,运用XRD、TEM和BET对合...     

Characterization of cell growth and photobiological H2 production of Chlamydomonas reinhardtii in ASSF industry wastewater

Photobiological H₂ production in microalgae is a promising approach for the development of alternative clean and renewable energy. As a unicellular green alga, Chlamydomonas reinhardtii is regarded as an ideal candidate for sustainable photo-H₂ production. However, growth and photo-H₂ producing are still expensive and energy extensive. Wastewater has been suggested as an economical resource for microalgae growth and biofuels production. In this study, we characterized the cell growth and photo-H₂ production of C. reinhardtii CC503 cultured in waste water from pressing process of fermented sweet sorghum stalks during Advanced Solid State Fermentation (ASSF). The maximal cells concentration reached 8.9 × 10⁶ cells/mL in ASSF wastewater medium (AWM) with the fastest growth rate of 0.19 × 10⁶ cells/h, compared to 18.2 × 10⁶ cells/mL and 0.36 × 10⁶ cells/h in TAP medium and to 1.3 × 10⁶ cells/mL and 0.02 × 10⁶ cells/h in BGII medium respectively. The optimized concentration of wastewater for algae cells growth was determined to be 13.3% (7.5 folds dilution), under which, surprisingly the photosynthetic H₂ evolution was increased by more than 700% compared to the cells grown in TAP medium. This system appears to be a good strategy for the development of an economical microalgal photobiological H₂ production scheme. Finally, the possible mechanism for such an H₂ enhancement was identified as the reduction of PSII activity in AWM grown cells.     

一种具有双模检测功能和高稳定性的唤醒接收机基带电路

This paper proposes a baseband circuit for wake-up receivers with double-mode detection and enhanced sensitivity robustness for use in the electronic toll collection system.A double-mode detection method,including amplitude detection and frequency detection,is proposed to reject interference and reduce false wake-ups.An improved closed-loop band-pass filter and a DC offset cancellation technique are also newly introduced to enhance the sensitivity robustness.The circuit is fabricated in TSMC 0.18μm 3.3 V CMOS technology with an area of 0.12 mm2.Measurement results show that the sensitivity is -54.5 dBm with only a±0.95 dBm variation from the 1.8 to 3.3 V power supply,and that the temperature variation of the sensitivity is±1.4 dBm from -50 to 100℃. The current consumption is 1.4 to 1.7μA under a 1.8 to 3.3 V power supply.     

漳州龙文高岭土的深加工开发技术研究

以闽南地区漳州龙文高岭土矿区的高岭土为研究对象,采用325目粗精矿为原料.利用先进的仪器设备对漳州龙文高岭土的矿物特征、漂白技术、超细剥片技术、煅烧增白技术进行一系列研究,并且使用工业化或大型中试设备进行产品深加工试验.获得了较好的效果.这些深加工技术研究为闽南漳州龙文一带高岭土矿的长期开发利用和深加工提供一定的技术支持和产品方向.     

四旋翼飞行器双环条件积分滑模控制

针对存在阵风干扰及未建模特性下的四旋翼飞行器轨迹跟踪控制,基于非线性滑模控制技术,结合条件积分思想及Lyapunov稳定性理论设计了一种位姿双环条件积分滑模控制器.在获得四旋翼非线性动力学模型后对其进行线性化,简化被控对象数学模型,提高控制器设计效率.利用条件积分滑模控制律设计了位置环和姿态环的轨迹跟踪控制器,实现了控...     

宝钢三期二炼钢二连铸三电系统概述(上)

叙述宝钢三期工程二钢二连铸单元采用４级计算机系统进行控制和管理,概要介绍系统的主要管理和控制功能,特别介绍了为提高炼钢－连铸－热轧一体化管理水平和提高产品质量所包括的１５个模型。值得指出的是,本系统４级计算机在大量信息集成基础上做到了与工程同步投入,系统投入水平高,投产后又进行了大量的优化工作,目前系统运行良好。     

Soft X-ray radiation effects on yeast cells with energies on and off the OK absorption edge by a soft X-ray microprobe

The cell killing abilities of soft X-rays on and off the oxygenK-shell edges on yeast cells have been investigated using amicrometer soft X-ray microprobe from synchrotron radiation.The dose depositions at different X-ray energies in the cellwere discussed. At the same time, the cells were irradiatedby ⁶⁰Co gamma-rays and the abilities in inducing yeast cellkilling were compared with those produced by soft X-rays. Theresults showed that soft X-rays on and off the O_K edge had higherability of radiation damage than ⁶⁰Co gamma-rays. The totalkilling abilities of the three soft X-rays on yeast cells werealmost similar and the differences of the X-rays in inducingyeast cell killing on and off the O_K edge were not obvious.