门控型像增强器开门时间测量

提出了采用超快激光脉冲与光纤阵列形成的光延时、跟CCD相机相结合的方法,对门控型像增强器进行了开门时间的测量,分析了该测量方法的可行性,建立了门控型像增强器开门时间的测量系统。用该测量方法对超高速光电分幅相机中的门控型像增强器开门时间进行了测量,得到了10,20,30,50 ns档开门时间的实验图片,与所加的快高压脉冲时间12.50,18.50,28.75,48.60 ns相比较,开门时间的测量精度得到了提高,该测量方法可用于超高速光电分幅相机曝光时间的标定。     

Delayed range-gating super-resolution imaging lidar with high accuracy

We present a range-gating delayed detection super-resolution imaging lidar with high accuracy based on the signal intensities of three consecutive delay samples. The system combines the range and signal intensity information from multi-pulse detections to calculate the pulse peak position under the assumption of a Gaussian pulse shape. Experimental results indicate that the proposed algorithm effectively calculates pulse peak position and exhibits excellent accuracy with super-resolution. Accuracy analysis shows that accuracy is best improved by enhancing signal-to-noise ratio, strategically selecting samples, reducing pulse width, and appropriately choosing the delayed periods between samples.     

Low-voltage antimony-doped SnO2 nanowire transparent transistors gated by microporous SiO2-based proton conductors

A battery drivable low-voltage transparent lightly antimony（Sb）-doped SnO2 nanowire electric-double-layer （EDL） field-effect transistor （FET） is fabricated on an ITO glass substrate at room temperature. An ultralow operation voltage of 1 V is obtained on account of an untralarge specific gate capacitance （- 2.14 μF/cm2） directly bound up with mobile ions-induced EDL （sandwiched between the top and bottom electrodes） effect. The transparent FET shows excellent electric characteristics with a field-effect mobility of 54.43 cm2/V. s, current on/off ration of 2 × 104, and subthreshold gate voltage swing （S = dVgs/d（logIds）） of 140 mV/decade. The threshold voltage Yth （0.1 V） is estimated which indicates that the SnO2 namowire transistor operates in an n-type enhanced mode. Such a low-voltage transparent nanowire transistor gated by a microporous SiO2-based solid electrolyte is very promising for battery-powered portable nanoscale sensors.     

KcsA钾通道的多级开放过程:靶向分子动力学模拟

钾离子通道是一种能开放或闭合孔道而控制钾离子跨膜流动的膜蛋白。Kv1.2结构是一种开式构型的钾通道结构,也是迄今获得的唯一一种来自真核细胞的钾通道结构。尽管导致Kv1.2结构内螺旋弯曲的PVP序列在KcsA等原核细胞钾通道中不存在,KcsA结构的直式内螺旋闭合构型仍常被作为Kv1.2等真核细胞钾通道的闭式模版。本文在靶向分子动力学模拟中迫使Kv1.2钾通道闭合为KcsA构型,我们发现Kv1.2无法适应KcsA的闭合构型,松弛后内螺旋恢复PVP铰链弯曲,在孔道的腔-门区域形成上下大中间小的沙漏状闭合构型。此构型使开闭构型转换效率更高,可能是钾通道从原核细胞的甘氨酸铰链进化到真核细胞的PXP铰链的原因所在。     

基于视频的精确放疗摆位系统研究

重点介绍了中国科学院等离子体物理研究所“精确放射治疗系统”课题组在基于视频的摆位方法领域的最新研究成果,如基于双目视觉的摆位系统、基于轮廓匹配的位置测量系统和呼吸门控系统。简要介绍了这些方法的原理、应用场合及应用前景。This paper introduces the newest research production on patient positioning method in accurate radiotherapy brought by Accurate Radiotherapy Treating System （ARTS） research team of Institute of Plasma Physics of Chinese Academy of Sciences, such as the positioning system based on binocular vision, the position-measuring system based on contour matching and the breath gate controlling system for positioning. Their basic principle, the application occasion and the prospects are briefly depicted.     

Locking Function of a Key Residue in Kinesin＇s Gating Mechanism

In kinesin＇s mechanochemical cycle, ATP＇s binding to the nucleotide-free leading head is exquisitely gated so that futile hydrolysis is effectively avoided, Experiments show that, when both kinesin heads bind to a microtubule~ ATP cannot bind to kinesin＇s leading head when the neck linker （NL） of this head has a backward orientation. How NL＇s backward orientation is maintained needs understanding on a structural basis. By using steered molecular dynamics and rrmtation simulations, we investigate the backward-pointing conformation of the leading head＇s NL under different inter-head tensions. We find that the NL cannot keep in a strict backward orientation solely by the inter-head tension. LYS325 （amino acid sequence in 2KIN） has an assistant locking function which locks the NL and β0 to the β-domain. This locking function has an enhanced positive cooperation with the inter-head tension. When the inter-head tension is weakened, this locking function can be broken, resulting in a loose backward orientation of the NL. The difference between the strict and loose backward orientation of the NL might be a crucial factor in the gating mechanism. These results are consistent with relevant experiments and proposals.     

基于内调制DFB激光器的高空间分辨率TGD-OFDR

提出了一种利用内调制频率调谐实现高空间分辨率的时间门控数字光频域反射仪（TGD-OFDR）方案,采用电流调谐的分布式反馈（DFB）二极管激光器作为探测光源提供较大的激光频率调谐范围的信号,利用马赫-曾德尔干涉仪（MZI）分析该DFB激光器的电流-频率响应特性后,由任意波形发生器产生的带有预失真的锯齿波信号驱动该DFB激光器,进而补偿激光器扫频时的非线性,同时采用一台波长可调节的稳频激光器的出射光充当本地稳频参考光。实验测试在74 km的光纤链路上实现了10 cm的空间分辨率,动态范围为23.3 dB。     

以壳聚糖为基底的分子印迹电化学传感器研究及倍硫磷测定

研制了一种以壳聚糖修饰层为基底的倍硫磷分子印迹电化学传感器。首次利用修饰电极对探针离子的吸附富集作用提高分子印迹传感器检测的灵敏度。采用交流阻抗法和循环伏安法对传感器响应过程进行电化学表征;对洗脱、重吸附、探针富集时间等实验条件进行优化;考察了壳聚糖对“门控制效应”测量模式的增敏效应。在优化条件下,该传感器对倍硫磷的检测范围为1 ~ 10 000 pg/mL,检出限为0.35 pg/mL。该传感器已成功用于蔬菜和水果中倍硫磷的测定,其加标回收率为99.0% ~ 109%,相对标准偏差为1.9% ~ 2.9%。     

基于VXI总线的四路门控积分器模件的研制

 介绍了一个基于标准总线VXI的四路门控积分器模块插件。在四路独立的纳秒门控积分电路的基础上,采用VXI寄存器基接口实现对各路门控积分器的数据采集和控制,采用Labwindows/CVI编写了数据采集系统软件,从而完成了纳秒级门控积分器的实用化的基本工作。电子学测试结果和现场打靶结果表明该系统完全符合实用系统的要求。     

超高速高性能门控型三分幅相机

提出了一种改进块匹配宏块分布排列的快速传感器电子稳像算法,通过陀螺传感器测量摄像系统的抖动,利用小范围快速块匹配算法估计局部运动矢量,再运用最小二乘法解算全局运动矢量.小范围快速块匹配算法得到的局部运动矢量准确度高,仅需部分局部运动矢量即可准确解算出全局运动矢量.基于此在保证运动矢量准确度情况下,对块匹配宏块的分布排列进行了改进,从而减少匹配宏块数量加快算法速度.通过对宏块网格模型的分析,得出对小范围快速块匹配算法进行宏块分布改进的方案,进而设计出快速传感器电子稳像算法.仿真及实验表明:运算时间提高89%左右,且算法准确度略高于改进前算法.