A novel laser beam generator in place at SGll

Researchers with the State Key Laboratory of High Field Laser Physics, the CAS Shanghai Institute of Optics and Fine Mechanics, have been successful in developing a multifunctional and high-energy laser beam system (also known as the ninth laser beam) at the Shenguang-II Laser Facility (SGII).     

A novel micropump droplet generator for aerosol drug delivery: Design simulations

One challenge of generating a liquid aerosol is finding an efficient way to break up bulk amounts of the compound into micron-sized droplets. Traditional methods of aerosol generation focus on the principle of creating the liquid droplets by blowing air at high speed over or through a liquid. In this study, a novel micropump droplet generator (MDG) is proposed based on a microfluidics device to produce monodisperse droplets on demand (DoD). The micropump design was employed to both pump the fluid into the air and to encourage droplet breakup and aerosol formation. Computational simulation modeling of the new MDG was developed and validated with comparisons to experimental data for current generators. The device was found to produce an aerosol similar to a vibrating orifice DoD device. Most importantly, the input power required by the newly proposed device (MDG) was several orders of magnitude below existing DoD generators for a similar droplet output. Based on the simulation results obtained in comparison with current DoD generators, the MDG device performed effectively at higher frequencies, smaller nozzle diameters, and regardless of the liquid viscosity of the solution.     

A noise-filtering event generator for PIDPlus controllers

In this paper we propose a new event generator, which has strong noise-filtering capabilities, to be used in event-based control systems with a PIDPlus controller. An approximate frequency analysis is performed in order to characterize the event generator system and tuning guidelines are provided for its design parameter. Simulation and experimental results obtained with a laboratory setup demonstrate the effectiveness of the methodology in providing a satisfactory performance related to set-point and load disturbance step responses with a total variation that is significantly reduced with respect to the standard cases.     

异步电机发电在西藏应用的探讨

西藏自治区拥有丰富的自然资源，由于客观条件的原因，仍有三分之二的人口没有用上电。本文在说明弄步电机发电优点的前提下，提出采用这种发电方式是解决偏僻地区用电问题的有效途径。     

A "place n play" modular pump for portable microfluidic applications

This paper presents an easy-to-use, power-free, and modular pump for portable microfluidic applications. The pump module is a degassed particle desorption polydimethylsiloxane (PDMS) slab with an integrated mesh-shaped chamber, which can be attached on the outlet port of microfluidic device to absorb the air in the microfluidic system and then to create a negative pressure for driving fluid. Different from the existing monolithic degassed PDMS pumps that are generally restricted to limited pumping capacity and are only compatible with PDMS-based microfluidic devices, this pump can offer various possible configures of pumping power by varying the geometries of the pump or by combining different pump modules and can also be employed in any material microfluidic devices. The key advantage of this pump is that its operation only requires the user to place the degassed PDMS slab on the outlet ports of microfluidic devices. To help design pumps with a suitable pumping performance, the effect of pump module geometry on its pumping capacity is also investigated. The results indicate that the performance of the degassed PDMS pump is strongly dependent on the surface area of the pump chamber, the exposure area and the volume of the PDMS pump slab. In addition, the initial volume of air in the closed microfluidic system and the cross-linking degree of PDMS also affect the performance of the degassed PDMS pump. Finally, we demonstrated the utility of this modular pumping method by applying it to a glass-based microfluidic device and a PDMS-based protein crystallization microfluidic device.     

某微车车架横梁结构及轻量优化改进

文章通过对某商用微车的车架横梁进行结构优化,更改原堆材料式的结构方式,取消两层钣金零件大面贴合焊接的连接,从而使得车架横梁结构巧妙,材料利用率好,成本更低。对比原来设计,新的横梁在结构上更精简,同时有利提升横梁的刚度强度。     

超声波发生器中信号源的设计与仿真

超声波发生器根据应用场合的不同,而要求有不同的电路设计方案,文章作者设计了一款应用于半导体焊线设备的超声波发生器的信号源电路,该电路采用英特矽尔公司生产的icl8038芯片,利用该芯片设计了一款高精度的波形发生器,通过选择不同电阻,电容等外部元器件,其设计的频率范围可以从0.001Hz到300KHz,并且也可以通过外部电压的扫描来产生不同频率的波形。文章作者用Proteus仿真软件对ICL8038芯片所设计的信号源电路进行了仿真。     

A novel signal representation in SEI: Manifold

Specific emitter identification (SEI), as an important problem in situational awareness, identifies emitters via unique characteristics. However, current SEI methods mostly suffer from appropriately setting the trade-off between comprehensiveness and efficiency when extracting fingerprint features. To address the issue, this paper provides a novel SEI framework with a separate representation module. Within the novel framework, manifolds are proposed to be signal representations and multi-level manifold features are extracted as fingerprint features. We first build the SEI model from the nonlinear dynamic perspective, where the SEI process identifies the nonlinear systems via a measurement sequence. Then, we demonstrate that manifolds can represent emitters equivalently and prove the one-to-one correspondence between manifolds and emitter individuals. Hence, manifolds can highlight unique nonlinear dynamic characteristics and simultaneously describe comprehensive system working processes. The coordinate delayed technique and manifold learning methods are employed to reconstruct the phase space and manifold, respectively. For accomplishing the identification task, multi-level manifold features, comprising intrinsic dimension, topological features, conformal features, and Riemannian metric features, are extracted from the reconstructed manifolds and input to an ensemble learning scheme, named Adaboost. Extensive simulation and real-world experiments agree with our analytical conclusions and confirm the proposed method’s efficiency. The results also demonstrate that the proposed method achieves a high recognition accuracy, outstanding adaptability, and strong robustness.     

一种应用于脉冲超宽带的新型门控积分方法

提出一种应用于脉冲超宽带相关接收机的新型门控积分方法,它利用简单的线性时不变系统实现带清除的积分．这种门控积分方法简化了系统结构,易于实现．论文引入误差函数和干扰函数评价等效积分性能,还以二阶低通滤波器为例,给出了等效积分应用在模拟匹配相关时的性能计算结果,表明等效方法完全适用于脉冲超宽带模拟相关接收机．     

A new feat of powerful laser system

CAS physicists have recently developed an intense femtosecond (fs) laser system with a peak output power of more than 350 TW. Dubbed Jiguang-Ⅲ (or XLite-Ⅲ), the work passed the acceptance check by a 10-member panel of experts under the auspices of CAS on last 27December. It was regarded as one of the best results of its kind in open literature so far.