墨水直写、喷墨打印和激光直写技术及其在微电子器件中的应用

直写技术是一种新型微加工技术,其加工过程不需模板并可在亚微米至厘米范围实现材料加工成型.墨水直写、喷墨打印和激光直写作为最常用的直写技术,具有强大的二维、三维成型能力和优异的成型精度,可实现金属、陶瓷、聚合物、水凝胶等复杂构型的程序化构筑,被广泛应用于微电子、组织工程、微流控等领域.阐述了这3种直写技术的构型原理和材料选择,重点介绍了其在微电子器件制造中的应用,讨论了当前研究的难点和热点问题,并对其未来发展趋势进行了展望.     

The Effect of Pulsed Sliding Surface Discharges on Supersonic Airflow past a Thin Wedge in Shock Tube

The influence of ~300-ns pulsed sliding surface discharges on supersonic airflow with M = 1.2–1.5 past a thin wedge has been studied in a shock tube at 0.12–0.14 kg/m³ gas density. It is established that inhomogeneity of the airflow-density field near the wedge leads to changes in the discharge current geometry and the structure of surface-discharge glow. The dynamics of discharge-initiated shock waves disturbing the quasi-stationary flow past the wedge was studied by the method of shadow visualization. It is shown that shock waves from intense surface-discharge channels in front of the wedge and behind its rear part can produce nonstationary action on the flow past the wedge surface, which lasts for up to 120 μs after the discharge pulse.     

Large capacitance and fast polarization response of thin electrolyte dielectrics by spin coating for two-dimensional MoS2 devices

Nano Research - A spin-coating method was applied to obtain thinner and smoother PEO/LiClO4 polymer electrolyte films (EFs) with a lower level of crystallization than those obtained using a...     

Integrated-optic array illuminator: a new design for guided-wave optical interconnections

An integrated array illuminator can be used not only as an opticalpower distributor for an array of guided-wave optic devices but also asa key element for guided-wave optical interconnections. We presenta new design for an integrated-optic array illuminator with focusingwaveguide diffractive doublet arrays. This integrated arrayilluminator allows independent optimizations of efficient and uniformoptical power distribution and focusing performance. Furthermore, the device can be fabricated with all-optical lithographic technologyand hence has the advantages of mass production with lowcost.     

Fabrication of large-volume microfluidic chamber embedded in glass using three-dimensional femtosecond laser micromachining

We report on fabrication of large-volume, square-shaped microfluidic chamber embedded in glass by scanning a tightly focused femtosecond laser beam inside a porous glass immersed in water. After the hollow structure is created in the porous glass substrate, the fabricated glass sample is post-annealed at 1,050°C during which it can be sintered into a compact glass. By the use of this technique, a 1 mm × 1 mm × 100 μm microchamber connected to four microfluidic channels is created inside the transparent glass substrate, showing that our technique allows for fabrication of not only thin channel structures with arbitrary lengths and configurations, but also hollow structures with infinitely large sizes.     

Robust stability for uncertain genetic regulatory networks with interval time-varying delays

This paper addresses the problem of robust stability of uncertain genetic regulatory networks (GRNs) with interval time-varying delays. We derive some new delay-range-dependent and delay-derivative-dependent/independent stability criteria by employing some free-weighting matrices and linear matrix inequalities. In our analysis, we carefully consider the relationship between the time-varying state delays and their bounds when calculating the upper bound of the derivative of Lyapunov functional. We hence show that, the rigorous requirement of other literatures that the time-derivatives of time-varying delays must be smaller than one is abandoned in the proposed scheme. The new criteria are applicable to both fast and slow time-varying delays. Finally, four numerical examples are presented to illustrate the effectiveness and the less conservativeness of the developed results.     

太赫兹技术在室内无线通信中的应用

该文通过对太赫兹通信相关器件的总结和相关信道特性的分析,调研了近年来国内外相关实验的结果,对重点实验结果做了着重描述,总结出了未来室内无线通信可能的发展方向和亟待解决的问题。太赫兹波段是介于毫米波与远红外的电磁辐射频段。室内无线局域网的高数据率传输要求通信系统运行于更高的频率以获得更大的带宽。太赫兹频率范围未受军事管制,可实现Gbit/s数据率,并且太赫兹频域不像光频受环境噪声干扰那么严重。全固态室温太赫兹器件的研究为太赫兹无线通信系统奠定了基础。已探明适于未来太赫兹室内通信系统运行的大气窗口。基于飞秒激光门控光导天线的太赫兹通信链路实现了太赫兹波载波音频信号的调制和解调。     

A reference-based blind source extraction algorithm

By utilizing a priori information available as reference, constrained independent component analysis (cICA) or independent component analysis with reference (ICA-R) achieves some advantages over other methods. However, ICA-R is very time-consuming; moreover, it is very difficult to determine its threshold parameter, once the value is improperly chosen the algorithm will fail to converge. In order to overcome these drawbacks, a very simple blind source extraction method, whose optimization function is simply the closeness measure between the desired output and its corresponding reference in ICA-R, is proposed in this paper. Experiments with synthesized data and real-world electrocardiograph data confirm its validity and superiority.     

Preventive maintenance scheduling for repairable system with deterioration

Maintenance as an important part in manufacturing system can keep equipment in good condition. Many maintenance policies help to decrease the unexpected failures and reduce high operational cost such as conventional preventive maintenance. But these conventional preventive maintenance policies have the same time interval T that may easily neglect system’s reliability, because the system deteriorates with increased usage and age. Hence, this study has developed a reliability-centred sequential preventive maintenance model for monitored repairable deteriorating system. It is supposed that system’s reliability could be monitored continuously and perfectly, whenever it reaches the threshold R, the imperfect repair must be performed to restore the system. In this model, system’s failure rate function and operational cost are both considered by the effect of system’s corresponding condition, which helps to decide the optimal reliability threshold R and preventive maintenance cycle number. Finally, through case study, the simulation results show that the improved sequential preventive maintenance policy is more practical and efficient.