EBoot下USB下载功能的实现

在基于WinCE构建的嵌入式系统中EBoot下载功能尤为重要。EBoot原始方案中具有网口与串口下载的实现而缺乏通过USB进行下载的功能。在USB功能单元层次上提出一种数据传输协议,并基于此协议在SEP5010嵌入式平台上实现EBoot下的USB数据传输,从而实现EBoot对USB下载功能的支持。实验结果表明,该方案可以达到799 kB/s的数据平均传输速度,在不增加额外电路的前提下实现了SEP5010平台上EBoot的USB数据下载功能。     

Estimation of time-varying connectivity patterns through the use of an adaptive directed transfer function

Frequency-derived identification of the propagation of information between brain regions has quickly become a popular area in the neurosciences. Of the various techniques used to study the propagation of activation within the central nervous system, the directed transfer function (DTF) has been well used to explore the functional connectivity during a variety of brain states and pathological conditions. However, the DTF method assumes the stationarity of the neural electrical signals and the time invariance of the connectivity among different channels over the investigated time window. Such assumptions may not be valid in the abnormal brain signals such as seizures and interictal spikes in epilepsy patients. In the present study, we have developed an adaptive DTF (ADTF) method through the use of a multivariate adaptive autoregressive model to study the time-variant propagation of seizures and interictal spikes in simulated electrocorticogram (ECoG) networks. The time-variant connectivity reconstruction is achieved by the Kalman filter algorithm, which can incorporate time-varying state equations. We study the performance of the proposed method through simulations with various propagation models using either sample seizures or interictal spikes as the source waveform. The present results suggest that the new ADTF method correctly captures the temporal dynamics of the propagation models, while the DTF method cannot, and even returns erroneous results in some cases. The present ADTF method was tested in real epileptiform ECoG data from an epilepsy patient, and the ADTF results are consistent with the clinical assessments performed by neurologists.      

Electrophosphorescent Polyfluorenes Containing Osmium Complexes in the Conjugated Backbone

Electrophosphorescent copolymers have been synthesized by covalent bonding of a red‐emitting osmium complex Os(bpftz), which contains two 3‐trifluoromethyl‐5‐(4‐tert‐butyl‐2‐pyridyl)triazolate (bpftz) cyclometalated ligands, into the backbone of a bipolar polyfluorene (PF) copolymer. Employing these copolymers, a highly efficient red polymer light‐emitting diode has been realised that has an external quantum efficiency of 18.0%, a maximum brightness of 38 000 cd m^?2, and an emission centered at 618 nm. In addition, after incorporating appropriate amounts of green‐emitting benzothiadiazole (BT) and the aforementioned Os(bpftz) into the bipolar PF, an efficient white‐light electroluminescent polymer is obtained that displays simultaneous blue, green, and red emissions.     

超临界干燥多孔硅的光致发光

对两种不同条件下制备的多孔硅进行了红外透射光谱测量，并对超临界干燥和自然干燥条件下的光致发光光谱进行了对比测量。用高分辨率透射电镜对其结构进行了观察，研究表明多孔硅的发光机理与其制备条件有关。     

Real time frequency domain fiberoptic temperature sensor

The excited state phosphorescence lifetime of alexandrite crystals is used to monitor temperature in the physiological range from 15-45°C with precision and accuracy of 0.2°C. A 500-μm cubic alexandrite crystal bounded to the distal end of an optical fiber of similar core dimensions is excited with pulsed Ne-He laser light. This apparatus uses a sampler for data acquisition and frequency domain methods for data fitting. The instrument amplifies the AC components of the detector output and band limits the signal to 12.5 kHz. The fundamental frequency of the excitation is set to 195.13 Hz to obtain 64 harmonics. This band limited signal is sampled and averaged over few hundred cycles in the time domain. The frequency domain representation of the data is obtained by employing fast Fourier transform algorithms. The phase delay and the modulation ratio of each sampled harmonic are then computed. Five to 50 values of the phase and modulations are averaged before computing the sensor lifetime. The instrument is capable of measuring precise and accurate excited state lifetimes from subpicowatt luminescent signals in plastic optical fibers. A least squares fit yields the lifetimes of single exponentials. A component of zero lifetime is introduced to account for the backscatter excitation seen by the photodetector leaking through optical interference filters. The phosphorescence lifetimes measured reproducibly to about three parts in a thousand are used to monitor physiological temperature. Temperatures are computed employing empirical polynomials. The system drift is negligible over 15 h of continuous operation. The instrumentation and methods allow 1.3-s update times and 30-s full response times     

Wearable,Healable, and Adhesive Epidermal Sensors Assembled from Mussel‐Inspired Conductive Hybrid Hydrogel Framework

Healable, adhesive, wearable, and soft human‐motion sensors for ultrasensitive human–machine interaction and healthcare monitoring are successfully assembled from conductive and human‐friendly hybrid hydrogels with reliable self‐healing capability and robust self‐adhesiveness. The conductive, healable, and self‐adhesive hybrid network hydrogels are prepared from the delicate conformal coating of conductive functionalized single‐wall carbon nanotube (FSWCNT) networks by dynamic supramolecular cross‐linking among FSWCNT, biocompatible polyvinyl alcohol, and polydopamine. They exhibit fast self‐healing ability (within 2 s), high self‐healing efficiency (99%), and robust adhesiveness, and can be assembled as healable, adhesive, and soft human‐motion sensors with tunable conducting channels of pores for ions and framework for electrons for real time and accurate detection of both large‐scale and tiny human activities (including bending and relaxing of fingers, walking, chewing, and pulse). Furthermore, the soft human‐motion sensors can be enabled to wirelessly monitor the human activities by coupling to a wireless transmitter. Additionally, the in vitro cytotoxicity results suggest that the hydrogels show no cytotoxicity and can facilitate cell attachment and proliferation. Thus, the healable, adhesive, wearable, and soft human‐motion sensors have promising potential in various wearable, wireless, and soft electronics for human–machine interfaces, human activity monitoring, personal healthcare diagnosis, and therapy.     

火箭俯仰角控制的H∞混合灵敏度设计

从滤波器设计出发提出了一种实用的构造挠性模型摄动界函数的方法,并分析了鲁棒性能加权函数的频带特性、带宽和增益与系统性能之间的关系.以火箭俯仰角控制为例详细分析了在使用加性不确定性描述系统挠性摄动和考虑扰动频谱的情况下如何通过H∞设计混合灵敏度控制器来获得系统的鲁棒稳定性和相应的鲁棒性能.     

3D Graphene Films Enable Simultaneously High Sensitivity and Large Stretchability for Strain Sensors

Integration of 2D membranes into 3D macroscopic structures is essential to overcome the intrinsically low stretchability of graphene for the applications in flexible and wearable electronics. Herein, the synthesis of 3D graphene films (3D‐GFs) using chemical vapor deposition (CVD) is reported, in which a porous copper foil (PCF) is chosen as a template in the atmospheric‐pressure CVD preparation. When the 3D‐GF prepared at 1000 °C (noted as 3D‐GF‐1000) is transferred onto a polydimethylsiloxane (PDMS) membrane, the obtained 3D‐GF‐1000/PDMS hybrid film shows an electrical conductivity of 11.6 S cm^?1 with good flexibility, indicated by small relative resistance changes (ΔR/R₀) of 2.67 and 0.36 under a tensile strain of 50% and a bending radius of 1.6 mm, respectively. When the CVD temperature is reduced to 900 °C (generating a sample noted as 3D‐GF‐900), the 3D‐GF‐900/PDMS hybrid film exhibits an excellent strain‐sensing performance with a workable strain range of up to 187% and simultaneously a gauge factor of up to ≈1500. The 3D‐GF‐900/PDMS also shows a remarkable durability in resistance in repeated 5000 stretching‐releasing cycles. Kinetics studies show that the response of ΔR/R₀ upon strain is related to the graphitization and conductivity of 3D‐GF which are sensitive to the CVD preparation temperature.     

宽带交换—ATM异军突起

异步转移模式（ＡＴＭ）正在以前所未有的速度向前发展，ＡＴＭ交换成为未来宽带ＩＳＤＮ的关键。本文分析了ＡＴＭ的产生背景，介绍了其基本概念和原理，讨论了ＡＴＭ网络的演进和应用，并概述了它在国内外的发展。     

石英晶振真空传感器及真空计的研制

本文研究了音叉型石英晶体谐振器的谐振阻抗与周围气压的关系，设计了一种全新的自稳幅自跟踪晶体振荡电路和精密动态阻抗测试电路，以测量石英晶振的谐振阻抗。实验测得，当晶振周围气体压强从１０－２Ｐａ上升到大气压时其谐振阻抗相对变化也几乎以相同数量级单调增加，阻抗随气压变化关系与理论分析和国外文献报道一致。利用石英晶振的气压敏感性，本文研制了一种新型的石英晶体真空计，量程从０．１Ｐａ到２×１０５Ｐａ，全量程内无须进行量程切换，各点测量误差小于１２％。