蓝牙4.2协议芯片BlueNRG-1的低功耗蓝牙通信设计

针对传统蓝牙通信系统设计中存在的电路设计复杂、功耗大、速率低和性价比低等问题,提出了一种基于蓝牙4.2协议的BlueNRG-1芯片蓝牙通信系统设计方案.首先,介绍了BlueNRG-1芯片的内部结构和功能;然后,进行了系统的硬件电路和控制程序的设计;最后,进行试验.试验的结果表明,该方案降低了功耗,简化了电路,具有体小便携、功耗低、性价比高、传输速率高和使用寿命长等优点.     

Multifunctional Superelastic Cellulose Nanofibrils Aerogel by Dual Ice-Templating Assembly

A superelastic aerogel with fast shape recovery performance from large compressive strain is highly desired for numerous applications such as thermal insulation in clothing, high-sensitive sensors, and oil contaminant removal. Fabrication of superelastic cellulose nanofibrils (CNF) aerogels is challenging as the CNF can assemble into non-elastic sheet-like cell walls. Here, a dual ice-templating assembly (DITA) strategy is proposed that can control the assembly of CNF into sub-micrometer fibers by extremely low temperature freezing (–196 °C), which can further assemble into an elastic aerogel with interconnected sub-micron fibers by freezer freezing (−20 °C) and freeze drying. The CNF aerogel from the DITA process demonstrates isotropic superelastic behavior that can recover from over 80% compressive strain along both longitudinal and cross-sectional directions, even in an extremely cold liquid nitrogen environment. The elastic CNF aerogel can be easily modified by chemical vapor deposition of organosilane, demonstrating superhydrophobicity (164° water contact angle), high liquid absorption (489 g g⁻¹ of chloroform absorption capacity), self-cleaning, thermal insulating (0.023 W (mK)⁻¹), and infrared shielding properties. This new DITA strategy provides a facile design of superelastic aerogels from bio-based nanomaterials, and the derived high performance multifunctional elastic aerogel is expected to be useful for a wide-range of applications.     

融合图特征的多机器人栅格地图拼接方法

现有的栅格地图拼接方法在地图重叠区域较小、地图特征较少、地图存在自相似性和非刚性形变的情况下匹配精度往往会大幅度下降甚至失配,提出了一种融合图特征的多机器人栅格地图拼接方法。提取待匹配栅格地图的ORB特征点并粗匹配,接下来建立ORB特征点之间的中值[K]近邻图;建立最优传输目标函数并融合ORB特征和图特征构建传输代价矩阵,同时建立增广节点筛选通过Sinkhorn算法求解最优匹配,RANSAC算法求解两张栅格地图之间的刚体变换,实现多机器人栅格地图的配准和拼接。通过实验验证了该方法具备较高的拼接精度,可应对重叠率低、特征不太明显的场景,展现出了较快的计算速度,并分析了相关参数对算法表现的影响。     

Low-thermal-budget Au-free ohmic contact to an ultrathin barrier AlGaN/GaN heterostructure utilizing a micro-patterned ohmic recess

A pre-ohmic micro-patterned recess process,is utilized to fabricate Ti/Al/Ti/TiN ohmic contact to an ultrathin-barrier(UTB) AlGaN/GaN heterostructure,featuring a significantly reduced ohmic contact resistivity of 0.56 Ω.mm at an alloy temperat-ure of 550 ℃.The sheet resistances increase with the temperature following a power law with the index of +2.58,while the spe-cific contact resistivity decreases with the temperature.The contact mechanism can be well described by thermionic field emis-sion (TFE).The extracted Schottky barrier height and electron concentration are 0.31 eV and 5.52 × 1018 cm-3,which suggests an intimate contact between ohmic metal and the UTB-AlGaN as well as GaN buffer.A good correlation between ohmic trans-fer length and the micro-pattern size is revealed,though in-depth investigation is needed.A preliminary CMOS-process-compat-ible metal-insulator-semiconductor high-mobility transistor (MIS-HEMT) was fabricated with the proposed Au-free ohmic con-tact technique.     

High-level synthesis for FPGAs: code optimization strategies for real-time image processing

High-level synthesis (HLS) is a potential solution to increase the productivity of FPGA-based real-time image processing development. It allows designers to reap the benefits of hardware implementation directly from the algorithm behaviors specified using C-like languages with high abstraction level. In order to close the performance gap between the manual and HLS-based FPGA designs, various code optimization forms are made available in today’s HLS tools. This paper proposes a HLS source code and directive manipulation strategy for real-time image processing by taking into account the applying order of different optimization forms. Experiment results demonstrate that our approach can improve more effectively the test implementations comparing to the other optimization strategies.     

Operator-Based Robust Nonlinear Control for SISO and MIMO Nonlinear Systems With PI Hysteresis

In this paper, operator based robust nonlinear control for single-input single-output (SISO) and multi-input multi-output (MIMO) nonlinear uncertain systems preceded by generalized Prandtl-Ishlinskii (PI) hysteresis is considered respectively. In detail, by using operator based robust right coprime factorization approach, the control system design structures including feedforward and feedback controllers for both SISO and MIMO nonlinear uncertain systems are given, respectively. In which, the controller design includes the information of PI hysteresis and its inverse, and some sufficient conditions for the controllers in both SISO and MIMO systems should be satisfied are also derived respectively. Based on the proposed conditions, influence from hysteresis is rejected, the systems are robustly stable and output tracking performance can be realized. Finally, the effectiveness of the proposed method is confirmed by numerical simulations.      

A tool for tracing network data plane via SDN/OpenFlow

SDN provides an approach to create desired network forwarding plane by programming applications. For a large-scale SDN network comprised of multiple domains and running multiple controller applications, it is difficult to measure and diagnose the problems of flow tables in data plane. Tracing the forwarding path of SDN is one of effective way for data plane state measurement. Previously proposed methods for debugging SDN were applied to a single administrative domain. There is less effort to trace the flow entries of the data plane in large-scale multi-domain SDN networks. In this paper, we propose a method of software defined data plane tracing in large-scale multi-domain SDN networks. Our method can trace forwarding paths, and get the matched flow entries and other customized trace information. We present the designs compatible with OpenFlow 1.0 and 1.3 switches. The performance and deployment effect are evaluated by simulation test and analysis. It shows that our method has better performance than traditional IP traceroute, and its deployment at about 20% of AS nodes can enable 70% of AS paths to be traceable.     

Some Issues on Core‐Annulus and Cluster Models of Circulating Fluidized Bed Reactors

The one‐dimensional cluster model and the core‐annulus model are examined based on existing correlations. The core‐annulus model is found to give reasonable agreement with ozone decomposition data when the effective interphase mass transfer rate constant is equal to about 0.1 1/s, which is one order smaller than the reported values based on gas tracer tests. The prediction from the core‐annulus model that the reactor performance decreases with increasing the riser diameter is found to be inconsistent with limited experimental data The one‐dimensional cluster model predicts that a riser reactor performs very close to the pseudo‐homogeneous plug flow reactor because of the high mass transfer rate between the cluster and the dilute phase. The improvement of model predictions lies in the better characterization of the cluster shape, size and the mass transfer rate between the cluster and the dilute phases.     

工业废料加固土的试验研究

利用炉渣和粉煤灰等废渣、并掺入适量水泥或石灰等胶凝剂来加固土壤，可以节约工程造价、改善环境。分别以水泥、石灰、水泥 石灰混合料加固由粉煤灰、粘土、细砂、淤泥．炉渣以不同配比组成的三种复合土，每种拌合物以相同的加水量分别制备3组试件．自然条件下养护3d．7d．28d后进行无侧限压强度试验、结果表明：A型复合土单掺水泥的加固效果最为显著，其早期和28d强度值均随水泥掺量的增加而显著提高；c型土则单掺石灰的效果最好．最佳掺量为15％；等量复掺“水泥 石灰”时．对B型土的加固效果最好，这说明掺入一定的水泥或石灰或同时加入水泥和石灰加固由粉煤灰，炉渣、软粘土、淤泥和细砂组成的复合土在技术上是可行的．     

磁稳定床反应器中己内酰胺加氢精制过程研究

对以非晶态合金（SRNA－4）为催化剂的磁稳定床已丙酰加氢精制过程进行了研究，研究了各种操作参数对反应结果的影响，考察了催化剂的稳定性，建立了反应器模型。实验结果表明，在磁稳定床反应器中对已丙酰胺水溶液加氢精制，可使已丙酰胺水溶液的PM值为100s提高到3000s以上，催化剂寿命1350h；与工业上搅拌釜工已丙酰胺加氢精制工艺相比，催化剂耗量可降低50％以上。