A Universal Platform for Macromolecular Deliveryinto Cells Using Gold Nanoparticle Layers via the Photoporation Effect

Although promising, it is challenging to develop a simple and universal method for the high‐efficiency delivery of biomacromolecules into diverse cells. Here, a universal delivery platform based on gold nanoparticle layer (GNPL) surfaces is proposed. Upon laser irradiation, GNPL surfaces show such good photothermal properties that absorption of the laser energy causes a rapid increase in surface temperature, leading to enhanced membrane permeability of the cultured cells and the diffusion of macromolecules into the cytosol from the surrounding medium. The high‐efficiency delivery of different macromolecules such as dextran and plasmid DNA into different cell types is achieved, including hard‐to‐transfect mouse embryonic fibroblasts (mEFs) and human umbilical vein endothelial cells (HUVECs), while cell viability is well maintained under optimized irradiation conditions. The platform vastly outperforms the leading commercial reagent, Lipofectamine 2000, especially in transfecting hard‐to‐transfect cell lines (plasmid transfection efficiency: ≈53% vs ≈19% for mEFs and ≈44% vs ≈8% for HUVECs). Importantly, as the gold nanoparticles (GNPs) constituting the GNPL are firmly immobilized together, the potential cytotoxicity caused by endocytosis of GNPs is effectively avoided. This platform is reliable, efficient, and cost‐effective with high‐throughput and broad applicability across different cell types, opening up an innovative avenue for high‐efficiency intracellular delivery.     

Quality of Protection in Cloud-Assisted Cognitive Machine-to-Machine Communications for Industrial Systems

Cloud-assisted cognitive machine-to-machine co- mmunications (CM2M) is a new paradigm to improve the mobile services, which have drawn considerable attention in industry and academia. In this paper, we consider the quality of protection (QoP) of information transmission in cloud-assisted CM2M communications. In such an environment, the secondary M2M system intends to share the primary spectrum on the condition that the secondary transmitter (ST) has to relay the primary message. However, the ST is a low-energy device which adopts the energy harvesting technique to power itself. In particular, we focus on secure information transmission for the primary system when the secondary users (SUs) are the potential eavesdroppers. We aim to jointly design power splitting and secure beamforming to maximize the secondary M2M system data rate subject to the secrecy requirement of the primary system and the ST power constraint. To solve this non-convex problem, we propose a computationally efficient two-stage optimization approach. Simulation results demonstrate that our proposed scheme achieves a significant transmission rate of the secondary M2M system while provides a high secrecy rate for the primary system compared to the scheme without energy harvesting.     

双掺杂多晶Si栅MOSFET的截止频率研究

在前期对双掺杂多晶Si栅(DDPG)LDMOSFET的电场、阈值电压、电容等特性所作分析的基础上,仍然采用双掺杂多晶Si栅结构,以低掺杂漏/源MOS(LDDMOS)为基础,重点研究了DDPG-LDDMOSFET的截止频率特性.通过MEDICI软件,模拟了栅长、栅氧化层厚度、源漏区结深、衬底掺杂浓度以及温度等关键参数对器件截止频率的影响,并与相同条件下P型单掺杂多晶Si栅(p-SDPG)MOSFET的频率特性进行了比较.仿真结果发现,在栅长90 nm、栅氧厚度2 nm,栅极P,n掺杂浓度均为5×1019cm-3条件下,截止频率由78.74 GHz提高到106.92 GHz,幅度高达35.8%.此结构很好地改善了MOSFET的频率性能,得出的结论对于结构的设计制作和性能优化具有一定的指导作用,在射频领域有很好的应用前景.     

基于FPGA的实时红外图像处理方法研究

随着计算机、集成电路等技术的飞速发展,红外图像处理无论在算法、结构上,还是在应用以及普及程度上都取得了长足的进展。本文在深入分析各种数字图像处理方法的基础上,采用了一种新的中值算法对传统红外图像处理方法进行了改进,有效地改善了数据的处理结果并明显降低了系统逻辑资源的占用。此外,还通过FPGA板卡对本算法其进行验证。实验结果表明,本系统设计的算法能够很好地完成大容量数据流的实时处理,达到了预期的设计目标。     

基于机器视觉技术的智能停车管理系统的研究

基于机器视觉技术的智能停车管理系统的研究是为了解决城市停车场激增、停车管理效率低下而涉及的一种智能交通系统的应用发展领域。现提出了一种由车辆检测模块、车牌识别模块、车位查询模块及车辆跟踪模块所构成的智能停车场管理系统,并对其中的车牌定位检测及识别以及车位查询模块进行了相应测试,结果较为合理。     

基于左手介质的贴片天线技术研究

介绍和分析了左手介质的构造原理和方法,通过对加载左手介质材料的贴片天线的研究,来说明左手介质天线的一些优异特性。仿真和实测结果表明,通过加载左手介质材料,普通贴片天线会产生新的特性,如工作频率的降低、天线增益的提高、方向性的增强等。而且,天线的物理尺寸能得到很大的减小,这就为高增益、高带宽的小型化贴片天线设计提供了新的方法和思路。     

The Influence of Film Morphology in High‐Mobility Small‐Molecule:Polymer Blend Organic Transistors

Organic field‐effect transistors (OFETs) based upon blends of small molecular semiconductors and polymers show promise for high performance organic electronics applications. Here the charge transport characteristics of high mobility p‐channel organic transistors based on 2,8‐difluoro‐5,11‐bis(triethylsilylethynyl) anthradithiophene:poly(triarylamine) blend films are investigated. By simple alteration of the film processing conditions two distinct film microstructures can be obtained: one characterized by small spherulitic grains (SG) and one by large grains (LG). Charge transport measurements reveal thermally activated hole transport in both SG and LG film microstructures with two distinct temperature regimes. For temperatures >115 K, gate voltage dependent activation energies (E_A) in the range of 25–60 meV are derived. At temperatures <115 K, the activation energies are smaller and typically in the range 5–30 meV. For both film microstructures hole transport appears to be dominated by trapping at the grain boundaries. Estimates of the trap densities suggests that LG films with fewer grain boundaries are characterized by a reduced number of traps that are less energetically disordered but deeper in energy than for small SG films. The effects of source and drain electrode treatment with self‐assembled monolayers (SAMs) on current injection is also investigated. Fluorinated thiol SAMs were found to alter the work function of gold electrodes by up to ～1 eV leading to a lower contact resistance. However, charge transport analysis suggests that electrode work function is not the only parameter to consider for efficient charge injection.     

Controlled Synthesis of Fe<Subscript>3</Subscript>O<Subscript>4</Subscript>/Ag Core–Shell Composite Nanoparticles with High Electrical Conductivity

The presented method provides an easy processing route to synthesize Fe₃O₄/Ag core–shell composite nanoparticles. Their structures were characterized by x-ray diffraction and transmission electron microscopy. The average size of the Fe₃O₄ core and Ag shell was about 32.0 nm and 5.0 nm (or 28.0 nm), respectively. Furthermore, magnetic measurements showed that the composite nanoparticles exhibited typical superparamagnetic behavior, specific saturation magnetization of ca. 24.0 emu/g, and intrinsic coercivity of 106.0 Oe. At the same time, high conductivity (64.7 S/cm) of the composite nanoparticles was also observed. This method provides an opportunity to synthesize other core–shell (Fe₃O₄) nanoparticles in a single step.     

某型交流变流机测试系统的设计

介绍了采用PX I总线的自动测试系统设计,硬件部分的组成和设计方法。软件部分采用面向对象、可视化设计的快速应用开发软件平台LabVIEW完成编辑、编译、连接、调试等开发。通过对某交流变流机进行测试,结果表明该系统测试精确度高,性能稳定可靠,操作简单,达到了设计要求。