pH‐Activated Near‐Infrared Fluorescence Nanoprobe Imaging Tumors by Sensing the Acidic Microenvironment

Imaging tumors in their early stages is crucial to increase the surviving rate of cancer patients. Currently most fluorescence probes visualize the neoplasia by targeting the tumor‐associated receptor over‐expressed on the cancer cell membrane. However, the expression level of these receptors in vivo is hard to predict, which limits their clinical translation. Furthermore, the signal output of these receptor‐targeting probes usually stays at a high level, which leads to a strong background signal in normal tissue due to non‐specific binding. In contrast to receptors, characteristics of the tumor microenvironment – such as acidosis – are pervasive in almost all solid tumors and can be easily accessed. In this work, a novel biodegradable nanoprobe InNP1 that demonstrates pH‐activated near‐infrared (NIR) fluorescence in both human glioblastoma U87MG cancer cells in vitro and the subcutaneous U87MG tumor xenografts in vivo is developed. Bio‐distribution, in vivo optical imaging, and autoradiography studies demonstrate that the pH‐activated NIR fluorescence is the dominant factor responsible for the high tumor/normal tissue (T/N) ratio of InNP1 in vivo. Overall, the work provides a nanoprobe prototype to visualize the solid tumor in vivo with high sensitivity and minimal systemic toxicity by sensing the tumor acidic microenvironment.     

Hydrogen‐Bonding‐Assisted Intermolecular Charge Transfer: A New Strategy to Design Single‐Component White‐Light‐Emitting Materials

This study reveals the mechanism of the dual‐emission properties for asymmetrical diphenylsulfone and diphenylketone derivatives. A series of asymmetrical diphenylketone and diphenylsulfone derivatives with dual‐emission properties are designed and synthesized. By single crystal structure analyses, various photophysical studies, and 2D ¹H–¹H NOSEY NMR studies, the lower energy emission bands in the dual‐emission spectra are successfully assigned to hydrogen‐bonding‐assisted intermolecular charge transfer emission. The emission properties of these compounds can easily be tuned in both solid state and solution state by destroying or strengthening the intermolecular hydrogen bonding. In addition, thermally activated delayed fluorescence characteristics for the intermolecular charge transfer emissions are also observed. The control of the intermolecular and intramolecular charge transfers serves as the basis for the generation of the white‐light emission. For compound CPzPO, nearly pure white‐light emission with CIE coordinates of (0.31, 0.32) is easily achieved by precipitation from dichloromethane and hexane mixed solvent system. These results clearly give an insight into the dual‐emission properties and provide a rational strategy for the design and synthesis of single‐component white‐light‐emitting materials and mechanoresponsive light‐emitting materials.     

LTE系统中下行频域资源分配算法的研究

在LTE系统中,下行频选分配依据子信道质量选取最好的信道来传输业务,提高系统吞吐量。本文从无线资源分配角度出发,针对现有频选算法的不足,提出一种改进型频选与非频选结合分配算法,实现频选资源选取的最优化,同时在资源分配时将频选分配和非频选分配算法进行合并处理,通过比较频选UE度量值和非频选UE度量值来决定当前资源块组(resource block group,RBG)的分配方式。通过系统级仿真可知,在提高资源分配合理性的同时,可以提高系统整体吞吐量。     

单路反馈射频功放预失真线性化方法

该文基于记忆多项式模型,提出一种采用单路反馈的射频功放预失真线性化新方法,只需用正交解调后的IQ信号中的一路,就可完成对预失真器模型参数的获取。该方法可消除使用正交解调器所带来的增益和相位不平衡问题,且节省了一路反馈采样电路,在降低成本、简化设计的同时还能提高预失真线性化的性能。仿真和物理实验结果表明,该文提出的方法是正确的,能达到比较好的线性化效果。     

监测一氧化碳的无线传感器网络节点设计

为了监测空气环境,针对煤炭不完全燃烧产生的一氧化碳有害气体,提出一种无线传感器网络(WSN)-氧化碳远程监测节点的设计方案.设计了以低功耗片上系统型微处理器C8051F930为控制器,采用金属氧化物半导体在加热条件下和一氧化碳发生氧化还原反应时电阻值随气体浓度变化而变化为检测原理的一氧化碳传感器TGS2442对气体传感信号采集、调理、转换、数据处理,通过支持802.15.4通信协议的无线射频芯片Si4432收发数据,实 现了对一氧化碳排放情况的远程监控.     

一种基于人工蜂群优化的有序盲源抽取方法

提出了一种基于人工蜂群优化的盲源抽取方法,该方法首先根据源信号的高阶统计特性构造了用于估计分离向量的目标函数,然后通过人工蜂群算法优化其函数获得最佳分离向量,并达到逐次恢复源信号的目的。仿真实验结果表明,该方法不仅能依4阶累积量绝对值降序地实现源信号的盲分离,还能同时分离服从亚高斯分布的图像信号和超高斯分布的语音信号。     

CMP承载器的初步研究

在CMP中,由于抛光垫在与其接触的晶圆边缘产生异常压力点,以及转台和承载器旋转的线速度之差在边缘处较其他点大得多,从而导致了晶圆边缘效应的产生。阐述了承载器在CMP中的作用,详细分析了边缘效应产生的原因和克服的方法。在承载器上采用与晶圆保持适当间隙的保持环结构,对保持环施加适当的压力,使保持环和晶圆位于同一抛光平面上;针对旋转式CMP设备固有的线速度之差导致片内非均匀性增大的问题,对200mm晶圆划分两区域进行微压力补偿,同时详细说明了压力补偿气路的设计和实现的功能,指出今后多区域微压力补偿将采用矩阵控制技术。     

Enhancing Representation of Deep Features for Sensor-Based Activity Recognition

Sensor-based activity recognition (AR) depends on effective feature representation and classification. However, many recent studies focus on recognition methods, but largely ignore feature representation. Benefitting from the success of Convolutional Neural Networks (CNN) in feature extraction, we propose to improve the feature representation of activities. Specifically, we use a reversed CNN to generate the significant data based on the original features and combine the raw training data with significant data to obtain to enhanced training data. The proposed method can not only train better feature extractors but also help better understand the abstract features of sensor-based activity data. To demonstrate the effectiveness of our proposed method, we conduct comparative experiments with CNN Classifier and CNN-LSTM Classifier on five public datasets, namely the UCIHAR, UniMiB SHAR, OPPORTUNITY, WISDM, and PAMAP2. In addition, we evaluate our proposed method in comparison with traditional methods such as Decision Tree, Multi-layer Perceptron, Extremely randomized trees, Random Forest, and k-Nearest Neighbour on a specific dataset, WISDM. The results show our proposed method consistently outperforms the state-of-the-art methods.

     

弹尾定心部全跳动的自动化检测技术

针对炮弹装填时炮膛的磨损和底火与击针对正问题,介绍一种炮弹弹尾定心部全跳动误差值的自动检测技术。该检测装置主要由自动升降机构、传动机构、轴向定位机构、压紧机构和检测机构等组成。将自动检测装置直接固定在弹体输送线架体上,进行弹尾定心部全跳动误差值检测时,弹体不必下线,可直接在弹体输送线上的检测工位进行,弹体的托起、轴向及径向定位和压紧、旋转和检测等所有动作均自动完成,只有百分表上的跳动值检测结果由人工读取。生产实践结果表明：该技术能提高炮弹装配生产的安全和自动化程度,减轻操作人员的劳动强度,提高生产效率。     

一种海上无线信道小尺度衰落特性的测试及分析方法

提供了一种海上无线信道小尺度衰落特性的测试及分析方法,在复杂海况环境下,无线信道出现了长多径、正幅度副径、第二多径群等特殊多径情况。该测试结果为根据特殊的信道特性对系统参数和算法等进行优化提供了技术基础。