阜阳市儿童预防接种信息系统数字化预防接种门诊试点效果评价

目的：了解依托儿童预防接种信息化系统建立的数字化接种门诊对预防接种工作流程中发挥的效果。方法：采用现况调查和自身前后对照的方法,收集和分析资料。结果：数字化接种门诊实施前后接种流程中各个阶段,差异有统计学意义（t=14.611、t =6.964、t =12.704、t =10.418、t =28.673、t =31.138,P＜0.05）,数字化后的患儿家属满意度高于数字化前,差异有统计学意义（χ2=80.954、χ2=103.156、χ2=4.536、χ2=64.737,P＜0.05）。结论：数字化预防接种门诊能够明显缩短疫苗接种效率并提高儿童家长的满意度。     

Salt‐Assisted Growth of P‐type Cu9S5 Nanoflakes for P‐N Heterojunction Photodetectors with High Responsivity

P‐n junctions based on two dimensional (2D) van der Waals (vdW) heterostructure are one of the most promising alternatives in next‐generation electronics and optoelectronics. By choosing different 2D transition metal dichalcogenides (TMDCs), the p‐n junctions have tailored energy band alignments and exhibit superior performance as photodetectors. The p‐n diodes working at reverse bias commonly have high detectivity due to suppressed dark current but suffer from low responsivity resulting from small quantum efficiency. Greater build‐in electric field in the depletion layer can improve the quantum efficiency by reducing recombination of charge carriers. Herein, Cu₉S₅, a novel p‐type semiconductor with direct bandgap and high optical absorption coefficient, is synthesized by salt‐assisted chemical vapor deposition (CVD) method. The high density of holes in Cu₉S₅ endows the constructed p‐n junction, Cu₉S₅/MoS₂, with strong build‐in electric field according to Anderson heterojunction model. Consequently, the Cu₉S₅/MoS₂ p‐n heterojunction has low dark current at reverse bias and high photoresponse under illumination due to the efficient charge separation. The Cu₉S₅/MoS₂ photodetector exhibits good photodetectivity of 1.6 × 10¹² Jones and photoresponsivity of 76 A W^?1 under illumination. This study demonstrates Cu₉S₅ as a promising p‐type semiconductor for high‐performance p‐n heterojunction diodes.     

光电成像干扰图像质量评估

干扰图像质量评估是光电成像干扰的一个难点问题,评估结果应与人类主观视觉感受相匹配.该文分析了光电干扰图像的特点和普通图像质量评估方法的局限性.然后,依据人眼主观视觉特性,利用四叉树数据结构划分方法,将干扰图像划分为边缘部分和非边缘部分.对于边缘部分,构造边缘比较函数评估干扰前后图像边缘变化的情况;对于非边缘部分,引入基...     

Humidity‐Resistive Triboelectric Nanogenerator Fabricated Using Metal Organic Framework Composite

With its light weight, low cost, and high efficiency, the triboelectric nanogenerator (TENG) is considered a sustainable and renewable energy source for self‐powered or mobile electronics. However, the performance of TENG is seriously affected by humid environment. Here, for the first time, TENG with improved performance under high humidity is obtained by adding HKUST‐1 (Cu₃(BTC)₂, (BTC = 1,3,5‐benzenetricarboxylate or trimesate)) to polydimethylsiloxane (PDMS) matrix. At 10% relative humidity (RH), an effective power (3.17 mW) of the composite TENG based on 5 wt% HKUST‐1 is obtained at a load resistance of 10 MΩ, which is 13 times higher than that of the TENG based on pure PDMS. More importantly, the performance of composite TENG remains constant or becomes higher even under high humidity, while that of conventional TENG dramatically decreases at the same condition. The excellent humidity‐resistive performance comes from the remarkably enhanced electron‐trapping capacity and dielectric constant due to the absorption of HKUST‐1 to water molecules. This work not only demonstrates that a metal organic framework is an effective filler to improve the performance of TENG but also provides a novel strategy to obtain high output properties under highly humid environments by increasing the electron‐trapping capacity and dielectric constant.     

Robust three, dimensional surface contouring method with digital holography

Nowadays digital holography (DH) is applied to thethree di mensional surface contouring,duetoits non-con-tact advantage[1-5].Moreover ,when a lensless Fouriertransform arrangement with the short-coherence lightsourceis employed in a DHrecording system,not…     

Excellent Field‐Emission Performances of Neodymium Hexaboride (NdB6) Nanoneedles with Ultra‐Low Work Functions

High‐quality NdB₆ nanostructures with a low work function are successfully synthesized via an one‐step catalyst‐free chemical vapor deposition process. Field emission properties of these nanostructures (curve nanowires, short‐straight nanorods, long‐straight nanowires, and nanoneedles) are systematically investigated and found to be strongly affected by the tip morphologies and temperatures. The nanoneedles with sharp tips demonstrate the lowest turn‐on (2.71 V/μm) and threshold (3.60 V/μm) electric fields, as well as a high current density (5.37 mA/cm²) at a field of 4.32 V/μm in comparision with other nanostructures. Furthermore, with an increase in temperature from room temperature to 623 K, the turn‐on field of the nanoneedles decreases from 2.71 to 1.76 V/μm, and the threshold field decreases from 3.60 to 2.57 V/μm. Such excellent performances make NdB₆ nanomaterials promising candidates for application in flat panel displays and nanoelectronics building blocks.     

Research on the memory order of the power‐line communication channel

As a memory channel, power‐line communication (PLC) channel can be modeled by the finite states Morkov model. The memory order in an finite states Morkov model is a key parameter, which is not solved in PLC systems yet. In the paper, the mutual information is used as a measure of the dependence between the different symbols, treated as the received scalar network analyzer, or amplitude of the current channel symbol or that of previous symbols. The joint distribution probabilities of the envelopes in PLC systems are computed based on the multi‐path channel model, which is commonly used in PLC. With the first‐order Markovian assumption, we confirm that given the information of the symbol immediately preceding the current one, any other previous symbol is independent of the current one in PLC systems. The field test is also performed to model the received OFDM signals with the help of autoregressive model. The results show that the first‐order autoregressive model is enough to model the fading channel in PLC systems, which means the amount of uncertainty remaining in the current symbol should be negligible, given the information corresponding to the immediately preceding one. Copyright © 2014 John Wiley & Sons, Ltd.     

6061-T6铝合金高速高功率CO_2激光填丝焊接性的研究

为实现6061-T6铝合金薄板的高速高功率CO2激光填丝焊接,选用了ER4043,ER5356两种焊丝进行了焊接性试验。利用鱼骨状试样对两种焊丝的激光焊接铝合金6061-T6的热裂纹敏感性进行了分析;利用金相显微镜、扫描电镜、显微硬度计以及万能材料试验机分析了焊接接头的组织与性能。研究结果表明,与填充ER5356焊丝相比,填充ER4043焊丝的焊接接头热裂纹敏感性较低,焊接速度可达6 m/min。焊缝主要是柱状晶、等轴晶及少量树枝晶,显微硬度在60~80 HV,拉伸强度可达240~262 MPa,弯曲性能良好。     

数据中继卫星系统的数据传输协议研究

首先介绍了美国中继卫星系统的基本概况,给出了其系统组成框图和连接关系,依据中继卫星系统数据传输任务和数据传输需求,并在分析比较ESA和CCSDS的星地数据传输管理协议的基础上,提出了使用CCSDS组织的AOS建议书作为数据中继卫星系统的数据传输协议建议,给出了数据传输帧的定义和初步操作建议。