纳米铜粉的制备——从PCB碱性蚀刻废液回收方法研究

利用碱性蚀刻废液通过化学还原的方法制备纳米铜粉。在碱性条件下用NaBH4作还原剂;表面分散剂和保护剂用聚乙烯比咯烷酮（PVP）、十六烷基三甲基溴化铵（CTAB）;研究结果表明,用碱性蚀刻废液制备纳米铜最佳的条件为：反应温度60℃,反应时间60min,PVP与CTAB的用量为1：5,制备出来的纳米铜粉为单质铜,颗粒粒径在100nm以内。     

分散处理及其相关技术

分散处理及其相关技术崔振远杨莉（河南省计算中心，郑州，４５０００３）１．前言分散处理技术在国际上有近２０年的发展历史，但人们对分散处理的研究仍持续不断，出现了越来越活跃的趋势。所谓分散处理，简单地讲是在具有多台处理器的计算机系统上，把分散在系统内的各...     

ADI推出最高性能BIackfin处理器

ADI最近推出一系列双核，IGHz处理能力的Blackfin处理器。ADSP—BF608和ADSP—BF609针对嵌入式视觉应用进行了优化，并均配备一个称为“流水线视觉处理器（PVP）”的高性能视频分析加速器。PVP由一组可配置的处理模块构成，     

关于（k,n）门通信密钥分散保管系统的讨论

本文提出了几种实现Ｓｈａｍｉｒ（１）提出的（ｋ，ｎ）门通信密钥分散保管系统的方法。这些方法克服了以往许多实现方法的一个共同缺点。     

基于灰度值评估法制备纳米CeO2胶体射流抛光液

纳米胶体射流是抛光加工半导体材料的新型工艺方法,其中射流抛光液的分散稳定性对抛光效果有较大影响.以直径为10 nm的CeO2为磨料,选取乙醇体积分数、聚乙烯吡络烷酮(PVP)质量分数和抛光液pH值为实验因素,利用图像灰度值法表征抛光液的分散稳定性,分析抛光液各组成参数对其分散稳定性的影响规律.利用Box-Behnken响应面法对纳米CeO2胶体抛光液的分散稳定性条件进行优化.研究结果表明,纳米CeO2胶体抛光液的最优分散条件为乙醇体积分数61％、PVP质量分数3％、抛光液pH值为10.在此最优条件下,制备的纳米胶体射流抛光液图像的灰度值为183,与响应面模型预测值非常吻合,且抛光液的分散性能良好且悬浮稳定.     

通信局(站)的接地与防雷

论述了分散接地与联合接地系统在防雷作用上的差异，归纳出通信局（站）在防雷与接地方面的若干原则。     

碳纳米管分散形态的电镜研究

未经处理的碳纳米管常呈现团聚形态。然而，团聚形态对进一步深入研究碳纳米管的性能与应用造成了很大的局限．所以，碳纳米管的有效分散至关重要。现在国内虽已对碳纳米管的分散进行了一定的探索，但却未能对分散务件进行定量标定。本文采取超声波振荡的方法进行分散，并细致、深入地探讨了不同分散务件对碳纳米管分散形态的影响，从而说明选用适当的碳纳米管原料、延长超声振荡时间以及降低悬浮液浓度都将有利于碳纳米管的充分分散。     

MIMO—MC—CDMA系统中信道估计算法的比轼

无线通信系统中最常用的就是使用导频来获得初始的信道响应,信道估计的目的就是通过导频序列来获得每个子信道上的信道状态信息（CSI）。但是对于何种场合要运用何种导频方式并没有具体的文章描述清楚,文中给出了MIMO—MC—CDMA系统中常用的3种信道估计算法,分别是基于分散导频（梳状导频）、正交导频、分组导频（块状导频）。通过分析这三种信道估计方法,得出结论。     

面向视频监控及通用信号处理的高性能Blackfin处理器

ADSP-BF60x系列处理器具有1GHZ内核性能和新的专用视觉加速器，支持将多功能分析技术广泛运用于嵌入式视觉应用。ADSP—BF608和ADSP-BF609针对嵌入式视觉应用进行了优化，并均配备一个称为“流水线视觉处理器（PVP）”的高性能视频分析加速器。PVP由一组可配置的处理模块构成，设计用于加速多达5个并行图像算法，从而实现极高的分析性能。     

乡镇有线电视建设中应注意的几个问题

乡镇有线电视建设由于用户分散，入户率不高（当地农村通常低于50％），有线电视用户分配方式与城市有较大的差别，因而处理一些技术问题也有不同，下面谈谈乡镇有线电视建设中须注意的几个问题。     

二硫化钼纳米薄片分散液的剥离制备

文中采用液相超声剥离粉末二硫化钼制备了纳米薄片分散液,通过紫外可见吸收光谱测定分散液的浓度,并探索了超声功率、超声时间以及二硫化钼初始浓度对纳米薄片分散液浓度的影响。实验结果表明,当超声功率为350 W,超声时间为48 h,二硫化钼初始浓度为10 mg/mL时,所制备的纳米薄片分散液浓度可达0.16 mg/mL。在剥离过程中加入聚乙烯吡咯烷酮,可以有效避免由于纳米薄片自身团聚而导致的分散液稳定性差的问题,所得到的二硫化钼纳米薄片分散液可稳定存放超过两个月;同时,PVP的加入可将二硫化钼纳米薄片分散液浓度提高至0.42 mg/mL。     

LED人工天窗瑞利散射材料的稳定性及光学性能研究

以纳米二氧化钛(nano-TiO2)为原料,选取六偏磷酸钠(SHMP)、曲拉通X-100(Tritor-X-100)、聚乙二醇(PEG)400、十二烷基硫酸钠(SDS)、十二烷基苯磺酸钠(SDBS)和十六烷基三甲基溴化铵(CTAB)做分散剂,采用超声手段在去离子水中制备得到nano-TiO2分散液。通过UV-Vis分光光度计测量样品的吸光度,分析了超声时间、分散剂种类与浓度对样品稳定性的影响,并对样品的光学性能进行检测。研究结果表明:加入SHMP,超声处理35min可获得吸光度维持在0.1左右的稳定nano-TiO2分散液,且在LED光源(CCT=10 000K)照射下,可以实现模拟天空光照射环境的瑞利散射效果。     

The Synergistic Effect of Prussian‐Blue‐Grafted Carbon Nanotube/Poly(4‐vinylpyridine) Composites for Amperometric Sensing

Because of its high activity and selectivity toward the reduction of hydrogen peroxide and oxygen, Prussian blue (PB) is usually considered as an “artificial enzyme peroxidase” and has been extensively used in the construction of electrochemical biosensors. In this study, we report on the construction of amperometric biosensors via grafting PB nanoparticles on the polymeric matrix of multiwalled carbon nanotubes (MWCNTs) and poly(4‐vinylpyridine) (PVP). The MWCNT/PVP/PB composite films were synthesized by casting films of MWCNTs wrapped with PVP on gold electrodes followed by electrochemical deposition of PB on the MWCNT/PVP matrix. The electrode modified with the MWCNT/PVP/PB composite film shows prominent electrocatalytic activity toward the reduction of hydrogen peroxide, which can be explained by the remarkable synergistic effect of the MWCNTs and PB. Therefore, fast amperometric response of this sensor to hydrogen peroxide was observed with a detection sensitivity of 1.3 μA μM ^–1 of H₂O₂ per square centimeter area and a detection limit of 25 nM . These results are much better than those reported for PB‐based amperometric sensors. In addition, a glucose biosensor fabricated by casting an additional glucose oxidase (GOD) containing Nafion film above the MWCNT/PVP/PB composite film shows promise for the sensitive and fast detection of glucose. The observed high stability, high sensitivity, and high reproducibility of the MWCNT/PVP/PB composite films make them promising for the reliable and durable detection of hydrogen peroxide and glucose.     

Room‐Temperature Phosphorescence From Films of Isolated Water‐Soluble Conjugated Polymers in Hydrogen‐Bonded Matrices

It is well known that luminescent conjugated polymers suffer serious loss of photoluminescence quantum yield (PLQY) in the solid state compared to dilute solution. This is due to efficient exciton migration in the solid, which enables the excitons to readily find low energy quenching sites. Here a new method to fabricate solid films with densely packed non‐interacting luminescent polymer chains, which yield very high PLQY and more astonishingly room temperature phosphorescence, is reported. Using water‐soluble conjugated polymers (WSCP) and polymeric surfactants such as poly(vinyl alcohol) (PVA) and poly(vinyl‐pyrrolidone) (PVP), films at 1:1 wt% or higher WSCP are produced and show room temperature phosphorescence; such behavior has never been observed before and clearly shows the very high degree of chain isolation that can be achieved in these hosts. The PVA or PVP not only breaks up WSCP aggregates in solution as an effective surfactant, PVA‐PVA or PVP‐PVP hydrogen bond formation upon drying locks in the isolation of the WSCP, avoiding segregation and yielding long time stability to these polymer/polymer nanomixtures. The method is found to work with a wide variety of WSCPs.     

二硫化钼催化析氢电极的构筑及其性能研究

针对目前MoS₂作为析氢催化剂时存在的活性位点数目少且材料导电性能差等问题,文中通过液相超声剥离法以及离心处理制备得到MoS₂/PVP分散液。PVP的辅助剥离作用使得剥离得到的MoS₂纳米片尺寸大幅减小,提高了MoS₂催化析氢活性位点的丰度;MoS₂在PVP辅助剥离过程中发生了2H相到1T相的转变,同样增强了催化析氢活性。文中选用含有导电铜层的PI基片作为电极基底,利用喷墨印刷技术将MoS₂/PVP催化剂固载于导电基底上制得催化析氢电极。该电极在10 mA·cm ^-2处的过电位为77 mV,Tafel斜率为65 mV·dec ^-1,这一结果表明该催化电极具有高催化活性。     

Low-Cost Multi-Function Electrolyte Additive Enabling Highly Stable Interfacial Chemical Environment for Highly Reversible Aqueous Zinc Ion Batteries

The practicality of aqueous zinc ion batteries (AZIBs) for large-scale energy storage is hindered by challenges associated with zinc anodes. In this study, a low-cost and multi-function electrolyte additive, cetyltrimethyl ammonium bromide (CTAB), is presented to address these issues. CTAB adsorbs onto the zinc anode surface, regulating Zn²⁺ deposition orientation and inhibiting dendrite formation. It also modifies the solvation structure of Zn²⁺ to reduce water reactivity and minimize side reactions. Additionally, CTAB optimizes key physicochemical parameters of the electrolyte, enhancing the stability of the electrode/electrolyte interface and promoting reversibility in AZIBs. Theoretical simulations combined with operando synchrotron radiation-based in situ Fourier transform infrared spectra and in situ electrochemical impedance spectra further confirm the modified Zn²⁺ coordination environment and the adsorption effect of CTAB cations at the anode/electrolyte interface. As a result, the assembled Zn-MnO₂ battery demonstrates a remarkable specific capacity of 126.56 mAh g⁻¹ at a high current density of 4 A g⁻¹ after 1000 cycles. This work highlights the potential of CTAB as a promising solution for improving the performance and practicality of AZIBs for large-scale energy storage applications.     

Optimization of nanocomposite gate insulators for organic thin film transistors

Nanocomposite gate insulators consisting of (Ba, Sr)TiO₃ (barium strontium titanate; BST) nanoparticles and crosslinked poly(4-vinyl phenol) (PVP) polymers were fabricated. Well-dispersed nanocomposite films were prepared by optimizing the BST nanoparticle size sorting process (ultrasound crushing and centrifuge method). The size-sorted BST nanoparticles (∼30 nm in size) were homogeneously mixed in the PVP host polymer in various BST contents, from 0 to 70 wt%, to tune the dielectric constant (κ) of the resulting nanocomposite films. The composite films exhibit three-fold increase in the κ value from 3.9 to 11.3. The physical properties including leakage current and surface roughness of the composites were also measured as a function of the BST loading content and particle dispersion. The relationship between these properties and the electrical performance of the corresponding organic thin film transistor were explored.     

Stability and Dispersion Analysis for ADI-FDTD Method in Lossy Media

The stability and dispersion analysis for the alternating-direction-implicit finite-difference time-domain (ADI- FDTD) method in lossy media is presented. Although the stability and numerical dispersion have been analyzed for the ADI-FDTD method, most of the analysis is dedicated to the cases of lossless media. Here, the stability and dispersion analysis is performed for the method in lossy media. The stability analysis theoretically proves the unconditional stability of the ADI-FDTD method in lossy media. Meanwhile, the dispersion analysis reveals the numerical loss and dispersion characteristics of this method. This will be meaningful for the evaluation and further development of the ADI-FDTD method in lossy media     

Effects of different electroplated gate electrodes on electrical performances of flexible organic thin film transistor and flexibility improvement

Various electroplated metal gate electrodes (Ni, Cu, and Au) on flexible polyimide (PI) substrates were applied to the fabrication of inverted staggered pentacene organic thin film transistors (OTFTs). The metal gate electrodes additively electroplated onto the patterned negative photoresist mask on the Cu(seed)/Cr(adhesion) layers sputter-deposited on the O₂-plasma-treated PI substrates were effective in obtaining good adhesion between the metal gate electrode and organic substrate. It was found that the reduction in the surface roughnesses of the electroplated metal gate and of the subsequently deposited PVP (poly-4-vinyl phenol) gate dielectric layers was a critical factor in improving the device performance. The Ni-gated OTFT exhibited the best electrical characteristics, with a field-effect mobility of ≅0.2 cm²/V-s and a current on/off ratio of ≅10³, due to the better chemical stability of the Ni electrode and the smoother surface of the PVP layer on the Ni electrode, as compared to the OTFTs with PVP/Cu or PVP/Au gates. The results of the flexibility test showed that the field-effect mobility and current on/off ratio were not changed significantly when the OTFTs were subjected to 10,000 cyclic bendings with a bending radius of 6 mm in tension mode (outward bending).