Bifunctional Mn-doped CoSe_(2) nanonetworks electrode for hybrid alkali/acid electrolytic H_(2) generation and glycerol upgrading

Electrolytic water splitting,as a promising route to hydrogen(H_(2))production,is still confronted with the sluggish anodic oxygen evolution reaction(OER)and its less value-added O2 production.Herein,we report a bifunctional electrode fabricated by in situ growth of Mn-doped CoSe_(2)nanonetworks on carbon fiber cloth(Mn-CoSe_(2)/CFC),which shows attractive electrocatalytic properties toward glycerol oxidation reaction(GOR)in alkali and hydrogen evolution reaction(HER)in acid.A flow alkali/acid hybrid electrolytic cell(fA/A-hEC)was then developed by coupling anodic GOR with cathodic HER with the Mn-CoSe_(2)/CFC bifunctional electrode.Such fA/A-hEC enables a rather low voltage of 0.54 V to achieve 10 mA cm^(-2),and maintain long-term electrolysis stability over 300-h operation at 100 mA cm^(-2)with Faraday efficiencies of over 99%for H_(2)and 90%for formate production.The designed bifunctional electrode in such innovative fA/A-hEC device provides insightful guidance for coupling energy-efficient hydrogen production with biomass upgradation.

Model of Multi-Source Nanonetworks for the Detection of BRCA1 DNA Alterations Based on LSPR Phenomenon

In this paper, we present a multi-source nanonetwork model for biomedical diagnosis applications, based on the Localized Surface Plasmon Resonance by different shape gold nanoparticles (i.e., cylinder, cube, and rod). We present the process of multi-source emission, diffusion, and reception of nanoparticles, based on the ligand/receptor binding. Then, a multi-detection process of DNA alterations is accomplished when nanoparticles are captured at the receiver. The colloidal particles are selectively functionalized with specific splice junctions of gene sequences to reveal simultaneously different alteration that could be associated to an early disease condition. Particularly, full-wave simulations have been carried out for the multi-detection of alternative splice junctions of breast cancer susceptibility gene 1. The proposed application is verified through numerical results and expressed in terms of Extinction-Cross Section, in the case of synchronous and asynchronous nanoparticles detection. We show that the proposed approach is able to detect DNA alterations, based on a selective nanoparticle reception process.

Hybrid artificial neural networks and analytical model for prediction of optical constants and bandgap energy of 3D nanonetwork silicon structures

The aim of this study is to develop a reliable method to determine optical constants for 3D-nanonetwork Si thin films manufactured using a pulsed-laser ablation technique that can be applied to other materials synthesized by this tech-nique.An analytical method was introduced to calculate optical constants from reflectance and transmittance spectra.Optical band gaps for this novel material and other important insights on the physical properties were derived from the optical constants.The existing optimization methods described in the literature were found to be complex and prone to errors while determining optical constants of opaque materials where only reflectance data is available.A supervised Deep Learning Algorithm was developed to accurately predict optical constants from the reflectance spectrum alone.The hybrid method introduced in this study was proved to be effective with an accuracy of 95%.

3D nickel-cobalt diselenide nanonetwork for highly efficient oxygen evolution

Active, stable and low-cost oxygen evolution reaction(OER) catalyst for electrochemical water splitting is key to efficient energy conversion and storage. Here, we report a three-dimensional(3D) nanonetwork as noble-metal-free electrode consisting of nickel cobalt diselenide(NiCoSe_2) nanobrush arrays on Ni foam(NF) through the initial hydrothermal reaction and subsequent thermal selenization process. Introducing ammonium fluoride as surface controller, different NiCoSe_2 hierarchical architecture can be modulated from nanorods, nanobrush to nanosheets. The unique brush-like NiCoSe_2 possesses high surface area for mass transfer, rough surface with rich active sites, 3D nanostructure preventing the accumulation of O2 bubbles. Compared to NiCoSe_2 nanorods/NF, NiCoSe_2 nanosheets/NF and commercial Ru O2,NiCoSe_2 nanobrush/NF exhibits an enhanced OER performance in alkaline media to reach a low overpotential of 274 m V at the current density of 10 m A/cm2, small Tafel slope and a long-term stability. The developed 3D nanonetwork highlights the nanoscale engineering and offers a promising alternative to noble metal catalysts for electrochemical water oxidation.

纳米网络中的太赫兹波大气传输和信道分析

利用太赫兹大气传输衰减模型,比对太赫兹时域光谱系统的实验结果,结合最新的HITRAN数据库,发展了一个适用于纳米尺度的太赫兹信道分析模型。提出了一个0.1~5THz宽的信道,分析了此信道在纳米尺度的传输损耗和最大传输数据率。研究结果表明,在纳米尺度0.1~5THz宽的信道的传输数据率达几百Gbit/s,随着天线增益等硬件性能的不断提升,信道的最大传输数据率将达Tbit/s,此研究对于纳米器件之间的快速、大数据量的信息共享具有重要的参考价值。

WO_3纳米网格的制备及其光催化性能研究

WO3是一种带隙约为2.6eV过渡金属半导体,可见光便能激发其光催化活性,这极大地提高了太阳光的利用率,但纯WO3纳米材料催化活性较低,针对这一难题,国内外研究者大多采取对其表面改性来提高它的光催化性能,对WO3本身进行原位研究的报道极少。实验致力于改进WO3纳米材料的形貌结构来拓展其光催化性能。分别采取CaCl2和Na2SO4为诱导盐,Na2WO4为W源,在一定的pH值条件下水热制备WO3纳米网格和纳米线;并研究了这两种不同形貌结构的WO3纳米材料的光催化活性。研究表明,WO3网格立体网格结构具有更好的催化性能。实验发现WO3网格独特的层状结构能减少太阳光的逃逸,增强对光的吸收;网格结构具有更大的比表面积,能增加光催化过程中催化剂与有机物的反应活性点;这两点可能是立体网格结构WO3促进光催化反应的重要原因。

负载感知的太赫兹纳米传感网的TDMA协议

针对基于TS-OOK(time spread on-off keying)调制的通信系统存在数据传输连续碰撞的问题,考虑到实际应用场景具备负载不均衡的特点,提出负载感知的TDMA (LATDMA)协议.该协议根据网络中源节点数目、源节点业务量大小以及太赫兹信道的传输特性,在传统TDMA协议基础上实现动态分配时隙.仿真结果表明:该协议是能量高效的,在时延和平均吞吐量方面均具有明显的优势,因此可以应用于时延要求较苛刻的网络场景中.

Reliability Analysis of Molecular Communication Based on Drift Diffusion in Different Topologies

Molecular communication is a novel nanoscale communication method. It can use ions, biochemical molecules or other information carriers to transmit information. However, due to molecules are easily accumulated in the channel to produce strong internal symbol interference, the information transmission in the channel is vulnerable to a low reliability. Therefore, reliability has become an important research issue in the field of molecular communication. At present, the existing reliability model of molecular communication does not take into account the drift velocity of the medium. Nevertheless, in some scenarios, it is often necessary to consider the effect of the drift velocity of the medium on the reliability of molecular communication. In this paper, we introduce the drift velocity of the medium and propose a reliability model of molecular communication based on drift diffusion (MCD2) in different topologies. Furthermore, in the case of transmission failure, a retransmission mechanism is used to ensure reliable transmission of information. Finally, we also compare the reliability performance of molecular communication between reliability model of MCD2 and reliability model of molecular communication based on free diffusion. The simulation results indicate that the proposed reliability model is superior to the existing reliability model of molecular communication based on free diffusion in analyzing the reliability of MCD2.

Embedded Coded Relay System for Molecular Communications

With the emergence of the COVID-19 pandemic,the World Health Organization(WHO)has urged scientists and industrialists to exploremodern information and communication technology(ICT)as a means to reduce or even eliminate it.The World Health Organization recently reported that the virus may infect the organism through any organ in the living body,such as the respiratory,the immunity,the nervous,the digestive,or the cardiovascular system.Targeting the abovementioned goal,we envision an implanted nanosystem embedded in the intra living-body network.The main function of the nanosystem is either to perform diagnosis and mitigation of infectious diseases or to implement a targeted drug delivery system(i.e.,delivery of the therapeutic drug to the diseased tissue or targeted cell).The communication among the nanomachines is accomplished via communication-based molecular diffusion.The control/interconnection of the nanosystem is accomplished through the utilization of Internet of bio-nano things(IoBNT).The proposed nanosystem is designed to employ a coded relay nanomachine disciplined by the decode and forward(DF)principle to ensure reliable drug delivery to the targeted cell.Notably,both the sensitivity of the drug dose and the phenomenon of drug molecules loss before delivery to the target cell site in long-distance due to the molecules diffusion process are taken into account.In this paper,a coded relay NM with conventional coding techniques such as RS and Turbo codes is selected to achieve minimum bit error rate(BER)performance and high signal-to-noise ratio(SNR),while the detection process is based on maximum likelihood(ML)probability and minimum error probability(MEP).The performance analysis of the proposed scheme is evaluated in terms of channel capacity and bit error rate by varying system parameters such as relay position,number of released molecules,relay and receiver size.Analysis results are validated through simulation and demonstrate that the proposed scheme can significantly improve delivery performance of the desirable drugs in the molecular communication system.

无线纳米网中太赫兹电磁波传输特性分析

针对基于太赫兹通信的电磁纳米网络,深入分析太赫兹电磁波路径传输特性以及大气分子吸收特性,从能耗的角度构建太赫兹信道传输的数学模型。分别针对不带反射路径的传输场景和带有反射路径的传输场景来分析路径传输特性;利用大气辐射原理来分析大气分子吸收特性。在不同传输距离和传输频率下,结合路径传输和大气分子吸收对太赫兹电磁波传输能量损耗进行仿真。结果表明:分子吸收损耗是太赫兹电磁波传输能量损耗的重要组成部分,大气分子吸收损耗与传输介质分子组成有关;路径传输损耗受到传输频率和距离的影响。分析结果对太赫兹通信频段的选择以及纳米节点能耗设计有重要参考价值。

仿生纳米测控技术

讨论了纳米技术、纳米测控技术与仿生纳米测控技术 ,论述了这一课题的重要意义 ,包括它对生物医学与工程技术的贡献。提出细胞是研究仿生纳米测控技术的优选对象 ,细胞膜是其最佳切入点。建立了仿生纳米测控技术的分子系统与分子网络模型。讨论了实现这些模型的纳米制造、生物技术、化学制造与混合制造等方法。强调了广义纳米制造方法的优越性。集成于细胞膜上的分子系统与分子网络是仿生纳米测控技术的典型 ,前者还可据此构建纳米机器人 ,后者还可据此组建纳米工厂。对纳米测控技术的应用前景作了展望 :指出了它将在测控心理活动 ;基因的诊断、治疗 ,组建单细胞纳米测控平台 ;

基于能量采集的分布式时分多址协议

纳米节点利用太赫兹通信能获得极高的传输速率,节点间的通信以及协调访问太赫兹信道都需要媒质接入控制(medium access control,MAC)协议.由于太赫兹信道的分子吸收噪声和纳米设备资源受限等特性,经典的MAC协议已不再适用.针对基于时域扩展开关键控(time spread on-off keying,TS-OOK)的太赫兹传感器网络的数据传输存在连续碰撞的问题以及纳米节点能量非常有限的问题,提出一种基于能量采集的分布式时分多址协议(distributed energy harvesting-based time division multiple access,DEH-TDMA).该协议引入压电式纳米能量采集系统,首先将纳米节点剩余能量和缓存区的数据包数量作为状态信息构建Markov决策过程模型,并根据节点的数据包传输量和能耗来设计收益函数,然后求解出最优策略,最终纳米节点根据自身状态和最优策略动态接入信道.仿真结果表明该协议在延长网络生命周期方面存在优势.

细菌纤维素/涤纶非织造布自编织复合材料的制备及其性能

为探索细菌纤维素/涤纶非织造布复合材料的结构与性能,以涤纶非织造布为基材,利用生物复合的方法,自编织制得细菌纤维素/涤纶非织造布复合材料。利用扫描电子显微镜、傅里叶红外变换光谱仪、热重分析仪、表面张力仪、万能试验机对复合材料的形貌、结构、热稳定性、亲疏水性、拉伸力学性能进行表征。结果表明:涤纶非织造布中纤维被细菌纤维素黏附、缠绕、穿插,二者实现较好地复合;复合材料中出现羟基官能团,红外光谱图发生轻微地红移现象;复合后材料的热稳定性、亲水性得到改善;对比涤纶非织造布,细菌纤维素/涤纶非织造布复合材料的拉伸力学性能提高,且复合材料的断裂强度随细菌纤维素含量的增加呈现先增加后下降的趋势。

纳米网络中基于分子扩散的振荡同步研究

纳米网络是在纳米尺度上连接纳米机器并实现他们之间相互通信以及信息共享的一种新型跨学科的网络通信方式,在生物医学、环境监测、工业生产和军事研究领域有着广泛的应用前景。纳米机器被认为是纳米尺度上最基本的功能设备,由振荡器产生的时钟周期是维持纳米机器正常工作的前提。通过建立数学模型描述分子扩散,理论推导计算出振荡周期的表达式,分析了不同维度下分子扩散的特点。目前在该领域,对纳米网络同步振荡的研究十分有限,故该课题的研究对今后纳米网络的发展及应用是非常有意义的。

Diffusion Based Molecular Communication:Principle,Key Technologies,and Challenges

Molecular communication(MC) is a kind of communication technology based on biochemical molecules for internet of bio-nano things, in which the biochemical molecule is used as the information carrier for the interconnection of nano-devices. In this paper, the basic principle of diffusion based MC and the corresponding key technologies are comprehensively surveyed. In particular, the state-ofthe-art achievements relative to the diffusion based MC are discussed and compared, including the system model, the system performance analysis with key influencing factors, the information coding and modulation techniques. Meanwhile, the multi-hop nano-network based on the diffusion MC is presented as well. Additionally, given the extensiveness of the research area, open issues and challenges are presented to spur future investigations, in which the involvement of channel model, information theory, self-organizing nano-network, and biochemical applications are put forward.

基于二维分子刷的超结构碳纳米网络的可控制备及其柔性超级电容器性能

三维碳纳米网络(3D CNNs)具有连通的导电骨架和多孔结构,可以提供多级传输通道,因此在许多领域有广阔的应用前景。然而,网络单元的物理堆叠难以形成长程导电通路,且引入微孔和小尺寸中孔的造孔过程通常比较复杂和昂贵。在本研究中,以聚丙烯醛接枝的氧化石墨烯分子刷为构筑单元、四(4-氨基苯基)甲烷为交联剂,通过席夫碱凝胶化,制备了分子刷纳米网络(MBNN);随后通过炭化处理获得超结构碳纳米网络(SHCNN)。由于MBNN良好的成炭性和纳米结构继承性,SHCNN具有氮掺杂微-中-大孔结构、高比表面积和高导电性杂化碳骨架,因此拥有丰富的活性位点并展示了良好的传质/传荷能力。作为柔性超级电容器电极,SHCNN在1 A g^(−1)的电流密度下,比电容为180 F g^(−1),在8 A g^(−1)下经10000次循环后的电容保持率高达91.4%。

分子纳米网络中地理机会路由算法设计与实现

分子通信是纳米网络的主要通信方式之一,是一种以生物化学分子作为信息载体的短距离通信技术。为了提高分子通信中的传输速率,将地理机会路由算法中选择候选节点的条件由比较距离大小优化为比较浓度值大小。在此基础上建立分子通信模型,并利用MATLAB进行实验仿真。对实验结果进行对比分析发现,以浓度作为判定条件的地理机会路由算法更优。

Synthesis of novel hierarchical porous polymers with a nanowire-interconnected network structure from core-shell polymer nanoobjects

Design and fabrication of the micro/nanostructures of the network units is a critical issue for porous nanonetwork structured materials. Significant progress has been attained in construction of the network units with zero-dimensional spherical shapes.However, owing to the limitations of synthetic methods, construction of porous building blocks in one dimension featuring high aspect ratios for porous nanonetwork structured polymer(PNSP) remains largely unexplored. Here we present the successful design and preparation of PNSP with a novel type of one-dimensional network unit, i.e., microporous heterogeneous nanowire. Well-defined core-shell polymer nanoobjects prepared from a gelable block copolymer, poly(3-(triethoxysilyl)propyl methacrylate)-block-polystyrene are employed as building blocks, and facilely transformed into PNSP via hypercrosslinking of polystyrene shell. The as-prepared PNSP exhibits unique three-dimensional hierarchical nanonetwork morphologies with large surface area. These findings could provide a new avenue for fabrication of unique well-defined PNSP, and thus generate valuable breakthroughs in many applications.

Ag纳米网络结构的光学特性

由局域表面等离子共振(LSPR)形成的周期性Ag纳米网络结构在深紫外到近红外波段的高透光透明导体中具有潜在应用,但纳米网络结构透射特性、导电特性及形态的关系仍有待进一步研究。首先,用有限元分析法从理论上分析了Ag纳米颗粒形态对LSPR特性的影响。然后,研究了沉积的Ag覆盖率对周期性纳米网络结构光透射特性的影响。最后,通过建立等效电阻模型,研究分析了Ag纳米网络结构的电阻率和透射率。结果表明,在沉积一定厚度的Ag纳米颗粒时可以获得具有较高透光性以及较小薄膜电阻的Ag纳米网络结构。

空心纳米网络结构聚苯乙烯及其炭材料的制备与结构调控

研究了纳米网络结构聚苯乙烯及其炭材料的结构设计、可控合成及其构效关系.以二氧化硅为载体,通过表面引发原子转移自由基聚合-傅克超交联联合法成功在分子水平上设计制备出具有空心微孔聚苯乙烯纳米球网络单元的三维纳米网络结构聚苯乙烯(HNNS-PS),并通过控制PS分子量对三维纳米网络结构进行调控.通过凝胶渗透色谱(GPC)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、热重分析(TGA)、N2吸附等手段考察HNNS-PS的纳米结构和形貌,利用IGA研究HNNS-PS的有机蒸汽吸附性能,并通过升温速率控制实现三维纳米网络结构在炭化过程中的可继承性.结果表明,通过调控PS分子量HNNS-PS网络单元粒径为263~332 nm,PS分子量越大,BET比表面积(BrunauerEmmett-Teller specific surface area,SBET)越大,最高可达450 m2 g-1,甲苯蒸汽吸附量最高可达534 mg g-1.此外,当炭化升温速率较低(1~2 K min-1)时,制得的空心纳米球炭网络保留了典型的三维纳米网络结构形貌,SBET最高可达696 m2 g-1.