Photoresponsive Transistors Based on Lead‐Free Perovskite and Carbon Nanotubes

Lead‐free perovskite materials are exhibiting bright application prospects in photodetectors (PDs) owing to their low toxicity compared with traditional lead perovskites. Unfortunately, their photoelectric performance is constrained by the relatively low charge conductivity and poor stability. In this work, photoresponsive transistors based on stable lead‐free bismuth perovskites CsBi₃I₁₀ and single‐walled carbon nanotubes (SWCNTs) are first reported. The SWCNTs significantly strengthen the dissociation and transportation of the photogenerated charge carriers, which lead to dramatically improved photoresponsivity, while a decent I_light/I_dark ratio over 10² can be maintained with gate modulation. The devices exhibit high photoresponsivity (6.0 × 10⁴ A W^?1), photodetectivity (2.46 × 10¹⁴ jones), and external quantum efficiency (1.66 × 10⁵%), which are among the best reported results in lead‐free perovskite PDs. Furthermore, the excellent stability over many other lead‐free perovskite PDs is demonstrated over 500 h of testing. More interestingly, the device also shows the application potential as a light‐stimulated synapse and its synaptic behaviors are demonstrated. In summary, the lead‐free bismuth perovskite‐based hybrid phototransistors with multifunctional performance of photodetection and light‐stimulated synapse are first demonstrated in this work.     

Self‐Hydrophobization in a Dynamic Hydrogel for Creating Nonspecific Repeatable Underwater Adhesion

Adhesive hydrogels are widely applied for biological and medical purposes; however, they are generally unable to adhere to tissues under wet/underwater conditions. Herein, described is a class of novel dynamic hydrogels that shows repeatable and long‐term stable underwater adhesion to various substrates including wet biological tissues. The hydrogels have Fe³⁺‐induced hydrophobic surfaces, which are dynamic and can undergo a self‐hydrophobization process to achieve strong underwater adhesion to a diverse range of dried/wet substrates without the need for additional processes or reagents. It is also demonstrated that the hydrogels can directly adhere to biological tissues in the presence of under sweat, blood, or body fluid exposure, and that the adhesion is compatible with in vivo dynamic movements. This study provides a novel strategy for fabricating underwater adhesive hydrogels for many applications, such as soft robots, wearable devices, tissue adhesives, and wound dressings.     

Electrode Design for Lithium–Sulfur Batteries: Problems and Solutions

Pursuit of advanced batteries with high‐energy density is one of the eternal goals for electrochemists. Over the past decades, lithium–sulfur batteries (LSBs) have gained world‐wide popularity due to their high theoretical energy density and cost effectiveness. However, their road to the market is still full of thorns. Apart from the poor electronic conductivity of sulfur‐based cathodes, LSBs involve special multielectron reaction mechanisms associated with active soluble lithium polysulfides intermediates. Accordingly, the electrode design and fabrication protocols of LSBs are different from those of traditional lithium ion batteries. This review is aimed at discussing the electrode design/fabrication protocols of LSBs, especially the current problems on various sulfur‐based cathodes (such as S, Li₂S, Li₂S_x catholyte, organopolysulfides) and corresponding solutions. Different fabrication methods of sulfur‐based cathodes are introduced and their corresponding bullet points to achieve high‐quality cathodes are highlighted. In addition, the challenges and solutions of sulfur‐based cathodes including active material content, mass loading, conductive agent/binder, compaction density, electrolyte/sulfur ratio, and current collector are summarized and rational strategies are refined to address these issues. Finally, the future prospects on sulfur‐based cathodes and LSBs are proposed.     

Porous Silicon Nanoparticles Embedded in Poly(lactic‐co‐glycolic acid) Nanofiber Scaffolds Deliver Neurotrophic Payloads to Enhance Neuronal Growth

Scaffolds made from biocompatible polymers provide physical cues to direct the extension of neurites and to encourage repair of damaged nerves. The inclusion of neurotrophic payloads in these scaffolds can substantially enhance regrowth and repair processes. However, many promising neurotrophic candidates are excluded from this approach due to incompatibilities with the polymer or with the polymer processing conditions. This work provides one solution to this problem by incorporating porous silicon nanoparticles (pSiNPs) that are preloaded with the therapeutic into a polymer scaffold during fabrication. The nanoparticle‐drug‐polymer hybrids are prepared in the form of oriented poly(lactic‐co‐glycolic acid) nanofiber scaffolds. Three different therapeutic payloads are tested: bpV(HOpic), a small molecule inhibitor of phosphatase and tensin homolog (PTEN); an RNA aptamer specific to tropomyosin‐related kinase receptor type B (TrkB); and the protein nerve growth factor (NGF). Each therapeutic is loaded using a loading chemistry that is optimized to slow the rate of release of these water‐soluble payloads. The drug‐loaded pSiNP‐nanofiber hybrids release approximately half of their TrkB aptamer, bpV(HOpic), or NGF payload in 2, 10, and >40 days, respectively. The nanofiber hybrids increase neurite extension relative to drug‐free control nanofibers in a dorsal root ganglion explant assay.     

A High‐Potential Anion‐Insertion Carbon Cathode for Aqueous Zinc Dual‐Ion Battery

Aqueous dual‐ion batteries (DIBs) are promising for large‐scale energy storage due to low cost and inherent safety. However, DIBs are limited by low capacity and poor cycling of cathode materials and the challenge of electrolyte decomposition. In this study, a new cathode material of nitrogen‐doped microcrystalline graphene‐like carbon is investigated in a water‐in‐salt electrolyte of 30 m ZnCl₂, where this carbon cathode stores anions reversibly via both electrical double layer adsorption and ion insertion. The (de)insertion of anions in carbon lattice delivers a high‐potential plateau at 1.85 V versus Zn²⁺/Zn, contributing nearly 1/3 of the capacity of 134 mAh g^?1 and half of the stored energy. This study shows that both the unique carbon structure and concentrated ZnCl₂ electrolyte play critical roles in allowing anion storage in carbon cathode for this aqueous DIB.     

From Passive Inorganic Oxides to Active Matters of Micro/Nanomotors

Controllable actuation and coordinating motion of artificial self‐propelled micro/nanomotors to mimic the motile natural microorganism systems are of great significance for constructing intelligent nanoscale machines. In particular, inorganic oxide particles have shown considerable promise in implementation of synthetic micro/nanomotors, due to their unique features and active response to environmental stimuli. This work critically reviews the recent progress in inorganic oxide‐based micro/nanomotors and focuses on their propulsion response to chemical and physical stimuli, especially emphasizing and discussing operating principles in the single engine, adaptive navigation under composite‐driven powers, and intriguing collective behaviors. The impact of oxide structure, multiple fields in motion controllability, and interaction between grouped micro/nanomotors are explored. Practical applications of individual and assembled micro/nanomotors in environmental and biomedical fields are demonstrated, including the removal of pollutants, drug delivery, cancer therapy, and in vivo imaging. Finally, current challenges for the development of novel micro/nanomotors and possible constraints toward the defined structure and accumulated toxicity are discussed along with future opportunities and directions. Owing to their facile synthesis, impressive physicochemical performances, high biocompatibility, and versatile actuations, it is expected that the association of inorganic oxides with micro/nanomotors will bring new and unique capabilities to the field of active matter.     

高功率半导体激光器端面泵浦Nd:YVO_4固体激光器热致损耗的研究

本文提出了一种测量端面泵浦固体激光器热致损耗的方法．研究了Ｎｄ（３＋）浓度分别为０．５％和２％两种Ｎｄ：ＹＶＯ４晶体,基模半径与泵浦光斑半径之比Ｗ１／Ｗｐ分别为０．５和１情形下热致损耗随泵浦功率的变化,结果表明：热致损耗随泵浦功率的增加而增大,且强烈依赖于Ｗ１／ＷＰ;大的基模半径会导致严重的热致损耗．Ｎｄ：ＹＶＯ４晶体的Ｎｄ３＋浓度对热致损耗也有很大影响,在大模半径情形,高浓度晶体的热致损耗远大于低浓度晶体,而且对于Ｗ１／Ｗｐ的依赖更为强烈．     

CSM无线网络滚动开通基站模式探讨

从滚动开通基站流程及在该建设模式下基站如何进行站址选择、天线参数及发射功率设计、小区频率规划等方面论述了一种将网络优化思想融于无线基站工程建设中的基站开通模式。     

VQ-based digital image watermarking method

A vector-quantisation (VQ)-based watermarking method is presented which utilises the codebook expansion technique. This method is efficient, provides enhanced security and the watermarked image is robust against the effects of VQ compression. Moreover, the watermark extraction can be performed without the original image. Experimental results are presented which demonstrate the effectiveness of this algorithm.     

基于参数模式识别的细菌分类检测技术

激光相位多普勒（ＰＤＡ）能够同时测量粒子的速度、大小和相对折射率。本文以ＰＤＡ技术为基础,测得污水中细菌的尺寸分布和相对折射率,并利用模糊模式识别技术计算贴近度〔２〕,根据择近原则实现了对污水水样中菌群的分类检测。