Hybrid Perovskite Quantum Dot/Non-Fullerene Molecule Solar Cells with Efficiency Over 15%

Organic-inorganic hybrid film using conjugated materials and quantum dots (QDs) are of great interest for solution-processed optoelectronic devices, including photovoltaics (PVs). However, it is still challenging to fabricate conductive hybrid films to maximize their PV performance. Herein, for the first time, superior PV performance of hybrid solar cells consisting of CsPbI₃ perovskite QDs and Y6 series non-fullerene molecules is demonstrated and further highlights their importance on hybrid device design. In specific, a hybrid active layer is developed using CsPbI₃ QDs and non-fullerene molecules, enabling a type-II energy alignment for efficient charge transfer and extraction. Additionally, the non-fullerene molecules can well passivate the QDs, reducing surface defects and energetic disorder. The champion CsPbI₃ QD/Y6-F hybrid device has a record-high efficiency of 15.05% for QD/organic hybrid PV devices, paving a new way to construct solution-processable hybrid film for efficient optoelectronic devices.     

Interfacial Engineering of Bifunctional Niobium (V)-Based Heterostructure Nanosheet Toward High Efficiency Lean-Electrolyte Lithium–Sulfur Full Batteries

High-efficiency lithium–sulfur (Li–S) batteries depend on an advanced electrode structure that can attain high sulfur utilization at lean-electrolyte conditions and minimum amount of lithium. Herein, a twinborn holey Nb₄N₅–Nb₂O₅ heterostructure is designed as a dual-functional host for both redox–kinetics–accelerated sulfur cathode and dendrite-inhibited lithium anode simultaneously for long-cycling and lean-electrolyte Li–S full batteries. Benefiting from the accelerative polysulfides anchoring–diffusion–converting efficiency of Nb₄N₅–Nb₂O₅, polysulfide-shutting is significantly alleviated. Meanwhile, the lithiophilic nature of holey Nb₄N₅–Nb₂O₅ is applied as an ion-redistributor for homogeneous Li-ion deposition. Taking advantage of these merits, the Li–S full batteries present excellent electrochemical properties, including a minimum capacity decay rate of 0.025% per cycle, and a high areal capacity of 5.0 mAh cm⁻² at sulfur loading of 6.9 mg cm⁻², corresponding to negative to positive capacity ratio of 2.4:1 and electrolyte to sulfur ratio of 5.1 µL mg⁻¹. Therefore, this work paves a new avenue for boosting high-performances Li–S batteries toward practical applications.     

Graphene-Based Heterostructure Composite Sensing Materials for Detection of Nitrogen-Containing Harmful Gases

Graphene-based heterostructure composite is a new type of advanced sensing material that includes composites of graphene with noble metals/metal oxides/metal sulfides/polymers and organic ligands. Exerting the synergistic effect of graphene and noble metals/metal oxides/metal sulfides/polymers and organic ligands is a new way to design advanced gas sensors for nitrogen-containing gas species including NH₃ and NO₂ to solve the problems such as poor stability, high working temperature, poor recovery, and poor selectivity. Different fabrication methods of graphene-based heterostructure composite are extensively studied, enabling massive progress in developing chemiresistive-type sensors for detecting the nitrogen-containing gas species. With the components of noble metals/metal oxides/metal sulfides/polymers and organic ligands which are composited with graphene, each material has its attractive and unique electrical properties. Consequently, the corresponding composite formed with graphene has different sensing characteristics. Furthermore, working ambient gas and response type can affect gas-sensitive characteristic parameters of graphene-based heterostructure composite sensing materials. Moreover, it requires particular attention in studying gas sensing mechanism of graphene-based heterostructure composite sensing materials for nitrogen-containing gas species. This review focuses on related scientific issues such as material synthesis methods, sensing performance, and gas sensing mechanism to discuss the technical challenges and several perspectives.     

Selective Wavelength Enhanced Photochemical and Photothermal H2 Generation of Classical Oxide Supported Metal Catalyst

Conventional views of constructing simply broadband catalysts for photothermal-enhanced catalysis do not realize that without designating photochemical and photothermal conversion to their optimal working spectra can lead to a performance trade-off. Here, spectrally selective designed photoredox and photothermal heating functions of a classical oxide supported metal catalyst are demonstrated, which exhibits markedly improved hydrogen reactivity. While photothermal hydrogen producing catalysis is previously demonstrated, distinctive wavelength dominant redox and thermal phenomena are not studied due to the complex interdependent behavior they exhibit. The exceptionally high H₂ evolution rate of 30.2 mmol g⁻¹ h⁻¹ (≈74 times that of the control sample) is attributed to the nonoverlapped light absorption and undisrupted charge transfer rationales. This study presents a proof-by-existence that spectrally tailored solar utilization strategy is broadly impactful for the hybrid photothermal–photochemical catalysis. Moreover, the spatially decoupled structural configuration may open up discrete parametric control over photoredox and photoheating functionalities.     

MPEG-2传输流解复用在内嵌ARM核的FPGA上的实现

本文介绍了MPEG-2传输流解复用的原理,使用内嵌ARM的FPGA芯片EPXA10实现了MPEG-2传输流的解复用,并从硬件设计和软件结构两个方面详细地介绍了设计思想。     

钛酸钡微晶粉粒的热刺激电流

研究了铁电微晶粉粒的热刺激电流及其铁电相变。对三种不同化学成分的钛酸钡粉料与硅油的混合物进行了热刺激电流测量。钛酸钡粉粒与硅油的混合物有很明显的热刺激电流(TSC)且表现出和铁电相变有关的明显的峰,显示出与粒径存在一定的关系;得出了样品的表观极化强度曲线。证明了当粉料与硅油混合后,用介电谱观测不到的粉料的铁电–顺电相变,用 TSC 方法可以观察到。     

超声共沉淀法合成锂离子电池正极材料

采用超声共沉淀法,合成尖晶石型掺杂锰酸锂Li1.05Co0.10Ni0.10Mn1.80O4前驱体,并使用三段热处理方式,制备出尖晶石产物。用粒度分布、XRD、SEM、EDS及电化学性能测试等对其进行表征。结果表明:与未处理试样相比,超声共沉淀法制备的产物的粒度分布变窄,体积比表面积由7.0116m2/cm3缩小至6.9789m2/cm3,晶格常数从0.822nm缩小至0.821nm,晶粒尺寸从67.41nm减小至57.78nm,晶形更加完整,颗粒均匀性更好。经装配成电池测定电化学性能,其充放电平台增长,比容量加大,循环性能更优越。     

DVB-S2中LDPC编解码分析

本文在简要介绍LDPC码的基础上，就DVB—S2标准中LDPC编解码过程进行了详细的分析，指出了值得关注和研究的元素。     

4G移动通信系统关键技术初探

随着移动通信用户需求与日俱增,现有的无线移动通信网络已不能满足日益增长的高速多媒体业务,于是很多国家投入到4G的研发中.本文对3G和4G做了简要的比较,并对4G网中将会用到的关键技术做了分析.     

La0.5Sr0.5CoO3的化学溶液淀积法制备与表征及其应用

采用化学溶液淀积法制备了具有纯钙钛矿结构和良好导电性能的La_(0.5)Sr_(0.5)CoO_3(LSCO)薄膜。LSCO的电阻率随着退火温度的升高、退火时间的增长和厚度增加而减小。650°C退火可以得到7mΩ·cm的电阻率。分别在LSCO和Pt衬底上制备了Bi_4Ti_3O_(12)(BTO)薄膜,分析结果表明,使用LSCO衬底对BTO的析晶有影响,击穿电压、铁电特性均有较大改善。