半导体材料研究的新进展

首先对作为现代信息社会的核心和基础的半导体材料在国民经济建设、社会可持续发展以及国家安全中的战略地位和作用进行了分析,进而介绍几种重要半导体材料如,硅材料、GaAs和InP单晶材料、半导体超晶格和量子阱材料、一维量子线、零维量子点半导体微结构材料、宽带隙半导体材料、光学微腔和光子晶体材料、量子比特构造和量子计算机用材料等目前达到的水平和器件应用概况及其发展趋势作了概述.最后,提出了发展我国半导体材料的建议.本文未涉及II-VI族宽禁带与II-VI族窄禁带红外半导体材料、高效太阳电池材料Cu(In,Ga)Se.CuIn(Se,S)等以及发展迅速的有机半导体材料等.     

Advanced Flexible Materials from Nanocellulose

With the increase of environmental pollution and depletion of fossil fuel resources, the utilization of renewable biomass resources for developing functional materials or fine chemicals is of great value and has attracted considerable attention. Nanocellulose, as a well-known renewable nanomaterial, is regarded as a promising nano building block for advanced functional materials owing to its unique structure and properties, as well as natural abundance. Typically, its high mechanical strength, structural flexibility, reinforcing capabilities, and tunable self-assembly behavior makes it highly attractive to fabricate flexible materials for various applications. Herein, the recent progress in the design, properties, and applications of advanced flexible materials from nanocellulose is comprehensively summarized. The preparation and properties of nanocellulose are first briefly introduced and discuss its merits in fabricating flexible materials. Then, various advanced flexible materials from nanocellulose are introduced, and the critical role of nanocellulose in constructing flexible materials is highlighted based on its intrinsic properties. After that, their applications in energy storage, electronics, sensor, biomedical, thermally insulating, photonic devices, etc., are presented. At last, the outlook of the current challenges and future perspectives for developing nanocellulose-derived flexible materials are discussed.     

Dielectric materials, devices, and circuits

Dielectric materials are continuing to play a very important role in the microwave communication systems. These materials are key in realization of low-loss temperature-stable resonators and filters for satellite and broadcasting equipment, and in many other microwave devices. High dielectric-constant materials are critical to the miniaturization of wireless systems, both for the terminals and base-stations, as well as for handsets. In this paper, a sequential evolution of the dielectric materials applications in microwave devices will be reviewed. This includes dielectric waveguides, low-loss temperature-stable ceramic materials, dielectric resonators, and filters. The recent advances in the multilayer circuit modules, dielectric antennas, and ferroelectrics are also described     

Opportunities and Challenges in Precise Synthesis of Transition Metal Single-Atom Supported by 2D Materials as Catalysts toward Oxygen Reduction Reaction

Transition metal single-atom catalysts (SACs) are currently a hot area of research in the field of electrocatalytic oxygen reduction reaction (ORR). In this review, the recent advances in transition metal single-atom supported by 2D materials as catalysts for ORR with high performance are reported. Due to their large surface area, uniformly exposed lattice plane, and adjustable electronic state, 2D materials are ideal supporting materials for exploring ORR active sites and surface reactions. The rational design principles and synthetic strategies of transition metal SACs supported by 2D materials are systematically introduced while the identification of active sites, their possible catalytic mechanisms as well as the perspectives on the future of transition metal SACs supported by 2D materials for ORR applications are discussed. Finally, according to the current development trend of ORR catalysts, the future opportunities and challenges of transition metal SACs supported by 2D materials are summarized.     

One‐Pot Synthesis of Framework Porphyrin Materials and Their Applications in Bifunctional Oxygen Electrocatalysis

Organic framework materials constructed by covalently linking organic building blocks into framework structures are highly regarded as paragons to precisely control the material structure at the atomic level. Herein, a direct synthesis methodology is proposed as a guidance for the bulk synthesis of organic framework materials. Framework porphyrin (POF) materials are one‐pot synthesized to demonstrate the advances of the direct synthesis methodology. The as‐synthesized POF materials are intrinsically 2D and exhibit impressive versatility in composition, structure, morphology, and function, delivering a free‐standing POF film, hybrids of POF and nanocarbon, and cobalt‐coordinated POF. When applied as electrocatalysts for oxygen reduction reaction and oxygen evolution reaction, the cobalt‐coordinated POF exhibits excellent bifunctional electrocatalytic performances comparable with noble‐metal‐based electrocatalysts. The direct synthesis methodology and resultant POF materials demonstrate the ability of controlling materials at the atomic level for energy electrocatalysis.     

Textile Technology for Soft Robotic and Autonomous Garments

Textiles have emerged as a promising class of materials for developing wearable robots that move and feel like everyday clothing. Textiles represent a favorable material platform for wearable robots due to their flexibility, low weight, breathability, and soft hand-feel. Textiles also offer a unique level of programmability because of their inherent hierarchical nature, enabling researchers to modify and tune properties at several interdependent material scales. With these advantages and capabilities in mind, roboticists have begun to use textiles, not simply as substrates, but as functional components that program actuation and sensing. In parallel, materials scientists are developing new materials that respond to thermal, electrical, and hygroscopic stimuli by leveraging textile structures for function. Although textiles are one of humankind's oldest technologies, materials scientists and roboticists are just beginning to tap into their potential. This review provides a textile-centric survey of the current state of the art in wearable robotic garments and highlights metrics that will guide materials development. Recent advances in textile materials for robotic components (i.e., as sensors, actuators, and integration components) are described with a focus on how these materials and technologies set the stage for wearable robots programmed at the material level.     

Fungal Engineered Living Materials: The Viability of Pure Mycelium Materials with Self-Healing Functionalities

Engineered living materials (ELMs) composed entirely of fungal cells offer significant potential due to their functional properties such as self-assembly, sensing, and self-healing. Alongside rapid developments in the ELM field, there is significant and growing interest in mycelium materials, which are made from the vegetative part of filamentous fungi, as a potential source of advanced functional materials. In order to advance the development of fungal ELMs that utilize the organism's ability to regenerate as self-repair, new methods for controlling and optimizing mycelium materials are needed, as well as a better understanding of the biological mechanisms behind regeneration. In this study, pure mycelium materials are fabricated for use as leather substitutes, and it is found that chlamydospores, thick-walled vegetative cells formed at the hyphal tip, may be the key to the material's self-healing properties. The results suggest that mycelium materials can survive in dry and oligotrophic environments, and self-healing is possible with minimal intervention after a two-day recovery period. Finally, the study characterizes the mechanical recovery and physical properties of damaged and healed samples, allowing for the first characterization of fungal ELMs.     

An Alternative Algorithm for Both Narrowband and Wideband Lorentzian Dispersive Materials Modeling in the Finite-Difference Time-Domain Method

In this study, an alternative algorithm is proposed for modeling narrowband and wideband Lorentzian dispersive materials using the finite-difference time-domain (FDTD) method. Previous algorithms for modeling narrowband and wideband Lorentzian dispersive materials using the FDTD method have been based on a recursive convolution technique. They present two different and independent algorithms for the modeling of the narrowband and wideband Lorentzian dispersive materials, known as the narrowband and wideband Lorentzian recursive convolution algorithms, respectively. The proposed alternative algorithm may be used as a general algorithm for both narrowband and wideband Lorentzian dispersive materials modeling with the FDTD method. The second-order motion equation for the Lorentzian materials is employed as an auxilary differential equation. The proposed auxiliary differential-equation-based algorithm can also be applied to solve the borderline case dispersive electromagnetic problems in the FDTD method. In contrast, the narrowband and wideband Lorentzian recursive convolution algorithms cannot be used for the borderline case. A rectangular cavity, which is partially filled with narrowband and wideband Lorentzian dispersive materials, is presented as a numerical example. The time response of the electric field z component is used to validate and compare the results     

Recent Progress in Nanostructured Cathode Materials for Lithium Secondary Batteries

Diversified and extended applications of lithium‐ion batteries demand the development of more enhanced materials that can be achieved by sophisticated synthetic methods. Combination of novel materials with strategic design of their shape on the nanometer scale enables a breakthrough to overcome problems experienced by present technologies. In this feature article, an overview is given of Mn‐based and polyanion‐based cathode materials with nanoscale features for lithium‐ion batteries as materials to replace conventional bulk cathode materials. Various synthetic methods coupled with nanostructuring as well as the benefits obtained from the nanostructure are described.     

半导体材料辐射效应的表征与分析

在辐射环境中,电子系统常用的半导体器件及电路会出现不同程度的性能退化,甚至发生失效.其根本原因来源于辐射致组成半导体器件的材料内部缺陷的产生和积累.表征和分析辐射致材料内部缺陷的种类、浓度、分布等信息,是半导体材料辐射效应研究的重要内容.从辐射致缺陷微观形貌、结构特征,及其引起的宏观电效应三方面,归纳总结了几种重要的半导体材料辐射效应的表征和分析方法,分析了每种方法的优缺点及适用范围,并指出半导体材料辐射效应表征与分析技术发展的方向,可为电子器件、半导体材料辐射效应领域的研究人员提供参考.     

Development and Testing of Energetic Materials: The Concept of High Densities Based on the Trinitroethyl Functionality

The development of new energetic materials is an emerging area of materials chemistry facilitated by a worldwide need to replace materials used at present, due to environmental considerations and safety requirements, while at the same time securing high performance. The development of such materials is complex, owing to the fact that several different and apparently mutually exclusive material properties have to be met in order for a new material to become widely accepted. In turn, understanding the basic principles of structure property relationships is highly desirable, as such an understanding would allow for a more rational design process to yield the desired properties. This article covers the trinitroethyl functionality and its potential for the design of next generation energetic materials, and describes relevant aspects of energetic materials chemistry including theoretical calculations capable of reliably predicting material properties. The synthesis, characterization, energetic properties, and structure property relationships of several new promising compounds displaying excellent material properties are reported with respect to different kinds of applications and compared to standard explosives currently used. Based on a review of trinitroethyl‐containing compounds available in the literature, as well as this new contribution, it is observed that high density can generally be obtained in a more targeted manner in energetic materials taking advantage of noncovalent bonding interactions, a prerequisite for the design of next generation energetic materials.     

Determining the relative permeability and conductivity of thin materials

In order to determine the relative permeability and conductivity of thin materials that could not be found using traditional methods, we constructed a shield box and developed a measuring system to estimate the unknown electric parameters of exotic shielding materials such as thin cloths. Thin electromagnetic shielding sheets of both nonmagnetic materials and ferromagnetic materials were used. The shielding effectiveness of the materials was measured as a function of frequency, and the results were compared with the calculated solutions for a multilayered model that was evaluated using the Sommerfeld integral that expresses near-field spherical waves by a composition of cylindrical waves. In these calculations, the relative permeability and conductivity were varied to determine the solution closest to the measured results. The least squares method was used to determine the best fitted values. Initially the nominal values of relative permeability were assumed, and the conductivity was found using the fitting technique. Then this determined value of the conductivity was assumed, and the relative permeability was found using the fitting technique. For the nonmagnetic materials, the estimated relative permeability was the same as the nominal values. For the ferromagnetic materials, the estimated relative permeability varied 0%-30% from the nominal values. For both types of materials, the estimated conductivities were 0%-9.8% different from nominal values. This research details a new method for evaluating the attenuation of interfering electromagnetic waves for thin materials.     

驱动器用陶瓷材料发展与展望

叙述了适用于制造驱动器的几种陶瓷材料,即压电陶瓷、电致伸缩陶瓷、相转变（反铁电-铁电）陶瓷和弛豫基铁电单晶材料,并对它们各自的优缺点及特性作了简单的评述,同时展望了它们在驱动器领域的应用前景。     

Automatic measurement for dielectric properties of solid material at 890 GHz

An automatic measurement system has been used to measure the complex dielectric constant of solid materials at 890GHz. This instrument can be used as a two-beam interferometer for determining the refractive index or as a transmitter for measuring the absorption coefficient of dielectric materials at FIR and SMMW frequency. The results for seven low-loss solid materials and the accuracy of the measurement are presented.     

Challenges for dielectric materials in future integrated circuit technologies

Dielectrics provide crucial functions in integrated circuits as gate dielectrics, transistor isolation structures, memory elements, interlevel dielectrics, and also provide charge storage in fast capacitors for power isolation. As the feature sizes of integrated circuits continues to decrease and speed increases, the performance requirements for these dielectrics increases significantly. Conventional materials such as thermal and CVD SiO₂ are being replaced with new materials such as high k gate dielectrics, and carbon doped SiO₂ for low k interlevel dielectrics. Even in package level power isolation capacitors, improvements in performance are becoming more difficult and new materials are needed. The challenges to dielectric materials will become even more severe as the industry approaches the l0 nm generation. In each of these applications, the requirements and integration issues are different, and this paper will highlight the long-term challenges for different applications of high k and low k materials. Nanotechnology has the potential to deliver new nano-structured materials to support these requirements, but significant challenges must be overcome before they can be useful.     

The compatibility of materials

The success of space-age endeavors depends greatly upon the materials used to construct a certain module, part, or subsystem, and the interaction between these materials and their immediate environment. A metal, for example, must retain its physical integrity in shape, ductility, and tensile strength over stringent stress and temperature ranges; it must be able to withstand proximity with other materials, metallic and nonmetallic, while maintaining chemical stability. Nonmetallic materials must be compounded to prevent such reactions as outgassing or decomposition at high altitudes; others, such as ablative ceramics, must disintegrate in a certain manner. In short, the demand for more specialized, more durable substances has created a new materials technology.     

Bio‐Inspired Synthesis of Minerals for Energy,Environment, and Medicinal Applications

Biomineralization, the natural pathway of assembling biogenic inorganic compounds, inspires us to exploit unique, effective strategies to fabricate functional materials with intricate structures. In this article, the recent advances in bio‐inspired synthesis of minerals—with a focus on those of calcium‐based minerals—and their applications to the design of functional materials for energy, environment, and biomedical fields are reviewed. Biomimetic mineralization is extending its application range to unconventional area such as the design of component materials for lithium‐ion batteries and elaborately structured composite materials utilizing carbon dioxide gas. Materials with highly enhanced mechanical properties are synthesized through emulating the nacre structure. Studies of bioactive minerals‐carbon hybrid materials show an expansion of potential applications to fields ranging from interdisciplinary science to practical engineering such as the fabrication of reinforced bone‐implantable materials.     

Recent Progress in MOF-Derived Porous Materials as Electrodes for High-Performance Lithium-Ion Batteries

In recent years, metal-organic frameworks, especially MOF-based derivatives, have been regarded as one of the best candidate electrode materials for the next generation of advanced materials, due to high porosity, large surface area, modifiable functional groups as well as controllable chemical composition. This review presents the corresponding synthesis methods, structural design, and electrochemical performance of MOF-derived materials, including metal oxides, metal sulfides, metal phosphides, and carbon materials, in high-performance lithium-ion batteries. Subsequently, the problems that exist in the current application of MOF-based derivatives as electrodes in lithium-ion batteries are discussed along with possible and feasible solutions. At last, some reasonable pathways and strategies for the design of MOF derivatives are also suggested.     

电子企业物料清单的作用与设计

电子企业的物料清单（BOM）（以下简称BOM）,首先由产品设计单位在产品设计之中产生,由物料管理部门作为其对生产单位发放配套计划要求的物料依据,生产部门作为其生产产品的依据,质检部门作为对产品进行生产确认的依据等等。由此可见：BOM是电子企业内部生产活动运行的重要工程文件,其编写方式与生产运行直接相关,编写的水平反应了企业的管理水平与技术水平。     

Progress in Triboelectric Materials: Toward High Performance and Widespread Applications

Triboelectric phenomena can be observed everywhere; however, they are consistently omitted from applications. Although almost all substances exhibit a triboelectrification effect in daily life, chemists as well as materials scientists have performed extensive investigations in both the aspects of basic science and practical applications to promote the development of triboelectric nanogenerators (TENGs). Here, a detailed survey of materials engineering for high triboelectric performance and multifunctional materials toward specific applications is summarized, including constructing micro/nanostructures, chemically modifying the frication surface, modulating bulk friction materials, the mechanism for improved performance, and preparing materials for implantable medical devices, bionic skin, and wearable electronic devices. Moreover, an in depth discussion of the current challenges and future efforts for strengthening the performance of TENGs is elaborated in detail, which will better guide new researchers toward a deeper understanding of and explorations about TENGs.