摘要：High performance low temperature co-fired ceramic(LTCC)dielectrics is highly desired for next generation information *** rational design is a key issue for the development of new LTCC *** comparison to the design of conventional electroceramics,more attention should be paid on the formation process of the material structure for that of LTCC,in addition to the physical properties,due to the special requirement in fabrication *** this paper,sintering mechanism of three types of LTCC materials,i.e.,glass-ceramics,glass ceramic composite,and glass bonded ceramics,as well as important factors of their dielectric properties are discussed and summarized,and the design strategies for LTCC dielectrics,based on new matrix materials with much lower sintering temperature or higher quality,are *** an example for rational design,oxyfluoride glass-ceramic based dielectrics,a new class of LTCC materials with lowεr,is analyzed.

摘要：Fractal theory and regression analysis were employed for the first time to investigate the effect of pore size and pore distribution on high-temperature mechanical properties of porous alumina ceramics （PAC）. In the present work, PAC with the comparable porosity, different pore sizes and pore distributions were prepared using carbon black as the pore-forming agent. Particular emphasis in this study was placed on the establishment of correlation between the thermal shock resistance and pore properties. The relationship between fractal dimension （Df） and thermal shock resistance parameter （l？st） in specimens presented the negative power function, indicating that low Df could benefit the improvement of thermal shock resistance in specimens. The results showed that the increase of pore size and pore sphericity leads to a reduced Df, the enhanced hot modulus of rupture （HMOR） and Rst. The decrease of proportion of micro-pores below 2 μm, the increase of mean pore size and pore sphericity could result in the decrease of Dr, and then improve Rst and HMOR of specimens. Based on the correlation between Rst and pore characteristics, PAC with improved thermal shock resistance could be achieved when their pore structure meets the above features.

摘要：A new class of media with abnormal electromagnetic parameters has been attracting increasing attention because of its exotic properties and potential ***,typical metamaterials are mainly composed of artificially designed metallic periodic ***,due to the limitations of available fabrication technologies,physical size and material effects,it is difficult to realize these abnormal properties by these artificial structures in the high-frequency ***,it is important to find materials with intrinsic abnormal electromagnetic *** this field,a new mechanism based on the interaction between polar lattice vibrations and electromagnetic waves has been *** this paper,we review progress in this field.

摘要：Hyperthermia has been considered as a promising healing treatment in bone regeneration. We designed a tissue engineering hydrogel based on magnetic nanoparticles to explore the characteristics of hyperthermia for osteogenic regeneration. This nanocomposite hydrogel was successfully fabricated by incorporating magnetic Fe_3O_4 nanoparticles into chitosan/polyethylene glycol(PEG) hydrogel, which showed excellent biocompatibility and were able to easily achieve increasing temperatures under an alternative magnetic field(AMF). With uniformly dispersed nanoparticles, the composite hydrogel resulted in high viability of mesenchymal stem cells(MSCs), and the elevated temperature contributed to the highest osteogenic differentiation ability compared with direct heat treatment applied under equal temperatures. Therefore, the nanoheat stimulation method using the magnetic nanocomposite hydrogel under an AMF may be considered as an alternative candidate in bone tissue engineering regenerative applications.

摘要：Oxygen electrocatalysis,exemplified by the oxygen reduction reaction(ORR)and oxygen evolution reaction(OER),is central to energy storage and conversion technologies such as fuel cells,metal-air batteries,and water ***,highly effective and inexpensive earth-abundant materials are sought after to replace the noble metal-based electrocatalysts currently in ***,metal-organic frameworks(MOFs)and carbon-based MOF derivatives have attracted considerable attention as efficient catalysts due to their exceedingly tunable morphologies,structures,compositions,and ***,we report two-dimensional(2D)MOF/MOF derivative coupled arrays on nickel foam as binder-free bifunctional ORR/OER catalysts with enhanced electrocatalytic activity and *** remarkable electrochemical properties are primarily attributed to fully exposed active sites and facilitated charge-transfer *** coupled and hierarchical nanosheet arrays produced via our growth-pyrolysis-regrowth strategy offer promise in the development of highly active electrodes for energy-related electrochemical devices.

摘要：A wearable and high-precision sensor for sound signal acquisition and recognition was fabricated from thin films of specially designed graphene woven fabrics （GWFs）. Upon being stretched, a high density of random cracks appears in the network, which decreases the current pathways, thereby increasing the resistance. Therefore, the film could act as a strain sensor on the human throat in order to measure one＇s speech through muscle movement, regardless of whether or not a sound is produced. The ultra-high sensitivity allows for the realization of rapid and low-frequency speech sampling by extracting the signature characteristics of sound waves. In this study, representative signals of 26 English letters, typical Chinese characters and tones, and even phrases and sentences were tested, revealing obvious and characteristic changes in resistance. Furthermore, resistance changes of the graphene sensor responded perfectly with pre-recorded sounds. By combining artificial intelligence with digital signal processing, we expect that, in the future, this graphene sensor will be able to successfully negotiate complex acoustic systems and large quantities of audio data.

摘要：The oxides with perovskite structure possess abundant physical properties, such as magnetism, dielectricity, photoelectricity, ferroelectricity, etc. The oxygen ions in the perovskite unit cell constitute an octahedral distribution. The deformation or tilting of the special oxygen octahedra structure leads to new performances or properties change. Here, we give a review of the relationship between magnetic and electrical behaviors and oxygen octahedral tilting in several typical perovskite oxides. An understanding of how to tune these properties by controlling the tilting during the sample growth can more effectively guide the design of new structures for high performance and inspiring their potential applications.

摘要：The ability to widely tune the optical properties of amorphous alloys is highly desirable especially for their potential applications in optoelectronic *** this work,we demonstrate that introducing oxygen into an amorphous alloy system of Co-Fe-Ta-B enables the formation of various amorphous derivatives ranging from metals to semiconductors,and eventually to *** oxygencontaining amorphous derivatives gradually become transparent with the opened bandgaps,leading to a continuous increase in their optical ***,the reflective metal-type amorphous alloy and transparent insulator-type amorphous oxide of the system can be integrated together to realize the full-color tuning over the entire visible spectral *** provides a new way to develop large-area color coatings with high design flexibility and full-color *** envisage that the design concept proposed in this work is also applicable to many other amorphous alloy systems,from which all types of amorphous materials including alloys,semiconductors and insulators may be developed to show unprecedented optical functionalities.

摘要：Two-dimensional （2D） materials have attracted growing attention since the discovery of graphene [1]. Transition metal dichalcogenide （TMD） semiconductors, such as MoS2 and WS2, became popular materials in recent years, because they usually have intrinsic bandgaps and an in- direct-to-direct bandgap transition from bulk to mono- layer limit [2-6]. Although graphene and TMDs are promising materials in field-effect devices [7-9], their heterostructures are more advanced in charge-splitting functions for the applications in optoelectronic devices [10-15].

摘要：过渡金属氧化物具有丰富的功能性,但其错综复杂的内部自由度对相图绘制和结构设计提出了挑战.本文中,我们引入了描述相图物理起源的轨道能级序(ELO),并通过对La_(0.67)Sr_(0.33)MnO_(3)(LSMO)氧化物的研究证明了其在相图预测中的有效性.结合DFT计算和实验,我们构建了氧含量和应变关联的LSMO相图,结果表明LSMO结构稳定性与ELO密切相关.据此发现了一种由ELO演化而产生的四倍氧有序相.最后,我们提出了描述轨道分裂程度的轨道弹性定律,阐明了ELO演化的起源,助力功能氧化物的设计.这项研究拓宽了材料科学领域的性能调控手段,并为从轨道角度预测相图提供了思路.