摘要：Phase transformation of two-dimensional(2D)nanomaterials can lead to significant changes in electronic and optical properties,which enables the development of novel *** strategies for phase engineering of 2D nanomaterials have drawn considerable attention in recent *** review focuses on the state-of-the-art progress in the phase transformation of 2D nanomaterials and their catalytic ***,the basic concepts of phase transformation and the outstanding electronic and optical properties induced by phase transformation are briefly ***,different strategies for achieving phase transformation are discussed in detail and classified into several types based on their characteristics,including(i)doping,(ii)external fields,(iii)optical irradiation,(iv)strain effect,(v)high-energy particle excitation,and(vi)thermal *** applications of 2D nanomaterials in catalysis based on phase transformation have also been ***,a summary of the technical challenges to phase control in 2D nanomaterials and potential opportunities for developing novel applications is presented.

摘要：The practical application of high-energy lithium–sulfur battery is plagued with two deadly *** is the“shuttle effect”originated from the sulfur cathode,and the other is the low Coulombic efficiency and security issues arising from the lithium metal *** addressing these issues,we propose a novel silicon-sulfurized poly(acrylonitrile)full *** this lithium metal-free system,the Li source is pre-loaded in the cathode,using a nitrogen evolution reaction(NER)to implant Li+into the silicon/carbon *** poly(acrylonitrile)based on a solid–solid conversion mechanism can fundamentally circumvent the“shuttle effect”.Meanwhile,the silicon/carbon anode can achieve more efficient utiliza-tion and higher security when compared with the Li metal *** full cell used in this technology can deliver a capacity of 1169.3 mAh g^(-1),and it can be stabilized over 100 cycles,implying its excellent elec-trochemical ***,the practical pouch cell with a high sulfur loading of 4.2 mg cm^(-2)can achieve a high specific energy of 513.2 Wh *** mechanism of the NER in cathode has also been investigated and analyzed by in situ ***,this battery design completely conforms to the current battery production technology because of the degassing of gasbag,resulting in a low manufactur-ing *** work will open the avenue to develop a lithium metal-free battery using the NER.

摘要：Sodium-ion batteries are promising for large-scale energy storage due to sodium's low cost and infinite abundance. The most popular cathodes for sodium-ion batteries, i.e., the layered sodium-containing oxides, usually exhibit reversible host rearrangement between P-type and O-type stacking upon charge/discharge. Herein we demonstrate that such host rearrangement is unfavorable and can be suppressed by introducing transition-metal ions into sodium layers. The electrode with stabilized P3-type stacking delivers superior rate capability, high energy efficiency, and excellent cycling performance. Owing to the cation-mixing nature, it performs the lowest lattice strain among all reported cathodes for sodium-ion batteries. Our findings highlight the significance of a stable host for sodium-ion storage and moreover underline the fundamental distinction in material design strategy between lithium-and sodium-ion batteries.

摘要：基于二维过渡金属硫化物的全包覆晶体管是后硅时代的理想电子器件,从玻尔兹曼输运理论出发,在考虑载流子的主要外秉散射机制后,针对三种典型的栅介质(Al_(2)O_(3),HfO_(2)和BN)构筑的单层MoS_(2)晶体管的电学性能进行了系统的理论研究。为解决介质中表面光学声子散射被高估这一常见问题,使计算更为准确,在电介质和沟道间的建模中引入了“死区”概念。重点针对微电子1nm及以下技术节点用途晶体管的电荷迁移率和电流密度等指标进行了探讨.研究表明,在沟道长度小于10nm的情况下,晶体管开态电流均可超2mAμm。上述结果阐明了基于单层半导体构筑晶体管在终极微缩条件下的性能潜力,对深度摩尔器件设计具有一定的参考价值。

摘要：We report the first atomically resolved scanning tunneling microscope （STM） imaging in a water-cooled magnet （WM）, for which extremely harsh vibrations and noise have been the major challenge. This custom WM-STM features an ultra-rigid and compact scan head in which the coarse approach is driven by our newly designed TunaDrive piezoelectric motor. A three-level spring hanging system is used for vibration isolation. Room-temperature raw-data images of graphite with quality atomic resolution were acquired in the presence of very strong magnetic fields, with a field strength up to 27 T, in a 32-mm-diameter bore WM with a maximum field strength of 27.5 T at a power rating of 10 MW, calibrated by nuclear magnetic resonance （NMR）. This record field strength of 27 T exceeds the maximal field strength achieved by the conventional supercon- ducting magnets. Besides, our WM-STM has paved the way to STM imaging using a 45 T, 32-mm-diameter bore hybrid magnet, which is the world＇s flagship magnet, producing the strongest steady magnetic field.

摘要：电化学一氧化氮传感器能够实时监测颅内一氧化氮浓度,对于了解大脑中一氧化氮的功能至关重要.然而,在大脑中使用的传统刚性传感电极面临着灵敏度低和植入后神经炎症引起一氧化氮浓度异常的问题.在这里,我们报道了一种结合物理和化学吸附能力、具有高灵敏度和准确性的电化学一氧化氮传感器.其对一氧化氮的物理和化学吸附能力分别来自于电极的高比表面积和丰富的羧基官能团.此外,柔软的电极可以与脑组织的力学性能相匹配,实现了一个高度适应的电极/组织界面.由此设计的颅内一氧化氮传感器表现出迄今为止所报道文献中最高的灵敏度,为3245 pA nmol^(-1)L,检测限为0.1 nmol L^(-1).电极在植入后未观察到显著的炎症反应以及过量的一氧化氮表达,提高了检测的准确性.该传感器成功捕捉了大脑中的一氧化氮波动,并实现了对多个脑区的同时检测,促进了对大脑中一氧化氮生理病理作用的研究.

摘要：Combining a progressive tandem junction design with a unique Si nanowire(SiNW)framework paves the way for the development of high‐onset‐potential photocathodes and enhancement of solar hydrogen ***,a radial tandem junction(RTJ)thin film water‐splitting photo‐cathode has been demonstrated experimentally for the first *** photocathode is directly fab‐ricated on vapor‐liquid‐solid‐grown SiNWs and consists of two radially stacked p‐i‐n junctions,featuring hydrogenated amorphous silicon(a‐Si:H)as the outer absorber layer,which absorbs short wavelengths,and hydrogenated amorphous silicon germanium(a‐SiGe:H)as the inner layer,which absorbs long *** randomly distributed SiNW framework enables highly efficient light‐trapping,which facilitates the use of very thin absorber layers of a‐Si:H(~50 nm)and a‐SiGe:H(~40 nm).In a neutral electrolyte(pH=7),the three‐dimensional(3D)RTJ photocathode delivers a high photocurrent onset of 1.15 V *** reversible hydrogen electrode(RHE),accompanied by a photocurrent of 2.98 mA/cm^(2) at 0 V ***,and an overall applied‐bias photon‐to‐current effi‐ciency of 1.72%.These results emphasize the promising role of 3D radial tandem technology in developing a new generation of durable,low‐cost,high‐onset‐potential photocathodes capable of large‐scale implementation。

摘要：传统的制冷、制热技术能源消耗量巨大,而利用太空和太阳作为天然冷源和热源的辐射制冷和太阳能制热技术由于零能耗、低碳排的特点受到了研究者们的广泛关注,然而,目前被动式制冷/制热器件通常只能实现单一功能、无法满足动态环境条件下多变的制冷/制热需求,本文提出了一种温度自适应的智能控温双层薄膜(STG),以辐射制冷技术和太阳能制热技术为基础,可以随温度响应实现不同环境条件下制冷/制热模式的智能切换,当温度低于其境界温度时,STG膜在太阳光波段从高反射切换为高吸收(反射率由0.962变为0.059),而中红外发射率始终保持在0.95.该光谱特性使得STG膜在夏季直射阳光(辐射峰值>900Wm)下能够实现比环境温度低5°C的亚环境日间辐射冷却,而在冬季则能实现550Wm²的太阳光加热功率。作者同时通过理论模拟验证当STG膜被大规模应用时,这种可智能切换的制冷/制热装置在节能方面展现出了巨大的应用潜力该设计策略能够为零能耗的热响应控温器件提供新的思路,并为实现能源的可持续发展提供新的途径。

摘要：Daytime radiative cooling with high solar refection and mid-infrared emission offers a sustainable way for cooling without energy ***,so far sub-ambient daytime radiative coolers typically possess white/silver color with limited aesthetics and *** various colored radiative cooling designs have been pursued previously,multi-colored daytime radiative cooling to a temperature below ambient has not been realized as the solar thermal effect in the visible range lead to signifcant thermal ***,we demonstrate that photoluminescence(PL)based colored radiative coolers(PCRCs)with high internal quantum effciency enable sub-ambient full-color *** an example of experimental demonstration,we develop a scalable electrostatic-spinning/inkjet printing approach to realize the sub-ambient multi-colored radiative coolers based on quantum-dot *** unique features of obtained PCRCs are that the quantum dots atop convert the ultraviolet–visible sunlight into emitted light to minimize the solar-heat generation,and cellulose acetate based nanofbers as the underlayer that strongly refect sunlight and radiate thermal *** a result,the green,yellow and red colors of PCRCs achieve temperatures of 5.4–2.2℃ below ambient under sunlight(peak solar irradiance>740 Wm),*** the excellent cooling performance and scalable process,our designed PCRC opens a promising pathway towards colorful applications and scenarios of radiative cooling.

摘要：通过设计特定的时空调制,合成磁性的概念最近被提出以实现对光子和声子等电荷中性粒子的非互易操控,但现有方案存在着隔离度低、信号频率变化等问题.本文设计了一种新型耦合共振腔系统,其中动态耦合的相位作为实现声学合成磁场的新机制并打破了系统的时间反演对称性,最终取得了优异的声波非互易传输.基于旋转波近似方法,作者严格推导出了实现系统强非互易声传输的参数条件.通过优化动态耦合之间的相位差以及耦合强度,实验展示了隔离度达45-dB和正向传输率达0.85的优异单向声传输.此外,这种单向声传输具有始末态频率不变和隔离方向可电控等重要特性.该研究突破了现有声波单向操控机制在效率和隔离度方面的局限,并为实现弗洛奎和非线性声学拓扑绝缘体提供了新途径.