A Piezoelectric and Electromagnetic Dual Mechanism Multimodal Linear Actuator for Generating Macro- and Nanomotion

Fast actuation with nanoprecision over a large range has been a challenge in advanced intelligent manufacturing like lithography mask aligner.Traditional stacked stage method works effectively only in a local,limited range,and vibration coupling is also challenging.Here,we design a dual mechanism multimodal linear actuator(DMMLA)consisted of piezoelectric and electromagnetic costator and coslider for producing macro-,micro-,and nanomotion,respectively.A DMMLA prototype is fabricated,and each working mode is validated separately,confirming its fast motion(0~50 mm/s)in macromotion mode,micromotion(0~135μm/s)and nanomotion(minimum step:0~2 nm)in piezoelectric step and servomotion modes.The proposed dual mechanism design and multimodal motion method pave the way for next generation high-precision actuator development.

Bilayer tellurene-metal interfaces

Tellurene, an emerging two-dimensional chain-like semiconductor, stands out for its high switch ratio, carrier mobility and excellent stability in air. Directly contacting the 2D semiconductor materials with metal electrodes is a feasible doping means to inject carriers. However, Schottky barrier often arises at the metal–semiconductors interface, impeding the transport of carriers. Herein, we investigate the interfacial properties of BL tellurene by contacting with various metals including graphene by using ab initio calculations and quantum transport simulations. Vertical Schottky barriers take place in Ag, Al, Au and Cu electrodes according to the maintenance of the noncontact tellurene layer band structure. Besides, a p-type vertical Schottky contact is formed due to the van der Waals interaction for graphene electrode. As for the lateral direction, p-type Schottky contacts take shape for bulk metal electrodes(hole Schottky barrier heights(SBHs) ranging from 0.19 to 0.35 eV). Strong Fermi level pinning takes place with a pinning factor of 0.02. Notably, a desirable p-type quasi-Ohmic contact is developed for graphene electrode with a hole SBH of 0.08 eV. Our work sheds light on the interfacial properties of BL tellurene based transistors and could guide the experimental selections on electrodes.

Tuning effect of silicon substitution on magnetic and high frequency electromagnetic properties of R2Fe17 and their composites

In this work, we report the tuning effect of the Si substitution on the magnetic and high frequency electromagnetic properties of R2 Fe17 compounds and their paraffin composites. It is found that the introduction of Si can remarkably improve the magnetic and electromagnetic properties of the R2 Fe17 compounds, making the R2 Fe17 exSix-paraffin composites excellent microwave absorption materials(MAMs). By introducing the Si element, their saturation magnetizations decrease slightly, while much higher Curie temperatures are obtained. Furthermore, better impedance match is reached due to the decrease of the high-frequency permittivity ε’ by about 40%e50%, which finally enhances the performance of the microwave absorption. The peak frequency(fRL) of the reflection loss(RL) curve moves toward high frequency domain and the qualified bandwidth(QB, RL≤-10 dB) increases remarkably. The maximum QB of 3.3 GHz(12.0 e15.3 GHz) is obtained for the Sm1.5 Y0.5 Fe15 Si2-paraffin composite(d = 1.0 mm) and the maximum RL of -53.6 dB is achieved for Nd2 Fe15 Si2-paraffin composite(d = 2.2 mm), both surpassing most of the reported MAMs. Additionally, a distinguished dielectric microwave absorption peak is observed, which further increases the QB in these composites.

Neutron diffraction studies of permanent magnetic materials

Neutron diffraction technology as an advanced material research technique has special advantages in studying magnetic materials compared to the conventional techniques such as X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),and X-ray photoelectron spectroscopy(XPS).In this review,the applications of neutron diffraction technology on permanent magnetic materials were briefly reviewed:(1)the determination of the crystal structure and magnetic structure of the typical permanent magnet material,(2)in situ neutron diffraction study of the crystal structure evolution of the permanent magnets,and(3)phase transition in permanent magnetic materials.

Approaching the uniaxiality of magnetic anisotropy in singlemolecule magnets

Single-molecule magnets(SMMs),which can exhibit slow magnetization relaxation and bulk-magnet-like hysteresis of purely molecular origin,are promising candidates for high-density information storage,molecular spintronics,and quantum computing.To realize their applications,it is crucial to improve the blocking temperature(TB)and the effective relaxation barrier(Ueff).Three decades of multidisciplinary research have yielded distinct SMMs with a state-of-the-art Ueff of up to 2,000 K and a TB of up to the liquid nitrogen region.Several strategies have been investigated and summarized,which revealed that enhancing the uniaxiality of magnetic anisotropy is critical for constructing high-performance SMMs.Therefore,magnetic anisotropy,a key property that connects the molecular structure symmetry and performance of SMMs,plays a fundamental role in dictating magneto-structural correlations.Understanding and employing magnetic anisotropy would be significantly beneficial for rationally designing high-performance SMMs.This review focuses on the magnetic anisotropy of SMMs.We illustrate the origin and manifestation of magnetic anisotropy in mononuclear 3d-and 4f-block metal complexes.We then introduce developed approaches to investigate magnetic anisotropy both theoretically and experimentally.Typical SMMs by optimizing uniaxial magnetic anisotropy through lanthanide metallocene,symmetry controlling,and low-coordination approaches are represented.Furthermore,the remaining challenges and opportunities in this field will be discussed.

A new dual-ion battery based on amorphous carbon

The Na-based dual-ion batteries(NDIBs),combining the advantages of Na-ion batteries and dual-ion batteries,are attracting more attention due to their merits of abundant source,low cost and high energy density.However,the main challenges faced by NDIBs are their low capacity and poor cycling.Herein,we report a new ion storage mechanism for high-performance NDIBs using amorphous carbon(AOMC)as cathode.Unlike the graphite carbon that can only accommodate the PF6-anion(typical DIB system),the AOMC herein can both accommodate Na+cation and PF6-anion due to its amorphous feature,which is conceptually new dual-ion system for achieving much higher capacity.Ex-situ X-ray photoelectron spectroscopy,X-ray diffraction and Raman studies reveal that the disordered carbon in the AOMC can be transformed to the partial graphitic stacking in short range,improving both capacity and cycling stability of NDIBs.As a consequence,the AOMC delivers a highly reversible storage capacity of 136 mAhg-1 for 800 cycles at a very high current density of 2.0 Ag-1,much higher than all the reported NDIBs.Such concept can be generalized to develop high-performance dual-ion full cell using sodium ion preintercalated materials as anode and AOMC as cathode.

Combinatory antitumor therapy by cascade targeting of a single drug

Combination therapy has shown its promise in the clinic for enhancing the efficacy of tumor treatment.However,the dose control of multiple drugs and their non-overlapping toxicity from different drugs are still great challenge.In this work,a single model drug,paclitaxel(PTX),is used to realize combination therapy and solve the problems mentioned above.Either PTX or its triphenylphosphine derivative(TPTX)is encapsulated in galactose-modified liposomes(GLips)to obtain GLips-P or GLips-TP,which are simply mixed in different ratios to finely control the proportion of PTX and TPTX.These mixed liposomes,GLips-P/TP,feature a cascade target delivery of PTX,from tissue to cell,and then to organelle.PTX plays a primary role to cause the cytotoxicity by microtubule bindings in cytoplasm,while TPTX is proved to increase the intracellular levels of caspase-3 and caspase-9 that cause apoptosis via a mitochondria-mediated pathway.Notably,GLips-P/TP 3:1 exhibited the significant drug synergy in both cytotoxicity assay of HepG2 cells and the treatment efficacy in Heps xenograft ICR mouse models.This work not only demonstrates the great promise of a cascade targeting delivery for precise tumor treatment,but also offers a novel platform to design combinatory therapy systems using a single drug.

Assembling High-Temperature Single-Molecule Magnets with Low-Coordinate Bis(amido)Dysprosium Unit[DyN_(2)]^(+)via Cl-K-Cl Linkage

Symmetryandaxialityarethought tobeguides toward the pursuit of high energy barrier and blocking temperature for thedysprosium(Ⅲ)(Dy^(Ⅲ))single-molecule magnets(SMMs).The Dy^(Ⅲ)complexeswith low coordination numbers are intended to satisfy axial symmetry.Here,we report four four-coordinate Dy^(Ⅲ)SMMs based on bis(arylamido)dysprosium building block{Dy(N^(RR’))2(μ-Cl)_(2)K}(N^(RR’)={N(SiMe_(3))(C_(6)H_(3)iPr_(2)-2,6)}^(−)),with two strong Dy–N and twoweak Dy–Cl bonds.Through fine-tuning of axial anisotropy,the SMM with the largest N–Dy–N angle of 139.24(15)°displayed magnetic hysteresis with a coercive field(H_(c))of 18.6 kOe at 2 K,which kept opening up to 35 K.Alternating current susceptibility measurement showed that the relaxation energy barrier reached as high as 1578 K,which is among the highest reported Dy^(Ⅲ)SMMs.Ab initio calculations revealed strong anisotropy and crystal-field axiality of the compound,despite the low symmetry,and provided a synthetically workable approach to construct high-performance SMMs useful in applications such as digital processing,transport electronics,quantumcomputing,and ultra-high-density data storage.

选择性溶解-再生长策略原位构筑非晶羟基氧化铁分级纳米管增强储锂性能

低成本、高容量金属氧化物/氢氧化物作为具有更高能量密度的锂离子电池的负极材料时具有显著优势.合理调控金属氧化物/氢氧化物的中空结构和无序的原子框架是提高其电化学性能的有效途径.本文提出了一种快速碱刻蚀方法,实现了非晶FeOOH分级纳米管的原位构筑.得益于增强的电子/离子动力学和对循环过程中的体积变化的有效缓冲,石墨烯修饰的非晶FeOOH分级纳米管展现出高倍率性能(在2000 mA g^−1的电流密度下容量可达~650 mA h g^−1)和优异的循环稳定性(循环1800次后容量仍保持在463 mA h g^−1),在目前报道的FeOOH基材料中处于领先水平.研究表明碱刻蚀过程中的选择性溶解-再生长机制,即FeVO4的溶解和FeOOH的原位成核再生长在非晶FeOOH分级纳米管的合成过程中具有重要作用.此外,这种选择性溶解-再生长机制是一种合成具有一维分级纳米结构的金属(例如Fe,Mn,Co和Cu)氧化物/羟基氧化物的普适方法.