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  • We develop a robust full-Brillouin zone soft-phonon-searching algorithm, with outstanding accuracy and efficiency in pinpointing general phonon instability within the joint material-reciprocal spaces in crystals. By combining finite-element modeling with embedded phonon algorithm and atomistic simulation, we show how a zone-boundary soft phonon is first triggered in a perfect aluminum crystal under nanoindentation, which subsequently leads to a transient new crystal phase and ensuing nucleation of a deformation twin. We propose a two-stage mechanism governing the transformation of unstable short-wave phonons into lattice defects, fundamentally different from that initially triggered by soft long-wavelength phonons.

    • Xiaohui Liu
    • Jianfeng Gu
    • Ju Li
    Original ArticleOpen Access
  • A new principle for management of dopant–dopant and dopant–host interactions by manipulation of mesoscale heterogeneity in a single active material is presented. The proposed mesoscale engineering approach results in dramatically inhomogeneous broadening of dopant, and for the first time show success in simultaneously extending emission bandwidth and flattening spectral shape in a doped glass and fiber.

    • Yongze Yu
    • Zaijin Fang
    • Jianrong Qiu
    Original ArticleOpen Access
  • A modified polybenzimidazole (mPBI) was synthesized to tame the polysulfides (PS) shuttling in Li–S batteries via dual actions. As a binder, the mPBI mechanically and chemically offers strong electrode integrity and high sulfur loading, inhibits sulfur loss and prolongs lifespan for sulfur electrode. As a functional agent, the mPBI builds a shield onto the separator to block PS migration so as to further suppress the PS shuttling. This strategy confers an excellent performance of 750 mAh g−1 (or 5.2 mAh cm−2) after 500 cycles at C/5 for the resultant Li–S battery with an ultralow capacity fading rate of 0.08% per cycle.

    • Gaoran Li
    • Can Wang
    • Shanqing Zhang
    Original ArticleOpen Access
  • (ac) Reciprocal space maps about (022) reflections of PZN-PT (011) under various poling states, exhibiting various ferroelastic strain states. (d) Electric impulse-induced non-volatile tuning of magnetic anisotropy between the distinct strain states A and B due to the ferroelectric partially coupled ferroelastic domain switching. (e) Hysteresis loops of magnetic resonance fields of FeGaB as a function of the electric field applied on PZN-PT (011), arising from the electric field-induced ferroelectric phase transition from rhombohedral to orthogonal (R–O).

    • Ming Liu
    • Tianxiang Nan
    • Nian X Sun
    Original ArticleOpen Access
  • A new mechanism of porosity-induced graded refractive index, which results in enhanced broadband anti-reflection properties that can extend the inherent properties of 1D materials, for example, wide band gap ZnO in this work, and modify it to achieve an unprecedented photodetection capability covering the entire visible-light range, is demonstrated.

    • Kapil Gupta
    • Jr-Ting Lin
    • Chuan-Pu Liu
    Original ArticleOpen Access
  • A novel magnetic droplet vaporization strategy was developed for efficient magnetic field-responsive cancer theranostics. Perfluorohexane (PFH)-encapsulated superparamagnetic hollow iron oxide nanoparticles with high magnetic-thermal energy transfer capability quickly respond to external alternating current (a.c.) magnetic field to produce thermal energy and raise the surrounding temperature of tumor tissue. The encapsulated PFH with desirable boiling point of about 56 °C can be vaporized to enhance the ultrasound imaging performance for responsive imaging. Such a magnetic–thermal energy transfer can further completely ablate and remove the tumor against a mice tumor xenograft model.

    • Yang Zhou
    • Ronghui Wang
    • Yuanyi Zheng
    Original ArticleOpen Access
  • Ultrafast reduction of graphene oxide sheets was achieved by intense pulsed light irradiation on a highly transparent and thermally stable polyimide substrate. The obtained reduced graphene sheets exhibited improved chemical sensing characteristics, which are promising in wearable chemical sensors for real-time environmental monitoring.

    • Seon-Jin Choi
    • Sang-Joon Kim
    • Il-Doo Kim
    Original ArticleOpen Access
  • We report novel azo-carbazoles that can be applied to updatable full-color holography. We introduced a molecular design concept of updatable full-color holographic systems based on spectroscopic and optical characteristics. Taking advantage of characteristics of the designed azo-carbazoles, updatable red, yellow and green holograms can be recorded, which enabled us monochromic hologram as well as full-color hologram in the future.

    • Kenji Kinashi
    • Takahiro Fukami
    • Naoto Tsutsumi
    Original ArticleOpen Access
  • Conventional memory devices are not disposable as they are mostly composed of non-renewable, non-biodegradable and some toxic materials, causing a serious damage for ecological system when they are emitted to the environment. Here we demonstrate an environment-friendly, disposable nonvolatile memory device composed of 99.3 vol.% nanocellulose. Our device consists of a nanocellulose-based resistive-switching layer and nanopaper substrate. The device exhibited the nonvolatile resistive switching with the capability of multilevel storage and the potential scalability down to single nanofiber level. Furthermore, the biodegradability of our memory device was confirmed by burying it into the natural soil for 26 days.

    • Umberto Celano
    • Kazuki Nagashima
    • Takeshi Yanagida
    Original ArticleOpen Access
  • Synchrotron radiation-based X-ray phase-contrast imaging was employed to observe the solid–liquid-vapor interface on superhydrophobic surfaces. The reconstructed 3D images revealed that the water exists in the Cassie-to-Wenzel transit state. The micro/nano-structures trapped a large amount air on the supherhydrophobic surface to repel water.

    • Zhanhao Hu
    • Ming Sun
    • Chunhai Fan
    Original ArticleOpen Access
  • We realized highly flexible tandem OLEDs using a graphene anode with very high electroluminescent efficiency ~205.9 cd A−1, 45.2% (~396.4 cd A−1, 87.3% with a hemispherical lens) and very low efficiency roll-off at high luminance ~6.6% at 10 000 cd m−2 (~3.8% with a hemispherical lens) by stacking two organic electroluminescence units using a easily controllable and low-temperature processable charge generation layer on thin flexible plastic substrates. The flexible OLEDs showed great flexibility against bending stress up to bending strain of 6.7%.

    • Tae-Hee Han
    • Min-Ho Park
    • Tae-Woo Lee
    Original ArticleOpen Access
  • Inspired by a popular self-assembled motif in proteins called amyloids, we have developed a series of hydrogels composed of amyloid nanofibrils. The gelation process could be induced via different stimuli, such as heating/cooling or change of pH. Human mesenchymal stem cells preferentially differentiate toward neurons when cultured on these hydrogels. Moreover, its shear thinning property facilitates transplantation of stem cells into the brain with minimally invasive surgery. We demonstrate here the utilization of injectable amyloid hydrogels, which promotes cell survival as well as neuronal differentiation in vivo.

    • Subhadeep Das
    • Kun Zhou
    • Samir K Maji
    Original ArticleOpen Access
  • We developed glycol chitosan-based thermo-reversible hydrogels that can provide a facile, convenient and reproducible method for the formation of 3D cell spheroids. The spontaneous formation of spheroids on HGC-coated plates was completed within 1 day. Furthermore, this system can be useful for co-culturing heterotypic cells to form spheroids that mimic biological systems.

    • Myeong Ok Cho
    • Zhengzheng Li
    • Kang Moo Huh
    Original ArticleOpen Access
  • Oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) are still kinetic barriers of regenerative fuel cell and metal–air batteries, requiring efficient and inexpensive bifunctional electrocatalysts to accelerate the reaction and improve energy efficiency. Herein, we develop Co9S8 particles in situ grown on nitrogen and sulfur co-doped porous carbon (Co9S8/NSPC) to replace the benchmark noble metal catalysts, which shows high catalytic activities including small potential gap, long-term durability and high selectivity. Importantly, the Zn–air battery with Co9S8/NSPC as air electrode displays low discharge/charge overpotential and good cyclic stability, making it the promising bifunctional catalyst for the practical applications.

    • Hai-xia Zhong
    • Kai Li
    • Xin-bo Zhang
    Original ArticleOpen Access
  • Indium tin oxide (ITO) is a well-known n-type degenerate semiconductor. Herein, mesoporous ITO is utilized as a photocathode material for p-type dye-sensitized solar cells in place of the commonly applied p-type semiconductors, such as nickel oxide. In conjunction with [Fe(acac)3]0/− as redox mediator and a new sensitizer, an impressive energy conversion efficiency of 1.96±0.12% was achieved. Photoelectron spectroscopy in air revealed that ITO exhibits a significant local density of states arising below −4.8 eV, which enables electron transfer to occur from ITO to the excited dye, giving rise to the sustained photocathodic current.

    • Ze Yu
    • Ishanie R Perera
    • Udo Bach
    Original ArticleOpen Access
  • The precision synthetic method of well-defined polymer microspheres by the π-allylnickel-catalyzed living coordination polymerization of allene derivatives under the dispersion polymerization conditions is described. Unlike the conventional dispersion polymerization systems, the use of a bifunctional monomer, 1,4-diallenoxybenzene, to this living dispersion polymerization successfully gave well-defined crosslinked living polymer microspheres that exhibit high solvent-tolerant properties. The postpolymerization of functional allene monomers in the living dispersion polymerization also proceeded smoothly to give functionalized polymer microspheres that enabled their applications to the solid-phase organic synthesis and the solid-supported transition metal catalysts.

    • Akira Yamauchi
    • Aya Shirai
    • Ikuyoshi Tomita
    Original ArticleOpen Access
  • We herein report a synergistic optimization procedure that combines point defect engineering, band structure engineering and multiscale microstructuring in p-type (Bi,Sb)2Te3 thermoelectric materials by Indium doping and hot deformation. As a result, a peak value of zT ~1.4 was attained in Bi0.3Sb1.625In0.075Te3 at 500 K, along with a state-of-the-art average zTav of ~1.3 between 400 and 600 K. These results demonstrate the efficacy of the multi-synergies that can also be applied to optimize other thermoelectric materials.

    • Zhaojun Xu
    • Haijun Wu
    • Xinbing Zhao
    Original ArticleOpen Access
  • Strong correlation between the local strain state and the electronic properties at orthorhombic–rhombohedral (O-R) phase boundaries in mixed-phase BFO thin films leads to electronic conductivity at these boundaries. This rather unusual electrical feature might find applications in nanotechnology.

    • Yooun Heo
    • Jin Hong Lee
    • Jan Seidel
    Original ArticleOpen Access
  • Three kinds of Ni3S2 nanostructures, namely Ni3S2 nanorods, Ni3S2 nanosheet@nanorods and Ni3S2 multi-connected nanorods were prepared using a one-step hydrothermal process via controlling the temperature. Owing to the good mechanical adhesion and electrical connection with the substrate, high contact area with the electrolyte and alleviated structural pulverization during the ion insertion/desertion process, Ni3S2 nanosheet-onto-Ni3S2 nanorods exhibited excellent rate capability and cycling stability. Asymmetric supercapacitor consisting of Ni3S2 nanosheet @nanorods electrode and activated carbon (AC) electrode displayed a volumetric energy density of 1.96 mWh cm−3, which can be used to bridge the performance gap between thin-film Li batteries and commercial AC//AC supercapacitors.

    • Xunhui Xiong
    • Bote Zhao
    • Meilin Liu
    Original ArticleOpen Access