Advances in Multiferroic Nanomaterials Assembled with Clusters

As an entirely new perspective of multifunctional materials, multiferroics have attracted a great deal of attention. With the rapidly developing micro- and nano-electro-mechanical system (MEMS&NEMS), the new kinds of micro- and nanodevices and functionalities aroused extensive research activity in the area of multiferroics. As an ideal building block to assemble the nanostructure, cluster exhibits particular physical properties related to the cluster size at nanoscale, which is efficient in controlling the multiferroic properties for nanomaterials. This review focuses on our recent advances in multiferroic nanomaterials assembled with clusters. In particular, the single phase multiferroic films and compound heterostructured multiferroic films assembled with clusters were introduced detailedly. This technique presents a new and efficient method to produce the nanostructured multiferroic materials for their potential application in NEMS devices

HAMNER: Headword Amplified Multi-span Distantly Supervised Method for Domain Specific Named Entity Recognition

To tackle Named Entity Recognition (NER) tasks, supervised methods need to obtain sufficient cleanly annotated data, which is labor and time consuming. On the contrary, distantly supervised methods acquire automatically annotated data using dictionaries to alleviate this requirement. Unfortunately, dictionaries hinder the effectiveness of distantly supervised methods for NER due to its limited coverage, especially in specific domains. In this paper, we aim at the limitations of the dictionary usage and mention boundary detection. We generalize the distant supervision by extending the dictionary with headword based non-exact matching. We apply a function to better weight the matched entity mentions. We propose a span-level model, which classifies all the possible spans then infers the selected spans with a proposed dynamic programming algorithm. Experiments on all three benchmark datasets demonstrate that our method outperforms previous state-of-the-art distantly supervised methods.Comment: 9 pages, 2 figure

Improved Ferroelectric and Leakage Properties of Ce Doped in BiFeO 3

Ce doped BiFeO3 thin films with a perovskite structure were prepared using solution-gelation method. It shows that the ferroelectric properties have been enhanced after doping Ce. The enhanced ferroelectric properties are attributed to the structural transformation and the reduced leakage current after doping rare metal of Ce. It has been found that the phase structures of the films transfer from rhombohedral symmetry structure to the coexistence of the tetragonal and orthorhombic symmetry structure. And Fe2+ ions have been reduced, which leads to the decreased leakage for Ce doped BiFeO3 thin films. The present work can provide an available way to improve the ferroelectric and leakage properties for multiferroic BiFeO3 based thin films

Integration of aggregation-induced emission and delayed fluorescence into electronic donor–acceptor conjugates

A series of luminogens comprised electron donors and acceptors are found to possess two types of interesting photophysical processes of aggregation-induced emission (AIE) and delayed fluorescence. According to theory calculation, restriction of intramolecular motions accounts for their AIE characteristics. Moreover, a separated distribution of the HOMOs and the LUMOs of these luminogens leads to small DEST values and therefore delayed fluorescence

Calibrating the atomic balance by carbon nanoclusters

Carbon atoms are counted at near atomic-level precision using a scanning transmission electron microscope calibrated by carbon nanocluster mass standards. A linear calibration curve governs the working zone from a few carbon atoms up to 34,000 atoms. This linearity enables adequate averaging of the scattering cross sections, imparting the experiment with near atomic-level precision despite the use of a coarse mass reference. An example of this approach is provided for thin layers of stacked graphene sheets. Suspended sheets with a thickness below 100 nm are visualized, providing quantitative measurement in a regime inaccessible to optical and scanning probe methods

一种食用油锁养保鲜生产工艺

为了解决食用油在储存过程中因发生各种变化而造成的品质下降问题，介绍了一种食用油的锁养保鲜生产工艺，包括全工段恒温灌装、充氮灌装和抗紫外瓶包装。实践证明，全工段恒温灌装有效避免了灌装油温过高产生负压造成的瓶内缩吸瘪，减少了标签不平整情况的发生；充氮灌装使食用油包装瓶内顶空残氧量低于6％，产品残氧量指标稳定；以色母为抗紫外助剂，制成的食品级食用油包装瓶可防止紫外线对食用油品质的影响。采用此生产工艺，可以有效提高食用油的品质并延长储存期。 In order to solve the problem of degradation of the quality of edible oil due to various changes that occur during the storage process, a fresh-keeping production technology of edible oil was introduced, including constant temperature filling in the whole section, nitrogen filling and UV resistant bottle packaging. The practice showed that the constant temperature filling in the whole section could effectively avoid the bottle shrinkage caused by the high filling oil temperature and negative pressure, and reduce the occurrence of uneven labels. Nitrogen filling could make the residual oxygen content in the processed edible oil bottle less than 6%, and the product residual oxygen index stable. The food grade edible oil packaging bottle made of color masterbatch as an anti-ultraviolet additive could prevent the influence of ultraviolet rays on the quality of edible oil. The use of this production process can effectively improve the quality of edible oil and extend the storage period

Microstructure and electrical properties of Nb‐doped SrTiO3‐BiFeO3 based lead‐free ceramics

In this work, Nb-doped 0.75SrTiO3-0.25BiFeO3 (ST-BF) lead-free ceramics are designed and synthesized using a conventional solid-state reaction method. The influence of Nb doping on the microstructure, dielectric, and electrical properties are systematically investigated. With the increase of Nb concentration, the crystal structure of ST-BF remains pseudo-cubic as exhibited in the X-ray diffraction patterns. The grain size is found to increase from 0.33 to 6.23 μm, and then decrease to 1.88 μm by Nb doping, along with a clear heterogeneous core–shell microstructure. A relatively low dielectric loss (∼0.1, at 1 kHz) and a stable dielectric constant (∼700, at 1 kHz) are obtained for the 0.03 Nb-doped ST-BF composition at room temperature. Impedance spectroscopy analysis shows that Nb doping in ST-BF increases the total resistivity, forming an electrically conductive core and a nonconductive shell, with enhanced activation energy. The results may provide a feasible approach to develop novel ST-based lead-free dielectric ceramics for capacitor application