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Most fluorescent probes based on carbon dots (CDs) fluorescence color or intensity change are still used for detection in solution, but in practical fluorescence detection applications, detection in the solid state is necessary. Therefore, a CDs-based fluorescence sensing device is designed in this paper, which can be used for water detection in liquid and solid states. Using oPD as a single precursor, yellow fluorescent CDs (y-CDs) were prepared by hydrothermal method, which can be used in the field of water detection and anti-counterfeiting by using its solvent-sensitive properties. First, y-CDs can be used to visually and intelligently detect the water content in ethanol. Secondly, it can be used to detect the Relative Humidity (RH) of the environment by combining it with cellulose to form a fluorescent film. Finally, y-CDs can also be used as a fluorescent material for fluorescence anti-counterfeiting. [ABSTRACT FROM AUTHOR]

Fluorescent carbon quantum dots (CQDs) have been widely used as anti‐counterfeiting materials due to their excellent optical properties, but the in‐depth studies on the effects of solvent and ink properties on the inkjet printing still very few. Using L‐ascorbic acid as a carbon source, CQDs were prepared by the solvothermal method and dissolved in different solvents. Then, the structures, morphologies, optical properties were characterized by Fourier transform infrared spectroscopy (FTIR), UV‐vis and fluorescence spectroscopic, and transmission electron microscope (TEM) in detail. The results show that there are many hydrophilic groups on the surface of the CQDs, and the luminescence mechanism is mainly based on the defective state of the oxygen surface. The solubility of the CQDs in a polar solvent is good, and it has good fluorescence emission performance, which is the result of the interaction between the polarity of the solvent and hydrogen bond. At the same time, the CQDs ink prepared in this experiment can be printed on the bond paper by inkjet to form a bright blue fluorescent pattern. [ABSTRACT FROM AUTHOR]

With the advent of self-driving cars, vehicular networking is gaining greater attention and the subject of extensive research. It is important to implement a more efficient and secure transportation system by enabling communication among objects on the road. Specifically, safety applications should be delivered in a reliable manner within a limited time period. Several time division multiple access (TDMA) protocols have been proposed to realize this. However, most of the existing research have proposed slot management approaches by taking into account the static topology; they have not sufficiently discussed research on “merging collision” arising from overlapping two or more collision domains due to vehicle mobility. In this study, we examine the effect of merging collision in terms of packet delivery ratio, overhead, and inter-basic safety message (inter-BSM) delay. 1 Delay between BSMs received in succession. To mitigate the effect of merging collision, we also propose a lightweight distributed TDMA protocol, where the order of vehicles on the road and their relative distances are exploited to determine the dedicated slot. The collision is further resolved using in-band signaling from the surrounding vehicles. Simulation studies show that the proposed scheme improves the performance of the packet delivery ratio (PDR) 10% more than the comparative protocol, and consequently achieves 97% and 95% PDRs, in highway and urban environment, respectively. Furthermore, the overhead and inter-BSM delay are substantially reduced. [ABSTRACT FROM AUTHOR]

The nitrogen‐sulfur co‐doped fluorescent carbon quantum dots (N/S‐CQDs) were synthesized from sulfanilic acid. The fluorescence emission was independent of the excitation wavelength. In this experiment, the carbonization degree of the precursors was adjusted by solvent‐thermal method to affect the sp2 conjugated dimension of CQDs, thus affecting the fluorescence performance of CQDs. They are well dispersed in water and ethanol, and have high selectivity for Fe3+. The detection range is 0.025∼0.4 mmol/L, and the detection limit is about 2.549 μmol/L. The CQDs prepared in this experiment emit light indirectly through the surface defect state. When CQDs is illuminated by light, the carriers generated by photons will emit light at a very fast speed due to the surface defect state, so the excited electrons in CQDs can be easily transferred to Fe3+, making the surface of CQDs more complete, thus leading to the quenching of CQDs fluorescence. [ABSTRACT FROM AUTHOR]

In spite of the TiO2 compact layer (TCL) being widely used, it still needs more study. This paper took Ni-doped TCLs as the research target, using an innovative two-step method perfectly prepared Ni-doped TCLs with different thicknesses. And then on the basis of Ni-doped TCLs, the TiO2 nanorod array (TNA) films were successfully prepared. The effects of Ni-doped TCLs with different thicknesses on the morphology, structure, and photoelectric performance of TNA films were investigated. The results indicated that Ni-doped TCLs with appropriate thickness can significantly improve performance of TNA films and obtain satisfactory PCE stability with time. Compared with the TNA films based on Ni:TCL5, Ni:TCL10, and Ni:TCL30, the TNA film with Ni:TCL20 exhibited better comprehensive photoelectric performance, the DSSCs based on this TNA film achieved the highest Jsc (10.191 mA cm−2), Voc (0.574 V), PCE (4.42%), and the most excellent PCE stability with time. [ABSTRACT FROM AUTHOR]

• 1D TNA films with ideal morphology were prepared by the two-step process. • The optical performance of 1D TNA films was enhanced by narrowing the bandgap. • The 1D TNA films achieved efficient charge separation with higher photocurrent density. One-dimensional TiO 2 nanorod array films (1D TNA films) were prepared by the two-step process. The results show that the density of 1D TNA films is significantly improved with the presence of TiO 2 compact layer (TCL) and the hydrothermal reaction time of 15 h. The TiO 2 crystallinity is improved. The utilization efficiency of the visible light is increased with the lower concentration of crystal defects. The charge recombination center caused by the defects decreased, while the electrons and holes were effectively separated, thus the charge recombination rate was lowered, and better charge transport performance caused the transient photocurrent to increase significantly. [ABSTRACT FROM AUTHOR]

Cobalt disulfide (CoS 2 ) is a promising thermal battery electrode material for its superior thermal stability and discharge performance. However, the low natural resource and poor air stability restrict its application in thermal battery fabrication. In this work, carbon coated CoS 2 composite was prepared by a facile one-pot hydrothermal method with glucose as carbon source. During the growth of CoS 2 , the glucose molecules were in situ adsorbed and carbonized on the surface of the as-synthesized CoS 2 , and the resultant carbon coating provided improved electrical conductivity and discharge performances to the composite. The thermal battery cell, which was fabricated with such a composite cathode and with a Li-Si anode, can output a capacity of 235.8 mAh g −1 and an energy density of 416.9 Wh kg −1 at a cut-off voltage of 1.7 V. This carbon coated CoS 2 composite also presented enhanced air stability. After being stored in dry air for 3 months, the composite can still provide a capacity of 232.4 mAh g −1 to 1.7 V, whereas the capacity of bare CoS 2 stored with the same condition dropped from 202.4 mAh g −1 to 189.7 mAh g −1 . [ABSTRACT FROM AUTHOR]

CoS 2 /CNTs composites were prepared by a facile and simple hydrothermal growth of CoS 2 in the presence of carbon nanotubes (CNTs), as a novel approach of synthesizing cathode composites for thermal battery fabrication. The incorporation of CNTs in the CoS 2 cathode materials thus synthesized effectively improved the electrical conductivity and discharge performance of the resultant cathode, without significantly compromising its thermal stability. The thermal battery cell fabricated with such a composite cathode and with a common Li–Si anode showed all functional features of a proper thermal battery cell. The specific discharge capacity at a cut-off voltage of 1.7 V was 219.8 mA h g −1 , and the corresponding energy density was 387.2 W h kg −1 . With a pulse current density of 500 mA cm −2 , the battery delivered a pulse power of 2.45 W, and maintained 64% of this power after 30 pulses. Regarding thermal stability, the CoS 2 /CNTs cathode was stable at least at 625 °C. [ABSTRACT FROM AUTHOR]

Different molar ratios of La:Ni (LaNiO/NiO) hollow nanofibers were prepared by electrospinning method. The morphologies and microstructures of the samples were examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The electrochemical properties of nanofibers were investigated by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS) analyses in an aqueous electrolyte (7 M KOH). Results showed that adding the conductive material (LNO) can enhance the specific capacitance and electrochemical stability of the NiO nanofibers. In particular, La:Ni = 1:2 (LNO:NiO = 1:1) showed a remarkable specific capacitance of 257.8 F g scaled to the total mass of the electrode or 942 F g scaled to the active mass (NiO) at a current density of 0.5 A g. The cycling tests operated at a potential window of 0 to 0.45 V with a current density of 0.5 A g suggested that the electrode had excellent cycling performance, with only 10 % capacitance loss after 1000 cycles. [ABSTRACT FROM AUTHOR]

Current flowing through heavy metals generates spin current by the spin Hall effect (SHE), and spin current exerts a torque on the adjacent magnetic layer, thereby switching the magnetization direction of the magnetic layer. Normally, an external magnetic field must be used to break symmetry in the response to the SHE torque, to realize deterministic switching. However, the presence of magnetic fields increases the difficulty in integrating spintronic devices with complementary metal-oxide-semiconductor. Thus, field-free spin–orbit torque switching has been a research hotspot. Here, symmetry-breaking has been realized by tilting the sample during the annealing process, resulting in a non-uniform diffusion of Ta atoms in the samples along the temperature gradient (x-direction), which was confirmed by transmission electron microscope mapping. As a result, the sample has demonstrated deterministic switching, in the absence of an external magnetic field, with a switching ratio of up to 88% and the critical current density of 1.5 × 107 A/cm2. Tilting annealing is a simple approach to achieve field-free switching. [ABSTRACT FROM AUTHOR]

In this paper, K-doped ZnO nanocrystalline powders were prepared by the sol-gel method at 500 °C. The effects of potassium (K) doping on the particle size, phase composition, and light absorption properties of zinc oxide nanocrystals were investigated by X-ray diffraction, transmission electron microscopy and ultraviolet–visible spectroscopy. The main crystalline phase of the powders before and after K doping is wurtzite ZnO. With the increased K doping amount, the purple and blue luminescent peaks are enhanced. The band gap of the sample obtained from the light absorption spectra initially increased with the K doping amount, then decreased, and increased again with the K doping amount, which is consistent with the theoretical calculation results. The calculated energy band and density of states results show that when the K doping amount is small, the band gap is reduced because the K doping forms the impurity level and the conduction band moves downward. This decrease is due to the two impurity levels generated at the bottom of the valence band. [ABSTRACT FROM AUTHOR]

Cracking the entangling code of protein–ligand interaction (PLI) is of great importance to structure-based drug design and discovery. Different physical and biochemical representations can be used to describe PLI such as energy terms and interaction fingerprints, which can be analyzed by machine learning (ML) algorithms to create ML-based scoring functions (MLSFs). Here, we propose the ML-based PLI capturer (ML-PLIC), a web platform that automatically characterizes PLI and generates MLSFs to identify the potential binders of a specific protein target through virtual screening (VS). ML-PLIC comprises five modules, including Docking for ligand docking, Descriptors for PLI generation, Modeling for MLSF training, Screening for VS and Pipeline for the integration of the aforementioned functions. We validated the MLSFs constructed by ML-PLIC in three benchmark datasets (Directory of Useful Decoys-Enhanced, Active as Decoys and TocoDecoy), demonstrating accuracy outperforming traditional docking tools and competitive performance to the deep learning-based SF, and provided a case study of the Serine/threonine-protein kinase WEE1 in which MLSFs were developed by using the ML-based VS pipeline in ML-PLIC. Underpinning the latest version of ML-PLIC is a powerful platform that incorporates physical and biological knowledge about PLI, leveraging PLI characterization and MLSF generation into the design of structure-based VS pipeline. The ML-PLIC web platform is now freely available at http://cadd.zju.edu.cn/plic/. [ABSTRACT FROM AUTHOR]

The rational design of chemical entities with desired properties for a specific target is a long-standing challenge in drug design. Generative neural networks have emerged as a powerful approach to sample novel molecules with specific properties, termed as inverse drug design. However, generating molecules with biological activity against certain targets and predefined drug properties still remains challenging. Here, we propose a conditional molecular generation net (CMGN), the backbone of which is a bidirectional and autoregressive transformer. CMGN applies large-scale pretraining for molecular understanding and navigates the chemical space for specified targets by fine-tuning with corresponding datasets. Additionally, fragments and properties were trained to recover molecules to learn the structure–properties relationships. Our model crisscrosses the chemical space for specific targets and properties that control fragment-growth processes. Case studies demonstrated the advantages and utility of our model in fragment-to-lead processes and multi-objective lead optimization. The results presented in this paper illustrate that CMGN has the potential to accelerate the drug discovery process. [ABSTRACT FROM AUTHOR]

Recently, band-splitting associated with spin polarization at K- and K′-points of the Brillouin zone has been found in centrosymmetric transition metal dichalcogenide materials. This discovery offers a possibility on centrosymmetric crystals for potential valleytronic applications. However, the origin of the band-splitting and the spin polarization in multilayer and bulk transition metal dichalcogenides remains unclear as the interlayer coupling should play a role when compared with that in monolayers. Here, by performing spin- and angle-resolved photoemission spectroscopy in bulk 2H-WSe2 at variable temperatures, we have quantitatively established contributions of the intralayer spin–orbit coupling and interlayer coupling. While the strength of the intralayer spin–orbit coupling is determined to be 450 meV, independent of the temperature, the strength of the interlayer coupling is found to increase from 68 to 172 meV as the temperature decreases from 300 to 80 K. This is also accompanied by an increase in the total band-splitting and a decrease in the spin polarization. This work reveals the micro-mechanism of spin and interlayer interaction in centrosymmetric materials, which provides a basis for the development of next-generation energy-efficient valleytronic devices. [ABSTRACT FROM AUTHOR]

Deep learning (DL) and machine learning contribute significantly to basic biology research and drug discovery in the past few decades. Recent advances in DL-based generative models have led to superior developments in de novo drug design. However, data availability, deep data processing, and the lack of user-friendly DL tools and interfaces make it difficult to apply these DL techniques to drug design. We hereby present ReMODE (Receptor-based MOlecular DEsign), a new web server based on DL algorithm for target-specific ligand design, which integrates different functional modules to enable users to develop customizable drug design tasks. As designed, the ReMODE sever can construct the target-specific tasks toward the protein targets selected by users. Meanwhile, the server also provides some extensions: users can optimize the drug-likeness or synthetic accessibility of the generated molecules, and control other physicochemical properties; users can also choose a sub-structure/scaffold as a starting point for fragment-based drug design. The ReMODE server also enables users to optimize the pharmacophore matching and docking conformations of the generated molecules. We believe that the ReMODE server will benefit researchers for drug discovery. ReMODE is publicly available at http://cadd.zju.edu.cn/relation/remode/. [ABSTRACT FROM AUTHOR]

Deep learning (DL) and machine learning contribute significantly to basic biology research and drug discovery in the past few decades. Recent advances in DL-based generative models have led to superior developments in de novo drug design. However, data availability, deep data processing, and the lack of user-friendly DL tools and interfaces make it difficult to apply these DL techniques to drug design. We hereby present ReMODE (Receptor-based MOlecular DEsign), a new web server based on DL algorithm for target-specific ligand design, which integrates different functional modules to enable users to develop customizable drug design tasks. As designed, the ReMODE sever can construct the target-specific tasks toward the protein targets selected by users. Meanwhile, the server also provides some extensions: users can optimize the drug-likeness or synthetic accessibility of the generated molecules, and control other physicochemical properties; users can also choose a sub-structure/scaffold as a starting point for fragment-based drug design. The ReMODE server also enables users to optimize the pharmacophore matching and docking conformations of the generated molecules. We believe that the ReMODE server will benefit researchers for drug discovery. ReMODE is publicly available at http://cadd.zju.edu.cn/relation/remode/. [ABSTRACT FROM AUTHOR]

The discharge performance of thermal batteries with long-life is mainly limited by the decrease of working temperature, due to the continuous heat release during the work process. In this contribution, we firstly propose a slow heat-supply component (SHSC) with layer structure, composed of reducers (Li–Si), oxidizers (CuO) and "lithium" permeation membrane (LPM), to compensate the released heat in thermal batteries. The LPM is composed of electronic conductor (CeO 2) and high Li+ molten salt conductor (LiCl–LiBr–KBr), which can modify the permeation rate of "lithium" by changing the electric conductivity. The results confirm that thereaction rates between Li–Si and CuO can be adjusted by changing the weights or compositions of LPM, and the heat supply rate of SHSC can be regulated. By using SHSC, the inner temperature of thermal batteries can be maintained properly. Moreover, the discharge capacity of thermal batteries with long working life, can achieve 10% increase at least, with SHSC as the heat supplied component, which are measured and confirmed in the real thermal batteries. [Display omitted] • A slow heat supply component (SHSC) with layer structure is constructed based on a composite membrane. • Inner temperature of thermal batteries is maintained properly. • Electrochemical performance of thermal batteries is improved by using SHSC as heat sources. [ABSTRACT FROM AUTHOR]

Ta/CoFeB/MgO/Ta multilayer known as the fundamental building block for magnetic tunneling junctions, has been studied for decades. However, its thermostability is normally less than 300 °C, which cannot meet the requirements for subsequent semiconductor processes. In this study, buffer layers of {Pt(t)/Ta(t)} n superlattices were introduced into CoFeB/MgO/Ta multilayers grown by magnetron sputtering. The growth period n and the single layer thickness t in the superlattice have been systematically explored. And it is found that the sample can maintain distinct perpendicular magnetic anisotropy (PMA) even after a 440 °C post-annealing treatment at n = 3 and t = 1.5 nm. This has been attributed to that the superlattice buffer layer might serve as a diffusion barrier, reducing Ta atoms from diffusing into the CoFeB/MgO interface. Less Ta at the interface results more FeO x formed and enhances the hybridization of Fe 2p and O 3d orbitals which increases the thermostability of PMA. This suggests that superlattice buffer layer provides a new approach to improve the materials' thermostability. • The {Pt(t)/Ta(t)} n superlattices were introduced into CoFeB/MgO/Ta multilayers grown by magnetron sputtering. • The {Pt(t)/Ta(t)} n superlattice can improve the thermostability of the films' PMA up to 440 °C. • The periodic structure reduces diffusion of Ta, enhances the orbital hybridization of Fe and O. [ABSTRACT FROM AUTHOR]

Pure and Ni-doped ZnO nanorod array films were prepared by the hydrothermal method. The effects of Ni doping on the phase composition, microstructure, and optical and electro-chemical properties of ZnO were investigated. The main crystalline phase of the powders before and after Ni doping is wurtzite ZnO. The luminescent peaks are significantly reduced after Ni doping. The light transmission and is the strongest when the doping concentration is 2 %. The light absorption spectrum confirms that the band gap decreased first and then decreased with the increase of Ni2+ doping concentration. According to the M–S (Mott - Schottky) plots, the Ni-doped ZnO is an n-type semiconductor. The current density initially increases with the increased Ni doping amount, and then decreases. First-principles calculation results of nickel-doped zinc oxide show that the energy level of impurities is formed after nickel ions replace zinc ions, which causes the conduction band is shifted down and the band gap is reduced. The impurity energy level causes a slight upward shift in the valence band, which increases the band gap. The calculated results are consistent with the experimental results. [ABSTRACT FROM AUTHOR]

In this work, α-MoO 3 nanoparticles are grown on the surface of nitrogen doped carbon nanotubes (N-CNTs) via a facile electrodeposition method. The morphology of as-prepared nanocomposite shows that the interconnected α-MoO 3 nanoparticles are homogeneously distributed on the surface of N-CNTs. When investigated as a cathode material for lithium ion batteries, the nanocomposite reveals a high reversible discharge capacity of 250 mA h g −1 at a current density of 30 mA g −1 , simultaneously with good cycling performance and excellent rate capability compared with pristine MoO 3 powder. Kinetics of this process is investigated by electrochemical impedance spectroscopy to understand the difference in electrochemical performance and the interface properties between the α-MoO 3 /N-CNTs nanocomposite and pristine MoO 3 powder electrode. The correlation between the unique structural features of α-MoO 3 /N-CNTs nanocomposite and its excellent electrochemical performance is also discussed. The excellent performance makes the as-prepared α-MoO 3 /N-CNTs nanocomposite a promising cathode material for high-performance lithium ion batteries. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents a novel face and fingerprint identity authentication system based on multi-route detection. To exclude the influence of pose on face recognition, a multi-route detection module is adopted, with parallel processing technology to speed the authentication process. Parallel processing technology is used to speed the authentication process. Fusion of face and fingerprint by support vector machine (SVM) which introduced a new normalization method improved the authentication accuracy. A new concept of optimal two-dimensional face is proposed to improve the performance of the dynamic face authentication system. Experiments on a real database showed that the proposed system achieved better results compared with face-only or fingerprint-only system. [Copyright &y& Elsevier]