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Recently, organic photovoltaics (OPVs) based on the blends of donor–acceptor (D–A) copolymers as efficient p-type materials and fullerene derivatives as acceptors have attracted considerable attention. In this paper, electron transport and electrical properties in a blend of D–A copolymer DTS-C0(F2) and methanofullerene derivative PC71BM are investigated. From an analysis of the temperature dependence of the current density–voltage (J − V) characteristics of electron-only device based on DTS-C0(F2):PC71BM blend, it is found that consistent descriptions for the experimental measurements are obtained using both the improved extended Gaussian disorder model (IEGDM) and the extended correlated disorder model (ECDM), within which spatial correlations between the transport site energies are absent and are included, respectively. By comparing the model parameters with the typical values of organic semiconductors, we view the more realistic intersite distance obtained using the IEGDM (1.9 nm) compared to the value obtained using the ECDM (0.48 nm) as an indication that in DTS-C0(F2):PC71BM blend correlations between the transport site energies are absent. Furthermore, it is shown that the effective mobility in DTS-C0(F2):PC71BM blend gradually increases with increasing temperature.

In this paper, the charge transport properties and energetic disorder are studied for pristine Si-PCPDTBT, mono-PCBM, bis-PCBM, and their blends of Si-PCPDTBT:mono-PCBM, Si-PCPDTBT:bis-PCBM. We show that the current density versus voltage curves of electron-only devices for mono-PCBM, bis-PCBM, Si-PCPDTBT:mono-PCBM, Si-PCPDTBT:bis-PCBM, and hole-only devices for Si-PCPDTBT, Si-PCPDTBT:mono-PCBM, Si-PCPDTBT:bis-PCBM cannot be accurately described using a conventional mobility model within which the mobility depends only on the electric field, but that a fully consistent description of all curves can be obtained using the improved extended Gaussian disorder model (IEGDM). Within the IEGDM, the presence of energetic disorder is described by a Gaussian density of states, and the mobility depends on the electric field and carrier density. Furthermore, we found that the mobility increases as the width of the Gaussian density of states decreases for both electron-only and hole-only devices, and the mobility is closely related to the energetic disorder. We view this as an indication that the energetic disorder appears to govern the charge transport in disordered organic semiconductors.

Crystal structure, morphology, magnetic, and dielectric properties of (1 − x)Bi2Fe4O9–xMgFe2O4 bicomponent ceramics are investigated in detail. The material has been synthesized via sol–gel method. Analysis of X-ray diffraction data of the bicomponent ceramics shows the coexistence of orthorhombic Bi2Fe4O9 and spinel MgFe2O4 phases with no third phase. Microstructural and surface morphology displays the homogeneous grain distribution with different grain sizes of Bi2Fe4O9 and MgFe2O4. The magnetic measurement shows decreasing coercivity and increasing values of remnant and saturation magnetization with the increase in MgFe2O4. Temperature-dependent dielectric properties and electrical modulus are conducted in the temperature range of 27–527 °C with the frequency ranging from 1 to 30 kHz. Two abnormal peaks are, respectively, observed at low and high temperature ranges. The variation of electric properties is closely related to the composition of MgFe2O4. The results of dielectric and electrical modulus indicate the appearance of dielectric relaxation in (1 − x)Bi2Fe4O9–xMgFe2O4. Combined with the study of activation energy, the dielectric relaxation is mainly induced by different electric responses of various charge carriers intrinsically dominating in a thermally activated process with the incorporation of MgFe2O4. The combination of Bi2Fe4O9 and MgFe2O4 enhances the coexistence of magnetic and electric properties in the present composites. It is quite promising from application point of view.

This study reports on MoO3 nanobelts as electrode material for high-performance supercapacitors. We find MoO3 nanobelts electrode exhibits a higher specific capacitance than MoO3 microrods electrode. Thus, an asymmetric supercapacitor utilizing the as-prepared MoO3 nanobelts as the positive electrode material and the carbon nanosheets as the negative electrode material achieves an impressive performance with an energy density of 25.69 Wh kg−1 at a power density of 1482.25 W kg−1. We further reveal that the exposed (010) facets in the crystalline MoO3 nanobelts might mainly contribute to its electrochemical performance.

This study reports iron phosphide (FeP) nanorod arrays on Ti substrates (FeP NRs/Ti) as anode for full sodium-ion batteries. The FeP nanorod arrays electrodes exhibit a high-rate capability of 414.7 mAh g−1 at 100 mA g−1 in the semi-battery tests (sodium foil as the counterpart) and 196.2 mAh g−1 at 2000 mA g−1. The high reversible capacity can be ascribed to an augmented sodium-ion diffusion coefficient (∼10−12 cm2 s−1) originated from the nanorod arrays. Besides, the binder-free and highly oriented- 1D FeP electrode helped to alleviate the volume change during (dis)charging processes thereby ensuring a long cycling life (207.7 mAh g−1 over 1000 cycles at 500 mA g−1). Electrochemical and ex-situ studies confirmed the significant contribution of pseudocapacitance to the highly electrochemical performance of FeP nanorod arrays. Most importantly, the sodium-ion full battery based on FeP NRs/Ti as anode and Na3V2(PO4)3 as cathode materials showed stable cycling performance over 200 cycles at a current rate of 1 C (1 C = 100 mA g−1, voltage range of 2.0–3.6 V), simultaneously possessing a high energy density of 185 Wh kg−1 at the power density of 200 W kg−1. We further successfully demonstrated an energy pack by combining four CH3NH3PbI3-xClx-based perovskite solar cells in series and a Na3V2(PO4)3-FeP NRs/Ti full sodium-ion battery, achieving a photoelectric conversion and storage efficiency of 5.2% under 1 sun light illumination.

In recent decades, advances in sodium-ion battery (SIB) technology have contributed immensely to energy production and storage technologies. Along with innovation of electrode materials for SIBs, the research focus has gradually shifted to metal chalcogenide anode materials for high performance. The metal chalcogenide exhibits high capacity due to conversion or alloying mechanism. Consequently, large volume expansion and low electric conductivity lead to inferior cycle and rate performance. In this review, we summarized recent development on the strategy of improving electrochemical sodium storage behavior for metal chalcogenide anode materials; followed by analyzing corresponding structural features and reaction mechanisms comprehensive. Generally, the common and effective methods include architecture design at nanoscale, compound with carbon material, rational and unique array structure, the control of cut-off voltage and heteroatom doping. Particular attention is placed on the design of nanocomposite arrays with various carbon matrices, which can remarkably enhance conductivity and structural stability. Finally, we discussed current challenges and proposed future directions for SIBs. This benefits to further investigation and improvement of metal chalcogenide anodes for SIBs in scientific and practical applications.

The DArk Matter Particle Explorer (DAMPE) is a satellite-borne experiment, in operation since 2015, aimed at studying high-energy gamma rays and cosmic nuclei fluxes. Of the various sub-detectors in the DAMPE payload, the Silicon-Tungsten tracKer-converter (STK) plays a significant role in the charge measurement of incoming ions. Depending on the angle of inclination of the impinging particle and its position of impact on these strips, the collected charge can spread between the strips which results in some fractional signal loss. The $\eta$ variable is used to identify this spread of charge across the strips and correct for the associated charge loss. This brings us closer to accurate determination of particle charge which is crucial for ensuring a good discrimination between particles. The $\eta$-correction is, therefore, expected to play an important role in the determination of heavy ions by the DAMPE detector. It has helped reduce the proton background for the helium identification in STK by a factor of 1.5 for MIP tracks. It has been sucessfully applied to carbon nuclei and its application to heavier nuclei is currently being studied.

Since its launch, in December 2015, the satellite-based DAMPE (DArk Matter Particle Explorer) particle detector is taking data smoothly. The Silicon-Tungsten tracKer-converter (STK) of DAMPE consists of six tracking planes (6x, 6y) of single-sided silicon micro-strip detectors mounted on seven support trays. The STK is able to measure the charge and precisely reconstruct the track of traversing charged particles. Tungsten plates (1 mm thick) are integrated in the second, third and fourth tray from the top to serve as $\gamma \rightarrow e^+e^−$ converters. Commissioned rapidly after the launch, the STK is running extremely well since then. The STK in-orbit calibration and performance during its first more than 5 years of operation, including the noise behaviour and the thermal and mechanical stability, are presented in this contribution.

The DArk Matter Particle Explorer (DAMPE) is the first Chinese cosmic-ray direct detection experiment. It has been operating smoothly on-orbit since its successful launch at the end of 2015. Currently, its sub-detectors and the satellite are in good working order. The DAMPE payload employs a BGO Calorimeter for energy measurements, trigger and e/p identification. The calorimeter is constructed of 308 BGO crystals, and PMTs are coupled to the crystals with optical filters to readout scintillation light. In this work, we present the status and performance of the calorimeter, including status of detector units, energy measurement, especially in TeV range, detector endurance, and long term performance in a duration of 65 months.

The Fermi bubbles are two large structures above and below the Galactic Plane. They are first discovered by Fermi-LAT and thought to be related to the jet or the wind from the Galactic center. The DArk Matter Particle Explorer (DAMPE) is a space-borne high energy particle telescope aiming at measuring cosmic rays and photons in a broad energy range. In this work, we use 4.8 years of DAMPE photon data to search for the emission from the Fermi Bubbles. We calculate the TS values of the lobes and the significance of its curved spectrum. The obtained spectral parameters are then compared with those from the Fermi-LAT. We also search for the emission from the cocoon in the southeast part of lobes. Since the Galactic diffuse emission (GDE) model is a major source of systematic uncertainty, we also switch to the GDE models calculated with Galprop and evaluate the influence.

The DArk Matter Particle Explorer (DAMPE), a space-based high energy particle detector, has been operated on-orbit for more than five years. The large geometric factor and good charge resolution enable DAMPE to have very good potential to measure cosmic-rays up to 100 TeV. Knowledge of the boron to carbon (B/C) flux ratio is very important in understanding the prop- agation of cosmic rays, especially in TeV energy range. In this contribution, the latest progress of the B/C flux ratio analysis based on the flight data collected by DAMPE during the 5 years of operation, is presented.

The measurement of the energy spectrum of cosmic ray helium nuclei from 70 GeV to 80 TeV using 4.5 years of data recorded by the DArk Matter Particle Explorer (DAMPE) is reported in this work. A hardening of the spectrum is observed at an energy of about 1.3 TeV, similar to previous observations. In addition, a spectral softening at about 34 TeV is revealed for the first time with large statistics and well controlled systematic uncertainties, with an overall significance of $4.3\sigma$. The DAMPE spectral measurements of both cosmic protons and helium nuclei suggest a particle charge dependent softening energy, although with current uncertainties a dependence on the number of nucleons cannot be ruled out., Comment: 11 pages, 13 figures, published in Phys. Rev. Lett. Add one more digit for first three columns in Table S2

左心室中部梗阻性肥厚型心肌病是一类罕见的肥厚型心肌病。该文报道1例中年男性因室性心动过速入院，电复律后心电图提示前侧壁及下壁ST段抬高，急诊冠状动脉造影提示前降支重度心肌桥，随后经超声心动图及心脏磁共振检查明确诊断为左心室中部梗阻性肥厚型心肌病（MVOHCM），心尖部室壁瘤（LVAA）。MVOHCM同时合并LVAA及前降支重度心肌桥且反复发生室性心动过速者罕见报道。该文结合文献分析了该病例的诊断依据、发病原因及治疗方案，以期为临床实践提供参考。.

Bi2−xBaxFe4O9 material (0 ≤ x ≤ 0.125) has been synthesized by sol–gel method. Structural characterization shows the single phase of orthorhombic Bi2Fe4O9. Moreover, the structure of Bi2−xBaxFe4O9 gradually presents a regular variation with increasing Ba content. Surface morphology of the samples is examined showing homogeneous grain distribution accompanied by the decreasing grain size with increase of Ba. Due to doping Ba, magnetic properties are significantly enhanced shown as the increasing remnant magnetization and saturation magnetization. Dielectric constant shows the increasing tendency with colossal values especially at high temperature range. In addition, the real part of ac conductivity exhibits the increasing trend with increasing frequency and the content of Ba. The analysis of impedance spectrum also suggests the increasing conductivity. The improvement in magnetic and electrical properties of Bi2Fe4O9 by substitution of Ba can be attributed to the different ionic radius of Ba2+ from Bi3+ to Fe3+ which results in the change of magnetic structure and morphology.

This study reports a general and rational two-step hydrothermal strategy to fabricate three-dimensional (3D) TiO2 nanowire@NiMoO4 ultrathin nanosheet core-shell arrays (TNAs-NMO) as additives-free anodes for lithium-ion batteries (LIBs). The TNAs-NMO electrode delivers a reversible capacity of up to 446.6 mA h g−1 over 120 cycles at the current density of 0.2 A g−1 and a high rate capacity of 234.2 mA h g−1 at 2.0 A g−1. Impressively, the capacity retention efficiency is 74.7% after 2500 cycles at the high rate of 2.0 A g−1. In addition, the full cell consisting of TNAs-NMO anode and LCO cathode can afford a specific energy of up to 220.3 W h kg−1 (based on the entire mass of both electrodes). The high electrochemical performance of the TNAs-NMO electrode is ascribed to its 3D core-shell nanowire array architecture, in which the TiO2 nanowire arrays (TNAs) and the ultrathin NiMoO4 nanosheets exhibit strong synergistic effects. The TNAs maintain mechanical integrity of the electrode and the ultrathin NiMoO4 nanosheets contribute to high capacity and favorable electronic conductivity.

In this paper, we investigate the hole transport and electrical properties in a small-molecule organic material N,N′-bis(1-naphthyl)-N,N′-diphenyl-1,1′-biphenyl-4,4′-diamine (NPB), which is frequently used in organic light-emitting diodes. It is shown that the thickness-dependent current density versus voltage (J–V) characteristics of sandwich-type NPB-based hole-only devices cannot be described well using the conventional mobility model without carrier density or electric field dependence. However, a consistent and excellent description of the thickness-dependent and temperature-dependent J–V characteristics of NPB hole-only devices can be obtained with a single set of parameters by using our recently introduced improved model that take into account the temperature, carrier density, and electric field dependence of the mobility. For the small-molecule organic semiconductor studied, we find that the width of the Gaussian distribution of density of states σ and the lattice constant a are similar to the values reported for conjugated polymers. Furthermore, we show that the boundary carrier density has an important effect on the J–V characteristics. Both the maximum of carrier density and the minimum of electric field appear near the interface of NPB hole-only devices.

DAMPE satellite has directly measured the cosmic ray proton spectrum from 40 GeV to 100 TeV and revealed a new feature at about 13.6 TeV., The precise measurement of the spectrum of protons, the most abundant component of the cosmic radiation, is necessary to understand the source and acceleration of cosmic rays in the Milky Way. This work reports the measurement of the cosmic ray proton fluxes with kinetic energies from 40 GeV to 100 TeV, with 2 1/2 years of data recorded by the DArk Matter Particle Explorer (DAMPE). This is the first time that an experiment directly measures the cosmic ray protons up to ~100 TeV with high statistics. The measured spectrum confirms the spectral hardening at ~300 GeV found by previous experiments and reveals a softening at ~13.6 TeV, with the spectral index changing from ~2.60 to ~2.85. Our result suggests the existence of a new spectral feature of cosmic rays at energies lower than the so-called knee and sheds new light on the origin of Galactic cosmic rays.

This work reports on nanoparticle-stacked Li 4 Ti 5 O 12 -TiO 2 nanowire arrays (SLTO) as anode for lithium and sodium ion battery (NIB). Our finding shows that the pseudocapacitive effect partly contributes to the performance for the NIBs based on the SLTO electrode due to a large size volume of Na + ions. More importantly, the SLTO nanowires constituting of the nanoparticles efficiently shorten ion diffusion length, thereafter accelerate ion insertion/extraction reaction and improve the rate capability. For the SLTO electrode, a specific capacity of 199.7 mAh g −1 can be achieved in the LIBs at a current rate of 0.75 C (voltage range of 1.0–3.0 V) and a specific capacity of 94.2 mAh g −1 is obtained in the NIBs at a high current rate of 15 C (voltage range of 0.5–2.5 V). Most importantly, the sodium ion full battery based on SLTO as anode and Na 3 V 2 (PO 4 ) 3 as cathode materials shows stable cycling performance with tiny capacity degradation (90.1 mAh g −1 ) after 200 cycles at a current rate of 4 C (voltage range of 1.0–4.0 V), simultaneously possessing a high energy density of 136.5 Wh kg −1 at the power density of 312 W kg −1 .

CoCr 2 O 4 /NiO has been successfully synthesized through two-step method. X-ray diffraction results present the coexistence of CoCr 2 O 4 and NiO with pure formation. Micrographs measured with scanning electron microscope and transmission electron microscope display the homogeneous and dense morphology with two kinds of nanoparticles. Exchange bias effect is observed in the sample. The exchange bias field is about 872 Oe at 10 K. As measuring temperature increases, exchange bias effect is weakened with decreasing coercive field. In addition, exchange bias field and the shift of magnetization show the linear relationship with increasing cooling field. The exchange bias behavior can be attributed to the exchange coupling at the disordered interfaces in the sample.

A series of (1−x)(0.7BiFeO3-0.3Bi0.5Na0.5TiO3)-xCoFe2O4 ceramics have been synthesized using the sol–gel method. Structural, microstructural, and multiferroic properties of the samples have been investigated. Magnetoelectric coupling has been also measured at room temperature. The structural and microstructural results show that perovskite 0.7BiFeO3-0.3Bi0.5Na0.5TiO3 and spinel CoFe2O4 can coexist in the ceramics without any observable impurities. The ceramics exhibit distinct ferromagnetic characteristics at room temperature. The dielectric constant and dielectric loss have been also studied as the function of frequency and temperature. The temperature dependence of dielectric properties displays a typical relaxor-like behavior at the temperature range of 150–300 °C. Due to magnetoelectric coupling, the dielectric anomaly at about 340 °C and the peak near 510 °C are respectively related to the ferroelectric transition of Bi0.5Na0.5TiO3 and magnetic transition of CoFe2O4. Impedance properties show the segment of arc at room temperature and the nearly perfect semicircle at higher temperature. Both Z′ and Z″ present regular change with the content of CoFe2O4. The room-temperature multiferroic properties of these new ceramics may be suitable for storage device applications. Variation of magnetoelectric coupling coefficient αE with the applied magnetic field.

Co 1− x Cu x Cr 2 O 4 (0.1≤ x ≤0.275) ceramics have been synthesized and identified as having the cubic structure. Doping Cu has the distinct influence on magnetic properties of the samples. Negative magnetization is discovered when content of Cu increases from x =0.125 to 0.25. As doping content increases, the maximum of magnetization in field-cooled curves shows a monotonous decreasing tendency. Whereas, the relative intensity of negative magnetization and the magnetization reversal temperature increase and then decrease presenting the maximums at x =0.225. Especially for x =0.225, negative magnetization behavior is also affected by cooling field and the negative value finally turns to positive at 12 kOe.

Polycrystalline NiCr1.9Mn0.1O4 within nanoscale has been synthesized by sol–gel method. X-ray diffraction results prove pure formation of the sample without any other impurities. Characterizations of scanning electron microscopy and X-ray fluorescence reveal the good crystallinity and desired element ratio of the phase. Magnetic hysteresis loop measured at 10 K after cooling the sample in applied field of 30 kOe shows asymmetry both in the field and magnetization axes with a bias field about 3316.5 Oe and a magnetization shift about 0.381 emu/g. This exchange bias (EB) behavior has also been studied as the function of measuring temperature and applied cooling field. The values of EB field and magnetization shift are found to depend strongly on temperature as well as the cooling field. The accompanying training effect is also observed in the sample. Irreversibility in temperature dependence of magnetization at different applied fields indicates the presence of spin-glass-like (SGL) phase. High field relaxation measurement confirms the existence of SGL state. The results suggest that different formation of ferromagnetic and antiferromagnetic sublattice orders with spin frustration due to the doping of Mn cations in the sample leads to these interesting magnetic properties.

We have successfully synthesized the CuCr 2 O 4 /Cr 2 O 3 nanogranular system through a high-temperature phase separation route from Cu doped Cr 2 O 3 nanoparticles, which are confirmed by X-ray diffraction measurements. Magnetic susceptibility shows two magnetic transitions at 130 K and 310 K corresponding to the ferrimagnetic and antiferromagnetic phases of CuCr 2 O 4 and Cr 2 O 3 , respectively. Significant exchange bias behavior could be observed in the field cooling magnetic hysteresis loop at low temperatures. Both exchange bias field (H EB ) and coercive field (H C ) decrease with increasing temperature and disappear near 200 K. This exchange bias behavior is discussed in terms of the existence of exchange coupling between the ferrimagnetic CuCr 2 O 4 and antiferromagnetic Cr 2 O 3 . The uncompensated spins in antiferromagnetic phase frozen along field cooling direction provide the pinning force on the ferrimagnetic spins leading to the exchange bias effect.

Co0.775Cu0.225Cr2O4 ceramics have been synthesized using the sol–gel method. Through annealed at different temperatures, all the samples are pure formation with cubic crystal structure proved by X-ray diffraction. A significant annealing temperature dependence of negative magnetization has been recorded. With increasing annealing temperature, the absolute values of maximum and minimum of the field-cooled magnetization show a monotonous increase. The relative intensity of negative magnetization is enhanced from 750 to 900 °C and then weakened with further increasing the annealing temperature. The relationship between annealing temperature and negative magnetization can be attributed to the particle growth during the annealing process. In addition, magnetic field dependence of magnetization at 10 K is also studied with different annealing temperatures and the crystallographic microstructure has an important effect on the magnetization. Temperature dependence of magnetization in ZFC and FC processes of Co0.775Cu0.225Cr2O4 ceramics annealed at 750 °C. Inset is the FC inverse susceptibility and the fitting of ferrimagnetic Curie–Weiss law down to nearly T C. Experimental result is plotted as circle, and the fitting is presented as the solid line.

CuCr2−x Fe x O4 ceramics have been successfully synthesized using the sol–gel method for the first time. With pure formation, material structure has been characterized by x-ray diffraction. The samples have been identified as having the spinel structure with formulae CuCr2−x Fe x O4. Micrographs obtained by scanning electron microscopy show the dense microstructure of the samples. The stoichiometric ratio of the ceramics has been measured through energy dispersive spectra. Magnetic properties of CuCr2−x Fe x O4 ceramics have been discussed. Temperature dependence of magnetization presents the gradually increasing irreversible temperature as the content of Fe element increases from x = 0 to 1. Coercive field (H C), remanent magnetization (M r), and saturation magnetization (M S) respectively display the monotonous variation phenomena with increasing content of Fe. The increasing M r, M S and the decreasing H C can be attributed to the change of magnetic exchange interaction because of the doped Fe. It also proves that the magnetic properties of CuCr2−x Fe x O4 ceramics can be effectively tuned by the doping content of Fe.

International audience; Sodium-ion batteries (SIBs) are considered as one of the most promising candidates for competing with lithium-ion batteries owing to significant natural abundance of sodium and similar reaction mechanism. The large radius of Na+ (1.02 Å) severely impedes the electrochemical performance, especially high-rate capability and long-cycle stability of SIBs. Together with the cathode and electrolyte, the anode determines full battery's operating voltage and plays a vital role in avoiding sodium dendrite in terms of redox potential. On this account, the anode holds a prime importance toward the development of advanced SIBs with high rate capability and superior durability. Herein, we present a review on the exciting advances in alloy- and conversion-type anode materials as well as solid-electrolyte interphase layer for SIBs aiming at the improvement of rate capability and cycling life. Finally, the challenges and some of the critical issues in alloy-type and conversion-type anode materials for sodium-ion batteries are addressed.

The DArk Matter Particle Explorer (DAMPE), a satellite-based cosmic ray and gamma-ray detector, was launched on December 17, 2015, and began its on-orbit operation on December 24, 2015. In this work we document the on-orbit calibration procedures used by DAMPE and report the calibration results of the Plastic Scintillator strip Detector (PSD), the Silicon-Tungsten tracKer-converter (STK), the BGO imaging calorimeter (BGO), and the Neutron Detector (NUD). The results are obtained using Galactic cosmic rays, bright known GeV gamma-ray sources, and charge injection into the front-end electronics of each sub-detector. The determination of the boundary of the South Atlantic Anomaly (SAA), the measurement of the live time, and the alignments of the detectors are also introduced. The calibration results demonstrate the stability of the detectors in almost two years of the on-orbit operation.

Room-temperature multiferroic 0.7BiFeO 3 –0.3Bi 0.5 Na 0.5 TiO 3 solid solution ceramics have been prepared by the sol–gel method. We have discussed the annealing temperature dependence of the multiferroic properties. The samples are annealed at 1023, 1123, 1223 and 1323 K for 3 h, respectively. X-ray diffraction patterns identify that all samples are pure. Scanning electron micrographs present the increasing grain size with higher annealing temperature. Magnetic, ferroelectric and dielectric properties are enhanced obviously with the increase in annealing temperature. The coexistence of ferroelectric and ferromagnetic properties is also proved at room temperature. In addition, it reveals that the optimal annealing temperature accompanied with favorable multiferroic properties of 0.7BiFeO 3 –0.3Bi 0.5 Na 0.5 TiO 3 solid solution ceramics is near 1223 K.

NiCr2O4/NiO ceramic has been synthesized successfully through co-precipitation method to study the magnetic properties. Field cooling (FC) magnetic hysteresis loops measured at low temperature show significant shift in both coercive field and remnant magnetization. It has been plotted that the exchange bias (EB) field can be as large as 11.86 kOe at 10 K followed with an enhanced coercive field. The variation of EB field and shift of remnant magnetization after FC processes shows a regular tendency with increasing temperature and cooling field. Known as training effect, the EB behavior also presents a strong dependence on loop cycle. The cycle dependence of large EB field, vertical shift of magnetization, and coercive field at low temperature can be ascribed to the pinned spins in spin-glass-like (SGL) phase of the system interface. The SGL phase has been proved by Almeida–Thouless line and high field relaxation effect. The disorder structure is responsible for the frustration interface and the formation of SGL phase in the interface.

The DArk Matter Particle Explorer (DAMPE), one of the four scientific space science missions within the framework of the Strategic Pioneer Program on Space Science of the Chinese Academy of Sciences, is a general purpose high energy cosmic-ray and gamma-ray observatory, which was successfully launched on December 17th, 2015 from the Jiuquan Satellite Launch Center. The DAMPE scientific objectives include the study of galactic cosmic rays up to $\sim 10$ TeV and hundreds of TeV for electrons/gammas and nuclei respectively, and the search for dark matter signatures in their spectra. In this paper we illustrate the layout of the DAMPE instrument, and discuss the results of beam tests and calibrations performed on ground. Finally we present the expected performance in space and give an overview of the mission key scientific goals., 45 pages, including 29 figures and 6 tables. Published in Astropart. Phys

This work, for the first time, reports on the Bi2Se3 nanocrystal array wrapped by amorphous carbon layer as anode for high-performance sodium-ion batteries. In addition to a remarkable lithium storage capability, the Bi2Se3 nanocrystal array assembling onto flexible carbon cloth exhibits an outstanding cyclical stability for sodium ion batteries, which delivers a discharge capacity of 652.1 mAh g−1 at 100 mA g−1 (∼ a rate of 0.1 C) after 100 cycles. Even at 1 A g−1, a reversible capacity of 210.2 mAh g−1 can be maintained undergoing 200 charge-discharge cycles. The excellent cycle and rate capabilities of Bi2Se3 nanocrystal array could be attributed to the stable structure, fast ion migration channel and low charge transfer resistance for electrochemical processes. Detailed investigation reveals the appreciated reversibility of stepwise conversion and alloying reaction of Bi2Se3 nanocrystal array with high Coulombic efficiency and reversible capacity.

Oily sewage is one of the wastes produced in the oil industry production process and its quantity has been increasing year by year, which influences the environment and human health severely. Electric flocculation method is one of the wide application electrochemical treatment technologies for the oily wastewater treatment at home and abroad, which has higher efficiency than other technologies at the aspect of the organic pollutants degradation. A simulative experiment device dealing with heavy oil sewage by the electric flocculation method has been designed. The mechanism of the electric flocculation method in removing organic matter of the heavy oil sewage by analyzing the change of the composition and content of the organic matter in water samples before and after the process of the electric flocculation has been studied. Research results show the carbon/tin dioxide electrode is better than the carbon/ruthenium dioxide electrode in removing organic matter; most alkanes matter in the oily wastewater hav...

High energy cosmic ray electrons plus positrons (CREs), which lose energy quickly during their propagation, provide an ideal probe of Galactic high-energy processes and may enable the observation of phenomena such as dark-matter particle annihilation or decay. The CRE spectrum has been directly measured up to $\sim 2$ TeV in previous balloon- or space-borne experiments, and indirectly up to $\sim 5$ TeV by ground-based Cherenkov $\gamma$-ray telescope arrays. Evidence for a spectral break in the TeV energy range has been provided by indirect measurements of H.E.S.S., although the results were qualified by sizeable systematic uncertainties. Here we report a direct measurement of CREs in the energy range $25~{\rm GeV}-4.6~{\rm TeV}$ by the DArk Matter Particle Explorer (DAMPE) with unprecedentedly high energy resolution and low background. The majority of the spectrum can be properly fitted by a smoothly broken power-law model rather than a single power-law model. The direct detection of a spectral break at $E \sim0.9$ TeV confirms the evidence found by H.E.S.S., clarifies the behavior of the CRE spectrum at energies above 1 TeV and sheds light on the physical origin of the sub-TeV CREs., Comment: 18 pages, 6 figures, Nature in press, doi:10.1038/nature24475

An 8-week feeding trial was conducted to establish the dietary vitamin E requirement of juvenile cobia. The basal diet was supplemented with 10, 20, 30, 40, 60, 120 mg vitamin E kg−1 as all-rac-α-tocopheryl acetate. The results indicated that fish fed the diets supplemented vitamin E had significantly higher specific growth rate, protein efficiency ratio, feed efficiency and survival rate than those fed the basal diet. It was further observed that vitamin E concentrations in liver increased significantly when the dietary vitamin E level increased from 13.2 to 124 mg kg−1. Fish fed the basal diet had significantly higher thiobarbituric acid-reactive substances concentrations in liver than those fed the diets supplemented vitamin E. Fish fed the diets supplemented with 45.7 and 61.2 mg kg−1 vitamin E had significantly higher red blood cell and haemoglobin than those fed the basal diet, while fish fed the diets supplemented with 61.2 and 124 mg kg−1 vitamin E had higher immunoglobulin concentration than those fish fed the basal diet. Lysozyme and superoxide dismutase were significantly influenced by the dietary vitamin E level. The dietary vitamin E requirement of juvenile cobia was established based on second-order polynomial regression of weight gain and lysozyme to be 78 or 111 mg all-rac-α-tocopheryl acetate kg−1 diet, respectively.

In this work, the directional solidification of an Nb–14Si–24Ti–2Cr alloy (at-%) was performed at 1900°C with withdrawal rates of 1·2, 6 and 18 mm min−1, and the alloy was then heat treated (HT) at 1450°C for 100 h. The microstructures and mechanical properties of the directionally solidified and HT alloy were investigated. The phases present in the sample were confirmed to be NbSS dendrites, lath-like Nb3Si, eutectic NbSS+Nb3Si and Ti enriched areas. As the withdrawal rate increased, the effects of directional solidification became more evident, and the microstructure became more refined. After the heat treatment, the microstructure was characterised by NbSS dendrites, residual Nb3Si and lamellar eutectic NbSS+Nb3Si, which was decomposed from the lath-like Nb3Si. An increase in the withdrawal rate resulted in a decrease in the room temperature fracture toughness of the HT alloy. However, the room temperature compressive strength of the HT alloy increased to 1593·9 MPa with increasing withdrawal r...

The conventional charge transport models based on density- and field-dependent mobility, only having a non-Arrhenius temperature dependence, cannot give good current-voltage characteristics of poly (2-methoxy-5-(2′-ethylhexyloxy)-p-phenylene vinylene) (MEH-PPV) hole-only devices. In this paper, we demonstrate that the current-voltage characteristics can give a good unified description of the temperature, carrier density and electric field dependence of mobility based on both the Arrhenius temperature dependence and the non-Arrhenius temperature dependence. Furthermore, we perform a systematic study of charge transport and electrical properties for MEH-PPV. It is shown that the boundary carrier density has an important effect on the current-voltage characteristics. Too large or too small values of boundary carrier density will lead to incorrect current-voltage characteristics. The numerically calculated carrier density is a decreasing function of the distance to the interface, and the numerically calculated electric field is an increasing function of the distance. Both the maximum of carrier density and the minimum of electric field appear near the interface.

Vehicle emission control regulations necessitate the removal of carbon monoxide (CO) from engine exhausts via CO oxidation. Although bismuth (Bi)-promoted platinum (Pt) catalysts show improvement in CO oxidation performance over pure Pt, it is still not known whether Bi acts simply as a site blocker to reduce CO poisoning or whether it is an active participant in the catalytic reactions. In this study, we report density functional theory-based CO oxidation energetics and kinetics in the presence of different Bi dopant configurations. Adsorption energies for both CO and oxygen atoms are found to be reduced by Bi doping. Bi dopant also creates surface areas in its vicinity where CO adsorption is prohibited, whereas molecular oxygen dissociation is promoted. Significant reduction is shown for CO oxidation barriers on Bi-modified Pt(111) surfaces leading to exothermic CO2 formation. Our results elucidate that promoting Pt with Bi affects both the electronic properties of the catalyst and alters the Pt ensembl...

A physically based mathematical model for the charge transport in field-effect transistors and lighting-emitting diodes based on disordered organic semiconductors has been presented. It is developed basing on the Gaussian disorder model and extends the pioneering work of Pasveer et al. [Phys. Rev. Lett. 94, 206601 (2005)] to higher carrier densities and large electric field. The experimental current voltage characteristics in devices based on semiconducting polymers are excellently reproduced with this model. Furthermore, we calculate and analyze some electrical properties for the relevant polymers in detail using this model.

High quality Co-doped ZnO films with good reproducibility have been prepared under different oxygen partial pressure by radio-frequency magnetron sputtering. These films were characterized using numerous characterization techniques including X-ray diffraction, electrical transport, and magnetization measurements. The effect of oxygen partial pressure on the structural, magnetic, and electrical properties of Co-doped ZnO films has been systematically studied. It was found that the structural, magnetic, and electrical properties of Co-doped ZnO films are dependent on oxygen partial pressure. The saturated magnetization of Co-doped ZnO films rapidly increases with decreasing oxygen partial pressure, whereas the resistivity decreases with decreasing oxygen partial pressure. Our findings indicate that the magnetic and electrical properties of Co-doped ZnO films can be tuned by careful control of oxygen partial pressure. In addition, it was further demonstrated that the oxygen vacancy defect is absolutely necessary to induce ferromagnetic couplings in Co-doped ZnO films.