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A new synthetic procedure to Metal/metal sulfide hierarchical pore array composites was described. That is, a layer of Ni-Co-S nanoflakes was in situ constructed on the Ni ordered bowl-like micro/nanoarrays through a two-step electrodeposition method with the assistance of a colloidal sphere template. Such as-grown hierarchical composites could increase the specific surface areas and provide more active sites for electrocatalytic reactions. It exhibited a high catalytic activity to glucose, with a high sensitivity of 1210.1 μM‧mM-1cm-2 and a wide linear range from 0.5 μM to 2.0 mM. This work provides another candidate material for the development of planar non-enzymatic glucose sensors.

Palladium diselenide (PdSe2), a noble transition metal dichalcogenide has attracted increasing attention in recent years due to its outstanding semiconductor properties. In this study, 2D PdSe2 nanofilms with thicknesses ranging from 2 to 28 nm and their heterostructures with Si substrates (PdSe2/Si heterostructures) were synthesized via a simple selenization method. Electrical transport characterizations based on field-effect transistor devices indicate that the few-layer PdSe2 nanofilms exhibit a p-type semiconducting behavior. The optimal sensing performance of the PdSe2/Si-8 sensor (8 nm-thick PdSe2) exhibits a comparable response toward NO2 gas (ΔR/Ra = ∼7.2% to 100 ppb and ∼18% to 1 ppm) at room temperature (RT). This response may result from the heterostructure effect and maze-type surface. Additionally, the PdSe2/Si-8 sensor has selectivity toward NO2 compared with other gases including NO, H2, CO, NH3, and C2H5OH. Furthermore, density functional theory (DFT) calculations reveal the largest adsorption energy and charge transfer between NO2 and the PdSe2 surface, which coincides well with the experimental results. Moreover, the PdSe2/Si-8 sensor also exhibits repeatability and long-term stability during about 4 months at RT. These results indicate that the PdSe2/Si heterostructures may be a promising nanomaterial for room-temperature NO2 gas-sensing devices.

Li-rich high-Mn oxides, xLi2MnO3·(1 − x)LiMO2 (x ≥ 0.5, M = Co, Ni, Mn…), have attracted extensive research interest due to their high specific capacity and low cost. However, slow Li2MnO3 activation and poor cycling stability have affected their electrochemical performance. Herein, to solve these problems, morphology regulation and LiAlF4 coating strategies have been synergistically applied to a Li-rich high-Mn material Li1.7Mn0.8Co0.1Ni0.1O2.7 (HM-811). This dual-strategy successfully promotes the activation process of the Li2MnO3 phase and thus improves the electrochemical performance of HM-811. Theoretical computation indicates that the LiAlF4 layer has a lower Li+ migration barrier than the HM-811 matrix, so it could boost the diffusion of Li+ ions and promote the activation of the Li2MnO3 phase. Benefiting from the morphology regulation and LiAlF4 coating, the HM-811 cathode shows a high initial charge capacity of >300 mA h g−1. In addition, the modified HM-811 could deliver superior electrochemical performance even at a low temperature of −20 °C. This work provides a new approach for developing high performance cathode materials for next-generation Li-ion batteries.

To ameliorate the inherent issues of the huge volume expansion and low conductivity of vanadium tetrasulfide (VS4) as an anode material for lithium ion batteries, the structural design must be significantly effective. Therefore, we prepared various Mo-doped VS4 materials for the first time, and found that Mo impacted the VS4 structure. It was confirmed that Mo-doping not only could repair the sulfur vacancies of VS4, but also introduce the formation of local amorphous structure. Because the intrinsic sulfur vacancies in VS4 were repaired, the electrical conductivity of Mo-doped VS4 was improved and the Mo-doped VS4 electrode showed a superior rate performance. Moreover, the amorphous structure of Mo-doped VS4 provided more sites for the storage of lithium ions, more channels for the transportation of lithium ions, and a stable buffer to accommodate the volume change of VS4. Based on the synergistic effect between the repaired sulfur vacancies and introduction of local amorphous structure after Mo-doping, both the electrochemical performance and kinetics of Mo-VS4 electrode were enhanced distinctly.

Lithium-sulfur batteries (LSBs) with extremely-high theoretical energy density (2600 Wh kg

Using thermal interface materials (TIMs) is generally considered an effective way to reduce thermal contact resistance. In this paper, effects of surface roughness, temperature and pressure on TIMs’ performance are investigated. A variety of TIMs including thermal pads, carbon-based materials, phase change materials (PCMs) and low-melting-point alloys (LMPAs) are experimentally studied, and their performance is compared with the case without using any TIM. Results indicate that, when pressure is below 0.3 MPa, the interface thermal resistance (ITR) decreases when the pressure increases, but such a trend is not obvious when pressure exceeds 0.3 MPa. The increase of surface roughness causes the ITR of thermal pads and carbon-based materials to increase, but does not affect the performance of PCMs and LMPAs. Interface thermal resistance of carbon-based materials decreases a little as temperature increases and that of thermal pads is not affected by temperature in test range. The ITR of PCMs and LMPAs sharply decreases when temperature exceeds phase change point. When surface roughness is 0.8 μm, thermal contact resistance of aluminum is 189 mm2·K·W−1 at 0.2 MPa and 153 mm2·K·W−1 at 0.4 MPa, but the ITR of thermal pads is 136–395 mm2·K·W−1 at 0.3 MPa and the ITR of one carbon-based material is 165 mm2·K·W−1 at 0.5 MPa.

Li-rich high-Mn oxides, xLi2MnO3·(1 - x)LiMO2 (x ≥ 0.5, M = Co, Ni, Mn…), have attracted extensive research interest due to their high specific capacity and low cost. However, slow Li2MnO3 activation and poor cycling stability have affected their electrochemical performance. Herein, to solve these problems, morphology regulation and LiAlF4 coating strategies have been synergistically applied to a Li-rich high-Mn material Li1.7Mn0.8Co0.1Ni0.1O2.7 (HM-811). This dual-strategy successfully promotes the activation process of the Li2MnO3 phase and thus improves the electrochemical performance of HM-811. Theoretical computation indicates that the LiAlF4 layer has a lower Li+ migration barrier than the HM-811 matrix, so it could boost the diffusion of Li+ ions and promote the activation of the Li2MnO3 phase. Benefiting from the morphology regulation and LiAlF4 coating, the HM-811 cathode shows a high initial charge capacity of300 mA h g-1. In addition, the modified HM-811 could deliver superior electrochemical performance even at a low temperature of -20 °C. This work provides a new approach for developing high performance cathode materials for next-generation Li-ion batteries.

The hot-rolled strip skin-pass mill is the important technological equipment of finishing process in the hot rolling plant, and its role is to apply a slight thickness reduction of approximately 1% - 4% to the finished products cooled to room temperature to repair flatness defects and improve the surface quality and mechanical properties. In this study, the initial flat roll contours were optimized to solve some problems such as the serious and non-uniform wear of work rolls and the poor shape control abilities of the strip. A three-dimensional rolls–strip coupling model of hot-rolled strip skin-pass mill was established using the nonlinear finite element software ABAQUS. The effects of the roll contours on the contact pressure between rolls and the control effect of bending forces were analyzed, and a variable contact-length backup roll (VCR) contour configured with a positive crown contour for work rolls was proposed. Compared with the initial flat roll contours, the average replacement cycle of work rolls for the optimized roll contours increased from 465.4 tons to 701.3 tons, the non-uniform wear amount was reduced by nearly 15%, and the adjustment ratio of the negative bending forces decreased from -100% to -40% by industrial experiments in the 1580 mm single-stand four-high hot-rolled strip skin-pass mill.

A novel one-pot epoxide hydrolase/alcohol dehydrogenase/transaminase cascade process for the asymmetric ring opening of racemic epoxides to enantiopure β-amino alcohols is reported. The product (S)-β-amino alcohols were obtained in 97–99% ee and 79–99% conversion from readily available racemic epoxides.

In order to provide an accurate prediction of the flow stress during the thermal deformation process, a physical model is established. In the model, it is assumed that the flow stress is mainly composed of short-range stress and long-range stress. The short-range stress is a friction stress needed to be overcome when dislocations pass short-range obstacles and through the lattice, and the long-range stress is athermal stress caused by the interaction of dislocation substructure. The model is established mainly based on the evolution of dislocation density which is described as a competitive process of work hardening and recovery. Meanwhile, the interaction between vacancies and dislocations is also taken into account. The effect of solutes and precipitation on stress is quantified. In addition, some experiments have been performed using two steels containing different amounts of Nb under various deformation conditions. The experimental results indicate the prediction accuracy of the model is satisfactory.

The crystal structure of the Li2MnSiO4 cathode material would collapse during the charge and discharge process because of that the Mn-O coordination polyhedron changed from [MnO4] into [MnO6] in the process of Mn+2 to Mn+4, but the Cr element could remain [CrO4] crystal ligand from Cr+2 to Cr+4, so Cr element substitution was used to improve the structural stability of the Li2MnSiO4 cathode material. In this work, Li2Mn1-xCrxSiO4/C nanocomposites were synthesized by solid-state method. XRD, SEM and TEM observations show that the as-prepared Li2Mn1-xCrxSiO4/C materials presents an orthorhombic crystal structure (S.G. Pmn21), the particle size of Li2Mn1-xCrxSiO4/C powder ranges from 50 to 100 nm. The XRD and XPS results indicate that Cr+2 is successfully doped into Li2MnSiO4 lattice and has well compatibility with Li2MnSiO4. The electrochemical results display that Li2Mn92.5%Cr7.5%SiO4/C exhibits significantly enhanced cycle stability and discharge capability. The initial discharge capacity of the Li2Mn92.5%Cr7.5%SiO4/C sample is 255 mAh g−1, and the discharge capacity was still about 60 mAh g−1 after 50 cycles. Furthermore, the XRD patterns, TEM images and Raman analysis reveal that the Cr doping enhances the structural stability of Li2Mn1-xCrxSiO4/C and improves the electrochemical activity of the cathode. Thus, the Li2Mn92.5%Cr7.5%SiO4/C have shown potential applications for lithium ion batteries.

A Monte Carlo method based on the GEANT4 toolkit has been developed to correct the full-energy peak (FEP) efficiencies of a high purity germanium (HPGe) detector equipped with a low background shielding system, and moreover evaluated using summing peaks in a numerical way. It is found that the FEP efficiencies of 60Co, 133Ba and 152Eu can be improved up to 18% by taking the calculated true summing coincidence factors (TSCFs) correction into account. Counts of summing coincidence γ peaks in the spectrum of 152Eu can be well reproduced using the corrected efficiency curve within an accuracy of 3%.

To investigate the efficiency of a new cascade biocatalysis system for the conversion of R, S-β-amino alcohols to enantiopure vicinal diol and β-amino alcohol. An efficient cascade biocatalysis was achieved by combination of a transaminase, a carbonyl reductase and a cofactor regeneration system. An ee value of > 99% for 2-amino-2-phenylethanol and 1-phenyl-1, 2-ethanediol were simultaneously obtained with 50% conversion from R, S-2-amino-2-phenylethanol. The generality of the cascade biocatalysis was further demonstrated with the whole-cell approaches to convert 10–60 mM R, S-β-amino alcohol to (R)- and (S)-diol and (R)- and (S)-β-amino alcohol in 90–99% ee with 50–52% conversion. Preparative biotransformation was demonstrated at a 50 ml scale with mixed recombinant cells to give both (R)- and (S)-2-amino-2-phenylethanol and (R)- and (S)-1-phenyl-1, 2-ethanediol in > 99% ee and 40–42% isolated yield from racemic 2-amino-2-phenylethanol. This cascade biocatalysis system provides a new practical method for the simultaneous synthesis of optically pure vicinal diol and an β-amino alcohol.

LiFeP 1- x Si x O 4 /(C + y Li 2 SiO 3 ), (0 ≤ x ≤ 0.04, 0 ≤ y ≤ 2%) composites with a particle size of about 200 nm were synthesized via a simple solid state route. In this work, silicon plays double roles-silicon doping in lattice to enhance the electronic conductance of LiFePO 4 , meanwhile Li 2 SiO 3 with high Li-ion conductivity and carbon hybrid coating can decrease the interface resistance between LiFePO 4 grain and electrolyte. In this work, starch and TEOS were used as carbon source and the silicon source respectively. XRD, SEM, TEM, EIS and galvanostatic charge-discharge test are used to characterize these samples. The effects of the modification on the microstructure and electrochemical performances of LiFePO 4 cathodes at 25 °C are systematically investigated. The results show the sample with x = 0.03 and y = 1.0 wt % exhibits excellent rate capacity and cycle performance among the investigated materials. Based on half-cell testing, the best sample achieves a high special discharge capacity of 119 mAh g −1 at 5C rate and a capacity of 94 mAh g −1 at the 10C rate with an excellent cycle life in the usual cycling voltage range 2.5–4.2 V. EIS result demonstrates that the R ct of the samples decrease greatly due to the modification of LiFePO 4 via doping and coating.

The density variation of supercritical carbon dioxide exerts significant effects on heat transfer and the adaptive flow path is verified to be effective in reducing pressure loss. Meanwhile, the effects differ from flow directions of supercritical carbon dioxide. Previous studies focused on heat transfer in vertical tubes rather than vertical heat transfer exchangers. In this paper, an experimental study of supercritical carbon dioxide in a vertical adaptive flow path heat exchanger is conducted to investigate the heat transfer and flow characteristics. The pressure of cold side varies from 14.2 MPa to 16.7 MPa and that of hot side varies from 8 MPa to 10 MPa. The inlet temperature of cold side is 328 K and that of hot side varies from 398 K to 418 K. When mass flow rate ratio increases, the minimum heat transfer effectiveness occurs at 0.6 and maximum overall heat transfer coefficient occurs at 0.65. Due to the effect of flow direction, the overall heat transfer coefficient of horizontal flow is approximately 9% higher than that of upward flow for cold side and 6% lower than that of downward flow for cold side. Hence, the downward flow (cold side) is suggested for installation of heat exchanger in Brayton cycle.

Timing-pick up detectors with excellent timing resolutions are essential in many modern nuclear physics experiments. Aiming to develop a Time-Of-Flight system with precision down to about 10 ps, we have made a systematic study of the timing characteristic of TOF detectors, which consist of several combinations of plastic scintillators and photomultiplier tubes. With the conventional electronics, the best timing resolution of about 5.1 ps (σ) has been achieved for detectors with an area size of 3 × 1 cm 2 . It is found that for data digitalization a combination of TAC and ADC can achieve a better time resolution than the currently available TDC. Simultaneous measurements of both time and pulse height are very valuable for the correction of time-walk effect.

Pt/Ni multilayer nanowire arrays were successfully fabricated inside the nanochannels of anodic aluminum oxide template by pulse electrodeposition method. The morphologies of the Pt/Ni nanowires were analyzed, which revealed that these nanowires had smooth surface and uniform diameter of about 70 nm. The ferromagnetic Ni layers were separated periodically by Pt layers along the axis of the nanowires. Magnetization measurements on the Pt/Ni nanowire arrays revealed a stronger magnetic anisotropy with the easy axis parallel to the nanowires. Following electrochemical performance tests indicated that the Pt/Ni multilayer nanowires comprising Pt and Ni layers showed enhanced electrocatalytic activity for methanol oxidation, as compared with pure Pt nanowires.

In typical nuclear physics experiments with radioactive ion beams (RIBs) selected by the in-flight separation technique, Si detectors or ionization chambers are usually equipped for the charge determination of RIBs. The obtained charge resolution relies on the performance of these detectors for energy loss determination, and this affects the particle identification capability of RIBs. We present an approach on improving the resolution of charge measurement for heavy ions by using the abundant energy loss information from different types of existing detectors along the beam line. Without altering the beam line and detectors, this approach can improve the charge resolution by more than 12\% relative to the multiple sampling ionization chamber of the best resolution., Comment: 8 pages, 5 figures

The study was conducted to scrutinize the outcome of isoliquiritigenin (ISL) against cerebral injury in septic mice. The sepsis was introduced using cecal ligation and puncture (CLP) method in experimental mice. The effect of ISL was quantified using the content of brain water and blood brain barrier (BBB) permeability. The effect on the levels of myeloperoxidase (MPO), superoxide dismutase (SOD), malondialdehyde (MDA) and glutathione (GSH) in brain homogenates was also determined. The effect of ISL on the levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 in serum was also estimated. The levels of various inflammatory biomarkers (COX-2 and PGE2) were also studied. The expression of NF-κB signalling cascade and inducible nitric oxide synthase (iNOS) was estimated by Western blot. Compared with CLP group, the brain water content was found to be reduced significantly together with the enhanced BBB integrity in ISL treated group. The level of MDA was reduced together with enhanced level of SOD and GSH in the ISL treated group. The levels of TNF-α, IL-1β, and IL-6 were also found to be modulated in ISL group. The level of COX-2 and PGE2 was reduced to near normal after ISL administration together with increase in the IκBα expression and reduction of p65 and p-p65 expression in a concentration-dependent manner. The expression of iNOS was also found to be reduced in ISL group. These results demonstrate that ISL causes protection of CLP-induced sepsis in experimental mice via multiple pathways.

The preparation and electrical properties of ZnO: (Li,N) thin film transistors were studied in this work. The Li–N dual doped ZnO films, as the active layers with thickness varied from 20 to 60 nm, were deposited on SiO 2 /n-type Si substrates by radio frequency magnetron sputtering. The transistor with 30-nm-thick ZnO: (Li,N) film shows the best performance with a field effect mobility of 33.6 cm 2 /V.s, a threshold voltage of −6 V and an on/off current ratio of 1.08 × 10 8 . And the time-dependent instability of the device was studied. The mobility increases to 41.5 cm 2 /V after 120 days, and then decreases to 31.2 cm 2 /V after 180 days, accompanied by a negative shift of threshold voltage and a decrease of on/off ratio as day increases. The main cause of the instability may be the adsorption of humidity from ambient air.

We report a facile synthesis of PtNi nanosheets on the flexible ITO/PET substrate by electrochemical deposition method. The morphology and composition of the PtNi nanosheets were characterized and it was revealed that the PtNi nanosheets were polycrystalline with a thickness of about 4 nm. The average Ni content in the nanosheets was about 10 at%. The results of the electrochemical measurements showed that the PtNi nanosheets have excellent catalytic activity and stability toward the electro-oxidation of methanol in alkaline medium, which making it more attractive for fuel cell applications.

Li 2 MnSiO 4 /C nanocomposites have been successfully prepared by a two-step method to accurately control the formation of the orthorhombic Pmnb phase, and phosphate substitution is used to improve the electrochemical performance of this cathode material. The structure and electrochemical properties are investigated using X-ray diffraction, scanning electron microscope and electrochemical tests. The crystal structure of this material is confirmed to be Pmnb polymorph and the average grain size is about 80–100 nm. The electrochemical tests indicate that Li 2.1 Mn 0.9 [PO 4 ] 0.1 [SiO 4 ] 0.9 /C nanocomposites deliver a discharge specific capacity of 216.9 mAh·g −1 after initial activation and it shows much enhanced electrochemical performance compared with Li 2 MnSiO 4 /C nanocomposites. Furthermore, the XRD patterns, HRTEM images and Raman analysis reveal the crystal structural changes of the two samples during cycling. Thus, this material has shown potential for high power applications in Li-ion batteries.

Compared to traditional manual-operation method for tunnel-wall deformation measurement, DCRP (Digital Close Range Photogrammetry) technique based on non-metric digital camera is a new emerging and more effective non-contact measurement method. In practical applications, the deformation parameter measurement jobs are throughout the entire process of the tunnel construction to ensure the safety of the project. There are urgent requirements for portability and miniaturization performances of the measurement system to reduce the interaction of measurement job and project construction. A configurable 3D control field equipment was presented, the control points of which could be freely configured according to the practical work conditions and do not need to be re-calibrated. A novel portable tunnel-wall deformation measurement system based on the non-metric digital camera and DLT algorithm was set up. Experimental results showed that the precision of the system for a large section tunnel-wall deformation measurement is better than 0.1‰. The system presented in the paper has the advantages of portability and miniaturization, as easy to implement fast and in-situ tunnel-wall deformation measurements.

Due to the high labor intensity of the maintenance workers, the narrow space and harsh environments in mining process of thin coal seam, an inspection robot to adapt to the thin seam environment instead of workers for the inspection work is urgently need . In this paper, we research on a bionic joint type inspection robot motion platform in thin coal seam, and study the kinematics analysis, which is a theoretical foundation for this kind of the robot platform control.

To help with the planning and design of distribution automation systems (DASs), the best amount of terminal units (TUs) mounted in a DAS is analyzed from the perspective of benefit/cost ratio first. From the perspective of reliability, the amount of various kinds of TUs in different situations is studied, that is only TUs with tele-control function, only TUs without tele-control function, a hybrid of TUs with tele-control function and TUs without tele-control function. Some circuit breakers with current protection mounted on some branches arc investigated at length. The following conclusions arc drawn that only one TU for each feeder is the best choice from the viewpoint of benefit/cost ratio, and that the demanded amount of various kinds of TUs depends on the reliability performance desired, the time of isolating the fault section by manual operation, the time of reparation, and the frequency of failure per-year. A DAS planning example with 220 feeders is given to illustrate the proposed methodology.

A new electrochemical sensor to determine Sunset yellow (SY) in foods has been developed. A composite consisting of highly dispersed polypyrrole (ppy) and single-walled carbon nanotube (ppy–SCNT) was synthesized as a modification via a facile method at room temperature. The ppy–SCNT composites were demonstrated to be highly sensitive for SY detection. The influences of pH value, amount of ppy–SCNT dispersion, accumulation time and scan rate on the signal enhancement of SY are discussed. Under optimal experimental conditions, the ppy–SCNT modified glass carbon electrode (ppy–SCNT/GCE) exhibited a wide linear response to SY ranging from 2.0 × 10−9 to 1.5 × 10−6 M with a high sensitivity of 91.53 μA μM−1 and a low detection limit of 3.0 × 10−10 M (S/N = 3). The novel ppy can prevent the aggregation of SCNT via π–π interaction, and enhance their electrochemical properties for the measurement of Sunset yellow in food samples. The novel sensor possesses following features: facile fabrication, easy operation and acceptable stability. The analysis of real sample drinks demonstrated that the electrode has excellent selectivity.

Atomic defects play an important role in the brittle deformation of nanowires at low temperatures. With molecular dynamics simulations, we study the influence of vacancy defects on the deformation and breaking behaviors of [10 oriented single-crystal gold nanowires at 50 and 150 K. The size of the nanowire is 10a × 10a × 30a (a stands for lattice constant, 0.408 nm for gold). It is shown that good crystalline structure appears in the whole deformation process, and it is in a brittle way at low temperature. The nanowire breaking behavior is sensitive to atomic vacancies when the atomic vacancy ratio is 1% in single-layer crystalline plane. Within the limitation of vacancy-induced breaking of the nanowire, the mechanical strengths increase under atomic vacancies. However, it decreases with the defect ratio increasing.

A new powder material, rice husk-plastic composite powder (RPC), was successfully developed for selective laser sintering (SLS) process. RPC is mainly composed of rice husk powder and a hot-melt adhesive powder, it is a green and biological material and its most important advantage is low-cost, but because the hull surface of rice is burr and not smooth, easily jammed between particles, poor mobility, is not the medium of easy flowing, so mixing process was successfully developed to prepare RPC powders. The preparation process is divided to three steps. First, before mix, the rice husk power is dried for reducing the hydrophilic nature of rice husk fiber and improving the wettability and the adhesion actions of the interface. Then, put the PES hot melt adhesive, the dried wood powder and the acetone solution which contain coupling agent and initiator together to mix evenly. At last, dry the basic material at the constant temperature of 45±2°C in the oven, add the organic filler and light stabilizer. Finally, RPC powder for SLS is got. As the result of SLS fabrication, part made by RPC powder is got, its mechanical properties and dimensional accuracy is satisfied.

The RIBLL2 in-flight separator at IMP, the secondary beam line between two storage rings at the \blue{\uwave{Heavy Ion Research Facility in Lanzhou (HIRFL-CSR)}}, has been commissioned to study the rare-isotope beam (RIB) physics at around 300 MeV/nucleon for the first time, in combination of the external target facility (ETF). The unambiguous particle identification in mass and charge states for $^{18}$O and $^{40}$Ar fragments has been achieved in recent experiments. A full realization of RIBLL2 will open many potentials to address important RIB physics problems at around 300 MeV/nucleon., Comment: 3 pages, 2 figures

Transfer robot of chemical mechanical polishing (TRCMP) has some joints. For an important kind of special transfer robot, it is used as automatic material processing equipment in the semiconductor manufacture. The TRCMP has nonlinear, strongly coupled, multi-joints and under actuated, and these characteristics brought some difficulties to model and control. A dynamic model of the TRCMP was based on Lagrange equation and Newton dynamics theory. Then linearization of the dynamics model was done and its state-space equations were established. This structure of the model established is very simple, and it can control the TRCMP effectively and easy. Simulation results proved the system stability, and experiment results analyzed verified that the model of TRCMP is valid and rational.

Solar-blind photoresistors based on Mg0.48Zn0.52O thin films were fabricated on r-plane sapphire substrates by radio-frequency plasma-assisted molecular beam epitaxy. High-quality a-plane-orientation single-phase wurtzite Mg0.48Zn0.52O thin films are demonstrated by X-ray diffraction and absorption spectra. The MgZnO photoresistors exhibit a large dark/photoresistance ratio up to 1.7 × 104 with the light intensity of 0.61 mW/cm2 at 260 nm. The spectral response shows a sharp response peak only in the solar-blind region with maximum responsivity of 1.5 × 10-3 Ω-1· W-1.

International audience; Neonicotinoid insecticides are widely used for controlling sucking pests, and sublethal effects can be expected in beneficial arthropods like natural enemies. Serangium japonicum is an important predator in many agricultural systems in China, and a potential biological control agent against Bemisia tabaci. We evaluated the toxicity of imidacloprid to S. japonicum and its impact on the functional response to B. tabaci eggs. S. japonicum adults exposed through contact to dried residues of imidacloprid at the recommended field rate on cotton against B. tabaci (4 g active ingredient per 100 l, i.e. 40 ppm [part per million]), and reduced rates (25, 20, 15 and 10 ppm) for 24 h showed high mortality rates. The mortality induced by a lowest rate, 5 ppm, was not significantly different than the control group and thus it was considered as a sublethal rate. The lethal rate 50 and hazard quotient (HQ) were estimated to be 11.54 ppm and 3.47 respectively, indicating a risk for S. japonicum in treated fields (HQ > 2). When exposed to dried residues of imidacloprid at the sublethal rate (5 ppm) on cotton leaves, functional response of S. japonicum to B. tabaci eggs was affected with an increase in handling time and a reduction in peak consumption of eggs. Imidacloprid residues also disturbed predator voracity, the number of B. tabaci eggs consumed on treated leaves being significantly lower than on untreated leaves. All effects disappeared within a few hours after transfer to untreated cotton leaves. Imidacloprid systemically applied at the recommended field rate (for cotton) showed no toxicity to S. japonicum, nor affected the functional response of the predator. Sublethal effects of imidacloprid on S. japonicum observed in our study likely negatively affect S. japonicum development and reproductive capacity and may ultimately reduce predator population growth. These results hint at the importance of assessing potential effects of imidacloprid on S. japonicum for developing effective integrated pest management programs of B. tabaci in China.

Ag/GZO/ZnO/Pt structure resistive switching devices were fabricated by radio frequency (RF) magnetron sputtering, in which ZnO was used as a buffer layer. These devices have large ratio of high resistance state (HRS) to low resistance state (LRS), which is 2 × 10 3 . The storage time measurement indicates that these devices have an excellent data retention characteristic. Moreover, the operation voltages are very low, which is 0.4 V (ON state) and −0.35/−0.55 V (OFF state). The electroforming process in initial state was not needed, and multistep reset process was found.

In this paper, the technique of approximate partition of unity is used to construct a class of neural networks operators with sigmoidal functions. Using the modulus of continuity of function as a metric, the errors of the operators approximating continuous functions defined on a compact interval are estimated. Furthmore, Bochner-Riesz means operators of double Fourier series are used to construct networks operators for approximating bivariate functions, and the errors of approximation by the operators are estimated.

In this paper, extreme learning machine (ELM) is used to reconstruct a surface with a high speed. It is shown that an improved ELM, called polyharmonic extreme learning machine (P-ELM), is proposed to reconstruct a smoother surface with a high accuracy and robust stability. The proposed P-ELM improves ELM in the sense of adding a polynomial in the single-hidden-layer feedforward networks to approximate the unknown function of the surface. The proposed P-ELM can not only retain the advantages of ELM with an extremely high learning speed and a good generalization performance but also reflect the intrinsic properties of the reconstructed surface. The detailed comparisons of the P-ELM, RBF algorithm, and ELM are carried out in the simulation to show the good performances and the effectiveness of the proposed algorithm.

Ag/ZnO/Pt structure resistive switching devices are fabricated by radio frequency (RF) magnetron sputtering at room temperature. The memory devices exhibit stable and reversible resistive switching behavior. The ratio of high resistance state to low resistance state can reach as high as 102. The retention measurement indicates that the memory property of these devices can be maintained for a long time (over 104 s under 0.1-V durable stress). Moreover, the operation voltages are very low, -0.4 V (OFF state) and 0.8 V (ON state). A high-voltage forming process is not required in the initial state, and multi-step reset process is demonstrated. Resistive switching device with the Ag/ZnO/ITO structure is constructed for comparison with the Ag/ZnO/Pt device.

We report on the electrical properties of bottom-gate ZnO thin film transistors (TFTs) with different active layer thicknesses. The ZnO active layer films with thickness varied from 20 to 100 nm were deposited by radio frequency (rf) magnetron sputtering on SiO 2 /p-Si substrate and annealed at a high temperature of 950 °C. The transistor with 40 nm thick ZnO exhibited the best performance, with a field effect mobility of 27.5 cm 2 /V s, a threshold voltage of −2.4 V and an on/off ratio of 7×10 3 .

In this paper, we propose a novel algorithm for coarse-to-fine foreground objects extraction. There are two general approaches for foreground objects extraction: background subtraction and image matting. Our new approach can not only improve detection accuracy compared with general background subtraction approaches, but also reduce computation burden compared with general image matting approaches. Firstly, we present a novel method called Motion-mask Gaussian Mixture Models (Motion-mask GMMs) to extract coarse foreground regions. This new approach can classify foreground and background pixels more accurately, especially when there are long-time stopping objects in the scene. Secondly, with the coarse foreground regions, we propose a novel approach to make foreground object extraction more accurate based on effective fusion of image registration and image matting. This new method overcomes the template drift problem during template updating and also reduces the expensive computational cost of image matting. Our proposed approach is tested with kinds of video sequences in indoor and outdoor environments. Experimental results demonstrate the accuracy and efficiency of our proposed approach for foreground object extraction.

We report the fabrication and electrical characteristics of thin film transistors based on MgZnO thin films with different thicknesses of MgO buffer layer. The MgZnO thin films with MgO buffer layers were grown on SiO2/p-Si substrates by plasma assisted molecular beam epitaxy. The effects of the buffer layer thickness on the structural properties of MgZnO films are investigated by X-ray diffraction, and the results show that the crystal quality of the MgZnO film is enhanced with 4 nm MgO buffer layer. The MgZnO TFT with 4 nm MgO buffer layer exhibits an n-type enhancement mode characteristics with a field effect mobility of 1.85 cm2/V s, a threshold voltage of 27.6 V and an on/off ratio of above 106.

Following the previous study [Chemistry Letters 2007, 10, 1278.] on specific electron transport pathway in porphyrin, the electron transfer through oligomeric porphyrin molecular wires was studied in this work using first principle density function theory and non-equilibrium Green’s function calculations. The effects of chain length on the transportation behavior were discussed in terms of the electronic structures and transmission spectra. Through the analysis of spatial distribution of molecular frontier orbit we found that with the chain length increased, the whole delocalization of molecular frontier orbit enlarged, so e-transitivity became better. The results demonstrated that the frontier orbital energy gap decreased when the chain length increased, so that it should be conductive to electronic transmission. We presumed that the oligomeric porphyrin can be used to make moleculer electronic devices.