Temperature-sensing array using the metal-to-insulator transition of Nd_(x)Sm_(1-x)NiO_(3)

Rare-earth nickelates(RENiO_(3))show widely tunable metal-to-insulator transition(MIT)properties with ignorable variations in lattice constants and small latent heat across the critical temperature(TMIT).Particularly,it is worth noting that compared with the more commonly investigated vanadium oxides,the MIT of RENiO_(3)is less abrupt but usually across a wider range of temperatures.This sheds light on their alternative applications as negative temperature coefficient resistance(NTCR)thermistors with high sensitivity compared with the current NTCR thermistors,other than their expected use as critical temperature resistance thermistors.In this work,we demonstrate the NTCR thermistor functionality for using the adjustable MIT of Nd_(x)Sm_(1-x)NiO_(3)within 200–400 K,which displays larger magnitudes of NTCR(e.g.,more than 7%/K)that is unattainable in traditional NTCR thermistor materials.The temperature dependence of resistance(R–T)shows sharp variation during the MIT of Nd_(x)Sm_(1-x)NiO_(3)with no hysteresis via decreasing the Nd content(e.g.,x≤0.8),and such a R–T tendency can be linearized by introducing an optimum parallel resistor.The sensitive range of temperature can be further extended to 210–360 K by combining a series of Nd_(x)Sm_(1-x)NiO_(3)with eight rare-earth co-occupation ratios as an array,with a high magnitude of NTCR(e.g.,7%–14%/K)covering the entire range of temperatures.

Metal-organic decomposition growth of thin film metastable perovskite nickelates with kinetically improved quantum transitions

The multiple quantum transitions within d-band correlation oxides such as rare-earth nickelates(RENiO_(3))triggered by critical temperatures and/or hydrogenation opened up a new paradigm for correlated electronics applications,e.g.ocean electric field sensor,bio-sensor,and neuron synapse logical devices.Nevertheless,these applications are obstructed by the present ineffectiveness in the thin film growth of the metastable RENiO_(3)with flexibly adjustable rare-earth compositions and electronic structures.Herein,we demonstrate a metal-organic decompositions(MOD)approach that can effectively grow metastable RENiO_(3)covering a large variety of the rare-earth composition without introducing any vacuum process.Unlike the previous chemical growths for RENiO_(3)relying on strict interfacial coherency that limit the film thickness,the MOD growth using reactive isooctanoate percussors is tolerant to lattice defects and therefore achieves comparable film thickness to vacuum depositions.Further indicated by positron annihilation spectroscopy,the RENiO_(3)grown by MOD exhibit large amount of lattice defects that improves their hydrogen incorporation amount and electron transfers,as demonstrated by the resonant nuclear reaction analysis and near edge X-ray absorption fine structure analysis.This effectively enlarges the magnitude in the resistance regulations in particular for RENiO_(3)with lighter RE,shedding a light on the extrinsic regulation of the hydrogen induced quantum transitions for correlated oxides semiconductors kinetically via defect engineering.

Highly Efficient Conversion of Solar Energy by the Photoelectric Converter and a Thermoelectric Converter

The analysis of the principle operation of the solar element is given in the work. The efficiency of the creation of combined high-efficiency converters of network energy in electric and thermal is indicated. A method for creating a combined photo thermo converter with a high value of the efficiency of a solar element has been found. A method for separating light from optical lenses is shown. The calculation of the light intensity into diffraction pattern is calculated using the Huygens-Fresnel principle. A new design of a highly efficient combined light-thermal converter into an electrical, with a solar element, operating on selective photoactive radiation is presented. The process of conversion of non-active radiation into electrical radiation by means of a thermo electronic converter is described. The ways of the solution of the problem connected with the reduction of the coefficient of its full effect as a function of temperature and characteristics are indicated.

Analysis of the Influence of the Blade Deformation on Wind Turbine Output Power in the Framework of a Bidirectional Fluid-Structure Interaction Model

The blades of large-scale wind turbines can obviously deform during operation,and such a deformation can affect the wind turbine’s output power to a certain extent.In order to shed some light on this phenomenon,for which limited information is available in the literature,a bidirectional fluid-structure interaction(FSI)numerical model is employed in this work.In particular,a 5 MW large-scale wind turbine designed by the National Renewable Energy Laboratory(NREL)of the United States is considered as a testbed.The research results show that blades’deformation can increase the wind turbine’s output power by 135 kW at rated working conditions.Compared with the outcomes of the simulations conducted using the model with no blade deformation,the results obtained with the FSI model are closer to the experimental data.It is concluded that the bidirectional FSI model can replicate the working conditions of wind turbines with great fidelity,thereby providing an effective method for wind turbine design and optimization.

Influence of the structure of TiO_2 , CeO_2 , and CeO_2-TiO_2 supports on the activity of Ru catalysts in the catalytic wet air oxidation of acetic acid

Ru catalysts, supported on TiO 2 , CeO 2 , and CeO 2 -TiO 2 , were prepared by the impregnation method. The effect of the structure of the supports on the activity of Ru catalysts was investigated in the catalytic wet air oxidation （CWAO） of acetic acid under 230℃ and 5 MPa in a batch reactor. Physical properties including the surface area, crystalline phase, and surface components of the Ru catalysts were characterized by N 2 adsorption, X-ray powder diffraction （XRD）, and X-ray photoelectron spectroscopy （XPS）. The CeO 2 -based Ru catalysts had good activity, and the prepared RuO 2 /CeO 2 catalyst showed markedly higher activity than the RuO 2 /CeO 2 -TiO 2 catalyst. The surface structure, the high amount of chemisorbed oxygen on the catalyst surface, and the suitable pH pzc value of the supports played an important role in the activity of the Ru catalysts in CWAO of acetic acid.

Active control of turbulence for drag reduction based on the detection of near-wall streamwise vortices by wall information

The spatial relations between the measurable wall quantities （streamwise shear stress τwx, spanwise shear stress τwz, and pressure fluctuations Pw） and the near-wall streamwise vortices （NWSV） are investigated via direct numerical simulation （DNS） databases of fully developed turbulent channel flow at a low Reynolds number. In the stan- dard turbulent channel flow, the results show that all the wall measurable variables are closely associated with the NWSV. But after applying a stochastic interference, the relation based on τwx breaks down while the correlations based on Pw and τwz are still robust. Hence, two wall flow quantities based on Pw and τwz are proposed to detect the NWSV. As an appli- cation, two new control schemes are developed to suppress the near-wall vortical structures using the actuation of wall blowing/suction and obtain 16 % and 11% drag reduction, respectively.

Progress of Microgravity Material Research During the Period of 2007-2009

Orbital experimental researches on crystal growth of Mn-doped GaSb and Bi2Se0.21Te2.79 are briefly summarized.The space experiments were completed in September of 2007 on broad the Foton-M3 satellite of Russia.Ground-based researches on the solidification behaviors of Al-Al3Ni,AlAl2Cu,Ag-Cu eutectic,Al-Pb monotectic and Cu-Co peritectic alloys in a 50-meter-high drop tube were investigated.New experimental results on the ultrasonic field and the temperature recycling induced to chiral symmetry breaking of NaClO3 crystal also were reported in the present paper.

Effect of Co^(2+)substitution in B-sites of the perovskite system on the phase formation,microstructure,electrical and magnetic properties of Bi0.5(Na0.68K0.22Li0.10)0.5TiO3 ceramics

Bi_(0.5)(Na_(0.68)K_(0.22)Li_(0.10))_(0.5)Ti_(1-x)Co_(x)O_(3) lead-free perovskite ceramics(BNKLT-xCo,x=0,0.005,0.010,0.015 and 0.020)were fabricated via the solid-state combustion technique.A small-amount of Co^(2+)ion substitution into Ti-sites led to modification of the phase formation,microstructure,electrical and magnetic properties of BNKLT ceramics.Coexisting rhombohedral and tetragonal phases were observed in all samples using the X-ray diffraction(XRD)technique.The Rietveld refinement revealed that the rhombohedral phase increased from 39%to 88%when x increased from 0 to 0.020.The average grain size increased when x increased.With increasing x,more oxygen vacancies were generated,leading to asymmetry in the bipolar strain(S-E)hysteresis loops.For the composition of x=0.010,a high dielectric constant(ε_(m))of 5384 and a large strain(S_(max))of 0.23%with the normalized strain (d*_(33))of 460 pm·V^(-1) were achieved.The BNKLT-0Co ceramic showed diamagnetic behavior but all of the BNKLT-xCo ceramics exhibited paramagnetic behavior,measured at 50 K.

Dipolar and Quadrupolar Modes of SiO_(2)/Au Nanoshell Enhanced Light Trapping in Thin Film Solar Cells

Dipolar and quadrupolar resonance wavelengths of SiO_(2)/Au nanoshell surface plasmons are designed at 560 nm to enhance the light trapping in thin film solar cells.In order to quantitatively describe the light trapping effect,the forward−scattering efficiency(FSE)and the light trapping efficiency(LTE)are proposed by considering the light scattering direction of SiO_(2)/Au nanoshells.Based on the Mie theory,the FSE and the LTE are calculated for SiO_(2)/Au nanoshells of different dimensions,and the contributions of the dipolar and quadrupolar modes to the light trapping effect are analyzed in detail.When the surface coverage of nanoshells is 5%,the LTEs are 21.7%and 46.9%for SiO_(2)/Au nanoshells with sizes of(31 nm,69 nm)and(53 nm,141 nm),respectively.The results indicate that the SiO_(2)/Au nanoshell whose quadrupolar mode peak is designed to the strongest solar energy flux density of the solar spectrum facilitates the further enhancement of light harvesting in thin film solar cells.

Novel hole transport layer of nickel oxide composite with carbon for high-performance perovskite solar cells

A depth behavioral understanding for each layer in perovskite solar cells （PSCs） and their inter[acial interactions as a whole has been emerged for further enhancement in power conversion efficiency （PCE）. Herein, NiO@Carbon was not only simulated as a hole transport layer but also as a counter electrode at the same time in the planar heterojunction based PSCs with the program wxAMPS （analysis of microelectronic and photonic structures）-lD. Simulation results revealed a high dependence of PCE on the effect of band offset between hole transport material （HTM） and perovskite layers. Meanwhile, the valence band offset （AEv） of NiO-HTM was optimized to be -0.1 to -0.3 eV lower than that of the perovskite layer. Additionally, a barrier cliff was identified to significantly influence the hole extraction at the HTM/absorber interface. Conversely, the AEv between the active material and NiO@Carbon-HTM was derived to be -0.15 to 0.15 eV with an enhanced efficiency from 15% to 16%.

Computational Study of Ternary Devices: Stable, Low-Cost,and Efficient Planar Perovskite Solar Cells

Although perovskite solar cells with power conversion efficiencies(PCEs) more than 22% have been realized with expensive organic charge-transporting materials, their stability and high cost remain to be addressed. In this work, the perovskite configuration of MAPbX(MA = CH_3 NH_3,X = I_3, Br_3, or I_2Br) integrated with stable and low-cost Cu:Ni Oxhole-transporting material, ZnO electron-transporting material, and Al counter electrode was modeled as a planar PSC and studied theoretically. A solar cell simulation program(wx AMPS), which served as an update of the popular solar cell simulation tool(AMPS: Analysis of Microelectronic and Photonic Structures), was used. The study yielded a detailed understanding of the role of each component in the solar celland its effect on the photovoltaic parameters as a whole. The bandgap of active materials and operating temperature of the modeled solar cell were shown to influence the solar cell performance in a significant way. Further, the simulation results reveal a strong dependence of photovoltaic parameters on the thickness and defect density of the light-absorbing layers. Under moderate simulation conditions, the MAPb Br_3 and MAPbI _2 Br cells recorded the highest PCEs of 20.58 and 19.08%, respectively, while MAPbI_3 cell gave a value of 16.14%.

Mathematical Constraints in Multiscale Subgrid-Scale Modeling of Nonlinear Systems

To shed light on the subgrid-seale （SGS） modeling methodology of nonlinear systems such as the Navier-Stokes turbulence, we define the concepts of assumption and restriction in the modeling procedure, which are shown by generalized derivation of three general mathematical constraints for different combinations of restrictions. These constraints are verified numerically in a one-dimensional nonlinear advection equation. This study is expected to inspire future research on the SGS modeling methodology of nonlinear systems.

Statistical downscaling of numerical weather prediction based on convolutional neural networks

Numerical Weather Prediction(NWP)is a necessary input for short-term wind power forecasting.Existing NWP models are all based on purely physical models.This requires mainframe computers to perform large-scale numerical calculations and the technical threshold of the assimilation process is high.There is a need to further improve the timeliness and accuracy of the assimilation process.In order to solve the above problems,NWP method based on artificial intelligence is proposed in this paper.It uses a convolutional neural network algorithm and a downscaling model from the global background field to establish a given wind turbine hub height position.We considered the actual data of a wind farm in north China as an example to analyze the calculation example.The results show that the prediction accuracy of the proposed method is equivalent to that of the traditional purely physical model.The prediction accuracy in some months is better than that of the purely physical model,and the calculation efficiency is considerably improved.The validity and advantages of the proposed method are verified from the results,and the traditional NWP method is replaced to a certain extent.

Doping Effect of Co at Ag Sites in Antiperovskite Mn3AgN Compounds

Antiperovskite compounds Mn3Ag1-xCoxN （x =0.2, 0.5 and 0.8） are synthesized and the doping effect of the magnetic element Co at the Ag site is investigated. The crystal structure is not changed by the introduction of Co. However, with the increase of the content of Co, the spin reorientation gradually disappears and the antiferromagnetic transition changes to the ferromagnetic transition at the elevated temperature when x = 0.8. In addition, all of the magnetic phase transitions at the elevated temperature are always accompanied by the abnormal thermal expansion behaviors and an entropy change. Moreover, when x = 0.8, the coefficient of linear expansion is -1.89 × 10^-6 K^-1 （290-310K, △T =20 K）, which is generally considered as the low thermal expansion.

Dynamic Simulation of Solid Adsorption Solar Refrigerator System with AC/CH₃OH as a Working Pair

Solid adsorption system, one of alternative refrigeration systems, is utilized to provide cold for refrigerator or air-conditioner and can be operated by assistance of solar heat. System performance study through computer usage to develop simulation program and simulate behaviors of system operation can give designed system which suits for user’s need. Also, the present study aims to develop dynamic simulation program of solid adsorption refrigeration system operated by solar assistance to simulate behaviors of system operation and its performance. Flat plate collectror is utilized to provide thermal energy for system’s adsorber and activated carbon/methanol is used to be a suitable working pair. Simulation procedure starts with various solar radiation intensities as input energy on solar collector and water is used as collector working fluid. Behavior of system operation can be considered to be 4 steps as isosteric heating, isobaric desorption, isosteric cooling and isobaric adsorption, respectively. This research studies the effect of varying solar radiation intensity on temperature, pressure of adsorber, adsorption ratio at each steps of system operated ranging from 6:00 am (the first day) to 6:00 am (the next day) and system performance which is defined as coefficient of performance, COP. In addition, the simulation result shows monthly average COP of 0.43 compared to a result of another previous research work under the same operating condition and the percentage error is 7.5%.

Nature of DNA-graphene Interaction System: An Theoretic Account

The nature of DNA-graphene interaction system was investigated by using molecular dynamic simulations and density functional theory calculations. The detailed adsorption behaviors of single-stranded DNA( ssDNA) and double-stranded DNA( dsDNA) on the surface of graphene were discussed. The π-π stacking would contribute to the maximum average loading of ssDNA( 167 segments) with the adsorption potential distribution at the range of-6. 0 eV to-2. 1 eV,higher than that of dsDNA( 30 segments) with the adsorption energy distribution ranging from-3. 0 eV to- 0. 2 eV. Gradually shielding the base of ssDNA using hydrogen atom and gradually changing ssDNA into dsDNA through base-pairing were performed to further detect the detailed interaction between DNA and graphene. E B for * CGC,G* GC,GC* C,and GCG* is-15. 130,-15. 276,-15. 137,and- 15. 271 eV,respectively. E B for GCGC-CGCG / graphene,GCGC-CGC / graphene,GCGC-CG / graphene,GCGC-C / graphene,and GCGC / graphene is-14. 941,-14. 700,-14. 204,-15. 561,and- 15. 810 eV,respectively. DOS of the adsorbed ssDNA down shifted 1. 885 eV,which becomes more stable and less reactive than the other cases. Further,oxidation reaction shows that graphene protects ssDNA from breaking by active oxide. And stable adsorption,protection from destroying,and undamaged desorption insure the possibility of graphene to deliver or hybrid DNA for novel and creative use.

Thermal Distribution Performance of NPCM: NaCl, NaNO₃and KNO₃in the Thermal Storage System

The experiment is studied on thermal distribution in the thermal energy storage system with non-phase change materials (NPCM): NaNO3, KNO3 and NaCl in the range of 25°C - 250°C. The cylindrical storage system was made of stainless steel with 25.6 cm-diameter and 26.8 cm-height that was contained of these NPCM. There was one pipe for heat transfer fluid (HTF) with 1.27 cm-diameter that manipulates in the storage tank and submerges to NPCM. The inner pipe was connected to the 2.27 cm-diameter outer HTF tube. The tube was further connected to the thermal pump, heater and load. The pump circulates the synthetic oil (Thermia oil) within the pipe for heat transferring purposes (charging and discharging). An electric heater is used as the heat source. The limitation of the charging oil temperature is maintained at 250°C with the flow rates in the range of 0.58 to 1.45 kg/s whereas the inlet temperature of the discharge oil is maintained at 25°C. Thermal performances of TES (thermal energy storage) such as charging and discharging times, radial thermal distribution, energy storage capacity and energy efficiency have been evaluated. The experimental results show that the radial thermal distribution of NaCl for TR inside, TR middle and TR outside was optimum of temperature down to NaNO3 and KNO3 respectively. Comparison of NPCMs with oil, flow rates for NaCl were charging and discharging heat transfer than KNO3 and NaNO3. The thermal stored NaCl ranged from 5712 - 5912 J;KNO3 ranged from 7350 - 7939 J and NaNO3 ranged from 6623 - 6930 J respectively. The thermal energy stored for experimental results got with along the KNO3, NaNO3 and NaCl respectively. The thermal energy efficiency of NaCl, KNO3 and NaNO3 was in the range 66% - 70%.

Growth and Characterization of InAs1-xSbx with Different Sb Compositions on GaAs Substrates

InAs1-xSbx with different compositions is grown by molecular beam epitaxy on （100）-oriented semi-insulating GaAs substrates. The increase of Sb content in the epilayer results in the deterioration of crystal quality and surface morphology. Hall measurements show that the carrier concentration increases with the composition of Sb. The electron mobility decreases initially, when Sb composition exceeds a certain value, and the mobility increases slightly. In this work, we emphasize the comparison of crystal quality, surface morphology and electrical properties of epilayers with different Sb compositions.

Production of Producer Gas from Densified Agricultural Biomass in Downdraft Gasifier and Its Application to Small Diesel Engines

Biomass is becoming one of the most popular renewable energy sources,especially from agricultural wastes.These wastes can be gasified and utilized in various industries.This experimental study investigated producer gas generation from densified agricultural fuels such as corncobs,rice husks,wood chips,and oil palm fronds in a 50 kWth throatless downdraft gasifier.This system produced combustible gases such as H_(2),CO,and CH_(4),which were utilized as a substitute for diesel fuel in a small diesel engine for power generation.The results showed that the gasifier performs successfully and seems to prefer pellets to briquettes.Producer gas contains 18%–20%carbon monoxide,1%–6%hydrogen,and 0.9%–1.9%methane.Maximum gasification efficiencies of 53%–71%were achieved with biomass pellets from wood chips,corncobs,oil palm fronds,and rice husks,with producer gas calorific value of 2.94–3.85 MJ/Nm^(3).The average fuel consumption rate was between 6.72–14.43 kg/h,while the producer gas yield was between 2–3 Nm^(3)/kg.The average gravimetric concentration of biomass tar in the raw product gas was found to be in the range of 23–50 g/Nm^(3),in which pelletized fuel appeared to show slightly lower tar than briquette fuel.The tar was primarily composed of five compounds:Benzo(a)pyrene,chrysene,pyrene,phenanthrene,1-methylnaphthalene,and several other polycyclic aromatic compounds.The producer gas from oil palm frond briquettes and biodiesel were tested in a gas engine system in a dual fuel mode.A thermal efficiency of 22.21%was achieved with 2500 W electric load and a 72%biodiesel displacement rate,respectively.