- 标题
- 摘要
- 关键词
- 实验方案
- 产品
过滤筛选
- 2019
- 2018
- Dual Material Gate (DMG)
- Vertical TFET
- Single Material Gate(SMG)
- Band-to-band tunneling (BTBT)
- characterization
- organic light-emitting diode
- mobility
- material parameter
- doping
- Electronic Science and Technology
- Optoelectronic Information Science and Engineering
- Fluxim AG
- Dresden Integrated Center for Applied Physics and Photonic Materials (IAPP) and Institute for Applied Physics, Technische Universit?t Dresden
- National Institute of Technology Silchar
-
Calculating the Minimum Thickness of Glass Fuse by Zr Kα Line for Phosphorus-Containing Zircon-Refractory Material
摘要： In this paper, we take Zr Kα line as the analysis object due to the existence of overlapping phenomenon, which the zirconium La line (0.607nm) and phosphorus Ka line (0.615nm), in phosphorus-containing zircon-refractory material. We discovered and calculated the critical thickness of glass fuse by the theoretical calculation method, and we verified the feasibility of the theory. By experiment we found that critical thickness of glass fuse can be reduced by adding additives in flux. Conventional thickness of glass fuse can reaches a critical thickness by adding 20% of calcium oxide (in the form of calcium carbonate was added) in flux. This method could also increase significantly the measurement sensitivity to guarantee good result.
关键词： Zircon-refractory material,Minimum thickness,Zr Kα line
更新于2025-09-23 15:22:29
-
Modeling and multiresponse optimization of cutting parameters in SPDT of a rigid contact lens polymer using RSM and desirability function
摘要： Amidst different conventional contact lens manufacturing techniques, single-point diamond turning (SPDT) is one of the recently developed ultra-high precision machining techniques employed in the fabrication of advanced contact lenses due to its capability of producing high optical surfaces of complex shapes and nanometric accuracy. SPDT is regarded as an effective process for the generation of high-quality functional surfaces in optical industries. However, despite advances in the ultra-high precision machining, it is not always easy to achieve a high-quality surface finish with maximum productivity. Machining parameters, namely cutting speed, feed rate, and depth of cut, play the lead role in determining the machine economics and quality of machining. The present study focuses on the determination of the optimum cutting conditions leading to minimum surface roughness as well as electrostatic charge and maximum productivity, in SPDT of the polymethyl methacrylate (PMMA) contact lens polymer using monocrystalline diamond cutting tool. The optimization is based on the response surface methodology (RSM) together with the desirability function approach. In addition, a mathematical model is developed for surface roughness (Ra), electrostatic charge (ESC), and material removal rate (MRR) using RSM regression analysis for a rigid contact lens polymer by the Design-Expert software. RSM allowed the optimization of the cutting conditions for minimal surface roughness, electrostatic charge, and maximal material removal rate which provides an effective knowledge base for process parameters, to make its enhancement of process performance in SPDT of contact lens polymer.
关键词： Electrostatic charge,Response surface methodology,Material removal rate,Surface roughness and optimization,PMMA contact lens polymer,Single-point diamond turning
更新于2025-09-23 15:22:29
-
Material Decomposition in X-ray Spectral CT Using Multiple Constraints in Image Domain
摘要： X-ray spectral CT appears as a new promising imaging modality for the quantitative measurement of materials in an object, compared to conventional energy-integrating CT or dual energy CT. We consider material decomposition in spectral CT as an overcomplete ill-conditioned inverse problem. To solve the problem, we make full use of multi-dimensional nature and high correlation of multi-energy data and spatially neighboring pixels in spectral CT. Meanwhile, we also exploit the fact that material mass density has limited value. The material decomposition is then achieved by using bounded mass density, local joint sparsity and structural low-rank (DSR) in image domain. The results on numerical phantom demonstrate that the proposed DSR method leads to more accurate decomposition than usual pseudo-inverse method with singular value decomposition (SVD) and current popular sparse regularization method with (cid:2)1-norm constraint.
关键词： Sparse representation,X-ray spectral CT,Material decomposition,Low-rank representation
更新于2025-09-23 15:22:29
-
Influence of Structure Modification of Silicon Carbide Materials on Their Dynamic Properties
摘要： SiC ceramic materials were prepared both by reactive and liquid-phase sintering. Structure was modified during preparation by introducing reinforcing SiC-filaments and by synthesizing grains self-reinforcing the structure. The armor-protection capacity was determined by estimating the bullet penetration delay time.
关键词： reinforced materials,bullet resistance of the ceramic material,cracking resistance,liquid-phase sintered silicon carbide (LPS-SiC),reaction-sintered silicon carbide (SiSiC)
更新于2025-09-23 15:21:21
-
Design of a novel nanoscale high-performance phase-change silicon photonic switch
摘要： We report the design of a novel high static performance on-off photonic switch by embedding the nanoscale phase-change material Ge2Sb2Te5 into a silicon-on-insulator waveguide. The state of the proposed switch can be changed using electrical/optical pulses, and no electrical bias is needed to maintain a particular state. The fundamental mode propagating through the silicon waveguide drastically alters its properties because of the large index change at the Si-Ge2Sb2Te5 interface and absorption in Ge2Sb2Te5. The photonic switch made of the silicon waveguide embedded with Ge2Sb2Te5 of volume 400 nm × 180 nm × 450 nm (length × height × width) provides a high extinction ratio of 43 dB with a low insertion loss of 2.76 dB in ON state at the communication wavelength of 1550 nm. There is a trade-off between the insertion loss and the extinction ratio. For 10 dB extinction ratio, the insertion loss can be as low as 1.2 dB with an extremely low active volume of 400 nm × 30 nm × 450 nm (length × height × width). Further, spectral response investigations reveal that this switch maintains an extinction ratio of more than 30 dB in the wavelength range of 1500–1600 nm. The high static performance of the photonic switch reported here is a direct consequence of the proper dimensions of the active volume of Ge2Sb2Te5 and its incorporation into the silicon-on-insulator waveguide. We also propose figure-of-merit for bias-free (nonvolatile) photonic switches that considers relevant parameters of static performance.
关键词： Silicon photonics,Phase-change material,Nanophotonics,Photonic switch
更新于2025-09-23 15:21:21
-
Ultrathin Flexible Carbon Fiber Reinforced Hierarchical Metastructure for Broadband Microwave Absorption with Nano Lossy Composite and Multi-scale Optimization
摘要： The implementation of thin structure for broadband microwave absorption is challenging due to requirement of impedance match across several frequency bands and poor mechanical properties. Herein, we demonstrate a carbon fiber (CF) reinforced flexible thin hierarchical metastructure (HM) composed of lossy materials including carbonyl iron (CI), multiwall carbon nanotube (MWCNT) and silicone rubber (SR) with thickness of 5mm and optimal concentration selected from twelve formulae. Optimization for the periodical unit size is applied and impacts of structural sizes on absorption performance is also investigated. An effective process combining the vacuum bag method and the hand lay-up technique is used to fabricate the HM. Experimental reflectivity of the absorber achieves broadband absorption below -10dB in 2-4GHz and 8-40GHz. Full band in 2-40GHz is covered below -8dB. Yielding stress of the HM is increased to 24MPa with attachment of CF while the fracture strain of the composite reaches 550%. The soft HM is suitable to adhere to curved surface of objects needed to be protected from microwave radiation detection and electromagnetic interference. Enhanced mechanical properties make it possible for further practical applications under harsh service environment such as ocean and machines with constant vibration.
关键词： broadband microwave absorption,hierarchical metastructure,dielectric-magnetic lossy material,flexible,mechanical properties
更新于2025-09-23 15:21:21
-
An Investigation into the Stability of Graphitic C <sub/>3</sub> N <sub/>4</sub> as a Photocatalyst for CO <sub/>2</sub> Reduction
摘要： The increasing CO2 concentration in the atmosphere exerts a significant influence on global warming and climate change. The capture and utilization of CO2 by conversion to useful products is an area of active research. In this work, the photo-driven reduction of CO2 was investigated using graphitic carbon nitride (g-C3N4) as a potential photocatalyst. The photocatalytic reduction of CO2 was investigated with g-C3N4 powder immobilized on a glass support in a batch gas phase photoreactor. The experiments were carried out under UV-Vis irradiation at 70°C and an initial pressure of 2.5 bar. The only gas phase product detected during the irradiation of the g-C3N4 in the presence of CO2 was CO, and the rate of production was observed to decrease over time. Oxygen doped g-C3N4 was also tested for CO2 reduction but had lower efficiency that the parent g-C3N4. Repeated cycles of photocatalytic CO2 reduction showed a decline in the activity of the g-C3N4. In the absence of CO2 some CO generation was also observed. Characterization of used and unused materials, using FTIR and XPS, showed an increase in the oxygen functional groups following UV-Vis irradiation or thermal treatment. While others report the use of g-C3N4 as a photocatalyst, this work highlights the important need for replicates and control testing to determine material stability.
关键词： CO2 reduction,photocatalysis,oxygen doping,graphitic carbon nitride,material stability,g-C3N4
更新于2025-09-23 15:21:21
-
Preparation and luminescent properties of mesoporous (SBA-15)-Eu2O3 nano materials
摘要： The CH3-(SBA-15) and (SBA-15)-Eu2O3 host-gust nanocomposite materials were synthesized by post-synthesis method, ultrasonic synthesis method (UM) and ultrasonic assisted synthesis methods (UAM). The X-ray diffraction (XRD), infrared spectroscopy (IR), scanning electron microscopy (SEM), transmission electron microscope (TEM) analysis and nitrogen adsorption-desorption method were used to observe the structure, the surface morphology and the chemical composites of the prepared products. The luminescent properties, and the luminescent intensity of the samples were studied by excitation and emission spectra. The results showed that, for the (SBA-15)-Eu2O3 composite materials, the hexagonal pore structure of the SBA-15 molecular sieve was maintained. The luminescent intensity of the UM sample was about 6 times higher than that of the mechanical mixture of SBA-15 and nano-Eu2O3 (5 wt %). The excitation spectrum intensity was 2 times higher than that of the mechanical mixture.
关键词： (SBA-15)-Eu2O3,Luminescence,SBA-15 molecular sieve,Trimethyl chlorosilane,Host-gust nanocomposite material
更新于2025-09-23 15:21:21
-
Sensitive Determination of Terbutaline Using a Platform Based on Nanoparticles of Europium Oxide and Carbon Nanotubes
摘要： This study presents a sensitive voltammetric determination of terbutaline (TER) on a platform based on carbon nanotubes (CNTs) and europium oxide nanoparticles (Eu2O3NPs) coated glassy carbon electrodes (GCEs). An ultrasonic bath was performed for the preparation of composite material. The material was characterized by energy dispersive X-ray spectroscopy (EDX), X-ray diffraction method (XRD) and scanning electron microscopy (SEM). The Eu2O3NPs/CNTs/GCE system was assessed for the oxidation of terbutaline (TER). A broad oxidation peak was appeared at 0.71 V using a bare GCE. However, the voltammetry of TER has been improved at a GCE coated with CNTs and a well-defined anodic peak exhibited at 0.61 V. Furthermore, the nanoparticles of Eu2O3 and CNTs coated GCE has greatly improved the electrochemical behaviour of TER and a sharp peak was appeared at 0.59 V. Cyclic voltammetry at Eu2O3NPs/CNTs/GCE also reveals a high catalytic effect for the oxidation of TER with an oxidation peak that is distinctly enhanced compared to GCE and CNTs/GCE. Eu2O3 nanoparticles were utilized to enhance the surface area of GCE and then improve the sensitivity of the procedure. The response of TER was linear over a concentration range of 2.0 3 10?8 M ?9.5 3 10?6 M with an LOD of 3.7 3 10?9 M. Square wave voltammetric analysis of tablets by Eu2O3NPs/CNTs/GCE yielded a recovery of 99.2 % with an RSD% of 3.2. The modified electrode (EuO2NPs/CNTs/GCE) provides accuracy and precision to the analysis of samples.
关键词： europium oxide nanoparticles,modified electrode,composite material,terbutaline
更新于2025-09-23 15:21:21
-
Directional fast neutron detection using a time projection chamber and plastic scintillation detectors
摘要： A new method for directional fast neutron detection is proposed based on a neutron time projection chamber (TPC) and position-sensitive plastic scintillation detectors. The detection system can efficiently locate the approximate location of a hot spot with 4π field-of-view using only the neutron TPC. Then, the system generates a high-resolution image of the hot spot using selected coincidence events in the TPC and the scintillation detectors. A prototype was built and tested using a 252Cf source. An efficiency of 7.1×10-3 was achieved for fast searching. The angular resolution was 7.8° (full width at half maximum, FWHM) for high-resolution imaging using the simple back projection method.
关键词： special nuclear material,neutron scatter imaging,time projection chamber,directional fast neutron detection,plastic scintillation detector
更新于2025-09-23 15:21:21