摘要：This study discusses about the optimization of spray characteristics of biodiesel fuel in a spray *** factors namely,fuel injection pressure,fuel temperature and fuel blends were chosen as the influencing factor for the set *** levels were chosen in each factor and spray tip penetration,spray cone angle and Sauter mean diameter(SMD) were taken as the response *** were designed by employing design of experiments method and Taguchi full factorial array was used to conduct the tests with different levels of the chosen *** Response Signal to Noise ratio(MRSN) was calculated for the response variables and the optimum combination level of factors was obtained simultaneously using Taguchi's parametric *** experiments were conducted for the obtained optimum combination level of factors and the results were compared with the normal operating conditions and significant improvement were observed in the response variables.

摘要：We present the design consideration and fabrication of 4H-SiC trenched-and-implanted vertical junction field-effect transistors （TI-VJFETs）. Different design factors, including channel width, channel doping, and mesa height, are con- sidered and evaluated by numerical simulations. Based on the simulation result, normally-on and normally-off devices are fabricated. The fabricated device has a 12 μm thick drift layer with 8 × 10^15 cm^-3 N-type doping and 2.6 μm channel length. The normally-on device shows a 1.2 kV blocking capability with a minimum on-state resistance of 2.33 mΩ.cm2, while the normally-off device shows an on-state resistance of 3.85 mΩ.cm2. Both the on-state and the blocking performances of the device are close to the state-of-the-art values in this voltage range.

摘要：Based on rate equations, a theoretical model of a fiber oscillator with a multimode gain fiber was built. We studied the effect of the rare earth doping profile in the core on the output characteristics of the multimode fiber oscillator. The results indicated that a pure fundamental mode can be obtained by partly doping the core of the large mode area （LMA） ytterbium doped fiber （YDF） in the fiber laser. Furthermore, a sole specific high-order mode can also be implemented by tailoring the rare earth doping profile according to the simulations. The mode coupling effect was also taken into account in the model. In spite of the mode coupling effect, the specific mode was able to dominate in the output of the fiber laser by utilizing the designed LMA YDF.

摘要：It has made significant progress in catalyst andreactor design for commercial current densities in CO_(2) electroreduction(CO_(2)ER).However,these catalyst systems haverarely been applied for a C2 gas product of ethane due to itscommonly inferior selectivity relative to other C1 and ***,bamboo-like amorphous Ni(OH)_(2) nanotubes wrapped Cu nanoparticles composite(Cu NPs@aNi(OH)_(2)NTs)are constructed for selective CO_(2)ER to ethane ina flow *** unique structure of Cu NPs@a-Ni(OH)_(2) NTsprovides a confined geometry to improve the adsorption of thereactive *** interface of Cu NPs and a-Ni(OH)_(2) NTs isstabilized by generating some NiOH *** producedCu@NiOH interface enhances the activation of CO_(2) to*C*OOH and strengthens the adsorption of*COL on Cu sitefor more*COH formation and its dimerization for finalethane ***,amorphous Ni(OH)_(2) nanotubes promote water dissociation for the hydrogenation ofcarbonous intermediates,contributing to ethane *** synthesized Cu NPs@a-Ni(OH)_(2) NTs can reach a Faradaicefficiency of 48.3%and a partial current density of−226.7 mA cm^(−2) for ethane at−0.7 V in a flow cell,with aremarkable stability for 24 *** work provides a rationalstrategy to engineer Cu-based composite for selective CO_(2)ERto ethane in a flow cell.

摘要：This article deals with the evaluation of the consumption of energy for a steady state solvent extraction in a novel L-shaped pulsed sieve-plate column, which is highly required for design and optimization of the periodic flow processes for industrial applications. In this regard, a comprehensive evaluation on the energy consumption in case of a pulsed flow for three different chemical systems is conducted and besides the influence of pulsation intensity, the effect of geometrical parameters including the plate spacing and the plate free area is investigated as well. Moreover, the concept of characteristic velocity models at flooding points is evaluated with respect to the variation of pressure drop along the column at different operational conditions.

摘要：During the operation of the rice combine harvester,the fuselage tilts due to the tilt and unevenness of the ground affect its maneuverability and operational *** at the problem of leveling due to the tilt of the field surface,this research developed an innovative dual-parallelogram chassis lifting mechanism for rice harvesters designed a hydraulic system to adjust the chassis height by extending the *** Adams simulation software,a detailed model of the lifting chassis was constructed to analyze its performance,revealing a direct correlation between the hydraulic cylinder extension and chassis ***,the mechanism could achieve leveling on slopes with inclination angles of up to 7.5°.Comprehensive evaluations of the liftable chassis system were conducted under both static and dynamic *** the static tests,the system exhibited the capacity for comprehensive or unilateral auto-leveling contingent upon the tilt,with leveling times and angular variations confined to 3.6 s and±0.4°,*** dynamic tests conducted on sloped fields and paddy soils,the system reduced post-leveling mean tilt angles and standard deviations remained below 1.2°and 0.6°,*** results demonstrated a substantial improvement in the stability and reliability of the chassis during *** research provides valuable insights into the design and optimization of automatic leveling mechanisms and structural innovations for harvester chassis.

摘要：The main factors and their varied disciplines affecting the heat transfer at the metal rheologic interface were studied from the waveguide mechanism of heat transfer of electrons and phonons, guiding the design of thermal contact resistance through studying the microscale mechanism of heat transfer at the interface. The results show that electron has stronger quantum tunneling effect when the thickness of oxide film is smaller than de Broglie wavelength of electron and the heat conduction of oxide film produces microscale effect. The thickness and nature of oxide film dominate the heat transfer at the metal rheologic interface. The main means to design the interface contact conductance are to control the formation of oxide film as well as the process of machining of roller surface and lubrication of interface.

摘要：A study is carried out on the structural design of wood-plastic composite floors. The geometric parameters of the cavities, the structure, and the means to optimize the performance of these light boards are investigated. Various structural parameters of the boards, such as size, shape, and the pattern of cavities are also studied. The optimal structure can be determined by calculation and analysis of the strength, stiffness, weight and cost of the material. A finite element model for the mechanical analysis of wood-plastic composite floors is established; and the results are used to verify the strength criteria under bending deformation, which is the most common loading condition of flooring board.

摘要：Using time-dependent multilevel approach （TDML）, this paper studies the dynamics of coherent control of Rydberg lithium atoms and demonstrates that Rydberg lithium atoms can be transferred to states of higher principal quantum number by exposing them to specially designed frequency-chirped laser pulses. The population transfer from n=70 to n=75 states of lithium atoms with efficiency more than 90% is achieved by means of the sequential adiabatic rapid passages. The results agree well with the experimental ones and show that the coherent control of the population transfer from the lower n to the higher n states can be accomplished by the optimization of the chirping parameters and the intensity of laser field.

摘要：We propose a design and optimization for directional coupling in terahertz hybrid-cladding hollow waveguide. It is composed of two square hollow waveguides which touch each other and are surrounded by a metallic layer. By employing the finite element method, the coupling performance and loss property are numerically investigated. Numerical results indi- cate that this directional coupler with hybrid-cladding can realize ultra-narrow-band coupling; it provides a low confinement loss performance： the confinement loss can reach as low as 6.27 × 10-5 cm- 1. Moreover, the further analyses of configura- tion and performance show that confinement loss and frequency range shift for the low-confinement-loss frequency regime can be realized and optimized by appropriately tuning the thickness values of the metallic and dielectric layer. In addition, through the further analysis of coupling performance, the possibilities of realizing ultra-narrow-band couplings in different frequency ranges are demonstrated. It is a powerful candidate for high precision optical fiber sensing, and communication in terahertz splitting fields.