We report for the first time a coherent red radiation at 689 nm by intracavity sum-frequency generation of the 1319- and 1444-nm laser-lines of two Nd:YAG lasers. Using type-II critical phase matching KTP crystal, 689-nm red laser was obtained by 1444- and 1319-nm intra-cavity sum-frequency mixing, and output power of 156 mW was obtained. At the output power level of 156 mW, the output power stability is better than 5.0% and laser beam quality M 2 factor is 1.23.
In order to improve the quality of colorful offset printing and know the process of ink transferring, this paper adopts the method of theoretical analysis and experiment, the velocity and pressure of the ink flow field are analyzed when the rubber roller deforms and the two rollers rotate, and the effective ink layer thickness is extracted, then the ink transferring rate can be got. The rubber roller’s deformation and ink transferring rate under different conditions are got, and factors, such as rotation velocity, deformation of rubber roller, ink layer thickness between two rollers, which affect the ink flow and transferring rate are analyzed.
: Aiming at the controlled object with large lag, model uncertainty and time variation due to the effects of working environment in printing process, and printing process requires few adjustment times, this paper designs a T-S fuzzy controller based on the theoretical model of printing color quality control, and uses the genetic algorithm to optimize the initial control rules of fuzzy controller . The optimization method aims at the problems of less known condition and the uncertain effects due to the environmental changes after the first printing. In the process of optimization, the theoretical model of the printing color quality control is used as the controlled object, and the parameters of control rule corresponding to the points of special error are optimized one by one, then the general fuzzy control rules can be got. Finally, an example illustrates the process of this method, and the robustness of the optimized fuzzy controller is analyzed. From the control results got by the optimized fuzzy controller, it can be seen that this method improves the control effects greatly, and reduces adjustment times. Finally, this paper gives some suggestions on its further perfection.
The influence of Cl- and Ca2+ on the naturally growing passive film of a new, alloyed stainless steel with 10% Cr and 0% Ni was investigated by electrochemical impedance spectroscopy, Mott-Schottky curves, X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). The results showed that Ca2+ had an inhabitation effect on passive film dissolution and that Cl- did not penetrate into the passive film, probably due to adsorption onto lower-energy oxygen vacancies and to the inhabitation effect of the space charge layer with a strong electric field. Local sites in the passive film thickened and the outer layer turned into an amorphous, porous structure due to its structural integrity. Additionally, the passive film remained passive in concrete.
To date, incineration is the main method of municipal solid waste (MSW) disposal. Fly ash and bottom ash (BA) are generated in large amounts from municipal
This paper aims to use lightweight aggregates to design ultra-high-performance lightweight concrete (UHPLC) via modified Andreasen and Andersen (MAA) model, which is promising to solve the issues on the high density of ultra-high-performance concrete and thus benefits its application in high-rise and long-span structures. To reduce the deadweight of ultra-high-performance concrete, UHPLC was prepared by lightweight aggregates, and its initial mixture was designed according to the MAA model in this study. To improve the mechanical properties and microstructure of UHPLC, the UHPLC developed in this work was modified via the incorporation of graphene oxide (GO). In addition, the micro-mechanical properties of UHPLC paste with/without GO were characterized via nanoindentation technique. Results showed that: (1) Due to the incorporation of GO, the flexural strength, compressive strength and elastic modulus of UHPLC increased by 7.1%–17.7%, 4.4%–21.9%, 4.1%–12.9%, respectively; (2) addition of GO led to a significant enhancement in the internal pore structure of UHPLC; (3) From the perspective of the mechanical properties and microstructure of UHPLC, the optimal content of GO was 0.06 wt%. The findings of this work can offer valuable insights for the fabrication of UHPLC.
The task of production scheduling is to determine the detailed machining path, time, machine tool, etc., for every work piece, according to the production
In a severe nuclear power plant accident, the molten core can be released into the reactor pit and interact with sacrificial concrete. In this paper, a simulation study is presented that aims to address the influence of sacrificial concrete properties on molten core-concrete interaction (MCCI). In particular, based on the MELCOR Code, the ferrosiliceous concrete used in European Pressurized Water Reactor (EPR) is taken into account with respect to the different ablation enthalpy and Fe 2 O 3 and H 2 O contents. Results indicate that the concrete ablation rate as well as the hydrogen generation rate depends much on the concrete ablation enthalpy and Fe 2 O 3 and H 2 O contents. In practice, the ablation enthalpy of sacrificial concrete is the higher the better, while the Fe 2 O 3 and H 2 O content of sacrificial concrete is the lower the better.
This paper analyzes the defect of some methods for controlling the ink key of offset printing machine, and presents the advantage of adaptive fuzzy control. Aiming at the problem that the processing curve of offset printing is changed by the environmental impact of production, this paper analyzes this non-real-time measurement and control system with time delay and less test data, and proposes the method of adaptive fuzzy control to amend the control table and adjust the slope of the control curve according to the detection deviations. Finally, the control rules are adjusted to meet the actual situation. By simulating the control arithmetic with the example of the control of printing ink keys under specific conditions using Matlab / Simulink, it is proved to be effective to achieve the expectative effect.
The employment of a core catcher is instrumental in enhancing the safety of nuclear power facilities in the event of severe accidents, with sacrificial materials serving as fundamental constituents. Currently, cement-based sacrificial materials are prevalently utilized due to their straightforward construction methodologies and economical production costs. These materials are designed to withstand significant impact loads arising from the descent of core melt during severe accidents. To augment the impact resilience of sacrificial materials, a novel functional ultra-high performance concrete (FUHPC) incorporating barium ferrite has been developed. Using the Modified Andreasen and Andersen particle packing model to determine the initial mixture of FUHPC, and the impact of barium ferrite on the mechanical and thermal properties of FUHPC was systematically evaluated. Furthermore, the influence of barium ferrite on the FUHPC's microstructure was examined with mercury intrusion porosity and scanning electron microscopy techniques. The findings indicate: (1) Optimal barium ferrite incorporation led to a decrease in the porosity and the threshold pore diameter of FUHPC; (2) The flexural and compressive strengths, as well as the elastic modulus of FUHPC, were found to increase within the ranges of 4.41%–17.50 %, 2.88%–22.91 %, and 5.80%–15.06 %, respectively, as a result of suitable barium ferrite additions; (3) At a barium ferrite concentration of 2 vol%, the chloride migration coefficient of FUHPC was reduced by 21.43 %; (4) The presence of barium ferrite enhanced the impact performance of FUHPC, with a 21.38 % increase in impact resistance noted at a barium ferrite content of 2 vol%; (5) In high-temperature scenarios, the formation of channels from melted polypropylene fibers served to mitigate the spalling of FUHPC; (6) Upon considering the effects of barium ferrite on both room temperature and elevated temperature performance, as well as on microstructural characteristics, the optimal barium ferrite content was determined to be 2 vol%.
We report a blue laser at 473 nm generation by intracavity frequency doubling of a continuous wave (CW) laser operation of a 946 nm Nd:YAG laser under in-band diode pumping at 869 nm. An BiBO crystal, cut for critical type I phase matching at room temperature is used for second harmonic generation of the laser. At an incident pump power of 8.6 W, as high as 721 mW of CW output power at 473 nm is achieved. The optical-to-optical conversion efficiency is up to 8.4%, and the fluctuation of the blue output power was better than 3.5% in the given 30 min.
We report for the first time a continuous-wave (CW) coherent radiation at 480 nm by intracavity sum-frequency generation of 900 nm Neodymium Doped Strontium and Lanthanum Aluminate (Nd:ASL) laser and 1030 nm Yb:Y3Al5O12 (Yb:YAG) laser. Blue laser is obtained by using a doubly cavity, type-I critical phase matching LiB3O5 (LBO) crystal sum-frequency mixing. With total pump power of 28.6 W, the blue laser at 480 nm of 170 mW is obtained. At the output power level of 170 mW, the blue power stability is better than 4.7% and laser beam quality M 2 factor is 1.43.
We report a green laser at 531 nm generation by intracavity frequency doubling of a continuous wave (cw) laser operation of a 1062 nm Nd:GAGG laser under in-band diode pumping at 808 nm. A LiB3O5 (LBO) crystal, cut for critical type I phase matching at room temperature is used for second harmonic generation of the laser. At an incident pump power of 18.5 W, as high as 933 mW of cw output power at 531 nm is achieved. The fluctuation of the green output power was better than 3.5% in the given 4 h.
This paper investigates the correlation of conductivity and damage evolution in carbon fiber reinforced conductive concrete. Under axial static loading and quasi-static cycle loading, the damage evolution is detected by ultrasonic technique, and the variation of resistivity is also inspected using real-time measurement method. According to the stress wave theory, the relationship between the damage evolution in concrete and variation of ultrasonic velocity is obtained, eventually concluding in the correlation of concrete damage and its resistivity. The research results indicate that concrete real-time damage and resistivity exhibits cubic polynomial correlation under the condition of a static load, and concrete resistivity and residual damage shows exponential growth rule under the condition of a cyclic load.
This study examines the feasibility of incorporating municipal solid waste incineration fly ash (MSWIFA) into the production of ecological concrete (EC) and ecological concrete pavement bricks. As a byproduct of urban waste incineration, MSWIFA contains hazardous pollutants such as dioxins and heavy metals, prompting the necessity for effective disposal methods to mitigate environmental impacts. The research investigates how varying levels of MSWIFA affect the properties of EC and evaluates the microstructural, economic, and ecological advantages of utilizing MSWIFA in EC production. Furthermore, the study evaluates the environmental risks associated with MSWIFA and the resultant concrete bricks. Key findings indicate that a 10 % substitution rate of MSWIFA enhances EC's flexural strength, compressive strength, ultrasonic pulse velocity, and elastic modulus, attributed to the elevated calcium and chloride ion concentrations that boost cement hydration and mechanical properties. Conversely, higher MSWIFA substitution results in reduced flexural and compressive strength and a decline in porosity due to increased chloride ion migration. Energy consumption, carbon emissions, and production costs consistently decrease with elevated MSWIFA substitution rates. Ecological concrete pavement bricks with a 20 % MSWIFA substitution ratio show enhanced flexural and compressive strengths compared to standard concrete bricks, along with superior performance post-freeze-thaw cycles. The environmental risk posed by MSWIFA is deemed low, and the heavy metal risk index in the ecological bricks is well below the low-risk threshold, suggesting negligible environmental risks. Overall, the findings advocate for the resource-efficient application of MSWIFA in manufacturing sustainable concrete materials with manageable environmental risk.
Siliceous concrete (SC) is applied in European Pressurized Water Reactor that is a key component of the third generation nuclear power plant. This paper investigates the mechanical properties and damage evolution of SC (with and without polypropylene fibers) exposed to high temperatures. The mass loss, compressive strength, splitting tensile strength and spalling sensitivity of SC before and after being heated to 200, 400, 600, 800, and 1000 °C are investigated. The ultrasonic testing technique was used to assess the thermal damage, by evaluating the variations of the ultrasonic wave velocity (UWV) for different temperature levels. According to the available literature, a new relationship between damage and UWV was proposed to establish a damage evolution model of SC. The results indicated that: (a) specimens without polypropylene (PP) fibers suffered severe spalling in the range 380-400°C and 470-510°C, while no spalling took place in the specimens with PP fibers in the whole range 25-1000°C; (b) the damage evolution with and without polypropylene fibers was similar, and could adequately be described by means of a Weibull distribution model.
An elaborative study was carried out on the growth mechanism and properties of the passive film for a new kind of alloyed corrosion-resistant steel (CR steel). The passive film naturally formed in simulated concrete pore solutions (pH = 13.3). The corrosion resistance was evaluated by various methods including open circuit potential (OCP), linear polarization resistance (LPR) measurements, and electrochemical impedance spectroscopy (EIS). Meanwhile, the 2205 duplex stainless steel (SS steel) was evaluated for comparison. Moreover, the passive film with CR steel was studied by means of X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), Atomic Force Microscope (AFM), and the Mott‑Schottky approach. The results showed that the excellent passivity of CR steel could be detected in a high alkaline environment. The grain boundaries between the fine passive film particles lead to increasing Cr oxide content in the later passivation stage. The filling of cation vacancies in the later passivation stage as well as the orderly crystalized inner layer contributed to the excellent corrosion resistance of CR steel. A passive film growth model for CR steel was proposed.
The untreated application of municipal solid waste incineration bottom ash (IBA) in cementitious materials can lead to compromised workability, deterioration of mechanical properties, and compromise durability. This paper examines the potential of utilizing Al2O3 micro-powder (ALMP) to enhance the mechanical performance and durability of cementitious materials fabricated with IBA. This paper focuses on the effect of different dosages of ALMP on the workability, mechanical performance and durability of high strength mortar (HSM) prepared by IBA. In addition, effect of ALMP on the ultrasonic pulse velocity (UPV), dynamic modulus of elasticity (DME) and microstructure of HSM was also investigated. Finally, the micro-mechanical performance of HSM paste was determined via nanoindentation experiment. Our study discovered that the integration of ALMP in HSM contrived with IBA notably amplified the flexural and compressive strengths by ranges of 1.12 %∼9.84 % and 3.78 %∼21.26 %, respectively. Simultaneously, the ALMP improved the UPV by an interval of 3.16 %∼9.49 %, and the DME by a parameter of 9.64 %∼18.69 %. Additionally, we observed considerable lowering of drying shrinkage in HSM by 4.96 %∼28.36 % and decline in the chloride migration coefficient by 7.45 %∼38.75 % due to ALMP's presence. Overall, based on the observed impact of ALMP on HSM's workability, mechanical properties, and microstructure, we suggest 10 wt% as the optimal doping amount for ALMP in HSM. Our investigation puts forward that implementing IBA in place of traditional quartz sand in the preparation of HSM could potentially attenuate energy consumption, carbon emissions, and production overheads. The findings of this study may offer instructive significance for improving the resource utilization of IBA in cement-based materials.
