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There are many kinds of distortion of carburizing and quenching gears, but they will be reflected in the grinding amount of gear flanks. Through theoretical analysis and long-term production practice, it is found that the change of tip diameter has the greatest influence on the grinding amount, the change of the helix angle and the circumferential warpage of gear rims takes the second place, and other factors have relatively little influence. The empirical formulas for calculating the maximum and minimum grinding amount of the tooth flank are given, according to the change of the tip diameter and other parameters. These formulas can be used to determine the case-hardened depth (CHD) in drawings, the reserved grinding amount of gear flanks during gear hobbing, and the target CHD during carburizing and quenching. After carburizing and quenching, the maximum and minimum grinding amount and the actual CHD can be calculated and predicted according to these formulas, so as to provide guidance for subsequent production.

In order to study the sedimentation characteristics and action mechanism of cationic polyacrylamide (CPAM) with different ionic degrees on the high muddied coal slime water, the particle size composition and mineral composition of the high muddied coal slime water from Lijiahao Coal preparation Plant were studied. The influence of ionic degree of CPAM on sedimentation velocity, turbidity of clarification zone, thickness of compression zone and sedimentation kinetics of high muddied coal slime water was studied by using the experimental method of flocculation sedimentation of coal slime water. Zeta potential on the surface of slime particles was measured, and the effect of CPAM with different ionic degree on the zeta potential of slime particles was analyzed. The stability of coal slime water under different ionic conditions was studied by using Turbiscan Lab stability analyzer. Based on the sedimentation characteristics and dynamic stability of coal slime water, the sedimentation mechanism of CPAM ion degree on coal slime water was analyzed. The results show that large amount of kaolinite particles and high content of fine particles are the main reasons for the difficult settlement of coal slime water. Under the same dosage, CPAM has a poor sedimentation effect on coal slime water when the ionic degree is low. When the ionic degree is high, the sedimentation velocity of coal slime water is lower, the thickness of compression zone is higher, and the turbidity is lower. The sedimentation effect of coal slime water is good when the ionic degree is high, and CPAM with ionic degree 30%-60% has the best sedimentation effect when the dosage is 36 g/m3, with fast sedimentation speed, low turbidity and thin compression zone thickness. CPAM has great influence on the sedimentation effect and stability of coal slime water. CPAM can reduce the Zeta potential value on particle surface, promote the formation of flocs in the sedimentation process of slime water, accelerate the sedimentation speed, reduce the stability of slime water and turbidity after the sedimentation of coal slime water, due to its long chain containing positive active groups that can easily adsorb with the surface of negatively charged slime particles. The principle of action with coal slime water is “electric neutralization”, “adsorption bridge” and “net capture and sweep”. It is a kind of excellent coal slime water treatment agent.

Flotation pulp phase bubble images are image data collected from the pulp inside the flotation cell and have significantly different visual characteristics compared to the flotation froth image data. A DA-Attention U-Net bubble segmentation model is proposed for bubble image data collected in situ from the flotation cell pulp solution using special equipment. This model improved the U-Net model by deploying the CBAM module with adjustments to the module structure based on the method of residual connection. As a result, the model owns both advantages in channel attention and spatial attention, assuring more weight is given to the foreground areas which contain bubbles in the image, and less information loss caused by the number of down-sampling. By deploying ASPP module with improvement based on the idea of Dense Connection, bubble features from multiple scales can be extracted, the information of front and back feature layers integrated, and the segmentation results analyzed using heat map and significance map. The research found that compared with the U-Net, the proposed model is more effective for bubble image segmentation, the training loss and Dice coefficient are reduced by 0.416 and 0.2, reaching 0.015 and 0.12 respectively, and the MIoU accuracy value and F1 _ Score value are improved by 0.331 and 0.229, reaching 0.952 and 0.985 respectively. Ablation experiments were conducted to verify the effectiveness of each module. The model s accurate segmentation of bubble images can lay the foundation for subsequent extraction of bubble features, which is important for future research on the use of pulp phase bubbles' information for optimal control of flotation processes. [ABSTRACT FROM AUTHOR]

This paper takes the lignite coal sample from Baori Hiller of Inner Mongolia as the research object.Through the coal flotation reverse flotation test and orthogonal test, the surface characteristics and flotation characteristics of lignite were analyzed and studied, and the types, dosages and processes of the lignite flotation were investigated.The results showed that the de-flotation effect of dodecyl amine(DDA)on lignite was better than that of octadecyl amine(ODA)and cetyltrimethylammonium bromide(CTAB).When the DDA dosage is 1 400 g/t, the reverse flotation efficiency is 6.89 %, the floating tail minimum ash is 11.23 %, the floating tail yield is 84.46 %, and the maximum difference between the floating fine and floating tail ash is 5.25 %. When the dosage of DDA is fixed and the dosage of dextrin is 1 600 g/t, the floating ash is divided into 15.58 %, the floating ash is 10.77 %, and the difference is 4.81 %; The effect of the amount of DDA, dextrin and octanol on the yield of floating tail was not significant, while the effect of DDA on floating tail ash was significant, but the effect of dextrin and octanol on floating tail ash was not significant.For lignite, continuous low-floating(10.20 %)and high recovery(up to 70 %)of clean coal can be obtained by successive multiple reverse flotation processes.Amine collectors have a good collection effect on minerals such as quartz, silicate and carbonate in lignite due to their physical adsorption and complex adsorption.In the pulp, the hydrogen atoms in the dextrin interact with a large number of strongly electronegative atoms such as oxygen and nitrogen present on the surface of the lignite to form a strong hydrogen bond, thereby forming a hydrophilic film on the surface of the coal particles, so that the coal particles become hydrophilic and suppressed.

Purpose: This study examined how inclusive leadership in the workplace promotes proactive behavior in employees based on self-determination theories and a model of motivation for proactive behavior. Design/methodology/approach: Using a sample of 270 employees from various provinces in China, we investigated the relationship between inclusive leadership (measured at Time 1), workplace gratitude (measured at Time 1) and proactive behaviors (measured at Time 2). To test our hypotheses, SEM analysis was conducted to measure the path coefficients, followed by bootstrapping analysis to assess the indirect impacts of gratitude at work. Findings: The results suggest that inclusive leadership could enhance subordinates' propensity to be grateful, which in turn will increase the frequency of their proactive behaviors. Originality/value: First, the evidence presented further validates the proposed association between inclusive leadership and proactive behavior, and it also enriches related theories. Second, our study introduced workplace gratitude as a mediator, deepening the understanding of the mechanisms linking inclusive leadership and proactive behavior. [ABSTRACT FROM AUTHOR]

In order to solve the problem of comprehensive utilization of concentrated brine in coal chemical industry, the flocculating settlement test was carried out by using concentrated brine instead of coagulant in coal chemical industry, and the effect of pH and gangue content on concentrated brine was investigated. In this paper, the Turbiscan Lab stability analyzer is used to analyze the stability of coal slurry system with different concentration of concentrated brine. The sedimentation rate and supernatant turbidity of coal slurry are analyzed by image analysis method. The results show that the gangue minerals in this coal sample are mainly kaolinite and quartz, and the clay minerals are mostly kaolinite. The coal chemical concentrated brine is used as a coagulant.With the increase of its dosage, the stability of slime water first becomes weak and then stronger, and the settlement effect is the best when the stability is the worst. However, the addition of excessive brine will introduce too many cations, which will lead to the stabilization of slime water. The higher the waste rock content, the more difficult the coal slurry to settle. The coal slurry settlement effect gets better and then worse with the decreasing of pH value. The optimum settlement condition is pH=5.

With the increasingly stringent control of NOx emissions, NH3-SCR, one of the most effective de-NOx technologies for removing NOx, has been widely employed to eliminate NOx from automobile exhaust and industrial production. Researchers have favored iron-based catalysts for their low cost, high activity, and excellent de-NOx performance. This paper takes a new perspective to review the research progress of iron-based catalysts. The influence of the chemical form of single iron-based catalysts on their performance was investigated. In the section on composite iron-based catalysts, detailed reviews were conducted on the effects of synergistic interactions between iron and other elements on catalytic performance. Regarding loaded iron-based catalysts, the catalytic performance of iron-based catalysts on different carriers was systematically examined. In the section on iron-based catalysts with novel structures, the effects of the morphology and crystallinity of nanomaterials on catalytic performance were analyzed. Additionally, the reaction mechanism and poisoning mechanism of iron-based catalysts were elucidated. In conclusion, the paper delved into the prospects and future directions of iron-based catalysts, aiming to provide ideas for the development of iron-based catalysts with better application prospects. The comprehensive review underscores the significance of iron-based catalysts in the realm of de-NOx technologies, shedding light on their diverse forms and applications. The hope is that this paper will serve as a valuable resource, guiding future endeavors in the development of advanced iron-based catalysts. [ABSTRACT FROM AUTHOR]

In this paper, coal-based porous carbon material with different specific surface area and pore size distribution was obtained by adjusting the proportion of KOH to coal based on Taixi anthracite.When the ratio of KOH to coal is 5:1 at the temperature of 800℃ for activation of 2 h, the obtained material has the highest specific surface area and pore volume(3 275 m2/g, 1.62 cm3/g).The adsorption amount of carbon dioxide at 0℃ and 100 kPa was 23.71%.The material is doped with nitrogen by using urea as a nitrogen source.Compound material was prepared through oxidation-reduction reaction on the carbon material loaded with manganese, which is used for a negative electrode material of a lithium ion battery.It exhibits good stability in charge-discharge cycles.The nitrogen and manganese dioxide are helpful to improve the specific capacitance of the material.

Metal cations are one of the important factors affecting the performance of anionic foaming agent.In this paper,based on the different metal cations with sodium dodecyl sulfate (SDS) solution system,the influence of cations on foaming characteristics and interfacial properties of sodium dodecyl sulfate were investigated.The foaming ability and foam stability of different SDS solution systems were analyzed by foam scanner. The foam morphology,diameter and distribution were statistical analyzed by image analysis method.By utilizing of interfacial tension/rheometer,and the interfacial viscoelasticity were tested.The results showed that the cations can reduce the foaming ability and the influence order is Al3+ > Mg2+ > Na+.The half-life of foam decreased firstly and then tends to be gently with the increase concentration of Mg2+ and Na+,but the half-life of foam decreased firstly and then increased,finally tends to be gentle with the increase of Al3+.The adverse effect of Al3+ on the foam structure is much larger than that of Na+ and Mg2+.The ability of Al3+ which reduce the foam diameter significantly.The composite solution surface is viscoelastic,and the effects of cations on dilational modulus is Al3+ > Mg2+ > Na+.