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Purpose: This study aims to investigate the effect of compound pit textures on the tribological properties of thrust cylindrical roller bearings (TCRBs) using several parameters, such as compound type, pit diameter, pit depth and pit area density. Design/methodology/approach: The surface texture parameters of the shaft washer (WS) raceway include pit diameter (D; 100, 300 and 500 µm), pit depth (H; 10 and 20 µm) and pit area density (S; 10%, 13% and 18%). Pits were produced on the WS of the TCRBs using laser marking equipment. The friction and wear performances of compound pit-textured TCRBs under starved lubrication conditions are studied using a friction and wear test rig. The influence mechanisms of the compound pit texture on the friction and wear properties of TCRBs are discussed through real tests and discussions. Findings: Compared with nontextured bearings, the average coefficient of friction (ACOFs) and wear loss of TCRBs with single/compound pit textures are reduced when rotating under starved lubrication. D has the greatest effect on the COFs curve. When D = 300 µm, H = 10 µm and S = 10%, the ACOF and wear loss are the lowest, that is, 0.0207 and 3.38 mg, respectively. Under the same lubrication conditions, compared with the nontextured bearing group, the COF and wear loss are reduced by 41.4 and 59.6%, respectively. Originality/value: This study provides a useful reference for the raceways of textured TCRBs. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this paper is to study the influence of dimple textures on the friction and wear properties of tapered roller bearings (TRBs) with many pattern parameters, e.g. diameter, depth and area density under starved lubrication. Design/methodology/approach: The pattern parameters include the dimple diameter (D; 60, 100 and 200 µm), dimple depth (H; 5, 10 and 20 µm) and area density (S; 6%, 12% and 24%). Dimples were fabricated on the outer ring (OR) of TRBs using a laser marking machine. The tribological properties of dimple-textured TRBs under starved lubrication were studied on a vertical universal friction wear tester with special friction pairs. The effect mechanisms of dimple textures on the tribological properties of TRBs are presented and summarized through experiments and discussions. Findings: When dimple-textured TRBs revolve under starved lubrication, the average coefficients of friction (ACOF) and wear losses are markedly lower than those of non-textured bearings. S has the greatest influence on the COF curve. When D is 100 µm and S is 24%, the ACOF and wear losses are both lowest, i.e. 0.00426 and 0.51 mg, respectively. Under the same test conditions, compared with the non-textured group, its COF and wear loss decreased by 35.6% and 62.5%, respectively. Originality/value: This work provides a useful reference for the research on the raceways of textured TRBs. [ABSTRACT FROM AUTHOR]

At present, in the research of transplanting machinery domestic and abroad, the link of pick-up plug seedlings is the bottleneck restricting the development of automatic transplanting machines. This research of test is focused on identifying whether the proposed influencing factors changes have significant impact on the soil matrix intact rate of manipulator pick-up plug seedlings. Tested influencing factors include 3 parts, i.e. soil moisture content, shape features of manipulator structures of pick-up plug seedlings and performance improvement of root system on soil matrix shear strength in the seedling stage. Among them, soil moisture content is from 35% to 65%, and water is mixed with the soil matrix to fill the matrix pore, which increases matrix compressive ability and improves the viscosity of soil inside, at the same time also affects the adhesion force between soil matrix and plug wall. Shape features of manipulator structures of pick-up plug seedlings contain finger-shaped, tongue-shaped and u-shaped, and with these 3 shapes the manipulator contacts with the soil matrix using contact type of line, plane, and closed profile line respectively. Research shows that the root system on soil matrix weaving, winding, reticular surround and twisting force between root system and matrix particles have a significant influence on soil shear strength. In this paper, the performance improvement of root system on soil matrix shear strength is tested in the seedling stage. And the soil matrix intact rate of seedlings is taken as test index. Through the test, the change rule that compression degree determines the compression quantity of pick-up plug seedlings manipulators with different structures is as follows: The force applied on soil matrix by finger-shaped manipulator is concentrated on a few lines, and there is strong pressure on the soil matrix under the same drawing force, so it has a big compression quantity and a big clamping quantity; The tongue-shaped has a large area and weak pressure on the soil matrix, so it needs a small clamping quantity; The U-shaped is also linear contact, but because its lower end is closed, which plays a role of holding up in the process of ascension, the clamping quantity is also small. At the same time, the compression quantity is reduced with the moisture content. Our test adopts the orthogonal experiment design, and chooses L9(34) orthogonal table; with the soil matrix intact rate of seedling as test index, through the analysis of variance and range, we obtain the primary and secondary influencing factors which affect pick-up plug seedlings, and also obtain the optimal level. Meanwhile, the causes are analyzed and a better environment in pick-up plug seedlings is proposed. The results of test show that the shape feature of manipulator structures of pick-up plug seedlings is the primary factor which obviously influences the effect of pick-up plug seedlings manipulator and determines the u-shaped structure is the best. For the moisture content, around 50% is the best. When the first pair of leaves of the seedlings grow up to pick-up plug seedlings, the performance improvement of root system on soil matrix shear strength in the seedling stage has little effect on soil reinforcement. The verification test is carried out, and the results show when the soil moisture content is 50%, the u-shaped manipulator of pick-up plug seedling can make the soil intact rate of seedling all above 80% and seedlings survival quickly, which proves that the selected factors' levels are reasonable. This test determines the key technical points for further study and improving the equipment of pick-up plug seedlings, so it establishes the important theoretical basis for exploring automatic transplanting for pick-up plug seedlings. [ABSTRACT FROM AUTHOR]

In order to make a sound joint of TC4 titanium alloy and 316 L stainless steel, Ti-Zr-Hf-Cu-Ni amorphous filler metal was used to braze the two alloys in this paper. The effects of brazing temperature on the interfacial microstructure and mechanical property were investigated. The results showed that the maximum shear strength of 205 MPa was obtained at 960 °C/10 min. The cross section of brazed joint could be divided into five distinctive reaction zones namely: 316L, diffuson layer I, weld seam center structure H, diffuson layer &, TC4. The typical interfadal rmcrostructure of the joint was phases formed around the diffusion kyer I close to 316L stainless steel substrate, whcti was the weak part of the brazed joints. Fracture analysss idcated that cracks imtiated at the diffusion layer I . [ABSTRACT FROM AUTHOR]

The microstructures and properties of TC4 titanium alloy prepared via TIG arc additive manufacturing were studied. The results show that the microstructure of the arc additive manufacturing TC4 titanium alloy is different from the as-cast characteristics of the arc additive manufacturing steel material, which has significant heat-treated characteristics. It is a basketweave structure composed of α and β phases. Analyzing the formation process, it can be found that the primary structure of the additive body is dendrites, which has obvious orientation at this time; with the action of multiple reheating in the subsequent additive process, since the low thermal conductivity of titanium, the additive body maintains a higher temperature, the dendrite composition gradually becomes uniform and transforms into anisotropic slender β crystal grains; then the temperature decreases and transforms into a two-phase basketweave structure of α and β, and the a phase is in a supersaturated state, the β-phase precipitated with nano-scale dots can be observed, the structure and performance is close to isotropic at this time, the tensile strength and the elongation after fracture at room temperature can reach up to 998 MPa and 8.7%, respectively. [ABSTRACT FROM AUTHOR]

Changes in protein and lipid levels may occur in the Alzheimer's disease brain, and DHA can have beneficial effects on it. To investigate the impact of DHA dietary intervention on brain protein and lipid profile in ApoE-/- mice and C57 mice. Three-month-old ApoE-/- mice and C57 mice were randomly divided into two groups respectively, and fed with control diet and DHA-fortified diet for five months. Cortical TC, HDL-C and LDL-C levels and cholesterol metabolism-related protein expression were measured by ELISA or immunohistochemistry methods. Hippocampus were collected for proteomic and lipidomics analysis by LC-MS/MS and differential proteins and lipid metabolites were screened and further analyzed by GO functional annotation and KEGG pathway enrichment analysis. DHA intervention decreased cortical TC level in both C57 and ApoE-/- mice (P < 0.05), but caused different change of cortical HDL-C, LDL-C level and LDL-C/HDL-C ratio in C57 and ApoE-/- mice (P < 0.05). Discrepant cortical and hippocampal LDLR, ABCG1, Lox1 and SORT1 protein expression was found between C57 and ApoE-/- mice (P < 0.05), and DHA treatment caused different changes of these proteins in C57 and ApoE-/- mice (P < 0.05). Differential hippocampal proteins and lipids profile were found in C57 and ApoE-/- mice before and after DHA treatment, which were mainly involved in vesicular transport and phospholipid metabolic pathways. ApoE genetic defect caused abnormal cholesterol metabolism, and affected protein and lipid profile, as well as discrepant response of hippocampal protein and lipids profile in the brain of mice given DHA fortified diet intervention. • C57 and ApoE-/- mice showed different protein and lipid profile in hippocampus • The hippocampal differential proteins in DHA-fed mice are mainly associated with vesicular transport. • DHA intervention caused change of hippocampal lipids profile, which mainly involved in the metabolism of glycerophospholipid. [ABSTRACT FROM AUTHOR]

To quantify medical staff preferences for providing health education service in hospitals. This study took medical staff in the department of internal medicine of hospitals in Beijing, China as the research subjects, and designed a discrete choice experiment (DCE) to investigate the health education service provision preferences of them. Through various methods, 8 attributes and corresponding levels were determined. An online survey was conducted among the medical staff of the sample hospitals from May to June 2023. Participants' preferences were analyzed using conditional logit and mixed logit models. Finally, 831 respondents completed the questionnaire, among which 600 cases passed the consistency test. All the attributes included in this study had an impact on medical staff' health education service preferences (P < 0.001). The most important one with the greatest impact on the health education service delivery behavior of the respondents was "department working atmosphere-encouraging health education" (β = 4.062, P < 0.001). In this study, the departmental work atmosphere and performance bonuses emerged as crucial factors influencing the engagement of medical staff in health education work. Hospitals should prioritize measures to improve the health education working atmosphere in departments to increase the enthusiasm of medical staff to provide services. • Staff from different level of hospitals had different importance ranking of factors. • All attributes in this study influence preference for providing health education services. • Department atmosphere was the most significant factor in health education service provision. • Taking targeted measures to enhance the motivation of medical staff in providing services is vital. [ABSTRACT FROM AUTHOR]

To reveal the effect of vein-bionic surface textures on the tribological behavior of cylindrical roller thrust bearings (CRTBs) under starved lubrication, six kinds of leaves (Forsythia, Clausena lansiu, Ash, Purple leaf plum, Pipal and Apricot) were chose and their simplified patterns were fabricated on the shaft washers of CRTBs using laser surface texturing. The coefficients of friction (COFs) of vein-bionic textured bearings were measured using a vertical universal wear test rig. Their mass losses and worn surfaces were also characterized. The results show that: There is important influence of the symmetry of vein-bionic textures and the number of secondary veins on the friction and wear properties of vein-bionic textured CRTBs under starved lubrication. Compared to the smooth group, the COFs and mass losses of vein-bionic textured bearings are all reduced. Among all groups, the tribological performance of bearings with a pattern inspired from Ash is the best. Its wear loss is reduced by 16.23% and its COF is reduced by 15.79%. This work would provide a valuable reference for the raceway design and optimization of roller rolling element bearings. [ABSTRACT FROM AUTHOR]

Presents an estimation algorithm for tracking the motion of a low-observable ballistic missile in a gravitational field. Phases of the flight of a ballistic missile; Problem formulation; Derivation of maximum-likelihood estimator based on probabilistic data association combined with amplitude information.

In this research, three types of vein-bionic texture patterns inspired by five kinds of leaves (Forsythia, Clausena lansium, Ash, Pipal, and Apricot) were designed and fabricated on the raceways of the shaft washers of cylindrical roller thrust bearings (CRTBs) through a fiber laser marking system. A vertical universal wear test rig was used to obtain the coefficient of friction (COF) of bearings under starved lubrication, with a customized tribo-pair. The wear losses of the shaft washers and the worn surfaces were characterized. The influence of different veins (chief, primary, secondary) and vein-structure characteristics (pattern symmetry, number of veins) on the tribological behavior of vein-bionic textured CRTBs is investigated and discussed. The results show that the original vein-bionic (V) pattern inspired by the Ash has the best friction-reducing performance, while the texture with the no-chief vein (NC) obtained by Clausena lansium has the best wear resistance. The chief vein mainly contributes to the low friction by enhancing the secondary lubrication effect and facilitating the formation of a protective nylon film. A reasonable mechanism for improving the tribological properties of resulting textures is proposed. [ABSTRACT FROM AUTHOR]