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The thermodynamic characteristics of double-row angular contact wheel bearings are important for the bearing operational condition monitoring and structural design. The load distribution and power consumption distribution of the bearing are obtained by establishing a thermal-force coupling model of the double-row angular contact wheel bearing. Combining with the thermal network and finite element analysis method, the steady-state temperature field of the bearing under test conditions is achieved. Also a box-type encapsulated fiber-optic grating temperature sensor is designed for investigating the effects of working condition parameters on the axial and circumferential temperature distributions of the bearing. And a comparative analysis with the predicted results is carried out. The results show that there are obvious temperature differences in the axial and circumferential direction of double-row angular contact wheel bearing under combined load. The speed, axial force and radial force all affect the bearing temperature rise and temperature distribution.

In order to improve the lubrication efficiency in the bearing cavity, this study establishes a simulation model of the fluid domain of the bearing cavity based on the computational fluid dynamics (CFD) method and systematically studies the flow characteristics of the lubricant and its lubrication mechanism in the high-speed rotary bearing. In the process of high-speed bearing operation, the lubricant is subject to the combined effect of centrifugal force and contact pressure, gradually spreads to both sides of the steel ball, and forms a stable oil film after injection from the nozzle. However, due to the influence of high pressure distribution in the contact area, the actual formation of the oil film coverage is relatively limited. In order to further optimize the lubrication effect, this study focuses on investigating the influence law of different injection speeds and rotational speeds on the bearing air curtain effect. The results of the study show that when the air curtain effect is enhanced, there will be significant shear interference on the trajectory of the lubricant, which is manifested in the phenomenon of “buckling” at the end of the lubricant, thus reducing the lubrication efficiency. To address this problem, this study innovatively proposes the air curtain obstruction coefficient K as a quantitative evaluation index, and through numerical simulation, it is found that the lubricant can effectively overcome the air curtain obstruction and achieve a better lubrication coverage when the value of K is reduced to below 0.4. Based on this finding, the study further confirmed that the lubrication efficiency of bearings can be significantly improved under different operating conditions by rationally regulating the injection rate.

This paper addresses the vibration characteristics of angular contact ball bearings in aircraft engines under variable load conditions. Based on multibody dynamics theory, a dynamic model of the bearing was established. Vibration data under actual operating conditions were obtained using an experimental test platform. This study systematically investigated the influence of rotational speed, axial load, and radial load on the vibration acceleration level of the bearing outer ring. Through a comparison of simulation and experimental data (with an error rate below 10%), the reliability of the model was validated. The results indicate that the bearing vibration acceleration level exhibits a nonlinear increasing relationship with rotational speed. An increase in radial load significantly amplifies the amplitude of acceleration-level fluctuations, while appropriately increasing axial load can reduce bearing vibration intensity. Under variable load coupling conditions, the dynamic interaction between axial and radial forces results in complex nonlinear vibration responses, with a 2 s acceleration time achieving the optimal balance between vibration suppression and efficiency (steady-state average of 70.4 dB). Additionally, the morphological characteristics of the cage center-of-gravity trajectory (such as trajectory disorder and poor smoothness) are closely related to vibration characteristics, revealing the critical role of dynamic load changes in bearing stability. The research results provide a theoretical basis for optimizing the operating conditions, vibration control, and reliability design of aircraft engine bearings.

Bio-based polyurethane (PU) is synthesized either via the prepolymerization or addition polymerization of bio-based polyols and isocyanates. PU synthesized from vegetable-oil-based polyols has excellent properties for various application needs. Bio-based PU coatings from renewable vegetable oil show good degradability in soil while controlling the nutrient release process. Castor oil, soybean oil, palm oil, olive oil, linseed oil, rapeseed oil, cottonseed oil, and recycled oil have been explored in the study of bio-based PU coatings for controlled nutrient release. Castor oil as a natural polyol has been widely studied. Generally, the epoxidation ring opening method is preferred to prepare bio-based polyols. Almost all of these studies used a drum coating machine to complete the coating process. To obtain better controlled release performance, a vegetable-oil-based PU (VPU) coating was modified by increasing the degrees of crosslinking and hydrophobicity and improving the coating uniformity. The nutrient release duration of the modified castor-oil-based PU-coated fertilizer reached 200 days. VPU-coated fertilizers, in contrast to traditional fertilizers, effectively reduce the detrimental impact on the environment. Although the preparation of VPU-coated fertilizers is still at the laboratory scale, application research has been carried out in field crops.

Polyurethane (PU) offers broad applications due to its excellent performance and diverse formulation design. In agriculture, PU coatings have been used to regulate nutrient release by using controlled release fertilizer (CRF). This gradual release ensures that plants receive sufficient nutrients throughout the growing cycle, improving the utilization rate of nutrients and reducing environmental pollution. Traditional petroleum-based PU coating in the production of CRF has been gradually replaced by bio-based PU due to its high cost and associated environmental risk. In this study, a bio-based PU coating synthesized from palm kernel oil-based polyol and methylene diphenyl diisocyanate (MDI) was coated onto urea granules using a micro scale coating machine. Two key parameters were studied, which are the NCO/OH ratio (0.8:1, 1:1, 1.2:1) and coating amount (4%, 9%, 14%). The bio-based PU coated urea could release nutrients by absorbing moisture from the air. The CRF with 9% coating amount and NCO/OH ratio of 1:1 reached 56 days release period. Pot experiments using mung beans indicated improved agronomic efficacy. The CRF with 4% coating and NCO/OH ratio at 1:1, resulted in 400% increase in dry weight compared to uncoated urea. Toxicity test showed that the bio-based PU microplastic had no adverse effect on the growth of mung beans. These findings suggest that palm kernel oil-based PU-coated fertilizers are a promising solution for sustainable agricultural practices.

Purpose. Mean platelet volume (MPV) and platelet distribution width (PDW) have been used to reflect the platelet activity in clinics. We assessed initial serum MPV and PDW levels in colorectal cancer (CRC) patients, in predicting the development of sepsis in CRC patients postoperatively. Patients and Methods. This study included 220 patients diagnosed with CRC. 55 patients were stratified to one group that developed sepsis postoperatively, and 165 patients were stratified to the other group that did not develop sepsis postoperatively. Clinical and laboratory characteristics were collected 3 days before the operation. Results. MPV (p<0.001) was significantly higher and PDW (p<0.001) was significantly lower in the sepsis group than in the nonsepsis group. Either MPV or PDW is independently associated with ICU mortality in sepsis patients with CRC. MPV is independently associated with 14-day, 28-day, and 90-day mortality and PDW is independently associated with 90-day mortality in patients with CRC. The prevalence of sepsis increased as MPV tertiles increased (p<0.001), and the prevalence of sepsis increased as PDW tertiles decreased (p<0.001). Conclusions. Serum MPV and PDW levels between CRC patients with/without sepsis postoperatively are significantly different. The initial serum MPV or PDW levels can potentially serve as a predictor of sepsis in CRC patients postoperatively.

Using the economical and environmental paraffin as core, Paraffin/SiO2 composite phase change materials (PCMs) were prepared by sol-gel method. Industrial water glass for preparation of the nano-SiO2 was served as a shell with the modification of silane coupling agent. We combined Soxhlet extraction with penetration circle for the coating rate and the optimization of preparation was obtained via SPSS. The composite PCMs were investigated by SEM, TG, FT-IR, DSC technique. The results indicated that the optimization of preparation(PH = 4.5 and T = 35°C) was available. When the efficient coating rate of paraffin reached up to 60.04%, the phase-transition temperature was 38.73°C and the enthalpy of phase change was 72.88J/g. Moreover, thermal stability and reliability of the paraffin/SiO2 composite PCMs were proved through TG curves. So it could be formulated that paraffin/SiO2 composite PCMs with no leakage, excellent thermal storage capacity could be employed in energy conservation as a kind of thermal functional material.

Typical commercial application of WAO on sludge treatment is first used in China, system design and debugging, and effect and cost performance is illustrated in this article. It reduces the temperature and pressure of a typical wet oxidation reaction, and the oxygen supplied is only 30- 50 % of the COD, which is specifically used to treat sludge. After the treatment, the sludge moisture content from 80 % to 45-48 %, and become harmless and stabilized, so it can be used as soil for gardens directly or mixed with other materials. As a supplementary carbon source for the nitrogen removal and phosphorus removal process, the separation solution is rich in organic acids and returned to the sewage plant after the heavy metal removal process. The operating cost of the entire process is 180-200 yuan per ton (80 % moisture content), mainly for electricity consumption.

Mechanically stable specific heterodimerization between small protein domains have a wide scope of applications, from using as a molecular anchorage in single-molecule force spectroscopy studies of protein mechanics, to serving as force-bearing protein linker for modulation of mechanotransduction of cells, and potentially acting as a molecular crosslinker for functional materials. Here, we explore the possibility to develop heterodimerization system with a range of mechanical stability from a set of recently engineered helix-heterotetramers whose mechanical properties have yet to be characterized. We demonstrate this possibility using two randomly chosen helix-heterotetramers, showing that their mechanical properties can be modulated by changing the stretching geometry and the number of interacting helices. These helix-heterotetramers and their derivatives are sufficiently stable over physiological temperature range. Using it as mechanically stable anchorage, we demonstrate the applications in single-molecule manipulation studies of the temperature dependent unfolding and refolding of a titin immunoglobulin domain and α-actinin spectrin repeats. Mechanically stable specific heterodimerization formed with reversible bonds are used as a molecular anchorage in single-molecule force spectroscopy studies with unique mechanical properties. Here authors develop a variety of heterodimerization molecular systems with a range of mechanical stability from a set of recently engineered helix-heterotetramers.