Si-doped TiB2 and undoped TiB2 coatings were deposited by mid-frequency magnetron sputtering. The effects of Si doping concentration (1.8 at.% and 8.9 at.%) on the microstructure, mechanical properties and tribological performance of TiB2 coating were investigated. The results showed that the undoped TiB2 coating exhibited a hexagonal TiB2 structure with (001) plane as the preferred orientation, a hardness of up to 51.2 +/- 3 GPa. The TiB2 coating with low-concentration (1.8 at.%) Si doping exhibited high hardness of 46.7 +/- 1.98 GPa and high fracture toughness. However, when the Si concentration increased to 8.9 at.%, the hardness of the coating decreased due to the increase of amorphous phase, and the fracture toughness of the coating decreased due to the presence of free Si. SiO2 tribofilms formed during the friction process reduced the interfacial adhesion between the 1.8 at.% Si-doped TiB2 coating and the titanium alloy grinding ball. The low-concentration (1.8 at.%) Si-doped TiB2 coating with the highest H/E (0.144) and H3/E2 ratios (0.97) exhibited the best adhesive wear resistance at 600 degrees C.

Element doping serves as a crucial strategy for surface modification of TiB2 coatings, improving the toughness, mitigating the residual stress and reducing the coefficient of friction of the coatings. Tungsten(W)-doped TiB2 coatings were deposited by magnetron sputtering with adjusting the working current of W target. The chemical compositions, microstructure, mechanical properties and tribological performance of the coatings were systematically investigated using EPMA, SEM, XRD, XPS, TEM, indentation tests and ball-on-disk tribometer. The results reveal that W doping weakens the crystallization of the TiB2 coatings. As the concentration of W increases, the content of TiB2 phase in the coatings decreases and that of WB2 phase increases. However, when the W concentration increases to 15.1 at.%, the content of WB2 in the coatings decreases again. The W element in the coatings mainly exists in the form of amorphous WB2 phase. The 10.7 at.% W-doped TiB2 coating demonstrates an optimal toughness and a moderate adhesion strength. W doping exhibits no statistically significant improvement in adhesive wear performance of the TiB2 coating at room temperature. However, the W-doped TiB2 coatings exhibit an improved anti-adhesive wear resistance at 600 degrees C, which is correlated with the presence of amorphous WB2 phase.

TiAlN, AlCrBN andTiAlN/AlCrBN coatings were deposited on cemented carbide by cathodic arc evaporation. SEM, TEM, XRD, nano-indentation test, Vickers indentation test, Rockwell indentation test and ball-on-disk tribological test were employed to characterize the microstructure, mechanical and tribological properties of the coatings. The results revealed that different from the fine columnar structure of TiAlN coating, AlCrBN coating exhibited an elliptical structure with grains sizes down to 5 nm.TiAlN/AlCrBN coating with approximately 24 nm thick modulation period demonstrated a polycrystalline structure consisting of fcc-(Al, Ti, Cr)N solid solution with (111) and (200) preferred orientation. The AlCrBN coating exhibited better wear resistance than TiAlN and TiAlN/AlCrBN coatings at room temperature due to its high fracture toughness and H/E. At room temperature, the wear mechanism of the three coatings was mainly abrasive wear. However, the main wear mechanism of TiAlN and TiAlN/AlCrBN coatings at 700 degrees C temperature transformed into obvious adhesive wear. TiAlN/AlCrBN coating exhibited excellent high-temperature oxidation resistance and stability due to the effect of interlayer interfaces, significantly reducing oxidation and adhesion phenomena under high-temperature wear conditions. Therefore, the main wear mechanism of TiAlN/AlCrBN coating still manifested as abrasive wear.

alpha-Al2O3 coating occupies a significant position in the domain of cutting tool coatings due to its superior thermal stability, exceptional wear resistance, and excellent corrosion resistance. In order to further broaden the application of alpha-Al2O3 coating, alpha-Al2O3 coating is deposited using the PVD method to circumvent the drawbacks of high temperature deposition associated with the CVD preparation and phase transformation-induced cracking. alpha-Cr2O3 layer has been employed as a nucleation template for alpha-Al2O3 coating to reduce the deposition temperature. This study investigates the role of alpha-Cr2O3 layer as a template in the nucleation process of alpha-Al2O3 coating through first-principles and thermodynamic calculations. The results show that the maximum nucleation energy barrier of alpha-Cr2O3(0001) on WC substrate is 23.00 eV/& Aring;3, whereas that of alpha-Al2O3(0001) on the same substrate ranges from 43.56 to 47.39 eV/& Aring;3. Besides, the nucleation energy barrier of alpha-Al2O3(0001) on alpha-Cr2O3(0001) is only 2.18 eV/& Aring;3. Therefore, from the thermodynamic perspective, it is easier to obtain a crystalline alpha-Al2O3 coating by depositing an alpha-Cr2O3(0001) template layer on WC-based cemented carbide substrate first and then depositing alpha-Al2O3 coating on top of the template layer. These findings provide theoretical support for experimentally expanding the utilization of template effect of alpha-Cr2O3 layer in nucleation of alpha-Al2O3 coating.

Siliconized layer was prepared on SUS403 stainless steel using molten salt method. The microstructure, wear and electrochemical properties of the siliconized layer were investigated. The results show that the growth activation energy of the siliconized layer is approximately 93.5 kJ/mol. The siliconized layer exhibits spinel-like grains, while the cross-sectional morphology displays a columnar structure. The siliconized layer is mainly composed of Fe3Si and Fe2Si. The microhardness and wear resistance of the siliconized layer has increased by 87

Using molecular dynamics simulations and density functional theory, we explored a novel approach involving surface-grafted self-assembled monolayer (SAM) molecular brushes. This strategy aims to achieve high selectivity for water-boric acid transport without compromising water permeance in polyamide membranes, resulting in a significant enhancement in selectivity along with an increase in water permeance. Our study systematically illustrated the transport behavior of water and boric acid across polyamide membranes incorporating nine distinct types of surface-grafted SAM molecular brushes. Our simulations demonstrated the critical role these SAM molecular brushes play in controlling selective transport, either enhancing or reducing it. These findings revealed the interaction between the SAMs molecular brushes and both water and boric acid, highlighting their impact on the water and boric acid transport mechanism. Overall, our findings suggested that rational integration of SAM-grafted molecular brushes into membrane surfaces can effectively disrupt water-boric acid interactions, decouple their migration, and achieve efficient selective transport without sacrificing water permeability. These molecular-level insights support the advancement and design of high-performance polymer membranes for small molecule separation applications.

We utilized molecular simulations to profoundly investigate how incorporating polymer chains affects membrane performance, providing molecular-level insights for selecting optimal polymer chains and uncovering novel selective mechanisms to achieve high boric acid separation in polyamide membranes. Our study illustrated the transport behavior of water and boric acid across polyamide membranes incorporating 13 different polymer chain patterns. Our simulations demonstrated that introducing polymer chains significantly improved water-boric acid selective transport without sacrificing water permeance, achieving a maximum enhancement in permselectivity. Notably, these findings highlight how polymer chains interact with membrane microstructures and influence the dynamics of water and boric acid, thereby affecting transport, rejection, and separation efficiency. Overall, our results indicate that the rational incorporation of polymer chains into membrane microstructure is a promising strategy to disrupt water-boric acid interactions, decouple their migration, and achieve highly efficient water transport and boric acid rejection. These insights into the mechanisms behind selective water-boric acid transport provide molecular-level guidance for developing advanced polymer membranes aimed at enhancing separation performance across various applications.

With superior ionic conductivity and (electro)chemical stability, garnet-type oxide Li6.4La3Zr1.4Ta0.6O12 (LLZTO) has been extensively studied and explored as advanced solid-state electrolyte (SSEs) for lithium ion batteries (LIBs). However, high-temperature sintering treatment at similar to 1200 degrees C to fabricate dense sheets is necessary to attain high ionic conductivity, whereas at the expense of degraded mechanical properties and poor contact with electrodes. Herein, we demonstrate a novel LLZTO-Li-4(BH4)(3)I composite solid electrolyte prepared by me-chanical milling, which features a bilayer coating structure where LiBO2 in the inner layer and Li-4(BH4)(3)I in the outer layer. The electrolyte pellets fabricated by a simple cold pressing treatment deliver an ionic conductivity of 3.69 x10(5) S cm(1) at 30 C-degrees and a Li(+)transference number of 0.9999, which successfully prevents the formation of lithium dendrites. Using this electrolyte, Li|Li symmetric batteries can work continuously for more than 2200 h at 35 and 60 C-degrees. Such performance improvement is ascribed to the sharp reduction in porosity, the enhanced mechanical properties and the improved interface contact after cold pressing the Li-4(BH4)(3)I-modified LLZTO composite to form an electrolyte pellet.

Human milk is the most valuable source of nutrition for infants. The structure and function of human milk oligosaccharides (HMOs), which are key components of human milk, have long been attracting particular research interest. Several recent studies have found HMOs to be efficacious in the prevention and treatment of necrotizing enterocolitis (NEC). Additionally, they could be developed in the future as non-invasive predictive markers for NEC. Based on previous findings and the well-defined functions of HMOs, we summarize potential protective mechanisms of HMOs against neonatal NEC, which include: modulating signal receptor function, promoting intestinal epithelial cell proliferation, reducing apoptosis, restoring intestinal blood perfusion, regulating microbial prosperity, and alleviating intestinal inflammation. HMOs supplementation has been demonstrated to be protective against NEC in both animal studies and clinical observations. This calls for mass production and use of HMOs in infant formula, necessitating more research into the safety of industrially produced HMOs and the appropriate dosage in infant formula.

The recovery of hydrogen (H2) form H2-containing gas mixtures, such as petrochemical refinery tail gas, plays a important role in energy conservation and cost reduction. The hydrate-membrane coupling separation process has been demonstrated as a more efficient and energy-saving approach for H2 recovery. This study aims to achieve the synergistic matching of hydration and permeation, so as to explore the underlying mechanisms of coupling and facilitate subsequent experimental studies. In this work, an effective method was developed to calculate the gas consumption rate during the stable growth stage of hydrates. Furthermore, a dynamic matching model of the hydrate-membrane coupling mechanism was employed to simulate the variations in the separation process using infinitesimal methods. The simulations indicate that the H2 concentration of product gas and the feed gas treatment capacity of the coupling method outperform those of hydrate separation and membrane separation alone. Overall, this study provides valuable insights into an efficient and energy-saving method for H2 recovery from H2-containing gas mixtures, utilizing the hydrate-membrane coupling method. These findings hold promising prospects for practical application in the future.

In an Accelerator Driven System (ADS), the spallation target typically has a power of several megawatts or above. As high-power targets are challenging to design, the targets studied in the past generally had a power of 2 MW or less. For the China initiative Accelerator Driven System (CiADS) under construction, a 2.5 MW lead-bismuth eutectic (LBE) target is planned. In this paper, thermal-hydraulic and structural analyses were performed to optimize the design of the LBE spallation target. As a first step, given other conditions being fixed, the influence of a single parameter on the target performances, i.e., the outlet size, the diameter of the guide tube, the angle of the transition section, and the vertical distance from the origin of the beam window (BW) hemisphere to the upper end of the transition section, were investigated. Subsequently, the multi-factor analysis was conducted by adopting a four-factor and four-level orthogonal test. Results indicated that the target optimized by the multi-factor analysis, performed much better than the original design and that obtained by the single-factor anal-ysis, providing a new approach for the parameter optimization of spallation target. Moreover, detailed analyses showed that the improved target met the thermal-hydraulic and mechanical design requirements.

Purpose:To analyze the factors affecting patients' prognoses based on the community acquired-bloodstream infection patient data from 2017 to 2021. Patients and Methods:The data of 940 patients were retrieved, having at least one positive bilateral blood culture within 48 hours of hospitalization, and grouped into survivor and non-survivor groups. The clinical characteristics, laboratory results, causative pathogen and other indicators were collected and compared, and risk factors were identified by applying Cox proportional hazard regression model to the data. Results:Community acquired-bloodstream infection is most commonly caused by Escherichia coli, Klebsiella species and Staphylococcus hominis. Among the total of 940 selected patients, 52 (5.5%) died during hospitalization. The demographic parameters like age and gender, clinical protocols like maintenance hemodialysis, glucocorticoid use during hospitalization, catheter placement, procaicitonin, total protein, albumin, creatinine, uric acid contents and Sequential Organ Failure Assessment scores were significantly different between the survivor and non-survivor groups. The survival analysis results revealed that age (HR=1.02, 95% CI: 1.00-1.05, P=0.002), glucocorticoid use during hospitalization (HR=3.69, 95% CI: 1.62-8.37, P=0.021) and Sequential Organ Failure Assessment score (HR=1.10, 95% CI: 1.03-1.18, P=0.004) might be the risk factors affecting 30-day mortality in patients with community acquired-bloodstream infection. Conclusion:The identified risk factors may help guide clinical treatment protocol for patients with community acquired-bloodstream infection, providing more effective treatment strategy selection with improved clinical outcomes.

Background The number of elderly comorbidity patients in our country is continuously increasing.With the accumulation of chronic diseases,older adults experience varying degrees of health loss.Currently,there is a lack of research analyzing the multi-level factors influencing the number of chronic conditions in elderly comorbidity patients.Objective To explore the factors influencing the number of chronic conditions in elderly patients from different levels combining with the etiology and characteristics of chronic diseases based on the health ecology model,so as to provide evidence for the management and prevention of chronic diseases in community-dwelling elderly comorbidity patients in our country.Methods In February 2023,a multi-stage stratified cluster random sampling method was used to select community-dwelling elderly(≥60 years old)comorbidity patients in Guangdong province as the survey subjects.A face-to-face interview was conducted using the"Survey Questionnaire on the Status and Influencing Factors of Elderly Patients with Multiple Chronic Conditions",which was based on the health ecology model and included five levels of individual trait,behavioral characteristic,interpersonal relationship,living and working conditions,and policy environment.The number of chronic conditions in elderly comorbidity patients was considered as the dependent variable,and an unordered multivariate Logistic regression analysis was conducted by incorporating independent variables according to the five levels.Results A total of 1 000 questionnaires were distributed,and 987 valid questionnaires were collected,with a recovery rate of 98.7%.Among the 987 elderly comorbidity patients,346(35.1%)had two concurrent chronic diseases,456(46.2%)had three concurrent chronic diseases,and 185(18.7%)had more than three concurrent chronic diseases.The results of unordered multivariate logistic regression analysis showed that,compared to elderly patients with two concurrent chronic diseases,disease duration less than 6 years and 6-10 years,local urban household were risk factors for elderly patients with three concurrent chronic diseases(P<0.05),with OR(95%CI)values of 2.100(1.284-3.435),1.948(1.201-3.158),and 4.103(1.496-11.250),respectively.Having at least 6 hours of sleep daily,self-rating good health status,taking 1-3 types of medication daily,regularly participating in social activities,level of junior high school or below and high school/secondary school,and having urban employee medical insurance/rural resident medical insurance were protective factors for elderly patients with three concurrent chronic diseases(P<0.05),with OR(95%CI)values of 0.528(0.322-0.867),0.570(0.325-0.998),0.385(0.261-0.569),0.348(0.208-0.582),0.412(0.175-0.972),0.486(0.298-0.790),and 0.392(0.242-0.634),respectively.Being male,exercising less than 3 times a week were risk factors for elderly patients with more than three concurrent chronic diseases(P<0.05),with OR(95%CI)values of 2.563(1.634-4.021),2.990(1.429-6.256),respectively.Having at least 6 hours of sleep daily,self-rating good and fair health status,taking 1-3 types of medication daily,having an annual average income below≤30 000 and>30 000-50 000 yuan,and having urban employee medical insurance/rural resident medical insurance were protective factors for elderly patients with more than three concurrent chronic diseases(P<0.05),with OR(95%CI)values of 0.300(0.159-0.565),0.247(0.125-0.487),0.448(0.240-0.837),0.288(0.178-0.467),0.318(0.155-0.654),0.489(0.293-0.816),and 0.416(0.229-0.755),respectively.Conclusion The proportion of elderly comorbidity patients having 2-3 types of chronic diseases is relatively high in Guangdong province,accounting for over 80%.The factors influencing the number of chronic conditions in elderly comorbidity patients are complex,including gender,duration of disease,physical activity,sleep quality,self-rated health status,medication adherence,household registration type,supervision by children or family members in medication adherence or exercise,income level,educational level,and type of medical insurance.Moreover,there are significant differences in the risk factors across different comorbidity counts.Therefore,corresponding intervention measures should be implemented at different levels to reduce the number of chronic conditions in elderly comorbidity patients and improve their overall health level.

The frequent dry-wet cycles in the Loess Plateau can lead to the deterioration of fiber-reinforced loess (FR loess), which in turn can cause collapse when exposed to rainfall erosion or immersion. In recent years, geopolymers have received considerable attention due to their advantages, such as solid waste disposal and low carbon dioxide emissions. In this paper, the effects of geopolymer, consisting of steel slag (SS), ground granulated blast furnace slag (GGBS), desulfurization gypsum (DG), and sodium silicate, on the durability and water stability of FR loess were studied by conducting dry-wet cycle tests, immersion tests, and unconfined compression tests. The results show that the unconfined compressive strength (UCS) of fiber-reinforced and geopolymer-stabilized loess (FRG loess) decreases exponentially with the increase of dry-wet cycles while increasing approximately linearly with geopolymer dosage. The water stability coefficient of FRG loess shows a logarithmic increase with dry-wet cycles and increases linearly with geopolymer dosage, and the higher the dosage, the greater the water stability. The stabilization and dry-wet deterioration mechanisms of FRG loess were investigated by XRD and SEM-EDS tests. It reveals that the main mineral phases of FRG loess are calcium silicate hydrate, calcium aluminate hydrate, calcium aluminate silicate hydrate gel, and ettringite crystal. The microstructure of FRG loess is quite dense, but after the dry-wet cycles, it appears some cracking and loosening. The pores and microcracks of the low-dosage samples develop distinctly under dry-wet cycles, whereas the microstructure of high-dosage samples shows significant overall stability. The study on the durability and water stability of FRG loess under dry-wet cycles suggests that the optimal geopolymer dosage should be 15%.

Exploiting crossing symmetry, the hadron scale pion valence quark distribution function is used to predict the kindred elementary valence quark fragmentation function (FF). This function defines the kernel of a quark jet fragmentation equation, which is solved to obtain the full pion FFs. After evolution to a scale typical of FF fits to data, the results for quark FFs are seen to compare favourably with such fits. However, the gluon FF is markedly different. Notably, although FF evolution equations do not themselves guarantee momentum conservation, inclusion of a gluon FF which, for four quark flavours, distributes roughly 11% of the total light-front momentum fraction, is sufficient to restore momentum conservation under evolution. Overall, significant uncertainty is attached to FFs determined via fits to data; hence, the features of the predictions described herein could potentially provide useful guidance for future such studies.

Carbon fiber reinforced cement-based composite material (CFRC) is a novel type of composite material that involves the incorporation of carbon fibers into ordinary concrete. This addition effectively enhances the tensile strength, deformation performance, and dynamic load resistance of reinforced concrete structures. Consequently, CFRC has found increasing applications in the construction industry. The objective of this research is to investigate the wear mechanisms of diamond tools during the sawing process of CFRC and offer guidance on cost reduction through the optimization of processing parameters. The wear analysis of diamond segments can be divided into two categories: matrix wear and diamond particle wear. The diamond particles can exist in different states, and the formation of voids resulting from the detachment of diamond particles is considered as a reference point. The analysis reveals that abrasive wear is the main mechanisms of matrix wear in CFRC sawing. The wear resistance is strongly influenced by the proportion of diamond particles in favorable states, which is determined by the applied loads and operating parameters. The proportion of diamond particles exhibits a clear variation with adjustments made to the feeding speed. Notably, an increase in feeding rate results in a significant decrease in the percentage of blunt particles, reducing it from 28% to 6%. To achieve a lower wear rate, a predictive model was established using Design Expert software based on the experimental results. The model demonstrated that a wear rate as low as 268.5 mm/m2 can be achieved with a flywheel speed of 78 r/min and a feeding speed of 90 mm/h. The optimization process, aimed at minimizing wear rate, was successfully carried out without compromising productivity.

Gaining a deeper understanding of the soil organic carbon sequestration potential (SOCsp) is crucial in our efforts to combat climate change, reduce emissions, enhance carbon sinks, and achieve sustainable development goals. However, there is a dearth of spatial information specifically for China in this field, and our knowledge regarding the factors influencing SOCsp remains somewhat limited. In this study, we used legacy soil data collected in the 1980s (1979-1985), combined with climatic landscape zoning, and adopted digital soil mapping techniques spatial prediction models of the density of soil carbon sequestration potential were built at each of the five depths. The results showed that the accuracy of the 0–30 cm model was greater than that of the 30–100 cm model. SOCsp was higher in northwestern, northern, and eastern China and lower in the southeastern Tibetan Plateau and northeastern China. Relatively high predict uncertainties were observed around the Tien Shan Mountains, in the southeastern part of the Tibetan Plateau, and northeastern China. The carbon sequestration potential of the soil at 0–1 m depth was 346.1 Pg (1 Pg = 1012 Kg), of which 0–30 cm accounted for 23.51% of the total. Scale- and location-specific effects were observed for environmental factors, that is, land use conversion, climate, and vegetation change, on SOCsp, with the two-factor effects being greater than the one factor effects. Our findings have provided a scientific basis for decision-making support for sustainable development and climate change responses. However, specialized investigations and studies on the effects of management practices are still necessary to estimate achievable soil organic carbon reserves more accurately and implement feasibility.

Most existing results on full-state error prescribed performance control for multiple-input multiple-output (MIMO) strict-feedback nonlinear systems typically impose demanding constraining conditions on the initial full-state errors, rendering the performance boundary nonuniform with respective to initial conditions, and consequently tedious offline computations for initial error (especially the initial virtual error) constraint verification is inevitable, which is highly undesirable or even impractical for the design and implementation of the corresponding controls. In this article, we present a novel adaptive control solution that allows the performance uniformness (with respect to the initial condition) and the transient behavior (with respect to error overshoot) to be addressed simultaneously under a unified framework. The key design steps and features include: 1) by constructing a nonlinear transformation based on the time-varying scaling function, the developed performance boundary is uniform to any initial condition; 2) the demanding condition on the initial values of full-state errors in the existing prescribed performance works is removed, allowing the designer more freedom to select design parameters and rendering the solution more user-friendly and less demanding in design and implementation; and 3) by making use of the minimum eigenvalues of the resultant diagonal matrix and imposing a critical negative feedback term in the control design, the stability of closed-loop system is ensured by the developed uniform control strategy. The effectiveness of the proposed approach is verified by simulations.

An amorphous AlTiO coating was prepared using arc ion plating. Its wear resistance and corrosion resistance were compared with those of AlTiN coating. The results indicated that the amorphous AlTiO coating had a dense structure, with H/E ratio and friction coefficient of 0.06 and 0.70, respectively, which were approaching to the values for the AlTiN coating. The friction and wear tests demonstrated that both AlTiN coating and AlTiO coating had good wear resistance. Electrochemical experiments demonstrated that the AlTiO coating exhibited excellent corrosion resistance, with a corrosion current density (Icorr) only 1.97% of that of the AlTiN coating. After neutral salt spray corrosion test with a duration of 500 h, the AlTiN coating was completely corroded, while only two corrosion spots were observed on the AlTiO coating.

In this note, we present an event-triggered robust adaptive control method with flexible prescribed performance for strict-feedback nonlinear systems. Unlike most existing event-triggered control results with only the inputs being triggered, here we introduce a triggering mechanism into the control law and the parameter estimator simultaneously, so that the communication resources are saved. It is worth noting that under the proposed triggering conditions, there are some challenges and difficulties in directly applying the backstepping technique, as the intermittent (triggering) parameter adaptive law introduces additional sampling errors. To address this issue, a decomposition technique for the event-triggered adaptive law and a new lemma for handling the event error are introduced, with which the execution error is gracefully counteracted with a properly designed compensation unit. Moreover, to ensure the flexible prescribed tracking performance, we incorporate a series of functional transformations into the control design. It is shown that, with the fixed control structure, only by adjusting the key parameters and time-varying function, the proposed control can generate multiple kinds of prescribed performance behaviors, which is more general and flexible than the existing prescribed performance controls. The effectiveness of our control scheme is verified by simulation results.