Search Results (450)

The crystal structure of kuliokite-(Y), Y₄Al(SiO₄)₂(OH)₂F₅, has been re-investigated using the material from the type locality the Ploskaya Mt, Kola peninsula, Russian Arctic. It has been shown that in contrast to previous studies, the mineral is monoclinic, Im, with a = 4.3213(1), b = 14.8123(6), c = 8.6857(3) Å, β = 102.872(4)°, and V = 541.99(3) ų. The crystal structure was solved and refined to R₁ = 0.030 on the basis of 3202 unique observed reflections. The average chemical composition determined by electron microprobe analysis is (Y_2.96Yb_0.49Er_0.27Dy_0.13Tm_0.07Lu_0.05Ho_0.05Gd_0.01Ca_0.01)_Σ4.04Al_0.92Si_2.04O₈-[(OH)_2.61F_4.42]_Σ7.03; the idealized formula is (Y,Yb,Er)₄Al[SiO₄]₂(OH)_2.5F_4.5. The crystal structure of kuliokite-(Y) contains two symmetrically independent Y sites, Y1 and Y2, coordinated by eight and seven X anions, respectively (X = O, F). The coordination polyhedra can be described as a distorted square antiprism and a distorted pentagonal bipyramid, respectively. The refinement of site occupancies indicated that the mineral represents a rare case of HREE fractionation among two cation sites driven by their coordination numbers and geometry. In agreement with the lanthanide contraction, HREEs are selectively incorporated into the Y2 site with a smaller coordination number and tighter coordination environment. The strongest building unit of the structure is the [AlX₂(SiO₄)₂] chain of corner-sharing AlX₆ octahedra and SiO₄ tetrahedra running along the a axis. The chains have their planes oriented parallel to (001). The Y atoms are located in between the chains, along with the F⁻ and (OH)⁻ anions, providing the three-dimensional integrity of the crystal structure. Each F⁻ anion is coordinated by three Y³⁺ cations to form planar (FY₃)⁸⁺ triangles parallel to the (010) plane. The triangles share common edges to form [F₂Y₂]⁴⁺ chains parallel to the a axis. The analysis of second-neighbor coordination of Y sites allowed us to identify the structural topology of kuliokite-(Y) as the only case of the skd network in inorganic compounds, previously known in molecular structures only. The variety of anionic content in the mineral allows us to identify the potential existence of two other mineral species that can tentatively be named ‘fluorokuliokite-(Y)’ and ‘hydroxykuliokite-(Y)’. Full article

This article focuses on the negative evaluation losses resulting from consumers’ dissatisfaction with the traceability level in agricultural product logistics activities. Based on the supply chain (SC) under the “agricultural product cooperative + live-streaming e-commerce” model, and in accordance with previous research, combined with the differences in the dominant role and the bearers of profit and loss in the SC. By applying Stackelberg game theory, different types of decisions are analyzed and solved. The research results show: (1) Centralized decision-making has advantages in terms of traceability level and SC profit performance. (2) In non-centralized decision-making models, when manufacturers bear negative evaluation losses and retailers act as the leaders of the SC, the overall decision-making effect is more ideal. When manufacturers or retailers act as the leaders of the SC and both bear the traceability costs, the decision-making effect is basically the same. (3) The traceability level sensitivity coefficient and the traceability level effect on traceability both have positive effects on the growth of SC profits and the improvement of the traceability level. (4) The maximization of profits for both parties can be achieved through the coordination of contracts. This study can enhance the traceability level of the agricultural product SC, encourage SC members to increase their investment in the traceability, reduce the profit impact from negative evaluations, and provide a reference for the sustainable development of the agricultural product SC. Full article

Fresh agricultural products have significant seasonality and perishability, and their cross-regional sales often face differences in market demand, price, and sales volume. In the context of government quality regulation, competition among retailers in different regions drives supply chain members to improve product quality, expand sales, and reduce losses. However, conflicts of interest under decentralized decision-making may lead to overall inefficiency. This article constructs a supply chain model consisting of a single Manufacturer and two regional Retailers to study the quality competition and coordination mechanism of cross-regional fresh food supply chains under government supervision. By comparing centralized and decentralized decision-making, it is found that although quality improvement in decentralized mode helps enhance competitiveness and sales performance, it is difficult to effectively increase profits and may even lead to a decline in profits. Therefore, this article proposes a cost-sharing contract to achieve supply chain coordination. Research has shown that this contract can effectively improve the overall profit of the supply chain and achieve Pareto improvement; under high market demand and strict regulatory penalties, the total profit of the supply chain increases, but the dominant Retailer benefits more, which can easily trigger the “Matthew effect”. The research results reveal the comprehensive impact of quality investment, contract coordination, market demand fluctuations, and regulatory intensity on supply chain performance, providing theoretical basis and management insights for improving the collaborative efficiency and policy design of cross-regional fresh food supply chains. Full article

This study examines green investment and emission reduction strategies in a two-tier supply chain under dual-carbon regulation that combines a carbon tax with a cap-and-trade mechanism. A multi-stage dynamic game model is developed, in which the manufacturer reduces emissions through recycling efforts and investments in green technology. We compare optimal decisions under centralized, decentralized, and coordinated structures, and propose an enhanced bilateral cost-sharing contract to improve collaboration. Numerical experiments validate the theoretical results, and sensitivity analyses provide further insights. The results show that while both carbon tax and permit trading increase emission reduction, the carbon tax may lower manufacturer profit, underscoring the need for coordinated policy design. Benchmarking proves more effective than grandfathering in stimulating green investment, particularly under high carbon prices and strong consumer environmental preferences. The proposed contract alleviates free riding, enhances overall supply chain profitability, and improves emission reduction performance. Policy implications highlight the importance of prioritizing benchmark allocation, promoting consumer environmental awareness, and encouraging firms to integrate carbon asset management with technological innovation. This research provides both theoretical and practical insights for designing effective carbon policies and collaborative mechanisms in green supply chains. Full article

In deepwater oil and gas transportation, Pipe-in-Pipe (PIP) systems are an effective solution for mitigating external loads while preserving internal thermal integrity. A finite element model with ITT elements and nonlinear spring contacts was developed in ABAQUS to simulate thermal expansion and contraction under extreme conditions. The coupled mechanical response of double-layer pipelines under non-uniform temperature fields and internal pressure was analyzed, focusing on stress distribution and deformation coordination between the inner and outer pipes. The inner pipe primarily sustains compressive or tensile stress depending on the thermal load direction, while the outer pipe experiences opposing stresses due to mechanical coupling. Distinct stress transfer zones are present near the pipe ends, governed by pipe-soil interaction and internal bending moments. The proposed model for double-layer pipelines under coupled thermal and internal pressure loads demonstrates a prediction accuracy within 5% as compared with benchmark numerical solutions. The simulations capture axial stress variations of up to 68% between extreme thermal expansion and contraction scenarios, with radial deformation ranging from 0.9 mm to 3.4 mm. These findings provide valuable insights into the safe and efficient design of subsea PIP systems, particularly for optimizing material selection and structural configuration in high-temperature, high-pressure environments. Full article

This study examines a three-tier e-commerce platform supply chain consisting of a manufacturer, an e-commerce platform, and a logistics provider, where three members invest in artificial intelligence. Market demand is modeled as a function of retail price and the AI investment efforts of three members. To coordinate the supply chain, all possible coalition forms and the cost-sharing contract are investigated. Game models under different scenarios are established and solved. The results show that: (1) Compared with the centralized structure, each member’s AI investment effort will decrease under decentralized structures; (2) The cost-sharing contract is always effective for the AI investment efforts of the manufacturer and platform, but it is effective for the logistics provider’s AI investment effort under certain conditions; (3) The cost-sharing contract effectively coordinates the e-commerce platform supply chain compared to the revenue-sharing contract. Market demand and supply chain profit are larger under the cost-sharing contract than under the fully decentralized structure. This paper provides a theoretical basis for the design of AI investment strategies, product pricing, and coordination mechanisms for supply chain members of the e-commerce supply chain. Full article

The rare earth (RE) aqua 4-nitrophenylacetate (4npa) complexes {[RE(4npa)₃(H₂O)₂]·2H₂O}_n (RE = La (1La), Nd (2Nd)), [Ce(4npa)₃(H₂O)₂]_n (3Ce), and {[RE₂(4npa)₆(H₂O)]·2H₂O}_n (RE = Gd (4Gd), Dy (5Dy), Y (6Y), Er (7Er), Yb (8Yb)) were synthesised by salt metathesis reactions of RE^III chlorides or nitrates with sodium 4-nitrophenylacetate Na(4npa) in aqueous ethanol. The structures of all the complexes were determined by single-crystal X-ray diffraction (SCXRD) except for RE = 4Gd, which was determined to be isomorphous with the 5Dy and 7Er complexes by X-ray powder diffraction (XRPD). All the complexes crystallise as one-dimensional polymers linked by bridging carboxylates. Complexes (1La–3Ce) have mononuclear repeating units with two coordinated waters and ten coordinate RE ions, 1La and 2Nd also have two waters of crystallization, but 3Ce has none. By contrast, complexes (4Gd–8Yb) have binuclear repeating units with a single coordinated water. Isomorphous 5Dy and 7Er have one nine coordinate and one eight coordinate metal ion, whilst isomorphous 6Y and 8Yb have two eight coordinate RE ions. In some cases, bulk powders have structures different from the corresponding single crystals. For example, bulk 1La is isomorphous with 3Ce owing to the loss of water of crystallization, and 8Yb exhibits coordination isomerism between single crystals and microcrystalline powder. Weight loss corrosion tests revealed that {[Dy₂(4npa)₆(H₂O)]·2H₂O}_n (5Dy) has the greatest inhibition efficiency (89%) of the complexes (1La–8Yb). The activities are comparable to those of the corresponding 4-hydroxyphenylacetates (4hpa) and far superior to those of 2-hydroxyphenylacetates (2hpa) and the unsubstituted phenylacetates. Whilst the coordination numbers generally decline with the lanthanoid contraction, there are deviations around 5Dy, 6Y, 7Er, and 8Yb, and the corrosion inhibition is optimised with a midrange size. Full article

Sales competition and recycling rivalry are critical factors affecting the operation of closed-loop supply (CLSC). The existing research on competitive CLSCs primarily analyzes the impact of competition between two sales entities and/or two recycling entities on management decisions. To make the study more realistic, this study constructs a Stackelberg game model with the manufacturer as a leader, and analyzes the impacts of competition among $n$ retailers ($\mathrm{w}\mathrm{h}\mathrm{e}\mathrm{r}\mathrm{e} n\ge 2$) and rivalry among $m$ third-party recyclers $(\mathrm{w}\mathrm{h}\mathrm{e}\mathrm{r}\mathrm{e} m\ge 2)$ on the decision-making and profits of both node enterprises and the supply chain system, and proposes a linear transfer-payment contract to coordinate the CLSC from an economic perspective. Numerical analyses are conducted to visualize the effects of competition on the decisions and profits. The key findings are as follows: (1) In the centralized system, inter-retailer competition reduces optimal order quantities but does not affect optimal retail prices. In the decentralized system, however, it decreases both optimal order quantities and retail prices. (2) Rivalry among recyclers reduces their optimal recycling volumes but does not affect their optimal recycling prices in the centralized system. In the decentralized system, however, such rivalry not only decreases recycling volumes but also increases optimal recycling prices. (3) The manufacturer’s product wholesale price and used product recycling price remain independent of competitive interactions among retailers and recyclers in the decentralized system. (4) Competition among retailers and recyclers positively affects the profits of the CLSC and the manufacturer, but negatively impacts those of retailers and recyclers. (5) When the reward–penalty factors for product order and used product recycling fall within a specific range, the linear transfer-payment contract can coordinate the CLSC in the presence of competition in both retail and recycling. (6) All enterprises’ profits are sensitive to the penalty–reward factor, but this sensitivities also gradually decrease as the number of retailers and (or) recyclers increases. Full article

Skeletal muscle, constituting 40–50% of total body mass, is vital for mobility, posture, and systemic homeostasis. Muscle contraction heavily relies on ATP, primarily generated by mitochondrial oxidative phosphorylation. Mitochondria play a key role in decoding intracellular calcium signals. The endocannabinoid system (ECS), including CB₁ receptors (CB₁Rs), broadly influences physiological processes and, in muscles, regulates functions like energy metabolism, development, and repair. While plasma membrane CB₁Rs (pCB₁Rs) are well-established, a distinct mitochondrial CB₁R (mtCB₁R) population also exists in muscles, influencing mitochondrial oxidative activity and quality control. We investigated the role of mtCB₁Rs in skeletal muscle physiology using a novel systemic mitochondrial CB₁ deletion murine model. Our in vivo studies showed no changes in motor function, coordination, or grip strength in mtCB₁ knockout mice. However, in vitro force measurements revealed significantly reduced specific force in both fast-twitch (EDL) and slow-twitch (SOL) muscles following mtCB₁R ablation. Interestingly, knockout EDL muscles exhibited hypertrophy, suggesting a compensatory response to reduced force quality. Electron microscopy revealed significant mitochondrial morphological abnormalities, including enlargement and irregular shapes, correlating with these functional deficits. High-resolution respirometry further demonstrated impaired mitochondrial respiration, with reduced oxidative phosphorylation and electron transport system capacities in knockout mitochondria. Crucially, mitochondrial membrane potential dissipated faster in mtCB₁ knockout muscle fibers, whilst mitochondrial calcium levels were higher at rest. These findings collectively establish that mtCB₁Rs are critical for maintaining mitochondrial health and function, directly impacting muscle energy production and contractile performance. Our results provide new insights into ECS-mediated regulation of skeletal muscle function and open therapeutic opportunities for muscle disorders and aging. Full article

Against the background of carbon neutrality, the impact of carbon quota allocation mechanism on supply chain’s decision-making of emission reduction has received increasing attention. This study analyzes the optimal decision-making behavior of manufacturing supply chains under three mechanisms: completely free, complete auction and hybrid. Meanwhile, the abatement cost-sharing contract is introduced and the backward induction method is applied to solve the optimal equilibrium solution under each mechanism. Combined with numerical simulation, this study further investigates the impacts of market demand and cost-sharing coefficient changes on the system profit. The result shows that the abatement cost-sharing contract can significantly improve the level of manufacturers’ abatement and the total profit of the supply chain. Among the mechanisms analyzed, the hybrid mechanism realizes the balance between efficiency and incentives and demonstrates stronger adaptability and policy flexibility. Full article

Green design by manufacturers is essential for achieving supply chain sustainability, and large retailers may exhibit altruistic preferences to incentivize such efforts. Accordingly, this study develops three game-theoretic models of a two-echelon supply chain composed of a manufacturer and a dominant retailer, with and without altruistic preferences, to examine how altruism and green design affect firms’ optimal decisions and environmental impact. In addition, two coordination mechanisms—green design cost-sharing and two-part tariff contracts—are proposed under altruistic preferences. We find that the dominant retailer’s altruistic preference can motivate the manufacturer to improve the green design level and increase system profit. Although the dominant retailer has altruistic preference, they cannot always lower the total environmental impact of products, so it is helpful to motivate the manufacturer to reduce the environmental adverse impact by increasing investments in green design. Both the two contracts designed in this paper can achieve incentive compatibility and perfect coordination of supply chain. However, with the retailer’s altruistic preference enhancement, the feasible range of the two contracts will be reduced. Full article

Understanding how contract functions influence contractors’ performance behaviors is critical for improving project outcomes in the construction industry. Drawing on contractual governance theory, this study explores the differential impacts of three core contract functions—control, coordination, and adaptation—on contractor behaviors, distinguishing between perfunctory and consummate performance. A mixed-methods approach is employed, combining a survey of 345 contractors with semi-structured interviews. Quantitative results indicate that contract control increases perfunctory behavior and reduces consummate behavior, contract coordination stimulates both types of behaviors, while contract adaptation reduces perfunctory behavior and enhances consummate behavior. Qualitative findings further identify boundary conditions such as fairness, trust, and project uncertainty. From a theoretical perspective, the study refines contractual governance theory by clarifying the behavioral implications of multifunctional contracts. From a practical perspective, it offers guidance for contract design that balances compliance and collaboration to encourage proactive contractor engagement. Full article

Muscle traits are critical determinants of meat quality and productivity in sheep, influenced by both breed and anatomical region. Hanzhong sheep, an indigenous Chinese breed, are prized for tender, low-odor meat; yet, the molecular mechanisms underlying these traits remain poorly understood. In this study, we integrated meat quality assessment with metabolomic and transcriptomic profiling of the longissimus dorsi (HZ-B) and triceps brachii (HZ-T) muscles to elucidate biochemical and molecular bases of regional differences. The results, derived from metabolomic profiling, demonstrated that the muscle tissue of Hanzhong sheep contained abundant proteins (95 kinds) and fatty acids (150 kinds). The greater tenderness of HZ-B compared to HZ-T was associated with higher levels of dipeptides such as carnosine (FC = 1.07) and anserine (FC = 1.04), as well as upregulated expression of oxidative fiber-related genes MYH2 (FC = 2.92) and TPM1 (FC = 2.15). In contrast, HZ-T showed enrichment of flavor-associated metabolites, including acylcarnitines and glutamate, alongside higher expression of FBXO32 (FC = 0.35) and MYBPC1 (FC = 0.47), linked to structural integrity and muscle contraction. Integrated analysis revealed strong associations between metabolite abundance (carnosine/anserine) and key genes (FBXO32/GADL1), suggesting coordinated regulation of meat quality traits. These findings provide mechanistic insights into the metabolic and transcriptomic determinants of muscle quality in Hanzhong sheep, offering a foundation for genetic improvement and conservation strategies. Full article

To address the challenges of multiple cost-influencing factors, high risks, and difficult control in highway construction projects, this study conducts a cost risk assessment based on the full-process perspective of project owners. Considering the long duration and distinct phases of highway construction projects, the study employs a literature-based statistical method to identify the factors influencing cost risks and establishes an evaluation index system for cost risk factors throughout the entire construction process. Based on questionnaire surveys, the study applies the Analytic Hierarchy Process (AHP) to calculate the initial weights of the cost risk factors. Then, the improved entropy weight method is used to compute the correction coefficients for the initial weights and determine the final weight of each influencing factor. By integrating the results from AHP, the comprehensive weights of all factors are obtained, thereby identifying the key factors affecting cost risks throughout the entire highway construction process. Additionally, cost risk prevention and control measures are proposed. The research findings indicate that among the 42 evaluation factors, the ten factors with the greatest impact on project cost risks are project positioning changes, price inflation, unclear or erroneous contract terms, lack of supervision by design units, delayed compensation payments, collusion in bidding (including bid-rigging and cover bidding), lack of coordination among different departments leading to schedule risks, construction claims risks, risks associated with bidding methods, and financing risks. These ten key factors are analyzed in detail, and corresponding risk prevention and control measures are proposed. Full article

Background: Entrusted budgets were introduced as part of the primary healthcare (PHC) system in Poland in July 2022. This initiative aimed to increase the role of PHC and enhance the accessibility of diagnostic services and specialist consultations/advice for patients. Methods: Data from the National Health Fund (NHF) databases regarding contracts between the NHF and healthcare providers in the field of PHC from 2022 to 2025 were analyzed. The share of contracts with entrusted budgets in the total number of PHC physician contracts was estimated in individual voivodships, as well as in counties, using the example of the Małopolskie Voivodship. It was assessed whether there were significant differences between voivodships and counties as well as the pace of implementation of the new solution. Results: Only 43.1% of PHC physicians have signed contracts with the NHF for coordinated care services for 2025, with this percentage varying significantly between voivodships, ranging from 24.8% in Opolskie Voivodship to 66.3% in Lubelskie Voivodship (p < 0.0001). For the vast majority of voivodships, no statistically significant increase in the share of service providers was demonstrated in the period from 2022 to 2025. Access to services between counties is also highly varied (from 10.0% to 76.5%), although the differences were not statistically significant (p = 0.217). Conclusions: The results indicate regional and local inequalities in access to services. It is necessary to implement incentive mechanisms within the contracting of health services between the NHF and providers that will ensure equal access to PHC services within entrusted budgets for all patients. The range of available services should be equal regardless of at which PHC facility a patient is registered. The current regulations concerning entrusted budgets, including the voluntary involvement of service providers, are not sufficient. Full article