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Pipe systems are broadly used in modern buildings and large transportation vehicles. The reduction of noise from pipes is one of the main concerns in their engineering applications. In this paper, the reduction of the radiated noise from pipes is studied experimentally using various attached structures. An experimental system is constructed in an anechoic room. Three types of attached structures are considered, including foam coatings, distributed absorbers and periodic absorbers. Via the comparison of basic pipe and pipes with different noise control designs, the reduction effects from the attached structures are compared and analysed. The results show that the radiated noise is effectively reduced by the foam coatings and distributed absorbers, especially, at most of the peaks of the noise. The distributed absorbers reduce the noise more on the whole. The low frequency peaks (below 200Hz) of the noise are reduced most by the periodic absorbers. Via the proper design of the structure types and corresponding parameters, the low frequency property, the broadband property and the reduction amplitude will be obviously enhanced.

Land-use change is the main driver of carbon storage change in terrestrial ecosystems. Currently, domestic and international studies mainly focus on the impact of carbon storage changes on climate, while studies on the impact of land-use changes on carbon storage in complex terrestrial ecosystems are few. The Jialing River Basin (JRB), with a total area of ~ 160,000 km 2 , diverse topography, and elevation differences exceeding 5 km, is an ideal case for understanding the complex interactions between land-use change and carbon storage dynamics. Taking the JRB as our study area, we analyzed land-use changes from 2000 to 2020. Subsequently, we simulated land-use patterns for business-as-usual (BAU), cropland protection (CP), and ecological priority (EP) scenarios in 2035 using the PLUS model. Additionally, we assessed carbon storage using the InVEST model. This approach helps us to accurately understand the carbon change processes in regional complex terrestrial ecosystems and to formulate scientifically informed land-use policies. The results revealed the following: (1) Cropland was the most dominant land-use type (LUT) in the region, and it was the only LUT experiencing net reduction, with 92.22% of newly designated construction land originating from cropland. (2) In the JRB, total carbon storage steadily decreased after 2005, with significant spatial heterogeneity. This pattern was marked by higher carbon storage levels in the north and lower levels in the south, with a distinct demarcation line. The conversion of cropland to construction land is the main factor driving the reduction in carbon storage. (3) Compared with the BAU and EP scenarios, the CP scenario demonstrated a smaller reduction in cropland area, a smaller addition to construction land area, and a lower depletion in the JRB total carbon storage from 2020 to 2035. This study demonstrates the effectiveness of the PLUS and InVEST models in analyzing complex ecosystems and offers data support for quantitatively assessing regional ecosystem services. Strict adherence to the cropland replenishment task mandated by the Chinese government is crucial to increase cropland areas in the JRB and consequently enhance the carbon sequestration capacity of its ecosystem. Such efforts are vital for ensuring the food and ecological security of the JRB, particularly in the pursuit of the “dual-carbon” objective.

Intercropping can obtain yield advantages, but the mechanism of yield advantages of maize-legume intercropping is still unclear. Then, we explored the effects of cropping systems and N input on yield advantages in a two-year experiment. Cropping systems included monoculture maize ( Zea mays L.) (MM), monoculture soybean ( Glycine max L. Merr.) (MS), monoculture peanut ( Arachis hypogaea L.) (MP), maize-soybean substitutive relay intercropping (IMS), and maize-peanut substitutive strip intercropping (IMP). N input included without N (N0) and N addition (N1). Results showed that maize’s leaf area index was 31.0% and 34.6% higher in IMS and IMP than in MM. The specific leaf weight and chlorophyll a (chl a) of maize were notably higher by 8.0% and 18.8% in IMS, 3.1%, and 18.6% in IMP compared with MM. Finally, N addition resulted in a higher thousand kernels weight of maize in IMS and IMP than that in MM. More dry matter accumulated and partitioned to the grain, maize's averaged partial land equivalent ratio and the net effect were 0.76 and 2.75 t ha −1 in IMS, 0.78 and 2.83 t ha −1 in IMP. The leaf area index and specific leaf weight of intercropped soybean were 16.8% and 26% higher than MS. Although soybean suffers from shade during coexistence, recovered growth strengthens leaf functional traits and increases dry matter accumulation. The averaged partial land equivalent ratio and the net effect of intercropped soybean were 0.76 and 0.47 t ha −1 . The leaf area index and specific leaf weight of peanuts in IMP were 69.1% and 14.4% lower than in the MP. The chlorophyll a and chlorophyll b of peanut in MP were 17.0% and 24.4% higher than in IMP. A less dry matter was partitioned to the grain for intercropped peanut. The averaged pLER and NE of intercropped peanuts were 0.26 and -0.55 t ha −1 . In conclusion, the strengthened leaf functional traits promote dry matter accumulation, maize-soybean relay intercropping obtained a win–win yield advantage, and maize-peanut strip intercropping achieved a trade-off yield advantage.

OH-PLIF quantitative measurements suffer from high temperature sensitivity and poor applicability of calibration constants, this paper combines absorption spectroscopy with dual-line temperature inversion to establish an explicitly temperature-corrected OH radical concentration inversion model. By simultaneously acquiring PLIF images and absorption spectrum data under varying hydrogen-oxygen mixture flow rates, the equivalent absorption path length is calculated and the temperature-dependent absorption cross-section σ(ν,T) is incorporated. This enables the dynamic response of the integral absorption rate to high-temperature flame environments. Results demonstrate that the established temperature-corrected model significantly reduces systematic errors caused by temperature variations, with calibration constant C fluctuating less than ±5% across different operating conditions. Further optimization via least-squares method yielded the optimal constant Copt = 0.01844. Its applicability was validated across various operating conditions, with average relative errors controlled within 4–6%. Compared to the uncorrected model, overall error decreased from 9.1% to 5.2%.

In the context of carbon neutrality, ammonia-coal co-firing is considered an effective way to reduce emissions from coal-fired units. This paper takes a 125 MW tangential combustion boiler as the research object and combines CFD and CHEMKIN models to study the effects of ammonia injection position (L1–L3) and blending ratio (0–30%) on combustion characteristics and NO generation. The results indicate that L1 (same-layer premixed injection) can form a continuous and stable flame structure and maintain low NO emissions. L2 (fuel-staged configuration) shows the highest burnout rate and strong denitration potential under high mixing conditions, while L3 has an unstable flow field and the worst combustion structure. NO emissions show a typical “first rise and then fall” trend with the blending ratio. L1 performs optimally in the range of 15–20%, and L2 peaks at 20%. Mechanism analysis indicates that R430 is the main NO generation reaction, while R15 and R427 dominate the NO reduction process. The synergistic reaction between NHx free radicals and coke can effectively inhibit the formation of NO and improve combustion efficiency.

Intercropping can increase crop N uptake and reduce carbon emissions. However, the effects of straw incorporation and N reduction on N use and carbon emissions in intercropping are still unclear. We explored the mechanism of N uptake, N use efficiency, and CO 2 emissions in the wheat-maize-soybean relay strip intercropping system. A two-year field experiment was conducted with two straw managements, i.e., wheat straw incorporation (SI) and straw removal (SR), and four N application levels of soybean, i.e., 60 (N60), 30 (N30), 15 (N15), and 0 kg N ha -1 (N0). We assessed soil properties, CO 2 emissions, and characteristics of roots, nodules, and aboveground N uptake of intercropped soybean. Results showed that geometry mean diameter of aggregate, soil porosity, soil total N, and soil urease activity were notably greater in SI than in SR. N input reduced from N60 to N30 did not significantly affect the soil total N content and urease activity in SI. The root length, root surface area, root volume, root biomass, root bleeding intensity, and inorganic N content of bleeding sap were greater in SI than in SR. In the SI, although the root length and surface area peaked at N60, the root biomass and inorganic N content of bleeding sap were insignificant between N60 and N30. The nodule number, nodule dry weight, nodule nitrogenase activity, and nodule nitrogen fixation potential in SI were notably increased compared with SR. The nodule nitrogen fixation potential in SI notably increased with the decrease of N input at the R3 stage, but it peaked in N30 at the R5 stage. On average, the aboveground N uptake and nitrogen recovery efficiency (RE) was notably higher by 43.7% and 76.8% in SI than in SR. SI+N30 achieved the greatest aboveground N uptake and RE. The CO 2 emission and accumulated CO 2 emission were notably greater in SI than in SR, and the accumulated CO 2 emission of SI was the lowest with N30 input. In conclusion, SI+N30 promoted N uptake and utilization efficiency with reduced CO 2 emissions during the soybean cropping season. It provides a potential strategy for sustainable agricultural development in intercropping systems.

Maize’s nitrogen (N) uptake can be improved through maize-legume intercropping. N uptake mechanisms require further study to better understand how legumes affect root growth and to determine maize’s absorptive capacity in maize-legume intercropping. We conducted a two-year field experiment with two N treatments (zero N (N0) and conventional N (N1)) and three planting patterns (monoculture maize ( Zea mays L.) (MM), maize-soybean ( Glycine max L. Merr .) strip intercropping (IMS), and maize-peanut ( Arachis hypogaea L.) strip intercropping (IMP)). We sought to understand maize’s N uptake mechanisms by investigating root growth and distribution, root uptake capacity, antioxidant enzyme activity, and the antioxidant content in different maize-legume strip intercropping systems. Our results showed that on average, the N uptake of maize was significantly greater by 52.5% in IMS and by 62.4% in IMP than that in MM. The average agronomic efficiency (AE) of maize was increased by 110.5 % in IMS and by 163.4 % in IMP, compared to MM. The apparent recovery efficiency (RE) of maize was increased by 22.3% in IMS. The roots of intercropped maize were extended into soybean and peanut stands underneath the space and even between the inter-rows of legume, resulting in significantly increased root surface area density (RSAD) and total root biomass. The root-bleeding sap intensity of maize was significantly increased by 22.7–49.3% in IMS and 37.9–66.7% in IMP, compared with the MM. The nitrate-N content of maize bleeding sap was significantly greater in IMS and IMP than in MM during the 2018 crop season. The glutathione (GSH) content, superoxide dismutase (SOD), and catalase (CAT) activities in the root significantly increased in IMS and IMP compared to MM. Strip intercropping using legumes increases maize’s aboveground N uptake by promoting root growth and spatial distribution, delaying root senescence, and strengthening root uptake capacity.

Background Frailty assessment is crucial for predicting outcomes in acute care settings; however, its application remains challenging. Therefore, this study aims to evaluate and compare two electronic medical record-based tools—the Canadian Institute for Health Information Hospital Frailty Risk Measure (CIHI-HFRM) and the United Kingdom Hospital Frailty Risk Score (UK-HFRS)—in older patients requiring urgent admission. Methods In this retrospective cohort study, we analyzed 35,564 patients aged 65 or older from the MIMIC-IV 2.0 database. Frailty was assessed using CIHI-HFRM and UK-HFRS. Primary outcomes included in-hospital mortality, one-year post-discharge mortality, post-discharge care needs, timely hospital discharge, and one-year readmission rates. Logistic regression, Cox regression, and competing risk models were used for analysis. Results The CIHI-HFRM and UK-HFRS were significantly associated with in-hospital mortality [odds ratio (OR) per point: CIHI-HFRM 1.10 (95% confidence interval (CI) 1.07–1.13); UK-HFRS 1.06 (95% CI 1.05–1.07)] and one-year post-discharge mortality [hazard ratio (HR) per point: CIHI-HFRM 1.08 (95% CI 1.06–1.09); UK-HFRS 1.05 (95% CI 1.04–1.05)]. Both measures were associated with prolonged hospital stays and post-discharge care needs, while only CIHI-HFRM was linked to one-year readmission risk. Conclusion The CIHI-HFRM and UK-HFRS effectively stratify adverse outcomes risk in older patients requiring urgent admission. They may be considered alongside traditional measures as part of a pragmatic multimodal pathway, which represents a potential direction for clinical application.

Applying Biochar (BC) or biofertilizers (BF) are potential approaches to reduce the nitrogen input and mitigate soil degradation in the maize soybean relay strip intercropping system (IS). In 2019 and 2020, a two-factor experiment was carried out to examine the effects of BC and BF on soil productivity and yield production in IS. 4 N input levels (8.4, 22.5, 45 kg, and 67.5 kg ha − 1 ) referred to as N0, N1, N2, and N3 were paired with various organic treatments, including BC (150 kg ha − 1 ), BF (300 kg ha − 1 ), and without organic amendments (CK). The results demonstrated that, despite BF decreasing the biomass and N distribution into grains, BF performed better on improved soybean yield (5.2–8.5%) by increasing the accumulation of soybean biomass (7.2 ~ 11.6%) and N (7.7%). Even though BC and BF have a detrimental effect on soybean nitrogen fixation by reducing nodule number and weight, the values of soybean nitrogenase activity and nitrogen fixation potential in BF were higher than those in BC. Additionally, BF performs better at boosting the soil’s nitrogen content and nitrate reductase and urease activity. BF increased the concentration of total N, soil organic matter, Olsen-phosphorus, and alkaline hydrolyzable N in the soil by 13.0, 17.1, 22.0, and 7.4%, respectively, compared to CK. Above all, applying BF combination with N2 (45 kg ha − 1 N) is a feasible strategy to raise crop grain output and keep soil productivity over the long term in IS.

Background The triglyceride-glucose (TyG) index is regarded as a dependable alternative for assessing insulin resistance (IR), given its simplicity, cost-effectiveness, and strong correlation with IR. The relationship between the TyG index and adverse outcomes in patients with coronary heart disease (CHD) is not well established. This study examines the association of the TyG index with long-term adverse outcomes in hospitalized CHD patients. Methods In this single-center prospective cohort study, 3321 patients hospitalized with CHD were included. Multivariate Cox regression models were employed to assess the associations between the TyG index and the incidence of all-cause mortality and major adverse cardiovascular events (MACEs). To examine potential nonlinear associations, restricted cubic splines and threshold analysis were utilized. Results During a follow-up period of 9.4 years, 759 patients (22.9%) succumbed to mortality, while 1291 (38.9%) experienced MACEs. Threshold analysis demonstrated a significant “U”-shaped nonlinear relationship with MACEs, with different hazard ratios observed below and above a TyG index of 8.62 (below: HR 0.71, 95% CI 0.50–0.99; above: HR 1.28, 95% CI 1.10–1.48). Notably, an increased risk of all-cause mortality was observed only when the TyG index exceeded 8.77 (HR 1.53, 95% CI 1.19–1.96). Conclusions This study reveals a nonlinear association between the TyG index and both all-cause mortality and MACEs in hospitalized CHD patients with CHD. Assessing the TyG index, particularly focusing on individuals with extremely low or high TyG index values, may enhance risk stratification for adverse outcomes in this patient population.