BACKGROUND Non-ST segment elevation myocardial infarction(NSTEMI)poses significant challenges in clinical management due to its diverse outcomes.Understanding the prognostic role of hematological parameters and derive...BACKGROUND Non-ST segment elevation myocardial infarction(NSTEMI)poses significant challenges in clinical management due to its diverse outcomes.Understanding the prognostic role of hematological parameters and derived ratios in NSTEMI patients could aid in risk stratification and improve patient care.AIM To evaluate the predictive value of hemogram-derived ratios for major adverse cardiovascular events(MACE)in NSTEMI patients,potentially improving clinical outcomes.METHODS A prospective,observational cohort study was conducted in 2021 at the Internal Medicine Clinic of the University Hospital in Tuzla,Bosnia and Herzegovina.The study included 170 patients with NSTEMI,who were divided into a group with MACE and a control group without MACE.Furthermore,the MACE group was subdivided into lethal and non-lethal groups for prognostic analysis.Alongside hematological parameters,an additional 13 hematological-derived ratios(HDRs)were monitored,and their prognostic role was investigated.RESULTS Hematological parameters did not significantly differ between non-ST segment elevation myocardial infarction(NSTEMI)patients with MACE and a control group at T1 and T2.However,significant disparities emerged in HDRs among NSTEMI patients with lethal and non-lethal outcomes post-MACE.Notably,neutrophil-to-lymphocyte ratio(NLR)and platelet-to-lymphocyte ratio(PLR)were elevated in lethal outcomes.Furthermore,C-reactive protein-to-lymphocyte ratio(CRP/Ly)at T1(>4.737)demonstrated predictive value[odds ratio(OR):3.690,P=0.024].Both NLR at T1(>4.076)and T2(>4.667)emerged as significant predictors,with NLR at T2 exhibiting the highest diagnostic performance,as indicated by an area under the curve of 0.811(95%CI:0.727-0.859)and OR of 4.915(95%CI:1.917-12.602,P=0.001),emphasizing its important role as a prognostic marker.CONCLUSION This study highlights the significant prognostic value of hemogram-derived indexes in predicting MACE among NSTEMI patients.During follow-up,NLR,PLR,and CRP/Ly offer important insights into the inflammatory processes underlying cardiovascular events.展开更多
Publisher Correction to:Journal of Forestry Research(2025)36:29 https://doi.org/10.1007/s11676-025-01823-0 In Fig.4c of this article,the lower part of the figure was unintentionally cropped and incomplete during the p...Publisher Correction to:Journal of Forestry Research(2025)36:29 https://doi.org/10.1007/s11676-025-01823-0 In Fig.4c of this article,the lower part of the figure was unintentionally cropped and incomplete during the publisher's production process.The published incorrect version and the corrected version of Fig.4 are given below.展开更多
This study aimed to optimize the application rates and base-topdressing ratios of nitrogen and potassium for flue-cured tobacco in Chaling,Zhuzhou,Hunan.The tobacco variety‘Yunyan 87’was planted and subjected to eig...This study aimed to optimize the application rates and base-topdressing ratios of nitrogen and potassium for flue-cured tobacco in Chaling,Zhuzhou,Hunan.The tobacco variety‘Yunyan 87’was planted and subjected to eight different treatments with different application rates and base-topdressing ratios of nitrogen and potassium.The effect of different treatments on the agronomic traits,dry matter accumulation,yield,and quality of tobacco were compared.The results showed that the growth period of each treatment became shortened as the application rates of nitrogen and potassium decreased and as the base-topdressing ratios of nitrogen and potassium increased.The dry matter accumulation decreased with the reduction in the application rates of nitrogen and potassium.The yield and output value of T1 were the highest,reaching 2097.39 kg/hm^(2)and 65018.90 yuan/hm^(2),respectively,both significantly increasing by 57.5%compared with those of the control(CK).In addition,the proportions of leaves of high and mid-high grade in T1 were also the highest,reaching 73.31%and 88.79%,respectively,both higher than those of CK.The appearance evaluation results showed that the appearance quality scores of tobacco leaves of grades B2F and C3F in T1 were the highest,reaching 51 points,both of which were 3 points higher than that those of CK.All the treatments were consistent in terms of color,maturity,leaf structure,body,oil,and color intensity.Therefore,it was suggested that the tobacco production in Chaling should appropriately increase the proportions of nitrogen and potassium as base fertilizers on the basis of conventional fertilization,which was conducive to improving the yield and appearance quality of flue-cured tobacco.展开更多
BACKGROUND Patients with type 2 diabetes mellitus(T2DM)face a heightened risk of future cardiovascular events.It is therefore important to stratify these patients according to their future cardiovascular event risk to...BACKGROUND Patients with type 2 diabetes mellitus(T2DM)face a heightened risk of future cardiovascular events.It is therefore important to stratify these patients according to their future cardiovascular event risk to allow early intervention and improve prognosis.Recent proposals have indicated that nontraditional lipoprotein ratios may be superior predictors of cardiovascular events compared to traditional lipid parameters.However,further evidence is required for widespread clinical ap-plication.AIM To elucidate the associations of nontraditional lipoprotein ratios with future cardiovascular events in patients with T2DM.METHODS This study performed post-hoc analysis of data obtained during a clinical trial involving 10182 participants.To ascertain the correlations between nontraditional lipoprotein ratios and future cardiovascular events,including major adverse cardiovascular events(MACEs)and congestive heart failure(CHF).We employed univariable and multivariable-adjusted Cox proportional hazards regression models.Potential dose-response relationships and threshold values were explored by conducting restricted cubic spline analyses and two-piecewise linear regression models.Possible relevant interactions influencing independent relationships were tested using subgroup and interaction analyses.RESULTS After adjustment for confounding factors,all nontraditional lipoprotein ratios studied were strongly associated with MACE risk in patients with T2DM.In comparison with patients in the lowest quartile,the hazard ratios(95%confidence intervals)of those in the highest quartile were 1.50(1.29-1.73),1.51(1.30-1.74),1.50(1.29-1.73),and 1.30(1.12-1.50)for total cholesterol/high-density lipoprotein cholesterol(HDL-C),low-density lipoprotein cholesterol/HDL-C,non-HDL-C/HDL-C,and remnant cholesterol/HDL-C,respectively.Similar findings were noted for CHF.Dose-response relationships between nontraditional lipoprotein ratios and MACE were observed,with threshold values of 7.29,6.29,and 2.15 for total cholesterol/HDL-C,non-HDL-C/HDL-C,and remnant cholesterol/HDL-C,respectively.However,no notable dose-response relationships were detected between nontraditional lipoprotein ratios and CHF.CONCLUSION Elevated nontraditional lipoprotein ratios may independently predict the risk of MACE and CHF in patients with T2DM.展开更多
A high-speed train travelling from the open air into a narrow tunnel will cause the“sonic boom”at tunnel exit.When the maglev train’s speed reaches 600 km/h,the train-tunnel aerodynamic effect is intensified,so a n...A high-speed train travelling from the open air into a narrow tunnel will cause the“sonic boom”at tunnel exit.When the maglev train’s speed reaches 600 km/h,the train-tunnel aerodynamic effect is intensified,so a new mitigation method is urgently expected to be explored.This study proposed a novel asymptotic linear method(ALM)for micro pressure wave(MPW)mitigation to achieve a constant gradient of initial c ompression waves(ICWs),via a study with various open ratios on hoods.The properties of ICWs and MPWs under various open ratios of hoods were analyzed.The results show that as the open ratio increases,the MPW amplitude at the tunnel exit initially decreases before rising.At the open ratio of 2.28%,the slope of the ICW curve is linearly coincident with a supposed straight line in the ALM,which further reduces the MPW amplitude by 26.9%at 20 m and 20.0%at 50 m from the exit,as compared to the unvented hood.Therefore,the proposed method effectively mitigates MPW and quickly determines the upper limit of alleviation for the MPW amplitude at a fixed train-tunnel operation condition.All achievements provide a ne w potential measure for the adaptive design of tunnel hoods.展开更多
BACKGROUND An efficient index holds the potential to predict rectal cancer prognosis.AIM To investigate the impact of neutrophil-to-lymphocyte ratio(NLR),platelet-tolymphocyte ratio(PLR),and monocyte-to-lymphocyte rat...BACKGROUND An efficient index holds the potential to predict rectal cancer prognosis.AIM To investigate the impact of neutrophil-to-lymphocyte ratio(NLR),platelet-tolymphocyte ratio(PLR),and monocyte-to-lymphocyte ratio(MLR)on rectal cancer prognosis.METHODS This retrospective study involved 180 patients with rectal cancer from the Changzhi People’s Hospital of Shanxi Province.A 2-mL blood sample was collected at 24 h preoperatively and 72 h postoperatively to measure neutrophils,lymphocytes,platelets,and monocytes using an automatic blood analyzer.Preoperative and postoperative NLR,PLR,and MLR were compared.Patients were followed up for 12 months and categorized into good and poor prognosis groups.A receiver operating characteristic curve was constructed to analyze their predictive values.RESULTS The NLR,PLR,and MLR values were significantly lower post-surgery(P<0.05).A total of 152 and 28 patients were categorized in the good and poor prognosis groups,respectively.Patients with poor prognoses exhibited slightly higher postoperative NLR,PLR,and MLR values than those with good prognoses(P<0.05).Receiver operating characteristic analysis showed that the area under the curve for NLR,PLR,and MLR was 0.828 with a sensitivity and specificity of 89.29%and 90.79%,respectively.These values were higher than individual NLR(area under the curve:0.660,sensitivity:67.86%,specificity:54.61%),PLR(0.668,75.00%,55.30%),and MLR(0.635,60.71%,48.03%),all showing statistically significant differences(P<0.05),effectively predicting patient outcomes.CONCLUSION The findings of this study indicated that NLR,PLR,and MLR values of patients with rectal cancer can be used to effectively predict the outcome of patients.展开更多
Driver distraction is a leading cause of traffic accidents,with fatigue being a significant contributor.This paper introduces a novel method for detecting driver distraction by analyzing facial features using machine ...Driver distraction is a leading cause of traffic accidents,with fatigue being a significant contributor.This paper introduces a novel method for detecting driver distraction by analyzing facial features using machine deep learning and 68 face model.The proposed system assesses driver tiredness by measuring the distance between key facial landmarks,such as the distance between the eyes and the angle of the mouth,to evaluate signs of drowsiness or disengagement.Real-time video feed analysis allows for continuous monitoring of the driver’s face,enabling the system to detect behavioral cues associated with distraction,such as eye closures or changes in facial expressions.The effectiveness of this method is demonstrated through a series of experiments on a dataset of driver videos,which proves that the approach can accurately assess tiredness and distraction levels under various driving conditions.By focusing on facial landmarks,the system is computationally efficient and capable of operating in real-time,making it a practical solution for in-vehicle safety systems.This paper discusses the system’s performance,limitations,and potential for future enhancements,including integration with other in-vehicle technologies to provide comprehensive driver monitoring.展开更多
Much of the research has focused on identifying bridge frequencies for health monitoring,while the bridge damping ratio also serves as an important factor in damage detection.This study presents an enhanced method for...Much of the research has focused on identifying bridge frequencies for health monitoring,while the bridge damping ratio also serves as an important factor in damage detection.This study presents an enhanced method for identifying bridge damping ratios using a two-axle,three-mass test vehicle,relying on wheel responses captured by only two mounted sensors.Damping ratio estimation formulas are derived using both the Hilbert Transform(HT)and Wavelet Transform(WT),with a consistent formulation that confirms accurate estimation is achievable with minimal instrumentation,particularly when addressing the support effect.A comparative analysis of the two signal processing techniques reveals the superior performance of WT in identifying bridge damping ratios.The effectiveness of the proposed procedure and formulas is validated through a detailed parametric study,demonstrating robustness across bridges with varying modal damping ratios and different spans using minimal sensors.Moreover,the present study shows that responses from only the first two spans of a multi-span bridge are sufficient for reliable damping estimation,underscoring the practicality and scalability of the procedure for structural health monitoring applications.展开更多
Cemented tailings backfill(CTB)is a crucial support material for ensuring the long-term stability of underground goafs.A comprehensive understanding of its compressive mechanical behavior is essential for improving en...Cemented tailings backfill(CTB)is a crucial support material for ensuring the long-term stability of underground goafs.A comprehensive understanding of its compressive mechanical behavior is essential for improving engineering safety.Although extensive studies have been conducted on the uniaxial compressive properties of CTB,damage constitutive models that effectively capture its damage evolution process remain underdeveloped,and its failure mechanisms are not yet fully clarified.To address these gaps,this study conducted systematic uniaxial compression tests on CTB specimens prepared with varying cement-tailings ratios.The results revealed distinct compaction and softening phases in the stress−strain curves.A lower cement-tailings ratio significantly reduced the strength and deformation resistance of CTB,along with a decrease in elastic energy accumulation at peak stress and dissipation energy in the post peak stage.Based on these findings,a modified damage constitutive model was developed by introducing a correction factor,enabling accurate simulation of the entire uniaxial compression process of CTB with different cement-tailings ratios.Comparative analysis with classical constitutive models validated the proposed model’s accuracy and applicability in describing the compressive behavior of CTB.Furthermore,particle size distribution and acoustic emission tests were employed to investigate the influence of cement-tailings ratio on failure mechanisms.The results indicated that a lower cement-tailings ratio leads to coarser particle sizes,which intensify shear-related acoustic emission signals and ultimately result in more pronounced macroscopic shear failure.This study provides theoretical support and practical guidance for the optimal design of CTB mix ratios.展开更多
Flow characteristics around a wall-mounted square cylinder have been numerically simulated at aspect ratios (AR) ranging from 4 to 7 at Re =10 000. Four turbulence models have been compared in terms of drag coefficien...Flow characteristics around a wall-mounted square cylinder have been numerically simulated at aspect ratios (AR) ranging from 4 to 7 at Re =10 000. Four turbulence models have been compared in terms of drag coefficient (C_D). The closest result has been provided by two turbulence models, namely, k-ε Realizable and k ?ω Shear Stress Transport (SST). Hence, these models were utilized to present the flow patterns of pressure distributions, turbulent kinetic energy values, velocity magnitude values with streamlines, streamwise velocity components, crossstream velocity components and spanwise velocity components on different planes. Flow stagnation has been attained in front of the cylinder. Pressure values peaked for the upstream region. Over the cylinders, the tip vortex structure was dominant owing to the influence of the free end. Flow separation from the top front edge of the body has been obtained. The dividing streamline affected by the flow separation was highly effective in the wake region and moved nearer to the body when the aspect ratio was decreased;the reason was the wake shrinkage owing to the decreasing aspect ratio. Upwash and downwash have been seen in the cylinder wake. These two models presented similar flow patterns and drag coefficients. These drag coefficients are in good agreement with those in previous studies.展开更多
Polysynthetic twinned(PST)TiAl single crystal specifically refers to a fully lamellar TiAl single crystal with parallel phase interfaces and twin interfaces grown by directional solidification.In this paper,PST single...Polysynthetic twinned(PST)TiAl single crystal specifically refers to a fully lamellar TiAl single crystal with parallel phase interfaces and twin interfaces grown by directional solidification.In this paper,PST single crystals with different phase ratios are obtained by annealing at specific temperatures and holding times.The results show that the diffusion rates of Ti and Al elements at various temperatures directly trigger and propel the surface recrystallization and variation in the internal phase ratio.When the temperature is lower than 1448 K,the diffusion rate of Ti is obviously higher than that of Al,which causes one denseα_(2)recrystallized layer to form on the surface of TiAl single crystals.Meanwhile,as more Ti elements migrate to the surface,theα_(2)phase ratio inside the TiAl single crystal thereby decreases.When the temperature exceeds 1448 K,the diffusion rate of Al gradually reverses to exceed that of Ti,which forms the surface sandwiched recrystallization dominated byγphase and simultaneously increasesα_(2)phase ratio inside the TiAl single crystal.The variation in the two-phase ratio directly induces a significant change in the lamellae thickness,which exhibits different tensile behaviors of PST-TiAl single crystal.When theα_(2)phase content is less than 20%,widerγlamellae make it easier for dislocations to be activated within its lamellae and continuously move across theγ/α_(2)interfaces,thereby obtaining better tensile plasticity.As theα_(2)phase content exceeds 30%,finerγlamellae inhibit the dislocation initiation,resulting in the fracture occurrence of TiAl single crystal before yielding.No matter how the phase ratio changes,the crack preferentially initiates withinα_(2)lamellae.However,the crack propagation follows different paths based on variousγlamella thicknesses.The fracture mode of PST-TiAl single crystal also changes from shear fracture along slip bands within theγlamella to brittle fracture along the{1¯100}planes withinα_(2)lamella.展开更多
This study employed a wet impregnation method to synthesize five types of Cu/HZSM-5 adsorbents with Si/Al ratios of 25,50,85,200,and 300,used for the removal of H_(2)S in lowtemperature,low-oxygen environments.The imp...This study employed a wet impregnation method to synthesize five types of Cu/HZSM-5 adsorbents with Si/Al ratios of 25,50,85,200,and 300,used for the removal of H_(2)S in lowtemperature,low-oxygen environments.The impact of different Si/Al ratios on the adsorption oxidative performance of Cu_(30)/HZSM-5–85 adsorbents was investigated.According to the performance test results,Cu_(30)/HZSM-5–85 exhibited the highest breakthrough capacity,reaching 231.75 mg H_(2)S/g_(sorbent).Cu/HZSM-5 sorbent maintains a strong ability to remove H_(2)S even under humid conditions and shows excellent water resistance.XRD,BET,and XPS results revealed that CuO is the primary active species,with Cu_(30)/HZSM-5–85 having the largest surface area and highest CuO content,providing more active sites for H_(2)S adsorption.H_(2)-TPR and O_(2)-TPD results confirmed that Cu_(30)/HZSM-5–85 sorbent exhibits outstanding redox properties and oxygen storage capacity,contributing to excellent oxygen transferability in the molecular sieve adsorption-oxidation process.With notable characteristics such as a large surface area,high desulfurization efficiency,and water resistance,Cu_(30)/HZSM-5–85 sorbents hold significant importance for industrial applications.展开更多
Background:Diabetes mellitus(DM)is a prevalent chronic metabolic condition characterized by high blood sugar levels,resulting from insufficient insulin production or ineffective insulin use,posing substantial global h...Background:Diabetes mellitus(DM)is a prevalent chronic metabolic condition characterized by high blood sugar levels,resulting from insufficient insulin production or ineffective insulin use,posing substantial global health issues.Research on the relationship between glycemic status and the ratio of neutrophils to lymphocytes(NLR)and monocytes to lymphocytes(MLR)is limited.This study aimed to fill these knowledge gaps by examining the connection between DM and inflammatory markers within the Asir region.Methods:Data from 3545 participants were retrospectively analyzed.The dataset,gathered between 2021 and 2023,comprises 38 laboratory tests obtained from the Future Lab Pioneer database.The study's inclusion criteria focused on diabetes profile tests(glycated hemoglobin[HbA1c]and fasting blood glucose[FBG])and manually computed inflammatory markers(NLR and MLR),which were stratified by age and sex.Results:This study demonstrated significant differences in NLR levels compared with FBG levels across all adult age groups and adult female participants(p<0.0001),as well as among all elderly age groups(p=0.0006)and elderly women(p=0.01).MLR levels were significant in all adult age groups(p=0.04)and in adult women(p=0.02).When NLR and MLR were compared to HbA1c levels,a significant difference in the mean NLR was found in adult women(p=0.005).Additionally,the mean MLR levels were significant in all adult age groups(p=0.04)and adult women(p=0.02).Conclusion:Although a larger sample size is necessary for this research,the results indicate that NLR and MLR could serve as valuable indicators for evaluating inflammation in people with disrupted glucose metabolism,particularly in adult and female populations.展开更多
The objective of this study was to investigate the geographical origin of Chinese teas using carbon and nitrogen stable isotope ratio technology.The results showed that inter-provincial dispersion of teas in Guangdong...The objective of this study was to investigate the geographical origin of Chinese teas using carbon and nitrogen stable isotope ratio technology.The results showed that inter-provincial dispersion of teas in Guangdong(GD),Guangxi(GX),Hainan(HA),Fujian(FJ),Shandong(SD),Sichuan(SC),Chongqing(CQ),and Henan(HN) provinces was high,while in Zhejiang(ZJ),Hubei(HB),Yunnan(YN),and Anhui(AH) provinces,it was low.Tea samples from GD,GX,HA,and FJ provinces were clustered in one group and separated from those from AH and HB provinces.Thus,carbon and nitrogen stable isotope ratio technology could discriminate teas from among some provinces of China,but not from among others.Better separation might be obtained with a combination of isotopic ratios and other indexes,such as elemental data and organic components.展开更多
A theoretical model with extensible yarns for plain-woven fabrics is developed to determine the calculation of Poisson ratios.The stress ratio( warp: weft),as one of parameters corresponding to Poisson ratio variation...A theoretical model with extensible yarns for plain-woven fabrics is developed to determine the calculation of Poisson ratios.The stress ratio( warp: weft),as one of parameters corresponding to Poisson ratio variations, is introduced to complement the theoretical model. To evaluate the reliability of the theoretical analysis,a series of biaxial tensile tests of a plain-woven fabric with nine stress ratios are conducted carefully,and the theoretical results are compared with the experimentally measured values. The effects of other influencing factors, including geometric and mechanical parameters of yarns,on Poisson ratios are analyzed thoroughly.This solution method could be applied without difficulty to estimations of Poisson ratios and realistic designs for plain-woven fabrics.展开更多
1 Introduction Lake Qinghai,famous as the largest inland saline lake in China,located on the high-altitude northeastern Tibetan Plateau,and four junctional zones of the East Asian summer monsoon(EASM),Indian summer mo...1 Introduction Lake Qinghai,famous as the largest inland saline lake in China,located on the high-altitude northeastern Tibetan Plateau,and four junctional zones of the East Asian summer monsoon(EASM),Indian summer monsoon(ISM),East Asian winter monsoon and the westerly jet stream prevail,making it sensitive to global climate change展开更多
Miniemulsion copolymerization of butyl mathacrylate （BMA） with fluoroacrylate （HFMA, TFMA） was carried out at 70 ℃ by employing potassium persulphate （KPS） as initiator. Copolymer compositions at low conversion...Miniemulsion copolymerization of butyl mathacrylate （BMA） with fluoroacrylate （HFMA, TFMA） was carried out at 70 ℃ by employing potassium persulphate （KPS） as initiator. Copolymer compositions at low conversion levels were determined by ^1H NMR spectra techniques. The reactivity ratios were evaluated by employing Kellen-Tudos （K-T） methods, which yields the apparent reactivity ratios, rBMA = 0.74, rHFMA = 0.87 and rBMA = 0.73, rTFMA = 0.75, respectively, and Q- and e-values of HFMA and TFMA were calculated by the Alfrey-Price method. The results show that HFMA and TFMA are more active than BMA, and the cross-propagation rate constant is greater than the self-propagation one in these two copolymerizations.展开更多
Environment isotopes(δ18O andδ2H)and Cl/Br ratios in surface water and groundwater are combined to investigate arsenic mobilization in aquifer system of the Jianghan Plain.The groundwater has relatively high arsenic...Environment isotopes(δ18O andδ2H)and Cl/Br ratios in surface water and groundwater are combined to investigate arsenic mobilization in aquifer system of the Jianghan Plain.The groundwater has relatively high arsenic concentrations,ranging from 3.6 to 1055.3μg/L with an average of 102.2μg/L,which exceeds China’s drinking water standard(10μg/L).The arsenic content of surface water samples is quite low with the range of 6.0–14.3μg/L,averaging 9.5μg/L.δ18O andδ2H values for surface water and groundwater samples plot close to the local meteoric water line(LMWL),reflecting their meteoric origin;a subset of the samples(shallow wells,10 m)shows a shift to LMWL,commensurate with mixing with surface water and evaporation.The correlations betweenδ18O values and Cl concentration and Cl/Br ratios as well as arsenic concentration demonstrated that surface water and groundwater interactions,including active exchange between river/pond water and groundwater and vertical infiltration from agricultural and aquacultural soils,were dominated processes affecting arsenic mobilization in shallow groundwater system and lateral recharge was the main process controlling arsenic behavior in deep groundwater system.The results of this study will be beneficial to understanding the causes of arsenic mobilization in Jianghan groundwaters at different depths.展开更多
The optimum pressure ratio distribution of a multistage reciprocating compressor is presented based on the assumption, i.e. the inter stage cooling is perfect and there are no pressure losses. The optimization of the...The optimum pressure ratio distribution of a multistage reciprocating compressor is presented based on the assumption, i.e. the inter stage cooling is perfect and there are no pressure losses. The optimization of the two or three stage pressure ratio is analyzed in two cases of constant heat transfer rate for the inter cooler or constant inter stage inlet temperature, based on the minimum of the sum of theoretical compression power at each stage about a multi stage reciprocating compressor. Furthermore, with an example of two stage compressor the influence on the sum of the power of each stage is analyzed when practical pressure ratio deviates from the optimum value. It is obtained that under different cooling conditions the optimum pressure ratio distribution of the multi stage compression is various, and the change of the optimum pressure ratio within a small range has little influence on the sum of the power each stage. For the two stage compression, this range can be represented as ε 1=(0 96～1 06)ε 1j .展开更多
[Objective]The paper was to investigate the effects of dietary concentrate to forage ratios on production performance and serum bio-chemical indicators of post-fattening Hainan Yellow Cattle.[Method]Sixteen Hainan Yel...[Objective]The paper was to investigate the effects of dietary concentrate to forage ratios on production performance and serum bio-chemical indicators of post-fattening Hainan Yellow Cattle.[Method]Sixteen Hainan Yellow Cattles with the same genetic backgrounds and similar initial weight of(242.22 ±0.71 kg) were randomly divided into four treatments.Cattles were fed with diets of different concentrate to forage ratios(20:80, group Ⅰ;30:70, Group Ⅱ;40:60, group Ⅲ;50:50, group Ⅳ).The trial lasted 62 d.[Result]The daily gain in experimental group Ⅳ was significantly higher than that in experimental group Ⅱ(P<0.05), but the feed gain ratio in experimental group Ⅳ was lower than those in other ex-perimental groups(P>0.05).The feed intake in experimental group Ⅳ was also markedly higher than those in experimental groups Ⅰ and Ⅱ(P<0.05).Compared with the experimental group Ⅱ, the gross profit of experimental group Ⅳ was significantly promoted(P<0.05).The alanine aminotransferase and aspartate aminotransferase activities in experimental group Ⅱ were markedly higher than those in experimental groups Ⅰ, Ⅲ and Ⅳ.[Conclusion]When the dietary concentrate to forage ratios was 50∶50, the production performance of post-fattening Hainan Yellow Cattle was better.展开更多
文摘BACKGROUND Non-ST segment elevation myocardial infarction(NSTEMI)poses significant challenges in clinical management due to its diverse outcomes.Understanding the prognostic role of hematological parameters and derived ratios in NSTEMI patients could aid in risk stratification and improve patient care.AIM To evaluate the predictive value of hemogram-derived ratios for major adverse cardiovascular events(MACE)in NSTEMI patients,potentially improving clinical outcomes.METHODS A prospective,observational cohort study was conducted in 2021 at the Internal Medicine Clinic of the University Hospital in Tuzla,Bosnia and Herzegovina.The study included 170 patients with NSTEMI,who were divided into a group with MACE and a control group without MACE.Furthermore,the MACE group was subdivided into lethal and non-lethal groups for prognostic analysis.Alongside hematological parameters,an additional 13 hematological-derived ratios(HDRs)were monitored,and their prognostic role was investigated.RESULTS Hematological parameters did not significantly differ between non-ST segment elevation myocardial infarction(NSTEMI)patients with MACE and a control group at T1 and T2.However,significant disparities emerged in HDRs among NSTEMI patients with lethal and non-lethal outcomes post-MACE.Notably,neutrophil-to-lymphocyte ratio(NLR)and platelet-to-lymphocyte ratio(PLR)were elevated in lethal outcomes.Furthermore,C-reactive protein-to-lymphocyte ratio(CRP/Ly)at T1(>4.737)demonstrated predictive value[odds ratio(OR):3.690,P=0.024].Both NLR at T1(>4.076)and T2(>4.667)emerged as significant predictors,with NLR at T2 exhibiting the highest diagnostic performance,as indicated by an area under the curve of 0.811(95%CI:0.727-0.859)and OR of 4.915(95%CI:1.917-12.602,P=0.001),emphasizing its important role as a prognostic marker.CONCLUSION This study highlights the significant prognostic value of hemogram-derived indexes in predicting MACE among NSTEMI patients.During follow-up,NLR,PLR,and CRP/Ly offer important insights into the inflammatory processes underlying cardiovascular events.
文摘Publisher Correction to:Journal of Forestry Research(2025)36:29 https://doi.org/10.1007/s11676-025-01823-0 In Fig.4c of this article,the lower part of the figure was unintentionally cropped and incomplete during the publisher's production process.The published incorrect version and the corrected version of Fig.4 are given below.
文摘This study aimed to optimize the application rates and base-topdressing ratios of nitrogen and potassium for flue-cured tobacco in Chaling,Zhuzhou,Hunan.The tobacco variety‘Yunyan 87’was planted and subjected to eight different treatments with different application rates and base-topdressing ratios of nitrogen and potassium.The effect of different treatments on the agronomic traits,dry matter accumulation,yield,and quality of tobacco were compared.The results showed that the growth period of each treatment became shortened as the application rates of nitrogen and potassium decreased and as the base-topdressing ratios of nitrogen and potassium increased.The dry matter accumulation decreased with the reduction in the application rates of nitrogen and potassium.The yield and output value of T1 were the highest,reaching 2097.39 kg/hm^(2)and 65018.90 yuan/hm^(2),respectively,both significantly increasing by 57.5%compared with those of the control(CK).In addition,the proportions of leaves of high and mid-high grade in T1 were also the highest,reaching 73.31%and 88.79%,respectively,both higher than those of CK.The appearance evaluation results showed that the appearance quality scores of tobacco leaves of grades B2F and C3F in T1 were the highest,reaching 51 points,both of which were 3 points higher than that those of CK.All the treatments were consistent in terms of color,maturity,leaf structure,body,oil,and color intensity.Therefore,it was suggested that the tobacco production in Chaling should appropriately increase the proportions of nitrogen and potassium as base fertilizers on the basis of conventional fertilization,which was conducive to improving the yield and appearance quality of flue-cured tobacco.
文摘BACKGROUND Patients with type 2 diabetes mellitus(T2DM)face a heightened risk of future cardiovascular events.It is therefore important to stratify these patients according to their future cardiovascular event risk to allow early intervention and improve prognosis.Recent proposals have indicated that nontraditional lipoprotein ratios may be superior predictors of cardiovascular events compared to traditional lipid parameters.However,further evidence is required for widespread clinical ap-plication.AIM To elucidate the associations of nontraditional lipoprotein ratios with future cardiovascular events in patients with T2DM.METHODS This study performed post-hoc analysis of data obtained during a clinical trial involving 10182 participants.To ascertain the correlations between nontraditional lipoprotein ratios and future cardiovascular events,including major adverse cardiovascular events(MACEs)and congestive heart failure(CHF).We employed univariable and multivariable-adjusted Cox proportional hazards regression models.Potential dose-response relationships and threshold values were explored by conducting restricted cubic spline analyses and two-piecewise linear regression models.Possible relevant interactions influencing independent relationships were tested using subgroup and interaction analyses.RESULTS After adjustment for confounding factors,all nontraditional lipoprotein ratios studied were strongly associated with MACE risk in patients with T2DM.In comparison with patients in the lowest quartile,the hazard ratios(95%confidence intervals)of those in the highest quartile were 1.50(1.29-1.73),1.51(1.30-1.74),1.50(1.29-1.73),and 1.30(1.12-1.50)for total cholesterol/high-density lipoprotein cholesterol(HDL-C),low-density lipoprotein cholesterol/HDL-C,non-HDL-C/HDL-C,and remnant cholesterol/HDL-C,respectively.Similar findings were noted for CHF.Dose-response relationships between nontraditional lipoprotein ratios and MACE were observed,with threshold values of 7.29,6.29,and 2.15 for total cholesterol/HDL-C,non-HDL-C/HDL-C,and remnant cholesterol/HDL-C,respectively.However,no notable dose-response relationships were detected between nontraditional lipoprotein ratios and CHF.CONCLUSION Elevated nontraditional lipoprotein ratios may independently predict the risk of MACE and CHF in patients with T2DM.
基金Project(24A0006)supported by the Key Project of Scientific Research Fund of Hunan Provincial Department of Education,ChinaProject(2024JJ5430)supported by the Natural Science Foundation of Hunan Province,ChinaProjects(2024JK2045,2023RC3061)supported by the Science and Technology Innovation Program of Hunan Province,China。
文摘A high-speed train travelling from the open air into a narrow tunnel will cause the“sonic boom”at tunnel exit.When the maglev train’s speed reaches 600 km/h,the train-tunnel aerodynamic effect is intensified,so a new mitigation method is urgently expected to be explored.This study proposed a novel asymptotic linear method(ALM)for micro pressure wave(MPW)mitigation to achieve a constant gradient of initial c ompression waves(ICWs),via a study with various open ratios on hoods.The properties of ICWs and MPWs under various open ratios of hoods were analyzed.The results show that as the open ratio increases,the MPW amplitude at the tunnel exit initially decreases before rising.At the open ratio of 2.28%,the slope of the ICW curve is linearly coincident with a supposed straight line in the ALM,which further reduces the MPW amplitude by 26.9%at 20 m and 20.0%at 50 m from the exit,as compared to the unvented hood.Therefore,the proposed method effectively mitigates MPW and quickly determines the upper limit of alleviation for the MPW amplitude at a fixed train-tunnel operation condition.All achievements provide a ne w potential measure for the adaptive design of tunnel hoods.
文摘BACKGROUND An efficient index holds the potential to predict rectal cancer prognosis.AIM To investigate the impact of neutrophil-to-lymphocyte ratio(NLR),platelet-tolymphocyte ratio(PLR),and monocyte-to-lymphocyte ratio(MLR)on rectal cancer prognosis.METHODS This retrospective study involved 180 patients with rectal cancer from the Changzhi People’s Hospital of Shanxi Province.A 2-mL blood sample was collected at 24 h preoperatively and 72 h postoperatively to measure neutrophils,lymphocytes,platelets,and monocytes using an automatic blood analyzer.Preoperative and postoperative NLR,PLR,and MLR were compared.Patients were followed up for 12 months and categorized into good and poor prognosis groups.A receiver operating characteristic curve was constructed to analyze their predictive values.RESULTS The NLR,PLR,and MLR values were significantly lower post-surgery(P<0.05).A total of 152 and 28 patients were categorized in the good and poor prognosis groups,respectively.Patients with poor prognoses exhibited slightly higher postoperative NLR,PLR,and MLR values than those with good prognoses(P<0.05).Receiver operating characteristic analysis showed that the area under the curve for NLR,PLR,and MLR was 0.828 with a sensitivity and specificity of 89.29%and 90.79%,respectively.These values were higher than individual NLR(area under the curve:0.660,sensitivity:67.86%,specificity:54.61%),PLR(0.668,75.00%,55.30%),and MLR(0.635,60.71%,48.03%),all showing statistically significant differences(P<0.05),effectively predicting patient outcomes.CONCLUSION The findings of this study indicated that NLR,PLR,and MLR values of patients with rectal cancer can be used to effectively predict the outcome of patients.
文摘Driver distraction is a leading cause of traffic accidents,with fatigue being a significant contributor.This paper introduces a novel method for detecting driver distraction by analyzing facial features using machine deep learning and 68 face model.The proposed system assesses driver tiredness by measuring the distance between key facial landmarks,such as the distance between the eyes and the angle of the mouth,to evaluate signs of drowsiness or disengagement.Real-time video feed analysis allows for continuous monitoring of the driver’s face,enabling the system to detect behavioral cues associated with distraction,such as eye closures or changes in facial expressions.The effectiveness of this method is demonstrated through a series of experiments on a dataset of driver videos,which proves that the approach can accurately assess tiredness and distraction levels under various driving conditions.By focusing on facial landmarks,the system is computationally efficient and capable of operating in real-time,making it a practical solution for in-vehicle safety systems.This paper discusses the system’s performance,limitations,and potential for future enhancements,including integration with other in-vehicle technologies to provide comprehensive driver monitoring.
文摘Much of the research has focused on identifying bridge frequencies for health monitoring,while the bridge damping ratio also serves as an important factor in damage detection.This study presents an enhanced method for identifying bridge damping ratios using a two-axle,three-mass test vehicle,relying on wheel responses captured by only two mounted sensors.Damping ratio estimation formulas are derived using both the Hilbert Transform(HT)and Wavelet Transform(WT),with a consistent formulation that confirms accurate estimation is achievable with minimal instrumentation,particularly when addressing the support effect.A comparative analysis of the two signal processing techniques reveals the superior performance of WT in identifying bridge damping ratios.The effectiveness of the proposed procedure and formulas is validated through a detailed parametric study,demonstrating robustness across bridges with varying modal damping ratios and different spans using minimal sensors.Moreover,the present study shows that responses from only the first two spans of a multi-span bridge are sufficient for reliable damping estimation,underscoring the practicality and scalability of the procedure for structural health monitoring applications.
基金Project(52374153)supported by the National Natural Science Foundation of ChinaProject(kq2502150)supported by the Natural Science Foundation of Changsha,China。
文摘Cemented tailings backfill(CTB)is a crucial support material for ensuring the long-term stability of underground goafs.A comprehensive understanding of its compressive mechanical behavior is essential for improving engineering safety.Although extensive studies have been conducted on the uniaxial compressive properties of CTB,damage constitutive models that effectively capture its damage evolution process remain underdeveloped,and its failure mechanisms are not yet fully clarified.To address these gaps,this study conducted systematic uniaxial compression tests on CTB specimens prepared with varying cement-tailings ratios.The results revealed distinct compaction and softening phases in the stress−strain curves.A lower cement-tailings ratio significantly reduced the strength and deformation resistance of CTB,along with a decrease in elastic energy accumulation at peak stress and dissipation energy in the post peak stage.Based on these findings,a modified damage constitutive model was developed by introducing a correction factor,enabling accurate simulation of the entire uniaxial compression process of CTB with different cement-tailings ratios.Comparative analysis with classical constitutive models validated the proposed model’s accuracy and applicability in describing the compressive behavior of CTB.Furthermore,particle size distribution and acoustic emission tests were employed to investigate the influence of cement-tailings ratio on failure mechanisms.The results indicated that a lower cement-tailings ratio leads to coarser particle sizes,which intensify shear-related acoustic emission signals and ultimately result in more pronounced macroscopic shear failure.This study provides theoretical support and practical guidance for the optimal design of CTB mix ratios.
文摘Flow characteristics around a wall-mounted square cylinder have been numerically simulated at aspect ratios (AR) ranging from 4 to 7 at Re =10 000. Four turbulence models have been compared in terms of drag coefficient (C_D). The closest result has been provided by two turbulence models, namely, k-ε Realizable and k ?ω Shear Stress Transport (SST). Hence, these models were utilized to present the flow patterns of pressure distributions, turbulent kinetic energy values, velocity magnitude values with streamlines, streamwise velocity components, crossstream velocity components and spanwise velocity components on different planes. Flow stagnation has been attained in front of the cylinder. Pressure values peaked for the upstream region. Over the cylinders, the tip vortex structure was dominant owing to the influence of the free end. Flow separation from the top front edge of the body has been obtained. The dividing streamline affected by the flow separation was highly effective in the wake region and moved nearer to the body when the aspect ratio was decreased;the reason was the wake shrinkage owing to the decreasing aspect ratio. Upwash and downwash have been seen in the cylinder wake. These two models presented similar flow patterns and drag coefficients. These drag coefficients are in good agreement with those in previous studies.
基金supported by the National Natural Science Foundation of China(NSFC)under Grant Nos.52288102,52322101,92163215,52174364,52101143,U23A20542the Fundamental Research Funds for the Central Universities under Grant No.30922010202+1 种基金the 100 Talents Plan of Hebei Province under Grant No.E2020100005the Natural Science Foundation of Hebei Province under Grant No.E2022203109.
文摘Polysynthetic twinned(PST)TiAl single crystal specifically refers to a fully lamellar TiAl single crystal with parallel phase interfaces and twin interfaces grown by directional solidification.In this paper,PST single crystals with different phase ratios are obtained by annealing at specific temperatures and holding times.The results show that the diffusion rates of Ti and Al elements at various temperatures directly trigger and propel the surface recrystallization and variation in the internal phase ratio.When the temperature is lower than 1448 K,the diffusion rate of Ti is obviously higher than that of Al,which causes one denseα_(2)recrystallized layer to form on the surface of TiAl single crystals.Meanwhile,as more Ti elements migrate to the surface,theα_(2)phase ratio inside the TiAl single crystal thereby decreases.When the temperature exceeds 1448 K,the diffusion rate of Al gradually reverses to exceed that of Ti,which forms the surface sandwiched recrystallization dominated byγphase and simultaneously increasesα_(2)phase ratio inside the TiAl single crystal.The variation in the two-phase ratio directly induces a significant change in the lamellae thickness,which exhibits different tensile behaviors of PST-TiAl single crystal.When theα_(2)phase content is less than 20%,widerγlamellae make it easier for dislocations to be activated within its lamellae and continuously move across theγ/α_(2)interfaces,thereby obtaining better tensile plasticity.As theα_(2)phase content exceeds 30%,finerγlamellae inhibit the dislocation initiation,resulting in the fracture occurrence of TiAl single crystal before yielding.No matter how the phase ratio changes,the crack preferentially initiates withinα_(2)lamellae.However,the crack propagation follows different paths based on variousγlamella thicknesses.The fracture mode of PST-TiAl single crystal also changes from shear fracture along slip bands within theγlamella to brittle fracture along the{1¯100}planes withinα_(2)lamella.
基金supported by the National Natural Science Foundation of China(Nos.52270106 and 22266021)Yunnan Major Scientific and Technological Projects(No.202202AG050005)Yunnan Fundamental Research Projects(No.202201AT070116).
文摘This study employed a wet impregnation method to synthesize five types of Cu/HZSM-5 adsorbents with Si/Al ratios of 25,50,85,200,and 300,used for the removal of H_(2)S in lowtemperature,low-oxygen environments.The impact of different Si/Al ratios on the adsorption oxidative performance of Cu_(30)/HZSM-5–85 adsorbents was investigated.According to the performance test results,Cu_(30)/HZSM-5–85 exhibited the highest breakthrough capacity,reaching 231.75 mg H_(2)S/g_(sorbent).Cu/HZSM-5 sorbent maintains a strong ability to remove H_(2)S even under humid conditions and shows excellent water resistance.XRD,BET,and XPS results revealed that CuO is the primary active species,with Cu_(30)/HZSM-5–85 having the largest surface area and highest CuO content,providing more active sites for H_(2)S adsorption.H_(2)-TPR and O_(2)-TPD results confirmed that Cu_(30)/HZSM-5–85 sorbent exhibits outstanding redox properties and oxygen storage capacity,contributing to excellent oxygen transferability in the molecular sieve adsorption-oxidation process.With notable characteristics such as a large surface area,high desulfurization efficiency,and water resistance,Cu_(30)/HZSM-5–85 sorbents hold significant importance for industrial applications.
文摘Background:Diabetes mellitus(DM)is a prevalent chronic metabolic condition characterized by high blood sugar levels,resulting from insufficient insulin production or ineffective insulin use,posing substantial global health issues.Research on the relationship between glycemic status and the ratio of neutrophils to lymphocytes(NLR)and monocytes to lymphocytes(MLR)is limited.This study aimed to fill these knowledge gaps by examining the connection between DM and inflammatory markers within the Asir region.Methods:Data from 3545 participants were retrospectively analyzed.The dataset,gathered between 2021 and 2023,comprises 38 laboratory tests obtained from the Future Lab Pioneer database.The study's inclusion criteria focused on diabetes profile tests(glycated hemoglobin[HbA1c]and fasting blood glucose[FBG])and manually computed inflammatory markers(NLR and MLR),which were stratified by age and sex.Results:This study demonstrated significant differences in NLR levels compared with FBG levels across all adult age groups and adult female participants(p<0.0001),as well as among all elderly age groups(p=0.0006)and elderly women(p=0.01).MLR levels were significant in all adult age groups(p=0.04)and in adult women(p=0.02).When NLR and MLR were compared to HbA1c levels,a significant difference in the mean NLR was found in adult women(p=0.005).Additionally,the mean MLR levels were significant in all adult age groups(p=0.04)and adult women(p=0.02).Conclusion:Although a larger sample size is necessary for this research,the results indicate that NLR and MLR could serve as valuable indicators for evaluating inflammation in people with disrupted glucose metabolism,particularly in adult and female populations.
基金Project supported by the National Key Technologies R&D Program of China during the 11th Five-Year Plan Period (No. 2006BAK02A18)the Innovation Team of the Safety Standards and Testing Technology for Agricultural Products of Zhejiang Province,China(No. 2010R50028)
文摘The objective of this study was to investigate the geographical origin of Chinese teas using carbon and nitrogen stable isotope ratio technology.The results showed that inter-provincial dispersion of teas in Guangdong(GD),Guangxi(GX),Hainan(HA),Fujian(FJ),Shandong(SD),Sichuan(SC),Chongqing(CQ),and Henan(HN) provinces was high,while in Zhejiang(ZJ),Hubei(HB),Yunnan(YN),and Anhui(AH) provinces,it was low.Tea samples from GD,GX,HA,and FJ provinces were clustered in one group and separated from those from AH and HB provinces.Thus,carbon and nitrogen stable isotope ratio technology could discriminate teas from among some provinces of China,but not from among others.Better separation might be obtained with a combination of isotopic ratios and other indexes,such as elemental data and organic components.
基金National Natural Science Foundations of China(Nos.51278299)Natural Science Foundation of the Jiangsu Province,China(No.BK 20150775)
文摘A theoretical model with extensible yarns for plain-woven fabrics is developed to determine the calculation of Poisson ratios.The stress ratio( warp: weft),as one of parameters corresponding to Poisson ratio variations, is introduced to complement the theoretical model. To evaluate the reliability of the theoretical analysis,a series of biaxial tensile tests of a plain-woven fabric with nine stress ratios are conducted carefully,and the theoretical results are compared with the experimentally measured values. The effects of other influencing factors, including geometric and mechanical parameters of yarns,on Poisson ratios are analyzed thoroughly.This solution method could be applied without difficulty to estimations of Poisson ratios and realistic designs for plain-woven fabrics.
基金financially supported by the project of National Natural Science Foundation of China (Grant No. 41073097)the project of Natural Science Foundation of Chongqing, China (Grant NO. cstc2013jcyja20001)
文摘1 Introduction Lake Qinghai,famous as the largest inland saline lake in China,located on the high-altitude northeastern Tibetan Plateau,and four junctional zones of the East Asian summer monsoon(EASM),Indian summer monsoon(ISM),East Asian winter monsoon and the westerly jet stream prevail,making it sensitive to global climate change
基金supported by National Natural Science Foundation of China(Nos.20576117 and 20806067)China Postdoctoral Science Foundation(No.20070420230).
文摘Miniemulsion copolymerization of butyl mathacrylate （BMA） with fluoroacrylate （HFMA, TFMA） was carried out at 70 ℃ by employing potassium persulphate （KPS） as initiator. Copolymer compositions at low conversion levels were determined by ^1H NMR spectra techniques. The reactivity ratios were evaluated by employing Kellen-Tudos （K-T） methods, which yields the apparent reactivity ratios, rBMA = 0.74, rHFMA = 0.87 and rBMA = 0.73, rTFMA = 0.75, respectively, and Q- and e-values of HFMA and TFMA were calculated by the Alfrey-Price method. The results show that HFMA and TFMA are more active than BMA, and the cross-propagation rate constant is greater than the self-propagation one in these two copolymerizations.
基金financially supported by the National Natural Science Foundation of China(Nos.41702245,41807186)the National Natural Science Foundation of Hubei Province(No.2017CFC862)the Fundamental Research Funds for the Central Universities,South-Central Minzu University(No.CZQ21013)。
文摘Environment isotopes(δ18O andδ2H)and Cl/Br ratios in surface water and groundwater are combined to investigate arsenic mobilization in aquifer system of the Jianghan Plain.The groundwater has relatively high arsenic concentrations,ranging from 3.6 to 1055.3μg/L with an average of 102.2μg/L,which exceeds China’s drinking water standard(10μg/L).The arsenic content of surface water samples is quite low with the range of 6.0–14.3μg/L,averaging 9.5μg/L.δ18O andδ2H values for surface water and groundwater samples plot close to the local meteoric water line(LMWL),reflecting their meteoric origin;a subset of the samples(shallow wells,10 m)shows a shift to LMWL,commensurate with mixing with surface water and evaporation.The correlations betweenδ18O values and Cl concentration and Cl/Br ratios as well as arsenic concentration demonstrated that surface water and groundwater interactions,including active exchange between river/pond water and groundwater and vertical infiltration from agricultural and aquacultural soils,were dominated processes affecting arsenic mobilization in shallow groundwater system and lateral recharge was the main process controlling arsenic behavior in deep groundwater system.The results of this study will be beneficial to understanding the causes of arsenic mobilization in Jianghan groundwaters at different depths.
文摘The optimum pressure ratio distribution of a multistage reciprocating compressor is presented based on the assumption, i.e. the inter stage cooling is perfect and there are no pressure losses. The optimization of the two or three stage pressure ratio is analyzed in two cases of constant heat transfer rate for the inter cooler or constant inter stage inlet temperature, based on the minimum of the sum of theoretical compression power at each stage about a multi stage reciprocating compressor. Furthermore, with an example of two stage compressor the influence on the sum of the power of each stage is analyzed when practical pressure ratio deviates from the optimum value. It is obtained that under different cooling conditions the optimum pressure ratio distribution of the multi stage compression is various, and the change of the optimum pressure ratio within a small range has little influence on the sum of the power each stage. For the two stage compression, this range can be represented as ε 1=(0 96～1 06)ε 1j .
基金Technical Development Project of Hainan Provincial Scientific Research Institutes(KYYS-2018-05)Special Funds for Central Government Guiding the Development of Local Science and Technology(ZY2019HN01).
文摘[Objective]The paper was to investigate the effects of dietary concentrate to forage ratios on production performance and serum bio-chemical indicators of post-fattening Hainan Yellow Cattle.[Method]Sixteen Hainan Yellow Cattles with the same genetic backgrounds and similar initial weight of(242.22 ±0.71 kg) were randomly divided into four treatments.Cattles were fed with diets of different concentrate to forage ratios(20:80, group Ⅰ;30:70, Group Ⅱ;40:60, group Ⅲ;50:50, group Ⅳ).The trial lasted 62 d.[Result]The daily gain in experimental group Ⅳ was significantly higher than that in experimental group Ⅱ(P<0.05), but the feed gain ratio in experimental group Ⅳ was lower than those in other ex-perimental groups(P>0.05).The feed intake in experimental group Ⅳ was also markedly higher than those in experimental groups Ⅰ and Ⅱ(P<0.05).Compared with the experimental group Ⅱ, the gross profit of experimental group Ⅳ was significantly promoted(P<0.05).The alanine aminotransferase and aspartate aminotransferase activities in experimental group Ⅱ were markedly higher than those in experimental groups Ⅰ, Ⅲ and Ⅳ.[Conclusion]When the dietary concentrate to forage ratios was 50∶50, the production performance of post-fattening Hainan Yellow Cattle was better.
