Valve-controlled hydraulic systems are the most common power-transmission solutions for construction machinery.However,because the centralized hydraulic pump matches the highest load pressure during multi-actuator ope...Valve-controlled hydraulic systems are the most common power-transmission solutions for construction machinery.However,because the centralized hydraulic pump matches the highest load pressure during multi-actuator operation,the light-load actuator must compensate for the load differences by throttling,which significantly reduces energy efficiency.In this study,we propose a load-difference equilibrium system using electrohydraulic energy storage.A hydraulic pump/motor and electric motor/generator module are used to boost the outlet-chamber pressure of the light-load actuator so that the inlet chamber pressures of each actuator can be maintained at the same level.Therefore,the proposed scheme can minimize throttling losses due to load differences and convert excess energy from light-load actuator circuits into electrical energy for storage and reutilization.The proposed scheme can also capture regenerative energy from overrunning loads.A low-pressure loss-control strategy was implemented for real-time control.Several tests were conducted to evaluate the working performance of the proposed and valve-controlled systems under different working conditions.The results show that,compared with the traditional valve-controlled system,the energy consumption and throttling losses of the proposed system can be reduced by 21.5%-37.3%and 79.4%-85.8%,respectively.Moreover,the overall energy-recovery efficiency was approximately 55.8%-64.0%.This study proposes a feasible energy-saving scheme for all types of valve-controlled construction machinery.展开更多
Magnesium hydride(MgH_(2))was highly regarded for its substantial hydrogen storage capacity of up to 7.6 wt%,but its commercial application was hindered by the high operating temperatures and slow kinetics.In this stu...Magnesium hydride(MgH_(2))was highly regarded for its substantial hydrogen storage capacity of up to 7.6 wt%,but its commercial application was hindered by the high operating temperatures and slow kinetics.In this study,the successful synthesis of the layered Ti_(2)NbC_(2) has significantly enhanced the hydrogen storage performance of MgH_(2).MgH_(2)+5 wt%Ti_(2)NbC_(2) began to release hydrogen at 190℃ and started to absorb hydrogen at room temperature.At a constant temperature of 275℃,complete hydrogen release was achieved in just 250 s,up to 6.9 wt%.At 150℃,the absorption of hydrogen reached 6.59 wt%within 200 s,and the hydrogen absorption activation energy was reduced to 41.517±3.981 kJ·mol^(−1),significantly improving the kinetic performance.Moreover,the composite material still exhibited excellent cyclic stability after 20 cycles at 275℃.In the process of hydrogen de/absorption of Ti_(2)NbC_(2) with MgH_(2),active substances Nb-H and Ti-H were generated in situ,which effectively weakened the Mg-H bond and acted as efficient“hydrogen pumps”to accelerate the re/dehydrogenation of MgH_(2).The unique layered structure and hydrogen affinity of Ti_(2)NbC_(2) provided an effective transfer channel for hydrogen migration,which was key to the excellent hydrogen storage performance of the MgH_(2)+Ti_(2)NbC_(2).展开更多
Photocatalytic hydrogen(H2)evolution via water spilling over semiconductors has been considered to be one of the most promising strategies for sustainable energy supply in the future to provide non-pollution and renew...Photocatalytic hydrogen(H2)evolution via water spilling over semiconductors has been considered to be one of the most promising strategies for sustainable energy supply in the future to provide non-pollution and renewable energy.The key to efficient conversion of solar-chemical energy is the design of an efficient structure for high charge separation and transportation.Therefore,cocatalysts are necessary in boosting photocatalytic H2 evolution.To date,semiconductor photocatalysts have been modified by various cocatalysts due to the extended light harvest,enhanced charge carrier separation efficiency and improved stability.This review focuses on recent developments of cocatalysts in photocatalytic H2 evolution,the roles and mechanism of the cocatalysts are discussed in detail.The cocatalysts can be divided into the following categories:metal/alloy cocatalysts,metal phosphides cocatalysts,metal oxide/hydroxide cocatalysts,carbon-based cocatalysts,dual cocatalysts,Z-scheme cocatalysts and MOFs cocatalysts.The future research and forecast for photocatalytic hydrogen generation are also suggested.展开更多
The effect of high-strength ammonia nitrogen acclimation on sludge activity in sequencing batch reactor(SBR)was investigated.Two batch experiments,RUN1 and RUN2,were conducted with the influent ammonia nitrogen concen...The effect of high-strength ammonia nitrogen acclimation on sludge activity in sequencing batch reactor(SBR)was investigated.Two batch experiments,RUN1 and RUN2,were conducted with the influent ammonia nitrogen concentrations 60 and 500 mg/L,respectively.The sludges inoculated from RUN1 and RUN2 were used to treat a series of influent with ammonia nitrogen concentrations of 59,232,368,604 and 1152 mg/L.It is found that the activated sludge acclimated to higher ammonia nitrogen concentrations revealed higher COD and NH 4+-N removal efficiencies,and slower DHA decrease.The results confirmed that the activities of the bacteria in activated sludge in SBR were inhibited by high-strength ammonia nitrogen,whereas the activated sludge acclimated to high-strength ammonia nitrogen showed substantial resistance to inhibition by influents containing high levels of ammonia nitrogen.展开更多
AIM:To investigate the effectiveness of 5-flurouracilbased neoadjuvant chemotherapy(NAC) for gastroesophageal and gastric cancer by meta-analysis.METHODS:MEDLINE and manual searches were performed to identify all publ...AIM:To investigate the effectiveness of 5-flurouracilbased neoadjuvant chemotherapy(NAC) for gastroesophageal and gastric cancer by meta-analysis.METHODS:MEDLINE and manual searches were performed to identify all published randomized controlled trials(RCTs) investigating the efficacy of the flurouracilbased NAC for gastroesophageal and gastric cancer,and RCTs of NAC for advanced gastroesophageal and gastric cancer vs no therapy before surgery.Studies that included patients with metastases at enrollment were excluded.Primary endpoint was the odds ratio(OR) for improving overall survival rate of patients with gastroesophageal and gastric cancer.Secondary endpoints were the OR of efficiency for down-staging tumor and increasing R0 resection in patients with gas-troesophageal and gastric cancer.Safety analyses were also performed.The OR was the principal measurement of effect,which was calculated as the treatment group(NAC plus surgery) vs control group(surgery alone) and was presented as a point estimate with 95% confidence intervals(CI).All calculations and statistical tests were performed using RevMan 5.1 software.RESULTS:Seven RCTs were included for the analysis.A total of 1249 patients with advanced gastroesophageal and gastric cancer enrolled in the seven trials were divided into treatment group(n = 620) and control group(n = 629).The quality scores of the RCTs were assessed according to the method of Jadad.The RCT quality scores ranged from 2 to 7(5-point scale),with a mean of 3.75.The median follow-up time in these studies was over 3 years.The meta-analysis showed that NAC improved the overall survival rate(OR 1.40,95%CI 1.11-1.76;P = 0.005),which was statistically significant.The 3-year progression-free survival rate was significantly higher in treatment group than in control group(37.7% vs 27.3%)(OR 1.62,95%CI 1.21-2.15;P = 0.001).The tumor down-stage rate was higher in treatment group than in control group(55.76% vs 41.38%)(OR 1.77,95%CI 1.27-2.49;P = 0.0009) and the R0 resection rate of the gastroesophageal and gastric cancer was higher in treatment group than in control group(75.11% vs 68.56%)(OR 1.38,95%CI 1.03-1.85;P = 0.03),with significant differences.No obvious safety concerns about mortality and complications were raised in these trials.There were no statistically significant differences in perioperative mortality(5.08% vs 4.86%)(OR 1.05,95%CI 0.57-1.94;P = 0.87 fixed-effect model) and in the complication rate between the two groups(13.25% vs 9.66%)(OR 1.40,95%CI 0.91-2.14;P = 0.12 fixed-effect model).Trials showed that patients from Western countries favored NAC compared with those from Asian countries(OR 1.40,95%CI 1.07-1.83).Monotherapy was inferior tomultiple chemotherapy(OR 1.40,95%CI 1.07-1.83).Intravenous administration of NAC was more advantageous than oral route(OR 1.41,95%CI 1.09-1.81).CONCLUSION:Flurouracil-based NAC can safely improve overall survival rate of patients with gastroesophageal/gastric cancer.Additionally,NAC can down the tumor stage and improve R0 resection.展开更多
Different components of PtPd bimetallic cocatalysts modified Zn_(0.5)Cd_(0.5)S nanorods have already been designed and prepared in this study.The obtained hybrid photocatalysts were tested and characterized by XPS,ICP...Different components of PtPd bimetallic cocatalysts modified Zn_(0.5)Cd_(0.5)S nanorods have already been designed and prepared in this study.The obtained hybrid photocatalysts were tested and characterized by XPS,ICP-OES and UV-Vis spectra,TEM and EDX tools.Such characterizations can prove the formation of PtPd bimetallic alloy particles in hybrid catalysts.Under visible light illumination,an outstanding hydrogen producing rate of 9.689mmol·g^(-1)·h^(-1) and a high AQY efficiency up to 10.43%at 420 nm are achieved in this work.In addition,thermodynamics(DFT calculations)and kinetics(Photoluminescence emission,photocurrent responses,electrochemical impedance spectroscopy and surface photovoltage spectra)investigations illustrate that PtPd bimetallic alloy has similar catalytic thermodynamic properties to Pt,which can greatly boost the charge separation and speed up the charge transfer,and decrease the activation energy of H2 generation.Notably,the calculation data suggests that Pt is thermodynamically favorable,while PtPd alloy is kinetically beneficial to H_(2)production,which can be ascribed to the higher activity of PtPd/Zn_(0.5)Cd_(0.5)S than Pt/Zn_(0.5)Cd_(0.5)S.This work can propose a fresh perspective for preparing high efficiency hybrid photocatalysts.展开更多
Ceramic spheres,typically with a particle diameter of less than 0.8 mm,are frequently utilized as a critical proppant material in hydraulic fracturing for petroleum and natural gas extraction.Porous ceramic spheres wi...Ceramic spheres,typically with a particle diameter of less than 0.8 mm,are frequently utilized as a critical proppant material in hydraulic fracturing for petroleum and natural gas extraction.Porous ceramic spheres with artificial inherent pores are an important type of lightweight proppant,enabling their transport to distant fracture extremities and enhancing fracture conductivity.However,the focus frequently gravitates towards the low-density advantage,often overlooking the pore geometry impacts on compressive strength by traditional strength evaluation.This paper numerically bypasses such limitations by using a combined finite and discrete element method(FDEM)considering experimental results.The mesh size of the model undergoes validation,followed by the calibration of cohesive element parameters via the single particle compression test.The stimulation elucidates that proppants with a smaller pore size(40μm)manifest crack propagation evolution at a more rapid pace in comparison to their larger-pore counterparts,though the influence of pore diameter on overall strength is subtle.The inception of pores not only alters the trajectory of crack progression but also,with an increase in porosity,leads to a discernible decline in proppant compressive strength.Intriguingly,upon crossing a porosity threshold of 10%,the decrement in strength becomes more gradual.A denser congregation of pores accelerates crack propagation,undermining proppant robustness,suggesting that under analogous conditions,hollow proppants might not match the strength of their porous counterparts.This exploration elucidates the underlying mechanisms of proppant failure from a microstructural perspective,furnishing pivotal insights that may guide future refinements in the architectural design of porous proppant.展开更多
Photocatalytic CO_(2) reduction to multi-carbon(C_(2+))products using solar energy is a promising route to carbon neutrality[1].Among these products,ethanol has attracted significant attention due to its high energy d...Photocatalytic CO_(2) reduction to multi-carbon(C_(2+))products using solar energy is a promising route to carbon neutrality[1].Among these products,ethanol has attracted significant attention due to its high energy density and convenient storage.However,achieving high selectivity for ethanol remains challenging because the reaction involves complex multi-electron transfer processes,and the ethanol pathway shares the same intermediate with the ethylene pathway,while the ethylene pathway has a thermodynamic advantage[2].This phenomenon makes it difficult to precisely control C-C coupling selectivity.展开更多
Manganese-based materials are influenced by the Jahn-Teller effect,causing the spontaneous dismutation of Mn^(3+)(2Mn^(3+)→Mn^(2+)+Mn^(4+))and the dissolution of Mn^(2+),which often results in diminished activity.Thi...Manganese-based materials are influenced by the Jahn-Teller effect,causing the spontaneous dismutation of Mn^(3+)(2Mn^(3+)→Mn^(2+)+Mn^(4+))and the dissolution of Mn^(2+),which often results in diminished activity.This study uniquely employs a W doping strategy to suppress this effect.Externally,a simple template-free method was initially used to prepare cobalt-and manganese-based precursors,followed by a W doping process during the synthesis of transition bimetallic phosphides.Ultimately,W-doped bimetallic phosphides(W-CoMnP)were obtained.The W-CoMnP material demonstrates excellent HER and OER performance with low overpotentials of 95 mV(η_(₁₀)HER)and 225 mV(η_(₅₀)OER),and can achieve overall water splitting at a voltage of 1.52 V while maintaining stable cycling for 24 h.To enable commercial application,W-CoMnP was incorporated into an anion exchange membrane(AEM)electrolysis water device,demonstrating continuous and stable hydrogen production under ambient temperature conditions.This study offers a promising strategy for the future development of catalysts for AEM electrolysis water devices.展开更多
Load-sensing systems use a centralized power source for energy supply and multiway valves for flow distribution and suffer from excessive throttling losses and low energy efficiency.Pump-controlled systems adopt volum...Load-sensing systems use a centralized power source for energy supply and multiway valves for flow distribution and suffer from excessive throttling losses and low energy efficiency.Pump-controlled systems adopt volumetric control methods to eliminate throttling losses.However,pump-controlled multi-actuator systems require excessive installed power.To address these issues,by combining the respective advantages of valve-and pump-controlled technologies,an open-closed circuit integrated pump-valve collaborative drive multi-actuator system consisting of pump-and valve-controlled units is proposed.The pump-controlled units manage the individual actuator motions,whereas the valve-controlled unit enhances the driving power of the pump-controlled units.In addition,to optimize the operation characteristics and energy consumption,a four-quadrant control strategy and an ultralow-pressure loss control strategy were proposed.Several experiments were conducted to evaluate the working performance of the proposed system and the load-sensing system under different working conditions.Experimental results demonstrated that the proposed system exhibited satisfactory velocity control characteristics.Compared with the traditional load-sensing system,the proposed system reduced throttling losses by 90.4−94.4%and energy consumption by 45.9−50.0%.Additionally,only 22.8%of the total energy consumption was attributed to the pump-controlled units,with the remainder provided by the valve-controlled unit.Compared with the traditional pump-controlled multi-actuator system,the proposed system achieved a 29.4%reduction in installed power,thereby lowering the system installed power and costs.This paper presents an electrohydraulic multi-actuator drive method that combines high energy efficiency and high power density and is suitable for electric construction machinery and other heavy equipment with multiple actuators.展开更多
Defect engineering significantly enhances electrocatalytic performance by modulating electronic structures and interfacial coordination,yet the dynamic correlation between defect evolution and catalytic activity durin...Defect engineering significantly enhances electrocatalytic performance by modulating electronic structures and interfacial coordination,yet the dynamic correlation between defect evolution and catalytic activity during reactions remains unclear.Herein,density functional theory(DFT)calculations first reveal the modulation of sulfur vacancy concentrations on Co_(9)S_(8)electronic structures,predicting that optimized vacancy concentrations enable highly efficient electrocatalytic water splitting.Experimentally fabricated Co_(9)S_(8)with appropriate sulfur vacancies exhibits superior bifunctional activity(HER:164 mV@_(η10);OER:297 mV@_(η100)).The MCS-assembled overall water splitting system demonstrates stable operation at 1.57 V(10 mA cm^(−2))for over 60 h.Experimental studies illustrate that sulfur vacancies preferentially adsorb OH^(−)during reactions,inducing the formation of CoOOH active phases.DFT analysis further indicates that OH^(−)adsorption weakens d-p orbital hybridization,optimizing hydrogen/oxygen intermediate adsorption energy barriers and ultimately enhancing catalytic performance.This work establishes novel paradigms for systematic development of catalysts through synergistic analysis of defect dynamics,electronic structures and catalytic performance.展开更多
Silicon carbide offers distinct advantages in the field of power electronic devices.However,manufacturing processes remain a significant barrier to its widespread adoption.Polycrystalline SiC is less expensive and eas...Silicon carbide offers distinct advantages in the field of power electronic devices.However,manufacturing processes remain a significant barrier to its widespread adoption.Polycrystalline SiC is less expensive and easier to produce than single crystal.But stabilizing and controlling its performance are critical challenges that must be addressed urgently.Due to its material properties and excellent performance in applications,3C-SiC is gaining increasing attention in research.This article presents the electrical and material properties of a series of polycrystalline 3C-SiC samples and investigates their interrelationship.The samples were examined using TEM,which confirmed their polycrystalline structure.Combined with XRD and Raman spectroscopy,the grain orientations within the samples were analyzed,and the presence of stress was verified.EBSD was employed to statistically examine the grain structure and size across samples.For samples with similar doping levels,grain size is the most influential factor in determining electrical characteristics.Further EBSD measurements reveal the relationship between resistivity and grain size as log(ρ)=-1.93+8.67/d.These findings provide a foundation for the quantitative control and application of polycrystalline 3C-SiC.This work offers theoretical evidence for optimizing the performance tuning of 3C-SiC ceramics and enhancing their effectiveness in electronic applications.展开更多
Non-coding RNAs (ncRNAs) are a large class of transcripts lacking evident protein coding potential, and play versatile roles in a diverse range of physiological and pathological processes. Mounting evidences have indi...Non-coding RNAs (ncRNAs) are a large class of transcripts lacking evident protein coding potential, and play versatile roles in a diverse range of physiological and pathological processes. Mounting evidences have indicated that ncRNAs are aberrantly expressed in a wealth of diseases such as cataract. Cataract is a cloudy lens caused by radiation, age, drugs and other factors. NcRNAs, including microRNAs, long non-coding RNAs, circular RNAs, have been identified to regulate the occurrence and development of cataract. Current studies indicate that ncRNAs exert the multifaceted functions in the lens of cataract patients and have been proved as potential diagnostic biomarkers or therapeutic targets for cataracts. This review summarizes the study of relationship between the lens and ncRNAs, which can provide a novel insight into the pathogenesis of cataract.展开更多
基金Supported by National Natural Science Foundation of China(Grant No.52075358)。
文摘Valve-controlled hydraulic systems are the most common power-transmission solutions for construction machinery.However,because the centralized hydraulic pump matches the highest load pressure during multi-actuator operation,the light-load actuator must compensate for the load differences by throttling,which significantly reduces energy efficiency.In this study,we propose a load-difference equilibrium system using electrohydraulic energy storage.A hydraulic pump/motor and electric motor/generator module are used to boost the outlet-chamber pressure of the light-load actuator so that the inlet chamber pressures of each actuator can be maintained at the same level.Therefore,the proposed scheme can minimize throttling losses due to load differences and convert excess energy from light-load actuator circuits into electrical energy for storage and reutilization.The proposed scheme can also capture regenerative energy from overrunning loads.A low-pressure loss-control strategy was implemented for real-time control.Several tests were conducted to evaluate the working performance of the proposed and valve-controlled systems under different working conditions.The results show that,compared with the traditional valve-controlled system,the energy consumption and throttling losses of the proposed system can be reduced by 21.5%-37.3%and 79.4%-85.8%,respectively.Moreover,the overall energy-recovery efficiency was approximately 55.8%-64.0%.This study proposes a feasible energy-saving scheme for all types of valve-controlled construction machinery.
基金supported by the National Natural Science Foundation of China(No.52201255)the Natural Science Foundation of Jiangsu Province(No.BK20210884)the Innovation and Entrepreneurship Program of Jiangsu Province(No.JSSCBS20211007).
文摘Magnesium hydride(MgH_(2))was highly regarded for its substantial hydrogen storage capacity of up to 7.6 wt%,but its commercial application was hindered by the high operating temperatures and slow kinetics.In this study,the successful synthesis of the layered Ti_(2)NbC_(2) has significantly enhanced the hydrogen storage performance of MgH_(2).MgH_(2)+5 wt%Ti_(2)NbC_(2) began to release hydrogen at 190℃ and started to absorb hydrogen at room temperature.At a constant temperature of 275℃,complete hydrogen release was achieved in just 250 s,up to 6.9 wt%.At 150℃,the absorption of hydrogen reached 6.59 wt%within 200 s,and the hydrogen absorption activation energy was reduced to 41.517±3.981 kJ·mol^(−1),significantly improving the kinetic performance.Moreover,the composite material still exhibited excellent cyclic stability after 20 cycles at 275℃.In the process of hydrogen de/absorption of Ti_(2)NbC_(2) with MgH_(2),active substances Nb-H and Ti-H were generated in situ,which effectively weakened the Mg-H bond and acted as efficient“hydrogen pumps”to accelerate the re/dehydrogenation of MgH_(2).The unique layered structure and hydrogen affinity of Ti_(2)NbC_(2) provided an effective transfer channel for hydrogen migration,which was key to the excellent hydrogen storage performance of the MgH_(2)+Ti_(2)NbC_(2).
基金financially supported by the National Natural Science Foundation of China(51572295,21273285 and 21003157)Beijing Nova Program(2008B76)Science Foundation of China University of Petroleum,Beijing(KYJJ2012-06-20 and 2462016YXBS05)~~
文摘Photocatalytic hydrogen(H2)evolution via water spilling over semiconductors has been considered to be one of the most promising strategies for sustainable energy supply in the future to provide non-pollution and renewable energy.The key to efficient conversion of solar-chemical energy is the design of an efficient structure for high charge separation and transportation.Therefore,cocatalysts are necessary in boosting photocatalytic H2 evolution.To date,semiconductor photocatalysts have been modified by various cocatalysts due to the extended light harvest,enhanced charge carrier separation efficiency and improved stability.This review focuses on recent developments of cocatalysts in photocatalytic H2 evolution,the roles and mechanism of the cocatalysts are discussed in detail.The cocatalysts can be divided into the following categories:metal/alloy cocatalysts,metal phosphides cocatalysts,metal oxide/hydroxide cocatalysts,carbon-based cocatalysts,dual cocatalysts,Z-scheme cocatalysts and MOFs cocatalysts.The future research and forecast for photocatalytic hydrogen generation are also suggested.
基金supported by the Foundation of the Ministry of Education(No.WTWER0702)
文摘The effect of high-strength ammonia nitrogen acclimation on sludge activity in sequencing batch reactor(SBR)was investigated.Two batch experiments,RUN1 and RUN2,were conducted with the influent ammonia nitrogen concentrations 60 and 500 mg/L,respectively.The sludges inoculated from RUN1 and RUN2 were used to treat a series of influent with ammonia nitrogen concentrations of 59,232,368,604 and 1152 mg/L.It is found that the activated sludge acclimated to higher ammonia nitrogen concentrations revealed higher COD and NH 4+-N removal efficiencies,and slower DHA decrease.The results confirmed that the activities of the bacteria in activated sludge in SBR were inhibited by high-strength ammonia nitrogen,whereas the activated sludge acclimated to high-strength ammonia nitrogen showed substantial resistance to inhibition by influents containing high levels of ammonia nitrogen.
文摘AIM:To investigate the effectiveness of 5-flurouracilbased neoadjuvant chemotherapy(NAC) for gastroesophageal and gastric cancer by meta-analysis.METHODS:MEDLINE and manual searches were performed to identify all published randomized controlled trials(RCTs) investigating the efficacy of the flurouracilbased NAC for gastroesophageal and gastric cancer,and RCTs of NAC for advanced gastroesophageal and gastric cancer vs no therapy before surgery.Studies that included patients with metastases at enrollment were excluded.Primary endpoint was the odds ratio(OR) for improving overall survival rate of patients with gastroesophageal and gastric cancer.Secondary endpoints were the OR of efficiency for down-staging tumor and increasing R0 resection in patients with gas-troesophageal and gastric cancer.Safety analyses were also performed.The OR was the principal measurement of effect,which was calculated as the treatment group(NAC plus surgery) vs control group(surgery alone) and was presented as a point estimate with 95% confidence intervals(CI).All calculations and statistical tests were performed using RevMan 5.1 software.RESULTS:Seven RCTs were included for the analysis.A total of 1249 patients with advanced gastroesophageal and gastric cancer enrolled in the seven trials were divided into treatment group(n = 620) and control group(n = 629).The quality scores of the RCTs were assessed according to the method of Jadad.The RCT quality scores ranged from 2 to 7(5-point scale),with a mean of 3.75.The median follow-up time in these studies was over 3 years.The meta-analysis showed that NAC improved the overall survival rate(OR 1.40,95%CI 1.11-1.76;P = 0.005),which was statistically significant.The 3-year progression-free survival rate was significantly higher in treatment group than in control group(37.7% vs 27.3%)(OR 1.62,95%CI 1.21-2.15;P = 0.001).The tumor down-stage rate was higher in treatment group than in control group(55.76% vs 41.38%)(OR 1.77,95%CI 1.27-2.49;P = 0.0009) and the R0 resection rate of the gastroesophageal and gastric cancer was higher in treatment group than in control group(75.11% vs 68.56%)(OR 1.38,95%CI 1.03-1.85;P = 0.03),with significant differences.No obvious safety concerns about mortality and complications were raised in these trials.There were no statistically significant differences in perioperative mortality(5.08% vs 4.86%)(OR 1.05,95%CI 0.57-1.94;P = 0.87 fixed-effect model) and in the complication rate between the two groups(13.25% vs 9.66%)(OR 1.40,95%CI 0.91-2.14;P = 0.12 fixed-effect model).Trials showed that patients from Western countries favored NAC compared with those from Asian countries(OR 1.40,95%CI 1.07-1.83).Monotherapy was inferior tomultiple chemotherapy(OR 1.40,95%CI 1.07-1.83).Intravenous administration of NAC was more advantageous than oral route(OR 1.41,95%CI 1.09-1.81).CONCLUSION:Flurouracil-based NAC can safely improve overall survival rate of patients with gastroesophageal/gastric cancer.Additionally,NAC can down the tumor stage and improve R0 resection.
文摘Different components of PtPd bimetallic cocatalysts modified Zn_(0.5)Cd_(0.5)S nanorods have already been designed and prepared in this study.The obtained hybrid photocatalysts were tested and characterized by XPS,ICP-OES and UV-Vis spectra,TEM and EDX tools.Such characterizations can prove the formation of PtPd bimetallic alloy particles in hybrid catalysts.Under visible light illumination,an outstanding hydrogen producing rate of 9.689mmol·g^(-1)·h^(-1) and a high AQY efficiency up to 10.43%at 420 nm are achieved in this work.In addition,thermodynamics(DFT calculations)and kinetics(Photoluminescence emission,photocurrent responses,electrochemical impedance spectroscopy and surface photovoltage spectra)investigations illustrate that PtPd bimetallic alloy has similar catalytic thermodynamic properties to Pt,which can greatly boost the charge separation and speed up the charge transfer,and decrease the activation energy of H2 generation.Notably,the calculation data suggests that Pt is thermodynamically favorable,while PtPd alloy is kinetically beneficial to H_(2)production,which can be ascribed to the higher activity of PtPd/Zn_(0.5)Cd_(0.5)S than Pt/Zn_(0.5)Cd_(0.5)S.This work can propose a fresh perspective for preparing high efficiency hybrid photocatalysts.
基金the financial support provided by Tianfu Yongxing Laboratory Organized Research Project Funding(No.2023CXXM01)the ARC linkage program(No.LP200100420).
文摘Ceramic spheres,typically with a particle diameter of less than 0.8 mm,are frequently utilized as a critical proppant material in hydraulic fracturing for petroleum and natural gas extraction.Porous ceramic spheres with artificial inherent pores are an important type of lightweight proppant,enabling their transport to distant fracture extremities and enhancing fracture conductivity.However,the focus frequently gravitates towards the low-density advantage,often overlooking the pore geometry impacts on compressive strength by traditional strength evaluation.This paper numerically bypasses such limitations by using a combined finite and discrete element method(FDEM)considering experimental results.The mesh size of the model undergoes validation,followed by the calibration of cohesive element parameters via the single particle compression test.The stimulation elucidates that proppants with a smaller pore size(40μm)manifest crack propagation evolution at a more rapid pace in comparison to their larger-pore counterparts,though the influence of pore diameter on overall strength is subtle.The inception of pores not only alters the trajectory of crack progression but also,with an increase in porosity,leads to a discernible decline in proppant compressive strength.Intriguingly,upon crossing a porosity threshold of 10%,the decrement in strength becomes more gradual.A denser congregation of pores accelerates crack propagation,undermining proppant robustness,suggesting that under analogous conditions,hollow proppants might not match the strength of their porous counterparts.This exploration elucidates the underlying mechanisms of proppant failure from a microstructural perspective,furnishing pivotal insights that may guide future refinements in the architectural design of porous proppant.
基金supported by National Natural Science Foundation of China(Nos.52473327,51572295 and 21273285)National Key R&D Program of China(Nos.2021YFA1501300,2019YFC1907602).
文摘Photocatalytic CO_(2) reduction to multi-carbon(C_(2+))products using solar energy is a promising route to carbon neutrality[1].Among these products,ethanol has attracted significant attention due to its high energy density and convenient storage.However,achieving high selectivity for ethanol remains challenging because the reaction involves complex multi-electron transfer processes,and the ethanol pathway shares the same intermediate with the ethylene pathway,while the ethylene pathway has a thermodynamic advantage[2].This phenomenon makes it difficult to precisely control C-C coupling selectivity.
文摘Manganese-based materials are influenced by the Jahn-Teller effect,causing the spontaneous dismutation of Mn^(3+)(2Mn^(3+)→Mn^(2+)+Mn^(4+))and the dissolution of Mn^(2+),which often results in diminished activity.This study uniquely employs a W doping strategy to suppress this effect.Externally,a simple template-free method was initially used to prepare cobalt-and manganese-based precursors,followed by a W doping process during the synthesis of transition bimetallic phosphides.Ultimately,W-doped bimetallic phosphides(W-CoMnP)were obtained.The W-CoMnP material demonstrates excellent HER and OER performance with low overpotentials of 95 mV(η_(₁₀)HER)and 225 mV(η_(₅₀)OER),and can achieve overall water splitting at a voltage of 1.52 V while maintaining stable cycling for 24 h.To enable commercial application,W-CoMnP was incorporated into an anion exchange membrane(AEM)electrolysis water device,demonstrating continuous and stable hydrogen production under ambient temperature conditions.This study offers a promising strategy for the future development of catalysts for AEM electrolysis water devices.
基金Supported by National Natural Science Foundation of China(Grant No.52075358).
文摘Load-sensing systems use a centralized power source for energy supply and multiway valves for flow distribution and suffer from excessive throttling losses and low energy efficiency.Pump-controlled systems adopt volumetric control methods to eliminate throttling losses.However,pump-controlled multi-actuator systems require excessive installed power.To address these issues,by combining the respective advantages of valve-and pump-controlled technologies,an open-closed circuit integrated pump-valve collaborative drive multi-actuator system consisting of pump-and valve-controlled units is proposed.The pump-controlled units manage the individual actuator motions,whereas the valve-controlled unit enhances the driving power of the pump-controlled units.In addition,to optimize the operation characteristics and energy consumption,a four-quadrant control strategy and an ultralow-pressure loss control strategy were proposed.Several experiments were conducted to evaluate the working performance of the proposed system and the load-sensing system under different working conditions.Experimental results demonstrated that the proposed system exhibited satisfactory velocity control characteristics.Compared with the traditional load-sensing system,the proposed system reduced throttling losses by 90.4−94.4%and energy consumption by 45.9−50.0%.Additionally,only 22.8%of the total energy consumption was attributed to the pump-controlled units,with the remainder provided by the valve-controlled unit.Compared with the traditional pump-controlled multi-actuator system,the proposed system achieved a 29.4%reduction in installed power,thereby lowering the system installed power and costs.This paper presents an electrohydraulic multi-actuator drive method that combines high energy efficiency and high power density and is suitable for electric construction machinery and other heavy equipment with multiple actuators.
基金financially supported by National Natural Science Foundation of China(No.52473327,51572295,21273285 and 21003157)National Key R&D Program of China(No.2021YFA1501300,2019YFC1907602).
文摘Defect engineering significantly enhances electrocatalytic performance by modulating electronic structures and interfacial coordination,yet the dynamic correlation between defect evolution and catalytic activity during reactions remains unclear.Herein,density functional theory(DFT)calculations first reveal the modulation of sulfur vacancy concentrations on Co_(9)S_(8)electronic structures,predicting that optimized vacancy concentrations enable highly efficient electrocatalytic water splitting.Experimentally fabricated Co_(9)S_(8)with appropriate sulfur vacancies exhibits superior bifunctional activity(HER:164 mV@_(η10);OER:297 mV@_(η100)).The MCS-assembled overall water splitting system demonstrates stable operation at 1.57 V(10 mA cm^(−2))for over 60 h.Experimental studies illustrate that sulfur vacancies preferentially adsorb OH^(−)during reactions,inducing the formation of CoOOH active phases.DFT analysis further indicates that OH^(−)adsorption weakens d-p orbital hybridization,optimizing hydrogen/oxygen intermediate adsorption energy barriers and ultimately enhancing catalytic performance.This work establishes novel paradigms for systematic development of catalysts through synergistic analysis of defect dynamics,electronic structures and catalytic performance.
基金supported in part by the Major Science and Technology Innovation Project of Shandong Province under Grant 2022CXGC010103Taishan Scholars Program of Shandong Province under Grant tstp20231210。
文摘Silicon carbide offers distinct advantages in the field of power electronic devices.However,manufacturing processes remain a significant barrier to its widespread adoption.Polycrystalline SiC is less expensive and easier to produce than single crystal.But stabilizing and controlling its performance are critical challenges that must be addressed urgently.Due to its material properties and excellent performance in applications,3C-SiC is gaining increasing attention in research.This article presents the electrical and material properties of a series of polycrystalline 3C-SiC samples and investigates their interrelationship.The samples were examined using TEM,which confirmed their polycrystalline structure.Combined with XRD and Raman spectroscopy,the grain orientations within the samples were analyzed,and the presence of stress was verified.EBSD was employed to statistically examine the grain structure and size across samples.For samples with similar doping levels,grain size is the most influential factor in determining electrical characteristics.Further EBSD measurements reveal the relationship between resistivity and grain size as log(ρ)=-1.93+8.67/d.These findings provide a foundation for the quantitative control and application of polycrystalline 3C-SiC.This work offers theoretical evidence for optimizing the performance tuning of 3C-SiC ceramics and enhancing their effectiveness in electronic applications.
文摘Non-coding RNAs (ncRNAs) are a large class of transcripts lacking evident protein coding potential, and play versatile roles in a diverse range of physiological and pathological processes. Mounting evidences have indicated that ncRNAs are aberrantly expressed in a wealth of diseases such as cataract. Cataract is a cloudy lens caused by radiation, age, drugs and other factors. NcRNAs, including microRNAs, long non-coding RNAs, circular RNAs, have been identified to regulate the occurrence and development of cataract. Current studies indicate that ncRNAs exert the multifaceted functions in the lens of cataract patients and have been proved as potential diagnostic biomarkers or therapeutic targets for cataracts. This review summarizes the study of relationship between the lens and ncRNAs, which can provide a novel insight into the pathogenesis of cataract.
