Irregular shape workface would result in the presence of coal pillar, which leads to high stress concentration and possibly induces coal bumps. In order to study the coal bump mechanism of pillars, static and dynamic ...Irregular shape workface would result in the presence of coal pillar, which leads to high stress concentration and possibly induces coal bumps. In order to study the coal bump mechanism of pillars, static and dynamic stress overlapping(SDSO) method was proposed to explain the impacts of static stress concentration and tremors induced by mining activities. The stress and deformation in surrounding rock of mining face were analyzed based on the field case study at 1303 workface in Zhaolou Coal Mine in China.The results illustrate that the surrounding rock of a workface could be divided into four different zones,i.e., residual stress zone, stress decrease zone, stress increase zone and original stress zone. The stress increase zone is prone to failure under the SDSO impact loading conditions and will provide elastic energy for inducing coal bump. Based on the numerical modelling results, the evolution of static stress in coal pillar as the size of gob increasing was studied, and the impact of dynamic stress was investigated through analyzing the characteristics of tremor activities. The numerical results demonstrate the peak value of vertical stress in coal pillar rises from about 30 MPa with mining distance 10 m to 52.6 MPa with mining distance 120 m, and the location of peak stress transfers to the inner zone of coal pillars as the workface moves forward. For the daily tremor activities, tremors with high energy released indicate high dynamic stress disturbance on the surrounding rock, therefore, the impact of dynamic stressing is more serious during workface extension period because the tremor frequency and average energy after workface extension are higher than those before the workface extension.展开更多
Coal-water interactions have profound influences on gas extraction from coal and coal utilization.Experimental measurements on three coals using X-ray photoelectron spectroscopy(XPS),low-temperature nitrogen adsorptio...Coal-water interactions have profound influences on gas extraction from coal and coal utilization.Experimental measurements on three coals using X-ray photoelectron spectroscopy(XPS),low-temperature nitrogen adsorption and dynamic water vapor sorption(DVS)were conducted.A mechanism-based isotherm model was proposed to estimate the water vapor uptake at various relative humidities,which is well validated with the DVS data.The validated isotherm model of sorption was further used to derive the isosteric heat of water vapor sorption.The specific surface area of coal pores is not the determining parameter that controls water vapor sorption at least during the primary adsorption stage.Oxidation degree dominates the primary adsorption,and which togethering with the cumulative pore volume determine the secondary adsorption.Higher temperature has limited effects on primary adsorption process.The isosteric heat of water adsorption decreases as water vapor uptake increases,which is found to be close to the latent heat of bulk water condensation at higher relative humidity.The results confirmed that the primary adsorption is controlled by the stronger bonding energy while the interaction energy between water molecules during secondary adsorption stage is relatively weak.However,the thermodynamics of coal-water interactions are complicated since the internal bonding interactions within the coal are disrupted at the same time as new bonding interactions take place within water molecules.Coal has a shrinkage/swelling colloidal structure with moisture loss/gain and it may exhibit collapse behavior with some collapses irreversible as a function of relative humidity,which further plays a significant role in determining moisture retention.展开更多
There is a growing concern in mining community about the contribution of nano-particulates to miner's health.Despite the health influence of respirable dusts and associated lung diseases have been recognized for d...There is a growing concern in mining community about the contribution of nano-particulates to miner's health.Despite the health influence of respirable dusts and associated lung diseases have been recognized for decades in the mining industry,the nano-scale particulates accompanying with complicated physiochemical properties and their enor-mous contribution in quantity have been drawing attentions only in recent a few years because of the advancement of nano-science discipline.In this review,we examine the current regulations of dusts exposure and the dominant mass-based monitoring methods to point out the ignorance of nano-particulates in mining industry.The recognized mining-related nano-particulates sources are summarized to identify the mechanically generated finer particulates including particles and aerosols.In addition,the mechanism of adverse health impact on miner with exposure to nano-scale particulates is discussed in a detail to emphasize their substantial detriment as a potential respiratory hazard.Characterization of the complex physiochemical properties of nano-particulates are then summarized and discussed because these properties could be different from regular respirable dusts due to their dramatically increased surface area and particulate counts.The intent of this review is to demonstrate the potential of adverse health effect of nano-particulate on the mine personals throughout the mining cycle and to identify the research gaps of the mine nano-particulate characterization and quantification.We suggest that further understanding of the mining induced nano-particulate properties and their pathogenesis are critical for the future engineering control measure to mitigate the potential health threat for future miners.展开更多
Upgrading ethanol to n-butanol is an attractive way for renewable n-butanol production. Herein, Cu was selected to modify NiMgAlO catalysts for improving ethanol conversion and n-butanol selectivity. Over the optimize...Upgrading ethanol to n-butanol is an attractive way for renewable n-butanol production. Herein, Cu was selected to modify NiMgAlO catalysts for improving ethanol conversion and n-butanol selectivity. Over the optimized 2%Cu-NiMgAlO catalyst, ethanol conversion and n-butanol selectivity were enhanced to 30.0% and 64.2%, respectively, in 200 h time on stream at 523 K. According to physicochemical characterizations and theoretical calculations, the key role of multiple active sites in this reaction was extensively investigated. The plate-like structure of hydrotalcite was maintained over 2%Cu-NiMgAlO catalysts, with an average Ni particle size of ca. 5.4 nm. The presence of Cu species created CuNi alloy sites and Lewis acid-base pairs, and increased hydrogen transfer and condensation reactions, resulting in elevated ethanol conversion and n-butanol selectivity. Additionally, CuNi alloy had a strong interaction with CuNiMgAl oxides, forming homogeneous boundary due to their close ionic radius and lattice matching, and afforded the long time stability in the ethanol to n-butanol reaction.展开更多
Coal remains one of the principal sources of energy for the world.During the extraction,transport,and processing of coal in underground and surface mining operations,sig-nificant amounts of airborne respirable dusts c...Coal remains one of the principal sources of energy for the world.During the extraction,transport,and processing of coal in underground and surface mining operations,sig-nificant amounts of airborne respirable dusts can be gen-erated and released to the working space.Chronic exposure to coal dusts puts the miners at risk for various lung dis-eases,including coal workers'pneumoconiosis,emphy-sema,silicosis,and chronic bronchitis.Apart from the miners'lung disease,the coal mine dusts also potentially increase the risk of mine explosion which has been rec-ognized as one of the most severe hazards in underground coal mine.展开更多
Catalytic conversion of ethanol to butanol is vital to bridge the gap between huge amounts of ethanol production,the limited blending ratio of ethanol in gasoline,and the outstanding performance of butanol.In this wor...Catalytic conversion of ethanol to butanol is vital to bridge the gap between huge amounts of ethanol production,the limited blending ratio of ethanol in gasoline,and the outstanding performance of butanol.In this work,a highly active binary catalytic system of FeNiOx and LiOH was developed for upgrading of ethanol to butanol.After 24 h reaction at 493 K,the selectivity to butanol reached 71% with>90% high carbon alcohols at 28% ethanol conversion,which was comparable to the performance of some noble metal homogeneous catalysts.展开更多
Hydraulic fracturing is an effective technology for coal reservoir stimulation.After fracturing operation and flowback,a fraction of fracturing fluid will be essentially remained in the formation which ultimately dama...Hydraulic fracturing is an effective technology for coal reservoir stimulation.After fracturing operation and flowback,a fraction of fracturing fluid will be essentially remained in the formation which ultimately damages the flowability of the formation.In this study,we quantified the gel-based fracturing fluid induced damages on gas sorption for Illinois coal in US.We conducted the high-pressure methane and CO_(2)sorption experiments to investigate the sorption damage due to the gel residue.The infrared spectroscopy tests were used to analyze the evolution of the functional group of the coal during fracturing fluid treatment.The results show that there is no significant chemical reaction between the fracturing fluid and coal,and the damage of sorption is attributed to the physical blockage and interactions.As the concentration of fracturing fluid increases,the density of residues on the coal surface increases and the adhesion film becomes progressively denser.The adhesion film on coal can apparently reduce the number of adsorption sites for gas and lead to a decrease of gas sorption capacity.In addition,the gel residue can decrease the interconnectivity of pore structure of coal which can also limit the sorption capacity by isolating the gas from the potential sorption sites.For the low concentration of fracturing fluid,the Langmuir volume was reduced to less than one-half of that of raw coal.After the fracturing fluid invades,the desorption hysteresis of methane and CO_(2)in coal was found to be amplified.The impact on the methane desorption hysteresis is significantly higher than CO_(2)does.The reason for the increasing of hysteresis may be that the adsorption swelling caused by the residue adhered on the pore edge,or the pore blockage caused by the residue invasion under high gas pressure.The results of this study quantitatively confirm the fracturing fluid induced gas sorption damage on coal and provide a baseline assessment for coal fracturing fluid formulation and technology.展开更多
Objectives:To explore and summarize the beneficial effects of a traditional Chinese medicine preparation,Tripterygium glycosides tablets(TGT),in rheumatoid arthritis(RA)animal models of neovascularization,and to provi...Objectives:To explore and summarize the beneficial effects of a traditional Chinese medicine preparation,Tripterygium glycosides tablets(TGT),in rheumatoid arthritis(RA)animal models of neovascularization,and to provide a reference for future clinical applications and research on its pharmacologic mechanism.Methods:We searched the databases PubMed,Embase,Web of Science,Chinese National Knowledge Infrastructure,VIP,Wan Fang and SinoMed(China Biomedical Document Service System)to identify studies of TGT with outcome indicators of angiogenesis-related factors that were published before April2020.Subgroup analysis and meta-regression were performed for dosage and duration of TGT.Statistical tests and subgroup analysis were conducted using RevMan 5.3,and meta-regression and sensitivity analysis were conducted using STATA/SE 15.0.Results:Fourteen studies of TGT in RA rats were included in this analysis.Treatment with TGT significantly reduces synovial microvessel density and the expression of vascular endothelial growth factor(VEGF),VEGF receptor 2,hypoxia inducible factor a,c-Fos,c-Jun,angiopoietin-1 and angiopoietin-2 compared with control groups(P<.05).Subgroup analysis did not show a significant association of the mRNA levels of VEGF in synovium,assessed using quantitative real-time PCR,with duration or dosage of TGT.Meta-regression analysis also indicated that the effects of dosage and duration were not significantly associated with differences in VEGF mRNA levels.Sensitivity analysis on VEGF m RNA levels did not fundamentally change the results.Conclusions:TGT can reduce synovial neovascularization by decreasing synovial microvessel density and expression of VEGF,VEGF receptor 2,hypoxia-inducible factor a,c-Fos,c-Jun,Ang-1 and Ang-2,thereby suppressing pannus formation and bone destruction in rat models of RA.Additional well-designed studies are required to confirm these findings.展开更多
This study investigated the effects of various grazing systems, including continuous grazing, rotational grazing, and no-grazing systems, on the community biomass in the Stipa breviflora Griseb desert grassland during...This study investigated the effects of various grazing systems, including continuous grazing, rotational grazing, and no-grazing systems, on the community biomass in the Stipa breviflora Griseb desert grassland during the grazing seasons in 2005, 2006, and 2007, based on study sites established in 1999. We found that the seasonal dynamics of the aboveground biomass were quite similar among the three treatments, which reached peak values in period from August to September during each study year. The continuous grazing system reduced the aboveground biomass from 2005 to 2007 under drought conditions, and the rotational grazing and no-grazing systems maintained more aboveground biomass than the continuous grazing system did. The belowground biomass declined with the increase of soil depth among the three treatments, and in the surface 20-cm soil layer it accounted for more than 60% of the total biomass. The belowground biomass was found to be highly correlated with soil depth under rotational grazing. The total belowground biomass within the 0--100-cm soil layer for rotational grazing was sig- nificantly higher than for continuous grazing and no-grazing, and had 15,775 kg/ha more biomass. Our results demonstrate that conservative rotational grazing can alleviate grassland deterioration by reserving more aboveground and belowground biomass than the continuous grazing system does.展开更多
Mechanical softening behaviors of shale in CO_(2)-water–rock interaction are critical for shale gas exploitation and CO_(2)sequestration.This work investigated the cross-scale mechanical softening of shale triggered ...Mechanical softening behaviors of shale in CO_(2)-water–rock interaction are critical for shale gas exploitation and CO_(2)sequestration.This work investigated the cross-scale mechanical softening of shale triggered by CO_(2)-water–rock interaction.Initially,the mechanical softening of shale following 30 d of exposure to CO_(2)and water was assessed at the rock-forming mineral scale using nanoindentation.The mechanical alterations of rock-forming minerals,including quartz,muscovite,chlorite,and kaolinite,were analyzed and compared.Subsequently,an accurate grain-based modeling(AGBM)was proposed to upscale the nanoindentation results.Numerical models were generated based on the real microstructure of shale derived from TESCAN integrated minerals analyzer(TIMA)digital images.Mechanical parameters of shale minerals determined by nanoindentation served as input material properties for AGBMs.Finally,numerical simulations of uniaxial compression tests were conducted to investigate the impact of mineral softening on the macroscopic Young’s modulus and uniaxial compressive strength(UCS)of shale.The results present direct evidence of shale mineral softening during CO_(2)-water–rock interaction and explore its influence on the upscale mechanical properties of shale.This paper offers a microscopic perspective for comprehending CO_(2)-water-shale interactions and contributes to the development of a cross-scale mechanical model for shale.展开更多
Currently, industrial production of isocyanates, or diisocyanates in particular, has been exclusively based on phosgene processes. Phosgene is extremely toxic and large amounts of corrosive HC1 are produced as a side ...Currently, industrial production of isocyanates, or diisocyanates in particular, has been exclusively based on phosgene processes. Phosgene is extremely toxic and large amounts of corrosive HC1 are produced as a side product. In the view of environment protection and society safety, development of non-phosgene processes for isocyanates production will be highly desired, and this should be one of the most important missions for green chemistry and catalysis. In this review, efforts for development of non-phosgene method for syntheses of isocyanates, i.e., catalytic syntheses of N-substituted carbamates from nitro- or amino-compounds with CO, dimethyl carbonate （DMC）, urea and even CO2 etc. as carbonyl sources, then thermal cracking of N-substituted carbamates to afford corresponding i socyanates, are summarized, and a brief prospect for non-phosgene syntheses of isocyanates is also addressed.展开更多
Nano CuO/ZSM-5 zeolite was prepared and used as a catalyst for dehydration of 1,4-butanediol(BDO) to tetrahydrofuran(THF) in liquid-phase. It was found that the 4.6 wt% CuO/ZSM-5 displayed good catalytic performance, ...Nano CuO/ZSM-5 zeolite was prepared and used as a catalyst for dehydration of 1,4-butanediol(BDO) to tetrahydrofuran(THF) in liquid-phase. It was found that the 4.6 wt% CuO/ZSM-5 displayed good catalytic performance, and nearly 100%of BDO conversion and more than 99% of THF selectivity could be achieved by a rotary evaporator reactor at 170 °C under the atmospheric pressure. With such mild reaction conditions, 2400 g BDO could be converted to THF over 1 g catalyst under semi-continuous operation. Characterizations with X-ray diffraction(XRD), temperature-programmed reduction(TPR),NH3-temperature programmed desorption(TPD), X-ray photoelectron spectroscopy(XPS), transmission electron microscope(TEM) and Brunauer-Emmett-Teller(BET) over fresh and used 4.6 wt% CuO/ZSM-5 were conducted. Based on the results of the characterization and catalytic performance of 4.6 wt% CuO/ZSM-5, it can be conjectured that the formed 1–3 nm CuO nanoparticles, suitable acidity of the catalyst due to the synergic interaction of CuO and ZSM-5 support promoted the dehydration of BDO to THF.展开更多
The use of antibiotics in animal feeding has been banned in many countries because of increasing concerns about the development of bacterial resistance to antibiotics and potential issues on food safety.Searching for ...The use of antibiotics in animal feeding has been banned in many countries because of increasing concerns about the development of bacterial resistance to antibiotics and potential issues on food safety.Searching for antibiotic substitutes is essential.Applying transgenerational epigenetic technology to animal production could be an alternative.Some environmental changes can be transferred to memorylike responses in the offspring through epigenetic mechanisms without changing the DNA sequence.In this paper,we reviewed those nutrients and non-nutritional additives that have transgenerational epigenetic effects,including some amino acids,vitamins,and polysaccharides.The paternal transgenerational nutritional epigenetic regulation was particularly focused on mechanism of the substantial contribution of male stud animals to the animal industries.We illustrated the effects of paternal transgenerational epigenetics on the metabolism and immunity in farming animals and proposed strategies to modulate male breeding livestock or poultry.展开更多
In the steelmaking industry,enhancing production cost-effectiveness and operational efficiency requires the integration of intelligent systems to support production activities.Thus,effectively integrating various prod...In the steelmaking industry,enhancing production cost-effectiveness and operational efficiency requires the integration of intelligent systems to support production activities.Thus,effectively integrating various production modules is crucial to enable collaborative operations throughout the entire production chain,reducing management costs and complexities.This paper proposes,for the first time,the integration of Vision-Language Model(VLM)and Large Language Model(LLM)technologies in the steel manufacturing domain,creating a novel steelmaking process management system.The system facilitates data collection,analysis,visualization,and intelligent dialogue for the steelmaking process.The VLM module provides textual descriptions for slab defect detection,while LLM technology supports the analysis of production data and intelligent question-answering.The feasibility,superiority,and effectiveness of the system are demonstrated through production data and comparative experiments.The system has significantly lowered costs and enhanced operational understanding,marking a critical step toward intelligent and cost-effective management in the steelmaking domain.展开更多
基金financially supported by National Science and Technology Key Project Fund of China (Nos.2016YFC0801401 and 2016YFC0600708)Fundamental Research Funds for the Central Universities of China (No.2009QM01)Yue Qi Distinguished Scholar Project,China University of Mining & Technology,Beijing,China
文摘Irregular shape workface would result in the presence of coal pillar, which leads to high stress concentration and possibly induces coal bumps. In order to study the coal bump mechanism of pillars, static and dynamic stress overlapping(SDSO) method was proposed to explain the impacts of static stress concentration and tremors induced by mining activities. The stress and deformation in surrounding rock of mining face were analyzed based on the field case study at 1303 workface in Zhaolou Coal Mine in China.The results illustrate that the surrounding rock of a workface could be divided into four different zones,i.e., residual stress zone, stress decrease zone, stress increase zone and original stress zone. The stress increase zone is prone to failure under the SDSO impact loading conditions and will provide elastic energy for inducing coal bump. Based on the numerical modelling results, the evolution of static stress in coal pillar as the size of gob increasing was studied, and the impact of dynamic stress was investigated through analyzing the characteristics of tremor activities. The numerical results demonstrate the peak value of vertical stress in coal pillar rises from about 30 MPa with mining distance 10 m to 52.6 MPa with mining distance 120 m, and the location of peak stress transfers to the inner zone of coal pillars as the workface moves forward. For the daily tremor activities, tremors with high energy released indicate high dynamic stress disturbance on the surrounding rock, therefore, the impact of dynamic stressing is more serious during workface extension period because the tremor frequency and average energy after workface extension are higher than those before the workface extension.
基金This study was sponsored by the Open Fund Project Funded by State Key Laboratory of Coal Mine Disaster Dynamics and Control,Chongqing University(Grant#2011DA105287-FW201903)We also want to thank the China Scholarship Council(CSC)for the financial support(Grant#201806430028).
文摘Coal-water interactions have profound influences on gas extraction from coal and coal utilization.Experimental measurements on three coals using X-ray photoelectron spectroscopy(XPS),low-temperature nitrogen adsorption and dynamic water vapor sorption(DVS)were conducted.A mechanism-based isotherm model was proposed to estimate the water vapor uptake at various relative humidities,which is well validated with the DVS data.The validated isotherm model of sorption was further used to derive the isosteric heat of water vapor sorption.The specific surface area of coal pores is not the determining parameter that controls water vapor sorption at least during the primary adsorption stage.Oxidation degree dominates the primary adsorption,and which togethering with the cumulative pore volume determine the secondary adsorption.Higher temperature has limited effects on primary adsorption process.The isosteric heat of water adsorption decreases as water vapor uptake increases,which is found to be close to the latent heat of bulk water condensation at higher relative humidity.The results confirmed that the primary adsorption is controlled by the stronger bonding energy while the interaction energy between water molecules during secondary adsorption stage is relatively weak.However,the thermodynamics of coal-water interactions are complicated since the internal bonding interactions within the coal are disrupted at the same time as new bonding interactions take place within water molecules.Coal has a shrinkage/swelling colloidal structure with moisture loss/gain and it may exhibit collapse behavior with some collapses irreversible as a function of relative humidity,which further plays a significant role in determining moisture retention.
基金support from NIOSH funding and related resources offered from the Department of Earth and Mineral Engineering at Penn State University for this manuscript.
文摘There is a growing concern in mining community about the contribution of nano-particulates to miner's health.Despite the health influence of respirable dusts and associated lung diseases have been recognized for decades in the mining industry,the nano-scale particulates accompanying with complicated physiochemical properties and their enor-mous contribution in quantity have been drawing attentions only in recent a few years because of the advancement of nano-science discipline.In this review,we examine the current regulations of dusts exposure and the dominant mass-based monitoring methods to point out the ignorance of nano-particulates in mining industry.The recognized mining-related nano-particulates sources are summarized to identify the mechanically generated finer particulates including particles and aerosols.In addition,the mechanism of adverse health impact on miner with exposure to nano-scale particulates is discussed in a detail to emphasize their substantial detriment as a potential respiratory hazard.Characterization of the complex physiochemical properties of nano-particulates are then summarized and discussed because these properties could be different from regular respirable dusts due to their dramatically increased surface area and particulate counts.The intent of this review is to demonstrate the potential of adverse health effect of nano-particulate on the mine personals throughout the mining cycle and to identify the research gaps of the mine nano-particulate characterization and quantification.We suggest that further understanding of the mining induced nano-particulate properties and their pathogenesis are critical for the future engineering control measure to mitigate the potential health threat for future miners.
基金supported by the National Science Foundation of China(21690081,21721004 and 21776268)the“Transformational Technologies for Clean Energy and Demonstration,”Strategic Priority Research Program of the Chinese Academy of Sciences(XDA 21060200)。
文摘Upgrading ethanol to n-butanol is an attractive way for renewable n-butanol production. Herein, Cu was selected to modify NiMgAlO catalysts for improving ethanol conversion and n-butanol selectivity. Over the optimized 2%Cu-NiMgAlO catalyst, ethanol conversion and n-butanol selectivity were enhanced to 30.0% and 64.2%, respectively, in 200 h time on stream at 523 K. According to physicochemical characterizations and theoretical calculations, the key role of multiple active sites in this reaction was extensively investigated. The plate-like structure of hydrotalcite was maintained over 2%Cu-NiMgAlO catalysts, with an average Ni particle size of ca. 5.4 nm. The presence of Cu species created CuNi alloy sites and Lewis acid-base pairs, and increased hydrogen transfer and condensation reactions, resulting in elevated ethanol conversion and n-butanol selectivity. Additionally, CuNi alloy had a strong interaction with CuNiMgAl oxides, forming homogeneous boundary due to their close ionic radius and lattice matching, and afforded the long time stability in the ethanol to n-butanol reaction.
文摘Coal remains one of the principal sources of energy for the world.During the extraction,transport,and processing of coal in underground and surface mining operations,sig-nificant amounts of airborne respirable dusts can be gen-erated and released to the working space.Chronic exposure to coal dusts puts the miners at risk for various lung dis-eases,including coal workers'pneumoconiosis,emphy-sema,silicosis,and chronic bronchitis.Apart from the miners'lung disease,the coal mine dusts also potentially increase the risk of mine explosion which has been rec-ognized as one of the most severe hazards in underground coal mine.
基金supported by the National Natural Science Foundation of China(21690081,21690084,21776268,and 21721004)the Strategic Priority Research Program of Chinese Academy of Sciences(XDA 21060200)~~
文摘Catalytic conversion of ethanol to butanol is vital to bridge the gap between huge amounts of ethanol production,the limited blending ratio of ethanol in gasoline,and the outstanding performance of butanol.In this work,a highly active binary catalytic system of FeNiOx and LiOH was developed for upgrading of ethanol to butanol.After 24 h reaction at 493 K,the selectivity to butanol reached 71% with>90% high carbon alcohols at 28% ethanol conversion,which was comparable to the performance of some noble metal homogeneous catalysts.
基金This study was sponsored by the open fund by Key Laboratory of Mining Disaster Prevention and Control(MDPC201911)the Independent Research Fund of Key Laboratory of Industrial Dust Prevention and Control&Occupational Health and Safety,Ministry of Education Anhui University of Science and Technology(EK20201001).
文摘Hydraulic fracturing is an effective technology for coal reservoir stimulation.After fracturing operation and flowback,a fraction of fracturing fluid will be essentially remained in the formation which ultimately damages the flowability of the formation.In this study,we quantified the gel-based fracturing fluid induced damages on gas sorption for Illinois coal in US.We conducted the high-pressure methane and CO_(2)sorption experiments to investigate the sorption damage due to the gel residue.The infrared spectroscopy tests were used to analyze the evolution of the functional group of the coal during fracturing fluid treatment.The results show that there is no significant chemical reaction between the fracturing fluid and coal,and the damage of sorption is attributed to the physical blockage and interactions.As the concentration of fracturing fluid increases,the density of residues on the coal surface increases and the adhesion film becomes progressively denser.The adhesion film on coal can apparently reduce the number of adsorption sites for gas and lead to a decrease of gas sorption capacity.In addition,the gel residue can decrease the interconnectivity of pore structure of coal which can also limit the sorption capacity by isolating the gas from the potential sorption sites.For the low concentration of fracturing fluid,the Langmuir volume was reduced to less than one-half of that of raw coal.After the fracturing fluid invades,the desorption hysteresis of methane and CO_(2)in coal was found to be amplified.The impact on the methane desorption hysteresis is significantly higher than CO_(2)does.The reason for the increasing of hysteresis may be that the adsorption swelling caused by the residue adhered on the pore edge,or the pore blockage caused by the residue invasion under high gas pressure.The results of this study quantitatively confirm the fracturing fluid induced gas sorption damage on coal and provide a baseline assessment for coal fracturing fluid formulation and technology.
基金the National Natural Science Foundation of China(No.81660836)。
文摘Objectives:To explore and summarize the beneficial effects of a traditional Chinese medicine preparation,Tripterygium glycosides tablets(TGT),in rheumatoid arthritis(RA)animal models of neovascularization,and to provide a reference for future clinical applications and research on its pharmacologic mechanism.Methods:We searched the databases PubMed,Embase,Web of Science,Chinese National Knowledge Infrastructure,VIP,Wan Fang and SinoMed(China Biomedical Document Service System)to identify studies of TGT with outcome indicators of angiogenesis-related factors that were published before April2020.Subgroup analysis and meta-regression were performed for dosage and duration of TGT.Statistical tests and subgroup analysis were conducted using RevMan 5.3,and meta-regression and sensitivity analysis were conducted using STATA/SE 15.0.Results:Fourteen studies of TGT in RA rats were included in this analysis.Treatment with TGT significantly reduces synovial microvessel density and the expression of vascular endothelial growth factor(VEGF),VEGF receptor 2,hypoxia inducible factor a,c-Fos,c-Jun,angiopoietin-1 and angiopoietin-2 compared with control groups(P<.05).Subgroup analysis did not show a significant association of the mRNA levels of VEGF in synovium,assessed using quantitative real-time PCR,with duration or dosage of TGT.Meta-regression analysis also indicated that the effects of dosage and duration were not significantly associated with differences in VEGF mRNA levels.Sensitivity analysis on VEGF m RNA levels did not fundamentally change the results.Conclusions:TGT can reduce synovial neovascularization by decreasing synovial microvessel density and expression of VEGF,VEGF receptor 2,hypoxia-inducible factor a,c-Fos,c-Jun,Ang-1 and Ang-2,thereby suppressing pannus formation and bone destruction in rat models of RA.Additional well-designed studies are required to confirm these findings.
基金funded by basic special funding from the central public welfare scientific research institutes (No.202-21)public sector projects in the Ministry of Agriculture(Nos. 201003019,201003061)scientific and technological innovation and incentive funds of Inner Mongolia autonomous region and major state basic research development program of China (973 Program) (2010CB833502)
文摘This study investigated the effects of various grazing systems, including continuous grazing, rotational grazing, and no-grazing systems, on the community biomass in the Stipa breviflora Griseb desert grassland during the grazing seasons in 2005, 2006, and 2007, based on study sites established in 1999. We found that the seasonal dynamics of the aboveground biomass were quite similar among the three treatments, which reached peak values in period from August to September during each study year. The continuous grazing system reduced the aboveground biomass from 2005 to 2007 under drought conditions, and the rotational grazing and no-grazing systems maintained more aboveground biomass than the continuous grazing system did. The belowground biomass declined with the increase of soil depth among the three treatments, and in the surface 20-cm soil layer it accounted for more than 60% of the total biomass. The belowground biomass was found to be highly correlated with soil depth under rotational grazing. The total belowground biomass within the 0--100-cm soil layer for rotational grazing was sig- nificantly higher than for continuous grazing and no-grazing, and had 15,775 kg/ha more biomass. Our results demonstrate that conservative rotational grazing can alleviate grassland deterioration by reserving more aboveground and belowground biomass than the continuous grazing system does.
基金supported by the China Postdoctoral Science Foundation(Grant Nos.2023TQ0247 and 2023M732715)the Postdoctoral Fellowship Program(Grade B)of China Postdoctoral Science Foundation(Grant No.GZB20230544)the National Natural Science Foundation of China(Grant Nos.U21A20153 and 41841018).
文摘Mechanical softening behaviors of shale in CO_(2)-water–rock interaction are critical for shale gas exploitation and CO_(2)sequestration.This work investigated the cross-scale mechanical softening of shale triggered by CO_(2)-water–rock interaction.Initially,the mechanical softening of shale following 30 d of exposure to CO_(2)and water was assessed at the rock-forming mineral scale using nanoindentation.The mechanical alterations of rock-forming minerals,including quartz,muscovite,chlorite,and kaolinite,were analyzed and compared.Subsequently,an accurate grain-based modeling(AGBM)was proposed to upscale the nanoindentation results.Numerical models were generated based on the real microstructure of shale derived from TESCAN integrated minerals analyzer(TIMA)digital images.Mechanical parameters of shale minerals determined by nanoindentation served as input material properties for AGBMs.Finally,numerical simulations of uniaxial compression tests were conducted to investigate the impact of mineral softening on the macroscopic Young’s modulus and uniaxial compressive strength(UCS)of shale.The results present direct evidence of shale mineral softening during CO_(2)-water–rock interaction and explore its influence on the upscale mechanical properties of shale.This paper offers a microscopic perspective for comprehending CO_(2)-water-shale interactions and contributes to the development of a cross-scale mechanical model for shale.
基金This work was supported by the National Natural Science Foundation of China （No. 21173240）.
文摘Currently, industrial production of isocyanates, or diisocyanates in particular, has been exclusively based on phosgene processes. Phosgene is extremely toxic and large amounts of corrosive HC1 are produced as a side product. In the view of environment protection and society safety, development of non-phosgene processes for isocyanates production will be highly desired, and this should be one of the most important missions for green chemistry and catalysis. In this review, efforts for development of non-phosgene method for syntheses of isocyanates, i.e., catalytic syntheses of N-substituted carbamates from nitro- or amino-compounds with CO, dimethyl carbonate （DMC）, urea and even CO2 etc. as carbonyl sources, then thermal cracking of N-substituted carbamates to afford corresponding i socyanates, are summarized, and a brief prospect for non-phosgene syntheses of isocyanates is also addressed.
基金supported by the National Natural Science Foundation of China(21173240)
文摘Nano CuO/ZSM-5 zeolite was prepared and used as a catalyst for dehydration of 1,4-butanediol(BDO) to tetrahydrofuran(THF) in liquid-phase. It was found that the 4.6 wt% CuO/ZSM-5 displayed good catalytic performance, and nearly 100%of BDO conversion and more than 99% of THF selectivity could be achieved by a rotary evaporator reactor at 170 °C under the atmospheric pressure. With such mild reaction conditions, 2400 g BDO could be converted to THF over 1 g catalyst under semi-continuous operation. Characterizations with X-ray diffraction(XRD), temperature-programmed reduction(TPR),NH3-temperature programmed desorption(TPD), X-ray photoelectron spectroscopy(XPS), transmission electron microscope(TEM) and Brunauer-Emmett-Teller(BET) over fresh and used 4.6 wt% CuO/ZSM-5 were conducted. Based on the results of the characterization and catalytic performance of 4.6 wt% CuO/ZSM-5, it can be conjectured that the formed 1–3 nm CuO nanoparticles, suitable acidity of the catalyst due to the synergic interaction of CuO and ZSM-5 support promoted the dehydration of BDO to THF.
基金National Natural Science Foundation of China(31902184)Shaanxi Provincial Science and Technology Association Young Talents Lifting Program Project(20220203)。
文摘The use of antibiotics in animal feeding has been banned in many countries because of increasing concerns about the development of bacterial resistance to antibiotics and potential issues on food safety.Searching for antibiotic substitutes is essential.Applying transgenerational epigenetic technology to animal production could be an alternative.Some environmental changes can be transferred to memorylike responses in the offspring through epigenetic mechanisms without changing the DNA sequence.In this paper,we reviewed those nutrients and non-nutritional additives that have transgenerational epigenetic effects,including some amino acids,vitamins,and polysaccharides.The paternal transgenerational nutritional epigenetic regulation was particularly focused on mechanism of the substantial contribution of male stud animals to the animal industries.We illustrated the effects of paternal transgenerational epigenetics on the metabolism and immunity in farming animals and proposed strategies to modulate male breeding livestock or poultry.
文摘In the steelmaking industry,enhancing production cost-effectiveness and operational efficiency requires the integration of intelligent systems to support production activities.Thus,effectively integrating various production modules is crucial to enable collaborative operations throughout the entire production chain,reducing management costs and complexities.This paper proposes,for the first time,the integration of Vision-Language Model(VLM)and Large Language Model(LLM)technologies in the steel manufacturing domain,creating a novel steelmaking process management system.The system facilitates data collection,analysis,visualization,and intelligent dialogue for the steelmaking process.The VLM module provides textual descriptions for slab defect detection,while LLM technology supports the analysis of production data and intelligent question-answering.The feasibility,superiority,and effectiveness of the system are demonstrated through production data and comparative experiments.The system has significantly lowered costs and enhanced operational understanding,marking a critical step toward intelligent and cost-effective management in the steelmaking domain.
