Visible light-driven environmentally friendly ZnO semiconductor for durable photocatalytic disinfection and purification of drinking water is very promising.However,the high requirement in ultraviolet absorption and r...Visible light-driven environmentally friendly ZnO semiconductor for durable photocatalytic disinfection and purification of drinking water is very promising.However,the high requirement in ultraviolet absorption and rapid recombination velocity of the photogenerated electron-hole severely hamper the sustainable implementation of ZnO in photocatalysis.Herein,by one"two birds with one stone"strategy,Fe-doping ZnO porous nanosheets(Fe-ZnOPN)composed of ultrafine nanoparticles can be constructed by hydrothermal synthesis of basic zinc carbonate and controlled low-temperature pyrolytic methods.By highly concentrated Fe-doping effect(>7 wt%),the tailoring ZnO nanograin size(~10 nm)and rich oxygen vacancy of catalyst were accessed by ion/vacancy diffusion and nanocrystal rearrangement,superior to the ZnO porous nanosheets(~37 nm).The obtained Fe-ZnOPN were endowed with a larger specific surface area,improved visible light harvesting ability,light response and separation of charge carriers.Such characters allowed the resulting catalyst to afford a 100%bactericidal efficiency against Pseudomonas aeruginosa and Staphylococcus aureus under visible light irradiation(>420 nm).Impressively,the Fe-ZnOPN could show practical disinfection ability in different water resources and multiple reuse ability.The mechanism study revealed that excellent photocatalytic disinfection performance of Fe-ZnOPN correlated with the in situ generated active oxidative substances,destruction of bacterial biofilm and resulting nucleic acids leakage,thereby causing irreversible physical damage.This study provided a new reference for designing environmentally friendly photocatalytic sterilization materials and disinfectants,which can be used in the practical disinfection of drinking water.展开更多
The synergy of metal/oxygen vacancy(O_(v))pairs is critical in catalyzing activation of C-H,C=C,and C-O bonds.However,gaining fundamental understanding on spatial distance of metallic and O_(v)sites on catalyst surfac...The synergy of metal/oxygen vacancy(O_(v))pairs is critical in catalyzing activation of C-H,C=C,and C-O bonds.However,gaining fundamental understanding on spatial distance of metallic and O_(v)sites on catalyst surface would lead to unexpected chemoselectivity toward important and challenging reactions.In this work,we have proposed and validated unique Ni-O-Ce-O_(v)enriched Ni/CeO_(2)catalysts prepared by a deposition-precipitation method,for the transfer hydrogenation of lignin-derived guaiacol toward cyclohexanol rather than benzene derivatives.The counter-intuitively designed high Ni loading Ni_(2)0/CeO_(2)catalyst(20 wt%Ni content)displays a distance of 0.5 nm for Ni/O_(v)pairs with a remarkable activity(TOF:166.5 h^(-1))and 90%+selectivity for C_(Ar)=C_(Ar)bond saturation,outperforming better metal-dispersed Ni_(5)/CeO_(2)catalyst with limited presence of Ni-O-Ce-O_(v)sites.The high hydrogenation activity against hydrogenolysis reactions on Ni_(2)0/CeO_(2)catalyst is attributed to tunable Ni/O_(v)distances,which constrain the cleavage of CAr-OH bond and deep deoxygenation.Such spatial distribution effect has also facilitated tandem dehydrogenation(O-H bond cleavage)and hydrogenation(C_(Ar)=C_(Ar)hydrogenation)reactions,leading to cyclohexanol as the target product in the absence of externally added H_(2).Insights into spatial distribution of O_(v)sites open an alternative perspective in designing efficient catalysts toward producing value-added cyclic oxygenates through upgrading of lignin compounds.展开更多
As energy demand increases,the depth of mining is increasing,and methane disasters grow more serious,efficient extraction of methane is the ultimate method of preventing and controlling methane disasters.The objective...As energy demand increases,the depth of mining is increasing,and methane disasters grow more serious,efficient extraction of methane is the ultimate method of preventing and controlling methane disasters.The objectives for this research are to explore the efficiency of N_(2) injection to enhance gas extraction from coal seams(N_(2)-ECGE)and its impact on coal seam permeability.By developing a fluid-solid coupling model and using COMSOL Multiphysics to perform numerical simulations,the changes in gas pressure,methane content,gas production,output rate and permeability of coal seams were comparatively analyzed under the two methods of direct extraction and N_(2)-ECGE.The research results show that N_(2)-ECGE can significantly improve the coal seam gas pressure and reduce the coal seam CH_(4) content,and the larger the N_(2) injection pressure the more significant the reduction effect.Meanwhile,N_(2)-ECGE can significantly increase the CH_(4) extraction and output rate,and the increase of N_(2) pressure further improves the extraction efficiency.In addition,the pressure of nitrogen injection has a remarkable effect on coal seam permeability,high pressure of nitrogen injection can increase the permeability in the time of no disturbance,but the rate of permeability decreases more quickly after disturbed.The effect of strain due to adsorption desorption on coal seam permeability dominates.Despite model construction limitations,this research offers essential theoretical and practical direction for N_(2) injection to enhance the permeability evolution law of coal seam gas extraction process.展开更多
Karst collapse columns typically appear unpredictably and without a uniform spatial arrangement,posing challenges for mining operations and water inrush risk assessment.As major structural pathways for mine water inru...Karst collapse columns typically appear unpredictably and without a uniform spatial arrangement,posing challenges for mining operations and water inrush risk assessment.As major structural pathways for mine water inrush,they are responsible for some of the most frequent and severe water-related disasters in coal mining.Understanding the mechanisms of water inrush in these collapse columns is therefore essential for effective disaster prevention and control,making it a key research priority.Additionally,investigating the developmental characteristics of collapse columns is crucial for analyzing seepage instability mechanisms.In such a context,this paper provides a comprehensive review of four critical aspects:(1)The development characteristics and hydrogeological properties of collapse columns;(2)Fluid-solid coupling mechanisms under mining-induced stress;(3)Non-Darcy seepage behavior in fractured rock masses;(4)Flow regime transitions and mass variation effects.Key findings highlight the role of flow-solid coupling in governing the seepage mechanisms of fractured rock masses within karst collapse columns.By synthesizing numerous studies on flow pattern transitions,this paper outlines the complete seepage process-from groundwater movement within the aquifer to its migration through the collapse column and eventual inflow into mine roadways or working faces-along with the associated transformations in flow patterns.Furthermore,the seepage characteristics and water inrush behaviors influenced by particle migration are examined through both experimental and numerical simulation approaches.展开更多
Electrochemical nitrate reduction to ammonia(NRA) can realize the green synthesis of ammonia(NH3) at ambient conditions, and also remove nitrate contamination in water. However, the current catalysts for NRA still fac...Electrochemical nitrate reduction to ammonia(NRA) can realize the green synthesis of ammonia(NH3) at ambient conditions, and also remove nitrate contamination in water. However, the current catalysts for NRA still face relatively low NH3yield rate and poor stability. We present here a core-shell heterostructure comprising cobalt oxide anchored on copper oxide nanowire arrays(CuO NWAs@Co_(3)O_(4)) for efficient NRA. The CuO NWAs@Co_(3)O_(4)demonstrates significantly enhanced NRA performance in alkaline media in comparison with plain CuO NWAs and Co_(3)O_(4)flocs. Especially, at-0.23 V vs. RHE, NH_(3) yield rate of the CuO NWAs@Co_(3)O_(4)reaches 1.915 mmol h^(-1)cm^(-2),much higher than those of CuO NWAs(1.472 mmol h^(-1)cm^(-2)), Co_(3)O_(4)flocs(1.222 mmol h^(-1)cm^(-2)) and recent reported Cu-based catalysts.It is proposed that the synergetic effects of the heterostructure combing atom hydrogen adsorption and nitrate reduction lead to the enhanced NRA performance.展开更多
The kagome metals AV_(3)Sb_(5)(A=K,Rb,Cs)under ambient pressure exhibit an unusual charge order,from which superconductivity emerges.In this work,by applying hydrostatic pressure using a liquid pressure medium and car...The kagome metals AV_(3)Sb_(5)(A=K,Rb,Cs)under ambient pressure exhibit an unusual charge order,from which superconductivity emerges.In this work,by applying hydrostatic pressure using a liquid pressure medium and carrying out electrical resistance measurements for RbV_(3)Sb_(5),we find that the charge order becomes suppressed under a modest pressure pc(1.4 GPa<pc<1.6 GPa),while the superconducting transition temperature Tc is maximized.Tc is then gradually weakened with further increase of pressure and reaches a minimum around 14.3 GPa,before exhibiting another{maximum}around 22.8 GPa,signifying the presence of a second superconducting dome.Distinct normal state resistance anomalies are found to be associated with the second superconducting dome,similar to KV_(3)Sb_(5).Our findings point to qualitatively similar temperature-pressure phase diagrams in KV_(3)Sb_(5) and RbV_(3)Sb_(5),{and suggest a close link}between the second superconducting dome and the high-pressure resistance anomalies.展开更多
The chronic use of morphine and other opioids is associated with opioid-induced hypersensitivity(OIH)and analgesic tolerance.Among the different forms of OIH and tolerance,the opioid receptors and cell types mediating...The chronic use of morphine and other opioids is associated with opioid-induced hypersensitivity(OIH)and analgesic tolerance.Among the different forms of OIH and tolerance,the opioid receptors and cell types mediating opioid-induced mechanical allodynia and anti-allodynic tolerance remain unresolved.Here we demonstrated that the loss of peripheralμ-opioid receptors(MORs)or MOR-expressing neurons attenuated thermal tolerance,but did not affect the expression and maintenance of morphine-induced mechanical allodynia and anti-allodynic tolerance.To confirm this result,we made dorsal root ganglia-dorsal roots-sagittal spinal cord slice preparations and recorded low-threshold Aβ-fiber stimulation-evoked inputs and outputs in superficial dorsal horn neurons.Consistent with the behavioral results,peripheral MOR loss did not prevent the opening of Aβmechanical allodynia pathways in the spinal dorsal horn.Therefore,the peripheral MOR signaling pathway may not be an optimal target for preventing mechanical OIH and analgesic tolerance.Future studies should focus more on central mechanisms.展开更多
Oxygen reduction reaction over Pt-based catalyst is one of the most significant cathode reactions in fuel cells.However,low reserves and high price of Pt have motivated researchers worldwide seeking enhanced utilizati...Oxygen reduction reaction over Pt-based catalyst is one of the most significant cathode reactions in fuel cells.However,low reserves and high price of Pt have motivated researchers worldwide seeking enhanced utilization efficiency and durability by doping non-noble metals to form Pt-based alloy catalysts.Alloying Pt with Co has been recognized as one of the most effective approaches to achieve this goal.PtCo bimetal combination is one of the most promising candidates to synthesize highly efficient catalysts for oxygen reduction reaction(ORR)applications,owing to its relatively more suitable oxygen binding energy for four-electron transfer reactions.Recently,impressive strategies have been developed to fabricate more active and stable PtCo-based multimetallic alloys with tailorable size and morphology.This paper aims to summarize the most recent highlights on the study of the relationship between preparation strategies,morphologies,electroactivities of the PtCo-based catalyst at atomic level and further the relevant reaction mechanism.The challenges and opportunities on the further development of electrocatalysts for fuel cells are included to provide reference for the practical application.展开更多
Bionic alumina samples were fabricated on convex dome type aluminum alloy substrate using hard anodizing technique. The convex domes on the bionic sample were fabricated by compression molding under a compressive stre...Bionic alumina samples were fabricated on convex dome type aluminum alloy substrate using hard anodizing technique. The convex domes on the bionic sample were fabricated by compression molding under a compressive stress of 92.5 MPa. The water contact angles of the as-anodized bionic samples were measured using a contact angle meter （JC2000A） with the 3μL water drop at room temperature. The measurement of the wetting property showed that the water contact angle of the unmodi- fied as-anodized bionic alumina samples increases from 90° to 137° with the anodizing time. The increase in water contract angle with anodizing time arises from the gradual formation of hierarchical structure or composite structure. The structure is composed of the micro-scaled alumina columns and pores. The height of columns and the depth of pores depend on the ano- dizing time. The water contact angle increases significantly from 96° to 152° when the samples were modified with self-assembled monolayer of octadecanethiol （ODT）, showing a change in the wettability from hydrophobicity to su- per-hydrophobicity. This improvement in the wetting property chemical modification. is attributed to the decrease in the surface energy caused by the展开更多
AIM: To determine whether the positive status of human epidermal growth receptor 2(HER2) can be regarded as an effective prognostic factor for patients with gastric cancer(GC) undergoing R0 resection.METHODS: A total ...AIM: To determine whether the positive status of human epidermal growth receptor 2(HER2) can be regarded as an effective prognostic factor for patients with gastric cancer(GC) undergoing R0 resection.METHODS: A total of 1562 GC patients treated by R0 resection were recruited. HER2 status was evaluated in surgically resected samples of all the patients using immunohistochemical(IHC) staining. Correlations between HER2 status and clinicopathological characteristics were retrospective analyzed. Hazard ratios(HRs) and 95% confidence intervals(CIs) were estimated using Cox proportional hazard model, stratified by age, gender, tumor location and tumor-nodemetastasis(TNM) stage, with additional adjustment for potential prognostic factors.RESULTS: Among 1562 patients, 548(positive rate = 35.08%, 95%CI: 32.72%-37.45%) were HER2 positive. Positive status of HER2 was significantly correlated with gender(P = 0.004), minority(P < 0.001), tumor location(P = 0.001), pathological grade(P < 0.001), TNM stage(P < 0.001) and adjuvant radiotherapy(74.67% vs 23.53%, P = 0.011). No significant associations were observed between HER2 status and disease free survival(HR = 0.19, 95%CI: 0.96-1.46, P = 0.105) or overall survival(HR = 1.19, 95%CI: 0.96-1.48, P = 0.118) using multivariate analysis, although stratified analyses showed marginally statistically significant associations both in disease free survival and overall survival, especially among patients aged < 60 years or with early TNM stages(Ⅰ and Ⅱ). Categorical age, TNM stage, neural invasion, and adjuvant chemotherapy were, as expected, independent prognostic factors for both disease free survival and overall survival. CONCLUSION: The positive status of HER2 based on IHC staining was not related to the survival in patients with GC among the Chinese population.展开更多
This paper reviews the development of U.S. longwall mining from an unknown to became the world standard in the past five decades with emphasis on automation. Large scale longwall face equipment were imported from Germ...This paper reviews the development of U.S. longwall mining from an unknown to became the world standard in the past five decades with emphasis on automation. Large scale longwall face equipment were imported from Germany and United Kingdom to increase production in the 1970 s and great effort was made to improve them to suit U.S. conditions, rather than domestic market. Automation began with the development of electrohydraulic shields in 1984 and continue to present. Introduction of first generation semi-automated longwall system occurred in 1995 and step-to-step improvement continues to present following the development of sensor technology and internet of things(IOT). Since then, emphasis on new development has been concentrated on the improvement of equipment reliability, miner's health and safety as well as production, including dust control techniques, proximity sensor, anti-collision and remote control. Automation is classified into two categories: automation of individual face equipment and automation of longwall system. The automation development of longwall system is divided into three stages: shearer-initiated-shield-advance(SISA), semi-automated longwall system, and remote control shearer.展开更多
Mine or longwall panel layout is a 3D structure with highly non-uniform stress distribution. Recognition of such fact will facilitate underground problem identification/investigation and solving by numerical modeling ...Mine or longwall panel layout is a 3D structure with highly non-uniform stress distribution. Recognition of such fact will facilitate underground problem identification/investigation and solving by numerical modeling through proper model construction. Due to its versatility, numerical modeling is the most popular method for ground control design and problem solving. However numerical modeling results require highly experienced professionals to interpret its validity/applicability to actual mining operations due to complicated mining and geological conditions. Underground ground control monitoring is routinely performed to predict roof behavior such as weighting and weighting interval without matching observation of face mining condition while the mining pressures are being monitored, resulting in unrealistic interpretation of the obtained data on mining pressure. The importance of ground control pressure monitoring and simultaneous observation of mining and geological conditions is illustrated by an example of shield leg pressure monitoring and interpretation in an U.S. longwall coal mine: it was found that the roof strata act like a plate, not an individual block of the size of a shield dimension, as commonly assumed by all researchers and shield capacity is not a fixed property for a longwall panel or a mine or a coal seam. A new mechanism on the interaction between shield's hydraulic leg pressure and roof strata for shield loading is proposed.展开更多
Background:Both hormonal therapy(HT) and maintenance capecitabine monotherapy(MCT) have been shown to extend time to progression(TTP) in patients with metastatic breast cancer(MBC) after failure of taxanes and anthrac...Background:Both hormonal therapy(HT) and maintenance capecitabine monotherapy(MCT) have been shown to extend time to progression(TTP) in patients with metastatic breast cancer(MBC) after failure of taxanes and anthracycline?containing regimens.However,no clinical trials have directly compared the efficacy of MCT and HT after response to first?line capecitabine?based combination chemotherapy(FCCT) in patients with hormone receptor(HR)?positive and human epidermal growth factor receptor 2(HER2)?negative breast cancer.Methods:We retrospectively analyzed the charts of 138 HR?positive and HER2?negative MBC patients who were in non?progression status after FCCT and who were treated between 2003 and 2012 at the Cancer Institute and Hospital,Chinese Academy of Medical Sciences,in Beijing,China.The median number of first?line chemotherapy cycles was 6(range,4–8);combined agents included taxanes,vinorelbine,or gemcitabine.Of these 138 patients,79 received MCT,and 59 received HT.Single?agent capecitabine was administered at a dose of 1250 mg/m2 twice daily for 14 days,followed by a 7?day rest period,repeated every 3 weeks.Of the 59 patients who received HT,37 received aromatase inhibitors(AIs),8 received selective estrogen receptor modulators(SERMs),and 14 received goserelin plus either AIs or SERMs.We then compared the MCT group and HT group in terms of treatment efficacy.Results:With a median follow?up of 43 months,patients in the HT group had a much longer TTP than patients in the MCT group(13 vs.8 months,P ease?free surviv= 0.011).When TTP was adjusted for age,menopausal status,Karnofsky performance status score,disal,site of metastasis,number of metastatic sites,and response status after FCCT,extended TTP was still observed for patients in the HT group(hazard ratio:0.63;95% confidence interval:0.44–0.93;P = 0.020).We also observed a trend of overall survival advantage for patients in the HT group vs.patients in the MCT group,but the difference was not significant(43 vs.37 months,P tients in the MCT g= 0.400).In addition,patients in the HT group gen?erally tolerated the treatment well,whereas paroup experienced grades 3–4 adverse events,the most frequent of which were hand?foot syndrome(15.8%) and hematologic abnormalities(7.6%).Conclusion:For HR?positive and HER2?negative MBC patients,HT might be considered a treatment after response to FCCT but prior to MCT as a long?term administration.展开更多
The rockburst dynamic disasters in the process of deep coal mining become more and more serious.Taking the rockburst occurred in the 23130 working face of Yuejin Coal Mine as the engineering background,we study the ch...The rockburst dynamic disasters in the process of deep coal mining become more and more serious.Taking the rockburst occurred in the 23130 working face of Yuejin Coal Mine as the engineering background,we study the characteristics of mining stress feld around roadway,the plastic failure morphological characteristics of surrounding rock and the accumulation/release law of elastic energy before and after burst.An analysis model quantitatively describing the physical process of rockburst in the mining roadway is established,and the calculation method of dynamic release of elastic energy in the physical process of rockburst is educed.The mechanism of rockburst in mining roadway is revealed.The results show that an“L-shaped”stress concentration zone is formed within 100 m of the 23130 working face,and the principal stress ratio of the surrounding rock of the transportation roadway is 2.59–4.26.The change of the direction of the maximum principal stress has a signifcant efect on the burst appearance characteristics.The failure strength of diferent sections of the mining roadway is characterized by the elastic energy release value.With the increase of the working face distance,the elastic energy released by burst failure and the expansion variation of failure boundary radius show a nonlinear variation law that tends to decrease steadily after sharp fuctuation.The closer to the working face,the higher the burst risk.At a distance of 10 m from the working surface,the maximum principal stress reaches its maximum value.The butterfy-shaped failure system generated by the surrounding rock of the roadway has energy self-sustainability,and the elastic energy released by the sudden expansion of the butterfy leaf is enough to cause a burst damage of 1.9 magnitude.This work could provide theoretical support for the prediction and prevention of rockburst.展开更多
Hydraulic fracturing and permeability enhancement are effective methods to improve low-permeability coal seams.However,few studies focused on methods to increase permeability,and there are no suitable prediction metho...Hydraulic fracturing and permeability enhancement are effective methods to improve low-permeability coal seams.However,few studies focused on methods to increase permeability,and there are no suitable prediction methods for engineering applications.In this work,PFC2D software was used to simulate coal seam hydraulic fracturing.The results were used in a coupled mathematical model of the interaction between coal seam deformation and gas flow.The results show that the displacement and velocity of particles increase in the direction of minimum principal stress,and the cracks propagate in the direction of maximum principal stress.The gas pressure drop rate and permeability increase rate of the fracture model are higher than that of the non-fracture model.Both parameters decrease rapidly with an increase in the drainage time and approach 0.The longer the hydraulic fracturing time,the more complex the fracture network is,and the faster the gas pressure drops.However,the impact of fracturing on the gas drainage effect declines over time.As the fracturing time increases,the difference between the horizontal and vertical permeability increases.However,this difference decreases as the gas drainage time increases.The higher the initial void pressure,the faster the gas pressure drops,and the greater the permeability increase is.However,the influence of the initial void pressure on the permeability declines over time.The research results provide guidance for predicting the anti-reflection effect of hydraulic fracturing in underground coal mines.展开更多
Neuroendocrine carcinoma of the breast (NECB) accounts for approximately 0.3%-0.5% of all breast cancers [1, 2]. Due to the rarity of NECB, current understanding of this disease in China is limited to case reports and...Neuroendocrine carcinoma of the breast (NECB) accounts for approximately 0.3%-0.5% of all breast cancers [1, 2]. Due to the rarity of NECB, current understanding of this disease in China is limited to case reports and small case series, and large data analysis is still lacking. Therefore, we conducted the most comprehensive literature search to date, aiming to analyze the clinicopathologic characteristics as well as treatment and outcome of NECB in the Chinese population.展开更多
基金financially supported by the National Natural Science Foundation of China(No.21908085)the Natural Science Foundation of Jiangsu Province+7 种基金China(No.BK20190961)the National Natural Science Foundation(No.42207474)the Natural Science Foundation of Jiangsu Province(No.BK20210895)the Science and Technology Project of Suzhou(No.SKJY2021138)the Science and Education Revitalizing Youth Project of Suzhou(No.KJXW2020049)Suzhou Hospital Association Infection Management Special Research(No.SZSYYXH-2023-ZY1)Suzhou Municipal Health Commission Expert Team Introduction Project(No.SZYJTD201904)Jiangsu Provincial Key Laboratory of Environmental Science and Engineering(No.JSHJZDSYS-202103)。
文摘Visible light-driven environmentally friendly ZnO semiconductor for durable photocatalytic disinfection and purification of drinking water is very promising.However,the high requirement in ultraviolet absorption and rapid recombination velocity of the photogenerated electron-hole severely hamper the sustainable implementation of ZnO in photocatalysis.Herein,by one"two birds with one stone"strategy,Fe-doping ZnO porous nanosheets(Fe-ZnOPN)composed of ultrafine nanoparticles can be constructed by hydrothermal synthesis of basic zinc carbonate and controlled low-temperature pyrolytic methods.By highly concentrated Fe-doping effect(>7 wt%),the tailoring ZnO nanograin size(~10 nm)and rich oxygen vacancy of catalyst were accessed by ion/vacancy diffusion and nanocrystal rearrangement,superior to the ZnO porous nanosheets(~37 nm).The obtained Fe-ZnOPN were endowed with a larger specific surface area,improved visible light harvesting ability,light response and separation of charge carriers.Such characters allowed the resulting catalyst to afford a 100%bactericidal efficiency against Pseudomonas aeruginosa and Staphylococcus aureus under visible light irradiation(>420 nm).Impressively,the Fe-ZnOPN could show practical disinfection ability in different water resources and multiple reuse ability.The mechanism study revealed that excellent photocatalytic disinfection performance of Fe-ZnOPN correlated with the in situ generated active oxidative substances,destruction of bacterial biofilm and resulting nucleic acids leakage,thereby causing irreversible physical damage.This study provided a new reference for designing environmentally friendly photocatalytic sterilization materials and disinfectants,which can be used in the practical disinfection of drinking water.
基金supported by the National Natural Science Foundation of China(22078365,22478437)the Natural Science Foundation of Shandong Province(ZR2023MB076)。
文摘The synergy of metal/oxygen vacancy(O_(v))pairs is critical in catalyzing activation of C-H,C=C,and C-O bonds.However,gaining fundamental understanding on spatial distance of metallic and O_(v)sites on catalyst surface would lead to unexpected chemoselectivity toward important and challenging reactions.In this work,we have proposed and validated unique Ni-O-Ce-O_(v)enriched Ni/CeO_(2)catalysts prepared by a deposition-precipitation method,for the transfer hydrogenation of lignin-derived guaiacol toward cyclohexanol rather than benzene derivatives.The counter-intuitively designed high Ni loading Ni_(2)0/CeO_(2)catalyst(20 wt%Ni content)displays a distance of 0.5 nm for Ni/O_(v)pairs with a remarkable activity(TOF:166.5 h^(-1))and 90%+selectivity for C_(Ar)=C_(Ar)bond saturation,outperforming better metal-dispersed Ni_(5)/CeO_(2)catalyst with limited presence of Ni-O-Ce-O_(v)sites.The high hydrogenation activity against hydrogenolysis reactions on Ni_(2)0/CeO_(2)catalyst is attributed to tunable Ni/O_(v)distances,which constrain the cleavage of CAr-OH bond and deep deoxygenation.Such spatial distribution effect has also facilitated tandem dehydrogenation(O-H bond cleavage)and hydrogenation(C_(Ar)=C_(Ar)hydrogenation)reactions,leading to cyclohexanol as the target product in the absence of externally added H_(2).Insights into spatial distribution of O_(v)sites open an alternative perspective in designing efficient catalysts toward producing value-added cyclic oxygenates through upgrading of lignin compounds.
基金supported by the National Natural Science Foundation of China(52374249,52130409,52121003)the National Key R&D Program(2023YFC3009003)+1 种基金the Basic Research Business Fees for Central Universities(2024JCCXAQ01)Open Fund of State Key Laboratory of Coal Mine Disaster Dynamics and Control(2011DA105287-FW202303).
文摘As energy demand increases,the depth of mining is increasing,and methane disasters grow more serious,efficient extraction of methane is the ultimate method of preventing and controlling methane disasters.The objectives for this research are to explore the efficiency of N_(2) injection to enhance gas extraction from coal seams(N_(2)-ECGE)and its impact on coal seam permeability.By developing a fluid-solid coupling model and using COMSOL Multiphysics to perform numerical simulations,the changes in gas pressure,methane content,gas production,output rate and permeability of coal seams were comparatively analyzed under the two methods of direct extraction and N_(2)-ECGE.The research results show that N_(2)-ECGE can significantly improve the coal seam gas pressure and reduce the coal seam CH_(4) content,and the larger the N_(2) injection pressure the more significant the reduction effect.Meanwhile,N_(2)-ECGE can significantly increase the CH_(4) extraction and output rate,and the increase of N_(2) pressure further improves the extraction efficiency.In addition,the pressure of nitrogen injection has a remarkable effect on coal seam permeability,high pressure of nitrogen injection can increase the permeability in the time of no disturbance,but the rate of permeability decreases more quickly after disturbed.The effect of strain due to adsorption desorption on coal seam permeability dominates.Despite model construction limitations,this research offers essential theoretical and practical direction for N_(2) injection to enhance the permeability evolution law of coal seam gas extraction process.
基金supported by the Natural Science Foundation of Henan Province(242300421246,222300420007,232300421134)the National Natural Science Foundation of China(52004082,52174073,52274079,42402255)+4 种基金the Science and Technology Project of Henan Province(232102321098)Zhongyuan Science and Technology Innovation Leading Talent Program(244200510005)the Program for Science&Technology Innovation Talents in Universities of Henan Province(24HASTIT021)the Program for the Scientific and Technological Innovation Team in Universities of Henan Province(23IRTSTHN005)the National Postdoctoral Researchers Program Foundation of China(GZC20230709)。
文摘Karst collapse columns typically appear unpredictably and without a uniform spatial arrangement,posing challenges for mining operations and water inrush risk assessment.As major structural pathways for mine water inrush,they are responsible for some of the most frequent and severe water-related disasters in coal mining.Understanding the mechanisms of water inrush in these collapse columns is therefore essential for effective disaster prevention and control,making it a key research priority.Additionally,investigating the developmental characteristics of collapse columns is crucial for analyzing seepage instability mechanisms.In such a context,this paper provides a comprehensive review of four critical aspects:(1)The development characteristics and hydrogeological properties of collapse columns;(2)Fluid-solid coupling mechanisms under mining-induced stress;(3)Non-Darcy seepage behavior in fractured rock masses;(4)Flow regime transitions and mass variation effects.Key findings highlight the role of flow-solid coupling in governing the seepage mechanisms of fractured rock masses within karst collapse columns.By synthesizing numerous studies on flow pattern transitions,this paper outlines the complete seepage process-from groundwater movement within the aquifer to its migration through the collapse column and eventual inflow into mine roadways or working faces-along with the associated transformations in flow patterns.Furthermore,the seepage characteristics and water inrush behaviors influenced by particle migration are examined through both experimental and numerical simulation approaches.
基金the financial support from National Natural Science Foundation of China (No. 21972102)National Key Research and Development Program of China (2021YFA0910400)+3 种基金Natural Science Foundation of Jiangsu Province (BK20200991)Suzhou Science and Technology Planning Project (SS202016)the USTS starting fund (No.332012104)the Natural Science Foundation of Suzhou University of Science and Technology (No.342134401)。
文摘Electrochemical nitrate reduction to ammonia(NRA) can realize the green synthesis of ammonia(NH3) at ambient conditions, and also remove nitrate contamination in water. However, the current catalysts for NRA still face relatively low NH3yield rate and poor stability. We present here a core-shell heterostructure comprising cobalt oxide anchored on copper oxide nanowire arrays(CuO NWAs@Co_(3)O_(4)) for efficient NRA. The CuO NWAs@Co_(3)O_(4)demonstrates significantly enhanced NRA performance in alkaline media in comparison with plain CuO NWAs and Co_(3)O_(4)flocs. Especially, at-0.23 V vs. RHE, NH_(3) yield rate of the CuO NWAs@Co_(3)O_(4)reaches 1.915 mmol h^(-1)cm^(-2),much higher than those of CuO NWAs(1.472 mmol h^(-1)cm^(-2)), Co_(3)O_(4)flocs(1.222 mmol h^(-1)cm^(-2)) and recent reported Cu-based catalysts.It is proposed that the synergetic effects of the heterostructure combing atom hydrogen adsorption and nitrate reduction lead to the enhanced NRA performance.
基金the National Key R&D Program of China(Grant Nos.2017YFA0303100 and 2016YFA0300202)the Key R&D Program of Zhejiang Province,China(Grant No.2021C01002)+3 种基金the National Natural Science Foundation of China(Grant Nos.11974306 and 12034017)the Fundamental Research Funds for the Central Universities of Chinasupport via the UC Santa Barbara NSF Quantum Foundry funded via the Q-AMASE-i program under award DMR-1906325support from the California Nano Systems Institute through the Elings fellowship program。
文摘The kagome metals AV_(3)Sb_(5)(A=K,Rb,Cs)under ambient pressure exhibit an unusual charge order,from which superconductivity emerges.In this work,by applying hydrostatic pressure using a liquid pressure medium and carrying out electrical resistance measurements for RbV_(3)Sb_(5),we find that the charge order becomes suppressed under a modest pressure pc(1.4 GPa<pc<1.6 GPa),while the superconducting transition temperature Tc is maximized.Tc is then gradually weakened with further increase of pressure and reaches a minimum around 14.3 GPa,before exhibiting another{maximum}around 22.8 GPa,signifying the presence of a second superconducting dome.Distinct normal state resistance anomalies are found to be associated with the second superconducting dome,similar to KV_(3)Sb_(5).Our findings point to qualitatively similar temperature-pressure phase diagrams in KV_(3)Sb_(5) and RbV_(3)Sb_(5),{and suggest a close link}between the second superconducting dome and the high-pressure resistance anomalies.
基金supported by grants from the Ministry of Science and Technology of China(2021ZD0203302)the National Natural Science Foundation of China(32170996)+4 种基金Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions(2021SHIBS0002)the Guangdong Science and Technology Committee(2019A1515010041,A2021319)the Shenzhen Innovation Committee of Science and Technology(ZDSYS20200811144002008)the Natural Science Foundation of Shenzhen University General Hospital(SUGH2018QD024)the Basic Research Project of Shenzhen Science and Technology Innovation Commission(JCYJ20210324100206017).
文摘The chronic use of morphine and other opioids is associated with opioid-induced hypersensitivity(OIH)and analgesic tolerance.Among the different forms of OIH and tolerance,the opioid receptors and cell types mediating opioid-induced mechanical allodynia and anti-allodynic tolerance remain unresolved.Here we demonstrated that the loss of peripheralμ-opioid receptors(MORs)or MOR-expressing neurons attenuated thermal tolerance,but did not affect the expression and maintenance of morphine-induced mechanical allodynia and anti-allodynic tolerance.To confirm this result,we made dorsal root ganglia-dorsal roots-sagittal spinal cord slice preparations and recorded low-threshold Aβ-fiber stimulation-evoked inputs and outputs in superficial dorsal horn neurons.Consistent with the behavioral results,peripheral MOR loss did not prevent the opening of Aβmechanical allodynia pathways in the spinal dorsal horn.Therefore,the peripheral MOR signaling pathway may not be an optimal target for preventing mechanical OIH and analgesic tolerance.Future studies should focus more on central mechanisms.
基金supported by the National Natural Science Foundation of China(22008262)Natural Science Foundation of Shandong Province(ZR2020QB187).
文摘Oxygen reduction reaction over Pt-based catalyst is one of the most significant cathode reactions in fuel cells.However,low reserves and high price of Pt have motivated researchers worldwide seeking enhanced utilization efficiency and durability by doping non-noble metals to form Pt-based alloy catalysts.Alloying Pt with Co has been recognized as one of the most effective approaches to achieve this goal.PtCo bimetal combination is one of the most promising candidates to synthesize highly efficient catalysts for oxygen reduction reaction(ORR)applications,owing to its relatively more suitable oxygen binding energy for four-electron transfer reactions.Recently,impressive strategies have been developed to fabricate more active and stable PtCo-based multimetallic alloys with tailorable size and morphology.This paper aims to summarize the most recent highlights on the study of the relationship between preparation strategies,morphologies,electroactivities of the PtCo-based catalyst at atomic level and further the relevant reaction mechanism.The challenges and opportunities on the further development of electrocatalysts for fuel cells are included to provide reference for the practical application.
基金The authors are grateful to the National Nature Science Foundation of China （Grant No. 50635030） and the development project on industrialization of bionic non-adhesive cooker （Grant No. 2006D90304010） for the support of this work.
文摘Bionic alumina samples were fabricated on convex dome type aluminum alloy substrate using hard anodizing technique. The convex domes on the bionic sample were fabricated by compression molding under a compressive stress of 92.5 MPa. The water contact angles of the as-anodized bionic samples were measured using a contact angle meter （JC2000A） with the 3μL water drop at room temperature. The measurement of the wetting property showed that the water contact angle of the unmodi- fied as-anodized bionic alumina samples increases from 90° to 137° with the anodizing time. The increase in water contract angle with anodizing time arises from the gradual formation of hierarchical structure or composite structure. The structure is composed of the micro-scaled alumina columns and pores. The height of columns and the depth of pores depend on the ano- dizing time. The water contact angle increases significantly from 96° to 152° when the samples were modified with self-assembled monolayer of octadecanethiol （ODT）, showing a change in the wettability from hydrophobicity to su- per-hydrophobicity. This improvement in the wetting property chemical modification. is attributed to the decrease in the surface energy caused by the
基金Supported by National Natural Science Foundation of ChinaNo.81360318+1 种基金the Application and Basic Research Program of Qinghai Province of ChinaNo.2014-Z-745
文摘AIM: To determine whether the positive status of human epidermal growth receptor 2(HER2) can be regarded as an effective prognostic factor for patients with gastric cancer(GC) undergoing R0 resection.METHODS: A total of 1562 GC patients treated by R0 resection were recruited. HER2 status was evaluated in surgically resected samples of all the patients using immunohistochemical(IHC) staining. Correlations between HER2 status and clinicopathological characteristics were retrospective analyzed. Hazard ratios(HRs) and 95% confidence intervals(CIs) were estimated using Cox proportional hazard model, stratified by age, gender, tumor location and tumor-nodemetastasis(TNM) stage, with additional adjustment for potential prognostic factors.RESULTS: Among 1562 patients, 548(positive rate = 35.08%, 95%CI: 32.72%-37.45%) were HER2 positive. Positive status of HER2 was significantly correlated with gender(P = 0.004), minority(P < 0.001), tumor location(P = 0.001), pathological grade(P < 0.001), TNM stage(P < 0.001) and adjuvant radiotherapy(74.67% vs 23.53%, P = 0.011). No significant associations were observed between HER2 status and disease free survival(HR = 0.19, 95%CI: 0.96-1.46, P = 0.105) or overall survival(HR = 1.19, 95%CI: 0.96-1.48, P = 0.118) using multivariate analysis, although stratified analyses showed marginally statistically significant associations both in disease free survival and overall survival, especially among patients aged < 60 years or with early TNM stages(Ⅰ and Ⅱ). Categorical age, TNM stage, neural invasion, and adjuvant chemotherapy were, as expected, independent prognostic factors for both disease free survival and overall survival. CONCLUSION: The positive status of HER2 based on IHC staining was not related to the survival in patients with GC among the Chinese population.
基金provided by the National Key R&D Program of China (No. 2017YFC060300204)the National Natural Science Foundation of China (Nos. 51604267 and 51704095)+1 种基金Yue Qi Young Scholar Project CUMTBYue Qi Distinguished Scholar Project (No. 800015Z1138)
文摘This paper reviews the development of U.S. longwall mining from an unknown to became the world standard in the past five decades with emphasis on automation. Large scale longwall face equipment were imported from Germany and United Kingdom to increase production in the 1970 s and great effort was made to improve them to suit U.S. conditions, rather than domestic market. Automation began with the development of electrohydraulic shields in 1984 and continue to present. Introduction of first generation semi-automated longwall system occurred in 1995 and step-to-step improvement continues to present following the development of sensor technology and internet of things(IOT). Since then, emphasis on new development has been concentrated on the improvement of equipment reliability, miner's health and safety as well as production, including dust control techniques, proximity sensor, anti-collision and remote control. Automation is classified into two categories: automation of individual face equipment and automation of longwall system. The automation development of longwall system is divided into three stages: shearer-initiated-shield-advance(SISA), semi-automated longwall system, and remote control shearer.
基金supported by the National Natural Science Foundation of China (Nos. 51604267 and 51704095)
文摘Mine or longwall panel layout is a 3D structure with highly non-uniform stress distribution. Recognition of such fact will facilitate underground problem identification/investigation and solving by numerical modeling through proper model construction. Due to its versatility, numerical modeling is the most popular method for ground control design and problem solving. However numerical modeling results require highly experienced professionals to interpret its validity/applicability to actual mining operations due to complicated mining and geological conditions. Underground ground control monitoring is routinely performed to predict roof behavior such as weighting and weighting interval without matching observation of face mining condition while the mining pressures are being monitored, resulting in unrealistic interpretation of the obtained data on mining pressure. The importance of ground control pressure monitoring and simultaneous observation of mining and geological conditions is illustrated by an example of shield leg pressure monitoring and interpretation in an U.S. longwall coal mine: it was found that the roof strata act like a plate, not an individual block of the size of a shield dimension, as commonly assumed by all researchers and shield capacity is not a fixed property for a longwall panel or a mine or a coal seam. A new mechanism on the interaction between shield's hydraulic leg pressure and roof strata for shield loading is proposed.
基金This work was sup-ported by National Natural Sclence Foundatlon of China(no.81202108)
文摘Background:Both hormonal therapy(HT) and maintenance capecitabine monotherapy(MCT) have been shown to extend time to progression(TTP) in patients with metastatic breast cancer(MBC) after failure of taxanes and anthracycline?containing regimens.However,no clinical trials have directly compared the efficacy of MCT and HT after response to first?line capecitabine?based combination chemotherapy(FCCT) in patients with hormone receptor(HR)?positive and human epidermal growth factor receptor 2(HER2)?negative breast cancer.Methods:We retrospectively analyzed the charts of 138 HR?positive and HER2?negative MBC patients who were in non?progression status after FCCT and who were treated between 2003 and 2012 at the Cancer Institute and Hospital,Chinese Academy of Medical Sciences,in Beijing,China.The median number of first?line chemotherapy cycles was 6(range,4–8);combined agents included taxanes,vinorelbine,or gemcitabine.Of these 138 patients,79 received MCT,and 59 received HT.Single?agent capecitabine was administered at a dose of 1250 mg/m2 twice daily for 14 days,followed by a 7?day rest period,repeated every 3 weeks.Of the 59 patients who received HT,37 received aromatase inhibitors(AIs),8 received selective estrogen receptor modulators(SERMs),and 14 received goserelin plus either AIs or SERMs.We then compared the MCT group and HT group in terms of treatment efficacy.Results:With a median follow?up of 43 months,patients in the HT group had a much longer TTP than patients in the MCT group(13 vs.8 months,P ease?free surviv= 0.011).When TTP was adjusted for age,menopausal status,Karnofsky performance status score,disal,site of metastasis,number of metastatic sites,and response status after FCCT,extended TTP was still observed for patients in the HT group(hazard ratio:0.63;95% confidence interval:0.44–0.93;P = 0.020).We also observed a trend of overall survival advantage for patients in the HT group vs.patients in the MCT group,but the difference was not significant(43 vs.37 months,P tients in the MCT g= 0.400).In addition,patients in the HT group gen?erally tolerated the treatment well,whereas paroup experienced grades 3–4 adverse events,the most frequent of which were hand?foot syndrome(15.8%) and hematologic abnormalities(7.6%).Conclusion:For HR?positive and HER2?negative MBC patients,HT might be considered a treatment after response to FCCT but prior to MCT as a long?term administration.
基金supported by the National Natural Science Foundation of China(52004291,52130409,51874314)the Research Fund of State and Local Joint Engineering Laboratory for Gas Drainage&Ground Control of Deep Mines(Henan Polytechnic University)(SJF202003)+1 种基金the Fundamental Research Funds for the Central Universities(2022XJAQ02)the Innovative Training Program for College Students(C202112035,C202112003).
文摘The rockburst dynamic disasters in the process of deep coal mining become more and more serious.Taking the rockburst occurred in the 23130 working face of Yuejin Coal Mine as the engineering background,we study the characteristics of mining stress feld around roadway,the plastic failure morphological characteristics of surrounding rock and the accumulation/release law of elastic energy before and after burst.An analysis model quantitatively describing the physical process of rockburst in the mining roadway is established,and the calculation method of dynamic release of elastic energy in the physical process of rockburst is educed.The mechanism of rockburst in mining roadway is revealed.The results show that an“L-shaped”stress concentration zone is formed within 100 m of the 23130 working face,and the principal stress ratio of the surrounding rock of the transportation roadway is 2.59–4.26.The change of the direction of the maximum principal stress has a signifcant efect on the burst appearance characteristics.The failure strength of diferent sections of the mining roadway is characterized by the elastic energy release value.With the increase of the working face distance,the elastic energy released by burst failure and the expansion variation of failure boundary radius show a nonlinear variation law that tends to decrease steadily after sharp fuctuation.The closer to the working face,the higher the burst risk.At a distance of 10 m from the working surface,the maximum principal stress reaches its maximum value.The butterfy-shaped failure system generated by the surrounding rock of the roadway has energy self-sustainability,and the elastic energy released by the sudden expansion of the butterfy leaf is enough to cause a burst damage of 1.9 magnitude.This work could provide theoretical support for the prediction and prevention of rockburst.
基金This work was supported by National Natural Science Foundation of China(52130409,52121003,52004291,51874314).
文摘Hydraulic fracturing and permeability enhancement are effective methods to improve low-permeability coal seams.However,few studies focused on methods to increase permeability,and there are no suitable prediction methods for engineering applications.In this work,PFC2D software was used to simulate coal seam hydraulic fracturing.The results were used in a coupled mathematical model of the interaction between coal seam deformation and gas flow.The results show that the displacement and velocity of particles increase in the direction of minimum principal stress,and the cracks propagate in the direction of maximum principal stress.The gas pressure drop rate and permeability increase rate of the fracture model are higher than that of the non-fracture model.Both parameters decrease rapidly with an increase in the drainage time and approach 0.The longer the hydraulic fracturing time,the more complex the fracture network is,and the faster the gas pressure drops.However,the impact of fracturing on the gas drainage effect declines over time.As the fracturing time increases,the difference between the horizontal and vertical permeability increases.However,this difference decreases as the gas drainage time increases.The higher the initial void pressure,the faster the gas pressure drops,and the greater the permeability increase is.However,the influence of the initial void pressure on the permeability declines over time.The research results provide guidance for predicting the anti-reflection effect of hydraulic fracturing in underground coal mines.
文摘Neuroendocrine carcinoma of the breast (NECB) accounts for approximately 0.3%-0.5% of all breast cancers [1, 2]. Due to the rarity of NECB, current understanding of this disease in China is limited to case reports and small case series, and large data analysis is still lacking. Therefore, we conducted the most comprehensive literature search to date, aiming to analyze the clinicopathologic characteristics as well as treatment and outcome of NECB in the Chinese population.
