Mitochondria play a crucial role as organelles,managing several physiological processes such as redox balance,cell metabolism,and energy synthesis.Initially,the assumption was that mitochondria primarily resided in th...Mitochondria play a crucial role as organelles,managing several physiological processes such as redox balance,cell metabolism,and energy synthesis.Initially,the assumption was that mitochondria primarily resided in the host cells and could exclusively transmit from oocytes to offspring by a mechanism known as vertical inheritance of mitochondria.Recent scholarly works,however,suggest that certain cell types transmit their mitochondria to other developmental cell types via a mechanism referred to as intercellular or horizontal mitochondrial transfer.This review details the process of which mitochondria are transferred across cells and explains the impact of mitochondrial transfer between cells on the efficacy and functionality of cancer cells in various cancer forms.Specifically,we review the role of mitochondria transfer in regulating cellular metabolism restoration,excess reactive oxygen species(ROS)generation,proliferation,invasion,metastasis,mitophagy activation,mitochondrial DNA(mtDNA)inheritance,immune system modulation and therapeutic resistance in cancer.Additionally,we highlight the possibility of using intercellular mitochondria transfer as a therapeutic approach to treat cancer and enhance the efficacy of cancer treatments.展开更多
Chinese coal reservoirs are characterized by low pressure and low permeability,which need to be enhanced so as to increase production.However,conventional methods for permeability enhancement can only increase the per...Chinese coal reservoirs are characterized by low pressure and low permeability,which need to be enhanced so as to increase production.However,conventional methods for permeability enhancement can only increase the permeability in fractures,but not the ultra-low permeability in coal matrices.Attempts to enhance such impermeable structures lead to rapid attenuation of gas production,especially in the late stage of gas extraction.Thermal stimulation by injecting high-temperature steam is a promising method to increase gas production.The critical scientific challenges that still hinder its widespread application are related to the evolution law of permeability of high-temperature steam in coal and the thermal deformation of coal.In this study,an experimental approach is developed to explore the high-temperature steam seepage coupled with the thermal deformation in coal under triaxial stress.The tests were conducted using cylindrical coal specimens of?50 mm×100 mm.The permeability and thermal strain in coal were investigated when high-temperature steam was injected at151.11,183.20,213.65,and 239.76°C.The experimental results reveal for the first time that as the amount of injected fluid increases,the steam permeability shows periodic pulsation changes.This paper introduces and explains the main traits of this discovery that may shed more light on the seepage phenomenon.When the injected steam temperature increases,the amplitude of pulsating permeability decreases,whereas the frequency increases;meanwhile,the period becomes shorter,the pulsation peak appears earlier,and the stabilization time becomes longer.The average peak permeability shows a“U-shaped”trend,decreasing first and then increasing as the steam temperature increases.Meanwhile,with the extension of steam injection time,the axial,radial,and volumetric strains of coal show a stage-wise expansion characteristic at different temperatures of steam injection,except for the radial strains at 151.11°C.A two-phase flow theory of gas–liquid is adopted to elucidate the mechanism of pulsating seepage of steam.Moreover,the influencing mechanism of inward and outward thermal expansion on the permeability of coal is interpreted.The results presented in this paper provide new insight into the feasibility of thermal gas recovery by steam injection.展开更多
Background: Birds produce alarm calls to convey information about threats. Some Passerine alarm calls consist of several note strings, but few studies have examined their function. Previous studies have shown that Jap...Background: Birds produce alarm calls to convey information about threats. Some Passerine alarm calls consist of several note strings, but few studies have examined their function. Previous studies have shown that Japanese Tits(Parus minor) can alter the calling rate and number and combination of notes in response to predators. We previously found the combinations of note types in Japanese Tit alarm calls to be significantly different in response to the Sparrowhawk(Accipiter nisus) and Common Cuckoo(Cuculus canorus).Methods: Through playback experiments, we tested whether the note strings in Japanese Tit alarm calls to the Common Cuckoo have different functions in conveying information. The note strings of selected alarm calls were divided into the categories of C and D, and different calls were then constructed separately based on the two note string categories. Original alarm calls(C–D), C calls and D calls were played back to male Japanese Tits during the incubation period.Results: Male Japanese Tits had a significantly stronger response to C calls than to C–D calls, and they showed a significantly stronger response to both C and C–D calls than to D calls, suggesting that Japanese Tits discriminated between the C and D calls.Conclusions: Our study demonstrated that the C-and D-category note strings of Japanese Tit alarm calls to the Common Cuckoo have different functions, which supports the previous finding that different note strings in an alarm call can provide different information to receivers. However, the exact meanings of these note strings are not yet known, and further investigation is therefore required.展开更多
TiO2 pigments are typically coated with inert layers to suppress the photocatalytic activity and improve the weatherability. However, the traditional inert layers have a lower refractive index compared to TiO2, and th...TiO2 pigments are typically coated with inert layers to suppress the photocatalytic activity and improve the weatherability. However, the traditional inert layers have a lower refractive index compared to TiO2, and therefore reduce the lightening power of TiO2. In the present work, a uniform, amorphous, 2.9-nm-thick TiO2 protective layer was deposited onto the surface of anatase TiO2 pigments according to pulsed chemical vapor deposition at room temperature, with Ti Cl4 as titanium precursor. Amorphous TiO2 coating layers exhibited poor photocatalytic activity, leading to a boosted weatherability. Similarly, this coating method is also effective for TiO2 coating with amorphous SiO2 and SnO2 layers. However, the lightening power of amorphous TiO2 layer is higher than those of amorphous SiO2 and SnO2 layers. According to the measurements of photoluminescence lifetime, surface photocurrent density, charge-transfer resistance, and electron spin resonance spectroscopy, it is revealed that the amorphous layer can prevent the migration of photogenerated electrons and holes onto the surface, decreasing the densities of surface electron and hole, and thereby suppress the photocatalytic activity.展开更多
The joint source scanning algorithm(SSA)scans locations and focal mechanisms of microseismic events simultaneously.Compared to the traditional source scanning algorithm,it yields much more events with extra informatio...The joint source scanning algorithm(SSA)scans locations and focal mechanisms of microseismic events simultaneously.Compared to the traditional source scanning algorithm,it yields much more events with extra information of focal mechanisms.The availability of more events and focal mechanisms make it possible to invert for a 2D gridded stress field.As a byproduct of hydrofracturing monitoring,the method offers a new way to extract stress field as a substitute to other more expensive technologies.This method is applied to a hydraulic fracturing dataset collected from one shale gas production field in the southeast of the Sichuan basin.A damped stress inversion is conducted to obtain a 2D stress field.five hydraulic-fracturing induced fractures can be determined from the result.The events associated with these fractures generally have relatively low stacked energy and are limited to the depth of horizontal well.One existing fault(possibly associated with the axis of the central Sichuan uplift)is also determined and the events associated with the existing fault generally have higher stacked energy and are more densely populated.The existing fault may also serve as a structural boundary where the rocks to the NW side are easier to be fractured while events on the other side are sparse with low stacked energy.The existing fault also divides the stress field into two regimes:the maximum compressional stress field to the NW and SE of the fault line are dominantly in NW-SE and N-S directions,respectively.展开更多
In this paper,a series of static/dynamic tensile tests are performed for glass fiber reinforced plastic(GFRP)composites.Using the combination of high-speed photography and digital image correlation(DIC)technology,true...In this paper,a series of static/dynamic tensile tests are performed for glass fiber reinforced plastic(GFRP)composites.Using the combination of high-speed photography and digital image correlation(DIC)technology,true stress-strain curves in different directions and strain rates are obtained.We also obtained the dynamic failure strain of the material in different directions,which are used to accurately describe the dynamic tensile and failure behavior of the material.The experimental results show that there is a stiffness change point N in three directions under different strain rate(10-3 s-1,10 s-1,100 s-1)tensile conditions.The stiffness before and after N point is recorded as Einitial and Echanged respectively.The values of Echanged in weft direction and warp direction are about 30%to 50%of Einitial,while Echanged in tilt direction is only about 10%of Einitial.The fiber has the highest strength in the weft direction and the tilt direction has the lowest strength.With the combination of high-speed photography and DIC technology,the dynamic failure parameters of different directions under the strain rate of 100 s-1 are obtained.The dynamic failure strains in three directions are 0.245,0.373 and 0.341,respectively.The parameters are verified by impact three-point bending test.These works can more accurately describe the dynamic mechanical behavior of glass fiber reinforced plastic(GFRP)composites and provide reference for the design of GFRP structures.展开更多
Compared to traditional pure metals or alloys based on just one principal element,high entropy alloys(HEAs)exhibit notable structural and physical characteristics,drawing significant attention.While significant advanc...Compared to traditional pure metals or alloys based on just one principal element,high entropy alloys(HEAs)exhibit notable structural and physical characteristics,drawing significant attention.While significant advancements have been made in the synthesis and utilization of HEAs,there is a lack of comprehensive understanding and systematic approach towards the rational design of electrocatalysts.This review begins by introducing the fundamental principles and impacts of HEAs,followed by an overview of traditional and emerging synthesis techniques;in particular,we categorize and critically analyze approaches.Subsequently,a detailed examination of the advancements and comparative performance of HEAs in specific electrocatalytic reactions is presented.The paper concludes by outlining the current challenges and opportunities associated with HEAs catalysts,along with offering personal insights on potential future developments.展开更多
The effects of lance height and bottom blown flowrate on the mixed time, the splashing amount, the penetrating depth, and the level fluctuation of an 85 t combined blown converter have been studied using a water model...The effects of lance height and bottom blown flowrate on the mixed time, the splashing amount, the penetrating depth, and the level fluctuation of an 85 t combined blown converter have been studied using a water model. The results show that the maximal stirring energy is provided to the bath at the top lance height of about 50-100 mm. When the top lance height is in the range ofg0- 110 mm, the splashing amount caused by the top jet can reach the maximal value. The appropriate operational parameters of Chongqing Iron and Steel Company （CISC） converter have been established that the top lance height is 1600-1760 mm and the bottom blowing flowrate is 240-480 Nm^3/h in the primary phase of a heat, 1100-1300 mm and 160-200 Nm^3/h in the second phase, and 1040-1120 mm and 200-350 Nm^3/h in the end phase. Also, the trial shows that the metallurgical result of the studied blow pattern is better than that of the former pattern. At the starting 3-4 min of a heat, the strong splashing is eliminated. 2008 University of Science and Technology Beijing. All rights reserved.展开更多
Experimental records in the cerebral cortex indicate that ammonia injection can lead to seizures. Considering that astrocytes play a vital role in mediating the uptake and absorption of ammonium ions in the extracellu...Experimental records in the cerebral cortex indicate that ammonia injection can lead to seizures. Considering that astrocytes play a vital role in mediating the uptake and absorption of ammonium ions in the extracellular space of the cortical circuit, we constructed a new astrocyte neuron coupling model, which is composed of a neuron and its astrocytes connected through the extracellular space, taking into account of the influence of extracellular ammonium ions. The numerical results verified the previous experimental observation that obtained epileptic firing modes of neurons and postsynaptic GABA reversal potential depolarization triggered by ammonia injection. In addition, we also determined the concentration–response relationship between the ammonium ion concentration and the time of entering epilepsy and predicted the threshold of the ammonium ion concentration for the onset of epilepsy.展开更多
The demand for converting CO_(2)into fuels or chemicals is on the rise to achieve a carbon-efficient circular economy.Biohybrid CO_(2)electrolysis shows potential for increasing production rates and diversifying produ...The demand for converting CO_(2)into fuels or chemicals is on the rise to achieve a carbon-efficient circular economy.Biohybrid CO_(2)electrolysis shows potential for increasing production rates and diversifying product spectra by combining electrocatalysts and microbial catalysts.However,it is important to note that utilizing a shared catholyte for biohybrid CO_(2)electrolysis has not demonstrated significant performance improvements to date.In this study,we developed a biohybrid CO_(2)electrolysis system utilizing a solid electrolyte operating in an external mode.The produced formic acid was extracted and used as an intermediate for microbial conversion.Impressively,the solid-electrolyte CO_(2)electrolysers obtained a remarkable total Faradic efficiency of 81.4%for formic acid production.In-situ mechanism studies unveiled metallic tin as the probable real active site,prompting further exploration of strategies to boost the activity and stability of electrocatalysts.In the bioconversion step,we achieved a noteworthy 8-day duration for generating bioelectricity,nearly 100%electron recovery for biomethane production,and 90.8%for acetate generation.Additionally,when ethanol was co-fed,a C_(6)specificity of 41.1%was observed for the generation of medium-chain fatty acids(MCFAs).This study presents groundbreaking experimental data that demonstrates the numerous advantages of utilizing hybrid systems as advanced synthesis techniques.展开更多
Zn-air batteries(ZABs)have been widely studied due to their high theoretical energy density,low cost,and high safety.However,the lack of efficient bifunctional electrocatalysts toward both the oxygen reduction reactio...Zn-air batteries(ZABs)have been widely studied due to their high theoretical energy density,low cost,and high safety.However,the lack of efficient bifunctional electrocatalysts toward both the oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)hinders their large-scale application.Herein,a dendritic NiS_(2)@Co-N-C/CNF nanoarchitecture is proposed.展开更多
The Yitong River is one of the largest secondary tributaries of the Songhua River. The area where the Yitong River flows is densely populated and contains the livestock and poultry breeding areas of northeast China. T...The Yitong River is one of the largest secondary tributaries of the Songhua River. The area where the Yitong River flows is densely populated and contains the livestock and poultry breeding areas of northeast China. These areas introduce a high risk of antibiotic contamination. In this study, the concentrations of four types of typical antibiotics including quinolones, tetracyclines, sulfonamides, and trimethoprim were determined by solid phase extraction-high performance liquid chromatography. The antibiotic resistance of Escherichia coli caused by antibiotic pollution was investigated. The concentration of total coliforms in the Yitong River was detected by the plate counting method. The antibiotic resistance of E. coli to quinolones, tetracyclines, sulfonamides, and trimethoprim was analyzed by the Kirby-Bauer method. The results showed that the concentration of total coliforms in the summer was higher than that in the spring. There was a seasonal difference in the resistance rate of E. coli to antibiotics except trimethoprim. The antibiotic resistance to fluoroquinolones was relatively low. The resistance rate to tetracyclines was higher during the summer. Moreover, resistance to several antibiotics was observed in all sections. This study provides basic data for research on pollution characteristics and prevention of antibiotic exposure in rivers.展开更多
With the fast pace of population aging,industrialization,and urbanization in China,the main source of elderly care is changing.Using China Health and Retirement Longitudinal Survey data,we investigate the elderly care...With the fast pace of population aging,industrialization,and urbanization in China,the main source of elderly care is changing.Using China Health and Retirement Longitudinal Survey data,we investigate the elderly care provision situation and find that spouses are currently the most important elderly care providers in China.We use a model to depict the trade-off between a caregiver's own health and the care quality obtained by the care recipient.The model predicts that under some conditions,the caregivers will provide care at the cost of their health.Employing a stratified propensity score matching method,we find that spouses'caregivers are more likely to have depression,physical pain,and hypertension than noncaregivers.The negative effects are larger for caregivers with a high level of care intensity or less support from other resources.Female spousal caregivers tend to suffer more from depression and physical pain than male spousal caregivers.Our findings suggest that policies toward"healthy aging"should target not only the disabled elderly but also their spousal caregivers who are also elderly people.展开更多
Dear Editor,The COVID-19 pandemic still greatly threatens the public health worldwide and novel vaccines to highly effectively combat SARS-CoV-2 remains an unmet clinical need.However,redox imbalance in immune cells u...Dear Editor,The COVID-19 pandemic still greatly threatens the public health worldwide and novel vaccines to highly effectively combat SARS-CoV-2 remains an unmet clinical need.However,redox imbalance in immune cells under extra stimulation by vaccine or pathogens greatly dampens the quality of the induced immunity.1 In addition,people infected with COVID-19 that characterized by immune system malfunction were also approved to be attributed by the robust oxidative stress.展开更多
Reverse auctions have been widely adopted for purchasing goods and services. This paper considers a novel winner determination problem in a multiple-object reverse auction in which the buyer involves loss-averse behav...Reverse auctions have been widely adopted for purchasing goods and services. This paper considers a novel winner determination problem in a multiple-object reverse auction in which the buyer involves loss-averse behavior due to uncertain attributes. A corresponding winner determination model based on cumulative prospect theory is proposed. Due to the NP-hard characteristic, a loaded route strategy is proposed to ensure the feasibility of the model. Then, an improved ant colony algorithm that consists of a dynamic transition strategy and a Max-Min pheromone strategy is designed. Numerical experiments are conducted to illustrate the effectiveness of the proposed model and algorithm. We find that under the loaded route strategy, the improved ant colony algorithm performs better than the basic ant colony algorithm. In addition, the proposed model can effectively characterize the buyer's loss-averse behavior.展开更多
In this paper, we are concerned with the symmetric positive solutions of a 2n-order boundary value problems on time scales. By using induction principle,the symmetric form of the Green＇s function is established. In o...In this paper, we are concerned with the symmetric positive solutions of a 2n-order boundary value problems on time scales. By using induction principle,the symmetric form of the Green＇s function is established. In order to construct a necessary and sufficient condition for the existence result, the method of iterative technique will be used. As an application, an example is given to illustrate our main result.展开更多
Artificial intelligence-based methods for picking microseismic phase arrivals have been widely adopted.How-ever,these methods are frequently challenged by complex and dynamic monitoring scenarios,where various types o...Artificial intelligence-based methods for picking microseismic phase arrivals have been widely adopted.How-ever,these methods are frequently challenged by complex and dynamic monitoring scenarios,where various types of environmental noise mask low-energy microseismic signals.Moreover,the paucity of labelled data often impairs the reliability and accuracy of their results.To address these issues,this study proposes a novel super-vised learning framework named FC-Net,which integrates automatic labelling via Fuzzy C-means clustering(FCM)with the U-Net architecture.Specifically,the FCM algorithm is employed to derive the probabilistic distributions of microseismic phase arrival times,which are then used as training labels for model training.The proposed FC-Net is equipped with soft attention gates(AGs)and recurrent-residual convolution units(RRCUs),which effectively enhance the network's ability to focus on key seismic features.The arrival time is determined as the moment when the predicted probability exceeds a predefined threshold for the first arrival pick.Evaluated on a field dataset collected from Southwest China,FC-Net is demonstrated to outperform the conventional U-Net method.The experimental results demonstrate that FC-Net achieves adaptive labeling,enhances the detection rate of microseismic events,and improves the precision of phase arrival picking.Furthermore,it exhibits strong generalization performance across microseismic events with varying signal-to-noise ratios(SNRs).展开更多
基金supported by the National Natural Science Foundation of China(Grant No.:82272749)the Natural Science Foundation of Liaoning Province,China(Grant No.:2022-MS-190).
文摘Mitochondria play a crucial role as organelles,managing several physiological processes such as redox balance,cell metabolism,and energy synthesis.Initially,the assumption was that mitochondria primarily resided in the host cells and could exclusively transmit from oocytes to offspring by a mechanism known as vertical inheritance of mitochondria.Recent scholarly works,however,suggest that certain cell types transmit their mitochondria to other developmental cell types via a mechanism referred to as intercellular or horizontal mitochondrial transfer.This review details the process of which mitochondria are transferred across cells and explains the impact of mitochondrial transfer between cells on the efficacy and functionality of cancer cells in various cancer forms.Specifically,we review the role of mitochondria transfer in regulating cellular metabolism restoration,excess reactive oxygen species(ROS)generation,proliferation,invasion,metastasis,mitophagy activation,mitochondrial DNA(mtDNA)inheritance,immune system modulation and therapeutic resistance in cancer.Additionally,we highlight the possibility of using intercellular mitochondria transfer as a therapeutic approach to treat cancer and enhance the efficacy of cancer treatments.
基金Fundamental Research Funds for the Universities of Henan Province,Grant/Award Number:NSFRF180305。
文摘Chinese coal reservoirs are characterized by low pressure and low permeability,which need to be enhanced so as to increase production.However,conventional methods for permeability enhancement can only increase the permeability in fractures,but not the ultra-low permeability in coal matrices.Attempts to enhance such impermeable structures lead to rapid attenuation of gas production,especially in the late stage of gas extraction.Thermal stimulation by injecting high-temperature steam is a promising method to increase gas production.The critical scientific challenges that still hinder its widespread application are related to the evolution law of permeability of high-temperature steam in coal and the thermal deformation of coal.In this study,an experimental approach is developed to explore the high-temperature steam seepage coupled with the thermal deformation in coal under triaxial stress.The tests were conducted using cylindrical coal specimens of?50 mm×100 mm.The permeability and thermal strain in coal were investigated when high-temperature steam was injected at151.11,183.20,213.65,and 239.76°C.The experimental results reveal for the first time that as the amount of injected fluid increases,the steam permeability shows periodic pulsation changes.This paper introduces and explains the main traits of this discovery that may shed more light on the seepage phenomenon.When the injected steam temperature increases,the amplitude of pulsating permeability decreases,whereas the frequency increases;meanwhile,the period becomes shorter,the pulsation peak appears earlier,and the stabilization time becomes longer.The average peak permeability shows a“U-shaped”trend,decreasing first and then increasing as the steam temperature increases.Meanwhile,with the extension of steam injection time,the axial,radial,and volumetric strains of coal show a stage-wise expansion characteristic at different temperatures of steam injection,except for the radial strains at 151.11°C.A two-phase flow theory of gas–liquid is adopted to elucidate the mechanism of pulsating seepage of steam.Moreover,the influencing mechanism of inward and outward thermal expansion on the permeability of coal is interpreted.The results presented in this paper provide new insight into the feasibility of thermal gas recovery by steam injection.
基金supported by the National Natural Science Foundation of China(31272331 and 31470458 to HW,31472013 and 31772453 to WL)the Fundamental Research Funds for the Central Universities(2412016KJ043)the Open Project Program of Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization(130028685)
文摘Background: Birds produce alarm calls to convey information about threats. Some Passerine alarm calls consist of several note strings, but few studies have examined their function. Previous studies have shown that Japanese Tits(Parus minor) can alter the calling rate and number and combination of notes in response to predators. We previously found the combinations of note types in Japanese Tit alarm calls to be significantly different in response to the Sparrowhawk(Accipiter nisus) and Common Cuckoo(Cuculus canorus).Methods: Through playback experiments, we tested whether the note strings in Japanese Tit alarm calls to the Common Cuckoo have different functions in conveying information. The note strings of selected alarm calls were divided into the categories of C and D, and different calls were then constructed separately based on the two note string categories. Original alarm calls(C–D), C calls and D calls were played back to male Japanese Tits during the incubation period.Results: Male Japanese Tits had a significantly stronger response to C calls than to C–D calls, and they showed a significantly stronger response to both C and C–D calls than to D calls, suggesting that Japanese Tits discriminated between the C and D calls.Conclusions: Our study demonstrated that the C-and D-category note strings of Japanese Tit alarm calls to the Common Cuckoo have different functions, which supports the previous finding that different note strings in an alarm call can provide different information to receivers. However, the exact meanings of these note strings are not yet known, and further investigation is therefore required.
基金Supported by the National Key R&D Program of China(2018YFB0605700).
文摘TiO2 pigments are typically coated with inert layers to suppress the photocatalytic activity and improve the weatherability. However, the traditional inert layers have a lower refractive index compared to TiO2, and therefore reduce the lightening power of TiO2. In the present work, a uniform, amorphous, 2.9-nm-thick TiO2 protective layer was deposited onto the surface of anatase TiO2 pigments according to pulsed chemical vapor deposition at room temperature, with Ti Cl4 as titanium precursor. Amorphous TiO2 coating layers exhibited poor photocatalytic activity, leading to a boosted weatherability. Similarly, this coating method is also effective for TiO2 coating with amorphous SiO2 and SnO2 layers. However, the lightening power of amorphous TiO2 layer is higher than those of amorphous SiO2 and SnO2 layers. According to the measurements of photoluminescence lifetime, surface photocurrent density, charge-transfer resistance, and electron spin resonance spectroscopy, it is revealed that the amorphous layer can prevent the migration of photogenerated electrons and holes onto the surface, decreasing the densities of surface electron and hole, and thereby suppress the photocatalytic activity.
基金the National Key R&D Program of China(Nos.2018YFC1503401,and 2016ZX05023004)National Natural Science Foundation of China(Nos.4217040570,and 41674059).
文摘The joint source scanning algorithm(SSA)scans locations and focal mechanisms of microseismic events simultaneously.Compared to the traditional source scanning algorithm,it yields much more events with extra information of focal mechanisms.The availability of more events and focal mechanisms make it possible to invert for a 2D gridded stress field.As a byproduct of hydrofracturing monitoring,the method offers a new way to extract stress field as a substitute to other more expensive technologies.This method is applied to a hydraulic fracturing dataset collected from one shale gas production field in the southeast of the Sichuan basin.A damped stress inversion is conducted to obtain a 2D stress field.five hydraulic-fracturing induced fractures can be determined from the result.The events associated with these fractures generally have relatively low stacked energy and are limited to the depth of horizontal well.One existing fault(possibly associated with the axis of the central Sichuan uplift)is also determined and the events associated with the existing fault generally have higher stacked energy and are more densely populated.The existing fault may also serve as a structural boundary where the rocks to the NW side are easier to be fractured while events on the other side are sparse with low stacked energy.The existing fault also divides the stress field into two regimes:the maximum compressional stress field to the NW and SE of the fault line are dominantly in NW-SE and N-S directions,respectively.
基金the National Department of Science and Technology(Grant 2016YFB1200505).
文摘In this paper,a series of static/dynamic tensile tests are performed for glass fiber reinforced plastic(GFRP)composites.Using the combination of high-speed photography and digital image correlation(DIC)technology,true stress-strain curves in different directions and strain rates are obtained.We also obtained the dynamic failure strain of the material in different directions,which are used to accurately describe the dynamic tensile and failure behavior of the material.The experimental results show that there is a stiffness change point N in three directions under different strain rate(10-3 s-1,10 s-1,100 s-1)tensile conditions.The stiffness before and after N point is recorded as Einitial and Echanged respectively.The values of Echanged in weft direction and warp direction are about 30%to 50%of Einitial,while Echanged in tilt direction is only about 10%of Einitial.The fiber has the highest strength in the weft direction and the tilt direction has the lowest strength.With the combination of high-speed photography and DIC technology,the dynamic failure parameters of different directions under the strain rate of 100 s-1 are obtained.The dynamic failure strains in three directions are 0.245,0.373 and 0.341,respectively.The parameters are verified by impact three-point bending test.These works can more accurately describe the dynamic mechanical behavior of glass fiber reinforced plastic(GFRP)composites and provide reference for the design of GFRP structures.
基金the financial support by the National Natural Science Foundation of China(52102241)the Primary Research and Development Program of Anhui Province(201904a05020087)the Doctor of Suzhou University Scientific Research Foundation(2022BSK019)。
文摘Compared to traditional pure metals or alloys based on just one principal element,high entropy alloys(HEAs)exhibit notable structural and physical characteristics,drawing significant attention.While significant advancements have been made in the synthesis and utilization of HEAs,there is a lack of comprehensive understanding and systematic approach towards the rational design of electrocatalysts.This review begins by introducing the fundamental principles and impacts of HEAs,followed by an overview of traditional and emerging synthesis techniques;in particular,we categorize and critically analyze approaches.Subsequently,a detailed examination of the advancements and comparative performance of HEAs in specific electrocatalytic reactions is presented.The paper concludes by outlining the current challenges and opportunities associated with HEAs catalysts,along with offering personal insights on potential future developments.
文摘The effects of lance height and bottom blown flowrate on the mixed time, the splashing amount, the penetrating depth, and the level fluctuation of an 85 t combined blown converter have been studied using a water model. The results show that the maximal stirring energy is provided to the bath at the top lance height of about 50-100 mm. When the top lance height is in the range ofg0- 110 mm, the splashing amount caused by the top jet can reach the maximal value. The appropriate operational parameters of Chongqing Iron and Steel Company （CISC） converter have been established that the top lance height is 1600-1760 mm and the bottom blowing flowrate is 240-480 Nm^3/h in the primary phase of a heat, 1100-1300 mm and 160-200 Nm^3/h in the second phase, and 1040-1120 mm and 200-350 Nm^3/h in the end phase. Also, the trial shows that the metallurgical result of the studied blow pattern is better than that of the former pattern. At the starting 3-4 min of a heat, the strong splashing is eliminated. 2008 University of Science and Technology Beijing. All rights reserved.
基金supported by the National Natural Science Foundation of China (Grant Nos. 12132012 and 11972275)the National Science Foundation for Young Scientists of China (Grant No. 12102240)。
文摘Experimental records in the cerebral cortex indicate that ammonia injection can lead to seizures. Considering that astrocytes play a vital role in mediating the uptake and absorption of ammonium ions in the extracellular space of the cortical circuit, we constructed a new astrocyte neuron coupling model, which is composed of a neuron and its astrocytes connected through the extracellular space, taking into account of the influence of extracellular ammonium ions. The numerical results verified the previous experimental observation that obtained epileptic firing modes of neurons and postsynaptic GABA reversal potential depolarization triggered by ammonia injection. In addition, we also determined the concentration–response relationship between the ammonium ion concentration and the time of entering epilepsy and predicted the threshold of the ammonium ion concentration for the onset of epilepsy.
基金supported by the National Natural Science Foundation of China(52370033,31970106)CAS Key Laboratory of Environmental and Applied Microbiology&Environmental Microbiology Key Laboratory of Sichuan Province,Chengdu Institute of Biology,Chinese Academy of Sciences(KLCAS-2023-1).
文摘The demand for converting CO_(2)into fuels or chemicals is on the rise to achieve a carbon-efficient circular economy.Biohybrid CO_(2)electrolysis shows potential for increasing production rates and diversifying product spectra by combining electrocatalysts and microbial catalysts.However,it is important to note that utilizing a shared catholyte for biohybrid CO_(2)electrolysis has not demonstrated significant performance improvements to date.In this study,we developed a biohybrid CO_(2)electrolysis system utilizing a solid electrolyte operating in an external mode.The produced formic acid was extracted and used as an intermediate for microbial conversion.Impressively,the solid-electrolyte CO_(2)electrolysers obtained a remarkable total Faradic efficiency of 81.4%for formic acid production.In-situ mechanism studies unveiled metallic tin as the probable real active site,prompting further exploration of strategies to boost the activity and stability of electrocatalysts.In the bioconversion step,we achieved a noteworthy 8-day duration for generating bioelectricity,nearly 100%electron recovery for biomethane production,and 90.8%for acetate generation.Additionally,when ethanol was co-fed,a C_(6)specificity of 41.1%was observed for the generation of medium-chain fatty acids(MCFAs).This study presents groundbreaking experimental data that demonstrates the numerous advantages of utilizing hybrid systems as advanced synthesis techniques.
基金supported by the National Natural Science Foundation of China(no.91961119)the Natural Science Foundation of Tianjin(no.S20YB26121).
文摘Zn-air batteries(ZABs)have been widely studied due to their high theoretical energy density,low cost,and high safety.However,the lack of efficient bifunctional electrocatalysts toward both the oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)hinders their large-scale application.Herein,a dendritic NiS_(2)@Co-N-C/CNF nanoarchitecture is proposed.
基金the Special S&T Project on Treatment and Control of Water Pollution (No. 2014ZX07201-011 -008)the National Natural Science Foundation of China (Grant No. 51809044)+3 种基金Environmental Protection Project of Ecology and Environment Department of 川in Province (2018-10)the China Postdoctoral Science Foundation (2018M630314)the Fundamental Research Funds for the Central Universities (No. 2412018QD020)the Jilin Province Science and Technology Development Projects (No. 20190103136JH).
文摘The Yitong River is one of the largest secondary tributaries of the Songhua River. The area where the Yitong River flows is densely populated and contains the livestock and poultry breeding areas of northeast China. These areas introduce a high risk of antibiotic contamination. In this study, the concentrations of four types of typical antibiotics including quinolones, tetracyclines, sulfonamides, and trimethoprim were determined by solid phase extraction-high performance liquid chromatography. The antibiotic resistance of Escherichia coli caused by antibiotic pollution was investigated. The concentration of total coliforms in the Yitong River was detected by the plate counting method. The antibiotic resistance of E. coli to quinolones, tetracyclines, sulfonamides, and trimethoprim was analyzed by the Kirby-Bauer method. The results showed that the concentration of total coliforms in the summer was higher than that in the spring. There was a seasonal difference in the resistance rate of E. coli to antibiotics except trimethoprim. The antibiotic resistance to fluoroquinolones was relatively low. The resistance rate to tetracyclines was higher during the summer. Moreover, resistance to several antibiotics was observed in all sections. This study provides basic data for research on pollution characteristics and prevention of antibiotic exposure in rivers.
基金supported financially by the National Natural Science Foundation of China(No.71974036)Humanities and Social Sciences of Ministry of Education PlanningFund(No.19YJA790111).
文摘With the fast pace of population aging,industrialization,and urbanization in China,the main source of elderly care is changing.Using China Health and Retirement Longitudinal Survey data,we investigate the elderly care provision situation and find that spouses are currently the most important elderly care providers in China.We use a model to depict the trade-off between a caregiver's own health and the care quality obtained by the care recipient.The model predicts that under some conditions,the caregivers will provide care at the cost of their health.Employing a stratified propensity score matching method,we find that spouses'caregivers are more likely to have depression,physical pain,and hypertension than noncaregivers.The negative effects are larger for caregivers with a high level of care intensity or less support from other resources.Female spousal caregivers tend to suffer more from depression and physical pain than male spousal caregivers.Our findings suggest that policies toward"healthy aging"should target not only the disabled elderly but also their spousal caregivers who are also elderly people.
基金This work was supported by the Natural Science Foundation of China(21877049-T.C.,32171296-T.C.,31871006-L.X.,32101044-H.L.)The National Science Fund for Distinguished Young Scholars(82225025-T.C.)+4 种基金University Innovation team project of Guangdong Province(2019KCXTD008)(T.C.)Natural Science Major Project of Guangdong Province(2019KZDXM029)(L.X.)Guangdong Basic and Applied Basic Research Foundation(2021B1515020018-L.X.,2020B1515120043-T.C.)Basic and Applied Basic Research Project of Guangzhou(202002030272-L.X.)China Postdoctoral Science Foundation(2020M681372)(H.L.).
文摘Dear Editor,The COVID-19 pandemic still greatly threatens the public health worldwide and novel vaccines to highly effectively combat SARS-CoV-2 remains an unmet clinical need.However,redox imbalance in immune cells under extra stimulation by vaccine or pathogens greatly dampens the quality of the induced immunity.1 In addition,people infected with COVID-19 that characterized by immune system malfunction were also approved to be attributed by the robust oxidative stress.
基金sponsored by the Distinguished Young Scholars Award of NSFC Grant #71325002the Major International Joint Research Project of NSFC Grant #71620107003+2 种基金the Foundation for Innovative Research Groups of NSFC Grant #61621004111 Project Grant #B16009the Fundamental Research Funds for State Key Laboratory of Synthetical Automation for Process Industries Grant #2013ZCX11
文摘Reverse auctions have been widely adopted for purchasing goods and services. This paper considers a novel winner determination problem in a multiple-object reverse auction in which the buyer involves loss-averse behavior due to uncertain attributes. A corresponding winner determination model based on cumulative prospect theory is proposed. Due to the NP-hard characteristic, a loaded route strategy is proposed to ensure the feasibility of the model. Then, an improved ant colony algorithm that consists of a dynamic transition strategy and a Max-Min pheromone strategy is designed. Numerical experiments are conducted to illustrate the effectiveness of the proposed model and algorithm. We find that under the loaded route strategy, the improved ant colony algorithm performs better than the basic ant colony algorithm. In addition, the proposed model can effectively characterize the buyer's loss-averse behavior.
基金Supported by NNSF of China(11201213,11371183)NSF of Shandong Province(ZR2010AM022,ZR2013AM004)+2 种基金the Project of Shandong Provincial Higher Educational Science and Technology(J15LI07)the Project of Ludong University High-Quality Curriculum(20130345)the Teaching Reform Project of Ludong University in 2014(20140405)
文摘In this paper, we are concerned with the symmetric positive solutions of a 2n-order boundary value problems on time scales. By using induction principle,the symmetric form of the Green＇s function is established. In order to construct a necessary and sufficient condition for the existence result, the method of iterative technique will be used. As an application, an example is given to illustrate our main result.
基金supported in part by the National Natural Science Foundation of China under Grant 62301349 and Grant 42174151in part by the Sichuan Provincial Department of Science and Technology under Grant 2025YFNH0001in part by the Young Scientists Fund of the National Natural Science Foundation of China under Grant 42104058.
文摘Artificial intelligence-based methods for picking microseismic phase arrivals have been widely adopted.How-ever,these methods are frequently challenged by complex and dynamic monitoring scenarios,where various types of environmental noise mask low-energy microseismic signals.Moreover,the paucity of labelled data often impairs the reliability and accuracy of their results.To address these issues,this study proposes a novel super-vised learning framework named FC-Net,which integrates automatic labelling via Fuzzy C-means clustering(FCM)with the U-Net architecture.Specifically,the FCM algorithm is employed to derive the probabilistic distributions of microseismic phase arrival times,which are then used as training labels for model training.The proposed FC-Net is equipped with soft attention gates(AGs)and recurrent-residual convolution units(RRCUs),which effectively enhance the network's ability to focus on key seismic features.The arrival time is determined as the moment when the predicted probability exceeds a predefined threshold for the first arrival pick.Evaluated on a field dataset collected from Southwest China,FC-Net is demonstrated to outperform the conventional U-Net method.The experimental results demonstrate that FC-Net achieves adaptive labeling,enhances the detection rate of microseismic events,and improves the precision of phase arrival picking.Furthermore,it exhibits strong generalization performance across microseismic events with varying signal-to-noise ratios(SNRs).
