Cleat serves as the primary flow pathway for coalbed methane(CBM)and water.However,few studies consider the impact of local contact on two-phase flow within cleats.A visual generalized model of endogenous cleats was c...Cleat serves as the primary flow pathway for coalbed methane(CBM)and water.However,few studies consider the impact of local contact on two-phase flow within cleats.A visual generalized model of endogenous cleats was constructed based on microfluidics.A microscopic and mesoscopic observation technique was proposed to simultaneously capture gas-liquid interface morphology of pores and throat and the two-phase flow characteristics in entire cleat system.The local contact characteristics of cleats reduced absolute permeability,which resulted in a sharp increase in the starting pressure.The reduced gas flow capacity narrowed the co-infiltration area and decreased water saturation at the isotonic point in a hydrophilic environment.The increased local contact area of cleats weakened gas phase flow capacity and narrowed the co-infiltration area.Jumping events occurred in methane-water flow due to altered porosity caused by local contact in cleats.The distribution of residual phases changed the jumping direction on the micro-scale as well as the dominant channel on the mesoscale.Besides,jumping events caused additional energy dissipation,which was ignored in traditional two-phase flow models.This might contribute to the overestimation of relative permeability.The work provides new methods and insights for investigating unsaturated flow in complex porous media.展开更多
Traditional cement-based slurries are often constrained by excessive cement consumption,prolonged setting times,and limited controllability,which hinder their broader engineering applications.To overcome these challen...Traditional cement-based slurries are often constrained by excessive cement consumption,prolonged setting times,and limited controllability,which hinder their broader engineering applications.To overcome these challenges,this study focuses on optimizing ordinary cement-based slurry through the incorporation of targeted additives and rational adjustment of mix proportions,with the aim of developing a rapid-setting,early-strength cementitious system.In particular,a series of comparative and orthogonal experiments were conducted to systematically examine the evolution of the slurry's macroscopic properties.In addition,the response surface methodology(RSM)was introduced to reveal the interaction mechanisms among key parameters,thereby establishing a quantitative foundation for the precise regulation of slurry performance.The comparative results demonstrate that silica fume significantly outperforms fly ash in enhancing both the rheological and mechanical behavior of the slurry.Regarding fluidity,the average consistency and slump of the silica fume mixture were reduced by 80 mm and 75 mm,respectively,compared with those containing fly ash,indicating more effective control of flowability.In terms of setting and strength development,the silica fume slurry exhibited a setting time up to 9.6 h shorter and a compressive strength up to 3.6 MPa higher under identical mix conditions.These results confirm the clear superiority of silica fume in promoting rapid solidification and early strength gain.展开更多
Heilongjiang reclamation area has made great progress since its development and construction, among which the agricultural and forestry colleges in China have played a key role in the input of talents for the producti...Heilongjiang reclamation area has made great progress since its development and construction, among which the agricultural and forestry colleges in China have played a key role in the input of talents for the production of reclamation area, and the spirit of the Great Wilderness has important strategic significance for the cultivation of agricultural and forestry talents. Taking Heilongjiang Bayi Agricultural University as an example, this paper analyzes the ways of the Great Northern Wilderness Spirit for cultivating application-oriented undergraduate talents in agricultural and forestry colleges, improving the curriculum system of undergraduate talents through innovation, strengthening the cultivation of students’ innovative ability, leading students’ scientific research and academic level, and enhancing students’ practical ability. To innovate the cultivation mode of application-oriented undergraduate talents in agricultural and forestry colleges under the guidance of the spirit of the Great Northern Wilderness, and to provide a reference mode for the cultivation of undergraduate talents in agricultural and forestry colleges in China.展开更多
Unreasonable fertilizer input and low fertilizer utilization seriously restrict the development of maize in Heilongjiang province. In this paper, the effects of biochar based fertilizer on the nutrient content of acid...Unreasonable fertilizer input and low fertilizer utilization seriously restrict the development of maize in Heilongjiang province. In this paper, the effects of biochar based fertilizer on the nutrient content of acidic soil and corn yield in Heilongjiang province were studied. The random block design was adopted, and seven treatments were set with four repetitions. The results showed that biochar based fertilizer increased the soil organic matter content in the mature stage of maize. The S1 (The biochar biobased fertilizer treatment 1 in acid soil), S2 (The biochar biobased fertilizer treatment 2 in acid soil), and S3 (The biochar biobased fertilizer treatment 3 in acid soil) treatments organic matter contents increased by 15.96%, 11.06% and 10.03% than SCK (The Acid Soil Control Check) respectively. The total nitrogen, total phosphorus, total potassium, total calcium of S1 treatment corn plants increased 16.81%, 15.34%, 31.20% and 22.96% than SCK. The S1 treatment increased the yield of corn, which was 1.94% higher than SCK. There was no significant difference between the yield of S2, S3 with SCK treatments, which achieved the effect of fertilization reducing.展开更多
Cleats are the main channels for fluid transport in coal reservoirs.However,the microscale flow characteristics of both gas and water phases in primary cleats have not been fully studied as yet.Accordingly,the local m...Cleats are the main channels for fluid transport in coal reservoirs.However,the microscale flow characteristics of both gas and water phases in primary cleats have not been fully studied as yet.Accordingly,the local morphological features of the cleat were determined using image processing technology and a transparent cleat structure model was constructed by microfluidic lithography using the multiphase fluid visualization test system.Besides,the effect of microchannel tortuosity characteristics on two‐phase flow was analyzed in this study.The results are as follows:(1)The local width of the original cleat structure of coal was strongly nonhomogeneous.The cleats showed contraction and expansion in the horizontal direction and undulating characteristics in the vertical direction.(2)The transient flow velocity fluctuated due to the structural characteristics of the primary cleat.The water‐driven gas interface showed concave and convex instability during flow,whereas the gas‐driven water interface presented a relatively stable concave surface.(3)The meniscus advanced in a symmetrical pattern in the flat channel,and the flow stagnated due to the influence of undulation points in a partially curved channel.The flow would continue only when the meniscus surface bypassed the stagnation point and reached a new equilibrium position.(4)Enhanced shearing at the gas-liquid interface increased the gas‐injection pressure,which in turn increased residual liquids in wall grooves and liquid films on the wall surface.展开更多
In this study,Zr_(41.2)Ti_(13.8)Cu_(12.5)Ni_(10)Be_(22.5) amorphous alloys samples with the same diameter(8 mm)were prepared by using self-designed molds(viz.refractory steel,pure graphite,and copper molds)with differ...In this study,Zr_(41.2)Ti_(13.8)Cu_(12.5)Ni_(10)Be_(22.5) amorphous alloys samples with the same diameter(8 mm)were prepared by using self-designed molds(viz.refractory steel,pure graphite,and copper molds)with different cooling capacities.Moreover,by eliminating the size effect,the effect of the cooling rate on the microstructure and compression deformation behavior of Zr_(41.2)Ti_(13.8)Cu_(12.5)Ni_(10)Be_(22.5) amorphous alloys was investigated.Differentiation of the cooling curves revealed that the instantaneous cooling rates of the alloy melt at the glass transition temperature(Tg)are 45,52,and 64 K·s^(-1) for refractory steel,pure graphite,and copper molds,respectively.X-ray diffraction,differential scanning calorimetry,and highresolution transmission electron microscopy analysis revealed that with the decrease in the cooling rate,trace icosahedral-like atomic clusters and nanocrystals appear in local areas of the amorphous alloy and that the amount of free volume decreases with the increase in the amount of icosahedra-like atomic clusters and nanocrystals.Compression test results revealed that the elastic strain,yield strength,and compressive strength of the amorphous alloy marginally change with the decrease in the cooling rate,while the plastic strain gradually increases.By fitting,the effective size of the vein-like pattern was linearly related to the enthalpy released during structural relaxation and plastic strain,indicating that at a low cooling rate,the trace nanocrystals in the amorphous alloy could not effectively improve its plasticity and that the amount of free volume mainly affects its plasticity.展开更多
Biochar of agricultural and forestry waste is one of the core ways to solve the greenhouse effect, and it is also the key measure to improve the land productivity of China’s low yield fields and realize the sustainab...Biochar of agricultural and forestry waste is one of the core ways to solve the greenhouse effect, and it is also the key measure to improve the land productivity of China’s low yield fields and realize the sustainable development of agriculture. Due to the large area of China’s albic soil, the long-term drought and flood disasters make it a typical low-yield field, which has not been effectively treated. Biochar provides new hope for improving low-yield albic soil. This paper introduces the basic properties of biochar, the albic soil formation mechanism, the low yield of albic soil factors and the improving theoretical basis of biochar. The paper introduces the technical features of the albic soil improvement and the advantages of the albic soil improvement by biochar. In the view of ascending low production potential, solving the greenhouse effect, achieving agricultural sustainable development, the application value and development prospects of albic soil improved by biochar are discussed.展开更多
Recently,tool learning with large language models(LLMs)has emerged as a promising paradigm for augmenting the capabilities of LLMs to tackle highly complex problems.Despite growing attention and rapid advancements in ...Recently,tool learning with large language models(LLMs)has emerged as a promising paradigm for augmenting the capabilities of LLMs to tackle highly complex problems.Despite growing attention and rapid advancements in this field,the existing literature remains fragmented and lacks systematic organization,posing barriers to entry for newcomers.This gap motivates us to conduct a comprehensive survey of existing works on tool learning with LLMs.In this survey,we focus on reviewing existing literature from the two primary aspects(1)why tool learning is beneficial and(2)how tool learning is implemented,enabling a comprehensive understanding of tool learning with LLMs.We first explore the“why”by reviewing both the benefits of tool integration and the inherent benefits of the tool learning paradigm from six specific aspects.In terms of“how”,we systematically review the literature according to a taxonomy of four key stages in the tool learning workflow:task planning,tool selection,tool calling,and response generation.Additionally,we provide a detailed summary of existing benchmarks and evaluation methods,categorizing them according to their relevance to different stages.Finally,we discuss current challenges and outline potential future directions,aiming to inspire both researchers and industrial developers to further explore this emerging and promising area.展开更多
While China has become the largest online market in the world with approximately 1 billion internet users,Baidu runs the world's largest Chinese search engine serving more than hundreds of millions of daily active...While China has become the largest online market in the world with approximately 1 billion internet users,Baidu runs the world's largest Chinese search engine serving more than hundreds of millions of daily active users and responding to billions of queries per day.To handle the diverse query requests from users at the web-scale,Baidu has made tremendous efforts in understanding users'queries,retrieving relevant content from a pool of trillions of webpages,and ranking the most relevant webpages on the top of the res-ults.Among the components used in Baidu search,learning to rank(LTR)plays a critical role and we need to timely label an extremely large number of queries together with relevant webpages to train and update the online LTR models.To reduce the costs and time con-sumption of query/webpage labelling,we study the problem of active learning to rank(active LTR)that selects unlabeled queries for an-notation and training in this work.Specifically,we first investigate the criterion-Ranking entropy(RE)characterizing the entropy of relevant webpages under a query produced by a sequence of online LTR models updated by different checkpoints,using a query-by-com-mittee(QBC)method.Then,we explore a new criterion namely prediction variances(PV)that measures the variance of prediction res-ults for all relevant webpages under a query.Our empirical studies find that RE may favor low-frequency queries from the pool for la-belling while PV prioritizes high-frequency queries more.Finally,we combine these two complementary criteria as the sample selection strategies for active learning.Extensive experiments with comparisons to baseline algorithms show that the proposed approach could train LTR models to achieve higher discounted cumulative gain(i.e.,the relative improvement DCG4=1.38%)with the same budgeted labellingefforts.展开更多
基金the financial support from the National Natural Science Foundation of China (No.42102127)the Postdoctoral Research Foundation of China (No.2024 M751860)。
文摘Cleat serves as the primary flow pathway for coalbed methane(CBM)and water.However,few studies consider the impact of local contact on two-phase flow within cleats.A visual generalized model of endogenous cleats was constructed based on microfluidics.A microscopic and mesoscopic observation technique was proposed to simultaneously capture gas-liquid interface morphology of pores and throat and the two-phase flow characteristics in entire cleat system.The local contact characteristics of cleats reduced absolute permeability,which resulted in a sharp increase in the starting pressure.The reduced gas flow capacity narrowed the co-infiltration area and decreased water saturation at the isotonic point in a hydrophilic environment.The increased local contact area of cleats weakened gas phase flow capacity and narrowed the co-infiltration area.Jumping events occurred in methane-water flow due to altered porosity caused by local contact in cleats.The distribution of residual phases changed the jumping direction on the micro-scale as well as the dominant channel on the mesoscale.Besides,jumping events caused additional energy dissipation,which was ignored in traditional two-phase flow models.This might contribute to the overestimation of relative permeability.The work provides new methods and insights for investigating unsaturated flow in complex porous media.
基金the National Natural Science Foundation of China(52278403).
文摘Traditional cement-based slurries are often constrained by excessive cement consumption,prolonged setting times,and limited controllability,which hinder their broader engineering applications.To overcome these challenges,this study focuses on optimizing ordinary cement-based slurry through the incorporation of targeted additives and rational adjustment of mix proportions,with the aim of developing a rapid-setting,early-strength cementitious system.In particular,a series of comparative and orthogonal experiments were conducted to systematically examine the evolution of the slurry's macroscopic properties.In addition,the response surface methodology(RSM)was introduced to reveal the interaction mechanisms among key parameters,thereby establishing a quantitative foundation for the precise regulation of slurry performance.The comparative results demonstrate that silica fume significantly outperforms fly ash in enhancing both the rheological and mechanical behavior of the slurry.Regarding fluidity,the average consistency and slump of the silica fume mixture were reduced by 80 mm and 75 mm,respectively,compared with those containing fly ash,indicating more effective control of flowability.In terms of setting and strength development,the silica fume slurry exhibited a setting time up to 9.6 h shorter and a compressive strength up to 3.6 MPa higher under identical mix conditions.These results confirm the clear superiority of silica fume in promoting rapid solidification and early strength gain.
文摘Heilongjiang reclamation area has made great progress since its development and construction, among which the agricultural and forestry colleges in China have played a key role in the input of talents for the production of reclamation area, and the spirit of the Great Wilderness has important strategic significance for the cultivation of agricultural and forestry talents. Taking Heilongjiang Bayi Agricultural University as an example, this paper analyzes the ways of the Great Northern Wilderness Spirit for cultivating application-oriented undergraduate talents in agricultural and forestry colleges, improving the curriculum system of undergraduate talents through innovation, strengthening the cultivation of students’ innovative ability, leading students’ scientific research and academic level, and enhancing students’ practical ability. To innovate the cultivation mode of application-oriented undergraduate talents in agricultural and forestry colleges under the guidance of the spirit of the Great Northern Wilderness, and to provide a reference mode for the cultivation of undergraduate talents in agricultural and forestry colleges in China.
文摘Unreasonable fertilizer input and low fertilizer utilization seriously restrict the development of maize in Heilongjiang province. In this paper, the effects of biochar based fertilizer on the nutrient content of acidic soil and corn yield in Heilongjiang province were studied. The random block design was adopted, and seven treatments were set with four repetitions. The results showed that biochar based fertilizer increased the soil organic matter content in the mature stage of maize. The S1 (The biochar biobased fertilizer treatment 1 in acid soil), S2 (The biochar biobased fertilizer treatment 2 in acid soil), and S3 (The biochar biobased fertilizer treatment 3 in acid soil) treatments organic matter contents increased by 15.96%, 11.06% and 10.03% than SCK (The Acid Soil Control Check) respectively. The total nitrogen, total phosphorus, total potassium, total calcium of S1 treatment corn plants increased 16.81%, 15.34%, 31.20% and 22.96% than SCK. The S1 treatment increased the yield of corn, which was 1.94% higher than SCK. There was no significant difference between the yield of S2, S3 with SCK treatments, which achieved the effect of fertilization reducing.
基金National Natural Science Foundation of China,Grant/Award Numbers:52074169,52174159,522741280。
文摘Cleats are the main channels for fluid transport in coal reservoirs.However,the microscale flow characteristics of both gas and water phases in primary cleats have not been fully studied as yet.Accordingly,the local morphological features of the cleat were determined using image processing technology and a transparent cleat structure model was constructed by microfluidic lithography using the multiphase fluid visualization test system.Besides,the effect of microchannel tortuosity characteristics on two‐phase flow was analyzed in this study.The results are as follows:(1)The local width of the original cleat structure of coal was strongly nonhomogeneous.The cleats showed contraction and expansion in the horizontal direction and undulating characteristics in the vertical direction.(2)The transient flow velocity fluctuated due to the structural characteristics of the primary cleat.The water‐driven gas interface showed concave and convex instability during flow,whereas the gas‐driven water interface presented a relatively stable concave surface.(3)The meniscus advanced in a symmetrical pattern in the flat channel,and the flow stagnated due to the influence of undulation points in a partially curved channel.The flow would continue only when the meniscus surface bypassed the stagnation point and reached a new equilibrium position.(4)Enhanced shearing at the gas-liquid interface increased the gas‐injection pressure,which in turn increased residual liquids in wall grooves and liquid films on the wall surface.
基金supported by the National Natural Science Foundation of China(Grant no.52071278/51827801)the National Key Research and Development Program of China(Grant no.2018YFA0703603)。
文摘In this study,Zr_(41.2)Ti_(13.8)Cu_(12.5)Ni_(10)Be_(22.5) amorphous alloys samples with the same diameter(8 mm)were prepared by using self-designed molds(viz.refractory steel,pure graphite,and copper molds)with different cooling capacities.Moreover,by eliminating the size effect,the effect of the cooling rate on the microstructure and compression deformation behavior of Zr_(41.2)Ti_(13.8)Cu_(12.5)Ni_(10)Be_(22.5) amorphous alloys was investigated.Differentiation of the cooling curves revealed that the instantaneous cooling rates of the alloy melt at the glass transition temperature(Tg)are 45,52,and 64 K·s^(-1) for refractory steel,pure graphite,and copper molds,respectively.X-ray diffraction,differential scanning calorimetry,and highresolution transmission electron microscopy analysis revealed that with the decrease in the cooling rate,trace icosahedral-like atomic clusters and nanocrystals appear in local areas of the amorphous alloy and that the amount of free volume decreases with the increase in the amount of icosahedra-like atomic clusters and nanocrystals.Compression test results revealed that the elastic strain,yield strength,and compressive strength of the amorphous alloy marginally change with the decrease in the cooling rate,while the plastic strain gradually increases.By fitting,the effective size of the vein-like pattern was linearly related to the enthalpy released during structural relaxation and plastic strain,indicating that at a low cooling rate,the trace nanocrystals in the amorphous alloy could not effectively improve its plasticity and that the amount of free volume mainly affects its plasticity.
文摘Biochar of agricultural and forestry waste is one of the core ways to solve the greenhouse effect, and it is also the key measure to improve the land productivity of China’s low yield fields and realize the sustainable development of agriculture. Due to the large area of China’s albic soil, the long-term drought and flood disasters make it a typical low-yield field, which has not been effectively treated. Biochar provides new hope for improving low-yield albic soil. This paper introduces the basic properties of biochar, the albic soil formation mechanism, the low yield of albic soil factors and the improving theoretical basis of biochar. The paper introduces the technical features of the albic soil improvement and the advantages of the albic soil improvement by biochar. In the view of ascending low production potential, solving the greenhouse effect, achieving agricultural sustainable development, the application value and development prospects of albic soil improved by biochar are discussed.
基金funded by the National Key R&D Program of China(2023YFA1008704),the National Natural Science Foundation of China(Grant No.62377044)Beijing Key Laboratory of Big Data Management and Analysis Methods,Major Innovation&Planning Interdisciplinary Platform for the“Double-First Class”Initiative,funds for building world-class universities(disciplines)of Renmin University of China,and PCC@RUC.The authors would like to extend their sincere gratitude to Yankai Lin for his constructive feedback throughout the development of this work.
文摘Recently,tool learning with large language models(LLMs)has emerged as a promising paradigm for augmenting the capabilities of LLMs to tackle highly complex problems.Despite growing attention and rapid advancements in this field,the existing literature remains fragmented and lacks systematic organization,posing barriers to entry for newcomers.This gap motivates us to conduct a comprehensive survey of existing works on tool learning with LLMs.In this survey,we focus on reviewing existing literature from the two primary aspects(1)why tool learning is beneficial and(2)how tool learning is implemented,enabling a comprehensive understanding of tool learning with LLMs.We first explore the“why”by reviewing both the benefits of tool integration and the inherent benefits of the tool learning paradigm from six specific aspects.In terms of“how”,we systematically review the literature according to a taxonomy of four key stages in the tool learning workflow:task planning,tool selection,tool calling,and response generation.Additionally,we provide a detailed summary of existing benchmarks and evaluation methods,categorizing them according to their relevance to different stages.Finally,we discuss current challenges and outline potential future directions,aiming to inspire both researchers and industrial developers to further explore this emerging and promising area.
基金This work was supported in part by the National Key R&D Program of China(No.2021ZD0110303).
文摘While China has become the largest online market in the world with approximately 1 billion internet users,Baidu runs the world's largest Chinese search engine serving more than hundreds of millions of daily active users and responding to billions of queries per day.To handle the diverse query requests from users at the web-scale,Baidu has made tremendous efforts in understanding users'queries,retrieving relevant content from a pool of trillions of webpages,and ranking the most relevant webpages on the top of the res-ults.Among the components used in Baidu search,learning to rank(LTR)plays a critical role and we need to timely label an extremely large number of queries together with relevant webpages to train and update the online LTR models.To reduce the costs and time con-sumption of query/webpage labelling,we study the problem of active learning to rank(active LTR)that selects unlabeled queries for an-notation and training in this work.Specifically,we first investigate the criterion-Ranking entropy(RE)characterizing the entropy of relevant webpages under a query produced by a sequence of online LTR models updated by different checkpoints,using a query-by-com-mittee(QBC)method.Then,we explore a new criterion namely prediction variances(PV)that measures the variance of prediction res-ults for all relevant webpages under a query.Our empirical studies find that RE may favor low-frequency queries from the pool for la-belling while PV prioritizes high-frequency queries more.Finally,we combine these two complementary criteria as the sample selection strategies for active learning.Extensive experiments with comparisons to baseline algorithms show that the proposed approach could train LTR models to achieve higher discounted cumulative gain(i.e.,the relative improvement DCG4=1.38%)with the same budgeted labellingefforts.
