Excavation-induced disturbances in deep tunnels will lead to deterioration of rock properties and formation of excavation damaged zone(EDZ).This excavation damage effect may affect the potential rockburst pit depth.Ta...Excavation-induced disturbances in deep tunnels will lead to deterioration of rock properties and formation of excavation damaged zone(EDZ).This excavation damage effect may affect the potential rockburst pit depth.Taking two diversion tunnels of Jinping II hydropower station for example,the relationship between rockburst pit depth and excavation damage effect is first surveyed.The results indicate that the rockburst pit depth in tunnels with severe damage to rock masses is relatively large.Subsequently,the excavation-induced damage effect is characterized by disturbance factor D based on the Hoek-Brown criterion and wave velocity method.It is found that the EDZ could be further divided into a high-damage zone(HDZ)with D=1 and weak-damage zone(WDZ),and D decays from one to zero linearly.For this,a quantitative evaluation method for potential rockburst pit depth is established by presenting a three-element rockburst criterion considering rock strength,geostress and disturbance factor.The evaluation results obtained by this method match well with actual observations.In addition,the weakening of rock mass strength promotes the formation and expansion of potential rockburst pits.The potential rockburst pit depth is positively correlated with HDZ and WDZ depths,and the HDZ depth has a significant contribution to the potential rockburst pit depth.展开更多
BACKGROUND To assess the effectiveness of Shugan Jieyu capsules on peripheral blood miR-124,miR-132,and brain-derived neurotrophic factor(BDNF)levels in patients with mild to moderate depression following coronary art...BACKGROUND To assess the effectiveness of Shugan Jieyu capsules on peripheral blood miR-124,miR-132,and brain-derived neurotrophic factor(BDNF)levels in patients with mild to moderate depression following coronary artery intervention[percuta-neous coronary intervention(PCI)]for coronary heart disease.Patients with mild-to-moderate depression of the liver-qi stagnation type after PCI for coronary heart disease at the 305th Hospital of the People’s Liberation Army were enrolled from June 2022 to November 2023 and randomly assigned to two groups:Experimental(treated with Shugan Jieyu capsules)and control(tr-eated with escitalopram oxalate tablets).This study compared the antidepressant effects of these treatments using 17-item Hamilton Rating Scale for Depression(HAMD-17)scores,metabolic equivalents,low-density lipoprotein cholesterol,BDNF,high-sensitivity C-reactive protein levels,miR-124 and miR-132 levels,distribution of immune-related lymphocyte subsets,and traditional Chinese me-dicine syndrome scores before and after 6 weeks of treatment.RESULTS No significant difference was observed in any index between the two groups before treatment(P>0.05).After treatment,the total efficacy rates were 93.33%and 90.00%in the experimental and control groups,respectively.Experimental group had significantly lower scores for the main and secondary syndromes compared to the control group(P<0.05).No significant difference was observed in the metabolic equivalents between the two groups be-fore and after treatment(P>0.05).The levels of low-density lipoprotein cholesterol,high-sensitivity C-reactive pro-tein,and miR-132 were significantly lower,whereas those of miR-124,BDNF,CD3+T lymphocytes,CD3+CD4+T helper lymphocytes,and CD3+CD4+/CD3+CD8+cells were significantly higher in the experimental group com-pared to the control group(P<0.05).The incidence of adverse reactions during experimental group was signi-ficantly lower than that in control group(P<0.05).CONCLUSION Shugan Jieyu capsules have good efficacy in patients with mild-to-moderate depression after PCI,and its me-chanism may contribute to the regulation of miR-124,miR-132,BDNF levels,and lymphoid immune cells.展开更多
We have investigated homoepitaxy of AlN films grown by molecular beam epitaxy on AlN/sapphire templates byadopting both the continuous growth method and the Al modulation epitaxy(AME)growth method.The continuous growt...We have investigated homoepitaxy of AlN films grown by molecular beam epitaxy on AlN/sapphire templates byadopting both the continuous growth method and the Al modulation epitaxy(AME)growth method.The continuous growthmethod encounters significant challenges in controlling the growth mode.As the precise Al/N=1.0 ratio is difficult toachieve,either the excessive Al-rich or N-rich growth mode occurs.In contrast,by adopting the AME growth method,sucha difficulty has been effectively overcome.By manipulating the supply time of the Al and nitrogen sources,we were able toproduce AlN films with much improved surface morphology.The first step of the AME method,only supplying Al atoms,is important to wet the surface and the Al adatoms can act as a surfactant.Optimization of the initial Al supply time caneffectively reduce the pit density on the grown AlN surface.The pits density dropped from 12 pits/μm^(2)to 1 pit/μm^(2)andthe surface roughness reduced from 0.72 nm to 0.3 nm in a 2×2μm^(2)area for the AME AlN film homoepitaxially grownon an AlN template.展开更多
Apples often exhibit bitter pits in response to metabolic disorders during ripening and storage;however, the mechanisms underlying the bitter pit(BP) development remain unclear. Here, metabolome and transcriptome anal...Apples often exhibit bitter pits in response to metabolic disorders during ripening and storage;however, the mechanisms underlying the bitter pit(BP) development remain unclear. Here, metabolome and transcriptome analyses were performed to investigate BP pulp of 'Fuji'. Two auxin-response genes, MdGH3.1 and MdSAUR36, were screened. Their expression as well as the auxin content in BP pulp were found to be higher than those in healthy pulp(P < 0.01). In the field, excess CO(NH2)2increased the incidence of BP. Moreover, the auxin content and MdGH3.1 expression increased in apples after nitrogen fertilization. On Day 30 before harvest, the two genes were transiently transferred to the fruit, and 20.69% and 23.21% of BP fruits were harvested. After 10 μmol·L-1auxin was infiltrated at low pressure into postharvest fruit, the increase in MdGH3.1 expression occurred earlier than that in MdSAUR36. MdGH3.1 increased the expression of MdSAUR36, but MdSAUR36 did not increase expression of MdGH3.1. Therefore, we suggest that MdGH3.1 acts upstream of MdSAUR36 during BP formation and that these genes induce BP formation by regulating auxin and phenylpropanoid biosynthesis.展开更多
Mining globally contributes to the growth of many economies of the world. Since its inception, the Zambian mining industry has contributed largely to the country’s economy. The various developments both in technology...Mining globally contributes to the growth of many economies of the world. Since its inception, the Zambian mining industry has contributed largely to the country’s economy. The various developments both in technology and knowledge have contributed to the scale at which mining is being done. Challenges in such a setting arise due to the socio-economic and environmental impacts of mining, which create multidimensional problems. The study investigated the importance of engaging stakeholders in progressive rehabilitation programs for large-scale open pit mines, using a case study of the Lumwana Mine and its host community, Manyama. A qualitative approach was used, and data was collected through one-on-one interviews. A combination of convenient and quota sampling was used to engage with host community leaders, professionals and academicians from various fields and institutions. Results showed that most participants had agreed that stakeholder engagement is important for progressive rehabilitation, but the challenge was that the host community and municipal council representatives were not aware of any progressive rehabilitation efforts at Lumwana Mine. This was attributed to a lack of stakeholder engagement and communication of mitigation progress activities by the Lumwana Mine. Results also revealed that the lack of environmental impact assessment regulations to compel companies to involve stakeholders throughout the entire life of the mine other than just at the pre-mining stage led to a lack of compliance and accountability in rehabilitation.展开更多
The quality and aroma of strong-flavor Baijiu are mainly dependent on Daqu,pit mud(PM),and the interaction of both.However,little is known about how their combination patterns affect the microbiome and metabolome of Z...The quality and aroma of strong-flavor Baijiu are mainly dependent on Daqu,pit mud(PM),and the interaction of both.However,little is known about how their combination patterns affect the microbiome and metabolome of Zaopei,especially the metabolic function of rare taxa.Here,an experiment on industrial size was designed to assess the effects of 6 combinations(3 kinds of Daqu×2 kinds of PM)on the composition and assembly of different taxa,as well as the flavor profile.The results showed that Zaopei's microbiota was composed of a few abundant taxa and enormous rare taxa,and rare bacterial and abundant fungal subcommunities were significantly affected by combination patterns.The assembly processes of abundant/rare taxa and bacterial/fungal communities were distinct,and environmental changes mediated the balance between stochastic and deterministic processes in rare bacteria assembly.Furthermore,specific combination patterns improved the flavor quality of Zaopei by enhancing the interspecies interaction,which was closely related to rare taxa,especially rare bacteria.These findings highlighted that rare bacteria might be the keystone in involving community interaction and maintaining metabolic function,which provided a scientific foundation for better understanding and regulating the brewing microbiota from the viewpoint of microbial ecology.展开更多
In open pit mining,uncontrolled block instabilities have serious social,economic and regulatory consequences,such as casualties,disruption of operation and increased regulation difficulties.For this reason,bench face ...In open pit mining,uncontrolled block instabilities have serious social,economic and regulatory consequences,such as casualties,disruption of operation and increased regulation difficulties.For this reason,bench face angle,as one of the controlling parameters associated with block instabilities,should be carefully designed for sustainable mining.This study introduces a discrete fracture network(DFN)-based probabilistic block theory approach for the fast design of the bench face angle.A major advantage is the explicit incorporation of discontinuity size and spatial distribution in the procedure of key blocks testing.The proposed approach was applied to a granite mine in China.First,DFN models were generated from a multi-step modeling procedure to simulate the complex structural characteristics of pit slopes.Then,a modified key blocks searching method was applied to the slope faces modeled,and a cumulative probability of failure was obtained for each sector.Finally,a bench face angle was determined commensurate with an acceptable risk level of stability.The simulation results have shown that the number of hazardous traces exposed on the slope face can be significantly reduced when the suggested bench face angle is adopted,indicating an extremely low risk of uncontrolled block instabilities.展开更多
Pitting corrosion is harmful during bridge construction,which will lead to uneven roughness of steel surfaces and reduce the thickness of steel.Hence,the effect of pitting corrosion on the mechanical properties of col...Pitting corrosion is harmful during bridge construction,which will lead to uneven roughness of steel surfaces and reduce the thickness of steel.Hence,the effect of pitting corrosion on the mechanical properties of cold-formed thin-walled steel stub columns is studied,and the empirical formulas are established through regression fitting to predict the ultimate load of web and flange under pitting corrosion.In detail,the failure modes and load-displacement curves of specimens with different locations,area ratios,and depths are obtained through a large number of non-linear finite element analysis.As for the specimens with pitting corrosion on the web,all the specimens are subject to local buckling failure,and the failure mode will not change with pitting corrosion,but the failure location will change with pitting corrosion location;the size,location,and area ratio of pitting corrosion have little influence on the ultimate load of cold-formed thin-walled steel short columns,but the loss rate of pitting corrosion section area has a greater impact on the ultimate bearing capacity.As for the specimen with flange pitting corrosion,the location and area ratio of pitting corrosion have less influence on the ultimate load of cold-formed thin-walled steel short columns,and the section area loss rate has greater influence on the ultimate bearing capacity;the impact of web pitting corrosion on the ultimate load is greater than that of flange pitting corrosion under the same condition of pitting corrosion section area.The prediction formulas of limit load which are suitable for pitting corrosion of web and flange are established,which can provide a reference for performance evaluation of corroded cold-formed thin-walled steel.展开更多
This paper primarily concerns the effective coordination of the procedures and methods employed in open pit mining operations under the background of river management.The central objective of this study is to identify...This paper primarily concerns the effective coordination of the procedures and methods employed in open pit mining operations under the background of river management.The central objective of this study is to identify a viable approach for ensuring rational and efficient development of open pit mineral resources while simultaneously protecting and restoring the ecological environment of the river.This approach should facilitate the realization of a harmonious symbiosis between mining and river management.The intricate mutual influence relationship between river management and open pit mining is first analyzed in depth,which provides a solid foundation for the subsequent coordination strategy development.In light of the aforementioned considerations,a set of coordination procedures for open pit mining based on river management conditions is proposed.These procedures emphasize the integration of river protection into the overall layout of mining at the planning stage.The implementation of scientific mining schemes,accompanied by rigorous control of the scope and depth of mining operations,has proven to be an effective means of reducing the impact of mining activities on river environments.This approach has also facilitated the achievement of a balance and coordination between mining and river management.展开更多
Micro- and nano-plastics (MNPs) are tiny plastic particles resulting from plastic product degradation. Soil MNPs have been identified as potential influential factors affecting various soil properties and crop biomass...Micro- and nano-plastics (MNPs) are tiny plastic particles resulting from plastic product degradation. Soil MNPs have been identified as potential influential factors affecting various soil properties and crop biomass productivity. This mini-review provides a synthesis of recent findings concerning their effects on soil physicochemical properties, microorganisms, organic carbon content, soil nutrients, greenhouse gas emissions, soil fauna, and their impacts on plant ecophysiology, growth, and production. The results indicate that MNPs may markedly impede soil aggregation ability, increase porosity, decrease soil bulk density, enhance water retention capacity, influence soil pH and electrical conductivity, and escalate soil water evaporation. Exposure to MNPs may predominantly induce changes in soil microbial composition, reducing the diversity and complexity of microbial communities and microbial activity while enhancing soil organic carbon stability, influencing soil nutrient dynamics, and stimulating organic carbon decomposition and denitrification processes, leading to elevated soil respiration and methane emissions, and potentially decreasing soil nitrous oxide emission. Additionally, MNPs may adversely affect soil fauna, diminish seed germination rates, promote plant root growth, yet impair plant photosynthetic efficacy and biomass productivity. These findings contribute to a better understanding of the impacts and mechanistic foundations of MNPs. Future research avenues are suggested to further explore the impacts and economic implications.展开更多
The management of overburden is an important task in open pit exploitations. Site topography and morphology as well as geological and geotechnical properties of natural and remoulded materials are the most important f...The management of overburden is an important task in open pit exploitations. Site topography and morphology as well as geological and geotechnical properties of natural and remoulded materials are the most important factors affecting the disposal phase. Economic and environmental requirements must be followed in order to achieve the best reclamation results, keeping into account site constraints such as slope stability, hauling and dumping issues, and interactions with groundwater. This paper deals with the above mentioned issues, illustrating a rational approach applied on the case of a large limestone quarry where the thickness of the overburden is relevant and the spoil material has to be dumped in a flooded pit. The proposed multidisciplinary approach led to the selection of most suitable methods for excavation, transportation and disposal. The selection was based on a detailed laboratory and site characterisation that defined favorable and adverse factors to be considered during the preliminary study of a large quarrying project.展开更多
To indirectly investigate the dislocation behavior of Fe-36wt%Ni Invar alloy by the etch pit method, polished Invar specimens were etched by a solution containing 4 g copper sulfate, 20 mL hydrochloric acid, and 20 mL...To indirectly investigate the dislocation behavior of Fe-36wt%Ni Invar alloy by the etch pit method, polished Invar specimens were etched by a solution containing 4 g copper sulfate, 20 mL hydrochloric acid, and 20 mL deionized water for 2 min. Etch pits in the etched surfaces were observed. All the etch pits in one specific grain exhibited similar shapes, which are closely related to the grain orienta-tions. These etch pits were characterized as dislocation etch pits. It was observed that etch pits arranged along grain boundaries, gathered at grain tips and strip-like etch pit clusters passed through a number of grains in the pure Invar specimens. After the addition of a small amount of alloying elements, the identification of a single dislocation etch pit is challenging compared with the pure Invar alloy. Thus, the observation of etch pits facilitates the investigation on the dislocation behavior of the pure Invar alloy. In addition, alloying elements may affect the densities and sizes of etch pits.展开更多
构建了一种基于IF模型的侧抑制神经网络群,用以实现位置定位.采用基于H-H模型简化的IF模型构造神经网络群并基于概率密度分布进行位置定位.在神经网络群学习过程中,运用PITS(progressive interactive training scheme)方法进行参数学习...构建了一种基于IF模型的侧抑制神经网络群,用以实现位置定位.采用基于H-H模型简化的IF模型构造神经网络群并基于概率密度分布进行位置定位.在神经网络群学习过程中,运用PITS(progressive interactive training scheme)方法进行参数学习,利用信息中心(IC)储存每次训练的结果,在保证输出收敛的情况下,比较跟踪结果的误差函数给出权值调整公式进行自学习.实验结果表明:基于IF模型构建的神经网络群可以实现位置定位.采用H-H模型简化的IF模型提高了学习效率和定位速度;运用PITS算法进行参数学习提高了定位精度.展开更多
Electrochemical techniques and fractal theory were employed to study the corrosion behaviors and pits distribution characteristics on the corroded surfaces of 304 stainless steel exposed in FeCl3 solution. Fractal fea...Electrochemical techniques and fractal theory were employed to study the corrosion behaviors and pits distribution characteristics on the corroded surfaces of 304 stainless steel exposed in FeCl3 solution. Fractal features of pits distribution over the corroded surfaces were observed and described by the fractal dimension. A 5-8-2 back-propagation (BP) artificial neural network model for the diagnoses of the pitting corrosion rate and pits deepness of 304 stainless steel under various conditions was developed by considering the fractal dimension as a key parameter for describing the pitting corrosion characteristics. The predicted results are well in agreement with the experimental data of pitting corrosion rate and pit deepness. The max relative errors between their experimental and simulation data are 6.69% and 4.62%, respectively.展开更多
The lower slope of furrow pits has following special features: small extent of weathering destruction, short time of production blasting damage, good arching effect of lower slope with small curvature radius, and good...The lower slope of furrow pits has following special features: small extent of weathering destruction, short time of production blasting damage, good arching effect of lower slope with small curvature radius, and good bottom effect of a pit end for transferring and bearing initial horizontal stresses in lower slope. The new principles provided theoretical basis for convex slope in furrow pits to reduce stripping. Similar phenomena and examples are supplied simultaneously.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.42077244).
文摘Excavation-induced disturbances in deep tunnels will lead to deterioration of rock properties and formation of excavation damaged zone(EDZ).This excavation damage effect may affect the potential rockburst pit depth.Taking two diversion tunnels of Jinping II hydropower station for example,the relationship between rockburst pit depth and excavation damage effect is first surveyed.The results indicate that the rockburst pit depth in tunnels with severe damage to rock masses is relatively large.Subsequently,the excavation-induced damage effect is characterized by disturbance factor D based on the Hoek-Brown criterion and wave velocity method.It is found that the EDZ could be further divided into a high-damage zone(HDZ)with D=1 and weak-damage zone(WDZ),and D decays from one to zero linearly.For this,a quantitative evaluation method for potential rockburst pit depth is established by presenting a three-element rockburst criterion considering rock strength,geostress and disturbance factor.The evaluation results obtained by this method match well with actual observations.In addition,the weakening of rock mass strength promotes the formation and expansion of potential rockburst pits.The potential rockburst pit depth is positively correlated with HDZ and WDZ depths,and the HDZ depth has a significant contribution to the potential rockburst pit depth.
基金the 305 Hospital Independent Scientific Research Fund,2024,No.24ZZJJLW-022.
文摘BACKGROUND To assess the effectiveness of Shugan Jieyu capsules on peripheral blood miR-124,miR-132,and brain-derived neurotrophic factor(BDNF)levels in patients with mild to moderate depression following coronary artery intervention[percuta-neous coronary intervention(PCI)]for coronary heart disease.Patients with mild-to-moderate depression of the liver-qi stagnation type after PCI for coronary heart disease at the 305th Hospital of the People’s Liberation Army were enrolled from June 2022 to November 2023 and randomly assigned to two groups:Experimental(treated with Shugan Jieyu capsules)and control(tr-eated with escitalopram oxalate tablets).This study compared the antidepressant effects of these treatments using 17-item Hamilton Rating Scale for Depression(HAMD-17)scores,metabolic equivalents,low-density lipoprotein cholesterol,BDNF,high-sensitivity C-reactive protein levels,miR-124 and miR-132 levels,distribution of immune-related lymphocyte subsets,and traditional Chinese me-dicine syndrome scores before and after 6 weeks of treatment.RESULTS No significant difference was observed in any index between the two groups before treatment(P>0.05).After treatment,the total efficacy rates were 93.33%and 90.00%in the experimental and control groups,respectively.Experimental group had significantly lower scores for the main and secondary syndromes compared to the control group(P<0.05).No significant difference was observed in the metabolic equivalents between the two groups be-fore and after treatment(P>0.05).The levels of low-density lipoprotein cholesterol,high-sensitivity C-reactive pro-tein,and miR-132 were significantly lower,whereas those of miR-124,BDNF,CD3+T lymphocytes,CD3+CD4+T helper lymphocytes,and CD3+CD4+/CD3+CD8+cells were significantly higher in the experimental group com-pared to the control group(P<0.05).The incidence of adverse reactions during experimental group was signi-ficantly lower than that in control group(P<0.05).CONCLUSION Shugan Jieyu capsules have good efficacy in patients with mild-to-moderate depression after PCI,and its me-chanism may contribute to the regulation of miR-124,miR-132,BDNF levels,and lymphoid immune cells.
基金supported by the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0303400)the National Key R&D Program of China(Grant No.2022YFB3605602)+2 种基金the Key R&D Program of Jiangsu Province(Grant Nos.BE2020004-3 and BE2021026)the National Naturaal Science Foundation of China(Grant No.61974065)Jiangsu Special Professorship,Collaborative Innovation Center of Solid-State Lighting and Energysaving Electronics.
文摘We have investigated homoepitaxy of AlN films grown by molecular beam epitaxy on AlN/sapphire templates byadopting both the continuous growth method and the Al modulation epitaxy(AME)growth method.The continuous growthmethod encounters significant challenges in controlling the growth mode.As the precise Al/N=1.0 ratio is difficult toachieve,either the excessive Al-rich or N-rich growth mode occurs.In contrast,by adopting the AME growth method,sucha difficulty has been effectively overcome.By manipulating the supply time of the Al and nitrogen sources,we were able toproduce AlN films with much improved surface morphology.The first step of the AME method,only supplying Al atoms,is important to wet the surface and the Al adatoms can act as a surfactant.Optimization of the initial Al supply time caneffectively reduce the pit density on the grown AlN surface.The pits density dropped from 12 pits/μm^(2)to 1 pit/μm^(2)andthe surface roughness reduced from 0.72 nm to 0.3 nm in a 2×2μm^(2)area for the AME AlN film homoepitaxially grownon an AlN template.
基金the Agricultural Variety Improvement Project of Shandong Province(Grant No.2019LZGC007)Taishan Scholar Foundation of Shandong Province(Grant No.tstp20221134)China Agriculture Research System Foundation(Grant No.CARS-27).
文摘Apples often exhibit bitter pits in response to metabolic disorders during ripening and storage;however, the mechanisms underlying the bitter pit(BP) development remain unclear. Here, metabolome and transcriptome analyses were performed to investigate BP pulp of 'Fuji'. Two auxin-response genes, MdGH3.1 and MdSAUR36, were screened. Their expression as well as the auxin content in BP pulp were found to be higher than those in healthy pulp(P < 0.01). In the field, excess CO(NH2)2increased the incidence of BP. Moreover, the auxin content and MdGH3.1 expression increased in apples after nitrogen fertilization. On Day 30 before harvest, the two genes were transiently transferred to the fruit, and 20.69% and 23.21% of BP fruits were harvested. After 10 μmol·L-1auxin was infiltrated at low pressure into postharvest fruit, the increase in MdGH3.1 expression occurred earlier than that in MdSAUR36. MdGH3.1 increased the expression of MdSAUR36, but MdSAUR36 did not increase expression of MdGH3.1. Therefore, we suggest that MdGH3.1 acts upstream of MdSAUR36 during BP formation and that these genes induce BP formation by regulating auxin and phenylpropanoid biosynthesis.
文摘Mining globally contributes to the growth of many economies of the world. Since its inception, the Zambian mining industry has contributed largely to the country’s economy. The various developments both in technology and knowledge have contributed to the scale at which mining is being done. Challenges in such a setting arise due to the socio-economic and environmental impacts of mining, which create multidimensional problems. The study investigated the importance of engaging stakeholders in progressive rehabilitation programs for large-scale open pit mines, using a case study of the Lumwana Mine and its host community, Manyama. A qualitative approach was used, and data was collected through one-on-one interviews. A combination of convenient and quota sampling was used to engage with host community leaders, professionals and academicians from various fields and institutions. Results showed that most participants had agreed that stakeholder engagement is important for progressive rehabilitation, but the challenge was that the host community and municipal council representatives were not aware of any progressive rehabilitation efforts at Lumwana Mine. This was attributed to a lack of stakeholder engagement and communication of mitigation progress activities by the Lumwana Mine. Results also revealed that the lack of environmental impact assessment regulations to compel companies to involve stakeholders throughout the entire life of the mine other than just at the pre-mining stage led to a lack of compliance and accountability in rehabilitation.
基金supported by the Cooperation Project of Luzhou Laojiao Co.,Ltd.Sichuan University (21H0997)。
文摘The quality and aroma of strong-flavor Baijiu are mainly dependent on Daqu,pit mud(PM),and the interaction of both.However,little is known about how their combination patterns affect the microbiome and metabolome of Zaopei,especially the metabolic function of rare taxa.Here,an experiment on industrial size was designed to assess the effects of 6 combinations(3 kinds of Daqu×2 kinds of PM)on the composition and assembly of different taxa,as well as the flavor profile.The results showed that Zaopei's microbiota was composed of a few abundant taxa and enormous rare taxa,and rare bacterial and abundant fungal subcommunities were significantly affected by combination patterns.The assembly processes of abundant/rare taxa and bacterial/fungal communities were distinct,and environmental changes mediated the balance between stochastic and deterministic processes in rare bacteria assembly.Furthermore,specific combination patterns improved the flavor quality of Zaopei by enhancing the interspecies interaction,which was closely related to rare taxa,especially rare bacteria.These findings highlighted that rare bacteria might be the keystone in involving community interaction and maintaining metabolic function,which provided a scientific foundation for better understanding and regulating the brewing microbiota from the viewpoint of microbial ecology.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.42102313 and 52104125)the Fundamental Research Funds for the Central Universities(Grant No.B240201094).
文摘In open pit mining,uncontrolled block instabilities have serious social,economic and regulatory consequences,such as casualties,disruption of operation and increased regulation difficulties.For this reason,bench face angle,as one of the controlling parameters associated with block instabilities,should be carefully designed for sustainable mining.This study introduces a discrete fracture network(DFN)-based probabilistic block theory approach for the fast design of the bench face angle.A major advantage is the explicit incorporation of discontinuity size and spatial distribution in the procedure of key blocks testing.The proposed approach was applied to a granite mine in China.First,DFN models were generated from a multi-step modeling procedure to simulate the complex structural characteristics of pit slopes.Then,a modified key blocks searching method was applied to the slope faces modeled,and a cumulative probability of failure was obtained for each sector.Finally,a bench face angle was determined commensurate with an acceptable risk level of stability.The simulation results have shown that the number of hazardous traces exposed on the slope face can be significantly reduced when the suggested bench face angle is adopted,indicating an extremely low risk of uncontrolled block instabilities.
基金funded by the‘Research Project of the Sucheng to Sihong Section of the Yanluo Expressway-Measurement Technology and Application of Bridge Quality Project Based on UAV Binocular Imaging(No.00-00-JSFW-20230203-029)’,received by H.Z.Wang.
文摘Pitting corrosion is harmful during bridge construction,which will lead to uneven roughness of steel surfaces and reduce the thickness of steel.Hence,the effect of pitting corrosion on the mechanical properties of cold-formed thin-walled steel stub columns is studied,and the empirical formulas are established through regression fitting to predict the ultimate load of web and flange under pitting corrosion.In detail,the failure modes and load-displacement curves of specimens with different locations,area ratios,and depths are obtained through a large number of non-linear finite element analysis.As for the specimens with pitting corrosion on the web,all the specimens are subject to local buckling failure,and the failure mode will not change with pitting corrosion,but the failure location will change with pitting corrosion location;the size,location,and area ratio of pitting corrosion have little influence on the ultimate load of cold-formed thin-walled steel short columns,but the loss rate of pitting corrosion section area has a greater impact on the ultimate bearing capacity.As for the specimen with flange pitting corrosion,the location and area ratio of pitting corrosion have less influence on the ultimate load of cold-formed thin-walled steel short columns,and the section area loss rate has greater influence on the ultimate bearing capacity;the impact of web pitting corrosion on the ultimate load is greater than that of flange pitting corrosion under the same condition of pitting corrosion section area.The prediction formulas of limit load which are suitable for pitting corrosion of web and flange are established,which can provide a reference for performance evaluation of corroded cold-formed thin-walled steel.
文摘This paper primarily concerns the effective coordination of the procedures and methods employed in open pit mining operations under the background of river management.The central objective of this study is to identify a viable approach for ensuring rational and efficient development of open pit mineral resources while simultaneously protecting and restoring the ecological environment of the river.This approach should facilitate the realization of a harmonious symbiosis between mining and river management.The intricate mutual influence relationship between river management and open pit mining is first analyzed in depth,which provides a solid foundation for the subsequent coordination strategy development.In light of the aforementioned considerations,a set of coordination procedures for open pit mining based on river management conditions is proposed.These procedures emphasize the integration of river protection into the overall layout of mining at the planning stage.The implementation of scientific mining schemes,accompanied by rigorous control of the scope and depth of mining operations,has proven to be an effective means of reducing the impact of mining activities on river environments.This approach has also facilitated the achievement of a balance and coordination between mining and river management.
文摘Micro- and nano-plastics (MNPs) are tiny plastic particles resulting from plastic product degradation. Soil MNPs have been identified as potential influential factors affecting various soil properties and crop biomass productivity. This mini-review provides a synthesis of recent findings concerning their effects on soil physicochemical properties, microorganisms, organic carbon content, soil nutrients, greenhouse gas emissions, soil fauna, and their impacts on plant ecophysiology, growth, and production. The results indicate that MNPs may markedly impede soil aggregation ability, increase porosity, decrease soil bulk density, enhance water retention capacity, influence soil pH and electrical conductivity, and escalate soil water evaporation. Exposure to MNPs may predominantly induce changes in soil microbial composition, reducing the diversity and complexity of microbial communities and microbial activity while enhancing soil organic carbon stability, influencing soil nutrient dynamics, and stimulating organic carbon decomposition and denitrification processes, leading to elevated soil respiration and methane emissions, and potentially decreasing soil nitrous oxide emission. Additionally, MNPs may adversely affect soil fauna, diminish seed germination rates, promote plant root growth, yet impair plant photosynthetic efficacy and biomass productivity. These findings contribute to a better understanding of the impacts and mechanistic foundations of MNPs. Future research avenues are suggested to further explore the impacts and economic implications.
文摘The management of overburden is an important task in open pit exploitations. Site topography and morphology as well as geological and geotechnical properties of natural and remoulded materials are the most important factors affecting the disposal phase. Economic and environmental requirements must be followed in order to achieve the best reclamation results, keeping into account site constraints such as slope stability, hauling and dumping issues, and interactions with groundwater. This paper deals with the above mentioned issues, illustrating a rational approach applied on the case of a large limestone quarry where the thickness of the overburden is relevant and the spoil material has to be dumped in a flooded pit. The proposed multidisciplinary approach led to the selection of most suitable methods for excavation, transportation and disposal. The selection was based on a detailed laboratory and site characterisation that defined favorable and adverse factors to be considered during the preliminary study of a large quarrying project.
文摘To indirectly investigate the dislocation behavior of Fe-36wt%Ni Invar alloy by the etch pit method, polished Invar specimens were etched by a solution containing 4 g copper sulfate, 20 mL hydrochloric acid, and 20 mL deionized water for 2 min. Etch pits in the etched surfaces were observed. All the etch pits in one specific grain exhibited similar shapes, which are closely related to the grain orienta-tions. These etch pits were characterized as dislocation etch pits. It was observed that etch pits arranged along grain boundaries, gathered at grain tips and strip-like etch pit clusters passed through a number of grains in the pure Invar specimens. After the addition of a small amount of alloying elements, the identification of a single dislocation etch pit is challenging compared with the pure Invar alloy. Thus, the observation of etch pits facilitates the investigation on the dislocation behavior of the pure Invar alloy. In addition, alloying elements may affect the densities and sizes of etch pits.
文摘构建了一种基于IF模型的侧抑制神经网络群,用以实现位置定位.采用基于H-H模型简化的IF模型构造神经网络群并基于概率密度分布进行位置定位.在神经网络群学习过程中,运用PITS(progressive interactive training scheme)方法进行参数学习,利用信息中心(IC)储存每次训练的结果,在保证输出收敛的情况下,比较跟踪结果的误差函数给出权值调整公式进行自学习.实验结果表明:基于IF模型构建的神经网络群可以实现位置定位.采用H-H模型简化的IF模型提高了学习效率和定位速度;运用PITS算法进行参数学习提高了定位精度.
基金the Natural Science Foundation of Liaoning Province (No.972210)
文摘Electrochemical techniques and fractal theory were employed to study the corrosion behaviors and pits distribution characteristics on the corroded surfaces of 304 stainless steel exposed in FeCl3 solution. Fractal features of pits distribution over the corroded surfaces were observed and described by the fractal dimension. A 5-8-2 back-propagation (BP) artificial neural network model for the diagnoses of the pitting corrosion rate and pits deepness of 304 stainless steel under various conditions was developed by considering the fractal dimension as a key parameter for describing the pitting corrosion characteristics. The predicted results are well in agreement with the experimental data of pitting corrosion rate and pit deepness. The max relative errors between their experimental and simulation data are 6.69% and 4.62%, respectively.
文摘The lower slope of furrow pits has following special features: small extent of weathering destruction, short time of production blasting damage, good arching effect of lower slope with small curvature radius, and good bottom effect of a pit end for transferring and bearing initial horizontal stresses in lower slope. The new principles provided theoretical basis for convex slope in furrow pits to reduce stripping. Similar phenomena and examples are supplied simultaneously.