Lithology identificationwhile drilling technology can obtain rock information in real-time.However,traditional lithology identificationmodels often face limitations in feature extraction and adaptability to complex ge...Lithology identificationwhile drilling technology can obtain rock information in real-time.However,traditional lithology identificationmodels often face limitations in feature extraction and adaptability to complex geological conditions,limiting their accuracy in challenging environments.To address these challenges,a deep learning model for lithology identificationwhile drilling is proposed.The proposed model introduces a dual attention mechanism in the long short-term memory(LSTM)network,effectively enhancing the ability to capture spatial and channel dimension information.Subsequently,the crayfishoptimization algorithm(COA)is applied to optimize the model network structure,thereby enhancing its lithology identificationcapability.Laboratory test results demonstrate that the proposed model achieves 97.15%accuracy on the testing set,significantlyoutperforming the traditional support vector machine(SVM)method(81.77%).Field tests under actual drilling conditions demonstrate an average accuracy of 91.96%for the proposed model,representing a 14.31%improvement over the LSTM model alone.The proposed model demonstrates robust adaptability and generalization ability across diverse operational scenarios.This research offers reliable technical support for lithology identification while drilling.展开更多
Cold tolerance is one of the important traits for grapevine,especially in regions with extremely low temperatures in winter.Vitis amurensis is wild species in the Vitis genus with excellent cold hardiness compared wit...Cold tolerance is one of the important traits for grapevine,especially in regions with extremely low temperatures in winter.Vitis amurensis is wild species in the Vitis genus with excellent cold hardiness compared with Vitis vinifera.However,metabolites that contribute to the cold tolerance of V.amurensis remain unknown.Here,the metabolomics of buds from V.amurensis‘Zuoshan-1'during cold acclimation(CA)were identified,and cold-sensitive cultivar(V.vinifera‘Jingzaojing')was used as the control.The buds were collected in October,November,and December in 2016 and 2018.The cold hardiness of the buds increased during CA in the two grapevines.However,browning was observed only in V.vinifera buds at temperature below-10℃.Among detected metabolites from buds,443 metabolites were overlapped between two years.Forty-four and thirty differentially accumulated metabolites(DAMs)were identified in V.amurensis and V.vinifera,respectively.Ten DAMs including monoacylglycerol(MAG,18:2)isomer 1,trehalose 6-phosphate,and D-glucose showed identical variations in the two grapevines,indicating conserved CA responses within the Vitis genus.Eighteen DAMs exhibited higher accumulation in V.amurensis than in V.vinifera.Maltotetraose,D-glucoronic acid,L-aspartic acid,azelaic acid,and 4-hydroxybenzoic acid were reported to accumulate during CA in other plants.Enhanced cold tolerance was detected in grapevine leaves with exogenous 5 mmol L^(-1)L-aspartic acid and 1%proanthocyanidins.Potential contributions of other DAMs found in V.amurensis such as Cyanidin 3-O-glucoside need to be further elucidated.Thus,eighteen metabolites accumulated in V.amurensis can be used for practical application in improvement of cold resistance in grapevine.Our findings provide new insights into understanding the cold hardiness of V.amurensis.展开更多
To address the issues of single warning indicators,fixed thresholds,and insufficient adaptability in coal and gas outburst early warning models,this study proposes a dynamic early warning model for gas outbursts based...To address the issues of single warning indicators,fixed thresholds,and insufficient adaptability in coal and gas outburst early warning models,this study proposes a dynamic early warning model for gas outbursts based on adaptive fractal dimension characterization.By analyzing the nonlinear characteristics of gas concentration data,an adaptive window fractal analysis method is introduced.Combined with boxcounting dimension and variation of box dimension metrics,a cross-scale dynamic warning model for disaster prevention is established.The implementation involves three key phases:First,wavelet denoising and interpolation methods are employed for raw data preprocessing,followed by validation of fractal characteristics.Second,an adaptive window cross-scale fractal dimension method is proposed to calculate the box-counting dimension of gas concentration,enabling effective capture of multi-scale complex features.Finally,dynamic threshold partitioning is achieved through membership functions and the 3σprinciple,establishing a graded classification standard for the mine gas disaster(MGD)index.Validated through engineering applications at Shoushan#1 Coal Mine in Henan Province,the results demonstrate that the adaptive window fractal dimension curve exhibits significantly enhanced fluctuation characteristics compared to fixed window methods,with local feature detection capability improved and warning accuracy reaching 86.9%.The research reveals that this model effectively resolves the limitations of traditional methods in capturing local features and dependency on subjective thresholds through multiindicator fusion and threshold optimization,providing both theoretical foundation and practical tool for coal mine gas outburst early warning.展开更多
As indispensable strategic materials for high-tech industries,rare earth elements and yttrium(REY)have become particularly important in recent years,raising the demand of developing new approaches for reclamation of R...As indispensable strategic materials for high-tech industries,rare earth elements and yttrium(REY)have become particularly important in recent years,raising the demand of developing new approaches for reclamation of REY from REY-rich materials such as coal combustion products(CCPs).In this study,five coal-fired power plants(CFPPs)in Guizhou of southwest China were selected for investigating REY concentrations of solid samples,atmospheric emissions,and recovery potentials.REY concentrations of feed fuels are higher in this study(147.2-468.6 mg/kg)than what have been reported previously for coals in China and the world.REY atmospheric emissions are extremely low(38.70-180.11 mg REY/t coal).REY are enriched in bottom ash and fly ash,with average of 658±296 mg/kg and maximum of 1257 mg/kg from the five CFPPs.Relative enrichment factors(REF)of REY in bottom ash and fly ash compared with the feed fuel are 0.86-1.02 and 0.91-1.04,respectively.REY concentrations in desulfurized gypsum are very low(6-17 mg/kg),and that is mostly inherited from limestone.Critical REY(Nd,Eu,Tb,Dy,Y,and Er)in bottom/fly ash account for 34%-39%of the total REY and the outlook coefficients(Cout1)are in the range of 0.89-1.11.This study indicates a promising prospect to reclaim REY from REYrich CCPs(bottom and fly ash)in CFPPs in Guizhou,especially in the central-north Guizhou,although such practices require further technology advancement.展开更多
The labyrinth seal in turbomachinery is a key element that restricts leakage flow among rotor-stator clearances from high-pressure regions to low-pressure regions. The fluid-induced forces on the rotor from seals duri...The labyrinth seal in turbomachinery is a key element that restricts leakage flow among rotor-stator clearances from high-pressure regions to low-pressure regions. The fluid-induced forces on the rotor from seals during machine operation must be accurately quantified to predict their dynamic behavior effectively. To understand the fluid-induced force characteristics of the labyrinth seal more fully, the effects of four types of pre-swirls on the leakage, flow field, and fluid-induced force of a rotary straight-through labyrinth gas seal (RSTLGS) were numerically investigated using the proposed steady computational fluid dynamics (CFD) method based on the three-dimensional models of the RSTLGS. The leakage, flow field, and fluid-induced force of the RSTLGS for six axial pre-swirl velocities, four radial preswirl angles, four circumferential positive pre-swirl angles, and four circumferential negative pre-swirl angles were computed under the same geometrical parameters and operational conditions. Mesh analysis ensures the accuracy of the present steady CFD method. The numerical results show that the four types of pre-swirls influence the leakage, flow field, and fluid-induced force of the RSTLGS. The axial pre-swirl velocity remarkably inhibits the fluid-induced force, and the circumferential positive pre-swirl angle and circumferential negative pre-swirl angle remarkably promote the fluid-induced force. The effects of the radial pre-swirl angle on the fluid-induced force are complicated, and the pressure forces and viscous forces show the maximum or minimum values at a specific radial pre-swirl angle. The pre-swirl has a negligible impact on the leakage. The four types of pre-swirls affect the leakage, flow field, and fluidinduced force of the RSTLGS to varying degrees. The pre-swirl is the influence factor affecting the leakage, flow field, and fluid-induced force of the RSTLGS. The conclusions will help to understand the fluid-induced force of labyrinth seals more fully, by providing helpful suggestions for engineering practices and a theoretical basis to analyze the fluid–structure interaction of the seal-rotor system in future research.展开更多
Histone H3 lysine 27 trimethylation(H3K27me3) is a histone modification associated with transcriptional repression. However, insights into the genome-wide pattern of H3K27me3 in grapevines are limited. Here, anti-H3K2...Histone H3 lysine 27 trimethylation(H3K27me3) is a histone modification associated with transcriptional repression. However, insights into the genome-wide pattern of H3K27me3 in grapevines are limited. Here, anti-H3K27 chromatin immunoprecipitation(ChIP), high-throughput sequencing, and transcriptome analysis were performed using leaves of Vitis amurensis. The leaves were treated at 4°C for 2 h and 24 h and used to investigate changes in H3K27me3 under chilling treatment. The results show that H3K27me3 is well-distributed both in gene regions(-50%) and in the intergenic region(-50%) in the grapevine genome(Vitis vinifera ‘Pinot Noir PN40024'). H3K27me3 was found to be localized in8 368 annotated gene regions in all detected samples(leaves at normal temperature and under chilling treatments) and mainly enriched in gene bodies with the adjacent promoter and downstream areas. The short-term chilling treatments(4°C for 2 h) induced 2 793 gains and 305losses in H3K27me3 modification. Subsequently, 97.3% of the alterations were restored to original levels after 24 h treatment. The ChIP-qPCR for five differential peaks showed similar results to the data for ChIP-seq, indicating that the chilling-induced H3K27me3 modification is reliable.Integrative analysis of transcriptome and ChIP-seq results showed that the expression of H3K27me3 target genes was significantly lower than those of non-target genes, indicating transcriptional repression of H3K27me3 in grapevine leaves. Furthermore, histone methylation alterations were detected in 82 genes and were related to either repression or activation of their expression during chilling stress. The findings provide the genome-wide H3K27me3 patterns in grapevines and shed light on uncovering its regulation in chilling stress responses.展开更多
Investigation on spatiotemporal variations of maximum seasonal freeze depth （MSFD） over the Heihe River Basin is of great importance for systematic understanding of regional climate and environmental change, ecologi...Investigation on spatiotemporal variations of maximum seasonal freeze depth （MSFD） over the Heihe River Basin is of great importance for systematic understanding of regional climate and environmental change, ecological-hydrological processes, water resources assessment, construction and resource development. Based on soil and air temperatures at the meteorological stations of the China Meteorological Administration （CMA） over the Heihe River Basin, MSFDs time series are structured into a composite time series over the 1960-2007 period. Evaluating the averaged MSFD time series for 1960 2007 reveals a statistically significant trend of 4.0 cm/decade or a net change of-19.2 cm for the 48-year period over the basin. The MSFD had significantly negative correlation with mean annual air temperature （MAAT）, winter air temperature, mean annual ground surface temperature （MAGST）, degree days of thawing for the air （DDTa） as well as for the surface （DDTs）, and degree days of freezing for the surface （DDFs）. While there was significantly positive correlation between DDF,. and MSFD time series, MSFD was deeper and changed greatly in the Heihe River source area. It was shallower in the east-central basin and gradually deepened in other sections of the basin. The MSFD distribution pattern in 2003-2005 is consistent with that of averaged degree days of freezing for air （DDFa） in 1960-2007. However, the maximum of MSFD may not be accurate, because there is no long term observation data in the deep seasonally frozen ground regions near the lower boundary of permafrost. With increasing elevation, averaged DDFa increased at a rate of 51.6 ℃-day/100m, therefore, the MSFG and the date reaching MSFG became deeper and later, respectively.展开更多
Changes in ground surface thermal regimes play a vital role in surface and subsurface hydrology, ecosystem diversity and productivity, and global thermal, water and carbon budgets as well as climate change. Estimating...Changes in ground surface thermal regimes play a vital role in surface and subsurface hydrology, ecosystem diversity and productivity, and global thermal, water and carbon budgets as well as climate change. Estimating spring, summer, autumn and winter air temperatures and mean annual air temperature（MAAT） from 1960 through 2008 over the Heihe River Basin reveals a statistically significant trend of 0.31 °C/decade, 0.28 °C/decade, 0.37 °C/decade, 0.50 °C/decade, and 0.37 °C /decade, respectively. The averaged time series of mean annual ground surface temperature（MAGST） and maximum annual ground surface temperature（MaxAGST） for 1972–2006 over the basin indicates a statistically significant trend of 0.58 °C/decade and 1.27 °C/decade, respectively. The minimum annual ground surface temperature（MinAGST） in the same period remains unchanged as a whole. Estimating surface freezing/thawing index as well as the ratio of freezing index to thawing index（RFT） in the period between 1959 and 2006 over the basin indicates a statistically significant trend of-42.5 °C-day/decade, 85.4 °C-day/decade and-0.018/decade, respectively.展开更多
Taxonomy plays an important role in understanding the origin, evolution, and ecological functionality of biodiversity. There are large number of unknown species yet to be described by taxonomists, which together with ...Taxonomy plays an important role in understanding the origin, evolution, and ecological functionality of biodiversity. There are large number of unknown species yet to be described by taxonomists, which together with their ecosystem services cannot be effectively protected prior to description. Despite this, taxonomy has been increasingly underrated insufficient funds and permanent positions to retain young talents. Further, the impact factordriven evaluation systems in China exacerbate this downward trend, so alternative evaluation metrics are urgently necessary. When the current generation of outstanding taxonomists retires,there will be too few remaining taxonomists left to train the next generation. In light of these challenges, all co-authors worked together on this paper to analyze the current situation of taxonomy and put out a joint call for immediate actions to advance taxonomy in China.展开更多
Bistate plates have found extensive applications in the domains of smart structures and energy harvesting devices.Most bistable curved plates are characterized by a constant thickness profile.Regrettably,due to the in...Bistate plates have found extensive applications in the domains of smart structures and energy harvesting devices.Most bistable curved plates are characterized by a constant thickness profile.Regrettably,due to the inherent complexity of this problem,relatively little attention has been devoted to this area.In this study,we demonstrate how deep learning can facilitate the discovery of novel plate profiles that cater to multiple objectives,including maximizing stiffness,forward snapping force,and backward snapping force.Our proposed approach is distinguished by its efficiency in terms of low computational energy consumption and high effectiveness.It holds promise for future applications in the design and optimization of multistable structures with diverse objectives,addressing the requirements of various fields.展开更多
As a key supporting equipment for the construction of LNG carriers,the installation platform undertakes the support and guarantee of LNG carrier tank internal construction.This paper takes the secondary shielding inst...As a key supporting equipment for the construction of LNG carriers,the installation platform undertakes the support and guarantee of LNG carrier tank internal construction.This paper takes the secondary shielding installation platform of A-type tank as the object of study,the study firstly considers the semi-rigidity of the nodes and the material nonlinearity based on finite element software,and then the residual structure is calculated using static nonlinear method after single truss,two trusses and three trusses are invalid simultaneously.The research results show that the truss with higher components importance coefficient has greater impact on the residual structure when the truss is invalid;After the 2 trusses of installation platform become invalid completely,the further progressive collapse will not occur;When A1-HJ,A2-HJ and A2-HJ are dismantled at the same time,it will lead to the local progressive damage,which can cause the collapse of large-scale structures.The research findings can support the design and use of the installation platform.展开更多
Cissus rotundifolia Lam.is an evergreen climber that mainly distributed in the tropical savannas of eastern Africa with excellent drought resistance.While the mechanism underlying drought stress response in C.rotundif...Cissus rotundifolia Lam.is an evergreen climber that mainly distributed in the tropical savannas of eastern Africa with excellent drought resistance.While the mechanism underlying drought stress response in C.rotundifolia remains unknown.In this study,we investigated the transcriptomics and flavonoid metabolomics responses of C.rotundifolia leaves under different drought conditions.We identified a total of 2401 differentially expressed genes(DEGs)in drought-treated leaves.The continuously increasing DEGs were significantly enriched in pathways related to phenylpropanoid biosynthesis,flavonoid biosynthesis,and galactose metabolism.The total flavonoids content were also found increased significantly during drought treatment in the leaves of C.rotundifolia.A total of 57 distinct flavonoids were identified using UPLC-MS/MS.Among them,nine out of ten differentially accumulated metabolites(DAMs)displayed notable accumulation profiles under drought conditions.These DAMs included two flavanols[(-)-Catechin gallate and(-)-gallocatechin gallate],two flavonols(myricetin and astragalin),four flavones(orientin,cynaroside,isoorientin,and vitexin),and one flavanone(naringenin-7-glucoside),indicating their pivotal roles in drought response.Additionally,a DEG with continuously high-expression,annotated flavone synthase(FLS)synthesises,and synthetizing myricetin under drought stress was tightly related to additional genes belonging to ABA-signaling genes,stomata movement genes,transcription factors,and protein kinases,these genes were contained Top 10 hub-genes of network constructed all DEGs.The results reflect the significance of FLS and potentially regulatory genes under drought conditions.These findings suggest that flavonoids play a pivotal role in the drought stress response of C.rotundifolia,advancing our understanding of flavonoids accumulation and the transcriptional regulation involved in this process.展开更多
Tuberculosis(TB)is a contagious disease that threatens human health worldwide.Combination chemotherapy is usually recommended for this disease.Recently,2 nitroimidazole-based agents,namely,delamanid and pretomanid,hav...Tuberculosis(TB)is a contagious disease that threatens human health worldwide.Combination chemotherapy is usually recommended for this disease.Recently,2 nitroimidazole-based agents,namely,delamanid and pretomanid,have been approved by regulatory agencies.JDB0131 is a novel,structurally optimized third-generation nitroimidazole antituberculosis agent that incorporates the advantages of earlier compounds.This multicenter,prospective,randomized phase 2a trial was conducted to evaluate its efficacy and safety in patients with tuberculosis(NCT06224036).In total,52 patients with newly diagnosed TB were recruited.JDB0131 was tested in a dose escalation manner(cohort 1:100 mg bid,cohort 2:200 mg qd,and cohort 3:200 mg bid).For comparison,delamanid(100 mg bid)and classic fixed-dose combination(FDC)regimens were included as controls.The primary endpoint was logarithmic changes in the number of colony formation units(CFUs)in the solid media culture of sputum TB(log10 CFU).The early bactericidal activity(EBA)of JDB0131 was better than that of delamanid.During the time interval between days 0 and 14,JDB0131 at a dose of 200 mg bid(cohort 3)showed superior efficacy over delamanid.At the end of drug intervention(day 14),JDB0131(all 3 dose levels)achieved superior time to positivity(TTP)over delamanid.Ninety-one adverse events(AEs),including no serious AEs,were attributed to JDB0131 in 30 patients.This trial identified a promising new drug for the increasing TB burden worldwide.展开更多
This study focused on Guizhou’s traditional fermented wind dried pork.Multiple analytical methods were used to understand its properties.High throughput sequencing was used to analyze microbial composition.Gas Chroma...This study focused on Guizhou’s traditional fermented wind dried pork.Multiple analytical methods were used to understand its properties.High throughput sequencing was used to analyze microbial composition.Gas Chromatography Ion Mobility Mass Spectrometry(GC-IMS)was used to identify flavor compounds.Nutritional content like protein,amino acids,fatty acids,cholesterol,and nitrite were determined by standard biochemical assays.Physicochemical indicators such as saponification value,peroxide value,acid value,and pH were measured by established procedures.The results showed that Acinetobacter sp.HRBLi 16,Latilactobacillus sakei,Brochothrix thermosphacta,and Pseudomonas fragi were dominant microbes.Nutritional and physicochemical changes included significant increases in saponification value,peroxide value,acid value,protein,amino acid,and fatty acid contents.Cholesterol content and pH decreased significantly,with nitrite below 1 mg/kg.Among 60 volatile flavor compounds in fermented samples,11 were unidentifiable,including 6 aldehydes,13 alcohols,8 esters,13 ketones,6 alkanes,2 heterocycles,and 1 acid.Multivariate interactive Mantel tests and Pearson correlation analysis revealed positive correlations:fatty acid-acid value;amino acid-cholesterol,acid value,peroxide value;protein-saponification value,pH.Also,volatile flavor compounds related to fatty acids,protein,saponification value,and microbial composition related to saponification value,protein,acid value,pH,cholesterol.These findings aid understanding of fermentation induced changes,offering insights for quality control and product development.展开更多
Aims The aim of this paper is to assess morphological and leaf stoichiometric responses of Dendrosenecio keniensis and Lobelia gregoriana to extreme environmental conditions along an elevation gradient in tropical mou...Aims The aim of this paper is to assess morphological and leaf stoichiometric responses of Dendrosenecio keniensis and Lobelia gregoriana to extreme environmental conditions along an elevation gradient in tropical mountains.Methods In this study,we assessed the variation of the morphological traits,including plant height,leaf area,leaf thickness,leaf dry weight,specific leaf area and the leaf stoichiometry traits nitrogen,carbon and phosphorous of the two endemic species D.keniensis and L.gregoriana.We further explored the relations of these morphological traits to soil organic carbon,soil total nitrogen,soil phosphorous,annual mean temperature,annual mean precipitation,annual total solar radiation,water vapor pressure and the topographic variables aspect,slope and hill shade along the elevation gradient.Ninety 10 m×10 m sampling plots were set up along the elevation gradient ranging from 3500 to 4300 m.We used 1 km×1 km grid cells to rasterize our study area in ArcGIS 10.5 for easy access to data pertaining to the climate of each elevation band.We performed linear regression of the morphological and leaf stoichiometric traits with elevation as explanatory variable.We conducted correlation analysis on the morphological and leaf stoichiometric traits with climatic,soil and topographic variables along the elevation gradient.Important Findings Dendrosenecio keniensis had wool-like pubescent leaves while L.gregoriana had mucilage packed succulent and waxy cuticle leaves to avoid freezing.Both species exhibited reduced metabolic rates as shown by the low leaf phosphorous content.Our results also showed that changes in morphology and leaf stoichiometry were determined by a combination of climate,soil and topographic variables that change along elevation on Mount Kenya.The observed variations in the morphological and leaf stoichiometric traits of D.keniensis and L.gregoriana,which grow side by side along the elevation gradient,were interpreted as adaptation to the harsh environmental conditions.展开更多
基金supported by the National Key Research and Development Program for Young Scientists,Chin(Grant No.2021YFC2900400)the Sichuan-Chongqing Science and Technology Innovation Cooperation Program Project,China(Grant No.2024TIAD-CYKJCXX0269)the National Natural Science Foundation of China,China(Grant No.52304123).
文摘Lithology identificationwhile drilling technology can obtain rock information in real-time.However,traditional lithology identificationmodels often face limitations in feature extraction and adaptability to complex geological conditions,limiting their accuracy in challenging environments.To address these challenges,a deep learning model for lithology identificationwhile drilling is proposed.The proposed model introduces a dual attention mechanism in the long short-term memory(LSTM)network,effectively enhancing the ability to capture spatial and channel dimension information.Subsequently,the crayfishoptimization algorithm(COA)is applied to optimize the model network structure,thereby enhancing its lithology identificationcapability.Laboratory test results demonstrate that the proposed model achieves 97.15%accuracy on the testing set,significantlyoutperforming the traditional support vector machine(SVM)method(81.77%).Field tests under actual drilling conditions demonstrate an average accuracy of 91.96%for the proposed model,representing a 14.31%improvement over the LSTM model alone.The proposed model demonstrates robust adaptability and generalization ability across diverse operational scenarios.This research offers reliable technical support for lithology identification while drilling.
基金supported by the National Key Research and Development Program of China(Grant No.2018YFD1000300)the National Natural Science Foundation of China(Grant Nos.32272691 and 32025032)+1 种基金the Grape Breeding Project of Ningxia(Grant No.NXNYYZ202101-04)the Major Program of Technological Innovation in Hubei Province(Grant No.2022BBA0022)。
文摘Cold tolerance is one of the important traits for grapevine,especially in regions with extremely low temperatures in winter.Vitis amurensis is wild species in the Vitis genus with excellent cold hardiness compared with Vitis vinifera.However,metabolites that contribute to the cold tolerance of V.amurensis remain unknown.Here,the metabolomics of buds from V.amurensis‘Zuoshan-1'during cold acclimation(CA)were identified,and cold-sensitive cultivar(V.vinifera‘Jingzaojing')was used as the control.The buds were collected in October,November,and December in 2016 and 2018.The cold hardiness of the buds increased during CA in the two grapevines.However,browning was observed only in V.vinifera buds at temperature below-10℃.Among detected metabolites from buds,443 metabolites were overlapped between two years.Forty-four and thirty differentially accumulated metabolites(DAMs)were identified in V.amurensis and V.vinifera,respectively.Ten DAMs including monoacylglycerol(MAG,18:2)isomer 1,trehalose 6-phosphate,and D-glucose showed identical variations in the two grapevines,indicating conserved CA responses within the Vitis genus.Eighteen DAMs exhibited higher accumulation in V.amurensis than in V.vinifera.Maltotetraose,D-glucoronic acid,L-aspartic acid,azelaic acid,and 4-hydroxybenzoic acid were reported to accumulate during CA in other plants.Enhanced cold tolerance was detected in grapevine leaves with exogenous 5 mmol L^(-1)L-aspartic acid and 1%proanthocyanidins.Potential contributions of other DAMs found in V.amurensis such as Cyanidin 3-O-glucoside need to be further elucidated.Thus,eighteen metabolites accumulated in V.amurensis can be used for practical application in improvement of cold resistance in grapevine.Our findings provide new insights into understanding the cold hardiness of V.amurensis.
基金funded by the National Key Research and Development ProgramFund for Young Scientists(No.2021YFC2900400)+5 种基金the National Natural Science Foundation of China(No.52304123)Fundamental Research Funds for the Central Universities(No.2024CDJXY025)Sichuan-Chongqing Science and Technology Innovation Cooperation Program Project(No.CSTB2024TIAD-CYKJCXX0016)Postdoctoral Research Foundation of China(No.2023M730412)Postdoctoral Fellowship Program of China Postdoctoral Science Foundation(No.GZB20230914)Chongqing Outstanding Youth Science Foundation Program(No.CSTB2023NSCQ-JQX0027)。
文摘To address the issues of single warning indicators,fixed thresholds,and insufficient adaptability in coal and gas outburst early warning models,this study proposes a dynamic early warning model for gas outbursts based on adaptive fractal dimension characterization.By analyzing the nonlinear characteristics of gas concentration data,an adaptive window fractal analysis method is introduced.Combined with boxcounting dimension and variation of box dimension metrics,a cross-scale dynamic warning model for disaster prevention is established.The implementation involves three key phases:First,wavelet denoising and interpolation methods are employed for raw data preprocessing,followed by validation of fractal characteristics.Second,an adaptive window cross-scale fractal dimension method is proposed to calculate the box-counting dimension of gas concentration,enabling effective capture of multi-scale complex features.Finally,dynamic threshold partitioning is achieved through membership functions and the 3σprinciple,establishing a graded classification standard for the mine gas disaster(MGD)index.Validated through engineering applications at Shoushan#1 Coal Mine in Henan Province,the results demonstrate that the adaptive window fractal dimension curve exhibits significantly enhanced fluctuation characteristics compared to fixed window methods,with local feature detection capability improved and warning accuracy reaching 86.9%.The research reveals that this model effectively resolves the limitations of traditional methods in capturing local features and dependency on subjective thresholds through multiindicator fusion and threshold optimization,providing both theoretical foundation and practical tool for coal mine gas outburst early warning.
基金Project supported by the K.C.Wong Education FoundationNational Natural Science Foundation of China(U1612442)+3 种基金Key Grant for Creative Research Groups of Guizhou Provincial Education Department(Qian-Jiao-He KY Zi2016047)Young Scientific Talents Growth Project of Guizhou Provincial Education Department(Qian-Jiao-He KY Zi 2016252)Doctoralof Zunyi Normal University(Zun-Shi BS 201815)Science and Technology Project of Guizhou Provincial Science and Technology Department(Qian-Ke-He-Ping-Tai-RenCai 20175727-07)。
文摘As indispensable strategic materials for high-tech industries,rare earth elements and yttrium(REY)have become particularly important in recent years,raising the demand of developing new approaches for reclamation of REY from REY-rich materials such as coal combustion products(CCPs).In this study,five coal-fired power plants(CFPPs)in Guizhou of southwest China were selected for investigating REY concentrations of solid samples,atmospheric emissions,and recovery potentials.REY concentrations of feed fuels are higher in this study(147.2-468.6 mg/kg)than what have been reported previously for coals in China and the world.REY atmospheric emissions are extremely low(38.70-180.11 mg REY/t coal).REY are enriched in bottom ash and fly ash,with average of 658±296 mg/kg and maximum of 1257 mg/kg from the five CFPPs.Relative enrichment factors(REF)of REY in bottom ash and fly ash compared with the feed fuel are 0.86-1.02 and 0.91-1.04,respectively.REY concentrations in desulfurized gypsum are very low(6-17 mg/kg),and that is mostly inherited from limestone.Critical REY(Nd,Eu,Tb,Dy,Y,and Er)in bottom/fly ash account for 34%-39%of the total REY and the outlook coefficients(Cout1)are in the range of 0.89-1.11.This study indicates a promising prospect to reclaim REY from REYrich CCPs(bottom and fly ash)in CFPPs in Guizhou,especially in the central-north Guizhou,although such practices require further technology advancement.
基金Supported by National Basic Research Program of China(973 Program,Grant No.2012CB026006)
文摘The labyrinth seal in turbomachinery is a key element that restricts leakage flow among rotor-stator clearances from high-pressure regions to low-pressure regions. The fluid-induced forces on the rotor from seals during machine operation must be accurately quantified to predict their dynamic behavior effectively. To understand the fluid-induced force characteristics of the labyrinth seal more fully, the effects of four types of pre-swirls on the leakage, flow field, and fluid-induced force of a rotary straight-through labyrinth gas seal (RSTLGS) were numerically investigated using the proposed steady computational fluid dynamics (CFD) method based on the three-dimensional models of the RSTLGS. The leakage, flow field, and fluid-induced force of the RSTLGS for six axial pre-swirl velocities, four radial preswirl angles, four circumferential positive pre-swirl angles, and four circumferential negative pre-swirl angles were computed under the same geometrical parameters and operational conditions. Mesh analysis ensures the accuracy of the present steady CFD method. The numerical results show that the four types of pre-swirls influence the leakage, flow field, and fluid-induced force of the RSTLGS. The axial pre-swirl velocity remarkably inhibits the fluid-induced force, and the circumferential positive pre-swirl angle and circumferential negative pre-swirl angle remarkably promote the fluid-induced force. The effects of the radial pre-swirl angle on the fluid-induced force are complicated, and the pressure forces and viscous forces show the maximum or minimum values at a specific radial pre-swirl angle. The pre-swirl has a negligible impact on the leakage. The four types of pre-swirls affect the leakage, flow field, and fluidinduced force of the RSTLGS to varying degrees. The pre-swirl is the influence factor affecting the leakage, flow field, and fluid-induced force of the RSTLGS. The conclusions will help to understand the fluid-induced force of labyrinth seals more fully, by providing helpful suggestions for engineering practices and a theoretical basis to analyze the fluid–structure interaction of the seal-rotor system in future research.
基金supported by the National Key Research and Development Program of China (Grant No. 2018YFD1000300)the National Natural Science Foundation of China (Grant No. 32025032)+1 种基金the Grape Breeding Project of Ningxia (Grant No. NXNYYZ202101-04)Major Program of Technological Innovation in Hubei Province (Grant No. 2019ABA093).
文摘Histone H3 lysine 27 trimethylation(H3K27me3) is a histone modification associated with transcriptional repression. However, insights into the genome-wide pattern of H3K27me3 in grapevines are limited. Here, anti-H3K27 chromatin immunoprecipitation(ChIP), high-throughput sequencing, and transcriptome analysis were performed using leaves of Vitis amurensis. The leaves were treated at 4°C for 2 h and 24 h and used to investigate changes in H3K27me3 under chilling treatment. The results show that H3K27me3 is well-distributed both in gene regions(-50%) and in the intergenic region(-50%) in the grapevine genome(Vitis vinifera ‘Pinot Noir PN40024'). H3K27me3 was found to be localized in8 368 annotated gene regions in all detected samples(leaves at normal temperature and under chilling treatments) and mainly enriched in gene bodies with the adjacent promoter and downstream areas. The short-term chilling treatments(4°C for 2 h) induced 2 793 gains and 305losses in H3K27me3 modification. Subsequently, 97.3% of the alterations were restored to original levels after 24 h treatment. The ChIP-qPCR for five differential peaks showed similar results to the data for ChIP-seq, indicating that the chilling-induced H3K27me3 modification is reliable.Integrative analysis of transcriptome and ChIP-seq results showed that the expression of H3K27me3 target genes was significantly lower than those of non-target genes, indicating transcriptional repression of H3K27me3 in grapevine leaves. Furthermore, histone methylation alterations were detected in 82 genes and were related to either repression or activation of their expression during chilling stress. The findings provide the genome-wide H3K27me3 patterns in grapevines and shed light on uncovering its regulation in chilling stress responses.
基金supported by the Global Change Research Program of China (No. 2010CB951402)the Natural Science Foundation of China (Nos. 91025013, 91325202)+1 种基金the State Key Laboratory of Frozen Soil Engineering (No. SKLFSE-ZY-06), CAS, Chinathe Major Research Plan of the Natural Science Foundation of China (No. 2013CBA01802)
文摘Investigation on spatiotemporal variations of maximum seasonal freeze depth （MSFD） over the Heihe River Basin is of great importance for systematic understanding of regional climate and environmental change, ecological-hydrological processes, water resources assessment, construction and resource development. Based on soil and air temperatures at the meteorological stations of the China Meteorological Administration （CMA） over the Heihe River Basin, MSFDs time series are structured into a composite time series over the 1960-2007 period. Evaluating the averaged MSFD time series for 1960 2007 reveals a statistically significant trend of 4.0 cm/decade or a net change of-19.2 cm for the 48-year period over the basin. The MSFD had significantly negative correlation with mean annual air temperature （MAAT）, winter air temperature, mean annual ground surface temperature （MAGST）, degree days of thawing for the air （DDTa） as well as for the surface （DDTs）, and degree days of freezing for the surface （DDFs）. While there was significantly positive correlation between DDF,. and MSFD time series, MSFD was deeper and changed greatly in the Heihe River source area. It was shallower in the east-central basin and gradually deepened in other sections of the basin. The MSFD distribution pattern in 2003-2005 is consistent with that of averaged degree days of freezing for air （DDFa） in 1960-2007. However, the maximum of MSFD may not be accurate, because there is no long term observation data in the deep seasonally frozen ground regions near the lower boundary of permafrost. With increasing elevation, averaged DDFa increased at a rate of 51.6 ℃-day/100m, therefore, the MSFG and the date reaching MSFG became deeper and later, respectively.
基金supported by the Chinese Academy of Sciences Key Research Program (No. KZZD-EW-13)the Natural Science Foundation of China (Nos. 91025013, 91325202)+1 种基金the State Key Laboratory of Frozen Soil Engineering (No. SKLFSE-ZY-06), CASthe Major Research Plan of the National Natural Science Foundation of China (No. 2013CBA01802)
文摘Changes in ground surface thermal regimes play a vital role in surface and subsurface hydrology, ecosystem diversity and productivity, and global thermal, water and carbon budgets as well as climate change. Estimating spring, summer, autumn and winter air temperatures and mean annual air temperature（MAAT） from 1960 through 2008 over the Heihe River Basin reveals a statistically significant trend of 0.31 °C/decade, 0.28 °C/decade, 0.37 °C/decade, 0.50 °C/decade, and 0.37 °C /decade, respectively. The averaged time series of mean annual ground surface temperature（MAGST） and maximum annual ground surface temperature（MaxAGST） for 1972–2006 over the basin indicates a statistically significant trend of 0.58 °C/decade and 1.27 °C/decade, respectively. The minimum annual ground surface temperature（MinAGST） in the same period remains unchanged as a whole. Estimating surface freezing/thawing index as well as the ratio of freezing index to thawing index（RFT） in the period between 1959 and 2006 over the basin indicates a statistically significant trend of-42.5 °C-day/decade, 85.4 °C-day/decade and-0.018/decade, respectively.
基金mainly supported by National Science Fund for Distinguished Young Scholars (31625024)a grant (2008DP173354) from the Key Laboratory of the Zoological Systematics and Evolution of the Chinese Academy of Sciences。
文摘Taxonomy plays an important role in understanding the origin, evolution, and ecological functionality of biodiversity. There are large number of unknown species yet to be described by taxonomists, which together with their ecosystem services cannot be effectively protected prior to description. Despite this, taxonomy has been increasingly underrated insufficient funds and permanent positions to retain young talents. Further, the impact factordriven evaluation systems in China exacerbate this downward trend, so alternative evaluation metrics are urgently necessary. When the current generation of outstanding taxonomists retires,there will be too few remaining taxonomists left to train the next generation. In light of these challenges, all co-authors worked together on this paper to analyze the current situation of taxonomy and put out a joint call for immediate actions to advance taxonomy in China.
文摘Bistate plates have found extensive applications in the domains of smart structures and energy harvesting devices.Most bistable curved plates are characterized by a constant thickness profile.Regrettably,due to the inherent complexity of this problem,relatively little attention has been devoted to this area.In this study,we demonstrate how deep learning can facilitate the discovery of novel plate profiles that cater to multiple objectives,including maximizing stiffness,forward snapping force,and backward snapping force.Our proposed approach is distinguished by its efficiency in terms of low computational energy consumption and high effectiveness.It holds promise for future applications in the design and optimization of multistable structures with diverse objectives,addressing the requirements of various fields.
文摘As a key supporting equipment for the construction of LNG carriers,the installation platform undertakes the support and guarantee of LNG carrier tank internal construction.This paper takes the secondary shielding installation platform of A-type tank as the object of study,the study firstly considers the semi-rigidity of the nodes and the material nonlinearity based on finite element software,and then the residual structure is calculated using static nonlinear method after single truss,two trusses and three trusses are invalid simultaneously.The research results show that the truss with higher components importance coefficient has greater impact on the residual structure when the truss is invalid;After the 2 trusses of installation platform become invalid completely,the further progressive collapse will not occur;When A1-HJ,A2-HJ and A2-HJ are dismantled at the same time,it will lead to the local progressive damage,which can cause the collapse of large-scale structures.The research findings can support the design and use of the installation platform.
基金supported by International cooperation program,Hubei provice(2024EHA068)the National Science Foundation of China(31961143026)Scientific Research Program of Sino-Africa Joint Research Center(SAJC201614,SAJL201607 and SAJC202101).
文摘Cissus rotundifolia Lam.is an evergreen climber that mainly distributed in the tropical savannas of eastern Africa with excellent drought resistance.While the mechanism underlying drought stress response in C.rotundifolia remains unknown.In this study,we investigated the transcriptomics and flavonoid metabolomics responses of C.rotundifolia leaves under different drought conditions.We identified a total of 2401 differentially expressed genes(DEGs)in drought-treated leaves.The continuously increasing DEGs were significantly enriched in pathways related to phenylpropanoid biosynthesis,flavonoid biosynthesis,and galactose metabolism.The total flavonoids content were also found increased significantly during drought treatment in the leaves of C.rotundifolia.A total of 57 distinct flavonoids were identified using UPLC-MS/MS.Among them,nine out of ten differentially accumulated metabolites(DAMs)displayed notable accumulation profiles under drought conditions.These DAMs included two flavanols[(-)-Catechin gallate and(-)-gallocatechin gallate],two flavonols(myricetin and astragalin),four flavones(orientin,cynaroside,isoorientin,and vitexin),and one flavanone(naringenin-7-glucoside),indicating their pivotal roles in drought response.Additionally,a DEG with continuously high-expression,annotated flavone synthase(FLS)synthesises,and synthetizing myricetin under drought stress was tightly related to additional genes belonging to ABA-signaling genes,stomata movement genes,transcription factors,and protein kinases,these genes were contained Top 10 hub-genes of network constructed all DEGs.The results reflect the significance of FLS and potentially regulatory genes under drought conditions.These findings suggest that flavonoids play a pivotal role in the drought stress response of C.rotundifolia,advancing our understanding of flavonoids accumulation and the transcriptional regulation involved in this process.
基金supported by the Sichuan Province Distinguished Young Science and Technology Program(2019JD100008,X.W.).
文摘Tuberculosis(TB)is a contagious disease that threatens human health worldwide.Combination chemotherapy is usually recommended for this disease.Recently,2 nitroimidazole-based agents,namely,delamanid and pretomanid,have been approved by regulatory agencies.JDB0131 is a novel,structurally optimized third-generation nitroimidazole antituberculosis agent that incorporates the advantages of earlier compounds.This multicenter,prospective,randomized phase 2a trial was conducted to evaluate its efficacy and safety in patients with tuberculosis(NCT06224036).In total,52 patients with newly diagnosed TB were recruited.JDB0131 was tested in a dose escalation manner(cohort 1:100 mg bid,cohort 2:200 mg qd,and cohort 3:200 mg bid).For comparison,delamanid(100 mg bid)and classic fixed-dose combination(FDC)regimens were included as controls.The primary endpoint was logarithmic changes in the number of colony formation units(CFUs)in the solid media culture of sputum TB(log10 CFU).The early bactericidal activity(EBA)of JDB0131 was better than that of delamanid.During the time interval between days 0 and 14,JDB0131 at a dose of 200 mg bid(cohort 3)showed superior efficacy over delamanid.At the end of drug intervention(day 14),JDB0131(all 3 dose levels)achieved superior time to positivity(TTP)over delamanid.Ninety-one adverse events(AEs),including no serious AEs,were attributed to JDB0131 in 30 patients.This trial identified a promising new drug for the increasing TB burden worldwide.
基金supported by the program of The Science and Technology Support Program of Guizhou Province,China(QKHZC-2023–466).
文摘This study focused on Guizhou’s traditional fermented wind dried pork.Multiple analytical methods were used to understand its properties.High throughput sequencing was used to analyze microbial composition.Gas Chromatography Ion Mobility Mass Spectrometry(GC-IMS)was used to identify flavor compounds.Nutritional content like protein,amino acids,fatty acids,cholesterol,and nitrite were determined by standard biochemical assays.Physicochemical indicators such as saponification value,peroxide value,acid value,and pH were measured by established procedures.The results showed that Acinetobacter sp.HRBLi 16,Latilactobacillus sakei,Brochothrix thermosphacta,and Pseudomonas fragi were dominant microbes.Nutritional and physicochemical changes included significant increases in saponification value,peroxide value,acid value,protein,amino acid,and fatty acid contents.Cholesterol content and pH decreased significantly,with nitrite below 1 mg/kg.Among 60 volatile flavor compounds in fermented samples,11 were unidentifiable,including 6 aldehydes,13 alcohols,8 esters,13 ketones,6 alkanes,2 heterocycles,and 1 acid.Multivariate interactive Mantel tests and Pearson correlation analysis revealed positive correlations:fatty acid-acid value;amino acid-cholesterol,acid value,peroxide value;protein-saponification value,pH.Also,volatile flavor compounds related to fatty acids,protein,saponification value,and microbial composition related to saponification value,protein,acid value,pH,cholesterol.These findings aid understanding of fermentation induced changes,offering insights for quality control and product development.
基金supported by National Science Foundation of China(31800176)Sino-Africa Joint Research Center,CAS,China(Y323771W07,SAJC201322).
文摘Aims The aim of this paper is to assess morphological and leaf stoichiometric responses of Dendrosenecio keniensis and Lobelia gregoriana to extreme environmental conditions along an elevation gradient in tropical mountains.Methods In this study,we assessed the variation of the morphological traits,including plant height,leaf area,leaf thickness,leaf dry weight,specific leaf area and the leaf stoichiometry traits nitrogen,carbon and phosphorous of the two endemic species D.keniensis and L.gregoriana.We further explored the relations of these morphological traits to soil organic carbon,soil total nitrogen,soil phosphorous,annual mean temperature,annual mean precipitation,annual total solar radiation,water vapor pressure and the topographic variables aspect,slope and hill shade along the elevation gradient.Ninety 10 m×10 m sampling plots were set up along the elevation gradient ranging from 3500 to 4300 m.We used 1 km×1 km grid cells to rasterize our study area in ArcGIS 10.5 for easy access to data pertaining to the climate of each elevation band.We performed linear regression of the morphological and leaf stoichiometric traits with elevation as explanatory variable.We conducted correlation analysis on the morphological and leaf stoichiometric traits with climatic,soil and topographic variables along the elevation gradient.Important Findings Dendrosenecio keniensis had wool-like pubescent leaves while L.gregoriana had mucilage packed succulent and waxy cuticle leaves to avoid freezing.Both species exhibited reduced metabolic rates as shown by the low leaf phosphorous content.Our results also showed that changes in morphology and leaf stoichiometry were determined by a combination of climate,soil and topographic variables that change along elevation on Mount Kenya.The observed variations in the morphological and leaf stoichiometric traits of D.keniensis and L.gregoriana,which grow side by side along the elevation gradient,were interpreted as adaptation to the harsh environmental conditions.
