期刊文献+
共找到138,069篇文章
< 1 2 250 >
每页显示 20 50 100
Effects of Soil Selenium(Se)Content and Exogenous Se Supplementation on Crop Se Content
1
作者 Mengyin LI Xiaotao ZHU +2 位作者 Shaoying LIAN Hanfang LI Jinmin ZHANG 《Agricultural Biotechnology》 2026年第1期39-41,共3页
[Objectives]This study was conducted to investigate the effects of soil selenium(Se)content and exogenous Se supplementation on crop Se levels and provide a theoretical basis for the production of Se-enriched agricult... [Objectives]This study was conducted to investigate the effects of soil selenium(Se)content and exogenous Se supplementation on crop Se levels and provide a theoretical basis for the production of Se-enriched agricultural products.[Methods]Thirty three representative townships in Xiayi County,Ningling County,and Yongcheng City were selected.Soil Se content and its impact on wheat Se level were measured.The effects of exogenous Se supplementation on the Se content of crops including soybean,wheat,peanut,corn,sweet potato,grape,crisp pear and apple were also investigated.[Results]Showed that the soil Se content in 18 townships of Xiayi County ranged from 0.08 to 0.34 mg/kg,and Se-adequate areas,Se-deficient areas and severely Se-deficient areas accounted for 27.78%,66.67%,and 0.055%of the total,respectively.In Ningling County,the soil Se content in 11 townships ranged from 0.13 to 0.23 mg/kg,and among them,Se-adequate areas and Se-deficient areas comprised 18.18%and 81.82%,respectively.In Yongcheng City,the soil Se content in 4 townships ranged from 0.16 to 0.23 mg/kg,and Se-adequate areas and Se-deficient areas constituted 75.00%and 25.00%,respectively.The soil Se content in 33 townships across Xiayi County,Ningling County,and Yongcheng City ranged from 0.07 to 0.34 mg/kg.However,the Se levels in wheat from all 33 townships fail to meet the standard for Se-enriched agricultural products.It indicates that relying solely on soil Se supply is insufficient for crops to achieve the Se level required for Se-enriched agricultural products.Exogenous Se supplementation could effectively increase the Se content in soybean,wheat,peanut,corn,sweet potato,grape,crisp pear,and apple.Among these,soybean,wheat and peanut showed the highest Se levels after supplementation,all exceeding 0.10 mg/kg and meeting the industry standard for Se-enriched agricultural products.[Conclusions]The results of this study indicates that exogenous Se supplementation can serve as a key measure for producing Se-enriched agricultural products. 展开更多
关键词 Exogenous Se SOIL CROP Se content
在线阅读 下载PDF
Unraveling genetic underpinnings of purine content in pork
2
作者 Cong Huang Min Zheng +8 位作者 Yizhong Huang Liping Cai Xiaoxiao Zou Tianxiong Yao Xinke Xie Bin Yang Shijun Xiao Junwu Ma Lusheng Huang 《Journal of Integrative Agriculture》 2026年第3期1099-1113,共15页
The significance of purine base content as an important nutrition indicator in foods arises from its potential to trigger hyperuricemia or gout via high-purine diet.Livestock meats,including pork,generally contain mod... The significance of purine base content as an important nutrition indicator in foods arises from its potential to trigger hyperuricemia or gout via high-purine diet.Livestock meats,including pork,generally contain moderate to high total purine content(TP).Recent research revealed substantial variations within and across pig breeds,implying genetic factors influencing this trait.Thus,this study aimed to unravel the genetic underpinnings governing purine base content in pork.The heritability estimates(h~2)for the four purine traits ranged from 0.14 to 0.35.A total of 14,36,19 and 25 quantitative trait loci(QTLs)were identified for guanine,adenine,hypoxanthine,and TP,respectively.Our comprehensive gene set enrichment analysis and gene network analysis revealed 15 promising candidate genes intricately interwoven within diverse purine metabolism pathways,such as purine ribonucleotide metabolic process,purine nucleotide metabolism and transport,and purine salvage pathways,all contributing to TP.Strikingly,most genetic variants significantly associated with TP displayed analogous effects on multiple purine bases.Two distinct and highly significant QTLs(P<10^(–12))emerged on Sus scrofa chromosome(SSC)12:one impacting guanine content and the other concurrently influencing adenine and hypoxanthine levels.The peak of the guanine QTL on SSC12 resided 1.1 kb downstream of the transmembrane protein 238 like(TMEM238L)gene and is encapsulated within a genomic segment characterized by the histone modification H3K27me3.Focused fine-mapping for the SSC12 QTL associated with adenine and hypoxanthine levels narrowed its scope to around 172 kb,encompassing the growth arrest specific 7(GAS7)and myosin heavy chain 13(MYH13)genes.However,the observed QTL effect was not attributed to any missense mutations within the two genes.This pioneering study unveils the genetic variations and candidate genes associated with purine content in livestock,laying a robust foundation for the selective breeding of pig lines with reduced purine base content. 展开更多
关键词 PIG purine content genetic architecture GWAS QTL
在线阅读 下载PDF
Content validation of the Global Adolescent and Child Physical Activity Questionnaire(GAC-PAQ)in low-,middle-,and high-income countries across 6 continents
3
作者 Richard Larouche Saulo Neves de Oliveira +45 位作者 Mahdi Rostami Haji Abadi Judy K.Benavides-Castro Olga L.Sarmiento Garazi Angulo Garay Gabriela Argumedo Joseph O.Ashaolu Ameneh Baghestani Jasmin Bhawra Javier Brazo-Sayavera Nutnaree Choonak Christine Delisle Nystrom Seth Evance Zdenek Hamrik Alejandra Jáuregui Piyakrita Kaewpikul Piyawat Katewongsa Anuradha Khadilkar Geoff Kira McPherry Kuntembwe Yang Liu Marie Lof Tom Loney Maria Lundgren Rubina Mandlik Martine Matapo-Kolisko Chidvilas More Tawonga W.Mwase-Vuma Nattaporn Nilwatta Adewale L.Oyeyemi Susan Paudel Nanthawan Pomkai Justin Richards Diego Augusto Santos Silva Melody Smith Narayan Subedi Dyah Anantalia Widyastari Oliver W.A.Wilson SaloméAubert Valerie Carson Rachel C.Colley Dale W.Esliger Nicholas Kuzik Taru Manyanga John J.Reilly Leigh M.Vanderloo Mark S.Tremblay 《Journal of Sport and Health Science》 2026年第2期52-67,共16页
Background:Investigators from low-,middle-,and high-income countries representing 6 continents contributed to the development of the Global Adolescent and Child Physical Activity Questionnaire(GAC-PAQ).The GAC-PAQ is ... Background:Investigators from low-,middle-,and high-income countries representing 6 continents contributed to the development of the Global Adolescent and Child Physical Activity Questionnaire(GAC-PAQ).The GAC-PAQ is designed to assess physical activity(PA)across all key domains(i.e.,school,chores,work/volunteering,transport,free time,outdoor time).It aimed to address multiple gaps in global PA surveillance(e.g.,omission of important PA domains,insufficient cultural adaptation,underrepresentation of rural areas in questionnaire validation studies).The purpose of this study was to assess the content validity of the GAC-PAQ among PA experts,8-to 17-year-olds,and one of their parents/guardians,and to discuss changes made to the questionnaire based on participants'feedback.Methods:Sixty-two experts in PA measurement and/or surveillance from 24 countries completed an online survey that included both closed-and open-ended questions about the content validity of the GAC-PAQ.The proportion of experts who agreed or strongly agreed with the items was calculated.Child-parent/guardian dyads from 15 countries(n=250;10-40 per country)participated in a structured cognitive interview to assess the clarity of the questions and response options,and they were encouraged to provide suggestions to improve clarity and facilitate completion of the questionnaire.Participating countries are:Aotearoa New Zealand,Brazil,Canada,China,Colombia,Czech Republic,India,Malawi,Mexico,Nepal,Nigeria,Spain,Sweden,Thailand,and the United Arab Emirates.Interviews were conducted in 13 different languages and structured by PA domain.Generic images were included to help participants in answering questions about PA intensity.Results:Expert agreement with the items for each domain exceeded 75%,and their qualitative feedback was used to revise the questionnaire before cognitive interviews.In general,participants found the questionnaire to be comprehensive.Adolescents(12-17 years)found it easier than children(8-11 years)to answer the questions.Several children struggled to answer questions about the duration and intensity of activities and/or concepts related to travel modes,active trips,and organized activities.Many parents/guardians were unsure about the frequency,duration,and intensity of their children's or adolescents'PA at school and/or recommended using more culturally relevant and appropriate images.Some participants misunderstood the concept of activities that“make you stronger”(intended to assess resistance activities)and/or struggled to differentiate between work,volunteering,and chores.Conclusion:Participants'feedback was used to develop a revised,simplified,and culturally adapted GAC-PAQ,which will be pilot-tested in all15 countries in an App that will include country-specific images and narration in local languages.Further research is needed to assess the reliability and validity of the revised GAC-PAQ. 展开更多
关键词 Measurement Surveillance content validity Global health Cultural adaptation
在线阅读 下载PDF
Comprehensive evaluation of seed iron content in peanut germplasm and identification of elite genotypes with high iron
4
作者 Jianbin Guo Li Huang +7 位作者 Huaiyong Luo Weigang Chen Bolun Yu Xiaojing Zhou Huifang Jiang Boshou Liao Yong Lei Nian Liu 《Oil Crop Science》 2026年第1期38-44,共7页
Iron is an essential mineral element that plays important roles in plant growth,development,and human health.Peanut is a valuable source of iron for human nutrition.Improving iron content in peanut seeds can enhance b... Iron is an essential mineral element that plays important roles in plant growth,development,and human health.Peanut is a valuable source of iron for human nutrition.Improving iron content in peanut seeds can enhance both yield potential and nutritional value.In this study,the seed iron content of the 401 peanut germplasm accessions was estimated and substantial variation among these accessions was observed,ranging from 9.02 to 50.60 mg/kg.The seed iron content of valencia type accessions was significantly higher than that of Peruvian,Virginia,and Irregular types.Landraces showed the highest average iron content,followed by advanced cultivars,breeding lines and interspecific hybrid cultivars.Accessions with red seed coat exhibited significantly higher iron content compared with those with pink seed coat.Correlation analysis revealed that the seed iron content significantly negatively correlated with hundred seed weight(HSW),resveratrol and oleic acid.Eight accessions with high iron content were identified with an average iron content of 32.46 mg/kg,including two elite genotypes that Zh.h4280 showed high resveratrol levels(1057.34μg/kg)and Zh.h1976 exhibited large seeds(HSW over 90g).Association analysis identified four markers,one of which,AHGS2053 stably explained with 5.75%–5.84%phenotypic variation.Accessions containing the favorable allele AHGS2053-250bp exhibited significantly higher iron content compared to those with alternative alleles.The results provide valuable germplasm resources and associated markers for breeding programs targeting high iron content in peanuts. 展开更多
关键词 PEANUT Iron content Germplasm accessions Comprehensive evaluation
在线阅读 下载PDF
Effects of Different Moisture Content on the Quality Characteristics of Sichuan Sausage during Frozen Storage
5
作者 Qi ZHOU Jiamin ZHANG +2 位作者 Lili JI Wei WANG Ting BAI 《Agricultural Biotechnology》 2026年第1期26-35,共10页
Sichuan sausages with moisture contents of 40%,45%,50%,and 60% were stored at-18℃for durations of 0,2,4,6,and 8 weeks to evaluate the effect of moisture content on the quality attributes of Sichuan sausages during fr... Sichuan sausages with moisture contents of 40%,45%,50%,and 60% were stored at-18℃for durations of 0,2,4,6,and 8 weeks to evaluate the effect of moisture content on the quality attributes of Sichuan sausages during frozen storage.Product indicators including pH,colour,thiobarbituric acid reactive substances(TBARS),total volatile basic nitrogen(TVB-N),texture,electronic nose(E-nose)response,and water-holding capacity(thawing and cooking losses)were determined.The results indicated that as storage time increased,water retention in Sichuan sausages with different moisture contents decreased,while the degree of protein and lipid oxidation increased.This led to an increase in pH value,a colour shift from red-bright to grey-brown,and a deterioration in palatability.Among the samples,sausages with 50% moisture content exhibited the lowest thawing and cooking losses,indicating superior water-holding capacity.After 8 weeks of storage,TBARS and TVB-N values for the 50% moisture group were 19.5%and 2.5%lower,respectively,than those of the 40%and 45%moisture groups,indicating a reduced degree of oxidation.Furthermore,Sichuan sausage with 50%moisture content demonstrated an appropriate pH and colour difference,along with excellent texture and flavour,as evidenced by its higher toughness and satisfactory hardness.In conclusion,Sichuan sausage with 50% moisture content demonstrated the highest overall quality under frozen storage conditions. 展开更多
关键词 Sichuan sausage Moisture content Storage time Quality characteristics
在线阅读 下载PDF
Analysis of Histochemical Localization and Content Influencing Factors of Saponins in Pseudostellaria heterophylla
6
作者 Huiqing PAN Yanda ZHANG +3 位作者 Zhenhua WANG Qi ZHAO Zuyun YE Xin WANG 《Medicinal Plant》 2026年第1期5-9,19,共6页
This paper provides a systematic review of the histochemical localization,content characteristics,and influencing factors of saponins in Pseudostellaria heterophylla based on an extensive literature survey.It provides... This paper provides a systematic review of the histochemical localization,content characteristics,and influencing factors of saponins in Pseudostellaria heterophylla based on an extensive literature survey.It provides an in-depth analysis and summary of the effects of biological factors,environmental conditions,agronomic practices,processing methods,and continuous cropping obstacles on the synthesis of P.heterophylla saponins,as well as their underlying mechanisms.Based on identified gaps in the current literature,future research directions and prospects are proposed.The findings of this review offer valuable insights for advancing the understanding of the saponin biosynthesis mechanisms in P.heterophylla and for enhancing its quality. 展开更多
关键词 Pseudostellaria heterophylla SAPONIN Histochemical localization content influencing factors Research progress
暂未订购
Particle size ratios and ice content effects on rock-ice avalanche propagation and deposition:Flume experiments and DEM simulations
7
作者 LUO Xin YANG Qingqing +1 位作者 HUO Zihao QIN Yao 《Journal of Mountain Science》 2026年第1期221-236,共16页
Rock-ice avalanches in cold high-mountain regions pose severe hazards due to their high mobility,yet the quantitative controls of particle-size ratio and ice content remain insufficiently constrained.This study invest... Rock-ice avalanches in cold high-mountain regions pose severe hazards due to their high mobility,yet the quantitative controls of particle-size ratio and ice content remain insufficiently constrained.This study investigates their coupled effects using inclinedflume experiments and Discrete Element Method(DEM)simulations,covering three gravel sizes(2-5 mm,5-7 mm,7-10 mm)and four ice-content levels(0%,20%,40%,60%).Run-out distance,velocity,energy components,flow regime(Savage number),and segregation indexαwere quantified.Increasing ice content significantly enhances mobility,but with diminishing marginal effectiveness.From 0%to 40%ice content,run-out distance increases by 41%-86%,whereas the additional increase from 40%to 60%contributes only 12%-23%.Particle-size ratio strongly governs segregation intensity.Fine-gravel groups reach segregation indices ofα=0.92-0.98,indicating nearly complete upward migration of ice,whereas medium-gravel and coarse-gravel groups exhibit much weaker segregation,stabilizing atα=0.68-0.74 and 0.60-0.69.Savage number analyses reveal marked flow-regime transitions.At 0%ice content,Savage numbers reach 1.0-1.5,indicating a collisional regime.Increasing ice content suppresses collisionality,with Savage numbers decreasing to 0.03-0.07 at 60%ice content,consistent with dense-regime flow.DEM energy analyses confirm this regime shift:for finegravel mixtures,collision energy decreases by 14%,while sliding-friction energy increases by 33%as ice content increases from 0%to 60%,reflecting enhanced overburden effects imposed by upward-segregated ice layers.Medium and coarse mixtures exhibit weaker or opposite energy-shift patterns,demonstrating strong size dependence.Mechanistically,large particle-size contrasts promote strong segregation and form dense basal rock layers that increase basal friction and reduce mobility.When particle sizes are similar or ice content is high,segregation remains limited,allowing ice to mix into the basal layer,thereby reducing basal friction and enhancing mobility.This research quantitatively demonstrates how composition controls particle spatial distribution,flow regime,and energy dissipation,offering new mechanistic insights into the propagation and deposition behaviors of rock-ice avalanches and improving hazard assessment in vulnerable high-mountain regions. 展开更多
关键词 Rock-ice avalanche DEM Flume experiment Ice content Particle size ratio SEGREGATION
原文传递
On clay contents of loess deposits at eight regions in Loess Plateau and Ili area,China
8
作者 Jiawei Liu Zhongqi Quentin Yue 《Journal of Rock Mechanics and Geotechnical Engineering》 2026年第3期2251-2265,共15页
This paper uses a complete washing and sieving method and accurately determines the clay mass contents in the loess deposits at the eight regions of Xianyang,Ili,Xi'an,Yan'an,Lvliang,Linfen,Xining,and Lanzhou ... This paper uses a complete washing and sieving method and accurately determines the clay mass contents in the loess deposits at the eight regions of Xianyang,Ili,Xi'an,Yan'an,Lvliang,Linfen,Xining,and Lanzhou in China.The method uses nylon cloth sieves with apertures from 0.0008 mm to 0.048 mm and standard steel sieves with apertures from 0.063 mm to 28 mm.It uses a rotary vibration machine to wash and sieve the loess into many clay,silt,sand,and gravel subgroups.The masses of the separated materials construct the complete mass-based particle size distribution(PSD)curves for the tested loesses.The results show that the Xianyang,Ili,Xi'an,Yan'an,Lvliang,Linfen,Xining,and Lanzhou loesses contain 65.28%,56.73%,56.76%,38.7%,31.78%,30.55%,30.1%,and 26.29%clay in mass.These clay contents are 1.3-14.9 times higher than the clay contents from the past publications for the eight types of loess.On the other hand,the plasticity data in past publications show that loess belongs to the clay type of soil.The clay contents in the publications are underestimated,which is caused by the inseparability of fine soils(or clay and silt mixture)from the existing PSD test methods.Macro-photographs,micro-photographs and SEM photographs present the separated materials of individual clay,silt,sand,and gravel particles.Particle sizes measured from the SEM photographs confirm their particle sizes within their size limits.The clay particles exhibit strong internal cohesion,while the silt,sand,and gravel particles are individual and non-cohesive.Atterberg limits test results further demonstrate the clay particles'high plasticity features and the silt particles'non-plasticity features. 展开更多
关键词 Complete washing and sieving method Clay content LOESS Loess plateau
在线阅读 下载PDF
ACSL4 is a target forβ-hydroxybutyrate-induced increase in fatty acid content and lipid droplet accumulation in bovine mammary epithelial cells
9
作者 Ming Li Jingjing Wang +8 位作者 Jia’nan Wen Juan JLoor Qianming Jiang Jingyi Wang Huijing Zhang Yue Yang Wei Yang Bingbing Zhang Chuang Xu 《Journal of Integrative Agriculture》 2026年第3期1137-1149,共13页
Ketosis,a common metabolic disease during early lactation,is associated with high circulating levels ofβ-hydroxybutyrate(BHB).A portion of BHB that reaches the mammary gland is utilized as precursor for synthesis of ... Ketosis,a common metabolic disease during early lactation,is associated with high circulating levels ofβ-hydroxybutyrate(BHB).A portion of BHB that reaches the mammary gland is utilized as precursor for synthesis of fatty acids.Recent findings from nonruminant studies revealed that long chain fatty acyl-CoA ligase 4(ACSL4)could play a role in the regulation of cellular fatty acid metabolism,but the mechanisms by which ACSL4 mediates cellular lipid metabolism in response to BHB remains unclear.To achieve the aims,we conducted in vivo or in vitro analyses using bovine mammary gland biopsies and the immortalized mammary epithelial cell line(MAC-T).The in vivo study(n=6 cows per group)involved healthy cows(plasma BHB<0.60 mmol L^(–1))or ketotic cows(plasma BHB>2.0 mmol L^(–1))from which mammary gland tissue was biopsied.In vitro,MAC-T cells were challenged with 0,0.3,0.6,1.2,or 2.4 mmol L^(–1)BHB for 24 h to determine an optimal dose.Subsequently,MAC-T were incubated with 1.2 mmol L^(–1)BHB for 0,3,6,12,24,or 48 h.Furthermore,MAC-T cells were treated with small interfering ACSL4(siACSL4)for 24 h or ACSL4 overexpression plasmid(pcACSL4)for 36 h followed by a challenge with 1.2 mmol L^(–1)BHB for 24 h.Results showed that increased mRNA and protein abundance of lipogenic genes were linked to both mammary gland and in vitro challenge with BHB.BHB increased fatty acid content by activating ACSL4 expression,whereas inhibition of ACSL4 reduced BHB-induced reactive oxygen species(ROS)overproduction,enhancement of mitochondrial membrane potential,increase in fatty acid content,and lipid droplet accumulation.Furthermore,we also elevated ACSL4 expression with an overexpression plasmid to clarify its molecular role in response to BHB challenge.ACSL4 overexpression enhances BHB-induced lipid droplet accumulation by increased fatty acid content.Overall,the information showed that ACSL4 is crucial for the process of producing fatty acids from exogenous BHB.Reduced ACSL4 decreased fatty acid content and lipid droplet accumulation,improved mitochondrial function,directed more fatty acids towards oxidation.Thus,ACSL4 plays an important role in determining the fate of intracellular fatty acids and BHB in BMECs. 展开更多
关键词 bovine mammary epithelial cells fatty acid content KETOSIS BHB ACSL4
在线阅读 下载PDF
Bypassing Typhoons Cause Three-dimensional Dramatic Changes in Temperature and Ocean Heat Content of the Yellow Sea and Bohai Sea:A Case Study with Super Typhoon Maysak(2020)
10
作者 Fangguo ZHAI Junyan ZHANG +4 位作者 Yucheng WANG Yujie DONG Yanping MA Cong LIU Zizhou LIU 《Advances in Atmospheric Sciences》 2026年第3期591-611,共21页
The Yellow Sea and Bohai Sea are among the global shelf seas susceptible to typhoons every year.Using observations and high-resolution numerical simulations,the current study investigates the dramatic changes in tempe... The Yellow Sea and Bohai Sea are among the global shelf seas susceptible to typhoons every year.Using observations and high-resolution numerical simulations,the current study investigates the dramatic changes in temperature and ocean heat content(OHC)of the Yellow Sea and Bohai Sea caused by Super Typhoon Maysak in early September 2020,which is representative of northward/northeastward-bypassing typhoons with centers just to the east of the study area.Temperature shows spatially coherent cooling in the upper mixed layer but warming in the subsurface layer in the majority of the offshore waters,due to wind-enhanced vertical mixing.In lower layers from the thermocline to sea bottom,temperature experiences significant warming in northeastern coastal waters of the Shandong Peninsula and in regions just off the Subei Shoal,but significant cooling in western coastal waters of the Korean Peninsula and southern coastal waters of the Shandong Peninsula.Significant temperature warming/cooling in lower layers is caused by coastal downwelling/upwelling.The total OHC of the study area decreases rapidly during Typhoon Maysak(2020)’s passage,which is generated comparably by latent heat loss at the sea surface and southward heat advection out of the study area at the southern boundary.Reduced shortwave radiation contributes positively but secondarily to the decreasing OHC during the first day.A numerical experiment suggests that Typhoon Maysak(2020)-induced OHC decline could have greatly affected the regional climate evolution in the following seasons.More studies are needed to fully understand the impacts of typhoons on regional climate changes in shelf seas at different time scales. 展开更多
关键词 shelf sea dynamics TYPHOON ocean heat content overturning currents regional climate change
在线阅读 下载PDF
Evaluation of the susceptibility to landslide geological disasters based on different slope units and an information content random forest model:a case study of the Longhua District,Shenzhen
11
作者 XIONG Haoyu RAN Xiangjin XUE Linfu 《Global Geology》 2026年第1期86-100,共15页
Slope units are divided according to the real topography and have clear geological characteristics,making them ideal units for evaluating the susceptibility to geological disasters.Based on the results of automaticall... Slope units are divided according to the real topography and have clear geological characteristics,making them ideal units for evaluating the susceptibility to geological disasters.Based on the results of automatically and manually corrected hydrological slope unit division,the Longhua District,Shenzhen City,Guangdong Province,was selected as the study area.A total of 15 influencing factors,namely Fluctuation,slope,slope aspect,curvature,topographic witness index(TWI),stream power index(SPI),topographic roughness index(TRI),annual average rainfall,distance to water system,engineering rock group,distance to fault,land use,normalized difference vegetation index(NDVI),nighttime light,and distance to road,were selected as evaluation indicators.The information volume model(IV)and random points were used to select non-geological disaster units,and then the random forest model(RF)was used to evaluate the susceptibility to geological disasters.The automatic slope unit and the hydrological slope unit were compared and analyzed in the random forest and information volume random forest models.The results show that the area under the curve(AUC)values of the automatic slope unit evaluation results are 0.931 for the IV-RF model and 0.716 for the RF model,which are 0.6%(IV-RF model)and 1.9%(RF model)higher than those for the hydrological slope unit.Based on a comparison of the evaluation methods based on the two types of slope units,the hydrological slope unit evaluation method based on manual correction is highly subjective,is complicated to operate,and has a low evaluation accuracy,whereas the evaluation method based on automatic slope unit division is efficient and accurate,is suitable for large-scale efficient geological disaster evaluation,and can better deal with the problem of geological disaster susceptibility evaluation. 展开更多
关键词 geological hazards slope unit information content random forest model susceptibility assessment SHENZHEN
在线阅读 下载PDF
Effect of water content on small-strain dynamic properties of rock using free-free testing
12
作者 Gunwoong Kim Sungmoon Hwang Kenneth H.Stokoe 《Journal of Rock Mechanics and Geotechnical Engineering》 2026年第3期2087-2103,共17页
As environmental concerns drive shifts in construction materials,rock is increasingly considered as an alternative to sand,reinforcing the importance of understanding its dynamic properties.This study investigates the... As environmental concerns drive shifts in construction materials,rock is increasingly considered as an alternative to sand,reinforcing the importance of understanding its dynamic properties.This study investigates the effect of water content on the small-strain dynamic properties of basalt samples using free-free laboratory testing.Free-free testing,which requires minimal equipment and preparation,provides an efficient and low-cost method for determining key dynamic properties,including three wave velocities(V_(s),V_(p),and V_(c)),material damping ratios,and Poisson's ratios.These properties are crucial for numerical modeling in earthquake analyses and geotechnical site characterization.The test consists of three components:(1)direct travel-time measurement,(2)torsional resonance testing,and(3)compressional resonance testing.A total of 20 rock samples were tested under systematically controlled water contents,ranging from fully dried to saturated,to quantify the effects on Poisson's ratio and material damping ratios.The results showed significant increases in both parameters with rising water content.The Poisson's ratio increased by up to 320%for aphanitic basalt and 150%for vesicular basalt,while the damping ratio rose up to 30-fold(D_(c,min))and 16-fold(D_(s,min)).These findings highlight the critical need to incorporate consideration of water content when characterizing dynamic rock properties for seismic and geotechnical analyses.The practical applicability of this research lies in improving in situ property interpretation and enhancing seismic design reliability by providing engineers with precise relationships between water content and dynamic rock behavior. 展开更多
关键词 Free-free test Water content Shear wave velocity Material damping ratio Poisson's ratio
在线阅读 下载PDF
Quantifying and predicting trait combinations to enhance ecological multifunctionality of urban broad-leaf forest tree species:leaf carbon content is an essential trait
13
作者 Ruiting Wang Sheng Xu +3 位作者 Kexin Gao Yixin Zhang Yan Li Xingyuan He 《Journal of Forestry Research》 2026年第1期98-110,共13页
Urban forests are highly multifunctional and provide numerous ecological functions.Plant functional traits individually or jointly influence the ecological multifunctionality of tree species(TS-EMF)and can also modify... Urban forests are highly multifunctional and provide numerous ecological functions.Plant functional traits individually or jointly influence the ecological multifunctionality of tree species(TS-EMF)and can also modify TSEMF in response to environmental changes.However,there has been limited exploration of multitrait combinations for predicting TS-EMF across seasons and of trait thresholds that enhance TS-EMF.Here,for 10 dominant tree species in urban forests of Northeast China,14 traits were measured and four aboveground and three belowground ecological functions assessed in three seasons.Ecological functions and TS-EMF differed significantly throughout the seasons(P<0.05).Synergistic relationships were found between carbon sequestration and oxygen release,between cooling and humidification,and between organic carbon accumulation and nutrient cycling.Notably,aboveground multifunctionality played a leading role in TS-EMF.With seasonal changes,resource allocation shifted toward traits related to resource acquisition rather than conservation to maintain TS-EMF.The combination of traits that predicted TS-EMF varied by type,accounting for up to 66.45%of the variation.TS-EMF was primarily driven by leaf structure in spring and by nutrient accumulation in autumn.Leaf carbon content(LCC)consistently served as a stabilizing factor for predicting TS-EMF across seasons.At 36.5-36.8 mg g^(-1),LCC had its optimal effect on TS-EMF.Other traits in combination that positively influence total TS-EMF include leaf nitrogen content(3.43-3.45 mg g^(-1)),leaf phosphorus content(0.80-0.83 mg g^(-1)),and leaf area(65.86-68.43 cm^(2)).Within these specified trait thresholds,Morus alba and Quercus mongolica were identified as key species.These findings suggest that the trade-off between various ecological functions can be managed by altering plant traits across seasons.This approach could provide a theoretical foundation for enhancing the TS-EMF of urban forests through trait-based management,offering practical guidance for selecting tree species. 展开更多
关键词 Ecological multifunctionality of tree species Traits combination Urban forests Leaf carbon content
在线阅读 下载PDF
Impact of heatwave and thinning on tree growth and soil water content in young lodgepole pine forests
14
作者 Yiping Hou Xiaohua Wei +4 位作者 Zhipeng Xu Sheena A.Spencer Ming Qiu Shixuan Lyu Wenfei Liu 《Forest Ecosystems》 2026年第1期83-94,共12页
Extreme climate events(e.g.,heatwaves and droughts)are becoming increasingly frequent due to global climate change,which inevitably affects tree growth and various other ecological processes.While the impacts of droug... Extreme climate events(e.g.,heatwaves and droughts)are becoming increasingly frequent due to global climate change,which inevitably affects tree growth and various other ecological processes.While the impacts of droughts on these processes have been widely evaluated,the effects of heatwaves on tree growth and soil water content(SWC)remain poorly understood,particularly those related to thinning treatment.In this study,we evaluated the impacts of the 2021 Pacific Northwest Heatwave and thinning on forest growth and SWC,as well as assessed how thinning might mitigate the heatwave's impacts in lodgepole pine forests in British Columbia,Canada.We measured meteorological data(air temperature,rainfall,solar radiation(SR),relative humidity(RH),and wind speed(W_(s)),sap flow,SWC,soil temperature(T_(s)),and tree diameters at the breast height(DBH)during the growing season(June–September)in the control(27,000 stems·ha^(-1)),lightly thinned(4,500 stems·ha^(-1)),and heavily thinned(1,100 stems·ha^(-1))experimental plots from 2018 to 2024.We found that thinning persistently and significantly(p<0.05)increased individual tree growth,with the most pronounced effects in the heavily thinned stands.The 2021 Pacific Northwest Heatwave led to an exceptionally hot growing season,significantly(p<0.05)reducing forest growth and SWC across all plots.Forest growth recovered in 2022 in the thinned plots but remained suppressed in the unthinned plots,suggesting that thinning effectively mitigated the impact of the heatwave on forest growth,while the heatwave's impacts were persistent in the unthinned plots.Our study highlights that thinning is a practical management strategy for improving tree growth and supporting climate change adaptation to extreme climate events. 展开更多
关键词 HEATWAVE THINNING Forest growth Soil water content Climate change adaptation Lodgepole pine Forest management
在线阅读 下载PDF
Differential accumulation mechanism of shale gas in superimposed basins:Insights from dynamic evolution of shale gas content and occurrence state
15
作者 Min Li Xiongqi Pang +6 位作者 Zhen Zhao Xin Ye Di Chen Pengwei Wang Chengxiang Wan Guanping Wang Xiaotong Ge 《Energy Geoscience》 2026年第1期55-71,共17页
By investigating the evolution of shale gas generation,storage,adjustment and accumulation under different structural settings in superimposed basins,this study elucidates the differential accumulation mechanisms of s... By investigating the evolution of shale gas generation,storage,adjustment and accumulation under different structural settings in superimposed basins,this study elucidates the differential accumulation mechanisms of shale gas.An improved evaluation method of shale gas content evolution in superimposed basins is proposed.This method incorporates the coupling effect of key geological factors such as temperature,pressure,organic matter abundance,maturity,and pore characteristics on the content and occurrence state of shale gas,as well as the configuration relationship between shale gas generation and storage throughout geological history.Using this approach,the gas evolution histories of the Longmaxi Formation shales in wells N201 and PY1 are reconstructed under varying geological conditions.The Longmaxi Formation shales in these wells are dominated by typeⅠkerogen,with original total organic carbon(TOC_(o))contents of 6.20 wt% and 4.92 wt%,respectively,indicating differences in the initial material basis for gas generation.At the maximum burial depth of approximately 5000 m,the Longmaxi Formation shale in well N201 exhibits a formation pressure coefficient of 2.05,an organic matter maturity of 2.2%,and organic pores accounting for 68%of the total porosity.The gas generation quantity(Q_(g))reaches 19.24 m^(3)/t,while the gas storage capacity(Q_(s))is 4.30 m^(3)/t.The actual total gas content(Q_(a)),constrained by Q_(s),is 4.30 m^(3)/t,with free gas comprising 94%.Following relatively moderate tectonic uplift,the Q_(a) in well N201 decreases to 4.03 m^(3)/t,with free gas accounting for 63%.In contrast,the Longmaxi Formation shale in well PY1 reached a maximum burial depth of 6300 m,associated with a formation pressure coefficient of 1.62,organic matter maturity of 2.5%,and organic pore proportion of 67%.Here,Q_(g) is 16.87 m^(3)/t,and both Q_(s) and Q_(a) are 3.65 m^(3)/t,with free gas accounting for 98%.After intense tectonic uplift,Q_(a) declines to 2.72 m^(3)/t,and the proportion of free gas drops to51%.Finally,a four-stage differential accumulation model of shale gas is established:Slow gas generation and only adsorbed gas occur in stageⅠ,which is primarily controlled by TOC content;both adsorbed gas and free gas present in stageⅡ,with free gas becoming dominant;rapid gas generation and free gas predominance are controlled by temperature and porosity in stageⅢ;and gas adjustment and accumulation are primarily controlled by temperature and pressure in stageⅣ. 展开更多
关键词 Differential enrichment of shale gas Gas content evolution Free gas Tectonic uplifting Superimposed basin
在线阅读 下载PDF
An Endosperm-Specific Early Nodulin-Like Gene Regulates Amylose Content in Rice
16
作者 ZHAO Dongsheng WU Dengfei +4 位作者 CHEN Siyu FAN Xiaolei LI Qianfeng ZHANG Changquan LIU Qiaoquan 《Rice science》 2026年第2期155-158,I0041-I0052,共16页
Amylose content(AC)is a key determinant of rice eating and cooking quality(ECQ).Lower AC is generally associated with improved palatability and is therefore a desirable trait in rice breeding;however,effective manipul... Amylose content(AC)is a key determinant of rice eating and cooking quality(ECQ).Lower AC is generally associated with improved palatability and is therefore a desirable trait in rice breeding;however,effective manipulation of AC remains a challenge.In this study,we identified AC6,a novel endosperm-specific early nodulin-like(ENODL)gene,belonging to a 32-member ENODL family.Using CRISPR/Cas9 technology,we generated an ac6 knockout allele,which exhibited a significant decrease in AC and produced improved ECQ without compromising grain appearance or yield.Subcellular localization analysis demonstrated that AC6 is a plastid-localized protein that likely regulates AC by interacting with the Waxy(Wx)protein.Moreover,expression of starch metabolism-related genes was markedly altered in developing ac6 endosperm.Our study highlights AC6 as a novel target gene for engineering rice germplasm with enhanced ECQ. 展开更多
关键词 RICE eating cooking quality plastid localized protein endosperm specific CRISPR Cas early nodulin gene amylose content subcellular localization
在线阅读 下载PDF
Cliffs of Contentment:From roads to Internet access, a remote mountainous village in Sichuan Province has transformed itself into a model of sustainable rural development and well-being
17
作者 MA LI 《ChinAfrica》 2026年第4期32-34,共3页
Amid the lingering chill of a Beijing spring during China’s annual Two Sessions,Zheng Wangchun strode into the lounge after finishing the morning’s group discussion.The deputy to the National People’s Congress and ... Amid the lingering chill of a Beijing spring during China’s annual Two Sessions,Zheng Wangchun strode into the lounge after finishing the morning’s group discussion.The deputy to the National People’s Congress and secretary of the CPC Gulu Village Branch,better known as Cliff Village,in Hanyuan County,Ya’an City,Sichuan Province,was still dressed in his Yi ethnic waistcoat. 展开更多
关键词 remote mountainous village sustainable rural development internet access Beijing Spring yi ethnic waistcoat cliffs contentment CPC Gulu village branch Chinas annual two sessions
原文传递
Content Determination of Zhuang Medicine Sauropus spatulifolius Beille from Guangxi
18
作者 Lixin SUN Yongshan JIN +8 位作者 Wenjing YANG Aipeng LI Yarong WEI Liangna SU Chengxu CHEN Fangyuan SHEN Yanmin LU Suoyi HUANG Lixiang LU 《Medicinal Plant》 2026年第1期1-4,共4页
[Objectives]To determine the content of Zhuang medicine Sauropus spatulifolius Beille from Guangxi.[Methods]The amino acid content of S.spatulifolius Beille was determined by ultraviolet spectrophotometry(UVs).The con... [Objectives]To determine the content of Zhuang medicine Sauropus spatulifolius Beille from Guangxi.[Methods]The amino acid content of S.spatulifolius Beille was determined by ultraviolet spectrophotometry(UVs).The content of kaempferol-3-O-gentiobioside in S.spatulifolius Beille was determined by liquid chromatography-mass spectrometry(LC-MS).Pesticide residues in S.spatulifolius Beille were detected by gas chromatography-mass spectrometry(GC-MS).Heavy metal elements arsenic(As),cadmium(Cd),and lead(Pb)in S.spatulifolius Beille were detected by inductively coupled plasma mass spectrometry(ICP-MS).[Results]The amino acid content in S.spatulifolius Beille was 3.233 mg/g,with a relative standard deviation(RSD)of 0.36%.The content of kaempferol-3-O-gentiobioside was 1.15μg/mL.No pesticide residues or heavy metals were detected in the S.spatulifolius Beille medicinal material.[Conclusions]This study improves the quality control system for S.spatulifolius Beille and provides a reference basis for the quality standard control of Zhuang medicine S.spatulifolius Beille from Guangxi. 展开更多
关键词 Zhuang medicine Sauropus spatulifolius Beille Liquid chromatography-mass spectrometry(LC-MS) Gas chromatography-mass spectrometry(GC-MS) Inductively coupled plasma mass spectrometry(ICP-MS) content determination
暂未订购
ZmGolS1 underlies natural variation of raffinose content and salt tolerance in maize 被引量:1
19
作者 Xiaoyan Liang Pan Yin +2 位作者 Fenrong Li Yibo Cao Caifu Jiang 《Journal of Genetics and Genomics》 2025年第3期346-355,共10页
Salt stress significantly inhibits crop growth and development,and mitigating this can enhance salt tolerance in various crops.Previous studies have shown that regulating saccharide biosynthesis is a key aspect of pla... Salt stress significantly inhibits crop growth and development,and mitigating this can enhance salt tolerance in various crops.Previous studies have shown that regulating saccharide biosynthesis is a key aspect of plant salt tolerance;however,the underlying molecular mechanisms remain largely unexplored.In this study,we demonstrate that overexpression of a salt-inducible galactinol synthase gene,ZmGolS1,alleviates salt-induced growth inhibition,likely by promoting raffinose synthesis.Additionally,we show that natural variation in ZmGolS1 transcript levels contributes to the diversity of raffinose content and salt tolerance in maize.We further reveal that ZmRR18,a type-B response regulator transcription factor,binds to the AATC element in the promoter of ZmGolS1,with this binding increases the transcript levels of ZmGolS1 under salt conditions.Moreover,a single nucleotide polymorphism(termed SNP-302T)within the ZmGolS1 promoter significantly reduces its binding affinity for ZmRR18,resulting in decreased ZmGolS1 expression and diminished raffinose content,ultimately leading to a salt-hypersensitive phenotype.Collectively,our findings reveal the molecular mechanisms by which the ZmRR18-ZmGolS1 module enhances raffinose biosynthesis,thereby promoting maize growth under salt conditions.This research provides important insights into salt tolerance mechanisms associated with saccharide biosynthesis and identifies valuable genetic loci for breeding salt-tolerant maize varieties. 展开更多
关键词 MAIZE Salt tolerance BIOMASS Raffinose content Transcriptional regulation
原文传递
Key techniques for precise measuring gas content in deep coal mine:In-situ pressure-and gas-preserved coring 被引量:2
20
作者 Ju Li Jianan Li +4 位作者 Tianyu Wang Guikang Liu Zhiqiang He Cong Li Heping Xie 《International Journal of Mining Science and Technology》 2025年第4期589-607,共19页
Gas content serves as a critical indicator for assessing the resource potential of deep coal mines and forecasting coal mine gas outburst risks.However,existing sampling technologies face challenges in maintaining the... Gas content serves as a critical indicator for assessing the resource potential of deep coal mines and forecasting coal mine gas outburst risks.However,existing sampling technologies face challenges in maintaining the integrity of gas content within samples and are often constrained by estimation errors inherent in empirical formulas,which results in inaccurate gas content measurements.This study introduces a lightweight,in-situ pressure-and gas-preserved corer designed to collect coal samples under the pressure conditions at the sampling point,effectively preventing gas loss during transfer and significantly improving measurement accuracy.Additionally,a gas migration model for deep coal mines was developed to elucidate gas migration characteristics under pressure-preserved coring conditions.The model offers valuable insights for optimizing coring parameters,demonstrating that both minimizing the coring hole diameter and reducing the pressure difference between the coring-point pressure and the original pore pressure can effectively improve the precision of gas content measurements.Coring tests conducted at an experimental base validated the performance of the corer and its effectiveness in sample collection.Furthermore,successful horizontal coring tests conducted in an underground coal mine roadway demonstrated that the measured gas content using pressure-preserved coring was 34%higher than that obtained through open sampling methods. 展开更多
关键词 Pressure-and gas-preserved coring Deep coal mines coring Gas migration model In-situ gas content
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部