Two sharp Chernoff type inequalities are derived for star bodies in R2,one is an extension of the dual Chernoff-Ou-Pan inequality,and the other is the reverse Chernoff type inequality.Furthermore,we establish a genera...Two sharp Chernoff type inequalities are derived for star bodies in R2,one is an extension of the dual Chernoff-Ou-Pan inequality,and the other is the reverse Chernoff type inequality.Furthermore,we establish a generalized dual symmetric mixed Chernoff inequality for two planar star bodies.As a direct consequence,a new proof of the dual symmetric mixed isoperimetric inequality is presented.展开更多
Although numerous studies have proposed explanations for the specific and relative effects of stand structure,plant diversity,and environmental conditions on carbon(C)storage in forest ecosystems,understanding how the...Although numerous studies have proposed explanations for the specific and relative effects of stand structure,plant diversity,and environmental conditions on carbon(C)storage in forest ecosystems,understanding how these factors collectively affect C storage in different community layers(trees,shrubs,and herbs)and forest types(mixed,broad-leaved(E),broad-leaved(M),and coniferous forest)continues to pose challenges.To address this,we used structural equation models to quantify the influence of biotic factors(mean DBH,mean height,maximum height,stem density,and basal area)and abiotic factors(elevation and canopy openness),as well as metrics of species diversity(Shannon–Wiener index,Simpson index,and Pielou’s evenness)in various forest types.Our analysis revealed the critical roles of forest types and elevation in explaining a substantial portion of variability in C storage in the overstory layer,with a moderate influence of stand factors(mean DBH and basal area)and a slightly negative impact of tree species diversity(Shannon–Wiener index).Notably,forest height emerged as the primary predictor of C storage in the herb layer.Regression relationships further highlighted the significant contribution of tree species diversity to mean height,understory C storage,and branch biomass within the forest ecosystem.Our insights into tree species diversity,derived from structural equation modeling of C storage in the overstory,suggest that the effects of tree species diversity may be influenced by stem biomass in statistical reasoning within temperate forests.Further research should also integrate tree species diversity with tree components biomass,forest mean height,understory C,and canopy openness to understand complex relationships and maintain healthy and sustainable ecosystems in the face of global climate challenges.展开更多
A systematic review and meta-analysis study was conducted to assess the effectiveness of probiotic/prebiotic/synbiotic supplementation on the effects of cardiovascular risk factors in patients with type 2 diabetes mel...A systematic review and meta-analysis study was conducted to assess the effectiveness of probiotic/prebiotic/synbiotic supplementation on the effects of cardiovascular risk factors in patients with type 2 diabetes mellitus(T2DM)based on data from randomized controlled trials(RCTs).We searched electronic databases including PubMed,Cochrane Library,Embase,and Web of Science to identify clinical trials published up to 31 March 2023.Data was pooled using a random-effects model if significant heterogeneity(I2>50%),otherwise use a fixed-effects model.Fifty-six trials that included 3317 patients were enrolled for analysis.Meta-analysis reported that probiotic/prebiotic/synbiotic supplementation significantly reduced systolic blood pressure(SBP)(weighted mean difference(WMD):-3.57 mmHg,95% confidence interval(CI):-5.36,-1.78;P=0.000),diastolic blood pressure(DBP)(WMD:-2.05 mmHg,95%CI:-3.07,-1.04;P=0.000),triglycerides(TG)(WMD:-16.10 mg/dL,95%CI:-20.16,-12.05;P=0.000),total cholesterol(TC)(WMD:-14.00 mg/dL,95%CI:-20.46,-7.55;P=0.000),low-density lipoprotein cholesterol(LDL-C)(WMD:-7.03 mg/dL,95%CI:-9.25,-4.81;P=0.000),fasting plasma glucose(FPG)(WMD:-16.57 mg/dL,95%CI:-20.39,-12.74;P=0.000),hemoglobin A1c(HbA1c)(WMD:-0.44%,95%CI:-0.68,-0.20;P=0.000),insulin(standardized mean difference(SMD):-0.37,95%CI:-0.53,-0.21;P=0.000),homeostatic model assessment of insulin resistance(HOMA-IR)(WMD:-1.05,95%CI:-1.56,-0.54;P=0.000),C-reactive protein(CRP)(SMD:-0.35,95%CI:-0.57,-0.13;P=0.002),tumor necrosis factor-α(TNF-α)(SMD:-1.07,95%CI:-1.57,-0.56;P=0.000),interleukin-6(IL-6)(SMD:-0.37,95%CI:-0.61,-0.13;P=0.003)levels,they also increased the high-density lipoprotein cholesterol(HDL-C)(WMD:3.70 mg/dL,95%CI:1.80,5.60;P=0.000)levels in T2DM patients,as compared to the placebo groups.This meta-analysis supports the use of probiotic/prebiotic/synbiotic supplementation as an adjunctive therapy to improve blood pressure,glycemic control parameters,lipid profile and inflammatory markers in patients with T2DM,which are well-known cardiovascular risk factors.展开更多
This study presents novel findings on the potential of phloretin,an apple polyphenol,to enhance the effectiveness of anti-human epidermal growth factor receptor-2(HER2)antibody therapy in HER2-positive breast cancer p...This study presents novel findings on the potential of phloretin,an apple polyphenol,to enhance the effectiveness of anti-human epidermal growth factor receptor-2(HER2)antibody therapy in HER2-positive breast cancer patients.Our research reveals that phloretin inhibits typeⅡglucose transporter(GLUT2)activity,significantly reducing cancer cell glucose uptake.We confirmed the overexpression of GLUT1 and GLUT2 mRNA in paired human breast tumor tissues,with GLUT2 overexpression associated explicitly with poorer survival rates in breast cancer patients.Treatment with phloretin was observed to increase the interaction between GLUT2 and HER2 proteins,attenuate glycolysis,and enhance the binding affinity of anti-HER2 antibody drugs to target human breast cancer cells.Furthermore,the efficacy of the combination therapy involving phloretin and antibody drugs was reaffirmed in a cell-derived xenograft tumor animal model,particularly in suppressing the growth of trastuzumab-resistant HER2-positive(HER2+)breast cancer.These significant findings suggest that targeting GLUT2 activity with phloretin in combination with anti-HER2 antibody drugs may help mitigate the development of drug-resistant breast cancer,offering valuable insights for enhancing tumor treatment strategies and contributing to developing more effective therapies.展开更多
Kerogen types exert a decisive effect on the onset and capacity of hydrocarbon generation of source rocks.Lacustrine source rocks in the Liaohe Western Depression are characterized by thick deposition,high total organ...Kerogen types exert a decisive effect on the onset and capacity of hydrocarbon generation of source rocks.Lacustrine source rocks in the Liaohe Western Depression are characterized by thick deposition,high total organic carbon(TOC)content,various kerogen types,and a wide range of thermal maturity.Consequently,their hydrocarbon generation potential and resource estimation can be misinterpreted.In this study,geochemical tests,numerical analysis,hydrocarbon generation kinetics,and basin modeling were integrated to investigate the differential effects of kerogen types on the hydrocarbon generation potential of lacustrine source rocks.Optimized hydrocarbon generation and expulsion(HGE)models of different kerogen types were established quantitatively upon abundant Rock-Eval/TOC/vitrinite reflectance(R_(o))datasets.Three sets of good-excellent source rocks deposited in the fourth(Es4),third(Es3),and first(Es1)members of Paleogene Shahejie Formation,are predominantly types I-II_(1),II_(1)-II_(2),and II-III,respectively.The activation energy of types I-II_(2)kerogen is concentrated(180-230 kcal/mol),whereas that of type III kerogen is widely distributed(150-280 kcal/mol).The original hydrocarbon generation potentials of types I,II_(1),II_(2),and III kerogens are 790,510,270,and 85 mg/g TOC,respectively.The Ro values of the hydrocarbon generation threshold for type I-III source rocks gradually increase from 0.42%to 0.74%,and Ro values of the hydrocarbon expulsion threshold increase from 0.49%to 0.87%.Types I and II_(1)source rocks are characterized by earlier hydrocarbon generation,more rapid hydrocarbon expulsion,and narrower hydrocarbon generation windows than types II_(2)and III source rocks.The kerogen types also affect the HGE history and resource potential.Three types(conventional,tight,and shale oil/gas)and three levels(realistic,expected,and prospective)of hydrocarbon resources of different members in the Liaohe Western Depression are evaluated.Findings suggest that the Es3 member has considerable conventional and unconventional hydrocarbon resources.This study can quantitatively characterize the hydrocarbon generation potential of source rocks with different kerogen types,and facilitate a quick and accurate assessment of hydrocarbon resources,providing strategies for future oil and gas exploration.展开更多
Type 2 diabetes mellitus(T2DM)is a complex metabolic disease threatening human health.We investigated the effects of Tegillarca granosa polysaccharide(TGP)and determined its potential mechanisms in a mouse model of T2...Type 2 diabetes mellitus(T2DM)is a complex metabolic disease threatening human health.We investigated the effects of Tegillarca granosa polysaccharide(TGP)and determined its potential mechanisms in a mouse model of T2DM established through a high-fat diet and streptozotocin.TGP(5.1×10^(3) Da)was composed of mannose,glucosamine,rhamnose,glucuronic acid,galactosamine,glucose,galactose,xylose,and fucose.It could significantly alleviate weight loss,reduce fasting blood glucose levels,reverse dyslipidemia,reduce liver damage from oxidative stress,and improve insulin sensitivity.RT-PCR and Western blotting indicated that TGP could activate the phosphatidylinositol-3-kinase/protein kinase B signaling pathway to regulate disorders in glucolipid metabolism and improve insulin resistance.TGP increased the abundance of Allobaculum,Akkermansia,and Bifidobacterium,restored the microbiota abundance in the intestinal tracts of mice with T2DM,and promoted short-chain fatty acid production.This study provides new insights into the antidiabetic effects of TGP and highlights its potential as a natural hypoglycemic nutraceutical.展开更多
With the development of green data centers,a large number of Uninterruptible Power Supply(UPS)resources in Internet Data Center(IDC)are becoming idle assets owing to their low utilization rate.The revitalization of th...With the development of green data centers,a large number of Uninterruptible Power Supply(UPS)resources in Internet Data Center(IDC)are becoming idle assets owing to their low utilization rate.The revitalization of these idle UPS resources is an urgent problem that must be addressed.Based on the energy storage type of the UPS(EUPS)and using renewable sources,a solution for IDCs is proposed in this study.Subsequently,an EUPS cluster classification method based on the concept of shared mechanism niche(CSMN)was proposed to effectively solve the EUPS control problem.Accordingly,the classified EUPS aggregation unit was used to determine the optimal operation of the IDC.An IDC cost minimization optimization model was established,and the Quantum Particle Swarm Optimization(QPSO)algorithm was adopted.Finally,the economy and effectiveness of the three-tier optimization framework and model were verified through three case studies.展开更多
In this paper,we investigate sufficient and necessary conditions such that generalized Forelli-Rudin type operators T_(λ,τ,k),S_(λ,τ,k),Q_(λ,τ,k)and R_(λ,τ,k)are bounded between Lebesgue type spaces.In order t...In this paper,we investigate sufficient and necessary conditions such that generalized Forelli-Rudin type operators T_(λ,τ,k),S_(λ,τ,k),Q_(λ,τ,k)and R_(λ,τ,k)are bounded between Lebesgue type spaces.In order to prove the main results,we first give some bidirectional estimates for several typical integrals.展开更多
For analytic functions u,ψin the unit disk D in the complex plane and an analytic self-mapφof D,we describe in this paper the boundedness and compactness of product type operators T_(u,ψ,φ)f(z)=u(z)f(φ(z))+ψ(z)f...For analytic functions u,ψin the unit disk D in the complex plane and an analytic self-mapφof D,we describe in this paper the boundedness and compactness of product type operators T_(u,ψ,φ)f(z)=u(z)f(φ(z))+ψ(z)f'(φ(z)),z∈D,acting between weighted Bergman spaces induced by a doubling weight and a Bloch type space with a radial weight.展开更多
In recent years,artificial intelligence(AI)has been widely used in the field of electricity,such as load prediction,fault diagnosis of the power equipment,intelligent scheduling of power grids.However,the application ...In recent years,artificial intelligence(AI)has been widely used in the field of electricity,such as load prediction,fault diagnosis of the power equipment,intelligent scheduling of power grids.However,the application of latest AI technology still has many technical difficulties to be solved.In the process of upgrading from the traditional power system to the new-type power system,AC grids,DC grids and micro grids coexist.In addition,there are huge amount of power equipment and electronic devices,and the coupling relationship is very complicated.Moreover,the high proportion of clean energy and flexible loads connected to the grid leads to the enhancement of the stochastic characteristics of the system.And short-term and ultra-short-term forecasts are much more difficult.Therefore,the editorial office of Global Energy Interconnection has planned the special issue of“Artificial Intelligence Applied in New-Type Power System”.展开更多
In this paper,we establish two transformation formulas for nonterminating basic hypergeometric series by using Carlitz's inversions formulas and Jackson s transformation formula.In terms of application,by speciali...In this paper,we establish two transformation formulas for nonterminating basic hypergeometric series by using Carlitz's inversions formulas and Jackson s transformation formula.In terms of application,by specializing certain parameters in the two transformations,four Rogers-Ramanujan type identities associated with moduli 20 are obtained.展开更多
Purpose:Accurately assigning the document type of review articles in citation index databases like Web of Science(WoS)and Scopus is important.This study aims to investigate the document type assignation of review arti...Purpose:Accurately assigning the document type of review articles in citation index databases like Web of Science(WoS)and Scopus is important.This study aims to investigate the document type assignation of review articles in Web of Science,Scopus and Publisher’s websites on a large scale.Design/methodology/approach:27,616 papers from 160 journals from 10 review journal series indexed in SCI are analyzed.The document types of these papers labeled on journals’websites,and assigned by WoS and Scopus are retrieved and compared to determine the assigning accuracy and identify the possible reasons for wrongly assigning.For the document type labeled on the website,we further differentiate them into explicit review and implicit review based on whether the website directly indicates it is a review or not.Findings:Overall,WoS and Scopus performed similarly,with an average precision of about 99% and recall of about 80%.However,there were some differences between WoS and Scopus across different journal series and within the same journal series.The assigning accuracy of WoS and Scopus for implicit reviews dropped significantly,especially for Scopus.Research limitations:The document types we used as the gold standard were based on the journal websites’labeling which were not manually validated one by one.We only studied the labeling performance for review articles published during 2017-2018 in review journals.Whether this conclusion can be extended to review articles published in non-review journals and most current situation is not very clear.Practical implications:This study provides a reference for the accuracy of document type assigning of review articles in WoS and Scopus,and the identified pattern for assigning implicit reviews may be helpful to better labeling on websites,WoS and Scopus.Originality/value:This study investigated the assigning accuracy of document type of reviews and identified the some patterns of wrong assignments.展开更多
The present study reports the structural characteristics of 3 polysaccharide fractions(SPS-F1,SPS-F2 and SPS-F3)isolated and purified from squash.SPS-F1(molecular weight(Mw)=12.30 kDa)and SPS-F2(Mw=19.40 kDa)were like...The present study reports the structural characteristics of 3 polysaccharide fractions(SPS-F1,SPS-F2 and SPS-F3)isolated and purified from squash.SPS-F1(molecular weight(Mw)=12.30 kDa)and SPS-F2(Mw=19.40 kDa)were likely to contain HG and RG-I domain of pectic polysaccharide,respectively.SPS-F2(Mw=270.4 kDa)was mainly composed of rhamnose,galactose and arabinose.The treatment with SPS decreased body weight gain,glucose and TG levels in type 2 diabetes rats.Besides,25 differential metabolites were identified based on urinary metabolomics analysis,which are crucial to the anti-diabetic effect of SPS.The regulation of nicotinamide N-oxide,histamine,cis-aconitate,citrate,L-malic acid,3-(3-hydroxyphenyl)propanoic acid and N-acetyl-L-aspartic acid were mainly associated with energy metabolism,gut microbiota and inflammation.Study of surface plasmon resonance revealed the binding kinetics with galectin-3(Gal-3)and fibroblast growth factor 2(FGF2).The K_(D)values of SPS-F2 and SPS-F3 to Gal-3 were 4.97×10^(-3)and 1.48×10^(-3)mol/L,indicating a weak binding affinity.All 3 fractions showed moderate binding to FGF2 and the affinity was SPS-F3>SPS-F2>SPS-F1.Thus,the metabolomics and SPR approach were proved to be a promising tool in exploring the anti-diabetes effects of SPS and provided a deep understanding of the mechanisms.展开更多
Recent studies indicated that vitamin A(VA)might be involved in the pathology of type 2 diabetes mellitus(T2DM).This cross-sectional study was conducted to explore the association between circulating VA level and T2DM...Recent studies indicated that vitamin A(VA)might be involved in the pathology of type 2 diabetes mellitus(T2DM).This cross-sectional study was conducted to explore the association between circulating VA level and T2DM.A total of 1818 subjects aged 50 years old and above were recruited from the community.Binomial logistic regression and restricted cubic spline(RCS)were applied to analyze the association of plasma VA level with the risk of T2DM.Serum VA and lipid-adjusted VA levels of T2DM patients were significantly higher than that of non-T2DM subjects(P<0.05).The ratios of plasma VA/total cholesterol(TC),VA/high-density lipoprotein cholesterol(HDL-c)and VA/low-density lipoprotein cholesterol(LDL-c)were positively associated with the risk of T2DM in the aging population(P<0.05).Compared with the Q1 level,subjects with Q2 to Q3 levels of plasma VA/triglyceride(TG)have decreased risk of T2DM(odds ratio(OR)Q2=0.68,P_(Q2)=0.021;ORQ3=0.59,P_(Q3)<0.01).Our results indicated that the imbalance of circulating lipids and VA might affect the relationship between VA and T2DM.The middle and aging subjects with higher ratios of plasma VA/TC,VA/HDL-c,and VA/LDL-c displayed increased risk for T2DM,but the moderate ratio of VA/TG might protect against risk of T2DM.展开更多
In the present paper,we prove the existence,non-existence and multiplicity of positive normalized solutions(λ_(c),u_(c))∈R×H^(1)(R^(N))to the general Kirchhoff problem-M■,satisfying the normalization constrain...In the present paper,we prove the existence,non-existence and multiplicity of positive normalized solutions(λ_(c),u_(c))∈R×H^(1)(R^(N))to the general Kirchhoff problem-M■,satisfying the normalization constraint f_(R)^N u^2dx=c,where M∈C([0,∞))is a given function satisfying some suitable assumptions.Our argument is not by the classical variational method,but by a global branch approach developed by Jeanjean et al.[J Math Pures Appl,2024,183:44–75]and a direct correspondence,so we can handle in a unified way the nonlinearities g(s),which are either mass subcritical,mass critical or mass supercritical.展开更多
It has been widely accepted that resistant starch(RS)provides numerous health benefits for human.In this research,we aimed at evaluating the performance of novel starch-lipid complexes,RS5,in comparison with RS2 on ph...It has been widely accepted that resistant starch(RS)provides numerous health benefits for human.In this research,we aimed at evaluating the performance of novel starch-lipid complexes,RS5,in comparison with RS2 on physical features,glucolipids metabolism,inflammation,and gut microbiota profiles of type 2 diabetes mellitus(T2DM)rats.The T2DM model was established by streptozotocin injection to the high-fat-sugar fed rats.According to a serial of biochemical analyses,we found that RS5 diets were strongly correlated with enhanced homeostatic model assessment for insulin secretion(HOMA-IS),high-density lipoprotein cholesterol(HDL-C),adiponectin(ADP),insulin action index(IAI),glucagon-like peptide-1(GLP1),and short-chain fatty acids(SCFAs)in T2DM rats whilst negatively associated with the low-density lipoprotein(LDL-C)and inflammatory cytokines,showing the capabilities to ameliorate T2DM symptoms by regulation of glucolipid metabolism,gut metabolites,and inflammation.On the other hand,RS2-enriched supplementations were influential in the mediation of insulin secretion to improve glucose metabolism.The increasing evidence collected herein suggested that intestinal microbiota could mediate glucolipids metabolism and alleviate inflammation after certain microflora nourished by RS.In addition,RS intake made an impact on phosphoinositide 3-kinase/protein kinase B signaling pathway that might contribute to the improvement of glucose metabolism,insulin resistance,and inflammatory responses.展开更多
This study investigated the effects of a xylitol-casein non-covalent complex(XC)on parameters related to type 2 diabetes mellitus(T2DM),in addition to related changes in gut microbiome composition and functions.High-f...This study investigated the effects of a xylitol-casein non-covalent complex(XC)on parameters related to type 2 diabetes mellitus(T2DM),in addition to related changes in gut microbiome composition and functions.High-fat-diet(HFD)+streptozotocin(STZ)-induced T2DM mice were treated with xylitol(XY),casein(CN),and XC,after which fecal samples were collected for gut microbiota composition and diversity analyses based on 16S rRNA high-throughput sequencing and multivariate statistics.XC decreased body weight and improved glucose tolerance,insulin sensitivity,pancreas impairment,blood lipid levels,and liver function in T2DM mice compared to XY-and CN-treated mice.Furthermore,XC modulated theα-diversity,β-diversity and gut microbiota composition.Based on Spearman’s correlation analysis,the relative abundances of Alistipes,Bacteroides,and Faecalibaculum were positively correlated and those of Akkermansia,Lactobacillus,Bifidobacterium,and Turicibacter were negatively correlated with the phenotypes related to the improvement of T2DM.In conclusion,we found that XC alleviated insulin resistance by restoring the gut microbiota of T2DM mice.Our results provide strong evidence for the beneficial effects of XC on T2DM and motivation for further investigation in animal models and,eventually,human trials.展开更多
Tree mortality significantly influences forest structure and function,yet our understanding of its dynamic patterns among a range of tree sizes and among different plant functional types(PFTs)remains incomplete.This s...Tree mortality significantly influences forest structure and function,yet our understanding of its dynamic patterns among a range of tree sizes and among different plant functional types(PFTs)remains incomplete.This study analysed size-dependent tree mortality in a temperate forest,encompassing 46 tree species and 32,565 individuals across different PFTs(i.e.,evergreen conifer vs.deciduous broadleaf species,shade-tolerant vs.shade-intolerant species).By employing all-subset regression procedures and logistic generalized linear mixed-effects models,we identified distinct mortality patterns influenced by biotic and abiotic factors.Our results showed a stable mortality patte rn in eve rgreen conifer species,contrasted by a declining pattern in deciduous broadleaf and shadetolerant,as well as shade-intolerant species,across size classes.The contribution to tree mortality of evergreen conifer species shifted from abiotic to biotic factors with increasing size,while the mortality of deciduous broadleaf species was mainly influenced by biotic factors,such as initial diameter at breast height(DBH)and conspecific negative density.For shade-tolerant species,the mortality of small individuals was mainly determined by initial DBH and conspecific negative density dependence,whereas the mortality of large individuals was subjected to the combined effect of biotic(competition from neighbours)and abiotic factors(i.e.,convexity and pH).As for shade-intolerant species,competition from neighbours was found to be the main driver of tree mortality throughout their growth stages.Thus,these insights enhance our understanding of forest dynamics by revealing the size-dependent and PFT-specific tree mortality patterns,which may inform strategies for maintaining forest diversity and resilience in temperate forest ecosystems.展开更多
Clifford analysis is an important branch of modern analysis;it has a very important theoretical significance and application value,and its conclusions can be applied to the Maxwell equation,Yang-Mill field theory,quan...Clifford analysis is an important branch of modern analysis;it has a very important theoretical significance and application value,and its conclusions can be applied to the Maxwell equation,Yang-Mill field theory,quantum mechanics and value problems.In this paper,we first give the definition of a quasi-Cauchy type integral in complex Clifford analysis,and get the Plemelj formula for it.Second,we discuss the H?lder continuity for the Cauchy-type integral operators with values in a complex Clifford algebra.Finally,we prove the existence of solutions for a class of linear boundary value problems and give the integral representation for the solution.展开更多
Identification of reservoir types in deep carbonates has always been a great challenge due to complex logging responses caused by the heterogeneous scale and distribution of storage spaces.Traditional cross-plot analy...Identification of reservoir types in deep carbonates has always been a great challenge due to complex logging responses caused by the heterogeneous scale and distribution of storage spaces.Traditional cross-plot analysis and empirical formula methods for identifying reservoir types using geophysical logging data have high uncertainty and low efficiency,which cannot accurately reflect the nonlinear relationship between reservoir types and logging data.Recently,the kernel Fisher discriminant analysis(KFD),a kernel-based machine learning technique,attracts attention in many fields because of its strong nonlinear processing ability.However,the overall performance of KFD model may be limited as a single kernel function cannot simultaneously extrapolate and interpolate well,especially for highly complex data cases.To address this issue,in this study,a mixed kernel Fisher discriminant analysis(MKFD)model was established and applied to identify reservoir types of the deep Sinian carbonates in central Sichuan Basin,China.The MKFD model was trained and tested with 453 datasets from 7 coring wells,utilizing GR,CAL,DEN,AC,CNL and RT logs as input variables.The particle swarm optimization(PSO)was adopted for hyper-parameter optimization of MKFD model.To evaluate the model performance,prediction results of MKFD were compared with those of basic-kernel based KFD,RF and SVM models.Subsequently,the built MKFD model was applied in a blind well test,and a variable importance analysis was conducted.The comparison and blind test results demonstrated that MKFD outperformed traditional KFD,RF and SVM in the identification of reservoir types,which provided higher accuracy and stronger generalization.The MKFD can therefore be a reliable method for identifying reservoir types of deep carbonates.展开更多
基金supported by the Postgraduate Scientic Research Innovation Project of Chongqing Normal University(YKC24010)Chunna Zeng's research was supported by the Major Special Project of the National Natural Science Foundation of China(12141101)+2 种基金the Young Top-Talent program of Chongqing(CQYC2021059145)the Technology Research Foundation of Chongqing Educational committee(KJZD-K202200509)the Natural Science Foundation Project of Chongqing(CSTB2024NSCQ-MSX0937)。
文摘Two sharp Chernoff type inequalities are derived for star bodies in R2,one is an extension of the dual Chernoff-Ou-Pan inequality,and the other is the reverse Chernoff type inequality.Furthermore,we establish a generalized dual symmetric mixed Chernoff inequality for two planar star bodies.As a direct consequence,a new proof of the dual symmetric mixed isoperimetric inequality is presented.
基金supported by the Fundamental Research Funds for the Central Universities(2021ZY89)the National Natural Science Foundation of China(32201258 and 32271652)+4 种基金Research Service Project on the Effects of Extreme Climate on Biodiversity and Conservation Strategies in Mentougou District(2024HXFWBH-XJL-02)the Fang Jingyun Ecological Study Studio of Yunnan Province(China)the State Scholarship Fund of China(2011811457)support to the Xingdian Scholar Fund of Yunnan Provincethe Double Top University Fund of Yunnan University.
文摘Although numerous studies have proposed explanations for the specific and relative effects of stand structure,plant diversity,and environmental conditions on carbon(C)storage in forest ecosystems,understanding how these factors collectively affect C storage in different community layers(trees,shrubs,and herbs)and forest types(mixed,broad-leaved(E),broad-leaved(M),and coniferous forest)continues to pose challenges.To address this,we used structural equation models to quantify the influence of biotic factors(mean DBH,mean height,maximum height,stem density,and basal area)and abiotic factors(elevation and canopy openness),as well as metrics of species diversity(Shannon–Wiener index,Simpson index,and Pielou’s evenness)in various forest types.Our analysis revealed the critical roles of forest types and elevation in explaining a substantial portion of variability in C storage in the overstory layer,with a moderate influence of stand factors(mean DBH and basal area)and a slightly negative impact of tree species diversity(Shannon–Wiener index).Notably,forest height emerged as the primary predictor of C storage in the herb layer.Regression relationships further highlighted the significant contribution of tree species diversity to mean height,understory C storage,and branch biomass within the forest ecosystem.Our insights into tree species diversity,derived from structural equation modeling of C storage in the overstory,suggest that the effects of tree species diversity may be influenced by stem biomass in statistical reasoning within temperate forests.Further research should also integrate tree species diversity with tree components biomass,forest mean height,understory C,and canopy openness to understand complex relationships and maintain healthy and sustainable ecosystems in the face of global climate challenges.
基金Jiangsu College of Nursing 2023 Special Fund for Research and Development of Medical-Educational Integration。
文摘A systematic review and meta-analysis study was conducted to assess the effectiveness of probiotic/prebiotic/synbiotic supplementation on the effects of cardiovascular risk factors in patients with type 2 diabetes mellitus(T2DM)based on data from randomized controlled trials(RCTs).We searched electronic databases including PubMed,Cochrane Library,Embase,and Web of Science to identify clinical trials published up to 31 March 2023.Data was pooled using a random-effects model if significant heterogeneity(I2>50%),otherwise use a fixed-effects model.Fifty-six trials that included 3317 patients were enrolled for analysis.Meta-analysis reported that probiotic/prebiotic/synbiotic supplementation significantly reduced systolic blood pressure(SBP)(weighted mean difference(WMD):-3.57 mmHg,95% confidence interval(CI):-5.36,-1.78;P=0.000),diastolic blood pressure(DBP)(WMD:-2.05 mmHg,95%CI:-3.07,-1.04;P=0.000),triglycerides(TG)(WMD:-16.10 mg/dL,95%CI:-20.16,-12.05;P=0.000),total cholesterol(TC)(WMD:-14.00 mg/dL,95%CI:-20.46,-7.55;P=0.000),low-density lipoprotein cholesterol(LDL-C)(WMD:-7.03 mg/dL,95%CI:-9.25,-4.81;P=0.000),fasting plasma glucose(FPG)(WMD:-16.57 mg/dL,95%CI:-20.39,-12.74;P=0.000),hemoglobin A1c(HbA1c)(WMD:-0.44%,95%CI:-0.68,-0.20;P=0.000),insulin(standardized mean difference(SMD):-0.37,95%CI:-0.53,-0.21;P=0.000),homeostatic model assessment of insulin resistance(HOMA-IR)(WMD:-1.05,95%CI:-1.56,-0.54;P=0.000),C-reactive protein(CRP)(SMD:-0.35,95%CI:-0.57,-0.13;P=0.002),tumor necrosis factor-α(TNF-α)(SMD:-1.07,95%CI:-1.57,-0.56;P=0.000),interleukin-6(IL-6)(SMD:-0.37,95%CI:-0.61,-0.13;P=0.003)levels,they also increased the high-density lipoprotein cholesterol(HDL-C)(WMD:3.70 mg/dL,95%CI:1.80,5.60;P=0.000)levels in T2DM patients,as compared to the placebo groups.This meta-analysis supports the use of probiotic/prebiotic/synbiotic supplementation as an adjunctive therapy to improve blood pressure,glycemic control parameters,lipid profile and inflammatory markers in patients with T2DM,which are well-known cardiovascular risk factors.
基金supported by the Science and Technology Council,Taiwan,China(NSTC 112-2320-B-039-057 and MOST 111-2320-B-039-067-MY3)the China Medical University,Taiwan,China(CMU112-S-18),awarded to Yuan-Soon Ho+1 种基金the China Medical University,Taiwan,China(CMU112-N-02),awarded to Li-Ching Chenthe Science and Technology Council,Taiwan,China(MOST 110-2320B-039-079)。
文摘This study presents novel findings on the potential of phloretin,an apple polyphenol,to enhance the effectiveness of anti-human epidermal growth factor receptor-2(HER2)antibody therapy in HER2-positive breast cancer patients.Our research reveals that phloretin inhibits typeⅡglucose transporter(GLUT2)activity,significantly reducing cancer cell glucose uptake.We confirmed the overexpression of GLUT1 and GLUT2 mRNA in paired human breast tumor tissues,with GLUT2 overexpression associated explicitly with poorer survival rates in breast cancer patients.Treatment with phloretin was observed to increase the interaction between GLUT2 and HER2 proteins,attenuate glycolysis,and enhance the binding affinity of anti-HER2 antibody drugs to target human breast cancer cells.Furthermore,the efficacy of the combination therapy involving phloretin and antibody drugs was reaffirmed in a cell-derived xenograft tumor animal model,particularly in suppressing the growth of trastuzumab-resistant HER2-positive(HER2+)breast cancer.These significant findings suggest that targeting GLUT2 activity with phloretin in combination with anti-HER2 antibody drugs may help mitigate the development of drug-resistant breast cancer,offering valuable insights for enhancing tumor treatment strategies and contributing to developing more effective therapies.
基金This research is supported by the Joint Fund of the National Natural Science Foundation of China(grant number U19B6003-02)the Cooperation Program of PetroChina Liaohe Oilfield Company(grant Number HX20180604)the AAPG Foundation Grants-in-Aid Program(grant number 22269437).This study has benefited considerably from PetroChina Liaohe Oilfield Company for data support.We also thank the editor and the anonymous reviewers for their professional suggestions and comments.
文摘Kerogen types exert a decisive effect on the onset and capacity of hydrocarbon generation of source rocks.Lacustrine source rocks in the Liaohe Western Depression are characterized by thick deposition,high total organic carbon(TOC)content,various kerogen types,and a wide range of thermal maturity.Consequently,their hydrocarbon generation potential and resource estimation can be misinterpreted.In this study,geochemical tests,numerical analysis,hydrocarbon generation kinetics,and basin modeling were integrated to investigate the differential effects of kerogen types on the hydrocarbon generation potential of lacustrine source rocks.Optimized hydrocarbon generation and expulsion(HGE)models of different kerogen types were established quantitatively upon abundant Rock-Eval/TOC/vitrinite reflectance(R_(o))datasets.Three sets of good-excellent source rocks deposited in the fourth(Es4),third(Es3),and first(Es1)members of Paleogene Shahejie Formation,are predominantly types I-II_(1),II_(1)-II_(2),and II-III,respectively.The activation energy of types I-II_(2)kerogen is concentrated(180-230 kcal/mol),whereas that of type III kerogen is widely distributed(150-280 kcal/mol).The original hydrocarbon generation potentials of types I,II_(1),II_(2),and III kerogens are 790,510,270,and 85 mg/g TOC,respectively.The Ro values of the hydrocarbon generation threshold for type I-III source rocks gradually increase from 0.42%to 0.74%,and Ro values of the hydrocarbon expulsion threshold increase from 0.49%to 0.87%.Types I and II_(1)source rocks are characterized by earlier hydrocarbon generation,more rapid hydrocarbon expulsion,and narrower hydrocarbon generation windows than types II_(2)and III source rocks.The kerogen types also affect the HGE history and resource potential.Three types(conventional,tight,and shale oil/gas)and three levels(realistic,expected,and prospective)of hydrocarbon resources of different members in the Liaohe Western Depression are evaluated.Findings suggest that the Es3 member has considerable conventional and unconventional hydrocarbon resources.This study can quantitatively characterize the hydrocarbon generation potential of source rocks with different kerogen types,and facilitate a quick and accurate assessment of hydrocarbon resources,providing strategies for future oil and gas exploration.
基金funded by the National Key Research and Development Program of China(2020YFD0900902)Zhejiang Province Public Welfare Technology Application Research Project(LGJ21C20001)Zhejiang Provincial Key Research and Development Project of China(2019C02076 and 2019C02075)。
文摘Type 2 diabetes mellitus(T2DM)is a complex metabolic disease threatening human health.We investigated the effects of Tegillarca granosa polysaccharide(TGP)and determined its potential mechanisms in a mouse model of T2DM established through a high-fat diet and streptozotocin.TGP(5.1×10^(3) Da)was composed of mannose,glucosamine,rhamnose,glucuronic acid,galactosamine,glucose,galactose,xylose,and fucose.It could significantly alleviate weight loss,reduce fasting blood glucose levels,reverse dyslipidemia,reduce liver damage from oxidative stress,and improve insulin sensitivity.RT-PCR and Western blotting indicated that TGP could activate the phosphatidylinositol-3-kinase/protein kinase B signaling pathway to regulate disorders in glucolipid metabolism and improve insulin resistance.TGP increased the abundance of Allobaculum,Akkermansia,and Bifidobacterium,restored the microbiota abundance in the intestinal tracts of mice with T2DM,and promoted short-chain fatty acid production.This study provides new insights into the antidiabetic effects of TGP and highlights its potential as a natural hypoglycemic nutraceutical.
基金supported by the Key Technology Projects of the China Southern Power Grid Corporation(STKJXM20200059)the Key Support Project of the Joint Fund of the National Natural Science Foundation of China(U22B20123)。
文摘With the development of green data centers,a large number of Uninterruptible Power Supply(UPS)resources in Internet Data Center(IDC)are becoming idle assets owing to their low utilization rate.The revitalization of these idle UPS resources is an urgent problem that must be addressed.Based on the energy storage type of the UPS(EUPS)and using renewable sources,a solution for IDCs is proposed in this study.Subsequently,an EUPS cluster classification method based on the concept of shared mechanism niche(CSMN)was proposed to effectively solve the EUPS control problem.Accordingly,the classified EUPS aggregation unit was used to determine the optimal operation of the IDC.An IDC cost minimization optimization model was established,and the Quantum Particle Swarm Optimization(QPSO)algorithm was adopted.Finally,the economy and effectiveness of the three-tier optimization framework and model were verified through three case studies.
基金supported by the Natural Science Foundation of Hunan Province of China(2022JJ30369)the Education Department Important Foundation of Hunan Province in China(23A0095)。
文摘In this paper,we investigate sufficient and necessary conditions such that generalized Forelli-Rudin type operators T_(λ,τ,k),S_(λ,τ,k),Q_(λ,τ,k)and R_(λ,τ,k)are bounded between Lebesgue type spaces.In order to prove the main results,we first give some bidirectional estimates for several typical integrals.
文摘For analytic functions u,ψin the unit disk D in the complex plane and an analytic self-mapφof D,we describe in this paper the boundedness and compactness of product type operators T_(u,ψ,φ)f(z)=u(z)f(φ(z))+ψ(z)f'(φ(z)),z∈D,acting between weighted Bergman spaces induced by a doubling weight and a Bloch type space with a radial weight.
文摘In recent years,artificial intelligence(AI)has been widely used in the field of electricity,such as load prediction,fault diagnosis of the power equipment,intelligent scheduling of power grids.However,the application of latest AI technology still has many technical difficulties to be solved.In the process of upgrading from the traditional power system to the new-type power system,AC grids,DC grids and micro grids coexist.In addition,there are huge amount of power equipment and electronic devices,and the coupling relationship is very complicated.Moreover,the high proportion of clean energy and flexible loads connected to the grid leads to the enhancement of the stochastic characteristics of the system.And short-term and ultra-short-term forecasts are much more difficult.Therefore,the editorial office of Global Energy Interconnection has planned the special issue of“Artificial Intelligence Applied in New-Type Power System”.
基金supported by the National Natural Science Foundation of China(12271234)。
文摘In this paper,we establish two transformation formulas for nonterminating basic hypergeometric series by using Carlitz's inversions formulas and Jackson s transformation formula.In terms of application,by specializing certain parameters in the two transformations,four Rogers-Ramanujan type identities associated with moduli 20 are obtained.
文摘Purpose:Accurately assigning the document type of review articles in citation index databases like Web of Science(WoS)and Scopus is important.This study aims to investigate the document type assignation of review articles in Web of Science,Scopus and Publisher’s websites on a large scale.Design/methodology/approach:27,616 papers from 160 journals from 10 review journal series indexed in SCI are analyzed.The document types of these papers labeled on journals’websites,and assigned by WoS and Scopus are retrieved and compared to determine the assigning accuracy and identify the possible reasons for wrongly assigning.For the document type labeled on the website,we further differentiate them into explicit review and implicit review based on whether the website directly indicates it is a review or not.Findings:Overall,WoS and Scopus performed similarly,with an average precision of about 99% and recall of about 80%.However,there were some differences between WoS and Scopus across different journal series and within the same journal series.The assigning accuracy of WoS and Scopus for implicit reviews dropped significantly,especially for Scopus.Research limitations:The document types we used as the gold standard were based on the journal websites’labeling which were not manually validated one by one.We only studied the labeling performance for review articles published during 2017-2018 in review journals.Whether this conclusion can be extended to review articles published in non-review journals and most current situation is not very clear.Practical implications:This study provides a reference for the accuracy of document type assigning of review articles in WoS and Scopus,and the identified pattern for assigning implicit reviews may be helpful to better labeling on websites,WoS and Scopus.Originality/value:This study investigated the assigning accuracy of document type of reviews and identified the some patterns of wrong assignments.
基金supported by the National Natural Science Foundation of China(32122069 and 31972191)the Beijing Outstanding Young Scientist Program(BJJWZYJH01201910011025)funded by National Institutes of Health Grants DK111958 and AG062344 to R.J.L.
文摘The present study reports the structural characteristics of 3 polysaccharide fractions(SPS-F1,SPS-F2 and SPS-F3)isolated and purified from squash.SPS-F1(molecular weight(Mw)=12.30 kDa)and SPS-F2(Mw=19.40 kDa)were likely to contain HG and RG-I domain of pectic polysaccharide,respectively.SPS-F2(Mw=270.4 kDa)was mainly composed of rhamnose,galactose and arabinose.The treatment with SPS decreased body weight gain,glucose and TG levels in type 2 diabetes rats.Besides,25 differential metabolites were identified based on urinary metabolomics analysis,which are crucial to the anti-diabetic effect of SPS.The regulation of nicotinamide N-oxide,histamine,cis-aconitate,citrate,L-malic acid,3-(3-hydroxyphenyl)propanoic acid and N-acetyl-L-aspartic acid were mainly associated with energy metabolism,gut microbiota and inflammation.Study of surface plasmon resonance revealed the binding kinetics with galectin-3(Gal-3)and fibroblast growth factor 2(FGF2).The K_(D)values of SPS-F2 and SPS-F3 to Gal-3 were 4.97×10^(-3)and 1.48×10^(-3)mol/L,indicating a weak binding affinity.All 3 fractions showed moderate binding to FGF2 and the affinity was SPS-F3>SPS-F2>SPS-F1.Thus,the metabolomics and SPR approach were proved to be a promising tool in exploring the anti-diabetes effects of SPS and provided a deep understanding of the mechanisms.
基金funded by the National Natural Science Foundation of China(8217350881973027)Beijing Highlevel Public Health Technical Personnel Training Program(No.2022-3-032)。
文摘Recent studies indicated that vitamin A(VA)might be involved in the pathology of type 2 diabetes mellitus(T2DM).This cross-sectional study was conducted to explore the association between circulating VA level and T2DM.A total of 1818 subjects aged 50 years old and above were recruited from the community.Binomial logistic regression and restricted cubic spline(RCS)were applied to analyze the association of plasma VA level with the risk of T2DM.Serum VA and lipid-adjusted VA levels of T2DM patients were significantly higher than that of non-T2DM subjects(P<0.05).The ratios of plasma VA/total cholesterol(TC),VA/high-density lipoprotein cholesterol(HDL-c)and VA/low-density lipoprotein cholesterol(LDL-c)were positively associated with the risk of T2DM in the aging population(P<0.05).Compared with the Q1 level,subjects with Q2 to Q3 levels of plasma VA/triglyceride(TG)have decreased risk of T2DM(odds ratio(OR)Q2=0.68,P_(Q2)=0.021;ORQ3=0.59,P_(Q3)<0.01).Our results indicated that the imbalance of circulating lipids and VA might affect the relationship between VA and T2DM.The middle and aging subjects with higher ratios of plasma VA/TC,VA/HDL-c,and VA/LDL-c displayed increased risk for T2DM,but the moderate ratio of VA/TG might protect against risk of T2DM.
基金supported by the NSFC(12271184)the Guangzhou Basic and Applied Basic Research Foundation(2024A04J10001).
文摘In the present paper,we prove the existence,non-existence and multiplicity of positive normalized solutions(λ_(c),u_(c))∈R×H^(1)(R^(N))to the general Kirchhoff problem-M■,satisfying the normalization constraint f_(R)^N u^2dx=c,where M∈C([0,∞))is a given function satisfying some suitable assumptions.Our argument is not by the classical variational method,but by a global branch approach developed by Jeanjean et al.[J Math Pures Appl,2024,183:44–75]and a direct correspondence,so we can handle in a unified way the nonlinearities g(s),which are either mass subcritical,mass critical or mass supercritical.
基金the National Natural Science Foundation of China(3203000230)the Fundamental Research Funds for the Central Universities,Nankai University(63231172)the Natural Science Foundation of Henan(222300420158),for supporting this research.
文摘It has been widely accepted that resistant starch(RS)provides numerous health benefits for human.In this research,we aimed at evaluating the performance of novel starch-lipid complexes,RS5,in comparison with RS2 on physical features,glucolipids metabolism,inflammation,and gut microbiota profiles of type 2 diabetes mellitus(T2DM)rats.The T2DM model was established by streptozotocin injection to the high-fat-sugar fed rats.According to a serial of biochemical analyses,we found that RS5 diets were strongly correlated with enhanced homeostatic model assessment for insulin secretion(HOMA-IS),high-density lipoprotein cholesterol(HDL-C),adiponectin(ADP),insulin action index(IAI),glucagon-like peptide-1(GLP1),and short-chain fatty acids(SCFAs)in T2DM rats whilst negatively associated with the low-density lipoprotein(LDL-C)and inflammatory cytokines,showing the capabilities to ameliorate T2DM symptoms by regulation of glucolipid metabolism,gut metabolites,and inflammation.On the other hand,RS2-enriched supplementations were influential in the mediation of insulin secretion to improve glucose metabolism.The increasing evidence collected herein suggested that intestinal microbiota could mediate glucolipids metabolism and alleviate inflammation after certain microflora nourished by RS.In addition,RS intake made an impact on phosphoinositide 3-kinase/protein kinase B signaling pathway that might contribute to the improvement of glucose metabolism,insulin resistance,and inflammatory responses.
基金supported by the “Thirteenth Five Year” National Science and Technology Plan Project of China (2018YFC1603703,2018YFC1604302)National Natural Science Foundation of China (2013BAD18B03)+1 种基金Shenyang Technological Innovation Project (Y170-028)LiaoNing Revitalization Talents Project (XLYC1902083)
文摘This study investigated the effects of a xylitol-casein non-covalent complex(XC)on parameters related to type 2 diabetes mellitus(T2DM),in addition to related changes in gut microbiome composition and functions.High-fat-diet(HFD)+streptozotocin(STZ)-induced T2DM mice were treated with xylitol(XY),casein(CN),and XC,after which fecal samples were collected for gut microbiota composition and diversity analyses based on 16S rRNA high-throughput sequencing and multivariate statistics.XC decreased body weight and improved glucose tolerance,insulin sensitivity,pancreas impairment,blood lipid levels,and liver function in T2DM mice compared to XY-and CN-treated mice.Furthermore,XC modulated theα-diversity,β-diversity and gut microbiota composition.Based on Spearman’s correlation analysis,the relative abundances of Alistipes,Bacteroides,and Faecalibaculum were positively correlated and those of Akkermansia,Lactobacillus,Bifidobacterium,and Turicibacter were negatively correlated with the phenotypes related to the improvement of T2DM.In conclusion,we found that XC alleviated insulin resistance by restoring the gut microbiota of T2DM mice.Our results provide strong evidence for the beneficial effects of XC on T2DM and motivation for further investigation in animal models and,eventually,human trials.
基金supported by the China Postdoctoral Science Foundation (No.2023M733712)the National Natural Science Foundation of China (No.31971491)。
文摘Tree mortality significantly influences forest structure and function,yet our understanding of its dynamic patterns among a range of tree sizes and among different plant functional types(PFTs)remains incomplete.This study analysed size-dependent tree mortality in a temperate forest,encompassing 46 tree species and 32,565 individuals across different PFTs(i.e.,evergreen conifer vs.deciduous broadleaf species,shade-tolerant vs.shade-intolerant species).By employing all-subset regression procedures and logistic generalized linear mixed-effects models,we identified distinct mortality patterns influenced by biotic and abiotic factors.Our results showed a stable mortality patte rn in eve rgreen conifer species,contrasted by a declining pattern in deciduous broadleaf and shadetolerant,as well as shade-intolerant species,across size classes.The contribution to tree mortality of evergreen conifer species shifted from abiotic to biotic factors with increasing size,while the mortality of deciduous broadleaf species was mainly influenced by biotic factors,such as initial diameter at breast height(DBH)and conspecific negative density.For shade-tolerant species,the mortality of small individuals was mainly determined by initial DBH and conspecific negative density dependence,whereas the mortality of large individuals was subjected to the combined effect of biotic(competition from neighbours)and abiotic factors(i.e.,convexity and pH).As for shade-intolerant species,competition from neighbours was found to be the main driver of tree mortality throughout their growth stages.Thus,these insights enhance our understanding of forest dynamics by revealing the size-dependent and PFT-specific tree mortality patterns,which may inform strategies for maintaining forest diversity and resilience in temperate forest ecosystems.
基金supported by the NSF of Hebei Province(A2022208007)the NSF of China(11571089,11871191)the NSF of Henan Province(222300420397)。
文摘Clifford analysis is an important branch of modern analysis;it has a very important theoretical significance and application value,and its conclusions can be applied to the Maxwell equation,Yang-Mill field theory,quantum mechanics and value problems.In this paper,we first give the definition of a quasi-Cauchy type integral in complex Clifford analysis,and get the Plemelj formula for it.Second,we discuss the H?lder continuity for the Cauchy-type integral operators with values in a complex Clifford algebra.Finally,we prove the existence of solutions for a class of linear boundary value problems and give the integral representation for the solution.
基金supported by the National Natural Science Foundation of China(No.U21B2062)the Natural Science Foundation of Hubei Province(No.2023AFB307)。
文摘Identification of reservoir types in deep carbonates has always been a great challenge due to complex logging responses caused by the heterogeneous scale and distribution of storage spaces.Traditional cross-plot analysis and empirical formula methods for identifying reservoir types using geophysical logging data have high uncertainty and low efficiency,which cannot accurately reflect the nonlinear relationship between reservoir types and logging data.Recently,the kernel Fisher discriminant analysis(KFD),a kernel-based machine learning technique,attracts attention in many fields because of its strong nonlinear processing ability.However,the overall performance of KFD model may be limited as a single kernel function cannot simultaneously extrapolate and interpolate well,especially for highly complex data cases.To address this issue,in this study,a mixed kernel Fisher discriminant analysis(MKFD)model was established and applied to identify reservoir types of the deep Sinian carbonates in central Sichuan Basin,China.The MKFD model was trained and tested with 453 datasets from 7 coring wells,utilizing GR,CAL,DEN,AC,CNL and RT logs as input variables.The particle swarm optimization(PSO)was adopted for hyper-parameter optimization of MKFD model.To evaluate the model performance,prediction results of MKFD were compared with those of basic-kernel based KFD,RF and SVM models.Subsequently,the built MKFD model was applied in a blind well test,and a variable importance analysis was conducted.The comparison and blind test results demonstrated that MKFD outperformed traditional KFD,RF and SVM in the identification of reservoir types,which provided higher accuracy and stronger generalization.The MKFD can therefore be a reliable method for identifying reservoir types of deep carbonates.
