期刊文献+
共找到109,006篇文章
< 1 2 250 >
每页显示 20 50 100
Recent advances in modelling structure-property correlations in high-entropy alloys 被引量:2
1
作者 Akash A.Deshmukh Raghavan Ranganathan 《Journal of Materials Science & Technology》 2025年第1期127-151,共25页
Since antiquity,humans have been involved in designing materials through alloying strategies to meet the ever-growing technological demands.In 2004,this endeavor witnessed a significant breakthrough with the discovery... Since antiquity,humans have been involved in designing materials through alloying strategies to meet the ever-growing technological demands.In 2004,this endeavor witnessed a significant breakthrough with the discovery of high-entropy alloys(HEAs)comprising multi-principal elements.Owing to the four“core-effects”,these alloys exhibit exceptional properties including better structural stability,high strength and ductility,improved fatigue/fracture toughness,high corrosion and oxidation resistance,superconductiv-ity,magnetic properties,and good thermal properties.Different synthesis routes have been designed and used to meet the properties of interest for particular applications with varying dimensions.How-ever,HEAs are providing new opportunities and challenges for computational modelling of the complex structure-property correlations and in predictions of phase stability necessary for optimum performance of the alloy.Several attempts have been made to understand these alloys by empirical and computa-tional models,and data-driven approaches to accelerate the materials discovery with a desired set of properties.The present review discusses advances and inferences from simulations and models spanning multiple length and time scales explaining a comprehensive set of structure-properties relations.Addi-tionally,the role of machine learning approaches is also reviewed,underscoring the transformative role of computational modelling in unravelling the multifaceted properties and applications of HEAs,and the scope for future efforts in this direction. 展开更多
关键词 High-entropy alloys DFT Molecular dynamics CALPHAD Machine learning Structure-property correlations
原文传递
Utilizing On-the-Go Soil Sensors to Explore Correlations between Electrical Conductivity, Soil Reflectance, Slope, and Elevation of Mississippi Farm Soils 被引量:1
2
作者 Reginald S. Fletcher 《Agricultural Sciences》 2025年第1期112-122,共11页
Ten physical and environmental variables collected from an on-the-go soil sensor at two field sites (MF3E and MF11S) in Mississippi, USA, were analyzed to assess soil variability and the interrelationships among the m... Ten physical and environmental variables collected from an on-the-go soil sensor at two field sites (MF3E and MF11S) in Mississippi, USA, were analyzed to assess soil variability and the interrelationships among the measurements. At MF3E, moderate variability was observed in apparent electrical conductivity shallow (ECas), slope, and ECa ratio measurements, with coefficients of variation ranging from 20% to 27%. In contrast, MF11S exhibited higher variability, particularly in ECas and ECad (deep) measurements, which exceeded 30% in their coefficient of variation values, indicating significant differences in soil composition and moisture content. Correlation analysis revealed strong positive relationships between the near-infrared-to-red ratio and red reflectance (r = 0.897***) soil values at MF3E. MF11S demonstrated a strong negative correlation between ECas and ECad readings with the x-coordinate (r ***). Scatter plots and fitted models illustrated the complexity of relationships, with many showing nonlinear trends. These findings emphasize the need for continuous monitoring and advanced modeling to understand the dynamic nature of soil properties and their implications for agricultural practices. Future research should explore the underlying mechanisms driving variability in the soil characteristics to enhance soil management strategies at the study sites. 展开更多
关键词 Mobile Soil Sensors NEAR-INFRARED Correlation Nonlinear
在线阅读 下载PDF
Correlations of resilience with coping styles and quality of life in patients with malignancies 被引量:1
3
作者 Xue-Jin Qin Man-Man Kang +4 位作者 Fei Zhong Jing-Jing Liu Zheng-Chun Zhu Di Zhang Ke Han 《World Journal of Psychiatry》 2025年第4期186-194,共9页
BACKGROUND Resilience is an individual’s ability and psychological rebound capacity to adapt well after experiencing adversity,trauma,etc.Patients with strong resilience can face illnesses actively.AIM To determine t... BACKGROUND Resilience is an individual’s ability and psychological rebound capacity to adapt well after experiencing adversity,trauma,etc.Patients with strong resilience can face illnesses actively.AIM To determine the association of resilience with coping styles and quality of life in patients with malignancies.METHODS This study included patients with malignant tumors who were hospitalized at Fuyang Hospital Affiliated to Anhui Medical University from March 2022 to March 2024.The Connor-Davidson Resilience Scale,Medical Coping Modes Questionnaire,Social Support Rating Scale,and the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 were utilized to assess patients’resilience,coping styles,social support,and quality of life,respectively.Pearson correlation analysis was conducted to assess the correlations.RESULTS A total of 175 patients with malignant tumors demonstrated no marked difference in terms of age,education level,employment status,monthly household income,and disease staging(P<0.05).Further,patients with malignancies demonstrated scores of 17.49±1.20,17.27±1.46,and 11.19±1.29 points in terms of coping styles in confrontation,avoidance,and resignation dimensions,respectively.Subjective support,objective support,and support utilization scores in terms of social support were 10.67±1.80,11.26±2.08,and 9.24±1.14 points,respectively.The total resilience score and tenacity,self-improvement,and optimism dimension scores were positively correlatedwith the confrontation coping style score,whereas the total resilience score and tenacity and self-improvementscores were negatively associated with avoidance and resignation coping style scores(P<0.05).The total resiliencescore and the tenacity dimension score were positively associated with physical,role,cognitive,emotional,andsocial functions,as well as global health status(P<0.05),and were inversely related to fatigue,insomnia,andeconomic difficulties(P<0.05).CONCLUSIONThe resilience of patients with malignancies is positively associated with the confrontation dimension in the copingstyle,the total and various social support domain scores,and the overall quality of life.Clinical medical staff needto pay attention to the effect of medical coping styles and social support on the resilience level of patients withmalignancies to further improve their quality of life. 展开更多
关键词 Malignant tumor RESILIENCE Coping style Quality of life CORRELATION
暂未订购
Correlations of the expression of Cx43,SCF^(FBXW7),p-cyclin E1(Ser73),p-cyclin E1(Thr77)and p-cyclin E1(Thr395)in colon cancer tissues
4
作者 Rong-Gang Luan Ming-Da Liu +9 位作者 Zi-Feng Deng Cong-Lan Lu Mei-Ling Yu Ming-Yu Zhang Rong Liu Ran An You-Liang Yao Dong-Bei Guo Yong-Xing Zhang Lei Zhao 《World Journal of Gastrointestinal Oncology》 SCIE 2025年第1期207-213,共7页
BACKGROUND Previous cellular studies have demonstrated that elevated expression of Cx43 promotes the degradation of cyclin E1 and inhibits cell proliferation through ubiquitination.Conversely,reduced expression result... BACKGROUND Previous cellular studies have demonstrated that elevated expression of Cx43 promotes the degradation of cyclin E1 and inhibits cell proliferation through ubiquitination.Conversely,reduced expression results in a loss of this capacity to facilitate cyclin E degradation.The ubiquitination and degradation of cyclin E1 may be associated with phosphorylation at specific sites on the protein,with Cx43 potentially enhancing this process by facilitating the phosphorylation of these critical residues.AIM To investigate the correlation between expression of Cx43,SKP1/Cullin1/F-box(SCF)FBXW7,p-cyclin E1(ser73,thr77,thr395)and clinicopathological indexes in colon cancer.METHODS Expression levels of Cx43,SCF^(FBXW7),p-cyclin E1(ser73,thr77,thr395)in 38 clinical colon cancer samples were detected by immunohistochemistry and were analyzed by statistical methods to discuss their correlations.RESULTS Positive rate of Cx43,SCF^(FBXW7),p-cyclin E1(Ser73),p-cyclin E1(Thr77)and p-cyclin E1(Thr395)in detected samples were 76.32%,76.32%,65.79%,5.26%and 55.26%respectively.Positive expressions of these proteins were not related to the tissue type,degree of tissue differentiation or lymph node metastasis.Cx43 and SCF^(FBXW7)(r=0.749),p-cyclin E1(Ser73)(r=0.667)and p-cyclin E1(Thr395)(r=0.457),SCF^(FBXW7) and p-cyclin E1(Ser73)(r=0.703)and p-cyclin E1(Thr395)(0.415)were correlated in colon cancer(P<0.05),and expressions of the above proteins were positively correlated in colon cancer.CONCLUSION Cx43 may facilitate the phosphorylation of cyclin E1 at the Ser73 and Thr195 sites through its interaction with SCF^(FBXW7),thereby influencing the ubiquitination and degradation of cyclin E1. 展开更多
关键词 Colon cancer CX43 SCF^(FBXW7) Phosphorylation of cyclin E1 Sites of cyclin E1 Correlation analysis
暂未订购
Application of Multiple Correlations Analysis in Portfolio Selection
5
作者 Ruili Sun Junpeng Jia Shiguo Huang 《Proceedings of Business and Economic Studies》 2025年第4期305-319,共15页
Portfolio selection based on the global minimum variance(GMV)model remains a significant focus in financial research.The covariance matrix,central to the GMV model,determines portfolio weights,and its accurate estimat... Portfolio selection based on the global minimum variance(GMV)model remains a significant focus in financial research.The covariance matrix,central to the GMV model,determines portfolio weights,and its accurate estimation is key to effective strategies.Based on the decomposition form of the covariance matrix.This paper introduces semi-variance for improved financial asymmetric risk measurement;addresses asymmetry in financial asset correlations using distance,asymmetric,and Chatterjee correlations to refine covariance matrices;and proposes three new covariance matrix models to enhance risk assessment and portfolio selection strategies.Testing with data from 30 stocks across various sectors of the Chinese market confirms the strong performance of the proposed strategies. 展开更多
关键词 Portfolio selection GMV model Semi-variance Asymmetric correlation Chatterjee correlation
在线阅读 下载PDF
Correlations of the net baryon number and electric charge in nuclear matter
6
作者 Xin-Ran Yang Guo-Yun Shao +1 位作者 Chong-Long Xie Zhi-Peng Li 《Nuclear Science and Techniques》 2025年第8期154-164,共11页
We investigated the correlations between the net baryon number and electric charge up to the sixth order related to the interactions of nuclear matter at low temperature and explored their relationship with the nuclea... We investigated the correlations between the net baryon number and electric charge up to the sixth order related to the interactions of nuclear matter at low temperature and explored their relationship with the nuclear liquid-gas phase transition(LGPT)within the framework of the nonlinear Walecka model.The calculations showed that strong correlations between the baryon number and electric charge existed near the LGPT,and higher-order correlations were more sensitive than the lower-order correlations near the phase transition.However,in the high-temperature region away from the LGPT,the rescaled lower-order correlations were relatively larger than most of the higher-order correlations.In addition,some of the fifth-and sixth-order correlations possibly changed sign from negative to positive along the chemical freeze-out line with decreasing temperature.In combination with future experimental projects at lower collision energies,the derived results can be used to study the phase structure of strongly interacting matter and analyze the related experimental signals. 展开更多
关键词 correlations of conserved charges Nuclear matter Nuclear liquid–gas phase transition Heavy-ion collision
在线阅读 下载PDF
Towards understanding the microstructure-mechanical property correlations of multi-level heterogeneous-structured Al matrix composites
7
作者 Yuesong Wu Xiaobin Lin +4 位作者 Xudong Rong Xiang Zhang Dongdong Zhao Chunnian He Naiqin Zhao 《Journal of Materials Science & Technology》 2025年第6期117-123,共7页
1.Introduction The strength-ductility trade-offdilemma has long been a per-sistent challenge in Al matrix composites(AMCs)[1,2].This is-sue primarily arises from the agglomeration of reinforcements at the grain bounda... 1.Introduction The strength-ductility trade-offdilemma has long been a per-sistent challenge in Al matrix composites(AMCs)[1,2].This is-sue primarily arises from the agglomeration of reinforcements at the grain boundaries(GBs),which restricts local plastic flow dur-ing the plastic deformation and leads to stress concentration[3,4].Recently,the development of concepts aimed at achieving hetero-geneous grain has emerged as a promising approach for enhanc-ing comprehensive mechanical properties[5,6]. 展开更多
关键词 reinforcements agglomeration comprehensive mechanical properties agglomeration reinforcements plastic deformation strength ductility trade off multi level heterogeneous structured Al matrix composites microstructure mechanical property correlations al matrix composites amcs
原文传递
The impact of tensor force on collective correlations and neutrinoless double-βdecay
8
作者 Chang-Feng Jiao Cen-Xi Yuan 《Nuclear Science and Techniques》 2025年第11期233-242,共10页
The tensor force changes the nuclear shell structure and thus may result in underlying influence of the collectivity and decay properties of the nucleus.We carefully examined the impact of the monopole and multipole e... The tensor force changes the nuclear shell structure and thus may result in underlying influence of the collectivity and decay properties of the nucleus.We carefully examined the impact of the monopole and multipole effects originating from the tensor force on both the collectivity and the matrix element for the neutrinoless double-β(0νββ)decay,using the generatorcoordinate method with an effective interaction.To analyze the effect of the tensor force,we employed an effective Hamiltonian associated with the monopole-based universal interaction that explicitly consists of the central,tensor,and spin-orbit coupling terms.The interferences among the shell structure,quadrupole collectivity,nucleon occupancy,and 0νββmatrix elements were analyzed in detail.A better understanding of the tensor force would be of great importance in reducing the theoretical uncertainty in 0νββnuclear matrix element calculations. 展开更多
关键词 Neutrinoless double-beta decay Collective correlations Tensor force
在线阅读 下载PDF
Canopy structural heterogeneity drives α and β species-genetic diversity correlations in a Chinese subtropical forest
9
作者 Zhiliang Yao Xia Pan +6 位作者 Xin Yang Xiaona Shao Bin Wang Yun Deng Zhiming Zhang Qiaoming Li Luxiang Lin 《Plant Diversity》 2025年第1期106-114,共9页
Patterns and drivers of species–genetic diversity correlations(SGDCs)have been broadly examined across taxa and ecosystems and greatly deepen our understanding of how biodiversity is maintained.However,few studies ha... Patterns and drivers of species–genetic diversity correlations(SGDCs)have been broadly examined across taxa and ecosystems and greatly deepen our understanding of how biodiversity is maintained.However,few studies have examined the role of canopy structural heterogeneity,which is a defining feature of forests,in shaping SGDCs.Here,we determine what factors contribute toα-andβ-species–genetic diversity correlations(i.e.,α-andβ-SGDCs)in a Chinese subtropical forest.For this purpose,we used neutral molecular markers to assess genetic variation in almost all adult individuals of the dominant tree species,Lithocarpus xylocarpus,across plots in the Ailaoshan National Natural Reserve.We also quantified microhabitat variation by quantifying canopy structure heterogeneity with airborne laser scanning on 201-ha subtropical forest plots.We found that speciesα-diversity was negatively correlated with geneticα-diversity.Canopy structural heterogeneity was positively correlated with speciesα-diversity but negatively correlated with geneticα-diversity.These contrasting effects contributed to the formation of a negativeα-SGDC.Further,we found that canopy structural heterogeneity increases speciesα-diversity and decreases geneticα-diversity by reducing the population size of target species.Speciesβ-diversity,in contrast,was positively correlated with geneticβ-diversity.Differences in canopy structural heterogeneity between plots had non-linear parallel effects on the two levels ofβ-diversity,while geographic distance had a relatively weak effect onβ-SGDC.Our study indicates that canopy structural heterogeneity simultaneously affects plot-level community species diversity and population genetic diversity,and species and genetic turnover across plots,thus drivingα-andβ-SGDCs. 展开更多
关键词 Dominant species Forest structure LIDAR Lithocarpus xylocarpus Speciesegenetic diversity correlation Subtropical evergreen broad-leaved forest
在线阅读 下载PDF
Cross-correlations between signal's components
10
作者 Quankun Zhao Sen Li +2 位作者 Changgui Gu Haiying Wang Huijie Yang 《Chinese Physics B》 2025年第2期483-494,共12页
Detecting coupling pattern between elements in a complex system is a basic task in data-driven analysis. The trajectory for each specific element is a cooperative result of its intrinsic dynamic, its couplings with ot... Detecting coupling pattern between elements in a complex system is a basic task in data-driven analysis. The trajectory for each specific element is a cooperative result of its intrinsic dynamic, its couplings with other elements, and the environment. It is subsequently composed of many components, only some of which take part in the couplings. In this paper we present a framework to detect the component correlation pattern. Firstly, the interested trajectories are decomposed into components by using decomposing methods such as the Fourier expansion and the Wavelet transformation. Secondly, the cross-correlations between the components are calculated, resulting into a component cross-correlation matrix(network).Finally, the dominant structure in the network is identified to characterize the coupling pattern in the system. Several deterministic dynamical models turn out to be characterized with rich structures such as the clustering of the components. The pattern of correlation between respiratory(RESP) and ECG signals is composed of five sub-clusters that are mainly formed by the components in ECG signal. Interestingly, only 7 components from RESP(scattered in four sub-clusters) take part in the realization of coupling between the two signals. 展开更多
关键词 coupling structure cross-correlation matrix component correlation network
原文传递
Detailed discussion of discrepancy between theoretical and observed spectral lines in Kr-like W^(38+)based on advanced consideration of core electron correlations
11
作者 Guo-Qing Peng Kai Wang +1 位作者 Jun Yan Wei Kang 《Chinese Physics B》 2025年第5期328-337,共10页
For the observed line at 799.23°A in tungsten EBIT experiment,which was assigned to be^(3)F_(4)^(o)−^(3)F_(3)^(o)([Ar]4s^(2)4p^(5)4d)of W^(38+)ion,there were noticeable deviations for most calculated wavelengths ... For the observed line at 799.23°A in tungsten EBIT experiment,which was assigned to be^(3)F_(4)^(o)−^(3)F_(3)^(o)([Ar]4s^(2)4p^(5)4d)of W^(38+)ion,there were noticeable deviations for most calculated wavelengths from the measured value.To clarify this issue,we carry out an extensive calculation for energy levels and transition properties of W^(38+)ion using the multi-configuration Dirac–Hartree–Fock and relativistic configuration interaction method,in which more deeper inner core electron correlations are included,and different forms of Breit interaction as well as quantum electrodynamics corrections are investigated.It is found that the inner core electron correlations can affect the total energy of levels,while only slightly modify the excited energy of levels in 4s^(2)4p^(5)4d complex.The present calculated wavelengths agree with the corresponding measured values excellently except the line at 799.23Å.Thus we are strongly suspicious this line should be misidentified,and suggest that new experiment with higher resolution and spectra analysis based on more accurate atomic data should be performed for W^(38+)ion. 展开更多
关键词 Kr-like W^(38+) the multi-configuration Dirac-Hartree-Fock(MCDHF)method electron correlation imbalance Breit interaction quantum electrodynamic(QED)
原文传递
高血压与帕金森病的共享基因位点识别研究
12
作者 周文超 梁佳琪 +3 位作者 姚尚满 薛朝 刘龙 郭相杰 《中国全科医学》 北大核心 2026年第2期201-206,共6页
背景高血压与帕金森病在观察性研究中已经表现出共病现象,但其共同遗传基础和因果关系尚未明确。目的本研究利用大规模全基因组关联研究(GWAS)的汇总数据,探讨高血压与帕金森病的共同遗传病因及因果关系。方法提取FinnGen项目R5版本中G... 背景高血压与帕金森病在观察性研究中已经表现出共病现象,但其共同遗传基础和因果关系尚未明确。目的本研究利用大规模全基因组关联研究(GWAS)的汇总数据,探讨高血压与帕金森病的共同遗传病因及因果关系。方法提取FinnGen项目R5版本中GWAS汇总统计数据(2162例帕金森病患者和216630例对照)和英国生物银行的汇总统计数据(包含129909例高血压患者和354689例对照),通过连锁不平衡得分回归(LDSC)和局部遗传力估计(ρ-HESS)评估整体和局部的遗传相关性。采用跨性状Meta分析揭示高血压与帕金森病共享的多效性基因组单核苷酸多态性(SNPs),并通过双向孟德尔随机化(MR)分析推断潜在的因果关系。结果遗传相关性分析显示,高血压与帕金森病之间未观察到整体相关性(r_(g)=0.067,P=0.527)。局部分析识别出3个边缘显著区域(P<0.05),但在Bonferroni校正后无统计学意义(P>0.05)。跨性状Meta分析确认了37个与高血压和帕金森病相关的SNPs。双向MR分析结果表明,高血压对帕金森病具有因果效应(β=0.655,SE=0.278,P=0.019),而帕金森病对高血压无反向因果效应(β=0.002,SE=0.001,P=0.179)。敏感性分析进一步验证了结果的稳健性。结论本研究发现高血压是帕金森病的危险因素,两者之间存在共同遗传基础和因果关系,共享遗传位点的识别在疾病预防和治疗策略中具有重要意义。 展开更多
关键词 高血压 帕金森病 遗传相关性 跨性状Meta分析 孟德尔随机化
暂未订购
Estimates of Heritability and Genetic Correlations for Growth Traits in Chinese Shrimp Fenneropenaeus chinensis 被引量:2
13
作者 何玉英 王清印 +3 位作者 谭乐义 李健 陈华增 李吉涛 《Agricultural Science & Technology》 CAS 2011年第4期613-616,共4页
[Objective] The aim was to estimate the heritability and genetic correlations of growth traits of Chinese shrimp Fenneropenaeus chinensis so as to provide basis and technical parameters for the breeding and selecting ... [Objective] The aim was to estimate the heritability and genetic correlations of growth traits of Chinese shrimp Fenneropenaeus chinensis so as to provide basis and technical parameters for the breeding and selecting of Chinese shrimp.[Method] 51 full-sib families(including 35 half-sib families)of the Chinese shrimp F.chinensis were obtained by artificial insemination.Four growth traits of these families were measured,including body length,cephalothorax length,abdorminal segment length and body weight.According to quantitative genetics theory,the heritability of each growth trait,genetic and phenotypic correlation among these traits was statistically studied.[Result] The heritability was 0.36-0.51 for body length,0.14-0.24 for cephalothorax length,0.25-0.50 for abdominal segment length,and 0.04-0.29 for body weight.High and positive genetic correlations were obtained among growth traits.The genetic correlation between body weight and abdominal segment length was the highest(0.92),followed by body length and abdominal segment length(0.91),body length and body weight(0.88),body weight and cephalothorax length(0.87),abdominal segment length and cephalothorax length(0.86),while the genetic correlation between body length and cephalothorax length was the lowest(0.83).[Conclusion] The phenotypic correlation of body length,cephalothorax length,abdorminal segment length and body weight of Chinese shrimp F.chinensis were from 0.80 to 0.90 with extremely significant difference(P0.01)among the four growth traits by t-test. 展开更多
关键词 Fenneropenaeus chinensis Growth traits HERITABILITY Genetic correlation
在线阅读 下载PDF
Repeat Sequences and Base Correlations in Human Y Chromosome Palindromes 被引量:1
14
作者 金能智 刘子贤 +1 位作者 齐燕姣 邱文元 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2009年第3期255-261,339,共8页
On the basis of information theory and statistical methods, we use mutual information, n- tuple entropy and conditional entropy, combined with biological characteristics, to analyze the long range correlation and shor... On the basis of information theory and statistical methods, we use mutual information, n- tuple entropy and conditional entropy, combined with biological characteristics, to analyze the long range correlation and short range correlation in human Y chromosome palindromes. The magnitude distribution of the long range correlation which can be reflected by the mutual information is PS〉PSa〉PSb (P5a and P5b are the sequences that replace solely Alu repeats and all interspersed repeats with random uneorrelated sequences in human Y chromosome palindrome 5, respectively); and the magnitude distribution of the short range correlation which can be reflected by the n-tuple entropy and the conditional entropy is PS〉P5a〉PSb〉random uncorrelated sequence. In other words, when the Alu repeats and all interspersed repeats replace with random uneorrelated sequence, the long range and short range correlation decrease gradually. However, the random nncorrelated sequence has no correlation. This research indicates that more repeat sequences result in stronger correlation between bases in human Y chromosome. The analyses may be helpful to understand the special structures of human Y chromosome palindromes profoundly. 展开更多
关键词 Human Y chromosome PALINDROME Mutual information Long range correlation Short range correlation
在线阅读 下载PDF
Vector Correlations and Product Rotational Alignments of Reactions Ca+RBr→CaBr+R(R=CH_(3),C_(2) H_(5) and n-C_(3) H_(7)) 被引量:1
15
作者 马建军 丛书林 +1 位作者 张志红 王艳秋 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 北大核心 2006年第2期117-122,共6页
The quasiclassical trajectory method is used to study the vector correlations of the reactions Ca+RBr (R=CH3, C2H5 and n-C3H7Br) and the rotational alignment of product CaBr. The product rotational alignment parame... The quasiclassical trajectory method is used to study the vector correlations of the reactions Ca+RBr (R=CH3, C2H5 and n-C3H7Br) and the rotational alignment of product CaBr. The product rotational alignment parameters at different collision energies and the vector correlations between the reagent and product are numerically calculated. The vector correlations are described by using the angle distribution functions P(θr), P(φr), P(θr, φr) and the polarization-dependent differential cross sections (PDDCSs). The peak values of P(θr) of the product CaBr from Ca+CH3Br are larger than those from Ca+C2H5Br and Ca+n-C3H7Br. The peak of P(θr) at φr= 3π/2 is apparently stronger than that at φr= x/2 for the three reactions Ca+RBr. The calculation results show that the rotational angular momentum of the product CaBr is not only aligned, but also oriented along the direction which is perpendicular to the scattering plane.The product CaBr molecules are strongly scattered forward. The orientation and alignment of the product angular momentum will affect the scattering direction of the product molecules to varying degrees. 展开更多
关键词 Quasiclassical trajectory Vector correlation Orientation and alignment
在线阅读 下载PDF
肥胖相关基因FTO表达水平与高脂血症性急性胰腺炎的相关性分析
16
作者 饶紫兰 吴世浪 许文集 《中外医学研究》 2026年第1期1-4,8,共5页
目的:分析肥胖相关基因脂肪量与肥胖相关基因(FTO)表达水平与高脂血症性急性胰腺炎(HTGP)的相关性。方法:选取2023年1月—2024年12月福建医科大学附属第二医院收治的100例HTGP患者为研究对象,根据《中国急性胰腺炎诊治指南(2021)》中急... 目的:分析肥胖相关基因脂肪量与肥胖相关基因(FTO)表达水平与高脂血症性急性胰腺炎(HTGP)的相关性。方法:选取2023年1月—2024年12月福建医科大学附属第二医院收治的100例HTGP患者为研究对象,根据《中国急性胰腺炎诊治指南(2021)》中急性胰腺炎(AP)严重程度分级诊断标准分为轻症组(65例)和中重症组(35例),另选取同期收治的高脂血症无AP患者(50例)作为对照组,健康体检者(30人)作为健康组。比较4组甘油三酯、FTO mRNA表达水平差异,采用Pearson相关系数分析FTO mRNA表达水平与甘油三酯水平的相关性,采用多因素logistic回归分析FTO mRNA表达水平与HTGP严重程度的关系,并绘制受试者工作特征(ROC)曲线评估FTO mRNA表达水平对HTGP严重程度的预测效能。结果:中重症组、轻症组、对照组BMI、饮酒史占比及甘油三酯、FTO mRNA表达水平均高于健康组,且中重症组>轻症组>对照组,差异有统计学意义(P<0.05);Pearson相关性分析显示,FTO mRNA表达水平与甘油三酯水平呈正相关(r=0.447,P<0.001)。BMI、饮酒史、甘油三酯水平、FTO mRNA表达水平均与HTGP严重程度有关(P<0.05),多因素logistic回归分析显示,BMI、甘油三酯、FTO mRNA表达水平是HTGP严重程度的独立危险因素(P<0.05)。ROC曲线分析显示,BMI、甘油三酯、FTO mRNA表达水平预测HTGP严重程度的ROC曲线下面积(AUC)分别为0.791、0.847、0.868,FTO mRNA的预测效能优于BMI(Z=2.968、1.996,P<0.05),当取cutoff值0.40时,FTO mRNA预测HTGP严重程度的灵敏度和特异度分别为90.00%、76.80%。结论:FTO mRNA在HTGP患者中高表达,是影响HTGP严重程度的危险因素,对HTGP严重程度有良好预测价值。 展开更多
关键词 肥胖相关基因 脂肪量与肥胖相关基因 高脂血症 急性胰腺炎 相关性
暂未订购
脂联素、胎盘生乳素与妊娠期糖尿病及新生儿出生体质量关系的研究
17
作者 杨敏 李岩 +3 位作者 乔炳龙 李超 马春玲 李灿 《精准医学杂志》 2026年第1期32-35,39,共5页
目的探讨产妇外周血、脐血和羊水中的脂联素(APN)和胎盘生乳素(hPL)水平与妊娠期糖尿病及新生儿出生体质量之间的关系,并分析APN和hPL之间的相关性。方法以2023年1—5月在青岛大学附属医院西海岸院区分娩的妊娠期糖尿病产妇41例为糖尿病... 目的探讨产妇外周血、脐血和羊水中的脂联素(APN)和胎盘生乳素(hPL)水平与妊娠期糖尿病及新生儿出生体质量之间的关系,并分析APN和hPL之间的相关性。方法以2023年1—5月在青岛大学附属医院西海岸院区分娩的妊娠期糖尿病产妇41例为糖尿病组,以同期在本院分娩的正常产妇41例为对照组。检测两组产妇外周血、脐血及羊水中APN和hPL水平并进行比较,APN和hPL的相关性及APN、hPL与新生儿出生体质量的相关性分析采用Spearman线性分析。结果糖尿病组产妇外周血、羊水、脐血中APN水平和脐血中hPL水平均明显低于对照组(t=-2.956~-2.436,P<0.05);对照组产妇脐血当中APN、hPL水平与新生儿出生体质量呈正相关(r=0.389、0.346,P<0.05),糖尿病组产妇脐血当中APN、hPL水平与新生儿出生体质量呈负相关(r=-0.324、-0.447,P<0.05);糖尿病组产妇脐血中hPL水平与脐血中APN水平呈正相关(r=0.341,P<0.05)。结论产妇外周血、脐血、羊水中的APN水平和脐血中的hPL水平降低可能与产妇妊娠期糖尿病的发生有关,脐血中APN、hPL水平与新生儿出生体质量的相关性可能受产妇血糖代谢的影响;脐血中APN水平升高可能会对脐血中hPL表达具有一定的促进作用。 展开更多
关键词 糖尿病 妊娠 脂联素 胎盘催乳激素 出生体质量 相关性分析 婴儿 新生
暂未订购
慢性阻塞性肺疾病病人营养状况及与肺部感染的相关性
18
作者 段云卉 张诗玄 +3 位作者 王融 田景丰 赵玲 贾凯 《安徽医药》 2026年第2期301-304,共4页
目的旨在分析慢性阻塞性肺疾病(COPD)病人营养状况及与肺部感染的关系。方法选取2022年9月至2023年8月首都医科大学附属北京朝阳医院收治的COPD病人120例,采用全自动生化仪检测血清白蛋白(ALB)、前白蛋白(PA)水平;采用主观全面评定法(S... 目的旨在分析慢性阻塞性肺疾病(COPD)病人营养状况及与肺部感染的关系。方法选取2022年9月至2023年8月首都医科大学附属北京朝阳医院收治的COPD病人120例,采用全自动生化仪检测血清白蛋白(ALB)、前白蛋白(PA)水平;采用主观全面评定法(SGA)进行营养状况评估;依据临床体征及肺部CT或者痰培养等辅助检查结果,将病人分为未感染组(n=71)、感染组(n=49)。多因素logistic回归分析探索COPD病人发生肺部感染的影响因素;受试者操作特征曲线(ROC曲线)分析营养指标在预测COPD病人发生肺部感染的效能。结果感染组身体质量指数(BMI)≤18.5 kg/m^(2)病人占比(61.22%比36.62%)、SGA评分[(4.05±1.03)分比(2.83±0.61)分]较未感染组明显升高(P<0.05),ALB[(31.27±4.52)g/L比(37.31±5.45)g/L]、PA[(129.39±16.57)g/L比(150.21±18.46)g/L]水平较未感染组明显降低(P<0.05);多因素logistic回归分析显示,BMI≤18.5kg/m^(2)占比、SGA评分升高是影响COPD病人发生肺部感染的危险因素(P<0.05),ALB升高、PA升高是其保护因素(P<0.05);ALB、PA、SGA评分及三者联合预测COPD病人发生肺部感染的AUC及其95%CI分别为0.80(0.72,0.87)、0.78(0.69,0.85)、0.84(0.76,0.90)、0.92(0.86,0.96),三者联合预测效能显著优于单一指标(Z三者联合-ALB=3.28、Z三者联合-PA=4.13、Z三者联合-SGA评分=2.78,P=0.001、<0.001、0.005)。结论发生肺部感染的COPD病人SGA评分升高,ALB、PA水平降低,且三者联合预测COPD病人发生肺部感染的效能较高。 展开更多
关键词 肺疾病 慢性阻塞性 营养状况 肺部感染 主观全面评定法 相关性
暂未订购
甘蔗横向种植机功能部件的关联性分析与布局设计
19
作者 麻芳兰 樊广坤 +3 位作者 苗金泽 陈彬 陈京盛 李科 《农机化研究》 北大核心 2026年第1期199-206,共8页
为提高种植机的作业质量,并解决甘蔗种植机漏播率高、播种不均匀、种植深度不足等问题,从功能部件布局的角度设计了一种能够全程机械化作业的预切式横向甘蔗种植机。通过对旋耕器与开沟后犁、开沟后犁与播种器、播种器与供种机构的关联... 为提高种植机的作业质量,并解决甘蔗种植机漏播率高、播种不均匀、种植深度不足等问题,从功能部件布局的角度设计了一种能够全程机械化作业的预切式横向甘蔗种植机。通过对旋耕器与开沟后犁、开沟后犁与播种器、播种器与供种机构的关联性进行分析和布局,确定了各机构之间的相对位置,并确定了影响蔗种在供种箱内有序排列的3个因素:斜板倾角、落种高度和斜板上移距离;通过ADAMS软件模拟蔗种在集蔗箱内的排列情况,得出了斜板倾角、落种高度和斜板上移距离的最佳参数分别为40°、180 mm和160 mm。田间试验结果显示,种植机平均播种间距为412.65 mm,略大于农艺要求的播种间距,这是由于拖拉机行进速度与理论值不匹配所致;平均种植深度、平均开沟深度、漏播率、播种合格率和播种间距变异系数分别为271.62 mm、296.68 mm、4.88%、95.12%和2.61%,相关作业性能指标均满足设计要求。 展开更多
关键词 甘蔗 横向种植机 预切种式 功能部件 关联性分析 布局设计 ADAMS
在线阅读 下载PDF
Correlations between Quality Index and Content of Cellulose and Lignin in Upper Leaves of Fluecured Tobacco in Wulin Mountain Area
20
作者 刘晓冰 孟霖 +4 位作者 梁盟 王程栋 宋文静 郑家宝 徐宜民 《Agricultural Science & Technology》 CAS 2015年第10期2135-2140,2143,共7页
In order to study the correlations among quality indexes of tobacco leaf and contents of cellulose and lignin in upper leaves of flue-cured tobacco, 48 B2F flue-cured tobacco samples in seven counties of Wulin mountai... In order to study the correlations among quality indexes of tobacco leaf and contents of cellulose and lignin in upper leaves of flue-cured tobacco, 48 B2F flue-cured tobacco samples in seven counties of Wulin mountain area in 2011 and 2012 were used as test materials to measure the contents of cellulose and lignin in tobacco leaves and analyze the differences among varieties and between years. Meanwhile, correlations among contents of cellulose and lignin and appearance quality, physical characteristics, general chemical components and indexes of senso- ry quality were studied. The results showed that the contents of cellulose and lignin had no significant difference among years and varieties. Cellulose content was sig- nificantly correlated with some indexes of appearance qualities, physical indexes, general chemical compositions and sensory qualities. Lignin content was significantly correlated with grayness and oil content but not other quality indexes of tobacco leaf. It could be seen that the differences of cellulose and lignin contents between different years and among varieties were not significant. Cellulose content was closely correlated with quality indexes of tobacco leaf while lignin content had a small effect on tobacco leaf quality. 展开更多
关键词 Flue-cured tobacco Upper leaf CELLULOSE LIGNIN Correlation analysis
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