期刊文献+
共找到7,492篇文章
< 1 2 250 >
每页显示 20 50 100
UNCERTAINTY PRINCIPLES AND SIGNAL RECOVERY RELATED TO THE CANONICAL FOURIER-BESSEL TRANSFORM
1
作者 Jihed SAHBANI Lazhar DHAOUADI 《Acta Mathematica Scientia》 2025年第5期2190-2207,共18页
The aim of this paper is to prove another variation on the Heisenberg uncertainty principle,we generalize the quantitative uncertainty relations in n different(time-frequency)domains and we will give an algorithm for ... The aim of this paper is to prove another variation on the Heisenberg uncertainty principle,we generalize the quantitative uncertainty relations in n different(time-frequency)domains and we will give an algorithm for the signal recovery related to the canonical Fourier-Bessel transform. 展开更多
关键词 Fourier Bessel transform linear canonical transform quantitative uncertainty principles Heisenberg uncertainty principle signal recovery
在线阅读 下载PDF
Crosstalk among canonical Wnt and Hippo pathway members in skeletal muscle and at the neuromuscular junction
2
作者 Said Hashemolhosseini Lea Gessler 《Neural Regeneration Research》 SCIE CAS 2025年第9期2464-2479,共16页
Skeletal muscles are essential for locomotion,posture,and metabolic regulation.To understand physiological processes,exercise adaptation,and muscle-related disorders,it is critical to understand the molecular pathways... Skeletal muscles are essential for locomotion,posture,and metabolic regulation.To understand physiological processes,exercise adaptation,and muscle-related disorders,it is critical to understand the molecular pathways that underlie skeletal muscle function.The process of muscle contra ction,orchestrated by a complex interplay of molecular events,is at the core of skeletal muscle function.Muscle contraction is initiated by an action potential and neuromuscular transmission requiring a neuromuscular junction.Within muscle fibers,calcium ions play a critical role in mediating the interaction between actin and myosin filaments that generate force.Regulation of calcium release from the sarcoplasmic reticulum plays a key role in excitation-contraction coupling.The development and growth of skeletal muscle are regulated by a network of molecular pathways collectively known as myogenesis.Myogenic regulators coordinate the diffe rentiation of myoblasts into mature muscle fibers.Signaling pathways regulate muscle protein synthesis and hypertrophy in response to mechanical stimuli and nutrient availability.Seve ral muscle-related diseases,including congenital myasthenic disorders,sarcopenia,muscular dystrophies,and metabolic myopathies,are underpinned by dys regulated molecular pathways in skeletal muscle.Therapeutic interventions aimed at preserving muscle mass and function,enhancing regeneration,and improving metabolic health hold promise by targeting specific molecular pathways.Other molecular signaling pathways in skeletal muscle include the canonical Wnt signaling pathway,a critical regulator of myogenesis,muscle regeneration,and metabolic function,and the Hippo signaling pathway.In recent years,more details have been uncovered about the role of these two pathways during myogenesis and in developing and adult skeletal muscle fibers,and at the neuromuscular junction.In fact,research in the last few years now suggests that these two signaling pathways are interconnected and that they jointly control physiological and pathophysiological processes in muscle fibers.In this review,we will summarize and discuss the data on these two pathways,focusing on their concerted action next to their contribution to skeletal muscle biology.However,an in-depth discussion of the noncanonical Wnt pathway,the fibro/a dipogenic precursors,or the mechanosensory aspects of these pathways is not the focus of this review. 展开更多
关键词 canonical Wnt"Wingless-related integration site"pathway beta-catenin(CTNNB1) Hippo pathway MYOGENESIS MYOTUBE neuromuscular junction satellite cell skeletal muscle fiber transcriptional co-activator with PDZ-binding motif(TAZ) T-cell-specific transcription factor/lymphoid enhancer-binding factor(TCF/LEF) TEA domain family member(TEAD) transducin-like enhancer of split(TLE) yes-associated protein 1(YAP1)
暂未订购
基于变量进水强化胞外聚合物蛋白质改善CANON污泥流失研究 被引量:1
3
作者 李冬 王远欣 +1 位作者 傅思博 张杰 《中国环境科学》 北大核心 2025年第5期2481-2489,共9页
对比研究了3种不同进水策略对CANON污泥EPS中蛋白质的影响,旨在探求变量进水策略对CANON污泥滞留能力的影响.R1采用常规进水策略作为对照组,而R2和R3采用不同的变量进水策略,分别启动CANON工艺.经过90d的运行后,R1,R2和R3反应器中SVI分... 对比研究了3种不同进水策略对CANON污泥EPS中蛋白质的影响,旨在探求变量进水策略对CANON污泥滞留能力的影响.R1采用常规进水策略作为对照组,而R2和R3采用不同的变量进水策略,分别启动CANON工艺.经过90d的运行后,R1,R2和R3反应器中SVI分别达到了62.93,53.10和57.59mL/g,这说明变量进水的策略可以改善污泥的沉降性能.R2和R3的PN/PS分别达到8.21和7.61,明显高于R1的5.56;三维荧光数据显示,R2的TB-EPS中芳香族蛋白占比达到32.47%,显著高于R1的11.58%和R3的10.5%;这表明变量进水策略会促进TB-EPS中芳香族蛋白的生成,进而提高污泥的疏水性,改善污泥沉降性能.比厌氧氨氧化活性(SAA)分别上升至4.03,4.68和4.36mg N/(g VSS·h),其中R2和R3污泥的SAA达到甚至超过了接种前厌氧氨氧化污泥的SAA,这说明反应器中已经形成了成熟的CANON颗粒污泥.虽然在反应初期R2和R3的微生物活性受到负荷波动的抑制,但随着时间的推移,微生物群体适应了环境变化,恢复了稳定的活性,分别在第54d和第51d实现了CANON工艺的启动.最终在第90d时,R1,R2和R3的总氮去除率分别达到了72.54%,70.14%和73.75%左右,实现了良好的脱氮性能. 展开更多
关键词 canon 变量进水 蛋白质组成 颗粒污泥 间歇曝气
在线阅读 下载PDF
基于长短周期循环优化CANON工艺脱氮性能
4
作者 李冬 付靓 +2 位作者 赖会彬 李尧 张杰 《中国环境科学》 北大核心 2025年第8期4256-4265,共10页
提出在全程自养脱氮(CANON)工艺中采用长短周期交替的方式抑制亚硝酸盐氧化菌(NOB),在长周期采用原位游离氨(FA)抑制NOB,当FA浓度低于NOB抑制阈值时,在短周期采用底物抑制的方式持续抑制NOB的活性.试验设置两组序批式反应器R1、R2,分别... 提出在全程自养脱氮(CANON)工艺中采用长短周期交替的方式抑制亚硝酸盐氧化菌(NOB),在长周期采用原位游离氨(FA)抑制NOB,当FA浓度低于NOB抑制阈值时,在短周期采用底物抑制的方式持续抑制NOB的活性.试验设置两组序批式反应器R1、R2,分别采用不同的长短周期交替模式.结果表明:R1、R2均取得良好的脱氮效果,R2的脱氮效果稍优于R1,R1、R2的总氮去除率(NRE)分别为78.73%、85.41%,出水NO_(3)^(-)-N浓度分别为14.02mg/L和7.21mg/L. R1、R2的比硝态氮生成速率(SNPR)在64d时分别降低至2.88,1.95mgN/(gMLVSS·h),NOB活性均得到了有效抑制.胞外聚合物(EPS)结果分析表明,长短周期交替的策略有利于促进微生物分泌EPS,R1、R2的EPS含量分别从接种时的40.22mg/gVSS上升至86.41和97.79mg/gVSS.高通量测序结果表明,系统内优势菌门为变形菌门(Proteobacteria)、拟杆菌门(Bacteroidota)和浮霉菌门(Planctomycetota).R1、R2以Nitrospira和Nitrobacter为代表的NOB生长均受到抑制,Nitrospira相对丰度由接种污泥的2.05%降至0.18%(R1)和0.11%(R2),Nitrobacter的丰度由接种污泥的1.97%降低到0.06%(R1)和0.05%(R2),AnAOB(Candidatus_Brocadia)丰度分别为8.92%(R1)和9.14%(R2),AOB(Nitrosomonas)丰度分别为4.28%(R1)和6.56%(R2),形成良好的协同作用. 展开更多
关键词 长短周期循环 全程自养脱氮工艺 短程硝化 亚硝酸盐氧化菌
在线阅读 下载PDF
基于缺氧时间调控内源性亚硝酸盐强化N-EPD-CANON工艺脱氮研究
5
作者 李冬 陈晓义 +2 位作者 傅思博 张景昭 张杰 《中国环境科学》 北大核心 2025年第5期2470-2480,共11页
采用SBR反应器,以模拟市政污水为进水基质,启动硝化-内源部分反硝化-全程自养脱氮(N-EPD-CANON)工艺.实验通过调控EPD单元缺氧时间考察了单元内亚硝酸盐积累量变化对CANON工艺脱氮性能,功能菌活性以及微生物群落结构的影响.结果表明:在... 采用SBR反应器,以模拟市政污水为进水基质,启动硝化-内源部分反硝化-全程自养脱氮(N-EPD-CANON)工艺.实验通过调控EPD单元缺氧时间考察了单元内亚硝酸盐积累量变化对CANON工艺脱氮性能,功能菌活性以及微生物群落结构的影响.结果表明:在缺氧时间为40min时,EPD单元可以有效地捕获进水有机物,同时维持有利于CANON稳定运行的适量浓度的内源性亚硝酸盐.长期稳定运行下CANON反应器的总氮去除率达到86.43%,比厌氧氨氧化活性(SAA)达到0.82gN/(gVSS·d).此外,EPS质量分数逐渐增长到69.17mg/gVSS,再通过3D-EEM结合PARAFAC技术对污泥的EPS荧光组分进行分析表明,内源性亚硝酸盐的强化作用能够在不改变EPS组成成分的前提下,有效提升了芳香族蛋白质的含量,有助于污泥颗粒化及其稳定性的提高.微生物群落分析揭示,在EPD系统中Candidatus Competibacter为优势菌属占24.61%,CANON系统中Nitrosomonas的相对丰度为2.67%,这保证了An AOB菌的NO_(2)^(-)-N供应.此外,AnAOB的主要组成部分Candidatus Brocadia菌属的相对丰度也达到了13.34%. 展开更多
关键词 全程自养脱氮工艺 内源部分反硝化 反硝化聚糖菌 市政污水
在线阅读 下载PDF
Canonical Transformations and Poisson Theory for Dynamics with Non-Standard Lagrangians 被引量:2
6
作者 ZHU Lin ZHANG Yi 《Wuhan University Journal of Natural Sciences》 CAS CSCD 2024年第2期106-116,共11页
The canonical transformation and Poisson theory of dynamical systems with exponential,power-law,and logarithmic non-standard Lagrangians are studied,respectively.The criterion equations of canonical transformation are... The canonical transformation and Poisson theory of dynamical systems with exponential,power-law,and logarithmic non-standard Lagrangians are studied,respectively.The criterion equations of canonical transformation are established,and four basic forms of canonical transformations are given.The dynamic equations with non-standard Lagrangians admit Lie algebraic structure.From this,we es-tablish the Poisson theory,which makes it possible to find new conservation laws through known conserved quantities.Some examples are put forward to demonstrate the use of the theory and verify its effectiveness. 展开更多
关键词 non-standard Lagrangians dynamical equations canonical transformation Poisson theory
原文传递
A systematic evaluation of computational methods for predicting translated non-canonical ORFs from ribosome profiling data
7
作者 Tianyu Lei Yue Chang +1 位作者 Chao Yao Hong Zhang 《Journal of Genetics and Genomics》 SCIE CAS CSCD 2024年第1期105-108,共4页
Ribosome profiling(Ribo-Seg)enables genome-wide survey of translational activities at nucleotide resolution by enriching and sequencing ribosome-protected fragments(RPFs)in the cell(Ingolia et al.,2009).Based on the c... Ribosome profiling(Ribo-Seg)enables genome-wide survey of translational activities at nucleotide resolution by enriching and sequencing ribosome-protected fragments(RPFs)in the cell(Ingolia et al.,2009).Based on the characteristic distribution of RPFs in Ribo-Seq,such as enrichment in open reading frames(ORFs)and three-nucleotide periodicity,many computational methods have been developed to detect translated ORFs from Ribo-Seq data(Wang et al.,2020a). 展开更多
关键词 translated enable canonical
原文传递
CRABP1-mediated non-canonical retinoic acid signaling in motor neurons and neural stem cells
8
作者 Li-Na Wei 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第6期1169-1170,共2页
Retinoic acid(RA),the active metabolite of vitamin A(the retinoids),elicits a wide spectrum of biological activities critical to the development and health of most of the organ systems including the nervous systems(Co... Retinoic acid(RA),the active metabolite of vitamin A(the retinoids),elicits a wide spectrum of biological activities critical to the development and health of most of the organ systems including the nervous systems(Corcoran et al.,2002).The effects of RA are mediated by two very distinct pathways;the first is manifested in the nucleus by binding to a large family of nuclear RA receptors(RARs)to regulate proper expression of RAtargeted genes. 展开更多
关键词 canonical SPECTRUM CRITICAL
暂未订购
Cross-Project Software Defect Prediction Based on SMOTE and Deep Canonical Correlation Analysis
9
作者 Xin Fan Shuqing Zhang +2 位作者 Kaisheng Wu Wei Zheng Yu Ge 《Computers, Materials & Continua》 SCIE EI 2024年第2期1687-1711,共25页
Cross-Project Defect Prediction(CPDP)is a method that utilizes historical data from other source projects to train predictive models for defect prediction in the target project.However,existing CPDP methods only consi... Cross-Project Defect Prediction(CPDP)is a method that utilizes historical data from other source projects to train predictive models for defect prediction in the target project.However,existing CPDP methods only consider linear correlations between features(indicators)of the source and target projects.These models are not capable of evaluating non-linear correlations between features when they exist,for example,when there are differences in data distributions between the source and target projects.As a result,the performance of such CPDP models is compromised.In this paper,this paper proposes a novel CPDP method based on Synthetic Minority Oversampling Technique(SMOTE)and Deep Canonical Correlation Analysis(DCCA),referred to as S-DCCA.Canonical Correlation Analysis(CCA)is employed to address the issue of non-linear correlations between features of the source and target projects.S-DCCA extends CCA by incorporating the MlpNet model for feature extraction from the dataset.The redundant features are then eliminated by maximizing the correlated feature subset using the CCA loss function.Finally,cross-project defect prediction is achieved through the application of the SMOTE data sampling technique.Area Under Curve(AUC)and F1 scores(F1)are used as evaluation metrics.This paper conducted experiments on 27 projects from four public datasets to validate the proposed method.The results demonstrate that,on average,our method outperforms all baseline approaches by at least 1.2%in AUC and 5.5%in F1 score.This indicates that the proposed method exhibits favorable performance characteristics. 展开更多
关键词 Cross-project defect prediction deep canonical correlation analysis feature similarity
在线阅读 下载PDF
Research on the Impact of Conception Vessel Dredging Therapy Based on the Theory of Shifting Essence and Changing Qi in Inner Canon of Huangdi on Physical and Mental Health
10
作者 Yizhou Shen Fengrun Liu 《Journal of Clinical and Nursing Research》 2025年第5期152-158,共7页
This study,based on the theory of shifting essence and changing Qi in Inner Canon of Huangdi,deeply explores the theoretical basis,operation method of Conception Vessel Dredging Therapy and its influence on human heal... This study,based on the theory of shifting essence and changing Qi in Inner Canon of Huangdi,deeply explores the theoretical basis,operation method of Conception Vessel Dredging Therapy and its influence on human health.Through case analysis and the statistical analysis of medical records during the pandemic,it reveals the remarkable effects of this method in regulating the endocrine system,improving metabolism,and relieving physical and mental diseases.It provides a theoretical and practical basis for the application of traditional Chinese medicine anti-aging therapy in the modern health field,and helps to explore new ways to delay aging and improve physical and mental health. 展开更多
关键词 Shifting essence and changing Qi Conception vessel dredging therapy Inner canon of Huangdi Endocrine regulation Metabolic improvement Anti-aging Mental health
暂未订购
Fe(Ⅱ)对CANON工艺脱氮性能及菌群结构的影响研究
11
作者 魏致远 罗奇 +3 位作者 畅犇泽 张帅 陈东之 阳广凤 《浙江海洋大学学报(自然科学版)》 2025年第2期152-157,166,共7页
为探究Fe(Ⅱ)对全程自养脱氮(CANON)系统脱氮性能、颗粒污泥及生物膜特性、菌群结构的影响,试验以涂布活性炭的聚氨酯纤维为生物膜填料构建了两组上流式颗粒污泥—生物膜CANON反应器。试验结果表明,在102 d的运行中,进水直接添加Fe(Ⅱ)... 为探究Fe(Ⅱ)对全程自养脱氮(CANON)系统脱氮性能、颗粒污泥及生物膜特性、菌群结构的影响,试验以涂布活性炭的聚氨酯纤维为生物膜填料构建了两组上流式颗粒污泥—生物膜CANON反应器。试验结果表明,在102 d的运行中,进水直接添加Fe(Ⅱ)的反应器R_(1)和添加EDTA络合Fe(Ⅱ)的反应器R_(2)的运行效果均比较稳定,但R_(2)具有最佳脱氮性能,氨氮和总氮去除率分别为92.6%±7.4%和61.7%±6.5%。相比载体生物膜,颗粒污泥上胞外聚合物含量更高,有利于颗粒污泥生长。CANON工艺的优势菌门为变形菌门Proteobacteria、浮霉菌门Planctomycete和硝化螺旋菌门Nitrospirae。CANON污泥中Nitrospira和Nitrosomonas分别是典型的硝化菌属(NOB)和氨氧化菌属(AOB)。Candidatus Kuenenia是CANON生物膜中主要的厌氧氨氧化菌(AnAOB)。 展开更多
关键词 全程自养脱氮 脱氮 颗粒污泥 生物膜 菌群结构
在线阅读 下载PDF
Canonical对偶理论在一类多项式全局优化中的应用 被引量:1
12
作者 朱经浩 谭素娥 《同济大学学报(自然科学版)》 EI CAS CSCD 北大核心 2011年第9期1373-1376,共4页
用Canonical对偶理论,讨论一类高阶多项式全局最优化问题的求解.首先将无约束多项式全局优化问题转换成箱体约束下的多项式全局优化问题,之后通过构造非线性变换对偶函数及相应的共轭函数,得到原问题的Canonical对偶问题.进一步通过求... 用Canonical对偶理论,讨论一类高阶多项式全局最优化问题的求解.首先将无约束多项式全局优化问题转换成箱体约束下的多项式全局优化问题,之后通过构造非线性变换对偶函数及相应的共轭函数,得到原问题的Canonical对偶问题.进一步通过求解对偶问题的最优解,导出原多项式全局优化问题的最优解,并给出对偶问题是凹函数的证明.最后应用所得方法,计算一个二元6次多项式全局最优化实例. 展开更多
关键词 canonical对偶理论 全局优化 高阶多元多项式
在线阅读 下载PDF
一类非线性优化的Canonical对偶函数
13
作者 朱经浩 严旺光 《同济大学学报(自然科学版)》 EI CAS CSCD 北大核心 2010年第2期307-310,共4页
研究如何获取球体约束下非线性优化的全局最小点.通过引入常微分方程和构造Canonical对偶函数的局部形式,引入了相应的对偶定理,勾勒出了原问题的KKT点和对偶问题的KKT点两者之间的关系.给出了凸乘子定义,对偶定理和搜寻全局最优点的方... 研究如何获取球体约束下非线性优化的全局最小点.通过引入常微分方程和构造Canonical对偶函数的局部形式,引入了相应的对偶定理,勾勒出了原问题的KKT点和对偶问题的KKT点两者之间的关系.给出了凸乘子定义,对偶定理和搜寻全局最优点的方法,并通过一些例子加以演示. 展开更多
关键词 canonical对偶函数 canonical对偶变换 全局最优化
在线阅读 下载PDF
一类非单调互补问题的Canonical对偶问题研究
14
作者 刘国山 丁冰洁 刁海璨 《运筹与管理》 CSSCI CSCD 北大核心 2021年第1期1-5,共5页
对于一类具有广泛应用背景的非单调互补问题,我们构建了这类问题的Canonical对偶问题。其对偶问题可以写成和原问题类似的互补问题。我们给出了对偶问题和原问题解之间的对偶关系,并且将对偶问题转化成一个一维优化问题,这不但可以方便... 对于一类具有广泛应用背景的非单调互补问题,我们构建了这类问题的Canonical对偶问题。其对偶问题可以写成和原问题类似的互补问题。我们给出了对偶问题和原问题解之间的对偶关系,并且将对偶问题转化成一个一维优化问题,这不但可以方便的求解这类问题,也为研究这类问题性质提供了一个非常直观的研究工具。最后,本文给出了几个算例来演示对偶问题的性质。 展开更多
关键词 互补问题 非线性优化 变分不等式 canonical对偶
在线阅读 下载PDF
Fe(Ⅱ)对CANON工艺处理城镇污水脱氮性能的影响 被引量:1
15
作者 张倩倩 廖祖刚 +3 位作者 冯泽通 刘金泽 符文婧 赵剑强 《安全与环境工程》 CAS CSCD 北大核心 2024年第2期291-300,共10页
全程自养脱氮(CANON)工艺,作为新型脱氮工艺应用于城镇污水深度脱氮过程中,有望降低污水处理的运行费用。考察了亚铁离子[Fe(Ⅱ)]对CANON工艺启动及稳定运行时脱氮性能的影响。结果表明:15~23℃条件下投加6.3 mg/L Fe(Ⅱ)时,可有效启动... 全程自养脱氮(CANON)工艺,作为新型脱氮工艺应用于城镇污水深度脱氮过程中,有望降低污水处理的运行费用。考察了亚铁离子[Fe(Ⅱ)]对CANON工艺启动及稳定运行时脱氮性能的影响。结果表明:15~23℃条件下投加6.3 mg/L Fe(Ⅱ)时,可有效启动并稳定运行CANON工艺处理城镇污水,该工艺氮去除负荷(NRR)、总氮去除率(TNRE)和氨氮去除率(ARE)分别为(4.8±1.1)g-N/(L^(3)·d)、(97±1)%和(44.2±9.3)%;相关性分析表明,通过调控Fe(Ⅱ)投加量可有效抑制亚硝酸盐氧化菌(NOB)的活性;本次优化的Fe(Ⅱ)投加量为6.3 mg/L,其对CANON工艺脱氮性能的影响机制与CANON工艺中功能微生物活性的提高、Fe(Ⅱ)与进水氨氮及其他氮化合物的循环反应、铁型反硝化过程以及铁型厌氧氨氧化过程的耦合有关。 展开更多
关键词 canon工艺 城镇污水 Fe(Ⅱ) 脱氮效能
在线阅读 下载PDF
Canonical Correlation Analysis of Agronomic Characters of Brassica juncea in Western China
16
作者 大次卓嘎 王建林 +1 位作者 次仁央金 王忠红 《Agricultural Science & Technology》 CAS 2011年第11期1600-1604,1666,共6页
[Objective] The study aimed at exploring the relationship among the agronomic characters of B. juncea in western China, in order to provide scientific basis for the breeding of B. juncea in western China. [Method] 39 ... [Objective] The study aimed at exploring the relationship among the agronomic characters of B. juncea in western China, in order to provide scientific basis for the breeding of B. juncea in western China. [Method] 39 B. juncea materials from western China were used for the canonical correlation analysis, and canonical correlations between each pair of the four ecological character (containing 18 variables) were verified, including yield characters (5 variables), caulis characters (6 variables), branch characters (3 variables) and pod characters (3 variables). [Result] Yield per plant of B. juncea in western China suffered a tremendous influence from effective pod number per plant while was not significantly affected by the total pod number per plant, seed number per pod and 1 000-seed weight; the most important character related with the yield character of B. juncea in western China was caulis character, followed by the branch character and pod character; yield characters, caulis characters, branch characters and pod characters of B. juncea in western China were closely correlated. [Conclusion] In order to improve the yield characters of B. juncea in western China, caulis characters should be focused on, followed by branch characters and pod characters; rapeseed varieties with high performance in total pod number per plant and effective pod number per plant should be chosen through the perspectives of effective branch number, plant height, pod number of main inflorescence, fruit stalk number of main inflorescence and other traits, while rapeseed varieties with high performance in seed number per pod and 1 000-seed weight should be chosen through the perspectives of beak length and other traits. 展开更多
关键词 Western China Brassica juncea Ecological character canonical correlation analysis Comparative study
在线阅读 下载PDF
Rapid ecotoxicological assessment of heavy metal combined polluted soil using canonical analysis 被引量:18
17
作者 CHEN Su-hua, ZHOU Qi-xing, SUN Tie-heng, LI Pei-jun (Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China. 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2003年第6期854-858,共5页
Quick, simple to perform, and cheap biomarkers were combined in a rapid assessment approach to measure the effects of metal pollutants, Cu, Cd, Pb and Zn in meadow burozem on wheat. Analysis of orthogonal design showe... Quick, simple to perform, and cheap biomarkers were combined in a rapid assessment approach to measure the effects of metal pollutants, Cu, Cd, Pb and Zn in meadow burozem on wheat. Analysis of orthogonal design showed that the significant zinc factor indicated both the inhibition rate of shoot mass and that of root elongation were affected by zinc(P<0.05 and P<0.01, respectively). The first toxicity canonical variable (TOXI), formed from the toxicity data set, explained 49% of the total variance in the toxicity data set; the first biological canonical variable(BIOL) explained 42% of the total variation in the biological data set. The correlation between the first canonical variables TOXI and BIOL (canonical correlation) was 0.94 (P<0.0001). Therefore, it is reliable and feasible to use the achievement to assess toxicity of heavy metal combined polluted soil using canonical analysis. Toxicity of soil combined polluted by heavy metals to plant community was estimated by comparing the IC 50 values describing the concentration needed to cause 50% decrease with grow rate compared to no metal addition. Environmental quality standard for soils prescribe that all these tested concentration of heavy metals in soil should not cause hazard and pollution ultimately, whereas it indicated that the soils in second grade cause more or less than 50% inhibition rates of wheat growth. So environmental quality standard for soils can be modified to include other features. 展开更多
关键词 heavy metal combined pollution ecological toxicity canonical analysis
在线阅读 下载PDF
Adsorption of Benzene and Propylene in Zeolite ZSM-5:Grand Canonical Monte Carlo Simulations 被引量:9
18
作者 SUN Xiao-yan LI Jian-wei +2 位作者 LI Ying-xia YAN Shi-cheng CHEN Biao-hua 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2009年第3期377-382,共6页
The adsorption behavior of benzene and propylene in zeolite ZSM-5 was studied by Grand Canonical Monte Carlo(GCMC) simulations. It could be found that benzene and propylene molecules showed different adsorption beha... The adsorption behavior of benzene and propylene in zeolite ZSM-5 was studied by Grand Canonical Monte Carlo(GCMC) simulations. It could be found that benzene and propylene molecules showed different adsorption behavior in the zeolite cavities. The loadings of propylene were significantly larger than those of benzene at 100 kPa. From the figures of potential energy distribution, the potential energy of benzene/zeolite was more negative than that of propylene/zeolite, so benzene could be adsorbed more stably than propylene. When the temperature was in- creased from 298 to 443 K at 100 kPa, the loading ofpropylene was reduced from 99 to 82 molecules, whereas that of benzene changed little. When benzene and propylene were adsorbed in zeolite simultaneously, the competitive adsorption of them occurred; therefore, the potential energy distribution could be changed significantly. Besides, the adsorption isotherms of benzene and propylene in ZSM-5 at 298 and 443 K were simulated. The results exhibit that the different factors influenced the molecular adsorption at various temperatures and pressures, leading to the diffe- rent rules for the adsorption of benzene and propylene molecules in the zeolite. At a low pressure, the unfavorable energy of propylene/zeolite and the "commensurate freezing" phenomenon of benzene would make the loadings of itself higher than those of propylene. When pressure was higher than 5 kPa, the adsorption of benzene in ZSM-5 would nearly reach saturation. 展开更多
关键词 ZSM-5 zeolite ADSORPTION Grand canonical monte carlo
在线阅读 下载PDF
Exact invariants and adiabatic invariants of Raitzin's canonical equations of motion for a nonlinear nonholonomic mechanical system 被引量:6
19
作者 乔永芬 李仁杰 孙丹姗 《Chinese Physics B》 SCIE EI CAS CSCD 2005年第10期1919-1925,共7页
The exact invariants and the adiabatic invariants of Raitzin's canonical equations of motion for a nonlinear nonholonomic mechanical system are studied. The relations between the invariants and the symmetries of the ... The exact invariants and the adiabatic invariants of Raitzin's canonical equations of motion for a nonlinear nonholonomic mechanical system are studied. The relations between the invariants and the symmetries of the system are established. Based on the concept of higher-order adiabatic invariant of a mechanical system under the action of a small perturbation, the forms of the exact invariants and adiabatic invariants and the conditions for their existence are proved. Finally, the inverse problem of the perturbation to symmetries of the system is studied and an example is also given to illustrate the application of the results. 展开更多
关键词 nonholonomic system Raitzin's canonical equation SYMMETRY PERTURBATION exactinvariant adiabatic invariant
原文传递
Generalized canonical transformation for second-order Birkhoffian systems on time scales 被引量:5
20
作者 Y.Zhang X.H.Zhai 《Theoretical & Applied Mechanics Letters》 CAS CSCD 2019年第6期353-357,共5页
The theory of time scales,which unifies continuous and discrete analysis,provides a powerful mathematical tool for the study of complex dynamic systems.It enables us to understand more clearly the essential problems o... The theory of time scales,which unifies continuous and discrete analysis,provides a powerful mathematical tool for the study of complex dynamic systems.It enables us to understand more clearly the essential problems of continuous systems and discrete systems as well as other complex systems.In this paper,the theory of generalized canonical transformation for second-order Birkhoffian systems on time scales is proposed and studied,which extends the canonical transformation theory of Hamilton canonical equations.First,the condition of generalized canonical transformation for the second-order Birkhoffian system on time scales is established.Second,based on this condition,six basic forms of generalized canonical transformation for the second-order Birkhoffian system on time scales are given.Also,the relationships between new variables and old variables for each of these cases are derived.In the end,an example is given to show the application of the results. 展开更多
关键词 BIRKHOFFIAN systems GENERALIZED canonical transformation Time scales CALCULUS Generating function
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