检索结果-南通市图书馆

Revealing the Structure-Property Difference of Natural Rubber Prepared by Different Methods: Protein and Gel Content are Key Factors

引用

Chinese Journal of Polymer Science 2024年第4期42卷 457-467页

作者： Shao-Qi Huang Jun-Qi Zhang yong Zhu ling-Min Kong lu-Sheng liao Fu-Quan Zhang Zheng-Tian Xie Jin-Rong Wu State Key laboratory of Polymer Materials Engineering College of Polymer Science and EngineeringSichuan UniversityChengdu610065China Hainan Provincial Key laboratory of Natural Rubber Processing Agricultural Products Processing Research Institute of Chinese Academy of Tropical Agricultural SciencesZhanjiang524001China

Natural rubber (NR) is widely used in various fields including aerospace, military industry and transportation due to its superior elasticity and comprehensive mechanical properties. Nonetheless, the commercial NR prepared by different methods usually exhibits different mechanical properties, primarily due to variations in processing conditions during the conversion from latex to bulk rubber material. Consequently, this poses challenges in scientific research and industrial production of NR. In order to assess the properties of various commercially available NR and identify key structural and compositional components, this study systematically compares and analyzes four representative NR raw materials: air dried sheet (ADS), ribbed smoked sheets (RSS), constant viscidity NR (CV), and whole field latex rubber (WF). The investigation focuses on evaluating their static mechanical behavior, SIC behavior, wear resistance, and fatigue resistance. The findings indicate that protein and gel content exhibit a crucial influence on the NR properties. These constituents contribute to the formation of a high-crosslinking density region, generating a heterogeneous network structure within the rubber. This structure amplifies strains during deformation, leading to earlier and stronger strain-induced crystallization (SIC). Among the four commercial NR brands, RSS demonstrates superior overall mechanical and dynamic properties owing to its high protein and gel content. This study serves as a valuable reference for comprehending the differences in properties among various commercial NR, thereby offering guidance for the actual processing and selection of NR.

关键词： Natural rubber Processingmethod Protein Gel content Property

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Performance enhancement of a viscoelastic bistable energy harvester using time-delayed feedback control

引用

Chinese Physics B 2024年第6期33卷 142-154页

作者：黄美玲杨勇歌刘洋 School of Mathematics and Statistics Guangdong University of TechnologyGuangzhou 510520China State Key laboratory for Strength and Vibration of Mechanical Structures Xi'an Jiaotong UniversityXi'an 710049China Exeter Small-Scale Robotics laboratory Engineering DepartmentUniversity of ExeterNorth Park RoadExeter EX44QFUK

This paper focuses on the stochastic analysis of a viscoelastic bistable energy harvesting system under colored noise and harmonic excitation, and adopts the time-delayed feedback control to improve its harvesting efficiency. Firstly, to obtain the dimensionless governing equation of the system, the original bistable system is approximated as a system without viscoelastic term by using the stochastic averaging method of energy envelope, and then is further decoupled to derive an equivalent system. The credibility of the proposed method is validated by contrasting the consistency between the numerical and the analytical results of the equivalent system under different noise conditions. The influence of system parameters on average output power is analyzed, and the control effect of the time-delayed feedback control on system performance is compared. The output performance of the system is improved with the occurrence of stochastic resonance(SR). Therefore, the signal-to-noise ratio expression for measuring SR is derived, and the dependence of its SR behavior on different parameters is explored.

关键词： energy harvesting bistability stochastic averaging method stochastic resonance time-delayed feedback control

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Eigenvalues for the Clamped Plate Problem of l_(ν)^(2) Operator on Complete Riemannian Manifolds

引用

Acta Mathematica Sinica,English Series 2024年第9期40卷 2223-2243页

作者： ling Zhong ZENG Jiangxi Provincial Center for Applied Mathematics&School of Mathematics and Statistics Jiangxi Normal UniversityNanchang 330022P.R.China

l_(ν) operator is an important extrinsic differential operator of divergence type and has profound geometric *** this paper,we consider the clamped plate problem of l_(ν)^(2)operator on a bounded domain of the complete Riemannian manifolds.A general formula of eigenvalues of l_(ν)^(2) operator is *** this general formula,we obtain some estimates for the eigenvalues with higher order on the complete Riemannian *** several fascinating applications,we discuss this eigenvalue problem on the complete translating solitons,minimal submanifolds on the Euclidean space,submanifolds on the unit sphere and projective *** particular,we get a universal inequality with respect to the l_(II) operator on the translating ***,it is very difficult to get universal inequalities for weighted laplacian and even laplacian on the complete Riemannian ***,this work can be viewed as a new contribution to universal estimate.

关键词： Mean curvature flows l_(ν)^(2)operator clamped plate problem eigenvalues Riemannian manifolds translating solitons

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Intermittent Theta Burst Stimulation Attenuates Cognitive Deficits and Alzheimer’s Disease-Type Pathologies via ISCA1-Mediated Mitochondrial Modulation in APP/PS1 Mice

引用

Neuroscience Bulletin 2024年第2期40卷 182-200页

作者： Yang Zhu Hao Huang Zhi Chen yong Tao ling-Yi liao Shi-Hao Gao Yan-Jiang Wang Chang-Yue Gao Department of Rehabilitation Medicine Daping HospitalArmy Medical UniversityChongqing 400042China Department of Neurology and Center for Clinical Neuroscience Daping HospitalArmy Medical UniversityChongqing 400042China Department of Special Medicine Daping HospitalArmy Medical UniversityChongqing 400042China

Intermittent theta burst stimulation(iTBS),a time-saving and cost-effective repetitive transcranial magnetic stimulation regime,has been shown to improve cognition in patients with Alzheimer’s disease(AD).However,the specific mechanism underlying iTBS-induced cognitive enhancement remains *** studies suggested that mitochondrial functions are modulated by magnetic ***,we showed that iTBS upregulates the expression of iron-sulfur cluster assembly 1(ISCA1,an essential regulatory factor for mitochondrial respiration)in the brain of APP/PS1 *** vivo and in vitro studies revealed that iTBS modulates mitochondrial iron-sulfur cluster assembly to facilitate mitochondrial respiration and function,which is required for ***,iTBS rescues cognitive decline and attenuates AD-type pathologies in APP/PS1 *** present study uncovers a novel mechanism by which iTBS modulates mitochondrial respiration and function via ISCA1-mediated iron-sulfur cluster assembly to alleviate cognitive impairments and pathologies in *** provide the mechanistic target of iTBS that warrants its therapeutic potential for AD patients.

关键词： Intermittent theta burst stimulation Alzheimer’s disease Iron-sulfur cluster assembly 1 Mitochondrial dysfunction Neurodegeneration

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Identification and characterization of camptothecin tailoring enzymes in Nothapodytes tomentosa

引用

Journal of Integrative Plant Biology 2024年第6期66卷 1158-1169页

作者： Yin Chen Jian-Ping Huang yong-Jiang Wang Meng-ling Tu Junheng li Bingyan Xu Guoqing Peng Jing Yang Sheng-Xiong Huang State Key laboratory of Phytochemistry and Plant Resources in West China and Yunnan Key laboratory of Natural Medicinal Chemistry Kunming Institute of BotanyChinese Academy of SciencesKunming 650201China University of Chinese Academy of Sciences Beijing 100049China Key laboratory for Economic Plants and Biotechnology Kunming Institute of BotanyChinese Academy of SciencesKunming 650201China

Camptothecin is a complex monoterpenoid indole alkaloid with remarkable antitumor *** that two C-10 modified camptothecin derivatives,topotecan and irinotecan,have been approved as potent anticancer agents,there is a critical need for methods to access other aromatic ringfunctionalized congeners(e.g.,C-9,C-10,etc.).However,contemporary methods for chemical oxidation are generally harsh and low-yielding when applied to the camptothecin scaffold,thereby limiting the development of modified *** herein,we have identified four tailoring enzymes responsible for C-9 modifications of camptothecin from Nothapodytes tomentosa,via metabolomic and transcriptomic *** consist of a cytochrome P450(Nt CPT9H)which catalyzes the regioselective oxidation of camptothecin to 9-hydroxycamptothecin,as well as two methyltransferases(Nt OMT1/2,converting 9-hydroxycamptothecin to 9-methoxycamptothecin),and a uridine diphosphate-glycosyltransferase(Nt UGT5,decorating 9-hydroxycamptothecin to9-β-D-glucosyloxycamptothecin).Importantly,the critical residues that contribute to the specific catalytic activity of Nt CPT9H have been elucidated through molecular docking and mutagenesis *** work provides a genetic basis for producing camptothecin derivatives through metabolic *** will hasten the discovery of novel C-9 modified camptothecin derivatives,with profound implications for pharmaceutical manufacture.

关键词： camptothecin biosynthesis enzymatic assay Nothapodytes tomentosa tailoring enzyme transcriptomic analysis

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Three-stage niobium mineralization at Bayan Obo, China

引用

National Science Review 2024年第4期11卷 102-110页

作者： Yan Yu Yang li Yu liu Xiao-Xiao ling li-Guang Wu li Yang lan Yang Bo Yang yong-Gang Zhao Xian-Hua li State Key laboratory of lithospheric Evolution Institute of Geology and Geophysics Chinese Academy of Sciences College of Earth and Planetary Science University of Chinese Academy of Sciences Ministry of Education Key laboratory of Orogenic Belts and Crustal Evolution School of Earth and Space SciencesPeking University Mining Research Institute Baotou Iron and Steel(Group) Co.LTD State Key laboratory of Baiyunobo Rare Earth Resource Research and Comprehensive Utilization

The Chinese Bayan Obo deposit is a world-class rare earth element(REE) deposit with considerable niobium(Nb) and iron(Fe) resources. A complete genetic understanding on all metals is fundamental for establishing genetic models at Bayan Obo. With extensive research being focused on REE enrichment, the timing and controls of Nb enrichment remain unresolved at Bayan Obo, which is mainly due to the challenges in dating, i.e. multistage thermal events, fine-grained minerals with complex textures and the rare occurrence of uranium-enriched minerals with mature dating methods. Based on robust geological and petrographic frameworks, here we conducted ion probe uranium-lead(U-Pb) dating of ferrocolumbite to unravel the timing, hence the genesis of Nb mineralization. Three types of hydrothermal ferrocolumbites—key Nb-bearing minerals—are identified based on their textures and mineral assemblages. They yield U-Pb ages of 1312 ± 47 Ma(n = 99), 438 ± 7 Ma(n = 93), and 268 ± 5 Ma(n = 19), respectively. In line with deposit geology, we tentatively link the first, second and third stage Nb mineralization to Mesoproterozoic carbonatite magmatism, ubiquitous early Paleozoic hydrothermal activity, and Permian granitic magmatism, respectively. While quantifying the contribution of metal endowment from each stage requires further investigation, our new dates highlight that multi-stage mineralization is critical for Nb enrichment at Bayan Obo, which may also have implications for the enrichment mechanism of Nb in REE deposits in general.

关键词： niobium mineralization U-Pb dating ferrocolumbite Bayan Obo

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

MODIFIED STOCHASTIC EXTRAGRADIENT METHODS FOR STOCHASTIC VARIATIONAl INEQUAlITY

引用

Journal of Computational Mathematics 2024年第2期42卷 390-414页

作者： ling Zhang lingling Xu School of Management and Economic Beijing Institute of TechnologyBeijing 100081China School of Mathematical Sciences Nanjing Normal UniversityNanjing 210023China School of Mathematical Sciences and Jiangsu Key laboratory for NSlSCS Nanjing Normal UniversityNanjing 210023China

In this paper,we consider two kinds of extragradient methods to solve the pseudo-monotone stochastic variational inequality ***,we present the modified stochastic extragradient method with constant step-size(MSEGMC)and prove the convergence of *** the strong pseudo-monotone operator and the exponentially growing sample sequences,we establish the R-linear convergence rate in terms of the mean natural residual and the oracle complexity O(1/ǫ).Second,we propose a modified stochastic extragradient method with adaptive step-size(MSEGMA).In addition,the step-size of MSEGMA does not depend on the lipschitz constant and without any line-search ***,we use some numerical experiments to verify the effectiveness of the two algorithms.

关键词： Stochastic variational inequality Pseudo-monotone Modified stochastic ex-tragradient methods Adaptive step-size

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

In-depth insights into critical role of aromatic C（sp2）–H on li+ storage

引用

Rare Metals 2024年第10期43卷 5449-5452页

作者： ling Qin Ye Zhou China-UK low Carbon College Shanghai Jiao Tong University

The development of high-sloping-capacity carbons enables the creation of high-power lithium-ion batteries and capacitors （lIBs/lICs）.Among the various heteroatomdoped carbon materials,hydrogen-rich carbon appears to be a promising candidate due to its facile synthesis and high capacity for li+***,conclusive data are still lacking to elucidate the fundamental function of the hydrogen-terminated groups （C-H configuration） in li+*** and his co-workers have utilized an ion-catalyzed self-template method to synthesize the hydrogen-rich carbon nanoribbon （HCNR） with high specific and rate *** HCNR?s li+storage mechanism is clarified by the use of in situ spectroscopy methods,which reveals that the sp2-hybridization of the

关键词： Aromatization

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Construction of CDKN2A-related competitive endogenous RNA network and identification of GAS5 as a prognostic indicator for hepatocellular carcinoma

引用

World Journal of Gastrointestinal Oncology 2024年第4期16卷 1514-1531页

作者： yong Pan Yi-Ru Zhang ling-Yun Wang li-Na Wu Ying-Qiu Ma Zhou Fang Shi-Bo li Department of Infectious Disease Zhoushan HospitalWenzhou Medical UniversityZhoushan 316021Zhejiang ProvinceChina State Key laboratory for the Diagnosis and Treatment of Infectious Diseases The First Affiliated Hospital of Zhejiang UniversityHangzhou 310003Zhejiang ProvinceChina Department of Infectious Disease The First Affiliated Hospital of Wenzhou Medical UniversityWenzhou 325035Zhejiang ProvinceChina

BACKGROUND Competitive endogenous RNA(ceRNA)is an innovative way of gene expression modulation,which plays a crucial part in ***,the intricacy and behavioral characteristics of the ceRNA network in hepatocellular carcinoma(HCC)remain *** To establish a cyclin dependent kinase inhibitor 2A(CDKN2A)-related ceRNA network and recognize potential prognostic indicators for *** The mutation landscape of CDKN2A in HCC was first explored using the cBioPortal *** expression analysis was implemented between CDKN2Ahigh and CDKN2Alow expression HCC *** targeted microRNAs were predicted by lncBasev3.0,and the targeted mRNAs were predicted by miRDB,and Targetscan *** univariate and multivariate analysis were utilized to identify independent prognostic *** CDKN2A was frequently mutated and deleted in *** single-cell RNA-sequencing analysis revealed that CDKN2A participated in cell cycle *** CDKN2A-related ceRNA network-growth arrest specific 5(GAS5)/miR-25-3p/SRY-box transcription factor 11(SOX11)was successfully ***5 was recognized as an independent prognostic biomarker,whose overexpression was correlated with a poor prognosis in HCC *** association between GAS5 expression and methylation,immune infilt-ration was ***,traditional Chinese medicine effective components targeting GAS5 were *** This CDKN2A-related ceRNA network provides innovative insights into the molecular mechanism of HCC formation and ***,GAS5 might be a significant prognostic biomarker and therapeutic target in HCC.

关键词： Hepatocellular carcinoma Competitive endogenous RNA Molecular mechanism Prognosis Biomarker

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Fundamentals and application in phytoremediation of an efficient arsenate reducing bacterium Pseudomonas putida ARS1

引用

Journal of Environmental Sciences 2024年第3期137卷 237-244页

作者： Ze-Wen Wang Guang Yang Jian Chen Yaoyu Zhou Avelino Nunez Delgado Hui-ling Cui Gui-lan Duan Barry P.Rosen yong-Guan Zhu Henan Institute of Advanced Technology Zhengzhou UniversityZhengzhou 450052China State Key lab of Urban and Regional Ecology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China Department of Cellular Biology and Pharmacology Florida International UniversityHerbert Wertheim College of MedicineMiamiFL33199USA University of Chinese Academy of Sciences Beijing 100049China Key laboratory of Urban Environment and Health Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China College of Resources and Environment Hunan Agricultural UniversityChangsha 410128China Department of Soil Science and Agricultura Chemistry Engineering Polytechnic SchoolUniversity of Santiago de CompostelaCampus Univ.s/n27002LugoSpain

Arsenic is a ubiquitous environmental ***-mediated arsenic biotransformations significantly infuence arsenic mobility and *** transformations by soil and aquatic organisms have been well documented,while little is known regarding effects due to endophytic *** endophyte Pseudomonas putida ARS1 was isolated from rice grown in arsenic contaminated *** ARS1 shows high tolerance to arsenite(As(Ⅲ))and arsenate(As(V)),and exhibits efficient As(V)reduction and As(Ⅲ)effux *** exposed to 0.6 mg/l As(V),As(V)in the medium was completely converted to As(Ⅲ)by *** ARS1 within 4 *** sequencing showed that *** ARS1 has two chromosomal arsenic resistance gene clusters(arsRCBH)that contribute to efficient As(V)reduction and As(Ⅲ)effux,and result in high resistance to *** globosa is a strong arsenic accumulator with high potential for arsenic phytoremediation,which takes up As(Ⅲ)more efficiently than As(V).Co-culture of *** ARS1 and *** enhanced arsenic accumulation in *** by 69%,and resulted in 91%removal of arsenic(at initial concentration of 0.6 mg/l As(V))from water within 3 *** study provides a promising strategy for in situ arsenic phytoremediation through the cooperation of plant and endophytic bacterium.

关键词： Arsenic Pseudomonas putida Arsenate reduction Endophyte Wolffia globosa Phytoremediation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：