期刊文献+
共找到53篇文章
< 1 2 3 >
每页显示 20 50 100
Mechanism of Diabatic Heating on Precipitation and the Track of a Tibetan Plateau Vortex over the Eastern Slope of the Tibetan Plateau
1
作者 Yuanchang DONG guoping li +3 位作者 Xiaolin XIE Long YANG Peiwen ZHANG Bo ZENG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第1期155-172,共18页
Existing studies contend that latent heating(LH)will replace sensible heating(SH)to become the dominant factor affecting the development of the Tibetan Plateau vortex(TPV)after it moves off the Tibetan Plateau(TP).How... Existing studies contend that latent heating(LH)will replace sensible heating(SH)to become the dominant factor affecting the development of the Tibetan Plateau vortex(TPV)after it moves off the Tibetan Plateau(TP).However,in the process of the TPV moving off the TP requires that the airmass traverse the eastern slope of the Tibetan Plateau(ESTP)where the topography and diabatic heating(DH)conditions rapidly change.How LH gradually replaces SH to become the dominant factor in the development of the TPV over the ESTP is still not very clear.In this paper,an analysis of a typical case of a TPV with a long life history over the ESTP is performed by using multi-sourced meteorological data and model simulations.The results show that SH from the TP surface can change the TPV-associated precipitation distribution by temperature advection after the TPV moves off the TP.The LH can then directly promote the development of the TPV and has a certain guiding effect on the track of the TPV.The SH can control the active area of LH by changing the falling area of the TPV-associated precipitation,so it still plays a key role in the development and tracking of the TPV even though it has moved out of the main body of the TP. 展开更多
关键词 eastern slope of the Tibetan Plateau diabatic heating Tibetan Plateau vortex precipitation distribution TRACK
下载PDF
Establishment of an Objective Standard for the Definition of Binary Tropical Cyclones in the Western North Pacific 被引量:3
2
作者 Fumin REN Yanjun XIE +2 位作者 Biwen YIN Mingyang WANG guoping li 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2020年第11期1211-1221,共11页
To develop an objective standard for defining binary tropical cyclones(BTCs)in the western North Pacific(WNP),two best-track datasets,from the China Meteorological Administration and the Joint Typhoon Warning Center,w... To develop an objective standard for defining binary tropical cyclones(BTCs)in the western North Pacific(WNP),two best-track datasets,from the China Meteorological Administration and the Joint Typhoon Warning Center,were adopted for statistical analyses on two important characteristics of BTCs-two TCs approaching each other,and counterclockwise spinning.Based on the high consistency between the two datasets,we established an objective standard,which includes a main standard for defining BTCs and a secondary standard for identifying typical/atypical BTCs.The main standard includes two requirements:two coexisting TCs are a pair of BTCs if(i)the separation distance is≤1800 km,and(ii)this separation maintains for at least 12 h.Meanwhile,the secondary standard defines a typical BTC as one for which there is at least one observation when the two TCs approach each other and spin counterclockwise simultaneously.Under the standard,the ratio of typical BTCs increases as the BTC duration increases or the minimum distance between the two TCs decreases.Then,using the JTWC dataset,it was found that there are 505 pairs of BTCs during the period 1951−2014,including 328 typical BTCs and 177 atypical BTCs,accounting for 65.0%and 35.0%of the total,respectively.In addition,a study of two extreme phenomena-the maximum approaching speed and the maximum counterclockwise angular velocity in typical BTCs-shows that the configuration of the circulation conditions and the distribution of the BTCs favor the formation of these extreme phenomena. 展开更多
关键词 objective standard binary tropical cyclones Western North Pacific
下载PDF
Exercise regulates cardiac metabolism: Sex does matter
3
作者 Tingting Yang Meiyu Hu +3 位作者 Michail Spanos guoping li Stephen C Kolwicz Jr Junjie Xiao 《Journal of Sport and Health Science》 SCIE 2022年第4期418-420,共3页
Cardiac substrate utilization remains a critical focus for the research community.1 Research has acknowledged the role of metabolic flexibility in the development and progression of cardiac dysfunction during a variet... Cardiac substrate utilization remains a critical focus for the research community.1 Research has acknowledged the role of metabolic flexibility in the development and progression of cardiac dysfunction during a variety of diseases and conditions.2,3 Under resting basal conditions,the heart relies on fatty acid metabolism as the primary energy source with glucose,lactate,ketone bodies,pyruvate,acetate,and branched-chain amino acids contributing as substrates depending on substrate availability,hormonal status,and myocardial conditioning.4 In addition to pathological states,physiological states,such as acute exercise,induce dynamic changes in substrate metabolism,including nearly a 10-fold increase in myocardial oxygen consumption.3,5 To meet the increased demand for energy during and after a bout of exercise,the heart muscle must exhibit metabolic flexibility and selectively utilize different substrates for adenosine triphosphate production.Moreover,metabolic substrate adaptations depend on the frequency,intensity,duration,and mode of exercise while multiple metabolic fluxes,such as the use,storage and mobilization of substrates must be coordinated to maintain energy homeostasis.1,2 Although many different processes of exercise-induced regulation and metabolic remodeling have been identified,35 the effect of exercise on cellular metabolism and the landscape of metabolic pathway regulation in response to both acute exercise and chronic exercise training remain unclear. 展开更多
关键词 METABOLISM CARDIAC utilize
下载PDF
Scalar Particles’ Tunneling and Effect of Quantum Gravity
4
作者 guoping li Xiaotao Zu 《Journal of Applied Mathematics and Physics》 2015年第2期134-139,共6页
According to the generalized uncertainty principle (GUP), the Klein-Gordon equation is corrected by the quantum gravity exactly. Hence, the corrected Klein-Gordon equation will be more precise on the expression of the... According to the generalized uncertainty principle (GUP), the Klein-Gordon equation is corrected by the quantum gravity exactly. Hence, the corrected Klein-Gordon equation will be more precise on the expression of the tunneling behavior. Then, the corrected Hawking temperature of the Gibbons-Maeda-Dilaton black hole is obtained near the horizon by quantum gravity. Analyzing the results carefully, it is obvious for us that the tunneling result is not only related to the mass of black hole, but also related to the mass and energy of outgoing fermions. Finally, we also infer that the tunneling radiation would be stopped at some particular temperature. 展开更多
关键词 The Quantum GRAVITY The Gibbons-Maeda-Dilaton Black Hole The Corrected KLEIN-GORDON Equation The Generalized Uncertainty PRINCIPLE
下载PDF
Quantum Corrections on Tunneling Radiation by the Generalized Uncertainty Principle
5
作者 Bingbing Chen guoping li +1 位作者 Xiaotao Zu Jian Tang 《Journal of Modern Physics》 2015年第5期578-583,共6页
Based on the generalized uncertainty principle (GUP), the researchers find that the quantum gravity affects the Klein-Gordon equation exactly. Hence, the Klein-Gordon equation which is corrected by GUP will be more su... Based on the generalized uncertainty principle (GUP), the researchers find that the quantum gravity affects the Klein-Gordon equation exactly. Hence, the Klein-Gordon equation which is corrected by GUP will be more suitable on the expression of the tunneling behavior. Then, the corrected Hawking temperature of the GHS black hole is obtained. After analyzing this result, we find out that the Hawking temperature is not only related to the mass of black hole, but also related to the mass and energy of outgoing fermions. Finally, we infer that the Hawking radiation will be stopped, and the remnants of black holes exist naturally. 展开更多
关键词 The Hawking Temperature The GHS Black HOLES The Quantum GRAVITY The Corrected KLEIN-GORDON Equation The Generalized Uncertainty PRINCIPLE
下载PDF
Exercise sustains the hallmarks of health 被引量:8
6
作者 Yan Qiu Benjamin Fernández-García +4 位作者 H.Immo Lehmann guoping li Guido Kroemer Carlos López-Otín Junjie Xiao 《Journal of Sport and Health Science》 SCIE CSCD 2023年第1期8-35,共28页
Exercise has long been known for its active role in improving physical fitness and sustaining health.Regular moderate-intensity exercise improves all aspects of human health and is widely accepted as a preventative an... Exercise has long been known for its active role in improving physical fitness and sustaining health.Regular moderate-intensity exercise improves all aspects of human health and is widely accepted as a preventative and therapeutic strategy for various diseases.It is well-documented that exercise maintains and restores homeostasis at the organismal,tissue,cellular,and molecular levels to stimulate positive physiological adaptations that consequently protect against various pathological conditions.Here we mainly summarize how moderate-intensity exercise affects the major hallmarks of health,including the integrity of barriers,containment of local perturbations,recycling and turnover,integration of circuitries,rhythmic oscillations,homeostatic resilience,hormetic regulation,as well as repair and regeneration.Furthermore,we summarize the current understanding of the mechanisms responsible for beneficial adaptations in response to exercise.This review aimed at providing a comprehensive summary of the vital biological mechanisms through which moderate-intensity exercise maintains health and opens a window for its application in other health interventions.We hope that continuing investigation in this field will further increase our understanding of the processes involved in the positive role of moderate-intensity exercise and thus get us closer to the identification of new therapeutics that improve quality of life. 展开更多
关键词 Beneficial effects of exercise Exercise-related physiological adaptations Hallmarks of health Moderate-intensity exercise Therapeutic exercise
下载PDF
SULF1作为特发性肺纤维化与肺腺癌共同基因的鉴定及其生物学功能分析
7
作者 王俊轶 鲁璐 +4 位作者 何翔 马丽娟 陈涛 李国平 于海杰 《中国肺癌杂志》 CAS CSCD 北大核心 2023年第9期669-683,共15页
背景和目的特发性肺纤维化(idiopathic pulmonary fibrosis,IPF)是一种原因不明的慢性、进行性、间质性肺疾病,确诊后中位生存期为3-5年。IPF与肺癌风险增加有关。因此,探索IPF和肺腺癌的关键共同致病基因和分子通路,对开发IPF合并肺腺... 背景和目的特发性肺纤维化(idiopathic pulmonary fibrosis,IPF)是一种原因不明的慢性、进行性、间质性肺疾病,确诊后中位生存期为3-5年。IPF与肺癌风险增加有关。因此,探索IPF和肺腺癌的关键共同致病基因和分子通路,对开发IPF合并肺腺癌的新治疗手段和个性化精准治疗策略的制定具有重要意义。方法利用基因表达综合(Gene Expression Omnibus,GEO)数据库中公开的IPF和肺腺癌基因表达数据集进行生物信息学分析。使用加权基因共表达网络分析识别涉及两种疾病进程的共同基因,进而功能富集分析。随后,联合额外数据集鉴定两种疾病的核心共同基因。并通过癌症基因组图谱计划(The Cancer Genome Atlas,TCGA)数据库和单细胞RNA测序数据集,分析核心共同基因与患者预后的关系,并评估其在肺腺癌中的表达模式、临床相关性、遗传特征和免疫相关功能。最后通过药物数据库筛选出相关的潜在治疗药物。结果两者之间有529个共同致病基因。其中,SULF1作为核心共同致病基因与患者预后不良相关,其在肺腺癌组织中的表达水平显著升高,同时与高突变频率、显著基因组异质性以及抑制性免疫微环境相关。随后的单细胞分析发现SULF1高表达主要源于肿瘤相关成纤维细胞。SULF1表达与肿瘤药物敏感性变化相关,并筛选出与靶向SULF1高表达成纤维细胞相关的潜在小分子药物。结论本研究鉴别出IPF和肺腺癌之间的共同分子途径和核心基因,其中SULF1可能作为两种疾病的潜在生物标志物和治疗靶点。 展开更多
关键词 肺肿瘤 特发性肺纤维化 加权基因共表达网络分析 SULF1 单细胞转录组学分析
下载PDF
π-Extension and chlorination of non-fullerene acceptors enable more readily processable and sustainable high-performance organic solar cells
8
作者 Ning Su Jianhua Chen +6 位作者 Mengran Peng guoping li Robert M.Pankow Ding Zheng Junqiao Ding Antonio Facchetti Tobin J.Marks 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第4期321-329,共9页
Organic solar cells(OSCs)processed without halogenated solvents and complex treatments are essential for future commercialization.Herein,we report three novel small molecule acceptors(NFAs)consisting of a Y6-like core... Organic solar cells(OSCs)processed without halogenated solvents and complex treatments are essential for future commercialization.Herein,we report three novel small molecule acceptors(NFAs)consisting of a Y6-like core but withπ-extended naphthalene with progressively more chlorinated end-capping groups and a longer branched chain on the Nitrogen atom.These NFAs exhibit good solubilities in nonchlorinated organic solvents,broad optical absorptions,closeπ-πstacking distances(3.63–3.84A),and high electron mobilities(~10^(-3)cm^(2)V^(-1)s^(-1)).The o-xylene processed and as-cast binary devices using PM6 as the donor polymer exhibit a PCE increasing upon progressive chlorination of the naphthalene end-capping group from 8.93%for YN to 14.38%for YN-Cl to 15.00%for YN-2Cl.Furthermore similarly processed ternary OSCs were fabricated by employing YN-Cl and YN-2Cl as the third component of PM6:CH1007 blends(PCE=15.75%).Compared to all binary devices,the ternary PM6:CH1007:YN-Cl(1:1:0.2)and PM6:CH1007:YN-2Cl(1:1:0.2)cells exhibit significantly improved PCEs of 16.49%and15.88%,respectively,which are among the highest values reported to date for non-halogenated solvent processed OSCs without using any additives and blend post-deposition treatments. 展开更多
关键词 Non-fullerene acceptors Non-chlorinated organic solvents Organic solar cells
下载PDF
MicroRNAs in heart and circulation during physical exercise 被引量:7
9
作者 lijun Wang Yicheng Lv +1 位作者 guoping li Junjie Xiao 《Journal of Sport and Health Science》 SCIE 2018年第4期433-441,共9页
Exercise training is beneficial to the cardiovascular system. MicroRNAs (miRNAs, miRs) are a class of conserved non-coding RNAs and play a wide-ranging role in the regulation of eukaryotic gene expression. Exercise ... Exercise training is beneficial to the cardiovascular system. MicroRNAs (miRNAs, miRs) are a class of conserved non-coding RNAs and play a wide-ranging role in the regulation of eukaryotic gene expression. Exercise training alters the expression levels of large amounts ofmiRNAs in the heart. In addition, circulating miRNAs appear to be regulated by exercise training. In this review, we will summarize recent advances in the regulation of miRNAs during physical exercise intervention in various cardiovascular diseases, including pathologic cardiac hypertrophy, myocardial fibrosis, ischemia-reperfusion injury, myocardial infarction, and heart failure. The regulatory role of circulating miRNAs after exercise training was also reviewed. In conclusion, miRNAs might be a valuable target for treatment of cardiovascular diseases and have great potential as biomarkers for assessment of physical performance.2018 Published by Elsevier B.V.on behalf of Shanghai University of Sport. This is an open access article under the CC BY-NC-ND license. (http://creativecommons.org/licenses/by-nc-nd/4.0/). 展开更多
关键词 Cardiovascular diseases Circulating microRNAs EXERCISE MICRORNAS
下载PDF
The landscape of epigenetic regulation and therapeutic application of N^(6)-methyladenosine modifications in non-coding RNAs
10
作者 Gui-e Xu Xuan Zhao +3 位作者 guoping li Priyanka Gokulnath lijun Wang Junjie Xiao 《Genes & Diseases》 SCIE CSCD 2024年第5期236-251,共16页
RNA N^(6)-methyladenosine(m^(6)A)methylation is the most abundant and conserved RNA modification in eukaryotes.It participates in the regulation of RNA metabolism and various pathophysiological processes.Non-coding RN... RNA N^(6)-methyladenosine(m^(6)A)methylation is the most abundant and conserved RNA modification in eukaryotes.It participates in the regulation of RNA metabolism and various pathophysiological processes.Non-coding RNAs(ncRNAs)are defined as small or long transcripts which do not encode proteins and display numerous biological regulatory functions.Similar to mRNAs,m^(6)A deposition is observed in ncRNAs.Studying RNA m^(6)A modifications on ncRNAs is of great importance specifically to deepen our understanding of their biological roles and clinical implications.In this review,we summarized the recent research findings regarding the mutual regulation between RNA m^(6)A modification and ncRNAs(with a specific focus on microRNAs,long non-coding RNAs,and circular RNAs)and their functions.We also discussed the challenges of m^(6)A-containing ncRNAs and RNA m^(6)A as therapeutic targets in human diseases and their future perspective in translational roles. 展开更多
关键词 Circular RNA Epigenetic regulation Long non-coding RNA MICRORNA Non-coding RNA RNA m^(6)A modification
原文传递
Fine-tuning redox ability of arylene-bridged bis(benzimidazolium)for electrochromism and visible-light photocatalysis
11
作者 Jing Wang Zenghui li +6 位作者 Xiaoyang liu Bochao Su Honghong Gong Chao Feng guoping li Gang He Bin Rao 《Chinese Chemical Letters》 SCIE CAS CSCD 2024年第9期140-144,共5页
In this study,a series of arylene-bridged bis(benzimidazolium)triflates 1^(–)6^(^(2+))·2[OTf^(–)]were synthesized by grafting differentπ-linkers with benzimidazolium scaffolds.Among them,compound 1^(2+)·2... In this study,a series of arylene-bridged bis(benzimidazolium)triflates 1^(–)6^(^(2+))·2[OTf^(–)]were synthesized by grafting differentπ-linkers with benzimidazolium scaffolds.Among them,compound 1^(2+)·2[OTf^(–)]with anthracene as the linker exhibited remarkable electron transfer capabilities across four distinct redox states.The inclusion of an anthracene unit as theπ-linker contributes to its exceptional redox and optoelectronic characteristics.Consequently,1^(2+)·2[OTf^(–)]was successfully utilized as both an electrochromic molecule in an ECD under applied voltage for the first time,and a highly efficient photocatalyst for the formation of carbon–phosphorus bonds via visible-light-induced cross-dehydrogenative coupling reactions. 展开更多
关键词 N-Heterocyclic carbenes(NHCs) Ionic radicals ELECTROCHROMISM PHOTOCATALYSIS
原文传递
Model construction and clinical therapeutic potential of engineered cardiac organoids for cardiovascular diseases
12
作者 Yongtao Wang Yan Hou +4 位作者 Tian Hao Marta Garcia-Contreras guoping li Dragos Cretoiu Junjie Xiao 《Biomaterials Translational》 2024年第4期337-354,共18页
Cardiovascular diseases cause significant morbidity and mortality worldwide.Engineered cardiac organoids are being developed and used to replicate cardiac tissues supporting cardiac morphogenesis and development.These... Cardiovascular diseases cause significant morbidity and mortality worldwide.Engineered cardiac organoids are being developed and used to replicate cardiac tissues supporting cardiac morphogenesis and development.These organoids have applications in drug screening,cardiac disease models and regenerative medicine.Therefore,a thorough understanding of cardiac organoids and a comprehensive overview of their development are essential for cardiac tissue engineering.This review summarises different types of cardiac organoids used to explore cardiac function,including those based on co-culture,aggregation,scaffolds,and geometries.The self-assembly of monolayers,multilayers and aggravated cardiomyocytes forms biofunctional cell aggregates in cardiac organoids,elucidating the formation mechanism of scaffold-free cardiac organoids.In contrast,scaffolds such as decellularised extracellular matrices,three-dimensional hydrogels and bioprinting techniques provide a supportive framework for cardiac organoids,playing a crucial role in cardiac development.Different geometries are engineered to create cardiac organoids,facilitating the investigation of intrinsic communication between cardiac organoids and biomechanical pathways.Additionally,this review emphasises the relationship between cardiac organoids and the cardiac system,and evaluates their clinical applications.This review aims to provide valuable insights into the study of three-dimensional cardiac organoids and their clinical potential. 展开更多
关键词 cardiac organoids cardiovascular diseases clinical applications scaffolds SELF-ASSEMBLY
原文传递
2020年8月10日四川芦山夜发特大暴雨的动热力结构及地形影响 被引量:12
13
作者 黄楚惠 李国平 +4 位作者 牛金龙 陈贝 陈功 郭善云 龙柯吉 《大气科学》 CSCD 北大核心 2022年第4期989-1001,共13页
由特殊喇叭口地形促成的四川雅安暴雨久已有名,研究颇多,而这一地区的暖区暴雨、夜发性暴雨的研究在业务预报和防灾减灾迫切需求的推动下也应加强。利用ERA5再分析资料,结合地面加密观测资料及中国气象局信息中心提供的三源融合近实时... 由特殊喇叭口地形促成的四川雅安暴雨久已有名,研究颇多,而这一地区的暖区暴雨、夜发性暴雨的研究在业务预报和防灾减灾迫切需求的推动下也应加强。利用ERA5再分析资料,结合地面加密观测资料及中国气象局信息中心提供的三源融合近实时降水资料,对造成2020年8月10日四川雅安芦山的特大暴雨过程的动热力结构演变、触发机制和地形影响进行了诊断分析,揭示了弱天气尺度强迫及特殊地形影响背景下暖区暴雨的水汽、动热力结构演变及触发机制。研究得出:(1)此例暴雨属于500 h Pa无明显影响系统、低层无急流背景下的东南风型暖区暴雨。在雅安“迎风坡”、“喇叭口”地形和芦山西南向“?”型峡谷地形的影响下,配合西太副高西进、东南暖湿气流加强和850 h Pa弱低涡辐合气流的共同作用而诱发产生,此次降水时间短,强度大。(2)降水开始到强盛期间,始终有边界层地形作用产生的抬升速度、气旋式涡度和水平辐合与系统性垂直上升运动、涡度和散度叠加,增强了低层辐合,加剧了垂直上升运动,促使降水加强。(3)差动θ平流使得暴雨区对流不稳定度增强。对流抑制能量为零的高能高湿环境中,500 h Paθ弱冷平流也是暖区暴雨触发的因素之一;傍晚地形冷平流触发了初始对流并沿海拔高度1500米地形线分布;暴雨区上游强降水造成雷暴冷池出流叠加山风在“?”型峡谷西侧形成γ中尺度辐合线,并移至“?”型谷地内维持;冷性气流在快速下山后亦以冷池形式维持在“?”型峡谷东侧山脉附近,形成强温度梯度,这些因素触发并维持了芦山夜间特大暴雨。 展开更多
关键词 夜发暴雨 特殊地形 对流不稳定 触发 冷池
下载PDF
Exercise-mediated regulation of autophagy in the cardiovascular system 被引量:6
14
作者 lijun Wang Jiaqi Wang +2 位作者 Dragos Cretoiu guoping li Junjie Xiao 《Journal of Sport and Health Science》 SCIE 2020年第3期203-210,共8页
Cardiovascular disease is the leading cause of human death worldwide. Autophagy is an evolutionarily conserved degradation pathway,which is a highly conserved cellular degradation process in which lysosomes decompose ... Cardiovascular disease is the leading cause of human death worldwide. Autophagy is an evolutionarily conserved degradation pathway,which is a highly conserved cellular degradation process in which lysosomes decompose their own organelles and recycle the resulting macromolecules.Autophagy is critical in maintaining cardiovascular homeostasis and function, and excessive or insufficient autophagy or autophagic flux can lead to cardiovascular disease. Enormous evidence indicates that exercise training plays a beneficial role in the prevention and treatment of cardiovascular diseases. The regulation of autophagy during exercise is a bidirectional process. For cardiovascular disease caused by either insufficient or excessive autophagy, exercise training restores normal autophagy function and delays the progression of cardiovascular disease.An in-depth exploration and discussion of exercise-mediated regulation of autophagy in the cardiovascular system can broaden our view about the prevention of various autophagy-related diseases through exercise training. In this article, we review autophagy and its related signaling pathways,as well as autophagy-dependent beneficial effects of exercise in cardiovascular system. 展开更多
关键词 AUTOPHAGY CARDIOVASCULAR DISEASES EXERCISE
下载PDF
聚酯改性环氧乙烷四氢呋喃/多异氰酸酯N100黏合剂的力学性能
15
作者 姜圣坤 李国平 +1 位作者 陶维斌 罗运军 《高分子材料科学与工程》 EI CAS CSCD 北大核心 2020年第12期56-62,共7页
为提升环氧乙烷四氢呋喃(PET)/N100黏合剂体系的高温力学性能,分别将聚己二酸己二醇酯(PHA)、聚己二酸乙二醇酯(PEA)、聚己二酸新戊二醇酯(PNA)、聚己内酯(PCL)引入到PET/N100体系中并进行性能测试。X射线衍射表明,受N100的影响,改性黏... 为提升环氧乙烷四氢呋喃(PET)/N100黏合剂体系的高温力学性能,分别将聚己二酸己二醇酯(PHA)、聚己二酸乙二醇酯(PEA)、聚己二酸新戊二醇酯(PNA)、聚己内酯(PCL)引入到PET/N100体系中并进行性能测试。X射线衍射表明,受N100的影响,改性黏合剂胶片不存在结晶衍射峰;利用红外光谱研究了聚酯加入后H键合羰基的含量的变化;低场核磁共振测试结果表明,聚酯的引入主要通过增加交联网络中耐高温的交联部分的含量来提升黏合剂的高温力学强度;差示扫描量热及力学性能测试结果表明,相容性较好的PHA,PNA,PCL引入黏合剂体系后常温下最大拉伸强度可达2 MPa左右,且温度升高至80℃时仍保有1.84 MPa的断裂强度。 展开更多
关键词 黏合剂 力学性能 环氧乙烷四氢呋喃 聚酯
下载PDF
超交联树脂的制备及对异戊醇的吸附性能
16
作者 林蜜彬 朱良 +3 位作者 肖凯军 赵凯 李国平 雷晶 《高分子材料科学与工程》 EI CAS CSCD 北大核心 2022年第10期142-150,共9页
以氯甲基化聚苯乙烯(PS-Cl)为前体,采用Friedel-Crafts反应制备了HCP树脂,并将其应用于异戊醇的吸附。扫描电镜、红外光谱、X射线衍射、热稳定性和比表面积分析结果表明,HCP树脂球面光滑,引入了羰基基团,晶型几乎不变,热稳定性增强,比... 以氯甲基化聚苯乙烯(PS-Cl)为前体,采用Friedel-Crafts反应制备了HCP树脂,并将其应用于异戊醇的吸附。扫描电镜、红外光谱、X射线衍射、热稳定性和比表面积分析结果表明,HCP树脂球面光滑,引入了羰基基团,晶型几乎不变,热稳定性增强,比表面积增加为955.83 m^(2)/g,微孔比表面积占BET比表面积的65.03%。探究证明,在85℃,4 h进行Friedel-Crafts反应制备的HCP树脂对异戊醇的吸附效果最佳;HCP树脂对异戊醇的吸附热力学更符合Freundlich模型且吸附是吸热的,吸附动力学属于准二级动力学吸附;经过5次循环使用后的吸附量为第1次吸附量的82.31%,表明HCP树脂具有较好的再生性和可循环利用性。 展开更多
关键词 超交联树脂 制备 异戊醇 吸附
下载PDF
Sideswiping Tropical Cyclones and Their Associated Precipitation over China 被引量:4
17
作者 Tian FENG Fumin REN +3 位作者 Da-lin ZHANG guoping li Wenyu QIU Hui YANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2020年第7期707-717,共11页
Tropical cyclone(TC)precipitation(TCP)has attracted considerable attention in recent decades because of its adverse socioeconomic impacts.In particular,considerable effort has been devoted to quantifying TCP and inves... Tropical cyclone(TC)precipitation(TCP)has attracted considerable attention in recent decades because of its adverse socioeconomic impacts.In particular,considerable effort has been devoted to quantifying TCP and investigating the precipitation of TCs that make landfall.However,precipitation over land induced by TCs that do not make landfall(i.e.,offshore),the so-called"sideswiping"TCs(STCs),is an important component of TCP but has attracted little attention from the research community to date.Here,best-track and daily precipitation data from the China Meteorological Administration during the 59 years of 1960-2018 are used to study STC precipitation(STP).Results show that:(i)the annual number of STCs fluctuates significantly from 3 to 17,with a mean frequency of 8.8 STCs per year;(ii)there are decreasing trends in STC frequency and STP amount over the past 59 years;(iii)both STC frequency and STP are high from July to October,with maxima in August;(iv)the distribution of STP,covering most of China’s coastal regions,is dominated by intense STCs,and the annual STP decreases from southeast coastal regions to northwest inland areas,with a maximum value over the islands of Taiwan and Hainan;and(v)extreme STP events could appear not only over the island and coastal areas,but also over inland areas such as Zhumadian of Henan Province due to the influences of local orography and favorable largescale forcing. 展开更多
关键词 COASTAL INLAND SOUTHEAST
下载PDF
Changes in Typhoon Regional Heavy Precipitation Events over China from 1960 to 2018 被引量:2
18
作者 Yangmei TIAN John LMCBRIDE +2 位作者 Fumin REN guoping li Tian FENG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2022年第2期272-283,共12页
In earlier studies,objective techniques have been used to determine the contribution of tropical cyclones to precipitation(TCP)in a region,where the Tropical cyclone Precipitation Event(TPE)and the Regional Heavy Prec... In earlier studies,objective techniques have been used to determine the contribution of tropical cyclones to precipitation(TCP)in a region,where the Tropical cyclone Precipitation Event(TPE)and the Regional Heavy Precipitation Events(RHPEs)are defined and investigated.In this study,TPE and RHPEs are combined to determine the Typhoon Regional Heavy Precipitation Events(TRHPEs),which is employed to evaluate the contribution of tropical cyclones to regional extreme precipitation events.Based on the Objective Identification Technique for Regional Extreme Events(OITREE)and the Objective Synoptic Analysis Technique(OSAT)to define TPE,temporal and spatial overlap indices are developed to identify the combined events as TRHPE.With daily precipitation data and TC best-track data over the western North Pacific from 1960 to 2018,86 TRHPEs have been identified.TRHPEs contribute as much as 20%of the RHPEs,but100%of events with extreme individual precipitation intensities.The major TRHPEs continued for approximately a week after tropical cyclone landfall,indicating a role of post landfall precipitation.The frequency and extreme intensity of TRHPEs display increasing trends,consistent with an observed positive trend in the mean intensity of TPEs as measured by the number of daily station precipitation observations exceeding 100 mm and 250 mm.More frequent landfalling Southeast and South China TCs induced more serious impacts in coastal areas in the Southeast and the South during 1990-2018 than1960-89.The roles of cyclone translation speed and"shifts"in cyclone tracks are examined as possible explanations for the temporal trends. 展开更多
关键词 TYPHOON regional heavy precipitation events CHANGES temporal and spatial characteristics
下载PDF
Hearing analysis in heterozygous and homozygous klotho gene deficient mice 被引量:2
19
作者 Na Yuan Shiwei Qiu +6 位作者 Qian Wang Wei Zhuang guoping li Tiantian Sun Shiming Yang Yuehua Qiao Xi Shi 《Journal of Otology》 CSCD 2018年第4期131-134,共4页
Objective: To understand the crucial role of the klotho gene in hearing development in mouse models.Methods: PCR was used to identify CBA mice with different genotypes, i.e. WT, heterozygous(klotho +/-)or homozygous(k... Objective: To understand the crucial role of the klotho gene in hearing development in mouse models.Methods: PCR was used to identify CBA mice with different genotypes, i.e. WT, heterozygous(klotho +/-)or homozygous(klotho-/-). Mice phenotype and weight were recorded postnatal 25 days(P-25) and auditory brainstem responses(ABR) were used to determine auditory function at P-60.Results: klotho-/-mice tended to have smaller size, lighter weight and higher ABR thresholds at P-60,showing early onset age-related hearing loss(ARHL).Conclusion: Heterozygous and homozygous klotho deficient mice exhibit different degrees of hearing loss at young age, with homozygous mice(klotho-/-) showing more severe hearing loss. Our results indicate that persisted expression of klotho protein in the inner ear may potentially delay the onset of ARHL and play an important role in the protection of auditory function. 展开更多
关键词 HOMOZYGOUS Klotho gene Inner ear Hearing loss
下载PDF
Analysis of a Vortex Precipitation Event over Southwest China Using AIRS and In Situ Measurements 被引量:8
20
作者 Chengcheng NI guoping li Xiaozhen XIONG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2017年第4期559-570,共12页
A strong precipitation event caused by the southwest vortex(SWV), which affected Sichuan Province and Chongqing municipality in Southwest China on 10–14 July 2012, is investigated. The SWV is examined using satelli... A strong precipitation event caused by the southwest vortex(SWV), which affected Sichuan Province and Chongqing municipality in Southwest China on 10–14 July 2012, is investigated. The SWV is examined using satellite observations from AIRS(Atmospheric Infrared Sounder), in situ measurements from the SWV intensive observation campaign, and MICAPS(Marine Interactive Computer-Aided Provisioning System) data. Analysis of this precipitation process revealed that:(1)heavy rain occurred during the development phase, and cloud water content increased significantly after the dissipation of the SWV;(2) the area with low outgoing longwave radiation values from AIRS correlated well with the SWV;(3) variation of the temperature of brightness blackbody(TBB) from AIRS reflected the evolution of the SWV, and the values of TBB reduced significantly during the SWV's development; and(4) strong temperature and water vapor inversions were noted during the development of the SWV. The moisture profile displayed large vertical variation during the SWV's puissant phase,with the moisture inversion occurring at low levels. The moisture content during the receding phase was significantly reduced compared with that during the developing and puissant phases. The vertical flux of vapor divergence explained the variation of the moisture profile. These results also indicate the potential for using AIRS products in studying severe weather over the Tibetan Plateau and its surroundings, where in situ measurements are sparse. 展开更多
关键词 precipitation event AIRS southwest vortex temperature profile moisture profile
下载PDF
上一页 1 2 3 下一页 到第
使用帮助 返回顶部