检索结果-南通市图书馆

The Combined Effects of the Tropical and Extratropical Quasi-biweekly Oscillations on the Record-setting Mei-yu Rainfall in the Summer of 2020

引用

Advances in Atmospheric Sciences 2023年第4期40卷 663-681,I0002-I0014页

作者： Zhen HUANG Shuanglin li Jianying Li Chao ZHANG Department of Atmospheric Science/Centre for Severe Weather and Climate and Hydro-geological Hazards China University of GeosciencesWuhan 430074China China Climate Change Research Center Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China State Key Laboratory of Severe Weather(LASW) Chinese Academy of Meteorological SciencesBeijing 100081China

During June-July 2020,the strongest recorded mei-yu rainfall occurred in the middle and lower reaches of the Yangtze River.The rainfall processes exhibited an obvious quasi-biweekly(biweekly in brief)variability,and there are altogether five cycles.It is found that the biweekly rainfall cycle mainly arises from the collaborative effects of biweekly variabilities from both the tropics and extratropics.As for the tropics,the biweekly meridional march and retreat of the western Pacific subtropical high(WPSH)is particularly evident.As for the extratropics,geopotential height anomalies near Lake Baikal are active.The former is attributed to the intensified biweekly activity of the southwest-northeast oriented EastAsian Pacific wave train(EAP)originating from the tropical western Pacific,while the latter is associated with the biweekly activities of the eastward propagating Eurasia mid-high latitudinal wave train and the westward propagating North Pacific wave train.Why the biweekly activities of these wave trains intensified is further diagnosed from the perspective of thermodynamical forcing and also from the modulation of interannual background on intraseasonal variability.It is found that the strongest recorded convection anchoring over the tropical western Indian Ocean(IO)triggers anomalous descent over the tropical western Pacific,which modulates the biweekly activity of the EAP.Meanwhile,the anomalous diabatic heating over the IO causes changes of the meridional thermodynamic contrast across the IO to the high latitudes,which modulates the extratropical wave trains.A further diagnosis of barotropic kinetic energy conversion suggests that the active occurrence of two extratropical biweekly wave trains is attributed to the increased efficiency of energy conversion from basic flow.The westward propagation of the extratropical North Pacific wave train is attributed to the weakened and northshifted upper-level westerly,which is caused by the SST warmth near the Kuroshio extension.

关键词： strongest recorded mei-yu rainfall in summer 2020 quasi-biweekly variability tropical convection westward propagation of the extratropical North Pacific wave train SSTA in the North Pacific

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

Condition monitoring and diagnosis of power equipment:review and prospective

引用

High Voltage 2017年第2期2卷 82-91页

作者： Shengtao li Jianying Li State Key Laboratory of Electrical Insulation and Power equipment Xi'an Jiaotong UniversityXi'an710049People's Republic of China

To ensure the power system operates safely and reliably,it is essential to monitor and evaluate the health condition of power equipment on-line or off-line.This study reviews the research status in condition monitoring and diagnosis of power equipment,including transformer,gas insulated switchgear,cable,external insulation,generator,and power capacitor in recent years.Although much progress has been made in technologies of condition monitoring and fault diagnosis such as test accuracy,fast and accurate fault localisation and recognition of fault types,there are still many deficiencies which needs further research work,including the reliability of signal collection from sensors,the accuracy of data treatment and analysis,anti-interference performance of test equipment,appropriate models used for condition evaluation.The prospective of condition monitoring and diagnosis technologies of power equipment are also presented in this study.It is proposed that the application of big data,internet of things and cloud computing should be expected and given special attention in the near future.

关键词： diagnosis power fault

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

Power loss transition of stable ZnO varistor ceramics: Role of oxygen adsorption on the stability of interface states at the grain boundary

引用

Journal of Advanced Ceramics 2023年第5期12卷 972-983页

作者： Zhuolin Cheng Rou li Yiwei Long Jianying Li Shengtao li Kangning Wu State Key Laboratory of Electrical Insulation and Power Equipment Xi’an Jiaotong UniversityXi’an 710049China Department of Thermal and Fluid Engineering University of TwenteEnschede 7500AEthe Netherlands

Highly stable ZnO varistor ceramics with steadily decreasing power loss have been put into applications in electrical and electronic systems for overvoltage protections, even with the absence of general understandings on their aging behaviors. In this paper, we investigated their aging nature via conducting comparative direct current (DC) aging experiments both in air and in nitrogen, during which variations of electrical properties and interface properties were measured and analyzed. Notably, continuously increasing power loss with severe electrical degradation was observed for the sample aged in nitrogen. The power loss transition was discovered to be closely related to the consumption of oxygen adsorption at the grain boundary (GB), which could, however, remain constant for the sample aged in air. The interface density of states (DOS) Ni, which is crucial for pinning the potential barrier, was proved to decrease in nitrogen, but keep stable in air. Therefore, it is concluded that the oxygen adsorption at the GB is significant for the stability of interface states, which further correlates to the long-term stability of modern stable ZnO varistor ceramics.

关键词： ZnO varistor ceramics aging power loss oxygen adsorption interface states

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

Metabolic fate of tea polyphenols and their crosstalk with gut microbiota

引用

Food Science and Human Wellness 2022年第3期11卷 455-466页

作者： Meiyan Wang Jianying Li Ting Hu Hui Zhao Tianjin Key Laboratory of Food and Biotechnology School of Biotechnology and Food ScienceTianjin University of CommerceTianjin 300134China Hubei Key Laboratory for EFGIR Huanggang Normal UniversityHuanggang 438000China

Tea represents an abundant source of naturally occurring polyphenols.Tea polyphenols(TPs)have received growing attentions for its wide consumption in the world,and more importantly its pleiotropic bioeffects for human health.After ingestion,TPs may undergo absorption and phase II reaction in the small intestine,and most undigested proportion would be submitted to the colon to interact with gut microbiota.Interactions between gut microbiota and TPs are bidirectional,including not only bacteria-mediated TPs metabolism,e.g.,removal of gallic acid moiety and ring fission to release phenolic acid catabolites,but also TPs-based modification of bacterial profiles.Crosstalk between TPs and gut microbes may benefit for gut barrier function,for example,improvement of the intestinal permeability to alleviate inflammation.Moreover,by reshaping microbial composition and associated metabolites,TPs may exert a systemic protection on host metabolism,which contributes to improve certain chronic metabolic disorders.Given that,further understanding of the metabolic fate of TPs and interplay with gut microbiota as well as potential health-promoting effects are of great significance to development and application of tea and their polyphenolic components in the future as dietary supplements and/or functional ingredients in medical foods.

关键词： Tea polyphenols Metabolism Gut microbiota Bioeffects

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

A direct bonding copper degradation monitoring method for insulated gate bipolar transistor modules: Boundary‐dependent thermal network combined with feedback control

引用

High Voltage 2023年第6期8卷 1264-1274页

作者： Xiaotong Zhang Zhuolin Cheng Xing Sun Kangning Wu Jianying Li State Key Laboratory of Electrical Insulation and Power Equipment Xi'an Jiaotong UniversityXi'anChina

The direct bonding copper(DBC)substrates of insulated gate bipolar transistor(IGBT)modules degrade inevitably under cycling thermo‐mechanical stress,causing potential threat to the reliability of IGBT modules.However,little attention has been paid to monitoring their degradation.This paper proposes a DBC degradation monitoring method for IGBT modules,which combines boundary‐dependent thermal network and feedback control.A thermal network is employed to describe the internal material degradation of IGBT modules and can be extracted from a finite‐element method model.The boundary conditions including power losses and DBC degradation are considered,enabling the thermal network suitable for various working conditions and different DBC degradation conditions of IGBT modules.The DBC degradation is characterised by its equivalent thermal conductivities measured in the thermal cycling ageing experiments.On the basis of the boundary‐dependent thermal network,feedback control is applied to monitor DBC degradation by regulating boundary‐dependent thermal impedances.Finally,the proposed model is verified from the effectiveness and accuracy of DBC degradation monitoring and junction temperature calculation.This method casts new light on thermal network modelling and could provide a feasible method for the monitoring of DBC degradation.

关键词： network bipolar transistor

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

A comprehensive review on the effects of green tea and its components on the immune function

引用

Food Science and Human Wellness 2022年第5期11卷 1143-1155页

作者： Jiachen Sun Shengjie Dong Jianying Li Hui Zhao School of Biotechnology and Food Science Tianjin University of CommerceTianjin 300133China School of Pharmaceutical Science and Technology Tianjin UniversityTianjin 300072China Faculty of Education and Sports Guangdong Baiyun UniversityGuangzhou 510450China

Green tea and its bioactive components possess many health-promoting and disease-preventing benefits,especially anti-inflammatory,antioxidant,anticancer,and metabolic modulation effects with multi-target modes of action.In contrast,the effects and mechanisms of tea and its components on the immune system are rarely reviewed.The study aimed to review the most potent compounds in tea that affect the immune systems and mechanisms associated with it.As a result of in vitro studies,animal models,and human trials,researchers have found that green tea extracts and compounds have the possibility of modulating the innate immune system,adaptive immune system,and intestinal immune system.In immune-related diseases,tea polyphenols are the most significant compounds that modify immune functions,though other compounds are being investigated and cannot be ruled out.The review provides a new perspective on how the immune-regulatory effects of tea and its components are exerted on immune systems,as well as how they affect the emergence and treatment of diseases.

关键词： Green tea Active components Innate immune system Adaptive immune system Intestinal immune system

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

Functional mechanism on stem cells by tea(Camellia sinensis)bioactive compounds

引用

Food Science and Human Wellness 2022年第3期11卷 579-586页

作者： Yao Cheng Jiachen Sun Hui Zhao Hongxing Guo Jianying Li School of Biotechnology and Food Science Tianjin University of CommerceTianjin 300134China The Third Central Clinical College Tianjin Medical UniversityTianjin 300170China

Camellia sinensis(tea),one of the most popular commercial crops,is commonly applied in all parts of the world.The main active ingredients of tea include polyphenols,alkaloids,polysaccharides,amino acids,aroma and volatile constitutes,all of which are potentially responsible for the activities of tea.Stem cells(SCs)are the immature and undifferentiated cells by a varying capacity for proliferation,self-renewal and the capability to differentiate into one or more different derivatives with specialized function or maintain their stem cell phenotype.Herein,a thorough review is conducted of the functional mechanism on SCs by tea bioactive compounds.

关键词： Functional mechanism Stem cell Camellia sinensis Bioactive compounds

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

Correlation between antioxidant depletion kinetic model and ageing behaviour of cross-linked polyethylene cable insulation

引用

High Voltage 2023年第2期8卷 231-238页

作者： Yingying Zheng Yiwei Long Delun Yi Haoran Zhang Jian Gao Kangning Wu Jianying Li State Key Laboratory of Electrical Insulation and Power Equipment Xi'an Jiaotong UniversityXi'anShaanxiChina

A concise kinetic model catering for the antioxidant reaction of thermally aged crosslinked polyethylene(XLPE)cable insulation before its abrupt performance deterioration is proposed for life prediction and condition assessment.The alternating current breakdown strength,elongation at break,carbonyl index,and pyrolysis activation energy of XLPE insulation are found to consistently display an abrupt change at a certain point of ageing time.This is strongly correlated to the depletion of the antioxidant whose content gradually decreases with ageing time and drops to a critical value,after which the abrupt degradation of the above macroscopic performances happens.Based on the simplified chain reactions of XLPE during thermal-oxidative ageing,a concise kinetic model about antioxidant prediction is accordingly established by solving the chemical kinetics equations.It indicates that the antioxidant content decays with the reciprocal of time before the abrupt degradation occurs.Results of antioxidant content predicted by the kinetic model at different temperatures matches well with the experimental results,and its reliability can also be proved by the Arrhenius relationship of the obtained results.The kinetic model proposed herein demonstrates satisfying conciseness and thus can be highly feasible in ageing condition assessment and life predicting of XLPE insulation.

关键词： kinetic insulation depletion

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

Ti-Fe_(2)O_(3)/Ni(OH)_(x) as an efficient and durable photoanode for the photoelectrochemical catalysis of PET plastic to formic acid

引用

Journal of Energy Chemistry 2023年第3期78卷 487-496,I0014页

作者： Xin li jianying Wang Mingze Sun Xufang Qian Yixin Zhao School of Environmental Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China Shanghai Institute of Pollution Control and Ecological Security Shanghai 200240China

Photoelectrochemical(PEC) technology provides a promising prospect for the transformation of polyethylene terephthalate(PET) plastic wastes to produce value-added chemicals.The PEC catalytic systems with high activity,selectivity and long-term durability are required for the future up-scaling industrial applications.Herein,we employed the interfacial modification strategy to develop an efficient and stable photoanode and evaluated its PEC activity for ethylene glycol(EG,derived from PET hydrolysate) oxidation to formic acid.The interfacial modification between Fe_(2)O_(3)semiconductor and Ni(OH)xcocatalyst with ultrathin TiO_(x) interlayer not only improved the photocurrent density by accelerating the kinetics of photogenerated charge carriers,but also kept the high Faradaic efficiency(over 95% in 30 h) towards the value-added formic acid product.This work proposes an effective method to promote the PEC activity and enhance the long-term stability of photoelectrodes for upcycling PET plastic wastes.

关键词： Plastic waste Formic acid Photoelectrochemical catalysis High durability Interfacial modiﬁcation

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

Heterocyclic Carbene-Catalyzed Hydride Transfer in the Hydroboration of Carbonyl Compounds

引用

Chinese Journal of Chemistry 2019年第7期37卷 679-683页

作者： Tianhao li jianying Zhang Chunming Cui State Key Laboratory of Elemento-Organic Chemistry Nankai University 94 Weijin Road Tianjin 300071 China

N-Heterocyclic carbene (NHC) enabled the highly efficient catalytic hydroboration of a wide range of ketones and aldehydes under mild conditions,and a new mechanism of catalytic hydroboration reaction which involves d... 详细信息

关键词： Hydride Transfer Carbonyl Compounds

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

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：