期刊文献+
共找到149篇文章
< 1 2 8 >
每页显示 20 50 100
Novel Strategies for Cognitive Enhancement via Noninvasive Neuromodulation
1
作者 Hongwei Li kun zhao Yong Liu 《Neuroscience Bulletin》 2025年第7期1311-1313,共3页
Cognitive enhancement is essential for maintaining the quality of life in healthy individuals and improving the ability of those with mental impairments.In recent years,noninvasive neuromodulation techniques(such as t... Cognitive enhancement is essential for maintaining the quality of life in healthy individuals and improving the ability of those with mental impairments.In recent years,noninvasive neuromodulation techniques(such as transcranial magnetic stimulation,transcranial direct-current stimulation,and transcranial ultrasound stimulation)have shown significant potential in enhancing cognitive functions[1,2].Existing technologies are limited mainly to superficial cortical regions,with limited efficacy in targeting deep brain areas and inadequate methods for evaluating their modulatory effects.Selecting stimulation parameters(such as locus,depth,and intensity)and assessing the impact of neuromodulation remains incompletely understood. 展开更多
关键词 noninvasive neuromodulation transcranial magnetic stimulation transcranial ultrasound stimulation transcranial magnetic stimulationtranscranial cognitive enhancement enhancing cognitive functions existing improving ability maintaining quality life
原文传递
A Comparative Analysis of Subtyping Methodologies on Cross-sectional sMRI Data
2
作者 Shirui Zhang Baitong Zhang +14 位作者 kun zhao Zhuangzhuang Li Pan Wang Dawei Wang Chengyuan Song Jie Lu Zengqiang Zhang Hongxiang Yao Tong Han Chunshui Yu Bo Zhou Ying Han Xi Zhang Pindong Chen Yong Liu 《Neuroscience Bulletin》 2025年第9期1689-1695,共7页
Dear Editor,Growing clinical evidence shows that brain disorders are heterogeneous in phenotype,genetics,and neuropathology[1].Diagnosis and treatment tend to be affected by symptom presentation and the heterogeneity ... Dear Editor,Growing clinical evidence shows that brain disorders are heterogeneous in phenotype,genetics,and neuropathology[1].Diagnosis and treatment tend to be affected by symptom presentation and the heterogeneity of pathology,potentially hindering clinical trials in the development of medical treatment.Brain-based subtyping studies utilize magnetic resonance imaging(MRI)and data-driven methods to discover the subtypes of diseases,providing a new perspective on disease heterogeneity. 展开更多
关键词 magnetic resonance imaging brain disorders magnetic resonance imaging mri clinical trials subtyping methodologies disease heterogeneity cross sectional data
原文传递
Alamandine inhibits pathological retinal neovascularization by targeting the MrgD-mediated HIF-1α/VEGF pathway
3
作者 kun zhao Yaping JIANG +4 位作者 Wen HUANG Yukang MAO Yihui CHEN Peng LI Chuanxi YANG 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 2025年第10期1015-1036,共22页
Retinopathy of prematurity(ROP)is a vision-threatening disorder that leads to pathological growth of the retinal vasculature due to hypoxia.Here,we investigated the potential effects of alamandine,a novel heptapeptide... Retinopathy of prematurity(ROP)is a vision-threatening disorder that leads to pathological growth of the retinal vasculature due to hypoxia.Here,we investigated the potential effects of alamandine,a novel heptapeptide in the renin-angiotensin system(RAS),on hypoxia-induced retinal neovascularization and its underlying mechanisms.In vivo,the C57BL/6J mice with oxygen-induced retinopathy(OIR)were injected intravitreally with alamandine(1.0µmol/kg per eye).In vitro,human retinal microvascular endothelial cells(HRMECs)were utilized to investigate the effects of alamandine(10µg/mL)on proliferation,apoptosis,migration,and tubular formation under vascular endothelial growth factor(VEGF)stimulation.Single-cell RNA sequencing(scRNA-seq)matrix data from the Gene Expression Omnibus(GEO)database and RAS-related genes from the Molecular Signatures Database(MSigDB)were sourced for subsequent analyses.By integrating scRNA-seq data across multiple species,we identified that RAS-associated endothelial cell populations were highly related to retinal neovascularization.The liquid chromatography-tandem mass spectrometry(LC-MS/MS)analysis revealed a significant decrease in alamandine levels in both the serum and retina of OIR mice compared to those in the control group.Next,alamandine ameliorated hypoxia-induced retinal pathological neovascularization and physiologic revascularization in OIR mice.In vitro,alamandine effectively mitigated VEGF-induced proliferation,scratch wound healing,and tube formation of HRMECs primarily by inhibiting the hypoxia-inducible factor-1α(HIF-1α)/VEGF pathway.Further,coincubation with D-Pro7(Mas-related G protein-coupled receptor D(MrgD)antagonist)hindered the beneficial impacts of alamandine on hypoxia-induced pathological angiogenesis both in vivo and in vitro.Our findings suggested that alamandine could mitigate retinal neovascularization by targeting the MrgD-mediated HIF-1α/VEGF pathway,providing a potential therapeutic agent for OIR prevention and treatment. 展开更多
关键词 Alamandine Pathological neovascularization Retinopathy of prematurity(ROP) Oxygen-induced retinopathy(OIR) Mas-related G protein-coupled receptor D(MrgD) Vascular endothelial growth factor(VEGF)
原文传递
Anisotropy of laser-induced electro-response in shale:Modelling and experimental validation
4
作者 Xuecong Liu Zhengchun Hong +2 位作者 Yuqi Jiao kun zhao Xinyang Miao 《International Journal of Mining Science and Technology》 2025年第10期1663-1676,共14页
Laser-induced electro-response(LIER),as a new method that complements conventional rock physics testing techniques,is expected to address issues such as of unclear mechanisms,model deficiency,inconsistent evaluation p... Laser-induced electro-response(LIER),as a new method that complements conventional rock physics testing techniques,is expected to address issues such as of unclear mechanisms,model deficiency,inconsistent evaluation parameters,and difficulty in separating multiple coupling factors in shale anisotropy evaluation,and establish a more complete and reliable shale physical property evaluation system.A testing strategy for out of plane anisotropy(OPA)was proposed for characterising anisotropy by LIER,where the near infrared(NIR)continuous laser(CL)and nanosecond pulsed laser(PL)were used to irradiate the surface of oblique cut shale,and the transverse LIER of the surface was measured.A LIER detection model is constructed from the laser-thermal effect,residual transverse polarization electric field and thermionic emission transport mechanism,which is strongly relying on laser power,bias voltage,and inclination angle of the measurement direction relative to the bedding plane of shale.For OPA test on the slice of oblique cut shale under CL irradiation,the relationship between the product of LIER simulation parameters and the tilting angle can be described by a cubic function and an impulse function with a maximum value at the threshold angle.In addition,the thermal accumulation and transient thermal effects are induced in the shale under a high-energy short laser pulse irradiation,and the simulation results indicate that there is an exponential relationship between the product of parameters in the LIER model and the tilt angle.Thus,for OPA test under CL and PL irradiations,it is recommended to use the product of parameters as an evaluation index for shale anisotropy.Furthermore,to solve the problem of multiple influencing factors entangled in the exponential term of the LIER model,the tangential LIER measurement was performed on the side of cylindrical shale core,where the provided LIER model effectively presented the anisotropy of tight shale plug,especially the effects of bias voltage and laser power on LIER were relatively separated as independent variables.Finally,the LIER at the end of laser drilling is presented well using the optimized model under a focused ns NIR PL irradiation,indicating that LIER is expected to be a real-time means for characterizing shale anisotropy during laser drilling processes.These results show that the present work is fundamental for the precise evaluation and effective development of anisotropic shale reservoirs,and will drive the advances of LIER in the exploration for shale oil and gas. 展开更多
关键词 Laser-induced electro-response SHALE ANISOTROPY Laser-thermal effect Polarization electric field Laser-induced plasma
在线阅读 下载PDF
Application of Three-Dimensional Wind Fields and Dual-Polarization Signals of an X-band Phased Array Weather Radar in Diagnosing Vertical Motion and Cloud Electrification in Convective Storms
5
作者 Zhengwei YANG Pak-wai CHAN +4 位作者 Ying-wa CHAN kun zhao Haiqin CHEN Churui CHEN Yuanyuan XU 《Advances in Atmospheric Sciences》 2025年第5期968-980,共13页
The Hong Kong Observatory(HKO)installed an X-band dual-polarization Phased Array Weather Radar(PAWR)at its wind profiler station at Sha Lo Wan(SLW)in 2021 to monitor high-impact weather in Hong Kong.The PAWR could com... The Hong Kong Observatory(HKO)installed an X-band dual-polarization Phased Array Weather Radar(PAWR)at its wind profiler station at Sha Lo Wan(SLW)in 2021 to monitor high-impact weather in Hong Kong.The PAWR could complete a volume scan in one minute with a spatial resolution of 30 meters.Dual polarimetric variables from the SLW PAWR,including differential reflectivity(ZDR),specific differential phase(KDP),and hydro-classification(HCL)products,were used to diagnose the vertical motion and lightning characteristics of mesoscale convective storms(MCS).Through variational data assimilation,three-dimensional(3-D)wind fields were constructed to validate the SLW PAWR observations.Two MCS events that occurred on 18 September 2022 and 17 June 2023 are central to this study.The findings include(1)negative ZDR serves as a good indicator of the occurrence of intense downdrafts associated with an MCS,a premise further supported by the 3-D wind field analysis results,(2)negative KDP suggested the formation of vertically aligned ice crystals which facilitated cloud electrification,and(3)HCL products indicated the presence of mixed ice crystals and graupel above the 0℃melting layer which promoted active cloud-to-cloud and cloud-to-ground lightning strokes.These results show that the SLW PAWR provides essential observations,which,when coupled with 3-D wind field analysis,can aid in enhancing the understanding of the dynamics and electrification processes within an MCS. 展开更多
关键词 Phased Array Weather Radar dual polarimetric variables mesoscale convective storms downdraft cloud electrification
在线阅读 下载PDF
Molybdenum-glycerate@zeolitic imidazolate framework spheres derived hierarchical nitrogen-doped carbon-encapsulated bimetallic selenides heterostructures for improved lithium-ion storage
6
作者 Ming Zhong Xue Guo +4 位作者 Yang Liu kun zhao Hui Peng Suijun Liu Xiaobo Zhang 《Chinese Chemical Letters》 2025年第5期728-732,共5页
In this work,the synthesis of uniform zeolitic imidazolate framework-coated Mo-glycerate spheres and their subsequent conversion into hierarchical architecture containing bimetallic selenides heterostructures and nitr... In this work,the synthesis of uniform zeolitic imidazolate framework-coated Mo-glycerate spheres and their subsequent conversion into hierarchical architecture containing bimetallic selenides heterostructures and nitrogen-doped carbon shell are reported.Selenization temperature plays a significant role in determining the phases,morphology,and lithium-ion storage performance of the composite.Notably,the optimal electrode demonstrates an ultrahigh reversible capacity of 1298.2 mAh/g after 100 cycles at 0.2 A/g and an outstanding rate capability with the capacity still maintained 505.7 mAh/g after 300 cycles at 1.0 A/g,surpassing the calculated theoretical capacity according to individual component and most of the reported MoSe@C-or ZnSe@C-based anodes.Furthermore,ex-situ X-ray diffraction patterns reveal the combined conversion and alloying reaction mechanisms of the composite. 展开更多
关键词 Zeolitic imidazolate framework Heterostructure Core-shell structure Electrode material Lithium-ion battery
原文传递
Airborne Investigation of Riming:Cloud and Precipitation Microphysics within a Weak Convective System in North China
7
作者 Xiangfeng HU Hao HUANG +9 位作者 Shaoyu HOU kun zhao Chuanfeng zhao Yinghui LU Jiefang YANG Rong ZHANG Delong zhao Weiguo LIU Dan ZHANG Haixia XIAO 《Advances in Atmospheric Sciences》 2025年第3期515-526,共12页
The process of riming significantly impacts the microphysical characteristics of clouds.This study uses aircraft and radar observation data in stratiform clouds with convection embedded that occurred in the central an... The process of riming significantly impacts the microphysical characteristics of clouds.This study uses aircraft and radar observation data in stratiform clouds with convection embedded that occurred in the central and southern regions of North China on 22 May 2017.The microphysical structural characteristics and processes near the embedded convection core and in the stratiform cloud are analyzed comparatively.Particular attention is given to the effect of riming on the microphysical properties near the upper boundary of the melting layer and to the factors influencing riming efficiency.The collaborative observations reveal that the particle size distributions observed near the convection core and in the stratiform region are close,while the particle properties like habit and riming degree are quite different.Above the melting layer,larger plate-like ice particles and supercooled water droplets(D>50μm)are more abundant near the convective core,leading to higher collision efficiencies between ice particles and supercooled water droplets.Larger fluctuation amplitudes of vertical airflow near the convective core also contribute to the increased riming activity and the formation of more heavily rimed particles,such as graupel.Furthermore,in situ measurements from airborne probes also revealed that above the melting layer,the riming process involves two stages:the mass of snow crystals grows as supercooled droplets merge internally without changing size,followed by external freezing that significantly enlarges the crystals. 展开更多
关键词 RIMING collision efficiency airflow fluctuation particle habit aircraft measurement
在线阅读 下载PDF
DJ-1 Activation Raf/ERK Pathways Promotes Autophagy Maturation of PC-12 Cells
8
作者 Xuezhong Li kun zhao +2 位作者 Yuansu Zhuang Xiaopeng Chen Yi Liu 《Advances in Parkinson's Disease》 2021年第1期1-13,共13页
Park 7 gene encodes a conserved protein called DJ-1 protein, which involves autophagy stress, but the mechanism is unclear. Therefore, it is necessary to explore the mechanism of DJ-1 regulation PC-12 autophagical str... Park 7 gene encodes a conserved protein called DJ-1 protein, which involves autophagy stress, but the mechanism is unclear. Therefore, it is necessary to explore the mechanism of DJ-1 regulation PC-12 autophagical stress. Using CRISPR/Cas9 technique to construct DJ-1 knockout PC-12 cell lines, we culture wild-type and DJ-1 knockout PC-12 cell lines, establish oxidative stress cell model by MPP+, and divide them into wild-type control group (WT), wild-type intervention group (WT + MPP+), DJ-1 knockout control group (KO) and DJ-1 knockout intervention group (KO + MPP+), and explore the role of DJ-1 in regulating neuronal autophagy stress by cell viability assay, immunofluorescence, confocal, western blotting and electron microscopy. The results show that the growth ability of DJ-1 knockout cells is inferior to that of normal cells, and DJ-1 knockout cells are more sensitive to oxidative stress and more vulnerable to damage than wild-type cells. Exposing to MPP+, DJ-1 proteins undergo oxidative responses at Cys-106 sites, while DJ-1 knockout PC-12 cells do not show similar responses. The wild-type PC-12 cells have the confocal in both anti-oxidant DJ-1 antibody and anti-C-Raf phosphorylation antibody. The activated DJ-1 induces the phosphorylation of C-Raf at Ser338 sites to activate directly C-Raf, and subsequently activates ERK1/2 signaling pathways to antagonize MPP+-induced neurotoxicity. Lack of DJ-1, oxidative stress can not promote C-Raf activation. Although the phosphorylation level of cell ERK is also increased, the increase of intranucleus pERK is not obvious. Wild type and DJ-1 knockout PC-12 cells can produce autophagical stress in the face of oxidative stress, but the proportion of autophagolysosomes produced in wild type PC-12 cells is larger than that in DJ-1 knockout cells. PD98059 can reduce autophagy stress in the state of oxidative stress in wild-type PC-12 cells, and the number of autophagolysosomes is similarly reduced, while sorafenib decreased slightly DJ-1 the autophagical stress, and the proportion of autophagolysosomes decreased more. Therefore, we can infer that activated DJ-1 directly phosphorylates C-Raf at Ser-338 sites, then activating C-Raf, subsequent activation of the MEK/ERK pathway. DJ-1 promotes autophagy maturation through the C-Raf/ERK pathway, thereby improving cell survival. 展开更多
关键词 DJ-1 C-RAF ERK Parkinson’s Disease Autophagical Maturation
暂未订购
Recent Progress in Dual-Polarization Radar Research and Applications in China 被引量:25
9
作者 kun zhao Hao HUANG +11 位作者 Mingjun WANG Wen-Chau LEE Gang CHEN Long WEN Jing WEN Guifu ZHANG Ming XUE Zhengwei YANG Liping LIU Chong WU Zhiqun HU Sheng CHEN 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2019年第9期961-974,共14页
Dual-polarization(dual-pol)radar can measure additional parameters that provide more microphysical information of precipitation systems than those provided by conventional Doppler radar.The dual-pol parameters have be... Dual-polarization(dual-pol)radar can measure additional parameters that provide more microphysical information of precipitation systems than those provided by conventional Doppler radar.The dual-pol parameters have been successfully utilized to investigate precipitation microphysics and improve radar quantitative precipitation estimation(QPE).The recent progress in dual-pol radar research and applications in China is summarized in four aspects.Firstly,the characteristics of several representative dual-pol radars are reviewed.Various approaches have been developed for radar data quality control,including calibration,attenuation correction,calculation of specific differential phase shift,and identification and removal of non-meteorological echoes.Using dual-pol radar measurements,the microphysical characteristics derived from raindrop size distribution retrieval,hydrometeor classification,and QPE is better understood in China.The limited number of studies in China that have sought to use dual-pol radar data to validate the microphysical parameterization and initialization of numerical models and assimilate dual-pol data into numerical models are summarized.The challenges of applying dual-pol data in numerical models and emerging technologies that may make significant impacts on the field of radar meteorology are discussed. 展开更多
关键词 DUAL-POLARIZATION RADAR QUANTITATIVE PRECIPITATION estimation PRECIPITATION MICROPHYSICS DROP size distribution numerical model
在线阅读 下载PDF
实体肿瘤消融的免疫效应及联合免疫治疗的临床研究现状 被引量:1
10
作者 赵堃 杨薇 《世界华人消化杂志》 CAS 2018年第23期1385-1389,共5页
随着医学的不断进步,消融作为一种实体肿瘤微创治疗技术,而大量应用于临床并获得较好疗效.肿瘤消融亦可对肿瘤微环境产生影响,从而为肿瘤特异性免疫识别提供一个良好的环境,而联合免疫治疗可进一步增强其抗肿瘤免疫效应,改善长期疗效.... 随着医学的不断进步,消融作为一种实体肿瘤微创治疗技术,而大量应用于临床并获得较好疗效.肿瘤消融亦可对肿瘤微环境产生影响,从而为肿瘤特异性免疫识别提供一个良好的环境,而联合免疫治疗可进一步增强其抗肿瘤免疫效应,改善长期疗效.关于肿瘤消融对机体免疫功能的影响以及免疫联合治疗近年来成为研究的热点,在临床病例中的应用逐渐增加,本文重点针对实体肿瘤消融的免疫效应及联合免疫治疗的临床研究文献进行总结,分析其临床应用现状. 展开更多
关键词 肿瘤消融 免疫治疗 免疫效应 肿瘤微环境
暂未订购
Seasonal Variations of Observed Raindrop Size Distribution in East China 被引量:24
11
作者 Long WEN kun zhao +1 位作者 Mengyao WANG Guifu ZHANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2019年第4期346-362,共17页
Seasonal variations of rainfall microphysics in East China are investigated using data from the observations of a twodimensional video disdrometer and a vertically pointing micro rain radar. The precipitation and rain... Seasonal variations of rainfall microphysics in East China are investigated using data from the observations of a twodimensional video disdrometer and a vertically pointing micro rain radar. The precipitation and rain drop size distribution(DSD) characteristics are revealed for different rain types and seasons. Summer rainfall is dominated by convective rain,while during the other seasons the contribution of stratiform rain to rainfall amount is equal to or even larger than that of convective rain. The mean mass-weighted diameter versus the generalized intercept parameter pairs of convective rain are plotted roughly around the "maritime" cluster, indicating a maritime nature of convective precipitation throughout the year in East China. The localized rainfall estimators, i.e., rainfall kinetic energy–rain rate, shape–slope, and radar reflectivity–rain rate relations are further derived. DSD variability is believed to be a major source of diversity of the aforementioned derived estimators. These newly derived relations would certainly improve the accuracy of rainfall kinetic energy estimation, DSD retrieval, and quantitative precipitation estimation in this specific region. 展开更多
关键词 RAINDROP size distribution precipitation MICROPHYSICS DISDROMETER SEASONAL variation East China
在线阅读 下载PDF
Interfacial Microstructure and Properties of a Vacuum Hot Roll-bonded Titanium-Stainless Steel Clad Plate with a Niobium Interlayer 被引量:21
12
作者 Zongan LUO Guanglei WANG +2 位作者 Guangming XIE Lipeng WANG kun zhao 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2013年第6期754-760,共7页
Vacuum hot roll bonding (VHRB) was used to bond pure titanium (Ti) plate to a 304 stainless steel (SS) plate with a niobium (Nb) interlayer, with the aim of producing a high-quality Ti-SS clad plate. The roll-... Vacuum hot roll bonding (VHRB) was used to bond pure titanium (Ti) plate to a 304 stainless steel (SS) plate with a niobium (Nb) interlayer, with the aim of producing a high-quality Ti-SS clad plate. The roll-bonding process was performed at different temperatures in the range of 850-1000℃, followed by characterization of microstructure and mechanical properties. The study demonstrates that the interfaces are free from cracks and discontinuities, and interdiffusion between the stainless steel and the titanium is effectively prevented by inserting a layer of pure Nb foil. No intermetallic reaction layer occurred at the Nb-Ti interface at any of the investigated temperatures. An intermetallic FeNb phase was formed at the Nb-SS interface when bonding was performed at 950 ℃ and above. The presence of the FeNb layer was confirmed by x-ray diffraction. The maximum shear strength of -396 MPa was obtained when bonding is carried out at 900 ℃. However, the formation of the FeNb layer at roll bonding temperature greater than 900 ℃ led to decrease in shear strength. Ductile fracture occurred through the Ti-Nb interface for roll-bonded temperatures of up to 900 ℃. On the other hand, at temperature of 950℃ and above, failure occurred through the Nb-SS interface, with brittle fracture characteristics. 展开更多
关键词 Vacuum hot roll bonding (VHRB) Clad plate INTERLAYER Interface SHEARSTRENGTH Intermetallic compound
原文传递
Circular RNAs and human glioma 被引量:16
13
作者 Jinglei Liu kun zhao +1 位作者 Nunu Huang Nu Zhang 《Cancer Biology & Medicine》 SCIE CAS CSCD 2019年第1期11-23,共13页
As a newly discovered type of RNA, circular RNAs(circRNAs) are widespread throughout the eukaryotic genome. The expression of circRNAs is regulated by both cis-elements and trans-factors, and the expression pattern of... As a newly discovered type of RNA, circular RNAs(circRNAs) are widespread throughout the eukaryotic genome. The expression of circRNAs is regulated by both cis-elements and trans-factors, and the expression pattern of circRNAs is cell type-and diseasespecific. Similar to other types of non-coding RNAs, functions of circRNAs are also versatile. CircRNAs have been reported previously to function as microRNA(miRNA) sponges, protein sponges, coding RNAs or scaffolds for protein complexes.Recently, several circRNAs have been reported to play important roles in human malignancies, including glioma. Here, we reviewed several reports related to circRNAs and glioma, as well as the potential diagnostic and therapeutic applications of circRNAs in brain cancer. In general, some circRNAs, such as circSMARCA5 and circCFH, are found to be expressed in a gliomaspecific pattern, these circRNAs may be used as tumor biomarkers. In addition, some circRNAs have been found to play oncogenic roles in glioma(e.g., circNFIX and circNT5E), whereas others have been reported to function as tumor suppressors(e.g.,circFBXW7 and circSHPRH). Furthermore, circRNA is a good tool for protein expression because of its higher stability compared to linear RNAs. Thus, circRNAs may also be an ideal choice for gene/protein delivery in future brain cancer therapies. There are some challenges in circRNA research in glioma and other diseases. Research related to circRNAs in glioma is comparatively new and many mysteries remain to be solved. 展开更多
关键词 CIRCULAR RNA GLIOMA MIRNA SPONGE translation protein SCAFFOLD MIRNA target
暂未订购
On the Key Dynamical Processes Supporting the 21.7 Zhengzhou Record-breaking Hourly Rainfall in China 被引量:24
14
作者 Peng WEI Xin XU +6 位作者 Ming XUE Chenyue ZHANG Yuan WANG kun zhao Ang ZHOU Shushi ZHANG Kefeng ZHU 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2023年第3期337-349,共13页
An extremely heavy rainfall event occurred in Zhengzhou,China,on 20 July 2021 and produced an hourly rainfall rate of 201.9 mm,which broke the station record for China's Mainland.Based on radar observations and a ... An extremely heavy rainfall event occurred in Zhengzhou,China,on 20 July 2021 and produced an hourly rainfall rate of 201.9 mm,which broke the station record for China's Mainland.Based on radar observations and a convection-permitting simulation using the WRF-ARW model,this paper investigates the multiscale processes,especially those at the mesoscale,that support the extreme observed hourly rainfall.Results show that the extreme rainfall occurred in an environment characteristic of warm-sector heavy rainfall,with abundant warm moist air transported from the ocean by an abnormally northward-displaced western Pacific subtropical high and Typhoon In-Fa(2021).However,rather than through back building and echo training of convective cells often found in warm-sector heavy rainfall events,this extreme hourly rainfall event was caused by a single,quasi-stationary storm in Zhengzhou.Scale separation analysis reveals that the extreme-rainproducing storm was supported and maintained by the dynamic lifting of low-level converging flows from the north,south,and east of the storm.The low-level northerly flow originated from a mesoscale barrier jet on the eastern slope of the Taihang Mountain due to terrain blocking of large-scale easterly flows,which reached an overall balance with the southerly winds in association with a low-level meso-β-scale vortex located to the west of Zhengzhou.The large-scale easterly inflows that fed the deep convection via transport of thermodynamically unstable air into the storm prevented the eastward propagation of the weak,shallow cold pool.As a result,the convective storm was nearly stationary over Zhengzhou,resulting in record-breaking hourly precipitation. 展开更多
关键词 extreme rainfall multiscale processes OROGRAPHY barrier jet low-level mesoscale vortex
在线阅读 下载PDF
Incidence and in-hospital mortality of acute aortic dissection in China: analysis of China Health Insurance Research (CHIRA) Data 2011 被引量:61
15
作者 Lei XIA Jing-Hu LI +1 位作者 kun zhao Hai-Yun WU 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2015年第5期502-506,共5页
Objective Acute aortic dissection (AAD) is a catastrophic event with high early mortality rate, but to date, no data on the incidence of AAD in China's Mainland is available. This study aimed to estimate the inc... Objective Acute aortic dissection (AAD) is a catastrophic event with high early mortality rate, but to date, no data on the incidence of AAD in China's Mainland is available. This study aimed to estimate the incidence of AAD in China and characterize the clinical profile, management and in-hospital outcomes of this vascular event. Methods We used the China Health Insurance Research Data (the CHIRA Data) 2011 which comprises all inpatient hospital records (300,886) during the period of Jan. 1st 2011 to Dec. 31 2011 of 3,335,000 randomly sampled beneficiaries (1,718,500 men and 1,616,500 women) from 25 cities and counties in different economic-geographic regions of China's Mainland. Patients with acute aortic dissection were identified according to International Classification of Disease 10m Revision (ICD-10) of I71.0, The estimated incidence of AAD was calculated using the equation: estimated incidence = 2.0 × (40% × hospital admission rate) + 60% × hospital admission rate. Results The hospital admission rate was 2.0/100,000 (65/3,325,000, 95% CI: 1.2-2.8). The estimated annual incidence of AAD was 2.8/100,000 (95% CI: 1.9-3.6) and was higher in male than in female (3.7 vs. 1.5, P 〈 0.001). The mean age was 58.9 ± 13.4 years. During the mean hospital stay of 23 ±6 days, the overall in-hospital mortality was 13.9% (9/65). Conclusions Our study showed relatively lower but not negligible incidence and in-hospital mortality of AAD in the mainland of China. The mean age of patients with AAD in Chinese was younger than that reported by researches from west countries, while the male to female incidence ratio is similar to those reported by other studies. 展开更多
关键词 Acute aortic dissection China health insurance research Incidence rate
在线阅读 下载PDF
Role of the Nocturnal Low-level Jet in the Formation of the Morning Precipitation Peak over the Dabie Mountains 被引量:16
16
作者 Peiling FU Kefeng ZHU +2 位作者 kun zhao Bowen ZHOU Ming XUE 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2019年第1期15-28,共14页
The diurnal variation of precipitation over the Dabie Mountains(DBM) in eastern China during the 2013 mei-yu season is investigated with forecasts of a regional convection-permitting model. Simulated precipitation is ... The diurnal variation of precipitation over the Dabie Mountains(DBM) in eastern China during the 2013 mei-yu season is investigated with forecasts of a regional convection-permitting model. Simulated precipitation is verified against surface rain-gauge observations. The observed morning precipitation peak on the windward(relative to the prevailing synoptic-scale wind) side of the DBM is reproduced with good spatial and temporal accuracy. The interaction between the DBM and a nocturnal boundary layer low-level jet(BLJ) due to the inertial oscillation mechanism is shown to be responsible for this precipitation peak. The BLJ is aligned with the lower-level southwesterly synoptic-scale flow that carries abundant moisture.The BLJ core is established at around 0200 LST upwind of the mountains. It moves towards the DBM and reaches maximum intensity at about 70 km ahead of the mountains. When the BLJ impinges upon the windward side of the DBM in the early morning, mechanical lifting of moist air leads to condensation and subsequent precipitation. 展开更多
关键词 nocturnal boundary layer low-level jet diurnal variation PRECIPITATION Dabie Mountains meiyu season
在线阅读 下载PDF
Development of an indirect competitive ELISA for simultaneous detection of enrofloxacin and ciprofloxacin 被引量:15
17
作者 Hai-tang ZHANG Jin-qing JIANG +5 位作者 Zi-liang WANG Xin-yao CHANG Xing-you LIU San-hu WANG kun zhao Jin-shan CHEN 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2011年第11期884-891,共8页
Modified 1-ethyl-3-(3-dimethylaminopropy) carbodiimide(EDC) method was employed to synthesize the artificial antigen of enrofloxacin(ENR),and New Zealand rabbits were used to produce anti-ENR polyclonal antibody(pAb).... Modified 1-ethyl-3-(3-dimethylaminopropy) carbodiimide(EDC) method was employed to synthesize the artificial antigen of enrofloxacin(ENR),and New Zealand rabbits were used to produce anti-ENR polyclonal antibody(pAb).Based on the checkerboard titration,an indirect competitive enzyme-linked immunosorbent assay(ELISA) standard curve was established.This assay was sensitive and had a linear range from 0.6 to 148.0 μg/kg(R2=0.9567),with the half maximal inhibitory concentration(IC50) and limit of detection(LOD) values of 9.4 μg/kg and 0.2 μg/kg,respectively.Of all the competitive analogues,the produced pAb exhibited a high cross-reactivity to ciprofloxacin(CIP)(87%),the main metabolite of ENR in tissues.After optimization,the matrix effects can be ignored using a 10-fold dilution in beef and 20-fold dilution in pork.The overall recoveries and coefficients of variation(CVs) were in the ranges of 86%-109% and 6.8%-13.1%,respectively.It can be concluded that the established ELISA method is suitable for simultaneous detection of ENR and CIP in animal tissues. 展开更多
关键词 ENROFLOXACIN CIPROFLOXACIN Indirect competitive ELISA Animal tissues
原文传递
Assimilating Surface Observations in a Four-Dimensional Variational Doppler Radar Data Assimilation System to Improve the Analysis and Forecast of a Squall Line Case 被引量:8
18
作者 Xingchao CHEN kun zhao +2 位作者 Juanzhen SUN Bowen ZHOU Wen-Chau LEE 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2016年第10期1106-1119,共14页
This paper examines how assimilating surface observations can improve the analysis and forecast ability of a four- dimensional Variational Doppler Radar Analysis System (VDRAS). Observed surface temperature and wind... This paper examines how assimilating surface observations can improve the analysis and forecast ability of a four- dimensional Variational Doppler Radar Analysis System (VDRAS). Observed surface temperature and winds are assimilated together with radar radial velocity and reflectivity into a convection-permitting model using the VDRAS four-dimensional variational (4DVAR) data assimilation system. A squall-line case observed during a field campaign is selected to investigate the performance of the technique. A single observation experiment shows that assimilating surface observations can influence the analyzed fields in both the horizontal and vertical directions. The surface-based cold pool, divergence and gust front of the squall line are all strengthened through the assimilation of the single surface observation. Three experiments--assimilating radar data only, assimilating radar data with surface data blended in a mesoscale background, and assimilating both radar and surface observations with a 4DVAR cost function--are conducted to examine the impact of the surface data assimilation. Independent surface and wind profiler observations are used for verification. The result shows that the analysis and forecast are improved when surface observations are assimilated in addition to radar observations. It is also shown that the additional surface data can help improve the analysis and forecast at low levels. Surface and low-level features of the squall line-- including the surface warm inflow, cold pool, gust front, and low-level wind--are much closer to the observations after assimilating the surface data in VDRAS. 展开更多
关键词 VDRAS 4-D data assimilation radar data surface data squall line
在线阅读 下载PDF
Recent Significant Tornadoes in China 被引量:21
19
作者 Ming XUE kun zhao +2 位作者 Mingjung WANG zhaohui LI Yongguang ZHENG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2016年第11期1209-1217,共9页
1.Introduction Compared with the United States,whose annual number of tornadoes can exceed 1000,the average number of tornadoes per year in China over the past half a century is estimated to be fewer than 100(Fan and... 1.Introduction Compared with the United States,whose annual number of tornadoes can exceed 1000,the average number of tornadoes per year in China over the past half a century is estimated to be fewer than 100(Fan and Yu,2015),even though both countries are located in a similar latitudinal zone of the Northern Hemisphere. 展开更多
关键词 LST Recent Significant Tornadoes in China
在线阅读 下载PDF
Isothermal oxidation behavior of TiAl intermetallics with different oxygen contents 被引量:8
20
作者 kun zhao Si-hui OUYANG +4 位作者 Yong LIU Bin LIU Xiao-peng LIANG Hui-zhong LI Yu WANG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2019年第3期526-533,共8页
Isothermal oxidation behaviors of Ti-45Al-2Fe-2Mo-1Cr intermetallics with different oxygen contents were studied under the condition of 950 °C, 100 h in air, and the oxidation kinetic parameters were also evaluat... Isothermal oxidation behaviors of Ti-45Al-2Fe-2Mo-1Cr intermetallics with different oxygen contents were studied under the condition of 950 °C, 100 h in air, and the oxidation kinetic parameters were also evaluated. The results show that the oxidation resistance of the TiAl intermetallics is negatively related to the oxygen content, and both the mass gain and thickness of oxide scale increase with the oxygen content. The sub-surface microstructure of the oxide scales varies with the oxygen content. Z phase is observed in the sub-surface area of the low-oxygen-content alloy, while the τ2(Al2FeTi) phase is found in the medium-oxygen-content and the high-oxygen-content alloys. The deterioration of oxidation resistance is due to the enhanced internal oxidation with the increase of oxygen content. It is possible to improve the oxidation resistance by controlling the oxygen content. 展开更多
关键词 TiAl intermetallics oxygen content isothermal oxidation oxidation kinetic
在线阅读 下载PDF
上一页 1 2 8 下一页 到第
使用帮助 返回顶部