检索结果-南通市图书馆

Can Current AGCMs Reproduce Historical Changes in the Atmospheric Diabatic Heating over the Tibetan Plateau?

在线全文

学校读者我要写书评

暂无评论

Atmospheric and Oceanic Science Letters 2014年第2期7卷 143-148页

作者： DUAN An-Min xiao zhi-xiang HU Jun DUAN An-Min xiao zhi-xiang HU Jun State Key Laboratory of Numerical Modelling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China University of Chinese Academy of Sciences Beijing 100049 China Key Laboratory of Meteorological Disaster Nanjing University of Information Science and Technology Ministry of Education Nanjing 210044 China

Recent studies have demonstrated a persistent decreasing trend in the spring sensible heat(SH) source over the Tibetan Plateau(TP) during the past three decades. By comparing simulations from nine state-of-the-art atmospheric general circulation models(AGCMs) driven by historical forcing fields with both observational data and five reanalysis datasets, the authors found that the AGCMs are unable to reproduce the change in the SH flux over the TP. This deficiency arises because the observed decreasing trend in SH flux depends primarily on the change in surface wind speed according to the bulk formula, whereas in the models it is also influenced largely by changes in the land-air temperature difference related to the systematic cold bias. In addition, an obvious discrepancy exists in other aspects of the diabatic heating simulated by the models, suggesting that a significant improvement is required in the physical schemes associated with land surface processes and diabatic heating over the complicated topography.

关键词： Tibetan Plateau AGCMs diabatic heating trend

Uncertainties in Quantitatively Estimating the Atmospheric Heat Source over the Tibetan Plateau

在线全文

学校读者我要写书评

暂无评论

Atmospheric and Oceanic Science Letters 2014年第1期7卷 28-33页

作者： DUAN An-Min WANG Mei-Rong xiao zhi-xiang State Key Laboratory of Numerical Modeling for Atmospheric Science and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of Sciences Nanjing University of Information Science&Technology University of Chinese Academy of Sciences

As a huge,intense,and elevated atmospheric heat source(AHS) approaching the mid-troposphere in spring and summer,the Tibetan Plateau(TP) thermal forcing is perceived as an important factor contributing to the formation and variation of the Asian summer *** numerous studies devoted to determine the strength and change of the thermal forcing of the TP on the basis of various data sources and methods,uncertainties remain in quantitative estimation of the AHS and will persist for the following reasons:(1) Routine meteorological stations cover only limited regions and show remarkable spatial inhomogeneity with most distributed in the central and eastern ***,all of these stations are situated at an altitude below 5000 ***,the large area above that elevation is not included in the data.(2) Direct observations on heat fluxes do not exist at most stations,and the sensible heat flux(SHF) is calculated by the bulk formula,in which the drag coefficient for heat is often treated as an empirical constant without considering atmospheric stability and thermal roughness length.(3) Radiation flux derived by satellite remote sensing shows a large discrepancy in the algorithm in data inversion and complex terrain.(4) In reanalysis data,besides the rare observational records employed for data assimilation,model bias in physical processes induces visible errors in producing the diabatic heating fields.

关键词： Tibetan Plateau atmospheric heat source data bias uncertainties

Multiparameter magnetic resonance imaging-based radiomics model for the prediction of rectal cancer metachronous liver metastasis

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastrointestinal Oncology 2025年第1期17卷 62-72页

作者： zhi-Da Long xiao Yu zhi-xiang Xing Rui Wang Department of Hepatobiliary and Pancreaticosplenic Surgery Jingzhou Hospital Affiliated to Yangtze UniversityJingzhou 434100Hubei ProvinceChina

BACKGROUND The liver,as the main target organ for hematogenous metastasis of colorectal cancer,early and accurate prediction of liver metastasis is crucial for the diagnosis and treatment of ***,this study aims to investigate the application value of a combined machine learning(ML)based model based on the multiparameter magnetic resonance imaging for prediction of rectal metachronous liver metastasis(MLM).AIM To investigate the efficacy of radiomics based on multiparametric magnetic resonance imaging images of preoperative first diagnosed rectal cancer in predicting MLM from rectal *** We retrospectively analyzed 301 patients with rectal cancer confirmed by surgical pathology at Jingzhou Central Hospital from January 2017 to December *** participants were randomly assigned to the training or validation queue in a 7:3 *** first apply generalized linear regression model(GLRM)and random forest model(RFM)algorithm to construct an MLM prediction model in the training queue,and evaluate the discriminative power of the MLM prediction model using area under curve(AUC)and decision curve analysis(DCA).Then,the robustness and generalizability of the MLM prediction model were evaluated based on the internal validation set between the validation queue *** Among the 301 patients included in the study,16.28%were ultimately diagnosed with MLM through pathological *** analysis showed that carcinoembryonic antigen,and magnetic resonance imaging radiomics were independent predictors of ***,the GLRM prediction model was developed with a comprehensive nomogram to achieve satisfactory *** prediction performance of GLRM in the training and validation queue was 0.765[95%confidence interval(CI):0.710-0.820]and 0.767(95%CI:0.712-0.822),*** with GLRM,RFM achieved superior performance with AUC of 0.919(95%CI:0.868-0.970)and 0.901(95%CI:0.850-0.952)in the training and validation queue,respect

关键词： Rectal cancer Metachronous liver metastases Magnetic resonance imaging Radiomics Machine learning

An Ionic Liquid-assisted Hydrothermal Synthesis of Ce02 Nanorods

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

无机材料学报 2015年第3期30卷 325-329页

作者： CHEN Ting JIANG Wei-Hui ZHANG xiao-Jun XIE zhi-xiang LIU Jian-Min JIANG Wan School of Material Science and Engineering Jingdezhen Ceramic Institute Jingdezhen 333001 China

CeO2 nanorods were synthesized by a hydrothermal method at 160℃ from CeC16-6H20 and NH3.H20 in the presence of an ionic liquid 1-butyl-3-methyl-imidazolium chloride （[Bmim]C1）. The phase and morphology of the result- ing products were characterized by X-ray diffraction （XRD） and high-resolution transmission electron microscopy （HRTEM）, respectively. The results reveal that morphology of CeO2 prepared in the presence of the ionic liquid is nano- rod while it changes to irregular nanoparticle without ionic liquid. The resulting nanorods are about 13-25 nm in diameter and 200-500 nm in length. With the increase of ionic concentration, nanorods were disappeared gradually and nanoparticles were obtained. Moreover, increasing the hydrothermal temperature to 180℃, nanospheres at size of 19-24 nm could be synthesized by aggregation of-2 nm nanocrystals.

关键词： cerium oxide soft template hydrothermal treatment ionic liquid nanorod

风能涡轮引信电机吹风装置的轴对称收缩段设计研究

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

机械科学与技术 2001年第3期20卷 397-398页

作者：陈志敏肖志祥西北工业大学飞机系西安710072

在文献 [1]计算吹风装置收缩段流场方法的基础上 ,提出了轴对称的设计方法 ,用该方法研究了几种收缩曲线对收缩段内流场的影响 ,并从中选择一条能满足吹风装置设计要求的曲线作为型面曲线。计算结果表明

关键词：收缩段数值模拟流场吹风装置风轮涡轮风洞试验

Impact of triglyceride-glucose index on the long-term prognosis of advanced gastric cancer patients receiving immunotherapy combined with chemotherapy

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2025年第5期31卷 68-83页

作者： zhi-Yuan Yao xiao Ma Yong-Zheng Cui Jie Liu Zheng-xiang Han Jun Song Department of Oncology The Affiliated Hospital of Xuzhou Medical CollegeXuzhou 221000Jiangsu ProvinceChina Department of Oncology The Second Affiliated Hospital of Nanjing Medical UniversityNanjing 210008Jiangsu ProvinceChina Department of Radiotherapy The Affiliated Hospital of Xuzhou Medical CollegeXuzhou 221000Jiangsu ProvinceChina Department of Gastrointestinal Surgery The Affiliated Hospital of Xuzhou Medical CollegeXuzhou 221000Jiangsu ProvinceChina

BACKGROUND Gastric cancer(GC)is the fifth most common malignancy and the third leading cause of death *** advancements in immunotherapies,patient prognosis remains poor,necessitating the identification of key prognostic factors to optimize the treatment *** resistance,as indicated by the triglyceride glucose(TyG)index,is increasingly recognized for its impact on cancer progression and immune modulation,and its potential role in GC prognosis is of particular *** To investigate whether the TyG index,a surrogate marker of insulin resistance,can predict the prognosis of patients with advanced GC receiving immunotherapy combined with *** This retrospective study included 300 patients with advanced GC who received sintilimab combined with *** patients were categorized into two groups according to high or low TyG index,and independent prognostic factors for overall survival(OS)were determined using Cox proportional hazards regression analysis,which led to the development of a nomogram *** Of the included patients,136 had a high TyG index and 164 had a low TyG *** median progression-free survival of the high TyG index group was significantly longer than that of the low TyG index ***,the median OS of the high TyG index group was significantly longer than that of the low TyG index *** ob-jective response and disease control rates in the two groups were 18.38%vs 9.15%and 58.82%vs 46.95%,*** significant difference was noted in the incidence of adverse reactions at any level between the two groups(P>0.05).In multivariate analysis,the Eastern Cooperative Oncology Group score,programmed cell death ligand 1 expression,and TyG index acted as independent prognostic factors for *** these factors,the hazard ratio of the TyG index was 0.36(95%confidence interval:0.36-0.55,P<0.001),and the nomogram model re-emphasized its importance as the main predictor of patient prognos

关键词： Triglyceride glucose index Gastric cancer Sintilimab Prognostic model Efficacy Safety

Thermo-Hydraulic Performances of Microchannel Heat Sinks with Different Types of Perforated Rectangular Blocks

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Fluid Dynamics & Materials Processing 2025年第1期21卷 87-105页

作者： Heng Zhao Honghua Ma Hui Liu xiang Yan Huaqing Yu Yongjun xiao xiao xiao School of Physics and Electronic Information Engineering Hubei Engineering UniversityXiaogan432000China Wuhan National Laboratory for Optoelectronics(WNLO) Huazhong University of Science and TechnologyWuhan430074China Institute of Engineering and Technology Hubei University of Science and TechnologyXianning437100China

The behavior of single-phase flow and conjugate heat transfer in micro-channel heat sinks(MCHS)subjected to auniform heat flux is investigated by means of numerical *** geometrical configurations areexamined,particularly,the combinations of rectangular solid and perforated blocks,used to create a disturbancein the *** analysis focuses on several key aspects and related metrics,including the temperature distribution,the mean Fanning friction factor,the pressure drop,the Nusselt number,and the overall heat transfer coefficientacross a range of Reynolds numbers(80–870).It is shown that the introduction of such blocks significantlyenhances the heat transfer performances of the MCHS compared to the straight-through flow ***,a case is found where the Nusselt number increases by 2.3 times relative to the reference *** integrationof perforated blocks facilitates the generation of vorticity within the channel,promoting the mixing of coldand hot ***,MCHS incorporating perforated rectangular blocks exhibit more pronounced heat transferbenefits at Reynolds numbers smaller than 400.

关键词： Micro-channel heat sink(MCHS) perforated rectangular blocks thermal performance convection heat transfer

Barrier Vibration Isolation to Work-Place Vibration and Its Influence on Uneven Subsidence of Pillar Foundation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Wuhan University Journal of Natural Sciences 2002年第4期7卷 445-450页

作者： Huang Ju-hua xiao xiang-zhi Dong xiang-huai Fu Ming-fu He Cheng-hong Yang Guo-tai Huazhong University of Science and Technology

Aiming at practice, the wave propagation in soil has been comprehensively studied on the basis of FEM analyzing model being established. An investigation has also been performed on how to solve the problems of simulating transient vibration in actual foundation with FEM, and the result of calculating to the real transient vibration of actual foundation with FEM software ANSYS agrees with that of measuring. The vibration variation in the ground and the uneven subsidence of the factory houses’ pillars, with and without barrier vibration isolation, are calculated by employing FEM. The results show that proper barrier isolation can diminish the ground vibration displacement but likely to magnify the dynamic stress and vibration frequency within a certain region, which would aggravate the uneven subsidence of the factory house pillars.

关键词： FEM vibration isolation by barrier pillar foundation subsidence

在线全文

学校读者我要写书评

暂无评论

导弹表面流动分离与后体减阻设计

宇航学报 2009年第5期30卷 1770-1776,1807页

作者：肖志祥周克克符松清华大学航天航空学院北京100084

采用基于压缩性修正的两方程K-ω-WD+模式数值求解雷诺平均的Navier-Stokes方程组,数值模拟导弹跨、超声速流动(含底部),研究导弹后体多台阶、环向凹槽等典型分离流动的被动减阻措施对阻力缩减的影响。与分离导致阻力增加的传统观点不同... 详细信息

采用基于压缩性修正的两方程K-ω-WD+模式数值求解雷诺平均的Navier-Stokes方程组,数值模拟导弹跨、超声速流动(含底部),研究导弹后体多台阶、环向凹槽等典型分离流动的被动减阻措施对阻力缩减的影响。与分离导致阻力增加的传统观点不同,通过分析计算结果发现多台阶能有效降低摩阻及底部阻力;环向凹槽则有利于降低摩擦阻力,底阻减小不明显;组合外形未必能获得较基准外形更多的阻力缩减,欲获得更多的阻力缩减,仍须开展更深入细致的工作。

关键词：多台阶环向凹槽流动分离与减阻