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数字化基础设施建设与旅游经济增长——基于中介效应与调节效应的机制检验

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经济问题 2022年第7期 112-121页

作者：冀雁龙李金叶赵华新疆大学经济与管理学院新疆乌鲁木齐830046 新疆大学新疆宏观经济高质量发展研究中心新疆乌鲁木齐830046 山西大同大学云冈学学院山西大同037009

在系统揭示数字化基础设施建设对旅游经济增长作用机理的基础上,基于2011—2019年的省级面板数据,构建数字化基础设施建设水平评价指标,运用面板固定效应模型、中介效应模型和调节效应模型进行实证检验。研究发现:数字化基础设施建设显... 详细信息

在系统揭示数字化基础设施建设对旅游经济增长作用机理的基础上,基于2011—2019年的省级面板数据,构建数字化基础设施建设水平评价指标,运用面板固定效应模型、中介效应模型和调节效应模型进行实证检验。研究发现:数字化基础设施建设显著促进旅游经济增长,内生性与稳健性检验均支持这一结论。进一步研究发现:数字化基础设施建设对国内旅游经济增长影响更大。分地区异质性检验显示:在东部地区、在长江经济带,数字化基础设施建设对旅游经济增长的促进作用更为明显。机制检验表明:数字化基础设施建设具有地区带动效应,主要通过经济发展、技术创新发挥部分中介作用;数字化基础设施建设还具有产业驱动效应,能够正向影响旅游产业效率以及旅游产业结构对旅游经济增长的作用效果。

关键词：数字化基础设施建设旅游经济增长中介效应调节效应

TRANSFORMING GROWTH FACTOR-β AND FIBROBLAST GROWTH FACTOR INDUCE LENS EPITHELIAL EXPLANT METAPLASIA:IMPLICATIONS FOR THE FORMATION OF SUBCAPSULAR OPACIFICATION

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Chinese Medical Sciences Journal 1998年第2期13卷 89-95页

作者：刘颉叶俊杰 DepartmentofPaediatrics ChineseUniversityofHongKongShatinNTHongKong DepartmentofOphthalmology PekingUnionMedicalCollegeHospitalCAMS＆PUMCBeijing100730

Objective. This study was to investigate the effects of transforming growth factor-β(TGFβ) and fi- broblast growth factor (FGF) in the subcapsular opacification formation of the lens. Methods. Lens epithelial explants from 10-day-old rats were cultured with TGFβ1 or TGFβ2 in the presence of FGF for 5 days, then were examined by light and electron microscopy, and by immunolocal- ization of smooth muscle(α-sm) actin and type I collagen. Results. In TGFβ/FGF-treated explants,extensive proliferation occured, with formation of spindle and star-shaped cells. These cells showed ultrastructure and biochemical features of fibroblast or myofibroblast. Prominent Golgi apparatus and rough endoplaic reticulum were observed in some cells. Intracellular micro- filaments with cytoplasmic dense babies and membrane associated dense bodies, features of smooth muscle cells, were also observed. Some cells showed reactivity to -sin actin antibody. TGFβ/FGF-treated ex- plants were strongly stained with type I collagen antibody. Condusion. In the presence of FGF, TGFβ1 and TGFβ2 induced lens epithelial cell (LEC ) proliferation and transformation into fibroblast or myofibroblast-like cells, with producing of abundant collagen matrix in the explants. The changes are similar to the metaplasia that occurrs in subcapsular opacification of the lens. The findings suggest that TGFβ and FGF plays a role in the pathogenesis of subcapsular opacification of the lens.

关键词：转化生长因子-β 纤维原细胞生长因子上皮组织囊下浑浊晶状体动物实验

Comparison of detrital mineral compositions between stream sediments of the Yangtze River (Changjiang) and the yellow River (Huanghe) and their provenance implication

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China Geology 2019年第2期2卷 169-178页

作者： Zhong-bo Wang Ri-hui Li Shou-ye Yang Feng-long Bai Xi Mei Jian Zhang Kai Lu Qingdao Institute of Marine Geology China Geological SurveyMinisitry of Natural ResourcesQingdao 266071China Laboratory for Marine Mineral Resources Qingdao National Laboratory for Marine Science and TechnologyQingdao 266071China State Key Laboratory of Marine Geology Tongji UniversityShanghai 200092China

A comparative comparative study on the detrital mineral composition of stream sediments of the Yangtze River (Changjiang) and yellow River (Huanghe) shows that, light minerals of the Yangtze River basin were mainly quartz, feldspar, and detritus, the compositional characteristics of light minerals differed among tributaries, the main stream had a generally higher maturity index than tributaries;heavy mineral content tended to decrease progressively from the upper stream to lower stream of the Yangtze River, the primary assemblage was magnetite-hornblende-augite-garnet-epidote, and diagnostic minerals of different river basins were capable of indicating the nature and distribution of the source rock. Detrital mineral assemblages in sediments of tributaries and the main stream of the yellow River were basically similar, Primary heavy mineral assemblage was opaque mineral-garnet-epidote-carbonate mineral and alteration mineral. Variations in the contents of garnet, opaque mineral, and hornblende mainly reflected the degree of sedimentary differentiation in suspended sediment and the hydrodynamic intensity of a drainage system. The heavy mineral differentiation index F revealed sedimentary differentiation of diagnostic detrital mineral composition due to changes in regional hydrodynamic intensity and can serve as an indicator for studying the dynamic sedimentary environment of a single-provenance river and the degree of sedimentary differentiation of its detrital minerals. Changes in detrital mineral content of the yellow River was not completely controlled by provenance but reflected gravity sorting of the detrital mineral due to variations in the ephemeral river hydrodynamic intensity and sedimentary environment, however the index changing of Yangtze River were mainly influenced by the complex sediment sources. Therefore caution must be exercised in using the detrital mineral composition of marginal sea to determine the contribution of the Yangtze River and yellow Riv

关键词： Yangtze River yellow River Sediment Detrital mineral Provenance implication

敲低长链非编码RNA H19(lncRNA H19)促进人结肠细胞自噬抑制脂多糖诱导的凋亡

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细胞与分子免疫学杂志 2024年第6期40卷 538-543页

作者：陈瑞张燕飞王军华陶明华冉剑涛杨杰王孜潘丽韩起西藏藏医药大学藏医药研究所西藏拉萨850007 西藏军区总医院核医学科西藏拉萨850000

目的探讨lncRNA H19在溃疡性结肠炎(UC)患者中的表达水平及其在UC中的作用。方法收集西藏军区总医院25名UC患者和25名健康体检者的结肠黏膜标本及血清标本,采用荧光定量PCR检测lncRNA H19表达水平,并对血清标本进行受试者工作特征(ROC... 详细信息

目的探讨lncRNA H19在溃疡性结肠炎(UC)患者中的表达水平及其在UC中的作用。方法收集西藏军区总医院25名UC患者和25名健康体检者的结肠黏膜标本及血清标本,采用荧光定量PCR检测lncRNA H19表达水平,并对血清标本进行受试者工作特征(ROC)曲线分析。采用脂多糖(LPS)处理建立体外HT29结肠细胞炎性模型,并采用荧光定量PCR检测lncRNA H19在结肠细胞的表达。通过慢病毒技术构建lncRNA H19低表达的HT29细胞株,噻唑蓝(MTT)法检测HT29细胞存活率,流式细胞术检测细胞凋亡率,Western blot法检测凋亡和自噬蛋白表达情况。采用自噬激动剂雷帕霉素处理后,MTT法观察对HT29细胞存活的影响。结果 lncRNA H19在UC患者结肠黏膜组织和血清中高表达,ROC曲线下面积为0.786。LPS刺激后,HT29细胞lncRNA H19表达显著升高,并与刺激时间正相关。敲低lncRNA H19可促进HT29细胞存活并抑制细胞凋亡,促进细胞自噬水平增加;雷帕霉素处理后,细胞存活率明显升高。结论敲低lncRNA H19促进结肠细胞自噬抑制LPS诱导的结肠细胞凋亡并促进其存活。

关键词：溃疡性结肠炎(UC) lncRNA H19 自噬凋亡

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Structure adapting of bulk FeS_(2) micron particles and the corresponding anode for high performance sodium-ion batteries

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Journal of Materiomics 2022年第6期8卷 1278-1286页

作者： Yong Li Daixin ye Wen Liu Rui Guo Haijuan Pei Hongbing Zhao Jiujun Zhang Jingying Xie Jilie Kong State Key Laboratory of Space Power-Sources Technology Shanghai Institute of Space Power SourcesShanghai200245China Department of Chemistry Fudan UniversityShanghai200433China Institute for Sustainable Energy/College of Sciences Shanghai UniversityShanghai200444China

The practical application of Pyrite iron disulfide (FeS_(2)) as anode material of sodium-ion battery is limitedby its low electronic conductivity, large volume changes during charge/discharge. To overcome thesechallenges, a novel structure design single-walled carbon nanotubes (SWCNTs) composited polyaniline(PANI)-wrapped FeS_(2) (FeS_(2)-PANI-SWCNTs) electrodes are successfully achieved in this work. PANI canprotect the FeS_(2) particles from collapse and offer a protective layer to relive the polysulfides shuttlingeffect, and also promote the electron and Naþ diffusion during the chemical conversion process. Underthe dual protection of PANI and SWCNTs, the FeS_(2)-PANI-SWCNTs film electrode demonstrates a goodstructural integrity, which accounts for the excellent rate capability and long cycling performance. Inaddition, the PANI coating and SWCNT network in the fabricated electrode can synergistically anchorpolysulfides and therefore strongly suppress shuttle effect during the chargeedischarge processes,resulting in less capacity loss. The anode with a loading 3.2 mg cm 2 of FeS_(2) coated with PANI exhibitsthe initial coulombic efficiency of 81.5% and delivers a specific capacity of 625.8 mAh g^(-1) after 100 cyclesat 200 mA g^(-1). High flexible and binder-free FeS_(2)-PANI-SWCNTs film anode demonstrates a reversiblecapacity of 537 mAh g^(-1) after 550 cycles at 1 A g^(-1). This research may offer an efficient method toimprove electrochemical performance of the metal sulfides in sodium-ion batteries.

关键词： Pyrite iron disulfide Polyaniline Single wall carbon nanotube Flexible Sodium-ion batteries

基于光谱特征的高寒山区森林生态系统水源涵养分布反演研究

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光谱学与光谱分析 2022年第2期42卷 530-536页

作者：牛腾卢杰于佳鑫武英达龙芊芊于强西藏农牧学院高原生态研究所西藏林芝860000 西藏高原森林生态教育部重点实验室西藏林芝860000 北京林业大学精准林业北京重点实验室北京100083 石家庄市林业局滹沱河国有林场河北石家庄050000 中国消防救援学院森林草原防灭火研究中心北京102202

森林生态系统水源涵养具有调节气候,维持生态水平衡等生态功能。青藏高原作为高寒地区,由于其高海拔,环境恶劣的特征,无法实地人工观测水源涵养量。为更好地获取高寒地区的水源涵养量,通过遥感反演的方式得到特定地区的水源涵养价值量... 详细信息

森林生态系统水源涵养具有调节气候,维持生态水平衡等生态功能。青藏高原作为高寒地区,由于其高海拔,环境恶劣的特征,无法实地人工观测水源涵养量。为更好地获取高寒地区的水源涵养量,通过遥感反演的方式得到特定地区的水源涵养价值量。以林芝巴宜区为研究区,研究区内林芝云杉、高山栎、高山松和雪层杜鹃四种植被为主要树种,遥感影像无法直接获得水源涵养信息,但可以通过构建植被叶片光谱信息与水源涵养量之间的定量关系来反演水源涵养价值量。研究不同植被与水源涵养量的定量关系,每种植被采集10个样点共1000个叶片样本和水源涵养数据,利用ASD光谱仪获取高光谱数据,通过相关性选取拟合参数,构建水源涵养回归模型。利用Sentinel-2遥感影像反演研究区内植被的水源涵养分布,并对反演结果进行验证。结果表明,四类植被叶片的反射光谱,均呈现出相似的规律性,在可见光波段差异不明显,近红外到中红外波段呈现出明显四个水吸收带,在红光到近红外波段(700~1400 nm)反射率最高。光谱反射率大小表现为高山栎>高山松>林芝云杉≈雪层杜鹃。通过实验获取植被冠层截流量、枯落物持水量和土壤含水量,三者之和代表植被的水源涵养量,分析植被的光谱特征与水源涵养量的关系,并通过Pearson系数评价波段参数与水源涵养的定量化关系,确定R_(540),R_(1950),NDWI和NDVI四个参数与水源涵养量显著相关。根据上述参数与四类植被的水源涵养量构建水源涵养回归模型,并通过模型反演研究区内植被水源涵养量,检验模拟精度,整体反演精度R^(2)大于0.7,RMSE基本小于10,说明预测模型反演效果较好,模型可有效估算森林生态系统的水源涵养量。

关键词：高寒山地区水源涵养高光谱预测模型遥感反演

阴阳坡效应下季冻区铁路路基水-热-力行为与轨道不平顺规律研究

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Journal of Central South University 2022年第11期29卷 3793-3810页

作者：任娟娟章恺尧郑健龙韦慧张亦弛杜威叶文龙 School of Traffic&Transportation Engineering Changsha University of Science&TechnologyChangsha 410114China School of Civil Engineering Southwest Jiaotong UniversityChengdu 610031China

阴阳坡效应会影响高速铁路路基温度场的分布规律,导致路基表层产生不均匀冻胀变形,进而造成无砟轨道产生静态不平顺,影响高速列车运行的平稳性和舒适性。本文建立了考虑阴阳坡效应的冻土水-热-力耦合模型,探究了季冻区高速铁路路基在冻... 详细信息

阴阳坡效应会影响高速铁路路基温度场的分布规律,导致路基表层产生不均匀冻胀变形,进而造成无砟轨道产生静态不平顺,影响高速列车运行的平稳性和舒适性。本文建立了考虑阴阳坡效应的冻土水-热-力耦合模型,探究了季冻区高速铁路路基在冻结过程中温度场发展过程以及土体的变形特性,分析了不均匀冻胀变形作用下的CRTSⅢ型板式无砟轨道钢轨不平顺变化规律。计算结果表明:高速铁路路基左右侧边坡由于所受太阳辐射量不同,阴坡冻结时间早于阳坡,而融化时间却晚于阳坡,这是引起路基不均匀冻胀的关键因素。不同线路走向会影响路基上部的温度变化和表层冻胀量,从而使无砟轨道结构变形存在差异。当线路为东北走向时随着走向角的不断增大,下行线的轨道水平不平顺不断减弱,上行线轨道水平不平顺则稍有增加,最终在南北走向时二者趋于一致。因此,在季冻区铁路选线时应最大程度避免东西走向,以尽可能减弱极端情况下的路基阴阳坡现象。

关键词：路基冻胀水-热-力耦合阴阳坡效应轨道不平顺

Evaluation of the Prostate Imaging Reporting and Data System for Magnetic Resonance Imaging Diagnosis of Prostate Cancer in Patients with Prostate-specific Antigen 〈20 ng/ml

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Chinese Medical Journal 2016年第12期129卷 1432-1438页

作者： Xuan Wang Jian-ye Wang Chun-Mei Li Ya-Qun Zhang Jian-long Wang Ben Wan Wei Zhang Min Chen Sa-Ying Li Gang Wan Ming Liu Department of Urology Beijing Hospital Beijing 100730 China Department of Radiology Beijing Hospital Beijing 100730 China Department of Pathology Beijing Hospital Beijing 100730 China Department of Medical Statistics Beijing Ditan Hospital Beijing 100015 China

Background： The European Society of Urogenital Radiology has built the Prostate Imaging Reporting and Data System （PI-RADS） for standardizing the diagnosis of prostate cancer （PCa）. This study evaluated the PI-RADS diagnosis method in patients with prostate-specific antigen （PSA）〈20 ng/ml. Methods： A total of 133 patients with PSA 〈20 ng/ml were prospectively recruited. T2-weighted （T2WI） and diffusion-weighted （DWI） magnetic resonance images of the prostate were acquired before a 12-core transrectal prostate biopsy. Each patient＇s peripheral zone was divided into six regions on the images; each region corresponded to two of the 12 biopsy cores. T2WI, DWI, and T2W1 ＋ DWI scores were computed according to PI-RADS. The diagnostic accuracy of the PI-RADS score was evaluated using histopathology of prostate biopsies as the reference standard. Results： PCa was histologically diagnosed in 169 （21.2%） regions. Increased PI-RADS score correlated positively with increased cancer detection rate. The cancer detection rate for scores 1 to 5 was 2.8%, 15.0%, 34.6%, 52.6%, and 88.9%, respectively, using T2W1 and 12.0%, 20.2%, 48.0%, 85.7%, and 93.3%, respectively, using DWI. For T2WI ＋ DWI, the cancer detection rate was 1.5% （score 2）, 13.5% （scores 3-4）, 41.3% （scores 5-6）, 75.9% （scores 7-8）, and 92.3% （scores 9-10）. The area under the curve for cancer detection was 0.700 （T2WI）, 0.735 （DWI） and 0.749 （T2WI ＋ DWI）. The sensitivity and specificity were 53.8% and 89.2%, respectively, when The summed score ofT2Wl ＋ DWI

关键词： Diagnosis Magnetic Resonance Imaging Prostate Cancer Prostate Imaging Reporting and Data System

木兰科植物叶片光合系统耐热性与叶片形态及温度生态位的关系

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植物生态学报 2023年第10期47卷 1432-1440页

作者：叶洁泓于成龙卓少菲陈新兰杨科明文印刘慧华南农业大学资源环境学院广州510642 中国科学院华南植物园园艺中心广州510520 华南国家植物园广州510520 中国科学院华南植物园退化生态系统植被恢复与管理重点实验室广东省应用植物学重点实验室广州510650

全球气候变化背景下,极端高温事件日益频繁,对植物的生长、存活造成严重威胁,准确评估植物的耐热性,对物种保育和适应性预测具有重要作用。木兰科是中国亚热带常绿阔叶林的标志类群,也是被子植物基部类群,具有重要的生态价值和演化生物... 详细信息

全球气候变化背景下,极端高温事件日益频繁,对植物的生长、存活造成严重威胁,准确评估植物的耐热性,对物种保育和适应性预测具有重要作用。木兰科是中国亚热带常绿阔叶林的标志类群,也是被子植物基部类群,具有重要的生态价值和演化生物学地位,然而目前对其耐热性尚缺乏了解。该研究以种植于同质园的23种木兰科植物为研究对象,利用叶绿素荧光技术研究了叶片光合系统的耐热性,同时测定了叶片形态性状,并基于这些物种在全球的分布地气候数据,分析了叶片光合系统耐热性与叶片形态及温度生态位的关系。发现木兰科植物光系统II最大光化学效率降低50%时的温度(T50)范围在46.1-56.7℃之间,且常绿物种的T50显著高于落叶物种。叶片形态方面,T50与叶面积显著正相关,与叶片厚度无显著相关关系。温度生态位方面,T50与年平均气温、最冷月最低气温呈显著正相关关系,但与最暖月最高气温无显著相关关系。T50具有较弱的系统发育信号,暗示T50受系统发育影响较小,受叶片形态与环境气候的影响较大。研究结果说明木兰科植物的叶片光合系统耐热性较强,但耐热性的气候适应可能并不受高温环境驱动,未来的高温事件对生活于更炎热地区的木兰科落叶植物威胁较大。

关键词：光合系统耐热性木兰科高温胁迫温度生态位叶片形态叶片习性

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