检索结果-南通市图书馆

基于文献分析和数据实证的融资租赁与实体经济投资关系研究

在线全文

学校读者我要写书评

暂无评论

天津大学学报（社会科学版） 2024年第4期26卷 320-330页

作者：吕冰叶倩彤赵洪科张宇天津大学管理与经济学部天津300072

融资租赁作为中小企业解决融资难题的重要工具,在我国得到了迅速的发展。文章从融资属性和融物属性两个方面探讨融资租赁的有效性,分析其对我国实体经济投资的作用。构建双向固定效应回归模型,研究融资租赁与银行信贷的互动关系;并通过... 详细信息

融资租赁作为中小企业解决融资难题的重要工具,在我国得到了迅速的发展。文章从融资属性和融物属性两个方面探讨融资租赁的有效性,分析其对我国实体经济投资的作用。构建双向固定效应回归模型,研究融资租赁与银行信贷的互动关系;并通过面板向量自回归模型,评估融资租赁对实体投资的影响。使用2015—2021年的宏观季度数据进行实证分析,结果显示融资租赁的融资属性和融物属性在促进实体经济投资方面具有显著差异。此外,研究还发现,不同区域的有效性存在差异。

关键词：融资租赁固定效应模型实体经济投资 PVAR模型

初夏东北冷涡指数的建立与分析(1961-2010)

在线全文

学校读者我要写书评

暂无评论

全球变化数据学报（中英文） 2024年第1期8卷 104-109,V0104-V0109页

作者：何丽烨马宁郭军天津市气候中心天津300074

东北冷涡是东亚中高纬度地区的重要天气系统,其频繁活动能够导致明显的气温和降水异常,具有显著的“气候效应”。使用水平分辨率为2.5°×2.5°、时间分辨率为逐日的NCEP/NCAR(美国国家环境预报中心和国家大气研究中心)再分析资料,研究... 详细信息

东北冷涡是东亚中高纬度地区的重要天气系统,其频繁活动能够导致明显的气温和降水异常,具有显著的“气候效应”。使用水平分辨率为2.5°×2.5°、时间分辨率为逐日的NCEP/NCAR(美国国家环境预报中心和国家大气研究中心)再分析资料,研究时段取1961–2010年。根据东北冷涡天气学定义,将符合下述条件的天气系统定义为一次冷涡天气过程:(1)在500hpa等压面上至少能分析出一根闭合等高线,并有冷中心或明显冷槽配合的低压环流系统;(2)冷涡中心出现在(35°N–60°N,115°E–145°E)范围内;(3)冷涡在上述地区的生命史为3天或3天以上。考虑海河流域的地理位置,根据逐年东北冷涡低压中心在西涡范围(115°E–125°E)达到的最南位置,界定对初夏(6月,下同)海河流域降水有显著影响的东北冷涡活动关键区域(38°N–48°N,115°E–125°E),统计出冷涡中心频次标准化值,形成初夏东北冷涡指数数据集(1961–2010)。数据集包括:(1)初夏标准化东北冷涡活动指数;(2)逐年初夏东北冷涡500 hpa位势高度低压中心在115°E–125°E区域的最南位置。该数据集存储为1个Excel文件(.xlsx格式),数据量约12.5 KB。

关键词：东北冷涡初夏降水海河流域气候效应

Plant physiological changes along an encroachment gradient: an assessment of US Mid-Atlantic serpentine barrens

在线全文

学校读者我要写书评

暂无评论

Journal of Plant Ecology 2018年第6期11卷 853-865页

作者： Nicole A.Havrilchak Jessica l.Schedlbauer Department of Biology West Chester University750 S.Church StreetWest ChesterPA 19383USA

Aims Serpentine barrens of the Mid-Atlantic United States are globally rare,grass-dominated ecosystems thought to exclude C3 spe-cies and characterized by unique soil ***,like many grassland ecosystems globally,these sites are presently facing encroachment by surrounding *** this ecosystem,the tendril climbing vine,Smilax rotundifolia,forms dense thickets around bar-rens that typically precede forest *** numerous factors speculatively initiate and promote encroachment in these systems,few studies have examined photosynthetic responses of serpentine grasses to changes in resource availability initiated by encroachers or physiological ability of encroaching *** to colonize high-light barren *** sought to under-stand both environmental and physiological dynamics of encroach-ment along an irradiance gradient in these *** At three serpentine barren sites in southeastern Pennsylvania,physiological responses of the native grasses Sorghastrum nutans and Schizachyrium scoparium to increased shading by ***-folia were ***,the physiological performance of *** in the forest understory was compared to that in sunlit barrens ***-saturated photosynthesis(A_(sat)),stomatal conductance(g_(s)),instantaneous transpiration efficiency(ITE),maximum efficiency of photosystem II(F_(v)/F_(m)),midday leaf water potential(ψ_(leaf))and specific leaf area(SlA)were measured for all species over the course of the 2014 growing ***-way analyses of variance were used to assess changes in these param-eters across growing environments,as well as seasonally for each *** regression analyses were also performed to inves-tigate the influence of vapor pressure deficit(D)and leaf tempera-ture(T_(leaf))on A_(sat) and *** Findings light-saturated photosynthesis was significantly greater in ***-difolia growing in sun than in the shade(Ply in th

关键词： encroachment photosynthesis serpentine barren Schizachyrium scoparium Smilax rotundifolia Sorghastrum nutans

Pulse cyclophosphamide therapy for inflammatory bowel disease

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

World Journal of Gastroenterology 2006年第8期12卷 1278-1280页

作者： Zsolt Barta lászló Tóth Margit Zeher 3~(rd) Department of Medicine Faculty of MedicineMedical and Health Science CentreUniversity of DebrecenDebrecenHungary Department of pathology Faculty of MedicineMedical and Health Science CentreUniversity of DebrecenDebrecenHungary

AIM:To assess the efficacy of intravenous cyclophos-phamide pulse therapy for refractory inflammatory boweldisease(IBD).METHODS:We included in our cohort eight patientswith(moderate/severe)steroid refractory IBD(4 withulcerative colitis and 4 with Crohn's disease).They allreceived 6 cycles of intravenous cyclophosphamide(800mg)per ***:patients entered into remission after the sec-ond/third cyclophosphamide *** activity *** were no side effects and *** thepatients went into long lasting *** Crohn's diseasepatients and 3 of 4 ulcerative colitis patients achievedcomplete *** patient with ulcerative colitisshowed an impressive clinical response but did not enterinto *** the maintenance,patients with Crohn'sdisease were treated with methotrexate(15 mg/wk)andpatients with ulcerative colitis were treated with azathio-prine(2.5 mg/kg body weight/d).CONClUSION:Remission was maintained in all pa-tients for 6 mo on the *** drug was well *** findings suggest that aggressive immuno-suppressive therapy may be useful in some refractorypatients and further controlled study should be consid-ered in order to fully evaluate this type of treatment as apotential therapy for IBD.

关键词： Crohn's disease Ulcerative colitis Cyclophos-phamide

The anti-scarring effect of corneal stromal stem cell therapy is mediated by transforming growth factorβ3

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

Eye and Vision 2020年第1期7卷 512-525页

作者： lin Weng James l.Funderburgh Irona Khandaker Moira l.Geary Tianbing Yang Rohan Basu Martha l.Funderburgh Yiqin Du Gary Hin-Fai Yam Department of Ophthalmology University of Pittsburgh School of medicine203 Lothrop StreetPittsburghPA 15213USA Shanghai lanhe Optometry and Ophthalmology Clinic Shanghai 200032People’s Republic of China

Background:Corneal stromal stem cells(CSSC)reduce corneal inflammation,prevent fibrotic scarring,and regenerate transparent stromal tissue in injured *** effects rely on factors produced by CSSC to block the fibrotic gene *** study investigated the mechanism of the scar-free regeneration ***:Primary human CSSC(hCSSC)from donor corneal rims were cultivated to passage 3 and co-cultured with mouse macrophage RAW264.7 cells induced to M1 pro-inflammatory phenotype by treatment with interferonγand lipopolysaccharides,or to M2 anti-inflammatory phenotype by interleukin-4,in a Transwell *** timecourse expression of human transforming growth factorβ3(hTGFβ3)and hTGFβ1 were examined by immunofluorescence and ***β3 knockdown for>70%in hCSSC[hCSSC-TGFβ3(si)]was achieved by small interfering RNA ***ïve CSSC and hCSSC-TGFβ3(si)were transplanted in a fibrin gel to mouse corneas,respectively,after wounding by stromal *** clarity and the expression of mouse inflammatory and fibrosis genes were ***:hTGFβ3 was upregulated by hCSSC when co-cultured with RAW cells under M1 *** of hCSSC to wounded mouse corneas showed significant upregulation of hTGFβ3 at days 1 and 3 post-injury,along with the reduced expression of mouse inflammatory genes(CD80,C-X-C motif chemokine ligand 5,lipocalin 2,plasminogen activator urokinase receptor,pro-platelet basic protein,and secreted phosphoprotein 1).By day 14,hCSSC treatment significantly reduced the expression of fibrotic and scar tissue genes(fibronectin,hyaluronan synthase 2,Secreted protein acidic and cysteine rich,tenascin C,collagen 3a1 andα-smooth muscle actin),and the injured corneas remained ***,hCSSC-TGFβ3(si)lost these anti-inflammatory and anti-scarring functions,and the wounded corneas showed intense ***:This study has demonstrated that the corneal regenerative effect of hCSSC is mediated by TGFβ3,inducing a s

关键词： Cornea wound healing Corneal stromal stem cells TGFβ3 Inflammation Fibrosis

Step Sintering of Microwave Heating and MicrowavePlasma Heating for Alumina Ceramics

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

Journal of Materials Science & Technology 1999年第5期15卷 419-422页

作者： Zhang, JS Cao, l Yang, YJ Diao, YX Shen, XX Chinese Acad Sci Met Res Inst Shenyang 110015 Peoples R China

The invention of microwave induced plasma during microwave heating makes it possible to confine plasma inside a crucible, in the pressure range of 1.33 pa to 0.5 Mpa, and above 900 degrees C. In this study, the step sintering of microwave heating and microwave plasma heating (SSMP) was proposed. In this process, microwave heating and plasma heating was ingeniously combined in one chamber, and vacuum was unnecessary for microwave induced plasma. In the first step, the microwave energy directly heated alumina ceramics to a given temperature, above which microwave will mainly ionize the gas and sustain a plasma. Then the plasma further heated alumina ceramics to the final temperature to finish sintering. Maintaining the advantages of microwave heating and plasma heating, this step sintering approach will overcome the limitation of both processes for processing ceramics, and it will be suitable for sintering all kinds of ceramics in principle.

关键词： Ceramic materials

Effect of Nitrogen Content on Microstructures and Mechanical Properties of WB_2(N) Films Deposited by Reactive Magnetron Sputtering

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2015年第12期31卷 1217-1225页

作者： Y.M.liu D.Y.Deng H.lei Z.l.Pei C.l.Jiang C.Sun J.Gong Institute of Metal Research Chinese Academy of Sciences

In the present study,WB 2（N） films are fabricated on silicon and YG8 substrates at different N 2 pressures by reactive magnetron *** influence of N 2 partial pressure（P （N2）） on the film microstructure and characteristics is studied systematically,including the chemical composition,crystalline structure,residual stress,surface roughness as well as the surface and the cross-section ***,nano-indentation and ball-on-disk tribometer are performed to analyze the mechanical and tribological properties of the *** results show that the addition of nitrogen apparently leads to the change of the structure from（1 0 1） to（0 0 1） orientation then to the amorphous structure with the formation of BN *** the addition of nitrogen can greatly refine the grain size and microstructure of the ***,the residual stress of the film is also found to change from tensile to compressive stress as a function of P （N2）,and the compressive stress increases with P （N2）,The WB 2（N） films with small nitrogen content,which are deposited at P （N2） of 0.004 and 0.006 pa,exhibit better mechanical,tribological and corrosion properties than those of other *** increase of nitrogen content accelerates the formation of BN phase and fast decreases the film *** addition,the large N 2 partial pressure gives rise to the target poisoning accompanied by the increase of the target voltage and the decrease of the deposition rate.

关键词： Reactive magnetron sputtering Nanocomposites WB 2(N) films Residual stress Mechanical properties

GO/CNC薄层纳米复合膜的制备及性能研究

在线全文

学校读者我要写书评

暂无评论

中国给水排水 2024年第11期40卷 65-72页

作者：吕永涛杨雅馨吝力潘永宝崔双科王磊西安建筑科技大学环境与市政工程学院陕西西安710055 陕西省膜分离技术研究院陕西省膜分离重点实验室陕西西安710055 陕西省现代建筑设计研究院有限公司陕西西安710021

为改善纳滤膜的性能,利用纤维素纳米晶(CNC)修饰氧化石墨烯(GO),合成了具有良好分散性的GO/CNC复合纳米材料,之后通过界面聚合引入聚酰胺(pa)层中制得改性纳滤膜,并进行形貌结构表征和性能测试。研究发现,GO/CNC改性膜表面具有更明显的... 详细信息

为改善纳滤膜的性能,利用纤维素纳米晶(CNC)修饰氧化石墨烯(GO),合成了具有良好分散性的GO/CNC复合纳米材料,之后通过界面聚合引入聚酰胺(pa)层中制得改性纳滤膜,并进行形貌结构表征和性能测试。研究发现,GO/CNC改性膜表面具有更明显的凸起褶皱结构、更高的粗糙度及亲水性,在0.6 Mpa下纯水通量可达38.45 l(/m2·h),较pa原膜与GO改性膜分别提升了84.86%和53.92%,Na2SO4和NaCl截留率分别为95.47%和6.65%。经pH=4、4000 mg/l的NaClO溶液浸泡4 h后,pa原膜的归一化纯水通量增加了近50%,归一化Na2SO4截留率降至0.89,而GO/CNC改性膜的归一化纯水通量仅增加了13%,Na2SO4截留率几乎无影响。上述结果表明,GO/CNC的添加可显著提升复合纳滤膜的渗透通量,同时具有良好的Na2SO4/NaCl分离选择性与耐氯性能。

关键词：氧化石墨烯纤维素纳米晶纳滤膜界面聚合耐氯性

内毒素诱导致新生大鼠肺损伤中肾病理改变及转录因子-κB和转化生长因子-β1表达的研究

在线全文

学校读者我要写书评

暂无评论

中国临床药理学杂志 2020年第5期36卷 514-517页

作者：崔维静赛依帕甘肃省人民医院儿科甘肃兰州730000

目的研究内毒素(lPS)诱导致新生大鼠肺损伤模型中肾病理改变及转录因子-κB(NF-κB)和转化生长因子-β1(TGF-β1)表达的变化。方法用3~5日龄SPF级大鼠尾部静脉注射lPS建立新生大鼠急性肺损伤(AlI)模型。实验分为对照组、6 h模型组和12 ... 详细信息

目的研究内毒素(lPS)诱导致新生大鼠肺损伤模型中肾病理改变及转录因子-κB(NF-κB)和转化生长因子-β1(TGF-β1)表达的变化。方法用3~5日龄SPF级大鼠尾部静脉注射lPS建立新生大鼠急性肺损伤(AlI)模型。实验分为对照组、6 h模型组和12 h模型组。按实验要求时间杀死大鼠,无菌留取标本。用全自动生化仪检测新生大鼠的肾功能,用试剂盒检测丙二醛(MDA)含量变化和超氧化物歧化酶(SOD)、总抗氧化能力(T-AOC)活性,用免疫组化法检测NF-κB和TGF-β1的表达水平。结果对照组、6 h模型组和12 h模型组的大鼠血清肌酸酐的含量分别为(15.02±0.48),(45.96±1.25)和(97.65±1.43)μmol·l^-1,血尿素氮的含量分别为(6.84±0.53),(10.35±0.84)和(14.68±0.25)μmol·l^-1,肾组织中MDA含量分别为(2.02±0.41),(3.21±0.63)和(5.01±0.18)nmol·mg^-1,SOD活性分别为(28.74±0.69),(18.25±0.36)和(14.58±0.15)U·g^-1,T-AOC活性分别为(2.38±0.25),(1.83±0.02)和(1.26±0.23)μmol·l-1,肾组织中NF-κB的相对表达量分别为(1.02±0.08),(1.43±0.19)和(1.87±0.14),TGF-β1的相对表达量分别为(0.97±0.04),(1.46±0.15)和(1.92±0.08),对照组的上述指标与6 h模型组和12 h模型组比较,差异均有统计学意义(均PlPS诱导致新生大鼠AlI模型的过程中,也会对肾造成一定的损伤;在对lPS的应激中,NF-κB/TGF-β1信号通路的氧化应激反应异常活化。

关键词：内毒素新生大鼠肺损伤肾病理改变转录因子-κB 转化生长因子-β1