检索结果-南通市图书馆

Effect of noncircular orifice plates on the near flow field of turbulent free jets

Chinese Physics B 2014年第12期23卷 298-306页

作者：徐敏义童杏清岳丹婷张健鹏米建春 Nathan g.J. Kalt P.A.M. Marine Engineering College Dalian Maritime University State Key Laboratory of Turbulence & Complex Systems College of Engineering Peking University Centre for Energy Technology and School of Mechanical Engineering University of Adelaide

In this paper, we experimentally investigate the near-field flow characteristics of turbulent free jets respectively issued from circular, triangular, diamond, rectangular, and notched-rectangular orifice plates into air surroundings. All the orifice plates have identical opening areas or equivalent diameters（De） and their aspect ratios（AR） range from 1 to 6.5. Planar particle image velocimetry（PIV） is used to measure the velocity field at the same Reynolds number of Re = 5 × 10^4,where Re = Ue De/ν with Ue being the exit bulk velocity and ν the kinematic viscosity of fluid. The mean and turbulent velocity fields of all the five jets are compared in detail. Results show that the noncircular jets can enhance the entrainment rate, reflected by the higher acceleration rates of mean velocity decay and spread, shorten the length of the unmixed core,expedite the increase of turbulent intensity compared with the circular counterpart shortened unmixed core, and increase turbulent intensity comparing to the circular counterpart. Among the five jets, the rectangular jet（AR = 6.5） produces the greatest decay rate of the near-field mean velocity, postpones the position at which the 鈥榓xis-switching鈥檖henomenon occurs. This supports that axis switching phenomenon strongly depends on jet initial conditions. In addition, the hump in the centerline variation of the turbulence intensity is observed in the rectangular and triangular jets, but not in the circular jet, nor in diamond jet nor in notched-rectangular jet.

关键词： noncircular jet free jet turbulence mixing axis-switching

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

Catalytic perfomance of rhodium chalcogen halides and rhodium chalcogenides over silica supports in methane oxidative carbonylation

引用

Journal of Natural gas Chemistry 2009年第4期18卷 399-406页

作者： S. V. Volkov g. R. Kosmambetova L. B. Kharkova O. V. Shvets O. g. Yanko V. I. gritsenko P. E. Strizhak V. I. Vernadskii Institute of general and Inorganic Chemistry of the Ukrainian National Academy of Sciences L. V. Pisarzhevsky Institute of Physical Chemistry of the Ukrainian National Academy of Sciences

The gas phase methane oxidative carbonylation was studied in the presence of molecular oxygen over silica materials including their mechanical mixtures with rhodium chalcogen chlorides obtained in non-aqueous inorganic media. The formation of Rh4SCl7, Rh4S9Cl2, Rh4SesCl3 and Rh3Se3Cl solids was confirmed by elemental analysis, IR absorption spectroscopy, XPS and X-ray diffraction. Silica, vanadium-, and molybdenum-containing mesoporous molecular sieves have been used as supports. It was found that productivity of oxygenates （methanol, methyl acetate and acetic acid） depends mainly on the method of the catalyst preparation and the type of the support.

关键词： catalysts rhodium chalcogen halides methane oxidative carbonylation silica supports

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

引用

World Journal of gastroenterology 2016年第47期22卷 10325-10340页

作者： Orsolya galamb Alexandra Kalmár Barbara Kinga Barták árpád V Patai Katalin Leiszter Bálint Péterfia Barnabás Wichmann gábor Valcz gábor Veres Zsolt Tulassay Béla Molnár Molecular Medicine Research group Hungarian Academy of Sciences 2~(nd) Department of Internal Medicine Semmelweis University 1~(st) Department of Paediatrics Semmelweis University

AIM To analyze colorectal carcinogenesis and age-related DNA methylation alterations of gene sequences associated with epigenetic clock Cpg sites. METHODS In silico DNA methylation analysis of 353 epigenetic clock Cp g sites published by Steve Horvath was performed using methylation array data for a set of 123 colonic tissue samples [64 colorectal cancer(CRC), 42 adenoma, 17 normal; gEO accession number: gSE48684]. Among the differentially methylated agerelated genes, secreted frizzled related protein 1(SFRP1) promoter methylation was further investigated in colonic tissue from 8 healthy adults, 19 normal children, 20 adenoma and 8 CRC patients using bisulfite-specific PCR followed by methylation-specific high resolution melting(MS-HRM) analysis. m RNA expression of age-related "epigenetic clock" genes was studied using Affymetrix HgU133 Plus2.0 whole transcriptome data of 153 colonic biopsy samples(49 healthy adult, 49 adenoma, 49 CRC, 6 healthy children)(gEO accession numbers: gSE37364, gSE10714, gSE4183, gSE37267). Whole promoter methylation analysis of genes showing inverse DNA methylationgene expression data was performed on 30 colonic samples using methyl capture *** Fifty-seven age-related Cp g sites including hypermethylated PPP1R16 B, SFRP1, SYNE1 and hypomethylated MgP, PIPOX were differentially methylated between CRC and normal tissues(P g sites differed significantly, including hypermethylated DKK3, SDC2, SFRP1, SYNE1 and hypomethylated CEMIP, SPATA18(P gion was significantly hypermethylated in CRC(55.0% ± 8.4 %) and adenoma tissue samples(49.9% ± 18.1%) compared to normal adult(5.2% ± 2.7%) and young(2.2% ± 0.7%) colonic tissue(P ghtly, but significantly increased in healthy adults compared to normal young samples(P gnificantly increased S

关键词： DNA methylation Aging Colorectal cancer Adenoma Epigenetic drift Epigenetic clock Secreted frizzled related protein 1

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

Prevalence and classification of equinus foot in bilateral spastic cerebral palsy

引用

World Journal of Pediatrics 2019年第3期15卷 276-280页

作者： Axel Horsch Marco g(o)tze Andreas geisbüsch Nicholas Beckmann Stefanos Tsitlakidis gregor Berrsche Matthias Klotz Heidelberg University Hospital Clinic for Orthopedics and Trauma SurgerySchlierbacher Landstr.200a69118 HeidelbergGermany

Background Equinus is a common deformity in children with bilateral spastic cerebral palsy (BSCP).While dynamic equinus usually is treated by conservative therapy,fixed contractures need surgical *** choose the appropriate surgical method,it is important to discriminate between isolated gastrocnemius shortening and combined gastrosoleus complex *** In a retrospective study 938 patients with BSCP were *** underwent gait analysis and clinical examination.248 patients (496 limbs) met the inclusion *** from motion analysis and clinical examination were used to calculate the prevalence and to further classify fixed equinus *** The prevalence of equinus was 83.3%.During clinical exam 246 (59.6%) limbs showed combined gastrosoleus complex contracture and 167 (40.4%) isolated gastrocnemius *** at stance and mean DF at initial contact were significantly reduced in combined contracture,while *** was increased (P g the results of previous studies,in this study there was a high prevalence of fixed equinus in patients with *** prevalence of equinus correlated with increasing *** half of the patients with fixed equinus show a different involvement of gastrocnemius and soleus muscle,we recommend to apply Silfverski(o)ld's test to discriminate between those two types to choose the appropriate surgical therapy.

关键词： Cerebral palsy Classification Equinus foot Equinus prevalence gait analysis

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

LE DANgER DES IMAgES Rhetorique et perversion du langage dans les Liaisons dangereuses

引用

法国研究 1992年第1期 138-157页

作者： gérard LAHOUATI

此文考察了拉克罗的书信体小说《危险联系》(1782)中的修辞问题及其俗套式的语言风格,指出该小说的风格本身就是文本意义的组成部分。作者在文中分析了阅读程式的暖昧性,讨论了某些比喻词的含义,考察了某些意象和修辞手法(迂回、暗指、... 详细信息

此文考察了拉克罗的书信体小说《危险联系》(1782)中的修辞问题及其俗套式的语言风格,指出该小说的风格本身就是文本意义的组成部分。作者在文中分析了阅读程式的暖昧性,讨论了某些比喻词的含义,考察了某些意象和修辞手法(迂回、暗指、双关……),进而说明:1.隐喻如何讲述故事;2.缺少活的隐喻以及缺少隐喻的创造如何成为叙事意义的基本因素。

关键词：隐喻考察书信体小说危险语言风格文本意义阅读程式修辞手法比喻词克罗

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

Methodology for Extraction of Tunnel Cross-Sections Using Dense Point Cloud Data

引用

Journal of geodesy and geoinformation Science 2021年第2期4卷 56-71页

作者： Yueqian SHEN Jinguo WANg Jinhu WANg Wei DUAN Vagner g.FERREIRA School of Earth Sciences and Engineering Hohai UniversityNanjing 211100China Key Laboratory qf Quantitative Remote Sensing Information Technology Chinese Academy of SciencesBeijing 100094China Nanjing Surveying and Mapping Research Institute Co. Ltd.Nanjing 210000China

Tunnel deformation monitoring is a crucial task to evaluate tunnel stability during the metro operation *** Laser Scanning(TLS)can collect high density and high accuracy point cloud data in a few minutes as an innovation technique,which provides promising applications in tunnel deformation ***,an efficient method for extracting tunnel cross-sections and convergence analysis using dense TLS point cloud data is ***,the tunnel orientation is determined using principal component analysis(PCA)in the Euclidean *** control points are introduced to detect and remove the unsuitable points by using point cloud division and then the ground points are removed by defining an elevation value width of 0.5 ***,a z-score method is introduced to detect and remove the *** the tunnel cross-section’s standard shape is round,the circle fitting is implemented using the least-squares ***,the convergence analysis is made at the angles of 0°,30°and 150°.The proposed approach’s feasibility is tested on a TLS point cloud of a Nanjing subway tunnel acquired using a FARO X330 laser *** results indicate that the proposed methodology achieves an overall accuracy of 1.34 mm,which is also in agreement with the measurements acquired by a total station *** proposed methodology provides new insights and references for the applications of TLS in tunnel deformation monitoring,which can also be extended to other engineering applications.

关键词： cross-section control point convergence analysis z-score method terrestrial laser scanning dense point cloud data

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

铝合金热处理用PAg淬火剂

引用

材料工程 1997年第1期25卷 14-16页

作者：赵海鸥 g.E.陶登 g.M.韦伯斯特 F.汤姆北京机电研究所美国联合碳化公司

综述已往的工作,确定PAg水溶性淬火液中主要的一类(美国航天工业命名的typeⅠ)淬火剂在铝合金热处理应用可能性的范围。

关键词：聚合物淬火剂铝合金淬火 PAg

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

Influence of age on outcome of total laparoscopic fundoplication for gastroesophageal reflux disease

引用

World Journal of gastroenterology 2007年第5期13卷 740-747页

作者： F Pizza g Rossetti P Limongelli g Del genio V Maffettone V Napolitano L Brusciano g Russo S Tolone M Di Martino A Del genio 1st Division of general and gastrointestinal Sur-gery Second University of Naples Via Pansini 5 Naples 80131 Italy

AIM: To demonstrate that age does not influence the choice of treatment for gastroesophageal reflux disease (gERD). We hypothesized that the outcome of total fun-doplication in patients > 65 years is similar to that of patients aged ≤ 65 ***: Four hundred and twenty consecu-tive patients underwent total laparoscopic fun-doplication for gERD. Three hundred and fifty-five patients were younger than 65 years (group Y), and 65 patients were 65 years or older (group E). The following elements were considered: pres-ence, duration, and severity of gERD symptoms; presence of a hiatal hernia; manometric evalu- ation, 24 h pH-monitoring data, duration of operation; incidence of complications; and length of hospital stay. RESULTS: Elderly patients more often had atypical symptoms of gERD and at manometric evaluation had a higher rate of impaired esophageal peristalsis in compari-son with younger patients. A mild intensity of heartburn often leads physicians to underestimate the severity of erosive esophagitis. The duration of the operation was similar between the two groups. The incidence of intra-operative and postoperative complications was low and the difference was not statistically significant between the two groups. An excellent outcome was observed in 92.9% young patients and 91.9% elderly patients. CONCLUSION: Laparoscopic antireflux surgery is a safe and effective treatment for gERD even in elderly pa-tients, warranting low morbidity and mortality rates and a significant improvement of symptoms comparable to younger patients.

关键词： gastroesophageal reflux disease Esophagitis Impaired peristalsis Hiatal hernia Laparoscopic totalfundoplication

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

genetic characterization of an almond germplasm collection and volatilome profiling of raw and roasted kernels

引用

Horticulture Research 2021年第1期8卷 463-481页

作者： M.Di guardo B.Farneti I.Khomenko g.Modica A.Mosca g.Distefano L.Bianco M.Troggio F.Sottile S.La Malfa F.Biasioli A.gentile Department of Agriculture Food and Environment(Di3A)University of Cataniavia Valdisavoia 595123 CataniaItaly Research and Innovation Centre Fondazione Edmund MachSan Michele all’AdigeTrentoItaly Dipartimento di Architettura University of PalermoViale delle ScienzeEd.1490128PalermoItaly National Center for Citrus Improvement College of Horticulture and LandscapeHunan Agricultural UniversityChangshaChina

Almond is appreciated for its nutraceutical value and for the aromatic profile of the *** this work,an almond collection composed of 96 Sicilian accessions complemented with 10 widely cultivated cultivars was phenotyped for the production of volatile organic compounds using a proton-transfer time-of-flight mass spectrometer and genotyped using the Illumina Infinium®18 K Peach SNP *** profiling of the aroma was carried out on fresh and roasted kernels enabling the detection of 150 mass *** eight,for the most related with sulfur compounds,furan containing compounds,and aldehydes formed by Strecker degradation,significantly increased during roasting,while the concentration of fifty-four mass peaks,for the most belonging to alcohols and terpenes,significantly *** hundred and seventy-one robust SNPs were selected and employed for population genetic *** analysis detected three subpopulations with the Sicilian accessions characterized by a different genetic stratification compared to those collected in Apulia(South Italy)and the International *** linkage-disequilibrium(LD)decay across the genome was equal to r^(2)=***,a high level of collinearity(r^(2)=0.96)between almond and peach was registered confirming the high synteny between the two genomes.A preliminary application of a genome-wide association analysis allowed the detection of significant marker-trait associations for 31 fresh and 33 roasted almond mass peaks *** accurate genetic and phenotypic characterization of novel germplasm can represent a valuable tool for the set-up of marker-assisted selection of novel cultivars with an enhanced aromatic profile.

关键词： kernels characterization aromatic

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

Ds＋ BRANCHINg FRACTIONS

引用

Chinese Physics C 2016年第10期40卷 729-731页

作者： J.L. Rosner C.g. Wohl University of Chicago LBNL

Figure 1 shows a partial breakdown of the Ds＋ branching fractions. The rest of this note is about how the figure was constructed. The values shown make heavy use of CLEO measurements of inclusive branching fractions ...

关键词：

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：