检索结果-南通市图书馆

EffECTS Of TREATMENT TIME ON CORROSION Of DIffUSION-ALLOYED COATINGS Of PURE MAGNESIUM

Acta Metallurgica Sinica(English Letters) 2007年第1期20卷 72-78页

作者： Y.P. Ma J. Li J. Zhu L. Yang Y.G. Liu Z.Y. Li f. Zhao School of Metallurgic Engineering Xi＇an University of Architecture ＆ Technology Xi＇an 710055 China

The corrosion resistance of pure magnesium with surface alloying layer obtained by a solid diffusion alloying technique has been analyzed. To establish the optimum treatment time, the experiments were performed at 480℃ for different solid diffusion time （8, 16, and 24h）. The diffusion interaction effectiveness between Zn, Al mix powder and the sample surface, depending on the treatment time for diffusion at given temperatures, has an obvious influence on corrosion resistance and corrosion mechanism. Corrosion properties were studied using the constant immersion test （in 3.0% NaCl solution, temperature is （28±1）℃, and time is 96h）. Optical microscopy （OM） and EDS （energy dispersive spectrum） composition analysis were used to examine the cross-sectional microstructural characteristics of alloyed layer of treated samples. It is shown that in comparison with the untreated samples, the treated ones possess a better corrosion resistance. The Al5Mg11Zn4 phase, which formed as a continuous phase due to the diffusion of Al, Zn, and Mg elements and subsequent interaction on the outermost layer of diffusion alloying zones （especially the samples treated for 24h at 480℃）, was inert to the chloride solution compared with pure magnesium and acted as a corrosion barrier, and therefore the best corrosion resistance was obtained. This protective action of Al5Mg11Zn4 phase was found to change with its amount, which was controlled by the diffusion time at given temperature. It was concluded that the continuous Al5Mg11Zn4 phase （WP-zone） of the reacted layer in pure magnesium was beneficial from the point of view of corrosion resistance.

关键词： pure magnesium solid diffusion treatment time microstructure corrosion

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

Condition transfer between prestressed bridges using structural state translation for structural health monitoring

引用

AI in Civil Engineering 2023年第1期2卷 23-37页

作者： furkan Luleci f.Necati Catbas Department of Civil Environmentaland Construction EngineeringUniversity of Central FloridaOrlandoFL 32816USA

Implementing Structural Health Monitoring(SHM)systems with extensive sensing layouts on all civil structures is obviously expensive and ***,estimating the state(condition)of dissimilar civil structures based on the information collected from other structures is regarded as a useful and essential *** this purpose,Structural State Translation(SST)has been recently proposed to predict the response data of civil structures based on the information acquired from a dissimilar *** study uses the SST methodology to translate the state of one bridge(Bridge#1)to a new state based on the knowledge acquired from a structurally dissimilar bridge(Bridge#2).Specifically,the Domain-Generalized Cycle-Generative(DGCG)model is trained in the Domain Generalization learning approach on two distinct data domains obtained from Bridge#1;the bridges have two different conditions:State-H and ***,the model is used to generalize and transfer the knowledge on Bridge#1 to Bridge#*** doing so,DGCG translates the state of Bridge#2 to the state that the model has learned after being *** one scenario,Bridge#2’s State-H is translated to State-D;in another scenario,Bridge#2’s State-D is translated to *** translated bridge states are then compared with the real ones via modal identifiers and mean magnitude-squared coherence(MMSC),showing that the translated states are remarkably similar to the real *** instance,the modes of the translated and real bridge states are similar,with the maximum frequency difference of 1.12%and the minimum correlation of 0.923 in Modal Assurance Criterion values,as well as the minimum of 0.947 in Average MMSC *** conclusion,this study demonstrates that SST is a promising methodology for research with data scarcity and population-based structural health monitoring(PBSHM).In addition,a critical discussion about the methodology adopted in this study is also offered to address some related concerns.

关键词： Structural state translation Structural health monitoring Domain generalization Population-based structural health monitoring Generative adversarial networks

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

Deep Stacked Ensemble Learning Model for COVID-19 Classification

引用

Computers, Materials & Continua 2022年第3期70卷 5467-5486页

作者： G.Madhu B.Lalith Bharadwaj Rohit Boddeda Sai Vardhan K.Sandeep Kautish Khalid Alnowibet Adel f.Alrasheedi Ali Wagdy Mohamed Department of Information Technology VNRVJIETHyderabad500090India Department of Computer Science and Engineering VNRVJIETHyderabad500090India LBEf Campus Kathmandu44600Nepal Statistics and Operations Research Department College of ScienceKing Saud UniversityRiyadh11451Kingdom of Saudi Arabia Operations Research Department Faculty of Graduate Studies for Statistical ResearchCairo UniversityGiza12613Egypt Wireless Intelligent Networks Center(WINC) School of Engineering and Applied SciencesNile UniversityGiza12588Egypt

COVID-19 is a growing problem worldwide with a high mortality *** a result,the World Health Organization(WHO)declared it a *** order to limit the spread of the disease,a fast and accurate diagnosis is required.A reverse transcript polymerase chain reaction(RT-PCR)test is often used to detect the ***,since this test is time-consuming,a chest computed tomography(CT)or plain chest X-ray(CXR)is sometimes *** value of automated diagnosis is that it saves time and money by minimizing human *** significant contributions are made by our *** initial purpose is to use the essential finetuning methodology to test the action and efficiency of a variety of vision models,ranging from Inception to Neural Architecture Search(NAS)***,by plotting class activationmaps(CAMs)for individual networks and assessing classification efficiency with AUC-ROC curves,the behavior of these models is visually ***,stacked ensembles techniques were used to provide greater generalization by combining finetuned models with six ensemble neural *** stacked ensembles,the generalization of the models ***,the ensemble model created by combining all of the finetuned networks obtained a state-of-the-art COVID-19 accuracy detection score of 99.17%.The precision and recall rates were 99.99%and 89.79%,respectively,highlighting the robustness of stacked *** proposed ensemble approach performed well in the classification of the COVID-19 lesions on CXR according to the experimental results.

关键词： COVID-19 classification class activation maps(CAMs)visualization finetuning stacked ensembles automated diagnosis deep learning

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

The Multi-Wavelength Quasar Survey IV. Quasars in the Leo Cluster

引用

Chinese Journal of Astronomy and Astrophysics 2007年第4期7卷 595-600页

作者： Yang Chen Yu Bai Xiang-Tao He Jiang-Hua Wu Jing Wang Qing-Kang Li Yan-Chun Sun Richard f. Green Wolfgang Voges Department of Astronomy Beijing Normal University Beijing 100875 National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 Large Binocular Telescope Observatory NOAO Tucson AZ85721 USA Max-Planck-Institute fur Extraterrestrische Physik D-85740 Garching Germany

We aim to provide a quasar sample that is more complete than any previous surveys by using a combined selection technique to reduce the selection effects. Here we present the observational results for the X-ray candidates in the field of the Leo Cluster. We found 33 X-ray AGNs in this field of which 10 are new discoveries. The X-ray data and optical spectra of these AGNs are given. We also study the near-IR properties of the X-ray-selected AGNs by using the data from 2MASS. Most of the AGNs in our sample span the color range 0.0〈B-J〈2.5,1.0〈 J-Ks 〈2.0 and 0.5〈H-Ks〈1.2.

关键词： galaxies: active: individual (Leo Cluster) - X-rays: galaxies: quasars

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

Relative damage stress and its application in the case of temperature cycling load

引用

Progress in Natural Science:Materials International 2001年第2期 78-82页

作者：马鑫钱乙余 YOSHIDA f. China China Currently with the State Key Laboratory of Reliability Physics of Electrunic Products Department of Mechanical Engineering Guangzhou 51610 Harbin 150001 Harbin Institute of Technology Higashi-Hiroshima 739 Hiroshima University Japan State Key Laboratory of Welding

Void damage is the main failure characteristics of constrained ductile metal foil. In order to evaluate the mechanical response of ductile metal under different temperatures, the concept of equivalent damage stress proposed by Lemaitre is modified by temperature normalization. A new concept of relative damage stress is advanced, and in the light of this concept, a reasonable explanation is given to the thermal fatigue life data of solder joints under temperature cycling.

关键词： damage stress temperature cycling load solder joint.

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Influence of LDH conversion coatings on the adhesion and corrosion protection of friction spot-joined AA2024-T3/Cf-PPS

引用

Journal of Materials Science & Technology 2021年第8期67卷 197-210页

作者： A.C.Bouali N.M.Andre M.R.Silva Campos M.Serdechnova J.f.dos Santos S.T.Amancio-filho M.L.Zheludkevich Institute of Materials Research Helmholtz-Zentrum G eesthacht.Magnesium Innovation CentreCorrosion and Surface TechnologyMax-Planck-Straβe 121502 CeesthachtGermany Institute of Materials Research Helmholtz-Zentrum GeesthachtMaterials MechanicsSolid State Joining ProcessesMax-Planck-Straβe 121502 CeesthachtGermany Graz University of Technology-TU Graz Institute of Materials Sciencejoining and FormingBMK Endowed Professorship for AviationKopemikusgasse 24/18010 GrazAustria faculty of Engineering University of KielKaiserstrasse 224143 KielGermany

Layered double hydroxide(LDH)conversion coatings loaded with corrosion inhibitors were suggested for the surface treatment of the aluminum alloy 2024-T3,prior to friction spot joining with carbon-fiber reinforced polyphenylene sulfide(AA2024-T3/Cf-PPS).Vanadate was used as a model corrosion *** shear testing method revealed an increase of approx.20%of the joint’s adhesion performance when treated with LDH and before exposure to salt *** evaluation of the joints after exposure to salt spray demonstrated a significant difference in the corrosion behavior of the joints when the AA2024-T3 is treated with LDH loaded with nitrate and vanadate *** LDH intercalated with nitrate revealed a clear improvement in the mechanical and corrosion resistance performance of the joints,even after 6 weeks of salt ***,the LDH intercalated with vanadate failed in providing protection against corrosion as well as preserving the mechanical properties of the *** effect of the galvanic corrosion was further investigated by zero resistance ammeter(ZRA)measurements as well as localized scanning vibrating electrode technique(SVET).

关键词： friction spot joining Layered double hydroxide Galvanic couple Corrosion protection Adhesion

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

Effect of increasing levels of nitrogen on yield of tea in different agro-ecological conditions of Pakistan

引用

Agricultural Science & Technology 2006年第1期7卷 14-22页

作者： f.S. Hamid Tahira Ahmad National Tea Research Institute Shinkiari Mansehra Pakistan Department of Biological Sciences Quaid-I-Azam University Islamabad Pakistan

field experiment was conducted on mature tea bushes of Qi-Men variety at two different altitudes from sea level i.e. at National Tea Research Institute Shinkiari (1000 m) and on farmer’s field in Konsh valley at village Battal (1500 m). Different levels of nitrogen with constant dose of phosphorus and potassium were applied to observe the optimal dose of nutrients for highest yield under local edaphic conditions. The experiment was repeated for three consecutive years. The highest yield of fresh tea leaves were obtained by the application of 420 kg ha-1 N followed by the application of 360 kg ha-1 N at 1000 masl. The highest dose of nitrogen also reduced significantly the soil pH in the upper (0-15cm) layer depth during 1998 and 1999. During the year 2000, the reduction in soil pH was observed by the application of highest dose of nitrogen but was non-significant at 5% level. The lower soil depth (15-30 cm) showed the reduction in pH with the highest dose of nitrogen during the experimental year but was statistically non significant. At the higher altitude of 1500 masl the highest yield of fresh tea leaves was obtained by the application of 420 kg ha-1 during the experimental years but the increase was significant during the year 1999 and 2000. The yield of the fresh tea leaves was positively correlated with the amount of nitrogen application at both the altitudes. The increasing amount of nitrogen decreased the soil pH at both the depths of 0-15cm and 15-30cm. Unlike the lower altitude (1000 m) there was no any significant reduction in the soil pH during 1998 and 1999. A significant reduction in soil pH was found in the year 2000.

关键词： Camellia Sinensis. L yield altitudes fertilizer effect soil pH Pakistan

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

Synthesis, Characterization and Remedial Action of Biogenic Silver Nanoparticles and Chitosan-Silver Nanoparticles against Bacterial Pathogens

引用

Journal of Renewable Materials 2022年第12期10卷 3093-3105页

作者： Piyush Kumar Gupta D.Karthik Kumar M.Thaveena Soumya Pandit Somya Sinha R.Ranjithkumar Walaa f.Alsanie Vijay Kumar Thakur Department of Life Sciences School of Basic Sciences and ResearchSharda UniversityGreater Noida201310Uttar PradeshIndia Viyen Biotech LLP CoimbatoreTamil Nadu641031India Department of Biotechnology Kongunadu Arts and Science CollegeCoimbatoreTamil Nadu641029India Department of Biotechnology Graphic Era Deemed to be UniversityDehradunUttarakhand248002India Department of Clinical Laboratories Sciences The Faculty of Applied Medical SciencesTaif UniversityTaif21944Saudi Arabia Biorefining and Advanced Materials Research Center SRUCEdinburghEH93JGUK Department of Mechanical Engineering School of EngineeringShiv Nadar UniversityNoidaGreater Noida201314India School of Engineering University of Petroleum&Energy Studies(UPES)DehradunUttarakhand248007India

Custard apple is a dry land *** leaves exhibit different pharmacological *** the present study,both silver(Ag)nanoparticles and chitosan-coated Ag(Chi-Ag)nanoparticles were fabricated using the aqueous leaf extract of the custard apple *** preliminary phytochemical analysis,various types of phytocompounds were found in the aqueous leaf extract of the same ***,both nanoparticles were physiochemically *** analysis exhibited the fingerprint vibrational peaks of active bioactive compounds in plant extract,Ag nanoparticles,and Chi-Ag ***/Visible spectral analysis revealed the highest absorbance peak at 419 nm,indicating the presence of Ag *** analysis presented the face-centered cubic(fCC)structure of both prepared ***,the average crystalline size of both Ag nanoparticles and Chi-Ag nanoparticles was calculated to be 23 and 74 nm,*** analysis showed the spherical and cubical shapes of Ag nanoparticles and Chi-Ag nanoparticles,*** analysis indicated a peak around 3.29 keV,conforming to the binding energies of Ag *** biogenic nanomaterial also showed strong antibacterial activity against all tested bacterial pathogens.

关键词： Custard apple chitosan Ag nanoparticles Chi-Ag nanoparticles antibacterial

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

New Double Integrals Weighted Cebysev Type Inequalities

引用

Journal of Mathematics and System Science 2012年第5期2卷 286-291页

作者： A. Guezane-Lakoud f. Aissaoui Laboratory of Advanced Materials University BadjiMokhtar-Annaba Annaba 23000 Algeria Department of Mathematics Guelma university Guelma 24000 Algeria

In the last years, the theory of integral inequalities are playing a very significant role in all fields of mathematics, many monographs have been devoted to this subject and present a very active and attractive field of research, the applications of integral inequalities have known a great development in many branches of mathematics in statistics, differential equations and numerical integration, The aim of this paper is to establish new extension of the weighted montgomery identity for double integrals then used it to establish new t^eby^evtype inequalities.

关键词： Cebysev type inequalities montgomery identity weighted peanokemel double integrals Cebysevinequalities weightedtCebysev inequalities ostrowski inequality.

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

A Note on the Cosmological Constant in <i>f</i>(<i>R</i>) Gravity

引用

Journal of Applied Mathematics and Physics 2017年第4期5卷 933-938页

作者： Peter K. f. Kuhfittig Department of Mathematics Milwaukee School of Engineering Milwaukee Wisconsin USA

The starting point in this note is f(R) modified gravity in a cosmological setting. We assume a spatially flat universe to describe late-time cosmology and the perfect-fluid equation of state to model the hypothesized dark energy. Given that on a cosmological scale, f(R) modified gravity must remain close to Einstein gravity to be consistent with observation, it was concluded that either (1) Einstein’s cosmological constant was the only acceptable model for the accelerated expansion, or that (2) the equation of state for dark energy was far more complicated than the perfect-fluid model and might even exclude a constant w.

关键词： Cosmological Constant f(R) Gravity

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：