检索结果-南通市图书馆

Metallurgical characteristics of armour steel welded joints used for combat vehicle construction

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2018年第5期14卷 590-606页

作者： g.Magudeeswaran v.Balasubramanian g.Madhusudan Reddy Department of Mechanical Engineering PSNA College of Engineering and TechnologyKothandaraman NagarMuthanampatti624 622DindigulTamilnaduIndia Centre for Materials Joining&Research Department of Manufacturing EngineeringAnnamalai UniversityAnnamalai Nagar608002Tamil NaduIndia Outstanding Scientist & Associate Director Defence Metallurgical Research LaboratoryKanchanbaghHyderabad500058TelanganaIndia

Austenitic stainless steel(ASS) and High nickel steel(HNS) welding consumables are being used for welding Q&T steels, as they have higher solubility for hydrogen in austenitic phase, to avoid hydrogen induced cracking(HIC) but they are very expensive. In recent years, the developments of low hydrogen ferritic steel(LHF) consumables that contain no hygroscopic compounds are utilized for welding Q&T steels. Heat affected zone(HAZ) softening is another critical issue during welding of armour grade Q&T steels and it depends on the welding process employed and the weld thermal cycle. In this investigation an attempt has been made to study the influence of welding consumables and welding processes on metallurgical characteristics of armour grade Q&T steel joints by various metallurgical characterization procedures. Shielded metal arc welding(SMAW) and flux cored arc welding(FCAW) processes were used for making welds using ASS, LHF and HNS welding consumables. The joints fabricated by using LHF consumables offered lower degree of HAZ softening and there is no evidence of HIC in the joints fabricated using LHF consumables.

关键词： Armour grade Q&T steel Heat affected zone softening Shielded metal arc welding process Flux cored arc welding process Austenitic stainless steel Low hydrogen ferritic steel High nickel steel

Clinical characteristics and treatment outcomes in patients with liver cirrhosis and lymphoma

在线全文

学校读者我要写书评

暂无评论

World Journal of Hepatology 2020年第2期12卷 34-45页

作者： JoséA gonzález-Regueiro Astrid Ruiz-Margáin Mariana Cruz-Contreras Ana M Montaña-Duclaud Andrea Cavazos-gómez Roberta Demichelis-gómez Ricardo U Macías-Rodríguez Department of gastroenterology Instituto Nacional de Ciencias Médicas y Nutrición SalvadorGastroenterologyInstituto Nacional de Ciencias Médicas y Nutrición Salvador ZubiránVasco de Quiroga 15Belisario Domínguez Sección XVITlalpanMexico City 14080Mexico Department of Hematology Instituto Nacional de Ciencias Médicas y Nutrición Salvador ZubiránVasco de Quiroga 15Belisario Domínguez Sección XVITlalpanMexico City 14080Mexico

BACKgROUND A significant number of patients with liver cirrhosis concomitantly develop some type of solid or hematological cancer,including *** of patients with lymphoma and cirrhosis is challenging for physicians due to the clinical characteristics related to cirrhosis,including biochemical and functional abnormalities,as well as portal hypertension and lack of scientific evidence,limiting the use of ***,experts recommend only offering oncological treatment to patients with compensated *** To evaluate the clinical characteristics and treatment outcomes in patients with cirrhosis and lymphoma treated with *** This was a case-control study conducted at a tertiary care center in *** was recorded from medical files and from 8658 possible candidates with cirrhosis and/or lymphoma(2000 to 2018).Only 23 cases had both diseases concomitantly;10 patients with cirrhosis and lymphoma(cases)met the selection criteria and were included,and 20 patients with lymphoma(controls)were included and matched according to age,sex,and date of diagnosis,type and clinical stage of *** patients received treatment with *** statistical analysis,descriptive statistics,Shapiro-Wilk test,Mann-Whitney U test,chisquare test and Fisher's exact test were *** was evaluated using Kaplan-Meier curves and Log-rank *** There were differences in biochemical variables inherent to liver disease and portal hypertension in patients with *** most frequent etiology of cirrhosis was hepatitis C virus(50%);80%were decompensated,the median Child-Turcotte-Pugh score was 7.5(6.75-9.25),and mean Model for End-stage Liver Disease was 11.5±*** lymphomas,non-Hodgkin's were the most common(90%),and diffuse large B cell subtype was the most frequent,with a higher International Prognostic Index in the cases(3 vs 2,P=0.049).The chemotherapy regimens had to be adjusted more frequently in the case

关键词： Cirrhosis Cancer Lymphoma Chemotherapy Treatment Survival Toxicity Adverse events

Bio-Inspired Intelligent Routing in WSN: Integrating Mayfly Optimization and Enhanced Ant Colony Optimization for Energy-Efficient Cluster Formation and Maintenance

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2024年第10期141卷 127-150页

作者： v.g.Saranya S.Karthik Department of Electronics and Communication Engineering Faculty of Engineering&TechnologySRM Institute of Science and TechnologyVadapalani CampusChennai600026India

Wireless Sensor Networks(WSNs)are a collection of sensor nodes distributed in space and connected through wireless *** sensor nodes gather and store data about the real world around ***,the nodes that are dependent on batteries will ultimately suffer an energy loss with time,which affects the lifetime of the *** research proposes to achieve its primary goal by reducing energy consumption and increasing the network’s lifetime and *** present technique employs the hybrid Mayfly Optimization Algorithm-Enhanced Ant Colony Optimization(MFOA-EACO),where the Mayfly Optimization Algorithm(MFOA)is used to select the best cluster head(CH)from a set of nodes,and the Enhanced Ant Colony Optimization(EACO)technique is used to determine an optimal route between the cluster head and base *** performance evaluation of our suggested hybrid approach is based on many parameters,including the number of active and dead nodes,node degree,distance,and energy *** objective is to integrate MFOA-EACO to enhance energy efficiency and extend the network life of the WSN in the *** proposed method outcomes proved to be better than traditional approaches such as Hybrid Squirrel-Flying Fox Optimization Algorithm(HSFLBOA),Hybrid Social Reindeer Optimization and Differential Evolution-Firefly Algorithm(HSRODE-FFA),Social Spider Distance Sensitive-Iterative Antlion Butterfly Cockroach Algorithm(SADSS-IABCA),and Energy Efficient Clustering Hierarchy Strategy-Improved Social Spider Algorithm Differential Evolution(EECHS-ISSADE).

关键词： Enhanced ant colony optimization mayfly optimization algorithm wireless sensor networks cluster head base station(BS)

Effect of Hardfaced Interlayer Thickness and Low Hydrogen Ferritic Capping on Ballistic Performance of Shielded Metal Arc Welded Armour Steel Joints

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 Iron and Steel Research International 2013年第12期20卷 82-91页

作者： M Balakrishnan v Balasubramanian g Madhusudhan Reddy Center for Materials Joining and Research(CEMAJOR) Department of Manufacturing EngineeringAnnamalai University Solidification Technology Division Metal Joining GroupDefense Metallurgical Research Laboratory(DMRL)

Armour grade quenched and tempered steel closely confirming to AISI 4340 is well known for its superior ballistic performance and hence used in the fabrication of combat vehicles. The traditional fillers like austenitic stain- less steel showed poor ballistic performance of these welded joints as compared to the base metal. Attempts have been made to deposit hardfaced interlayer between austenitic stainless steel weld metals. Though this method, mar-- ginal improvements in ballistic performance can be yielded, and cracks were observed in between base metal and hardfaced layer. Thickness of the hardfaced interlayer plays a vital role for the effective ballistic performance. Thus, an attempt has been made to investigate the effect of hardfaced interlayer thickness on ballistic performance of ar- mour steel welds. The results of effect of buttering, low hydrogen ferritic （LHF） filler and three different hardfaced layer thicknesses （4, 5.5 and 7 ram） on ballistid performance of shielded metal arc welded armour steel joints were given.

关键词： armour steel low hydrogen ferritic electrode sandwich structure ballistic performance hardfacing metallography

Joint effect of quasicrystalline icosahedral and L1_(2)-strucutred phases precipitation on the grain structure and mechanical properties of aluminum-based alloys

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2021年第28期87卷 196-206页

作者： A.g.Mochugovskiy N.Yu.Tabachkova M.Esmaeili ghayoumabadi v.v.Cheverikin A.v.Mikhaylovskaya National University of Sciences and Technology“MISIS” 119049Leninskiy Ave.4MoscowRussia Prokhorov.general Physics Institute of the Russian Academy of Sciences MoscowRussia

Dispersoid hardening is a key factor in increasing the recrystallization resistance and mechanical strength of non-heat treatable aluminum-based *** and Zr are the main elements that form dispersoids in commercial Al-based *** this work,the annealing-induced precipitation behavior,the grain structure,and the mechanical properties of Al-3.0 Mg-1.1 Mn and Al-3.0 Mg-1.1 Mn-0.25 Zr alloys were *** microstructure and the mechanical properties were significantly affected by annealing regimes after casting for both *** research demonstrated a possibility to form high-density distributed quasicrystalline-structured I-phase precipitates with a mean size of 29 nm during low-temperature annealing of as-cast *** manganese-bearing precipitates of I-phase increased recrystallization resistance and significantly enhanced the mechanical strength of the alloys *** estimated strengthening effect owing to I-phase precipitation was 150 *** to the formation of L1_(2)-structured Al3Zr dispersoids with a mean size of 5.7 nm,additional alloying with Zr increased yield strength by about 90 *** L1_(2)-phase strengthening effect was estimated through the dislocation bypass looping and shearing mechanisms.

关键词： Aluminum alloy Quasicrystals Dispersoid hardening Recrystallization Mechanical properties

Liberalization of Staple Crops： Lessons from the Mexican Experience in Maize

在线全文

学校读者我要写书评

暂无评论

Journal of Agricultural Science and Technology 2010年第3期4卷 95-101页

作者： A. Yunez-Naude v. serrano Center for Economic Studies El Colegio de Mexico Camino al Ajusco 20 Mexico City C.P. 10740 Mexico

In this paper the authors inquire why, after more than 25 years of domestic agricultural reforms in Mexico and 15 years of trade liberalization of maize under the North American Free Trade Agreement （NAFTA）, the domestic production of maize, a non-competitive crop and the major staple in Mexico, has increased. The authors present new empirical evidence showing that, as expected, maize prices in Mexico dropped until 2006 and have experienced a process of convergence with USA prices, and maize imports from the USA have increased. However, despite lower prices, maize production in Mexico has trended upward since 1992, two years before the beginning of NAFTA＇s implementation. Based on the heterogeneity of maize production in Mexico, three possible explanations are proposed to explain this unexpected outcome： government supports to big commercial farmers in the agriculturally rich North of Mexico; the persistence of maize production by subsistence farmers; and to a lesser degree, increasing yields on some irrigated maize farms. We finish the paper by drawing lessons from the experience of Mexico for other Less Developed Countries.

关键词： Domestic and trade liberalization price convergence structural change

Evolution of ionization waves in a multi-pulsed plasma jet:the role of memory charges

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Plasma Science and Technology 2023年第3期25卷 95-103页

作者： N Yu BABAEvA g v NAIDIS v F TARASENKO D A SOROKIN Cheng ZHANg Tao SHAO Joint Institute for High Temperatures Russian Academy of Sciences Institute of High Current Electronics Siberian BranchRussian Academy of Sciences Institute of Electrical Engineering Chinese Academy of Sciences University of Chinese Academy of Sciences

In this paper,we discuss the properties of ionization waves(IWs)in a multi-pulsed plasma jet while using the two-dimensional computational *** IWs are generated by application of three short negative pulses with a repetition frequency 12.5 *** simulations are performed continuously during a single run while accounting for charges accumulated inside(surface charges)and outside(space charges)the *** plasma forming gas mixture(He/O2=99.8%/0.2%)is injected through the discharge tube into the surrounding humid *** show that an IW can emerge from the tube exit at a pulse rising edge(as a negative IW)and at a falling edge of the same pulse(as a positive IW).It is demonstrated that remnants of the negative and positive charges play an essential role in the discharge *** first pulse travels the shortest distance as it propagates through the initially non-ionized *** IWs developing during the second pulse essentially enlarge the plasma plume *** the same time,the IWs generated by the third pulse eventually decay due to the remnants of charges accumulated during the previous *** memory charges can lead to the IW extinction.

关键词： helium plasma jet multiple pulses positive and negative ionization waves

Eosinophilic esophagitis: Current concepts in diagnosis and treatment

在线全文

学校读者我要写书评

暂无评论

World Journal of gastroenterology 2019年第32期25卷 4598-4613页

作者： Andrés gómez-Aldana Mario Jaramillo-Santos Andrés Delgado Carlos Jaramillo Adán Lúquez-Mindiola Departament of Internal Medicine Section of GastroenterologySanta Fe Foundation of Bogotá(Fundación Santa Fe de Bogotá)Bogotá220246Colombia University of Los Andes Bogotá111711Colombia Department of Endoscopy Caldas UniversityManizales 275Colombia Department of Endoscopy Surgeons’Union SAS(Joint stock company)(Union de cirujanos SAS)Manizales 170001661Colombia Department of gastroenterology Gut MédicaBogotá110221001Colombia

Eosinophilic esophagitis is an immune-allergic pathology of multifactorial etiology(genetic and environmental)that affects both pediatric and adult *** symptoms,which include heartburn,regurgitation,and esophageal stenosis(with dysphagia being more frequent in eosinophilic esophagitis in young adults and children),are similar to those of gastroesophageal reflux disease,causing delays in diagnosis and *** endoscopic findings such as furrows,esophageal mucosa trachealization,and whitish exudates may suggest its presence,this diagnosis should be confirmed histologically based on the presence of more than 15 eosinophils per high-power field and the exclusion of other causes of eosinophilia(parasitic infections,hypereosinophilic syndrome,inflammatory bowel disease,among others)for which treatment could be ***,the 3“D”s(“Drugs,Diet,and Dilation”)are considered the fundamental components of *** first 2 components,which involve the use of proton pump inhibitors,corticosteroids,immunosuppressants and empirical diets or guided food elimination based on allergy tests,are more useful in the initial phases,whereas endoscopic dilation is reserved for esophageal ***,the most important aspects of eosinophilic esophagitis pathophysiology will be reviewed,in addition to evidence for the various treatments.

关键词： Eosinophilic esophagitis Corticoid Esophageal stenosis Diet Dilation Proton pump inhibitor

Production and mechanical properties of nano SiC particle reinforced Ti-6Al-4v matrix composite

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 2017年第1期27卷 82-90页

作者： g.SIvAKUMAR v.ANANTHI S.RAMANATHAN CISL Department of PhysicsAnnamalai UniversityTamilnadu 608002India Physics Section FEATAnnamalai UniversityTamilnadu 608002India Manufacturing Engineering Department Annamalai UniversityTamilnadu 608002India

Different mass fractions （0, 5%, 10%, and 15%） of the synthesized nano SiC particles reinforced Ti-6Al-4v （Ti64） alloy metal matrix composites （MMCs） were successfully fabricated by the powder metallurgy method. The effects of addition of SiC particle on the mechanical properties of the composites such as hardness and compressive strength were investigated. The optimum density （93.33%） was obtained at the compaction pressure of 6.035 MPa. Scanning electron microscopic （SEM） observations of the microstructures revealed that the wettability and the bonding force were improved in Ti64 alloy/5% nano SiCp composites. The effect of nano SiCp content in Ti64 alloy/SiCp matrix composite on phase formation was investigated by X-ray diffraction. The correlation between mechanical parameter and phase formation was analyzed. The new phase of brittle interfaced reaction formed in the 10% and 15% SiCp composite specimens and resulted in no beneficial effect on the strength and hardness. The compressive strength and hardness of Ti64 alloy/5% nano SiCp MMCs showed higher values. Hence, 5% SiCp can be considered to be the optimal replacement content for the composite.

关键词： titanium alloy nano SiC particle powder metallurgy hardness compressive strength