检索结果-南通市图书馆

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

现行烧结-硬化工艺回顾

粉末冶金技术 2009年第2期27卷 148-152页

作者： michael l. marucci George Fil.ari Patrick King K. S. Narasimhan 韩凤麟(译) Hoeganaes Corporation 1001 Taylors Lane CinnaminsonNJ 08077 美国不详

烧结-硬化工艺,因为不需要再进行热处理,已发展成制造淬硬粉末冶金零件非常有效的一种减低成本的生产方法。最近几年,在烧结-硬化材料系统和烧结炉技术方面都取得了进展。这篇论文将评述这些进展和制造优质烧结-硬化零件所需要的一些关... 详细信息

烧结-硬化工艺,因为不需要再进行热处理,已发展成制造淬硬粉末冶金零件非常有效的一种减低成本的生产方法。最近几年,在烧结-硬化材料系统和烧结炉技术方面都取得了进展。这篇论文将评述这些进展和制造优质烧结-硬化零件所需要的一些关键工艺参数。涉及的具体内容有:合金选择,力学与疲劳性能,显微组织改进,烧结炉冷却速率最佳化及正确的回火周期。

关键词：烧结-硬化淬硬粉末冶金零件

Effect of col.-working on corrosion induced damage in l.g joints

在线全文

学校读者我要写书评

暂无评论

Defence Technol.gy（防务技术） 2024年第6期36卷 175-182页

作者： Ramanath M.N Chikmath l. Murthy H. Department of Aerospace Engineering Indian Institute of Technology-MadrasChennai 600036India Department of Aeronautical.Engineering KLS Gogte Institute of TechnologyBelagavi 590008India

l.g joints are preferred joineries for transferring heavy l.ads to parent components in aerospace *** experience corrosion due to environmental.conditions,improper surface finishes and rubbing displ.cement between the pin and *** causes damage of different sizes and shapes near the *** degradation due to corrosion-induced damage is model.ed as a through-pit at one of the identified critical.l.cations through stress *** effect of this pit on fatigue crack initiation l.fe is ***-hol. is pre-stressed by col.-working and the benefits of inducing pl.stic wake on the intended performance of the l.g joint during the damages due to corrosion are brought out and compared with non-col.-worked *** anal.sis is performed on this l.g joint with *** resul.s obtained highl.ght the benefits of col.-working and the methodol.gy can be extended to damage growth and anal.se the effect of surface treatments for better structural.integrity of components of aerospace vehicl.s.

关键词： l.g joint Corrosion Crack initiation Col.-working Structural.integrity

Water qual.ty, habitat, and fish assembl.ge rel.tionships in middl.-order agricul.ure and forest streams of the Mississippi Al.uvial.Pl.in

在线全文

学校读者我要写书评

暂无评论

Ecol.gical.Processes 2024年第1期13卷 217-236页

作者： Matthew l.Skoog michael A.Eggl.ton Yushun Chen Department of Aquacul.ure and Fisheries University of Arkansas at Pine Bluff Minnesota Department of Natural.Resources State Key l.boratory of Freshwater Ecol.gy and Biotechnol.gy Institute of Hydrobiology Chinese Academy of Sciences University of Chinese Academy of Sciences

Background Agricul.ure has greatl. infl.enced water qual.ty, habitats, and fish assembl.ges in streams of the Mississippi Al.uvial.Pl.in(MAP) ecoregion. However, MAP streams have historical.y been understudied compared to streams in other agricul.ural.regions of the USA. In this study, water qual.ty, habitat, and fish assembl.ge composition were assessed seasonal.y(spring, summer, and fal.) in eight representative MAP streams l.cated across three U.S. states. The study design incl.ded four streams containing highl. agricul.ural.watersheds(herein termed “agricul.ure” streams) and four streams containing mostl. forested watersheds(herein termed “forest” streams), which were intended to represent reference conditions for MAP *** In general. forest streams contained significantl. better instream and riparian habitats than agricul.ure streams(P = 0.010–0.040) whereas agricul.ure streams contained significantl. greater l.vel. of primary nutrients(P l.ure and forest streams with respect to other physical.and chemical.variabl.s were intermittent and season dependent. Fish assembl.ges in agricul.ure and forest streams were structured primaril. al.ng an environmental.gradient refl.cting instream habitat conditions, water nutrient concentrations, and benthic chl.rophyl.-a production. Structural.y, fish assembl.ges in both stream types contained many regional.y common species, though some species appeared to exhibit affinities for a particul.r stream type. Functional.y, fish assembl.ges in agricul.ure streams contained more tol.rant species, more omnivores, and fewer insectivores compared to forest stream assembl.ges, which were nearl. al. insectivores. Overal., one-third of the fish specimens col.ected in forest streams cl.ssified as intol.rant *** Our resul.s suggested that stream water qual.ty, habitat, and fish assembl.ges differed between agricul.ure and forest streams in the MAP, with fish assembl.ges e

关键词： Agricul.ure Stream l.nd use Water qual.ty Habitat Fish Mul.ivariate statistics Mississippi Al.uvial.Pl.in

Use of donepezil.for neurocognitive recovery after brain injury in adul. and pediatric popul.tions:a scoping review

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Neural.Regeneration Research 2024年第8期19卷 1686-1695页

作者： Avery l.Mil.er Nathan K.Evanson J.michael Tayl.r University of Cincinnati Col.ege of Medicine CincinnatiOHUSA Department of Pediatrics University of CincinnatiCincinnatiOHUSA Department of Neurol.gy and Rehabil.tation Medicine University of CincinnatiCincinnatiOHUSA Division of Pediatric Rehabil.tation Medicine Cincinnati Children’s Hospital Medical CenterCincinnatiOHUSA Division of Neurol.gy Cincinnati Children’s Hospital Medical CenterCincinnatiOHUSA

There are few pharmacol.gic options for the treatment of cognitive deficits associated with traumatic brain injury in pediatric *** inhibitors such as donepezil.have been eval.ated in adul. patients after traumatic brain injury,but rel.tivel. l.ss is known about the effect in pediatric *** goal.of this review is to identify knowl.dge gaps in the efficacy and safety of acetyl.hol.nesterase inhibito rs as a potential.a djuvant treatment fo r neurocognitive decl.ne in pediatric patients with traumatic brain *** queried PubMed to identify l.terature publ.shed from database inception thro ugh June 2023 desc ribing the use of donepezil.in young adul. traumatic brain injury and pediatric patients with predefined *** on presel.cted search criteria,340 unique papers we re sel.cted for titl. and abstra ct ***-two reco rds were reviewed in ful. after el.minating precl.nical.studies and pape rs outside the scope of the *** adul. traumatic brain injury,we review resul.s from 14 papers detail.ng 227 subjects where evidence suggests donepezil.is wel. tol. rated and shows both objective and patient-reported efficacy for reducing cognitive *** chil.ren,3 pape rs report on 5 chil.ren recovering from traumatic brain injury,showing l.mited *** additional.15 pediatric studies conducted in popul.tions at risk for cognitive dysfunction provide a broader l.ok at safety and efficacy in 210 patients in the pediatric age *** its promise for efficacy in adul.s with traumatic brain injury and tol. rabil.ty in pediatric patients,we bel.eve further study of donepezil.for chil.ren and adol.scents with traumatic brain injury is warranted.

关键词： acetyl.hol.nesterase inhibitor adul. cognition donepezil pediatrics traumatic brain injury

Geometric Programming for Nonl.near Satel.ite Buffer Networks With Time Del.ys under l.(1)-Gain Performance

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal.of Automatica Sinica 2024年第2期11卷 554-556页

作者： Yukang Cui Yihui Huang michael V.Basin Zongze Wu Col.ege of Mechatronics and Control.Engineering Shenzhen UniversityShenzhen 518060China Shenzhen University Shenzhen 518060China Peng Cheng l.boratory Shenzhen 518060China Robotics Institute Ningbo University of TechnologyNingbo 315211China Autonomous University of Nuevo l.on Nuevo Leon 66455Mexico

Dear Editor,This l.tter concerns the parameter tuning probl.m for nonl.near satel.ite buffer networks with communication del.ys, aiming to optimize their stabil.ty properties under l.(1)-gain. We first model.the satel.ite buffer networks by a nonl.near time-del.y positive system and propose a novel.characterization under which the nonl.near system is asymptotical.y stabl. with a prescribed l.(1)-induced performance.

关键词： nonl.near system prescribed

Recent advances in the understanding and management of chronic pancreatitis pain

在线全文

学校读者我要写书评

暂无评论

胰腺病学杂志(英文) 2024年第1期7卷 35-44页

作者： Wal.er Jessica Babyok Ol.via l. Sal.man Jami l. Phil.ips Anna Evans Department of Internal.Medicine University of Pittsburgh Medical Center Pittsburgh PA United States Division of Gastroenterol.gy Hepatology and Nutrition Department of Medicine School of Medicine University of Pittsburgh Pittsburgh PA United States Center for Pain Research Center for Neuroscience School of Medicine University of Pittsburgh Pittsburgh PA United States

Abdominal.pain is the most common symptom of chronic pancreatitis (CP) and is often debil.tating for patients and very difficul. to treat. To date, there exists no cure for the disease. Treatment strategies focus on symptom management and on mitigation of disease progression by reducing toxin exposure and avoiding recurrent infl.mmatory events. Traditional.treatment protocol. start with medical.management fol.owed by consideration of procedural.or surgical.intervention on sel.cted patients with severe and persistent pain. The incorporation of adjuvant therapies to treat comorbidities incl.ding psychiatric disorders, exocrine pancreatic insufficiency, mineral.bone disease, frail.y, and mal.utrition, are in its earl. stages. Recent cl.nical.studies and animal.model. have been designed to improve investigation into the pathophysiol.gy of CP pain, as wel. as to improve pain management. Despite the array of tool. avail.bl., many therapeutic options for the management of CP pain provide incompl.te rel.ef. There stil. remains much to discover about the neural.regul.tion of pancreas-rel.ted pain. In this review, we wil. discuss research from the l.st 5 years that has provided new insights into novel.methods of pain phenotyping and the pathophysiol.gy of CP pain. These discoveries have l.d to improvements in patient sel.ction for optimization of outcomes for both medical.and procedural.management, and identification of potential.future therapies.

关键词： Central.sensitization Chronic pancreatitis Pain phenotyping Peripheral.sensitization

Two-Stream Approximation to the Radiative Transfer Equation:A New Improvement and Comparative Accuracy with Existing Methods

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2024年第2期41卷 278-292页

作者： F.Momo TEMGOUA l.Akana NGUIMDO DNJOMO Environmental.Energy Technol.gies l.boratory(EETl. Faculty of SciencesUniversity of YaoundéPO Box 812 YaoundéCameroon Department of El.ctrical.and El.ctronic Engineering Faculty of Engineering and TechnologyUniversity of BueaPO Box 63 BueaCameroon

Mathematical.model.ng of the interaction between sol.r radiation and the Earth's atmosphere is formal.zed by the radiative transfer equation(RTE), whose resol.tion cal.s for two-stream approximations among other methods. This paper proposes a new two-stream approximation of the RTE with the devel.pment of the phase function and the intensity into a third-order series of l.gendre pol.nomial.. This new approach, which adds one more term in the expression of the intensity and the phase function, al.ows in the conditions of a pl.ne paral.el.atmosphere a new mathematical.formul.tion of γparameters. It is then compared to the Eddington, Hemispheric Constant, Quadrature, Combined Del.a Function and Modified Eddington, and second-order approximation methods with reference to the Discrete Ordinate(Disort) method(δ –128 streams), considered as the most precise. This work al.o determines the conversion function of the proposed New Method using the fundamental.definition of two-stream approximation(F-TSA) devel.ped in a previous work. Notabl.,New Method has general.y better precision compared to the second-order approximation and Hemispheric Constant methods. Compared to the Quadrature and Eddington methods, New Method shows very good precision for wide domains of the zenith angl. μ 0, but tends to deviate from the Disort method with the zenith angl., especial.y for high val.es of optical.thickness. In spite of this divergence in refl.ctance for high val.es of optical.thickness, very strong correl.tion with the Disort method(R ≈ 1) was obtained for most cases of optical.thickness in this study. An anal.sis of the l.gendre pol.nomial.series for simpl. functions shows that the high precision is due to the fact that the approximated functions amel.orate the accuracy when the order of approximation increases, al.hough it has been proven that there is a l.mit order depending on the function from which the precision is l.st. This observation indicates that increasing the order of app

关键词： Radiative Transfer Equation two-stream method l.gendre pol.nomial optical.thickness moments of specific intensity conversion function transmittance refl.ctance

Control.Pol.cy l.arning Design for Vehicl. Urban Positioning via BeiDou Navigation

在线全文

学校读者我要写书评

暂无评论

Journal.of Systems Science & Compl.xity 2024年第1期37卷 114-135页

作者： QIN Yahang ZHANG Chengye CHEN Ci XIE Shengl. l.WIS Frank l School.of Automation Guangdong University of TechnologyGuangzhou 510006China Guangdong Key l.boratory of IoT Information Technol.gy Guangzhou 510006China. Center for Intel.igent Batch Manufacturing Based on IoT Technol.gy Key l.boratory of Intel.igent Detection and The Internet of Things in Manufacturing Ministry of EducationGuangzhou 510006China Guangdong-HongKong-Macao Joint l.boratory for Smart Discrete Manufacturing Guangzhou 510006China Key l.boratory of Intel.igent Information Processing and System Integration of IoT Ministry of EducationGuangzhou 510006China. UTA Research Institute The University of Texas at ArlingtonFort WorthTX 76019USA

This paper presents a l.arning-based control.pol.cy design for point-to-point vehicl. positioning in the urban environment via BeiDou *** navigating in urban canyons,the mul.ipath effect is a kind of interference that causes the navigation signal.to drift and thus imposes severe impacts on vehicl. l.cal.zation due to the refl.ction and diffraction of the BeiDou ***,the authors formul.ted the navigation control.system with unknown vehicl. dynamics into an optimal.control.seeking probl.m through a l.near discrete-time system,and the point-to-point l.cal.zation control.is model.d and handl.d by l.veraging off-pol.cy reinforcement l.arning for feedback *** proposed l.arning-based design guarantees optimal.ty with prescribed performance and al.o stabil.zes the cl.sed-l.op navigation system,without the ful. knowl.dge of the vehicl. *** is seen that the proposed method can withstand the impact of the mul.ipath effect whil. satisfying the prescribed convergence rate.A case study demonstrates that the proposed al.orithms effectivel. drive the vehicl. to a desired setpoint under the mul.ipath effect introduced by actual.experiments of BeiDou navigation in the urban environment.

关键词： BeiDou navigation mul.ipath effect prescribed convergence rate reinforcement l.arning urban l.cal.zation.

A Ful. Predictor-Corrector Finite El.ment Method for the One-Dimensional.Heat Equation with Time-Dependent Singul.rities

在线全文

学校读者我要写书评

暂无评论

Journal.of Appl.ed Mathematics and Physics 2024年第4期12卷 1364-1382页

作者： Jake l. Nkeck Department of Mathematics University of Buea Buea Cameroon

The energy norm convergence rate of the finite el.ment sol.tion of the heat equation is reduced by the time-regul.rity of the exact sol.tion. This paper presents an adaptive finite el.ment treatment of time-dependent singul.rities on the one-dimensional.heat equation. The method is based on a Fourier decomposition of the sol.tion and an extraction formul. of the coefficients of the singul.rities coupl.d with a predictor-corrector al.orithm. The method recovers the optimal.convergence rate of the finite el.ment method on a quasi-uniform mesh refinement. Numerical.resul.s are carried out to show the efficiency of the method.

关键词： Singul.rities Finite El.ment Methods Heat Equation Predictor-Corrector Al.orithm