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An approach for optimization of the wall thickness (weight) of a thick-walled cylinder under axially non-uniform internal service pressure distribution

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Defence Technology（防务技术） 2017年第3期13卷 150-157页

作者： Onur Güngor MKE Kurumu Mühimmat Fabrikas Ar-Ge Müdürlügü 71100 Merkez

Today, improving the weight/load carrying capacity ratio of a part is the matter of studies in most of the scientific and industrial *** dimensions, the amount of material removed from outer and inner radius while manufacturing and the service pressure applied affect the residual stress distribution throughout the wall thickness and hence the load-bearing capacity of a thick-walled cylinder. Calculation of residual stresses after autofrettage process and optimization of autofrettage outline dimensions by using the amount of service pressures applied are common issues in *** this study, mandrel-cylinder tube interference dimensions were renovated by using traditional methods for swage autofrettage process of a gun barrel. Also, the residual stresses in the cylinder after autofrettage process, inside and outside material removal process and the variable service pressure throughout the cylinder applied were taken into consideration and incorporated into the design. By using the constrained optimization method, wall thickness(thus the weight) was optimized(minimized)to achieve the specified safety factor along the length of the cylinder. For the same cylinder, the results of the suggested analytical/with residual stress calculation approach were compared to analytical/without residual stress calculation results and numerical topology optimization method calculation results. Since the experimental measurement results are not yet available, it was not possible to compare them with the calculation *** suggested approach enabled 22.9% extra weight reduction in proportion to numerical topology optimization and enabled 4.2% extra weight reduction in proportion to analytical/without residual stress *** this approach, the gain from residual stresses after autofrettage operation, the loss of residual stresses after material removal, and the effects of service pressures can be taken into account for each stage of design.

关键词：尺寸优化圆筒壁厚厚壁圆筒载重量残余应力分析非均匀应力计算方法自增强材料

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Mechanical and thermal properties of RETaO4(RE=Yb,Lu,Sc)ceramics with monoclinic-prime phase

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Journal of Materials Science & Technology 2020年第17期52卷 20-28页

作者： Lin Chen Mingyu Hu Jun Guo Xiaoyu Chong Jing Feng Faculty of Material Science and Engineering Kunming University of Science and TechnologyKunming 650093People's Republic of China School of Engineering Brown UniversityProvidenceRl02912USA

As candidate thermal/environmental barrier coatings(T/EBCs),the structure characteristics and comprehensive properties of monoclinic-prime(m')RETaO4(RE=Yb,Lu,Sc)with excellent Al2O3/SiO2 chemical compatibility are *** thermal insulation protection will be provided by m'RETaO4 due to their low thermal conductivity(~1.6 Wm^-1 K^-1,900℃)and prominent thermal radiation resistance,which is much better than those of YSZ(~2.5 Wm^-1 K^-1,1000℃)and La-12 Zr2O7(~2.0 Wm^-1 K,900℃).The thermal expansion coefficients(TECs)are 3.0–8.0×10^-6 K^-1(200-1200℃),which is suitable for T/EBCs ***,absence of phase transition and extraordinary chemical compatibility with Al2O3/SiO2 up to 1500℃indicate the potential application *** documented governing mechanisms of m'RETaO4 properties will enable researchers to promote their application in the future investigation.

关键词： Ceramics Thermal/environmental barrier coatings Rare earth tantalates Mechanical property Thermal conductivity Chemical compatibility

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Incidenee and time-varying predictors of HIV and sexually transmitted infections among male sex workers in Mexico City

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Infectious Diseases of Poverty 2021年第1期10卷 36-45页

作者： Karla Y.Ganley Marta Wilson-Barthes Andrew R.Zullo Sandra G.Sosa-Rubi Carlos J.Conde-Glez Santa Garcia-Cisneros Mark N.Lurie Brandon D.L.Marshall Don Operario Kenneth H.Mayer Omar Galarraga Department of Narrative Medicine Columbia UniversityNew YorkNYUSA Department of Epidemiology School of Public HealthBrown UniversityProvide neeRlUSA Department of health Services Policyand PracticeSchool of Public HealthBrown University121 South Main StreetBox G-121S-2ProvidenceRl 02912USA National Institute of Public health(INSP) CuernavacaMorelosMexico Department of Behavioral and Social Science School of Public HealthBrown UniversityProvidenceRlUSA Fenway health and Harvard University BostonMAUSA.

Background:Male sex workers are at high-risk for acquisition of sexually transmitted infections(STIs),including human immunodeficiency virus(HIV).We quantified incidence rates of STIs and identified their time-varying predictors among male sex workers in Mexico ***:From January 2012 to May 2014,male sex workers recruited from the largest HIV clinic and community sites in Mexico City were tested for chlamydia,gonorrhea,syphilis,hepatitis,and HIV at baseline,6-months,and *** nee rates with 95%bootstrapped confide nee limits were *** examined potential timevarying predictors using generalized estimating equations for a population averaged ***:Among 227 male sex workers,median age was 24 and baseline HIV prevalence was 32%.Incidence rates(per 100 person-years)were as follows:HIV[5.23;95%confidence interval(CI):2.15-10.31],chlamydia(5.15;95%CI:2.58-9.34),gonorrhea(3.93;95%CI:1.88-7.83),syphilis(13.04;95%CI:8.24-19.94),hepatitis B(2.11;95%CI:0.53-4.89),hepatitis C(0.95;95%CI:0.00-3.16),any STI except HIV(30.99;95%CI:21.73-40.26),and any STI including HIV(50.08;95%CI:37.6062.55).In the multivariable-adjusted model,incident STI(excluding HIV)were lower among those who reported consistently using condoms during anal and vaginal intercourse(odds ratio=0.03,95%CI:0.00-0.68)compared to those who reported inconsistently using condoms during anal and vaginal ***:Incidence of STIs is high among male sex workers in Mexico *** condom use is an important protective factor for STIs,and should be an important comp on ent of interventions to prevent incide nt infect i ons.

关键词： Male sex worker Men who have sex with men HIV Sexually transmitted infection Transmission Risk factor Mexico

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From Academic Nitpicking to a =New Culture Movement＇： How Newspapers Turned Academic Debates into the Center of ~May Fourth＂

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Frontiers of History in China 2014年第4期9卷 534-557页

作者： Elisabeth Forster Faculty of History University of Oxford Oxford OX 1 2RL United Kingdom

Abstract In early 1919, people like Hu Shi and Chen Duxiu were regarded as members of an ivory-tower ＂academic faction＂（xuepai）, embroiled in a debate with an opposing ＂faction.＂ After the May Fourth demonstrations, they were praised as the stars of a ＂New Culture Movement.＂ However, it was not obvious how the circle around Hu Shi and Chert Duxiu was associated with the May Fourth demonstrations. This link hinged on the way in which newspapers like Shenbao reported about the academic debates and the political events of May Fourth. After compartmentalizing the debating academics into fixed xuepai, Shenbao ascribed warlord-political allegiances to them. These made the Hu-Chen circle look like government victims and their ＂factional＂ rivals like the warlords＇ allies. When the atmosphere became hostile to the government during May Fourth, Hu Shi＇s ＂faction＂ became associated with the equally victimized May Fourth demonstrators. Their ideas were regarded as （now popular） expressions of anti-government sentiment, and soon this was labeled the core of the ＂New Culture Movement.＂ The idea and rhetoric of China＇s ＂New Culture Movement＂ in this way emerged out of the fortuitous concatenation of academic debates, newspaper stories, and political events.

关键词： May Fourth Movement New Culture Movement Shenbao academicfactions (xuepai) Chinese newspapers

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Therapeutic potential of rutin in male infertility:A mini review

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Journal of Integrative Medicine 2023年第2期21卷 130-135页

作者： Damilare Emmanuel Rotimi Tobiloba Christiana Elebiyo Oluwafemi Adeleke Ojo SDG 03 Group–Good health&Well-being Landmark UniversityOmu-Aran 251101Kwara StateNigeria Department of Biochemistry Landmark UniversityOmu-Aran 251101Kwara StateNigeria Phytomedicine Molecular Toxicologyand Computational Biochemistry Research Laboratory(PMTCB-RL)Department of BiochemistryBowen UniversityIwo 232101Osun StateNigeria

Male infertility has become a problem worldwide,and recent research has emphasized the development of more effective therapy *** natural compounds,rutin has been widely studied for its potential to treat dysfunction related to male infertility,including a reduction in sperm quality,spermatogenesis disruption and structural disruption in the testis.A thorough review of scientific literature published in several databases,including Google Scholar,PubMed/MEDLINE and Scopus,was used to synthesize the present state of research on the role of rutin in male reproductive *** has been shown to possess antiapoptotic,antioxidant and anti-inflammatory activities,among others,which are crucial in the management of male *** investigations have shown that rutin protects against male infertility and have explored the underlying mechanisms *** present review,therefore,assesses the therapeutic mechanisms involved in male infertility treatment using *** was able to mitigate the induced oxidative stress,apoptosis,inflammation,and related physiological processes that can cause testicular dysfunction.

关键词： Antioxidant Inflammation Rutin Sperm Testicularfunction

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A genome-wide scan for pleiotropy between bone mineral density and nonbone phenotypes

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Bone Research 2020年第3期8卷 356-364页

作者： Maria A.Christou Georgios Ntritsos Georgios Markozannes Fotis Koskeridis Spyros N.Nikas David Karasik Douglas P.Kiel Evangelos Evangelou Evangelia E.Ntzani Department of Hygiene and Epidemiology Clinical and Molecular Epidemiology UnitSchool of MedicineUniversity of loanninaloanninaGreece Department of Medicine Beth Israel Deaconess Medical CenterHarvard Medical SchoolHinda and Arthur Marcus Institute for Aging ResearchHebrew SeniorLifeand the Broad Institute of MIT&HarvardCambridgeMAUSA Azrieli Faculty of Medicine Bar llan UniversitySafedIsrael Department of Epidemiology and Biostatistics Imperial College LondonLondonUK Department of health Services Policy and PracticeCenter for Research Synthesis in HealthSchool of Public HealthBrown UniversityProvidenceRlUSA

Osteoporosis is the most common metabolic bone disorder globally and is characterized by skeletal fragility and microarchitectural *** pleiotropy occurs when a single genetic element is associated with more than one *** aimed to identify pleiotropic loci associated with bone mineral density(BMD)and nonbone phenotypes in genome-wide association *** the discovery stage,the NHGRI-EBI Catalog was searched for genome-wide significant associations(P value<5 x 108),excluding bone-related *** was used to identify proxies of the significantly associated single nucleotide polymorphisms(SNPs)(r2=1).We then assessed putative genetic associations of this set of SNPs with femoral neck(FN)and lumbar spine(LS)BMD data from the GEFOS *** variants were claimed at a false discovery rate<1.4x 103 for FN-BMD and<1.5 x 10-3 for *** of these genetic markers was performed among more than 400000 UK Biobank participants of European ancestry with available genetic and heel bone ultrasound *** the discovery stage,72 BMD-related pleiotropic SNPs were identified,and 12 SNPs located in 11 loci on 8 chromosomes were replicated in the UK *** SNPs were associated,in addition to BMD,with 14 different *** pleiotropic associations were exhibited by rs479844(AP5B1,O V O L 1 genes),which was associated with dermatological and allergic diseases,and rs4072037(M U C 1 gene),which was associated with magnesium levels and gastroenterological *** conclusion,12 BMD-related genome-wide significant SNPs showed pleiotropy with nonbone *** associations can deepen the genetic understanding of bone-related diseases by identifying shared biological mechanisms with other diseases or traits.

关键词： magnesium globally Replication

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Hyperpycnal (over density) flows and deposits

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Journal of Palaeogeography 2020年第3期9卷 267-287页

作者： Carlos Zavala Departamento de Geologia Universidad Nacional del SurSan Juan 6708000 Bahia BlancaArgentina GCS Argentina 5rl Molina Campos 1508000 Bahia BlancaArgentina

A hyperpycnal flow forms when a relatively dense land-derived gravity flow enters into a marine or lacustrine water reservoir. As a consequence of its excess of density, the incoming flow plunges in coastal areas, generating a highly dynamic and often long-lived dense underflow. Depending on the characteristics of the parent flow(flow duration and flow rheology) and basin salinity, the resulting deposits(hyperpycnites) can be very *** to flow duration, land-derived gravity flows can be classified into short-lived or long-lived flows. Shortlived gravity flows last for minutes or hours, and are mostly related to small mountainous river discharges, alluvial fans, collapse of natural dams, landslides, volcanic eruptions, j?kulhlaups, etc. Long-lived gravity flows last for days,weeks or even months, and are mostly associated with medium-to large-size river *** the rheology of the incoming flow, hyperpycnal flows can be initiated by non-Newtonian(cohesive debris flows), Newtonian supercritical(lahars, hyperconcentrated flows, and concentrated flows) or Newtonian subcritical flows(pebbly, sandy or muddy sediment-laden turbulent flows). Once plunged, non-Newtonian and Newtonian supercritical flows require steep slopes to accelerate, allow the incorporation of ambient water and develop flow transformations in order to evolve into a turbidity current and travel further basinward. Their resulting deposits are difficult to differentiate from those related to intrabasinal turbidites. On the contrary, long-lived Newtonian subcritical flows are capable of transferring huge volumes of sediment, freshwater and organic matter far from the coast even along gentle or flat slopes. In marine settings, the buoyant effect of interstitial freshwater in pebbly and sandy hyperpycnal flows can result in lofting due to flow density reversal. Since the excess of density in muddy hyperpycnal flows is provided by silt-clay sediments in turbulent suspension, lofting

关键词： Hyperpycnal flows Hyperpycnites Turbidites Sediment gravity flows

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Numerical evaluation of an autofrettaged thick-walled cylinder under dynamically applied axially non-uniform internal service pressure distribution

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Defence Technology（防务技术） 2018年第5期14卷 412-416页

作者： Onur Güngor Veli celik MKE Kurumu Müimmat Fabrikasι Ar-Ge Müdürlügü 71100MerkezKιrkkaleTurkey Yιldιrum Beyazιt üniversitesi Doga Bilimleri Fakültesi 06010KeciorenAnkaraTurkey

A dynamical moving pressure structural numerical calculation model using the internal ballistics calculation pressure-time results was constituted and the vicinity of the internal ballistics and quasiinternal ballistics structural model was checked. The Von Mises stresses obtained by the dynamical structural numerical model calculations and the Von Mises stresses calculated from the shot test strain measurements were compared. The difference for the worse case was 20% and for the best case was 0.1%.Furthermore, the model gave better agreement for the higher charge masses. The numerical structural quasi-internal ballistics computation model created was verified for the top charge mass which represents the highest stress condition and used in a gun barrel design.

关键词： Gun tube design Thick wall cylinder Residual stress Internal ballistics Service pressure Wall thickness Numerical modeling of internal ballistics

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Inflammation,epigenetics,and metabolism converge to cell senescence and ageing:the regulation and intervention

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Signal Transduction and Targeted Therapy 2021年第7期6卷 2106-2134页

作者： Xudong Zhu Zhiyang Chen Weiyan Shen Gang Huang John M.Sedivy Hu Wang Zhenyu Ju Key Laboratory of Ageing and Cancer Biology of Zhejiang Province Institute of Ageing ResearchHangzhou Normal University School of MedicineHangzhouChina Key Laboratory of Regenerative Medicine of Ministry of Education Guangzhou Regenerative Medicine and Health Guangdong LaboratoryInstitute of Ageing and Regenerative MedicineJinan UniversityGuangzhouChina Division of Pathology and Experimental Hematology and Cancer Biology Cincinnati Children's Hospital Medical CenterCincinnatiOHUSA Department of Molecular Biology Cell Biology and BiochemistryBrown UniversityProvidenceRlUSA

Remarkable progress in ageing research has been achieved over the past *** perceptions and experimental evidence pinpoint that the decline of physical function often initiates by cell senescence and organ *** dynamics and immunometabolic reprogramming link to the alterations of cellular response to intrinsic and extrinsic stimuli,representing current hotspots as they not only(re-)shape the individual cell identity,but also involve in cell fate *** review focuses on the present findings and emerging concepts in epigenetic,inflammatory,and metabolic regulations and the consequences of the ageing *** therapeutic interventions targeting cell senescence and regulatory mechanisms,using state-of-the-art techniques are also discussed.

关键词： consequences ageing representing

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Multilevel analysis of the central-peripheral-target organ pathway:contributing to recovery after peripheral nerve injury

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Neural Regeneration Research 2025年第10期20卷 2807-2822页

作者： Xizi Song Ruixin Li Xiaolei Chu Qi Li Ruihua Li Qingwen Li Kai-Yu Tong Xiaosong Gu Dong Ming Academy of Medical Engineering and Translational Medicine Tianjin UniversityTianjinChina Haihe Laboratory of Brain-Machine Interface and Human-Machine Fusion TianjinChina Department of Rehabilitation Tianjin University Tianjin HospitalTianjinChina Department of Hand Microsurgery Tianjin University Tianjin HospitalTianjinChina School of Exercise and health Tianjin University of SportTianjinChina Department of Biomedical Engineering the Chinese University of Hong KongHong Kong Special Administrative RegionChina

Peripheral nerve injury is a common neurological condition that often leads to severe functional limitations and *** on the pathogenesis of peripheral nerve injury has focused on pathological changes at individual injury sites,neglecting multilevel pathological analysis of the overall nervous system and target *** has led to restrictions on current therapeutic *** this paper,we first summarize the potential mechanisms of peripheral nerve injury from a holistic perspective,covering the central nervous system,peripheral nervous system,and target *** peripheral nerve injury,the cortical plasticity of the brain is altered due to damage to and regeneration of peripheral nerves;changes such as neuronal apoptosis and axonal demyelination occur in the spinal *** nerve will undergo axonal regeneration,activation of Schwann cells,inflammatory response,and vascular system regeneration at the injury *** damage to target organs can occur,including skeletal muscle atrophy and sensory receptor *** then provide a brief review of the research advances in therapeutic approaches to peripheral nerve *** main current treatments are conducted passively and include physical factor rehabilitation,pharmacological treatments,cell-based therapies,and physical ***,most treatments only partially address the problem and cannot complete the systematic recovery of the entire central nervous system-peripheral nervous system-target organ ***,we should further explore multilevel treatment options that produce effective,long-lasting results,perhaps requiring a combination of passive(traditional)and active(novel)treatment methods to stimulate rehabilitation at the central-peripheral-target organ levels to achieve better functional recovery.

关键词： central nervous system central peripheral target organ multilevel pathological analysis nerve regeneration peripheral nerve injury peripheral nervous system target organs therapeutic approach

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