检索结果-南通市图书馆

Origin of superior low-cycle fatigue resistance of an interstitial metastable high-entropy alloy

Journal of Materials Science & Technology 2022年第20期115卷 115-128页

作者： Seyed Amir Arsalan Shams jae wung bae jae Nam Kim Hyoung Seop Kim Taekyung Lee Chong Soo Lee Graduate Institute of Ferrous Technology Pohang University of Science and TechnologyPohang 37673Republic of Korea Department of Materials Science and Engineering Pohang University of Science and TechnologyPohang 37673Republic of Korea School of Mechanical Engineering Pusan National UniversityBusan 46241Republic of Korea

In this study, the deformation behaviors and related microstructural evolutions were investigated in either monotonic or cyclic deformation modes in an interstitial metastable high-entropy alloy. These investigations aimed to reveal the mechanisms underlying the superior low-cycle fatigue(LCF) life of this alloy.A thermomechanical process was applied to induce fine-grained(FG) and coarse-grained(CG) microstructures in Fe–30Mn–10Co–10Cr–0.4C(atomic percentage) alloy. Their superior combination of strength and ductility was attributed to the appearance of deformation-induced ε-martensite and the presence of carbon. The CG alloy showed a greater volume fraction of ε-martensite than the FG alloy in the monotonic deformation mode, and vice versa in the cyclic mode. Such a disparity was interpreted in light of the back-stress effect of the relaxed γ-grain boundaries in the latter mode. Meanwhile, the γ-to-ε phase transformation under cyclic loading at low strain amplitudes(0.4%) barely led to an improved fatigue life as compared with that at higher strain amplitudes(≥ 0.55%). The high reversibility of partial dislocation motions under cyclic loading and delaying the formation of dislocation cells through the martensitic transformation could explain why the alloys investigated in this study exhibited a superior LCF life compared with high-entropy alloys reported in previous studies.

关键词： High-entropy alloy Transformation-induced plasticity Monotonic deformation Cyclic deformation Low-cycle fatigue Stacking faults

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

Pedicled abdominal flap using deep inferior epigastric artery perforators for forearm reconstruction: A case report

引用

World Journal of Clinical Cases 2024年第4期12卷 828-834页

作者： jae Hyung Jeon Kyung Wook Kim Hong bae Jeon Department of Plastic and Reconstructive Surgery Dankook University HospitalCheonan 31116ChungnamSouth Korea Department of Orthopaedic Surgery Dankook University HospitalDankook University College of MedicineCheonan 31116ChungnamSouth Korea Department of Plastic and Reconstructive Surgery Dankook University HospitalDankook University College of MedicineCheonan 31116ChungnamSouth Korea

BACKGROUND Pedicled abdominal flaps are a widely used surgical technique for forearm reconstruction in patients with soft tissue ***,some drawbacks include restricted flap size,partial flap loss,and donor-site *** address these concerns,we present a case of a pedicled abdominal flap using the deep inferior epigastric artery perforators(DIEP)for forearm reconstruction in a patient with a large soft tissue *** SUMMARY A 46-year-old male patient was admitted to our hospital with forearm injury caused by a pressing machine.A 15 cm×10 cm soft tissue defect with complete rupture of the ulnar side structures of the forearm was *** week after orthopedic management of the neurovascular injury and fractures using the first stage of Masquelet technique,the patient was referred to the plastic and recon-structive surgery department for wound *** debridement and negative-pressure wound therapy revealed a 20 cm×15 cm soft tissue defect.A pedicle abdominal flap with the DIEP was used to cover the *** weeks later,the flap was detached from the abdomen,and the abdominal defect was directly ***,the second stage of Masquelet technique was performed at the fracture site at week ***,all donor and recipient sites healed without complications,such as flap dehiscence,infection,hematoma,or *** site osteosynthesis was achieved without *** Pedicled abdominal flap using the DIEP provides a reliable option for forearm reconstruction in patients with large soft tissue defects.

关键词： Forearm injury Open fracture reduction Perforator flap Deep inferior epigastric artery perforators Case report

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

Surgical Repair of Ventricular Septal Defect in Neonates: Indications and Outcomes

引用

Congenital Heart Disease 2024年第1期19卷 69-83页

作者： jae Hong Lee Sungkyu Cho jae Gun Kwak Hye Won Kwon Woong-Han Kim Mi Kyoung Song Sang-Yun Lee Gi Beom Kim Eun Jung bae Department of Thoracic and Cardiovascular Surgery Research Institute for Convergence of Biomedical Science and TechnologyPusan National University Yangsan HospitalYangsanKorea Department of Thoracic and Cardiovascular Surgery Seoul National University Children’s HospitalSeoulKorea Department of Pediatrics Seoul National University Children’s HospitalSeoulKorea

Background:The optimal surgical timing and clinical outcomes of ventricular septal defect(VSD)closure in neo-nates remain *** aimed to evaluate the clinical outcomes of VSD closure in neonates(age≤30 days).Methods:We retrospectively reviewed 50 consecutive neonates who underwent VSD closure for isolated VSDs between August 2003 and June *** for the procedure included congestive heart failure/failure to thrive and pulmonary *** adverse events(MAEs)were deﬁned as the composite of all-cause mortality,reoperation,persistent atrioventricular block,and signiﬁcant(≥grade 2)valvular ***:The median age and body weight at operation were 26.0 days(interquartile range[IQR],18.8–28.3)and 3.7 kg(IQR,3.3–4.2),*** median follow-up duration was 110.4 months(IQR,56.8–165.0).Seven patients required preoperative respiratory support,andﬁve had signiﬁcant(≥grade 2)preoperative valvular *** early mortality occurred due to irreversible cardiogenic shock;no late mortality was *** reopera-tion was due to hemodynamically signiﬁcant residual VSD at 103.8 months *** overall survival,freedom from reoperation,and freedom from MAE at 15-years were 98.0%,96.3%,and 94.4%,***-operative mechanical ventilation was associated with a longer duration of postoperative mechanical ventilation(p<0.001)and a longer length of intensive care unit stay(p<0.001).Conclusions:VSD closure with favorable outcomes without morbidities is feasible even in ***,neonates requiring preoperative respiratory support may require careful postoperative management considering the long-term postoperative ***,surgical VSD closure might be indicated earlier in neonates with respiratory compromise.

关键词： Ventricular septal defect neonate early surgery neonatal surgery

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

Multi-faceted small molecule for Alzheimer’s disease

引用

Neural Regeneration Research 2023年第10期18卷 2198-2199页

作者： Min Hee Park Hee Kyung Jin jae-sung bae KNU Alzheimer’s Disease Research Institute Department of PhysiologySchool of MedicineKyungpook National UniversityDaeguSouth Korea KNU Alzheimer’s Disease Research Institute Department of Laboratory Animal MedicineCollege of Veterinary MedicineKyungpook National UniversityDaeguSouth Korea

The main pathologies of Alzheimer’s disease(AD)are the accumulation of amyloid-B(AB)and tau ta ngles,and these two fundamental pathologies accompany the va rious neuropathological features,such as neuroinfla mmation,... 详细信息

关键词： Alzheimer tau amyloid

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

Semantic Segmentation by Using Down-Sampling and Subpixel Convolution: DSSC-UNet

引用

Computers, Materials & Continua 2023年第4期75卷 683-696页

作者： Young-Man Kwon Sunghoon bae Dong-Keun Chung Myung-jae Lim Department of Medical IT Eulji University553Sanseong-daeroSujeong-guSeongnam-siGyeonggi-do13135Korea

Recently, semantic segmentation has been widely applied toimage processing, scene understanding, and many others. Especially, indeep learning-based semantic segmentation, the U-Net with convolutionalencoder-decoder architecture is a representative model which is proposed forimage segmentation in the biomedical field. It used max pooling operationfor reducing the size of image and making noise robust. However, instead ofreducing the complexity of the model, max pooling has the disadvantageof omitting some information about the image in reducing it. So, thispaper used two diagonal elements of down-sampling operation instead ofit. We think that the down-sampling feature maps have more informationintrinsically than max pooling feature maps because of keeping the Nyquisttheorem and extracting the latent information from them. In addition,this paper used two other diagonal elements for the skip connection. Indecoding, we used Subpixel Convolution rather than transposed convolutionto efficiently decode the encoded feature maps. Including all the ideas, thispaper proposed the new encoder-decoder model called Down-Sampling andSubpixel Convolution U-Net (DSSC-UNet). To prove the better performanceof the proposed model, this paper measured the performance of the UNetand DSSC-UNet on the Cityscapes. As a result, DSSC-UNet achieved89.6% Mean Intersection OverUnion (Mean-IoU) andU-Net achieved 85.6%Mean-IoU, confirming that DSSC-UNet achieved better performance.

关键词： Semantic segmentation encoder-decoder U-Net DSSC-UNet subpixel convolution down-sampling

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

Effects of Al addition on microstructure and mechanical properties of extruded Mg-3Bi alloy

引用

Journal of Magnesium and Alloys 2022年第7期10卷 1887-1898页

作者： Sang-Cheol Jin jae Won Cha Jun Ho bae Hui Yu Sung Hyuk Park School of Materials Science and Engineering Kyungpook National UniversityDaegu 41566Republic of Korea Implementation Research Division Korea Institute of Materials ScienceChangwon 51508Republic of Korea School of Materials Science and Engineering Hebei University of TechnologyTianjin 300130China

Effects of Al addition to a Mg±Bi binary alloy on its microstructural characteristics and tensile properties after extrusion are investigated via extrusion of Mg-3Bi±x Al(x=0,1,and 2 wt%)billets and analysis of the extruded *** Al addition negligibly affects the second-phase particles of the extruded alloy;however,an increase in the Al content causes significant decreases in the average grain size and maximum texture intensity of the extruded material owing to an increase in the area fraction of dynamically recrystallized(DRXed)*** Al addition improves the strength of the extruded alloy;this improvement is attributed to the enhanced grain-boundary hardening and solid-solution hardening effects induced by grain refinement and Al solute atoms,*** the Al content increases from 0 wt%to 1 wt%and 2 wt%,the tensile elongation increases substantially from 2.8%to 9.4%and 16.9%,*** reduction in the number and size of un DRXed grains with increasing Al content suppresses the formation and coalescence of cracks in the un DRXed grains during tension,which results in a significant improvement in the tensile ductility of the extruded *** tensile deformation,large undesirable twins that act as crack initiation sites are locally formed in the un DRXed grains of the Mg-3Bi alloy,whereas relatively smaller twins are uniformly formed in both the DRXed and the un DRXed grains of the Mg-3Bi-2Al ***,the extruded Mg-3Bi-2Al alloy has a substantially higher tensile yield strength±elongation product(2924 MPa%)than the extruded Al-free B3 alloy(381 MPa%).

关键词： Mg-Bi-Al alloy Extrusion Microstructure Strength Ductility

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

Comparative study of extrudability, microstructure, and mechanical properties of AZ80 and BA53 alloys

引用

Journal of Magnesium and Alloys 2023年第1期11卷 249-258页

作者： Sang-Cheol Jin jae Won Cha Jongbin Go Jun Ho bae Sung Hyuk Park School of Materials Science and Engineering Kyungpook National UniversityDaegu 41566Republic of Korea Department of Materials Science and Engineering Kyoto UniversityKyoto 606-8501Japan Advanced Metals Division Korea Institute of Materials ScienceChangwon 51508Republic of Korea

The extrudability,microstructural characteristics,and tensile properties of the Mg–5Bi–3Al(BA53)alloy are investigated herein by comparing them with those of a commercial Mg–8Al–0.5 Zn(AZ80)*** AZ80 is extruded at 400℃,severe hot cracking occurs at exit speeds of 4.5 m/min or *** contrast,BA53 is successfully extruded without any surface cracking at 400℃ and at high exit speeds of 21–40 m/*** extruded at 3 m/min(AZ80–3)and 40 m/min(BA53–40),both AZ80 and BA53 exhibited completely recrystallized microstructures with abasal ***,BA53–40 has a coarser grain structure owing to grain growth promoted by the high temperature in the deformation ***80–3 contains a continuous network of Mg_(17)Al_(12) particles along the grain boundaries,which form via static precipitation during natural air-cooling after the material exits the extrusion ***53–40 contains coarse Mg_(3)Bi_(2) particles aligned parallel to the extrusion direction along with numerous uniformly distributed fine Mg_(3)Bi_(2) ***80–3 has higher tensile strength than BA53–40 because the relatively finer grains and larger number of solute atoms in AZ80–3 result in stronger grain-boundary and solid-solution hardening effects,*** BA53 is extruded at a high temperature and extrusion speed of 400℃ and 40 m/min,respectively,the extruded material has a high tensile yield strength of 188 *** can be primarily attributed to the large particle hardening effect resulting from the numerous fine Mg_(3)Bi_(2) particles.

关键词： Mg-Bi-Al alloy Extrusion Hot cracking Second phase Tensile properties

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

On the stacking fault forming probability and stacking fault energy in carbon-doped 17 at%Mn steels via transmission electron microscopy and atom probe tomography

引用

Journal of Materials Science & Technology 2022年第20期115卷 177-188页

作者： Hyo Ju bae Kwang Kyu Ko Muhammad Ishtiaq Jung Gi Kim Hyokyung Sung jae Bok Seol Department of Materials Engineering and Convergence Technology Center for K-metalGyeongsang National University(GNU)Jinju 52828South Korea

Assessing the stacking fault forming probability(P_(sf)) and stacking fault energy(SFE)in medium-or highMn base structural materials can anticipate and elucidate the microstructural evolution before and after ***,these two parameters have been determined from theoretical calculations and empirical ***,the estimation of SFE values in Fe–Mn–C ternary systems is a longstanding debate due to the complicated nature of carbon:that is,whether the carbon doping indeed plays an important role in the formation of stacking faults;and how the amount of carbon atoms exist at grain boundaries or at internal grains with respect to the nominal carbon doping ***,the use of atom probe tomography and transmission electron microscopy(TEM)unveils the influence of carbondoping contents on the structural properties of dual-phase Fe–17 Mn–x C(x=0–1.56 at%)steels,such as carbon segregation free energy at grain boundaries,carbon concentration in grain interior,interplanar D-spacings,and mean width of intrinsic stacking faults,which are essential for SFE *** next determined the Psfvalues by two different methods,viz.,reciprocal-space electron diffraction measurements and stacking fault width measurements in real-space TEM ***,SFEs in the Fe–17 Mn–x C systems were calculated on the basis of the generally-known SFE *** found that the high amount of carbon doping gives rise to the increased SFE from 8.6 to 13.5 m J/m^(2)with non-linear *** SFE trend varies inversely with the mean width of localized stacking faults,which pass through both other stacking faults and pre-existingε-martensite plates without much difficulty at their intersecting *** high amount of carbon doping acts twofold,through increasing the segregation free energy(due to more carbon at grain boundaries)and large lattice expansion(due to increased soluble carbon at internal grains).The experimental data obtained here strengthens the composition-

关键词： Stacking fault formation probability Stacking fault energy High-Mn steel Electron diffraction

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

A feasible route to produce 1.1 GPa ferritic-based low-Mn lightweight steels with ductility of 47%

引用

Journal of Materials Science & Technology 2022年第22期117卷 225-237页

作者： Kwang Kyu Ko Hyo Ju bae Eun Hye Park Hyeon-Uk Jeong Hyoung Seok Park jae Seok Jeong Jung Gi Kim Hyokyung Sung Nokeun Park jae Bok Seol Department of Materials Engineering and Convergence Technology Center for K-metalGyeongsang National University(GNU)Jinju 52828South Korea School of Materials Science and Engineering Yeungnam UniversityGyeongbuk 38541South Korea Materials Research Team R&D Hyundai MobisYongin 16891South Korea Materials Technology Development Team Doosan Heavy Industries&ConstructionChangwon 51711South Korea

High- and medium-Mn (H/M-Mn) base lightweight steels are a class of ultrastrong structural materials with high ductility compared to their low-Mn counterparts with low strength and poor ***, producing these H/M-Mn materials requires the advanced or high-tech manufacturing techniques, which can unavoidably provoke labor and cost concerns. Herein, we have developed a facilestrategy that circumvents the strength–ductility trade-off in low-Mn ferritic lightweight steels, by employing low-temperature tempering-induced partitioning (LTP). This LTP treatment affords a typical Fe-2.8Mn-5.7Al-0.3C (wt.%) steel with a heterogeneous size-distribution of metastable austenite embeddedin a ferrite matrix for partitioning more carbon into smaller austenite grains than into the larger austenite ones. This size-dependent partitioning results in slip plane spacing modification and lattice strain,which act through dislocation engineering. We ascribe the simultaneous improvement in strength andtotal elongation to both the size-dependent dislocation movement in austenite grains and the controlleddeformation-induced martensitic transformation. The low-carbon-partitioned large austenite grains increase the strength and ductility as a consequence of the combined martensitic transformation andhigh dislocation density-induced hardening and by interface strengthening. Additionally, high-carbonpartitioned small austenite grains enhance the strength and ductility by planar dislocation glide (inthe low strain regime) and by cross-slipping and delayed martensitic transformation (in the high strainregime). The concept of size-dependent dislocation engineering may provide different pathways for developing a wide range of heterogeneous-structured low-Mn lightweight steels, suggesting that LTP maybe desirable for broad industrial applications at an economic cost.

关键词： Low-Mn lightweight steel Carbon partitioning Metastable austenite Dislocation movement

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

Relationships between Pathological Patterns and Vocal Qualities Estimated by Acoustic Parameters

引用

Chinese Journal of Integrative Medicine 2015年第5期21卷 346-354页

作者： Young-jae Park Young-bae Park Department of Diagnosis and Biofunctional Medicine College of Korean MedicineKyung Hee University Department of Diagnosis and Biofunctional Medicine Kyung Hee University Hospital at Gangdong

Objective： To examine whether vocal characteristics estimated by acoustic parameters were associated with phlegm, yin deficiency, or cold-heat patterns. Methods： A total of 75 college students （males：females = 53：22） aged 19-24 years were enrolled in this study. Each subject was asked to complete the phlegm pattern questionnaire （PPQ）, yin deficiency questionnaire （YDQ） and cold-heat questionnaire （CHQ）. For the acoustic analysis, each subject was asked to produce a sustained vowel sound （/a/） for 3 s to be used to calculate acoustic parameters. Then, habitual fundamental frequency （F0）, jitter, shimmer, F0 tremor, mean F0, standard deviation of F0, maximum F0, minimum F0, normalized noise energy, harmonic-to-noise ratio, signal-to-noise ratio, amplitude tremor, and power ratio were calculated using the Dr. Speech software. Finally, four hierarchical regression models with pattern questionnaire scores as dependent variables were formed to examine which factors among acoustic parameters, sex, and age were predictive of those pattern scores. Results： PPQ, YDQ, heat, and cold pattern scores all formed significant regression model equations and the adjusted R2 values were 0.281, 0.164, 0.156, and 0.170, respectively. There were aging effects in the PPQ and YDQ models （standardized β =0.199, 0.271, respectively）. Vocal tremor-related Fo tremor and vocal ringing-related power ratio parameters were associated with PPQ and YDQ scores. Gender was directly predictive of PPQ and indirectly moderated the relationship between power ratio and YDQ score. Vocal pitch- related habitual F0 and mean F0 were associated with heat and cold scores. These results indicate that the vocal qualities of phlegm- and yin deficiency-susceptible subjects tend to be ringing and less tremorous, and those of heat- and cold-susceptible subjects tend to be high-pitched. Conclusion： Our study results suggest that vocal characteristics estimated by acoustic parameters are partially predictive of phlegm,

关键词： Chinese medicine syndrome oriental medicine acoustic parameters

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

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：