检索结果-南通市图书馆

Effect of Heat Treatment Process on Properties of 1000 MPa Ultra-High Strength Steel

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2011年第2期18卷 64-69页

作者： YU Wei QIAN ya-jun wu Hui-bin yaNG Yue-hui Metallurgical Engineering Institute University of Science and Technology Beijing Beijing 100083 China

Two types of steel, C-Mn-CrMo B microalloyed steel and C-Mn-Mo-Nb-Cu-B microalloyed steel, are designed to develop 1000 MPa ultra high strength steel. Two kinds of processes, thermomeehanical controlled process （TMCP） combined with traditional off-line quenching and tempering （QT） process versus controlled rolling process （CR） combined with direct quenching and tempering （DQ＋T） process, are applied. The effect of heat treatment processing mode on the microstructure and mechanical properties is studied. The relationship between microstructure and mechanical properties is investigated by SEM and TEM. After tempering at 450 to 550 ℃ for 1 h, the steel produced by TMCP＋QT process shows combination of excellent strength and low temperature toughness. The yield strength is above 1 000 MPa, elongation above 15% and impact energy at -40 ℃ more than 30 J. After tempering at 450 ℃, a large number of ε-Cu particles precipitated in C-Mn-Mo-Nb-Cu-B steel produced by CR＋DQ＋T process lead to a significant increase in yield strength. And after tempering at 500 to 600 ℃, the yield strength of the steel is further improved to 1 030 MPa because of precipitates, such as nitride or carbide of niobium, carbide of molybedenum and vanadium. When the tempering temperature is increased above 620 ℃, the yield strength is still higher than 1 000 MPa and elongation is above 20% and impact energy at --40 ℃ is more than 35 J. After tempering at above 500 ℃, the toughness of the steel treated by TMCP＋QT process is superior to that of steel by CR＋DQ＋T process.

关键词： heat treatment high strength steel microstructure mechanical property

Spatial Distribution of HOCN Around Sagittarius B2

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2022年第3期22卷 61-71页

作者： Si-Qi Zheng Juan Li jun-Zhi Wang Feng Gao ya-jun wu Shu Liu Shang-Huo Li Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030China Key Laboratory of Radio Astronomy Chinese Academy of SciencesNanjing 210033China University of Chinese Academy of Sciences Beijing 100049China Hamburger Sternwarte Universitaet HamburgGojenbergsweg 112D-21029HamburgGermany National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China Korea Astronomy and Space Science Institute 776 Daedeokdae-roYuseong-guDaejeon 34055Republic of Korea

HOCN and HNCO abundance ratio in molecular gas can tell us the information of their formation *** performed high-sensitivity mapping observations of HOCN,HNCO,and HNC^(18)O lines around Sagittarius B2(Sgr B2)with the IRAM 30 m telescope at the 3 mm *** 4_(04)-3_(03)and HOCN 4_(04)-3_(03)are used to obtain the abundance ratio of HNCO to *** ratio of HNCO 4_(04)-3_(03)to HNC^(18)O 4;-3;is used to calculate the optical depth of HNCO 4_(04)-3_(03).The abundance ratio of HOCN and HNCO is observed to range from 0.4%to0.7%toward most positions,which agrees well with the gas-grain ***,the relative abundance of HOCN is observed to be enhanced toward the direction of Sgr B2(S),with HOCN to HNCO abundance ratio of~0.9%.The reason for that still needs further *** on the intensity ratio of HNCO and HNC^(18)O lines,we updated the isotopic ratio of;O/;O to be 296±54 in Sgr B2.

关键词： ISM:abundances ISM:interstellar clouds ISM:interstellar molecules

Different approaches for treating myopic choroidal neovascularization:a network Meta-analysis

在线全文

学校读者我要写书评

暂无评论

International Journal of Ophthalmology(English edition) 2023年第12期16卷 2105-2116页

作者： ya-jun wu Yu-Liang Feng Jia-Song yang Hua Fan Wen-Sheng Li Aier School of Ophthalmology Central South UniversityChangsha 410000Hunan ProvinceChina Department of Ophthalmology Shanghai Aier Eye HospitalShanghai 200235China Shanghai Aier Eye Institute Shanghai 200235China

AIM:To evaluate the efficacy of intravitreal injection of anti-vascular endothelial growth factor(anti-VEGF),photodynamic therapy(PDT),and laser treatment(LT)for anatomical and functional improvement in myopic choroidal neovascularization(mCNV)***:Two researchers independently searched PubMed,Cochrane Library,Web of Science,and other databases to screen studies comparing best-corrected vision acuity(BCVA)and foveal center thickness(FCT)changes after mCNV ***-treatment chorioretinal atrophy(CRA)is a secondary outcome *** retrieval time limit is from the database construction to January 30,***:A total of 1072 eyes in 16 articles were *** the RCTs,intravitreal bevacizumab(IVB)and intravitreal ranibizumab(IVR)were superior to PDT(MD=0.18,95%CI:0.02,0.40,MD=0.18,95%CI:0.01,0.42)in improving BCVA of mCNV patients(P<0.05).The relative effectiveness in improving BCVA,from high to low,appeared to be IVR,intravitreal aflibercept(IVA),IVB,LT,PDT,and sham first followed by IVA(Sham/IVA).While improving the FCT from high to low was IVA,IVR,IVB,*** retrospective studies,the results of BCVA after long-term treatment showed that all the therapeutic effects from high to low was IVA,intravitreal conbercept(IVC),IVR,IVB,IVB/IVR,PDT with IVB/IVR,*** effect of improving FCT was IVA,IVR,IVC,PDT,and IVB from high to *** in the effects of improving CRA,the IVB appeared to be higher than IVR,while the PDT was the smallest,but none of the differences in the results were statistically ***:Anti-VEGF has the best effect on longterm vision improvement in mCNV patients,using IVB or IVR alone to treat mCNV may be better than IVB or IVR combined with *** is no significant difference in the improvement of visual acuity,macular edema,and CRA in mCNV patients treated with any different anti-VEGF drugs.

关键词： myopic choroidal neovascularization aflibercept bevacizumab conbercept laser treatment ranibizumab photodynamic therapy

Vitrectomy with internal limiting membrane peeling versus its flap insertion for macular hole in high myopia: a Meta-analysis

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

International Journal of Ophthalmology(English edition) 2020年第1期13卷 141-148页

作者： ya-jun wu Jie Rao Kang-Rui wu Na wu Yi Cheng Xiao-Xuan Xu Li yan Yi Shao Yu Tian Xiao-Rong wu Department of Ophthalmology the First Affiliated Hospital of Nanchang UniversityNanchang 330006Jiangxi ProvinceChina Department of Ophthalmology the Second Xiangya HospitalCentral South UniversityChangsha 410008Hunan ProvinceChina

AIM: To compare the anatomic and functional outcomes between vitrectomy with internal limiting membrane(ILM) peeling and internal ILM flap insertion technique for high myopia macular hole(MH).METHODS: Pub Med, Cochrane Library, EMBASE, and CNKI were systematically searched, and all studies involved MH were included. The closure rate of MH and the postoperative best-corrected visual acuity(BCVA) at 6 mo after the initial surgery were the primary measures. All statistical tests were performed in Review Manager ***: Five studies that included 151 eyes of 151 patients were finally included, all of which were retrospectively comparative studies. Between the pars plana vitrectomy(PPV) with ILM peeling surgery and the ILM insertion technique, the latter had significantly better efficacy with respect to the closure rate of MH(OR=21.32, 95%CI=7.25-62.67, P<0.001);However, regarding BCVA at 6 mo after the initial surgery in MH, there was no statistical significance between the groups(OR=-0.04, 95%CI=-0.22-0.14, P=0.66). In addition, regarding the rate of retinal reattachment after the initial surgery, the two different methods were not significantly different(OR=2.22, 95%CI=0.34-14.32, P=0.4).CONCLUSION: Both ILM peeling and ILM insertion technique could significantly improve anatomic outcomes of MH in high myopia with or without retinal detachment(RD), and anatomic outcomes are more effective. However, there is no statistical significance in BCVA at 6 mo after the initial surgery in MH, or in the rate of retinal reattachment after the first surgery, between the two methods.

关键词： macular hole high myopia best-corrected visual acuity retinal attachment Meta-analysis

A novel Doppler frequency measurement method based on the closed-loop signal correlation for deep space exploration

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

Research in Astronomy and Astrophysics 2021年第9期21卷 75-82页

作者： Tao Deng Mao-Li Ma Qing-Bao He Qing-Hui Liu ya-jun wu Xin Zheng Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030China University of Chinese Academy of Sciences Beijing 100049China Southern University of Science and Technology Shenzhen 518055China

In deep space exploration,it is necessary to improve the accuracy of frequency measurement to meet the requirements of precise orbit determination and various scientific studies.A phase detector is one of the key modules that restricts the tracking performance of phase-locked loop(PLL).Based on the phase relationship between adjacent signals in the time domain,a novel phase detector is presented to replace the arctangent phase *** new PLL,which is a closed loop signal correlation algorithm,shows good performance in tracking signals with high precision and the tracking accuracy of frequency of1 second integration is close to Cramer-Rao lower bound(CRLB)when setting proper *** data processing results further illustrate the excellent performance of the novel PLL.

关键词： Doppler measurement:Cramer-Rao lower bound carrier tracking:phase locked loop signal correlation

A digital pulsar backend based on FPGA

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2017年第1期17卷 97-102页

作者： Jin-Tao Luo Lan Chen Jin-Lin Han Ali Esamdin ya-jun wu Zhi-Xuan Li Long-Fei Hao Xiu-Zhong Zhang National Time Service CenterChinese Academy of SciencesXi'an 710600China Key Laboratory of Time and Frequency Primary Standards Chinese Academy of SciencesXi'an 710600China National Astronomical Observatories Chinese Academy of SciencesBeijing 100012China Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China Shanghai Institute of Technology Shanghai 200235China Yunnan Observatories Chinese Academy of SciencesKunming 650011China Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030China

A digital pulsar backend based on a Field Programmable Gate Array （FPGA） is developed. It is designed for incoherent de-dispersion of pulsar observations and has a maximum bandwidth of 512MHz. The channel bandwidth is fixed to 1 MHz, and the highest time resolution is 10 p.s. Testing observations were carried out using the Urumqi 25-m telescope administered by Xinjiang Astronomical Observatory and the Kunming 40-m telescope administered by Yunnan Observatories, targeting PSR J0332＋5434 in the L band and PSR J0437-4715 in the S band, respectively. The successful observation of PSR J0437-4715 demonstrates its ability to observe millisecond pulsars.

关键词： instrumentation miscellaneous - methods data analysis - pulsars general

A bibliometric analysis of molybdenum-based nanomaterials in the biomedical field

在线全文

学校读者我要写书评

暂无评论

Tungsten 2024年第1期6卷 17-47页

作者： Zhi-Qiang Wang ya-Wen Pan Jing wu Hong-Bin Qi Shuang Zhu Zhan-jun Gu School of Science China University of GeosciencesBeijing 100083China CAS Key Laboratory for Biomedical Eff ects of Nanomaterials and Nanosafety Institute of High Energy PhysicsBeijing 100049China CAS Center for Excellence in Nanoscience National Center for Nanoscience and Technology of ChinaChinese Academy of SciencesBeijing 100190China College of Materials Science and Optoelectronic Technology University of Chinese Academy of SciencesBeijing 100049China

Molybdenum(Mo)-based nanomaterials have been widely used in biomedical fields due to their various nanostructures and unique physical/chemical *** various reviews have described the development of Mo-based materials in the biomedical field,an objective and comprehensive summary and analysis of research trends in this field is still ***,we used the bibliometric analysis method to analyze all relevant literature on the biological application of Mobased nanomaterials in recent ***,we use bibliometric tools to analyze the dataset by year,country/region,institution and research hotspot to obtain the research ***,based on objectively identified research hotspots,the biomedical applications of Mo-based nanomaterials are reviewed comprehensively,mainly including sensors,cancer imaging/therapy and antibacterial ***,we discussed the application prospects and challenges of Mo-based *** article provides a new perspective to understand the current research progress and further promote the development of Mobased nanomaterials in biomedical research.

关键词： Molybdenum Nanomaterial Biomedicine Bibliometric analysis

Robust textile-based spoof plasmonic frequency scanning antenna for on-body IoT applications

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第8期67卷 269-284页

作者： Zhao-Min CHEN jun-Lin ZHAN Hao CHEN ya LI Hongjun HE wu yaNG Zhen-Guo LIU Wei-Bing LU State Key Lab of Millimeter Waves School of Information Science and EngineeringSoutheast University Center for Flexible RF Technology Frontiers Science Center for Mobile Information Communication and SecuritySoutheast University Future Research Laboratory China Mobile Research Institute Purple Mountain Laboratories

Securing a comfortable, wearable compact frequency beam scanning antenna(FBSA) with robustness to deformation, low specific absorption rate(SAR), and good coverage of the surrounding environment for Internet of Things(IoT) applications, such as on-body navigation and wireless communication is an emerging challenge. In this work, a robust textile-based spoof plasmonic frequency scanning antenna utilizing higher-order modes is presented, which is also robust to deformation caused by the activities of the human body. The innovative design of the element ensures the high-efficiency transmission of the fundamental mode of spoof surface plasmon polaritons(SSPP) structure, providing the potential of being a multifunctional composite device in the compact on-body network. Besides, an artificial magnetic conductor(AMC) is designed underneath the SSPP structure, obtaining a low SAR value(0.113 W/kg), which ensures the safety of users. As a practical realization of this concept, a textile-based spoof plasmonic antenna was fabricated in the microwave regime and the performed experimental results show the proposed antenna has a single-beam radiation characteristic with a 70° beam scanning angle range when the frequency is 4.7–6.0 GHz with a high average realized gain of 13.15 dBi. And it still maintains a steady performance when faced with structure deformation, which proves its robustness. Wireless communication quality experiments are performed to demonstrate the proposed antenna can measure the angles of targets and realize wireless signal transmission to specific targets as the frequency varies, it may find great potential in the field of on-body IoT applications.

关键词： frequency beam scanning antenna (FBSA) Internet of Things (IoT) on-body communication spoof surface plasmon polaritons (SSPP) textile-based antenna

同方期刊数据库

Polymer electrolytes for flexible zinc-air batteries:Recent progress and future directions

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第7期17卷 6058-6079页

作者： Jing wu Wen-ya wu Suxi Wang Dan Kai Enyi Ye Warintorn Thitsartarn Janet Beng Hoon Tan Jianwei Xu Qingyu yan Qiang Zhu Xian jun Loh Institute of Sustainability for Chemicals Energy and Environment(ISCE2)Agency for ScienceTechnology and Research(A*STAR)1 Pesek RoadJurong IslandSingapore 627833Singapore Institute of Materials Research and Engineering(IMRE) Agency for ScienceTechnology and Research(A*STAR)2 Fusionopolis WayInnovis#08-03Singapore 138634Singapore School of Materials Science and Engineering Nanyang Technological University50 Nanyang AvenueSingapore 639798Singapore School of Chemistry Chemical Engineering and BiotechnologyNanyang Technological University21 Nanyang LinkSingapore 637371Singapore Department of Material Science and Engineering National University of Singapore9 Engineering Drive 1#03-09 EASingapore 117575Singapore

This review article delves into the development of electrolytes for flexible zinc-air batteries(FZABs),a critical component driving the advancement of flexible *** started by surveying the current advancements in electrolyte technologies,including solid-state and gel-based types,and their contributions to enhance the flexibility,efficiency,and durability of ***,we explored the challenges in this domain,focusing on maintaining electrolyte stability under mechanical stress,ensuring compatibility with flexible substrates,optimizing ion conductivity,and under harsh environmental ***,the key issues regarding interface details between electrolyte and the electrodes are covered as *** then discussed the future of electrolyte development in FZABs,highlighting potential avenues such as materials development,sustainability,in-situ studies,and battery *** review offers an in-depth overview of the advancements,challenges,and potential breakthroughs in creating electrolytes for FZABs over the past five *** serves as a guide for both researchers and industry professionals in this dynamic area.

关键词： flexible zinc-air batteries electrolyte polymer hydrogel electrolyte-electrode interface