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Journal of Materials Science & Technology 2022年第7期102卷 105-114页

作者： Shucai Zhang Jiangtao Yu Huabing Li Zhouhua Jiang yifeng geng Hao Feng Binbin Zhang Hongchun Zhu School of Metallurgy Northeastern UniversityShenyang 110819China School of Materials and Metallurgy University of Science and Technology LiaoningAnshan 114051China

The influence of Ce addition on the solidification structure and σphase of super austenitic stainless steel S32654 was systematically investigated via microstructural characterization and thermodynamic calcula- tion. The results indicate that a small addition of Ce could modify MgO and MnS into Ce-bearing inclu- sions Ce_(2)O_(3)and Ce_(2)O_(2)S. Ce addition led to noticeable refinement of both the dendrite structure and σphase. The refinement mechanism could be attributed to the combined actions of effective Ce-bearing inclusions and solute Ce. Effective Ce-bearing inclusions could serve as heterogeneous nucleation cores of austenite as well as σphase, which provided a favorable prerequisite for their refinement. Solute Ce significantly enhanced the undercooling degree of the system, further promoting dendrite structure re- finement. Meanwhile, solute Ce improved the eutectic precipitation conditions of σphase and further promoted its nucleation, while the dendrite refinement limited its growth space. Finally, more fine and dispersed σphase particles formed in S32654 with Ce addition. The refinement of dendrite structure and σ phase will reduce the temperature and time required for high-temperature homogenization, which is beneficial to the hot working of this steel.

关键词： Super austenitic stainless steel Cerium Solidification structure Sigma phase Refinement

SwiftArray: Accelerating Queries on Multidimensional Arrays

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Tsinghua Science and Technology 2014年第5期19卷 521-530页

作者： yifeng geng Xiaomeng Huang Guangwen Yang Department of Computer Science and Technology Tsinghua University Ministry of Education Key Laboratory for Earth System Modeling Tsinghua University

Scientific instruments and simulation programs are generating large amounts of multidimensional array data. Queries with value and dimension subsetting conditions are commonly used by scientists to find useful information from big array data, and data storage and indexing methods play an important role in supporting queries on multidimensional array data efficiently. In this paper, we propose SwiftArray, a new storage layout with indexing techniques to accelerate queries with value and dimension subsetting conditions. In SwiftArray, the multidimensional array is divided into blocks and each block stores sorted values. Blocks are placed in the order of a Hilbert space-filling curve to improve data locality for dimension subsetting queries. We propose a 2-D-Bin method to build an index for the blocks＇ value ranges, which is an efficient way to avoid accessing unnecessary blocks for value subsetting queries. Our evaluations show that SwiftArray surpasses the NetCDF-4 format and FastBit indexing technique for queries on multidimensional arrays.

关键词： multidimensional array indexing space-filling curve

Learning to focus: cascaded feature matching network for few-shot image recognition

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Science China(Information Sciences) 2021年第9期64卷 90-102页

作者： Mengting CHEN Xinggang WANG Heng LUO yifeng geng Wenyu LIU School of Electronic Information and Communications Huazhong University of Science and Technology

Generally, deep networks learn to recognize a category of objects by training on a large number of annotated images accurately. However, a meta-learning problem known as a low-shot image recognition task occurs when a few images with annotations are available for learning a recognition model for a single category. Consequently, the objects in testing/query and training/support image datasets are likely to vary in terms of size, location, style, and so on. In this paper, we propose a method, cascaded feature matching network(CFMN), to solve this problem. We train the meta-learner to learn a more fine-grained and adaptive deep distance metric using feature matching block, which aligns associated features together and naturally ignores non-discriminative features. By applying the proposed feature matching block in different layers of the network, multi-scale information among the compared images is incorporated into the final cascaded matching feature, which boosts the recognition performance and generalizes better by learning on relationships. Moreover, the experiments for few-shot learning(FSL) using two standard datasets:miniImageNet and Omniglot, confirm the effectiveness of our proposed method. Besides, the multi-label fewshot task is first studied on a new data split of the COCO dataset, which further shows the superiority of the proposed feature matching network when performing the FSL in complex images.

关键词： few-shot learning image recognition feature matching self-attention

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飞行员力量训练与评估方法研究

载人航天 2024年第1期30卷 29-36页

作者：徐艳谭清坡杨景慧李宝辉孟男高峰王海霞李毅峰耿喜臣空军军医大学空军特色医学中心北京100142 解放军95809部队医院沧州061000 解放军94565部队蚌埠233000

针对持续高载荷防护、预防颈腰部损伤等问题,制定针对臀腿、腰腹、胸背、肩颈部肌群及呼吸肌力量与力量耐力训练方案及体能评估方案。16名志愿者训练12周,在训练前后分别进行肌肉力量与耐力及模拟空战能力的评估,记录分析G耐量、蹬力耐... 详细信息

针对持续高载荷防护、预防颈腰部损伤等问题,制定针对臀腿、腰腹、胸背、肩颈部肌群及呼吸肌力量与力量耐力训练方案及体能评估方案。16名志愿者训练12周,在训练前后分别进行肌肉力量与耐力及模拟空战能力的评估,记录分析G耐量、蹬力耐量、呼吸耐量以及各项力量测试指标的变化。结果表明:训练后各项力量指标均显著提高(P<0.001),深蹲、硬拉的力量均增长了1倍以上,颈部8个方向的力量增长了97.57%~245.05%,腰部8个方向的力量增长了125.69%~233.47%;模拟空战能力的各项指标均显著增长(P<0.001),左、右腿最大蹬力分别增长了59.99%、62.49%,蹬力曲线时间延长了5倍,训练后10名志愿者完成了8 G曲线、6名志愿者完成了9 G曲线,最大呼气与吸气压力分别增加了28.94%、32.37%(P<0.05),呼吸肌耐量增加了324.10%。研究结果表明了飞行员力量训练方案和评估方案的有效性及可行性。

关键词：飞行员加速度体能抗荷动作离心机

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慢增长率模式+Gz暴露时表面肌电的变化

空军军医大学学报 2024年第2期45卷 175-179页

作者：杨景慧李宝辉卫晓阳蒋科王红杨明浩王海霞张立辉徐艳耿喜臣李毅峰金朝空军特色医学中心加速度生理研究室北京100142

目的通过观察慢增长率(GOR)模式+Gz暴露时的表面肌电(sEMG)变化,分析做HP抗荷动作时下肢及腹部肌肉的用力特点,探讨sEMG在综合抗荷措施防护效果评定中的应用。方法 6名男性志愿者在载人离心机上进行了4组GOR模式+Gz暴露试验:GOR1、GOR2... 详细信息

目的通过观察慢增长率(GOR)模式+Gz暴露时的表面肌电(sEMG)变化,分析做HP抗荷动作时下肢及腹部肌肉的用力特点,探讨sEMG在综合抗荷措施防护效果评定中的应用。方法 6名男性志愿者在载人离心机上进行了4组GOR模式+Gz暴露试验:GOR1、GOR2、GOR3、GOR4模式。4组受试者在感觉周边灯消失时终止暴露,同时记录+Gz暴露时的双侧腹直肌、股直肌、胫骨前肌及腓肠肌sEMG信号。结果在4种(GOR1、GOR2、GOR3、GOR4)+Gz暴露模式下受试者加速度耐力依次增加,差异有统计学意义(F=174.477,P<0.01)。GOR2、GOR4+Gz暴露时股直肌、腓肠肌和胫骨前肌的积分肌电值(iEMG)平均值较安静时均显著升高(P<0.05);与GOR1模式相比,GOR2模式时股直肌(P=0.014)和腓肠肌(P=0.027)的iEMG平均值增加显著。与GOR2模式相比,GOR3模式股直肌(P=0.044)和腓肠肌(P=0.020)及GOR4时的两侧腓肠肌(P=0.023)iEMG平均值均显著降低。在GOR1、GOR3和GOR4模式下,腹直肌贡献率最高,GOR2时胫骨前肌贡献率最高。GOR4时3名受试者的小腿肌群先激活,另2名受试者是腹直肌先激活。不同试验组间各肌群的中值频率斜率值无统计学差异。结论通过分析+Gz暴露时的sEMG变化,可从肌肉紧张用力程度和疲劳水平等方面为综合抗荷措施的防护效果评定提供客观依据。

关键词：加速度载人离心机慢增长率模式表面肌电

Abnormal intra-network architecture in extra-striate cortices in amblyopia: a resting state fMRI study

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Eye and Vision 2019年第1期6卷 156-163页

作者： Zhuo Lu Yufeng Huang Qilin Lu Lixia Feng Benedictor Alexander Nguchu Yanming Wang Huijuan Wang geng Li yifeng Zhou Bensheng Qiu Jiawei Zhou Xiaoxiao Wang Center for Biomedical Engineering University of Science and Technology of ChinaHefeiAnhui 230027People’s Republic of China Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Science University of Science and Technology of ChinaHefeiAnhui 230027People’s Republic of China CAS Key Laboratory of Brain Function and Diseases and School of Life Sciences University of Science and Technology of ChinaHefeiAnhui 230027People’s Republic of China Shenyang Aerospace University ShenyangLiaoning 110136People’s Republic of China Department of Ophthalmology First Affiliated Hospital of Anhui Medical UniversityHefeiAnhuiPeople’s Republic of China Asia Pediatric Ophthalmologist Association Rm 2006CC Wu Bldg.302-308 Hennessy Rd.WanchaiHong KongPeople’s Republic of China School of Ophthalmology and Optometry and Eye hospital Wenzhou Medical UniversityWenzhouZhejiang 325003People’s Republic of China

Background:Amblyopia(lazy eye)is one of the most common causes of monocular visual impairment.Intensive investigation has shown that amblyopes suffer from a range of deficits not only in the primary visual cortex but also the extra-striate visual cortex.However,amblyopic brain processing deficits in large-scale information networks especially in the visual network remain unclear.Methods:Through resting state functional magnetic resonance imaging(rs-fMRI),we studied the functional connectivity and efficiency of the brain visual processing networks in 18 anisometropic amblyopic patients and 18 healthy controls(HCs).Results:We found a loss of functional correlation within the higher visual network(HVN)and the visuospatial network(VSN)in amblyopes.Additionally,compared with HCs,amblyopic patients exhibited disruptions in local efficiency in the V3v(third visual cortex,ventral part)and V4(fourth visual cortex)of the HVN,as well as in the PFt,hIP3(human intraparietal area 3),and BA7p(Brodmann area 7 posterior)of the VSN.No significant alterations were found in the primary visual network(PVN).Conclusion:Our results indicate that amblyopia results in an intrinsic decrease of both network functional correlations and local efficiencies in the extra-striate visual networks.

关键词： Amblyopia fMRI Resting state Extra-striate cortices Visuospatial network Graph analysis

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不同飞行员抗荷体能训练方案效果评价

航天医学与医学工程 2024年第1期35卷 38-41页

作者：杨景慧耿喜臣杨明浩金朝李宝辉于婕刘宇航王海霞卫晓阳蒋科张立辉李毅峰朱倩昀张小雪徐艳空军特色医学中心加速度生理研究室北京100142

目的建立兼顾飞行员无氧及有氧能力训练的科学训练方案,探索飞行员体能训练有氧无氧的适宜配比。方法根据“飞行人员体格检查标准”选拔两批次健康受试者共16名,年龄18~24岁。两批次受试者分别采用不同的有氧无氧配比训练方案,训练周期... 详细信息

目的建立兼顾飞行员无氧及有氧能力训练的科学训练方案,探索飞行员体能训练有氧无氧的适宜配比。方法根据“飞行人员体格检查标准”选拔两批次健康受试者共16名,年龄18~24岁。两批次受试者分别采用不同的有氧无氧配比训练方案,训练周期为3个月。训练前后受试者心肺功能变化采用运动心肺功能测试系统评价,无氧能力变化采用力量变化作为评价指标。结果训练后两种训练方案受试者的杠铃深蹲、屈腿硬拉及杠铃卧推10RM及3RM负重均显著增加(P0.05)。心肺功能测试结果显示,训练前后两组受试者所能耐受的最大负荷、最大心率及呼吸商均显著增加(P<0.01)。与方案①试验组受试者比较,训练前后方案②试验组受试者的最大负荷[方案①为(29.12±19.69)W,方案②为(72.00±46.24)W]及呼吸商(方案①为0.11±0.09,方案②为0.28±0.16)的提升幅度均增加,差异有统计学意义(P<0.05)。结论方案②试验组受试者的无氧及有氧能力均有效提升,说明该训练方案中有氧与无氧训练的配比设置更佳。

关键词：抗荷体能训练抗荷耐力飞行员运动心肺功能测试呼吸商

Recent progress in interface modification for dye-sensitized solar cells

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Science China Chemistry 2010年第8期53卷 1669-1678页

作者： MA BeiBei,GAO Rui,WANG LiDuo,ZHU yifeng,SHI YanTao,geng Yi,DONG HaoPeng & QIU Yong Key Lab of Organic Optoelectronics & Molecular Engineering of Ministry of Education Department of Chemistry,Tsinghua University,Beijing 100084,China Key Lab of Organic Optoelectronics & Molecular Engineering of Ministry of Education Department of Chemistry Tsinghua University Beijing China

Interface modification on the TiO2/dye/electrolyte interface of dye-sensitized solar cells (DSCs) is one of the most effective approaches to suppress the charge recombination,improve electron injection and transportation,and thus ameliorate the conversion efficiency and stability of DSCs.Conventional research focusing on the photoanodes interface modification before sensitization in dye-sensitized solar cells has been carried out and reviewed.However,recent studies showed that post-modification after sensitization of the TiO2 electrode also plays a significant role on the TiO2/dye/electrolyte interface.This post-modification using the immersing method could deprotonate dye molecules,prohibit the dye aggregation and retard the recombination reaction.As a result,it has great influence on the devices' photovoltaic performance.This interface modification could also provide an approach to broaden the response of the solar spectrum by introducing an alternative assembling structure.An in-situ meaning of using a co-adsorbent is employed to modify the interface in the DSCs,which could retard the aggregation of the dye molecules and enhance the conversion efficiency.In addition,electrolyte additives can be used to modify the TiO2/dye/electrolyte interface through some unique mechanisms.Based on the background of interface modification of photoanodes before sensitization,this review introduces various interface modifications after sensitization of dye-sensitized solar cells and their mechanisms.

关键词： dye-sensitized solar cell TiO2 electrode interface modification electron recombination

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伦理审查视角下临床研究知情同意书质量分析

中国医院管理 2022年第2期42卷 64-68页

作者：耿雯倩耿苗苗李宪辰江一峰上海市第一人民医院上海200080

目的从伦理审查的视角调查医院临床研究中知情同意书质量,分析申办者和研究者发起的临床研究中知情同意书存在的主要问题,对其要点进行评价归纳并提出建议。方法收集整理上海市某三级甲等医院伦理委员会2013年1月—2020年12月接受伦理... 详细信息

目的从伦理审查的视角调查医院临床研究中知情同意书质量,分析申办者和研究者发起的临床研究中知情同意书存在的主要问题,对其要点进行评价归纳并提出建议。方法收集整理上海市某三级甲等医院伦理委员会2013年1月—2020年12月接受伦理审查的临床研究项目知情同意书共计678项,根据《药物临床试验质量管理规范》要求对知情同意书的内容和语言等要素进行统计分析。结果完全符合规范的知情同意书311份(占45.9%),存在要素和/或语言问题的知情同意书367份(占54.1%),问题主要体现在研究过程(占23.7%)、可能的风险(占15.5%)、受损害后的赔偿补偿(占15.0%)和研究相关费用的告知(占14.2%)等方面;申办者发起的临床研究的知情同意书合格率高于研究者发起的临床研究。结论合格的知情同意书文本应保证内容完整和语言规范,以达到信息完整、理解无误、自愿同意的效果,确保受试者做出符合其真实意愿的选择。对于知情同意书质量的保障,需要包括申办者、研究者和伦理委员会在内的临床研究各相关方的共同努力。

关键词：伦理审查临床研究知情同意书受试者伦理委员会

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苯氧基单茂钛配合物催化乙烯与1-辛烯共聚

石油化工 2023年第10期52卷 1375-1379页

作者：耿毅丰宋文波韩书亮李昊坤中石化(北京)化工研究院有限公司北京100013

以四种不同取代基的苯氧基单茂钛配合物为主催化剂,与三异丁基铝、阳离子硼酸盐形成催化体系,催化乙烯与1-辛烯共聚,利用DSC,GPC等方法对共聚物进行表征,探索了不同取代基的苯氧基单茂钛配合物与不同阳离子的硼酸盐对共聚的影响,以及聚... 详细信息

以四种不同取代基的苯氧基单茂钛配合物为主催化剂,与三异丁基铝、阳离子硼酸盐形成催化体系,催化乙烯与1-辛烯共聚,利用DSC,GPC等方法对共聚物进行表征,探索了不同取代基的苯氧基单茂钛配合物与不同阳离子的硼酸盐对共聚的影响,以及聚合条件对共聚以及共聚物性能的影响。实验结果表明,该催化体系下得到的共聚物密度为0.86~0.88 g/cm^(3),与通用乙烯基弹性体密度相似;在合适条件下,该催化体系的共聚活性可达4.94×10^(6)g/mol。

关键词：单茂金属配合物乙烯-辛烯共聚乙烯基弹性体