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yoLOv4-Balance:样本均衡的目标检测网络

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软件导刊 2024年第2期23卷 1-8页

作者：周泽清於跃成顾宙瑜江苏科技大学计算机学院江苏镇江212000

针对因数据集中小目标样本数量不足且分布不均衡,导致算法对小目标检测精度低的问题,在多尺度目标检测模型yoLOv4的基础上,提出一种融合动态损失反馈与数据增强的多尺度目标检测算法yoLOv4-Balance。首先,提出一种基于图像组合拼接的数... 详细信息

针对因数据集中小目标样本数量不足且分布不均衡,导致算法对小目标检测精度低的问题,在多尺度目标检测模型yoLOv4的基础上,提出一种融合动态损失反馈与数据增强的多尺度目标检测算法yoLOv4-Balance。首先,提出一种基于图像组合拼接的数据增强算法U-Mix,均衡小目标样本的分布,提高数据集中的小目标学习样本质量。其次,基于模型训练迭代时的Loss反馈,提出一种利用动态损失反馈的多尺度模型训练算法DLF,以提高训练过程中小目标样本损失对模型学习的贡献度。实验结果表明,该算法在MSCOCO数据集上的平均精度较基线模型yo⁃LOv4提升了约2.1%,对小目标样本的检测精度提升了约2.8%。该算法不会引入额外的计算开销,且模型收敛快速,有助于高效进行训练。

关键词：目标检测样本均衡数据增强反馈驱动多尺度

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不同铝硅比对莫来石材料显微结构及性能的影响

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人工晶体学报 2018年第4期47卷 806-809,821页

作者：胡其国顾幸勇董伟霞罗婷邱柏欣景德镇陶瓷大学材料科学与工程学院景德镇333403

选用铝矾土作为铝源,煤矸石为硅源,氟化铝和五氧化二钒为添加剂,通过固相反应原位制备了主晶相为莫来石相的晶体。利用X射线衍射仪和扫描电子显微镜以及相应的EDS等手段对莫来石进行了表征分析,并考察了在不同铝硅比的条件下对所制试样... 详细信息

选用铝矾土作为铝源,煤矸石为硅源,氟化铝和五氧化二钒为添加剂,通过固相反应原位制备了主晶相为莫来石相的晶体。利用X射线衍射仪和扫描电子显微镜以及相应的EDS等手段对莫来石进行了表征分析,并考察了在不同铝硅比的条件下对所制试样的显气孔率、吸水率、体积密度、抗折强度以及显微结构的变化特征。结果表明:当铝矾土与煤矸石的铝硅摩尔比为3.05∶2时,显气孔率为23.6%、吸水率为10.55%、体积密度为2.3 g/cm^3、抗折强度为114 MPa,试样的综合性能最优。

关键词：铝硅比原位合成莫来石显微结构

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Chemical Shifts of ^(23)Na in NaCl Crystal Specimens Implanted with Xenon Ions

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Chinese Physics Letters 1999年第8期16卷 563-564页

作者： LIANg Jia-chang XU Zhou LE Xiao-yun ZHAO Wei-jiang YU Fu-chun LIU Zhi CHEN Rong-ti SUN Xian-ping ZHENg Xi-zhi DU yo-ru ZHAO Ming-xin SHEN Lian-fang gu Hong-en LI Yi SU Yi Department of Basic Sciences Civil Aviation Institute of ChinaTianjin 300300 Institute of Heavy Ion Physics Peking UniversityBeijing 100871 Department of Chemistry Nankai UniversityTianjin 300071 Laboratory of Magnetic Resonance and Atomic and Molecular Physics Wuhan Institute of Physics&MathematicsChinese Academy of SciencesWuhan 430071 Department of Applied Physics Tianjin UniversityTianjin 300072 Department of Physics Tianjin Normal UniversityTianjin 300074

Na clusters containing 10 to less than 1000 metal sodium atoms and blisters containing xenon inclusions were formed in NaCl crystal specimens prepared by xenon ion implantation to single crystal NaCl with Auences more than or equal to 2×10^(16)/cm^(2)at the energy of *** indicated that on the condition of xenon ion Auences more than or equal to 1×10^(17)/cm^(2)the xenon inside the inclusions formed in NaCl crystal specimens is in solid state and the solid state molecules NaXe are formed through the Combination of Xe with Na in Na *** chemical shift of ^(23)Na in solid state molecules NaXe relative to 23Na in single crystal NaCl was measured and is equal to-17ppm.

关键词： crystal implantation state

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职业和老龄化关系

职业与健康 2009年第12期25卷 1304-1305页

作者：顾和平张亚东上海市闸北区芷江西路街道社区卫生服务中心 200070

世界人口老龄化已被各国认为是21世纪的主要问题之一,其中职业人群和老龄化的关系也日益凸现,人口老龄化即是科学发展和社会进步的象征.但又给社会、家庭、卫生服务机构带来新的压力,与经济发展产生新的矛盾.为缓和或解决这种压力和矛盾... 详细信息

世界人口老龄化已被各国认为是21世纪的主要问题之一,其中职业人群和老龄化的关系也日益凸现,人口老龄化即是科学发展和社会进步的象征.但又给社会、家庭、卫生服务机构带来新的压力,与经济发展产生新的矛盾.为缓和或解决这种压力和矛盾,联合国开始关注老龄化问题,1989年国际职业卫生协会(ICOH)成立了'职业与老龄化'科学委员会,1992年第47届联合国大会通过了,并定为1999年

关键词：老龄化职业人群健康状况卫生干预措施

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MR扩散加权成像评价涎腺功能的初步研究

中华放射学杂志 2012年第5期46卷 425-429页

作者：张云燕欧丹顾雅佳何霞云毛健沈茜刚岳磊彭卫军复旦大学附属肿瘤医院放射诊断科复旦大学上海医学院肿瘤学系上海200032 复旦大学附属肿瘤医院放疗科

目的探讨利用MRDWI评价不同生理状态下涎腺功能的可行性。方法对30例涎腺功能正常的鼻咽癌患者行DWIEPI扫描，b值取0、400、600、800、1000s／mm2。先于静息状态下对腮腺及颌下腺各扫描1次，然后给患者含服维生素C100mg×6片，于酸刺激... 详细信息

目的探讨利用MRDWI评价不同生理状态下涎腺功能的可行性。方法对30例涎腺功能正常的鼻咽癌患者行DWIEPI扫描，b值取0、400、600、800、1000s／mm2。先于静息状态下对腮腺及颌下腺各扫描1次，然后给患者含服维生素C100mg×6片，于酸刺激状态下重复对腮腺扫描7次，每次间隔18s。比较静息状态下腮腺和颌下腺ADC值的差别，以及酸刺激前后腮腺ADC值的变化。采用配对t检验对两组间数据进行比较。结果静息状态下，腮腺的ADC值[（1．23±0．12）×10-3mm2／s]显著低于颌下腺[（1．34±0．07）×10-3mm2／s，t=4．545，P〈0．01]。酸刺激后第1次扫描腮腺ADC值为（1．41±0．19）×10-3mm。／s，高于静息时基值（t=10．254，P〈0．01）。随后ADC值在基值上波动，酸刺激后ADC的最小值为（1．24±0．14）×10-3mm2／s，与基值比较差异无统计学意义（t=1．329，P〉0．05）；最大值为（1．49±0．20）×10-3mm2／s，7次扫描的平均值为（1．36±0．17）×10-3mm2／s，均与基值比较差异有统计学意义（t值分别为15．127、11．905，P值均〈0．01）。结论MRDWI通过ADC值的量化，可观察到不同生理状态下涎腺功能的变化。

关键词：涎腺磁共振成像,弥散

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High-resolution electronic spectra of yttrium oxide(yo)Ⅱ:spectroscopic study on the [33.2]2Π and A'2?5/2 states

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High-resolution electronic spectra of yttrium oxide(YO)Ⅱ:sp...

High-resolution electronic spectra of yttrium oxide(yo)Ⅰ:identification of the D2Σ+ state

第十五届全国化学动力学会议

作者：张强 D Zhang B Zhu J gu D Zhao Y Chen Hefei National Laboratory for Physical Sciences at the Microscale Department of Chemical PhysicsUniversity of Science and Technology of China

The [33.2]Π and A’Δ electronic states of the astrophysically relevant yttrium oxide(yo) molecule have been experimentally studied at high resolution for the first time. The yo molecules are produced using the same method as in Part I of this work, i.e., by corona discharge of oxygen between the tips of two yttrium needles in a supersonic jet expansion. In this presentation, different spectroscopic detection schemes, including laser excitation spectroscopy, disperse fluorescence, optical-optical double resonance spectroscopy, and fluorescence depletion spectroscopy, are employed to identify the newly discovered [33.2]Π state, and to precisely measure the ro-vibrational energies of the A’Δ state. The AΠ state is used as the intermediate resonance state in the optical-optical double resonance experiment to reveal the spin-orbital coupling nature of the [33.2]Π state. To determine accurate spectroscopic constants of the ‘optically dark’ A’Δ state, a ‘pump-probe’ fluorescence depletion experiment is performed, where the newly discovered [33.2]Π state is used in the pump scheme.

关键词： yo laser induced fluorescence optical-optical double resonance

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High-resolution electronic spectra of yttrium oxide(YO)Ⅰ:id...

Weichang'an and 5-fluorouracil suppresses colorectal cancer in a mouse model

第十五届全国化学动力学会议

作者：张德萍 Q Zhang B Zhu J gu D Zhao Y Chen Hefei National Laboratory for Physical Sciences at the Microscale Department of Chemical PhysicsUniversity of Science and Technology of China

Yttrium oxide(yo) is an important constitute in atmospheres of cool stars, and has long been considered as a key indicator in defining the S-type stars. It is also one of the benchmark molecules used for laser cooling and molecular trapping in a magneto-optical trap(MOT). Here, we present the high resolution spectroscopic study on the DΣ–XΣ electronic transition of yo in the 400–440 nm region using laser induced fluorescence. yo molecules are produced by corona discharge of oxygen between the tips of two yttrium needles in a supersonic jet expansion. An unambiguous spectroscopic identification of the DΣ–XΣ transition becomes possible from a combined analysis of the moderate-resolution laser excitation spectrum and dispersed fluorescence spectrum. By using a home-made KTP crystal based single-longitude-mode optical parametric oscillator(OPO) as a narrowband light source, we have also recorded spectra of DΣ–XΣ(0, 0) and(1, 0) bands with a spectral resolution of 0.018 cm, which allows to fully resolve the spin-rotational fine structure and partially resolve hyperfine nuclear spin splitting in the experimental spectra. Accurate spectroscopic constants for DΣ v′ = 0 and 1 levels have been determined from a rotational analysis of the high resolution spectra. Severe perturbations are observed in the experimental spectra, and are considered to originate from interactions with at least one nearby Π electronic state, e.g., the undetected CΠ state. We have also measured the radiative lifetimes of BΣ v’ = 0, and DΣ v’ = 0 and 1 states for the first time, based on which the BΣ–XΣ(0, 0) and DΣ–XΣ(0/1, 0) band oscillator strengths have been determined. The spectroscopic data presented here are of implications in astronomical observations of yo molecules in atmospheres of exoplanets and cool stars.

关键词： yo high-resolution spectra laser excitation spectrum dispersed fluorescence spectrum

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World Journal of gastroenterology 2015年第4期21卷 1125-1139页

作者： Li Tao Jin-Kun Yang Ying gu Xin Zhou Ai-guang Zhao Jian Zheng Ying-Jie Zhu Department of Oncology Longhua Hospital Shanghai University of Traditional Chinese Medicine Department of Pharmacy Longhua HospitalShanghai University of Traditional Chinese Medicine

AIM: To examine the effect of Weichang'an(WCA) and 5-fluorouracil(5-Fu) on colorectal tumor and hepatic metastasis in a mouse model. METHODS: Quantitative determination of hesperidin, the effective component in WCA decoction, was performed using Hp LC. In vitro cytotoxicity of WCA was determined by treating HCT-116 cells with WCA diluents or serum extracted from rats that received WCA by oral gavage for 1 wk and MTT assays. Forty-eight nude mice received cecum implantation with tumor blocks subcutaneously amplified from human colon cancer cell line HCT-116. Mice were randomly divided into four treatment groups: control(CON), WCA, 5-Fu and combination(WCA + 5-Fu). pathological examination of tumors consisted of tissue sectioning and hematoxylin and eosin staining. Tumor weight and size were measured, and the number of metastatic l e s i o n s wa s c o u n t e d. S e r u m c a r c i n o e m b r yo n i c antigen(CEA) level was determined by ELISA. The expression levels of tumor genesis and metastasisrelated proteins β-catenin and matrix metalloproteinase(MMp)-7 were measured by real-time quantitative reverse transcriptase polymerase chain reaction(RTp CR), immunohistochemistry and immunoblotting. Cell fractionation was used to investigate intracellular distribution of β-***: parenchymal tumors were palpable in the abdomens of nude mice 2 wk post-implantation and orthotopic tumor formation rate was 100% in all groups. 5-Fu treatment alone significantly decreased tumor weight compared to the CON group(1.203 ± 0.284 g vs 1.804 ± 0.649 g, p g the tumor weight(1.140 ± 0.464 g vs 1.804 ± 0.649 g, p g/L vs 43.040 ± 11.273 μg/L, p < 0.05). Expression of β-cat

关键词： Colorectal cancer Hepatic metastasis Weichang’an f

A single-longitudinal-mode optical parametric oscillator for high resolution spectroscopy of free radicals

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A single-longitudinal-mode optical parametric oscillator for...