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COmPOSITION DESIGN FOR A BEARING STEEL WITh LImITED hARDENABILITY

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Acta metallurgica Sinica(English Letters) 1996年第5期9卷 379-382页

作者： L. P. Xu m. h. Xu L. Li Y.A. min X.Z Xuand R.h .Liu (Department of materials Science and Engineering, Shanghai University, Shanghai 200072, China) (Shanghai No.5 Iron and Steel Factory, Shanghai 200940,China)

The composition of a bearing steel was designed for limited hardenability by use of Grossmann's method. A medium frequency induction Process was applied to heat bearings to ensure penetrant heating and suitable solving of carbon and other elements in the matrix. The hardened depth measured from the end quenching test samples and actual bearings matches well with the designed one.

关键词： bearing steel limited hardenability composition design

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国际金融案例

Characteristic of the equivalent impedance for an mxn RLC network with an arbitrary boundary

作者： m. h.·莫菲特

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Frontiers of Information Technology & Electronic Engineering 2017年第12期18卷 2070-2081页

作者： Zhi-zhong TAN hong ZhU Jihad h. ASAD Chen XU hua TANG Department of Physics Nantong University Nantong 226019 China College of Science Changzhou Institute of Technology Changzhou 213002 China Department of Physics Palestine Technical University Tulkarm p.o. Box 7 Palestine School of Electronics and lnformation Nantong University Nantong 226019 China Departrnent of Physics Yunhe Teachers College Pizhou 221300 China

Considerable progress has been made recently in the development of techniques to determine exactly two-point resistances in networks of various topologies. In particular, a general resistance formula of a non-regular mxn resistor network with an arbitrary boundary is determined by the recursion-transform （RT） method. however, research on the complex impedance network is more difficult than that on the resistor network, and it is a problem worthy of study since the equivalent impedance has many different properties from equivalent resistance. In this study, the equivalent impedance of a non-regular mxn RLC network with an arbitrary boundary is studied based on the resistance formula, and the oscillation characteristics and resonance properties of the equivalent impedance are discovered. In the RLC network, it is found that our formula leads to the occurrence of resonances at the boundary condition holding a series of specific values with an external alternating current source. This curious result suggests the possibility of practical applications of our formula to resonant circuits.

关键词： RLC network Resonance properties Oscillation characteristics Amplitude-frequency

间断或持续PTh刺激对骨及间充质干细胞的不同分化作用

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中华医学杂志 2018年第10期98卷 781-787页

作者：张瀶曦 Deepak h. Balani Sophia Trinh henry m. kronenberg 母义明解放军总医院内分泌科北京100853 Endocrine Unit Massachusetts General Hospital and Harvard Medical School Boston 02114 USA

目的探讨不同甲状旁腺素（PTh）给药情况下及撤药后，骨及间充质干细胞的不同分化作用机制。方法6周龄雄性C57/BL6J小鼠，基因型为SOX9－creERT/Td－Tomato/Osteocalcin－GFP，分为间断PTh刺激及撤药组（PTh 500 μg·kg^－1·d^－1，... 详细信息

目的探讨不同甲状旁腺素（PTh）给药情况下及撤药后，骨及间充质干细胞的不同分化作用机制。方法6周龄雄性C57/BL6J小鼠，基因型为SOX9－creERT/Td－Tomato/Osteocalcin－GFP，分为间断PTh刺激及撤药组（PTh 500 μg·kg^－1·d^－1，皮下注射）、持续PTh刺激及撤药组（PTh泵，80 μg·kg^－1·d^－1，速度0.25 μl/h，皮下埋入）、空白对照组及撤药对照组，共6组，每组8只。分别于给药2周及撤药2周时观察小鼠血清中钙离子浓度及骨密度，并取小鼠胫骨骨骼分别进行病理及免疫荧光染色。结果间断PTh刺激组血清钙离子浓度一过性升高，达（1.36±0.03）mmol/L。持续PTh泵刺激组血清中钙离子浓度逐渐升高，48 h达高峰[（2.33±0.03）mmol/L]，2周后恢复正常（1.12～1.27 mmol/L）。PTh刺激2周后，间断组[（0.047±0.002）g/cm2]和持续组[（0.046±0.001）g/cm2]骨密度均高于对照组[（0.044±0.001）g/cm2]，但间断组和持续组差异无统计学意义。停药2周后，三组间BmD差异无统计学意义。股骨病理可见间断组骨皮质不明显，大量的骨小梁增生，伴少量纤维组织增生；持续PTh刺激大片纤维组织增生，尤以骨皮质内侧显著，撤药后纤维化消失。间断PTh刺激后骨细胞和成骨细胞明显升高，撤药后明显下降；衬里细胞数量骤减，撤药后有所增加；破骨细胞给药及撤药后差异均无统计学意义。持续PTh刺激破骨细胞增多，衬里细胞骤减，撤药后破骨细胞和衬里细胞增加，成骨细胞减少。腓骨干骺端免疫荧光显示，间断PTh刺激组大量未分化的Td－tomato间充质干细胞，撤药后较前明显减少。持续PTh组少量未分化的Td－tomato间充质干细胞增生，撤药后较前减少。结论间断PTh刺激可通过增加未分化的间充质干细胞和成骨细胞数量，将衬里细胞转换为骨细胞和成骨细胞，进而促进骨生成；持续PTh刺激可使少量未分化的间充质干细胞、成骨细胞和骨细胞增生，伴大量纤维化增生和破骨细胞数量骤增，最终可能导致代谢性骨病，撤药后衬里细胞明显增加，或有利于代谢性骨病的缓解。

关键词：甲状旁腺素间充质干细胞骨成骨细胞破骨细胞

利用微泡对家兔体内淋巴血液系统进行三维超分辨率超声成像

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国际医学放射学杂志 2019年第4期 486-487页

作者：陈萍 J.Zhu E.m.Rowland S.harput k.Riemer C.h.Leow B.Clark Department of Bioengineering Imperial College LondonSouth Kensington Campus

摘要淋巴结(LN)微循环的变化可以提示转移。转移淋巴结的定性和定量仍然是疾病预后和实施治疗计划的必要条件,但是缺乏可靠的无创性成像技术。三维超分辨率(SR)

关键词：三维超分辨微血管结构

铀矿fs-LA-ICP-mS原位微区U-Pb定年

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中国科学：地球科学 2015年第10期45卷 1304-1315页

作者：宗克清陈金勇胡兆初刘勇胜李明范洪海孟艳宁地质过程与矿产资源国家重点实验室中国地质大学地球科学学院武汉430074 核工业北京地质研究院北京100029

利用飞秒激光剥蚀电感耦合等离子体质谱(fs-LA-ICP-mS)对锆石和铀矿之间的Pb/U分馏行为,以及纳米比亚白岗岩中晶质铀矿进行了详细的原位微区U-Pb年代学研究.结果表明,fs-LA-ICP-mS分析过程中铀矿和锆石之间表现出显著不同的Pb/U分馏行为... 详细信息

利用飞秒激光剥蚀电感耦合等离子体质谱(fs-LA-ICP-mS)对锆石和铀矿之间的Pb/U分馏行为,以及纳米比亚白岗岩中晶质铀矿进行了详细的原位微区U-Pb年代学研究.结果表明,fs-LA-ICP-mS分析过程中铀矿和锆石之间表现出显著不同的Pb/U分馏行为,利用锆石标准物质m257校正铀矿U-Pb定年标准物质GBW04420得到的年龄偏大17%.因此,精确的铀矿LA-ICP-mS原位微区U-Pb定年需要基体匹配的标准物质进行校正.以GBW04420为外标,利用fs-LA-ICP-mS在10?m,1 hz激光条件,同时配备信号匀化装置(SSD)的前提下,对两个来自纳米比亚罗辛(Rossing)铀矿床东南侧欢乐谷(Gaudeanmus)地区的白岗岩岩石薄片中晶质铀矿进行了分析.其中一个样品给出的U-Pb谐和年龄为(507±1)ma(2?,n=21),两个样品206Pb/238U加权平均年龄分别为(504±3)ma(2?,n=21)和(503±3)ma(2?,n=22).分析结果与前人的热电离质谱为基础的同位素稀释法(ID-TImS)结果一致((509±1)和(508±12)ma).同时与铀矿共生锆石给出的U-Pb上交点年龄结果 ((506±33)ma(2?,n=29)和(501±51)ma(2?,n=29))在误差范围内相同.由于共生高U锆石严重的Pb丢失,所以铀矿定年相对于共生锆石定年结果更为精确可靠.GBW04420是一个可以用于铀矿原位微区U-Pb同位素准确定年的标准物质.

关键词：铀矿 fs-LA-ICP-mS U-Pb定年元素分馏罗辛铀矿 GBW04420

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Generation mechanism of 100 mG magnetic fields in the interaction of ultra-intense laser pulse with nanostructured target

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high Power Laser Science and Engineering 2020年第2期8卷 50-55页

作者： J.m.Tian h.B.Cai W.S.Zhang E.h.Zhang B.Du S.P.Zhu Graduate School China Academy of Engineering PhysicsBeijing 100088China Institute of Applied Physics and Computational mathematics Beijing 100094China Center for Applied Physics and Technology HEDPSand College of EngineeringPeking UniversityBeijing 100871China

Experimental and simulation data[moreau et al.,Plasma *** 62,014013(2019);kaymak et al.,***.117,035004(2016)]indicate that self-generated magnetic fields play an important role in enhancing the flux and energy of relativistic electrons accelerated by ultra-intense laser pulse irradiation with nanostructured arrays.A fully relativistic analytical model for the generation of the magnetic field based on electron magneto-hydrodynamic description is presented *** analytical model shows that this self-generated magnetic field originates in the nonparallel density gradient and fast electron current at the interfaces of a nanolayered target.A general formula for the self-generated magnetic field is found,which closely agrees with the simulation scaling over the relevant intensity *** result is beneficial to the experimental designs for the interaction of the laser pulse with the nanostructured arrays to improve laser-to-electron energy coupling and the quality of forward hot electrons.

关键词： nanolayered target self-generated magnetic field ultra-intense laser pulse

Underestimated ^(14)C-based chronology of late Pleistocene high lake-level events over the Tibetan Plateau and adjacent areas: Evidence from the Qaidam Basin and Tengger Desert

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Science China Earth Sciences 2015年第1期58卷 183-194页

作者： LONG hao ShEN Ji State key Laboratory of Lake Sciences and Environment Nanjing Institute of Geography and LimnologyChinese Academy of Sciences State key Laboratory of Loess and Quaternary Geology Institute of Earth EnvironmentChinese Academy of Sciences

The palaeolake evolution across the Tibetan Plateau and adjacent areas has been extensively studied, but the timing of late Pleistocene lake highstands remains controversial. Robust dating of lacustrine deposits is of importance in resolving this issue. This paper presents 14 C or optically stimulated luminescence(OSL) age estimates from two sets of late Quaternary lacustrine sequences in the Qaidam Basin and Tengger Desert(northeastern Tibetan Plateau). The updated dating results show:(1) the radiocarbon dating technique apparently underestimated the age of the strata of >30 ka BP in Qaidam Basin;(2) although OSL and 14 C dating agreed with each other for holocene age samples in the Tengger Desert area, there was a significant offset in dating results of sediments older than ~30 ka BP, largely resulting from radiocarbon dating underestimation;(3) both cases imply that most of the published radiocarbon ages(e.g., older than ~30 ka BP) should be treated with caution and perhaps its geological implication should be revaluated; and(4) the high lake events on the Tibetan Plateau and adjacent areas, traditionally assigned to mIS 3a based on 14 C dating, are likely older than ~80 ka based on OSL chronology.

关键词： dating Plateau Desert Tibetan older Pleistocene holocene lacustrine dated quartz

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双能CT对比增强平衡期测定细胞外体积分数作为胰腺导管腺癌Ⅳ期病人的预后因素

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国际医学放射学杂志 2020年第3期 370-371页

作者： Y.Fukukura Y.kumagae R.higashi h.hakamada m.Nakajo k.maemura 张国栋 Department of Radiology Graduate School of Medical and Dental Sciences Kagoshima University

摘要目的与单能CT(SECT)比较,评估在双能CT(DECT)对比增强平衡期计算细胞外体积(ECV)分数的可行性,以预测化疗后远处转移(Ⅳ期)的胰腺导管腺癌(PDAC)

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