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Rare Metals 2021年第5期40卷 1232-1238页

作者： tian-chi ji Min-Xiang Pan Hong-Liang Ge Qiong Wu Peng-Yue Zhang Magnetism Key Laboratory of Zhejiang Province China Jiliang UniversityHangzhou 310018China

In the present work,the magnetization reversal behavior for the melt spinning(Nd_(0.8)Ce_(0.2))_(2)Fe_(12)Co_(2-x)Zr_(x)B(x=0,0.5)permanent alloys with high coercivity was investigated by analyzing the hysteresis curves and the recoil *** to the Zr-free alloy,the Zr-doped sample obtains higher magnetic properties:coercivity of H_(cj)=650.5 kA·m^(-1),squareness of H_(k)/H_(cj)=0.76 and maximum energy product of(BH)_(max)=131.0 kJ·m^(-3).The first-order reversal curves(FORCs)analysis was taken to identify optimal conditions of exchange coupling for the Zr-free and Zr-doped *** coercivity mechanism of theα-Fe/Nd_(2)Fe_(14)B nanocomposite alloys was analyzed by the angular dependence of the coercive field as measured for the Zr-doped *** results show that the magnetic reverse process of the Zr-doped sample can be explained by the pinning model.

关键词： Magnetization reversal Coercivity mechanism First-order reversal curve(FORC) Nanocomposite

单一及多组分混合物绿松石仿制品的光谱学特征研究

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光谱学与光谱分析 2025年第1期45卷 183-190页

作者：杨池玉汪田田张维肖汤维茜同济大学浙江学院浙江嘉兴314051

对市场新出现的一类仿制品进行了拉曼光谱、红外光谱、化学成分、紫外-可见-近红外吸收光谱分析,对其主要谱学特征进行了归纳总结。结果表明这类仿制品主要由重晶石、三水铝石、方解石粉末单一组分或多组分混合压制再经环氧树脂类或丙... 详细信息

对市场新出现的一类仿制品进行了拉曼光谱、红外光谱、化学成分、紫外-可见-近红外吸收光谱分析,对其主要谱学特征进行了归纳总结。结果表明这类仿制品主要由重晶石、三水铝石、方解石粉末单一组分或多组分混合压制再经环氧树脂类或丙烯酸酯类有机物胶结,并经人工染剂染色而成。红外光谱显示:单一矿物组分仿制品和绿松石差异明显,重晶石仿制品显示[SO_(4)]^(2-)的1078 cm^(-1)吸收峰等,方解石仿制品显示[CO_(3)]^(2-)的1476±cm^(-1)吸收峰等;多组分仿制品可见综合了多种矿物特征的吸收光谱,谱学特征复杂。根据缺失水峰,或仅显示三水铝石结构水OH-导致的3623、3528、3472和3388 cm^(-1)吸收峰,指纹区显示[SO_(4)]^(2-)、[CO_(3)]^(2-)相关吸收峰,可初步区分于绿松石。显微拉曼光谱测试结果表明多组分仿制品的不同测试位置矿物组成不同,可分别测试到三水铝石(3360、3432、3522、3614 cm^(-1))、重晶石(989 cm^(-1))、方解石(1088 cm^(-1))的特征峰,结合显微拉曼光谱及化学分析结果可进一步确认仿制品的具体矿物组成。紫外-可见-近红外吸收光谱表明样品均经人工染剂染色,显示633±、713±nm吸收宽峰或610±、675±nm吸收宽峰。

关键词：三水铝石重晶石方解石振动光谱微区分析

急性心肌梗死相关线粒体基因的生物信息学鉴定与验证

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中国组织工程研究 2025年第31期29卷 6697-6707页

作者：田宇诗付强李冀黑龙江中医药大学基础医学院黑龙江省哈尔滨市150040 黑龙江中医药大学黑龙江省哈尔滨市150040

背景:线粒体在急性心肌梗死损伤和修复中具有重要意义,因此基于线粒体基因探索急性心肌梗死发病进展具有重要的临床意义。目的:探究线粒体基因是否可以作为评估急性心肌梗死进展的可靠生物标志物。方法:从高通量基因表达数据库下载急性... 详细信息

背景:线粒体在急性心肌梗死损伤和修复中具有重要意义,因此基于线粒体基因探索急性心肌梗死发病进展具有重要的临床意义。目的:探究线粒体基因是否可以作为评估急性心肌梗死进展的可靠生物标志物。方法:从高通量基因表达数据库下载急性心肌梗死数据集GSE66360,GSE12288,在线粒体蛋白质数据库获取人类线粒体基因集;对急性心肌梗死数据集GSE66360进行差异基因分析及加权基因共表达网络分析,两者取交集后获得基因进行蛋白质-蛋白质相互作用分析、基因本体论和京都基因与基因组百科全书分析;将交集基因与人类线粒体基因取交集以获得差异线粒体基因,对差异线粒体基因进行基因集富集分析和免疫浸润分析,并在外部数据集GSE12288中进行受试者工作特征曲线分析,验证线粒体差异基因的表达特征。结果与结论:①获得急性心肌梗死差异基因548个,差异基因分析及加权基因共表达网络分析显示Blue模块包含基因最多(4992个),二者交集基因共有116个,其中肿瘤坏死因子、白细胞介素1B、白细胞介素6、Toll样受体4和白细胞介素10为核心基因;②基因本体论分析显示生物过程主要涉及炎症反应、肿瘤坏死因子产生的正调控及细胞表面受体信号通路,细胞组成主要涉及三级颗粒膜、质膜外层和质膜等,分子功能主要涉及免疫球蛋白G结合、跨膜信号受体活性及趋化因子活性等,京都基因与基因组百科全书分析显示,这些基因主要涉及肿瘤坏死因子、白细胞介素17及核转录因子κB通路;③共获得8个差异线粒体基因,经过最小绝对收缩和选择算子和比例风险回归模型分析后筛选出4个特征基因,包括佛波醇-12-肉豆酸酯-13-乙酰基诱导蛋白1、BCL2-相关蛋白A1、溶质载体家族25成员37和脱氧核糖核酸聚合酶β,并分别对应了肿瘤蛋白53、氧化磷酸化、硫代谢及甘油磷脂代谢通路;④受试者工作特征曲线分析显示4个特征基因均具有诊断意义,并与静息树突状细胞、幼稚B细胞呈显著负相关性;⑤提示佛波醇-12-肉豆酸酯-13-乙酰基诱导蛋白1、BCL2-相关蛋白A1、溶质载体家族25成员37和脱氧核糖核酸聚合酶β表达特征可作为预测急性心肌梗死中线粒体功能的潜在生物标志物,可进一步提高急性心肌梗死预测的准确性。

关键词：线粒体急性心肌梗死生物信息学机器学习免疫浸润分析氧化应激炎症凋亡

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Determination of the shedding frequency of cavitation cloud in a submerged cavitation jet based on high-speed photography images

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Journal of Hydrodynamics 2021年第1期33卷 127-139页

作者： chi Peng Shou-ceng tian Gen-sheng Li State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum(Beijing)Beijing 102249China

To accurately determine the shedding frequency of the cavitation cloud in a submerged cavitation jet,the spectral analysis and the proper orthogonal decomposition(POD)for high-speed photography images are *** spectrums of 6 different kinds of image signals(the area-averaged gray level,the line-averaged gray level,the point gray level,the cavitation length,width,and area)are calculated and *** line-averaged gray level is found to be optimal in determining the shedding frequency but an accurate frequency can only be obtained in the stable-frequency zone where the cavitation cloud *** repeated experiments,the plateau-shape distribution of the main frequency is established with a deviation of 10.8%.A revised Reynolds number Re'is defined and the shedding frequency can be correlated to Re'by a power law when the cavitation number is less than *** relationship is validated by the experimental data in *** first mode of the POD characterizes the ensemble-average of the cavitation cloud while the second mode is the major part of the cavitation cloud transient *** modes 2-5 are organized in pairs,which confirms the periodic feature of the cavitation cloud in the submerged cavitation *** the nozzle exit,the modes 2-5 are symmetrically distributed in the jet shear *** shedding frequency of the cloud cavitation can also be precisely determined by performing the spectral analysis of the weighting coefficients of the mode *** paper shows that the two parameters,namely,the line-averaged gray level and the weighting coefficients of the mode 2,can be confidently used to calculate the shedding frequency of the cavitation cloud in a submerged cavitation jet.

关键词： Cavitation jet shedding frequency high-speed photography spectral analysis proper orthogonal decomposition(POD)

Resonant Heating of Ions by Parallel Propagating Alfvén Waves in Solar Coronal Holes

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chinese Journal of Astronomy and Astrophysics 2005年第3期5卷 285-294页

作者： tian-XiZhang jing-XiuWang chi-jieXiao NationalAstronomicalObservatories ChineseAcademyofSciencesBeijing100012／／CenterforSpacePlasmaandAeronomicResearchTheUniversityofAlabamainHuntsvilleHuntsvilleAL35899USA NationalAstronomicalObservatories ChineseAcademyofSciencesBeijing100012

Resonant heating of H, O+5, and Mg+9 by parallel propagating ion cyclotron Alfven waves in solar coronal holes at a heliocentric distance is studied using the heating rate derived from the quasilinear theory. It is shown that the particle-AlfVen-wave interaction is a significant microscopic process. The temperatures of the ions are rapidly increased up to the observed order in only microseconds, which implies that simply inserting the quasilinear heating rate into the fluid/MHD energy equation to calculate the radial dependence of ion temperatures may cause errors as the time scales do not match. Different species ions are heated by Alfven waves with a power law spectrum in approximately a mass order. To heat O+5 over Mg+9 as measured by the Ultraviolet Coronagraph Spectrometer (UVCS) in the solar coronal hole at a region ≥ 1.9.R, the energy density of Alfven waves with a frequency close to the O+5-cyclotron frequency must be at least double of that at the Mg+9-cyclotron frequency. With an appropriate wave-energy spectrum, the heating of H, O+5 and Mg+9 can be consistent with the UVCS measurements in solar coronal holes at a heliocentric distance.

关键词： acceleration of particles - plasmas - waves - solar wind - Sun: corona

siRNA-mediated DNA methylation and H3K9 dimethylation in plants

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Protein & Cell 2013年第9期4卷 656-663页

作者： chi Xu jing tian Beixin Mo College of Life Science Shenzhen Key Laboratory of Microbial Genetic EngineeringShenzhen UniversityShenzhen 518060China College of Life Science Shenzhen Key Laboratory of Marine Biological Resources and Ecological EnvironmentShenzhen UniversityShenzhen 518060China

Heterochromatic siRNAs regulate transcriptional gene silencing by inducing DNA methylation and histone H3K9 *** advances have revealed the distinct phases involved in siRNA mediated silencing pathway,although the precise functions of a number of factors remain undesignated,putative mechanisms for the con-nection between DNA and histone methylation have been investigated,and much effort has been invested to understand the biological functions of siRNA-mediated epigenetic modifi *** this review,we summarize the mechanism of siRNA-mediated epigenetic modification,which involves the production of siRNA and the recruit-ments of DNA and histone methytransferases to the target sequences assisted by complementary pairing between 24-nt siRNAs and nascent scaffold RNAs,the roles of siRNA-mediated epigenetic modifi cation in maintaining genome stability and regulating gene expression have been dis-cussed,newly identified players of the siRNA mediated silencing pathway have also been introduced.

关键词： epigenetic DNA methylation histone meth-ylation heterochromatic siRNA argonaute

A novel method for identifying influential nodes in complex networks based on gravity model

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chinese Physics B 2022年第5期31卷 791-801页

作者： Yuan jiang Song-Qing Yang Yu-Wei Yan tian-chi Tong ji-Yang Dai School of Information Engineering Nanchang Hangkong UniversityNanchang 330063China School of Automation Nanjing University of TechnologyNanjing 210094China

How to identify influential nodes in complex networks is an essential issue in the study of network characteristics.A number of methods have been proposed to address this problem,but most of them focus on only one *** on the gravity model,a novel method is proposed for identifying influential nodes in terms of the local topology and the global *** method comprehensively examines the structural hole characteristics and K-shell centrality of nodes,replaces the shortest distance with a probabilistically motivated effective distance,and fully considers the influence of nodes and their neighbors from the aspect of *** eight real-world networks from different fields,the monotonicity index,susceptible-infected-recovered(SIR)model,and Kendall’s tau coefficient are used as evaluation criteria to evaluate the performance of the proposed method compared with several existing *** experimental results show that the proposed method is more efficient and accurate in identifying the influence of nodes and can significantly discriminate the influence of different nodes.

关键词： influential nodes gravity model structural hole K-shell

Effect of Swirl Cup's Secondary Swirler on Flow Field and Ignition Performance

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Journal of Thermal Science 2015年第5期24卷 488-495页

作者： WANG Xiaofeng LIN Yuzhen ZHANG chi tian Xingpeng School of Energy and Power Engineering Beihang University

In a gas turbine engine combustor, highly swiding combustion is usually adopted to stabilize flame and reduce pollutant emissions. Swirl cup, as an air blast atomizer, is widely used to provide a uniform presentation of fuel droplets to the combustor dome. This paper investigated the effect of secondary swirler on the flow field down- stream of the swirl cup using particle image velocimetry （PIV）. Three swirl cups＇ non-reacting flow field were studied： case A, B and C with secondary swirler vane angle 53°, 60° and 68° respectively. Detailed mean and transient velocities and vorticity in the center plane were obtained. From the PIV results, a sharp contrast flow field was obtained for case A to other two cases due to the lower secondary swirling intensity. The recirculation zone is collapsed in disorder for the case A. Ignition tests of the three cups were completed in a single cup com- bustor. In general, the ignition performance increases with the increasing of the secondary swirling intensity. For case A, the ignition performance is very unstable and has much randomness and there is no clear lean ignition boundary can be generated. This work can further understand the swirl behavior and ignition mechanism.

关键词： Swirl cup swirl number ignition PIV

Improved space-time processing for X channel using precoders

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The Journal of china Universities of Posts and Telecommunications 2014年第5期21卷 31-36页

作者： tian Xin-ji LI Ya School of Computer Science and Technology Henan Polytechnic University

The article investigates how to send perfect space-time codes with low feedback amount and symbol-by-symbol decoding for X channel using precoders. It is assumed that two users are introduced with two antennas and two receivers. Each user employs a rate-2 space-time block code and follows certain rule when sending codewords. The multi-user interference is eliminated by pre-coding at the transmitter and linear processing at the receiver. Compared with the existing scheme for the same scene, the proposed scheme greatly reduces feedback amount and improves the transmission efficiency, while keeping the same decoding complexity. Simulations demonstrate the validity of the proposed scheme.

关键词： X channel space-time code pre-coding multi-user interference feedback amount transmission efficiency

Quantum Phase Transition in Quasi-two-dimensional Heisenberg Antiferromagnet with Single-Ion Anisotropy

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Communications in Theoretical Physics 2007年第1期47卷 171-180页

作者： ji An-Chun tian Guang-Shan School of Physics Peking University Beijing 100871 China

In the present paper, we investigate the quantum phase transition in a spatially anisotropic antiferrornagnetic Heisenberg model of S =1 with single-ion energy anisotropy. By using the Schwinger boson representation, we calculate the Gaussian correction to the critical value J⊥^c caused by quantum spin fluctuations. We find that, for the positive single-ion energy, a nonzero value of J⊥^c is always needed to stabilize the antiferromagnetic long-range order in this model. It resolves a difference among literature and shows clearly that the effect of quantum fluctuations may qualitatively change a result obtained by the mean-field theories on lower-dimensional systems.

关键词： spatially anisotropic Heisenberg model single-ion anisotropy functional integration Schwinger-Boson representation