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An optimized sequential extraction scheme for molybdenum association in environmental samples

Acta Geochimica 2016年第2期35卷 111-119页

作者： Liang Liang Jian-ming zhu State Key Laboratory of Environmental Geochemistry Institute of Geochemistry Chinese Academy of SciencesGuiyang 550081 People's Republic of China State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences Beijing 100083China University of Chinese Academy of Sciences Beijing 100049People's Republic of China

By comparing three sequential extraction pro- cedures, a new optimized extraction scheme for the molyb- denum association in environmental samples was proposed. Five operational steps were described as exchangeable （KH2PO4 ＋ K2HPO4： including water-soluble）, associated with organic matter （NaOH）, Fe-Mn oxides and/or carbonates （HC1）, sulfides （H2O2） and residue （HNO3 ＋ HF ＋ H2O2）. An optimized extraction scheme was com- pared with Tessier＇s procedure and the Commission of European Communities Bureau of Reference （BCR） was applied to black shales. Results showed Tessier＇s procedure gave the lowest concentration values for exchangeable molybdenum and the highest values for the residual molybdenum, which could not present the efficiency of the extraction reagents. BCR＇s procedure showed the highest values in oxidizable molybdenum and presented four fractions of molybdenum, which did not demonstrate the fractions of molybdenum in the black shales in detail. The optimized extraction scheme demonstrated a certain improvement on extraction efficiency over Tessier＇s proce- dure for the lowest residual molybdenum, and revealed morefeatured fraction information of molybdenum in black shales than BCR＇ s. Therefore, after a comparison with other two extraction procedures, the optimized extraction scheme proved suitable for the molybdenum in black shales and it also showed an accurate determination of the molybdenum in the fractions and source of bioavailable Mo.

关键词： Molybdenum Sequential extractionprocedure Black shales

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An Adaptive Single Neural Control for Variable Step-Size P&O MPPT of Marine Current Turbine System

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China Ocean Engineering 2021年第5期35卷 750-758页

作者： LI ming-zhu WANG Tian-zhen ZHOU Fu-na SHI ming Logistics Engineering College Shanghai Maritime UniversityShanghai 201306China Shanghai Investigation Design and Research Institute Co.LtdShanghai 200434China

Marine current energy has been increasingly used because of its predictable higher power *** to the external disturbances of various flow velocity and the high nonlinear effects on the marine current turbine(MCT)system,the nonlinear controllers which rely on precise mathematical models show poor performance under a high level of parameters’*** paper proposes an adaptive single neural control(ASNC)strategy for variable step-size perturb and observe(P&O)maximum power point tracking(MPPT)***,to automatically update the neuron weights of SNC for the nonlinear systems,an adaptive mechanism is proposed to adaptively adjust the weighting and learning ***,aiming to generate the exact reference speed for ASNC to extract the maximum power,a variable step-size law based on speed increment is designed to strike a balance between tracking speed and accuracy of P&O *** robust stability of the MCT control system is guaranteed by the Lyapunov *** simulation results show that this strategy has favorable adaptive performance under variable velocity conditions,and the MCT system operates at maximum power point steadily.

关键词： marine current turbine system perturb and observe single neural control adaptive mechanism maximum power point tracking

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Effect of friction heat on tribological behavior of M2 steel against GCr15 steel in dry sliding systems

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Journal of University of Science and Technology Beijing 2007年第6期14卷 512-516页

作者： ming Qiu Yongzhen Zhang Jun zhu School of Mechatronic Engineering Henan University of Science and Technology Luoyang 471003 China Theory of Lubrication and Bearing Institute Xi＇an Jiaotong University Xi＇an 710049 China School of Material Science and Engineering Henan University of Science and Technology Luoyang 471003 China

The tribological behavior depends significantly on friction heat under high sliding velocity. Many factors influence the conduction rate of friction heat, such as thermophysical properties of the pairs, the formation components of interface-film, environment mediums, etc. Through theoretical and experimental studies on surface temperature, the heat partition approaches have been applied to the pairs of M2 steel against GCr 15 steel to compare and discuss their tribological behavior in dry sliding contact. The results indicate that the values of the contact pressure have little effect on the heat partition at a high sliding velocity of 40 m/s. Furthermore, the degree of correlation between the dynamic temperature and friction coefficient is obvious, and the correlation degree of parameters increases as the pressure grows. A close correlation exists among the temperatures measured from different points of the pin specimen. At last, X-ray diffraction analysis denotes that the carbides of secondary M6C are separated out during the process of friction.

关键词： heat partition contact temperature dry friction dynamic temperature

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基于Fe3O4@AuNPs富集分离和酶剪切策略的表面增强拉曼光谱传感器用于帕金森病诊断

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中国科学:化学 2025年第2期55卷 521-529页

作者：周明庄艳雯曹小卫朱环宇杜守云刘敏华灌云县人民医院神经内科扬州大学医学院灌云县人民医院重症医学科

生物标志物的灵敏准确的检测有助于帕金森病（PD）的诊断.本研究制备了一种基于Fe3O4@AuNPs富集分离和酶剪切策略的表面增强拉曼散射（SERS）传感器,用于检测PD血清中miR-221.合成的Fe3O4@AuNPs兼具磁性纳米粒子和金纳米粒子的优点,可... 详细信息

生物标志物的灵敏准确的检测有助于帕金森病（PD）的诊断.本研究制备了一种基于Fe3O4@AuNPs富集分离和酶剪切策略的表面增强拉曼散射（SERS）传感器,用于检测PD血清中miR-221.合成的Fe3O4@AuNPs兼具磁性纳米粒子和金纳米粒子的优点,可以形成大量的“热点”,显著提升了SERS传感器的性能.当miR-221存在时,miR-221与拉曼信号分子Cy5标记的互补单链DNA（ssDNA-221）配对杂交形成miR-221-ssDNA-221双链.在双链特异性剪切酶（DSN）的作用下,核酸双链被切割,导致Cy5远离Fe3O4@AuNPs表面,SERS信号降低.根据Cy5的SERS强度,实现目标miR-221的快速定量检测.结果显示,SERS传感器对血清中miR-221的检测限（LOD）低至5.72aM.此外,该测试平台也具有良好的特异性和重现性.为了验证其临床应用的可行性,使用SERS传感器对PD小鼠和健康小鼠血清中miR-221进行分析,并通过qRT-PCR验证了SERS的准确性.SERS有望成为临床中PD筛查的可靠工具.

关键词：表面增强拉曼散射磁性富集分离酶剪切策略帕金森病 miRNA

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基于SMAA-GTDM的水库调度风险型群决策模型

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中国农村水利水电 2025年第2期 106-113页

作者：王雅琴孔祥意朱非林朱冰韩明宇钟平安河海大学水文水资源学院江苏南京210098 水利部信息中心北京100053

随机环境下的水库多目标优化调度结果是一组具有不确定性的非劣解集,传统的确定性决策方法难以定量考虑水库调度决策过程中的综合不确定性因素和风险。若按确定性决策结果进行调度,会给水库实际调度带来风险。为应对不确定性因素对水库... 详细信息

随机环境下的水库多目标优化调度结果是一组具有不确定性的非劣解集,传统的确定性决策方法难以定量考虑水库调度决策过程中的综合不确定性因素和风险。若按确定性决策结果进行调度,会给水库实际调度带来风险。为应对不确定性因素对水库调度决策问题的影响,减小随机环境下水库调度决策的风险,提出了一种考虑多重不确定性的水库调度风险型群决策模型。首先,采用概率分布量化了决策指标的不确定性。然后,提出了基于熵权法、模糊层次分析法、博弈论和偏差最小准则的决策群体偏好冲突消解和赋权方法,采用可行权重空间推求指标权重可行域。最后,建立了基于SMAA-GTDM的水库调度风险型群决策模型,提出了风险型群决策的两阶段流程,并定义了决策风险度指标对决策结果进行可靠性评估。以大渡河流域瀑布沟水库防洪调度为实际案例,与确定性GTDM模型做了对比分析,论证了SMAA-GTDM风险型群决策模型及其两阶段决策流程在处理风险决策问题方面的可行性和优越性。进一步与原始的SMAA-2模型开展对比验证,结果表明,两个模型结果中综合排序最优方案获得最优排序的概率分别为68.95%、45.61%,置信因子分别为69.1%、46.22%,决策风险度分别为0.04%、1.55%,说明SMAA-GTDM模型能在随机环境下提供更明确的排序结果,显著减小决策风险,可为水库调度提供更为稳健的决策支撑。

关键词：水库调度风险型群决策随机多准则可接受性分析理论灰靶决策组合赋权决策可靠性

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Mitotic inheritance of DNA methylation: more than just copy and paste

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Journal of Genetics and Genomics 2021年第1期48卷 1-13页

作者： Xuan ming Bing zhu Yingfeng Lia National Laboratory of Biomacromolecules Institute of BiophysicsChinese Academy of SciencesBeijing 100101China College of Life Sciences University of Chinese Academy of SciencesBeijing 100049China

Decades of investigation on DNA methylation have led to deeper insights into its metabolic mechanisms and biological *** understanding was fueled by the recent development of genome editing tools and our improved capacity for analyzing the global DNA methylome in mammalian *** review focuses on the maintenance of DNA methylation patterns during mitotic cell *** discuss the latest discoveries of the mechanisms for the inheritance of DNA methylation as a stable epigenetic *** also highlight recent evidence showing the rapid turnover of DNA methylation as a dynamic gene regulatory mechanism.A body of work has shown that altered DNA methylomes are common features in aging and *** discuss the potential links between methylation maintenance mechanisms and diseaseassociated methylation changes.

关键词： DNMT1 Mitotic DNA methylation inheritance Neighboring reinforcement model Aging-associated methylation changes

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A Kinematical Calibration of the Galactocentric Distance

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Chinese Journal of Astronomy and Astrophysics 2007年第1期7卷 120-128页

作者： ming Shen Zi zhu Department of Astronomy Nanjing University Nanjing 210093

We present a new determination of the Galactocentric distance by a pure kinematical model. Two subgroups of components from the Galactic thin disk, the O-B5 stars and the Galactic open clusters, were selected for our analysis. On the basis of kinematical data of around 1200 O-B5 stars, we obtained an estimated value of Ro=8.25-4-0.79 kpc, while a similar evaluation from 270 Galactic open clusters gives Ro=7.95-4-0.62 kpc. Considering the scatter of Ro given by individual investigators with different methods, our present determinations agree well with the best value proposed by Reid.

关键词： Galaxy kinematics and dynamics-stars early-type-open clusters and associations

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Integrated HI emission in galaxy groups and clusters

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Research in Astronomy and Astrophysics 2017年第10期17卷 15-26页

作者： Mei Ai ming zhu Jian Fu National Astronomical Observatories Chinese Academy of Sciences Key Laboratory of Radio Astronomy Chinese Academy of Sciences University of Chinese Academy of Sciences Key Laboratory for Research in Galaxies and Cosmology Shanghai Astronomical Observatory Chinese Academy of Sciences

The integrated HI emission from hierarchical structures such as groups and clusters of galax- ies can be detected by FAST at intermediate redshifts. Here we propose to use FAST to study the evolution of the global HI content of clusters and groups over cosmic time by measuring their integrated HI emissions. We use the Virgo Cluster as an example to estimate the detection limit of FAST, and have estimated the integration time to detect a Virgo type cluster at different redshifts （from z = 0.1 to z ---- 1.5）. We have also employed a semi-analytic model （SAM） to simulate the evolution of HI contents in galaxy clusters. Our simulations suggest that the HI mass of a Virgo-like cluster could be 2-3 times higher and the physical size could be more than 50% smaller when redshift increases from z = 0.3 to z = 1. Thus the integration time could be reduced significantly and gas rich clusters at intermediate redshifts can be detected by FAST in less than 2 hours of integration time. For the local Universe, we have also used SAM simulations to create mock catalogs of clusters to predict the outcomes from FAST all sky surveys. Comparing with the optically selected catalogs derived by cross matching the galaxy catalogs from the SDSS survey and the ALFALFA survey, we find that the HI mass distribution of the mock catalog with 20 s of integration time agrees well with that of observations. However, the mock catalog with 120 s of integration time predicts many more groups and clusters that contain a population of low mass HI galaxies not detected by the ALFALFA survey. A future deep HI blind sky survey with FAST would be able to test such prediction and set constraints on the numerical simulation models. The observational strategy and sample selections for future FAST observations of galaxy clusters at high redshifts are also discussed.

关键词： galaxy clusters -- neutral hydrogen (HI) -- galaxy evolution

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Cyclic Lateral Responses of Monopiles Considering the Influence of Pile−Soil Relative Stiffness in Sand

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China Ocean Engineering 2022年第2期36卷 247-257页

作者： WANG Yang zhu ming-xing GONG Wei-ming DAI Guo-liang WU Jin-biao zhu Wen-bo Key Laboratory of Concrete and Prestressed Concrete Structures of the Ministry of Education Southeast UniversityNanjing 211189China School of Civil Engineering Southeast UniversityNanjing 211189China School of Civil Engineering and Architecture Jiangsu University of Science and TechnologyZhenjiang 212003China Department of Built and Environment Engineering The University of NewcastleCallaghanNew South WalesAustralia

The existing studies have primarily focused on the effect of cyclic load characteristics(namely,cyclic load ratio and amplitude ratio)on cyclic lateral response of monopiles in sand,with little attention paid to the effect of pile−soil relative stiffness(K_(R)).This paper presents a series of 1-g cyclic tests aimed at improving understanding of the cyclic lateral responses of monopiles under different pile−soil *** systems are arranged by two model piles with different stiffness,including four different slenderness ratios(pile embedded length,L,normalized by diameter,D)under medium dense *** K_(R)-values are calculated by a previously proposed method considering the real soil stress *** test results show that the lateral accumulation displacement increases significantly with the increment of the K_(R)-value,while the cyclic secant stiffness performs *** maximum pile bending moment increases with the cycle number for the rigid pile−soil system,but shows a decreasing trend in the flexible *** an uppermost concern,an empirical model is proposed to predict the accumulated displacement of arbitrary pile−soil systems by combining the results from this study with those from previous experimental *** validity of the proposed model is demonstrated by 1-g and centrifuge tests.

关键词： monopile 1-g model test lateral cyclic loading sand pile−soil relative stiffness prediction model

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An improved analysis method for assessing the nuclear-heating impact on the stability of toroidal field magnets in fusion reactors

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Nuclear Science and Techniques 2024年第6期35卷 163-176页

作者： Yu-Dong Lu Jin-Xing Zheng Xu-Feng Liu huan Wu Jian Ge Kun Xu ming Li Hai-Yang Liu Lei zhu Fei Liu Institute of Plasma Physics Hefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031China University of Science and Technology of China Hefei 230026China

The superconducting magnet system of a fusion reactor plays a vital role in plasma confinement,a process that can be dis-rupted by various operational factors.A critical parameter for evaluating the temperature margin of superconducting magnets during normal operation is the nuclear heating caused by D-T *** study investigates the impact of nuclear heat-ing on a superconducting magnet system by employing an improved analysis method that combines neutronics and thermal *** the magnet system,toroidal field(TF)magnets are positioned closest to the plasma and bear the highest nuclear-heat load,making them prime candidates for evaluating the influence of nuclear heating on *** enhance the modeling accuracy and facilitate design modifications,a parametric TF model that incorporates heterogeneity is established to expedite the optimization design process and enhance the accuracy of the computations.A comparative analysis with a homogeneous TF model reveals that the heterogeneous model improves accuracy by over 12%.Considering factors such as heat load,magnetic-field strength,and cooling conditions,the cooling circuit facing the most severe conditions is selected to calculate the temperature of the *** selection streamlines the workload associated with thermal-hydraulic *** approach enables a more efficient and precise evaluation of the temperature margin of TF ***,it offers insights that can guide the optimization of both the structure and cooling strategy of superconducting magnet systems.

关键词： Superconducting magnet Nuclear heating Neutronics Thermal hydraulics

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