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Nitrogen isotope stratigraphy of the Early Cambrian successions in the Tarim Basin:Spatial variability of nitrogen cycling and its implication for paleo-oceanic redox conditions

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Acta geochimica 2024年第4期43卷 785-801页

作者： Bi Zhu Xuefeng Li lu ge Yongquan Chen Institute of Earth’s Critical Zone School of Earth Sciences and EngineeringHohai UniversityNanjing 210098China Research Institute of Exploration and Development Tarim Oil Field CompanyPetroChinaKorlaChina

The Early Cambrian represents a critical time period characterized by extraordinary biological innovations and dynamic redox conditions in *** isotopic signatures of ancient sediments have the potential to elucidate the evolutionary path of marine redox states and the biogeochemical nitrogen cycle within the water column of the Early Cambrian *** existing research on this topic has predominantly focused on South China,the exploration of other continental margins has been limited,leaving contradictory hypotheses *** this study,pairedδ^(15)N andδ^(13)C org analyses were performed on the Lower Cambrian successions from the Shiairike section(inner ramp)and Well Tadong 2(deep shelf/basin)in the northwestern and eastern Tarim Basin,*** data from the Shiairike section reveal a discernible shift in the operation of different nitrogen cycles for the black chert-shale unit,also referred to as the black rock series in Chinese literature,of the Yurtus Formation(Fortunian stage to lower Stage 3).Oscillatingδ^(15)N values for its lower part are suggestive of alternating anaerobic assimilation of NH 4+and denitrification/*** is likely attributed to a shallow,unstable chemocline consistent with the upwelling and incursion of deep,anoxic waters during a major *** contrast,aerobic nitrogen cycling,indicated by positiveδ^(15)N values of>2‰,dominated the upper part alongside a reduction in upwelling *** the other hand,theδ^(15)N signatures of Xishanbulake and Xidashan Formations of Well Tadong 2,which encompass a time interval from the Cambrian Fortunian Age to Age 4,are indicative of N_(2)fixation by diazotrophs as the major nitrogen *** two studied intervals,although not time-equivalent,exhibit separated states of nitrogen cycling at least during the deposition of the Yurtus black rock *** spatially different nitrogen cycling of the studied sections is compatible with a redox-stratified ocean dur

关键词： Nitrogen isotopes Early Cambrian Tarim Black rock series

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Shear flow induced vibrations of long slender cylinders with a wake oscillator model

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Acta Mechanica Sinica 2011年第3期27卷 330-338页

作者： Fei ge Wei lu Lei Wang You-Shi Hong State Key Laboratory of Nonlinear Mechanics Institute of Mechanics CAS 100190 Beijing China

A time domain model is presented to study the vibrations of long slender cylinders placed in shear flow. Long slender cylinders such as risers and tension legs are widely used in the field of ocean engineering. They are subjected to vortex-induced vibrations（VIV） when placed within a transverse incident flow. A three dimensional model coupled with wake oscillators is formulated to describe the response of the slender cylinder in cross-flow and in-line directions. The wake oscillators are distributed along the cylinder and the vortex-shedding frequency is derived from the local current velocity. A non-linear fiuid force model is accounted for the coupled effect between cross-flow and in-line vibrations. The comparisons with the published experimental data show that the dynamic features of VIV of long slender cylinder placed in shear flow can be obtained by the proposed model,such as the spanwise average displacement,vibration frequency,dominant mode and the combination of standing and traveling waves. The simulation in a uniform flow is also conducted and the result is compared with the case of nonuniform flow. It is concluded that the flow shear characteristic has significantly changed the cylinder vibration behavior.

关键词： Vortex-induced vibration Vortex-induced wave Shear flow Wake oscillator Long slender cylinder

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Nitrogen-rich three-dimensional porous carbon mosaicked Na_(4)ge_(9)O_(20)as anode material for high-performance lithium-ion batteries

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Rare Metals 2023年第2期42卷 438-448页

作者： Hao-Miao Zhang Jing Chen Rou lu Cong-ge lu Shuang Zhou Zhi Chang An-Qiang Pan School of Materials Science and Engineering Central South UniversityChangsha410083China School of Physics and Materials Nanchang UniversityNanchang330031China

germanium-based material has attracted numerous attentions and been regarded as a promising anode material for lithium-ion batteries due to its high theoretical ***,drastic pulverization and rapid capacity fading caused by large volume variation during cycling limit its practical *** this work,three-dimensional N-doped carbon framework-wrapped Na_(4)ge_(9)O_(20)nanoparticles(3D Na_(4)ge_(9)O_(20)@N-C)have been synthesized via freeze-drying approach with NaCl as both template and sodium source for *** employment of NaCl has two special roles:on the one hand,the NaCl crystals act as template and facilitate the formation of 3D porous structure,while on the other hand,the NaCl crystals serving as sodium source and support the ion exchange between NaCl and geO_(2)promote the formation of Na_(4)ge_(9)O_(20).Benefiting from the unique method,the prepared 3D Na_(4)ge_(9)O_(20)@N-C not only suppresses the volume change by using carbon as buffer layers but also demonstrates an improved electronic conductivity and a shortened ionic *** utilized as an anode material for LIBs,the 3D Na_(4)ge_(9)O_(20)@N-C composites deliver high reversible capacity(896.2 mAh·g^(-1)at0.1 A·g^(-1)after 100 cycles),good cycling stability(520.8 mAh·g^(-1)at 2.0 A·g^(-1)after 400 cycles)and excellent rate performance(636.0 mAh·g^(-1)at 2.0 A·g^(-1)).This work provides a strategy to improve the electrochemical performance of germanium-based anode materials for lithium-ion batteries.

关键词： germanium-based anode Na_(4)ge_(9)O_(20) Ndoped carbon Porous nanostructure Lithium-ion batteries(LIBs)

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Electrostatically Controlled Nematic and Smectic Assembly of Gold Nanorods

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Chemical Research in Chinese Universities 2013年第5期29卷 929-933页

作者： WEI Wen-bo CHEN Kuan ge Guang-lu National Center for Nanoscience and Technology Beijing 100190 P. R. China

The assembly of gold nanorods（GNRs） into different liquid crystalline structures can be controlled by tuning their surface electric potential, After mildly removing excess surfactants in the GNRs solution, the electrostatic interaction between GNRs can be tuned by adjusting counter ion concentration. Specifically, nematic and smectic structures formed after solvent evaporation at low and high bromide concentrations, respectively. These results could be helpful for fabricating anisotropy enabled devices composed of metal and semiconductor nanorods.

关键词： Nanorod Nanostructure Self-assembly

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Analysis of Dynamic Tensile Process of Fiber Reinforced Concrete by Acoustic Emission Technique

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Journal of Wuhan University of Technology(Materials Science) 2018年第5期33卷 1129-1139页

作者： WANG Yan CHEN Shijie ge lu ZHOU Li HU Hongxiang College of Civil and Transportation Engineering Hohai UniversityNanjing 210098China Shenzhen Municipal Design&Research Institute Co. LtdShenzhen 518029China ChongQing Municipal Designing Research Institute ChongQing 400020China

The fiber reinforced concrete has good dynamic mechanical properties. But corresponding research lacks the dynamic damage characteristics of the polypropylene fiber（fiber of low elastic modulus） and steel fiber（fiber of high elastic modulus） reinforced concrete under medium strain rate（10-6 s-1-10-4 s-1）. In order to study the effect of strain rate on the damage characteristics of fiber reinforced concrete during the full curve damage process, the real time dynamic acoustic emission（AE） technique was applied to monitor the damage process of fiber reinforced concrete at three strain rates. The AE wavelet energy spectrum in ca8 frequency band and average AE peak frequency at three strain rates were analyzed. With the accumulation of damage, the AE wavelet energy spectrum in ca8 frequency band increased first and then decreased, and the average AE peak frequency increased gradually. With the increase of strain rate, the AE wavelet energy spectrum in ca8 frequency band and average AE peak frequency decreased gradually. The polypropylene fiber content has more obvious effect on the Dynamic increase factor（DIF） of the peak stress than the steel fiber content. The theoretical basis was provided for the monitoring of dynamic damage of fiber reinforced concrete based on the AE technique.

关键词： acoustic emission steel fiber polypropylene fiber strain rate acoustic emission wavelet energy spectrum peak frequency

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Effect of Graphite Content and Granularity on Mechanical and Tribological Properties of Bronze Alloyed Powder Composite

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Journal of Iron and Steel Research International 2005年第1期12卷 54-57页

作者： DENG Chen-hong CHEN Guang-zhi ge Qi-lu Central Iron and Steel Research Institute

The bronze alloyed powder composite containing nanoparticles was developed by hot *** effects of the content and granularity of graphite on hardness,machinability,bending strength,compression strength,and friction and wear behavior of the composites were *** microstructures of the specimens were analyzed by *** results showed that the graphites are distributed in net when nanographites are added,resulting in the decrease of mechanical properties and abrasive *** the content of nanographite is 10%,the composite is *** graphite is distributed in the form of block when micrographite is added,improving the mechanical properties and abrasive *** track was studied by SEM.

关键词： nanoparticle mechanical property friction wear abrasive resistance

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Trace Elements Characteristics of Black Shales from the Ediacaran Doushantuo Formation, Hubei Province, South China： Implications for Redox and Open vs. Restricted Basin Conditions

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Journal of Earth Science 2018年第2期29卷 342-352页

作者： Bi Zhu Shaoyong Jiang Daohui Pi lu ge Jinghong Yang Institute of Isotope Hydrology School of Earth Sciences and Engineering Hohai University Nanjing 210098 China State Key Laboratory of geological Processes and Mineral Resources Faculty of Earth Resources Collaborative Innovation Center for Exploration of Strategic Mineral Resources China University of Geosciences Wuhan 430074 China State Key Laboratory for Mineral Deposits Research School of Earth Sciences and Engineering Nanjing University Nanjing 210093 China

In the present study, we carried out trace element analyses of black shales of the Edia- caran Doushantou Formation from two sections （Jiulongwan, Baiguoyuan） in Hubei Province, South China. Mo-U characteristics of black shales from the two sections and compiled Mo-U data of Dou- shantuo black shales from sections of a variety of sedimentary facies described the temporal/spatial variability in the redox conditions of paleo-seawater during deposition of the Donshantuo Formation. Changes in Mo-U patterns of the Doushantuo Member II （DST2） shales of open marine environments are consistent with a shift from a predominately oxic to a predominately anoxic ocean during their deposition. Mo-U patterns of the DST2 black shales from intra-shelf sections reflect basin restriction may have happened in the intra-shelf basin and are compatible with the redox-stratified model of the intra-shelf basin. Mo-U patterns of black shales of the Doushantuo Member IV （DST4） reveal that the shales from intra-shelf sections have more pronounced Mo enrichment and more significant enrich- ment of Mo over U than the slope shales, indicating the operation of a Mn particulate shuttle in the intra-shelf basin. High Mo/TOC ratios of the DST4 at the intra-shelf sections, in combination with similar Mo-TOC patterns of the DST4 from both intra-shelf and slope sections, indicate the intra- shelf basin was well connected to the open ocean during deposition of the DST4.

关键词： Doushantuo Formation Mo-U eovariation Mo/TOC South China.

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Structure and electrochemical characteristics of Mg–Ti–Ni-based electrode alloys synthesized by mechanical milling

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Journal of Iron and Steel Research International 2021年第10期28卷 1329-1340页

作者： Zhong-hui Hou Xin Wei Wei Zhang Ze-ming Yuan Hui Yong Qi-lu ge Department of Functional Material Research Central Iron and Steel Research InstituteBeijing100081China Inner Mongolia University of Science and Technology Baotou014010Inner MongoliaChina

The vacuum induction melting was adopted to fabricating Mg_(50−x)Ti_(x)Ni_(45)Al_(3)Co_(2)(x=0,1,2,3,4 at.%)composites protected by the high-purity helium ***,the surface modification treatment of the as-cast alloys was carried out by mechanically coating *** amorphous and nanocrystalline Mg_(50−x)Ti_(x)Ni_(45)Al_(3)Co_(2)(x=0–4)+50 wt.%Ni hydrogen storing alloys as the negative materials in batteries were prepared through ball milling,and the influences of milling time and Ti dosage on the structure and electrochemical hydrogen storing behaviors of the corresponding samples were studied in *** electrochemical testing reveals that the as-milled alloys have excellent performances and can finish the electrochemical hydrogenation and dehydrogenation at indoor *** the first cycle without activation,the ball milling alloy obtains the maximum value of discharge *** capacity and cyclic steadiness of the composites conspicuously grow as Ti content and milling duration ***,the capacity retaining rate at 100th cycle and the discharge capacity of 30 h milling samples augment from 53%to 78%and from 435.2 to 567.2 mAh/g with changing Ti content from 0 to *** same performances of the alloy(x=4)are enhanced from 61%to 78%and from 379.9 to 567.2 mAh/g,respectively,with extending milling ***,high rate discharge ability,potential-step measurements,potentiodynamic polarization curves and electrochemical impedance spectrum manifest that the electrochemical kinetics properties can achieve significant amelioration as Ti content varies and milling duration is extended.

关键词： MgNi-based alloy Ti substitution of Mg Surface modification Mechanical milling Electrochemical performance

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Detection and analysis system for hybridization images of lab-in-a-tube microarray

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Chinese Science Bulletin 2005年第24期50卷 2896-2900页

作者： LIU Quanjun ZHOU Qin BAI Yunfei ge Qinyu lu Zuhong State Key Laboratory of Bioelectronics Southeast University Nanjing210096 China

A lab-in-a-tube microarray system is developed for sample inspection and signal detection by fabricating a flat transparent window cap of the Eppendorf tube. The oli- gonucleotide microarray is immobilized on the inner surface of the cap. A small vessel is placed in an Eppendorf tube for storing hybridization solutions. With the microarray system, the full biochemical processes, including gene fragment am- plification, fluorescence labeling, hybridization, and fluores- cence detection, have been performed in the sealed tube without opening the cap. The images are obtained from a fluorescence microscope and captured by a CCD, and the data are transported to a computer through the universal serial bus (USB). After noise reduction, signal intensity is deter- mined from hybridization image and the presence of gene fragments is identified. The final data output includes sample information, process steps, and hybridization results. A lab-in- a-tube microarray system for detecting ten respiratory vi- ruses at a single detection is designed. High detection throug- hput and accuracy have been demonstrated with the system.

关键词：呼吸道病毒病毒检测杂交图象处理

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无人机遥感监测在双柳煤矿采空区监测中的应用分析

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能源与节能 2025年第1期 321-323页

作者：葛璐山西汾西矿业(集团)有限责任公司双柳煤矿山西吕梁033000

双柳煤矿开采完毕后地表裂隙监测精度不够,部分区域监测不到位,为保证矿井开采区域监测全覆盖,采用无人机遥感监测技术对双柳煤矿采空区进行监测分析。研究表明,无人机遥感监测技术可以形成RKT数据,反演形成地表等高线云图,并拍摄地表... 详细信息

双柳煤矿开采完毕后地表裂隙监测精度不够,部分区域监测不到位,为保证矿井开采区域监测全覆盖,采用无人机遥感监测技术对双柳煤矿采空区进行监测分析。研究表明,无人机遥感监测技术可以形成RKT数据,反演形成地表等高线云图,并拍摄地表实物照片。通过在双柳煤矿采空区进行无人机遥感监测,发现地表裂缝5条,与地下采空区情况基本一致。实物照片显示,地表裂缝呈两端窄中间宽的形状,和开采情况基本一致。研究结果和研究方法对于其他矿井采空区监测具有一定指导意义。

关键词：地表裂缝无人机遥感监测等高线云图裂缝形状

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