检索结果-南通市图书馆

Development of a high-speed digital pulse signal acquisition and processing system based on MTCA for liquid scintillator neutron detector on EAST

引用

Nuclear Science and Techniques 2023年第10期34卷 60-72页

作者： Yong-qiang Zhang Li-Qun Hu guo-qiang zhong Hong-Rui Cao Jin-Long Zhao Li Yang qiang Li Institute of Plasma Physics Hefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031China University of Science and Technology of China Hefei 230026China Institute of Energy Hefei Comprehensive National Science CenterHefei 230031China

In this experimental study, involving deuterium–deuterium fusion neutron emission spectroscopy measurement on the experimental advanced superconducting tokamak(EAST), a liquid scintillator detector(BC501 A) was employed. This decision was based on the detector's superior sensitivity, optimal time-response, and its exceptional n–γ discrimination capability. This detector emits fast pulse signals that are as narrow as 100 ns, with high count rates that can peak at several Mcps. However, conventional nuclear circuits faced challenges in performing pulse height analysis, n–γ pulse shape discrimination, and in recording the entire pulse waveform under such high count rate conditions. To address these challenges, a high-speed digital pulse signal acquisition and processing system was designed. The system was developed around a micro-telecommunications computing architecture. Within this structure, a signal acquisition and processing(SAQP) module communicated through PCI Express links, achieving a bandwidth of up to 1.6 GB/s. To accurately capture the detailed shape of the pulses, four channels of analog-to-digital converters were used, each with a 500-MSPS sampling rate and a 14-bit resolution, ensuring an accuracy that surpassed 11 bits. An n–γ discrimination algorithm, based on the two-gate integral method, was also developed. Implemented within field programmable gate arrays, this algorithm provided a real-time n–γ discrimination spectrum for pulse height analysis. The system underwent rigorous testing in a laboratory setting and during an EAST experiment. The results confirmed that the innovative SAQP system can satisfy the demanding requirements of high-parameter experiments, manage count rates of up to 2 Mcps, execute real-time n–γ discrimination algorithms, and record entire pulse waveforms without any data loss.

关键词： EAST NES High-speed MTCA n–γdiscrimination Entire pulse waveform

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Study on the gamma rays and neutrons energy response optimization of a scintillating fiber detector for EAST with Geant4

引用

Nuclear Science and Techniques 2023年第9期34卷 40-49页

作者： Wei-Kun Chen Li-Qun Hu guo-qiang zhong Rui-Jie Zhou Bing Hong qiang Li Li Yang Institute of Plasma Physics Hefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031China University of Science and Technology of China Hefei 230026China Institute of Energy Hefei Comprehensive National Science Center(Anhui Energy Laboratory)Hefei 230031China

A new scintillating fiber detector inside magnetic shielding tube was designed and assembled for use in the next round of fusion experiments in the experimental advanced superconducting tokamak to provide D–T neutron yield with time *** this study,Geant4 simulations were used to obtain the pulse height spectra for ideal signals produced when detecting neutrons and gamma rays of multiple *** of the main sources of interference was found to be low-energy neutrons below 10–5 MeV,which can generate numerous secondary particles in the detector components,such as the magnetic shielding tube,leading to high-amplitude output *** address this issue,a compact thermal neutron shield containing a 1-mm Cd layer outside the magnetic shielding tube and a 5-mm inner Pb layer was specifically *** effects on the measurement of fast neutrons and the shielding effect on gamma rays were *** can suppress the height of the signals caused by thermal neutrons to a level below the height corresponding to neutrons above 4 MeV because the yield of the latter is used for detector *** addition,the detector has relatively flat sensitivity curves in the fast neutron region,with the intrinsic detection efficiencies(IDEs)of approximately 40%.For gamma rays with energies that are not too high(<8 MeV),the IDEs of the detector are only approximately 20%,whereas for gamma rays below 1 MeV,the response curve cuts off earlier in the low-energy region,which is beneficial for avoiding counting saturation and signal accumulation.

关键词： Sci-Fi detector D–T fusion neutron Thermal neutron shield Energy response Geant4

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Development of a wide-range and fast-response digitizing pulse signal acquisition and processing system for neutron flux monitoring on EAST

引用

Nuclear Science and Techniques 2022年第3期33卷 126-136页

作者： Li Yang Hong-Rui Cao Jin-Long Zhao Zi-Han Zhang qiang Li guo-Bin Wu Yong-qiang Zhang guo-qiang zhong Li-Qun Hu Zi-Jun Zhang Institute of Plasma Physics Hefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031China University of Science and Technology of China Hefei 230026China Hefei University of Technology Hefei 230009China

The neutron count rate fluctuation reaches six orders of magnitude between the ohmic plasma scenario and high power of auxiliary heating on an experimental advanced superconducting tokamak(EAST).The measurement result of neutron flux monitoring(NFM)is a significant feedback parameter related to the acquisition of radiation protection-related information and rapid fluctuations in neutron emission induced by plasma magnetohydrodynamic ***,a wide range and high time resolution are required for the NFM system on *** satisfy these requirements,a digital pulse signal acquisition and processing system with a wide dynamic range and fast response time was *** present study was conducted using a field-programmable gate array(FPGA)and peripheral component interconnect extension for instrument express(PXIe)*** digital dual measurement modes,which are composed of the pulse-counting mode and AC coupled square integral's Campbelling mode,were designed to expand the measurement range of the signal acquisition and processing *** time resolution of the signal acquisition and processing system was improved from 10 to 1 ms owing to utilizing highspeed analog-to-digital converters(ADCs),a high-speed PXIe communication with a direct memory access(DMA)mode,and online data preprocessing technology of *** signal acquisition and processing system was tested experimentally in the EAST radiation *** test results showed that the time resolution of NFM was improved to 1 ms,and the dynamic range of the neutron counts rate was expanded to more than 10^(6) counts per *** Campbelling mode was calibrated using a multipoint average linear fitting method;subsequently,the fitting coefficient reached ***,the newly developed pulse signal acquisition and processing system ensures that the NFM system meets the requirements of high-parameter experiments conducted on EAST more effectively.

关键词： EAST Neutron flux monitoring High time resolution Wide range Pulse signal acquisition and processing system

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

In situ anchoring in carbon matrix of Bi2O2CO3 as a high-performance anode material for Li-ion batteries

引用

Rare Metals 2024年第8期43卷 3634-3646页

作者： Pu-qiang He Jun guo Hui Huang zhong-Cheng guo Faculty of Metallurgy and Energy Engineering Kunming University of Science and Technology Research Center of Metallurgical Electrode Materials Engineering Technology Kunming Hendera Science and Technology Co. Ltd.

Bismuth-based anode materials have been regarded as promising Li-ion batteries due to their high theoretical ***,their low conductivity and associated volume expansion inhabited their *** this work,Bi2O2CO3@C composites were successfully synthesized by in situ anchoring of flower-like Bi2O2CO3nanosheets on a carbon-based substrate via *** unique composited structure of Bi2O2-CO3@C leads to a stable specific capacity of 547 mAh·g-1after 100 cycles at a current density of 0.1 A·***,it demonstrates excellent rate capability with a specific capacity of 210 mAh·g-1at 5 A·*** 550 cycles at a current density of 0.5 A·g-1,a high reversible capacity of nearly 400 mAh·g-1was ***,in situ X-ray diffraction measurements clearly demonstrate the conversion between Bi and Li3Bi during alloying/dealloying,confirming the good electrochemical reversibility of the materials for Li *** reaction kinetics of Bi2O2CO3@C were further investigated using galvanostatic intermittent titration ***,Bi2O2-CO3@C exhibited excellent long-term stability,maintaining its high reversible capacity for over 200 cycles at a current density of 0.5 A·g-1in a full cell configuration using Li1.20Mn0.54Ni0.13Co0.13O2as the cathode *** result further underscores its promising potential for lithium-ion *** work may provide inspiration for the design of alloy-type negative electrode materials for high-performance rechargeable batteries.

关键词： Bi 2 O 2 CO 3 Composite materials Anode materials Full batteries

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Optimization study and design of scintillating fiber detector for DT neutron measurements on EAST with Geant4

引用

Nuclear Science and Techniques 2022年第11期33卷 33-45页

作者： Wei-Kun Chen Li-Qun Hu guo-qiang zhong Bing Hong Rui-Jie Zhou Kai Li Li Yang Institute of Plasma Physics Hefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031China University of Science and Technology of China Hefei 230026China Hefei Comprehensive National Science Center Institute of EnergyHefei 230031China School of Mechanical and Vehicle Engineering West Anhui UniversityLuan 237012China

Real-time monitoring of the 14-MeV D-T fusion neutron yield is urgently required for the triton burnup study on the Experimental Advanced Superconducting Tokamak (EAST). In this study, we developed an optimal design of a fast-neutron detector based on the scintillating fiber (Sci-Fi) to provide D-T neutron yield through Geant4simulation. The effect on the detection performance is concerned when changing the number of the Sci-Fis embedded in the probe head, minimum distance between the fibers, length of the fibers, or substrate material of the probe head. The maximum number of scintillation photons generated by the n/γ source particles and output by the light guide within an event (event:the entire simulation process for one source particle) was used to quantify the n/γ resolution of the detector as the main basis. And the intrinsic detection efficiency was used as another evaluation criterion. The results demonstrate that the optimal design scheme is to use a 5 cm probe head whose substrate material is pure aluminum, in which 463 Sci-Fis with the same length of 5 cm are embedded, and the minimum distance between the centers of the two fibers is 2 mm. The optimized detector exhibits clear directionality in the simulation, which is in line with the expectation and experimental data provided in the literature. This study presents the variation trends of the performance of the SciFi detector when its main parameters change, which is beneficial for the targeted design and optimization of the Sci-Fi detector used in a specific radiation environment.

关键词： Sci-Fi detector Optimal design n/c resolution Intrinsic detection efficiency Geant4

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Microvesicles with mitochondrial content are increased in patients with sepsis and associated with inflammatory responses

引用

World Journal of Clinical Cases 2023年第2期11卷 342-356页

作者： Hai-Jun Zhang Jin-Yi Li Chao Wang guo-qiang zhong Department of Cardiology The First Affiliated Hospital of Guangxi Medical UniversityNanning 530000Guangxi Zhuang Autonomous RegionChina Department of Cardiology The First Affiliated HospitalHengyang Medical SchoolUniversity of South ChinaHengyang 421000Hunan ProvinceChina Department of Cardiology The Affiliated Hospital of Guilin Medical UniversityGuilin 541000Guangxi Zhuang Autonomous RegionChina

BACKGROUND Endothelial activation plays an important role in sepsis-mediated inflammation,but the triggering factors have not been fully *** carrying mitochondrial content(mitoMVs)have been implicated in several diseases and shown to induce endothelial *** To explore whether mitoMVs constitute a subset of MVs isolated from plasma of patients with sepsis and contribute to endothelial *** MVs were isolated from human plasma and characterized by confocal microscopy and flow *** cytokines,including interleukin(IL)-6,IL-8 and tumour necrosis factor(TNF)-α,and soluble vascular cell adhesion molecule(sVCAM)-1 were detected by *** umbilical vein endothelial cells(HUVECs)were stimulated with the circulating MVs to evaluate their effect on endothelial *** MitoMVs were observed in plasma from patients with *** with those in healthy controls,expression of MVs,mitoMVs,proinflammatory cytokines and sVCAM-1 was *** number of mitoMVs was positively associated with TNF-αand *** vitro,compared with MVs isolated from the plasma of healthy controls,MVs isolated from the plasma of patients with sepsis induced expression of OAS2,RSAD2,and CXCL10 in *** were taken up by HUVECs,and sonication of MVs significantly reduced the uptake of mitoMVs by HUVECs and expression of the above three type I IFNdependent *** MitoMVs are increased in the plasma of patients with sepsis,which induces elevated expression of type I IFN-dependent *** suggests that circulating mitoMVs activate the type I IFN signalling pathway in endothelial cells and lead to endothelial activation.

关键词： Sepsis Microvesicles Mitochondria Microvesicles carrying mitochondrial content

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Performance of real‑time neutron/gamma discrimination methods

引用

Nuclear Science and Techniques 2023年第1期34卷 102-110页

作者： Shi‑Xing Liu Wei Zhang Zi‑Han Zhang Shuang Lin Hong‑Rui Cao Cheng‑Xin Song Jin‑Long Zhao guo‑qiang zhong School of Electronics Hefei University of TechnologyHefei 230009China China Nuclear Power Engineering Co. LtdBeijing 100840China Institute of Plasma Physics Hefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031China

Nuclear security usually requires the simultaneous detection of neutrons and gamma *** the development of crystalline materials in recent years,Cs2LiLaBr6(CLLB)dual-readout detectors have attracted extensive attention from researchers,where real-time neutron/gamma pulse discrimination is the critical factor among detector performance *** study investigated the discrimination performance of the charge comparison,amplitude comparison,time comparison,and pulse gradient_(m)ethods and the effects of a Sallen–Key filter on their *** results show that the figure of merit(FOM)of all four methods is improved by proper *** them,the charge comparison method exhibits excellent noise resistance;moreover,it is the most_(s)uitable method of real-time discrimination for CLLB ***,its discrimination performance depends on the parameters t_(s),t_(m),and t_(e).When t_(s)corresponds to the moment at which the pulse is at 10%of its peak value,t_(e)requires a delay of only 640–740 ns compared to t_(s),at which time the potentially optimal FOM of the charge comparison method at 3.1–3.3 MeV is greater than *** FOM obtained using the t_(m)value calculated by a proposed maximized discrimination difference model(MDDM)and the potentially optimal FOM differ by less than 3.9%,indicating that the model can provide good guidance for parameter selection in the charge comparison method.

关键词： Charge comparison Maximized discrimination difference model Pulse filtering Real time n-γdiscrimination

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

An anchor-based spectral clustering method

引用

Frontiers of Information Technology & Electronic Engineering 2018年第11期19卷 1385-1396页

作者： Qin ZHANG guo-qiang zhong Jun-yu DONG Department of Computer Science and Technology Ocean University of China Science and Information College Qingdao Agricultural University

Spectral clustering is one of the most popular and important clustering methods in pattern recognition,machine learning, and data mining. However, its high computational complexity limits it in applications involving truly large-scale datasets. For a clustering problem with n samples, it needs to compute the eigenvectors of the graph Laplacian with O(n^3) time complexity. To address this problem, we propose a novel method called anchor-based spectral clustering(ASC) by employing anchor points of data. Specifically, m(m≤n) anchor points are selected from the dataset, which can basically maintain the intrinsic(manifold) structure of the original data. Then a mapping matrix between the original data and the anchors is constructed. More importantly, it is proved that this data-anchor mapping matrix essentially preserves the clustering structure of the data. Based on this mapping matrix, it is easy to approximate the spectral embedding of the original data. The proposed method scales linearly relative to the size of the data but with low degradation of the clustering performance. The proposed method, ASC,is compared to the classical spectral clustering and two state-of-the-art accelerating methods, i.e., power iteration clustering and landmark-based spectral clustering, on 10 real-world applications under three evaluation *** results show that ASC is consistently faster than the classical spectral clustering with comparable clustering performance, and at least comparable with or better than the state-of-the-art methods on both effectiveness and efficiency.

关键词： Clustering Spectral clustering Graph Laplacian Anchors

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Potential transformation of organic matter by microbes in cryoconite,Tibetan Plateau

引用

Science China Earth Sciences 2024年第6期67卷 1978-1989页

作者： Bixi guo Yongqin LIU Kevin Xu zhong Quan SHI Chen HE qiang ZHENG Ruanhong CAI State Key Laboratory of Tibetan Plateau Earth System Environment and Resources(TPESER)Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China Center for the Pan-Third Pole Environment Lanzhou UniversityLanzhou 730000China Department of Earth Oceanand Atmospheric SciencesUniversity of British ColumbiaVancouverBC V6T 1Z4Canada State Key Laboratory of Heavy Oil Processing Petroleum Molecules Engineering Center(PMEC)China University of PetroleumBeijing 102249China State Key Laboratory for Marine Environmental Science Collage of Ocean and Earth SciencesXiamen UniversityXiamen 361102China Fujian Key Laboratory of Marine Carbon Sequestration Xiamen UniversityXiamen 361005China

Microorganisms play an essential role in the glacier carbon cycle;how they transform organic matter in mountain glacial cryoconite remains to be ***,we applied ultra-high resolution Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS)and deep sequencing of 16S rRNA gene,to investigate the temporal microbial transformation of dissolved organic matter(DOM)of the Tibetan Plateau *** the 60-day incubation,we found that DOM in cryoconite underwent a three-stage transformation,with decreasing bioavailability over *** microbial community did not change much in the first week while degrading DOM molecules that were associated with higher H/C_(wa)and lower O/C_(wa).During days 15-30,DOM composition remained stable while microbial diversity *** day 60,the DOM was microbially converted into a higher state of recalcitrance,with higher values of aromatic index,O/C_(wa),and lower H/C_(wa),which contained molecules containing more *** among various microbial taxa,like Cyanobacteria,Bacteroidota,Gammaproteobacteria,Firmicutes,and Actinobacteriota,drove the DOM transformation in *** study sheds light on the in-situ transformation of DOM composition meditated by microbial populations in cryoconite at a temporal scale,providing new insights into understanding the microbial roles in the glacier organic carbon transformation.

关键词： Cryoconite Dissolved organic matter Biodegradation Microbial community Temporal variation

来源：

维普期刊数据库

同方期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

New insights into the deposition of natural gas hydrate on pipeline surfaces:A molecular dynamics simulation study

引用

Petroleum Science 2024年第1期21卷 694-704页

作者： Jun Zhang Hai-qiang Fu Mu-Zhi guo Zhao Wang Li-Wen Li Qi Yin You-guo Yan Wei Wei Wei-Feng Han Jie zhong School of Materials Science and Engineering China University of Petroleum(East China)Qingdao 266580ShandongChina School of Petroleum Engineering China University of Petroleum(East China)Qingdao 266580ShandongChina Department of Alternative Energy PetroChina Research Institute of Petroleum Exploration&DevelopmentLangfang 065007HebeiChina

Natural gas hydrate(NGH)can cause pipeline blockages during the transportation of oil and gas under high pressures and low *** hydrate adhesion on pipelines is viewed as an efficient way to prevent NGH *** studies suggested the water film can greatly increase hydrate adhesion in gas-dominant ***,by performing the molecular dynamics simulations,we find in water-dominant system,the water film plays different roles in hydrate deposition on Fe and its corrosion ***,due to the strong affinity of water on Fe surface,the deposited hydrate cannot convert the adsorbed water into hydrate,thus,a water film *** water affinities decrease(Fe>Fe_(2)O_(3)>FeO>Fe_(3)O_(4)),adsorbed water would convert to amorphous hydrate on Fe_(2)O_(3)and form the ordered hydrate on FeO and Fe_(3)O_(4)after hydrate *** absorbed water film converts to amorphous or to hydrate,the adhesion strength of hydrate continuously increases(Fe

关键词： Deposition Natural gas hydrate Pipelines Water affinity Adhesion strength

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：