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A deep kernel method for lithofacies identification using conventional well logs 被引量:1
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作者 Shao-Qun Dong Zhao-Hui Zhong +5 位作者 Xue-Hui Cui Lian-Bo Zeng Xu Yang jian-jun liu Yan-Ming Sun jing-Ru Hao 《Petroleum Science》 SCIE EI CAS CSCD 2023年第3期1411-1428,共18页
How to fit a properly nonlinear classification model from conventional well logs to lithofacies is a key problem for machine learning methods.Kernel methods(e.g.,KFD,SVM,MSVM)are effective attempts to solve this issue... How to fit a properly nonlinear classification model from conventional well logs to lithofacies is a key problem for machine learning methods.Kernel methods(e.g.,KFD,SVM,MSVM)are effective attempts to solve this issue due to abilities of handling nonlinear features by kernel functions.Deep mining of log features indicating lithofacies still needs to be improved for kernel methods.Hence,this work employs deep neural networks to enhance the kernel principal component analysis(KPCA)method and proposes a deep kernel method(DKM)for lithofacies identification using well logs.DKM includes a feature extractor and a classifier.The feature extractor consists of a series of KPCA models arranged according to residual network structure.A gradient-free optimization method is introduced to automatically optimize parameters and structure in DKM,which can avoid complex tuning of parameters in models.To test the validation of the proposed DKM for lithofacies identification,an open-sourced dataset with seven con-ventional logs(GR,CAL,AC,DEN,CNL,LLD,and LLS)and lithofacies labels from the Daniudi Gas Field in China is used.There are eight lithofacies,namely clastic rocks(pebbly,coarse,medium,and fine sand-stone,siltstone,mudstone),coal,and carbonate rocks.The comparisons between DKM and three commonly used kernel methods(KFD,SVM,MSVM)show that(1)DKM(85.7%)outperforms SVM(77%),KFD(79.5%),and MSVM(82.8%)in accuracy of lithofacies identification;(2)DKM is about twice faster than the multi-kernel method(MSVM)with good accuracy.The blind well test in Well D13 indicates that compared with the other three methods DKM improves about 24%in accuracy,35%in precision,41%in recall,and 40%in F1 score,respectively.In general,DKM is an effective method for complex lithofacies identification.This work also discussed the optimal structure and classifier for DKM.Experimental re-sults show that(m_(1),m_(2),O)is the optimal model structure and linear svM is the optimal classifier.(m_(1),m_(2),O)means there are m KPCAs,and then m2 residual units.A workflow to determine an optimal classifier in DKM for lithofacies identification is proposed,too. 展开更多
关键词 Lithofacies identification Deepkernel method Well logs Residual unit Kernel principal component analysis Gradient-free optimization
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Analytical solution for Non-Darcian effect on transient confined-unconfined flow in a confined aquifer
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作者 Peng-yu Shi jian-jun liu +3 位作者 Yi-jie Zong Kai-qing Teng Yu-ming Huang Liang Xiao 《Journal of Groundwater Science and Engineering》 2023年第4期365-378,共14页
This paper presents a new analytical solution to investigate the mechanism of transient confinedunconfined flow in a confined aquifer induced by pumping with a large rate during mine drainage.The study focuses on unde... This paper presents a new analytical solution to investigate the mechanism of transient confinedunconfined flow in a confined aquifer induced by pumping with a large rate during mine drainage.The study focuses on understanding the impact of non-Darcian effect on flow towards a fully penetrated pumping well.The nonlinear relationship between specific discharge and the hydraulic gradient is described using Izbash's equation.A novel approximate method is developed to linearize the mathematical model,and the solution is derived using the Boltzmann transform.The proposed solution is validated by comparing it with previous works.The findings indicate that increased non-Darcian index,quasi-hydraulic conductivity,and specific storage have negatively affect the development of the unconfined region and aquifer drawdown,as greater turbulence flow accelerates recharge to the pumping well.Drawdown is found to be sensitive to the non-Darcian index,quasi-hydraulic conductivity,while it is unaffected by specific yield and specific storage.The conclusions provide valuable insights for mine drainage and the application of geological and hydrological conditions. 展开更多
关键词 Non-Darcian flow Izbash equation Boltzmann transform Sensitivity analysis
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Identification of survival-associated biomarkers based on three datasets by bioinformatics analysis in gastric cancer
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作者 Long-Kuan Yin Hua-Yan Yuan +4 位作者 jian-jun liu Xiu-Lian Xu Wei Wang Xiang-Yu Bai Pan Wang 《World Journal of Clinical Cases》 SCIE 2023年第20期4763-4787,共25页
BACKGROUND Gastric cancer(GC)is one of the most common malignant tumors with poor prognosis in terms of advanced stage.However,the survival-associated biomarkers for GC remains unclear.AIM To investigate the potential... BACKGROUND Gastric cancer(GC)is one of the most common malignant tumors with poor prognosis in terms of advanced stage.However,the survival-associated biomarkers for GC remains unclear.AIM To investigate the potential biomarkers of the prognosis of patients with GC,so as to provide new methods and strategies for the treatment of GC.METHODS RNA sequencing data from The Cancer Genome Atlas(TCGA)database of STAD tumors,and microarray data from Gene Expression Omnibus(GEO)database(GSE19826,GSE79973 and GSE29998)were obtained.The differentially expressed genes(DEGs)between GC patients and health people were picked out using R software(x644.1.3).The intersections were underwent between the above obtained co-expression of differential genes(co-DEGs)and the DEGs of GC from Gene Expression Profiling Interactive Analysis database,and Gene Ontology(GO)analysis,Kyoto Encyclopedia of Gene and Genome(KEGG)pathway analysis,Gene Set Enrichment Analysis(GSEA),Protein-protein Interaction(PPI)analysis and Kaplan-Meier Plotter survival analysis were performed on these DEGs.Using Immunohistochemistry(IHC)database of Human Protein Atlas(HPA),we verified the candidate Hub genes.RESULTS With DEGs analysis,there were 334 co-DEGs,including 133 up-regulated genes and 201 down-regulated genes.GO enrichment analysis showed that the co-DEGs were involved in biological process,cell composition and molecular function pathways.KEGG enrichment analysis suggested the co-DEGs pathways were mainly enriched in ECM-receptor interaction,protein digestion and absorption pathways,etc.GSEA pathway analysis showed that co-DEGs mainly concentrated in cell cycle progression,mitotic cell cycle and cell cycle pathways,etc.PPI analysis showed 84 nodes and 654 edges for the co-DEGs.The survival analysis illustrated 11 Hub genes with notable significance for prognosis of patients were screened.Furtherly,using IHC database of HPA,we confirmed the above candidate Hub genes,and 10 Hub genes that associated with prognosis of GC were identified,namely BGN,CEP55,COL1A2,COL4A1,FZD2,MAOA,PDGFRB,SPARC,TIMP1 and VCAN.CONCLUSION The 10 Hub genes may be the potential biomarkers for predicting the prognosis of GC,which can provide new strategies and methods for the diagnosis and treatment of GC. 展开更多
关键词 Gastric cancer Survival-associated biomarkers Bioinformatics analysis Hub genes
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助推行业发展 引领科技进步——结核病领域团体标准工作实践 被引量:2
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作者 高磊 张浩然 +4 位作者 王瑾 冯岚 成诗明 刘剑君 金奇 《中国防痨杂志》 CAS CSCD 2020年第1期8-11,共4页
2017年新修订的《中华人民共和国标准化法》正式确立了团体标准的法律地位,团体标准成为我国标准体系的一部分。本文主要介绍了结核病领域的标准化工作现状,以及中国防痨协会团体标准工作的实践,探讨了结核病团体标准研制的重点方向。... 2017年新修订的《中华人民共和国标准化法》正式确立了团体标准的法律地位,团体标准成为我国标准体系的一部分。本文主要介绍了结核病领域的标准化工作现状,以及中国防痨协会团体标准工作的实践,探讨了结核病团体标准研制的重点方向。在当前机遇和挑战并存的前提下,积极培育和引导发展团体标准将为推动结核病领域标准化工作、提升“诊、防、治”的能力建设做出重要贡献。 展开更多
关键词 结核 团体标准 标准化
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Respiratory Distress Resulting from Gastroesophageal Reflux Is not Asthma,but Laryngotracheal Irritation,Spasm,even Suffocation 被引量:20
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作者 Zhong-gao Wang Ji-min Wu +5 位作者 jian-jun liu Li-yin Wang Yun-gang Lai Ibrahim M Ibrahim Xiu-jie Wang Herbert Dardik 《Chinese Medical Sciences Journal》 CAS CSCD 2009年第2期130-132,共3页
DESPITE the strong association between gastroesophageal reflux disease (GERD) and asthma has been undisputedly established and widely recognized by experts in advanced countries. Yet few topics in medicine are as cont... DESPITE the strong association between gastroesophageal reflux disease (GERD) and asthma has been undisputedly established and widely recognized by experts in advanced countries. Yet few topics in medicine are as controversial 展开更多
关键词 支气管 哮喘 反流 食管 呼吸 痉挛 窒息
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Effects of varicocele on testosterone, apoptosis and expression of StAR mRNA in rat Leydig cells 被引量:14
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作者 De-Yi Luo Gang Yang +2 位作者 jian-jun liu Yu-Ru Yang Qiang Dong 《Asian Journal of Andrology》 SCIE CAS CSCD 2011年第2期287-291,共5页
The aim of this study was to explore the effects of varicocele on the morphology and function of Leydig cells in the rat testis. Forty male Sprague-Dawley rats were divided into two groups: the experimental group und... The aim of this study was to explore the effects of varicocele on the morphology and function of Leydig cells in the rat testis. Forty male Sprague-Dawley rats were divided into two groups: the experimental group underwent surgery to create a left varicocele (VC), and the control group underwent a sham operation. Serum testosterone and intratesticular testosterone levels were measured using a radioimmunoassay after 4 and 8 weeks of operation. Leydig cells were studied for apoptosis and expression of steroidogenetic acute regulatory (STAR) protein mRNA levels. Serum testosterone levels declined after 4 and 8 weeks of operation but were not significant (P〉0.05). However, the intratesticular testosterone levels after 8 weeks were significantly decreased compared with the control group (P〈0.01). The mean apoptosis index of Leydig cells in the experimental group was significantly higher than that in the control group after 4 or 8 weeks (P〈0.01). StAR mRNA levels in the Leydig cells of the experimental group were significantly lower compared to those of the control group (P〈0.01). Our data show that varicocele did impair Leydig cell function by increasing apoptosis and suppressing the expression of the StAR protein. 展开更多
关键词 APOPTOSIS Leydig cell steroidogenic acute regulatory protein TESTOSTERONE VARICOCELE
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Breast Cancer Resistance Protein Expression and 5-Fluorouracil Resistance 被引量:5
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作者 JIAN-HUI YUAN JIN-QUAN CHENG +7 位作者 LONG-YUAN JIANG WEI-DONG JI LIANG-FENG GUO jian-jun liu XING-YUN XU JING-SONG HE XIAN-MING WANG ZHI-XIONG ZHUANG 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2008年第4期290-295,共6页
Objective To filtrate breast cancer resistance protein (BCRP)-mediated resistant agents and to investigate clinical relationship between BCRP expression and drug resistance. Methods MTT assay was performed to filtra... Objective To filtrate breast cancer resistance protein (BCRP)-mediated resistant agents and to investigate clinical relationship between BCRP expression and drug resistance. Methods MTT assay was performed to filtrate BCRP-mediated resistant agents with BCRP expression cell model and to detect chemosensitivity of breast cancer tissue specimens to these agents. A high performance liquid chromatography (HPLC) assay was established, and was used to measure the relative dose of intracellular retention resistant agents. RT-PCR and immunohistochemistry (IHC) were employed to investigate the BCRP expression in breast cancer tissue specimens. Results MTT assay showed that the expression of BCRP increased with the increasing resistance of 5-fluorouracil (5-Fu) (P〈0.05, n=3) in the cell model, while HPLC assay indicated that the intracellular retention dose of 5-Fu was significantly correlated with the expression of BCRP (t=-0.897, P〈0.05, n=3). A total of 140 breast cancer tissue specimens were collected. BCRP-positive expression was detected in forty-seven specimens by both RT-PCR and IHC. As shown by MTT assay subsequently, the resistance index (RI) of 47 BCRP-positive breast cancer tissue specimens to 5-Fu was 7-12 times as high as that of adjacent normal tissue samples. BCRP expression was related to 5-Fu resistance (R2=0.8124, P〈0.01). Conclusion Resistance to 5-Fu can be mediated by BCRR Clinical chemotherapy for breast cancer patients can be optimized based on BCRP-positive expression. 展开更多
关键词 Breast cancer resistance protein 5-FLUOROURACIL Breast cancer RESISTANCE CHEMOTHERAPY
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Rearrangement on surface structures by boride to enhanced cycle stability for LiNi0.80Co0.15Al0.05O2 cathode in lithium ion batteries 被引量:3
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作者 Shubiao Xia Wenjin Huang +5 位作者 Xiang Shen Jiaming liu Feixiang Cheng jian-jun liu Xiaofei Yang Hong Guo 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2020年第6期110-118,I0005,共10页
The side reaction between the active material and liquid-electrolyte cause structural damage and particle pulverization is one of the important factors leading to the capacity decay of LiNi0.80Co0.15Al0.05O2(NCA)mater... The side reaction between the active material and liquid-electrolyte cause structural damage and particle pulverization is one of the important factors leading to the capacity decay of LiNi0.80Co0.15Al0.05O2(NCA)materials in Li ion batteries(LIBs).Surface modification is an effective strategy for NCA cathodes,which could alleviate the degradation associated with surface processes.Herein,a surface structure rearrangement of NCA cathode secondary particles was reported by in-situ forming a solid electrolyte LiBO2.The LiBO2 is beneficial for alleviating the stress during charge/discharge process,thereby slowing down the rate of cracks formation in the secondary particles,which facilitates the Li+de-intercalation as well as prevents penetration of the liquid-electrolyte into the interior of the particles.As a result,the surface structure rearrangement NCA(RS-NCA)delivers a high discharge capacity of 202.5 m Ah g^-1 at 0.1 C,and exhibits excellent cycle stability with discharge capacity retaining 148 m Ah g^-1 after 200 cycles at 2 C.This surface structure rearrangement approach provides a new viewpoint in designing high-performance high-voltage LIBs. 展开更多
关键词 LiNi0.80Co0.15Al0.05O2 Surface structure REARRANGEMENT Particle PULVERIZATION Crack Cycle stability
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Gravitational Deformation Measurement Method for the Main Reflector and Sub-reflector of the 70 m Antenna by Laser Scanner 被引量:2
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作者 Lian-Bo Fu jian-jun liu +4 位作者 Wei Yan De-Qing Kong Xin Ren Chen-Di liu Hong-Bo Zhang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2022年第9期1-9,共9页
Large antennas play an important role in deep space exploration and astronomical research. However, their performances are inevitably affected by the main reflector surface deformation and sub-reflector displacement r... Large antennas play an important role in deep space exploration and astronomical research. However, their performances are inevitably affected by the main reflector surface deformation and sub-reflector displacement resulting from the factors of wind, temperature, and gravity, among which the effect of gravity is especially pronounced. In this work, a three-dimensional laser scanner was employed to measure the main reflector and subreflector gravitational deformation of the Tianjin 70 m antenna at different elevation angles. Here, we solved the antenna main reflector deformation and sub-reflector displacement, and analyzed the deformation law of the antenna under the action of gravity. A new measurement method of antenna main reflector deformation and subreflector displacement is realized by mutual verification of the measured results and theoretical simulations. This method will help to improve the antenna performance and provide a reference to optimize the design of largeaperture antennas. 展开更多
关键词 telescopes techniques:radar astronomy planets and satellites:detection
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Analysis of the geomorphology surrounding the Chang'e-3 landing site 被引量:6
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作者 Chun-Lai Li Ling-Li Mu +8 位作者 Xiao-Duan Zou jian-jun liu Xin Ren Xing-Guo Zeng Yi-Man Yang Zhou-Bin Zhang Yu-Xuan liu Wei Zuo Han Li 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2014年第12期1514-1529,共16页
Chang'e-3 (CE-3) landed on the Mare Imbrium basin in the east part of Sinus Iridum (19.51°W, 44.12°N), which was China's first soft landing on the Moon and it started collecting data on the lunar surfa... Chang'e-3 (CE-3) landed on the Mare Imbrium basin in the east part of Sinus Iridum (19.51°W, 44.12°N), which was China's first soft landing on the Moon and it started collecting data on the lunar surface environment. To better understand the environment of this region, this paper utilizes the available high-resolution topography data, image data and geological data to carry out a detailed analysis and research on the area surrounding the landing site (Sinus Iridum and 45 km×70 km of the landing area) as well as on the topography, landform, geology and lunar dust of the area surrounding the landing site. A general topographic analysis of the surrounding area is based on a digital elevation model and digital elevation model data acquired by Chang'e-2 that have high resolution; the geology analysis is based on lunar geological data published by USGS; the study on topographic factors and distribution of craters and rocks in the surrounding area covering 4km^4km or even smaller is based on images from the CE-3 landing camera and images from the topographic camera; an analysis is done of the effect of the CE-3 engine plume on the lunar surface by comparing images before and after the landing using data from the landing camera. A comprehensive analysis of the results shows that the landing site and its surrounding area are identified as typical lunar mare with flat topography. They are suitable for maneuvers by the rover, and are rich in geological phenomena and scientific targets, making it an ideal site for exploration. 展开更多
关键词 atlases -- methods: data analysis -- techniques: image processing --techniques: photometric
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A method and results of color calibration for the Chang'e-3 terrain camera and panoramic camera 被引量:6
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作者 Xin Ren Chun-Lai Li +5 位作者 jian-jun liu Fen-Fei Wang Jian-Feng Yang En-Hai liu Bin Xue Ru-Jin Zhao 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2014年第12期1557-1566,共10页
The terrain camera (TCAM) and panoramic camera (PCAM) are two of the major scientific payloads installed on the lander and rover of the Chang'e 3 mission re- spectively. They both use a Bayer color filter array c... The terrain camera (TCAM) and panoramic camera (PCAM) are two of the major scientific payloads installed on the lander and rover of the Chang'e 3 mission re- spectively. They both use a Bayer color filter array covering CMOS sensor to capture color images of the Moon's surface. RGB values of the original images are related to these two kinds of cameras. There is an obvious color difference compared with human visual perception. This paper follows standards published by the International Commission on Illumination to establish a color correction model, designs the ground calibration experiment and obtains the color correction coefficient. The image qual- ity has been significantly improved and there is no obvious color difference in the corrected images. Ground experimental results show that: (1) Compared with uncor- rected images, the average color difference of TCAM is 4.30, which has been reduced by 62.1%. (2) The average color differences of the left and right cameras in PCAM are 4.14 and 4.16, which have been reduced by 68.3% and 67.6% respectively. 展开更多
关键词 Moon -- methods: data analysis -- techniques: image processing
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Extended π-conjugated N-containing heteroaromatic hexacarboxylate organic anode for high performance rechargeable batteries 被引量:1
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作者 Shu-Biao Xia Teng liu +4 位作者 Wen-Jin Huang Hong-Bo Suo Fei-Xiang Cheng Hong Guo jian-jun liu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2020年第12期303-311,共9页
Organic electrode materials are desirable for green and sustainable Li-ion batteries(LIBs) due to their light-weight, low cost, abundance and multi-electron transfer reactions during battery operation. However, the su... Organic electrode materials are desirable for green and sustainable Li-ion batteries(LIBs) due to their light-weight, low cost, abundance and multi-electron transfer reactions during battery operation. However, the successful utilization of organic electrodes is hindered by their poor electrical conductivity and low cyclic stability. Herein, a facile synthesis of π-conjugated N-containing heteroaromatic hexacarboxylate(Li6-HAT) compound and its electrochemical performance as an anode material in LIBs is reported.The as-synthesized Li6-HAT electrode renders an ultrahigh initial capacity of 1126.3 m Ah g^(-1) at the current density of 100 m A g^(-1). Moreover, π-conjugated N-containing heteroaromatic center provide excellent reversibility of(de)lithiation process, resulting in excellent capacity retention. Furthermore, a combination of density functional theory(DFT) calculations, in-situ Fourier transform infrared(FTIR) and ex-situ X-ray photoelectron spectroscopy(XPS) characterization reveal that the π-conjugated nitrogen and carboxyl oxygen act as electrochemically active sites during the charge/discharge process. The current work provides novel insights into the charge storage mechanism of organic electrodes and opens up avenues for further development and utilization of organic electrodes in Li-ion batteries. 展开更多
关键词 Li-ion batteries Hexacarboxylate π-conjugated compounds N-containing Organic anode
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Data preprocessing and preliminary results of the Moon-based Ultraviolet Telescope on the CE-3 lander 被引量:4
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作者 Wei-Bin Wen Fang Wang +8 位作者 Chun-Lai Li Jing Wang Li Cao jian-jun liu Xu Tan Yuan Xiao Qiang Fu Yan Su Wei Zuo 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2014年第12期1674-1681,共8页
The Moon-based Ultraviolet Telescope (MUVT) is one of the payloads on the Chang'e-3 (CE-3) lunar lander. Because of the advantages of having no at- mospheric disturbances and the slow rotation of the Moon, we can... The Moon-based Ultraviolet Telescope (MUVT) is one of the payloads on the Chang'e-3 (CE-3) lunar lander. Because of the advantages of having no at- mospheric disturbances and the slow rotation of the Moon, we can make long-term continuous observations of a series of important celestial objects in the near ultra- violet band (245-340 nm), and perform a sky survey of selected areas, which can- not be completed on Earth. We can find characteristic changes in celestial brightness with time by analyzing image data from the MUVT, and deduce the radiation mech- anism and physical properties of these celestial objects after comparing with a phys- ical model. In order to explain the scientific purposes of MUVT, this article analyzes the preprocessing of MUVT image data and makes a preliminary evaluation of data quality. The results demonstrate that the methods used for data collection and prepro- cessing are effective, and the Level 2A and 2B image data satisfy the requirements of follow-up scientific researches. 展开更多
关键词 Chang'e-3 mission -- the Moon-based Ultraviolet Telescope -- data preprocessing -- near ultraviolet band
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The New Wuqing 70 m Radio Telescope and Measurements of Main Electronic Properties in the X-band 被引量:1
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作者 De-Qing Kong Chun-Lai Li +6 位作者 Hong-Bo Zhang Yan Su jian-jun liu Xin-Ying Zhu Jun-Duo Li Xi-Ping Xue Chen Li 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2022年第3期122-132,共11页
The new Wuqing 70 m radio telescope is first used for the downlink data reception in the first Mars exploration mission of China,and will be used for the other deep space communications and radio astronomical observat... The new Wuqing 70 m radio telescope is first used for the downlink data reception in the first Mars exploration mission of China,and will be used for the other deep space communications and radio astronomical observations in the future.The main specifications and measurement results of some properties in the X-band are introduced in this paper,such as pointing calibration,gain and efficiency,system noise temperature,system equivalent flux density,and variations with elevation.The 23 parameters pointing calibration model considering the atmospheric refraction correction in real time is presented in the telescope,and the pointing accuracy reaches 570 in azimuth direction and 607 in elevation direction for different weather conditions.More than 62%efficiencies are achieved at full elevation range,and more than 70%in the mid-elevation.The system equivalent flux density of the X-band in the mid-elevation reaches 26 Jy. 展开更多
关键词 telescopes astronomical instrumentation methods and techniques atmospheric effects
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Structural and electrical properties of carbon-ion-implanted ultrananocrystalline diamond films 被引量:1
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作者 徐辉 刘建军 +3 位作者 叶海涛 D J Coathup A V Khomich 胡晓君 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第9期426-433,共8页
We investigate the structural and electrical properties of carbon-ion-implanted ultrananocrystalline diamond(UNCD)films. Impedance spectroscopy measurements show that the impedance of diamond grains is relatively st... We investigate the structural and electrical properties of carbon-ion-implanted ultrananocrystalline diamond(UNCD)films. Impedance spectroscopy measurements show that the impedance of diamond grains is relatively stable, while that of grain boundaries(GBs)(Rb) significantly increases after the C~+ implantation, and decreases with the increase in the annealing temperature(Ta) from 650℃ to 1000℃. This implies that the C~+ implantation has a more significant impact on the conductivity of GBs. Conductive atomic force microscopy demonstrates that the number of conductive sites increases in GB regions at Ta above 900℃, owing to the formation of a nanographitic phase confirmed by high-resolution transmission electronic microscopy. Visible-light Raman spectra show that resistive trans-polyacetylene oligomers desorb from GBs at Ta above 900℃, which leads to lower Rb of samples annealed at 900 and 1000℃. With the increase in Ta to 1000℃, diamond grains become smaller with longer GBs modified by a more ordered nanographitic phase, supplying more conductive sites and leading to a lower Rb. 展开更多
关键词 ultrananocrystalline diamond C-ion implantation ANNEALING electrical properties
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Data processing and preliminary results of the Chang'e-3 VIS/NIR Imaging Spectrometer in-situ analysis 被引量:3
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作者 Bin liu Chun-Lai Li +7 位作者 Guang-Liang Zhang Rui Xu jian-jun liu Xin Ren Xu Tan Xiao-Xia Zhang Wei Zuo Wei-Bin Wen 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2014年第12期1578-1594,共17页
The Chang'e-3 Visible and Near-infrared Imaging Spectrometer (VNIS) is one of the four payloads on the Yutu rover. After traversing the landing site during the first two lunar days, four different areas are detecte... The Chang'e-3 Visible and Near-infrared Imaging Spectrometer (VNIS) is one of the four payloads on the Yutu rover. After traversing the landing site during the first two lunar days, four different areas are detected, and Level 2A and 2B ra- diance data have been released to the scientific community. The released data have been processed by dark current subtraction, correction for the effect of temperature, radiometric calibration and geometric calibration. We emphasize approaches for re- flectance analysis and mineral identification for in-situ analysis with VNIS. Then the preliminary spectral and mineralogical results from the landing site are derived. After comparing spectral data from VNIS with data collected by the Ma instrument and samples of mare that were returned from the Apollo program, all the reflectance data have been found to have similar absorption features near 1000 nm except lunar sample 71061. In addition, there is also a weak absorption feature between 1750-2400nm on VNIS, but the slopes of VNIS and Ma reflectance at longer wavelengths are lower than data taken from samples of lunar mare. Spectral parameters such as Band Centers and Integrated Band Depth Ratios are used to analyze mineralogical features. The results show that detection points E and N205 are mixtures of high-Ca pyroxene and olivine, and the composition of olivineat point N205 is higher than that at point E, but the compositions of detection points S3 and N203 are mainly olivine-rich. Since there are no obvious absorption features near 1250 nm, plagioclase is not directly identified at the landing site. 展开更多
关键词 Chang'e-3 -- VNIS -- in-situ analysis -- data processing
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Reconstructing the landing trajectory of the CE-3 lunar probe by using images from the landing camera 被引量:3
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作者 jian-jun liu Wei Yan +3 位作者 Chun-Lai Li Xu Tan Xin Ren Ling-Li Mu 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2014年第12期1530-1542,共13页
An accurate determination of the landing trajectory of Chang'e-3 (CE-3) is significant for verifying orbital control strategy, optimizing orbital planning, accu- rately determining the landing site of CE-3 and anal... An accurate determination of the landing trajectory of Chang'e-3 (CE-3) is significant for verifying orbital control strategy, optimizing orbital planning, accu- rately determining the landing site of CE-3 and analyzing the geological background of the landing site. Due to complexities involved in the landing process, there are some differences between the planned trajectory and the actual trajectory of CE-3. The land- ing camera on CE-3 recorded a sequence of the landing process with a frequency of 10 frames per second. These images recorded by the landing camera and high-resolution images of the lunar surface are utilized to calculate the position of the probe, so as to reconstruct its precise trajectory. This paper proposes using the method of trajectory reconstruction by Single Image Space Resection to make a detailed study of the hov- ering stage at a height of 100 m above the lunar surface. Analysis of the data shows that the closer CE-3 came to the lunar surface, the higher the spatial resolution of im- ages that were acquired became, and the more accurately the horizontal and vertical position of CE-3 could be determined. The horizontal and vertical accuracies were 7.09 m and 4.27 m respectively during the hovering stage at a height of 100.02 m. The reconstructed trajectory can reflect the change in CE-3's position during the powered descent process. A slight movement in CE-3 during the hovering stage is also clearly demonstrated. These results will provide a basis for analysis of orbit control strategy, and it will be conducive to adjustment and optimization of orbit control strategy in follow-up missions. 展开更多
关键词 Moon - methods: data analysis - techniques: image processing
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Data processing and initial results from the CE-3 Extreme Ultraviolet Camera 被引量:3
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作者 Jian-Qing Feng jian-jun liu +10 位作者 Fei He Wei Yan Xin Ren Xu Tan Ling-Ping He Bo Chen Wei Zuo Wei-Bin Wen Yan Su Yong-Liao Zou Chun-Lai Li 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2014年第12期1664-1673,共10页
The Extreme Ultraviolet Camera (EUVC) onboard the Chang'e-3 (CE-3) lander is used to observe the structure and dynamics of Earth's plasmasphere from the Moon. By detecting the resonance line emission of helium i... The Extreme Ultraviolet Camera (EUVC) onboard the Chang'e-3 (CE-3) lander is used to observe the structure and dynamics of Earth's plasmasphere from the Moon. By detecting the resonance line emission of helium ions (He+) at 30.4 nm, the EUVC images the entire plasmasphere with a time resolution of 10 min and a spatial resolution of about 0.1 Earth radius (RE) in a single frame. We first present details about the data processing from EUVC and the data acquisition in the commissioning phase, and then report some initial results, which reflect the basic features of the plas- masphere well. The photon count and emission intensity of EUVC are consistent with previous observations and models, which indicate that the EUVC works normally and can provide high quality data for future studies. 展开更多
关键词 space vehicles: instruments: Extreme Ultraviolet Camera -- Earth: plas-masphere -- method: data processing
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Analytical solutions for constant-rate test in bounded confined aquifers with non-Darcian effect 被引量:1
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作者 Yi-jie Zong Li-hua Chen +4 位作者 jian-jun liu Yue-hui liu Yong-xin Xu Fu-wan Gan Liang Xiao 《Journal of Groundwater Science and Engineering》 2022年第4期311-321,共11页
This paper proposes a simplified analytical solution considering non-Darcian and wellbore storage effect to investigate the pumping flow in a confined aquifer with barrier and recharge boundaries.The mathematical mode... This paper proposes a simplified analytical solution considering non-Darcian and wellbore storage effect to investigate the pumping flow in a confined aquifer with barrier and recharge boundaries.The mathematical modelling for the pumping-induced flow in aquifers with different boundaries is developed by employing image-well theory with the superposition principle,of which the non-Darcian effect is characterized by Izbash’s equation.The solutions are derived by Boltzmann and dimensionless transformations.Then,the non-Darcian effect and wellbore storage are especially investigated according to the proposed solution.The results show that the aquifer boundaries have non-negligible effects on pumping,and ignoring the wellbore storage can lead to an over-estimation of the drawdown in the first 10 minutes of pumping.The higher the degree of non-Darcian,the smaller the drawdown. 展开更多
关键词 Non-Darcian effect Bounded aquifer Wellbore storage Izbash’s equation Analytical solution
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Data processing for the Active Particle-induced X-ray Spectrometer and initial scientific results from Chang'e-3 mission 被引量:2
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作者 Xiao-Hui Fu Chun-Lai Li +11 位作者 Guang-Liang Zhang Yong-Liao Zou jian-jun liu Xin Ren Xu Tan Xiao-Xia Zhang Wei Zuo Wei-Bin Wen Wen-Xi Peng Xing-Zhu Cui Cheng-Mo Zhang Huan-Yu Wang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2014年第12期1595-1606,共12页
The Active Particle-induced X-ray Spectrometer (APXS) is an important payload mounted on the Yutu rover, which is part of the Chang'e-3 mission. The sci- entific objective of APXS is to perform in-situ analysis of ... The Active Particle-induced X-ray Spectrometer (APXS) is an important payload mounted on the Yutu rover, which is part of the Chang'e-3 mission. The sci- entific objective of APXS is to perform in-situ analysis of the chemical composition of lunar soil and rock samples. The radioactive sources, 55Fe and 109Cd, decay and produce a-particles and X-rays. When X-rays and a-particles interact with atoms in the surface material, they knock electrons out of their orbits, which release energy by emitting X-rays that can be measured by a silicon drift detector (SDD). The elements and their concentrations can be determined by analyzing their peak energies and in- tensities. APXS has analyzed both the calibration target and lunar soil once during the first lunar day and again during the second lunar day. The total detection time lasted about 266 min and more than 2000 frames of data records have been acquired. APXS has three operating modes: calibration mode, distance sensing mode and detection mode. In detection mode, work distance can be calculated from the X-ray counting rate collected by SDD. Correction for the effect of temperature has been performed to convert the channel number for each spectrum to X-ray energy. Dead time correction is used to eliminate the systematic error in quantifying the activity of an X-ray pulse in a sample and derive the real count rate. We report APXS data and initial results during the first and second lunar days for the Yutu rover. In this study, we analyze the data from the calibration target and lunar soil on the first lunar day. Seven major elements, including Mg, A1, Si, K, Ca, Ti and Fe, have been identified. Comparing the peak areas and ratios of calibration basalt and lunar soil the landing site was found to be depleted in K, and have lower Mg and A1 but higher Ca, Ti, and Fe. In the future, we will obtain the elemental concentrations of lunar soil at the Chang'e-3 landing site using APXS data. 展开更多
关键词 data analysis -- composition -- Moon
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