85 results on '"H. W. GUO"'
Search Results
2. Effective Motion Sensors and Deep Learning Techniques for Unmanned Ground Vehicle (UGV)-Based Automated Pavement Layer Change Detection in Road Construction
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Tirth Patel, Brian H. W. Guo, Jacobus Daniel van der Walt, and Yang Zou
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construction progress monitoring ,automation ,deep learning ,sensor ,road construction ,LSTM ,Building construction ,TH1-9745 - Abstract
As-built progress of the constructed pavement should be monitored effectively to provide prompt project control. However, current pavement construction progress monitoring practices (e.g., data collection, processing, and analysis) are typically manual, time-consuming, tedious, and error-prone. To address this, this study proposes sensors mounted using a UGV-based methodology to develop a pavement layer change classifier measuring pavement construction progress automatically. Initially, data were collected using the UGV equipped with a laser ToF (time-of-flight) distance sensor, accelerometer, gyroscope, and GPS sensor in a controlled environment by constructing various scenarios of pavement layer change. Subsequently, four Long Short-Term Memory network variants (LSTMs) (LSTM, BiLSTM, CNN-LSTM, and ConvLSTM) were implemented on collected sensor data combinations for developing pavement layer change classifiers. The authors conducted the experiment to select the best sensor combinations for feature detection of the layer change classifier model. Subsequently, individual performance measures of each class with learning curves and confusion matrices were generated using sensor combination data to find out the best algorithm among all implemented algorithms. The experimental result demonstrates the (az + gx + D) sensor combination as the best feature detector with high-performance measures (accuracy, precision, recall, and F1 score). The result also confirms the ConvLSTM as the best algorithm with the highest overall accuracy of 97.88% with (az + gx + D) sensor combination data. The high-performance measures with the proposed approach confirm the feasibility of detecting pavement layer changes in real pavement construction projects. This proposed approach can potentially improve the efficiency of road construction progress measurement. This research study is a stepping stone for automated road construction progress monitoring.
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- 2022
- Full Text
- View/download PDF
3. Improved Template-Matching-based FRUC Method in Inter-Frame Video Coding.
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S. C. Song, H. W. Guo, C. Zhu, Y. B. Gao, Y. B. Lin, and J. H. Zheng
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- 2018
- Full Text
- View/download PDF
4. Lessons Learned on Adopting Automated Compliance Checking in the AEC Industry: A Global Study
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Yang Zou, Brian H. W. Guo, Eleni Papadonikolaki, Johannes Dimyadi, and Lei Hou
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Strategy and Management ,Industrial relations ,General Engineering ,Building and Construction ,Management Science and Operations Research - Published
- 2023
5. Testing the Effects of the Digital Linguistic Landscape on Engineering Education for Smart Construction
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Lin Xu, Jingxiao Zhang, Yin Yuan, Junwei Zheng, Simon P. Philbin, Brian H. W. Guo, and Ruoyu Jin
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Engineering ,Article Subject ,General Computer Science ,General Mathematics ,General Neuroscience ,ComputingMilieux_COMPUTERSANDEDUCATION ,Humans ,Learning ,Linguistics ,General Medicine ,Students - Abstract
This study investigates the mechanism of digital linguistic landscapes in enabling engineering education for smart construction according to the educational dimensions of A (ability), S (skill), and K (knowledge). A questionnaire survey was conducted based on the core concepts of the informative dimension and symbolic dimension in digital language landscape as well as the ability dimension, knowledge dimension, and skill dimension in engineering education. Structural equation modeling (SEM) was used as the test method. The results of the research demonstrate that the informative dimension and symbolic dimension are two main aspects of DLL in education of engineering students for smart construction. Additionally, DLL has a significant positive impact on the ability, knowledge, and skill education of engineering students for smart construction. The research has theoretical and practical significance, as it not only enriches research on the relationship between DLL and engineering education for smart construction but also expands the theoretical understanding of engineering education from the perspective of linguistics. Furthermore, the study explores the path of the practical application of digital language landscape to engineering education for smart construction.
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- 2022
6. Bridging the gap between building information modelling education and practice: a competency-based education perspective
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Brian H. W. Guo, Vicente A. Gonzalez, Taija Puolitaival, Wallace Enegbuma, Yang Zou, Tampere University, and Civil Engineering
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212 Civil and construction engineering ,Management of Technology and Innovation ,Strategy and Management ,Building and Construction - Abstract
This study reports a case study that investigates the gap between BIM tertiary education and the building industry’s needs in New Zealand (NZ). In specific, it aims to (1) identify the industry’s requirements on BIM competencies, (2) examine the status quo of BIM tertiary education in NZ, and (3) identify and analyse the gaps between current BIM education and the industry’s needs. Data were collected through BIM job advertisement to identify the industry’s requirements of BIM competencies and top BIM uses. Data of thirty-three courses were also collected from nine tertiary institutions. Results indicated that there were discrepancies between the type and level (i.e. cognitive levels) of BIM competencies. It was indicated that missing links existed in almost all BIM uses that were taught, except 4D modelling. A large proportion of learning outcomes were focused on ‘understanding’ for several BIM uses, while NZ BIM Handbook requires higher levels of application and evaluation. To bridge the gaps, core competence sets should be determined by disciplines. BIM competencies can also be classified based on BIM uses, BIM processes and phases, and project roles. This paper proposed a conceptual framework, which suggests the way ahead towards future competency-based BIM education. acceptedVersion
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- 2022
7. Civil engineering students’ perceptions of emergency remote teaching: a case study in New Zealand
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Brian H. W. Guo, Mark Milke, and Ruoyu Jin
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General Engineering ,Education - Published
- 2022
8. Investigating the New Zealand Off-Site Manufacturing Industry’s Readiness for Automated Compliance Checking
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Yang Zou, Yuqing Wu, Brian H. W. Guo, Eleni Papadonikolaki, Johannes Dimyadi, and Sze Nga Hung
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Strategy and Management ,Industrial relations ,Building and Construction ,Civil and Structural Engineering - Published
- 2022
9. [Characteristics and risk factors of functional constipation in children aged 0-4 years in Xi 'an]
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T, Li, J J, Huang, L, Shang, X, Jiang, Y, Lin, X Z, Liu, H W, Guo, W, Zhang, and B X, Wang
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Male ,Feces ,Risk Factors ,Surveys and Questionnaires ,Humans ,Infant ,Female ,Child ,Defecation ,Constipation - Published
- 2022
10. [Diagnosis and treatment of a case of infection caused by shark fin stabbing right hand for more than two years]
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Z X, Xue, L K, Wang, S S, Sun, F F, Zhou, H W, Guo, and X J, Ma
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Seafood ,Sharks ,Animals ,Humans - Abstract
海分枝杆菌是一种少见的非典型分枝杆菌,易从皮肤破损处侵入人体而导致感染,主要引起皮肤软组织和手部慢性感染。本文报告1例因“鱼翅刺伤后致右手反复感染不愈2年余”的患者,入院后明确诊断为海分枝杆菌感染并启动规范抗感染治疗,患者右手感染得到有效控制。报道该病例,旨在提高公众对海分枝杆菌感染的认识及引起足够重视。.
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- 2022
11. Effect of processed maize stover as an alternative energy source in swine production
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Q. Q. Yin, H. W. Guo, M. L. Li, C. Q. Liu, X. W. Dang, P. Wang, J. Chang, and F. S. Lu
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Nutrient digestibility ,biology ,Chemistry ,business.industry ,Enzyme assay ,biology.protein ,Alternative energy ,Production (economics) ,Animal Science and Zoology ,Fermentation ,Food science ,Energy source ,business ,Stover ,Food Science - Published
- 2020
12. [A clinical and pathological report of delayed encephalopathy after heat stroke]
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A J, Lu, M, Cheng, C X, Dong, H W, Guo, B Z, Cao, and H Q, Hu
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Adult ,Male ,Brain Diseases ,Heat Stroke ,Brain ,Humans ,Magnetic Resonance Imaging ,Retrospective Studies - Published
- 2021
13. lncRNA NEAT1 regulates cerebral ischemia/reperfusion injury through miR-1306-5p
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X Z, Meng, W W, Jiang, H W, Guo, M, Li, M M, Zhao, F J, Yu, and Z T, Gu
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MicroRNAs ,Reperfusion Injury ,Humans ,RNA, Long Noncoding ,Brain Ischemia ,Cell Proliferation - Published
- 2021
14. [Clinical application of the gasless unilateral axillary approach in endoscopic thyroid surgery]
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J J, Xu, L Z, Zhang, Q H, Zhang, H W, Guo, Z, Tan, J F, Wang, L H, Jiang, C M, Zheng, M H, Ge, and X B, Lan
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Adult ,Male ,Adolescent ,Endoscopy ,Middle Aged ,Carcinoma, Papillary ,Young Adult ,Thyroidectomy ,Humans ,Female ,Thyroid Neoplasms ,Child ,Aged ,Retrospective Studies - Published
- 2020
15. Genetic diversity of mtDNA D-loop sequences in four native Chinese chicken breeds
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Xuelian Liu, Ruili Han, Zhuanjian Li, Xiangtao Kang, Guoxi Li, H W Guo, Cuicui Li, Xinlei Wang, and G R Sun
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0301 basic medicine ,Mitochondrial DNA ,China ,animal structures ,Biology ,medicine.disease_cause ,DNA, Mitochondrial ,Haplogroup ,Nucleotide diversity ,03 medical and health sciences ,D-loop ,Polymorphism (computer science) ,medicine ,Animals ,Phylogeny ,Genetics ,Mutation ,Genetic diversity ,Base Sequence ,Haplotype ,0402 animal and dairy science ,Genetic Variation ,04 agricultural and veterinary sciences ,General Medicine ,040201 dairy & animal science ,030104 developmental biology ,Haplotypes ,embryonic structures ,Animal Science and Zoology ,Female ,Chickens ,Food Science - Abstract
1. To explore the genetic diversity of Chinese indigenous chicken breeds, a 585 bp fragment of the mitochondrial DNA (mtDNA) region was sequenced in 102 birds from the Xichuan black-bone chicken, Yunyang black-bone chicken and Lushi chicken. In addition, 30 mtDNA D-loop sequences of Silkie fowls were downloaded from NCBI. The mtDNA D-loop sequence polymorphism and maternal origin of 4 chicken breeds were analysed in this study. 2. The results showed that a total of 33 mutation sites and 28 haplotypes were detected in the 4 chicken breeds. The haplotype diversity and nucleotide diversity of these 4 native breeds were 0.916 ± 0.014 and 0.012 ± 0.002, respectively. Three clusters were formed in 4 Chinese native chickens and 12 reference breeds. Both the Xichuan black-bone chicken and Yunyang black-bone chicken were grouped into one cluster. Four haplogroups (A, B, C and E) emerged in the median-joining network in these breeds. 3. It was concluded that these 4 Chinese chicken breeds had high genetic diversity. The phylogenetic tree and median network profiles showed that Chinese native chickens and its neighbouring countries had at least two maternal origins, one from Yunnan, China and another from Southeast Asia or its surrounding area.
- Published
- 2017
16. An Improved Vision-Based Lane Departure Warning System under High Speed Driving Condition
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H W Guo, Y Zou, and X T Liu
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History ,Lane departure warning system ,Vision based ,Computer science ,Real-time computing ,Computer Science Applications ,Education - Abstract
Recently, Lane departure warning system has attracted great attention as it contributes to vehicle active safety. In this paper, a vision-based lane departure warning system under high-speed driving is proposed. The system consists of two functional parts: lane markings detection and vehicle departure identification. The Hough Transform is applied to detect lane boundaries, which is a most effective detection method with high reliability. Based on the road line, a method using several Euclidean-distance-related parameters to calculate vehicle’s position and its deviating status is proposed, which addresses the problem of efficient detection of lane departure under high-speed driving condition. The algorithm is tested and verified in various real driving conditions and proved a reliable and steady performance.
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- 2019
17. Maximizing Drilling Performance with Real-Time Drilling Vibration Mitigation in the Deep Wells
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H. Y. Ge, G. H. Wang, H. W. Guo, X. Z. Chen, and M. Cui
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Engineering ,Petroleum engineering ,business.industry ,Mechanical engineering ,Drilling ,Vibration mitigation ,business - Abstract
The present Tarim Basin of China presents drilling chanllenges moving toward deeper hydrocarbon reservoirs, which includes more complex formation, poor bit cutting efficiency and wellbore integrity. The paper introduces the development and application of optimizer of drilling operating parameters named as Smart Driller Indicator (SDI) which worked to deliver continuous improvement in axial vibration and stick-slip mitigation for the presented field. SDI is based on a soft-closed-loop solution called NAVO real-time vibration monitoring and calculating the optimal drilling parameters for that formation by maintaining an optimum relationship between ROP and energy input. From the perspectives of rock mechanics and conservation of energy, the ideal performance in the optimum proportion among drilling parameters, ROP and MSE have been derived from comprehensive analysis of optimized drilling mechanism. An advanced damped forced torsional vibrarion model in frenquency-domain was developed. Field validation for real-time estimates produced by the model was conducted by a drilling mechanics module sub. In drlling process, if the ROP is not as good as expected, SDI will automatically evaluates the new hole conditions including the mechanical properties of the formation, bit wear condition and vibration etc, and updates the optimum drilling parameters. The drillers just adjust drilling parameters to follow them, a higher ROP (rate of penetration) and a longer bit run can be achieved. SDI has been applied for more than 20 wells with total footage of over 30,000ft and has shown about 20%-54% ROP improvement and longer bit life compared with conventional driller's drilling habits and totally 125 days and about 1 million dollars have been saved. As an effective tool for further excavating the potential of ROP, SDI might achieve satisfactory outcomes that overcome the drilling challenges of carbonate formation, gravel and igneous in deep wells.
- Published
- 2016
18. Is the large-scale sidereal anisotropy of the galactic cosmic-ray intensity really instable at TeV energies?
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H. Nanjo, T. Shirai, Danzengluobu, Zhenyong Feng, C. F. Feng, Haibing Hu, M. Amenomori, K. Kasahara, L. L. Jiang, Y. Zhang, M. Sakata, A. F. Li, A. Shiomi, Gui-Ming Le, Jing Huang, Chihiro Kato, H. M. Zhang, X. X. Zhou, Y. Q. Guo, H. Sugimoto, X. B. Qu, X. L. Qian, J. S. Liu, A. F. Yuan, H. R. Wu, J. Shao, I. Ohta, C. X. Liu, Huihai He, X. R. Meng, Zhaoyang Feng, N. Tateyama, W. Y. Chen, L. Xue, Harufumi Tsuchiya, K. Mizutani, D. Chen, Z. T. He, Masaki Nishizawa, X. Y. Zhang, Shunsuke Ozawa, Kazuoki Munakata, T. K. Sako, Labaciren, N. Hotta, Y. Katayose, Y. Yamamoto, Shoji Torii, Zhaxisangzhu, X. J. Bi, K. Hibino, X. H. Ding, H. B. Hu, H. W. Guo, Hsiao-Chi Lu, Y. H. Tan, M. Shibata, F. Kajino, Zicai Yang, S. Yasue, Q. B. Gou, Masato Takita, L. K. Ding, Jia Zhang, Yi Zhang, M. Ohnishi, S. Udo, Takashi Saito, W. J. Li, Ying Zhang, Huaguang Wang, S. W. Cui, Takeshi Saito, Kazumasa Kawata, L. M. Zhai, T. Yuda, and H. Y. Jia
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Physics ,Astrophysics::High Energy Astrophysical Phenomena ,Astronomy ,Astronomy and Astrophysics ,Cosmic ray ,Astrophysics ,Amplitude ,Observatory ,Sidereal time ,Physics::Space Physics ,Milagro ,High Energy Physics::Experiment ,Right ascension ,Anisotropy ,Heliosphere - Abstract
The sidereal cosmic-ray anisotropy at TeV energies has a large-scale deficit region distributed between 150 and 240 degrees in right ascension, which is called the “loss-cone”. The Milagro experiment reported the detection of a steady increase in the loss-cone amplitude at 6 TeV from July 2000 to July 2007. In this paper, we examine Milagro’s claim using the data collected by the Tibet air-shower experiment from November 1999 through December 2008. No time dependence was found in the loss-cone amplitude at 4.4, 6.2, and 11 TeV. If the increase in the loss-cone amplitude were, as Milagro argued, due to variations in the heliosphere in relation to solar activities, the same tendency would be seen at sub-TeV energies where the anisotropy is far more sensitive to solar activities. At 0.6 TeV, however, Matsushiro underground muon observatory reported no significant increase in the loss-cone amplitude during the corresponding period.
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- 2012
19. Observation of the Fermi pulsar catalog at TeV energies with the Tibet air shower experiment
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X. X. Zhou, Y. Yamamoto, Yu-Sa Wang, H. Sugimoto, T. K. Sako, X. Y. Zhang, Q. Huang, Shoji Torii, G. C. Yu, Haibing Hu, Y. Zhang, M. Sakata, A. Shiomi, Kazumasa Kawata, C. Fan, Gui-Ming Le, S. Yasue, Jia Zhang, H. C. Li, LuHua Jiang, Masato Takita, X. Y. Gao, Danzengluobu, C. F. Feng, X. C. Yang, T. Yuda, X. H. Ding, H. W. Wang, Y. Q. Lou, H. R. Wu, X. R. Meng, M. Shibata, H. Nanjo, L. Xue, T. Shirai, Yi Zhang, Shunsuke Ozawa, Y. G. Wang, Zhaoyang Feng, K. Mizutani, Y. H. Tan, M. Ohnishi, J. Y. Li, H. Y. Jia, S. Udo, Hong-peng Lu, Liming Ding, N. Tateyama, Ying Zhang, H. W. Guo, A. F. Yuan, H. M. Zhang, S. W. Cui, Zhenyong Feng, Takashi Saito, D. Chen, B. S. Wang, Zhaxisangzhu, M. Amenomori, Z. H. Ye, Kazuoki Munakata, H. H. He, Ning Zhang, K. Hibino, N. Hotta, Masaki Nishizawa, I. Ohta, Labaciren, Harufumi Tsuchiya, To. Saito, Y. Katayose, Q. B. Gou, Hailan Hu, X. J. Bi, Q. X. Geng, C. T. Yan, K. Kasahara, J. Mu, A. F. Li, Jing Huang, Chihiro Kato, M. He, C. X. Liu, and F. Kajino
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Physics ,Telescope ,Air shower ,Physics and Astronomy (miscellaneous) ,Pulsar ,law ,Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics::Instrumentation and Methods for Astrophysics ,Astronomy ,Astronomy and Astrophysics ,Astrophysics ,Fermi Gamma-ray Space Telescope ,law.invention - Abstract
Using the Tibet-III air shower array, we search for steady TeV -rays from 18 pulsars in the Fermi Large Area Telescope pulsar catalog. Among them, we ob- serve 8 sources including the Crab instead of the expected
- Published
- 2011
20. Cosmic-ray energy spectrum around the knee obtained by the Tibet experiment and future prospects
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N. Hotta, J. Y. Li, Hsiao-Chi Lu, S. W. Cui, C. F. Feng, Q. Huang, G. M. Le, X. C. Yang, Labaciren, H. B. Hu, B. S. Wang, Q. X. Geng, Zhaxisangzhu, Takeshi Saito, D. Chen, Takashi Sako, Kazuoki Munakata, Kazumasa Kawata, C. Fan, H. H. He, Z. H. Ye, Masaki Nishizawa, X. Y. Gao, Takashi Saito, Jieru Ren, Danzengluobu, A. Nagai, Huaguang Wang, Yizhang, M. Sakata, K. Kasahara, J. Mu, S. L. Lu, Y. G. Wang, M. Amenomori, Jia Zhang, A. F. Li, Jing Huang, C. T. Yan, M. Shibata, Shunsuke Ozawa, A. F. Yuan, X. R. Meng, G. C. Yu, I. Ohta, X. H. Ding, Zhaoyang Feng, Shoji Torii, H. Y. Jia, T. Yuda, S. Udo, Y. Q. Lou, H. R. Wu, K. Hibino, Haibing Hu, Y. H. Tan, H. Onuma, N. Tateyama, X. J. Bi, Harufumi Tsuchiya, K. Mizutani, Y. Katayose, Y. Zhang, A. Shiomi, H. Nanjo, Y. Yamamoto, Yu-Sa Wang, X. Wang, T. Shirai, H. M. Zhang, X. X. Zhou, H. Sugimoto, S. Yasue, H. W. Guo, Masato Takita, M. Ohnishi, L. K. Ding, T. Ouchi, Z. Y. Feng, X. Y. Zhang, F. Kajino, Chihiro Kato, M. He, L. Xue, and Ning Zhang
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Physics ,Atmospheric Science ,Range (particle radiation) ,Proton ,Physics::Instrumentation and Detectors ,Astrophysics::High Energy Astrophysical Phenomena ,Detector ,Astrophysics::Instrumentation and Methods for Astrophysics ,Phase (waves) ,Aerospace Engineering ,chemistry.chemical_element ,Flux ,Astronomy and Astrophysics ,Cosmic ray ,Spectral line ,Nuclear physics ,Geophysics ,chemistry ,Space and Planetary Science ,General Earth and Planetary Sciences ,Helium - Abstract
The observation of the extensive air showers has been carried out since 1990 by Tibet air-shower array to study the origin of the cosmic-rays. In order to investigate the chemical composition around the knee, air-shower core detector was used in two experimental phases aiming to separate light primary elements (proton and helium). In a first phase experiment made in 1996-1999, primary proton and helium spectra were measured using a hybrid detector consisted of Tibet II air-shower array, emulsion chambers, and burst detectors. The result indicated that the fraction of light elements among the all particle spectrum is less than 30%. We performed the second phase experiment in 2002-2005 to measure proton + helium together to confirm the previous result with higher statistics by improving the detection efficiency for the air-shower cores. The P + He spectrum was obtained in a good agreement with previous result by several times higher statistics. The flux of the light elements, together with the all-particle energy spectrum, indicates the dominance of nuclei heavier than helium in the energy range around the knee. We also present the outline of the next phase experiment, which is to measure the heavy elements around the knee, using low threshold air-shower core detector named YAC. (C) 2010 COSPAR. Published by Elsevier Ltd. All rights reserved.
- Published
- 2011
21. Cosmic-ray energy spectrum around the knee observed with the Tibet air-shower experiment
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Jia Zhang, N. Hotta, H. C. Li, Liming Ding, X. X. Zhou, H. Nanjo, T. Shirai, T. Yuda, Labaciren, H. Sugimoto, Y. Q. Lou, H. R. Wu, Masaki Nishizawa, Ying Zhang, S. W. Cui, H. H. He, X. Y. Zhang, C. F. Feng, Chihiro Kato, Y. Yamamoto, Q. Huang, X. R. Meng, Takashi Saito, Yu-Sa Wang, M. He, Zhaoyang Feng, C. X. Liu, M. Shibata, Y. G. Wang, Yi Zhang, A. F. Yuan, Y. Katayose, Kazumasa Kawata, C. Fan, Q. X. Geng, G. C. Yu, D. Chen, Z. H. Ye, L. Xue, K. Mizutani, Kazuoki Munakata, S. Yasue, M. Ohnishi, F. Kajino, Masato Takita, X. H. Ding, H. W. Guo, S. Udo, C. T. Yan, Hong-peng Lu, K. Hibino, Haibing Hu, B. S. Wang, Zhaxisangzhu, Zhenyong Feng, X. J. Bi, M. Amenomori, Y. Zhang, A. Shiomi, Y. H. Tan, K. Kasahara, J. Mu, Q. B. Gou, A. F. Li, Jing Huang, H. W. Wang, Hailan Hu, J. Y. Li, I. Ohta, H. M. Zhang, T. K. Sako, To. Saito, Shoji Torii, H. Y. Jia, Shunsuke Ozawa, LuHua Jiang, X. Y. Gao, Danzengluobu, X. C. Yang, N. Tateyama, Harufumi Tsuchiya, M. Sakata, Gui-Ming Le, and Ning Zhang
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Physics ,Air shower ,Physics and Astronomy (miscellaneous) ,Energy spectrum ,Astronomy and Astrophysics ,Cosmic ray ,Astrophysics - Published
- 2011
22. Bismuth/Polyaniline/Glassy Carbon Electrodes Prepared with Different Protocols for Stripping Voltammetric Determination of Trace Cd and Pb in Solutions Having Surfactants
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G. C. Yang, Z. M. Wang, H. W. Guo, Erjia Liu, and Nay Win Khun
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Materials science ,Stripping (chemistry) ,Inorganic chemistry ,Analytical chemistry ,chemistry.chemical_element ,Square wave ,Glassy carbon ,Analytical Chemistry ,Anode ,Bismuth ,chemistry.chemical_compound ,chemistry ,Electrode ,Polyaniline ,Electrochemistry ,Thin film - Abstract
To improve reproducibility, stability and sensitivity, a bismuth (Bi) thin film was coated on glassy carbon (GC) substrates which surfaces were modified with a porous thin layer of polyaniline (PANI) via multipulse potentiostatic electropolymerization to form Bi/PANI/GC electrodes (Bi/PANI/GCEs). The Bi/PANI/GCEs were used successfully for simultaneous detection and determination of Cd2+ and Pb2+ ions, and various parameters were studied with reference to square wave anodic stripping voltammetric (SWASV) signals. The experimental results depicted that the environment-friendly Bi/PANI/GCEs had the ability to rapidly monitor trace heavy metals even in the presence of surface-active compounds.
- Published
- 2010
23. Recent Results on Gamma-Ray Observation by the Tibet Air Shower Array and Related Topics
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Xiaoqun Wang, Haibing Hu, Y. Katayose, C. T. Yan, Kazumasa Kawata, Jieru Ren, X. Y. Gao, C. Fan, Y. G. Wang, A. Nagai, Y. Zhang, T. Yuda, A. F. Yuan, Y. Q. Lou, A. Shiomi, Hailan Hu, G. M. Le, X. J. Bi, H. Wang, Liming Ding, H. M. Zhang, K. Hibino, K. Mizutani, Y. H. Tan, M. Shibata, H. Sugimoto, H. W. Guo, X. X. Zhou, Hong Wu, H. Nanjo, Q. Huang, T. Shirai, Yi Zhang, F. Kajino, Takashi Saito, Chihiro Kato, B. S. Wang, M. He, Z. H. Ye, Shoji Torii, S. Udo, J. Y. Li, H. H. He, S. L. Lu, Masaki Nishizawa, Jia Zhang, N. Tateyama, G. C. Yu, Y. Yamamoto, Yu-Sa Wang, Harufumi Tsuchiya, M. Ohnishi, Takashi Sako, D. Chen, Kazuoki Munakata, S. Yasue, Xuan Zhang, Masato Takita, X. C. Yang, K. Kasahara, J. Mu, S. Ozawa, A. F. Li, Ning Zhang, Jing Huang, N. Hotta, H. Y. Jia, X. R. Meng, M. Sakata, To. Saito, Cunfeng Feng, Zhaoyang Feng, X. H. Ding, Zhenyong Feng, I. Ohta, M. Amenomori, T. Ouchi, Q. X. Geng, L. Xue, Hong-peng Lu, and Shuwang Cui
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Physics ,Nuclear physics ,Scintillation ,Air shower ,Muon ,Gamma ray ,General Physics and Astronomy ,Astronomy - Abstract
The Tibet-III air shower array, consisting of 789 scintillation detectors, has been operating successfully at Yangbajing in Tibet since 1999. Some recent results on gamma-ray observation by the Tibet-III air shower array are introduced and its future prospects of gamma-ray observation will be discussed.
- Published
- 2009
24. Chemical Composition of Cosmic Rays around the Knee Observed by the Tibet Air-Shower-Core Detector
- Author
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Shuwang Cui, X. C. Yang, G. M. Le, I. Ohta, F. Kajino, Jia Zhang, L. Xue, M. Shibata, Kazumasa Kawata, C. Fan, H. Wang, Hong-peng Lu, Chihiro Kato, M. He, H. Sugimoto, Jieru Ren, K. Mizutani, To. Saito, G. C. Yu, Takashi Sako, B. S. Wang, X. H. Ding, Zhenyong Feng, Hailan Hu, Takashi Saito, H. Y. Jia, M. Amenomori, J. Y. Li, C. T. Yan, Q. Huang, H. M. Zhang, Z. H. Ye, X. J. Bi, Yi Zhang, M. Sakata, Shoji Torii, Q. X. Geng, T. Yuda, M. Ohnishi, H. W. Guo, X. X. Zhou, S. Udo, X. R. Meng, S. Ozawa, Y. Q. Lou, Liming Ding, S. Yasue, Cunfeng Feng, Xiaoqun Wang, Zhaoyang Feng, K. Hibino, Haibing Hu, Y. H. Tan, Masato Takita, Masaki Nishizawa, N. Tateyama, Y. Yamamoto, Yu-Sa Wang, Y. Zhang, Harufumi Tsuchiya, A. Shiomi, T. Ouchi, Hong Wu, Y. Katayose, H. Nanjo, H. H. He, T. Shirai, K. Kasahara, J. Mu, Y. G. Wang, S. L. Lu, A. F. Yuan, A. F. Li, Jing Huang, X. Y. Gao, A. Nagai, D. Chen, Kazuoki Munakata, Ning Zhang, N. Hotta, and Xuan Zhang
- Subjects
Physics ,Range (particle radiation) ,Detector ,General Physics and Astronomy ,chemistry.chemical_element ,Cosmic ray ,Astrophysics ,Nuclear physics ,Core (optical fiber) ,Air shower ,chemistry ,Energy spectrum ,Chemical composition ,Helium - Abstract
Recent results and future prospects of the Tibet air-shower experiment are reported on the all-particle energy spectrum and the chemical composition of cosmic rays around 10 15 eV energy range. The knee of the all-particle energy spectrum has been clearly observed at the energy around 4 ×10 15 eV by Tibet III air-shower array located at Yangbajing, Tibet, China (atmospheric depth 606 g/cm 2 , area 37,000 m 2 ). The energy spectrum of light components (protons and helium) measured by air-shower-core detector exhibits steeper power index than that of direct measurements below 10 14 eV, leading to decreasing fraction of the light component toward the knee. Hence, it is strongly suggested that the origin of the knee is related with the change of the chemical composition of cosmic rays. A new air-shower-core detector called `YAC' is under the preparation for explicit measurement of the heavy component.
- Published
- 2009
25. MULTI-TeV GAMMA-RAY OBSERVATION FROM THE CRAB NEBULA USING THE TIBET-III AIR SHOWER ARRAY FINELY TUNED BY THE COSMIC RAY MOON'S SHADOW
- Author
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M. Amenomori, X. J. Bi, D. Chen, S. W. Cui, null Danzengluobu, L. K. Ding, X. H. Ding, C. Fan, C. F. Feng, Zhaoyang Feng, Z. Y. Feng, X. Y. Gao, Q. X. Geng, H. W. Guo, H. H. He, M. He, K. Hibino, N. Hotta, Haibing Hu, H. B. Hu, J. Huang, Q. Huang, H. Y. Jia, F. Kajino, K. Kasahara, Y. Katayose, C. Kato, K. Kawata, null Labaciren, G. M. Le, A. F. Li, J. Y. Li, Y.-Q. Lou, H. Lu, S. L. Lu, X. R. Meng, K. Mizutani, J. Mu, K. Munakata, A. Nagai, H. Nanjo, M. Nishizawa, M. Ohnishi, I. Ohta, H. Onuma, T. Ouchi, S. Ozawa, J. R. Ren, T. Saito, T. Y. Saito, M. Sakata, T. K. Sako, M. Shibata, A. Shiomi, T. Shirai, H. Sugimoto, M. Takita, Y. H. Tan, N. Tateyama, S. Torii, H. Tsuchiya, S. Udo, B. Wang, H. Wang, X. Wang, Y. Wang, Y. G. Wang, H. R. Wu, L. Xue, Y. Yamamoto, C. T. Yan, X. C. Yang, S. Yasue, Z. H. Ye, G. C. Yu, A. F. Yuan, T. Yuda, H. M. Zhang, J. L. Zhang, N. J. Zhang, X. Y. Zhang, Y. Zhang, Yi Zhang, null Zhaxisangzhu, and X. X. Zhou
- Subjects
Physics ,Scintillation ,Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics (astro-ph) ,Gamma ray ,FOS: Physical sciences ,Astronomy and Astrophysics ,Cosmic ray ,Astrophysics ,magnetic fields ,Power law ,Air shower ,Crab Nebula ,cosmic rays ,Space and Planetary Science ,pulsars: individual (Crab pulsar) ,Moon ,ISM: individual (Crab Nebula) ,Cherenkov radiation ,Energy (signal processing) ,gamma rays: observations - Abstract
The Tibet-III air shower array, consisting of 533 scintillation detectors, has been operating successfully at Yangbajing in Tibet, China since 1999. Using the dataset collected by this array from 1999 November through 2005 November, we obtained the energy spectrum of $\gamma$-rays from the Crab Nebula, expressed by a power law as $(dJ/dE) = (2.09\pm0.32)\times10^{-12} (E/{\rm 3 TeV})^{-2.96\pm0.14} {\rm cm}^{-2} {\rm s}^{-1} {\rm TeV}^{-1}$ in the energy range of 1.7 to 40 TeV. This result is consistent with other independent $\gamma$-ray observations by imaging air Cherenkov telescopes. In this paper, we carefully checked and tuned the performance of the Tibet-III array using data on the moon's shadow in comparison with a detailed Monte Carlo simulation. The shadow is shifted to the west of the moon's apparent position as an effect of the geomagnetic field, although the extent of this displacement depends on the primary energy positively charged cosmic rays. This finding enables us to estimate the systematic error in determining the primary energy from its shower size. This error is estimated to be less than $\pm$12% in our experiment. This energy scale estimation is the first attempt among cosmic-ray experiments at ground level. The systematic pointing error is also estimated to be smaller than $0\fdg011$. The deficit rate and position of the moon's shadow are shown to be very stable within a statistical error of $\pm$6% year by year. This guarantees the long-term stability of point-like source observation with the Tibet-III array. These systematic errors are adequately taken into account in our study of the Crab Nebula., Comment: 12 pages, 16 figures, accepted by ApJ
- Published
- 2009
26. Cyclic Voltammetric Behavior of Nitrogen-Doped Tetrahedral Amorphous Carbon Films Deposited by Filtered Cathodic Vacuum Arc
- Author
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Nay Win Khun, Erjia Liu, and H. W. Guo
- Subjects
Materials science ,Inorganic chemistry ,Analytical chemistry ,chemistry.chemical_element ,Vacuum arc ,Electrochemistry ,Nitrogen ,Analytical Chemistry ,symbols.namesake ,Amorphous carbon ,chemistry ,X-ray photoelectron spectroscopy ,symbols ,Cyclic voltammetry ,Raman spectroscopy ,Deposition (law) - Abstract
Nitrogen-doped tetrahedral amorphous carbon (ta-C : N) films were deposited by filtered cathodic vacuum arc (FCVA) technique using nitrogen as a background gas. The structure of the ta-C : N films was studied with X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy in terms of nitrogen flow rate used during the film deposition. Potential windows of the films measured in deaerated and unstirred solutions, such as 0.5 M HCl, 0.1 M KCl, 0.1 M NaCl, 0.1 M KOH, and 0.1 M NaOH, were about 2.4, 2.32, 3.2, 3.1, and 3.25 V, respectively. This study showed that the potential windows of the ta-C : N films were also affected by nitrogen flow rate. The ta-C : N films used in this study had the desired voltammetric characteristics suitable for electrochemical analysis.
- Published
- 2008
27. The cosmic-ray energy spectrum around the knee measured by the Tibet-III air-shower array
- Author
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J. Y. Li, Shoji Torii, Y. Yamamoto, H. M. Zhang, X. X. Zhou, H. Sugimoto, Takashi Sako, Ning Zhang, Q. Huang, M. Sakata, L. Xue, C. T. Yan, Takeshi Saito, Xiaoqun Wang, X. R. Meng, H. H. He, T. Yuda, N. Hotta, Jia Zhang, Y. Q. Lou, H. R. Wu, Haibing Hu, Zhaoyang Feng, Katsuaki Kasahara, S. L. Lu, Hong-peng Lu, Zhaxisangzhu, X. J. Bi, H. Onuma, Y. Zhang, T. Sasaki, Y. Katayose, K. Mizutani, Labaciren, A. Shiomi, D. Chen, X. H. Ding, K. Hibino, H. W. Guo, X. C. Yang, Y. H. Tan, B. Wang, L. K. Ding, T. Ouchi, H. B. Hu, M. Amenomori, I. Ohta, Q. X. Geng, X. Y. Gao, Kazuoki Munakata, Shunsuke Ozawa, Danzengluobu, A. Nagai, S. Yasue, X. Y. Zhang, N. Tateyama, H. Y. Jia, Masato Takita, J. Mu, A. F. Li, H. Nanjo, M. Shibata, Jing Huang, T. Shirai, Harufumi Tsuchiya, S. W. Cui, G. C. Yu, Y. G. Wang, Yi Zhang, A. F. Yuan, Chihiro Kato, M. He, Masaki Nishizawa, Jieru Ren, Z. H. Ye, C. F. Feng, G. M. Le, Z. Y. Feng, S. Ayabe, F. Kajino, K. Kawata, Takashi Saito, Huaguang Wang, M. Ohnishi, and S. Udo
- Subjects
Physics ,Nuclear and High Energy Physics ,Spectral index ,Range (particle radiation) ,business.industry ,Detector ,Flux ,Cosmic ray ,Atomic and Molecular Physics, and Optics ,Computational physics ,Air shower ,Optics ,Position (vector) ,business ,Energy (signal processing) - Abstract
We present an updated all-particle energy spectrum using data collected in the period from 2000 November through 2004 October by Tibet III air-shower array. The energy determination of the air showers is made by fitting the lateral density distribution of the shower particles to the modified NKG function which is optimized by simulation calculation using interaction models of QGSJET01c and SIBYLL2.1 taking into account of the detector configurations. It is shown that the model dependence in the energy determination is not significant, being less than 5% in the absolute flux value, and we obtained the cosmic ray energy spectrum in a wide range over 3 decades between 10(14) eV and 10(17) eV, in which the position of the knee is clearly seen at around 4 PeV. The spectral index is -2.68 +/- 0.02(stat.) below 1PeV, while it is -3.12 +/- 0.01(stat.) above 4 PeV. The various systematic errors are under study now.
- Published
- 2008
28. A large underground water Cherenkov muon detector array with the Tibet air shower array for Gamma-ray astronomy in the 100 TeV region: detector design and simulation
- Author
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C. T. Yan, T. Yuda, Y. Q. Lou, H. R. Wu, Jia Zhang, K. Mizutani, M. Amenomori, J. Y. Li, H. Y. Jia, M. Shibata, H. W. Guo, Chihiro Kato, M. He, H. Onuma, T. Sasaki, Labaciren, K. Hibino, T. Ouchi, H. Nanjo, Z. H. Ye, K. Kawata, I. Ohta, L. K. Ding, S. Yasue, Jieru Ren, T. Shirai, C. F. Feng, Masato Takita, Y. G. Wang, Q. Huang, H. H. He, G. M. Le, Takashi Saito, L. Xue, Shunsuke Ozawa, Huaguang Wang, A. F. Yuan, Zhaxisangzhu, Takashi Sako, B. Wang, Z. Y. Feng, Y. Yamamoto, S. L. Lu, H. M. Zhang, S. Ayabe, G. C. Yu, X. Y. Zhang, X. X. Zhou, X. Y. Gao, M. Ohnishi, Y. Katayose, X. H. Ding, X. R. Meng, H. Sugimoto, S. Udo, D. Chen, Zhaoyang Feng, N. Tateyama, Danzengluobu, Y. H. Tan, A. Nagai, Shoji Torii, F. Kajino, Xiaoqun Wang, Haibing Hu, Harufumi Tsuchiya, Y. Zhang, A. Shiomi, Masaki Nishizawa, M. Sakata, X. C. Yang, H. B. Hu, Q. X. Geng, Ning Zhang, S. W. Cui, N. Hotta, Hsiao-Chi Lu, J. Mu, A. F. Li, Yi Zhang, Jing Huang, Kazuoki Munakata, Takeshi Saito, Katsuaki Kasahara, and X. J. Bi
- Subjects
Physics ,Nuclear and High Energy Physics ,Physics::Instrumentation and Detectors ,Astrophysics::High Energy Astrophysical Phenomena ,Detector ,Monte Carlo method ,Astrophysics::Instrumentation and Methods for Astrophysics ,Gamma-ray astronomy ,Atomic and Molecular Physics, and Optics ,Physics::Geophysics ,Nuclear physics ,Air shower ,High Energy Physics::Experiment ,Sensitivity (control systems) ,Cherenkov radiation ,Muon detector - Abstract
We are planning to build a large water-Cherenkov-type muon detector array around the Tibet air shower array for Gamma-ray astronomy in the 100 TeV Region. In this paper, we describe the design of the Tibet MD array and details of the Monte Carlo simulation to demonstrate the sensitivity of the Tibet AS+MD array.
- Published
- 2008
29. A large underground water Cherenkov muon detector array with the Tibet air shower array for the Gamma-ray astronomy in the 100 TeV region: Overview and physics goal
- Author
-
G. C. Yu, Jieru Ren, S. Ayabe, I. Ohta, Ning Zhang, Labaciren, Q. X. Geng, N. Hotta, Hsiao-Chi Lu, C. F. Feng, H. Y. Jia, J. Y. Li, J. Mu, M. Shibata, Jia Zhang, F. Kajino, A. F. Li, Jing Huang, Shoji Torii, Y. G. Wang, Chihiro Kato, Y. Katayose, A. F. Yuan, M. He, Takashi Sako, X. J. Bi, G. M. Le, D. Chen, K. Hibino, Xiaoqun Wang, H. Onuma, Haibing Hu, T. Sasaki, X. R. Meng, Zhaxisangzhu, Kazuoki Munakata, Zhaoyang Feng, S. W. Cui, B. Wang, H. H. He, Takeshi Saito, Q. Huang, Y. Zhang, Katsuaki Kasahara, T. Ouchi, K. Mizutani, X. X. Zhou, S. L. Lu, Shunsuke Ozawa, H. Nanjo, T. Shirai, A. Shiomi, M. Ohnishi, X. H. Ding, L. K. Ding, H. M. Zhang, Y. H. Tan, Yi Zhang, H. Sugimoto, H. W. Guo, S. Udo, Y. Yamamoto, X. Y. Zhang, Masaki Nishizawa, C. T. Yan, Takashi Saito, K. Kawata, Huaguang Wang, Z. H. Ye, T. Yuda, Y. Q. Lou, H. R. Wu, X. Y. Gao, Danzengluobu, A. Nagai, L. Xue, M. Amenomori, S. Yasue, Masato Takita, N. Tateyama, Harufumi Tsuchiya, X. C. Yang, H. B. Hu, and M. Sakata
- Subjects
Physics ,Nuclear and High Energy Physics ,Muon ,COSMIC cancer database ,Physics::Instrumentation and Detectors ,Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics::Instrumentation and Methods for Astrophysics ,Gamma ray ,Astronomy ,Cosmic ray ,Gamma-ray astronomy ,Atomic and Molecular Physics, and Optics ,Particle detector ,Nuclear physics ,Air shower ,High Energy Physics::Experiment ,Cherenkov radiation - Abstract
The Tibet air shower array with effective area 37,000 m 2 located at 4300m in altitude, in Tibet, China, is sensitive to celestial gamma rays with energies above a few TeV. We have a plan to add a large underground muon detector array to it in order to discriminate cosmic gamma rays from cosmic-ray hadrons and to increase its sensitivity by approximately one order of magnitude to cosmic gamma rays in the 100 TeV energy region. The overview of the plan will be briefly described.
- Published
- 2008
30. Northern Sky Survey for Gamma-ray Point Sources in 100 TeV Region with the Tibet Air Shower Array
- Author
-
H. Y. Jia, X. Y. Gao, C. T. Yan, Jia Zhang, Danzengluobu, A. Nagai, B. Wang, Takashi Saito, Katsuaki Kasahara, J. Mu, M. Amenomori, Chihiro Kato, M. He, H. H. He, Huaguang Wang, H. Onuma, Masaki Nishizawa, T. Yuda, T. Sasaki, A. F. Li, Jing Huang, Y. Q. Lou, H. R. Wu, Yi Zhang, C. F. Feng, Shunsuke Ozawa, Zhaxisangzhu, Y. Katayose, Jieru Ren, Takashi Sako, Q. Huang, G. M. Le, D. Chen, F. Kajino, Y. Yamamoto, L. Xue, Q. X. Geng, S. L. Lu, M. Ohnishi, S. Yasue, X. R. Meng, J. Y. Li, Shoji Torii, S. Udo, K. Mizutani, Kazuoki Munakata, G. C. Yu, Zhaoyang Feng, Z. Y. Feng, Masato Takita, S. Ayabe, K. Hibino, Z. H. Ye, S. W. Cui, Takeshi Saito, X. J. Bi, T. Ouchi, L. K. Ding, K. Kawata, X. H. Ding, Ning Zhang, Y. H. Tan, N. Hotta, H. M. Zhang, X. X. Zhou, Hsiao-Chi Lu, H. Sugimoto, M. Shibata, Xiaoqun Wang, Haibing Hu, Labaciren, Y. Zhang, A. Shiomi, N. Tateyama, Y. G. Wang, A. F. Yuan, Harufumi Tsuchiya, X. Y. Zhang, H. W. Guo, X. C. Yang, H. B. Hu, M. Sakata, I. Ohta, H. Nanjo, and T. Shirai
- Subjects
Physics ,Nuclear and High Energy Physics ,Astrophysics::High Energy Astrophysical Phenomena ,media_common.quotation_subject ,Astrophysics::Instrumentation and Methods for Astrophysics ,Gamma ray ,Extrapolation ,Flux ,Astronomy ,Cosmic ray ,Astrophysics ,Declination ,Atomic and Molecular Physics, and Optics ,Galaxy ,Air shower ,Sky ,media_common - Abstract
We searched for steady 100 TeV gamma-ray point sources from −10° to +70° in declination based on six year data obtained from Nov. 1999 to Nov. 2005 by the Tibet air shower array. No new source was found and no significant excess of events could be detected from known TeV sources. We set flux upper limits above 100 TeV on several nearby objects located inside Our Galaxy. All of them are slightly higher than extrapolation from lower energies by a factor of 1 to 20. Our new project named Tibet MD will improve our sensitivity by a factor of ∼10 in this energy region. We would discover ∼10 new sources and be able to measure cutoff energy of known and unknown sources, which might lead to identification of the origin of cosmic rays.
- Published
- 2008
31. Spectral index of high-energy cosmic rays by the Compton-Getting effect at solar time frame with the Tibet air shower array
- Author
-
K. Kawata, Ning Zhang, H. H. He, Xiaoqun Wang, M. Amenomori, Jieru Ren, N. Hotta, Haibing Hu, X. C. Yang, H. W. Guo, Labaciren, Q. X. Geng, G. C. Yu, M. Shibata, F. Kajino, H. Nanjo, S. L. Lu, T. Shirai, Y. Zhang, T. Ouchi, H. B. Hu, A. Shiomi, Takashi Sako, Takashi Saito, Hsiao-Chi Lu, X. H. Ding, Huaguang Wang, L. Xue, K. Mizutani, H. M. Zhang, X. R. Meng, X. J. Bi, M. Ohnishi, X. X. Zhou, X. Y. Gao, Y. H. Tan, K. Hibino, S. Yasue, Zhaoyang Feng, S. Udo, Danzengluobu, J. Y. Li, Katsuaki Kasahara, A. Nagai, H. Sugimoto, Masato Takita, Z. Y. Feng, Y. G. Wang, S. Ayabe, Kazuoki Munakata, Shunsuke Ozawa, A. F. Yuan, J. Mu, A. F. Li, Jing Huang, Chihiro Kato, M. He, M. Sakata, B. Wang, Zhaxisangzhu, X. Y. Zhang, Y. Katayose, C. T. Yan, D. Chen, Shoji Torii, I. Ohta, N. Tateyama, T. Yuda, H. Y. Jia, Harufumi Tsuchiya, Y. Q. Lou, H. R. Wu, Jia Zhang, C. F. Feng, H. Onuma, T. Sasaki, Q. Huang, G. M. Le, Y. Yamamoto, L. K. Ding, Z. H. Ye, Masaki Nishizawa, Takeshi Saito, S. W. Cui, and Yi Zhang
- Subjects
Physics ,Nuclear and High Energy Physics ,Spectral index ,Astrophysics::High Energy Astrophysical Phenomena ,Astronomy ,Cosmic ray ,Astrophysics ,Atomic and Molecular Physics, and Optics ,Air shower ,Solar time ,Orbital motion ,Ultra-high-energy cosmic ray ,Anisotropy ,Energy (signal processing) - Abstract
We report on the spectral index of cosmic rays around 10 TeV energy region obtained by observation of the Compton-Getting anisotropy due to the terrestrial orbital motion around the Sun with the Tibet III air shower array during the period from 1999 to 2005. The spectral index has turned out to be 2.99 ± 0.54 , which is consistent with 2.74 by the direct energy spectrum measurement. This method is a new approach to measure the spectral index and is complementary to the conventional energy spectrum measurement.
- Published
- 2008
32. Ferromagnetism and Nonmetallic Transport of Thin-Filmα−FeSi2: A Stabilized Metastable Material
- Author
-
Wolter Siemons, D. G. Mandrus, C. Parish, David J. Singh, Liang Qiao, German D. Samolyuk, Weiyu Wang, Siwei Tang, H. W. Guo, Jieyu Yi, E. A. Payzant, Zheng Gai, Y. W. Zhang, Thomas Z. Ward, Ke Jin, G. M. Stocks, Xiaoguang Zhang, Claudia Cantoni, Guixin Cao, and M. D. Biegalski
- Subjects
Materials science ,Condensed matter physics ,Ferromagnetism ,Magnetoresistance ,Phase (matter) ,Magnetic refrigeration ,General Physics and Astronomy ,Electronic structure ,Thin film ,Electronic band structure ,Pulsed laser deposition - Abstract
The epitaxially stabilized metallic α-FeSi2 thin films on Si(001) were grown using pulsed laser deposition. While the bulk material of α-FeSi2 is a high temperature metastable phase and nonmagnetic, the thin film is stabilized at room temperature and shows unusual electronic transport and magnetic properties due to strain modification. The transport renders two different conducting states with a strong crossover at 50 K accompanied by an onset of ferromagnetism as well as a substantial magnetocaloric effect and magnetoresistance. These experimental results are discussed in terms of the unusual electronic structure of α-FeSi2 obtained within density functional calculations and Boltzmann transport calculations with and without strain. Our findings provide an example of a tailored material with interesting physics properties for practical applications.
- Published
- 2015
33. Primary cosmic-ray energy spectrum around the knee energy region measured by the Tibet hybrid experiment
- Author
-
M Amenomori, S Ayabe, S W Cui, null Danzengluobu, L K Ding, X H Ding, C F Feng, Z Y Feng, X Y Gao, Q X Geng, H W Guo, H H He, M He, K Hibino, N Hotta, Haibing Hu, H B Hu, J Huang, Q Huang, H Y Jia, F Kajino, K Kasahara, Y Katayose, C Kato, K Kawata, null Labaciren, G M Le, J Y Li, H Lu, S L Lu, X R Meng, K Mizutani, J Mu, K Munakata, A Nagai, H Nanjo, M Nishizawa, M Ohnishi, I Ohta, H Onuma, T Ouchi, S Ozawa, J R Ren, T Saito, M Sakata, T Sasaki, M Shibata, A Shiomi, T Shirai, H Sugimoto, M Takita, Y H Tan, N Tateyama, S Torii, H Tsuchiya, S Udo, T Utsugi, B S Wang, H Wang, X Wang, Y G Wang, H R Wu, L Xue, Y Yamamoto, C T Yan, X C Yang, S Yasue, Z H Ye, G C Yu, A F Yuan, T Yuda, H M Zhang, J L Zhang, N J Zhang, X Y Zhang, Y Zhang, Yi Zhang, null Zhaxisangzhu, X X Zhou, and The Tibet Asã Collaboration
- Subjects
Physics ,History ,Range (particle radiation) ,Proton ,chemistry.chemical_element ,Cosmic ray ,Spectral line ,Computer Science Applications ,Education ,Nuclear physics ,chemistry ,Primary (astronomy) ,Energy spectrum ,Helium ,Energy (signal processing) - Abstract
The Tibet hybrid experiment composed of emulsion chambers, burst detectors and the Tibet-II air-shower array was done at Yangbajing (4,300m above sea level, 606 g/cm2) in Tibet. For 3-year operation, we have observed 177 γ-families (ΣEγ > 20 TeV) accompanying air showers with the shower size Ne > 2 × 105. Using this data set and a neural network method to select proton and helium induced events, the primary proton and helium energy spectra are deduced between 1015 and 1016eV. The proton spectrum, thus obtained, can be expressed by a single power-law function with a differential index of −3.01±0.11 and −3.05±0.12 based on the QGSJET+HD and SIBYLL+HD models, respectively, which are steeper than that extrapolated from the direct observations of −2.74±0.01 in the energy range below 1014 eV. Our result suggests that the main component responsible for making the knee structure of the all-particle spectrum should be composed of nuclei heavier than helium.
- Published
- 2006
34. Primary proton spectrum around the knee observed by the Tibet air-shower experiment
- Author
-
Jieru Ren, M. Ohnishi, Katsuaki Kasahara, Kazumasa Kawata, H. Y. Jia, G. C. Yu, T. Ouchi, Xuan Zhang, J. Y. Li, X. Y. Gao, L. Xue, Q. Huang, N. Tateyama, J. Mu, Zhaxisangzhu, G. M. Le, Shoji Torii, X. H. Ding, Jing Huang, K. Hibino, Yi Zhang, Y. Yamamoto, Harufumi Tsuchiya, N. Hotta, Z. Y. Feng, A. Nagai, M. Amenomori, S. Ayabe, H. Nanjo, T. Shirai, Hsiao-Chi Lu, K. Mizutani, X. R. Meng, Haibing Hu, N. J. Zhang, Chihiro Kato, M. He, Shunsuke Ozawa, H. W. Guo, M. Shibata, To. Saito, Jia Zhang, Y. Zhang, Kazuoki Munakata, I. Ohta, S. W. Cui, F. Kajino, C. T. Yan, X. C. Yang, A. F. Yuan, Z. H. Ye, H. Onuma, T. Yuda, T. Sasaki, S. Yasue, H. R. Wu, Q. X. Geng, X. Wang, Masato Takita, H. B. Hu, Huaguang Wang, Masaki Nishizawa, Labaciren, L. K. Ding, M. Sakata, Danzengluobu, Cunfeng Feng, A. Shiomi, Y. H. Tan, H. H. He, H. M. Zhang, X. X. Zhou, Yu Wang, H. Sugimoto, S. Udo, S. L. Lu, Y. Katayose, and D. Chen
- Subjects
Physics ,Atmospheric Science ,Range (particle radiation) ,Proton ,Astrophysics::High Energy Astrophysical Phenomena ,Aerospace Engineering ,chemistry.chemical_element ,Flux ,Astronomy and Astrophysics ,Cosmic ray ,Spectral line ,Nuclear physics ,Geophysics ,Air shower ,chemistry ,Space and Planetary Science ,General Earth and Planetary Sciences ,Nuclear emulsion ,Helium - Abstract
Simultaneous observation of gamma-families and their accompanying air showers was performed at Yangbajing (4300 m above sea level) in Tibet with the emulsion chambers and burst detectors which were linked with the Tibet-II air-shower array. For three years operation, we observed 177 gamma-families (Sigma E-gamma > 20 TeV) accompanying air showers with the size N-e > 2 x 10(5). Using this data and the simulation code CORSIKA, we obtained the primary proton spectrum in the energy range of 10(15)-10(16) eV. The slope of the observed spectrum is steeper than that extrapolated smoothly from the lower energy region below 10(14) eV, irrespective of the interaction models assumed in the simulation. The uncertainty of the absolute flux of protons due to the interaction model dependence involved in the simulation codes is at most 30%, which is much weaker than results of other air-shower experiments. Our experiment shows low intensity of light components (proton and helium) independent of the interaction models suggesting that the main component responsible for making the knee structure of the all-particle spectrum is composed of nuclei heavier than helium. This is the first measurement of the differential energy spectra of primary protons by selecting them event by event at the knee energy region.
- Published
- 2006
35. Variation of Sun shadow in the Solar Cycle 23 observed with the Tibet air shower array
- Author
-
Labaciren, H. R. Wu, N. Tateyama, K. Mizutani, X. H. Ding, Z. Y. Feng, S. Ayabe, Harufumi Tsuchiya, Shunsuke Ozawa, X. R. Meng, Q. X. Geng, M. Amenomori, C. T. Yan, Xuan Zhang, B. S. Wang, Zhaxisangzhu, T. Yuda, X. Wang, Jieru Ren, X. C. Yang, F. Kajino, Y. Katayose, H. B. Hu, M. Shibata, Y. G. Wang, Chihiro Kato, Huaguang Wang, A. F. Yuan, M. He, Y. Yamamoto, H. Y. Jia, Haibing Hu, I. Ohta, Q. Huang, G. M. Le, H. W. Guo, J. Mu, N. Hotta, M. Izumi, M. Sakata, K. Hibino, L. Xue, G. C. Yu, X. Y. Gao, Jing Huang, S. Udo, Danzengluobu, N. J. Zhang, Hsiao-Chi Lu, Cunfeng Feng, Katsuaki Kasahara, Z. H. Ye, H. Nanjo, T. Shirai, Masaki Nishizawa, L. K. Ding, Kazuoki Munakata, Y. Zhang, M. Ohnishi, S. Yasue, S. W. Cui, A. Nagai, Takeshi Saito, Masato Takita, Jia Zhang, Kazumasa Kawata, A. Shiomi, H. Onuma, T. Sasaki, H. M. Zhang, X. X. Zhou, H. Sugimoto, Y. H. Tan, H. H. He, S. L. Lu, J. Y. Li, Shoji Torii, T. Utsugi, and T. Ouchi
- Subjects
Physics ,Solar minimum ,Atmospheric Science ,Aerospace Engineering ,Astronomy ,Astronomy and Astrophysics ,Cosmic ray ,Astrophysics ,Solar maximum ,Solar cycle ,Geophysics ,Earth's magnetic field ,Space and Planetary Science ,Physics::Space Physics ,Shadow ,Astrophysics::Solar and Stellar Astrophysics ,General Earth and Planetary Sciences ,Astrophysics::Earth and Planetary Astrophysics ,Interplanetary spaceflight ,Sun path - Abstract
According to many solar observations, the solar activity, during the Solar Cycle 23, is gradually declining to the quiet phase from the high state in 2000–2004. The Tibet air shower array has been continuing the observation of the shadow that cosmic rays make in the direction of the sun or the moon since 1991. We have shown the influence of the magnetic field around the sun, the interplanetary and the geomagnetic fields for the sun shadow at the multi-TeV region. We discuss the variation of the Sun’s shadow with the Gnevyshev gap (GG) in the maximum phase of the Solar Cycle 23. Unfortunately, the bottom in GG corresponds to off-observation period. Nonetheless, we found the anti-correlation between the significance of the Sun’s shadow and the variation of the magnetic field intensity around GG, although the statistical significance is not so high. It is expected that a detailed analysis of the Sun’s shadow will reveal interesting features of the anti-correlation.
- Published
- 2006
36. Are protons still dominant at the knee of the cosmic-ray energy spectrum?
- Author
-
M. Sakata, Xuan Zhang, Danzengluobu, Cunfeng Feng, Jia Zhang, Kazuoki Munakata, S. W. Cui, N. Tateyama, Katsuaki Kasahara, N. Hotta, Hsiao-Chi Lu, H. Nanjo, Harufumi Tsuchiya, Y. G. Wang, T. Shirai, Takeshi Saito, S. Yasue, J. Y. Li, A. F. Yuan, K. Hibino, H. Y. Jia, Jieru Ren, L. Xue, Kazumasa Kawata, Masato Takita, Shoji Torii, Zhaxisangzhu, X. C. Yang, A. Nagai, Z. H. Ye, H. B. Hu, J. Mu, Jing Huang, X. H. Ding, H. Onuma, T. Sasaki, H. W. Guo, I. Ohta, Shunsuke Ozawa, Labaciren, K. Mizutani, H. M. Zhang, X. X. Zhou, T. Ouchi, Yi Zhang, M. Amenomori, Masaki Nishizawa, G. C. Yu, H. Sugimoto, Z. Y. Feng, S. Ayabe, Y. Yamamoto, Q. Huang, G. M. Le, Haibing Hu, C. T. Yan, X. R. Meng, Y. Zhang, T. Yuda, A. Shiomi, N. J. Zhang, H. R. Wu, Chihiro Kato, M. He, Y. H. Tan, L. K. Ding, H. H. He, F. Kajino, S. L. Lu, Y. Katayose, D. Chen, X. Y. Gao, M. Ohnishi, S. Udo, M. Shibata, Q. X. Geng, X. Wang, and Huaguang Wang
- Subjects
Physics ,Nuclear and High Energy Physics ,Range (particle radiation) ,Proton ,Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics (astro-ph) ,Monte Carlo method ,Hadron ,FOS: Physical sciences ,chemistry.chemical_element ,Cosmic ray ,Astrophysics ,Spectral line ,Nuclear physics ,chemistry ,Event (particle physics) ,Helium - Abstract
A hybrid experiment consisting of emulsion chambers, burst detectors and the Tibet II air-shower array was carried out at Yangbajing (4,300 m a.s.l., 606 g/cm$^2$) in Tibet to obtain the energy spectra of primary protons and heliums. From three-year operation, these energy spectra are deduced between $10^{15}$ and $10^{16}$ eV by triggering the air showers associated with a high energy core and using a neural network method in the primary mass separation. The proton spectrum can be expressed by a single power-law function with a differential index of $-3.01 \pm 0.11$ and $-3.05 \pm 0.12$ based on the QGSJET+HD and SIBYLL+HD models, respectively, which are steeper than that extrapolated from the direct observations of $-2.74 \pm 0.01$ in the energy range below $10^{14}$ eV. The absolute fluxes of protons and heliums are derived within 30% systematic errors depending on the hadronic interaction models used in Monte Carlo simulation. The result of our experiment suggests that the main component responsible for the change of the power index of the all-particle spectrum around $3 \times 10^{15}$ eV, so-called ``knee'', is composed of nuclei heavier than helium. This is the first measurement of the differential energy spectra of primary protons and heliums by selecting them event by event at the knee energy region., Comment: This paper has been accepted for publication Physics Letters B on October 19th, 2005. This paper has been accepted for publication Physics Letters B on October 19th, 2005
- Published
- 2006
37. Observation of Multi-T[CLC]e[/CLC]V Gamma Rays from the Crab Nebula using the Tibet Air Shower Array
- Author
-
M. Amenomori, S. Ayabe, P. Y. Cao, null Danzengluobu, L. K. Ding, Z. Y. Feng, Y. Fu, H. W. Guo, M. He, K. Hibino, N. Hotta, Q. Huang, A. X. Huo, K. Izu, H. Y. Jia, F. Kajino, K. Kasahara, Y. Katayose, null Labaciren, J. Y. Li, H. Lu, S. L. Lu, G. X. Luo, X. R. Meng, K. Mizutani, J. Mu, H. Nanjo, M. Nishizawa, M. Ohnishi, I. Ohta, T. Ouchi, J. R. Ren, T. Saito, M. Sakata, T. Sasaki, Z. Z. Shi, M. Shibata, A. Shiomi, T. Shirai, H. Sugimoto, K. Taira, Y. H. Tan, N. Tateyama, S. Torii, T. Utsugi, C. R. Wang, H. Wang, X. W. Xu, Y. Yamamoto, G. C. Yu, A. F. Yuan, T. Yuda, C. S. Zhang, H. M. Zhang, J. L. Zhang, N. J. Zhang, X. Y. Zhang, null Zhaxisangzhu, null Zhaxiciren, W. D. Zhou, and (The Tibet ASγ Collaboration)
- Subjects
Physics ,Scintillation ,Physics::Instrumentation and Detectors ,Astrophysics::High Energy Astrophysical Phenomena ,Detector ,Astrophysics::Instrumentation and Methods for Astrophysics ,Gamma ray ,Astronomy and Astrophysics ,Astrophysics ,Crab Nebula ,Air shower ,Space and Planetary Science ,Energy spectrum ,High Energy Physics::Experiment ,Cherenkov radiation ,Energy (signal processing) - Abstract
The Tibet experiment, operating at Yangbajing (4,300 m above sea level), is the lowest energy air shower array and the new high density array constructed in 1996 has sensitivity to $\gamma$-ray air showers at energies as low as 3 TeV. With this new array, the Crab Nebula was observed in multi-TeV $\gamma$-rays and a signal was detected at the 5.5 $\sigma$ level. We also obtained the energy spectrum of $\gamma$-rays in the energy region above 3 TeV which partially overlaps those observed with imaging atmospheric Cherenkov telescopes. This is the first observation of $\gamma$-ray signals from point sources with a conventional air shower array using scintillation detectors.
- Published
- 1999
38. Sun's shadow by 10 TeV cosmic rays under the influence of solar activity
- Author
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Zhaxiciren, B. Z. Dai, X. Y. Zhang, K. Taira, W. D. Zhou, I. Ohta, P. Y. Cao, N. Hotta, Z. Z. Shi, C. R. Wang, Z. Y. Feng, Hsiao-Chi Lu, H. Nanjo, Y. Yamamoto, S. Ayabe, N. Tateyama, T. Shirai, P. X. Wang, Shoji Torii, T. Yuda, N. J. Zhang, M. Ohnishi, H. W. Guo, J. Y. Li, Dongming Mei, K. Mizutani, Jia Zhang, C. S. Zhang, Jieru Ren, Huaguang Wang, A. Shiomi, Labaciren, S. M. Liu, M. Shibata, To. Saito, H. M. Zhang, Y. Katayose, X. W. Xu, M. Sakata, T. Sasaki, H. Sugimoto, H. Y. Jia, Katsuaki Kasahara, M. Amenomori, T. Ouchi, T. Utsugi, G. C. Yu, K. Izu, L. K. Ding, S. J. Zhou, C. Shi, F. Kajino, Zhaxisangzhu, X. R. Meng, Q. Huang, K. Hibino, W. Xie, M. He, Y. Fu, A. X. Huo, A. F. Yuan, Masaki Nishizawa, S. L. Lu, Y. H. Tan, G. X. Luo, and J. Mu
- Subjects
Physics ,Atmospheric Science ,Sunspot ,Astrophysics::High Energy Astrophysical Phenomena ,Aerospace Engineering ,Astronomy ,Astronomy and Astrophysics ,Astrophysics ,Coronal loop ,Solar cycle ,Nanoflares ,Solar wind ,Geophysics ,Space and Planetary Science ,Physics::Space Physics ,Coronal mass ejection ,Astrophysics::Solar and Stellar Astrophysics ,General Earth and Planetary Sciences ,Astrophysics::Earth and Planetary Astrophysics ,Heliospheric current sheet ,Interplanetary magnetic field - Abstract
We examined the Sun's shadow by 10 TeV cosmic rays observed with the Tibet air shower array during the period from 1991 through 1997. The results suggest that there is a causal relation between the shadow's movement and the changing inclination of the heliospheric current sheet of the large-scale solar magnetic field. Thus, further observations with higher statistics may provide direct information on the relation between a time variation of the large-scale structure of the solar and interplanetary magnetic fields and the phase of solar activity cycle.
- Published
- 1999
39. Sensitivity of ARGO-YBJ to different composition models in the energy range 10 ÷ 500 TeV
- Author
-
C. BACCI, K. Z. BAO, F. BARONE, B. BARTOLI, S. BUSSINO, E. CALLONI, B. Y. CAO, R. CARDARELLI, S. CATALANOTTI, S. CAVALIERE, F. CESARONI, P. CRETI, DANZENGLUOBU, B. D'ETTORRE PIAZZOLI, M. DE VINCENZI, T. DI GIROLAMO, G. DI SCIASCIO, Z. Y. FENG, Y. FU, X. Y. GAO, Q. X. GENG, H. W. GUO, H. H. HE, M. HE, Q. HUANG, M. IACOVACCI, N. IUCCI, H. Y. JAI, C. L. JING, F. M. KONG, H. H. KUANG, LABACIREN, B. LI, J. Y. LI, Z. Q. LIU, H. LU, X. H. MA, S. M. MARI, X. R. MENG, L. MILANO, J. MU, Z. R. PENG, P. PISTILLI, L. SAGGESE, R. SANTONICO, P. R. SHEN, C. STANESCU, L. R. SUN, S. C. SUN, A. SURDO, Y. H. TAN, S. VERNETTO, C. R. WANG, H. WANG, H. Y. WANG, Y. N. WEI, H. T. YANG, Q. K. YAO, G. C. YU, X. D. YUE, A. F. YUAN, M. ZHA, H. M. ZHANG, J. L. ZHANG, N. J. ZHANG, X. Y. ZHANG, ZHAXISANGZHU, ZHAXICIREN, Q. Q. ZHU, BERNARDINI, Paolo, DE MITRI, Ivan, MANCARELLA, Giovanni, MARSELLA, GIOVANNI, MARTELLO, Daniele, PANAREO, Marco, C., Bacci, K. Z., Bao, F., Barone, B., Bartoli, Bernardini, Paolo, S., Bussino, E., Calloni, B. Y., Cao, R., Cardarelli, S., Catalanotti, S., Cavaliere, F., Cesaroni, P., Creti, Danzengluobu, B., D'ETTORRE PIAZZOLI, DE MITRI, Ivan, M., DE VINCENZI, T., DI GIROLAMO, G., DI SCIASCIO, Z. Y., Feng, Y., Fu, X. Y., Gao, Q. X., Geng, H. W., Guo, H. H., He, M., He, Q., Huang, M., Iacovacci, N., Iucci, H. Y., Jai, C. L., Jing, F. M., Kong, H. H., Kuang, Labaciren, B., Li, J. Y., Li, Z. Q., Liu, H., Lu, X. H., Ma, Mancarella, Giovanni, S. M., Mari, Marsella, Giovanni, Martello, Daniele, X. R., Meng, L., Milano, J., Mu, Panareo, Marco, Z. R., Peng, P., Pistilli, L., Saggese, R., Santonico, P. R., Shen, C., Stanescu, L. R., Sun, S. C., Sun, A., Surdo, Y. H., Tan, S., Vernetto, C. R., Wang, H., Wang, H. Y., Wang, Y. N., Wei, H. T., Yang, Q. K., Yao, G. C., Yu, X. D., Yue, A. F., Yuan, M., Zha, H. M., Zhang, J. L., Zhang, N. J., Zhang, X. Y., Zhang, Zhaxisangzhu, Zhaxiciren, Q. Q., Zhu, Baccia, The ARGO YBJ C. o. l. l. a. b. o. r. a. t. i. o. n. C., K. Z., Baob, F., Baronec, B., Bartolic, P., Bernardinid, S., Bussinoa, E., Callonic, B. Y., Caoe, R., Cardarellif, S., Catalanottic, S., Cavalierec, F., Cesaronid, P., Cretid, Danzengluobug, B., D’Ettorrepiazzolic, M., De Vincenzia, T., Di Girolamoc, G., Di Sciascioc, Z. Y., Fengh, Y., Fue, X. Y., Gaoi, Q. X., Gengi, H. W., Guog, H. H., Hej, M., Hee, Q., Huangh, M., Iacovaccic, N., Iuccia, H. Y., Jaih, C. L., Jingj, F. M., Konge, H. H., Kuangj, Labacireng, B., Lib, J. Y., Lie, Z. Q., Liui, H., Luj, X. H., Maj, G., Mancarellad, Mari, Stefano Maria, A, G., Marsellad, D., Martellod, X. R., Mengg, L., Milanoc, J., Mui, M., Panareod, Z. R., Pengj, P., Pistillia, L., Saggesec, R., Santonicof, P. R., Shenj, C., Stanescua, L. R., Sunb, S. C., Sunb, A., Surdod, Y. H., Tanj, S., Vernettok, C. R., Wange, H., Wangj, H. Y., Wangj, Y. N., Weib, H. T., Yangj, Q. K., Yaob, G. C., Yuh, X. D., Yueb, A. F., Yuang, M., Zhaj, H. M., Zhangj, J. L., Zhangj, N. J., Zhange, X. Y., Zhange, Zhaxisangzhug, Zhaxicireng, and Q. Q., Zhuj
- Subjects
Physics ,Nuclear and High Energy Physics ,Resistive touchscreen ,Range (particle radiation) ,ARGO-YBJ ,Detector ,Cosmic ray ,STRIPS ,Cosmic Ray ,Atomic and Molecular Physics, and Optics ,Charged particle ,law.invention ,Nuclear physics ,law ,Shower detectors ,Cosmic Ray, Resistive Plate Counters, Composition Model, Extensive Air Showers ,Energy (signal processing) ,Argo - Abstract
The ARGO-YBJ experiment is currently under construction at the Yangbajing Cosmic Ray Laboratory (4300 m a.s.l.).The detector consists of a central carpet, 74 × 78 m2, made of a single layer of Resistive Plate Counters (RPCs), and surrounded by a partially instrumented guard ring for a total instrumented area of about 6700 m2. The digital read-out, performed by means of pick-up electrodes 6.7 × 62 cm2 (strip), allows to measure the charged particle number of small size air showers. The technique of counting the number of fired strips on the ARGO carpet corresponds to operate in the 10÷500 TeV energy region where both direct and indirect measurements on the primary cosmic radiation have been performed. Many composition models have been proposed by different experiments. In this work we discuss the ability of the ARGO detector to discriminate among some models.
- Published
- 2004
40. Understanding the impact of double screen-printing on silicon solar cells by 2-D numerical simulations
- Author
-
Mauro Zanuccoli, R. De Rose, H.-W. Guo, Paolo Magnone, Michel Frei, Enrico Sangiorgi, Marco Galiazzo, Giorgio Cellere, Diego Tonini, Claudio Fiegna, Magnone P., De Rose R., Zanuccoli M., Tonini D., Galiazzo M., Cellere G., Guo H., Frei M., Sangiorgi E., and Fiegna C.
- Subjects
SOLAR CELLS ,NUMERICAL ANALYSIS ,Materials science ,Silicon ,business.industry ,Open-circuit voltage ,Numerical analysis ,Electrical engineering ,chemistry.chemical_element ,Aspect ratio (image) ,law.invention ,chemistry ,law ,Screen printing ,Solar cell ,Optoelectronics ,business ,Short circuit ,Voltage - Abstract
In this work we investigate c-Si solar cells in which a two steps (double) screen-printing is implemented for the front contact in order to increase the aspect ratio of the fingers. To this purpose numerical simulations are performed on a solar cell and metallization properties are defined according to experimental data. The analysis of solar cells with conventional single screen-printing is also performed for comparison. In agreement with experiments we show the efficiency improvement of double printing over single printing. The analysis of electrical parameters (fill factor, short-circuit current and open-circuit voltage) allows to understand the source of the enhanced efficiency.
- Published
- 2011
41. Numerical simulation and modeling of rear point contact solar cells
- Author
-
Claudio Fiegna, Mukul Agrawal, Paolo Magnone, Michel Frei, Mauro Zanuccoli, Enrico Sangiorgi, R. De Rose, H.-W. Guo, Zanuccoli M., De Rose R., Magnone P., Frei M., Guo H.-W., Agrawal M., Sangiorgi E., and Fiegna C.
- Subjects
Work (thermodynamics) ,Materials science ,Equivalent series resistance ,Silicon ,Computer simulation ,business.industry ,Numerical analysis ,NUMERICAL ANALYSIS ,SOLAR CELLS ,Energy conversion efficiency ,Mechanical engineering ,chemistry.chemical_element ,Monocrystalline silicon ,Optics ,chemistry ,Point (geometry) ,business - Abstract
High efficiency silicon monocrystalline solar cells commonly adopt point contacted rear surfaces to reduce the recombination losses in the rear side of the device. However, the reduction of the rear contact surface leads to an increase of series resistance losses. Modeling and analysis of rear point contact solar cells is strategic to optimize the device design by taking into account several competing physical mechanisms. Owing to their complicated geometries, the analysis of these devices requires three-dimensional (3-D) numerical simulation. In this work we analyze the influence of the most important geometrical and electrical parameters on the conversion efficiency of rear point contact solar cells.
- Published
- 2011
42. 2-D Numerical analysis of the impact of the highly-doped profile on selective emitter solar cell performance
- Author
-
Michel Frei, H.-W. Guo, Enrico Sangiorgi, R. De Rose, Marco Galiazzo, Claudio Fiegna, Paolo Magnone, Giorgio Cellere, Diego Tonini, Mauro Zanuccoli, De Rose R., Zanuccoli M., Magnone P., Tonini D., Galiazzo M., Cellere G., Frei M., Guo H.-W., Fiegna C., and Sangiorgi E.
- Subjects
Materials science ,Silicon ,business.industry ,NUMERICAL ANALYSIS ,SOLAR CELLS ,Doping ,technology, industry, and agriculture ,chemistry.chemical_element ,law.invention ,chemistry ,law ,Solar cell ,Optoelectronics ,Condensed Matter::Strongly Correlated Electrons ,Process window ,Diffusion (business) ,business ,Current density ,Helium ,Common emitter - Abstract
Two-dimensional (2-D) numerical simulations have been performed to investigate the impact of the doping profile in the metal-contacted highly-doped regions for c-Si selective emitter (SE) solar cells. Numerical results show that the doping profile under the metallization significantly influences the recombination effects on the front-side of the SE cell and consequently its performance. A strong impact on the short-circuit current density of the solar cell has been seen. This is mainly due to the inclusion of large alignment tolerances used in the SE diffusion for the subsequent metallization process, leading to broad highly-doped areas. In this regard, a quantitative analysis of this effect has been carried out. The results reveal that an improved alignment, allowing a reduction of the alignment tolerances, leads to a wider process window of doping profiles and hence better SE cell performance.
- Published
- 2011
43. TeV Gamma Ray Survey on the Direction of Fermi-LAT Pulsars with the Tibet Air Shower Array
- Author
-
H. M. Zhang, X. X. Zhou, H. Sugimoto, Ning Zhang, Q. Huang, N. Hotta, Jian Huang, Haibing Hu, X. Y. Zhang, Y. Zhang, Y. G. Wang, A. Shiomi, G. C. Yu, Z. H. Ye, Q. X. Geng, A. F. Yuan, N. Tateyama, H. H. He, K. Mizutani, M. Shibata, X. R. Meng, Ying Zhang, Jia Zhang, To. Saito, B. S. Wang, Zhaxisangzhu, S. W. Cui, Zhaoyang Feng, K. Kawata, S. Yasue, Harufumi Tsuchiya, C. F. Feng, H. C. Li, C. T. Yan, T. K. Sako, H. W. Guo, Shoji Torii, L. Xue, H. Nanjo, T. Shirai, Q. B. Gou, Masato Takita, D. Chen, L. L. Jiang, Yi Zhang, Kazuoki Munakata, C. Fan, X. J. Bi, X. C. Yang, T. Yuda, H. B. Hu, X. H. Ding, Y. Q. Lou, H. R. Wu, Hong-peng Lu, Y. Katayose, K. Kasahara, J. Mu, M. Sakata, Y. H. Tan, J. Y. Li, A. F. Li, Gui-Ming Le, I. Ohta, Masaki Nishizawa, M. Amenomori, L. K. Ding, K. Hibino, S. Ozawa, X. Y. Gao, Danzengluobu, Y. Yamamoto, Yu-Sa Wang, Labaciren, Chihiro Kato, M. He, Takashi Saito, Huaguang Wang, H. Y. Jia, C. X. Liu, M. Ohnishi, S. Udo, F. Kajino, and Z. Y. Feng
- Subjects
Physics ,symbols.namesake ,Air shower ,Crab Nebula ,Pulsar ,Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics::Instrumentation and Methods for Astrophysics ,Gamma ray ,symbols ,High Energy Physics::Experiment ,Astrophysics ,Poisson distribution ,Fermi Gamma-ray Space Telescope - Abstract
We search for steady TeV γ-rays from 18 pulsars in the Fermi-LAT pulsar catalog using the Tibet air shower array. We observe 8 sources including the Crab against expected 0.41 sources at a significance of 2σ or more among the 18 pulsars. The chance probability from Poisson statistics is estimated to be 1.4×10-8.With the Crab excluded, it is estimated to be 1.8×10-7. These low chance probabilities clearly show that the Fermi pulsars have a statistically significant correlation with TeV γ-ray excesses observed by the Tibet air shower array.
- Published
- 2010
44. Development of no-rinse screen printable etch paste for contact via in dielectric films
- Author
-
Timothy W. Weidman, Michael P. Stewart, H.-W. Guo, Sunhom Paak, Suketu A. Parikh, L. Zhao, Rohit Mishra, Prabhat Kumar, Zhenhua Zhang, and Hemant P. Mungekar
- Subjects
Materials science ,Silicon ,business.industry ,Contact resistance ,chemistry.chemical_element ,Carrier lifetime ,Dielectric ,Nitride ,chemistry.chemical_compound ,chemistry ,Silicon nitride ,Aluminium ,Optoelectronics ,business ,Silicon oxide - Abstract
Screen printable etch paste was developed for low cost patterning of dielectric films. This technique offers a simple print and bake approach to pattern without the need for a rinse step. Residue analysis of the etched area showed no sign of any organic residue left behind by the etch process. High carrier lifetime indicates no significant contamination or silicon surface damage. The etched via diameter of 150 µm was demonstrated in thermal oxide while smaller via size of 100 µm was achieved in silicon nitride (SiN x ) or a combination of silicon oxide and nitride. Contact resistance measurement through the etched vias using TLM method showed values less than 3mΩ.cm2. The etch paste and process technique can be easily used in PERC cell as well as advanced architecture Interdigitated Back Contact (IBC) cell for low cost patterning.
- Published
- 2010
45. On Temporal Variations of the Multi-TeV Cosmic Ray Anisotropy using the Tibet III Air Shower Array
- Author
-
H. C. Li, M. Ohnishi, Y. G. Wang, K. Kawata, S. Udo, A. F. Yuan, C. F. Feng, X. Y. Gao, Danzengluobu, A. Nagai, X. C. Yang, Q. Huang, M. Amenomori, H. Y. Jia, L. L. Jiang, Y. Q. Lou, H. R. Wu, H. B. Hu, Labaciren, H. H. He, Y. Yamamoto, Yu-Sa Wang, T. K. Sako, Z. Y. Feng, H. Nanjo, T. Shirai, Donghong Chen, K. Hibino, M. Sakata, Chihiro Kato, K. Mizutani, J. Y. Li, M. He, Y. Katayose, X. R. Meng, X. Y. Zhang, Jia Zhang, S. Torii, Gui-Ming Le, C. X. Liu, Haibing Hu, L. Xue, C. Fan, Zhaoyang Feng, Masaki Nishizawa, G. C. Yu, Takashi Saito, Huaguang Wang, Q. B. Gou, I. Ohta, N. Tateyama, Kazuoki Munakata, S. Ozawa, Ang Li, Ning Zhang, F. Kajino, Y. Zhang, Harufumi Tsuchiya, N. Hotta, H. W. Guo, A. Shiomi, L. K. Ding, Z. H. Ye, X. H. Ding, T. Yuda, S. Yasue, B. S. Wang, Zhaxisangzhu, Masato Takita, Y. H. Tan, H. M. Zhang, X. X. Zhou, H. Sugimoto, Q. X. Geng, C. T. Yan, K. Kasahara, J. Mu, Jing Huang, X. J. Bi, M. Shibata, Yi Zhang, Takeshi Saito, Ying Zhang, S. W. Cui, and H. Lu
- Subjects
Physics ,High Energy Astrophysical Phenomena (astro-ph.HE) ,Astrophysics::High Energy Astrophysical Phenomena ,Observation period ,FOS: Physical sciences ,Astronomy and Astrophysics ,Cosmic ray ,Astrophysics ,Solar cycle ,Air shower ,Space and Planetary Science ,Sidereal time ,Solar Activities ,Magnitude (astronomy) ,Physics::Space Physics ,Anisotropy ,Astrophysics - High Energy Astrophysical Phenomena - Abstract
We analyze the large-scale two-dimensional sidereal anisotropy of multi-TeV cosmic rays by Tibet Air Shower Array, with the data taken from 1999 November to 2008 December. To explore temporal variations of the anisotropy, the data set is divided into nine intervals, each in a time span of about one year. The sidereal anisotropy of magnitude about 0.1% appears fairly stable from year to year over the entire observation period of nine years. This indicates that the anisotropy of TeV Galactic cosmic rays remains insensitive to solar activities since the observation period covers more than a half of the 23rd solar cycle., 18 pages, 2 figures, accepted by The Astrophysical Journal
- Published
- 2010
46. Heliospheric signatures seen in the sidereal anisotropy of high-energy galactic cosmic ray intensity
- Author
-
X. J. Bi, H. Nanjo, T. Shirai, Takeshi Saito, József Kóta, B. S. Wang, Zhaxisangzhu, K. Hibino, Haibing Hu, H. C. Li, S. Ozawa, C. Fan, K. Kasahara, J. Mu, K. Mizutani, A. F. Li, Y. Zhang, L. Xue, A. Shiomi, G. C. Yu, N. Tateyama, Q. X. Geng, Ying Zhang, H. M. Zhang, Labaciren, S. W. Cui, H. Y. Jia, K. Kawata, X. X. Zhou, Harufumi Tsuchiya, C. T. Yan, I. Ohta, Y. Katayose, H. Sugimoto, M. Shibata, Yi Zhang, M. Amenomori, Q. Huang, X. C. Yang, Jian Huang, H. B. Hu, Z. Y. Feng, Y. G. Wang, A. F. Yuan, X. Y. Zhang, Y. Yamamoto, T. Yuda, D. Chen, Kazuoki Munakata, L. Jiang, Ning Zhang, Y. Q. Lou, H. R. Wu, N. Hotta, Yu-Sa Wang, M. Sakata, H. W. Guo, Hsiao-Chi Lu, Gui-Ming Le, Chihiro Kato, M. He, Z. H. Ye, C. X. Liu, C. F. Feng, F. Kajino, L. K. Ding, S. Yasue, Jia Zhang, Q. B. Gou, S. Torii, Masato Takita, Takashi Saito, Huaguang Wang, Masaki Nishizawa, X. Y. Gao, Danzengluobu, M. Ohnishi, T. K. Sako, S. Udo, H. H. He, X. H. Ding, Y. H. Tan, J. Y. Li, X. R. Meng, and Zhaoyang Feng
- Subjects
Physics ,Amplitude ,Air shower ,Energetic neutral atom ,Astrophysics::High Energy Astrophysical Phenomena ,Physics::Space Physics ,Astronomy ,Cosmic ray ,Context (language use) ,Astrophysics ,Magnetohydrodynamics ,Anisotropy ,Heliosphere - Abstract
Mapping the global heliosphere by detecting energetic neutral atoms (ENAs), IBEX derived the semi‐direct information on the structure of the large‐scale magnetic field surrounding the heliosphere. Multi‐TeV galactic cosmic rays (GCRs) also sense the global structure of the magnetic field within the whole heliosphere as well as the field surrounding the heliosphere, and can provide an additional tool to explore the global structure of these fields. We analyze, in this context, the multi‐TeV GCR intensity observed with the Tibet Air Shower (AS) experiment, which clearly shows a midscale component structure observed as the excess intensity along Gurnett’s HDP (Hydrogen Deflection Plane), as well as the global component structure. We find that the amplitude of the midscale component is only weakly dependent on GCR energy, while its angular extension along the HDP plane monotonously decreases with increasing energy. On the basis of these results, we discuss the possible origin of the midscale anisotropy.
- Published
- 2010
47. An Updated Search of Steady TeV $\gamma-$Ray Point Sources in Northern Hemisphere Using the Tibet Air Shower Array
- Author
-
Z. H. Ye, X. Y. Zhang, Y. Wang, H. Y. Jia, J. R. Ren, X. C. Yang, Ji-Long Zhang, Y. G. Wang, X. R. Meng, Han-Rong Wu, Haibing Hu, S. W. Cui, L. K. Ding, Hui-Min Zhang, C. Fan, Hui Wang, Hong-Bo Hu, H. W. Guo, X. J. Bi, Xiao-Hong Ding, You-Heng Tan, X. X. Zhou, Zhaoyang Feng, Ang Li, Yi Zhang, M. He, Q Huang, Jy Li, S. L. Lu, Yong Zhang, Zhaxisangzhu, C. F. Feng, Z. Y. Feng, L. Xue, B. Wang, GC Yu, Y. Q. Lou, Q. Yuan, N. J. Zhang, Gui-Ming Le, A. F. Yuan, H. Lu, Q. X. Geng, Danzengluobu, Labaciren, X. Y. Gao, Huihai He, and J. Mu
- Subjects
Physics ,Nuclear and High Energy Physics ,media_common.quotation_subject ,Astrophysics::High Energy Astrophysical Phenomena ,Northern Hemisphere ,Gamma ray ,Astrophysics::Instrumentation and Methods for Astrophysics ,Flux ,Astronomy and Astrophysics ,Astrophysics ,Declination ,Power law ,Air shower ,Crab Nebula ,Sky ,Instrumentation ,media_common - Abstract
Using the data taken from Tibet II High Density (HD) Array (1997 February-1999 September) and Tibet-III array (1999 November-2005 November), our previous northern sky survey for TeV $\gamma-$ray point sources has now been updated by a factor of 2.8 improved statistics. From $0.0^{\circ}$ to $60.0^{\circ}$ in declination (Dec) range, no new TeV $\gamma-$ray point sources with sufficiently high significance were identified while the well-known Crab Nebula and Mrk421 remain to be the brightest TeV $\gamma-$ray sources within the field of view of the Tibet air shower array. Based on the currently available data and at the 90% confidence level (C.L.), the flux upper limits for different power law index assumption are re-derived, which are approximately improved by 1.7 times as compared with our previous reported limits., Comment: This paper has been accepted by hepnp
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- 2008
48. Underground Prototype Water Cherenkov Muon Detector with the Tibet Air Shower Array
- Author
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H. Y. Jia, Y. Wang, Y. G. Wang, X. H. Ding, H. M. Zhang, S. Yasue, X. X. Zhou, Masato Takita, S. W. Cui, Y. Yamamoto, Ning Zhang, H. Sugimoto, T. Yuda, N. Hotta, X. Y. Gao, Y. H. Tan, Y. Q. Lou, A. F. Yuan, H. R. Wu, Danzengluobu, A. Nagai, H. H. He, Q. Huang, Jia Zhang, Xiaoqun Wang, Hsiao-Chi Lu, X. C. Yang, G. C. Yu, Jieru Ren, Takashi Sako, Yi Zhang, Haibing Hu, Shunsuke Ozawa, S. L. Lu, X. R. Meng, Y. Zhang, K. Hibino, B. S. Wang, Takeshi Saito, Masaki Nishizawa, Zhaoyang Feng, Zhaxisangzhu, A. Shiomi, K. Mizutani, J. Y. Li, H. W. Guo, M. Shibata, H. B. Hu, I. Ohta, C. F. Feng, D. Chen, Y. Katayose, Kazuoki Munakata, Shoji Torii, L. K. Ding, C. Fan, G. M. Le, T. Ouchi, Labaciren, H. Nanjo, S. Udo, T. Shirai, M. Sakata, Z. H. Ye, N. Tateyama, Chihiro Kato, K. Kawata, M. He, Harufumi Tsuchiya, Z. Y. Feng, F. Kajino, M. Amenomori, L. Xue, C. T. Yan, M. Ohnishi, Takashi Saito, Huaguang Wang, X. J. Bi, K. Kasahara, J. Mu, A. F. Li, Jing Huang, Q. X. Geng, and X. Y. Zhang
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Physics ,Muon ,Physics::Instrumentation and Detectors ,business.industry ,Cherenkov detector ,Astrophysics::High Energy Astrophysical Phenomena ,Detector ,Astrophysics::Instrumentation and Methods for Astrophysics ,Gamma ray ,Astronomy ,Cosmic ray ,Gamma-ray astronomy ,law.invention ,Optics ,Air shower ,law ,High Energy Physics::Experiment ,business ,Cherenkov radiation - Abstract
We are planning to build a 10,000 m2 water‐Cherenkov‐type muon detector (MD) array under the Tibet air shower (AS) array. The Tibet AS+MD array will have the sensitivity to detect gamma rays in the 100 TeV region by an order of the magnitude better than any other previous existing detectors in the world. In the late fall of 2007, a prototype water Cherenkov muon detector of approximately 100 m2 was constructed under the existing Tibet AS array. The preliminary data analysis is in good agreement with our MC simulation. We are now ready for further expanding the underground water Cherenkov muon detector.
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- 2008
49. The energy spectrum of all-particle cosmic rays around the knee region observed with the Tibet-III air-shower array
- Author
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K. Hibino, Haibing Hu, Y. G. Wang, Ning Zhang, Zhaxisangzhu, Y. Zhang, A. Shiomi, N. Hotta, H. Wang, A. F. Yuan, Y. H. Tan, Shuwang Cui, X. J. Bi, C. T. Yan, Takashi Sako, S. Yasue, X. H. Ding, Masato Takita, Zhenyong Feng, F. Kajino, T. Yuda, Xuan Zhang, X. X. Zhou, Z. H. Ye, Jieru Ren, H. Sugimoto, Y. Q. Lou, X. R. Meng, M. Amenomori, Shunsuke Ozawa, Labaciren, Zhaoyang Feng, M. Ohnishi, Y. Katayose, Y. Yamamoto, H. H. He, Chihiro Kato, Hong Wu, Shoji Torii, M. He, Q. Huang, D. Chen, G. C. Yu, K. Mizutani, T. Ouchi, S. L. Lu, X. Y. Gao, X. Wang, Danzengluobu, A. Nagai, Jia Zhang, L. Xue, I. Ohta, Kazuoki Munakata, H. W. Guo, M. Shibata, S. Ayabe, B. Wang, H. Onuma, T. Sasaki, Hailan Hu, Masaki Nishizawa, Hong-peng Lu, S. Udo, H. M. Zhang, G. M. Le, H. Nanjo, T. Shirai, M. Sakata, Cunfeng Feng, X. C. Yang, H. Y. Jia, N. Tateyama, Harufumi Tsuchiya, To. Saito, Katsuaki Kasahara, J. Mu, A. F. Li, Jing Huang, Q. X. Geng, Liming Ding, Yi Zhang, Takeshi Saito, Kazumasa Kawata, and J. Y. Li
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Physics ,Systematic error ,Atmospheric Science ,Range (particle radiation) ,Spectral index ,Astrophysics (astro-ph) ,knee ,Aerospace Engineering ,FOS: Physical sciences ,Astronomy and Astrophysics ,Cosmic ray ,Astrophysics ,Knee region ,air shower ,Geophysics ,Air shower ,cosmic rays ,Space and Planetary Science ,Energy spectrum ,General Earth and Planetary Sciences ,Particle - Abstract
We have already reported the first result on the all-particle spectrum around the knee region based on data from 2000 November to 2001 October observed by the Tibet-III air-shower array. In this paper, we present an updated result using data set collected in the period from 2000 November through 2004 October in a wide range over 3 decades between $10^{14}$ eV and $10^{17}$ eV, in which the position of the knee is clearly seen at around 4 PeV. The spectral index is -2.68 $\pm$ 0.02(stat.) below 1PeV, while it is -3.12 $\pm$ 0.01(stat.) above 4 PeV in the case of QGSJET+HD model, and various systematic errors are under study now., Comment: 12 pages, 7 figures, accepted by Advances in space research
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- 2008
- Full Text
- View/download PDF
50. New estimation of the spectral index of high-energy cosmic rays as determined by the Compton-Getting anisotropy
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S. Yasue, Hong Wu, X. Y. Gao, Y. G. Wang, Chihiro Kato, M. He, Xuan Zhang, H. Sugimoto, A. F. Yuan, T. K. Sako, Gui-Ming Le, Y. Yamamoto, Y. H. Tan, Zhaoyang Feng, Cunfeng Feng, M. Shibata, Yu Wang, N. Hotta, Shoji Torii, L. Xue, Huihai He, C. Fan, Yi Zhang, Katsuaki Kasahara, Hong-peng Lu, X. J. Bi, Harufumi Tsuchiya, Liming Ding, Labaciren, S. L. Lu, J. Mu, K. Kawata, Hailan Hu, H. Onuma, K. Mizutani, X. C. Yang, Xiaoqun Wang, X. H. Ding, Zhenyong Feng, H. M. Zhang, S. Udo, K. Hibino, Haibing Hu, Jing Huang, Masato Takita, M. Sakata, H. Nanjo, G. C. Yu, Y. Katayose, H. Y. Jia, H. W. Guo, M. Amenomori, D. Chen, J. R. Ren, J. Y. Li, Y. Zhang, A. Shiomi, B. Wang, Shuwang Cui, C. T. Yan, Y. Q. Lou, To. Saito, M. Ohnishi, T. Shirai, T. Yuda, Ang Li, J. L. Zhang, Kazuoki Munakata, Ning Zhang, F. Kajino, Zhaxisangzhu, X. R. Meng, Z. H. Ye, X. X. Zhou, Masaki Nishizawa, T. Ouchi, Q. Huang, Shunsuke Ozawa, Danzengluobu, A. Nagai, H. Wang, I. Ohta, Q. X. Geng, N. Tateyama, and Takashi Saito
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Physics ,Spectral index ,Astrophysics::High Energy Astrophysical Phenomena ,Hadron ,Astrophysics (astro-ph) ,Astrophysics::Instrumentation and Methods for Astrophysics ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics ,Measure (mathematics) ,Atmosphere ,Amplitude ,Space and Planetary Science ,Energy spectrum ,High Energy Physics::Experiment ,Ultra-high-energy cosmic ray ,Anisotropy - Abstract
The amplitude of the Compton-Getting (CG) anisotropy contains the power-law index of the cosmic-ray energy spectrum. Based on this relation and using the Tibet air-shower array data, we measure the cosmic-ray spectral index to be $-3.03 \pm 0.55_{stat} \pm < 0.62_{syst}$ between 6 TeV and 40 TeV, consistent with $-$2.7 from direct energy spectrum measurements. Potentially, this CG anisotropy analysis can be utilized to confirm the astrophysical origin of the ``knee'' against models for non-standard hadronic interactions in the atmosphere., accepted to ApJL
- Published
- 2007
- Full Text
- View/download PDF
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