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Effects of pressure relief holes on coal burst:Insights from true-triaxial unloading tests

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第9期16卷 3378-3394页

作者： Fuqiang Ren Murat Karakus Giang nguyen thomas Bruning School of Civil Engineering University of Science and Technology LiaoningAnshan114051China Mining and Petroleum Engineering The University of AdelaideAdelaideSouth Australia5005Australia State Key Laboratory for Geomechanics&Deep Underground Engineering China University of Mining and TechnologyBeijing100083China School of Architecture and Civil Engineering The University of AdelaideSouth Australia5005Australia

Drilling pressure relief is one of the methods to reduce the risk of coal bursts in deep ***,the effect of the drill hole orientations has not been studied well enough to understand their impact on the burst failure *** this study,we investigated two designs of drill hole *** first design includes drill holes located on the upper free face of the rectangular samples and labelled as upper hole(UH)and centre hole(CH)e the long axes of the drill holes are aligned with minor principal stress,s3,*** second design includes drill holes at the top(th)and the side(SH)of the rectangular samples in which the long axes of the drill holes are aligned with the maximum,s1,and intermediate principal stress,s2,directions,*** coal samples with the proposed drill hole orientations were subjected to the true-triaxial unloading coal burst *** results show that the drill holes reduce the risk of coal ***,we found that the intensity of coal burst was significantly reduced with the SH-type,followed by the *** also observed that the coal burst intensity is reduced better for the CH,UH,th,and SH-type drilling ***,it was found that the orientations of drill holes have little influence on the failure mode(splitting).the acoustic emission(AE)activities for coal with drill holes noticeably decreased,especially for the UH and CH *** drill holes reduced the upper limit of the AE entropy(chaos of microcracks generation).However,regarding reducing the coal burst risk,the th and SH are less effective than UH and CH.

关键词： Coal burst Triaxial unloading Drilling orientation Ejection characteristic Acoustic emission(AE)

Shilian Dashan With the Propagation of the Caodong Sect in Cochinchina in the Seventeenth Century

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Philosophy Study 2024年第4期14卷 194-203页

作者： Ngoc Phuong nguyen Guangxi University for Nationalities NanningChina

the prosperous development of the“Maritime Silk Road”in the 17th century not only brought convenience in sea transportation and promoted trade between countries,but also acted as a bridge connecting *** bridge has the function of cultural exchange between peoples,especially in introducing and promoting China’s cultural and ideological quintessence with neighboring *** this period,Linji and Caodong sects of Chinese Zen Buddhism were spread directly into Cochinchina of Dai Viet through Chinese senior monks who followed merchant ships to this *** them was the Most Venarable Shilian Dashan,a senior monk at Changshou Temple,Guangzhou,who accepted Lord nguyen Phuc Chu’s invitation to teach the Soto Dharma in Cochinchina for nearly two years(1695-1696).based on the study of relevant historical documents and autobiographical works on this trip byMost ***,the article presents his biography and ***,this article analyzes the method of spreading Dharma,Chan ideology,as well as the significance of his Dharma propagation activities for Buddhism in Cochinchina at that time.

关键词： Shilian Dashan Buddhism in Cochinchina Caodong Chan

High-temperature corrosion of sintered RE_(2)Si_(2)O_(7)(RE=yb and Ho)environmental barrier coating materials by volcanic ash

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International Journal of Minerals,Metallurgy and Materials 2024年第7期31卷 1628-1638页

作者： Ayahisa Okawa Son thanh nguyen Tadachika Nakayama thi-Mai-Dung Do Hisayuki Suematsu Shu yin Takuya Hasegawa Tsuneo Suzuki Takashi Goto Koichi Niihara Institute of Multidisciplinary Research for Advanced Materials Tohoku UniversitySendai 980-8577Japan Department of Creative Engineering National Institute of TechnologyKushiro 084-0916Japan Extreme Energy-Density Research Institute Nagaoka University of TechnologyNagaoka 940-2188Japan Advanced Institute for Materials Research(WPI-AIMR) Tohoku UniversitySendai 980-8577Japan

Rare-earth silicates are promising environmental barrier coatings(EBCs)that can protect SiC_(f)/Si C_(m)substrates in next-genera tion gas turbine ***,RE_(2)Si_(2)O_(7)(RE=yb and Ho)shows potential as an EBC due to its coefficient of thermal expansion(CTE)compatible with substrates and high resistance to water vapor *** target operating temperature for next-generation tur bine blades is 1400°*** is inevitable during adhesion to molten volcanic ash,and thus,understanding the corrosion behavior o the material is crucial to its *** study investigates the high-temperature corrosion behavior of sintered RE_(2)Si_(2)O_(7)(RE=yb and Ho).Samples were prepared using a solid-state reaction and hot-press *** were then exposed to volcanic ash at 1400°C for 224,and 48 *** 48 h of exposure,volcanic ash did not react with.yb_(2)Si_(2)O_(7)but penetrated its interior,causing *** Ho_(2)Si_(2)O_(7)was partially dissolved in the molten volcanic ash,forming a reaction zone that prevented volcanic ash melts from penetrating the *** increasing heat treatment time,the reaction zone expanded,and the thickness of the acicular apatite grains increased the Ca:Si ratios in the residual volcanic ash were mostly unchanged for yb_(2)Si_(2)O_(7)but decreased considerably over time for Ho_(2)Si_(2)O_(7).th Ca in volcanic ash was consumed and formed apatite,indicating that RE^(3+)ions with large ionic radii(Ho>yb)easily precipitated apatit from the volcanic ash.

关键词： environmental barrier coating volcanic ash rare-earth disilicate corrosion

越南学生“常常”“往往”习得偏误及教学对策研究

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越南学生“常常”“往往”习得偏误及教学对策研究

作者： nguyen thI LUU Ly（阮氏琉璃）河北大学

学位级别：硕士

“常常”“往往”是汉语中典型的频率副词,在语义、句法和语用特征方面较为复杂且不易区分。笔者作为越南留学生,在学习汉语过程中发现,越南学生受母语的影响在理解和应用“常常”“往往”时遇到了显著的障碍。为了探究越南学生在习得... 详细信息

“常常”“往往”是汉语中典型的频率副词,在语义、句法和语用特征方面较为复杂且不易区分。笔者作为越南留学生,在学习汉语过程中发现,越南学生受母语的影响在理解和应用“常常”“往往”时遇到了显著的障碍。为了探究越南学生在习得“常常”“往往”时出现的偏误情况,并据此提出适用于越南学生的教学与学习策略,文章从本体角度对“常常”“往往”进行了对比分析,从语义、句法及语用三个角度综合比较了“常常”与“往往”的共性与差异。研究显示,尽管这两个词在词性和功能方面有很大相似性,但在语义和使用上各有特点。在此基础上,文章将汉语的“常常”“往往”与越南语中相应的词语进行了对照分析,发现越南语中有“th(?)(?)ng”“th(?)(?)ng th(?)(?)ng”“th(?)(?)ng xuyên”“th(?)(?)ng hay”“lu(?)n lu(?)n”几个词语与汉语的“常常”“往往”在语义上非常相似,但在句法特征和语用情景方面,越南语中的相应表达表现出较强的灵活性和自由度。为更确切地了解越南学生习得“常常”“往往”的情况,本文以问卷调查的形式考察了越南学生在习得“常常”“往往”时的感受和可能存在的偏误。通过对问卷情况的分析,总结出越南学习者的偏误可分为语义偏误、句法偏误和语用偏误三种类型。文章从语义及句法复杂性、学习者母语及教学媒介语因素、教材因素等三个角度进行了原因分析,研究结果表明,母语影响是导致越南学生在汉语学习中出现偏误的重要因素之一,同时也指出了教材在处理这些频率副词时存在的不足。基于以上研究,本文有针对性地提出了面向越南学生习得“常常”“往往”的教学对策。在教材编写方面,建议提高翻译的精确度、注释的准确性,并增强练习的针对性。对于教师,本文倡导采用情境教学法、对比教学法以及强化实践练习。此外,给越南学生的语言习得提出了若干建议,包括通过汉语思维减少母语负迁移、善于对比以及敢于交际的学习策略。

关键词：越南学生常常往往问卷调查教学对策

Negative Index Materials and their Applications:Recent Mathematics Progress(Dedicated to Ham Brezis for his 70th birthday with esteem)

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Chinese Annals of Mathematics,Series B 2017年第2期38卷 601-628页

作者： Hoai-Minh nguyen EPFL SB MAthAA CAMA Station 8CH-1015 LausanneSwitzerland

Negative index materials are artificial structures whose refractive index has negative value over some frequency range. these materials were first investigated theoretically by Veselago in 1946 and were confirmed experimentally by Shelby, Smith, and Schultz in2001. Mathematically, the study of negative index materials faces two difficulties. Firstly,the equations describing the phenomenon have sign changing coefficients, hence the ellipticity and the compactness are lost in general. Secondly, the localized resonance, i.e.,the field explodes in some regions and remains bounded in some others as the loss goes to 0, might appear. In this survey, the author discusses recent mathematics progress in understanding properties of negative index materials and their applications. the topics are reflecting complementary media, superlensing and cloaking by using complementary media, cloaking a source via anomalous localized resonance, the limiting absorption principle and the well-posedness of the Helmholtz equation with sign changing coefficients.

关键词： Negative index materials, Localized resonance, Cloaking, Superlensing

Alfapump®implantable device in management of refractory ascites:An update

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World Journal of Hepatology 2022年第7期14卷 1344-1356页

作者： Delphine Weil-Verhoeven Vincent Di Martino Guido Stirnimann Jean Paul Cervoni Eric nguyen-Khac thierry thévenot Service d’Hépatologie Et Soins Intensifs Digestifs CHRU Jean MinjozBesançon 25030France EA 4266 EPILAB Universitéde Bourgogne Franche-ComtéBesançon 25030France Department of Visceral Surgery and Medicine Inselspital University Hospital and University of BernBern 3010Switzerland Service d’Hépato-Gastroentérologie CHU Amiens-PicardieAmiens 80080France

Refractory ascites(RA)is a frequent and life-threatening complication of *** selected patients with RA,transjugular intrahepatic portosystemic shunt(TIPS)placement and liver transplantation(LT)are currently considered the best therapeutic alternatives to repeated large volume *** patients with a contraindication to TIPS or LT,the alfapump®system(Sequana Medical,Ghent,Belgium)has been developed to reduce the need for iterative paracentesis,and consequently to improve the quality of life and nutritional *** report here recent data on technical progress made since the first implantation,the efficacy and tolerance of the device,the position of the pump in the therapeutic arsenal for refractory ascites,and the grey areas that remain to be clarified regarding the optimal selection of patients who are potential candidates for this treatment.

关键词： Alfapump Refractory ascites Automated low flow ascites pump Cirrhosis Liver

Eucalyptus Plantation in France for Biomass Production-From theoretical Areas to Probable Hectares

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Eucalyptus Plantation in France for Biomass Production-From ...

越南食品加工业供应链融资能力评价与应用研究

the 19th European Biomass Conference and Exhibition

作者： nguyen thé,N. Fraysse,J.y. Melun,F.

In the framework of the VALERBIO project,we studied the potential for biomass production from Short Rotation Coppice（SRC） in *** different possible species,we focussed on eucalyptus which turns to be an interesting candidate for marginal *** risk mapping was done by combining an inventory of known frost damages and the corresponding meteorological *** explaining the damages were built and subsequently,meteorological data were processed to give the probability of occurrence of these *** calculations were spatialized in order to map this *** sensitivity mapping was done by using different p H soil maps and particularly the European soil database（parent material layer）.Crossing the two constraints with different additional information on elevation and slope resulted in a map of suitable areas for eucalyptus,which represents some 11 million theoretical hectares covering more particularly the south and west part of *** probable areas were calculated by refining the theoretical figures with different assumptions:focussing on farm lands only and considering marginal ones,either uncultivated lands or former fallows,where SRC are more likely to develop,particularly with hardy species like *** final step consisted in setting different scenarios of mobilization for these marginal *** the most optimistic scenario proposed some 600 000 ha,the most probable one gives a maximum area cover of some 40 000 ha of eucalyptus,that would still have to be confronted with the competition of other energy crops or other energy *** natural uncertainties in the assumptions,this approach enables to spatialize the possibilities of development of this promising specie for biomass production and to locate the most suitable and probable regions of development.

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越南食品加工业供应链融资能力评价与应用研究

作者： nguyen th HONG HANH 东北大学

学位级别：硕士

处于强劲增长态势的越南食品加工业占据国内经济市场的同时扩大了出口量,但是由于中小企业数量众多,一直面临融资难的困境,影响了企业的发展。随着经济全球发展和一体化竞争的日趋激烈,供应链融资这一创新性的融资模式应运而生,它将信... 详细信息

处于强劲增长态势的越南食品加工业占据国内经济市场的同时扩大了出口量,但是由于中小企业数量众多,一直面临融资难的困境,影响了企业的发展。随着经济全球发展和一体化竞争的日趋激烈,供应链融资这一创新性的融资模式应运而生,它将信息流、资金流、物流融合起来,能够帮助解决越南中小食品加工企业的融资困难。但由于越南供应链融资业务开展得比较晚,相应的法律法规和服务体系建设还没有完善,所以供应链中各参与主体在实际业务过程中面临许多难题与阻碍,从而产生了很多不确定性风险,这严重阻碍了供应链融资业务健康有序的发展。因此,如何确定供应链融资能力的影响因素,并进行供应链融资能力的评价就成为研究的关键。本文在梳理供应链融资相关理论的基础上,针对越南食品加工业的融资特点,找出影响其供应链融资能力的因素,并将相关因素引入到评价食品加工企业供应链融资能力的指标体系中,利用模糊综合评价-AHP方法建立了供应链融资能力评价模型。并以越南食品加工业中的Vinamilk企业供应链融资业务发展为背景,利用所建立的评价模型对其供应链融资能力进行了更为现实的评价。研究表明,通过系统评估越南食品加工企业的供应链融资能力,可以找出增强供应链融资能力的关键要素,为提供越南食品加工企业的供应链融资能力提供建议和对策。

关键词：越南食品加工业供应链融资融资能力模糊评价

Assessment by microsatellite analysis of genetic diversity and population structure of Enhalus acoroides from the coast of Khanh Hoa Province, Vietnam

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Acta Oceanologica Sinica 2019年第1期38卷 144-150页

作者： Xuan-Vy nguyen Papenbrock Jutta Department of Marine Botany Institute of Oceanography Vietnam Academy of Science and Technology Graduate University of Science and Technology Institute of Botany Leibniz University Hannover

Seagrass beds degraded significantly since the last century on both, global and local scale. the seagrass species Enhalus acoroides(Linnaeus f.) Royle is a common species found in almost all marine ecosystems including bays,lagoons and around offshore islands in tropical regions of the West Pacific. It was shown that genetic diversity is an essential indicator of the conditions of ecosystems. In the present study, microsatellite markers were used to assess the genetic diversity and population structure of six distinct seagrass beds along the coast of the Khanh Hoa Province, Vietnam. the results indicate that the genetic diversity of the populations in the open sea is higher than in the lagoon. Seagrass beds occurring in disturbed sites show reduced genetic diversity. the fixing index value(FST) depicts a relatively high genetic structure among populations. Structure analysis clusters the populations into open sea and lagoon populations and cluster analysis and AMOVA indicate a significant difference between the two groups. there are low but non-significant positive correlations between geographic and genetic *** different habitats of the open sea and the lagoon are probably responsible for forming two groups.

关键词： Enhalus acoroides genetic diversity lagoon open sea population structure