期刊文献+
共找到70篇文章
< 1 2 4 >
每页显示 20 50 100
FAIR Principles:Interpretations and Implementation Considerations 被引量:30
1
作者 Annika Jacobsen Ricardo de Miranda Azevedo +41 位作者 Nick Juty Dominique Batista Simon Coles Ronald Cornet Melanie Courtot Merce Crosas Michel Dumontier Chris T.Evelo Carole Goble Giancarlo Guizzardi Karsten Kryger Hansen Ali Hasnain Kristina Hettne Jaap Heringa Rob W.W.Hooft Melanie Imming Keith G.Jeffery Rajaram Kaliyaperumal Martijn GKersloot Christine R.Kirkpatrick Tobias Kuhn Ignasi Labastida Barbara Magagna PeterMcQuilton Natalie Meyers Annalisa Montesanti Mirjam van Reisen Philippe Rocca-Serra Robert Pergl Susanna-Assunta Sansone Luiz Olavo Bonino da Silva Santos Juliane Schneider George Strawn Mark Thompson Andra Waagmeester Tobias Weigel Mark D.Wilkinson Egon L.Willighagen Peter Wittenburg Marco Roos Barend Mons Erik Schultes 《Data Intelligence》 2020年第1期10-29,293-302,322,共31页
The FAIR principles have been widely cited,endorsed and adopted by a broad range of stakeholders since their publication in 2016.By intention,the 15 FAIR guiding principles do not dictate specific technological implem... The FAIR principles have been widely cited,endorsed and adopted by a broad range of stakeholders since their publication in 2016.By intention,the 15 FAIR guiding principles do not dictate specific technological implementations,but provide guidance for improving Findability,Accessibility,Interoperability and Reusability of digital resources.This has likely contributed to the broad adoption of the FAIR principles,because individual stakeholder communities can implement their own FAIR solutions.However,it has also resulted in inconsistent interpretations that carry the risk of leading to incompatible implementations.Thus,while the FAIR principles are formulated on a high level and may be interpreted and implemented in different ways,for true interoperability we need to support convergence in implementation choices that are widely accessible and(re)-usable.We introduce the concept of FAIR implementation considerations to assist accelerated global participation and convergence towards accessible,robust,widespread and consistent FAIR implementations.Any self-identified stakeholder community may either choose to reuse solutions from existing implementations,or when they spot a gap,accept the challenge to create the needed solution,which,ideally,can be used again by other communities in the future.Here,we provide interpretations and implementation considerations(choices and challenges)for each FAIR principle. 展开更多
关键词 FAIR guiding principles FAIR implementation FAIR convergence FAIR communities choices and challenges
原文传递
氢气爆炸特性研究(英文) 被引量:17
2
作者 Hidenori Matsui 《中国安全生产科学技术》 CAS 2005年第6期3-9,共7页
本文研究、总结了氢气与空气(氢气与氧气)的混合物的爆炸特性。即氢气在空气中,在比较低燃烧界限的情况下,只有向上的传播和非常少的超压可以观测得到。正因为氢气的这种特性,将氢应用于科技将极大地推进社会进步,氢燃料将成为一种主要... 本文研究、总结了氢气与空气(氢气与氧气)的混合物的爆炸特性。即氢气在空气中,在比较低燃烧界限的情况下,只有向上的传播和非常少的超压可以观测得到。正因为氢气的这种特性,将氢应用于科技将极大地推进社会进步,氢燃料将成为一种主要的能源。然而,氢技术应用的成功与否主要取决于氢使用的安全性。所以,必须掌握实际使用时氢气燃烧的性能。本文在日本过去十年实验数据的基础上,通过实验研究了氢气与空气混合物的燃点。研究了氢气、氧气混合物经氮气稀释后,按化学当量比例将不同浓度的氢气与空气进行混合,并得出了低温下的爆炸压力特性。随后,分别讨论了在初始压力下一致的情况下,试管直径相同的状况下,氢气与空气混合浓度相同的情况下,这三种爆轰传播限制之间的关系。得出了在空气中直接点燃的发生爆轰的最小试管直径,最小的装药量之间的关系,进行了爆轰危险性分级。最后,文章概括比较了氢与其他燃料的燃烧特性,评估了氢气燃烧过程中的危险与安全因素。 展开更多
关键词 爆炸 特性 氢气 安全
下载PDF
雨水滞蓄措施在城区减洪之水文机制及容量研究 被引量:12
3
作者 廖朝轩 蔡耀隆 +1 位作者 黄伟民 Cheng Mow-soung 《水科学进展》 EI CAS CSCD 北大核心 2006年第4期538-542,共5页
针对雨水滞蓄设施在城区减洪之设置方式及容量计算,以就地消减雨洪(On-site Control)及分散配置原则提出设置规划流程与容量计算方式。对于雨水滞蓄措施之减洪机制进行水文分析,并选择台湾台北县汐止地区为算例进行规划。与目前以减少... 针对雨水滞蓄设施在城区减洪之设置方式及容量计算,以就地消减雨洪(On-site Control)及分散配置原则提出设置规划流程与容量计算方式。对于雨水滞蓄措施之减洪机制进行水文分析,并选择台湾台北县汐止地区为算例进行规划。与目前以减少开发增加洪峰量为目的之滞洪设施规划方式相比,本研究提出之规划方式可同时减少开发增加径流峰值与体积,且所需设计容量较少。 展开更多
关键词 雨水滞蓄措施 城区减洪 容量 水文分析
下载PDF
IPCC第四次评估报告中对不确定性的处理方法 被引量:12
4
作者 Martin R. Manning 戴晓苏(译) 罗勇(校) 《气候变化研究进展》 CSCD 2006年第5期233-237,共5页
在第四次评估报告中,IPCC建立了一种处理不确定性的方法,该方法是对第三次评估报告所用方法的进一步发展。通过综合分析,简要讨论了这一方法的主要特征,并介绍了IPCC为主要作者制定的“关于不确定性的指导意见”。需要注意的是,术语“... 在第四次评估报告中,IPCC建立了一种处理不确定性的方法,该方法是对第三次评估报告所用方法的进一步发展。通过综合分析,简要讨论了这一方法的主要特征,并介绍了IPCC为主要作者制定的“关于不确定性的指导意见”。需要注意的是,术语“可能性(likelihood)”和“信度(confidence)”都可作为表述不确定性的方法。尽管上述术语之间的差异在第三次评估报告中就已存在,并在指导意见完成之前成为争论的主题之一,但是,现在已经认识到这两种方法在描述不确定性时是互补的。 展开更多
关键词 IPCC 第四次评估报告 不确定性 处理方法
下载PDF
2022年川渝时空复合型极端事件:一种新型气候灾害 被引量:6
5
作者 郝增超 陈阳 +3 位作者 冯思芳 廖圳 安宁 李普曦 《Science Bulletin》 SCIE EI CAS CSCD 2023年第13期1337-1339,共3页
During the summer of 2022,a parade of extremes,including heatwaves,droughts,forest fires,and heavy rainfall hit the Sichuan-Chongqing region(SCR),Southwest China(Fig.S1 online),resulting in rippling socioeconomic and ... During the summer of 2022,a parade of extremes,including heatwaves,droughts,forest fires,and heavy rainfall hit the Sichuan-Chongqing region(SCR),Southwest China(Fig.S1 online),resulting in rippling socioeconomic and environmental impacts(Fig.1).Though none of these events are uncommon to the region,their combination in such a daisy-chained fashion is unusual.Here,taking a compound event perspective,we thoroughly reviewed the unfolding of such cascading hazards,and sorted out the pathway of their impacts multiplying.This analysis unmasks previously underestimated and underappreciated vulnerability of multiple critical sectors in the energy-food-water-ecology nexus to increasingly connected extremes.Several key steps are finally outlined with the aim of improving our coping capabilities against impending spatiotemporally compound hazards. 展开更多
关键词 RAINFALL CHONGQING thoroughly
原文传递
Quantitative parameters in novel spectral computed tomography:Assessment of Ki-67 expression in patients with gastric adenocarcinoma 被引量:2
6
作者 Li-Ting Mao Wei-Cui Chen +6 位作者 Jian-Ye Lu Han-Liang Zhang Yong-Song Ye Yu Zhang Bo Liu Wei-Wei Deng Xian Liu 《World Journal of Gastroenterology》 SCIE CAS 2023年第10期1602-1613,共12页
BACKGROUND The level of Ki-67 expression has served as a prognostic factor in gastric cancer.The quantitative parameters based on the novel dual-layer spectral detector computed tomography(DLSDCT)in discriminating the... BACKGROUND The level of Ki-67 expression has served as a prognostic factor in gastric cancer.The quantitative parameters based on the novel dual-layer spectral detector computed tomography(DLSDCT)in discriminating the Ki-67 expression status are unclear.AIM To investigate the diagnostic ability of DLSDCT-derived parameters for Ki-67 expression status in gastric carcinoma(GC).METHODS Dual-phase enhanced abdominal DLSDCT was performed preoperatively in 108 patients with gastric adenocarcinoma.Primary tumor monoenergetic CT attenuation value at 40-100 kilo electron volt(kev),the slope of the spectral curve(λ_(HU)),iodine concentration(IC),normalized IC(nIC),effective atomic number(Z^(eff))and normalized Z^(eff)(nZ^(eff))in the arterial phase(AP)and venous phase(VP)were retrospectively compared between patients with low and high Ki-67 expression in gastric adenocarcinoma.Spearman’s correlation coefficient was used to analyze the association between the above parameters and Ki-67 expression status.Receiver operating characteristic(ROC)curve analysis was performed to compare the diagnostic efficacy of the statistically significant parameters between two groups.RESULTS Thirty-seven and 71 patients were classified as having low and high Ki-67 expression,respectively.CT_(40 kev-VP),CT_(70 kev-VP),CT_(100 kev-VP),and Z^(eff)-related parameters were significantly higher,but IC-related parameters were lower in the group with low Ki-67 expression status than the group with high Ki-67 expression status,and other analyzed parameters showed no statistical difference between the two groups.Spearman’s correlation analysis showed that CT_(40 kev-VP),CT_(70 kev-VP),CT_(100 kev-VP),Z^(eff),and n Z^(eff) exhibited a negative correlation with Ki-67 status,whereas IC and nIC had positive correlation with Ki-67 status.The ROC analysis demonstrated that the multi-variable model of spectral parameters performed well in identifying the Ki-67 status[area under the curve(AUC)=0.967;sensitivity 95.77%;specificity 91.89%)].Nevertheless,the 展开更多
关键词 Spectral computer tomography Quantitative parameters Gastric carcinoma Iodine concentration Effective atomic number Ki-67 expression
下载PDF
Hot spot tracking of f lood remote sensing research over the past 22 years:abibliometric analysis using CiteSpace
7
作者 HUO Hong LIU Yan LI Yang 《地球环境学报》 CSCD 2024年第4期612-623,共12页
Background,aim,and scope In the context of climate change,extreme precipitation and resulting f looding events are becoming increasingly severe.Remote sensing technologies are advantageous for monitoring such disaster... Background,aim,and scope In the context of climate change,extreme precipitation and resulting f looding events are becoming increasingly severe.Remote sensing technologies are advantageous for monitoring such disasters due to their wide observation range,periodic revisit capabilities,and continuous spatial coverage.These tools enable real-time and quantitative assessment of f lood inundation.Over the past 20 years,the field of remote sensing for f loods has seen significant advancements.Understanding the evolution of research hotspots within this field can offer valuable insights for future research directions.Materials and methods This study systematically analyzes the development and hotspot evolution in the field of f lood remote sensing,both domestically and internationally during 2000—2021.Data from CNKI(China National Knowledge Infrastructure)and WOS(Web of Science)databases are utilized for this analysis.Results(1)A total of 1693 articles have been published in this field,showing a stable growth trend post-2008.Significant contributors include the Chinese Academy of Sciences,Beijing Normal University,Wuhan University,the Italian National Research Council,and National Aeronautics and Space Administration.(2)High-frequency keywords from 2000 to 2021 include“remote sensing”“f lood”“model”“classification”“GIS”“climate change”“area”,and“MODIS”.(3)The most prominent keywords were“GIS”(8.65),“surface water”(7.16),“remote sensing”(7.07),“machine learning”(6.52),and“sentinel-2”(5.86).(4)Thirteen cluster labels were identified through clustering,divided into three phases:2000—2009(initial exploratory stage),2010—2014(period of rapid development),and 2015—2021(steady development of remote sensing for f loods and related disasters).Discussion The field exhibits strong phase-based development,with research focuses shifting over time.From 2000 to 2009,emphasis was on remote sensing image application and f lood model development.From 2010 to 2014,the focus shift 展开更多
关键词 f lood remote sensing CITESPACE review knowledge graph analysis
下载PDF
Porous high-entropy rare-earth phosphate(REPO_(4),RE=La,Sm,Eu,Ce,Pr and Gd)ceramics with excellent thermal insulation performance via pore structure tailoring
8
作者 Peixiong Zhang Enhui Wang +3 位作者 Jingjing Liu Tao Yang Hailong Wang Xinmei Hou 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第7期1651-1658,共8页
Thermal insulation materials play an increasingly important role in protecting mechanical parts functioning at high temperatures.In this study,a new porous high-entropy(La_(1/6)Ce_(1/6)Pr_(1/6)Sm_(1/6)Eu_(1/6)Gd_(1/6)... Thermal insulation materials play an increasingly important role in protecting mechanical parts functioning at high temperatures.In this study,a new porous high-entropy(La_(1/6)Ce_(1/6)Pr_(1/6)Sm_(1/6)Eu_(1/6)Gd_(1/6))PO_(4)(HE(6RE_(1/6))PO_(4))ceramics was prepared by combining the high-entropy method with the pore-forming agent method and the effect of different starch contents(0–60vol%)on this ceramic properties was systematically investigated.The results show that the porous HE(6RE_(1/6))PO_(4)ceramics with 60vol%starch exhibit the lowest thermal conductivity of 0.061 W·m^(-1)·K^(-1)at room temperature and good pore structure stability with a linear shrinkage of approximately1.67%.Moreover,the effect of large regular spherical pores(>10μm)on its thermal insulation performance was discussed,and an optimal thermal conductivity prediction model was screened.The superior properties of the prepared porous HE(6RE_(1/6))PO_(4)ceramics allow them to be promising insulation materials in the future. 展开更多
关键词 porous high-entropy(La_(1/6)Ce_(1/6)Pr_(1/6)Sm_(1/6)Eu_(1/6)Gd_(1/6))PO_(4) ceramics high-entropy strategy pore-forming agent method thermal insulation material thermal conductivity
下载PDF
Distribution of lightning spatial modes and climatic causes in China 被引量:2
9
作者 Mingyi Xu Xiushu Qie +6 位作者 Chenxi Zhao Shanfeng Yuan Ji Li Yuyu Tao Guangyu Shi Wenjing Pang Lijuan Shi 《Atmospheric and Oceanic Science Letters》 CSCD 2023年第2期63-70,共8页
本文利用中国气象局国家雷电监测网(CNLDN)的地闪观测数据集,分析了2010-2020年中国陆地区域地闪空间模态分布特征及其可能的气候成因.研究发现,夏季地闪第一模态的方差贡献率为32.86%,其分布从北到南呈现出“-+-”的经向跷跷板模式,当... 本文利用中国气象局国家雷电监测网(CNLDN)的地闪观测数据集,分析了2010-2020年中国陆地区域地闪空间模态分布特征及其可能的气候成因.研究发现,夏季地闪第一模态的方差贡献率为32.86%,其分布从北到南呈现出“-+-”的经向跷跷板模式,当东太平洋和印度洋的海温异常增暖,西北太平洋的海温异常变冷时,在中国黄海,东海及热带西太平洋地区激发出气旋性环流,随着水汽南下至华南地区,与来自孟加拉湾的水汽汇合,上升运动在此加强,从而使得该地区的雷电活动增强.表明厄尔尼诺-南方涛动(ENSO)现象,是发生在中国陆地区域的地闪活动的气候驱动因子。 展开更多
关键词 雷电气候学 中国 云地闪 厄尔尼诺-南方涛动 太平洋
下载PDF
多肽靶向嵌合体通过促进tau蛋白特异性去磷酸化治疗阿尔茨海默病和其他tau蛋白病
10
作者 苏静芬 肖越 +11 位作者 魏林郁 雷慧杨 孙飞 王围霞 尹君 熊瑞 李师宏 张配 周颖 王小川 郑杰 王建枝 《Science Bulletin》 SCIE EI CAS CSCD 2024年第8期1137-1152,共16页
Abnormal hyperphosphorylation and accumulation of tau protein play a pivotal role in neurodegeneration in Alzheimer’s disease(AD)and many other tauopathies.Selective elimination of hyperphosphorylated tau is promisin... Abnormal hyperphosphorylation and accumulation of tau protein play a pivotal role in neurodegeneration in Alzheimer’s disease(AD)and many other tauopathies.Selective elimination of hyperphosphorylated tau is promising for the therapy of these diseases.We have conceptualized a strategy,named dephosphorylation-targeting chimeras(DEPTACs),for specifically hijacking phosphatases to tau to debilitate its hyperphosphorylation.Here,we conducted the step-by-step optimization of each constituent motif to generate DEPTACs with reasonable effectiveness in facilitating the dephosphorylation and subsequent clearance of pathological tau.Specifically,for one of the selected chimeras,D16,we demonstrated its significant efficiency in rescuing the neurodegeneration caused by neurotoxic K18-tau seeds in vitro.Moreover,intravenous administration of D16 also alleviated tau pathologies in the brain and improved memory deficits in AD mice.These results suggested DEPTACs as targeted modulators of tau phosphorylation,which hold therapeutic potential for AD and other tauopathies. 展开更多
关键词 TAU Dephosphorylation-targeting chimeras Therapeutic potential TAUOPATHY
原文传递
Corrosion and Scaling Threat in Upstream Oil Operation
11
作者 Nasir Ullattumpoyil Talal M. Al-Ghamdi Nasser R. Al-Hajri 《World Journal of Engineering and Technology》 2024年第2期426-437,共12页
Corrosiveness or scaling is an inherent threat to oil operations. The primary cause for this threat is the presence of water having complex geochemical matrix. Unanticipated water production, particularly if it contai... Corrosiveness or scaling is an inherent threat to oil operations. The primary cause for this threat is the presence of water having complex geochemical matrix. Unanticipated water production, particularly if it contains unwanted impurities, can significantly impact hydrocarbon production. The current paper discusses the degree of threat posed to oil operation facilities based on the water characteristics. Methodology involved the collection and analysis of water samples from major sources in oil industry such as groundwater, wellheads and seawater. The parameters tested include geochemical, microbiological and pollutants. The lab data was used to develop scaling and corrosion prediction indices such as Langelier Saturation Index (LSI), Ryznar Stability Index (RSI) and Puckorius Scaling Index (PSI). The study indicated varying water chemistry for different sources. Mixing of those waters may lead to ionic saturation and scaling in different facilities. Presence of the SRB and GAB in some water sources also posed threat to water system by forming fouling and corrosion. Seawater used for offshore oilfields water injection to maintain reservoir pressure and improve oil recovery showed scaling tendency, whereas under different reservoir pressure, it can cause corrosion. Some of the samples also had corrosion residuals such as iron, which indicated active corrosion. Current study showed higher alkalinity with high sulfate for one groundwater sample with presence of active corrosion residuals such as dissolved iron and manganese. The study showed positive value for LSI which indicated supersaturation of the water samples with respect to calcium carbonate (CaCO<sub>3</sub>) and scale forming. Similarly, for RSI and PSI, the value was below six which confirmed the scaling potential for all the samples. Even though the index value was pointing towards scaling potential, the geochemistry, microbiology and presence of other impurities indicated corrosion threat to the oil and gas industrial facilities. The study concluded th 展开更多
关键词 Formation Water Petroleum Reservoirs GROUNDWATER Saturation Indices Corrosiveness
下载PDF
Development of a PARCS/Serpent model for neutronics analysis of the Dalat nuclear research reactor 被引量:5
12
作者 Viet-Phu Tran Kien-Cuong Nguyen +4 位作者 Donny Hartanto Hoai-Nam Tran Vinh Thanh Tran Van-Khanh Hoang Pham Nhu Viet Ha 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2021年第2期32-44,共13页
Cross-sectional homogenization for full-core calculations of small and complex reactor configurations,such as research reactors,has been recently recognized as an interesting and challenging topic.This paper presents ... Cross-sectional homogenization for full-core calculations of small and complex reactor configurations,such as research reactors,has been recently recognized as an interesting and challenging topic.This paper presents the development of a PARCS/Serpent model for the neutronics analysis of a research reactor type TRIGA Mark-II loaded with Russian VVR-M2 fuel(known as the Dalat Nuclear Research Reactor or DNRR).The full-scale DNRR model and a supercell model for a shim/safety rod and its surrounding fuel bundles with the Monte Carlo code Serpent 2 were proposed to generate homogenized fewgroup cross sections for full-core diffusion calculations with PARCS.The full-scale DNRR model with Serpent 2 was also utilized as a reference to verify the PARCS/Serpent calculations.Comparison of the effective neutron multiplication factors,radial and axial core power distributions,and control rod worths showed a generally good agreement between PARCS and Serpent 2.In addition,the discrepancies between the PARCS and Serpent 2 results are also discussed.Consequently,the results indicate the applicability of the PARCS/Serpent model for further steady state and transient analyses of the DNRR. 展开更多
关键词 PARCS Serpent 2 Group constant DNRR
下载PDF
Effect of traveling-wave magnetic field on dendrite growth of high-strength steel slab: Industrial trials and numerical simulation 被引量:1
13
作者 Cheng Yao Min Wang +5 位作者 Youjin Ni Dazhi Wang Haibo Zhang Lidong Xing Jian Gong Yanping Bao 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2023年第9期1716-1728,共13页
The dendrite growth behavior of high-strength steel during slab continuous casting with a traveling-wave magnetic field was studied in this paper. The morphology of the solidification structure and composition distrib... The dendrite growth behavior of high-strength steel during slab continuous casting with a traveling-wave magnetic field was studied in this paper. The morphology of the solidification structure and composition distribution were analyzed. Results showed that the columnar crystals could deflect and break when the traveling-wave magnetic field had low current intensity. With the increase in current intensity, the secondary dendrite arm spacing and solute permeability decreased, and the columnar crystal transformed into an equiaxed crystal. The electromagnetic force caused by the traveling-wave magnetic field changed the temperature gradient and velocity magnitude and promoted the breaking and fusing of dendrites. Dendrite compactness and composition uniformity were arranged in descending order as follows:columnar-toequiaxed transition (high current intensity), columnar crystal zone (low current intensity), columnar-to-equiaxed transition (low current intensity), and equiaxed crystal zone (high current intensity). Verified numerical simulation results combined with the boundary layer theory of solidification front and dendrite breaking–fusing model revealed the dendrite deflection mechanism and growth process. When thermal stress is not considered, and no narrow segment can be found in the dendrite, the velocity magnitude on the solidification front of liquid steel can reach up to 0.041 m/s before the dendrites break. 展开更多
关键词 high-strength steel traveling-wave magnetic field dendrite growth numerical simulation
下载PDF
Analysis of coal pillar stability(ACPS): A new generation of pillar design software 被引量:5
14
作者 Christopher Mark Zach Agioutantis 《International Journal of Mining Science and Technology》 EI CSCD 2019年第1期87-91,共5页
Thirty years ago, the analysis of longwall pillar stability(ALPS) inaugurated a new era in coal pillar design.ALPS was the first empirical pillar design technique to consider the abutment loads that arise from full ex... Thirty years ago, the analysis of longwall pillar stability(ALPS) inaugurated a new era in coal pillar design.ALPS was the first empirical pillar design technique to consider the abutment loads that arise from full extraction, and the first to be calibrated using an extensive database of longwall mining case histories.ALPS was followed by the analysis of retreat mining stability(ARMPS) and the analysis of multiple seam stability(AMSS). These methods incorporated other innovations, including the coal mine roof rating(CMRR), the Mark-Bieniawski pillar strength formula, and the pressure arch loading model. They also built upon ever larger case history databases and employed more sophisticated statistical methods.Today, these empirical methods are used in nearly every underground coal mine in the US. However,the piecemeal manner in which these methods have evolved resulted in some weaknesses. For example,in certain situations, it may not be obvious which program is the best to use. Other times the results from the different programs are not entirely consistent with each other. The programs have also not been updated for several years, and some changes were necessary to keep pace with new developments in mining practice. The analysis of coal pillar stability(ACPS) now integrates all three of the older software packages into a single pillar design framework. ACPS also incorporates the latest research findings in the field of pillar design, including an expanded multiple seam case history data base and a new method to evaluate room and pillar panels containing multiple rows of pillars left in place during pillar recovery.ACPS also includes updated guidance and warnings for users and features upgraded help files and graphics. 展开更多
关键词 PILLAR design GROUND control STABILITY Empirical METHODS
下载PDF
Influence of non-iso-velocity casting on flow-field index of a 41-ton six-strand Tundish by physical and numerical modeling
15
作者 Hang-hang Zhu Min Wang +3 位作者 Cheng Yao Zhong-liang Wang Xiao-liang Wang Yan-ping Bao 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2023年第1期51-63,共13页
The flow-field index in a 41-ton six-strand tundish is considered through adjusting the ratio of the casting velocity between the strands to eliminate the negative impact of iso-velocity casting in multi-strand tundis... The flow-field index in a 41-ton six-strand tundish is considered through adjusting the ratio of the casting velocity between the strands to eliminate the negative impact of iso-velocity casting in multi-strand tundish on the consistency of each strand due to the large ratio of length to width with narrow shape structure,resulting in poor consistency of each strand.In particular,the response time of strand-1 and strand-6 is relatively long,which affects the uniformity of the temperature field and flow field of the entire tundish.On the basis of verifying that the error between the numerical simulations and hydraulic experiments is less than 6%,six cases with the casting velocity ratio changing from 0.8 to 1.3(with an interval of 0.1)are considered by calculation of numerical models.It is concluded that the consistency of each flow can be obviously improved by increasing the casting velocity ratio between side-strand and middle-strand.With increasing the casting velocity ratio,the flow field in the tundish became much active,the temperature field presented well uniformity,and the tracer concentration distribution in local dead zones was improved. 展开更多
关键词 Six-strand tundish Non-iso-velocity casting Casting velocity ratio Residence time distribution curve Tracer concentration
原文传递
Inoculation of Chlorella and Food Waste Improves the Physio-Morphological Features of Red Pepper by Regulating Activating Antioxidant Defense System
16
作者 Sang-Mo Kang Shifa Shaffique +9 位作者 Muhammad Imran Su-Mi Jeon Shabir Hussain Wani Muhammad Aaqil Khan Peter Odongkara Eun-Hae Kwon Yosep Kang Joon-Ik Son Won-Chan Kim In-Jung Lee 《Phyton-International Journal of Experimental Botany》 SCIE 2023年第9期2699-2711,共13页
Food waste is recognized as a valuable source for potential agricultural applications to supply organic matter and nutrients to arable soil.However,the information on the combined application of food waste and the pla... Food waste is recognized as a valuable source for potential agricultural applications to supply organic matter and nutrients to arable soil.However,the information on the combined application of food waste and the plant growth-promoting bacterial strain,Chlorella,related to plant metabolic features and sodium chloride content in arable soil is limited.The present study was conducted to investigate the exogenous application of food waste along with Chlorella,which improved the physio-morphological features of red pepper.Our results revealed that this combination enhanced the organic matter in the soil,ultimately improving the fertility rate of the soil,and the physio-morphological features,such as chlorophyll a content(24.5±0.7),root(7.8±0.7)cm and shoot length(12.1±0.7)cm,fresh weight(2.1±0.05)g,dry weight(0.19±0.05)g,mineral contents,and hormonal concentration(ABA by up to 2 folds).The combined treatment also minimized free radicals via the activation of the intrinsic antioxidant series cascade and electrolyte leakage.Our findings showed that adding Chlorella and food wastes improved growth characteristics and can be used as a green bio-fertilizer for sustainable agriculture. 展开更多
关键词 Food waste CHLORELLA HORMONE ANTIOXIDANT
下载PDF
Effect of electromagnetic stirrer centered outside the mold on steel flow field of bloom continuous casting
17
作者 Li-dong Xing Yan-ping Bao +1 位作者 Min Wang Yi-hong Li 《China Foundry》 SCIE CAS CSCD 2023年第5期461-468,共8页
Mold electromagnetic stirring technology for optimizing the flow of molten steel is now widely used in the continuous casting production process of high-quality steels.However,studies on the case that the center of th... Mold electromagnetic stirring technology for optimizing the flow of molten steel is now widely used in the continuous casting production process of high-quality steels.However,studies on the case that the center of the electromagnetic stirrer is located outside the mold have not been reported.Herein,the effect of the electromagnetic stirrer centered outside the mold on the steel flow field was studied in detail by means of numerical simulations.A Gauss meter was used to measure the magnetic induction intensity at different positions,currents,and frequencies.The test results were compared with the simulation results of electromagnetic stirring to calibrate and verify the accuracy of the electromagnetic model.Then,electromagnetic force was introduced into the flow field model as a source term to study its effect on the flow field under anomalous conditions.The results show that when the center of the electromagnetic stirrer is located outside the mold,the magnetic field strength is about twice as strong as that located inside the mold.This also leads to an increase in the flow velocity near the electromagnetic stirrer.As a result,the optimal electromagnetic stirring parameters(200 A,2.5 Hz)were specified when the center of the electromagnetic stirrer is located outside the mold. 展开更多
关键词 numerical modeling electromagnetic stirring fluid flow outside the mold BLOOM
下载PDF
A Three-Dimensional Model for the Formation Pressure in Wellbores under Uncertainty
18
作者 Jiawei Zhang Qing Wang +4 位作者 Hongchun Huang Haige Wang Guodong Ji Meng Cui Hongyuan Zhang 《Fluid Dynamics & Materials Processing》 EI 2023年第9期2305-2314,共10页
Formation pressure is the key parameter for the analysis of wellbore safety.With increasing drilling depth,how-ever,the behavior of this variable becomes increasingly complex.In this work,a 3D model of the formation p... Formation pressure is the key parameter for the analysis of wellbore safety.With increasing drilling depth,how-ever,the behavior of this variable becomes increasingly complex.In this work,a 3D model of the formation pres-sure under uncertainty is presented.Moreover a relevant algorithm is elaborated.First,the logging data of regional key drilling wells are collected and a one-dimensional formation pressure profile along the well depth is determined.Then,a 3D model of regional formation pressure of the hierarchical group layer is defined by using the Kriging interpolation algorithm relying on a support vector machine(SVM)and the formation pressure of the drilled wells.To validate the method,the formation pressure of one pre-drilled well is compared with the well logging results.The comparison reveals that the maximum relative error is less than 4.5%.The software based on this model is complemented by a computer visualization technology,which provides a relevant tool for under-standing and analyzing the 3D formation pressure.The outcomes of this study are intended to support the char-acterization of areas with missing or poor 3D seismic data and provide more accurate information for the analysis of wellbore integrity. 展开更多
关键词 Formation pressure with uncertainty well integrity kriging interpolation 3D pressure body
下载PDF
Produced Water Geochemistry from an Upstream Oil Operation
19
作者 Nasir Ullattumpoyil 《Journal of Geoscience and Environment Protection》 2023年第6期155-168,共14页
Oil and gas industries generate a significant amount of water during the production. The composition of this water varies with the geologic age, depth, and geochemistry of the region along with the chemicals added dur... Oil and gas industries generate a significant amount of water during the production. The composition of this water varies with the geologic age, depth, and geochemistry of the region along with the chemicals added during the process. Geochemistry of formation water is used for aquifer identification, pollution problems, water compatibility studies, corrosion monitoring, water-quality control, water flooding, exploration, and to diagnose wellbore integrity issues. The current study investigates the spatial and temporal variation of produced water geochemistry from one of the largest conventional oil field, Ghawar field, Saudi Arabia. Produced water from different wellheads were collected and analyzed for different geochemical characteristics. Sixteen wells from ABQQ, nineteen wells from ANDR and twenty wells from SDGM area were selected for the current study. Sampling and analysis were performed as per the standard procedures. Results indicated that the pH of the sample varied from 6.0 to 7.4, and Electrical conductivity from 94200 to 102690 μS/cm. The spatial variation of major cations and anions were also recorded and represented by graphical plots. Metal analysis indicated the highest concentration for boron, which is 20.5 mg/L at ABQQ area, whereas all other metals are very low in concentration. Temporal variation of a single well at SDGM area indicated drastic change in the ionic concentration, whereas the geochemistry remains same as indicated by Tickler plot. The water type of the respective area was studied by tickler plots, which indicated same source of formation water in different wells at ABQQ, ANDR and SDGM areas. The ionic concentration is also used to predict corrosion and scaling issues. By Langelier Saturation Index (LSI) and Ryznar Stability Index (RSI), the sample from all the wells showed higher scaling potential. The study concludes that the water type in different areas under Ghawar field remains same regardless of drastic changes in the ionic concentration, which can be used to diagnose wel 展开更多
关键词 Formation Water Petroleum Reservoirs GROUNDWATER Ghawar Field Tickler Plot
下载PDF
Effect of Land Uses on Soil Erodibility in the Njala Area of Southern Sierra Leone
20
作者 Denis Magnus Ken Amara Ibrahim Benya +8 位作者 Sheku Alfred Kanu Daniel Hindogbe Saidu Raymond Morie Musa Osman Sidie Vonu Fayia Brima Joseph Christian Adamu Mboma Michael Jusu Foday Turay Abdulai Kamara 《Open Journal of Soil Science》 CAS 2022年第10期475-489,共15页
Soil loss through erosion continues to pose serious challenges to increasing the smallholder agricultural productivity in Sierra Leone. While emphasis on sustainable land use practices continue to gain attention among... Soil loss through erosion continues to pose serious challenges to increasing the smallholder agricultural productivity in Sierra Leone. While emphasis on sustainable land use practices continue to gain attention among land users, however, the rate of adoption among smallholder farmers is still very low and hence, in most part of the country soil fertility has been declining at alarming rates. In the Njala area, studies have shown that soil loss ranges from moderate to high. Though soil erosion has been identified as a major soil fertility declining factor, however, the effect of land use practices on the inherent resistance of soil materials to erosion is lacking. This study was therefore conducted to assess the effect of land uses on soil erodibility. The results showed that the soils are coarse sandy loam with high sand content. The dispersion ratios and erosion indices of soils under cassava, plantain, maize and guava were above the minimum thresholds of 15.0 and 10.0 respectively, thus indicating that these soils are highly erodible compared to soils under fallow and sweet potato which have dispersion ratios and erosion indices below the minimum thresholds. Clay content was inversely proportional to and significantly correlated with dispersion ratio and erosion index while the correlations between silt + clay, dispersion ration and erosion index, and silt, silt + clay and dispersion ratio were negative and non-significant. Considering the coarse nature of soils, landscape features and high erodibility indices, these soils would need special soil and water conservation practices to counter further degradation. These may include following, agroforestry, silvi-pasture, controlled and rotational grazing. In addition, awareness of sense of self-responsibility and forest policies and regulations are needed. 展开更多
关键词 Soil Erosion Land Use Agriculture SMALLHOLDERS Soil Texture ERODIBILITY Soil Fertility DEFORESTATION
下载PDF
上一页 1 2 4 下一页 到第
使用帮助 返回顶部