检索结果-南通市图书馆

A fuzzy extension for SHOIQ based on comparisons between degrees of membership

在线全文

学校读者我要写书评

暂无评论

science China(Information sciences) 2013年第8期56卷 166-176页

作者： KANG DaZhou XU BaoWen LI YanHui Department of Computing science and technology Nanjing University Jiangsu institute of Software quality

The current fuzzy extensions for description logics do not support representing and reasoning with complex fuzzy knowledge about comparisons between degrees of membership,which is very useful in practical *** investigate a novel approach of extending the description logic SHOIQ to SHOIQ FC by annotating concepts and roles based on comparison *** FC provides the ability to represent complex fuzzy knowledge,in addition to the expressive power of the fuzzy description logic *** main contributions are a decidability proof for the consistency problem of SHOIQ FC knowledge bases,as well as its tableau-based reasoning algorithm.

关键词： fuzzy description logic knowledge representation reasoning algorithm

Effect of Tempcore Processing on Mitigating Problems of Tramp Elements in Low C Steel Produced from Recycled Material

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2015年第7期22卷 582-589页

作者： Ahmed RAMADAN A.Y.SHASH I.S.EL-MAHALLAWI D.SENK Taha MATTAR quality Department Faculty of Engineering Cairo university institute of Ferrous Metallurgy RWTH-Aachen University Central Metallurgical Research and development institute

The effect of tramp elements in the steel was intensively studied. It was found that the solubility of tramp elements decreased as the temperature decreased under normal cooling conditions. The tramp elements （Cu, Pb, and Sn） diffused toward the grain boundaries, and intermetallic compounds or rich phases which have low melting points were formed, causing reduction in ductility and failure during the bending test. Rebars with Cu content which were left to air cooling after the last step showed drop in elongation, up to 32 %. On contrast, the samples with high per- centage of tramp elements （Cu, Pb, and Sn） in the billet, which were rolled and subjected to Tempcore process, did not show drop in elongation or failure in bending test （especially for rebar with diameter less than 32 mm）; however, copper must be less than 0.35 mass% to prevent the precipitation of Cu-rich zones of critical size in 32 mm. When quench- ing was applied, the tramp elements remained in the interstitial supersaturated solid solution positions inside the grains and would not have the chance to diffuse and form precipitates, hindering the copper precipitates from reac- hing the critical size necessary for impairing the properties. This would hinder the occurrence of the harmful effect of the tramp elements on the elongation or the hot shortness after rolling.

关键词： recycled steel hot shortness crack susceptibility Tempcore process tramp element residual melt

Universal D'Alembert Principle and Equation of Motion for Any Order Nonholonomic Systems in Derivative Space

在线全文

学校读者我要写书评

暂无评论

Chinese science Bulletin 1993年第20期38卷 1708-1711页

作者：梁天麟 kunming institute of technology Kunming 650093 PRC

The important development has been made in studying nonholonomic systems, but many theoretical and practical problems still need to be solved. In order to suit development of analytical mechanism itself and the need of wide-ranging application to other subjects and modem engineering technology, its research method, the mathematical models got with this method and final forms of differential equations of motion still need to be further studied. This article gives up the traditional method which was used to study the nonholonomic systems in 3N dimensional Euclid space "E3N".

关键词： mth-order derivative space"E_(3N)"and corresponding generalized coordinates mth-order nonholonomic system correspondent kinetic energy

High mechanical strengths and ductility of stainless steel 304L fabricated using selective laser melting

在线全文

学校读者我要写书评

暂无评论

Journal of Materials science & technology 2019年第2期35卷 388-394页

作者： Q.B.Nguyen Z.Zhu F.L.Ng B.W.Chua S.M.L.Nai J.Wei Singapore institute of Manufacturing technology institute of Research and development Duy Tan University

Achieving not only high mechanical strengths but also high ductility is recently established using an additive manufacturing technique called selective laser melting. In the present study, stainless steel 304 L fully dense samples were successfully printed using the 3 D systems – ProX 300 printing machine. The ductility and tensile yield strength were almost two and three times higher compared to those of ASTM cast's alloy. Honey comb like nano-cellular structure with different orientation was observed in the fine grains(~4μm) due to fast cooling rate. In addition, the formation of martensite phase in random grains is also a contributor to the strengths. Furthermore, negative residual stresses in the build and horizontal directions were detected and assisted further increase in the tensile strength. Fractography revealed the ductile feature of plastic deformation and the crack openings at unmelted particles or pores.

关键词： Additive manufacturing Stainless steel Powder Selective laser melting

Ionization Potential Depression Model for Warm/Hot and Dense Plasmas

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2024年第8期41卷 45-57页

作者： Chensheng Wu Fuyang Zhou Jun Yan Xiang Gao Yong Wu Chunhua Zeng Jianguo Wang institute of Applied Physics and Computational Mathematics Beijing 100088China Faculty of science Kunming University of Science and TechnologyKunming 650500China

For warm/hot and dense plasmas(WDPs),ionization potential depression(IPD)plays a crucial role in determining its ionization balance and understanding the resultant microscopic plasma properties.A sophisticated and unified IPD model is necessary to resolve those existing discrepancies between theoretical and experimental ***,the applicability of those widely used IPD models nowadays is limited,especially for the nonlocal thermodynamic equilibrium(non-LTE)dense plasma produced by short-pulse *** this work,we propose an IPD model that considers inelastic atomic processes,in which three-body recombination and collision ionization processes are found to play a crucial role in determining the electron distribution and IPD for a *** IPD model is validated by reproducing latest experimental results of Al plasmas with a wide-range condition of 70 eV–700 eV temperature and 0.2–3 times solid density,as well as a typical non-LTE system of hollow Al *** is demonstrated that the present IPD model has a significant temperature dependence due to the consideration of the inelastic collision *** a lower computational cost and wider application range of plasma conditions,the proposed model is expected to provide a promising tool to study the ionization balance and the atomic processes,as well as the related radiation and particle transports properties of the WDP.

关键词： properties. collision determining

A novel method for improving cerussite sulfidization

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2016年第6期23卷 609-617页

作者： Qi-cheng Feng Shu-ming Wen Wen-juan Zhao Qin-bo Cao Chao Lü State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization Kunming University of Science and Technology kunming Metallurgical Research institute

Evaluation of flotation behavior, solution measurements, and surface analyses were performed to investigate the effects of chloride ion addition on the sulfidization of cerussite in this study. Micro-flotation tests indicate that the addition of chloride ions prior to sulfidization can significantly increase the flotation recovery of cerussite, which is attributed to the formation of more lead sulfide species on the mineral surface. Solution measurement results suggest that the addition of chloride ions prior to sulfidization induces the transformation of more sulfide ions from pulp solution onto the mineral surface by the formation of more lead sulfide species. X-ray diffraction and energy-dispersive spectroscopy indicate that more lead sulfide species form on the mineral surface when chloride ions are added prior to sulfidization. These results demonstrate that the addition of chloride ions prior to sulfidization can significantly improve the sulfidization of cerussite, thereby enhancing the flotation performance.

关键词： cerussite sulfidization chloride surface analysis

Status and distribution changes of the endangered Green Peafowl (Pavo muticus) in China over the past three decades (1990s-2017)

在线全文

学校读者我要写书评

暂无评论

Avian Research 2018年第2期9卷 102-110页

作者： Dejun Kong Fei Wu Pengfei Shan Jianyun Gao Dao Yan Weixiong Luo Xiaojun Yang Key Laboratory of Special Biological Resource development and Utilization of Universities in Yunnan Province Kunming University Kunming 650214 China Bird Group Kunming Institute of Zoology Chinese Academy of Sciences Kunming 650223 China kunming Survey and Design institute of State Forestry Administration Kunming 650216 China

Background： Understanding the changes in population dynamics, including demographics, distribution and threats is essential for species status *** endangered Green Peafowl （Povo muticus） has experienced sharp population declines and d stribution range diminishing both in China and Southeast Asia. Field population surveys have not been conducted in China since the 1990s, which hindered conservation planning and ***： With interview and line transects methods, we figured out the population and distribution changes of Green Peafowl across its historical ranges over the past three decades in China during ***： The Green Peafowl once habituated in 54 counties in China. Nearly 60% of the distribution counties were lost in the past three decades, with the left 22 counties distributed in central, southern and western Yunnan, SW China. Population decrease detected in all distribution areas except for Shuangbai and Xinping county where more than 60% of the total population is located. Only about 30% of the former bird population were recorded with the same interviewing method as 20 years *** birds, 1 carcass, 6 calls and 12 footprints were detected along the 865 km line transects, indicating extremely low encounter rate of Green Peafowl in field. Sharp decreases in flock sizes were also detected, from 8-20 birds per flock in the 1990s to 3-5 birds at present. Poaching and habitat conversion are two widespread and long-lasting threats, while poison tion affect regional population＇s survival. Large flocks of 18 ng caused mortality in the past and hydropower construc -27 birds were discovered in the field, which increases our confidence of population recovery of this endangered pheasant in ***： Only interviewed bird number and counts based on line transects were presented in this study, without further population estimation due to limitation of the data sets. Although the actual population of this cryptic bird must be

关键词： Green Peafowl Population decline Range concentration Endangered species Southwestern China

Progress in Microwave technology Applied to the Recovery of Precious Metals from the Secondary Resources

在线全文

学校读者我要写书评

暂无评论

贵金属 2012年第A1期33卷 33-39页

作者： WANG Shixing PENG Jinhui CHEN Anran ZHANG Zebiao Faculty of Metallurgical and Energy Engineering Kunming University of Science and TechnologyKunming 650093China Ytmnan institute of Supervision and Inspection for Product quality Kunming 650000China

The recovery of precious metals from the secondary resources by microwave technology has emerged in recent years. Microwave technology as a new method for the recovery of precious metals has shown significant advantages against the conventional recovery procedures. This paper presents a review of the advances in microwave technology applied to the recovery of precious metals from the secondary resources. Many different applications are considered, including microwave-assisted leaching, microwave augmented ashing and microwave pyrolysis. In general, microwave enhanced recovery of precious metals from secondary resources.

关键词： microwave recovery precious metals secondary sources

Poly(lactic acid)-aspirin microspheres prepared via the traditional and improved solvent evaporation methods and its application performances

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2023年第8期60卷 194-204页

作者： Xiaolin Pan Mengyuan Gao Yun Wang Yanping He Tian Si Yanlin Sun School of Chemical Engineering Kunming University of Science and TechnologyKunming 650504China

Drug-loaded microspheres are significant for the development of modern pharmaceutical products. It is well known that the taken of aspirin for long-term increases the risk of serious gastrointestinal complications, therefore a controllable delivery of aspirin is of importance to lighten those side effects. In this work, poly(lactic acid)(PLA) was chosen as the carrier to prepare PLA-aspirin microspheres by using the traditional and the improved solvent evaporation methods. It was found that no matter which experimental condition was, the encapsulation efficiency of aspirin was higher by using the improved method than that of the traditional method. Specifically, when the concentration of polyvinyl alcohol = 1%(mass),the polymer concentration = 1:20, the oil/water rate = 1:2.5, PLA-aspirin microspheres were obtained via the improved method with a high yield of 82.83%(mass) and an encapsulation efficiency of 44.09%. PLAaspirin microspheres were then prepared continuously using the improved method, which further enhanced the encapsulation efficiency to 54.56%. Approximate 85% aspirin released from microspheres within 7 days. Obvious degradation which was represented by reduction on hardness was observed by soaking microspheres in PBS for 60 days. This work is of interest because it provides a continuous route to prepare PLA-aspirin microspheres continuously with a high drug encapsulation efficiency.

关键词： Aspirin Degradation Foam-transfer Microspheres Poly(lactic acid) Slow-release