检索结果-南通市图书馆

Aging Behaviors of W-Ni-Fe Ternary Alloys with High Ni-to-Fe Ratios

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 Materials Science & Technology 2003年第6期19卷 631-633页

作者： Ronghua li, Jihua HUANG, Sheng YIN and Jun ZHAOSchool of Materials Science & Engineering, university of Science & Technology {2., beijing 100083, China Sch. of Mat. Sci. and Eng. Univ. of Sci. and Technol. Beijing Beijing 100083 China

The hardness variation of two kinds of alloys with 36 wt pct W content and 7/3, 9/1 Ni-to-Fe ratios during strain aging at 800℃ was studied. The microstructures of the aged alloys were analyzed by X-ray diffraction and TEM. The results show that the strain aging hardness of W-Ni-Fe ternary alloy with 7/3 Ni-to-Fe ratio decreases monotonically with the increase of aging time. Under the same conditions, the hardness of 9/1 Ni-to-Fe ratio alloy decreases in the initial aging stage, but then increases as aging process goes on. X ray diffraction and TEM analysis show that there is not any precipitation depositing from the alloy with 7/3 Ni-to-Fe ratio during aging. The monotonic decrease in hardness of this alloy during aging process results from the recovery, recrystallization and solid solubility declining. In the alloy of 9/1 Ni-to-Fe ratio, the fine β phase precipitates dispersively during aging which hardens the alloy. The two different kinds of mechanisms (the softening one and the hardening one) decide the hardness variation of the alloy with 9/1 Ni-to-Fe ratio mentioned above.

关键词： W-Ni-Fe Tungsten heavy alloys Ni-to-Fe ratio Strain aging β phase

Effects of Na/K ratio on the phase structure and electrical properties of Na_xK_(1-x)NbO_3 lead-free piezoelectric ceramics

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2010年第2期29卷 220-225页

作者： ZHANG Qian, ZHANG Boping, li Haitao, and SHANG Pengpeng School of Materials Science and Engineering, university of Science and Technology {2., beijing 100083, China School of Materials Science and Engineering University of Science and Technology Beijing

Lead-free piezoelectric NaxK1-xNbO3（x = 0.3-0.8）（NKN） ceramics were fabricated by normal sintering at 1060°C for 2.*** and electrical properties of the ceramics were investigated with a special emphasis on the influence of Na *** grain size of the produced dense ceramic was decreased by increasing Na content.A discontinuous change in the space distance was found at the composition close to Na0.7K0.3NbO3 ceramic, which indicates the presence of a transitional composition between two different orthorhombic phases, which is similar to the behavior of morphotropic phase boundary（MPB） in NaxK1-xNbO3 *** MPB-like behavior contributes to the enhanced piezoelectric coefficient d33 of 12. pC/N, planar-mode electromechanical coupling coefficient kP of 2..6%, and dielectric constant εr of 703, respectively for the Na0.7K0.3NbO3 *** temperature TC and the transitional temperature TO-T from orthorhombic to tetragonal phase are observed at around 42.°C and 2.0°C, respectively.

关键词： lead-free piezoelectric ceramics NKN sintering morphotropic phase boundary(MPB)

Effect of SPM Scanning Range on the Micromorphology Parameters

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 1998年第1期12卷 36-38页

作者： libing liao Suozai li (School of materials Science and engineering, China university of Geosciences, beijing 100083, China) School of Materials Science and Engineering China University of Geosciences Beijing 100083 China

The surface of a compact disk is analyzed by using SPM and the quantitative micromorphology analysissoftware SPMIAS developed by the author. Images at the same position but with different scanning ranges areobtained under the same experimental conditions. Micromorphology parameters are calculated and compared, andthe relationship between the changing of the scanning range and the changing of micromorphology parameters issummarized.

关键词： Scanning Probe Microscope(SPM) micromorphology micromorphology parameters

Development of SPM Quantitative Micromorphology Analysis Software

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 1999年第2期13卷 136-138页

作者： Suozai li libing liao(School of Materials Science and Engineering, China university of Geosciences, beijing 100083, China) School of Materials Science and Engineering China University of Geosciences Beijing 100083 China

Scanning Probe Microscope (SPM) has great advantages in quantitative micromorphology analysis because of its conveniencein obtaining micromorphology information of materials on nanometer or atomic scale under control of a computer. Based on an established SPM quantitative micromorphology analysis model, an SPM image analysis software Which can calculate both two- and three-dimensional micromorphology parameters is developed.

关键词： SPM quantitative micromorphology analysis software

Influence of Heat Treatment on Cr18Mn18 High Nitrogen Steel Precipitating Behavior and Microstructure

在线全文

学校读者我要写书评

暂无评论

稀有金属材料与工程 2011年第S3期40卷 111-113页

作者： li Jingyuan, Feng Shufei, Fang Fei, Chen Yulai university of Science and Technology {2., beijing 100083,China Univ Sci & Technol beijing Beijing 100083 Peoples R China

The grain size and precipitate amount which are affected by heat treatment have significant impact on the properties of high nitrogen austenitic stainless steel. In this study, Cr18Mn18 high nitrogen steel sheet is employed to investigate the effects of precipitate on austenitic grain size. It can be seen that the lamella precipitates which are rich in nitrogen and chromium nucleate in the austenite grain boundary and grow inward into grain when aged at 800 ℃ through electron probe micro-analyzer. The transmission electron microscopy results demonstrate that the precipitate is Cr2. and its morphology are detected as ellipsoid-like with major axis of 100-300 nm and minor axis of 50-100 nm roughly. The experiment show that coarsen of the austenite grain is quite critical at 1000-1100 ℃. However, the samples which pre-precipitated at 800 ℃ for 2.0 min to obtain the most nitride precipitate exhibits much smaller grain size than the as-rolled samples after solid solution treated at 1000, 1050 and 1100 ℃ for 2.0 min. The results show that the nitride precipitates in the grain boundary can effectively pin the austenite grain boundary and inhibit the grain growth.

关键词： high nitrogen austenitic stainless steel heat treatment precipitate microstructure

Digital close-range photogrammetric application to small-scale physical simulation experiment

在线全文

学校读者我要写书评

暂无评论

中国有色金属学会会刊：英文版 2011年第S3期21卷 681-685页

作者： li Chun-yi1, CUI Xi-min2. YU Yi-ju3 1. School of Surveying and Landing Information Engineering, Henan Polytechnic university, Jiaozuo 454003, Ch{2. 2. College of Geoscience and Surveying Engineering, Ch{2. university of Mining and Technology, beijing 100083, Ch{2. 3. Surveying and Mapping Press, beijing 100045, Ch{2. [a] School of Surveying and Landing Information Engineering Henan Polytechnic University Jiaozuo 454003 China [b] College of Geoscience and Surveying Engineering China University of Mining and Technology Beijing 100083 China [c] Surveying and Mapping Press Beijing 100045 China

In order to research the possibility of digital close-range photogrammetric surveying in small scale physical simulation experiment, physical model coinciding with engineering practice was constructed based on similar theory. The datum processing method and surveying precision of digital close-range photogrammetric were analyzed. And the function relationship between overburden subsidence factor qr and the ratio z/H of stratum horizon z and mining depth H was researched. The results show that surveying points position mean error along horizontal direction is ±0.131 mm and vertical direction is ±0.192.mm. Therefore, multi-taking station cross direction digital close-range photogrammetric can completely satisfy the precision need of physical simulation experiment. And the empirical formula can be utilized to represent evolution law of stratum subsidence factor.

关键词： close-range photogrammetric physical simulation light-rays adjustment surveying precision subsidence factor

A Fuzzy Model for Evaluating the Mining Condition of Underground Coal Mines

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 1999年第4期13卷 242-245页

作者： Zhongrue li Shaowen Zhang(Resources Engineering School, university of Science and Technology {2., Beding 100083, China) Resources Engineering School University of Science and Technology Beijing Beijing 100083 China

In mining industries no mines are identical and each mine has its own unique set of mining conditions. In order to study thecondition of mines for efficiency, safety and economy reasons, a fuzzy model is presented based on fuzzy evaluation. Relevant data fromfive mines were collected and the model was used to evaluate the mining condition of these mines. The evaluation results are in conformity with the real situation.

关键词： fuzzy model mining condition coal mine

Incised valley filling deposits:an important pathway system for long-distance hydrocarbon migration—a case study of the Fulaerji Oilfield in the Songliao Basin

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2009年第3期6卷 230-238页

作者： Xin Renchen liu Hao li Guifan School of Ocean Sciences China University of Geosciences Beijing 100083 China School of the Earth Sciences and Resources China University of Geosciences Beijing 100083 China

In this paper, incised valley filling deposits, which formed an important pathway system for long-distance hydrocarbon migration, are discussed in detail based on core and logging data. The sequence SQy2. of the Cretaceous Yaojia Formation is the main hydrocarbon-bearing layer in the Fulaerji Oilfield. The hydrocarbon source of the oilfield is the Qijia-Gulong Sag which is about 80 km away from the Fulaerji Oilfield. The transport layer of long-distance hydrocarbon migration is the overlapped sandstone complex which fills the incised valley. The incised valley developed during the depositional period from the late Qingshankou Formation to the early Yaojia Formation of Cretaceous （SQqna-SQy0 was about 70 km long and 2. km wide, and extended in the NW-SE direction. The overlapped filling of the incised valley mainly occurred in the expanding system tract of the third-order sequence SQy2. （ESTy2.）. Towards the basin, incised valley filling deposits overlapped on the delta developed in the early period, and towards the basin margin, incised valley filling deposits were covered by the shore-shallow lacustrine sandy beach bar developed in the maximum flooding period. All of the delta, the incised valley filling and the shore-shallow sandy beach bar are sandstone-rich, and have high porosity and permeability, and can form an effective hydrocarbon migration and accumulation system. Deltaic sand bodies collected and pumped hydrocarbon from the active source, incised valley filling depositional system completed the long-distance hydrocarbon migration, and lithological traps of shore-shallow lacustrine sandy beach bar accumulated hydrocarbon. The incised valley filling sequences are multi-cycle： an integrated shortterm filling cycle was developed on the erosion surface, and the sequences upward were mud-gravel stone, medium-fine sandstone containing terrigenous gravels and muddy pebbles with cross bedding, silty mudstone with ripple bedding, and mudstone. The incised valley fi

关键词： Songliao Basin Fulaerji Oilfield Yaojia Formation incised valley filling migration pathway system

Theoretical analysis of alloy multiplying factor by the empirical electron theory of solids and molecules

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2007年第6期50卷 807-814页

作者： SONG YuePeng1,2. liU GuoQuan2. li Zhilin3, FENG ChengMing1 1 Mechanical and Electronic Engineering College, Shandong Agricultural university, Tai’an 2.1018, China 2.College of Materials Science and Engineering, university of Science and Technology, beijing 100083, China 3 College of Material Science and Engineering, beijing university of Chemical Technology, beijing 10002., China Mechanical Electronic Engineering College Shandong Agricultural University Tai’an 271018 China College of Materials Science Engineering University of Science Technology Beijing 100083 China College of Material Science Engineering Beijing University of Chemical Technology Beijing 100029 China

By introducing the distribution probability of structural units in austenite contain- ing alloying elements and considering its effects on phase transformation, this paper establishes a calculation model of distribution probability of structural units. A new valence electron structure (VES) parameter-transformation effect coefficient of alloying elements (HL), is defined and then studied both theoretically and ex- perimentally. The relationship between the parameter HL and the multiplying factor (the quenching capability factor) of alloying elements is studied. The results indi- cate that the two parameters (HL and the quenching capability factor) have the same variation characteristic and substance feature. Therefore, the multiplying factor virtually expresses the relative quantity of structural units in the alloying elements-containing austenite.

关键词： multiplying factor (the quenching capability factor), empirical electron theory of solids and molecules, transformation effect coefficient of alloying elements, structural units in austenite containing alloying elements