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Properties Evolution of a Powder Metallurgical Titanium Alloy with Yttrium Addition

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稀有金属材料与工程 2011年第S3期40卷 298-300页

作者： Liu Haiyan1, Tang Huiping1, He Weiwei1, Liu Yanbin2, Jia Wenpeng1, Liu Yong2 1State Key Laboratory for Porous Metals Materials, Northwest Institute for Nonferrous Metal research, Xi′an 710016, china 2 State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, china NW Inst Nonferrous Met Res State Key Lab Porous Met Mat Xian 710016 Peoples R China Cent S Univ State Key Lab Powder Met Changsha 410083 Hunan Peoples R China

P/M Ti-Fe-Mo-Y alloys with different Rare-earth Y Content are prepared by blend element method, its sintering and hot deformation behaviors are studied together with microstructure and mechanical properties. The microstructures and properties of the alloying titanium were testified by the analysis of Optical microscopy (OM), X-ray diffraction (XRD), scanning electron microscopy (SEM).The result indicated that Y element absorbs free oxygen and purify the Ti powder surface, promoting densification process. With appropriate vacuum and temperature, the blend element metal powder sintering relative density can reach more than 97%. Microstructure and mechanical properties analysis shown that Y element composed Y2O3 particles which refine grains and improve plasticity, elevate alloy distortion ability. After hot deformation, grains crashed and flow line appears, the mechanical properties of Ti-Fe-Mo-Y alloy prompted which also validated by large amount of dimples appear in tensile fracture surface.

关键词： P/M Ti-Fe-Mo-Y alloy blend element method hot deformation

Current status and future tendency of lake eutrophication in china

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中国科学：生命科学英文版 2005年第z2期48卷 948-954页

作者： JIN Xiangcan, XU Qiujin & HUANG Changzhu Chinese research Academy of Environmental Sciences, Beijing 100012, china 1. Chinese research Academy of Environmental Sciences 100012 Beijing China

Current trophic status and trend of Chinese freshwater lakes were investigated in this study. The results showed that all lakes studied were commonly undergoing the eutrophication process, water quality decreased and lake's ecosystem is being declined. Most of the urban lakes are facing serious eutrophication. Many medium-sized lakes are in metrophic or eutrophic status, some local water are even approaching the hypertrophic level. The famous five freshwater lakes in china have entered into eutrophication in the condition of higher nutrient load. Lake Taihu, Hongze and Caohu are already in eutrophic state. Eutrophic lakes are mainly distributed in the middle and lower reaches of Yangtze River and Yungui plateau. Lake eutrophication developed rapidly. Among the 34 lakes studied in 1970's, most of lakes were in the mesotrophic status,mesotrophic water area accounted for 91.8%. With the nine year of 1978-1987 the area percentage of oligotrophic lakes decreased from 3.2% to 0.53%, and that of eutrophic lakes increased from 5.0% to 55.01%. Recent data showed 57.5% lakes were in eutrophic and hypertrophic status of the 40 surveyed *** trend of Lake Taihu, Chaohu and Xuanwu in the region of the middle and lower reaches of Yangtze River was predicated using the ecological stress model. The results showed that in 2008 Lake Taihu, Chaohu and Xuanwu might be of eutrophication, eutrophication and hypertrophication, respectively if no control measurement is taken. Provided the pollution water treatment rate is 60% in 2030, approximately 30 billion ton pollution water would still be discharged directly in the lakes. Therefore, in 2030 the urban lakes in china might be eutrophication or hypertrophication, and most of the medium-sized lakes at the urban-rural fringe might be in eutrophication or hypertrophication. The famous five biggest freshwater lakes in china might be eutrophication if control countermeasures are taken as *** eutrophication has become a serious

关键词： Lake trophic status eutrophication prediction china.

The chemical stability of heavy metals in a natural water system

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Journal of Environmental Sciences 1989年第1期1卷 55-64页

作者： Tang Hongxiao, Xue Hanbin, Mao Meizhou, Luan Zhaokun1 research Center for Eco-Environmental Sciences,Academia Sinica,P,O.Box 934,Beijing 100083,china

A comprehensive investigation of heavy metal pollutants in Xiangjiang river was accomplished to evaluate their chemical stability through three different ways: (1) Chemical speciation by direct measurements; (2) Chemical equilibrium model simulation; (3) Sediment extraction experiments. All the results demonstrated that the directly bioavailable fraction was in a very limited amount. The metal bound to organic ligands, adsorbed particles and precipitated species presented a buffer for solution species. The majority of metals occured in the residues as solid particulates. It was inferred that the heavy metal pollutants in this aquatic system exhibited a high chemical stability. The critical limits of discharging load and pH values were suggested.

关键词： chemical speciation chemical equilibrium model heavy metal.

Fabrication and Performances of 1-3-2 Piezoelectric Ceramic/Polymer Composite

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稀有金属材料与工程 2006年第S3期 511-513页

作者： Likun Wang~1 Guang Li~2 Hongliang Du~1 Lei Qin~1 Shuxiang Li~1 (1.Sensor Technology research Center,Beijing Information Technology Institute,Beijing 100101,china) (2.National Ocean Technology Center,Tianjin 300111,china)

A novel 1-3-2 piezoelectric composite has been developed,which consists of piezoelectric ceramic plate and 1-3 piezoelectric *** composite was fabricated by dicing PZT ceramic along mutual perpendicular two directions and then filling epoxy into *** piezoelectric and electromechanical properties of the novel composite were determined. The results show a coefficient d_ （33） of 405pC/N,a vibration displacement of 113.5pm,an acoustic impendence of 13.3 Mraly, a bandwidth of 12kHz and a thickness electromechanical coupling coefficient of 0.56.

关键词： 1-3-2 piezoelectric composite fabrication performances

Geomorphologic evolution and environmental changes in the Shaluli Mountain region during the Quaternary

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Chinese Science Bulletin 2005年第1期50卷 52-57页

作者： ZHOU Shangzhe1,2, XU Liubing1, CUI Jianxin1, ZHANG Xiaowei1 & ZHAO Jingdong1 1. National Laboratory of Western china’s Environmental Systems of Ministry of Education of china and Department of Geography, Lan- zhou University, Lanzhou 730000, china 2. Department of Geography, South china Normal University, Guang- zhou 510631, china National Laboratory of Western china''s Environmental Systems of Ministry of Education of china and Department of Geography Lanzhou University Lanzhou 730000 China Department of Geography South China Normal University Guangzhou 510631 China

Geologic and geomorphologic evidence from the Shaluli Mountain indicates that the planation surface that formed in the Late Tertiary disintegrated during the Late Pliocene-Early Quaternary. At the same time, rift ba- sins appeared on some parts of the planation surface, and began to accumulate fluvial-lacustrine sediment. These are interpreted as being the response of this region to Phase-A of the Qingzang Tectonic Movement. After this, the Shaluli Mountain continued to rise in several pulses. Faulting and incision by some large tributaries of the Jinsha and Yalong Rivers resulted in several rift river valleys and the earliest terraces. Generally, the planation surface in this region had been uplifted to about 3500—3700 m a.s.l. no later than 550—600 ka BP, after the Kunlun-Huanghe Tectonic Move- ment, and coupled with global glacial climate, and resulted in the earliest glaciation recognized so far in the Hengduan Mountains. At the same time, loess was deposited in the Ganzi area of the northern Shaluli Mountain. During the last glacial period, the Shaluli Mountain approached its present altitude and developed several large ice caps, such as the Daocheng Ice Cap and Xinlong Ice Cap, as well as several huge valley glaciers. These paleoglaciers produced some of the most spectacular glacial topography on the Tibetan Pla- teau.

关键词：地形学环境变化 Shaluli山脉展平面西藏高原 ESR-年代测定

Modeling the Roles of Precipitation Increasing in Glacier Systems Responding to Climate Warming—Taking Xinjiang Glaciated Region as Example

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Journal of Mountain Science 2005年第4期2卷 306-312页

作者： WANG Xin XIE Zichu LIU Shiyin TAO Jianjun HAN Yongshun YANG Yuelong research Institute of Geo-spatial Information Science Hunan University of Science ＆ Technology Xiangtan 411201 Hunan China Key Laboratory of Ice Core and Cold Region＇s Environment Cold and Arid Regions Environmental and Engineering Research Institute CAS Lanzhou 730000 China Institute of Resources and Environment Hunan Normal University Changsha 410081 China Institute of Tibetan Plateau research CAS Beijing 100029 China

The studies on prediction of climate in Xinjiang almost show that the precipitation would increase in the coming 50 years, although there were surely some uncertainties in precipitation predictions. On the basis of the structure of glacier system and nature of equilibrium line altitude at steady state （ELAo）, a functional model of the glacier system responding to climate changes was established, and it simultaneously involved the rising of summer mean temperature and increasing of mean precipitation. The results from the functional model under the climatic scenarios with temperature increasing rates of 0.01, 0.03 and 0.05 K/year indicated that the precipitation increasing would play an evident role in glacier system responding to climate change： if temperature become 1 ℃ higher, the precipitation would be increased by 10%, which can slow down the glaciers retreating rate in the area by 4 %, accelerate runoff increasing rate by 8 % and depress the ELAo rising gradient by 24 m in northern Xinjiang glacier system where semi-continental glaciers dominate, while it has corresponding values of only 1%, 5 % and 18m respectively in southern Xinjiang glacier system, where extremely continental glaciers dominate.

关键词： Glacier system climate warming precipitation increasing role

CHARACTERISTICS OF FLUVIAL PROCESSES AND STABILITY OF THE BRAIDED RIVER SECTIONS WITHIN THE MIDDLE AND LOWER REACHES OF THE YANGTZE RIVER

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International Journal of Sediment research 1988年 52-75页

作者： Luo Haichao 1. Senior Engineer, Yangtze River Scientific research Institute, Wuhan , china.

The middle and lower reaches of the Yangtze River are defined as typical models of braided channel patterns with a predominant character of gradual alternation between the main and branch channel. Herewith described comprehensively are the geomorphological feature of braiding and the characteristics of runoff and sediment load while great attention is paid on the study of the evolution cycle of mutual alternation of the main and the branch and the conditions which control the braided river to maintain a relative stability for a reasonably long period. It is found that: 1. The maintenance of relative stability is due to the favourable conditions of flow and sediment diversion to the branch; 2. Mutual alternation occurs due to the changes-of-flow feature which cause the transverse gradient at the point of diversion to be changed and consequently the redistribution of flow and sediment into the branch. In the last part of this paper comparison is made with some known braided rivers, both in china and abroad and analysis is carried on for all effective factors, concluding is that Yangtze River should be classified as a very favourable forked river with highly developed islands and with high stability.

关键词： Braided channel pattern geomorphological feature allu- vial plain forking arm sediment-bifurcating ratio dynamic axis.

Neuroglobin mutation associated with hypoxia adaptation in Tibet chicken

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Progress in Natural Science:Materials International 2007年第12期17卷 1419-1424页

作者： Zhang Lifan1, Liu Chong2, Lian Linsheng3, Zhao Chunjiang1, Bao Haigang1 and Wu Changxin1(1. College of Animal Science and Technology, china Agricultural University, Beijing 100094, china 2. College of Biological Science, china Agricultural University, Beijing 100094, china 3. College of Animal Science and Technology, Yunnan Agricultural University, Kunming 650201, china) College of Animal Science and Technology China Agricultural University Beijing 100094 China College of Biological Science China Agricultural University Beijing 100094 China College of Animal Science and Technology Yunnan Agricultural University Kunming 650201 China

Globin protein family plays an important role in storing and transporting oxygen. As a newly reported globin, the revealed function of neuroglobin includes binding and storing oxygen as well as facilitating the utilization of oxygen in neuronal cells. In the present study, mutations in exons of chicken Ngb gene were identified with the method of sequencing and created restriction site PCR in Tibet chicken and other four lowland chicken breeds. The mutations of Lys-2224(E4)-Asn and Ser-2279(E4)-Gly were identified in exon 4 of the gene. The Lys-2224(E4)-Asn mutation existed only in Tibet chicken and the mutation frequencies increased with increasing altitude. Analysis of the haplotype and diplotype of the two mutations in Tibet chicken populations of different altitudes showed that the frequencies of TG haplotype and TTGG diplotype also increased with increasing altitude, while the reverse tendency was found on GGAA diplotype. Under the hypoxic simulation incubation, the main haplotype was TG in living embryos and GA in dead embryos. The results showed that the Lys-2224(E4)-Asn mutation may be a specific mutation associated with hypoxia adaptation in Tibet chicken.

关键词： Tibet chicken neuroglobin hypoxia adaptation Ngb gene mutation.

Studies on the Condensed Structure of Vacuum Cast Atactic Polystyrene Films

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Chemical research in Chinese Universities 2000年第4期16卷 363-368页

作者： WANG You, HE Chu-ning and SHEN Jing-shu (Polymer Physics Laboratory, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, china) WU Li-heng and SONG Qing (china Textile Academy, Beijing 100025, china) Chinese Acad Sci Inst Chem Polymer Phys Lab Beijing 100080 Peoples R China china Text Acad Beijing 100025 Peoples R China

The condensed structure of atactic-polystyrene (a - PS ) films cast from the solutions of differ- ent concentrations in dichloromethane under vacuum and atmospheric conditions was studied by differential scanning calorimetry(DSC). It was found that only under vacuum evaporating conditions did the endothermic peak in the DSC curves of a-PS films depend on the concentration of the a-PS solution. For the samples cast from the solution of concentration below 0. 010 g/mL, no endothermal peak was observed, but for those cast from the solution of concentration above 0. 020 g/mL, obvious endothermal peaks appeared. The onset of the endothermal peak is correlated with the critical overlapping concentration c' (0. 010-0. 020 g/mL), which is in agreement with the theoretically calculated one (Ccal=0.014 g/mL).

关键词： Differential scanning calorimeter(DSC) Critical overlapping concentration Atactic polystyrene film