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Preparation and properties of solution-processed zinc tin oxide films from a new organic precursor

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science china Chemistry 2011年第4期54卷 651-655页

作者： ZHAO YunLong,DUAN Lian,QIAO Juan,ZHANG DeQiang,DONG GuiFang,WANG LiDuo & QIU Yong key laboratory of Organic Optoelectronics & Molecular engineering,{3. of education department of Chemistry,tsinghua university,Beijing 100084,china 1. key laboratory of Organic Optoelectronics & Molecular engineering Ministry of Education department of Chemistry Tsinghua University Beijing 100084 China

Transparent,smooth and dense zinc tin oxide (ZTO) thin films have been successfully produced by using a new precursor solution,zinc acetate and tin(II) 2-ethylhexanoate mixed with 2-ethanolamine in *** ZTO films have been prepared by spin-coating,followed by thermal treatment in oxygen *** morphology,composition,crystallinity and band gap energy (Eg) of the ZTO thin films have been characterized by Atomic Force Microscopy (AFM),Atomic Emission Spectrometry (AES),X-ray Diffraction (XRD) and UV-vis *** conductivity of ZTO is about 9.8×10-9 S/cm,as estimated from the current-voltage (I-V) *** effect of the thermal treatment process on the morphology of ZTO thin films is also discussed.

关键词： zinc tin oxide (ZTO) solution-processed organic precursor thermal treatment process conductivity transparent

Influence of Ru addition on microstructure and stress-rupture property of Ni-based single crystal superalloys

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Progress in Natural science:materials International 2010年第1期20卷 61-69页

作者： Jing-yang CHEN~1,Qiang FENG~(1,2),La-mei CAO~3.Zu-qing SUN~1 1.State key laboratory for advanced Metals and {3.,university of science and Technology Beijing, Beijing 100083.china 2.National Center for {3. Service Safety,university of science and Technology Beijing,Beijing 100083.china 3.National key laboratory of science and Technology on advanced High Temperature Structural {3., Beijing Institute of Aeronautical {3.,Beijing 100095,china Univ Sci & Technol Beijing State Key Lab Adv Met & Mat Beijing 100083 Peoples R China Univ Sci & Technol Beijing Natl Ctr Mat Serv Safety Beijing 100083 Peoples R China Beijing Inst Aeronaut Mat Natl Key Lab Sci & Technol Adv High Temp Struct M Beijing 100095 Peoples R China

The effects of Ru on the microstructure and stress-rupture property were investigated in two experimental Ni-based single crystal superalloys with and without Ru addition(5.1%,mass fraction).The results indicate that the morphology ofγ' precipitates in the dendrite core and interdendritic region are intermediate and nearly spherical,respectively,in the Ru-free alloy after being aged at 1100℃for 8 *** Re partitioning ratio increases due to Ru addition and Ru partitioned preferentially to theγphase in both dendrite core and interdendritic region of the Ru-containing alloy,which results in more negative lattice misfit and more cuboidalγ' ***,theγ' volume fraction increases while the precipitate size and y channel width decreases due to Ru addition in both dendrite core and interdendritic *** addition improves the stress-rupture life at 1100℃/140 MPa significantly due to higherγ' volume fraction,more negative lattice misfit and a well rafting structure as well as lessγchannel width.

关键词： Ni-based superalloys ruthenium elemental partitioning ratio lattice misfit γ’ morphology stress-rupture property

Influence of sample surface condition on nano indentation experiment

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Rare Metals 2002年第2期21卷 131-132页

作者： WANG Yanli, LIN Zhi, LIN Junpin, PENG Jihua, and CHEN GuoliangState key laboratory for advanced Metals and {3., university of science and Technology Beijing, Beijing 100083. china university of science and Technology Beijing State Key Laboratory for Advanced Metals and Materials 北京 100083

The microhardness and elastic modules of the materials weremeasured using the Nano Indenter II, which is a new measuring systemfor the mechanical properties of materials on nano-scale. It candetermine themicrohardness, elastic modules and other mechanicalproperties of materials through measuring applied load and depthunder indenter tip. The results indicated that surface condition ofsample such as the surface roughness affects the experimental preci-sion.

关键词： microhardness elastic modules Nano Indenter

Dynamic behavior of polymer surface and the time dependence of contact angle

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science china Chemistry 2005年第6期48卷 553-559页

作者： WANG Xinping1, CHEN Zhifang1 & SHEN Zhiquan2 1. key laboratory of advanced Textile {3. and Manufacturing Technology of education ministry, department of Applied Chemistry, Zhejiang Institute of science and Technology, Hangzhou 3.003., china 2. department of Polymer science and engineering, Zhejiang university, Hangzhou 3.0027, china 1. department of Applied Chemistry Zhejiang Institute of Science and Technology Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Education Ministry 310033 Hangzhou China 2. department of Polymer science and engineering Zhejiang University 310027 Hangzhou China

Time-dependent contact angles were measured by depositing sessile drops of wa-ter on the polymer surfaces and monitoring the drop shape as a function of time. It was found that contact angles decreased sharply with contact time and the equilibrium contact angle was finally attained after a certain time. Values of starting (θ s) and equilibrium contact angles (θ e) obtained by the sessile drop method depend on polymer properties. The Wilhelmy plate technique was used to measure advancing and receding contact angles. The variations of starting (θ s) and equilibrium contact angles (θ e), advancing (θ a) and receding contact angles (θ r) have been studied on the oxidized surface of polymers containing polybutadiene block to explore the cause of time-dependence in contact angle measurement and the meaning of θ s and θ e. The results showed the linear relationships between starting (θ s) and advancing contact angles (θ a), the equilibrium (θ e) and receding contact angles (θ r). The similar relationship was also established between the contact angle hysteresis (θ a?θ r) and differences (θ s ?θ e) in starting contact angles and equilibrium contact angles. Therefore, time-dependence in contact angle measurement was mainly attributed to the surface reconstruction when water drops were deposited on polymer surfaces. The starting contact angle was contributed by the hydrophobic component on polymer surface and the equilibrium contact angle mainly by the hydrophilic component of polymer. These results not only demonstrated the interdependency between two contact angle measurements, the sessile drop method and the Wilhelmy plate technique, but also provided the experimental evidence to explain the cause of time-dependent contact angle. This may also provide a new method to study dynamic behavior of polymer surface.

关键词： contact angle, surface dynamic behavior, polymer surface, dynamic contact angle, time-dependence.

EFFECTS OF SUBMERGED MACROPHYTES ON SEDIMENT SUSPENSION AND NH_4-N RELEASE UNDER HYDRODYNAMIC CONDITIONS

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Journal of Hydrodynamics 2010年第6期22卷 810-815页

作者： WANG Chao WANG Cun WANG Ze key laboratory of Integrated Regulation and Resource department on Shallow Lakes Ministry of EducationHohai University Nanjing 210098 China State key laboratory of Hydrology-Water Resources and Hydraulic engineering Hohai University Nanjing210098 China College of Mechanics and materials Hohai University Nanjing 210098 China

Aquatic vegetation affects sediment suspension and nutrient release by changing the flow structure. Experiments on the influence of submerged vegetation on flow structure, sediment suspension, and NH4-N release were carried in a flume with natural submerged vegetation. Turbulence characteristics in the vegetation section were measured using a three-dimensional acoustic Doppler velocimeter. The effects of submerged vegetation on bed shear stress （ τb ）, sediment suspension, and NH4-N release were analyzed. Results show that with vegetation, bed shear stress is reduced by about 20% - 80%, which, in turn, reduces sediment suspension. The impact of submerged vegetation on sediment suspension and NH4-N release should be considered along with flow intensity. When the flow Reynolds number is relatively small, the submerged vegetation is quite capable of inhibiting sediment suspension and reducing NH4-N release, but when the Reynolds number reaches a certain value, the presence of aquatic plants exacerbates sediment suspension and promotes NH4-N release. Results also reveal that a highly significant positive correlation exists between NH4-N concentration and water turbidity in both vegetated and non-vegetated channels.

关键词： sediment suspension submerged macrophytes turbulence behavior bed shear stress turbidity

A novel synthetic route for LiFePO_4/C cathode materials by addition of starch for lithium-ion batteries

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Chinese Chemical Letters 2007年第2期18卷 237-240页

作者： Shao Hua Luo, Zi Long Tang, Jun Biao Lu, Zhong Tai Zhang State key laboratory of New Ceramics and Fine Processing, department of materials science and engineering,{3., Beijing 100084, china Graduate School at Shenzhen,{3., Shenzhen 518055, china [a]State key laboratory of New Ceramics and Fine Processing Department of Materials Science and Engineering Tsinghua University Beijing 100084 China [b]Graduate School at Shenzhen Tsinghua University Shenzhen 518055 China

LiFePO4/Carbon composite cathode material was prepared using starch as carbon source by spray-pelleting and subsequent pyrolysis in N2. The samples were characterized by XRD, SEM, Raman, and their electrochemical performance was investigated in terms of cycling behavior. There has a special micro-morphology via the process, which is favorable to electrochemical properties. The discharge capacity of the LiFePO4.C composite was 170 mAh g-1, equal to the theoretical specific capacity at 0.1 C rate. At 4 C current density, the specific capacity was about 80 mAh g-1, which can satisfy for transportation applications if having a more flat discharge flat.

关键词： Lithium-ion batteries Cathode material Carbon coated LiFePO4 Spray-pelleting

Molecular dynamics simulation of amorphous segregation in Ag-Rh alloys

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Rare Metals 2003年第3期22卷 164-168页

作者： ZHANG Jingxiang and BIAN Xiufangkey laboratory of Liquid Structure and Heredity of materials, {3. of education, Shandong university, Jinan 250061, china Shandong university Key Laboratory of Liquid Structure and Heredity of Materials Ministry of Education Jinan 250061

Molecular dynamics simulation was carried out to investigate the liquid andamorphous microstructures of binary Ag_x-Rh_((100-x)) (x = 25, 50, 75 in atom fraction) *** feature of homogeneous interatomic binding of Ag-Rh liquid was found and probed, whichcan be retained into amorphous solids upon rapid cooling. Homogeneous binding may occur when thedifference in the elemental atomic sizes is less than 10%. The icosahedra in liquid before theformation of amorphous state exist in a stable state and the network formed by 1551-clusters inmolten alloys would inhibit the crystallization and diffusion of atoms. A higher degree of1551-clusters will be favorable to form metallic glasses.

关键词： metallic glass amorphous segregation molecular dynamics liquid structure Ag-Rh alloy

Zinc up-regulated the expression of the rice metallonthionein gene family and enhanced the zinc tolerance of yeast cells

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Progress in Natural science:materials International 2007年第10期17卷 1166-1171页

作者： Xu Yufeng, Zhou Gongke, Li Yiqin and Liu Jinyuan(laboratory of Molecular Biology and Protein science laboratory of the {3. of education, department of Biological sciences and Biotechnology, tsinghua university, Beijing 100084, china) laboratory of Molecular Biology and Protein science laboratory of the {3. of education Department of Biological Sciences and Biotechnology Tsinghua University Beijing 100084 China

Northern blot and functional complementation assay were employed to analyze the effects of zinc on expression of ten rice metallothionein genes (OsMT-Is) in rice seedlings and the growth of yeast cells transformed with OsMT-Is. Northern blot revealed that in shoots of the rice seedlings treated with different Zn2+concentrations, expression of most members of OsMT-I family was increased, except the type 4 OsMT-Is (OsMT-I-4a, 4b and 4c). In roots, Zn2+significantly increased the transcription of OsMT-I-1b and OsMT-I-2c, but reduced the trascription of OsMT-I-1a and OsMT-I-3.. When these ten cDNAs were heterologously expressed in zinc sensitive yeast mutant, all transgenic yeasts showed increased tolerance to Zn2+, and zinc accumulation in these yeast cells also increased. These indicated that OsMT-I family members might respond to extra Zn2+, and they could enhance Zn2+ tolerance of cells by direct binding Zn2+.

关键词： rice metallothionein induced expression Zn2+ tolerance.

Methods for Improving Volume Stability of Steel Slag as Fine Aggregate

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Journal of Wuhan university of Technology(materials science) 2008年第5期23卷 737-742页

作者：伦云霞 key laboratory of Silicate materials {3. and engineering of ministry of education Wuhan University of Technology

Suitable methods for enhancing the volume stability of steel slag utilized as fine aggregate were determined. The effects of steam treatment at 100 ℃ and autoclave treatment under 2.0 MPa on the soundness of steel slag sand were investigated by means of powder ratio, linear expansion, compressive and flexural strength. DTA, EDX, XRD and ethylene glycol methods were employed to analyze both the treated slags and susceptible expansion grains. Experimental results indicate that powder ratio, content of free lime and rate of linear expansion can express the improvement in volume stability of different treated methods. Steam treatment process cannot ultimately prevent specimens from cracking and decrease of strength, but mortar made from autoclave treated slag keeps integration subjected to hot water of 80℃ until 28 d and its strength do not show significant decrement. The hydration of over-burn free lime and periclase phase are the main cause for the disintegration or crack of untreated and steam treated steel slag＇s specimens. Autoclave treatment process is more effective than steam treatment process on enhancement of volume stability of steel slag.

关键词： steel slag fine aggregate volume stability steam treatment process autoclave treatment process