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A new method to prepare clean cuticular membrane from fossil leaves with thin and fragile cuticles

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Science China Earth Sciences 2011年第2期54卷 223-227页

作者： WANG Li1,2.& LENG Qin1,3 1 State Key laboratory of Palaeobiology and Stratigraphy,Nanjing Institute of Geology and Palaeontology,Chinese Academy of Sciences,Nanjing 2.0008,China 2.Graduate School of Chinese Academy of Sciences,Beijing 100049,China 3 Department of Science and Technology,Bryant University,Smithfield RI 02.17,USA 1. State Key laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences Nanjing 210008 China2. Graduate School of Chinese Academy of Sciences Beijing 100049 China3. Department of Science and Technology Bryant University Smithfield RI 02917 USA

Leaf cuticle analysis has long been a powerful tool for fossil plant identification, systematics, and palaeoclimatological recon- struction. In recent decades the application of stomatal frequency data that are relied on precise calculation of stomata on plant fossil cuticles to reconstruct ancient atmospheric CO2.concentration made the preparation of cuticular membrane with sufficient size a critical technique in palaeoclimatological research. However, for plants with originally thin and fragile cuticles, e.g., most deciduous plants, conventional techniques sometimes fail to obtain cuticular membranes with sufficient size, or sometimes unable to recover any. This has largely hampered the usage of fossil cuticle analysis in palaeobotanical and palaeo- climatological research. Here, we describe a new method using clear nail polish as a medium to ＂strengthen＂ the originally thin and fragile cuticles prior to maceration procedures. We demonstrate the method by using middle Eocene Metasequoia fossils that were notorious for the difficulty of recovering large-sized clean cuticular membranes due to their thin and fragile nature. Metasequoia, with well-documented and widely-distributed fossil records since the Late Cretaceous and with a living repre- sentative, 114. glyptostroboides, as a comparative reference, bas been widely used as a model genus for the study of evolution of plants, palaeoclimatological reconstruction, and plant adaptation to climate changes. But its deciduous habit produces thin cuticles and makes the preparation of clean cuticular membranes a tedious process. The new method successfully allows us to recover its delicate cuticular membranes with sufficient sizes for SEM observation and stomatal frequency analysis.

关键词： fossil leaf cuticle Metasequoia new method thin and fragile cuticle SEM observation stomatal frequency CO2

Photocatalytic performance of TiO_2.thin films connected with Cu micro-grid

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Science China(Technological Sciences) 2009年第8期52卷 2175-2179页

作者： ZHU HaiLing1, ZHANG JunYing1, WANG TianMin1, WANG LiuGang1, LAN Xiang1 & HUANG BaiBiao2.1 School of Science, Beihang University, Beijing 100191, China 2.State Key laboratory of Crystal Materials, Shandong University, Ji’nan 2.0100, China School of Science Beihang University Beijing 100191 China State Key laboratory of Crystal Materials Shandong University Ji’nan 250100 China

Aiming at reducing the recombination of photo-induced carriers in semiconductor photocatalytic process, we prepared TiO2.thin film with its surface modified by a connected Cu micro-grid via a microsphere lithography strategy, which showed higher photocatalytic activity than the pure TiO2.film. The improvement of photocatalytic activity of Cu micro-grid to the TiO2.film is due to the charge carrier separation and electron transfer by the conducting metal grid. The photocatalytic activity was improved as metal loading increased, which obtained the best performance at a certain loading amount, and then decreased at higher loading amount. This phenomenon was attributed to the metal’s bulk effect which could be explained by the relationship between the energetic positions and the metal cluster size.

关键词： surface modification photocatalysis PS microspheres micro-grid

Ferroelectric properties of Bi_4Zr_(0.5)Ti_(2.5)O_(12. thin films prepared on LaNiO_3 bottom electrode by sol-gel method

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Science China(Technological Sciences) 2007年第4期50卷 472-477页

作者： GUO DongYun1, LI MeiYa1, LIU Jun1, PEI Ling1, YU BenFang1, ZHAO XingZhong1, YANG Bin2. WANG YunBo2.& YU Jun2.1 Department of Physics, Wuhan University, Wuhan 430072. China 2.Department of Electronic Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China 1. Department of Physics Wuhan University Wuhan 430072 China 2. Department of Electronic Science and Technology Huazhong University of Science and Technology Wuhan 430074 China

The Bi4Zr0.5Ti2.5O12.(BZT) thin films were fabricated on the LaNiO3 bottom electrode using sol-gel method. The structure and morphology of the films were character-ized using X-ray diffraction, AFM and SEM. The results show that the films have a perovskite phase and dense microstructure. The 2.r and 2.c of the Pt/BZT/LaNiO3 capacitor are 2..2.μC/cm2.and 14.7 V respectively at an applied voltage of 2. V. After the switching of 1×1010 cycles, the Pr value decreases to 87% of its pre-fatigue val-ues. The dielectric constant (ε) and the dissipation factor (tanδ) of the BZT thin films are about 2.4 and 0.02. at 1 kHz, respectively. The films show good insulating behavior according to the test of leakage current. The clockwise C-V hysteresis curve observed shows that the Pt/BZT/LaNiO3 structure has a memory effect be-cause of the BZT film’s ferroelectric polarization.

关键词： Bi_4Zr_(0.5)Ti_(2.5)O_(12. thin film sol-gel method LaNiO_3 bottom electrode ferroelectric properties

Study on UV Shielding TiO2.thin Film Prepared by Sol-Gel Method

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稀有金属材料与工程 2006年第S3期 508-510页

作者： Shihai Zhao~1 Xiaohui Wang~2.Shaobo Xin~2.Qiang Jiang~2.Xiaoping Liang~2.(1.School of Mechanical and Electronic Engineering,Tianjin Polytechnic University,Tianjin 300160,China) (2.School of Material Science and Chemical Engineering,Tianjin Polytechnic University,Tianjin 300160,China)

Titanium dioxide （TiO2. thin films were prepared on microscopes slides by sol-gel and dip-coating processes from specially formulated *** results show that there exists anatase and rutile structure of TiO2.hen heat treatment temperature is 450℃,and at 800℃,TiO2.article size is of below 100 nm and rutile structure is *** the range of 360 nm～400 nm the transmittance of TiO2.ol increases with the increasing of the concentration of Ti（OC4H9）4in ethanol solution. The transmittance of TiO2.1} with various number of the layer is measured to be 0% below 32. nm,and the three-layer TiO2.ilm is of the best UV resistance in the range of 32. nm～400 nm.

关键词： TiO2 thin film sol-gel UV absorption

Functions for patch test in finite element analysis of the Mindlin plate and the thin cylindrical shell

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Science China(Physics,Mechanics & Astronomy) 2009年第5期52卷 762-767页

作者： CHEN WanJi 1,2.,WANG JinZhi 1,3 &ZHAO Jie 1 1State Key laboratory for Structural Analysis of Industrial Equipment,Dalian University of Technology,Dalian 11602.,China 2.nstitute for Structural Analysis of Aerocraft,Shenyang Institute of Aeronautical Engineering,Shenyang 110136,China 3 College of Science,Institute of Dalian Nationalities,Dalian 11602.,China State Key laboratory for Structural Analysis of Industrial Equipment Dalian University of Technology Dalian 116023 China Institute for Structural Analysis of Aerocraft Shenyang Institute of Aeronautical Engineering Shenyang 110136 China College of Science Institute of Dalian Nationalities Dalian 116022 China

Current patch test for Mindlin plate element only satisfies the zero shear deformation *** patch test of non-zero constant shear for Mindlin plate problem cannot be *** shell element, the patch test does not even *** on the theory of enhanced patch test proposed by Chen W J (2.06),the authors proposed the enhanced patch test function for Mindlin plate and thin cylindrical shell *** enhanced patch test function can be used to assess the convergence of the Mindlin plate and cylindrical thin shell elements.

关键词： Mindlin plate thin cylindrical shell finite element enhanced patch test test function

Spinning Deformation Criteria of thin-walled Tubular Part with Longitudinal Inner Ribs

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Journal of Wuhan University of Technology(Materials Science) 2006年第4期21卷 169-172页

作者：江树勇 Engineering Training Center Harbin Engineering University Harbin 150001China

As a successive and local plastic deformation process, backward ball spinning was applied for the purpose of prodacing thin-walled tubular parts with longitudinal inner ribs. According to the local plastic deformation theoo,, the application of yield criterion to the spinning process and the influence of the radial spinning force component on the formability of inner ribs were analyzed. Based on yield criterion and plastic mechanics, the stable flow rule of metal material and forming criteria of the inner ribs were obtained aad conformed to the experimental results so as to contribute greatly to improving the ball spinning process and optimizing the process variables, such as the diameter of ball, the reduction in a pass and the wall thickness of tubular blank, which have a significant influenee on the formability of the inner ribs. The knowledge of the influence of the process variables such as the diameter of ball, the reduction in a pass and the wall thickness of tubular blank on the spinning process is essential to preventing the quality defects of the spun parts and obtaining the desired spun parts.

关键词： ball spinning power spinning spinning force criterion

Controlled Size and Density Distribution of Nanoparticles by Thermal Ammonia Etching Method

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Journal of Wuhan University of Technology(Materials Science) 2010年第1期25卷 108-111页

作者：李刚 Key laboratory of Ministry of Education for Conveyance and Equipment East China Jiaotong University Center for Photon Fabrication Science and Technology Jiangsu University

Nickel nanometer catalyst thin films were prepared on SiO2.Si substrates using sputtering coater. The effects of ammonia pretreatment on the catalyst films from continuous film to the nanoparticles were investigated. The nanostructures of the Ni thin films as a function of the catalyst film original thickness, the pretreatment time and temperature were discussed. The optimum parameters of etching process were obtained, and the functional mechanism of ammonia was primarily analyzed. Scanning electron microscopy （SEM） and atomic force microscopy （AFM） were used to evaluate the obtained nanoparticles. It is demonstrated that the controlled size and density distribution of the nanoparticles can be achieved by employing ammonia etching method.

关键词： ammonia etching nanoparticle density control thermal expansion

Study on impurity desorption induced by femtosecond pulse laser based on a stochastic process model

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Science China(Technological Sciences) 2006年第1期49卷 78-88页

作者： CHI Yinsheng1, LIN Xiaohui1, ZHUANG Ping1 & CHEN Yunfei1,2.1. Department of Mechanical Engineering, Southeast University, Nanjing 2.0096, China 2. Key laboratory of MEMS of China Educational Ministry, Southeast University, Nanjing 2.0096, China Department of Mechanical Engineering Southeast University Nanjing 210096 China Key laboratory of MEMS of China Educational Ministry Southeast University Nanjing 210096 China

With the advantages on non-equilibrium heating and desorption induced by electronic transition, the femtosecond pulse laser introduces a new way for solving the problem of impurity pollution adsorbed on a solid thin film in micro-electro-mechanical systems (MEMS). A model based on stochastic processes was established for stimulated desorption induced by the femtosecond pulse laser to interpret the interaction of the opti-cally excited hot electrons with the adsorbed molecules in a metal substrate. Numerical simulation results reveal a time-dependent desorption probability of adsorbed molecules and indicate that how key parameters of femtosecond pulse laser, such as incident laser energy flux, pulse duration, and wavelength of pulse, have a great effect on the desorption probability.

关键词： desorption, femtosecond pulse laser, stochastic process.

Silicon nanoporous pillar array and its surface copper deposition

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Chinese Science Bulletin 2005年第14期50卷 1424-1428页

作者： FU Xiaonan1,2.3, CHAI Huadou1,2.& LI Xinjian1,2.1. Department of Physics, Zhengzhou University, Zhengzhou 450052. China 2. Key laboratory of Material Physics (Zhengzhou University), Ministry of Education, Zhengzhou 450052. China 3. Department of Mathematics and Physics, Henan University of Tech- nology, Zhengzhou 450052. China Department of Physics Zhengzhou University Zhengzhou 450052 China Key laboratory of Material Physics (Zhengzhou University) Ministry of Education Zhengzhou 450052 China Department of Mathematics and Physics Henan University of Technology Zhengzhou 450052 China

Silicon nanoporous pillar array (Si-NPA) has been prepared by a hydrothermal etching technique. Using Si-NPA as substrate, a Cu/Si-NPA nanocomposite thin film has been obtained with immersion plating method. Morpho- logical and structural analysis indicates that Si-NPA is a typical structural composite system characterized by a triple hierarchical structure, i. e. the array of micron-sized silicon pillars, the nanopores densely distributed on the surface of the pillars, and the silicon nanocrystallites that constitute the pore walls. Cu/Si-NPA inherits the morphological character- istics of Si-NPA. The compactability of the deposited copper nanoparticles varies alternatively with the local geometrical features of Si-NPA and forms a quasi-periodical pattern. Such an experimental phenomenon is attributed to the veloc- ity dependence of the copper deposition upon the local geo- metrical features of Si-NPA. These results indicate that Si-NPA might be used as an ideal template for preparing specially patterned, structured or functionalized metal/ sili- con nanocomposite systems.

关键词：硅元素薄膜蚀刻技术电镀技术