检索结果-南通市图书馆

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

在线全文

学校读者我要写书评

暂无评论

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 Materials and Manufacturing technology of Education Ministry, department of Applied Chemistry, Zhejiang Institute of {2. and technology, Hangzhou 310033, china 2. department of Polymer {2. and Engineering, Zhejiang university, Hangzhou 31002., china department of Applied Chemistry Zhejiang Institute of Science and Technology Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Education Ministry Hangzhou China department of Polymer science and Engineering Zhejiang University 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.

Complete quantum circuit of Haar wavelet based MRA

在线全文

学校读者我要写书评

暂无评论

Chinese science Bulletin 2005年第16期50卷 1796-1798页

作者： HE Yuguo1,2.& SUN Jigui1,3 1. College of Computer science and technology, Jilin {2., changchun 130012. china 2. department of Computer science and Engineering, Beijing Institute of technology, Beijing 100081, china 3. Key Laboratory of Computation and Knowledge Engineering of Min-istry of Education, Jilin {2., changchun 130012. china College of Computer science and technology Jilin University Changchun China department of Computer science and Engineering Beijing Institute of Technology Beijing China Key Laboratory of Computation and Knowledge Engineering of Ministry of Education Jilin University Changchun China

Wavelet analysis has applications in many ar- eas, such as signal analysis and image processing. We pro- pose a method for generating the complete circuit of Haar wavelet based MRA by factoring butterfly matrices and con- ditional perfect shuffle permutation matrices. The factoriza- tion of butterfly matrices is the essential part of the design. As a result, it is the key point to obtain the circuits of I 2. ⊕ W ⊕ I 2. ? 2. ?2. In this paper, we use a simple means to de- velop quantum circuits for this kind of matrices. Similarly, the conditional permutation matrix is implemented entirely, combined with the scheme of Fijany and Williams. The cir- cuits and the ideas adopted in the design are simple and in- telligible.

关键词：量子计算量子算法量子电路 Haar微波 MRA

Experimental remolding on the caprock's 3D strain field of the Indosinian-Yanshanian epoch in Tongling deposit concentrating area

在线全文

学校读者我要写书评

暂无评论

science china Earth {2. 2005年第7期48卷 863-874页

作者： DENG Jun1,HUANG Dinghua2.WANG Qingfei1,WAN Li1,SUN Zhongshi3,YANG Liqiang1 & GAO Bangfei1 1. State Key Laboratory of Geological Processes and Mineral Resources,china university of Geo{2.,Beijing 100083,china 2. Faculty of Earth {2.,china university of Geo{2.,Wuhan 430074,china 3. department of Earth {2.,Jilin university,{12. 130061,china State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences Beijing 100083 China Faculty of Earth sciences China University of Geosciences Wuhan 430074 China department of Earth sciences Jilin University Changchun 130061 China

Based on field observations and rheology analysis, we perform one analogue experiment and remold the 3D structural frame of Tongling deposit concentrating area firstly. Then we disassemble and dialyze the 3D structures of the model using the methods of "slicing" and "stripping". A series of sliced planes vertical to the fold hinges show similar landscapes of that in the drill hole profiles. Meanwhile, layer stripping analysis indicates that the deformation features of each layer in the model are qualitatively analogical to those obtained from field observations. Through contrasting the 3D structure between the experimental model and the field phenomena, we verify the following 3D deformation features of the caprock in this area: (1) the Tongling area mainly consists of three series of NE S-typed fold groups; (2. in the uniform stress field, the incoherent folds universally develop in different positions, along different axes as well as in different strata; (3) the faults propagate upward which are mostly inter-bedded detachment faults, while the fold amplitudes decrease while going deeper; and (4) the folds and cleavages are highly developed in the Silurian System indicating that the deformation effect of the Indosin-ian-Yanshanian structural layer terminates at this layer, which suggests that the Silurian System is the crucial layer for the inversion between brittle and plastic deformation domains and the underlying strata are subject to the control of another deformation system with distinct properties.

关键词： Tongling deposit concentrating area Indosinian-Yanshanian epoch 3D structural frame of the caprock analogue experiment slicing and stripping analysis structural model.

Stochastic resonance in surface catalytic oxidation of carbon monoxide induced by colored noise

在线全文

学校读者我要写书评

暂无评论

science china Chemistry 2004年第2期47卷 106-112页

作者： GONG Yubing1,2. HOU Zhonghuai1 & XIN Houwen1 1. department of Chemical Physics, university of {2. and technology of china, Hefei 2.002., china 2. department of Physics, Yantai Teachers university, Yantai 2.402., china department of Chemical Physics University of Science and Technology of China Hefei China department of Physics Yantai Teachers University Yantai China

The dynamical behavior of surface catalytic oxidation reaction of Pt(110)/CO+O2.modulated by colored noise, under the condition of specific temperature, has been investigated when the partial pressure of CO gas is near the supercritical Hopf bifurcation point. By computer simulation the oscillation and stochastic resonance induced by colored noise are observed. The influences of the intensity and correlation time of colored noise on stochastic resonance are discussed. The range of sensitivity of the system to the environmental fluctuation is analyzed.

关键词： colored noise, stochastic resonance, surface catalytic reaction of Pt(110)/CO+O2. supercritical Hopf bifurcation, signal-to-noise ratio (SNR).

Congruences on ideal nil-extension of completely regular semigroups

在线全文

学校读者我要写书评

暂无评论

Chinese science Bulletin 1998年第5期43卷 379-381页

作者： REN Xueming 1, 2.GUO Yuqi 2.and CEN Jiaping (Shum Kar-ping) 31. department of Mathematics, Xi’an university of Architecture & {2., Xi’an 710055, china 2. department of Mathematics, Yunnan university, Kunming 650091, china 3. department of department of Mathematics Xi’an University of Architecture & Technology Xi’an China department of Mathematics Yunnan University Kunming China department of Mathematics Chinese University of Hong Kong Hong Kong

Let S be an ideal nil-extension of a completely regular semigroup K by a nil semigroup Q with zero. A concept of admissible congruence pairs (δ,ω) of S is introduced, where δ and ω are a congruence on Q and a congruence on K respectively. It is proved that every congruence on S can be uniquely respresented by an admissible congruence pair (δ,ω) of S. Suppose that ρ K denotes the Rees congruence induced by the ideal K of S. Then it is shown that for any congruence σ on S,a mapping Γ:σ|→(σ Q,σ K) is an order-preserving bijection from the set of all congruences on S onto the set of all admissible congruence pairs of S,where σ K is the restriction of σ to K and σ Q=(σ∨ρ K)/ρ K. Moreover,the lattice of congruences of S is also discussed. As a special case,every congruence on completely Archimedean semigroups S is described by an admissible quarterple of S. The following question is asked: Is the lattice of congruences of the completely Archimedean semigroup a semimodular lattice?

关键词： completely regular semigroups ideal nil-extension congruences.

Internal noise stochastic resonance in CO oxidation on nm-sized palladium particles

在线全文

学校读者我要写书评

暂无评论

science china Chemistry 2005年第5期48卷 395-401页

Based on a stochastic mesoscopic model, the influence of internal noise on the oscillatory kinetics of the catalytic oxidation of CO on nm-sized palladium particles is studied, using the chemical Langevin equations, Poisson approximation algorithm, and exact stochastic simulation algorithm. The reaction rate oscillations are of stochastic nature due to considerable internal noise in such mesoscopic systems. It is found that the performance of the stochastic oscillations undergoes a maximum with the variation of internal noise level for a given CO partial pressure, which demonstrates the occurrence of internal noise stochastic resonance. This phe-nomenon implies that optimal internal noise would favor the reaction rate oscillation of CO oxi-dation on nm particles. Such a phenomenon is robust to the change of external parameters, such as CO pressures.

关键词： nanometer-sized palladium particles, surface catalytic CO oxidation, internal noise, stochastic resonance, chemical Langevin equation.

Theoretical calculation of the finishing rolling impact work in non-quenched and tempered Si-Mn steel

在线全文

学校读者我要写书评

暂无评论

science china(Technological {2.) 2006年第2期49卷 137-146页

作者： LIU Zhilin1, LIN Cheng1 & WANG Ping2.1. department of Materials and Chemical Engineering, Liaoning Institute of technology, Jinzhou 12.001,{2. 2. Mechanical department, Armor technique Institute of PLA, changchun 130117,{2. department of Materials and Chemical Engineering Liaoning Institute of Technology Jinzhou China Mechanical department Armor technique Institute of PLA Changchun China

Based on the hot-continuous rolling technology, the finishing rolling impact work α k of the non-quenched and tempered Si-Mn steel is theoretically calculated with the covalent electron number nA of the strongest bond in alloying phases, and the smallest interface electron density difference Δρ of alloying phase interface and the number of atom states σ which keep the interface electron density continuous. Calculations show that the solution strengthening, the precipitation strengthening, and the interface strengthening will result in the decrease of the finishing rolling impact work α k, and the effects of the number of atom states σ which keep the interface electron density continuous on the finishing rolling impact work α k are different. Taking the impact work and the number of atom states σ 0 keeping the electron density continuous of the phase interface α-Fe/α-Fe-C between α-Fe and α-Fe-C as reference values, the impact work of the interface will increase when σ of some interface is larger than σ 0; otherwise, the impact will decrease. Therefore, the finishing rolling impact work α k can be calculated with the impact value of the refined α-Fe matrix and the influence amounts caused by the solution strengthening, the precipitation strengthening, the interface strengthening, and the number of atom states σ which keep the interface electron density continuous. The calculated results agree well with the measured ones. In this paper, the effect of S on the impact work is also discussed.

关键词： electron structure parameters, non-quenched and tempered steel, impact work and calculation.

Pressure-induced crystallite breaking in La_(0.7)Sr_(0.3)Mn_(0.9)Fe_(0.1)O_3 nanosolids

在线全文

学校读者我要写书评

暂无评论

Chinese science Bulletin 1998年第6期43卷 458-461页

作者： ZHENG Fanlei 1, 2. SUI Yu 1, 3, XU Dapeng 1 and SU Wenhui 1, 4 1. department of Physics, Jilin university,{2., china 2. changchun Institute of Physics, Chinese Academy of sciences,{2., china 3. Institute of Metal R department of Physics Jilin University Changchun Chinas changchun Institute of Physics Chinese Academy of Sciences Changchun China Institute of Metal Research Chinese Academy of Sciences Shenyang China International Center for Materials Physics Chinese Academy of Sceinces Shenyang China Center for Condensed Matter and Radiation Physics CCAST (World Lab.) Beijing China

In the compacting process of the La 0.7Sr 0.3Mn 0.9Fe 0.1O 3 nanosolids under the pressure range of 0.0-4.5 GPa, the apparent pressure-induced crystallite breaking phenomenon in these nanosolids was observed. With increasing pressure up to 4.5 GPa, the average grain size decreases by 46% while the magnetization of nanosolids decrease by 40% and their coercive increases by 35%. This kind of breaking has a close relation to the existence of oxygen deficiency in La 0.7Sr 0.3Mn 0.9Fe 0.1O 3 nanoparticles. A simple and convenient method for preparing the bulk nanosolids with a large number of clean interfaces has been suggested.

关键词： nanosolid pressure-induced breaking high pressure.

Effects of MoO_3 Amounts on Sintering and Electrical Properties of Ce_(0.8)Nd_(0.2.O_(1.9)

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2012年第1期28卷 9-13页

作者： ZHOU De-feng1, ZHAO Gui-chun1, YANG Mei1, XIA Yan-jie2.and MENG Jian2.1. School of Chemistry and Life science, changchun {2. of technology, changchun 130012. P. R. china 2. State Key Laboratory of Rare Earth Resources Utilization, changchun Institute of Applied Chemistry, Chinese Academy of sciences, changchun 13.02., P. R. china School of Chemistry and Life science Changchun University of Technology Changchun 130012 changchun Institute of Applied Chemistry Chinese Academy of Sciences State Key Laboratory of Rare Earth Resources Utilization Changchun 130022

The high purity （Ce0.8Nd0.2.1.9）1-x（MoO3）x（x=0, 0.005, 0.010, 0.02.; Ce0.8Nd0.2.1.9=NDC） solid solutions were prepared by modified sol-gel method. The structures and electric conductivities were characterized by X-ray diffraction（XRD）, field-emission scanning electron microscopy（FESEM） and electrochemical impedance spectros copy（EIS）. The XRD results show that the materials were pure phase with a cubic fluorite structure. Compared to the undoped-NDC samples, MoO3 doped-NDC showed higher sintered density（over 96%） at reduced sintering tempera ture. The electric conductivity（σt） of （Ce0.8Nd0.2.1.9）1-x（MoO3）x at 400 °C was 9.58×10-4 S/cm when x=0.010, which was higher than that of undoped-NDC samples（σt=3.2.×10-4 S/cm）. The obtained optimal amount of the MoO3 was x=0.010 in this system.

关键词： Neodymium-doped ceria Molybdenum oxide Sol-gel method Grain boundary conductivity