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Study on the two and three-parameter working stability regions of 3.-TZP suspension

science China(Technological sciences) 2006年第5期49卷 547-568页

作者： CHEN Youqiang1, 2, ZHANG Xinni3. CHEN Sha’ou3.& qi Ping3.1. department of {3., qingdao university, qingdao 266071, China 2. department of {3., Tsinghua university, beijing 100084, China 3. department of Physics, qingdao university, qingdao 266071, China 1. department of chemistry Qingdao University Qingdao 266071 China 2. department of chemistry Tsinghua University Beijing 100084 China 3. department of Physics Qingdao University Qingdao 266071 China

We determined the variation tendency of viscosity (η) at various solids load- ing (α) for 3.-TZP suspension as a function of dispersant concentration (Cw) using vis- cosity measurement, measured the diameter of particles as a function of Cw in very dilute suspension using light scattering method, and obtained the surface features of the sedi- ment of suspension with different Cw using SEM. We also discussed the influence of the microstructure of adsorbed polymer layers on particles and their interactions in the dis- persing medium on the stability of suspension. Then two different stable states and two different unstable states for 3.-TZP suspension were given. Accordingly, the (Cw, η), (Cw, α), and (α, η) two-parameter, and (Cw, α, η) three-parameter stability maps were con- structed. Based on the DLVO theory calculations, the dispersant concentration, particle distance (r), and interparticle potential energy (VT) maps with various solids loading for 3.-TZP aqueous suspension were also constructed. In (Cw, r) two-parameter coordinate system, the stable motion region map for particles was established. The Cw, α, and VT,max (the highest potential energy) surface of the potential barrier map was obtained through calculation and simulation on the basis of the surfaces of Cw, r, VT maps introduced above. The (Cw, α) two-parameter stability map was then obtained from the Cw, α, VT,max map. The results showed that this theoretical map can qualitatively prove the experimentally obtained results—the existence of different dispersed states of particles in suspension system and the variation tendency of suspension stability with changing each parame- ter—were reasonable.

关键词： 3.-TZP, suspension, stability, DLVO theory, interparticle potential energy.

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Fabrication of multi-sectional TiO_2 nanotube arrays by anodization

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science China chemistry 2010年第5期53卷 1067-1072页

作者： LI Shiqi,YIN JianBo & ZHANG GengMin Key Laboratory for the Physics and chemistry of Nanodevices and department of Electronics,{3. university,beijing 100871,China 1. Key Laboratory for the Physics and chemistry of Nanodevices and department of Electronics Peking University Beijing 100871 China

We report a facile method to grow multi-sectional TiO2 nanotube arrays consisting of alternating bamboo-shaped and smooth-walled nanotube sections by *** key factors are necessary for obtaining these ***,in order to avoid possible disruptions between the conjoint sections of the nanotube,the distribution of hydrogen ions is suggested not to be fiercely disturbed when switching from the first to the second ***,to avoid the disruption of the nanotube at the joint which results from the disparity in diameters between sections,the direct current voltage is set to be the maximum of the square wave *** newly developed TiO2 nanotube arrays are expected to have potential applications in solar cells,drug release and delivery systems.

关键词： titanium dioxide titania nanotube anodic oxidation

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SYNTHESIS AND CHARACTERIZATION OF POLYSILOXANE CONTAINING OLIGO(OXYETHYLENE)SULFATE SALT

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Chinese Journal of polymer science 2000年第2期18卷 109-113页

作者： Shu-wen Hu Zheng-cheng Zhang FanYi Shi-bi Fang Xin-feng Zhang Fu-mian Li department of chemistry, {3. university, beijing 100871, China Chinese Acad Sci Inst Chem Beijing 100080 Peoples R China peking Univ Dept Chem Beijing 100871 Peoples R China

Solvent-free polymeric alkali-metal ion conductors, consisting of a comb-like polysiloxane with oligo(oxyethylene) side chains and pendant sulfate groups were synthesized by the hydrosilylation of allyl oligo(oxyethylene) sulfate salt and allyl methoxy oligo(oxyethylene) with poly(methylhydrosiloxane). The factors influncing the ionic conductivity of the resulting polymer such as the electrolyte content and the nature of the alkali-metal were investigated. The temperature dependence of conductivity was determined, and the ionic conductivity of the polymer follows the Vogel-Tammann-Fulcher (VTF) equation.

关键词： hydrosilylation electrolytes ionic conductivity

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Electronic structure and magnetism of R(Fe,Si)_(12) (R=Y,Nd)

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science China(Physics,Mechanics & Astronomy) 2006年第2期49卷 195-202页

作者： SUN Guang’ai1, CHEN Bo1, DU Honglin2, FAN Zhijian1, GAO Tao3.& qi Xinhua3.. Institute of Nuclear Physics and chemistry, China Academy of engineering Physics, Mianyang 621900, China 2. {3. of physics, peking university, beijing 100871, China 3. Institute of Atomic and Molecular Physics, Sichuan university, Chengdu 610065, China 1. Institute of Nuclear Physics and chemistry China Academy of Engineering Physics Mianyang 621900 China 2. department of physics Peking university Beijing 100871 China 3. Institute of Atomic and Molecular Physics Sichuan University Chengdu 610065 China

The newly developed full-potential linearized augmented plane wave (LAPW) and local orbitals (lo) based on standard APW methods are briefly introduced, and the structure and magnetic properties of R(Fe, Si)12 compounds (R = Y, Nd) are calculated using the method. The distribution of Si at different sites is analyzed based on total energy of one crystal unit with structure having been optimized. The characters of magnetic mo-ments, total density of states (TDOS) and partial density of states (PDOS) for different crystal sites Si occupies are obtained and analyzed. The results show that the total mag-netic moments of RFe10Si2 (R = Y, Nd) are larger than those of RFe10M2 (M = Ti, V, Cr, Mn, Mo and W) and the hybridization mechanism is seen as follows. Si(8j) reduce the mag-netic moments of Fe at three sites, however, Si(8f) mainly reduce the magnetic moments of Fe(8i) and Fe(8j) atoms. The Curie temperature is markedly enhanced by the introduc-tion of Si atoms according to spin fluctuation of DOS at Fermi level.

关键词： (L)APW+lo method R(Fe Si)12(R = Y Nd) magnetic moment Density of state.

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Ordered Bicontinuous Network Structures Regulated by Orientational Interactions in a Rod-Coil Block Copolymer

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Chinese Journal of polymer science 2024年第5期42卷 636-642,I0008页

作者： Xiao-Lin Lyu Shi-Chu Yang An-qi Xiao Ping-Ping Hou Wei Zhang Hong-Bing Pan Zhi-Hao Shen Xing-He Fan qi-feng Zhou beijing National Laboratory for Molecular sciences Key Laboratory of Polymer Chemistry and Physics of Ministry of EducationCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing100871China Key Laboratory of Advanced Materials Technologies International(HongKong Macao and Taiwan)Joint Laboratory on Advanced Materials TechnologiesCollege of Materials Science and EngineeringFuzhou UniversityFuzhou350108China

The rich phase behavior of block copolymers(BCPs)has drawn great attention in recent ***,the double diamond(DD)phase is rarely obtained because of the competition between the minimization of interfacial energy and packing ***,a rod-coil BCP containing mesogen-jacketed liquid crystalline polymer is designed to acquire ordered bicontinuous network *** reduction of internal energy originating from the orientational interaction among the rod blocks can compensate for the free energy penalty of packing frustration to stabilize the DD *** resulting BCP can also experience lamellae-to-DD and double gyroid-to-lamellae transitions by changing the annealing *** results make the rod-coil BCP an excellent candidate for the self-assembly of ordered network structures,demonstrating great potential in nanopatterning and metamaterials.

关键词： Block copolymer Rod-coil Ordered bicontinuous phase Double diamond Double gyroid

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polymerIZATION OF p-DIETHYNYLBENZENE INITIATED BY Ni(C≡CC_6H_4C≡CH)_2(PPH_3._2

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Chinese Journal of polymer science 2001年第3期19卷 303-309页

作者： Mu-jie Yang Xiao-wei Zhan department of polymer science and {3. Zhejiang university Hangzhou 3.0027, China Present address: Institute of chemistry, Chinese Academy of sciences, beijing 100080, China 浙江大学浙江杭州

Homogeneous polymerization of p-diethynylbenzene initiated by nickel acetylide Ni(C ≡ C C_6H_4 C ≡ CH)_2(PPh_3._2has been investigated in terms of different solvents, addition agents, atmosphere gases, catalyst concentrations, monomerconcentrations and polymerization temperatures. The yield and catalytic efficiency approach 88% and 11. 1 kg polymer/molNi, respectively, under the optimum conditions: [cat] = 0.01 mol/L, [M] = 1.0 mol/L, NEt_3.cat (mol ratio) = 3.5, 1,4-dioxane/toluene (volume ratio) = 1 and T = 25℃ for 5 h. The polymerization rate equation can be expressed as R_p =k_p[M][cat]~2, where k_p= 0.47 L^2. mol^(-2)·S^(-1) (25℃). The overall polymerization activation energy was found to be203.kJ·mol^(-1). Poly(p-diethynylbenzene) so obtained is soluble in THF, CHCl_3.and toluene with weight-average molecularweights as high as 27, 100 and a rich-trans extended π-conjugated polyene chain structure with pendent groups ofp-C_6H_4C≡CH.

关键词： polymerization p-Diethynylbenzene Nickel acetylide Catalyst

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FABRICATION AND AFM/FFM STUDIES OF C_(60)-CONTAINING POLYELECTROLYTE SELF-ASSEMBLED FILMS

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Chinese Journal of polymer science 2002年第3期20卷 197-203页

作者： Lan Huang Xiao-rong Hou Yuan-kang He Xiao-liang Zheng Fang Wei Xin-sheng Zhao Wei-xiao Cao college of chemistry & Molecular engineering {3. university beijing 100871, China peking Univ Coll Chem & Mol Engn Beijing 100871 Peoples R China

An initial investigation on the roughness and frictional properties of the self-assembled thin films from polyelectrolytes is presented. Star-shaped C-60-Poly(styrene-maleic anhydride) was successful prepared. The multilayer thin films have been fabricated on mica with diazoresin as the cationic polyelectrolyte and hydrolyzed star-shaped C-60-poly(styrene-maleic anhydride) as the anionic polyelectrolyte via self-assembly technique. The crosslinking structure of the films is formed from the conversion of ionic bond to covalent bond after UV irradiation. AFM/FFM investigations provide insights into the roughness and frictional properties on a microscale. The roughness depends strongly on the number of film layers in the case of C-60-containing films. The frictional forces of the films exhibited a well behaved non-linear relationship in response to the change of applied load. It supports the prediction of enhanced load-bearing property Of C60-containing thin films.

关键词： star-shaped C-60-poly(styrene-maleic anhydride) self-assembly film AFM/FFM roughness frictional properties

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Thermodynamic evaluation and hydrothermal preparation of K_xNa_(1-x)NbO_3

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Rare Metals 2008年第4期27卷 371-377页

作者： ZHANG Ci LV Haijun GUO Min ZHANG Mei WANG Xidong department of Physical chemistry University of Science and Technology Beijing Beijing 100083 China college of engineering. peking {3. Beijing 100871 China

The Gibbs free energies of reaction △rGτ of KNbO3.and NaNbO3.were calculated and then that of KxNa1-xNbO3.was estimated. On the basis of the thermodynamic calculation results, the hydrothermal temperatures were designed at 100, 160, and 23.℃ respectively. However, NaNbO3.was prepared when the heating temperature was higher than 160℃, and KNbO3.and KxNa1-xNbO3.were obtained at 23.℃, suggesting that only at a higher temperature the kinetic requirement is satisfied. According to the X-ray diffraction results, both the solid solutions, NaNbO3.based solid solution, Na1-xKxNbO3. and KNbO3.based solid solution, K1-xNaxNbO3. were hydrothermally synthesized in 6 mol/L alkali （NaOH and KOH） solution at 23.℃.

关键词： KNbO3 NaNbO3 thermodynamic calculation hydrothermal synthesis Gibbs free energy

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Syntheses, structures and magnetic properties of a family of one-dimensional M(Ⅱ)-lanthanide(Ⅲ) (M = Ni(Ⅱ) and Zn(Ⅱ)) coordination polymers

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science China chemistry 2007年第3期50卷 308-317页

作者： ZHANG Wen, ZHAO Fei, LIU Tao & GAO Song beijing National Laboratory for Molecular sciences, State Key Laboratory of Rare Earth Materials chemistry and Applications, {3. of chemistry and Molecular engineering, peking university, beijing 100871, China 1. beijing National Laboratory for Molecular sciences State Key Laboratory of Rare Earth Materials Chemistry and Applications College of Chemistry and Molecular Engineering Peking University Beijing 100871 China

A series of 1D nickel(II)/zinc(II)-lanthanide(III) coordination polymers, [M(μ-L)2Ln(NO3.3.n·solvents (HL = bis(2-pyridylcarbonyl)amine; M = Ni, Ln = Gd (1·NiGd), Tb (2·NiTb), Dy (3.NiDy), Ho (4·NiHo), Y (5·NiY); M = Zn, Ln = Gd (6·ZnGd), Tb (7·ZnTb), Dy (8·ZnDy), Ho (9·ZnHo); solvents = H2O or H2O-ethanol), was synthesized and characterized. All of the complexes are isostructural at 293.K and crystallize in the orthorhombic space group Fddd. Magnetic measurements were performed on 1―9, where weak ferromagnetic interaction is found in 1·NiGd, ferromagnetic interaction in 2·NiTb and 3.NiDy, and antiferromagnetic interaction in 4·NiHo. A remarkable dc magnetic field dependence of ac susceptibilities was found in this series of complexes.

关键词： nickel lanthanide 3.-4f coordination polymer magnetic property

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Study of Photostimulable Luminescence Materials Sr_9Ca(PO_4)_6Cl_2:Eu

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Rare Metals 1989年第4期9卷 49-53页

作者： Song qingfang China Criminal Police Institute,Shenyang 11003.Wang Yanji Zhao Wei Su Mianzeng department of chemistry,{3. university,beijing 100871 China Criminal Police Institute 辽宁沈阳北京大学北京

The polycrystalline Sr_9Ca(PO_4)_6Cl_2:Eu has been synthesized by solid state *** reaction condition,the appropriate raw materials and their quantity used,which may affect the photostimulable luminescence (PSL),have been systematically inves- *** properties of this PSL phosphor as a material for storing and reproducing the X-ray image in computer-aided radiography have been reported briefly.

关键词： Eu PO4 Study of Photostimulable Luminescence Materials Sr9Ca Sr Cl

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