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The 4th Joint china/Japan Chemical Engineering Symposium

作者： Xiao-Jie Jua Liang-Yin Chua b Li Liua Peng Mia Ming-Yu Zhouaand Shi-bo Zhanga a School of Chemical Engineering Sichuan University Chengdu Sichuan 610065 china.b institute for nanobiomedical technology and membrane biology State Key Laboratory of biotherapy Sichuan University Chengdu Sichuan 610065 china.

Dual thermo- and ion-responsive cross-linked poly（N-isopropylacrylamide-co-benzo-18-crown-6-acrylamide）（P（NIPAM-co-bCAm）） hydrogel was successfully prepared via thermally-initiatedfree-radical cross-linking copolymerization. both the structures and stimuli-sensitive properties of theprepared hydrogel were characterized. The results indicated that the incorporation of crown ether groups intothe poly（N-isopropylacrylamide） chains produced a smart hydrogel that responded to both temperature andion stimuli. When the crown ether units captured ba2+ ions in their cavities and formed stable bCAm/ba2+complexes, the lower critical solution temperature （LCST） of the hydrogel increased due to the repulsionamong charged bCAm/ba2+ complex groups and osmotic pressure within the hydrogel resulted from aDonnan potential that arose from mobile counter ions to the crown ether bound ba2+. Whereas crown etherscaptured Cs+ ions, the LCST shifted to a lower temperature because of the formation of 2:1 sandwichcomplexes. Unexpectedly, the LCST of the cross-linked P（NIPAM-co-bCAm） hydrogel in K+ solution didnot shift to a higher temperature, which was definitely different from the previously reported linearP（NIPAM-co-bCAm） copolymer in K+ solution. The reason may be due to the following: if the copolymerchains were cross-linked, the cavities of crown ethers were close to each other;because the stability constantof bCAm/K+ complex is not high enough, therefore the electrostatic repulsion among K+ ions affected theformation of stable bCAm/K+ complexes inside the cross-linked P（NIPAM-co-bCAm） hydrogel. The resultsof this work provide valuable information for development of dual thermo- and ion-responsive hydrogelswhich have potential applications in drug controlled-release systems or biomedical fields.

关键词： hydrogel ion-responsive N-isopropylacrylamide benzo-18-crown-6-acrylamide

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A designed amphiphilic peptide containing the silk fibroin motif as a potential carrier of hydrophobic drugs

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Progress in Natural Science:Materials International 2009年第11期19卷 1529-1536页

作者： Qinghan Zhou~a,Juan Lin~a,Jing Wang~a,Feng Li~a,Fushan Tang~a,Xiaojun Zhao~(a,b,c,*) a institute for nanobiomedical technology and membrane biology,West china Hospital,Sichuan University,Chengdu 610041,china.b State Key Lab of biotherapy of Human Diseases,Cancer Center,West china Medical School,West china Hospital,Sichuan University, Chengdu 610041,china c Center for biomedical Engineering NE47-378,Massachusetts institute of technology,MA 02139-4307,USA institute for nanobiomedical technology and membrane biology West China Hospital Sichuan University Chengdu 610041 China State Key Lab of biotherapy of Human Diseases Cancer Center West China Medical School West China Hospital Sichuan University Chengdu 610041 China Center for biomedical Engineering NE47-378 Massachusetts Institute of Technology MA 02139-4307 USA

The amphiphilic peptide is becoming attractive as a potential drug carrier to improve the dissolvability of hydrophobic drugs in an aqueous system;thus,facilitating drug uptake by target ***,we report a novel designed amphiphilic peptide,Ac-RADAGAGA-RADAGAGA -NH2,which was able to stabilize pyrene,a hydrophobic model drug we chose to study in aqueous *** designed peptide formed a colloidal suspension by encapsulating pyrene inside the peptide-pyrene *** phosphatidylcholine(EPC) vesicles were used to mimic cell bilayer *** found that pyrene was released from the peptide coating into the EPC vesicles by mixing the colloidal suspension with EPC vesicles,which was followed by steady fluorescence spectra as a function of time.A calibration curve for the amount of pyrene released into the EPC vesicles at a given time was used to determine the final concentration of pyrene released into the lipid vesicles from the peptide-pyrene *** release rate of the peptide-pyrene complex was calculated to quantify the transfer of pyrene into EPC vesicles.

关键词： Pyrene Hydrophobicity Drug carrier Fluorescence Amphiphilic peptide

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Chaotic attitude and reorientation maneuver for completely liquid-filled spacecraft with flexible appendage

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Acta Mechanica Sinica 2009年第2期25卷 271-277页

作者： b. Yue Department of Mechanics, School of Science,beijing institute of technology, 100081 beijing, china Department of Mechanics School of Science Beijing Institute of Technology Beijing China

The present paper investigates the chaotic attitude dynamics and reorientation maneuver for completely viscous liquid-filled spacecraft with flexible appendage. All of the equations of motion are derived by using Lagrangian mechanics and then transformed into a form consisting of an unperturbed part plus perturbed terms so that the system＇s nonlinear characteristics can be exploited in phase space. Emphases are laid on the chaotic attitude dynamics produced from certain sets of physical parameter values of the spacecraft when energy dissipation acts to derive the body from minor to major axis spin. Numerical solutions of these equations show that the attitude dynamics of liquid-filled flexible spacecraft possesses characteristics common to random, non- periodic solutions and chaos, and it is demonstrated that the desired reorientation maneuver is guaranteed by using a pair of thruster impulses. The control strategy for reorientation maneuver is designed and the numerical simulation results are presented for both the uncontrolled and controlled spins transition.

关键词： Nonlinear attitude dynamics Attitude reorientation maneuver Control strategyLiquid-filled spacecraft

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Enhanced activity of yqhD oxidoreductase in synthesis of 1,3-propanediol by error-prone PCR

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Progress in Natural Science:Materials International 2008年第12期18卷 1519-1524页

作者： Hongmei Li~a Jia Chen~a Yinghua Li~b a institute of Food Science and biological technology,University of Shanghai for Science and technology,Shanghai 200093,china.b institute of Pharmaceutical Engineering,Zhejiang University,Hangzhou 310027,china institute of Food Science and biological technology University of Shanghai for Science and Technology Shanghai 200093 China institute of Pharmaceutical Engineering Zhejiang University Hangzhou 310027 China

yqhD oxidoreductase was determined to be an NADP-dependent dehydrogenase,and was more active toward 3-HPA when compared to 1,3-propanediol *** further improve enzyme activity towards 3-hydroxypropionaldehyde (3-HPA),error-prone PCR was implemented to mutant yqhD *** mutants,D99QN147H and Q202A with increased catalytic and affinity efficiency,were obtained after one round of error-prone polymerase chain *** the catalytic efficiency of the mutant D99QN147H was up to 4-fold greater than the wild enzyme (0.0375 min-1mM-1vs.0.0078 min-1mM-1).The recombined strain containing pEY28yqhD D99QN147H yielded 28 g L-1of 1,3-propanediol in the fed-batch Lb cultures (1 L volume) with an initial 3-HPA concentration of 40 g L-1,which was higher than the 21 and 17 g L-1of 1,3-propanediol from the mutant Q202A and the wild-type,*** for propionaldehyde,the optimal mutant D99QN147H also exhibited higher activity on a range of substituted aldehydes than the wild- type.

关键词： yqhD oxidoreductase Error-prone PCR Catalytic efficiency 1,3-Propanediol

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A video encryption method based on chaotic maps in DCT domain

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Progress in Natural Science:Materials International 2008年第10期18卷 1299-1304页

作者： Shuguo Yang~(a,b,*) Shenghe Sun~a ~a School of Electrical Engineering and Automation,Harbin institute of technology,Harbin 150001,china ~b Qingdao University of Science and technology,Qingdao 266061,china School of Electrical Engineering and Automation Harbin Institute of Technology Harbin 150001 China Qingdao University of Science and technology Qingdao 266061 China

This paper proposes a new and secure video encryption method based on chaotic maps in DCT domain,which is quite in keeping with the common ideas and the frequent practices of video *** select the I-frames of the video sequence as encryption objects. First,we introduce two coupling chaotic maps to scramble the DCT coefficients of every original I-frame,and receive the scrambled ***,we encrypt the DCT coefficients of the scrambled 1-frame using another chaotic *** the whole process,we use three chaotic maps and five keys;the I-frame is encrypted ***,we performed several tests and the experimental results have proved our method to be secure and efficient.

关键词： Video encryption Chaotic map I-frame Scrambling Video sequence

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Theoretical observation of hexaatomic molecules containing pentacoordinate planar carbon

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Science china Chemistry 2008年第11期51卷 1030-1035页

作者： LUO Qiong State Key Laboratory of Explosion Science and technology, beijing institute of technology, beijing 100081, china State Key Laboratory of Explosion Science and technology Beijing Institute of Technology Beijing China

The smallest molecules up to date containing a D5h pentacoordinate planar carbon (PPC) atom, Cbe5 and Cbe54-, are presented by means of ab initio calculations. To gain a better understanding about which electronic factors contribute to their stabilization, natural bond orbital (NbO) analysis and the nucleus independent chemical shifts (NICS) were calculated. The data reported here suggest that D5h Cbe5 is σ aromaticity in nature, while in D5h Cbe54- π aromaticity is dominating. The classical octet rule is well satisfied in both molecules, and is one of the fundamental reasons to understand the stability of the pentagon structures. The be5 ring serves as σ donor in D5h Cbe5, and π-acceptor in D5h Cbe54-. The D5h Cbe54- possessing 18 valence electrons with a closed-shell electron configuration is the most plau-sible candidate for experimental detection.

关键词： pentacoordinate planar carbon be5 ring ab initio

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Dark output characteristic of γ-ray irradiated CMOS digital image sensors

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Rare Metals 2002年第1期21卷 79-84页

作者： MENG Xiangti and KANG A iguo institute of Nuclear Energy technology, Tsinghua University, beijing 100084, china institute of Nuclear Energy technology Tsinghua University 北京 100084

The quality of dark output images from the CMOS (complementarymetal oxide semiconductor) black and white (b & W) digital imagesensors captured before and after γ-ray irradiation was studied. Thecharacteristic parameters of the dark output images captured atdifferent radiation dose, e.g. average brightness and itsnon-uniformity of dark out- put images, were analyzed by our testsoftware. The primary explanation for the change of the parameterswith the radi- ation dose was given.

关键词： CMOS digital image sensor gamma radiation dark output characteristic Si

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Effects of alternating magnetic field on the corrosion rate and corrosion products of copper

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Rare Metals 2008年第3期27卷 324-328页

作者： GUO bin ZHANG Peng JIN Yongping CHENG Shukang School of Materials Science and Engineering Harbin Institute of Technology Harbin 150001 China institute of Electromagnetic and Electronic technology Harbin Institute of Technology Harbin 150001 China

The effects of alternating magnetic field on the corrosion morphologies, corrosion rate, and corrosion products of copper in 3.5% NaCl solution, sea water, and magnetized sea water were investigated using electrochemical test, scanning electron microscopy/energy dispersive analysis system of X-ray （SEM/EDAX）, and X-ray diffraction （XRD）. The results show that the corrosion rate of copper in magnetized sea water is minimal. Moreover, the surface of the specimen in magnetized sea water is uniform and compact as compared with those in 3.5% NaCl solution and sea water. The corrosion products of copper in magnetized sea water are mainly Cu2O and CuCl2. However, the corrosion products in sea water are CuCl, Cu2Cl（OH）3, and FeCl3-6H2O. The electrochemical corrosion mechanisms of copper in the three media were also discussed.

关键词： corrosion sea water alternating magnetic field copper corrosion products

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Recent advances in fermentative biohydrogen production

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Progress in Natural Science:Materials International 2008年第3期18卷 253-258页

作者： Xuemei Liu a,b, Nanqi Ren a, Funan Song b, Chuanping Yang b, Aijie Wang a a Harbin institute of technology, Harbin 150010, china.b Northeast Forestry University, Harbin 150040, china Harbin institute of technology Harbin 150010 China Northeast Forestry University Harbin 150040 China

Hydrogen energy, as a kind of clean energy with great potential, has been a hotspot for study worldwide. based on the recent research on biohydrogen production, this paper gives a brief review on the following aspects: fermentative hydrogen production process and the engineering control statagy, key factors affecting the effciency of hydrogen production, such as substrates, cysteine, metal ions, anaerobic fermentation terminal products, and formic acid and ammonia. Moreover, anaerobic fermentative hydrogen-producing strain and reg- ulation and control of enzyme gene in fermentative hydrogen production are also discussed. Finally, the prospect of anaerobic fermen- tative biohydrogen production is proposed in three study areas, namely developing new techniques for breeding hydrogen-producing bacteria, exploitations of more strains and gene resources, and intensifying the application of microbial molecular breeding in hydrogen production.

关键词： Fermentation biohydrogen production Regulation and control Novel strains

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Structures and aromaticity of the planar Al_2P_2^(n-) (n=1―4) clusters

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Science china Chemistry 2009年第12期52卷 2237-2242页

作者： XU WenGuo,ZHANG YuanChun & ZHAI Lei institute of Chemical Physics,beijing institute of technology,beijing 100081,china institute of Chemical Physics Beijing Institute of Technology Beijing China

Clusters Al2P2n-(n = 1―4) were theoretically investigated using density functional theory (DFT) methods at the b3LYP/6-311+G* and b3PW91/6-311+G* levels of theory. The calculated results showed that the planar structure (D2h symmetry) of Al2P2n-(n = 1―4) species was the global minimum. And the negative nucleus-independent chemical shift (NICS) value of Al2P2n-(n = 1―4) species indicated the existence of a ring current in the planar structure (D2h symmetry). A detailed molecular orbital (MO) analysis revealed that the planar structures (D2h symmetry) had π aromaticity,which further exhibited the strongly aromatic character for Al2P2n-(n = 1―4) species.

关键词： DFT calculation geometric structure nucleus-independent chemical shift molecular orbital

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