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Adsorption behavior of hexadecyltrimethylammonium bromide (CTAB) to mica substrates as observed by atomic force microscopy

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Science China Chemistry 2005年第2期48卷 101-106页

作者： ZHAO Feng1,2. DU Yukou1, YANG Ping1, LI Xingchang2.& TANG Ji’an2.1. Chemistry and Chemical Engineering Department, Suzhou University, Suzhou 2.5006, China 2. Key Laboratory of Colloid and Interface Science, Institute of Chemistry, Chinese Academy of Sciences, beijing 100080, China Correspondence should be addressed to Tang Ji’an (email: jatang@***) Chemistry and Chemical Engineering Department Suzhou University Suzhou China Key Laboratory of Colloid and Interface Science Institute of Chemistry Chinese Academy of Sciences Beijing China

atomic force microscopy is employed to study the adsorption behavior of CTAB to mica surfaces. Results show that conformational transitions from globular micelles→cylindrical micelles→flat films are observed in the process of the adsorption of CTAB to mica at twice the bulk critical concentration. However, in 0.5 cmc CTAB solution, the adsorbed CTAB molecules to mica form the layered film structures, and apparent conformational transitions do not appear. Meanwhile, the phenomena of the adsorption of CTAB to mica and the dissociation of mica sur- faces are periodically observed.

关键词： atomic force microscopy (AFM), micelle, behavior of adsorption, the dissociation of mica surfaces.

An improved method for phasing crystal structures with low non-crystallographic symmetry using cryo-electron microscopy data

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Protein & Cell 2015年第12期6卷 919-923页

作者： Jia Wang (1) (2. (3. Weiguang Wang (1) (2. Wen Song (2. (3. ({3. Zhifu Han (2. (3. ({3. Heqiao Zhang (2. (3. ({3. Jijie Chai (2. (3. ({3. Hongwei Wang (2. (3. ({3. Jiawei Wang (1) (2. 1.State Key Laboratory of Membrane Biology School of Life Sciences Tsinghua University Beijing 100084 China 2.Center for Structural Biology School of Life Sciences Tsinghua University Beijing 100084 China 3.Tsinghua-Peking Center for Life Sciences School of Life Sciences Tsinghua University Beijing 100084 China 4.Ministry of Education Key Laboratory of Protein Science School of Life Sciences Tsinghua University Beijing 100084 China

Cryo-electron microscopy （cryo-EM） and macromolecular crystallography （MX） both allow the creation of three-dimensional images of biological macromolecules. EM data usually provide access to three-dimensional reconstructions of large biological complexes at low resolution, whereas MX usually delivers atomic or quasi-atomic resolution structures （1-3.A）.

关键词： Phase Error Molecular Replacement Histogram Match TLR13.Molecule Solvent Flatten

Experimental realization of quantum cryptography communication in free space

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Science China(Physics,Mechanics & Astronomy) 2005年第2期48卷 237-246页

作者： WANG Chuan1, ZHANG Jingfu1, WANG Pingxiao1, DENG Fuguo1, AI Qing1 & LONG Guilu1,2.1. Department of Physics, Key Laboratory for Quantum Information and Measurements, Tsinghua Univer- sity, beijing 100084. China 2. Center for {2. and Molecular NanoSciences, Tsinghua University, beijing 100084. China Department of Physics Key Laboratory for Quantum Information and Measurements Tsinghua University Beijing China atomic and Molecular NanoSciences Tsinghua University Beijing China

Utilizing linear optical devices, the principle of B92.quantum key distribution (QKD) protocol is demonstrated in free space with a distance of transmission of 2.2.meters. The faint laser pulses with 650 nm wavelength are used as the single photon sources. The experimental results show that the eavesdropping behavior in the signal transmission can be detected. We also discuss the problems and solutions in using the quantum cryptography communication practically. It is pointed out that one of the approaches to increasing the distance of the quantum communication is to overcome the attenuation of the single photon in transmission. This could not be solved by the use of single photon source, and new quantum communication protocols are needed to solve these problems.

关键词： quantum key distribution, free space, linear optics, faint pulses.

Tungsten-182.Mssbauer experiments at liquid nitrogen temperature

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Chinese Science Bulletin 2001年第9期46卷 732-734页

作者： HUANG Runsheng, LIU Bing, ZHANG Jinrong, LIU Cong & GAO Xuekui1. Physics Department of Nanjing University, Nanjing 2.0093. China 2. China Institute of atomic {3., {2. 102.13. China Physics Department of Nanjing University Nanjing China China Institute of atomic energy Beijing China

A good 182.a Mossbauer source and an apparatus designed specially were made. 182. transmission Mossbauer experiments were successfully carried out, both of the source and absorber at liquid nitrogen temperature. It wa... 详细信息

关键词： Mossbauer effect 182. Mossbauer effect.

Surface roughness and removal rate in magnetorheological finishing of a subsurface damage free surface

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Progress in Natural Science:Materials International 2005年第6期15卷 538-544页

作者： CHENG Haobo1*, WANG Yingwei2. FENG Zhijing1 and CHENG Kai3.1. State Key Laboratory of Tribiology, Tsinghua University, beijing 100084. China 2. Department of Material Sciences, Changchun University of Science and Technology, Changchun 13.02., China 3. Faculty of Information and Engineering Systems, City Campus, Leeds LS1 3.E, UK) State Key Laboratory of Tribiology Tsinghua University Beijing 100084 China Department of Material Sciences Changchun University of Science and Technology Changchun 130021 China Faculty of Information and Engineering Systems City Campus Leeds LS1 3HE United Kingdom

Based on computer-controlled optical surfacing, a new technique called magnetorheological finishing (MRF), is presented. The new technique combines the features of conventional loose abrasive machining with a wheel shaped polishing tool. The tool incorporates a host of features and has unprecedented fabricating versatility. The pre-polishing and fine polishing processes can be performed only by adjusting different parameters. The material removal function is studied theoretically and the results of simulation present a Gaussian distribution feature. Based on the established theoretical model, material removal rate experiments involving a parabolic mirror are designed and carried out to determine the effect of controllable parameters on size of the gap between the workpiece and the polishing wheel, rotating speed of the polishing wheel, concentration of volume fraction of non-magnetic particles and polishing time. Further experiments are carried out on the surface microstructure of the workpiece, the final surface roughness with an initial value of 10.98 nm reaches 1.2. nm root mean square (RMS) after 2. min of polishing. The subsurface damage experiment and the atomic force microscopy (AFM) measurement on the polished surface can also verify the feasibility of the MRF technique.

关键词： magnetorheological finishing surface roughness computer controlled optical surfacing subsurface damage removal function.

Synthesis of superheavy nuclei with ^(2.8)U target

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Science China(Physics,Mechanics & Astronomy) 2009年第10期52卷 1482-1488页

作者： LIU ZuHua1,3.& BAO JingDong2.4.1 Key Laboratory of Beam Technology and Material Modification of Ministry of Education,beijing Normal University,beijing 100875,China 2.Department of Physics,beijing Normal University,beijing 100875,China 3.China Institute of {4. energy,beijing 102.13.China 4.Center of Theoretical Nuclear Physics,National Laboratory of Heavy Ion Accelerator of Lanzhou,Lanzhou 73.000,China Key Laboratory of Beam Technology and Material Modification of Ministry of Education Beijing Normal University Beijing China China Institute of atomic energy Beijing China Department of Physics Beijing Normal University Beijing China Center of Theoretical Nuclear Physics National Laboratory of Heavy Ion Accelerator of Lanzhou Lanzhou China

The production of superheavy nuclei with Z=108-116 via hot fusion reactions of the neutron-rich projectiles with 2.8U target is systematically *** results show that the production cross sections of superheavy nuclei do not decrease monotonously as the atomic number Z *** cross sections of the superheavy nuclei at Z = 112.and 115 are enhanced as compared with the whole Z-trend in synthesis of the superheavy nuclei,which clearly illustrates that the reactions with large negative Q-value and shell correction are more favorable to synthesize superheavy nuclei.

关键词： superheavy nuclei fusion reaction cross section 2.8U target

Properties of the 3.2.-[52.] band in the odd-N rare-earth nuclei

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Science China(Physics,Mechanics & Astronomy) 2011年第S1期54卷 37-43页

作者： CHEN Liang1,2. ZHOU XiaoHong1,2. ZHANG YuHu1, ZHANG ShuangQuan3.& ZHU LiHua4.1Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 73.000, China 2.raduate University of Chinese Academy of Sciences, beijing 10004., China 3.tate Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, beijing 100871, China 4.hina Institute of atomic energy, beijing 102.13. China Institute of Modern Physics Chinese Academy of Sciences Lanzhou China Graduate University of Chinese Academy of Sciences Beijing China State Key Laboratory of Nuclear Physics and Technology School of Physics Peking University Beijing China China Institute of atomic energy Beijing China

High-spin states in 161Er have been studied experimentally via the 150Nd(16O, 5n) reaction at a beam energy of 86 MeV. Three rotational bands built on the 5/2.[64.], 3.2.[52.], and 11/2.[505] configurations have been extended up to high-spin states, and particularly, the α = -1/2.branch of the ground state 3.2.[52.] band has been revised significantly. It is found that signature inversion occurs in the 3.2.[52.] band after the band crossing in 161Er. The systematics of the signature inversion associated with the 3.2.[52.] configuration in the rare-earth region is discussed. The band properties are analyzed within the framework of a triaxial particle-rotor model, and a triaxial deformation is proposed to the 3.2.[52.] band.

关键词： high-spin states signature inversion triaxial particle-rotor model

Measuring-basis-encrypted six-state quantum key distribution scheme

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Progress in Natural Science:Materials International 2006年第1期16卷 84-89页

作者： CHEN Pan1, DENG Fuguo1, WANG Pingxiao1 and LONG Guilu1,2.(Key Laboratory for Quantum Information and Measurements and Department of Physics, Tsinghua University, beijing 100084. China 2. Key Laboratory for {2. and Molecular NanoSciences, Tsinghua University, beijing 100084. China) Key Laboratory for Quantum Information and Measurements Department of Physics Tsinghua University Beijing 100084 China Key Laboratory for atomic and Molecular NanoSciences Tsinghua University Beijing 100084 China

A six-state quantum key distribution scheme with measuring-basis encryption technique, which is based on the six-state protocol and the MBE protocol, is proposed. In this modified six-state quantum key distribution protocol, Alice and Bob use a control key to synchronize the use of their measuring-basis so that they always use the same measuring-basis. This modified six-state quantum key distribution protocol retains the advantage of higher security and at the same time has a higher efficiency.

关键词： quantum key distribution measuring-basis encrypted six-state security.

AFM study on the adsorption and aggregation behavior of dissolved humic substances on mica

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Science China Chemistry 2006年第3期49卷 256-266页

作者： GE Xiaopeng1, ZHOU Yanmei2. Lü Chunhua1 & TANG Hongxiao1 1. State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, beijing 100085, China 2. School of Civil Engineering & Architecture, beijing Jiaotong University, beijing 10004., China State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing China School of Civil Engineering & Architecture Beijing Jiaotong University Beijing China

Humic substances constitute the major organic fractions of soils, sediments and natural waters, and play a dominant role in the binding, mobilization, transport and ultimate fate of organic contaminants in subsurface systems. In this paper, two humic acid samples, Guanting and Tianjin, with different origin and chemical compositions have been investigated with AFM imaging for their adsorption and aggregation behaviors on mica. While the Tianjin humic sample is found to form small spheres with 2.0 to 3.0 nm in diameter at lower concentrations, irregular loop-chain assemblies of hundreds of nanometer in diameter with the chain width of about 4. nm are dominant for the Guanting humic sample, which may attribute to the more polar aliphatic fractions in the chemical composition in the latter. The heterogeneous and polydisperse nature of humic substances with multiple structural features, such as sponge-like structures, perforated sheets, aggregate of spheres, branches and chain-like assemblies etc., is apparent at higher concentrations for both humic samples, showing morphologically new evidence for the dominant view of the humic dual-mode sorption model. With naphthalene introduced, the assemblies of Guanting humic substances clearly become more compact with significantly narrowed branches and less porous the perforated sheet-like structures. It is indica- tive of that smaller nanometer scale rings present along the perforated assemblies could potentially represent hydrophobic domains, which may facilitate the adsorption and aggregation of naphthalene onto the natural particle surfaces and therefore lead to an important role of dissolved humic sub- stances in the sorption of environmental pollutants.

关键词： atomic force microscopy (AFM) dissolved humic substances morphology aggregation adsorption