Acta Phys Research Articles

Preparation, Characterization and Gas Sensing Mechanism of ZnO-Doped SnO<sub>2</sub> Nanofibers

SnO2 nanofibers were fabricated by electrospinning, using SnCl2∙2H2O as the raw material. The influences of ZnO doping on the morphologies, structures, and compositions of the SnO2 nanofibers were studied by introducing different amounts of ZnO into the SnO2. The crystallography and microstructures of the synthesized SnO2/ZnO composite nanofibers with different molar ratios of Sn to Zn were investigated using thermogravimetric/differential thermal analysis (TG-DTA), X-ray diffraction (XRD), Fouriertransform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and energy dispersive X-ray (EDX) spectroscopy. The obtained SnO2/ZnO composite nanofibers with different ZnO contents had hollow hierarchical structures composed of nanocrystals. Different amounts of ZnO gave different structures. The characterization results showed that the introduction of ZnO into SnO2 played an important role in the SnO2 nanofiber structure. The gas sensing properties of sensors based on different ZnO-doped SnO2 nanofibers were tested. The results indicated that the methanol-sensing performance of the sensor containing SnO2/ZnO in a molar ratio of 1:1 was better than those of the others. The sensing mechanisms of ZnO-doped SnO2 nanofibers were examined in detail. Possible reasons for the enhanced 781 Acta Phys. -Chim. Sin. 2014 Vol.30

Hirshfeld Charge as a Quantitative Measure of Electrophilicity and Nucleophilicity: Nitrogen-Containing Systems

To accurately predict the capability and possible reaction site for atoms in molecules to donate or accept electrons in chemical processes, i.e., to quantitatively determine electrophilicity, nucleophilicity, and regioselectivity, is an important yet incomplete task. Earlier, we proposed using the Hirshfeld charge and information gain as two equivalent descriptors for this purpose, based on the Information Conservation Principle we recently proposed. This idea was successfully applied to two series of molecular systems to confirm its validity. However, our previous work is hindered by the fact that the involved element is carbon. It is unclear if 2055 Acta Phys. -Chim. Sin. 2014 Vol.30

Molecular Dynamics Simulation of Dopamine Diffusion within and Permeation through POPC Phospholipid Bilayer Membrane

Dopamine, which is an important neural transmitter in brain tissue, needs to move freely within and through cell membranes to fulfill its function. The molecular dynamics of dopamine diffusion within and permeation through, cell membranes are involved in smoothing dopamine molecular protective channels, associated with schizophrenia and Parkinson′s disease. In the present work, using a 1palmitoyl2oleoylglycero3phosphatedylcholine (POPC) phospholipid bilayer membrane to model the cell membrane, we obtained the freeenergy changes (ΔG) for dopamine diffusion within and permeation through the cell membrane, using molecular dynamics simulations, and probed the molecular dynamics of dopamine diffusion and permeation. The obtained values of ΔG for dopamine diffusion within the cell membrane were 10-54 kJ∙mol-1 at 310 K, which implies that dopamine diffuses easily horizontally and vertically within the cell membrane to protect smoothing of the protective channel. However, it is not easy for dopamine to permeate through the cell membrane, because ΔG for this process was 117-125 kJ∙mol-1 (310 K). Superfluous dopamine passes through the dopamine molecular protective channel and enters the middle region of the phospholipid bilayer membrane, and then diffuses easily along the horizontal and vertical orientations within the cell membrane, even permeating through the cell membrane, preventing 183 Acta Phys. -Chim. Sin. 2014 Vol.30 schizophrenia. It is therefore important for the normal function of a biological cell membrane to protect smoothing of dopamine molecular protective channels, preventing schizophrenia. These results are in agreement with other experimental observations.

Effect of CO<sub>2</sub> Pretreatment Operation Conditions on the Catalytic Performance and Structure of Ni-Co Bimetallic Catalyst

The performance of the Ni-Co bimetallic catalyst was significantly improved by a novel H2 and CO2 (HCD) pretreatment in the dry reforming of methane compared with traditional H2 pretreatment. The effects of the HCD pretreatment operating conditions, such as pretreatment time, temperature, gas feeding ratio, and gas flow rate, on the catalytic performance of Ni-Co bimetallic catalyst were investigated. The optimal pretreatment time, temperature, gas feeding ratio (CH4/CO2), and gas flow rate were 0.5-1 h, 780800 °C, 0:10, and 175-200 mL∙min-1, respectively. Biogas was simulated with CH4 and CO2 in a volume ratio of 1 and without any other diluted gas. The catalyst was characterized by Xray diffraction (XRD), transmission electron microscopy (TEM), and thermogravimetry (TG) coupled to differential scanning calorimetry (DSC). In a 511 h stability test under the optimized operating conditions, the catalyst pretreated with both H2 and CO2 exhibited excellent stability. The average conversions of CH4 and CO2, selectivities for H2 and CO, and volume ratio of H2/CO were 96%, 97%, 98%, 99%, and 0.98, respectively. The average carbon deposition rate over the Ni-Co bimetallic catalyst was only about 0.2 mg∙g-1∙h-1. The characterization results revealed that the sintering speed of the metal greatly decreased with testing time, and the metal particle will not greatly sinter with further testing time. The amount of deposited carbon on the catalyst gradually decreased and growth of filamentous carbon over the surface of the catalyst could be inhibited. 1325 Acta Phys. -Chim. Sin. 2014 Vol.30

Investigation of concealed objects detection in visible, infrared and terahertz ranges of radiation

One of the most crucial social issues is assuring the safety of crowded public places like e.g. airports. One aspect of this problem is the detection of potentially dangerous objects hidden under person’s clothing. There are various solutions to find different suspicious elements: from simple metal detectors up to X-ray scanners. Moreover, some of available solutions are harmful to human beings. Therefore, there is a great potential in using multispectral surveillance imagers in security systems and that is why we investigate the possibilities of concealed object detection by screening people using non-invasive cameras working in various spectral ranges. Full Text: PDF References C. Jansen et al., "Terahertz imaging: applications and perspectives", Appl. Optics 19, 49 (2010). CrossRef M.C. Kemp, "Millimetre wave and terahertz technology for the detection of concealed threats: a review", Proc. SPIE 6402, 64020D (2006). CrossRef E. Grossman et al., "Passive terahertz camera for standoff security screening", Appl. Optics 19, 49 (2010). CrossRef L. Yun-Shik, Principles of Terahertz Science and Technology (Springer 2008). CrossRef X. Zhang, J. Xu, Introduction to THz Wave Photonics (Springer 2010). CrossRef B.B. Hu, M.C. Nuss, "Imaging with terahertz waves", Opt. Lett. 20, 16 (1995). CrossRef M. Piszczek, M. Kowalski, M. Szustakowski, "Measurement Stand for TeraEYE Inspection", Acta Phys. Pol. A 4, 120 (2011). DirectLink M. Kastek et al., "Multispectral and hyperspectral measurements of soldier's camouflage equipment", Proc. SPIE 8382, 83820K (2012). CrossRef M. Kastek et al., "Method of gas detection applied to infrared hyperspectral sensor", Phot. Lett. Poland 4, 4 (2012). CrossRef http://www.digitalbarriers.com/products/thruvision/ DirectLink M. Kastek, T. Piątkowski, P. Trzaskawka, "Infrared imaging fourier transform spectrometer as the stand-off gas detection system", Metrology and Measurement Sys. 18, 4 (2011). DirectLink M. Kowalski, N. Palka, M. Piszczek, M. Szustakowski, "Hidden Object Detection System Based on Fusion of THz and VIS Images", Acta Phys. Pol. A 124, 3 (2013). CrossRef M. Kowalski, N. Palka, M. Piszczek, M. Szustakowski, "Processing of THz images acquired by passive camera", Phot. Lett. Poland 4, 3 (2012). CrossRef M. Kowalski, N. Palka, M. Piszczek, M. Szustakowski, "The methodology of THz-VIS fused images evaluation", Phot. Lett. Poland 5, 1 (2013). CrossRef

A Multiparty Controlled Bidirectional Quantum Secure Direct Communication and Authentication Protocol Based on EPR Pairs

A multiparty controlled bidirectional quantum secure direct communication and authentication protocol is proposed based on EPR pair and entanglement swapping. The legitimate identities of communicating parties are encoded to Bell states which act as a detection sequence. Secret messages are transmitted by using the classical XOR operation, which serves as a one-time-pad. No photon with secret information transmits in the quantum channel. Compared with the protocols proposed by Wang et al. [Acta Phys. Sin. 56 (2007) 673; Opt. Commun. 266 (2006) 732], the protocol in this study implements bidirectional communication and authentication, which defends most attacks including the ‘man-in-the-middle’ attack efficiently.

Nonlinear discrete light propagation in photonic liquid crystal fibers

In this report, the results of numerical simulations describing (discrete) light propagation in photonic liquid crystal fibers (PLCFs) are presented. Specifically, the deviation in the spatial broadening of the beams characterized by different initial widths is analyzed. In this context, particular attention is devoted to the cases in which thermal (optical) nonlinearity in liquid crystals (LCs) is taken into account. Spatial light localization and/or delocalization are demonstrated, with the final scenario determined by the initial width and amplitude of the light beam. In particular, possibility of the discrete soliton generation is demonstrated. A qualitative comparison with experimental data obtained in analogous conditions (with use of specific PLCF samples) is also made. Full Text: PDF References P. St. J. Russell, "Photonic Crystal Fibers", Science 299, 358 (2003). CrossRef E. Poli, A.Cucinotta, S. Selleri, Photonic Crystal Fibers. Properties and Applications (Springer, The Netherlands 2007). T.R. Woliński et al., "Emerging photonic devices based on photonic liquid crystal fibers", Phot. Lett. Poland 3(1), 20 (2011). CrossRef I-C. Khoo, S-T. Wu, Optics and Nonlinear Optics of Liquid Crystals (World Scientific Pub., Singapore 1993). CrossRef J. Schirmer et al., "Birefringence and Refractive Indices Dispersion of Different Liquid Crystalline Structures", Mol. Cryst. Liq. Cryst. 307(1), 17 (1997). CrossRef J. Fleischer, M. Segev, N. Efremidis, D. Christodoulides, "Observation of two-dimensional discrete solitons in optically induced nonlinear photonic lattices", Nature 422, 147 (2003). CrossRef F. Lederer, Y. Silberberg, "Discrete Solitons", Opt. Photon. News 2, 48 (2002). CrossRef A. Szameit, D. Blömer, "Hexagonal waveguide arrays written with fs-laser pulses", J. Burghoff, Appl. Phys. B 82, 507 (2006). CrossRef K.A. Rutkowska, K. Orzechowski, "Discrete light propagation in microstructured fibers infiltrated with liquid crystals", Proc. SPIE 8697, 86971F (2012). CrossRef M.S. Chychłowski et al., "Photo-Induced Orientation of Nematic Liquid Crystals in Microcapillaries", Acta Phys. Pol. A, 118, 1100 (2010). DirectLink

Preparation of Grafted PTFE Fiber Metallic Complexes and Their Photocatalytic Degradation Abilities

Polyacrylic acid grafted polytetrafluoroethylene (PAA-g-PTFE) fibers were coordinated with Fe + ions and with a mixture of Cu + and Fe + ions to prepare PAA-g-PTFE Fe and Cu-Fe bimetallic complexes. The chemical structures and light adsorption properties of the complexes were characterized using Fourier transform infrared (FTIR) spectrometry and UV-Vis diffuse reflection spectroscopy (DRS), respectively. The complexes were used as heterogeneous photo-Fenton catalysts in the oxidative degradation of the azo dye, Reactive Blue 222, in different pH aqueous media. The results indicate that Fe + coordinates with six carboxyl groups grafted on the surface of PAA-g-PTFE in the presence or absence of Cu + ion, and improved light adsorption properties are achieved in the UV and visible regions. When both metal ions coexist in solution, the Cu ion coordinates more easily with PAA-g-PTFE than Fe to produce a PAA-g-PTFE Cu-Fe bimetallic complex. Moreover, PAA-g-PTFE Fe significantly increases the degradation of Reactive Blue 222 in the pH range 3-9 under visible irradiation. However, at high pH conditions (>7) the catalytic ability is reduced. Increasing the Fe content, and especially incorporating Cu ions in the complex, dramatically improves the catalytic reusability at high pH value. [Article] doi: 10.3866/PKU.WHXB201210152 www.whxb.pku.edu.cn 物理化学学报(Wuli Huaxue Xuebao) Acta Phys. -Chim. Sin. 2013, 29 (1), 157-166 January Received: August 20, 2012; Revised: October 15, 2012; Published on Web: October 15, 2012. ∗Corresponding author. Email: dyefib@yahoo.com.cn; Tel: +86-22-83955359. The project was supported by the Tianjin Municipal Science and Technology Committee for a Research Program of Application Foundation and Advanced Technology, China (11JCZDJ24600) and National Natural Science Foundation of China (20773093). 天津市应用基础与前沿技术重点研究计划(11JCZDJC24600)和国家自然科学基金(20773093)资助项目 C Editorial office of Acta Physico-Chimica Sinica 157 Vol.29 Acta Phys. -Chim. Sin. 2013

Influence of Surface Acidity of Y Zeolites on the Adsorption of Organic Molecules by <em>In situ</em> Fourier Transform Infrared Spectroscopy

The surface acidity of Y-type zeolites (HY and NaY) modified by solid state ion exchange (SSIE) and liquid phase ion exchange were characterized by in situ Fourier transform infrared (FTIR) spectroscopy using pyridine as the probe molecule (Py-FTIR). The adsorption of single probe molecules (thiophene, cyclohexene and benzene) and double probe molecules (thiophene and cyclohexene, thiophene and benzene) compared with sorbents were studied using in situ FTIR spectroscopy. The results indicated that the Bronsted acid (B acid) of HY (L-CeY) is the catalytic center of cyclohexene dimerized alkenyl carbenium ions and thiophene oligomerization, while the Lewis acid (L acid) is the major center of adsorption of thiophene, cyclohexene, and benzene. In addition, there is strong chemisorption and competitive adsorption of cyclohexene and thiophene, which provides evidence for the poor performance [Article] doi: 10.3866/PKU.WHXB201303183 www.whxb.pku.edu.cn 物理化学学报(Wuli Huaxue Xuebao) Acta Phys. -Chim. Sin. 2013, 29 (6), 1273-1280 June Received: January 2, 2013; Revised: March 18, 2013; Published on Web: March 18, 2013. ∗Corresponding author. Email: lsong56@263.net; Tel/Fax: +86-24-56860658. The project was supported by the National Natural Science Foundation of China (20976077, 21076100), Major Program of Petroleum Refining of Catalyst of Petro China Company Limited (10-01A-01-01-01), Innovation Team of Liaoning Province Colleges, China (200T110), and Construction Project of Liaoning Province High-end Talent Team. 国家自然科学基金(20976077, 21076100),中国石油天然气股份有限公司炼油催化剂重大专项(10-01A-01-01-01),辽宁省高校创新团队项目 (200T110)及辽宁省高端人才队伍建设项目资助 C Editorial office of Acta Physico-Chimica Sinica 1273 Vol.29 Acta Phys. -Chim. Sin. 2013 of removing sulfur. The S-CeY zeolite has abundant of weak Lewis acid sites. The sorbent is good at absorbing thiophene, while the influence of the competition adsorption of cyclohexene was not predominately. As to NaY zeolite, there is no preference for adsorption of thiophene, cyclohexene and benzene.

Acoustic band fracture variation of low frequency transmission zone in one-dimensional solid-fluid periodic structures under omnidirectional incidence

摘要 利用传递矩阵法, 从理论上建立了全向入射条件下一维固-流周期结构中的声传播模型, 在此基础上计算、分析并比较了无限周期结构的声能带结构和有限周期结构中的声传输特性. 研究结果表明, 当声波以一定的入射角入射时, 固-流周期结构的低频通带区域存在一个声裂隙, 该声裂隙所对应的入射角大小与构成周期结构的固体层和流体层的密度或结构尺寸无关, 而仅取决于构成该周期性结构材料的波速. 关键词: 传递矩阵 / 全向入射 / 固-流周期结构 / 声裂隙 Abstract In order to study the characteristics of acoustic/elastic wave propagation in one-dimensional (1D) solid-fluid periodic structure incited by omnidirectional incidence, a theoretical model of wave propagation in 1D solid-fluid periodic structure is established using a transfer matrix method. Based on this model, the band structures of the infinite case and the transmission properties of the finite one are further calculated and analyzed. The results show that an acoustic band fracture appears in the low frequency transmission zone for a certain incident angle. The corresponding incident angle of the fracture is non-relevant to the mass densities or the thicknesses of the solid and fluid layers constituting the periodic structure, and determined only by the wave velocity of the constituent material. Keywords: transfer matrix / omnidirectional incidence / solid-fluid periodic structure / acoustic band fracture 作者及机构信息 刘聪, 徐晓东, 刘晓峻 1. 南京大学, 近代声学教育部重点实验室, 南京 210093 基金项目: 国家自然科学基金(批准号: 11074126, 11274171, 11074124)和高等学校博士学科点专项科研基金(批准号: 20120091110001)资助的课题. Authors and contacts Liu Cong, Xu Xiao-Dong, Liu Xiao-Jun 1. Key Laboratory of Modern Acoustics, Nanjing University, Nanjing 210093, China Funds: Project supported by the National Natural Science Foundation of China (Grant Nos. 11074126, 11274171, 11074124) and the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20120091110001). 参考文献 [1] Kushwaha M S, Halevi P, Dobrzynski L, Djafari-Rouhani B 1993 Phys. Rev. Lett. 71 2022 [2] Martinezsala R, Sancho J, Sanchez J V, Gomez V, Llinares J, Meseguer F 1995 Nature 378 241 [3] Wang G, Wen J H, Han X Y, Zhao H G 2003 Acta Phys. Sin. 52 1943 (in Chinese) [王刚, 温激鸿, 韩小云, 赵宏刚 2003 物理学报 52 1943] [4] Wen J H, Wang G, Yu D L, Zhao H G, Liu Y Z 2005 J. Appl. Phys. 97 114907 [5] Gao G Q, Ma S L, Jin F, Kim T B, Lu T J 2010 Acta Phys. Sin. 59 393 (in Chinese) [高国钦, 马守林, 金峰, 金东范, 卢天健 2010 物理学报 59 393] [6] Zhao D G, Liu Z Y, Qiu C Y, He Z J, Cai F Y, Ke M Z 2007 Phys. Rev. B 76 144301 [7] Jia H, Ke M Z, He Z J, Peng S S, Liu G Q, Mei X F, Liu Z Y 2009 J. Appl. Phys. 106 044512 [8] Wei Q, Cheng Y, Liu X J 2011 Acta Phys. Sin. 60 124301 (in Chinese) [魏琦, 程营, 刘晓峻 2011 物理学报 60 124301] [9] El Hassouani Y, El Boudouti E H, Djafari-Rouhani B, Aynaou H, Dobrzynski L 2006 Phys. Rev. B 74 144306 [10] El Hassouani Y, El Boudouti E H, Djafari-Rouhani B, Rais R 2007 J. Phys.: Conf. Ser. 92 012113 [11] Kafesaki M, Economou E N 1999 Phys. Rev. B 60 11993 [12] Sigalas M M, Garcia N 2000 J. Appl. Phys. 87 3122 [13] Notomi M 2000 Phys. Rev. B 62 10696 施引文献

Significantly Improved Visible Light Photocatalytic Activity of <em>γ</em>-Bi<sub>2</sub>MoO<sub>6</sub> by Surface Modification with Cu<sub>2</sub>O Nanoparticles

Nanosized cuprous oxide (Cu2O) was used to modify the surface of γ-Bi2MoO6, resulting in highly efficient visible-light-responsive Cu2O/γ-Bi2MoO6 composite photocatalysts. The obtained photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), X-ray photoelectron spectroscopy (XPS), and UV-Vis diffuse reflectance spectrum (UV-Vis-DRS) to determine their phase structures, micromorphologies, and light absorption properties. The important role of surface-modified Cu2O in improving the photocatalytic activity of γ-Bi2MoO6 under visible light irradiation was studied using the degradation of methylene blue (MB). The results showed that Cu2O nanoparticles with average size of ~10 nm modified the surface of the γ-Bi2MoO6. The nanoparticles delivered both an obvious red-shift of absorption threshold and intensity of the γ-Bi2MoO6, as well as enhanced separation efficiency of photogenerated carriers, thereby leading to significant enhancement in photocatalytic activity. When the amount of Cu2O was 1.5%, [Article] doi: 10.3866/PKU.WHXB201301151 www.whxb.pku.edu.cn 物理化学学报(Wuli Huaxue Xuebao) Acta Phys. -Chim. Sin. 2013, 29 (4), 813-820 April Received: October 31, 2012; Revised: January 14, 2013; Published on Web: January 15, 2013. ∗Corresponding authors. HAN Yu-Qi, Email: hanyq@hxu.edu.cn; Tel: +86-936-8282067. WANG Fang, Email: wangfang987@126.com; Tel: +86-936-8282066. The project was supported by the National Natural Science Foundation of China (51263008), Principal Fund of Hexi University, China (XZ2010), University Science and Technology Innovation Project of Hexi University, China, and General Projects of Key Laboratory of Hexi Corridor Resources Utilization of Gansu Universities, China (XZ1012). 国家自然科学基金(51263008),河西学院校长基金(XZ2010),河西学院大学生科技创新项目和甘肃省高校河西走廊特色资源利用省级重点实 验室面上项目(XZ1012)资助 C Editorial office of Acta Physico-Chimica Sinica 813 Vol.29 Acta Phys. -Chim. Sin. 2013 the photocatalytic activity of the Cu2O/γ-Bi2MoO6 composite photocatalyst was 6.4 times higher than that of pristine γ-Bi2MoO6.

Comparison of Enzymatic Activities and Electroactivities of Adsorbed Glucose Oxidase on Several Nanomaterial-Modified Electrodes

The quartz-crystal microbalance technique was used to monitor the adsorption of glucose oxidase (GOx) on bare Au, Au-electrodeposited Au (Aued/Au), multiwalled carbon nanotube (MWCNT)modified Au (MWCNTs/Au), and Au-electrodeposited MWCNT-modified Au (Aued/MWCNTs/Au) electrodes. The mass of GOx at saturated adsorption was obtained in each case. The amperometric responses of these enzyme electrodes were examined, and the mass-specific bioactivities of the immobilized (adsorbed) GOx (MSBAi) were evaluated through anodic potentiostatic detection of enzymatically generated H2O2 in the presence of glucose. The direct electrochemistry of adsorbed GOx was studied by cyclic voltammetry, to obtain the electroactivity percentage of the immobilized (adsorbed) GOx (EAPi) in each case. We found that the amounts of enzyme adsorbed and the amperometric responses of these enzyme electrodes follow the order GOx/MWCNTs/Au>GOx/Aued/MWCNTs/Au>GOx/Aued/Au>GOx/Au; the MSBAi values follow the order GOx/Au>GOx/Aued/MWCNTs/Au≥GOx/Aued/Au>>GOx/MWCNTs/Au; and the EAPi values follow the order GOx/MWCNTs/Au>GOx/Aued/MWCNTs/Au>>GOx/Aued/Au≥GOx/Au. The experimental data are interpreted based on hydrophobic/hydrophilic interactions among enzyme molecules and the nanomaterials, [Article] doi: 10.3866/PKU.WHXB201306042 www.whxb.pku.edu.cn 物理化学学报(Wuli Huaxue Xuebao) Acta Phys. -Chim. Sin. 2013, 29 (8), 1727-1734 August Received: March 23, 2013; Revised: June 4, 2013; Published on Web: June 4, 2013. ∗Corresponding author. Email: xieqj@hunnu.edu.cn; Tel: +86-731-88865515. The project was supported by the National Natural Science Foundation of China (21175042, 21075036), Hunan Provincial Educational Department, China (11A069), and Program for Science and Technology Innovative Research Team in Higher Educational Institutions Hunan Province, China. 国家自然科学基金(21175042, 21075036)、湖南省教育厅(11A069)和湖南省高校科技创新团队资助项目 C Editorial office of Acta Physico-Chimica Sinica 1727 Vol.29 Acta Phys. -Chim. Sin. 2013 as well as the amount of adsorbed GOx. It was also verified that the total enzymatic activity of all the electrode-adsorbed enzyme molecules is positively related to the amperometric responses of the enzyme electrodes. This work is useful in studying the immobilization of enzyme on nanomaterials and thus-prepared amperometric enzyme electrodes.

Heterobinuclear Zn-Eu or Zn-Tb Complexes Formed from Benzimidazole Derivatives and Metal Salts: Synthesis, Structures and Photophysical Properties

Four isostructural heterobinuclear Zn-Ln (Ln=Eu or Tb) complexes are prepared through the self-assembly of benzimidazole derivatives 2-(2-hydroxy-3-methoxyphenyl)benzimidazole (HL) or 2-(5bromo-2-hydroxy-3-methoxyphenyl)benzimidazole (HL) with Zn(CH3COO)2·2H2O and Eu(NO3)3·6H2O or Tb(NO3)3·6H2O. The complexes are characterized by single-crystal X-ray diffraction, Fourier transform infrared (FTIR) spectroscopy, elementary analysis, and electrospray ionization mass spectrometry (ESIMS). Three of the complexes form single crystals, while the fourth is polycrystalline. UV-Vis absorption, excitation and emission spectra of the Tb -based complexes reveal strong, characteristic luminescence from Tb + with emissive lifetimes in the microsecond range. Therefore, Tb + has been sensitized from the excited state of the ligands because of effective intramolecular energy transfer. The Eu complexes do not show characteristic emission because of deactivation by a different pathway. [Article] doi: 10.3866/PKU.WHXB201305081 www.whxb.pku.edu.cn 物理化学学报(Wuli Huaxue Xuebao) Acta Phys. -Chim. Sin. 2013, 29 (7), 1408-1414 July Received: February 4, 2013; Revised: May 8, 2013; Published on Web: May 8, 2013. ∗Corresponding authors. ZHAO Shun-Sheng, Email: shshzhao@xust.edu.cn. LU Xing-Qiang, Email: lvxq@nwu.edu.cn. The project was supported by the National Natural Science Foundation of China (21103135, 21173165, 21073139), Natural Science Basic Research Plan in Shaanxi Province of China (2011JQ2011), Scientific Research Program Funded by Shaanxi Provincial Education Commission, China (12JK0622), and Foundation of Xiʹan University of Science and Technology, China (2010QDJ030). 国家自然科学基金(21103135, 21173165, 21073139),陕西省自然科学基础研究计划(2011JQ2011),陕西省教育厅自然科学专项(12JK0622)和西 安科技大学博士启动金(2010QDJ030)资助项目 C Editorial office of Acta Physico-Chimica Sinica 1408 ZHAO Shun-Sheng et al.: Luminescent Zn-Tb Complexes Formed by Benzimidazole Derivatives and Metal Salts No.7

Application of Time-Resolved Coherent Anti-Stokes Raman Scattering Technique on the Study of Photocatalytic Hydrogen Production Kinetics

Based on the laser pulse output from a femtosecond regenerative amplifier and optical parametric amplifier (OPA), a broadband time-resolved coherent anti-Stokes Raman scattering (CARS) setup was assembled. Using this setup, the relationship of hydrogen CARS spectra to its amount in a mixture with air and the relevant detection time-delay were studied. Hydrogen CARS spectra without nonresonant background interference were obtained by adjusting the detection time-delay. The observed CARS intensity exhibited a linear relationship with the square of hydrogen concentration, which is consistent with the theoretical prediction. The signal-to-noise ratio showed that when the pressure of hydrogen-air mixed gas was 0.1 MPa, the detection limit of our setup was less than 0.2%. Using this setup, the hydrogen production kinetics of a platinum(II) terpyridyl acetylide molecular-cobalt catalysttriethanolamine (TEOA) system was studied. The kinetic mechanism of hydrogen production was discussed by considering the effect of changing pH. The results indicate that a high proton concentration will reduce the hydrogen production efficiency. This can be attributed to the inhibition of hydrolysis of TEOA under acidic conditions, because it is the electron and proton donor in this hydrogen production system. [Article] doi: 10.3866/PKU.WHXB201304281 www.whxb.pku.edu.cn 物理化学学报(Wuli Huaxue Xuebao) Acta Phys. -Chim. Sin. 2013, 29 (8), 1632-1638 August Received: January 31, 2013; Revised: April 28, 2013; Published on Web: April 28, 2013. ∗Corresponding author. Email: lmfu@chem.ruc.edu.cn; Tel: +86-10-62516604. The project was supported by the National Key Basic Research Program of China (973) (2009CB220008). 国家重点基础研究发展规划项目(973) (2009CB220008)资助 C Editorial office of Acta Physico-Chimica Sinica 1632 吕永钢等:利用时间分辨相干反斯托克斯拉曼散射技术研究光催化产氢反应动力学 No.8

Decoupling multimode vibrational relaxations in multi-component gas mixtures: Analysis of sound relaxational absorption spectra

Decoupling the complicated vibrational—vibrational (V—V) coupling of a multimode vibrational relaxation remains a challenge for analyzing the sound relaxational absorption in multi-component gas mixtures. In our previous work [Acta Phys. Sin. 61 174301 (2012)], an analytical model to predict the sound absorption from vibrational relaxation in a gas medium is proposed. In this paper, we develop the model to decouple the V—V coupled energy to each vibrational—translational deexcitation path, and analyze how the multimode relaxations form the peaks of sound absorption spectra in gas mixtures. We prove that a multimode relaxation is the sum of its decoupled single-relaxation processes, and only the decoupled process with a significant isochoric-molar-heat can be observed as an absorption peak. The decoupling model clarifies the essential processes behind the peaks in spectra arising from the multimode relaxations in multi-component gas mixtures. The simulation validates the proposed decoupling model.

Asymmetric Fireballs in Symmetric Collisions

Author(s): Bialas, A; Bzdak, A; Zalewski, K | Abstract: This contribution reports on the results obtained in the two recently published papers [A. Bialas, A. Bzdak, K. Zalewski, Phys. Lett. B710, 332 (2012); A. Bialas, K. Zalewski, Acta Phys. Pol. B 43, 1357 (2012)] demonstrating that data of the STAR Collaboration show a substantial asymmetric component in the rapidity distribution of the system created in central Au-Au collisions, implying that boost invariance is violated on the event-by-event basis even at the mid c.m. rapidity.

Electrochemical Preparation of Ni-Sn Active Cathode and Its Electrocatalytic Hydrogen Evolution Reaction Mechanisms in Alkaline Solution

A simple galvanostatic electrodeposition method was used to synthesize an active Ni-Sn electrode on a Cu foil substrate. Characterization by high-resolution transmission electron microscopy (HRTEM), energy-dispersive spectroscopy (EDS), and X-ray diffraction (XRD) revealed that the crystal structures of the deposited films transformed from amorphous structures composed of Ni crystal embryos and amorphous Ni-Sn to Ni3Sn4/Ni3Sn2 mixed crystals with increasing Sn content. Scanning electron microscope (SEM) images indicated that the amorphous Ni-Sn electrode possessed a smooth surface with uniform distribution of small particles, whereas the Ni3Sn4/Ni3Sn2 mixed crystalline electrode exhibited a rough surface composed of lamellar structures. The polarization curves measured in 1 mol·L-1 NaOH solution at 25 °C indicated that the amorphous Ni-Sn electrode showed a smaller overpotential (85 mV) and better electrocatalytic performance for hydrogen evolution than the mixed crystalline electrode. Electrochemical impedance spectroscopy (EIS) results showed that the hydrogen evolution reaction occurs 1479 Acta Phys. ⁃Chim. Sin. 2013 Vol.29 on the Ni-Sn alloy electrode under a mixture of Volmer and Heyrovsky control. The higher activity of the amorphous Ni-Sn electrode was attributed to the faster charge transfer and electrochemical adsorption and desorption rates of hydrogen atoms compared with those on the mixed crystalline electrode.

Double-Proton-Transfer Reaction in Guanine-Cytosine Base Pair Embedded in B-Form DNA

The double-proton-transfer reaction of the isolated guanine-cytosine (GC) base pair and four DNA trimers with different nucleobase sequences (dATGCAT, dGCGCGC, dTAGCTA, and dCGGCCG) are studied by quantum mechanical calculations using ONIOM(M06-2X/6-31G*:PM3). Proton-transfer patterns, energy and structural properties are analyzed to gain insight into the double-proton-transfer mechanism with consideration to environmental factors. In the gas phase, a stepwise mechanism is found for the dCGGCCG trimer, and a concerted mechanism is found in the other four models. The computational results demonstrate that electrostatic interaction of the peripheral and middle base pairs have a pronounced effect on double-proton-transfer pattern of GC base pairs. The structures with dATGCAT and dGCGCGC sequences facilitate H4a proton transfer and those with dTAGCTA and dCGGCCG sequence facilitate H1 proton transfer. The high proton affinity of cytosine at N3 facilitates H1 proton transfer. In aqueous solution, electrostatic interactions are reduced and the products of single-proton-transfer in the stepwise mechanism are stabilized. This results in a stepwise transfer pattern becoming favorable. Solvent effects favor the single-proton-transfer reaction more than gas phase conditions, but increase the reaction energy of double-proton-transfer. 1233 Acta Phys. ⁃Chim. Sin. 2013 Vol.29

Effective Adsorption of Functional Biological Macromolecules on Stainless Steel Surface with Micro/Nanoporous Texture

Stainless steel (AISI 316L) is commonly used as a material in medical devices. Modification of the metal surface with bioactive molecules and/or nanoparticles to develop next-generation smart biomaterial, e.g., cardiovascular stents, has recently attracted great attention. The present work investigated adsorption of antibodies and enzymes on micro/nanoporous 316L stainless steel compared with that on smooth and gold-coated stainless steel surfaces. The experimental results showed that the micro/nanoporous stainless steel surface produced by electrochemical erosion can adsorb a large amount of proteins (antibodies or horse radish peroxidase (HRP)), with comparable or better results than the sputtered-gold surface. Washes with surfactants (e.g., 10% bull serum albumin (BSA) or 0.2% Tween 20 solution) did not remove the enzymes/antibodies. In contrast, pretreatment of the metal plates with 5% Tween 20 halved antibody adsorption but did not affect adsorption of HRP. The wettability of the porous metal surface coated with proteins depended on the protein species and amount of protein adsorbed. The 1595 Acta Phys. ⁃Chim. Sin. 2013 Vol.29 protein-coated porous surface was hydrophilic (water contact angle<50°), which should make it biocompatible. The proteins on the micro/nanoporous stainless steel surface retained their high biological activity; in particular, micro/nanoporous stainless steel stents modified with an anti-CD34 antibody using the present method can effectively and selectively capture KG-1 cells. Our work provides a basis for developing novel polymer-free, smart, economic biomaterials with stainless steel for biomedical applications.

Effect of Surface Promoters-Modifying on Catalytic Performance of Cu/ZnO/Al&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt; Methanol Synthesis Catalyst

Surface promoters-modified Cu/ZnO/Al2O3 (CZA) catalysts were prepared by a coprecipitationpost impregnation method and evaluated in methanol synthesis from syngas. The effects of Zr, Ba, and Mn as promoters, the reaction temperature and run time over CZA and Zr-promoted CZA catalysts on catalytic performance were investigated, respectively. The catalysts were characterized by X-ray diffraction (XRD), N2-sorption, reactive N2O sorption, X-ray photoelectron spectroscopy (XPS), temperature-programmed desorption of H2 (H2-TPD), scanning electron microscopy (SEM), and highresolution transmittance electron microscopy (HR-TEM). The results showed that the space-time yield (STY) of methanol can be increased noticeably over the Zror Ba-promoted CZA catalyst before and after the heating treatment of the catalysts. The introduction of Mn as a promoter onto the CZA catalyst led to a decrease in the STY of methanol before heating treatment. The introduction of Zr as a promoter onto the CZA catalyst can decrease the temperature at which the STY of methanol reached the highest value and also improve the catalytic stability. A hydrogen molecule can be adsorbed and then activated over Cu and ZnO. The strong interaction between Cu and ZnO is favorable for improving the catalytic performance of the CZA catalyst. The decrease in catalytic performance after heating treatment of the CZA catalysts is attributed to a growth of Cu crystallites. Based on the results of catalytic performance and characterization, a possible “bidirectional but synchronous catalytic reaction course”in methanol synthesis from syngas over a CZA 2047 Acta Phys. -Chim. Sin. 2013 Vol.29 catalyst is proposed.