Terahertz Electric Field Induced Double Strand Breakage and Vibrations of dsDNA in a Gold Nanoslit

Objective This work examines the impact of external electric fields at terahertz(THz)frequencies on doublestranded deoxyribonucleic acid(dsDNA)systems adsorbed on Au(111)surfaces in aqueous environments.Methods The investigation utilizes a molecular dynamics(MD)approach at the atomic level and vibrational dynamics calculations using the GolDNA-Amber force field.Results The results reveal that the sugar-phosphate backbone of the DNA exhibits reduced adherence to the gold surface,while the side chains display a stronger affinity.When subjecting the hydrated DNA strands to an electric field with frequencies up to 10 THz,peak intensities of vibrational dynamic density(VDoS)are observed at five different frequencies.Moreover,the strong electric field causes hydrogen bonds in the DNA within the slit to break.The sensitivity to the electric field is particularly pronounced at 8.8 THz and 9.6 THz,with different vibrational modes observed at varying electric field strengths.Conclusion These findings contribute to an enhanced understanding of the molecular organization of gold-plated charged biological interfaces.

Research on the quality control technology for the Astragalus membranaceus extraction solution in cosmetics

Calycosin-7-glucoside,which is the target ingredient of the Astragalus membranaceus extraction solution,was studied by the high-performance liquid chromatography-diode array detector method(HPLC-DAD),and a high-performance liquid chromatography-electrospray ionization detector method(HPLC-CAD)was also established for fingerprint chromatogram analysis.Meanwhile,the heavy metal content was tested to build a quality control standard for Astragalus membranaceus extraction solution.Result shows a good linearity in 4-80μg/mL mass concentration range with the correlation coefficient r=0.999,RSD=2.4%,and the recovery rate is between 99.2%-102.7%.The fingerprint chromatogram analysis features with 14 specific peaks,including 5 identified components.The similarity is between 0.485 to 0.995.Content of heavy metals such as lead,mercury,and cadmium are below the detection limit,and the content of arsenic is less than 2 mg/kg.This research results can serve as process optimization basis and quality control standards for Astragalus membranaceus extraction solution,and provide reference to quality control and research guideline for other cosmetics using herbal extracts as raw materials.

《渔舟唱晚》两个版本辨析——“金灼南谱”与“娄树华谱”比较

《渔舟唱晚》是我国流传甚广的著名古筝曲。近几十年来,对这首筝曲的作者是娄树华,还是金灼南,学术界存在不同的看法。本文通过查阅文献资料,对"金谱"和"娄谱"两个版本的相同之处与不同之处进行比较辨析,认为将《渔舟唱晚》标示为"金灼南、娄树华编曲",更符合历史客观事实。

Synchrotron-Radiation Photoemission Study of Growth and Stability of Au Clusters on Rutile TiO2（110）-1×1

The growth and thermal stability of Au clusters on a partially-reduced rutile TiO2 （110）-1 × 1 surface were investigated by high-resolution photoelectron spectroscopy using synchrotron- radiation-light. The valence-band photoelectron spectroscopy results demonstrate that the Ti^3＋3d feature attenuates quickly with the initial deposition of Au clusters, implying that Au clusters nucleate at the oxygen vacancy sites. The Au4f core-level photoelectron spectroscopy results directly prove the existence of charge transfer from oxygen vacancies to Au clusters. The thermal stability of Au clusters on the partially-reduced and stoichiometric TiO2（110） surfaces was also comparatively investigated by the annealing experiments. With the same film thickness, Au clusters are more thermally stable on the partially-reduced TiO2（110） surface than on the stoichiometric TiO2（110） surface. Meanwhile, large Au nanoparticles are more thermally stable than fine Au nanoparticles.

Analysis of Volatile Constituents in Lonicera japonica Thunb. from Different Origins by GC-MS

[Objective] This study aimed to analyze the volatile constituents in Lonicera japonica Thunb. from different origins. [Method] HP-5MS capillary columns were used and column temperature was controlled by a program. MS analysis was performed with EI and quadruple mass analyzer. The volatile constituents in L. japonica Thunb. were identified by NIST02 and Wiley275 libraries, and their relative contents were determined with chromatographic peak area normalization method. [Result] According to GC-MS total ion-current chromatograms, 35 volatile constituents were identified in L. japonica Thunb. from Guangxi Zhuang Autonomous Region, mainly including methyl linolenate, n-hexadecanoic acid and ζ-muurolene; 18 volatile constituents were identified in L. japonica Thunb. from Hunan Province, mainly including n-hexadecanoic acid, linoleic acid and α-curcumene. [Conclusion] Main volatile constituents in L. japonica Thunb. from two different origins varied significantly.

Determination of Stability Constants of Cadmium-Glycine Complexes by a Unified Treatment for Potentiometric and Polarographic Data

The cadmium（Ⅱ）-glycine system was studied by the two experimental techniques, ion sensitive electrode （ISE） and differential pulse polarography （DPP）, and the experimental data obtained were used by a unified mathematical treatment to calculate the complex stability constants. The combination of the two techniques is of many advantages as ISE can be performed at low [LT]：[MT] ratios and significantly higher [MT], whereas DPP could be used well at large [LT]：[MT] ratios and much smaller [MT]. This makes it possible to study a metal-ligand system in a relatively broader range of experimental conditions that, in turn, provides more information about the metakligand system of interest. Applying the unified mathematical treatment to the cadmium-glycine system, two new complexes MHL and ML2（OH） as well as three complexes ML, ML2 and ML3, reported in literatures, could be modeled and all their stability constants have been refined.

The Determination of Heavy Metal Elements in Sipunculs nudus by MWD-ICP-AES

In order to develop a method for measuring of elements in Sipunculus nudus, the contents of Cu, Pb, Cd, Cr, Mn, As, Hg and Ba were determined by actively coupled plasma atomic emission spectrometry （MWD） and microwave digestion （ICP-AES）. The results showed that correlation coefficients al kept higher than 0.999 and the recovery rates of sample added standard solutions were in 98%-114%. The results indicated that the contents of Cu, Pb, Cd, Cr, Mn, As, Hg and Ba were 17.119, 3.781, 0.695, 7.351, 1997.982, 0.620, 0.144, 4.249 mg/kg respectively. The contents of Mn exceeded national limit by hundredfold, Cd sevenfold, Pd fourfold, Cd three-and-a-half-fold, and As onefold. Sipunculs nudus became seriously pol uted. Therefore, it is necessary to formulate robust policies to fol ow closely and pay close attention to coastal areas pol ution around Dongfang City.

Corrosion and electrochemical behaviors of 7A09 Al-Zn-Mg-Cu alloy in chloride aqueous solution

The corrosion and electrochemical behaviors of 7A09 Al？Zn？Mg？Cu alloy were investigated in 3.5% NaCl （mass fraction） solution using complementary techniques such as scanning electron microscopy （SEM）, metallographic microscopy and electrochemical measurements. The results show that both pitting corrosion from or around the intermetallic particles and intergranular corrosion are observed after the immersion test due to the inhomogeneous nature of the microstructure of the 7A09 alloy. The preferential dissolution of the anodic Cu-depleted zone along grain boundaries is believed to be the possible cause of intergranular corrosion. The passivation and depassivation of this alloy show significant dependence of immersion time, owing to the formation and dissolution of various passive films on the sample surfaces. Furthermore, the corrosion process and corrosion mechanism were also analyzed.

Comparative Study on the Infrared Spectra of Straight Guard Hairs of Leopard Cat and Golden Cat

[Objective] The paper was to compare the infrared spectra of straight guard hairs of leopard cat and golden cat. [Method] The straight guard hairs of leopard cat and golden cat were detected and analyzed by FTIR （Fourier Transform Infrared Spectroscopy）. [Result] There was significant interspecific difference in the infrared spectra and second derivative spectra for the middle part of guard hair. An evident M-shaped bimodal absorption peak appeared in golden cat at 648 and 654 cm-1, respectively, while did not appear in leopard cat. The second derivative spec-tra of golden cat at wave numbers from 709 to 763 cm -1 were mainly unimodal peaks with strong peak intensity, while that of leopard cat mainly was M-shaped bi-modal absorption peak with weak peak intensity. It indicated that there was obvious difference in the structure of protein side chain in guard hairs of these two animals. [Conclusion] The FTIR analysis showed great application foreground in the study of animal hairs for interspecific identification.

CO Oxidation by Neutral Gold-Vanadium Oxide Clusters

Oxidation of CO by gas-phase atomic clusters is being actively studied to understand the molecular-level mechanisms of heterogeneous CO oxidation over related catalytic surfaces. However, it is experimentally challenging to study CO oxidation by neutral heteronuclear metal oxide clusters because of the difficulty of cluster ionization and detection without fragmentation. Herein, the neutral AuVO2-4 clusters were experimentally generated and their reactions with CO and O2 were studied. The experimental results showed that CO adsorption is the dominant channel on the interactions of AuVO4 and AuVO3 with CO, and AuVO2 can pick up an O2 molecule to generate AuVO4. Theoretical studies indicated that the oxidation of the trapped CO in AuVO3,4CO into CO2 is exothermic while the reaction barriers have to be overcome at the elevated temperatures. A catalytic cycle for CO oxidation by AuVO2-4 is proposed.

Vibrational Spectra and Density Functional Theory Calculations of Metallotriphenylcorroles

The infrared absorption and Raman scattering spectra were measured for the metallotriph- enylcorroles （MTPCs, M=Cu, Co, Ni, Mn）. The ground-state structures and vibrational spectra of MTPCs have been calculated with the density functional theory. The observed Raman and IR bands have been assigned based on the calculation results. Due to the symmetry lowering, the vibrational spectra of MTPCs are much more complex than metal- loporphyrins, and several skeletal modes are found strongly coupled to the phenyl vibrations. The relationship between the Raman/IR frequencies and the structures of TPC ring is in-vestigated. It is found that the vibrations involving the Cα^I Cα^I stretch and CαCm stretchare sensitive to the size of corrole core. In particular, the frequency of v5, which is assigned to Cα^I Cα^I stretch in coupling with the CαCm symmetric stretch, increases linearly with the decrease of the corrole core-sizes and may be used as a mark band to evaluate the structural change of the metallocorroles.

Study of Cadmium-Doped Zinc Oxide Nanocrystals with Composition and Size Dependent Band Gaps

Cadrniurn-doped zinc oxide nanocrystals in the quantum confinement region have been firstly synthesized by a fast and facile sonochernical method. The alloyed structure of the nanocrystals is confirmed by X-ray diflraction, transmission electron rnicroscopy, and infrared analysis. With the increase of cadmium to zinc molar ratio from 0 to 2.0, the crystallite sizes of the samples decrease from 5.1 nrn to 2.6 nrn, and the band gaps of the samples show a red shift then a blue shift, and a red shift again. The variations of band gaps of the samples can be interpreted by the crystallite size and the composition. It is found that both the non-therrnal equilibrium environrnent established in the sonochernical reaction and the coordination ability of triethylene glycol solvent play crucial roles in the current preparation.

Effect of micro arc oxidation treatment on localized corrosion behaviour of AA7075 aluminum alloy in 3.5% NaCl solution

Alumina coating was formed on AA7075 aluminum alloy by micro arc oxidation（MAO） method and its corrosion and stress corrosion cracking（SCC） behaviors were examined in 3.5%（mass fraction） NaCl solution.Electrochemical impedance spectroscopy（EIS） was used to evaluate the degradation of the coating as a function of immersion time and was modeled with appropriate equivalent circuits.Constant load stress corrosion cracking（SCC） results followed by post-test metallographic observations demonstrated the usefulness of MAO coating to avoid the premature failure of the alloy due to severe localized corrosion initiated by Cu-and Fe-rich intermetallic phases.

MRS study on lentiform nucleus in idiopathic Parkinson‘s disease with unilateral symptoms

Objective: To investigate changes in magnetic resonance spectroscopy (MRS) of lentiform nucleus during the early stage of Parkinson抯 disease. Methods: Twenty-five patients with idiopathic Parkinson disease with unilateral symptoms (IPDUS) and 25 healthy volunteers were enrolled in this study. MRS of the lentiform nucleus in each patient was taken and then concentrations of N-acetylaspartate (NAA), Creatine (Cr) and Choline (Cho) were calculated. Results: Compared to that in the control, NAA/ (Cho+Cr) was significantly lower in the lentiform nucleus contralateral to symptoms and even that in the ipsilateral side in IPDUS patients (all P<0.05); while there was no difference between the two sides in the healthy volunteer (P>0.05). The ratio of NAA/(Cho+Cr) ipsilateral to the sympatomatic side of the patient was also lower than that of the control (P<0.05). Conclusions: there might be some changes with MRS on the lentiform nucleus during the early stage of idiopathic Parkinson抯 disease with unilateral symptom. MRS may be one of the reliable methods for early or even sub-clinical diagnosis.

Electric Conductivity Study of o-Substituted Phenoxo Iron （Ⅲ） Complexes

The coordination nature of a number of substituted sodiumphenoxides to iron （Ⅲ） ion has been studied. The o-nitrosodiumphenoxide was found to have different coordination behaviour from that the sodium salts of salicylic acid and methylsalicylate showed. The structure of the complexes, the number of the ligands being coordinated to the metal ion, has also been determined by titration, uv-vis spectroscopy, atomic absorption and the flame test. In addition, other sodium phenoxides were also involved in this study for comparison. An electric conductivity study on the resulting complexes was carried out and all complexes were found to be semiconductors.

Adakitic rocks associated with the Shilu copper–molybdenum deposit in the Yangchun Basin,South China,and their tectonic implications

South China is famous for the extensive magmatism and polymetallic mineralization that took place there in the Mesozoic. Shilu is a large porphyry–skarn Cu–Mo deposit in the Yangchun Basin, South China. The lithology of the Shilu intrusion is granodiorite and quartz diorite, both of which are high-K calc-alkaline series, with high Sr([400 ppm) content along with low Y and Yb contents. Most of the samples have characteristics of adakite except for a few samples that have slightly higher Y and Yb contents, which may be plausibly explained by crustal contamination. Laser Ablation Inductively Coupled Plasma Mass Spectrometry zircon U–Pb dating revealed ages between 106.6 ± 1.3 and 103.9 ± 0.5 Ma, with multiple magmatic pulses. Molybdenite Re–Os isochron age of 102.2 ± 2.9 Ma(MSWD = 9.4) was determined, which is identical to the youngest zircon U–Pb age(103.9 ± 0.5 Ma) within error.The Shilu intrusion has high oxygen fugacity as indicated by high zircon Ce^(4+)/Ce^(3+) and Eu_N/Eu_N* ratios. Considering the geochemical characteristics(high Sr, and low Y and Yb contents), high oxygen fugacity, and copper mineralization of the Shilu intrusion, it was most likely formed by partial melting of a subducted young oceanic slab. Whole-rock Sr–Nd isotope-, zircon Hf isotope-, and whole-rock trace element analyses show that Shilu adakitic magmas may have interacted with type II enriched mantle and/or crustal materials during ascent. South China was affected by the Pacific tectonic regime to the east and the Neo-Tethys tectonic regime to the south in the Cretaceous. Based on the Pacific Plate drifting and rotation history, it is hard to explain how the Pacific Plate would have subducted and melted, forming adakitic rocks in the Shilu region. Considering the tectonic history of Southeast Asia and the South China Sea, the Neo-Tethys trench should have been much closer to the South China Block in the Cretaceous, and thus have had a greater impact on the South China Block. Based on the subduction direction, time of subduction,and distance between the Neo-Tethys subduction zone and the Shilu deposit, subduction of the Neo-Tethys ridge is the best mechanism for explaining the Shilu adakitic rocks and Cu–Mo mineralization.

Structural and Electronic Properties of ConC3-/0 and ConC4-/0 （n=1-4） Clusters： Mass-Selected Anion Photoelectron Spectroscopy and Density Functional Theory Calculations

We investigated the structural evolution and elecfronic properties of ConC3-/0 and ConC4-/0 （n=1-4） clusters by using mass-selected photoelectron spectroscopy and density functional theory calculations. The adiabatic and vertical detachment energies of CO1-4C3- and COl-4C4- were obtained from their photoelectron spectra. By comparing the theoretical results with the experimental data, the global minimum structures were determined. The results indicate that the carbon atoms of ConC3-/0 and ConC4-/0 （n=1-4） are separated from each other gradually with increasing number of cobalt atoms but a C2 unit still remains at n=4. It is interesting that the Co2C3- and Co2C4- anions have planar structures whereas the neutral Co2C3 and Co2C4 have linear structures with the Co atoms at two ends. The Co3C3- anion has a planar structure with a Co2C2 four-membered ring and a Co3C four-membered ring sharing a Co-Co bond, while the neutral Co3C3 is a three-dimensional structure with a C2 unit and a C atom connecting to two faces of the Co3 triangle.

Infrared Spectra,Structures and Bonding of Binuclear Transition Metal Carbonyl Cluster Ions

Binuclear transition metal carbonyl clusters serve as the simplest models in understand- ing metal-metal and ligand bonding that are important organometallic chemistry catalysis. Binuclear first row transition metal carbonyl ions are produced via a pulsed laser vaporiza- tion/supersonic expansion cluster ion source in the gas phase. These ions are studied by mass-selected infrared photodissociation spectroscopy in the carbonyl stretching frequency region. Density functional theory calculations have been performed on the geometric struc- tures and vibrational spectra of the carbonyl ions. Their geometric and electronic structures are determined by comparison of the experimental IR spectra with the simulated spectra. The structure and the metM-metal and metal-CO bonding of both saturated and unsaturated homonuclear as well as heteronuclear carbonyl cluster cations and anions are discussed.

Synthesis and Antimicrobial Activity of Boron-doped Titania Nano-materials

Antibacterial activity of boron-doped TiO2(B/TiO2) nano-materials under visible light irradiation and in the dark was investigated. A simple sol-gel method was used to synthesize TiO2 nano-materials. X-ray diffraction pattern of B/TiO2 nano-materials represents the diffraction peaks relating to the crystal planes of TiO2(anatase and rutile). X-ray photoelectron spectroscopy result shows that part of boron ions incorporates into TiO2 lattice to form a possible chemical environment like Ti O B and the rest exist in the form of B2O3. The study on antibacterial effect of B/TiO2 nano-materials on fungal Candida albicans(ATCC10231), Gram-negative Escherichia coli(ATCC25922) and Gram-positive Staphylococcus aureus(ATCC6538) shows that the antibacterial action is more significant on Candida albicans than on Escherichia coli and Staphylococcus aureus. Under visible light irradiation, the antibacterial activity is superior to that in the dark.

Study on the Influence of Ni Modifying on Phase Transformation and Photocatalytic Activity of TiO_2

The Ni-modified TiO2 was synthesized using two methods including co-precipitation(Ni doped TiO2, Ni-TiO2) and wet impregnation(Ni loaded TiO2, Ni/TiO2). The surface and bulk crystalline phases of Ni-modified TiO2 were investigated by using X-ray diffractometry(XRD), UV Raman spectroscopy, TEM, and SEM. It is observed that Ni doping can promote the phase transition and grain size growth of TiO2. Moreover, the propagation of the rutile phase from the bulk into the surface region of TiO2 is increased when the Ni doping amount reaches up to 3%. However, in Ni/TiO2, it is found out that the surface and bulk phase transformation of TiO2 can be inhibited after impregnation of 1% of Ni on the TiO2. Compared with the co-precipitation method, Ni species may be more enriched in the surface of the Ni/TiO2 sample upon adoption of the impregnation method, and the direct contact of anatase particles of TiO2 is avoided. As a consequence, the phase transition in the surface and bulk region of TiO2 can be effectively inhibited by Ni loading. Additionally, the activity of the photocatalytic degradation of RhB on the 3Ni-TiO2-600 ℃ sample is higher than that on the 3 Ni/TiO2-600 ℃ sample. The phase junction formed between anatase and rutile in the surface region of 3Ni-TiO2-600 ℃ may the main reason for its high photocatalytic activity.