1,3-二吗啉基丙烷与Hg(Ⅱ)和Zn(Ⅱ)的配合物:合成、结构与抗菌研究

以1,3-二吗啉基丙烷(DMP)为配体合成了2个配合物:Hg(DMP)Cl₂(1)和Zn(DMP)Cl₂(2),并对其结构进行了表征。单晶X-射线结构分析表明,2个配合物中的金属离子都与2个N原子和2个Cl原子配位,形成扭曲四面体配位结构。配体和配合物对3种革兰氏阳性菌(S. aureus ATCC25923,E. faecalis ATCC23212和S. epidermidis ATCC34384)和3种革兰氏阴性菌(E. coli ATCC25922,P. aeruginosa ATCC27853和K. pneumonia ATCC70063)都具有抗菌活性,且在一定条件下,Hg(Ⅱ)配合物的抗菌活性超过了作为标准的磺胺异恶唑药物。     

Inactivation of Staphylococcus Aureus and Listeria Monocytogenes in Milk and Cream of Chicken Soup by High Hydrostatic Pressure and Bacteriocins

By the application of HHP; 5.50 and 5.70 log cycle reduction was obtained for S. aureus 485, in milk and cream of chicken soup samples, respectively. Storage of HHP treated milk samples for 24 h at 4 °C gave positive result for S. aureus 765 where no growth was observed for L. monocytogenes strains. Incubation of food samples for an additional 48 h at 37 °C showed growth of L. monocytogenes strains as S. aureus strains. When a bacteriocin-based biopreservative (BP 1 ) was combined with pressurization more than 8 log-cycle reduction in cell population of the resistant strains of S. aureus and L. monocytogenes was achieved in milk. Milk and cream of chicken soup samples were stored at 25 °C and milk samples showed no growth up to 30 day where as Gram-positive bacterial strains in cream of chicken showed growth after 3 days with a rapid increase in cell number thereafter.     

Physico-chemical properties of deuteriated compounds 3rd communication. The viscosity of n-heptane

The kinematic viscosity of mixtures of perdeuteriated and protiated heptane has been measured between 15° and 35° and is given in polynomial form as a function of concentration and temperature. Using the McAllister equation to describe viscosity [4], it can be shown that the interactions between molecules containing the same or different isotopic species differ slightly.     

Physikalisch-chemische Eigenschaften deuterierter Verbindungen. 4. Mitteilung. Deuterierung von Kohlenwasserstoffen durch heterogen katalysierten Isotopenaustausch im Gegenstrom

The Deuteration of Hydrocarbons by Heterogeneous Catalysis in a Counter-current Column A counter-current method for the perdeuteration of liquid hydrocarbons by heterogeneously catalysed isotope exchange with deuterium gas is described. The efficiency of the column which was developed for this purpose has been investigated and optimised as a function of the experimental variables. The limits of the applicability of this method are discussed.     

Electrochemical Sensing Platform Based on Graphene Oxide-chitosan for Simultaneous Determination of some Antihypertensive Drugs

The development of selective and simple methods for the determination of different analytes is of great interest. This is the first time to show the applicability of graphene oxide-chitosan (GO-CS) nanocomposite for designing an electrochemical nanosensor for determination of Amlodipine, Valsartan, and Hydrochlorothiazide, simultaneously. Differential pulse voltammetrics current of AML, HCT, and VAL increased linearly in the ranges of 0.1–110, 0.1–110, and 1–230 μM with LOD of 5.5×10⁻², 3.5×10⁻² and 8.6×10⁻² μM, respectively. Finally, GO-CS/GCE was used for the detection of these drugs in commercial tablets and compared with the reference method (HPLC).     

Nanoscopic measurements of the electrostriction responses in P(VDF/TrFE) ultra-thin-film copolymer using atomic force microscopy

Atomic force microscopy (AFM) has been used as a new method to perform nanoscale measurements of the electrostriction coefficients in the lamellae structure of the ferroelectric P(VDF/TrFE) 73/27 copolymers. The result found shows that the electrostriction coefficient inside (in the middle of) the lamella crystals is 6×10^-19 (m²V^-2), which is three times larger than that at the boundary, 2×10^-19 (m²V^-2). To explain the dependence of the electrostriction coefficients with those two regions, some suggestions are proposed. By heat treatment at 140 °C during 2 h, the sample changed its morphology as well as its crystallinity; the amorphous phase is much reduced and the degree of the crystallinity inside the lamellae is higher than that in the border. Also, it is suggested that in the lamellae’s boundary the macromolecular chains come to an end, or one monolayer folds over the other layer. In this case, the electrostriction was suppressed due to the loss of surface energy in the lamellae’s boundary. The achievements will supply a guideline to develop new and better devices for electromechanical and actuator applications. Received: 23 June 2000 / Accepted: 23 August 2000 / Published online: 5 October 2000     

Extending Fibre Nonlinear Interference Power Modelling to Account for General Dual-Polarisation 4D Modulation Formats

In optical communications, four-dimensional (4D) modulation formats encode information onto the quadrature components of two arbitrary orthogonal states of polarisation of the optical field. Many analytical models available in the optical communication literature allow, within a first-order perturbation framework, the computation of the average power of the nonlinear interference (NLI) accumulated in coherent fibre-optic transmission systems. However, all such models only operate under the assumption of transmitted polarisation-multiplexed two-dimensional (PM-2D) modulation formats, which only represent a limited subset of the possible dual-polarisation 4D (DP-4D) formats. Namely, only those where data transmitted on each polarisation channel are mutually independent and identically distributed. This paper presents a step-by-step mathematical derivation of the extension of existing NLI models to the class of arbitrary DP-4D modulation formats. In particular, the methodology adopted follows the one of the popular enhanced Gaussian noise model, albeit dropping most assumptions on the geometry and statistic of the transmitted 4D modulation format. The resulting expressions show that, whilst in the PM-2D case the NLI power depends only on different statistical high-order moments of each polarisation component, for a general DP-4D constellation, several other cross-polarisation correlations also need to be taken into account.     

基于1,3-二吗啉基丙烷的Hg(Ⅱ)和Zn(Ⅱ)配合物:合成、结构与抗菌活性

以1,3-二吗啉基丙烷(DMP)为配体合成了2个配合物：Hg(DMP)Cl₂(1)和Zn(DMP)Cl₂(2),并对其结构进行了表征。单晶X-射线结构分析表明,2个配合物中的金属离子都与2个N原子和2个Cl原子配位,形成扭曲四面体配位结构。配体和配合物对3种革兰氏阳性菌(S. aureus ATCC 25923,E. faecalis ATCC 23212和S. epidermidis ATCC 34384)和3种革兰氏阴性菌(E. coli ATCC 25922,P. aeruginosa ATCC 27853和K. pneumonia ATCC 70063)都具有抗菌活性,且在一定条件下,Hg(Ⅱ)配合物的抗菌活性超过了作为标准的磺胺异恶唑药物。     

Nanocrystalline nickel films with lotus leaf texture for superhydrophobic and low friction surfaces

Nanostructured Ni films with high hardness, high hydrophobicity and low coefficient of friction (COF) were fabricated. The surface texture of lotus leaf was replicated using a cellulose acetate film, on which a nanocrystalline (NC) Ni coating with a grain size of 30 ± 4 nm was electrodeposited to obtain a self-sustaining film with a hardness of 4.42 GPa. The surface texture of the NC Ni obtained in this way featured a high density (4 × 10³ mm⁻²) of conical protuberances with an average height of 10.0 ± 2.0 μm and a tip radius of 2.5 ± 0.5 μm. This structure increased the water repellency and reduced the COF, compared to smooth NC Ni surfaces. The application of a short-duration (120 s) electrodeposition process that deposited “Ni crowns” with a larger radius of 6.0 ± 0.5 μm on the protuberances, followed by a perfluoropolyether (PFPE) solution treatment succeeded in producing a surface texture consisting of nanotextured protuberances that resulted in a very high water contact angle of 156°, comparable to that of the superhydrophobic lotus leaf. Additionally, the microscale protuberances eliminated the initial high COF peaks observed when smooth NC Ni films were tested, and the PFPE treatment resulted in a 60% reduction in the steady-state COFs.     

Treatment of the composite fabric’s shaping using a Lagrangian formulation

In this paper, we are interested in the simulation of prepreg composite deformation by deep-drawing and laying-up. It uses new bi-component finite elements made of woven material in which the nodal interior loads are deduced from fibre tensile strain energy and not polymerized resin membrane energy. Specific treatment is used to analyze the frictional-contact problem between the deformable prepreg composite and the steel rigid tools. The frictional-contact method is based on the Lagrangian formulation and the preconditioned conjugate gradient method. Some numerical tests are given to investigate the performance of the numerical strategies.