Durch β-Strahlen bewirkte Änderung des Ascorbinsäuregehaltes von Samen der Vicia faba, 1. Mitt.

Zusammenfassung Der Ascorbinsäuregehalt der trockenen Samen dreier Vicia faba-Arten wurde bestimmt. Die durchschnittliche Änderung des Vitamin C-Gehaltes der Samen während der Keimung und die Wirkung der von kleinen Mengen³²P-Phosphat abgegebenen -Strahlung auf die Keimlinge wurde untersucht.Mit 4 Abbildungen     

Mutual irradiation graft copolymerization of acrylic acid on to nylon-6 via liquid and vapour phases

Liquid phase and vapour phase grafting of acrylic acid on to nylon-6 were performed by the mutual irradiation technique. Liquid phase direct irradiation grafting was carried out in air either in the presence or in the absence of redox salt. The redox salt led to a sharp increase in the grafting yield and prevented excessive homopolymerization of acrylic acid. The effects of total dose, solvent type and composition, and monomer concentration on the direct grafting in the liquid and vapour phases were studied The data indicate that, if conditions were kept fixed, the vapour phase technique gives rise to lower grafting yields than the liquid phase method.     

On the product solutions of Storm—Liouville equations with many parameters in a space of the type L2

In this paper the Storm—Liouville system of differential equations of many parameters is considered. The existence of the solutions which belong to a space of the type L₂ under some conditions is proved. Moreover, an estimation is given from below and from above for the number of linearly independent solutions of the system in some singular end.     

Three-fold photoelectron counting statistics for gaussian light

The three-fold generating function Q(λ₁, λ₂, λ₃) for photocount statistics is evaluated directly from the gap integral equation in the short counting time regime. The triple joint probabilities and the triple photoelectron correlation function are obtained via Q(λ₁, λ₂, λ₃) in terms of the field correlation function of the incident quasimonochromatic radiation. Three-fold moments are also evaluated via another approach which permits an extension to arbitrary counting times.     

Taylor dispersion analysis of metallic-based nanoparticles – A short review

Taylor dispersion analysis (TDA) is an interesting tool for nanoparticle (NP) size determination, feasible using simple capillary electrophoresis apparatus. Based upon the radial diffusion of analytes upon a laminar stream, the diffusion coefficient of species is easily estimable. Moreover, TDA is generally more adequate than conventional dynamic light scattering methodologies as it is less dependent on the polydispersity of the sample, leading to accurate measurement and reliable results. This review provides every paper mentioning the use of TDA for metallic-based NPs size determination. Diverse strategies for the detection of metallic NPs (like UV–visible and inductively coupled plasma–mass spectrometry – ICP–MS – for instance) and interpretation of the Taylorgrams are discussed. Based upon the literature, advices on future prospects are also indicated, especially for the comparison of TDA results with other classical techniques.     

Magnetic NiFe2O4 Nanoparticles Prepared via Non-Aqueous Microwave-Assisted Synthesis for Application in Electrocatalytic Water Oxidation

Phase-pure spinel-type magnetic nickel ferrite (NiFe₂O₄) nanocrystals in the size range of 4 to 11 nm were successfully synthesized by a fast and energy-saving microwave-assisted approach. Size and accessible surface areas can be tuned precisely by the reaction parameters. Our results highlight the correlation between size, degree of inversion, and magnetic characteristics of NiFe₂O₄ nanoparticles, which enables fine-tuning of these parameters for a particular application without changing the elemental composition. Moreover, the application potential of the synthesized powders for the electrocatalytic oxygen evolution reaction in alkaline media was demonstrated, showing that a low degree of inversion is beneficial for the overall performance. The most active sample reaches an overpotential of 380 mV for water oxidation at 10 mA cm⁻² and 38.8 mA cm⁻² at 1.7 V vs. RHE, combined with a low Tafel slope of 63 mV dec⁻¹.     

A New Pt(II) Complex with Anionic s-Triazine Based NNO-Donor Ligand: Synthesis,X-ray Structure,Hirshfeld Analysis and DFT Studies

The reaction of PtCl₂ with s-triazine-type ligand (HTriaz) (1:1) in acetone under heating afforded a new [Pt(Triaz)Cl] complex. Single-crystal X-ray diffraction analysis showed that the ligand (HTriaz) is an NNO tridentate chelate via two N-atoms from the s-triazine and hydrazone moieties and one oxygen from the deprotonated phenolic OH. The coordination environment of the Pt(II) is completed by one Cl⁻¹ ion trans to the Pt-N_(hydrazone). Hirshfeld surface analysis showed that the most dominant interactions are the H···H, H···C and O···H intermolecular contacts. These interactions contributed by 60.9, 11.2 and 8.3% from the whole fingerprint area, respectively. Other minor contributions from the Cl···H, C···N, N···H and C···C contacts were also detected. Among these interactions, the most significant contacts are the O···H, H···C and H···H interactions. The amounts of the electron transfer from the ligand groups to Pt(II) metal center were predicted using NBO calculations. Additionally, the electronic spectra were assigned based on the TD-DFT calculations.     

Macromolecular engineering of polylactones and polylactides. XXV. Synthesis and characterization of bioerodible amphiphilic networks and their use as controlled drug delivery systems

Well-defined α,ω-methacryloyl poly-ε-caprolactone (PCL) and poly(d,l )-lactide P(D,L)LA dimacromonomers have been synthesized by living ring-opening polymerization of the parent monomers initiated by diethylaluminum 2-hydroxyethylmethacrylate (Et₂Al O (CH₂)₂ O C(O) C(CH₃)CH₂) and terminated by reaction of the propagating Al alkoxide groups with methacryloyl chloride. These dimacromonomers have been copolymerized with a hydrophilic comonomer, i.e., 2-hydroxyethylmethacrylate, in bulk at 65°C by using benzoyl peroxide as a free-radical initiator. The swelling ability of the amphiphilic PHEMA/PCL or P(D,L)LA networks has been investigated in both aqueous and organic media. Effect of network composition and molecular weight of the dimacromonomer on the swelling kinetics and the equilibrium solvent uptake has been studied. Lipophilic dexamethasone acetate and the hydrophilic sodium phosphate counterpart have been incorporated into the amphiphilic gels and their release has been studied in relation to the gel characteristics. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 2401–2411, 1999     

Straightforward Regio- and Diastereoselective Synthesis,Molecular Structure,Intermolecular Interactions and Mechanistic Study of Spirooxindole-Engrafted Rhodanine Analogs

Straightforward regio- and diastereoselective synthesis of bi-spirooxindole-engrafted rhodanine analogs 5a–d were achieved by one-pot multicomponent [3 + 2] cycloaddition (32CA) reaction of stabilized azomethine ylide (AYs 3a–d) generated in situ by condensation of L-thioproline and 6-chloro-isatin with (E)-2-(5-(4-chlorobenzylidene)-2,4-dioxothiazolidin-3-yl)-N-(2-morpholinoethyl)acetamide. The bi-spirooxindole-engrafted rhodanine analogs were constructed with excellent diastereo- and regioselectivity along with high chemical yield. X-ray crystallographic investigations for hybrid 5a revealed the presence of four contiguous stereocenters related to C11, C12, C19 and C22 of the spiro structure. Hirshfeld calculations indicated the presence of many short intermolecular contacts such as Cl...C, S...S, S...H, O...H, N...H, H...C, C...C and H...H interactions. These contacts played a very important role in the crystal stability. The polar nature of the 32CA reaction was studied by analysis of the conceptual DFT reactivity indices. Theoretical study of this 32CA reaction indicated that it takes place through a non-concerted two-stage one-step mechanism associated with the nucleophilic attack of AY 3a to the electrophilic ethylene derivative.     

Nonrelativistic Shifted-1 Expansion Technique for Three- and Two-Dimensional Schrodinger Equation

The shifted-1 expansion techniques (SLET) has been developed to get eigenvalues of Schrödinger equation in three (30) and two dimensions (2D). SLET simply consists of 1/l as a perturbation parameter, where l= 1 -β.β is a suitable shift, l is the angular-momentum quantum number for the 3D-case, l = |m| for the 2D-case, and m is the magnetic quantum number. Unlike the shifted large-N expansion theory (SLNT), SLET seems to be applicable to a wider number of problems of significant interest in physics.