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41.
I Halaciuga JI Njagi K Redford DV Goia 《Journal of colloid and interface science》2012,383(1):215-221
Anisotropic conductive adhesives (ACAs) are widely used as interconnect materials in the manufacturing of LCD screens. To be integrated in a broader range of applications, several technical and economical issues still need to be addressed. Encapsulating the polymer particles within continuous, compact, and adhering metallic conductive shells is one of these challenges. This work describes a method for depositing nickel layers with different thickness (30-120nm) onto monosized polymer particles. The novelty of the approach consists in modifying the surface of polymer particles with linear polymeric amines. We show that by increasing amine chain length the structure and adhesion of deposited nickel shell are significantly improved. The effect of key parameters of the electroless Ni plating are discussed and illustrated. 相似文献
42.
Gabi Drochioiu Ionel Mangalagiu Ecaterina Avram Karin Popa Alin Constantin Dirtu Ioan Druta 《Analytical sciences》2004,20(10):1443-1447
A new sensitive spectrophotometric method has recently been developed for the trace determination of cyanide with ninhydrin. Cyanide ion was supposed to act as a specific base catalyst. Nevertheless, this paper demonstrates that the reported assay is based on a novel reaction of cyanide with 2,2-dihydroxy-1,3-indanedione, which affords purple or blue colored salts of 2-cyano-1,2,3-trihydroxy-2H indene. Hydrindantin is merely an intermediary of the reaction. The formation of a stable and isolable ninhydrin-cyanide compound has been confirmed by its preparation in crystalline form. Also, it is thoroughly characterized by elemental as well as MS, IR, UV/VIS and 1H NMR analyses. The Ruhemann's sequence of reactions of cyanide with ninhydrin has been reconsidered and an adequate mechanism of the reaction is proposed. As a consequence, the interference of oxidizers as well as copper, silver and mercury ions with the cyanide determination has been elucidated. 相似文献
43.
Klaus H. Ebert Reinhold E. Schulz Hans J. Breunig
Cristian Silvestru
Ionel Haiduc 《Journal of organometallic chemistry》1994,470(1-2):93-98Addition of BiBr3 to Mes3Bi (Mes = 2, 4, 6-Me3C6H2) in Et2O gives 86% of Mes2BiBr (1) as yellow crystals. Reaction of 1 with Ph2PS2NH4 in a 1 : 1 molar ratio gives a quantitative yield of MesBi(S2PPh2)2 (2) rather than the expected dimesitylbismuth compound. The crystal and molecular structures of 1 and 2 were determined at 153 K and 173 K, respectively. They contain Mes2BiBr molecules with trigonal pyramidal coordination around Bi. The mean Bi---C bond distance is 2.27 Å and the Bi---Br bond distance is 2.690(2) Å. The angles around Bi vary between 89.4 and 106.4°. Intermolecular Bi…Br contacts of 3.795 Å, indicating weak secondary bonding, give rise to zig-zag shaped (Bi---Br)x chains. In the polymeric chain the coordination geometry around bismuth atoms can be described as pseudo-trigonal bipyramidal. The crystals of 2 consist of discrete monomeric MesBi(S2PPh2)2 molecules with a symmetry plane containing the metal atom and the aromatic ring of the attached mesityl group. The dithiophosphinato ligands exhibit an anisobidentate coordination pattern with long and short phosphorus—sulfur bonds, i.e. P(1)---S(1) 2.051(31) Å and P(1)---S(2) 1.980(3) Å, related to short and long bismuth—sulfur distances, respectively, i.e. Bi---S(1) 2.662(2) Å and Bi---S(2) 3.123(3) Å. This leads to a square-pyramidal geometry around the bismuth atom, with the metal lying 0.33 Å above the basal plane formed by the four sulfur atoms. 相似文献
44.
M. Curtui I. Haiduc L. Ghizdavu 《Journal of Radioanalytical and Nuclear Chemistry》2001,250(2):359-362
The extraction of uranium(VI) from aqueous solutions with dibutylditiophosphoric acid in organic solvents was studied. The influence of different factors as pH of the aqueous phase, extractant concentration and nature of solvent was investigated in order to find the optimum conditions for separation of metal from aqueous nitrate solutions. The effect of neutral donor extractants was also searched and the efficiency of the extraction was calculated. 相似文献
45.
46.
D. A. Artemenkov V. Bradnova P. I. Zarubin I. G. Zarubina N. A. Kachalova A. D. Kovalenko A. I. Malakhov G. I. Orlova P. A. Rukoyatkin V. V. Rusakova E. Stan R. Stanoeva M. Haiduc S. P. Kharlamov I. Tsakov M. M. Chernyavsky T. V. Shchedrina 《Physics of Atomic Nuclei》2007,70(7):1222-1225
The results of investigation of the fragmentation of relativistic nuclei 9Be in an emulsion, which is accompanied by the formation of two 1.2-A-GeV He fragments, are presented. The angular measurements of the 9Be → 2He events are analyzed. The 9Be → 8Be + n fragmentation channel with the decay of 8Be from the ground (0+) and first excited (2+) states into a pair of α particles appears to be dominant. 相似文献
47.
Ionel Danut Savu Sorin Vasile Savu Nicusor Alin Sirbu 《Journal of Thermal Analysis and Calorimetry》2014,115(2):1427-1437
Laser marking is based on the laser heating of the subjected material, the heating being below the melting temperature or thermal degradation starting point. Within and nearby the mark, the material is chemically, physically and mechanically affected. This means that the main characteristics are changing in such a way that the material is ageing. Thermal and mechanical analysis can be used to determine the modification of the material, which is important and necessary to know for predicting its use lifetime. This paper investigates the physical and mechanical modification of the polymer HDPE100, when laser marking is applied. Burst stress, elongation and relaxation modulus were determined for the base material, within the heat affected zone and within the laser burned mark. Information on the crystallization rate and on the elongation viscosity is also reported. According to the results, the polyethylene has very fast crystallization and that affects the marking process if lower than appropriate maintaining during heating process is applied. It becomes stabile after 0.23 min, when it is tested at 103 °C. The elongation viscosity was analysed and values of 105 Pa s were recorded for 10 s, which is a usual time of applying pressure. The performed analysis revealed about 10 % difference between the relaxation modulus of the irradiated and non-irradiated HDPE. 相似文献
48.
Marius V. Campian Ionel Haiduc Edward R. T. Tiekink 《Journal of chemical crystallography》2010,40(11):1029-1034
Abstract
Distorted octahedral coordination geometries based on a N2S4 donor set are found in each of the molecular structures of the title complexes Mn(S2COCH2CH3)2 (1,10-phenanthroline) (1) and Mn(S2COCH2CH3)2 (2,2′-bipyridyl) (2). Analyses of the geometric parameters indicate that the five-membered ring in (1) has significantly more aromatic character than the analogous ring in (2). In terms of coordination of the xanthate ligands, one ligand in (1) is considerably more aromatic than the remaining ligands. This latter feature allows for the formation of C−H···π (S2C) interactions leading to a supramolecular chain in (1). By contrast, in (2), the crystal packing is dominated by C−H···O contacts, which lead to a supramolecular chain with 41 symmetry, which combine with C−H···S contacts to consolidate the three-dimensional architecture. Unit cell data for (1): hexagonal, space group R ˉ3, a = 35.228(5) and c = 9.0086(13) ?; and for (2): tetragonal, space group I41/a, a = 31.120(7) and c = 8.306(2) ?. 相似文献49.
Rodica-Mariana Ion Mihaela-Lucia Ion Radu Claudiu Fierascu Sever Serban Irina Dumitriu Constantin Radovici Ionel Bauman Stelian Cosulet Valentin Ioan Remus Niculescu 《Journal of Thermal Analysis and Calorimetry》2010,102(1):393-398
The present work is focused on thermoanalytical investigations as thermogravimetric analysis (TG) and derivative thermal analysis
(DTG), applied for the characterization of some samples collected from archaeological sites (Brasov and Trofeum Traiani) located
in different regions of Romania. New informations derived about ceramic technologies concerning raw materials and binding
materials (mineralogical components) have been obtained. All these experimental results have been correlated with related
techniques as X-ray diffraction (XRD), energy-dispersive X-ray fluorescence (EDXRF) and inductively coupled plasma—atomic
emission spectrometry (ICP-AES). By progressive heating in static air atmosphere and in the temperature range of 20–800 °C,
all investigated materials exhibit three main successive processes, associated with the dehydration and thermo-oxidative degradations.
The rate of the first thermooxidative process, temperatures corresponding to the maximum rate of the second thermooxidative
process and shrinkage temperature were associated with the damage of the investigated materials due to environmental impact.
Heating also affects the contact between the fine-sized clay matrix and mineral clast fragments, appearing in reaction rims,
sometimes showing newly formed phases. The temperature at which ancient ceramics and pottery were fired varies over a wide
range (600–800 °C) depending on the type of clay used, although firing temperatures not above 30–400 °C have also been suggested.
Clay minerals, as the main material for production of ceramics and pottery, show some characteristic reactions (dehydroxylation,
decomposition, transformation) in the course of firing (heating effects) and several thermoanalytical criteria can be used
for reconstruction of former production conditions. 相似文献
50.
Peter G. Jones Ionel I. Mangalagiu 《Acta Crystallographica. Section C, Structural Chemistry》2009,65(6):o300-o302
Two polymorphs of the title compound [systematic name: 1‐(2,4‐dihydroxyphenyl)ethanone], C8H8O3, were investigated. The known structure [designated (I‐M); P21/c, Z = 4; previously investigated at room temperature by Robert, Moore, Eichhorn & Rillema (2007). Acta Cryst. E 63 , o4252] was redetermined at low temperature, and a new form [(I‐O); P212121, Z = 12] was discovered in the same sample. In both forms, the molecules are planar (apart from the methyl H atoms) and they contain intramolecular O—H...O=C hydrogen bonds. In polymorph (I‐M), molecules are linked into chains by a single intermolecular O—H...O hydrogen bond, and the chains are linked into sheets by two C—H...O hydrogen bonds. Three O—H...O hydrogen bonds link the molecules of polymorph (I‐O) into chains and neighbouring chains are connected by one C—H...O interaction to form an offset layer structure. Two weak methyl C—H...O interactions link the layers. 相似文献