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Observations of the physical behaviour (motions) of the valence (frontier) electrons in the iconic benchmark hydride molecules C[H.sub.4], N[H.sub.3], and [H.sub.2]O are used to provide a direct experimental evaluation of hybridization and of the localized and delocalized orbital models of molecular electronic structure, after more than 80 years since the initial proposals of these theoretical concepts. Our previously published experimental measurements of valence (frontier) electron momentum probability distributions, made by electron momentum spectroscopy (EMS), are compared with those calculated using the localized molecular orbital (LMO) model and a range of hybrid orbital models, as well as with the delocalized canonical molecular orbital (CMO) and density functional theory Kohn-Sham orbital (KSO) models. In all cases, the electron momentum probability distributions calculated with LMOs and localized hybrid orbital type models are inconsistent with the experimental observations. In contrast, those calculated with the delocalized CMOs and KSOs are in very good agreement with the experimental measurements. These findings are of importance in those research applications such as reactivity, drug and novel material design, and also in molecular electronics, where the shapes and orientations of particular valence (frontier) orbital electron density probability distributions (and not the total electron densities) are considered to be key determining factors. These findings and their implications are also of pedagogical significance in chemistry and molecular physics. Key words: hybrid orbitals, localized and delocalized orbitals, calculated and experimental valence electron probability distributions. Par observation du comportement physique (mouvements) des electrons de valence (frontieres) dans les emblematiques molecules d'hydrure types, C[H.sub.4], N[H.sub.3] et [H.sub.2]O, nous avons realise une evaluation experimentale directe de l'hybridation et des modeles d'orbitales localisees et delocalisees de la structure electronique moleculaire, plus de 80 ans apres les premiers enonces de ces concepts theoriques. Nous avons compare nos mesures experimentales des distributions probabilistes du moment des electrons de valence (frontieres), que nous avons publiees anterieurement etrealisees par spectroscopie de moment electronique (EMS, electron momentum spectroscopy), aux valeurs que nous avons calculees a l'aide du modele d'orbitales moleculaires localisees (LMO, localized molecular orbital) et d'un ensemble de modeles d'orbitales hybrides, en plus de les comparer a celles obtenues par le modele d'orbitales moleculaires canoniques (CMO, canonical molecular orbital) delocalisees et par le modele d'orbitales de Kohn-Sham (KSO, Kohn-Sham orbital) en theorie de la fonctionnelle de la densite. Dans tous les cas, les distributions probabilistes du moment electronique calculees a l'aide des modeles de type LMO et d'orbitales hybrides localisees ne concordent pas avec les observations experimentales. Par contre, celles qui ont ete calculees a l'aide des modeles de type CMO delocalisees et KSO concordent tres bien avec les valeurs experimentales. Ces resultats sont importants dans le contexte d'applications de la recherche telles que la conception de medicaments et de nouveaux materiaux basee sur la reactivite, et aussi dans le domaine de l'electronique moleculaire, ou les formes et les orientations des distributions probabilistes de la densite de certaines orbitales d'electrons de valence (frontieres)--et non de la densite electronique totale--sont considerees comme des facteurs determinants. En outre, ces resultats et leurs implications representent une valeur pedagogique en chimie et en physique moleculaire. [Traduit par la Redaction] Mots-cles : orbitales hybrides, orbitales localisees et delocalisees, valeurs theorique et experimentale de la distribution probabiliste des electrons de valence., Introduction Adequate visual and theoretical orbital models of molecular electronic structure are essential for obtaining a better understanding of fundamental phenomena in research applications such as molecular design and predictions [...]

The copper(I) iodide/1,4-bis(2-hydroxy-3,5-di-tert-butylbenzyl)piperazine (CuI-L2) system catalyzed the cross-coupling reactions between aryl halides and aqueous ammonia in water to produce primary aromatic amines in good yields. The protocol was simple and efficient, avoiding the need for inert atmosphere, additional base, or other additives. Key words: copper, catalysis, cross coupling, water chemistry, aqueous ammonia, primary arylamine. Le systeme iodure de cuivre(I)/1,4-bis(2-hydroxy-3,5-di-ieri-butylbenzyl)piperazine (CuI-L2) catalyse les reactions de couplages croisees entre les halogenures d'aryles et une solution aqueuse d'ammoniaque pour conduire a la formation d'amines aromatiques primaires avec de bons rendements. Le protocole est simple et efficace, il ne necessite pas d'atmosphere inerte, de base additionnelle ou d'autres additifs. Mots-cles : cuivre, catalyse, couplage croise, chimie dans l'eau, solution aqueuse d'ammoniaque, arylamine primaire., Introduction Ammonia is an attractive source of nitrogen in organic synthesis owing to its great abundance and low cost. (1) In recent years, the palladium- or copper-catalyzed coupling of aryl [...]

The application of electron-transfer dissociation (ETD) to obtain single-residue resolution in hydrogen exchange-mass spectrometry (HX-MS) experiments has recently been demonstrated. For such measurements, it is critical to ensure that the level of gas-phase hydrogen scrambling is negligible. Here we utilize the abundant loss of ammonia upon ETD of peptide ions as a universal reporter of positional randomization of the exchangeable hydrogens (hydrogen scrambling) during HX-ETD experiments. We show that the loss of ammonia from peptide ions proceeds without depletion of deuterium when employing optimized mild electrospray ion source settings for the HX-ETD analysis of a selectively labeled model peptide and peptides derived from fully labeled [beta]-microglobulin. Hydrogen scrambling, as induced by excessive vibrational excitation of peptide ions during harsh declustering conditions, is easily detected by a depletion of deuterium when deuterated ammonia is lost from peptides during ETD. This straightforward method requires no modifications to the experimental workflow and has the great advantage that the occurrence of hydrogen scrambling can be directly detected in the actual peptides analyzed in the HX-ETD experiment. 10.1021/ac101889b

Legume rotations and animal manures can reduce synthetic fertilizer use in row crops, but only long-term experiments can elucidate effects of multiple legume rotations and decades of manure additions on soil gas emissions. In 2006 and 2007, we measured soil-atmosphere fluxes of [N.sub.2]O, N[H.sub.3,] and C[O.sub.2] in maize (Zea may L.) crops within a replicated experiment comparing continuous maize to maize-alfalfa (Medicago sativa L.) rotations initiated in 1969. In both systems, comparisons of synthetic fertilizer N and manure N were initiated in 1990. With synthetic fertilizer as the main N source, mean C[O.sub.2]-C fluxes (from March 31st to October 18th) were lower from continuous maize (CC, 512 [+ or -] 132 g [m.sup.-2] growing [season.sup.-1]) than from maize following alfalfa (CA, 691 [+ or -] 91 g [m.sup.-2] growing [season.sup.-1]). In contrast, with manure as the main N source, mean soil C[O.sub.2]-C fluxes from CC (943 [+ or -] 111 g [m.sup.-2] growing [season.sup.-1]) were greater than from CA (682 [+ or -] 21g [m.sup.-2] growing season-l). Soil C[O.sub.2]-C emissions correlated with long-term inputs of manure. Synthetically fertilized continuous maize had lower [N.sub.2]O-N fluxes (0.36 [+ or -] 0.26 g [m.sup.-2] growing [season.sup.-1]) than other treatments (0.55-0.58 g [m.sup.-2] growing [season.sup.-1]). Nitrous oxide-N fluxes were not correlated with current N inputs or soil nitrate concentrations, suggesting that long-term treatment effects (e.g., on soil structure, labile C, or microbial communities) contribute to contemporary [N.sub.2]0 variation. Elevated N[H.sub.3]fluxes (>5 mg N[H.sub.3][m.sup.-2] [h.sup.-1] followed manure applications, but within weeks there were no significant treatment differences in N[H.sub.3]fluxes. These results suggest that short-term or single- factor studies may not capture important interactions among crop rotations and N sources affecting greenhouse gas emissions from agricultural soils. doi: 10.2136/sssaj2009.0446

Extraction of soil with solvents is commonly used to isolate fractions of soil organic matter (SOM) thought to cause soil water repellency. Previous studies have assessed the efficiency of extraction procedures by determining sample water repellency and SOM content, before and after extraction, and the ability of extracts to render wettable materials repellent. Here we use atomic force microscopy (AFM) for the direct, high-resolution examination of the effects of the most commonly used solvent (isopropanol/ammonia) on physicochemical properties of soil particle surfaces. Particles, from three pairs of wettable and water repellent sandy soils, were examined before and after Soxhlet extraction and following extract application to extracted soil material. Complementary evidence was provided by comparison with the effects of exposing clean sand to organic compounds of known composition. The extraction rendered all soils wettable and resulted in a reduction in particle surface area covered by SOM. Subsequent exposure of these wettable particles to extracts (i) re-introduced some level of water repellency despite achieving only a minimal increase in SOM; (ii) led to a more uniform scatter of soft regions, indicative of SOM; but (iii) did not consistently recreate original surface features. The outcomes suggest that (i) although isopropanol/ ammonia extraction may be able to isolate key compounds involved in causing water repellency, these compounds appear to be obtained in a form with little affinity for clean mineral surfaces; (ii) the extent and distribution of SOM on soil particle surfaces appears to be a critical factor in the expression of water repellency. doi: 10.2136/sssaj2009.0455

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.solener.2009.12.009 Byline: S.D. Delekar (a), M.K. Patil (a), B.V. Jadhav (b), K.R. Sanadi (b), P.P. Hankare (b) Keywords: Cadmium lead chalcogenide; Chemical synthesis; X-ray diffraction; Mott-Schottky plot; Photoelectrochemical studies Abstract: Optimum composition Cd.sub.0.7Pb.sub.0.3Se thin films have been deposited using the chemical bath containing cadmium sulfate octahydrate, lead nitrate, tartaric acid, potassium hydroxide, ammonia, and sodium selenosulfate onto fluorine-doped tin oxide glass substrate. The various deposition parameters such as composition of reactive bath, pH of the solution, deposition temperature, deposition time, speed of rotation, etc. have been optimized for obtaining good quality film. X-ray diffraction studies revealed the polycrystalline nature of sample with the solid solution of lead (II) ions in CdSe host lattice, having a hexagonal phase structure. Scanning electron micrograph suggested that the grains were non-uniformly distributed over the substrate surface. Film composition was determined by atomic absorption spectroscopy as well as energy dispersive X-ray atomic spectroscopy. Optical absorption data showed the presence of direct transition with energy band gap 1.80eV for the deposited thin films. The dark specific conductance of Cd.sub.0.7Pb.sub.0.3Se thin films was found to the order of 10.sup.-6 (I[c]cm).sup.-1 having n-type semiconducting nature. Photoelectrochemical characterization was carried out using sulfide/polysulfide electrolyte with 1.401% efficiency. Author Affiliation: (a) Department of Chemistry, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad, Sub-center Osmanabad 413 501, Maharashtra, India (b) Solid State Research Laboratory, Department of Chemistry, Shivaji University, Kolhapur 416 004, Maharashtra, India Article History: Received 1 September 2009; Revised 19 November 2009; Accepted 12 December 2009 Article Note: (miscellaneous) Communicated by: Associate Editor Takhir Razykov

While constructed treatment wetlands are very efficient at polishing nitrate from secondary effluent, they are much less effective at removing ammonia. A key factor that limits ammonia oxidation via biological nitrification in vegetated wetlands is low levels of dissolved oxygen. This study evaluated the effectiveness of side-stream oxygenation to enhance ammonia removal in replicate surface-flow experimental mesocosms containing wetland sediment and plants (Typha spp.). Mesocosms had a water volume of 29.5 L, a hydraulic retention time of 5 days, and a hydraulic loading rate of 4.3 cm/d, and were loaded with synthetic secondary effluent contain l0 mg-N/L of ammonia. Relative to nonoxygenated controls, oxygenation increased ammonia removal rates by an order of magnitude. Areal removal rates increased from 40 mg-N/[m.sup.2]/d to 450 mg-N/[m.sup.2]/d, concentration removal efficiency increased from 10 to 95%, and area-based first-order removal rates increased from < 2 m/year to 50-75 m/year. Ammonia removal rates in oxygenated mesocosms were 2- to 4-fold higher than rates reported for full-scale constructed wetlands treating secondary effluent. Results show that oxygen-activated nitrification wetlands, a hybrid of conventional oxygenation technology and wetland ecotechnology, hold promise in economically enhancing rates of ammonia removal and shrinking the wetland area needed to polish ammonia-dominated secondary effluent. Further study is needed to confirm that oxygenation can promote high rates of ammonia removal at the field scale. DOI: 10.1061/(ASCE)EE.1943-7870.0000053 CE Database subject headings: Water pollution; Ammonia; Water treatment; Nitrification; Wetlands; Wastewater management; Water quality.

In recent years the application of partial nitrification techniques has been denoted as very promising. These methods arc based on the oxidation of ammonia to nitrite and the inhibition of the nitratation using different strategies. In most cases, this inhibition causes an increase in the concentration of nitrite. However, the effect of high nitrite concentrations under low dissolved oxygen (DO) conditions on the nitrification process is not well understood. In this paper, the effect of ammonia, nitrite, and nitrate concentrations on the nitrification process under low dissolved oxygen concentrations were studied using respirometric techniques. Results showed that the specific oxygen uptake rate (SOUR) followed a Monod-type equation with respect to the DO concentration. The coefficient SOU[R.sub.m] was constant with respect to the ammonia, nitrite, and nitrate within the tested concentrations; in addition, [K.sub.O] was constant with respect to ammonia and nitrate but it increased linearly with the nitrite concentration, suggesting that nitrite was a competitive inhibitor of the SOUR. The inhibitory effect of nitrite was reverted by washing, in accordance with a competition model. From the data obtained using the open respirometer, the ratio between the oxygen consumption (OC) corresponding to each pulse of ammonia at different nitrite concentrations and the OC in the absence of nitrite (O[C.sub.O]) was calculated. The experimental ratio OC/O[C.sub.O]) was almost constant with respect to the nitrite concentration and it was close to the literature value. Finally, simulation results agree with the experimental data confirming that the proposed competition model represented adequately the inhibitory effect of nitrite on the respiration rate of ammonia-oxidizing bacteria. DOI: 10.1061/(ASCE)0733-9372(2008)134:3(184) CE Database subject headings: Nitrification; Ammonia; Nitrates; Biological treatment; Bacteria; Simulation.

The recent discovery of ammonia-oxidizing archaea (AOA) dramatically changed our perception of the diversity and evolutionary history of microbes involved in nitrification. In this study, a moderately thermophilic (46[degrees]C) ammonia-oxidizing enrichment culture, which had been seeded with biomass from a hot spring, was screened for ammonia oxidizers. Although gene sequences for crenarchaeota116S rRNA and two subunits of the ammonia monooxygenase (amoA and amoB) were detected via PCR, no hints for known ammonia-oxidizing bacteria were obtained. Comparative sequence analyses of these gene fragments demonstrated the presence of a single operational taxonomic unit and thus enabled the assignment of the amoA and amoB sequences to the respective 16S rRNA phylotype, which belongs to the widely distributed group 1.1b (soil group) of the Crenarchaeota. Catalyzed reporter deposition (CARD)-FISH combined with microautoradiography (MAR) demonstrated metabolic activity of this archaeon in the presence of ammonium. This finding was corroborated by the detection of amoA gene transcripts in the enrichment. CARD-FISH/ MAR showed that the moderately thermophilic AOA is highly active at 0.14 and 0.79 mM ammonium and is partially inhibited by a concentration of 3.08 mM. The enriched AOA, which is provisionally classified as ''Candidatus Nitrososphaera gargensis,' is the first described thermophilic ammonia oxidizer and the first member of the crenarchaeotal group 1.1b for which ammonium oxidation has been verified on a cellular level. Its preference for thermophilic conditions reinvigorates the debate on the thermophilic ancestry of AOA. ammonia oxidation | archaea | nitrification | thermophile | amoA

The thermochemistry of various atmospheric nanoclusters is studied to explain the importance of ammonia in their growth. Ammonia is found to be extremely significant for their growth, as it enhances the growth of small water-sulfuric acid clusters in atmospheric conditions.

The state-specifc vibrational predissociation (VP) dynamics of the hydrogen-bonded ammonia-acetylene dimer were studied. Ammonia fragments were detected following vibrational excitation of Ch stretch, the vibrational state distributions show distinct state specificity among channels with low translational energy release and the calculations show that dissociation takes place from bent geometries.

Infrared spectroscopy was used to study the NH stretching vibrations in small ammonia clusters in He droplets. The measured spectra show well-resolved bands and the formation of a hydrogen bond in ammonia dimers leads to an increase of the infrared intensity by about a factor 4, in the larger clusters the infrared intensity per hydrogen bond is close that found in dimers.

The mechanism and energetics of the reactions of trimethylindium (TMIn) with H[N.sub.3] and N[H.sub.3] in the gas phase were investigated by density functional theory and ab initio calculations. The result indicate that the reaction with H[N.sub.3] forms a new stable product, dimethylindiumnitride, C[H.sub.3]-In=N-C[H.sub.3] via another stable In[(C[H.sub.3]).sub.2][N.sub.3] intermediate.

A detailed study of the solvation of [Cu.sup.2} with gas-phase clusters of water and ammonia was performed. The results show that the unit [[Cu[(X).sub.8]].sup.2} of the complex has special significance and it is proposed that the hydrogen-bonded structure associated with this ion is responsible for stabilizing the dipositive charge on [Cu.sup.2} in aqueous solution.

A series of early metal-promoted Ru-, Pd-, Pt-, and Rh-doped mesoporous tantalum oxide catalysts were synthesized by using a variety of dopant ratios and dopant precursors to explore the effects of these parameters on the catalytic activity of N[H.sub.3] synthesis from [H.sub.2] and [N.sub.2].

A report is presented to describe how students can be empowered to construct the full, double minimum inversion potential for ammonia by performing intrinsic reaction coordinate calculations. This work can be associated with the third year physical chemistry lecture laboratory or an upper level course in computational chemistry.

A new kinetic mechanism of the NO + N[H.sub.3] reaction is used on Pt{100} in order to simulate the spatiotemporal traveling waves. The Irurzun, Mola and Imbihl (IMI model) has predicted the presence of macroscopic oscillations in the partial pressures of the reactants coexisting with front wave patterns on the surface.

Ferredoxin-dependent glutamate synthase (FdGltS), 2-oxoglutarate (2-OG) and L-glutamine (L-Glu) contribute to the activation of the glutaminase site and to ammonia transfer through the tunnel in a two step process. This process requires partial activation upon binding of 2-OG at the synthase site, followed by full activation brought about by glutamine binding.

A study was conducted to explore the interaction of molecular hydrogen with the small molecules HF, [H.sub.2]O, N[H.sub.3], and LiOH. The interaction energy for the simultaneous interaction of [H.sub.2] with two LiOH molecules has not exceeded the value obtained for the interaction with a single LiOH molecule.

The effects of mineral fertilizer (NPK) and organic manure on the community structure of soil ammonia-oxidizing bacteria (AOB) are examined in a long-term fertilizer experiment. The results have shown that long-term application of N fertilizers might result in increased soil nitrification potential and the ammonia-oxidizing bacteria (AOB) community shifts in soil.

The fabrication and characterization of tungsten oxide nanofibers is described using the electrospinning technique and sol-gel chemistry. The results have shown that the as-prepared tungsten oxide ceramic nanofibers have a quick response to ammonia with various concentrations, indicating potential applications of the electrospun tungsten oxide nanofibers as a sensor material for gas detection.

A number of compounds that contain unsymmetric 'hybrid' ligands were synthesized to understand molybdenum-centered catalytic dinitrogen reduction. The findings show that electron-donating ligands might speed the rate of ammonia for dinitrogen exchange but the increase of the rate of exchange of ammonia for dinitrogen was not sufficient to avoid the shunt that prevents catalytic turnover.

The synthesis of [HIPT[N.sub.3]N]V compounds, including [[HIPT[N.sub.3]N]V([N.sub.2])].sup.-] along with some preliminary studies concerned with the catalytic reduction of dinitrogen is reported. While the chemistry of V complexes is largely tractable and well-behaved, no ammonia was formed from dinitrogen using V(THF), [{V[N.sub.2]}.sup.-], or V=NH as the initial species under conditions that were successful in the analogous Mo system.

The densities of N, NH, N[H.sub.2] radicals in a remote Ar-N[H.sub.3]-Si[H.sub.4] plasma used for high-rate silicon nitride deposition are examined for different gas mixtures and plasma settings by using cavity ringdown absorption spectroscopy and threshold ionization mass spectroscopy. It is concluded that N and N[H.sub.2] radicals are mainly responsible for the N incorporation in the silicon nitride film, while Si atoms are most likely brought to the surface in the form of Si[H.sub.x] radicals.

The abundance and population structure of ammonia-oxidizing bacteria (AOB) in canal sediments receiving wastewater discharge was investigated in a polyphasic, culture-independent study. It was revealed that the AOB communities influenced by the wastewater discharge were dominated by Nitrosomonas, were similar to each other and were less diverse than the communities outside of the immediate discharge zone.

In this paper we tackle issues relevant to model based control design for a Urea based Selective Catalytic Reduction (SCR) process relevant to automotive applications. A three state, control oriented, lumped parameter model of the system is used to investigate essential controllability and observability properties of the Urea-SCR plant. Results from the controllability and observability analysis of both nonlinear and linearized models are shown to have realistic implications. Observer design for predicting gas phase ammonia slip is outlined and results presented. An altered definition of the catalyst efficiency is used in control design. It is shown that this altered definition lends itself readily to control synthesis in the Sliding Mode framework while satisfying the dual control objectives of maximizing N[O.sub.x] reduction and minimizing ammonia slip. [DOI: 10.1115/1.2234494]

The kidney plays an important role in ammonia metabolism. In this study the hypothesis was tested that the kidney can acutely diminish ammonia release after portacaval shunting. Thirteen patients with cirrhosis (6 female/7 male, age 54.4 [+ or -] 3.3 yr) were studied. Blood was sampled prior to and 1 h after transjugular intrahepatic stent-shunt (TIPSS) insertion from the portal vein, a hepatic vein, the right renal vein, and the femoral vein, and renal and liver plasma flow were measured. Prior to TIPSS, renal ammonia release was significantly higher than ammonia release from the splanchnic region, which was not significantly different from zero. TIPSS insertion did not change arterial ammonia concentration or ammonia release from the splanchnic region but reduced renal ammonia release into the circulation (P < 0.05) to values that were not different from zero. TIPSS resulted in a tendency toward increased venous-arterial ammonia concentration differences across leg muscle. Post-TIPSS ammonia efflux via portasystemic shunts was estimated to be seven times higher than renal efflux. Kidneys have the ability to acutely diminish systemic ammonia release after portacaval shunting. Diminished renal ammonia release and enhanced muscle ammonia uptake are important mechanisms by which the cirrhotic patient maintains ammonia homeostasis after portasystemic shunting. cirrhosis doi:10.1152/ajpgi.00165.2005

X-ray photoelectron spectroscopy is used to characterize the surface chemistry of atomic layer depositions (ALD) of titanium nitride films using alternate doses of TiCl4 and NH3. In terms of the incorporation of contaminants in the grown films, it is found that chlorine is deposited in small quantities on the surface whereas oxygen is detected all throughout the grown films.

The synchrotron based vacuum ultraviolet-pulsed field ionization-photoelectron (VUV-PFI-PE) spectrum of ammonia (N[H.sub.3]) is measured in the energy range 10-12-12.12 eV using a room temperature N[H.sub.3] sample. It is demonstrated that the two-color IR-VUV-photoion depletion (PID) detection scheme is a valuable method for identifying the rotational nature of autoionizing Rydberg resonances.

The first determination of the temperature dependence of the rate constant [k.sub.1] for the endothermic reaction is presented and compared with the isoelectronic and also endothermic reaction. Ground-state CI atoms were generated by 193 nm excimer laser photolysis of CCl4 and reacted under pseudo-first-order conditions with excess N[H.sub.3].

The Car-Parrinello molecular dynamics (CPMD) method is used to study the dynamic characteristics of the cation-pi interaction between ammonium and benzene in gaseous and aqueous media. This method has provided strong evidence that cation-pi interactions might take place even on the surface of proteins or nucleic acids in an aqueous environment.

The adsorption of NH3 onto model Fe(110) and Fe(111) surfaces is studied using molecular orbital and density functional theories in order to understand the nature of the interactions between organic molecules and metal surfaces. The study of adsorption of NH3 onto Fe(110) and Fe(111) surfaces have shown that organic amine acts as electron donor and is adsorbed onto the Fe surface, which behaves as an electron acceptor.

Two approaches are reported for the preparation of N-substituted beta-enamino ester piperidines featuring an exocyclic tetrausbstituted double bond, based either on the direct alkylation of piperidine beta enamino esters or on the intromolecular cyclization of linear amino beta-keto esters. The key role of ammonia as reagent acting both as nucleophile and a base is underlined.

Expanded density functional theory calculations were used for reexamining the reactivity of yttrium atoms toward ammonia. Further NH3 molecules adsorption is possible by the di-amide species for the formation of Y(NH2)NH3 and Y(NH2)2(NH3)2.

Resonant two-photon ionization (R2PI) and UV-UV hole-burning spectroscopies were used for examining the analogues three-membered solvent-wire clusters. The threshold for the excited-state hydrogen-atom transfer reaction is found to be ~200cm-1 for 7HQ.(NH3)3, ~350 cm-1 for both isomers of the 7HQ.(NH3)2.H2O cluster and ~600 cm-1 for 7HQ.NH.(H2O)2.

The anodic dissolution of silicon in acid solutions of ammonium fluoride was investigated in aqueous and water-alcohol media using a rotating disk voltammetry and impedance spectroscopy. The important differences and similarities shown by investigations in aqueous and water-alcohol media are provided.

The N-doped TiO(sub 2) layer was prepared by pretreating the TiO(sub 2) precursor in the NH(sub 3)/ ethanol fluid under supercritical, denoted as TiO(sub2)N(SC). The activity of the TiO(sub 2)N(SC) first increased and then decreased with the increase ind the N-content.

A large structural family of the supramolecualr complexes with the general composition [(M(super 11)X(sub 4)M(super 1)@ 18c6(sub 4)][TIX(sub 4)](sub 2).nH(sub 2)O(M(super 11) = Cu, Co, Zn, Mn; M(super 1) = NH(sub 4), Rb, TI; X = Cl, Br) is investigated. It is found that the compounds are versatile host lattices for tetrahedrally coordinated transition metal units become obvious by the large group of known host-guest complex compounds.

A novel strategy is described to improve the growth performance of Lactococcus lactis by heterologous production of food-grade transglutaminase. The results have provided a novel way to boost the growth yield of Lactococcus lactis, which is a vital step for the purposes of producing proteins of commercial interest using Lactococcus lactis as a host.