Structural Characterization of Sputter-Deposited 304 Stainless Steel+10 wt pct Al Coatings

An SS304?+?10?wt pct Al (with a nominal composition of Fe-18Cr-8Ni-10Al by wt pct and corresponding to Fe-17Cr-6Ni-17Al by at. pct) coating was deposited on a 304-type austenitic stainless steel (Fe-18Cr-8Ni by wt pct) substrate by the magnetron sputter-deposition technique using two targets: 304-type stainless steel (SS304) and Al. The as-deposited coatings were characterized by X-ray diffraction, transmission electron microscopy, and three-dimensional (3-D) atom probe techniques. The coating consists of columnar grains with ?? ferrite with the body-centered cubic (bcc) (A2) structure and precipitates with a B2 structure. It also has a deposition-induced layered structure with two alternative layers (of 3.2 nm wavelength): one rich in Fe and Cr, and the other enriched with Al and Ni. The layer with high Ni and Al contents has a B2 structure. Direct confirmation of the presence of B2 phase in the coating was obtained by electron diffraction and 3-D atom probe techniques.     

Preparation and performance of CeO_2 hollow spheres and nanoparticles

CeO_2 hollow spheres were synthesized by polystryrene sphere(PS) templates and CeO_2 nanoparticles were prepared by a facile method. The as-obtained products were characterized by scanning electron microscopy(SEM), N_2 adsorption-desorption, X-ray diffraction(XRD), Fourier transform infrared spectroscopy(FTIR) and UV-vis diffuse reflectance spectra. The results showed that the structure of the obtained CeO_2 hollow spheres was hollow microsphere with a diameter of 380 nm and the average particle size of CeO_2 nanoparticles was about 1700 nm. The two samples' Brunauer-Emmett-Teller(BET) surface area was 67.1 and 37.2 m~2/g. The CeO_2 hollow spheres had a better performance than nanoparticles at UV-shielding because of higher surface area and the structure of hollow sphere.     

Synthesis of a novel phosphate ester of a vitamin E derivative and its antioxidative activity

A novel phosphate ester containing a chromanol structure was synthesized from 1,2-diacyl-sn-glycero-3-phospho-2'-hydroxyethyl-2',5',7',8'-tetramethyl- 6' -hydroxychroman (PCh) by hydrolysis catalyzed by phospholipase C from Bacillus cereus. The structure of the product was found by spectral analyses to be 2-(2',5',7',8'-tetramethyl-6'-hydroxychromanyl)ethylphosphate++ + (Ch-P). Ch-P was highly soluble in the aqueous phase at neutral pH values and exerted higher antioxidative activity than alpha-tocopherol and PCh in the Fe(III)/ascorbic acid-catalyzed peroxidation of a fish oil emulsion and the autoxidation of a rat brain homogenate.     

Crystal structure of apo-glycine N-methyltransferase (GNMT)

The crystal structure of the recombinant apo-form of glycine N-methyltransferase (GNMT) has been determined at 2.5 A resolution. GNMT is a tetrameric enzyme (monomer Mr = 32,423Da, 292 amino acids) that catalyzes the transfer of a methyl group from S-adenosylmethionine (AdoMet) to glycine with the formation of S-adenosylhomocysteine (AdoHcy) and sarcosine (N-methylglycine). GNMT is a regulatory enzyme, which is inhibited by 5-methyltetrahydrofolate pentaglutamate and believed to control the ratio of AdoMet to AdoHcy in tissues. The crystals belong to the orthorhombic space group P2(1)2(1)2 (a = 85.39, b = 174.21, c = 44.71 A) and contain one dimer per asymmetric unit. The AdoMet-GNMT structure served as the starting model. The structure was refined to an R-factor of 21.9%. Each monomer is a three-domain structure with a large cavity enclosed by the three domains. The tetramer resembles a square with a central channel about which N-terminal domains are intertwined. Only localized changes of the residues involved in the binding pocket are observed for the apo-GNMT structure when compared to that determined in the presence of substrate and substrate analog.     

Co-crystallization and characterization of the photosynthetic reaction center-cytochrome c2 complex from Rhodobacter sphaeroides

The photosynthetic reaction center (RC) of Rhodobacter sphaeroides and cytochrome c2 (cyt c2), its physiological secondary electron donor, have been co-crystallized. The molar ratio of RC/cyt c2 was found by SDS-PAGE and optical absorbance changes in the co-crystals to be 4. The crystals diffracted X-rays to 3.5 angstroms. However, the resolution degraded during data collection. A data set, 82.5% complete, was collected to 4.5 angstroms. The crystals belong to the tetragonal space group P4(3)2(1)2, with unit cell dimensions of a = b = 142.7 angstroms and c = 254.8 angstroms. The positions of the RCs in the unit cell were determined by molecular replacement. A comparable search for the cyt c2 by this method was unsuccessful because of the small contribution of the cytochrome to the total scattering and because of its low occupancy. The cyt c2 was positioned manually into patches of difference electron density, adjacent to the periplasmic surface of the M polypeptide subunit of the RC. The difference electron density was not sufficient for precise positioning of the cyt c2, and its orientation was modeled by placing the exposed edge of the heme toward the primary donor of the reaction center D and by forming pairs for electrostatically interacting RC and cyt c2 amino acid residues. The RC-cyt c2 structure derived from the co-crystal data was supported by use of omit maps and structure refinement analyses. Cyt c2 reduces the photooxidized primary donor D+ in 0.9 +/- 0.1 micros in the co-crystals, which is the same as the fast electron transfer rate in vivo and in solution. This result provides strong evidence that the structure of the complex in the co-crystal is the same as in solution. Two additional methods were used to investigate the structure of the RC-cyt c2 complex: (i) Docking calculations based on interprotein electrostatic interactions identified possible binding positions of the cyt c2 on the RC. The cyt c2 position with the lowest electrostatic energy is very similar to that of the cyt c2 in the proposed co-crystal structure. (ii) Site-directed mutagenesis was used to modify two aspartic acid residues (M184 and L155) on the periplasmic surface of the RC. Cyt c2 binding affinity to these RCs and electron transfer rates to D+ in these RCs support the co-crystal structure of th RC-cyt c2 complex.     

Octoxynol presence in bear-bile

The presence of octoxynol from dried bear-bile was examined. Octoxynol was coextracted when glycolipids by Folch-Suzuki partition method. Octoxynol formed mixed-micelles with glycosphingolipids. The glycolipids were purified by DEAE-Sephadex A-25 column chromatography. The fractions containing mixed micelles were obtained from linear gradient solvent of 0.05M-0.5M ammonium acetate in methanol. HPLC ( Bondapak-NH(2) - linked to a Bondapak-C(18) column) chromatogram showed five peaks. Two possible structures for the fourth peak fraction were proposed as (CH(3))(3)C-CH(2)-C(CH(3))(2)-C(6)H(4)-OR and (CH(3))(3)C-C(CH(3))(2)-CH(2)-C(6)H(4)-OR by NMR spectroscopy. The structure was further confirmed by electrospray tandem mass spectrometry (ESI MS/MS). The spectrum showed a protonated molecule at m/z 559 and three different series of ions with mass difference of 44 were detected in the MS/MS spectrum. Therefore, the structure of the fourth peak fraction from HPLC was confirmed as octoxynol, (CH(3))(3)C-CH(2)-C(CH(3))(2)-C(6)H(4)-(OCH(2)-CH(2))n-OH, based on mass spectrometry and NMR spectroscopy.     

Preparation and electrochemical properties of Y-doped Li3V2（PO4）3 cathode materials for lithium batteries

Y-doped Li3V2(PO4)3 cathode materials were prepared by a carbothermal reduction(CTR) process. The properties of the Y-doped Li3V2(PO4)3 were investigated by X-ray diffraction (XRD) and electrochemical measurements. XRD studies showed that the Y-doped Li3V2(PO4)3 had the same monoclinic structure as the undoped Li3V2(PO4)3. The Y-doped Li3V2(PO4)3 samples were investigated on the Li extraction/insertion performances through charge/discharge, cyclic voltammogram (CV), and electrochemical impedance spectra (EIS). The optimal doping content of Y was x=0.03 in Li3V2-xYx(PO4)3 system. The Y-doped Li3V2(PO4)3 samples showed a better cyclic ability. The electrode reaction reversibility was enhanced, and the charge transfer resistance was decreased through the Y-doping. The improved electrochemical performances of the Y-doped Li3V2(PO4)3 cathode materials were attributed to the addition of Y3+ ion by stabilizing the monoclinic structure.     

Implicit Sequence Learning: Effects of Level of Structure, Adult Age, and Extended Practice.

The influence of structure and age on sequence learning was investigated by testing 24 young and 24 older participants for 10 sessions in an alternating serial response time task in which pattern trials alternated with random trials. Individuals encountered lag-2 or lag-3 structure, and learning was measured by the difference (in response time and accuracy) between pattern and random trials. Both ages learned lag-2 structure, but the young learned more than the older participants. Only the young people learned lag-3 structure, and they did so more slowly and to a lesser degree than they learned lag-2 structure. These age deficits in higher order sequence learning after extended practice are consistent with simultaneity theory and with theories positing that age-related deficits in neuromodulation lead to less distinctive representations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Crystal structure and infrared spectrum of thallium holmium polyphosphate, TIHo(PO3)4

Crystals of thallium-holmium polyphosphate TIHo(PO3)4 were grown by flux method technique and characterized by single crystal X-ray diffraction. Structure of TIHo(PO3)4 was solved for the first time, and it crystallized in the monoclinic P21/n space group with the following unit-cell dimensions: a=1.02225(3) nm, b=0.88536(2) nm, c=1.09541(4) nm, β=105.888(1)°, V=0.95354(5) nm3 and Z=4. The crystal structure was solved from 2174 independent reflections with final R1(F2)=0.0442 and Rw(F<2)=0.0861 refined with 164 parameters. The atomic arrangement could be described as a long chain polyphosphate organization. Holmium atoms had eighffold coordination. The structure of T1Ho(PO3)4 consisted of HoO8 polyhedra sharing oxygen atoms with phosphoric group PO4. Infrared spectrum was investigated at room temperature in the frequencies range, 350-4000 cm-1, showing some characteristic vibration bands of infinite chain structure of PO4 tetrahedra linked by bridging oxygen.     

Structural elucidation of the lipopolysaccharide core regions of the wild-type strain PAO1 and O-chain-deficient mutant strains AK1401 and AK1012 from Pseudomonas aeruginosa serotype O5

Lipopolysaccharide (LPS) of the Pseudomonas aeruginosa serotype O5 wild-type strain PAO1 and derived rough-type mutant strains AK1401 and AK1012 was isolated by a modified phenol/chloroform/petroleum-ether extraction method. Deoxycholate/PAGE of the LPS from the rough mutant AK1401 indicated two bands near the dye front with mobilities similar to those of the parent strain, indicating that both LPS contain a complete core and a species comprising a core and one repeating unit. Composition analysis of the LPS from strains PAO1 and AK1401 indicated that the complete core oligosaccharide was composed of D-glucose (four units), L-rhamnose (one unit), 2-amino-2-deoxy-D-galactose (one unit), L-glycero-D-manno-heptose (Hep; two units), 3-deoxy-D-manno-octulosonic acid (Kdo; two units), L-alanine (one unit) and phosphate (three units). The glycan structure of the LPS was determined by one-dimensional and two-dimensional (2D) NMR techniques in combination with MS-based methods on oligosaccharide samples obtained from the LPS by delipidation procedures. The locations of three phosphomonoester groups on the first heptose residue were established by a two-dimensional 31P (omega1)-half-filtered COSY experiment on the reduced core oligosaccharide sample of the LPS from the wild-type strain. The presence of a 7-O-carbamoyl substituent was observed on the second heptose. The structure of the core region of the O-chain-deficient LPS from P. aeruginosa serotype 05 is as follows: [structure: see text] where R1 is beta-D-Glcp-(1-->2)-alpha-L-Rhap-(1-->6)-alpha-D-Glcp-(1--> and R2 is alpha-D-Glcp-(1-->6)-beta-D-Glcp-(1->. A structural model is presented that is also representative of that for P. aeruginosa serotype O6 LPS. A revised structure for the serotype O6 mutant strain A28 is presented.     

Synthesis and characterization of yttrium and antimony codoped SnO₂ conductive nanoparticles

Y was used as a dopant in preparing conductive powder to improve its performance. Y and Sb co-doped SnO2 conductive nanoparticles were prepared by the complexation-coprecipitation method with Sn,Sb2O3 and Y2O3 as the raw materials. Crystal phase,thermal behavior and structure of the prepared conductive nanoparticles were characterized by X-ray diffraction(XRD) ,thermal analysis(TG-DSC) ,Fourier transform infrared(FTIR) and transmission electron microscopy(TEM) techniques,respectively. The Y and Sb co-doped SnO2 conductive nanoparticles with a structure of tetragonal rutile had intense absorption in 4000-2500 cm-1,and the diameter ranged from 10 to 30 nm. The resistivity of Y and Sb co-doped SnO2 conductive nanoparticles was as low as 0.09 Ω·cm which was 4.6 times lower than that of Sb doped SnO2 conductive nanoparticles.     

Synthesis and Characterizations of Rare Earth Compounds RE(HCO 2) 3(HNO 2)(H 2CO 2)(RE=Y, Tb, Dy, Ho, Er, Yb, Tm)

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Synthesis, crystal structure and characterization of one-dimension complex constructed by terbium(Ⅲ) and 2-iodobenzoate

The complex of [Tb(2-IBA)3(H2O)2]n (2-IBA=2-iodobenzoate) was prepared by solvent method from TbCl36H2O and 2-iodo-benzoic acid. The crystal structure was determined with X-ray single-crystal diffraction. The X-ray diffraction analysis indicated that the title complex crystallized in triclinic crystal system and Pi space group. The Tb3+ ion was coordinated by six oxygen atoms from five 2-IBA ligands and two oxygen atoms from two water molecules, giving a distorted square-antiprism polyhedral geometry. The carboxyl groups were bonded to the Tb3+ ions with bidentate-bridging and bidentate-chelating coordination modes. The adjacent Tb3+ ions were linked by two bidentate-bridging 2-IBA ligands, forming I-D chain structure. The fluorescence spectrum of the complex showed four main peaks at 489, 543, 587, and 618 nm, Corresponding to 5D4→7F (J=6-3) transition emissions of the Tb3+ ion, respectively.     

Two-dimensional elution map of GalNAc-containing N-linked oligosaccharides

We have previously published a two-dimensional (2-D) mapping technique for N-linked oligosaccharides using pyridylaminated derivatives (PA-oligosaccharides) (N. Tomiya et al. Anal. Biochem. 171, 73-90, 1988). We now report an extension of this method to GalNAc-containing N-linked oligosaccharides. The new 2-D map was prepared from the elution data of 40 different GalNAc-containing oligosaccharides, 16 of which were obtained directly from human urinary kallidinogenase by digestion with glycopeptidase A. The other 24 oligosaccharides were derived by subsequent digestion of the 16 original oligosaccharides with beta-galactosidase or alpha-fucosidase. Each of the 40 oligosaccharide derivatives was separated by high-performance liquid chromatography using ODS-silica and amide-silica columns. The 2-D map constructed by plotting elution position of each oligosaccharide (expressed in terms of glucose units) can be useful as such in delineating the structure of an unknown oligosaccharide by direct placement of its elution positions in the 2-D map. Multiple regression analysis of the data as performed previously yielded parameters related to the contribution of each component monosaccharide unit to the elution profile. The best results were obtained when the GalNAc-containing PA-oligosaccharides were classified into an F-series (those containing Fuc alpha 6GlcNAc-PA) and a Z-series (all others), based on our previous classification method. These calculated values are useful in predicting oligosaccharide structure from known elution values as well as to predict elution volumn from a known structure. The structure of a minor GalNAc-containing oligosaccharide in human urinary kallidinogenase was elucidated using these newly calculated values.     

Evidence of the construct validity of developmental ratings of managerial performance.

The construct validity of developmental ratings of managerial performance was assessed by using 2 data sets, each based on a different 360° rating instrument. Specifically, the authors investigated the nature of the constructs measured by developmental ratings, the structural relationships among those constructs, and the generalizability of results across 4 rater perspectives (boss, peer, subordinate, and self). A structure with 4 lower order factors (Technical Skills, Administrative Skills, Human Skills, and Citizenship Behaviors) and 2 higher order factors (Task Performance and Contextual Performance) was tested against competing models. Results consistently supported the lower order constructs, but the higher order structure was problematic, indicating that the structure of ratings is not yet well understood. Multisample analyses indicated few practically significant differences in factor structures across perspectives. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stage structure in objective moral judgments.

Analyzed the responses of 160 junior high, senior high, undergraduate, and graduate students to the Defining Issues Test, which measures Kohlbergian moral developments. The study was designed to investigate whether stage and item scores displayed the structure expected of variables that measure a hierarchical, personality-development sequence. Consistent with expectations, (a) the intercorrelations of stage scores displayed a simplex-like structure; (b) factor loadings for stage scores approximated a 2-factor, semicircular configuration with variables ordered by stage along the semicircle; and (c) along the 1st scaling dimension, variables were ordered by stage and persons were ordered by age. The pattern of the stage scores was consistent with the ordering of stages in L. Kohlberg's (1969) theory, except that Stage 2 reasons were assigned more importance by some Ss than would be expected from their position in the developmental sequence. The observed structure of the moral judgments is interpreted as evidence for a hierarchical sequence partially consistent with the one in Kohlberg's theory. (29 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Synthesis, Crystal Structure and Fluorescent Properties of a New One-Dimensional Polymer [Sm（ sal ） 4 （ phen）2 Na ] n

A growing attention has been paid to the investi gation of fluorescence enhancement of the lanthanidessince the lanthanides have low absorptivity and poorquantum yields. Fluorescence enhancement has gener ally been achieved through ligand sensitization in re cent years[1~4]. In emission process, an organic lig and is first excited by absorption of light, followed byenergy transfer from the ligand to the excited levels ofa lanthanide, which then emits. Moreover, the fluo rescence of th…     

Design of peptides using alpha,beta-dehydro-residues: synthesis, crystal structure and molecular conformation of Boc-L-Val-delta Phe-delta Phe-L-Val-OCH3

The peptide Boc-L-Val-delta Phe-delta Phe-L-Val-OCH3 was synthesized by the azlactone method in solution phase, and its crystal and molecular structures were determined by x-ray diffraction method. Single crystals were grown by slow evaporation from a methanol/water solution at 6 degrees C. The crystals belong to an orthorhombic space group P212121 with a = 10.478 (6) A, b = 13.953 (I), c = 24.347 (2) and Z = 4. The structure was determined by direct methods and refined by least squares procedure to an R value of 0.052. The structure consists of a peptide and a water molecule. The peptide adopts two overlapping beta-turn conformations of Types II and I' with torsion angles: phi 1 = -54.8 (6) psi 1 = 130.5 (4), phi 2 = 65.8 (5), psi 2 = 12.8 (6), phi 3 = 79.4 (5), psi 3 = 3.9 (7) degrees. The conformation is stabilized by intramolecular hydrogen bonds involving Boc CO and NH of delta Phe3 and CO of Val1 and NH of Val4. The molecules are tightly packed in the unit cell. The crystal structure is stabilized by hydrogen bonds involving NH of delta Phe2 and CO of a symmetry related (x-1/2, 1/2-y, -z) delta Phe2. The solvent-water molecule forms two hydrogen bonds with peptide molecule involving NH of Val1 as an acceptor and another with CO of a symmetry related (1-x, y-1/2, 1/2 -z) delta Phe3 as a donor. These studies indicate that a tetrapeptide with two consecutive delta Phe residues sequenced with valines on both ends adopts two overlapping beta-turns of Types II and I'.     

磁控溅射制备YBCO超导薄膜的AFM研究

采用中空柱阴极直流磁控溅射装置制备YBCO超导薄膜,应用原子力显微镜（AFM）研究了在最佳工艺条件下沉积在LaAlO3和Zr(Y)O2上的具有c轴取向的YBCO超导薄膜及其相应衬底的表面形貌,生长的YBCO膜都具有较好的表面结构,在LaAlO3单晶衬底上的YBCO膜形成大颗粒岛状结构,颗粒生长整齐,尺寸大小均匀;生长在单晶Zr(Y)O2上的YBCO膜则形成起伏较大的层状与岛状生长的混合结构,这些差别的产生与衬底的初始状况及制备过程中膜与衬底的界面作用有关。分析了形成超导薄膜不同表面形貌的原因,从生长机理角度讨论了表面形貌与缺陷和位错的形成机制。