Fast computation of adaptive wavelet expansions

In this paper we describe and analyze an algorithm for the fast computation of sparse wavelet coefficient arrays typically arising in adaptive wavelet solvers. The scheme improves on an earlier version from Dahmen et al. (Numer. Math. 86, 49–101, 2000) in several respects motivated by recent developments of adaptive wavelet schemes. The new structure of the scheme is shown to enhance its performance while a completely different approach to the error analysis accommodates the needs put forward by the above mentioned context of adaptive solvers. The results are illustrated by numerical experiments for one and two dimensional examples.     

Three characteristic reactions of organocobalt compounds in organic synthesis

Organocobalt compounds in organic synthesis have three characteristic reactions. The first occurs because cobalt has a high affinity to carbon–carbon π‐bonds or carbon–nitrogen π‐bonds. The second occurs because cobalt has a high affinity to carbonyl groups. The third is due to cobalt easily tending to form square‐planar bipyramidal six‐coordination structures with four nitrogen atoms or two nitrogen atoms and two oxygen atoms at the square‐planar position, and to bond with one or two carbon atoms at the axial position. The first characteristic reactions are the representative reactions of organocobalt compounds with a mutually bridged bond between the two π‐bonds of acetylene and the cobalt–cobalt bond of hexacarbonyldicobalt. These are reactions with a Co₂(CO)₆ protecting group to reactive acetylene bond, the Nicholas reactions, the Pauson–Khand reactions ([2 + 2 + 1] cyclizations), [2 + 2 + 2] cyclizations, etc. These reactions are applied for the syntheses of many kinds of pharmaceutically useful compounds. The second reactions are carbonylations that have been used or developed as industrial processes such as hydroformylation for the manufacture of isononylaldehyde, and carbonylation for the production of phenylacetic acid from benzyl chloride. The third reactions are those reactions with the B₁₂‐type catalysts, and they have recently been used in organic syntheses and are utilized as catalysts for stereoselective syntheses. These reactions have been used as new applications for organic syntheses. Copyright © 2007 John Wiley & Sons, Ltd.     

π‐conjugated polymers having diaza[12]annulene rings and aminopenta‐2,4‐dienylidene groups generated by the ring opening of pyridinium rings

Reactions of N‐(2,4‐dinitrophenyl)pyridinium chloride with 2,5‐dimethyl‐1,4‐phenylenediamine in 1:2, 1:1.5, 1:1, and 2:1 molar ratios caused the ring opening of the pyridinium ring and thereby yielded polymers ( P1 – P4 ) consisting of 5‐(2,5‐dimethyl‐1,4‐phenylene)penta‐2,4‐dienylideneammonium chloride (unit A) and N‐2,5‐dimethyl‐1,4‐phenylene diaza[12]annulenium dichloride (unit B). The ¹H NMR spectra suggested that the composition ratios of unit A to unit B in P1 – P4 were 0.98:0.02, 0.94:0.06, 0.81:0.19, and 0.79:0.21, respectively. P1 – P4 showed an absorption maximum (λ_max) at a longer wavelength than the monomers because of the expansion of the π‐conjugation system. Films of P3 and P4 showed λ_max at a considerably longer wavelength than those in solution, and this was attributable to the ordered structures of the polymers in the solid state. Powder X‐ray diffraction analysis supported the ordered structures of P3 and P4 . Pellets molded from P3 and P4 exhibited a metallic luster, whereas those from P1 and P2 did not show such a luster. Cyclic voltammetry measurements indicated that P1 – P4 were electrochemically active in films. The thermal stability of the polymers depended on the composition ratios of unit A to unit B. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1507–1514, 2007     

Melt properties and crystal morphology of polydodecamide plasticized by benzenesulfonamides

The melt of polydodecamide (PA‐12) shows a significant viscosity decrease upon incorporation of benzenesulfonamide plasticizers (BSAs), this effect being maximum for a monofunctional BSA with a 12‐carbon‐atom‐long alkyl chain. Nonexhaustive X‐ray diffraction analysis developed on isothermally crystallized samples validated a two‐phase model for describing PA‐12 plasticized by N‐(n‐butyl)benzenesulfonamide (BBSA). The massive presence of BBSA between the lamellar crystals was established, and lamellar fragmentation was also observed. Further, a steady increase in PA‐12 crystallinity with an increasing BBSA content was evident (and confirmed by DSC) and is consistent with the plasticizer easing the mobility of polymer chains during crystallization. Large melting point depressions resulting from both polymer–plasticizer miscibility and lamellar fragmentation were observed with several mono‐ and bifunctional BSA plasticizers. Phase separation in PA‐12 solid state was only observed at 20 mol % of ?SO₂NH₂, alhough miscibility occurred in the melt. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 2022–2034, 2001     

Finely continuously differentiable functions

In Lávi?ka [A remark on fine differentiability, Adv. Appl. Clifford Algebras 17 (2007) 549–554], it is observed that finely continuously differentiable functions on finely open subsets of the plane are just functions which are finely locally extendable to usual continuously differentiable functions on the whole plane. In this note, it is proved that, under a mild additional assumption, this result remains true even in higher dimensions. Here the word “fine” refers to the fine topology of classical potential theory.     

A Pillar-Based High-Throughput Myogenic Differentiation Assay to Assess Drug Safety

High-throughput, pillar-strip-based assays have been proposed as a drug-safety screening tool for developmental toxicity. In the assay described here, muscle cell culture and differentiation were allowed to occur at the end of a pillar strip (eight pillars) compatible with commercially available 96-well plates. Previous approaches to characterize cellular differentiation with immunostaining required a burdensome number of washing steps; these multiple washes also resulted in a high proportion of cellular loss resulting in poor yield. To overcome these limitations, the approach described here utilizes cell growth by easily moving the pillars for washing and immunostaining without significant loss of cells. Thus, the present pillar-strip approach is deemed suitable for monitoring high-throughput myogenic differentiation. Using this experimental high-throughput approach, eight drugs (including two well-known myogenic inhibitory drugs) were tested at six doses in triplicate, which allows for the generation of dose–response curves of nuclei and myotubes in a 96-well platform. As a result of comparing these F-actin (an actin-cytoskeleton protein), nucleus, and myotube data, two proposed differentiation indices—curve-area-based differentiation index (CA-DI) and maximum-point-based differentiation index (MP-DI) were generated. Both indices successfully allowed for screening of high-myogenic inhibitory drugs, and the maximum-point-based differentiation index (MP-DI) experimentally demonstrated sensitivity for quantifying drugs that inhibited myogenic differentiation.     

A strongly consistent information criterion for linear model selection based on M-estimation

In this paper, a linear model selection procedure based on M-estimation is proposed, which includes many classical model selection criteria as its special cases. It is shown that the proposed criterion is strongly consistent under certain mild conditions, for instance without assuming normality of the distribution of the random errors. The results from a simulation study are also presented. Received: 13 October 1997 / Revised version: 10 August 1998     

多壁碳纳米管修饰金电极测定维生素B12

抗贫血药物维生素B12(VB12)俗称(氰)钴胺素,维生素B12是DNA合成的必需物质,若体内缺乏它,就会引起巨幼细胞贫血,高同型半胱氨酸血症和神经系统损害。因此,检测维生素B12可为血液系统和神经系统一些疾病的诊治提供依据[1],建立快捷简便的检测方法,在药物分析和医学检验中有应用价值。测定VB12的方法有高效液相色谱法[2]、荧光法[3]、毛细管电泳法[4]、伏安法[5]等。作者研究了VB12在碳纳米管修饰金电极上的电化学行为,并用以测定了VB12样品的含量,结果令人满意。1实验部分1.1仪器与试剂CHI618B电化学工作站(上海辰华仪器公司);KQ?400…     

Simulation study of semi-superjunction power MOSFET with SiGe pillar

The feasibility of applying the semi-superjunction (Semi-SJ) with SiGe-pillar (SGP) concept to Power MOSFET is studied in this paper. The electrical performances of SGP are compared with the conventional Power MOSFET through 3D device simulation work in terms of specific-on resistance (_Ron)$\left(R_{on}\right)$, breakdown-voltage (BV  ), the effect to change the Ge mole fraction in the SGP and the thermal stabilization. The results show that the _Ron$R_{on}$ is reduced by 44% on the base of BVs   reducing only 4.8%, tradeoff _Ron$R_{on}$ vs. BV and thermal stabilization of SGP are superior to that of conventional Semi-SJ since the strain effect inducing into the SGP structure in the low power device application.     

光生电荷梯度连续传递链的构筑及对光催化性能的增强作用

选取能带位置匹配的γ-Bi₂O₃,α-Bi₂O₃和Bi₄Ti₃O₁₂,采用等体积浸渍法原位构筑了具有梯度能级的Bi₄Ti₃O₁₂@α/γ-Bi₂O₃三元同素结光催化剂.光催化降解高浓度罗丹明B(Rh B)和四氯苯酚(4-CP)的实验结果表明,相比于γ-Bi₂O₃和α/γ-Bi₂O₃,Bi₄Ti₃O₁₂@α/γ-Bi₂O₃显示出优异的光催化活性,其中0. 5%Bi₄Ti₃O₁₂@α/γ-Bi₂O₃显示了最佳的光催化性能,光降解...