Oxidation activity of Au nanoparticles on aerogel supports

We have prepared titania aerogel and titania-coated silica aerogel incorporating thiol-capped Au nanoparticles. Both composite materials showed high CO oxidation activity after they were calcined at 673 K. Compositional and morphological changes driven by calcination were evaluated with thermogravimetry and X-ray diffractometry. From the results, it was suggested that the nanoparticles transformed from a faulted to a near-regular FCC structure presumably in concert with the formation of firm contacts between the nanoparticles and the gel substrates. While the diameters of the Au particles in the titania aerogel considerably increased upon calcination, those in the titania-coated silica aerogel were almost unchanged. As a consequence, the latter composite aerogel showed higher activity for oxidation of CO.     

基于辐射的温度测量方程的构造研究

基于辐射的温度测量方程，以采用选择不同的波长，不同的温度和不同的谱色（滤色片子以技术实现）等方法进行构造，依据这些方法获得的测量数据彼此之间线性无关，从而可以将被测物体发射率函数的具体形式和温度予以确定。     

EVIDENCE FOR INVOLVEMENT OF PHYTOCHROME REGULATION IN MALE STERILITY OF A MUTANT OF Oryza sativa L.

Abstract— A rice mutant ( Oryza sativa L. Nongken 58S) "Hubei photoperiod-sensitive genie male-sterile rice" ( ms mutant) has been found to be male sterile under long day cycles (LD) and fertile in short day cycles (SD). After formation of the secondary rachis-branch primodia the mutant plants under SD were interrupted in the middle of the long night phase (night break) for 10 days with 5 min pulses of red light (R) or far-red light (FR). Rates of normal pollen and seed setting of the mutant treated by R or R → FR → R declined significantly, while the rates after FR or R → FR treatments were similar to those under SD alone. The result of these induction reversion experiments is consistent with the operational criteria for the involvement of photochrome. Wild-type rice ( O. sativa L. Nongken 58) under the same treatment showed no change in fertility. Experiments on the effect of different dark intervals (20 s to 15 min) between R and FR on male sterility of the ms mutant showed that the longer the dark interval, the greater the escape of R induction from FR reversibility. Treatment with SD or LD after formation of pollen mother cells had no influence on fertility of the ms mutant plants treated previously with R or FR night breaks.     

Method for studying boundary value problems with nonlinear boundary conditions

A constructive approach to the determination of an approximate solution of a boundary value problem with nonlinear boundary conditions g[z (0), z (T)]=0 is proposed. Existence of the exact solution is proved, and error estimates for the constructed approximate solution are provided.Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 42, No. 7, pp. 951–957, July, 1990.     

Synthesis, Characterization, Spectroscopic Properties of 2-（4-Dimethylaminophenyl）-5-fluoro-6-（morpholin-4-yl）-1H-benzimidazole and its Interaction with Calf Thymus DNA

Benzimidazole compounds have attracted a renewed interest recently owing to theirpotential applications in high-performance composite materials, electronic chemicals,photosensitive materials, and their special potentials in biological and/or medicinalapplication1,2. Typically, aromatic compounds with near planar structures and contain-ing hydrogen-donor groups or groups, which are capable of being protonated, havespecial interactions with DNA via intercalation, hydrogen-bonding, and so on3.Me…     

深海远程正交频分复用水声通信簇约束的分布式 压缩感知信道估计*

在深海远程正交频分复用(Orthogonal Frequency Division Multiplexing,OFDM)水声通信中,信道时延较长,导致信道频率选择性衰落严重,传统的压缩感知信道估计算法性能大幅下降。为此,本文利用深海远程信道在一定时间内具有相关性并呈较稳定簇状分布的特点,在分布式压缩感知信道估计中引入簇区域信息,进行簇约束的多数据块联合稀疏信道估计,提出一种簇约束的分布式压缩感知信道估计方法,并在深海开展了定点远程水声通信实验进行验证,实验结果表明,与传统的分布式压缩感知信道估计算法相比,本方法的能够降低50%左右的误码率。     

Numerical simulation: The dynamic behavior of reinforced concrete plates under normal impact

This investigation deals with the use of the finite element method on the reinforced concrete structural dynamic response and failure behavior when subjected to the projectile impacts of different velocities, using the test conducted in [S.J. Hanchak, M.J. Forrestal, E.R. Young, J.Q. Ehrgott, Perforation of concrete slabs with 48 MPa (7 ksi) and 140 MPa (20 ksi) unconfined compressive strengths, Int. J. Impact Eng. 12 (1992) 1–7]. The Johnson–Holmquist concrete material constitutive law model is employed to simulate the large strains, high strain states and high pressures to which the concrete is subjected. The projectile impact velocity ranges from 381 m/s to 1058 m/s. Numerical simulations demonstrate that the Johnson–Holmquist concrete material constitutive model can describe the different failure modes without any predefined defects in the element mesh, and normally obtain good agreement between the numerical simulations and test results.     

Unprecedented Quassinoids with Promising Biological Activity from Harrisonia perforata

Perforalactone A ( 1 ), a new 20S quassinoid with a unique cagelike 2,4‐dioxaadamantane ring system and a migrated side chain, was isolated from the plant Harrisonia perforata together with two biosynthetically related new quassinoids. The structures of these natural products were elucidated by NMR spectroscopy, X‐ray diffraction analysis, computational modeling, and the CD excitation chirality method. The compounds exhibited notable biological properties, including insecticidal activity against Aphis medicaginis Koch and antagonist activity at the nicotinic acetylcholine receptor of Drosophila melanogaster. The structural features of these compounds may be related to their promising biological characteristics. Their biosynthesis and an alternative origin of quassinoid‐type natural products are also discussed.