Two‐Dimensional Hollow TiO2 Nanoplates with Enhanced Photocatalytic Activity

Two‐dimensional anatase TiO₂ hollow nanoplates were firstly synthesized through a facile synthesis route by using α‐Fe₂O₃ nanoplates as removable templates. Two‐dimensional hollow TiO₂ nanoplates with different ratios of anatase and rutile phases were obtained by adjusting the calcining temperature. The average diameters were around 600 nm, and the shell thickness was approximately 30 nm. The photocatalytic performance of TiO₂ was investigated by decomposing rhodamine B under simulated sunlight. Among the TiO₂ samples, the anatase TiO₂ hollow nanoplates manifested a significant enhancement in the photocatalytic performances. The excellent catalytic performance can be attributed to the unique structure of the two‐dimensional anatase TiO₂ hollow nanoplates, including a large surface area and increased dye–photocatalyst contact areas as well as more active sites for photodegradation.     

Benzamides and quinazolines from a mangrove actinomycetes Streptomyces sp. (No. 061316) and their inhibiting caspase-3 catalytic activity in vitro

One new benzamide, 3-hydroxyl-2-N-iso-butyryl-anthranilamide (1), together with two known benzamides (2, 3) and three known quinazolines (4-6), was isolated from a mangrove actinomycetes Streptomyces sp. (No. 061316), which displayed inhibiting Caspase-3 activity in vitro. The structure of 1 was elucidated by electrospray ionization (ESI)-MS, NMR spectroscopies and X-ray crystal diffraction. After evaluation of all compounds for their inhibitory effect on Caspase-3 in vitro, 3-hydroxyl-anthranilamide (2) and 8-hydroxyl-2,4-dioxoquinazoline (6) showed activity against Caspase-3 with IC(50) values of 32 and 36 μM, respectively.     

Highly Reversible Lithium Storage in Hierarchical Ca2Ge7O16 Nanowire Arrays/Carbon Textile Anodes

Aligned Ca₂Ge₇O₁₆ nanowire arrays were successfully grown on carbon textiles to form hierarchical 3D structures by using a facile hydrothermal method on a large scale. Typical Ca₂Ge₇O₁₆ nanowires are single crystals that show preferred growth along the [001] direction. The 3D hierarchical structures were used as binder‐free anodes for lithium‐ion batteries, which showed the features of highly reversible capacity (900–1100 mA h g^?1 at a current density of 300 mA g^?1), remarkable cycling stability, even over 100 cycles, and good rate capability, with a capacity of about 500 mA h g^?1 at 3 A g^?1. Furthermore, highly bendable full cells were also fabricated, which showed high flexibility, with little voltage change after bending 600 times, and superior temperature tolerance within the range 4–60 °C, thus demonstrating their promising potential for applications in high‐performance lithium‐ion batteries.     

论高斯

高斯(C.F.Gauss,1777—1855)生于德国Brunswick,1795—98求学于Gttinsen大学。1807—55任天文观测台台长及Gttingen大学教授。 大家都知道高斯的名言:“数学是科学的女王,算术是数学的女王”这里“算术”是在古希腊人的意义下理解的,指的初等数论,而区别于近代的解析数论。     

Propagation of computer virus under the influences of infected external computers and removable storage media

In reality, a portion of infected external computers could enter the Internet, and removable storage media could carry virus. To our knowledge, nearly all previous models describing the spread of computer virus ignore the combined impact of these two factors. In this paper, a new dynamical model is established based on these facts. A systematic analysis of the model is performed, and it is found that the unique (viral) equilibrium is globally asymptotically stable. Some simulation experiments are also made to justify the model. Finally, a result and some applicable measures for suppressing viral spread are suggested.     

Synthesis and mechanism studies of novel drum-like Cd(OH)2 superstructures

Novel drum-like Cd(OH)(2) superstructures with uniform size were synthesized on a large scale through a facile one-pot hydrothermal route with the co-existence of ammonia and biopolymer sodium carboxymethyl cellulose solutions.     

Metal-organic frameworks constructed from flexible V-shaped ligands: adjustment of the topology, interpenetration and porosity via a solvent system

Three new metal-organic frameworks (MOFs) are designed by the assembly of flexible V-shaped ligands and paddle-wheel second building units (SBUs). The topology, interpenetration numbers and porosity of frameworks have been well controlled by a solvent system.     

Impact of Effective Stress and Matrix Deformation on the Coal Fracture Permeability

The permeability of coal is an important parameter in mine methane control and coal bed methane exploitation because it determines the practicability of methane extraction. We developed a new coal permeability model under tri-axial stress conditions. In our model, the coal matrix is compressible and Biot’s coefficient, which is considered to be 1 in existing models, varies between 0 and 1. Only a portion of the matrix deformation, which is represented by the effective coal matrix deformation factor $f_\mathrm{m}$ , contributes to fracture deformation. The factor $f_\mathrm{m}$ is a parameter of the coal structure and is a constant between 0 and 1 for a specific coal. Laboratory tests indicate that the Sulcis coal sample has an $f_\mathrm{m}$ value of 0.1794 for $\hbox {N}_{2}$ and $\hbox {CO}_{2}$ . The proposed permeability model was evaluated using published data for the Sulcis coal sample and is compared to three popular permeability models. The proposed model agrees well with the observed permeability changes and can predict the permeability of coal better than the other models. The sensitivity of the new model to changes in the physical, mechanical and adsorption deformation parameters of the coal was investigated. Biot’s coefficient and the bulk modulus mainly affect the effective stress term in the proposed model. The sorption deformation parameters and the factor $f_\mathrm{m}$ affect the coal matrix deformation term.