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The model and shape equation of compression and shear fracture nucleus of rock of earthquakes are briefly recounted in this paper. Recently rock breaking areas with two special shapes have been discovered on palisade of foundation pit excavated for dam in Hunan Province, PR China. The on-the-spot investigation indicates that all two broken areas once had the stress concentration point, and the broken area was initiated and expanded from this point. Both internal crack propagation and the outline shape are consistent separately with the rock compression and shear fracture nucleus with leaf shape of KI, KII mode and the rock compression and torsion fracture nucleus with bud shape of KI, KIII mode given by the shape equations. The further research on the forming process of rock compression and shear fracture nucleus is helpful for impending earthquake prediction. [ABSTRACT FROM AUTHOR]

Abstract: Effects of different pretreatment protocols in (NH4)2HPO4 activation of rice straw on porous activated carbon evolution were evaluated. The pore structure, morphology and surface chemistry of obtained activated carbons were investigated by nitrogen adsorption, scanning electron microscopy and Fourier transform infrared spectroscopy. It was found that pretreatment combining impregnation with (NH4)2HPO4 and preoxidation could significantly affect the physicochemical properties of prepared activated carbons. The apparent surface area and total pore volume as high as 1154m2/g and 0.670cm3/g were obtained respectively, when combined process of impregnation followed by preoxidation at 200°C and activation at 700°C was carried out. Meanwhile, the activated carbon yield and maximum methylene blue adsorption capacity up to 41.14% and 129.5mg/g were achieved, respectively. The results exhibited that (NH4)2HPO4 could be an effective activating agent for producing activated carbons from rice straw. [ABSTRACT FROM AUTHOR]

The interaction of CH2I2 and CH2ICl with 60 fs laser pulses at 800 and 400 nm has been studied using TOF-MS. Molecular detachment of I2+ and ClI+ are observed. The generation of I2+ and ClI+ can be understood by a concerted elimination mechanism. The kinetic energy released is estimated from the peak splitting of I2+ obtained in the TOF-MS, originated from Coulomb explosion. According to the results, multiphoton ionization is excluded from the possible mechanisms. The observed phenomena are attributed to the interaction of the intense laser field with the molecular potential energy surfaces. [Copyright &y& Elsevier]

1. The hyperpolarization-induced, cation-selective current Ih is widely observed in peripheral sensory neurons of the vagal and dorsal root ganglia, but the peak magnitude and voltage- and time-dependent properties of this current vary widely across afferent fibre type. 2. Using patch clamp investigations of rat isolated vagal ganglion neurons (VGN) identified as myelinated A-type afferents, we established a compendium of functional correlates between changes in membrane potential and the dynamic discharge properties of these sensory neurons as a result of the controlled recruitment of Ih using the current clamp technique. 3. Two robust reponses were observed in response to hyperpolarizing step currents: (i) upon initiation of the negative step current, there was a rapid hyperpolarization of membrane potential followed by a depolarizing voltage sag (DVS) towards a plateau in membrane potential as a result of steady state recruitment of Ih; and (ii) upon termination of the negative step current, there was a rapid return to the pretest resting membrane potential that often led to spontaneous action potential discharge. These data were strongly correlated ( r2 > 0.9) with a broad compendium of dynamic discharge characteristics in these A-type VGN. 4. In response to depolarizing step currents of increasing magnitude, the discharge frequency of the A-type VGN responded with increases in the rate of sustained repetitive discharge. Upon termination of the depolarizing step current, there was a post-excitatory membrane hyperpolarization of a magnitude that was strongly correlated with action potential discharge rate ( r2 > 0.9). 5. Application of the selective hyperpolarization-activated cyclic nucleotide gated (HCN) channel blockers ZD7288 (10 μmol/L) or CsCl (1.0 mmol/L) abolished Ih and all of the aforementioned functional correlates. In addition to reducing the excitability of the A-type VGN to step depolarizing currents. 6. Because there is increasing evidence that the HCN channel current may represent a valid target for pharmacological intervention, the quantitative relationships described in the present study could potentially help guide the molecular and/or chemical modification of HCN channel gating properties to effect a particular outcome in VGN discharge properties, ideally well beyond merely selective blockade of a particular HCN channel subtype. [ABSTRACT FROM AUTHOR]

Various polycyclic arenes, such as naphthalenes, tetrahydroantharacenes, tetrahydrotetracenes, dihydropentacenes, and dihydropentaphenes are prepared from 2-alkenylphenyl ketones and aldehydes by the catalytic use of copper(II) trifluoromethanesulfonate (Cu(OTf)2) or trifluoromethanesulfuric acid (TfOH). [ABSTRACT FROM AUTHOR]

Abstract: Performance of the novel fiber-ball filter was investigated for the treatment of high-turbidity surface water. Impact of different operating parameters, such as coagulant type, coagulant dose and filtration velocity on the effluent turbidity, dissolved organic carbon (DOC) and head loss, as well as the particle removal characteristics were studied. The clean-bed filtration results showed that the fiber-ball filters had a great potential for the removal of turbidity matters. Addition of polymeric aluminum ferric chloride (PAFC) enhanced the removal of effluent turbidity and DOC, while the head loss was also increased. The effluent turbidity could be <0.5NTU and the removal efficiency of DOC was ∼16% when the PAFC was dosed at 12mg/L. The effluent turbidity and DOC increased slightly with increasing filtration velocities (30–50m/h) due to the greater drag forces resulted from higher filtration velocities. However, the head loss was also increased. The particle removal characteristics indicated that large particles were primarily removed in the top 30cm of the filter bed and the deep depth in the bottom 20cm played an important role in preventing the occurrence of turbidity breakthrough. It was also found that particles in the size larger than 2μm could be well removed by the fiber-ball filters, implying the potential application for the removal of protozoa like Cryptosporidium (3–15μm) to meet the desired requirement for drinking water treatment during depth filtration. [Copyright &y& Elsevier]

Various polycyclic arenes are efficiently synthesized using different (alkenylphenyl)carbonyl compounds as starting materials. [ABSTRACT FROM AUTHOR]