Study on Statistical Features About Weak Earthquake Activity Before Moderately Strong Earthquakes in the Middle Northern Part of the Qinghai-Xizang (Tibet) Block

In regards to the earthquakes recording M ≥ 5.0 that occurred in middle northern part of the Qinghai-Xizang （Tibet） Block from 1970 - 2003, in this study we describe the temporal and spatial centralization features of the weak earthquakes and the enhancement and anomalous quiescence of their seismic activity before main shocks through 4 parameters, which are basically not correlated： earthquake time centralization degree parameter Ct, earthquake space centralization degree parameter Cd, η value and weak earthquake frequency and so on. On the basis of calculation results, it has been seen that before earthquakes with M ≥ 5.0 took place in the middle northern part of the Qinghal-Xizang （Tibet） Block, the frequency of weak earthquakes often shows ascent and drop, their strength shows an obvious enhancement and the centralization distribution with time and space is evident.

A Preliminary Study on a Seismotectonic Model for the Active Faults in the Xining Urban Area

On the basis of the Xining active urban fault survey, we studied the relationship between the active urban fault and fold deformation. The result of this research shows that the Huangshuihe fault and the NW-striking fault on the northern bank of the Huangshulbe River are tensional faults on top of an anticline, the Nanchuanhe fault is a transverse tear fault resulting from differential folding on two sides of the fault, the east bank of the Beichuanhe River fault is a compressional fault developed on the core or climb of a syncline. By balance profile analysis of fold deformation and inversion of gravity anomaly data, we obtained the depth of the detachment plane and established the seismotectonic model of the ）fining urban area. Based on the seismotectonic model, we analyzed the earthquake potential of the active urban fault.

Electrode material promoted dehydrogenative homo-/cross-coupling of weakly activated naphthalenes

Herein,we reported an electrochemical dehydrogenative homo-/cross-coupling of weakly activated naphthalene in the exogenous transition metal-and oxidants-free manner.Benefiting from the microscopic interaction between the reactants and the carbon plate anode,the electropolymerization of aromatic rings was suppressed.And a series of binaphthyl and naphthalene-aryl privileged scaffolds were obtained in 28%–90%yields by homo-or cross-coupling.This C(sp2)-H activation strategy featured atom and step economy as well as the ready scalability.

Pd-catalyzed ortho-olefination of aromatic acetyl esters

A Pd（Ⅱ）-catalyzed ortho-olefination of aromatic acetic esters is described which features with an excellent funcitional group tolerance, good yields, mild reaction conditions, good scalability as well as high chemo-and regio-selectivity.