教学出其不意 课堂精彩出奇

真正启智润心的教学,需要教师超越平铺直叙的“告诉”,引领学生在种种思想奇遇后拥有豁然开朗的收获。教师出其不意的教学往往能够赋予课堂强烈的吸引力,带给学生丰富的感悟,有利于打造富有张力的精彩课堂。教师匠心独运的思政课堂充满别具一格的教育智慧,可旁敲侧击以曲径通幽传文化,可反弹琵琶以教学反转析道理,可趣味表达以诙谐素材深印象,可小中见大用传奇故事育精神。

Stability analysis of shallow tunnels subjected to seepage with strength reduction theory

Based on strength reduction theory,the stability numbers of shallow tunnels were investigated within the framework of upper and lower bound theorems of limit analysis. Stability solutions taking into account of water seepage were presented and compared with those without considering seepage. The comparisons indicate that the maximum difference does not exceed 3.7%,which proves the present method credible. The results show that stability numbers of shallow tunnels considering seepage are much less than those without considering seepage,and that the difference of stability numbers between considering seepage and without considering seepage increase with increasing the depth ratio. The stability numbers decrease with increasing permeability coefficient and groundwater depth. Seepage has significant effects on the stability numbers of shallow tunnels.

Identification of Telecom Operators' Core Distribution Channels Based on Strategic Value Evaluation System

The strategic value evaluation ofphysical channels is the main purpose of thispaper.To interpret this value,we refine finance,location and competition dimensions.Atotal of 166 social high-star channels are selected as empirical samples.Practice showsthat all second-layer indicators can be quantified by information system or artificial collection.The weight of three first-layer indicatorscan be defined by correlation analysis.The valuecomprehensive ranking of the channels is clearbased on the first-layer and second-layer indicators.In the sample group in this study,theweight of location value is higher.The resultson channels' strategic value research may provide further insights on business value,servicevalue and other related fields.

Limit analysis of roof collapse in tunnels under seepage forces condition with three-dimensional failure mechanism

The state of roof collapse in tunnels is actually three-dimensional, so constructing a three-dimensional failure collapse mechanism is crucial so as to reflect the realistic collapsing scopes more reasonably. According to Hoek-Brown failure criterion and the upper bound theorem of limit analysis, the solution for describing the shape of roof collapse in circular or rectangular tunnels subjected to seepage forces is derived by virtue of variational calculation. The seepage forces calculated from the gradient of excess pore pressure distribution are taken as external loading in the limit analysis, and it is of great convenience to compute the pore pressure with pore pressure coefficient. Consequently, the effect of seepage forces is taken as a work rate of external force and incorporated into the upper bound limit analysis. The numerical results of collapse dimensions with different rock parameters show great validity and agreement by comparing with the results of that with two-dimensional failure mechanism.

THEORETICAL ANALYSIS OF THE STABILITY OF A DEEP ROADWAY

In this paper the thickness of a broken zone, a state parameter of roadway surrounding rock, is used as the index to evaluate the stabi1ity of surrounding rock of a deep roadway. The paper gives a theoretic formula for calculating the thickness of the broken zone. The author points out that not only the ultimate strength of rockmass but its residual strength and strain-softening level all have a great influence on the stability of surrounding rock of a deep roadway. The paper’s results show that to reinforce surrounding rock, raise its residual strength and lower its strain-softening level should be taken as a basic requirement for supports of a deep roadway. In addition, the research also indicates that it is impossible for roadway supports to change surrounding rock states of a deep roadway, so it is certain for them to work in a broken state. For this reason, a sufficient yieldable quantity is necessary for roadway supports used in deep mining.

Experimental and numerical analysis of secondary disasters induced by oxygen rich combustion within a tunnel

Various physical parameters, including gas concentrations (O2, CO, CH4, and H2) and temperatures at dif- ferent air velocities, were determined for full scale wood fires in the Chongqing Coal Research Institute fire test tunnel. Both experimental measurements and numerical simulations are discussed. The numer- ical analysis was performed with the computational fluid dynamics software package ''FLUENT''. The results show that the experimental data agree with the simulation results. The results verify that Roberts' theory of burning is correct. They also prove that the air velocity is the key factor that determines the type of combustion. Also, it is shown that secondary disasters are unlikely for oxygen rich combustion with a limited fire load.

Justice as the Virtue of ＂No Unacceptable Harm to the Human＂

Through a semantic analysis of such common words as ＂good,＂ ＂right,＂ and ＂rights,＂ this article tries to argue that ＂justice＂ as a value-term basically means ＂no unacceptable harm to the human＂ or ＂respecting the deserved rights of the human＂ in the meta-ethical sense. In real life, then, the becoming of universal justice as an authentic moral virtue depends first and foremost upon the concrete and dynamic cultivation of such a universalistic ethical attitude： regarding neither merely oneself nor some persons specially related to oneself, but everyone as the ＂human,＂ and valuing all of them morally important and dignified so as not to do morally unacceptable harm to them, but to respect their deserved rights.