指向学习升级:课堂学习场景的重构

我们需要重构学生课堂学习的场景,改变传统的学习方式,形成知识沉淀的完整链路:“营火”让学生在“中心化”课堂中得到启蒙;“水源”创设与同伴交流的时空;“洞穴”为学生创建自主体验与消化沉思的机会;最后让学生登上“山顶”,学以致用,从而实现学习的升级。

Controlling factors of high-quality volcanic reservoirs of Yingcheng Formation in the Songnan gas field

Predicting high-quality volcanic reservoirs is one of the key issues for oil and gas exploration in the Songnan gas field.Core,seismic,and measurement data were used to study the lithologies,facies,reservoir porosity,and reservoir types of the volcanic rocks in the Songnan gas field.The primary controlling factors and characteristics of the high-quality volcanic reservoirs of the Yingcheng Formation in the Songnan gas field were investigated,including the volcanic eruptive stage,edifice,edifice facies,cooling unit,lithology,facies,and diagenesis.Stages with more volatile content can form more high-quality reservoirs.The effusive rhyolite,explosive tuff,and tuff lava that formed in the crater,near-crater,and proximal facies and in the high-volatility cooling units of large acidic-lava volcanic edifices are the most favorable locations for the development of the high-quality reservoirs in the Songnan gas field.Diagenesis dissolution,which is controlled by tectonic action,can increase the size of secondary pores in reservoirs.Studying the controlling factors of the high-quality reservoirs can provide a theoretical basis for the prediction and analysis of high-quality volcanic reservoirs.

Effects of Chinese Fir，Loblolly Pine and Deciduous Oak Forests on Nutrient States of Soils in Northern Subtro－pics of China

This paper deals with a study on the effects of Chinese fir, loblolly pine and deciduous oak forests on thenutrient status of soils in northern subtropics of China, adopting the principle of forest ecology in the caseof similar climate and soil type. The experimental area was situated in the Xiashu Experimental Centre ofForest, where the soil is yellow-brown soil derived from siliceous slope wash. Sample plots of these 3 standswere established to study the nutrient status in litter, the amount of nutrient uptake by roots, the quantityof nutrient output by percolating water outside the deep layer of soil, and the seasonal dynamics of availablenutrient in surface soil. It was shown that the intensity of nutrient cycling in soil under deciduous oak wasthe highest, and the effect of oak in improving soil fertility was the best. The result of improving soil fertilityby Chinese fir was the most inferior, though the intensity of nutrient cycling under that stand was higherthan that under loblolly pine stand. The influence of loblolly pine on the improvement of soil fertility wasbetter than that of Chinese fir, in spite of its lowest intensity of nutrient cycling.

Relationship Between Working Capital Management and Profitability in Turkey Industrial Listed Companies

The present study investigated the effect of working capital management component on corporate profitability. A sample of 106 firms listed on Borsa Istanbul Stock Exchange （BIST） for the period of 2003-2013 was used. The secondary data for analysis were taken from Bloomberg＇s Database. The present study aims to explore the effect of working capital management components on corporate profitability. We observed that there was a negative correlation between gross operating profit and accounts receivables （A/R）. We also found that there was a positive correlation between gross operating profit and number of days inventory. But they did not affect the profitability of firms in the study at a significant level.

Architecture of volcanic sequence and its structural control of Yingcheng Formation in Songliao Basin

Yingcheng Formation is a set of volcanic strata composed of lava rocks,volcanic clastic rocks and sedimentary rocks,filled in some fault depressions in Songliao Basin,early Cretaceous.The study about litho-facies succession of Yingcheng Formation in the outcropped area of the southeast margin and in Xujiaweizi fault depression and its distribution based on analysis of seismic data,shows that the sequence of volcanic strata is quite different from the clastic sedimentary sequence.To study the architecture of volcanic sequence and its structural control of Yingcheng Formation in Songliao Basin,in this work,dividing of the volcanic sequence and dating of the sequence boundaries were finished firstly,then displacement and displacement rate of faults were calculated.The results show that,sample ages of top of the first member,the seconde member,and the third member are 127 Ma,115 Ma,110.7 Ma,respectively and sample age of the bottom of the third member is 114.7 Ma.The maximum displacement and displacement rate of the fault 1 are 3 km and 300 m/Ma,respectively,and those of the fault 2 are 3 km and 1000 m/Ma.Studies suggest that,the cooling unit of lava rock or pyroclastic rock is a basic genetic stratigraphic unit in volcanic sequence stratigraphy.Cooling units can construct a parasequence reflecting a volcanic eruption stage.A sequence was superimposed by some parasequences,responding to a volcanic active cycle.There are three types of volcanic sequences in Yingcheng Formation: type of explosion,type of effusion and type of mixed explosion-effusion.The surface of the volcanic sequence,an unconformity surface widely spread and traced in seismic profiles,is a base for analysis of volcanic sequence.The development of volcanic sequence was controlled by faulting,and the curves of fault displacement(rate)can reflect this control.The preservation of volcanic sequence was controlled by the type of volcanic structure and the regional subsidence,also different from that of the sedimentary.The type of volcanic structure of Xujiaweizi was a volcanic depression during the forming of Yingcheng Formation,and the breakdowns of volcanoes and structural subsidence were key factors in the volcanic sequences preservation.