借助信息技术在英语教学中培养学生研究性学力的初探

本文主要阐述在初中英语课堂教学中,依托牛津英语教材,借助信息技术,通过体验、实践、讨论、合作、探究等方式,培养学生研究性学历的实践研究,并以"Barbecues are Fun"课为例,加以具体说明。从而得到启示:信息技术英语学科教学的合理整合,有利于培养学生研究性学力的提升。

论化学研究性学力的培养

在研究性学习及学力理论的研究基础上提出研究性学力的概念.研究性学力培养的路径包括:激活学生的问题意识;培养学生的研究能力和研究方法;以化学体验为平台,催生学生感悟化学的能力;以自主建构为生长点,保持学生反思和批判的张力.

初中英语任务型分层作业的研究

任务型学习已成为外语教学中一个熟悉的名词，在注重课堂任务化的同时，我们应该根据学生的差异，布置不同层次的任务型作业，以此来促进、补充课堂教学，提高学生的英语能力与研究性能力。与此同时，还应该根据实际，对于任务型作业进行分层评价。笔者通过一年的实践发现通过任务型作业分层，确实能有效地培养学生的研究性学力。

A numerical study of macro-mesoscopic mechanical properties of gangue backfill under biaxial compression

Based on the Particle Flow Code(PFC^(2D)) program,we set up gangue backfill models with different gangue contents and bond strength,and studied the stress-strain behaviours,the pattern of shear band and force chains,motion and fragmentation of particles under biaxial compression.The results show that when the bond strength or contents of gangue are high,the peak strength is high and the phenomena of post-peak softening and fluctuation are obvious.When gangue contents are low,the shape of the shear band is symmetrical and most strong force chains transfer in soil particles.With an increase in gangue content,the shape of the shear band becomes irregular and the majority of strong force chains turn to transfer in gangue particles gradually,most of which distribute along the axial direction.When the gangue content is higher than 50%,the interconnectivity of strong force chains decreases gradually:at the same time,the strong force chains become tilted and the stability of the system tends to decrease.With an increase in external loading,the coordination numbers of the system increase at first and then decrease and the main pattern of force chains changes into columnar from annular.However,after the forming of the advantageous shear band,the force chains external to the shear band maintain their columnar shape while the inner ones bend obviously.As a result,annular force chains form.

Influence of impurities on microstructure and mechanical properties of ZK60 magnesium alloy

The influence of impurity content on the microstructure and mechanical properties of ZK60 magnesium alloys was investigated by optical microscopy,scanning electron microscopy and tensile test.ZK60 alloys were prepared by changing holding time of alloy melt during semi-continuous casting in order to control the content of impurity elements.The alloy with lower purity content is found to have less second precipitates and larger grain size in the as-cast state.However,in the as-extruded state,reducing impurities brings about a decrease in grain size and an increase in yield strength from 244 MPa to 268 MPa,while the elongations in the as-extruded alloys with different contents of impurities are almost the same.After T5 treatment,impurity content is found to have more obvious effect on the yield strength of ZK60 alloy.The yield strength of ZK60-45 alloys with low impurity content is increased up to 295 MPa after T5 treatment.

The automobile steel of the third generation in B-pillar reinforced panel

The fundamental research and industry, trials of the third generation automobile steel QP980 were introduced in this paper, including chemical ingredient, mechanical properties, microstructure, forming limit and basic perform- ance parameters. The application of QP steel of the B-pillar was researched, and the QP980, DP600 and hot forming steel were compared in the aspect of formability, safety and cost. The resuhs showed that the QP980 replacing DP600 steel single piece carl reduce the weight by 2.4 kg. The security and performance is basically the same as that of hot forming steel using 22MnB5, and the cost is reduced by 30 %.

Study on Interface mechanical behavior of steel tube reinforced concrete composite pile

Currently for the steel tube reinforced concrete composite pile research, although predecessors make a comprehensive research on the composite pile beating performance, design technology, but there are still many problems have not been solved, such as the steel tube reinforced concrete pile composite interracial force learn performance research is still in the initial stage. In this paper, we mainly discuss the research methods of several interface mechanical properties and propose the possibility of studying the mechanical properties of the steel tube reinforced concrete composite pile by using the principle of ultrasonic speckle.

Violence in Partnership and Persisting Problems of Assistance

The paper focuses on an attempt to answer questions concerning domestic violence in accordance with the epistemology in contemporary scientific research. The phenomenology of violence is defined with respect to the superficial as well as the essential side of the phenomena. The problems are covered with respect to interdisciplinary relations. We endeavor to open a broader view. The underlying research represents an alternative approach, attempting to reach a cumulative view based on the data acquired from various contexts. In social science research, it is important to look at the social reality not only through the numbers of quantitative research, because social reality is constructed in various ways. The issues of elimination of violence against women in Slovakia are entrenched in the program of various institutions. Based on the performed analysis, inconsistencies in the approach to providing assistance are identified as the most important problem. The paper deals with the institutional issues persisting in dealing with situations and identifies the fundamental failures of social intervention that still exist, among other reasons, due to the stereotypical, discriminatory perceptions of the issues by the competency.

Effects of a Kind of Non-smooth Blade on the Performance of an Axial Fan

This paper presents an experimental investigation of effects of a kind of streamwise-grooved blade on the performance of an axial-flow fan. The flow field at 25% chord downstream from the trailing edge at hub was measured using a 5-hole pressure probe at different mass-flow conditions. The fan performance of the groove blades was compared with that of the smooth blades. The measurement results indicate that： （ 1 ） the non-smooth blades increase mass flow of the fan at the same throttle conditions except a near stall condition; （2） the non-smooth blades reduce the relative total pressure loss in the rotor passage and increase the fan＇s total pressure rise at the test mass-flow conditions except the near stall condition; （3） Negative benefits are obtained at a near stall condition when the smooth blades are replaced by the non-smooth ones. The fan mass flow decreases 0.9% while the total-pressure rise decreases 2.4% at the near stall condition.

Existence of strong solutions in critical spaces for barotropic viscous fluids in larger spaces Dedicated to the NSFC-CNRS Chinese-French summer institute on fluid mechanics in 2010

This paper is dedicated to the study of viscous compressible barotropic fluids in dimension N ≥ 2. We address the question of well-posedness for large data having critical Besov regularity. Our result improves N the analysis of Danchin and of the author inasmuch as we may take initial density in BN/p p,1 with 1 ≤ p 〈 ＋∞. Our result relies on a new a priori estimate for the velocity, where we introduce a new unknown called effective velocity to weaken one of the couplings between the density and the velocity. In particular, our result is the first in which we obtain uniqueness without imposing hypothesis on the gradient of the density.

Numerical Study of Effects of Mach number on Aerodynamic Performance of Large Enthalpy Drop Stationary Cascade

Based on the method to change blade loading type along blade height, that is, applying aft-loading at both end zones of cascade while applying fore-loading in the mid zone of cascade, HTC(Harbin Turbine Company) designed a twisted and bowed stationary cascade with low aspect ratio and large enthalpy drop. To verify the aerodynamic performance of such cascade, firstly, low-speed wind tunnel tests were conducted to validate the calculation results of commercial software CFX, and then numerical simulations were made for the aerodynamic performance of the cascade at different Mach numbers. The simulation results show that the large enthalpy drop stationary cascade designed by HTC can offer good aerodynamic performance while keeping its high-load characteristics in the change range of outlet Mach number as stated in this paper.

Numerical Investigation of the Interaction between Mainstream and Tip Shroud Leakage Flow in a 2-Stage Low Pressure Turbine

The pressing demand for future advanced gas turbine requires to identify the losses in a turbine and to understand the physical mechanisms producing them. In low pressure turbines with shrouded blades, a large portion of these losses is generated by tip shroud leakage flow and associated interaction. For this reason, shroud leakage losses are generally grouped into the losses of leakage flow itself and the losses caused by the interaction between leakage flow and mainstream. In order to evaluate the influence of shroud leakage flow and related losses on turbine performance, computational investigations for a 2-stage low pressure turbine is presented and discussed in this paper. Three dimensional steady multistage calculations using mixing plane approach were performed including detailed tip shroud geometry. Results showed that turbines with shrouded blades have an obvious advantage over unshrouded ones in terms of aerodynamic performance. A loss mechanism breakdown analysis demonstrated that the leakage loss is the main contributor in the first stage while mixing loss dominates in the second stage. Due to the blade-to-blade pressure gradient, both inlet and exit cavity present non-uniform leakage injection and extraction. The flow in the exit cavity is filled with cavity vortex, leakage jet attached to the cavity wall and recirculation zone induced by main flow ingestion. Furthermore, radial gap and exit cavity size of tip shroud have a major effect on the yaw angle near the tip region in the main flow. Therefore, a full calculation of shroud leakage flow is necessary in turbine performance analysis and the shroud geometric features need to be considered during turbine design process.

Combined Experimental and Numerical Investigations on the Roughness Effects on the Aerodynamic Performances of LPT Blades

The aerodynamic performance of a high-load low-pressure turbine blade cascade has been analyzed for three different distributed surface roughness levels(Ra) for steady and unsteady inflows. Results from CFD simulations and experiments are presented for two different Reynolds numbers(300000 and 70000 representative of take-off and cruise conditions, respectively) in order to evaluate the roughness effects for two typical operating conditions. Computational fluid dynamics has been used to support and interpret experimental results, analyzing in detail the flow field on the blade surface and evaluating the non-dimensional local roughness parameters, further contributing to understand how and where roughness have some influence on the aerodynamic performance of the blade. The total pressure distributions in the wake region have been measured by means of a five-hole miniaturized pressure probe for the different flow conditions, allowing the evaluation of profile losses and of their dependence on the surface finish, as well as a direct comparison with the simulations. Results reported in the paper clearly highlight that only at the highest Reynolds number tested(Re=300000) surface roughness have some influence on the blade performance, both for steady and unsteady incoming flows. In this flow condition profile losses grow as the surface roughness increases, while no appreciable variations have been found at the lowest Reynolds number. The boundary layer evolution and the wake structure have shown that this trend is due to a thickening of the suction side boundary layer associated to an anticipation of transition process. On the other side, no effects have been observed on the pressure side boundary layer.