“活”学“活”用--基于生活教育理论的小学英语教学浅谈

陶行知先生的教育思想核心是生活教育理论,这一理论主张将教育与生活紧密结合。在英语教学领域,这一理论的应用尤其重要。小学英语教学中,教师应当灵活运用生活资源,为学生创造真实的英语语言环境,让他们在生活中实际运用英语,从而提升英语水平。文章将从英语教学内容、英语课堂构建和英语作业设计三个角度,深入探讨生活教育理论在小学英语教学中的应用策略,以供教育工作者参考。

化“被”学为“活”学——转变学习方式浅谈

转变学习方式，注重过程教学，在数学教学中，通过创设情境，提供一些现实的数学模型，让学生通过数学建模，以及探索研究活动，亲身经历数学知识建构（或数学化）的过程．因此，在课堂上积极引导学生主动参与、合作交流，使学生真正成为教学的主体，教学的真正目的，就是教学生学会学习．

以生活为蓝本 让学生“活”学数学

小学数学课堂教学应引入学生生活的源头活水，积极创设相应的问题情境，激发学习兴趣，探索数学现象，发展数学能力，解决实际问题，使学生获得成功的体验，为他们的发展奠定一生受用的基础。

如何让农村学生“活”学语文

新课标对中小学语文教育提出新的要求,但具体到我校教育实际情况,城乡差距开始显现,通过逐年积累,我们学校的课程资源是丰富的,但不少老师却浪费这些有用的课程资源,那么,如何让农村学生“活”学语文?这是值得我们探索的一个问题。

思想品德课教学中开展社会实践活动模式的探析

随着思想品德课教学具有时代性、实践性、思想性。在思想品德课中增加社会实践活动,收集社会实践的模式,符合新课标提出的以德育为核心,以培养创新精神和实践能力为重点,全面推进素质教育,有利于学生的自我发展、自我完善、健全学生人格,实现人生价值。

Supported Ziegler-Natta catalysts from MgCl_(2)·nROH precursors and its catalytic behaviors for diene copolymerization

Heterogeneous TiCl4/MgCl_(2) type Ziegler-Natta(Z-N)catalysts with unique advantages like low cost,high activity,high stereoregularity and pretty particle morphology,contribute to more than 130 Mt polyolefin large-scale production.However,most researches related with heterogeneous Z-N catalysts focused onα-olefin polymerizations like ethylene,propylene,etc.

Effect of ultrasonic and mechanical vibration treatments on evolution of Mn-rich phases and mechanical properties of Al−12Si−4Cu−1Ni−1Mg−2Mn piston alloys

Effects of ultrasonic vibration(UV)and mechanical vibration(MV)on the Mn-rich phase modification and mechanical properties of Al−12Si−4Cu−1Ni−1Mg−2Mn piston alloys were investigated.The results show that the UV and UV+MV treatments can significantly refine and fragmentize the microstructures.In addition,UV treatment can significantly passivate the primary Mn-rich Al15Mn3Si2 intermetallics.The formation mechanisms of refinement and passivation of the grains and non-dendrite particles were discussed.Compared with the gravity die-cast alloys,the UV and UV+MV treated alloys exhibit improved tensile and creep resistance at room and elevated temperatures.These results can be attributed to the refinement of theα(Al)grains and the secondary intermetallics,the increased proportion of refined heat-resistant precipitates,and the formation of nano-sized Si particles.The ultimate tensile strength of the UV treated alloys at 350℃ exceeds that of commercial piston alloys.This indicates the high application potential of the developed piston alloys in density diesel engines.

Ab initio molecular dynamics simulation reveals the influence of entropy effect on Co@BEA zeolite-catalyzed dehydrogenation of ethane

The C–H bond activation in alkane dehydrogenation reactions is a key step in determining the reaction rate.To understand the impact of entropy,we performed ab initio static and molecular dynamics free energy simulations of ethane dehydrogenation over Co@BEA zeolite at different temperatures.AIMD simulations showed that a sharp decrease in free energy barrier as temperature increased.Our analysis of the temperature dependence of activation free energies uncovered an unusual entropic effect accompanying the reaction.The unique spatial structures around the Co active site at different temperatures influenced both the extent of charge transfer in the transition state and the arrangement of 3d orbital energy levels.We provided explanations consistent with the principles of thermodynamics and statistical physics.The insights gained at the atomic level have offered a fresh interpretation of the intricate long-range interplay between local chemical reactions and extensive chemical environments.

On joint analysing XMM-NuSTAR spectra of active galactic nuclei

A recently released XMM-Newton note revealed a significant calibration issue between nuclear spectroscopic telescope array(NuSTAR)and XMM-Newton European Photon Imaging Camera(EPIC)and provided an empirical correction to the EPIC effective area.To quantify the bias caused by the calibration issue in the joint analysis of XMM-NuSTAR spectra and verify the effectiveness of the correction,in this work,we perform joint-fitting of the NuSTAR and EPIC-pn spectra for a large sample of 104 observation pairs of 44 X-ray bright active galactic nuclei(AGN).The spectra were extracted after requiring perfect simultaneity between the XMM-Newton and NuSTAR exposures(merging good time intervals(GTIs)from two missions)to avoid bias due to the rapid spectral variability of the AGN.Before the correction,the EPIC-pn spectra are systematically harder than the corresponding NuSTAR spectra by■subsequently yielding significantly underestimated cutoff energy E_(cut)and the strength of reflection component R when performing joint-fitting.We confirm that the correction is highly effective and can commendably erase the discrepancy in best-fitΓ,E_(cut),and R.We thus urge the community to apply the correction when joint-fitting XMM-NuSTAR spectra,but note that the correction is limited to 3–12 keV and therefore not applicable when the soft X-ray band data are included.Besides,we show that as merging GTIs from two missions would cause severe loss of NuSTAR net exposure time,in many cases,joint-fitting yields no advantage compared with utilizing NuSTAR data alone.Finally,We present a technical note on filtering periods of high background flares for XMM-Newton EPIC-pn exposures in the small window(SW)mode.

Effect of total flavonoids of epimedium on liver microsomal CYP 1A2,CYP3A4 and CYP2E 1 activities in rats

To assess the potential effect of total flavonoids of epimedium （TFE） on cytochrome P450 and activity of its main isoforms in rat liver microsomes. TFE （300 mg/kg） was administered once daily to male Sprague-Dowley rats by gavage for fifteen days. The total cytochrome P450 content and its main isoforms CYP1A2, CYP3A4 and CYP2E1 activities in rat liver microsomes were detected. The activity of CYP1A2 was measured by fluorometry and the activities of CYP3A4 and CYP2E1 were determined by measuring the amount of methanal and p-aminophenol formed using UV/Vis spectrophotometer, respectively. Administration of TFE significantly increased the total CYP450 content and activities ofCYP1A2, CYP3A4 and CYP2E1 in rat liver microsomes, compared with the control group. Particularly, the activities of CYP1A2 and CYP2E1 were enhanced significantly （P〈0.01）. TFE induced the increase in total CYP450 content and its main isoforms CYP1A2, CYP3A4 and CYP2E1 activities in rat liver microsomes.

Herpetin, a New Bioactive Lignan Isolated from Herpetospermum caudigerum

Aim To study the chemical constituents of seeds of Herpetospermum caudigerum. Methods Column chromatography was used in the isolation procedure, and the structure was elucidated by spectral data, whose pharmacologic activity was assayed in vitro. Results A new compound named herpetin was isolated, whose structure was determined to be 3-benzofuran methanol-2, 3-dihydm-2-（4- hydroxy-3-methoxyphenyl ）-4-methoxy-6-[ tetrahydm-2-（ 3-hydroxy-4-methoxyphenyl ）-3-methanol ]-2- furanmethyl, showed significant inhibitory effects on HBV-DNA and the replication and expression of HBsAg and HBeAg. Conclusion Herpetin offers wide research and development prospect.

Regeneration of activated carbon adsorbed EDTA by electrochemical method

Activated carbon after saturated adsorption of EDTA was used as particle electrode in a three-dimensional electrode reactor to treat EDTA-containing wastewater.Electrochemical method was used to regenerate activated carbon after many times of electrolysis.Based on the analysis of infrared spectra of activated carbon after adsorption and repeated electrolysis,EDTA was degraded into glycine,and then non-catalytic activated associated complex was formed with N—H bond on the activated carbon.The catalytic ability of the activated carbon vanished and the EDTA degradation efficiency was dropped.Activated carbon could be effectively regenerated by electrochemical method in the three-dimensional reactor.Effects of electric current,conductivity and pH on activated carbon regeneration were investigated,and the optimum conditions were concluded as follows：100-300 mA of current intensity,1.39 mS/cm of electric conductivity,60 min of electrolysis time and pH 6.0-8.0.Under the optimized conditions,the activity of the activated carbon can be recovered and the residual total organic carbon（TOC） was below 10 mg/L（the initial TOC was 200 mg/L） in the three-dimensional electrode reactor.

Influence of Ga and In on microstructure and electrochemical properties of Mg anodes

The influence of Ga and In on the electrochemical properties of Mg anode materials were investigated by the polarization and galvanostatic curve tests. The microstructure and the corroded surface of the Mg-In-Ga alloys were observed by scanning electron microscopy （SEM）. The corrosion product of the Mg-0.8%In （mass fraction） and Mg-0.8%Ga-0.3%In alloy were determined by X-ray diffraction. The results show that no second phase exists in the Mg-xIn （x=0-0.8%） allloys. Intergranular compounds containing Ga and In elements occur in the Mg-0.8%In-xGa （x=0-0.8%） alloys. The addition of In into Mg as well as the addition of 0.05%-0.5%Ga into Mg-In alloy promotes the corrosion resistance. The addition of Ga into Mg-In alloys also promotes the electrochemical activity. The Mg-0.8%In-0.8%Ga alloy has the most negative mean potential,-1.682 V, which is more negative than -1.406 V in AZ91D. The corrosion type of the Mg-In-Ga alloys is general corrosion and the corrosion product is Mg（OH）2.

Effect of mechanical activation on dissolution kinetics of neutral leach residue of zinc calcine in sulphuric acid

Neutral leach residue of zinc calcine （NLRZC） was mechanically activated by a stirring ball mill. Subsequently, the changes in physicochemical properties and dissolution kinetics in sulphuric acid were studied. The crystalline structure, morphology, particle size and specific surface area of the non-activated and mechanically activated NLRZC were characterized by X-ray diffraction, scanning electron microscope, particle size analyzer and volumetric adsorption analyzer, respectively. The characterization results indicate that mechanical activation （MA） induced remarkable changes in the physicochemical properties of NLRZC. The leaching experiments show that MA significantly enhances the leaching reactivity of NLRZC using the zinc extraction as evaluating index. After NLRZC is mechanically activated for 30 min and 60 min, the activation energy decreases from 56.6 kJ/mol of non-activated NLRZC to 36.1 kJ/mol and 29.9 kJ/mol, respectively. The reaction orders of the non-activated, 30 and 60 min activated NLRZC dissolution with respect to H2SO4 concentration were found to be 0.34, 0.30, and 0.29, respectively.

Non-isothermal thermal decomposition kinetics of high iron gibbsite ore based on Popescu method

The thermal decomposition kinetics of high iron gibbsite ore was investigated under non-isothermal conditions.Popescu method was applied to analyzing the thermal decomposition mechanism.The results show that the most probable thermal decomposition mechanism is the three-dimensional diffusion model of Jander equation,and the mechanism code is D3.The activation energy and pre-exponential factor for thermal decomposition of high iron gibbsite ore calculated by the Popescu method are 75.36 kJ/mol and 1.51×10-5 s-（-1）,respectively.The correctness of the obtained mechanism function is validated by the activation energy acquired by the iso-conversional method.Popescu method is a rational and reliable method for the analysis of the thermal decomposition mechanism of high iron gibbsite ore.

Mechanism of mechanical activation for spontaneous combustion of sulfide minerals

In order to uncover the intrinsic reasons for spontaneous combustion of sulfide minerals,representative samples were collected from typical metal mines to carry out the mechanical activation experiment.The structures and heat behaviors of activated samples were characterized by scanning electron microscopy（SEM）,X-ray diffraction（XRD） analysis,and simultaneous thermal analysis（STA）.It is found that the sulfide minerals after mechanical activation show many changes with increased specific surface areas,aggregation phenomenon,decreased diffraction peak intensity,broadened diffraction peak,declined initial temperatures of heat release and self-ignition points.A new theory for explaining the spontaneous combustion of sulfide minerals is put forward：the chemical reaction activity of sulfide minerals is heightened by all kinds of mechanical forces during the mining,and the spontaneous combustion takes place finally under proper environment.

Effects of Fe content on photocatalytic activity of CaTiO_3-Fe_x

CaTiO 3-Fex was characterized by X-ray diffractometry, scanning electron microscopy equipped with an energy dispersive spectrometry system, Fourier transform infrared spectra, and UV-visible spectra. Effects of Fe content on photocatalytic activity of CaTiO3-Fex were investigated through measuring photocatalytic degradation rate of methylene blue. The results show that chemical compositions of CaTiO3-Fex remained unchanged with increasing Fe content from 0 to 4.745%. However, the light absorption ability of CaTiO3-Fex exhibited a significant increase with increasing Fe content. Photocatalytic degradation of methylene blue over CaTiO3-Fex followed the first-order reaction kinetics. Based on changes of the concentration of methylene blue and its degradation kinetics, CaTiO3-Fe0.474% has shown to have optimal photocatalytic activity. The degradation rate of methylene blue over CaTiO3-Fe0.474% was almost 100% under UV-visible light irradiation for 3.0 h. The kobs of methylene blue over CaTiO 3-Fe0.474% was 1.33 h-1 and was 7 times that over CaTiO3-Fe0.

Inactivation Kinetics of β-N-Acetyl-D-Glucosaminidase from Prawn (Penaeus vannamei) by Formaldehyde

β-N-Acetyl-D-glucosaminidase （NAGase, EC.3.2.1.52） is chitinolytic enzymes and disintegrate dimmer and trimer a composition of oligomers of N-acetyl-β-D-glucosamine （NAG） into monomer. Prawn （P. vannamei） NAGase is involved in digestion and molting processes. Some pollutants in seawater affect the enzyme activity causing loss of the biological function of the enzyme, which affects the exuviating shell and threatens the survival of the animal. The effect of formaldehyde on prawn （P. vannamei） β-N-acetyl-D-glucosaminidase activity for the hydrolysis of pNP-NAG has been studied. The results show that formaldehyde, at appropriate concentrations, can lead to reversible inactivation of the enzyme, and the IC50 is estimated to be 1.05mol· L^-1. The inactivation mechanism obtained from Lineweaver-Burk plots shows that the inactivation of the enzyme by formaldehyde belongs to the competitive type. The inactivation kinetics of the enzyme by formaldehyde has been studied using the progress-of-substrate-reaction method described by Tsou, and the rate constants have been determined. The results show that k＋0 is much larger than k-0, indicating the free enzyme molecule is fragile in the formaldehyde solution.

Effects of Hg and Ga on microstructures and electrochemical corrosion behaviors of Mg anode alloys

The effects of Hg and Ga on the electrochemical corrosion behaviors of the Mg-2%Hg, Mg-2%Ga and Mg-2%Hg-2%Ga (mass fraction) alloys were investigated by measurements of polarization curves, galvanostatic tests and measurements of electrochemical impedance spectroscopy. Scanning electron microscopy, X-ray diffractometry and energy dispersive spectrometry were employed to characterize the microstructures and the corroded surface of the above alloys. The results demonstrate that the microstructure of the Mg-2%Ga alloy is solid solution and the Mg-2%Hg and Mg-2%Hg-2%Ga alloys have white second-phases at the grain boundaries. The Mg-2%Ga alloy has the worst electrochemical activity and the best corrosion resistance, showing a mean potential of -1.48 V and a corrosion current density of 0.15 mA/cm2. The Mg-2%Hg-2%Ga alloy has the best electrochemical activity and the worst corrosion resistance, showing a mean potential of -1.848 V and a corrosion current density of 2.136 mA/cm2. The activation mechanism of the Mg-Hg-Ga alloy is dissolution-deposition of the Hg and Ga atoms.

Photocatalytic activity of Fe-doped diopside

UV-visible light induced photocatalytic degradation of methylene blue (MB) over Fe-doped diopside was investigated. The structure, composition, morphology and absorption property of UV-visible light of as-prepared samples were characterized using XRD, SEM, FTIR and UV-vis DRS. The experimental results show that doping Fe3+ induced the formation of some new species in diopside, and promoted light adsorption property of diopside in UV-visible region. Photochemical reactivity of Fe-doped diopside obviously depended on the content of doping Fe3+. The diopside with 1.848% Fe3+ exhibited the superior photocatalytic activity with 95% degradation of MB under UV-visible light for 3 h. The photocatalytic degradation kinetics of MB over all samples showed the first-order reaction nature.