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化学是一门到初三才开设的课程,内容浅显且较少,是学生化学知识的基点,化学教学要注重基础知识的同时,首要任务应放在培养学生的思维能力上.思维能力是人脑通过对输入信息加工整合而制作出思维产品的能力,是思维的逻辑性、批评性、灵活性、创造性的综合体现.在初中化学教学中,只有调动学生学习的主动性,发挥学生主体作用,学生思维才能提高.
一、思维能力培养的重要性(略)
二、化学思维能力培养方法与手段
激发学生的学习兴趣,增强求知欲.爱因斯坦曾经说过“兴趣是最好的老师”,初中化学是化学学科的启蒙阶段,此时的学生好奇心强,富于幻想,容易接受新生事物,是最容易培养学生学习兴趣的时候. 相似文献
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To establish wireless channel suitable for the cabin environment, the power coverage was investigated with distributed antenna system and centralized antenna system based on the actual measurement of channel impulse response. The results indicated that the distributed antenna system has more uniform power coverage than the centralized antenna system. The average relative errors of receiving power of both antennas were calculated. The optimal position of the centralized antenna was obtained by Gaussian function refinement, making the system achieve a better transmission power with the same coverage effect, and providing a reference for antenna location in the future real communication in the cabin. 相似文献
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Themobilecommunicationchannelinurbanandsuburbanareas,typicallymodeledasafrequency selectivemultipathRayleighfadingchannel,bringsasignificantchallengetothereliableandeffectivetransmissionofdigi talinformation .Orthogonalfrequencydivisionmultiplex ing (OFDM )hasbeenputforwardasthecriticaltechnol ogyinthenextgenerationmobilecommunicationsystem .Theideaofmulticarriermodulationistodividethetrans missionchannelintoanumberoforthogonalsubchannelsorsubcarriers.Thiscanleadtoahigherspectralefficien cya… 相似文献
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Differential frequencyhopping(DFH) as a digital radiotechnology has satisfyingfeatures of multipathfading mitiga-tion,spectral re-use ,non-interferingspreadspectrumoper-ation,andinterferenceresistance[1].Sincetheintroductionof controllable redundancy into… 相似文献
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The all-phase fast Fourier transform (apFFT) is proposed as a digital demodulation algorithm in place of the fast Fourier transform (FFT) for orthogonal frequency division multiplexing (OFDM) based multiple-input multiple-output (MIMO) communication systems. The amplitude spectrum of apFFT-demodulated symbols is the square of that of the FFT, which helps reduce the Gaussian noise to a great extent. Moreover, the phases of apFFT symbols are not affected by the frequency shift between the transmitter and receiver oscillators. These properties particularly appeal to MIMO systems over frequency-selective fading channels. The proposed MIMO-OFDM system employing the apFFT is validated using the spatial channel model (SCM) proposed by the third generation partnership project (3GPP). The simulation results demonstrate that the performance of the proposed system after compensating for the rate loss due to zero bits inserted in the space-frequency OFDM (SF-OFDM) coding scheme, still considerably outperforms the conventional system over 3GPP SCM channels, especially under poor channel conditions. 相似文献
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Asymmetric stereoscopic video coding can take advantage of binocular suppression in human vision by representing one of the two views in lower quality.This paper proposes a bit allocation strategy for asymmetric stereoscopic video coding.In order to improve the accuracy of bit allocation and rate control in the left view,a proportionalintegral-derivative controller is adopted.Meanwhile,to control the quality fluctuation between consecutive frames of the left view,a quality controller is adopted.Besides,a fuzzy controller is proposed to control the variation in quality between the left and right views by comparing the PSNR disparity of two views with a fixed threshold,which is used to quantize the binocular psycho-visual redundancy and adjust the quantization parameter (QP) of the right view correspondingly.The proposed algorithm has been implemented in H.264/AVC video codec,and the experimental results show its effectiveness in rate control while keeping a good quality for the left view,and fewer bits are allocated for the right view so that the overall bit rate is saved by 7.2% at most without the loss of subjective visual quality for stereoscopic video. 相似文献
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当前英语写作教学改革迫在眉睫,传统英语写作教学方法已不适应新时期学生学习节奏,且传统教学方式存在的课堂形式单一、学生驱动力不足等问题,是制约学生写作能力提升的短板。本文基于2011年到2021年教学实践数据,以采取非线性写作思维,快速构建素材模块,驱动学生的自主能动性,通过开发形式多样的内容和互动活动,动态研究课堂教学反应,打破僵化写作公式,鼓励和倡导一种富有创造力的思维模式。文章通过研究发现：搭建素材模块+非线性串联模块元素,能够快速组织写作所需内容,显著提升学生的内容生产水平,且该结论在经过长期教学成果检验后依然成立。本文拓展了写作教学方式方法,快速化解学生对英语写作中极易产生的心防,激发学生写作兴趣,能够提高学生英语写作能力水平,且具有实践意义。 相似文献
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