对CALL环境下大学英语教学的思考

文章指出了CALL环境下的大学英语教学具有教学内容更丰富、学习渠道更多和师生联系更方便的优势,并指出了存在资源的浪费、教师技术和理论知识的缺乏、学生的电子阅读技能不足等问题。     

高职英语分层教学法效果的实证研究——以盐城纺织职业技术学院为例

高职学生入学时的英语水平差异较大,给英语教学带来了极大的影响,为此,盐城纺织职业技术学院进行了高职英语分层教学的实践探索,文章就英语分层教学法的效果展开研究,最后总结了几点教学心得。     

Recognition and sensing of anions through synergistic effects using simple benzimidazolium-urea receptors

Benzimidazolium-based receptors 1-3 were designed and synthesized. On the basis of fluorescence, UV-Vis, and 1H NMR spectroscopic studies, and X-ray single crystal structure analysis, it was confirmed that the receptor 1 displays strong (C-H)+···X, N-H···X hydrogen bonds and charge-charge interactions with anions. More importantly, these investigations demonstrated that the charged (C-H)+ benzimidazolium and urea moieties play a synergistic role in anion recognition.     

基于改进遗传算法的桁架结构优化

桁架是一种广泛应用于工程领域的结构形式,对其结构优化有重要的意义.文章提出了随种群的进化而动态变化的自适应交叉算子和变异算子,以提高算法的优化效率及增强收敛性;引入了精英保留策略,以克服各代种群最佳个体未能保护的缺点.建立以最小化结构总重量为目标函数的桁架优化数学模型,并应用改进的遗传算法对桁架结构进行优化求解.通过实例验证了所建模型以及对算法改进的有效性和实用性.     

Synthesis process of Ba-ferrites from α-FeOOH and γ-FeOOH and investigation of magnetic properties

The claviform BaFe₁₂O₁₉ crystals were synthesized by the precipitation-toptactic reaction method using α-FeOOH and γ-FeOOH as raw materials respectively. The synthesis processes of BaFe₁₂O₁₉, studied by XRD, SEM, EDS, FT-IR, and TG-DTA techniques, included preparations of precursor γ and precursor α, formations of α-Fe₂O₃ and BaFe₂O₄, and production of rod-like BaFe₁₂O₁₉ through dehydroxylation of pod-like FeOOH, followed by reactions of α-Fe₂O₃ with BaCO₃ and BaFe₂O₄. The crystallinity of α-Fe₂O₃ and BaCO₃ from precursor α was better than from precursor γ due to the direct dehydroxylation of α-FeOOH, resulting in a lower nucleation rate and better crystallinity of BaFe₂O₄. BaFe₁₂O₁₉ prepared from precursor α showed lower crystallinity and purity with a higher length-diameter ratio than from precursor γ. The VSM results proved that the appearance of final products had an important influence on magnetic properties.     

Radon-Nikodym theorem in signed Loeb space

This paper gives the Radon-Nikodym theorem in signed Loeb space under 1-saturated nonstandard model. First,the nonstandard characterization of absolute continuity is discussed,on which Radon-Nikodym theorem in signed Loeb space is obtained. Then,some facts about a finite signed Loeb measure and its variation are shown.     

Range walk and array rotation in space-time adaptive processing: effects and compensations

This paper proposes a unified clutter model incorporating the effects of range walk and array rotation for space-time adaptive processing (STAP) in airborne multi-channel early-warning radar. Based on this clutter model, STAP performance is then analyzed from the perspective of covariance matrix tapering (CMT). For STAP performance degradation due to array rotation, a determinate compensation method is proposed based on the CMT method. Numerical examples are provided to verify the analysis and the proposed compensation method.     

Birds of a Feather Protest Together: Theorizing Self-Organizing Political Protests with Flock Theory

The current research theorizes decentralized and self-organized political protests via flock theory (Rosen 2002), a theory of emergent self-organization in communicative human interaction. Flock theory draws from a theoretical basis of emergence and self-organizing systems, and is presented as a theory of decentralized communication structures. Focusing on the optimization of decentralized networks and roadmap based coordination of organizationally homopholous foci; the current theory poses a model of human interaction that captures the potentially egalitarian effects of cooperative evolution and collective action. Case studies of two separate decentralized political protests against Korean government and FARC are offered as evidences of such phenomena.     

Effect of intermittent aeration on the treatment performance in a submerged membrane bioreactor

In order to improve removal for nitrogen in a pilot-scale submerged membrane bioreactor (SMBR), intermittent aeration was conducted, and the effect on the treatment performance under four kinds of operation condition (run 1, continuous aeration; run 2, 60/60 min aeration on/off time; run 3, 60/90 min aeration on/off time; run 4, 60/75 min aeration on/off time) was evaluated. The results showed that depending on the specific on/off of the aeration time ratio, removal efficiency of nitrogen could be improved significantly, and the removal rates of total nitrogen (TN) under different operation conditions were 28.0%, 59.5%, 66.8% and 70.7%, respectively. There were no obvious differences for removal rates for COD_Cr and ammonia among different operation conditions. In general, intermittent aeration could be used as a feasible way to improve treatment performance for nitrogen in the SMBR.