一次函数解法全析

江湖多险，中考路艰。 八年级上，江湖上出现了一门派“一次函数”，门中八大高手个个身手不丹，八大高手中，“取值范围”暗器一绝，防不胜防；“函数概念”功力深厚，刀法精湛；“函数表达式”轻功江湖少有人及……最令人不寒而粟的是“创新题型”，变化多端，深不可测。     

八年级数学课堂有效提问探究

八年级数学课堂教学过程中,课堂提问环节的设置具有极其重要的现实作用,其不仅有助于引导学生的学科问题思考,而且还能在很大程度上吸引学生的学习注意力,激发学生的学科学习兴趣。本文主要结合实际教学情形,就课堂提问环节的重要性进行相应的分析探究,并提出课堂教学过程中有效提问的教学策略,以期促进八年级数学课堂教学质量的提升。     

老照片里的昔日行当

笔者在十几年老照片的收集中,发现其中有相当数量的老照片,记录了如今已消声匿迹的民风民俗、各种行当和物件等等。透过这些泛黄、甚至是残缺的老照片,我们可以穿越时空,探寻他们的生存轨迹和来龙去脉。剃头挑子一头热街头巷尾揽顾客剃头业的兴起是在满清入关之     

谈古代诗歌的平仄

唐代近体诗的格律就是平仄交替，它是我国特有的诗律。它与我国古代汉语相适应，又符合美学和生理学的要求。它是我国古代诗人们在创作实践中不断探索的成果。千余年来，平仄律已经影响到中国文化的各个方面。     

八年级《语文》上册中几处语病指瑕

笔在教学中发现，人教版八年级《语》上册有儿处语病，需待商榷，现列举如下：     

九十年代以来古典词学研究的八大领域

二十世纪九十年代以来,古典词学在词学史研究、词学理论研究、词学文献研究、词学个案研究、词学流派研究、词学文化研究、词学接受研究、词学学术史研究八大领域都取得了可见的成绩。这标示出我国古典词学研究的强劲态势,也预示了我国古典词学研究在本世纪前几十年间的基本走向。     

Synthetic and biological studies on a cyclopolypeptide of plant origin

Objective: A natural cyclic peptide previously isolated from Citrus medica was synthesized by coupling oftetrapep-tide units Boc-Leu-Pro-Trp-Leu-Ome and Boc-Ile-Ala-Ala-Gly-Ome after proper deprotection at carboxyl and amino terminals followed by cyclization of linear octapeptide segment.Methods: Solution phase technique was adopted for the synthesis of cyclooctapeptide--sarcodactylamide.Required tetrapeptide units were prepared by coupling of Boc-protected dipeptides viz.Boc-Leu-Pro-OH and Boc-Ile-Ala-OH with respective dipeptide methyl esters Trp-Leu-Ome and Ala-Gly-Ome.Cyclization of linear octapeptide unit was done by p-nitrophenyl ester method.The structure of synthesized cyclopolypeptide was elucidated by FTIR,1H NMR,13C NMR,FABMS spectral data and elemental analysis.The newly synthesized peptide was evaluated for dif-ferent pharmacological activities including antimicrobial,anthelmintic and cytotoxic activities.Results: Synthesis of sarcodac-tylamide was accomplished with >78% yield utilizing dicyclohexylcarbodiimide (DCC) as coupling agent.Newly synthesized peptide possessed potent cytotoxic activity against Dalton's lymphoma ascites (DLA) and Ehrlich's ascites carcinoma (EAC) cell lines,in addition to moderate anthelmintic activity against earthworms Megascoplex konkanensis,Pontoscotex corethruses and Eudrilus sp.Moreover,cyclopolypeptide displayed good antimicrobial activity against pathogenic fungi Candida albicans and Gram-negative bacteria Pseudomonas aeruginosa,in comparison to standard drugs griseofulvin and ciprofloxacin.Conclusion: Solution phase technique employing DCC and triethylamine (TEA) as base proved to be effective for the synthesis of natural cyclooctapeptide.N-methyl morpholine (NMM) was found to be a better base for the cyclization of linear octapeptide unit in comparison to TEA and pyridine.     

八年级（上）第一单元教案

人类的历史就是一部战争的历史。屈辱的战争。我们不应该忘记；和平的阳光。我们更应该珍惜。解读历史，审视现在，展望未来。世界应早日铸剑为犁……本单元选文以叙事类文章为主。有新闻、小说、通讯、书信等文体。有的谴责非正义战争的残酷．有的记叙正义战争的胜利：作者既有“指点江山”的一代伟人，也有“激扬文字”的中外著名作家。学习本单元，要求：1．把握课文内容；2．评价人物形象；3．品味特色语言；4．体验特定情景与人物心情。     

指导背诵例谈

师：同学们，在大屏幕上，老师出示了三段文字，你分别感受到了怎样的声音呢？