“绿色植物与生物圈的物质循环”教学案例

1教材分析"绿色植物与生物圈的物质循环"是七年级生物学上册(苏教版)的内容,教材要求学生从生物圈的角度认识绿色植物在自然界物质循环中的作用,使学生清晰地认识"生物圈是一个整体",以培养学生热爱大自然和珍惜绿色植物的美好情感,增强学生关注自然及保护环境的社会责任感。     

“乐享”化学课堂——记桂林市荔浦中学化学教师石秀梅

正笔者曾在桂林市荔浦中学的师生中作调查,了解大家对该校化学老师石秀梅的印象。得到的答案居然十分相似,许多她教过的学生都认为她是个既有气质又有教学智慧的老师。笔者问学生:"石秀梅老师有什么样的教学智慧?"有的学生说:"石老师总能将知识点与生活实际联系起来,让人觉得化学并不高深莫测,离我们日常生活很近。"有的学生说:"石老师常让我们自己推导出结论,一节课下来,感觉学到了真知识。"还有的学生说:"我很喜欢上石老师的化学课,因为     

化合物[HO-4,6-di-C(CH3)3-C6H2-2-CH2{(NCHCHN)CH2}]的合成与晶体结构

根据文献合成4,6-^tBu2-1-（HO）C6H2CH2Cl;利用亲核取代反应合成了一种芳氧功能化的咪唑[HO-4,6-di—C（CH3）3-C6H2-2-CH2{（NCHCHN）CH2}]。芳氧功能化的咪唑通过元素分析,核磁和单晶衍射表征。晶体结构表明其晶体属单斜晶系,空间群为P2 1／e,化学式为C18H26N2O,晶胞参数为a=18．694（3）A,b=10．2501（15）A,c=9．1536（15）A,α（deg）=90deg,β（deg）=103．006（4）deg,γ（deg）=90deg,V（A^3）=1708．9（5）A^3,Z=4,最终R1=0．1160,wR2=0．2263．     

一体式生物膜反应器生物强化反硝化研究

在反应器挂膜启动阶段和运行阶段投加好氧反硝化菌纯培养物,进行生物强化反硝化研究。结果表明,在反应器启动过程中投加好氧反硝化菌,可缩短系统的启动时间;在反应器运行过程中间歇投加好氧反硝化菌能提高系统对污染物的去除效果,同时可增强系统处理的稳定性。     

2-（4-甲氧羰基苯基）-5-氨基-6-羟基苯并嚼唑的热分解机理及动力学

采用热重法（TG）测定了2-（4-甲氧羰基苯基）-5-氨基-6-羟基苯并嗯唑（MAB）的热分解过程,测定了MAB及其在热分解过程中不同阶段产物的红外光谱,运用量子化学GAMESS软件计算了MAB分子的键级,推断了MAB的热分解机理,结果表明MAB的热分解过程是一个五阶段过程,起始步骤是甲基酯的分解、根据不同升温速率下的热重曲线计算得到MAB第一阶段热分解反应的表观活化能Eα=157．1kJ·mol^-1和指前因子A=3．715×10^13。     

Polychlorinated dibenzo-p-dioxins and dibenzofurans in flue gas emissions from municipal solid waste incinerators in China

Polychlorinated dibenzo-p-dioxins and furalls(PCDD/Fs)emissions in flue gas from two types of municipal solid waste incinerators(MSWIs)most commonly used in China were investigated in this study.The selected incinerators include two grate-type MSWIs:MSWl-A(350 t/d)and MSWI-B(150 t/d),and two fluidized bed MSWIs:MSWI-C(400 t/d) and MSWI-D (400 t/d),which are all equipped with semi-dry lime scrubber and bag filter except MSWI-D equipped with cyclone and wet scrubber(WS)as air pollutant conffol device(APCD).Results indicated that the emission concentration and the international toxic equivalents(I-TEQs)of the PCDD/Fs from the stacks were in the range of 1.210～10.273 ng/Nm3 and 0.019～0.201 ngI-TEQ/Nm3,respectively.They were greatly lower than the emission regulation standard of PCDD/FS in China(1.0 ng I-TEQ/Nm3).However,only the PCDD/Fs emission Ievel from MSWI-C Was below 0.1 ng I-TEQ/Nm3.Although the homologue profiles were distinct,the contributions of the 2,3,7,8-subsituted congenem to the total I-TEQ were similar among all the investigated MSWIs.Two major 2,3,7,8-substituted congeners,2,3,4,7,8-PeCDF and 1,2,3,7,8-PeCDD,account for 47% and 9%(average values)of the total I-TEQ values,respectively.The correlation between PCDD/Fs levels and composition of flue gas Was also discussed.     

Polychlorinated dibenzo-p-dioxins and dibenzofurans in flue gas emissions from municipal solid waste incinerators in China

Polychlorinated dibenzo-p-dioxins and furans （PCDD/Fs） emissions in flue gas from two types of municipal solid waste incinerators （MSWIs） most commonly used in China were investigated in this study. The selected incinerators include two grate-type MSWIs： MSWI-A （350 t/d） and MSWI-B 050 t/d）, and two fluidized bed MSWIs： MSWI-C （400 t/d） and MSWI-D （400 t/d）, which are all equipped with semi-dry lime scrubber and bag filter except MSWI-D equipped with cyclone and wet scrubber （WS） as air pollutant control device （APCD）. Results indicated that the emission concentration and the international toxic equivalents （I-TEQs） of the PCDD/Fs from the stacks were in the range of 1.210-10.273 ng/Nm^3 and 0.019-0.201 ng I-TEQ/Nm^3, respectively. They were greatly lower than the emission regulation standard of PCDD/Fs in China （1.0 ng I-TEQ/Nm^3）. However, only the PCDD/Fs emission level from MSWI-C was below 0.1 ng I-TEQ/Nm^3. Although the homologue profiles were distinct, the contributions of the 2,3,7,8-subsituted congeners to the total I-TEQ were similar among all the investigated MSWIs. Two major 2,3,7,8-substituted congeners, 2,3,4,7,8-PeCDF and 1,2,3,7,8-PeCDD, account for 47% and 9% （average values） of the total I-TEQ values, respectively. The correlation between PCDD/Fs levels and composition of flue gas was also discussed.     

锅炉给水除氧技术的分析与比较

锅炉给水中的溶解氧会腐蚀热力系统的金属。腐蚀产物在锅炉热负荷较高处结成铜铁垢，使传热恶化，甚至造成爆管或在汽轮机高压缸中沉积，使汽轮机效率降低。因此，经过软化或除盐的补给水和凝结水，在进入锅炉之前一般都要进行除氧。只有这样才能确保锅炉的使用寿命，降低事故发生的危害。     

初中生物学六个版本教材中“呼吸作用”实验的比较与改进

1六个版本教材实验的设置呼吸作用的学习,可以帮助学生了解其与光合作用的区别和联系,知道绿色植物是维持生物圈中碳—氧平衡的途径,对提高学生的生命观念和社会责任等生物学学科核心素养具有重要的作用。因此,在人教版、苏教版、河北版、济南版、北师大版和浙教版中都设置了与“呼吸作用”有关的实验,让学生在实验中探究植物呼吸作用现象的同时,掌握呼吸作用的概念和实质,但设置的具体实验又有所差异。     

CoV基电催化剂合成及锌-空电池性能研究

贵金属催化剂通常被认为是氧还原反应和氧析出反应缓慢的四电子转移机理的最佳电催化剂.但由于其成本高,资源稀少且稳定性不足,使大规模的商业化受到了限制.因此,在同等催化性能的条件下,低成本且环境友好的非贵金属电催化剂将成为未来电催化剂工程的重点.以二氰二胺为碳源,利用基团配位作用结合冷冻干燥策略,经过碳化处理制备CoV碳纳米管复合材料(命名为CoV-NC).通过扫描电镜、X-射线衍射光谱、N2吸附—脱附曲线等对样品进行形貌和结构表征.在0.1 M KOH电解液中,CoV-NC催化剂的ORR起始电位为0.931V,并具有较高的极限电流密度.在电流密度为10 mA·cm-2时,OER电压仅为1.63 V,证明CoV-NC具有较好的ORR和OER催化活性.作为空气—正极材料组装成的一次锌-空电池,在5 mA·cm-2电流密度下可连续放电166 h,性能优于商业Pt/C催化剂.