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1.
针对商品检验与分析专业课程体系和教学内容存在的问题,并根据网络调研和实地考察的有关资料,探讨了商品检验与分析专业课程体系设置以及实践环节和教学内容等方面的具体改革措施。  相似文献   

2.
蓖麻油与乳酸的共聚物合成与表征   总被引:2,自引:1,他引:1  
用熔融聚合法合成了一种蓖麻油和乳酸的共聚物.以丁二酸酐作为共聚体系的引发剂和封端剂,制得端羧基共聚物P(LA-CO)-COOH.研究了反应条件对共聚物分子量的影响,通过核磁共振表征了共聚物的结构.DSC和TG研究表明,蓖麻油链段的引入破坏了聚乳酸的结晶性,提高了共聚物的热稳定性.  相似文献   

3.
胞嘧啶与一氧化碳复合物的结构与性质   总被引:1,自引:0,他引:1  
在B3LYP/6-311+G**水平上对胞嘧啶…CO复合物体系进行了理论计算, 发现了6个能量极小的复合物. 其结合方式是CO的C或O原子与胞嘧啶的N—H键形成氢键, 最稳定的复合物的结合能为-8.72 kJ·mol-1. CO的C原子与胞嘧啶的结合具有更强的优势, C原子结合的复合物中CO的键长缩短, 而O结合的复合物中CO键长伸长. 同时, 对复合物的振动分析发现, 在C原子结合的复合物中CO的伸缩频率蓝移, 而O结合的复合物中CO伸缩频率是红移的.  相似文献   

4.
利用多媒体教学手段,在工科院校开设面向文科专业学生的化学与社会课程,探讨了在内容上分专题讲述,并辅以生动有趣的实验教学及考核方式多样化的教学模式。  相似文献   

5.
介绍黎明职业大学高分子材料加工技术专业的核心课程《高分子材料分析与测试》的课程设计和教学改革的做法。课程以实现学生向"准员工"的转变为教学目标。通过对行业企业进行调研,确定该课程的对接岗位为质量检验岗位,工作内容为化验、质检和品管,基于岗位工作内容进行课程设计。采用项目化方式,三个工作内容分别对应以典型方法、典型产品和典型常识为项目进行模块设计。以模块任务为中心,将教师的"讲"与学生的"练"有机结合起来,综合应用提倡学生互教的交互培训法、引导学生自主学习的主题探究法、锻炼学生专业素质的四阶段技能训练法等教学方法。  相似文献   

6.
高分子化学与物理实验教学探索与实践   总被引:3,自引:0,他引:3  
根据东北大学应用化学专业特点,本文对高分子化学与物理实验教学的内容、方法及模式进行了全面的改革和深化。近年来,通过实践"巩固基础,加强综合性、设计性及研究性实验,开展趣味性实验,推广微型化实验,改革实验教学方法及完善实验考核方式"的改革模式表明:这对培养学生的实验动手能力、创新能力、科研能力及节能减排与环保意识等是十分必要的,同时也有利于激发学生的进取心和创造欲望,拓宽学生的思路,及提高学生的实验兴趣、主观能动性以与发现问题、分析问题、解决问题的应用能力。  相似文献   

7.
自从1955年科学家们发现了芬芳糖耐量因子(GTF),并证实了(GTF)具有生物活性的重要结构成分是三价铬后,铬及其所有化合物的生物学功能受到了科学家们广泛的重视,如运用于保健品、强化食品、营养补充利中、富集蔬菜和富集茶叶中等等。  相似文献   

8.
化学与申奥   总被引:1,自引:0,他引:1  
本文探讨了化学在申奥中的意义,分别介绍了绿色奥运、科技奥运、人文奥运中的化学问题。  相似文献   

9.
缺陷与催化     
谢超  周波  周灵  吴雨洁  王双印 《化学进展》2020,32(8):1172-1183
催化技术在现代工业生产和日常生活中发挥着举足轻重的作用,开发高效的催化剂是催化领域重要的研究方向。近些年来,许多研究发现催化剂的缺陷对其催化活性有着重要的影响,同时各种各样的缺陷催化剂也被开发出来。尽管如此,缺陷与催化活性之间的关系仍有待厘清。本文围绕这一主题,分别介绍了固体缺陷化学的基础、催化剂中缺陷的类型、表征、可控构筑以及在催化中的作用和动态变化,最后进行总结和展望。希望通过本文阐明催化剂缺陷化学研究的起源与发展,强调缺陷对催化的重要性,为今后高效催化剂的进一步开发与机理研究提供指导。  相似文献   

10.
酒与人类     
酒与人类生活密切相关。本文从化学、生理学的角度介绍了酒的生产历史、生产过程,对人体和社会的危害及益处。  相似文献   

11.
ISO/TR 18394 provides guidance for the identification of chemical effects on x‐ray or electron‐excited Auger electron spectra as well as for applications of these effects in chemical characterization of surface/interface layers of solids. In addition to elemental composition, information can be obtained on the chemical state and the surrounding local electronic structure of the atom with the initial core hole from the changes of Auger electron spectra upon the alteration of its local environment. The methods of identification and use of chemical effects on Auger electron spectra, as described in this Technical Report, are very important for accurate quantitative applications of Auger electron spectroscopy. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

12.
《Chemical physics letters》1986,124(2):181-186
Quantum-mechanical calculations on a realistic system show that excitation of a local mode may be accomplished by using two lasers. More importantly, this local mode does not decay into the bath modes of the molecule even at very long times. This excitation is accomplished using two lasers tuned to two eigenstates whose wavefunctions interfere to give the local excitation. Most significantly, this observation for a model system implies that mode specific control of chemical reactions may be accomplished using two lasers to excite two overtone transitions.  相似文献   

13.
论述了应用型地方高校材料化学专业构建稳定的人才培养体系的必要性和紧迫性。结合教学实践重点阐述了在课程体系设置、课堂教学、实验教学、校外实践等教学环节的改革,以及师资素质培养和转型、专业差异化发展、与地方经济融合等方面的有益探索。通过数据展现了在新的培养体系中取得的积极效果。最终通过政策引导,以产教融合为主线,构建稳定的适合地方应用型高校办学实际的专业人才培养体系。  相似文献   

14.
Information on the electronic structure of a molecule and its chemical bonds is encoded in the molecular normal vibrational modes. However, normal vibrational modes result from a coupling of local vibrational modes, which means that only the latter can provide detailed insight into bonding and other structural features. In this work, it is proven that the adiabatic internal coordinate vibrational modes of Konkoli and Cremer [Int. J. Quantum Chem. 67, 29 (1998)] represent a unique set of local modes that is directly related to the normal vibrational modes. The missing link between these two sets of modes are the compliance constants of Decius, which turn out to be the reciprocals of the local mode force constants of Konkoli and Cremer. Using the compliance constants matrix, the local mode frequencies of any molecule can be converted into its normal mode frequencies with the help of an adiabatic connection scheme that defines the coupling of the local modes in terms of coupling frequencies and reveals how avoided crossings between the local modes lead to changes in the character of the normal modes.  相似文献   

15.
Resolution studies of scanning electrochemical microscopy (SECM) have been performed in the feedback mode and in the generator/collector mode at circular model structures. A quantitative correlation of the loss in resolution and the increase in distance between tip and sample is found. Measuring a band electrode of just 500 nm width, the high sensitivity of the SECM in identifying chemically active sites is proven. Applied to polymer samples, the chemical composition was determined in the feedback mode at high lateral resolution. The difference in electrical conductivity allows one to distinguish between doped and undoped parts of a polyaniline film. By scanning above a blend consisting of polypyrrole and polypropylene, a map of the local chemical composition was obtained. In this context, the influence of the tip overpotential on the image is discussed.  相似文献   

16.
Scanning tunneling microscopy (STM) and noncontact tapping mode atomic force microscopy (AFM) have been employed to study on a local scale the structural and, for the first time, the chemical changes of carbon black (CB) particles following plasma oxidation. STM imaging of the pristine, untreated particles revealed a relatively ordered structure of tiny crystallites with a few amorphous regions. After plasma treatment, the crystallites were no longer observed and the CB particle surface exhibited a noticeable and ubiquitous increase in atomic-scale disorder. Phase contrast images obtained with noncontact tapping mode AFM indicated that the untreated CB particles were essentially hydrophobic as a pristine basal surface of graphite, but with occasional hydrophilic patches. By contrast, their plasma-treated counterparts displayed enhanced hydrophilicity as a result of the introduction of oxygen onto the CB surface, the presence of which was evidenced by X-ray photoelectron spectroscopy, but most significantly, such enhancement was observed to be quite uniform at a local scale of individual particles. The possibility of investigating on a very local scale the chemical behavior of oxidized CB particles should be useful for the control and optimization of their dispersion properties in different systems.  相似文献   

17.
"学生演示-集体评课-全班实验"三环节教学模式是高师教学论实验课程的主要形式,我们对化学专业教学论实验课程教学现状进行了教学观察和调研,从教学内容的选择、教学组织形式、教学管理形式、课程评价方式等方面进行优化,取得明显的教学效果。这对促进高师院校的化学实验教学改革、培养创新型实验教学能力的师范生有一定的参考价值。  相似文献   

18.
韶关学院自2012年起开始了"一托四化"应用技术型化学本科人才培养模式的探索,提出了以优秀教学团队建设为依托,通过对理论教学"主体化"、实践教学"平台化"、教学资源"精品化"、考评方式"多元化",构建"一托四化"应用技术型人才培养模式,探索了一条地方本科院校应用技术型人才培养的有效途径。  相似文献   

19.
This review article considers the origin of vibrational anharmonicity in molecules, and the effects that vibrational resonances have on the anharmonicity constants which may be extracted from spectroscopic observations. The importance of the effects of Darling—Dennison resonances, which increase with increasing excitation, as well as Fermi resonances, are considered. The local mode approach to X—Y stretching vibrations is dealt with, as a means of simultaneously accounting for Darling—Dennison resonances and of inter-relating normal mode stretching anharmonicity constants, thus reducing the number of parameters to be determined. The inclusion of Fermi resonances, as necessary, into the calculation is next considered, and the joint local mode-normal mode analysis explained.Applications to ethylenic and methyl group molecules are made. The success of the analyses is demonstrated through complete sets of physically representative anharmonicity constants which reproduce vibrational observations into the visible (16 500 cm−1), and which are mutually self-consistent over molecules containing the same functional groups.Extensions of the simple local mode model are considered, as means of achieving anharmonicity parameters which should describe more closely the molecular potential energy surface, and hence the concomitant physical and chemical processes which it controls.  相似文献   

20.
辽河减压渣油中非卟啉镍的XAFS研究   总被引:6,自引:0,他引:6  
为获得石油中非卟啉Ni的结构信息,采用荧光法对辽河减压清油中非叶琳Ni的 K边进行了XAFS测试非叶琳Ni第一配位壳层的结构和Ni-四苯基卟啉(NiTPP)的配 位结构类似,也是4个氮原子,呈平面四方构型为0.192nm,在较高的配位壳层,二 者存在一定的差别此外,根据XAFS测试,对石油中非卟啉Ni讨论.  相似文献   

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