课堂教学渗透研究性学习思想之我见——“溴乙烷”教学的设想与实践

根据研究性学习“学以致用”的观点 ,“溴乙烷”课堂教学的目标设计、教学方法的设计和教学过程的设计应当围绕教学重点以寻求和解决问题为线索来进行 ,将小组研讨作为主要的学习形式 ,其中提出值得探究的问题是前提 ,交流和深度研讨是关键 ,贯穿于提问和研究解决问题全过程的反馈与评价起到激起趣、引起思、构起链。

中学有机化学CAI课件的制作和应用

以“溴乙烷 卤代烃”教学为例,介绍了多媒体课件的制作,并初步探讨了CAI课件在中学有机化学教学中的应用.

Flame retardancy and its mechanism of polymers flame retarded by DBDPE/Sb_2O_3

The flammability characterization and thermal composition of polymers flame retarded by decabromodiphenylethane (DBDPE) and antimony trioxide (Sb2O3) were studied by cone calorimeter and thermogravimetry (TG). The results show that ABS/DBDPE/Sb2O3 has the similar flammability parameters and thermal composition curves to ABS/DBDPO/Sb2O3. It suggests that DBDPE/Sb2O3 has the similar flame retardant behavior to DBDPO/Sb2O3. The heat release rate (HRR) and the effect heat combustion (EHC) curves of polymers flame retarded by DBDPE/Sb2O3 all decrease, but the mass loss rate (MLR) curve slightly increase. It shows that the decrease of HRR is not due to the increase of char formation ratio but the generation of incombustible gases. The major flame retardant mechanism of DBDPE/Sb2O3 is gas phase flame retardant mechanism. Increasing content of Sb2O3 in DBDPE/Sb2O3 can improve the flame retardant property and thermal stability of acrylonitrile butadiene styrene. Sb2O3 has a good synergistic effect with DBDPE.

Synthesis and characterization of porous cobalt oxide/copper oxide nanoplate as novel electrode material for supercapacitors

A promising Co3O4/Cu O composite electrode material was successfully synthesized through a facile hydrothermal and calcination process. Effects of the surfactants hexadecyltrimethyl ammonium bromide（CTAB） and polyvinylpyrrolidone（PVP） on the morphology and electrochemical performance of the composite were investigated. Powder X-ray diffraction（XRD）, scanning electron microscopy（SEM）, transmission electron microscopy（TEM） and nitrogen adsorption-desorption experiment were employed to characterize the microstructures and morphologies of the composite. Meanwhile, the electrochemical performances of the samples were studied using cyclic voltammetry（CV）, galvanostatic charge-discharge test and electrochemical impedance spectroscopy（EIS）. The results show that the porous Co3O4/Cu O-CTAB nanoplates own the best performance and exhibits a high specific capacitance of 398 F/g at 1 A/g with almost 100% capacitance retention over 2000 cycles, and it retains 90% of capacitance at 10 A/g.

Role of cellular immunity in halothane hepatitis: an in vitro study

Objective: To explore the effect of cellular immunity in halothane hepatitis. Methods: Hepatotoxicity model was established by exposing male Hartley guinea pigs to 1% halothane via inspiration for 4 h each time for 1 or 3 times within a 42-day interval. Then their hepatocytes and lymphocytes were collected and divided into 2 parts for different cultures. Hepatocytes were cultivated with or without 1% halothane for 4 h and lymphocytes were cultivated with or without 12.5 μg/ml trifluoroacetylated guinea pig serum albumin (TFA-GSA). Then the 2 kinds of hepatocytes were co-cultivated with lymphocytes (1:100) with or without TFA-GSA induction respectively and the supernatant fluid was taken after 24, 48 and 72 h to determine the concentration of alanine aminotransferase (ALT). The halothane cultivated hepatocytes were co-cultivated with various proportion of TFA-GSA antigen induced lymphocytes and ALT was determined after 48 h to determine the proper proportion of hepatocytes and lymphocyte. Results: Lymphocytes of 3 times halothane induced guinea pigs caused a significant increase of ALT in hepatocytes with or without halothane induction. But the lymphocytes of 1 time halothane induced guinea pigs only caused a significant increase of ALT in hepatocytes with induction of halothane. The increase of ALT was only seen after 48- and 72-hour co-culture. The proper proportion of hepatocytes and lymphocytes was 1:100 for lymphocytes cytotoxicity. Conclusion: Lymphocytes is sensitized after inhalation of halothane and generates cytotoxicity to hepatocytes. The immune response of lymphocytes to hepatocytes will be enhanced by repeated inhalation of halothane. The cellular immunity may be one of the mechanisms of halothane induced hepatotoxicity.

Neurological responses of embryo-larval zebrafish to short-term sediment exposure to decabromodiphenylethane

Decabromodiphenylethane （DBDPE） has been widely used as an alternative flame retardant due to the restriction or phase-out of traditional polybrominated diphenyl ethers （PBDEs）, and is of increasing concern regarding its ubiquity, persistence, and potential adverse effects. In the present study, the toxicological effects of DBDPE were evaluated using zebrafish as an in vivo model. Upon being exposed to DBDPE-polluted sediments for a short term, it was found that the mortality and malformation of zebrafish （including edema, bent notochord, and bent tail） were not affected even at the highest concentration tested （1000.0μg/kg dry sediment）. Regarding behavioral responses, it was found that zebraflsh larvae of 48 hours post fertilization （hpf） in all groups escaped successfully with a touch to the dorsal fin. However, when exposed to the highest DBDPE concentration, the larvae of 120 hpf exhibited significantly smaller distances as compared to the control. Moreover, the results of the acetylcholinesterase （ACHE） activity, the expression levels of two important nerve-related genes, and the cell apoptosis all indicated that DBDPE posed low neurotoxicity in embryo-larval zebrafish. The results in this study shed some light on the potential risks of DBDPE in the real environment and highlight the application of the sediment exposure route in the future.