化学实验室危险、剧毒、易制毒化学品的管理异同

通过对高等学校化学实验室危险化学品、剧毒化学品、易制毒化学品的采购、运输、库房保管、领取、使用等方面的管理异同进行比较,保证剧毒化学品和易制毒化学品的合法使用,消除安全隐患,提高高等学校化学实验室危险化学品、剧毒化学品、易制毒化学品的安全管理水平.     

肼还原法制备纳米镍粉的研究

以肼作还原剂在水—乙醇体系中能够制备出高纯度的纳米镍粉。该反应动力学研究表明NiCl2与N2H4的反应分两段进行，且在第一阶段反应中，对反应物Ni^2 、N2H4和产物Ni的反应级数分别为1、0和1级。此外，对N2H4和Ni^2 的不同摩尔比对反应也存在影响。     

半胱胺对肉鸡部分血清化学参数及酶活性的影响

144只一日龄的AA肉仔鸡随机分为4组(n=36),预饲一周后分别在试验组基础日粮中添加50mg/kg、100mg/kg、150mg/kg的半胱胺,分别于2、4、6周龄采颈静脉血,分离血清,测定四组血清钙、磷和葡萄糖含量及ALT、AST、ALP活性,研究半胱胺对肉鸡部分血清化学参数及酶活性的影响.结果表明,饲料中添加适量的Cs能升高AA肉鸡的血钙水平,而对鸡血清磷、葡萄糖含量没有明显影响;添加50～100mg/kg的Cs对ALT、AST活性没有明显的影响;而饲料中添加Cs对ALP活性有一定影响.     

Stereoselective glucuronidation of carvedilol by Chinese liver microsomes

Objective: To study the stereoselective glucuronidation of carvedilol (CARV) by three Chinese liver microsomes. Methods: The metabolites of CARV were identified by a hydrolysis reaction with β-glucuronidase and HPLC-MS/MS. The enzyme kinetics for CARV enantiomers glucuronidation was determined by a reversed phase-high pressure liquid chromatogra-phy (RP-HPLC) assay using (S)-propafenone as internal standard after precolumn derivatization with 2,3,4,6-tetra-O-acetyl-β-D-glucopyranosylisothiocyanate. Results: Two CARV glucuronides were found in three Chinese liver microsomes incubated with CARV. The non-linear regression analysis showed that the values of Km and Vmax for (S)-CARV and (R)-CARV enantiomers were (118±44) μmol/L, (2 500±833) pmol/(min·mg protein) and (24±7) μmol/L, (953±399) pmol/(min·mg protein), respectively. Conclusion: These results suggested that there was a significant (P<0.05) stereoselective glucuronidation of CARV enantiomers in three Chinese liver microsomes, which might partly explain the enantioselective pharmacokinetics of CARV.     

化学势判据应用条件

推证出化学势判据的应用条件,是封闭物系中各相的温度有一个共同确定的值T的同时,各相的压强在微过程中各具确定的值,但可以不相等,从而在理论上拓宽了化学势判据的应用.     

关于基础教育化学实验课的改革

新一轮的基础教育课程改革中，化学课程改革的关键所在在于实验课的改革。我国化学实验教学长期采用单一的演示实验和验证性实验，过于注重化学知识传授，在很大程度上抑制了学生创新思维的发展和实践操作能力的提高。化学实验教学的改革要充分利用多种教学媒体，探索实验教学新模式，逐步实现实验教学由“知识型”向“能力型”转变，切实培养学生创新精神和实践能力，全面推进素质教育。     

ZnCl2活化笋壳活性炭的制备及其对亚甲基蓝的吸附动力学研究

以笋壳为原料,采用氯化锌为活化剂制备活性炭,通过正交实验研究各影响因素对活性炭性能的影响。通过静态吸附实验研究ZnCl₂活化笋壳活性炭对亚甲基蓝的吸附特性,并从动力学角度探讨其吸附机理。结果表明,制备活性炭主要影响因素为活化温度,其次是ZnCl₂浓度,活化时间影响最小。制备活性炭的最佳条件是:ZnCl₂浓度为3 mol/L,活化温度控制在400 ℃,活化时间2 h。活性炭对亚甲基蓝的吸附符合准二级动力学方程和Elovich方程,吸附速率控制步骤主要为膜扩散控制。等温吸附曲线与Langmuir型和Freundlich型均拟合较好,吸附过程是优惠吸附。     

催化动力学法测定亚硝酸根的研究进展

亚硝酸根广泛地存在于土壤、水体、食品等物质中，是水质、环境、食品等检测的重要项目．建立简便、快速、灵敏的测定亚硝酸根的方法，在食品和环境分析中具有重要意义．本文综述了催化动力学法测定NO2^-的发展状况，包括反应体系、线性范围、检出限、应用对象等，还探讨和展望了催化动力学法测定NO2^-的研究方向和发展前景．     

基于工作过程的“化工机械设备技术”课程改革与实践

化工机械设备技术是一门理论与实践结合紧密,综合性和实践性很强的专业课程,按照基于工作过程的项目化教学方式组织实施教学,有利于实现教学目标。文章从课程体系、教学内容、教学手段、考核方法等方面对该课程的改革进行了探索,并提出了解决办法。     

Side-to-side differences in lower extremity biomechanics during multi-directional jump landing in volleyball athletes

Side-to-side differences of lower extremities may influence the likelihood of injury. Moreover, adding the complexity of jump-landing direction would help to explain lower extremity control during sport activities. The aim was to determine the effects of limb dominance and jump-landing direction on lower extremity biomechanics. Nineteen female volleyball athletes participated. Both dominant limbs (DLs) and non-dominant limbs (NLs) were examined in single-leg jump-landing tests in four directions, including forward (0°), diagonal (30° and 60°), and lateral (90°) directions. Kinematic marker trajectories and ground reaction forces were collected using a 10 camera Vicon system and an AMTI force plate. Repeated measures ANOVA (2?×?4, limb?×?direction) was used to analyse. The finding showed that, at peak vertical GRF, a significant interaction of limb dominance and direction effects was found in the hip flexion angle and lower extremity joint kinetics (p?<?.05). NLs and DLs exhibited significantly different strategies while landing in various directions. Significantly higher increase of ankle dorsiflexion angle was observed in lateral direction compared to other directions for both DLs and NLs (p?<?.05). Increasingly using ankle dorsiflexion was observed from the forward to the lateral direction for both DLs and NLs. However, NLs and DLs preferentially used different strategies of joint moment organization to respond to similar VGRFs in various directions. The response pattern of DLs might not be effective and may expose DLs to a higher injury risk, especially with regard to landing with awkward posture compared with NLs.