亚甲基蓝法测试钻井液中膨润土含量实验的改革及实施成效

针对"油田化学基础实验"课程中亚甲基蓝法测试钻井液中膨润土含量实验测试结果的偏差,通过影响因素分析和测试条件优化,改进了亚甲基蓝法测试钻井液膨润土含量实验。并将改进后的方法应用到基础实验教学、开放实验和科学研究中,在石油工程专业大学生动手能力、创新能力、求真精神、工程意识培养及辅助科学研究和指导现场施工等方面取得了成效。     

废弃植物油酯交换制备生物柴油

培养学生的绿色环保意识和可持续发展意识是应用化学专业本科人才培养方案的基本要求之一。目前实验教学中培养学生绿色环保和可持续发展意识的实验项目较少,针对这一问题,在综合化学实验中增加本新创实验项目。实验以废弃菜籽油和甲醇为原料,氢氧化钠和氯化胆碱为催化剂,生成的副产物甘油与氯化胆碱原位形成低共熔体系,与产品形成液-液两相,促使反应正向进行,简化后处理,提高产品纯度和产率。GC-MS (Gas chromatographymassspectrometer)结果表明,产品纯度大于99%,产率接近85%。分离出的低共熔体系可循环使用。燃烧热测试表明其热值与矿物柴油相当。实验使用的原料安全低毒,涉及基础有机化学实验、物理化学燃烧热测定、分析化学等多门基础实验课程的基本操作和表征,适合作为应用化学专业三年级综合化学实验教学实验项目的补充。通过本实验,有利于让学生更加系统地理解和掌握化学实验技术,培养其主动探索精神,锻炼其综合实践能力,同时,将绿水青山、环保低碳、变废为宝等课程思政理念融于综合化学实验教学。     

科研项目式实验教学设计:废弃口罩变防伪标识荧光碳点

将废弃口罩转化成高价值的防伪加密荧光碳点材料科研项目设计转化为本科实验。该实验交叉化学、材料和环境多学科知识,融合新颖性、创造性和实用性,提供了一种环保策略,而且揭示了碳点的组织结构、表面化学态、电子跃迁及光学性能知识。通过该实验,可以培养学生基于电子-分子-纳米尺度的材料化学视角分析解决问题的能力,提升学生对理论知识的理解力、实验操作的执行力、团队协作的连接力和科学素养的创造力。     

生物浸出回收废弃镍-镉电池研究

在中国,只有不到1%的废弃干电池被回收,因此有必要寻找一种既经济、快速,又利于环保的处理废弃干电池方法.生物浸出是回收废弃干电池有毒金属效果最好的方法之一.本研究应用本地下水道废水经驯化培养后产生的酸性废水作浸出菌种,考察pH值、生化反应器污水停留时间(RTB)、浸取时间、生化反应液是否添加Fe粉等实验条件对废弃镍-镉电池镍、镉浸出率的影响.结果表明,在pH值1.8~2.1、RTB 5 d、浸取时间50 d、生化反应液添加Fe粉条件下,可使镍-镉电池中镍、镉浸出率分别达到87.6%和86.4%,从而为工业生产提供了科学依据.     

加强实验教学过程管理促进实验教学目标达成

实验教学目标的达成依赖于严格的实验过程的科学管理。本文介绍了大连理工大学基础化学实验中心通过《化学实验指导手册》的编制和严格执行,培养学生的实验安全环保意识,加强对实验过程的指导。将实验各环节纳入考核范畴,目的在于着力培养学生良好的实验习惯,规范实验报告撰写和提高学生的创新思维能力,从而有效地监控和保证了实验教学质量。     

程序升温热重法测定废弃塑料热分解动力学参数

本文采用程序升温热重法实验研究了废弃塑料热分解动力学.在实验结果进行讨论的基础上计算了废弃塑料热分解的动力学参数,结果表明,所选废弃塑料试样热分解反应表观活化能在100.72～225.89 kJ/mol之间.     

精馏芳樟醇的釜残液溶解废弃聚苯乙烯泡沫的研究

本文探索了利用芳樟醇釜残液溶解泡沫塑料的可行性.实验表明,芳樟醇釜残液中含有83%的倍半萜烯,能溶解泡沫塑料.在50℃,溶解时间为50 min时,1 mL芳樟醇釜残液能溶解0.29 g废弃聚苯乙烯泡沫塑料.该釜残液与常用于泡沫塑料溶解的有机溶剂比,具有挥发性小、安全和环保的特点.     

输液皮条在电解实验改进装置中的应用

利用输液皮条等废弃物品对电解实验装置进行综合改进,设计出适合学生探究电解原理的新装置,为实现课堂教学过程的探究化提供方便.     

碱熔-碲共沉淀分离-电感耦合等离子体原子发射光谱(ICP-AES)法测定废弃环保催化剂中铂钯铑

准确测定废弃环保催化剂中铂、钯、铑含量,是实现废弃环保催化剂贵金属高效回收和处置的重要保障技术条件之一,对回收铂族金属、湿法冶金生产物料平衡考察、保证买卖双方公平、公正交易等都具有重要的意义。采用碱熔分解废弃环保催化剂样品,碲共沉淀富集铂、钯、铑并与共存离子分离,采用电感耦合等离子体原子发射光谱法（ICP-AES）测定铂、钯、铑含量。结果表明,在1.2~2.7 mol/L盐酸体系中,加入碲沉淀剂,以二氯化锡为还原剂,能完全沉淀富集铂、钯、铑。铂、钯、铑校准曲线的线性范围为0.50～50.00 μg/mL,线性相关系数分别为0.99998、0.99996、0.99997;铂、钯、铑的检出限分别为2.6 μg/g、0.9 μg/g、1.2 μg/g;方法中铂、钯、铑的测定范围为25～25000 μg/g。按照实验方法测定废弃环保催化剂中铂、钯、铑,结果相对标准偏差(RSD,n=11)为0.2%～3.6%;加标回收率为96%～109%     

和医学相关有机化合物绿色鉴别实验的设计*

为了将医用化学实验中“有机化合物的鉴别”实验更加密切地与医学相关专业结合,并提高实验操作的安全性,降低化学试剂的毒性与刺激性,甄选出一系列与医学密切相关的有机化合物作为待鉴别试剂,同时设计绿色环保、安全低毒、现象明显、操作简便、成本低廉的鉴别方法,为学生实验方案的设计提供指导。以期提高医学生学习的积极性与主动性,促进学生灵活运用知识分析问题、解决问题,为相关教学工作的改进提供借鉴意义。     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

A carbanion induced synthesis of highly congested pyrazole and imidazole containing heterocycles

An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.     

正丁胺对激光染料荧光谱影响的研究

用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.     

Selective synthesis of 4,5-dihydroimidazo- and imidazo[1,5-a]quinoxalines via modified Pictet–Spengler reaction

An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6a–g and imidazo[1,5-a]quinoxalines 7a–h by the reaction of 2-imidazolyl anilines 4a–c with aryl aldehydes 5a–k under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4a–b was found to be instrumental for the success of the reaction.     

Understanding the Diels-Alder reactivity of 1,2-azaborine analogues

The Diels-Alder reactivity of 1,2-heteroborines (H₄C₄B(H)X, X?=?NH, PH, AsH; O, S, Se) has been computationally explored by means of Density Functional Theory (DFT) calculations. The influence of the HB?=?X fragment on the reactivity of the system has been quantitatively analyzed in detail by means of the so-called Activation Strain Model (ASM) of reactivity. It is found that the interaction between these species and the dienophile is significantly stronger than that computed for their all-carbon isoelectronic counterpart, benzene. In addition, the strain energy plays a key role in the observed reactivity trends. The role of the aromaticity strength of these heteroarenes on the reactivity is also assessed.