MOOCs offer solutions to traditional constraints faced in chemistry experimental teaching,such as limited lab space,insufficient equipment,and rigid scheduling,However,challenges like underutilization,reluctance from students,and faculty unfamiliarity can undermine these efforts.To address these issues,the National Demonstration Center for Experimental Chemistry and Chemical Engineering Education(Beijing University of Chemical Technology)has explored how to effectively use MOOCs to enhance teaching quality.The team has established an extensive array of online experimental teaching resources,implemented a synergistic blended learning model,and developed both a faculty skill enhancement program and a comprehensive system for tracking and feedback on teaching quality.These initiatives have significantly improved educational effects.

Laboratory safety is an important part in the process of chemistry laboratory teaching, and it is also one of the key tasks of every school at all levels.A five-in-one laboratory safety mechanism, including laboratory technology lecture, laboratory safety and environmental protection class, safety explanation and demonstration in the process of experimental project implementation, emergency evacuation drill in laboratory accidents and laboratory fire drill, has been gradually formed after many years of teaching and exploration at the Experimental Teaching Center of Chemistry, Beijing University of Chemical Engineering.These measures greatly improve the safety awareness of students in the lab class, ensure the experiment proceeded in safely and stably, and ensure a good order of campus teaching effectively.This paper analyzes the above "five-in-one" chemistry laboratory safety education teaching mode, hoping to explore how to ensure the safety of chemistry laboratory teaching with all colleagues.

为解决能源短缺和环境污染等问题,探究半导体光催化材料去除有机污染物,以MIL-125(Ti)为光催化剂载体,g-C3N4为有机半导体,Fe3O4@SiO2为磁性载体,通过溶剂热法合成了一系列不同质量配比的可见光响应型MIL-125(Ti)复合材料.通过傅里叶变换红外光谱仪、X射线衍射仪、场发射扫描电子显微镜、热重分析仪等对复合材料的样品组成、结构、形貌及光学性能等进行表征分析.进一步通过正交试验评价该复合材料去除罗丹明B的性能.研究结果表明,最适宜去除罗丹明B的操作工艺条件为:光催化时间为4.0h,g-C3N4与MIL-125(Ti)的质量配比为1:20,催化剂投加量为0.01g,罗丹明B溶液的浓度为10.0mg/L.在该条件下罗丹明B的去除率可达到96.57％.经过4次循环实验后,去除率仍能达到86.52％.g-C3N4/MIL-125(Ti)磁性复合材料的制备工艺和去除有机染料机理可为相关研究提供借鉴.

Sand erosion is a serious problem in the relatively arid and semiarid areas. A novel chemical sand fixing agent (LSUF) synthesized by lignosulfonate graft urea-formaldehyde was introduced in this study. It was made by polymerization of lignin sulfonate, urea and formaldehyde. The newly synthesized product had good water solubility, potentially good biodegradation, and produced no additional pollution. The results showed that the strength test, water-retaining test and wind erosion test of LSUF was better than the sand fixing agent composition by urea-formaldehyde (UF). The LSUF is an environment-friendly products and, it can be considered as an ideal sand fixing agents to control sand erosion in the relatively arid and semiarid areas.

A series of structurally diverse 4-trifluoromethyl β-sultams was conveniently synthesized via the sulfa-Staudinger cycloadditions of 2,2,2-trifluoroethanesulfonyl chloride with different imines under very mild conditions. The products were obtained in yields up to 75%, and in cis/trans ratios ranging from 59:41 to 12:78.

An environmental friendly sand-fixation & dust suppressant has been prepared by seed emulsion poly merization using xanthan gum (XG) as grafted substrate and methyl acrylate (MA) and vinyl acetate (VAc) as comonomers.The influences of the monomer ratio,the amount of emulsifier sodium dodecyl benzene sulfonate (SDBS),the amount of initiator ammonium persulfate (APS),the reaction temperature and the amount of xanthan gum (XG) on the quality of the polymer emulsion were studied.According to the results of the optimization experiments,when the monomer mass ratio (mMA∶ mvAc) was 3∶5,the mass fraction of emulsifier,initiator and grafted substrate were 5.0％,1.2％ and 4.0％ respectively,and the reaction temperature was 65 ℃,the viscosity,compressive strength,product appearance,fluidity and static stability of the sand-fixation & dust suppressant all reached their optimum values.FT-IR spectroscopy and TG-DTA showed that the co-monomers were successfully grafted on to the substrate.The product also had excellent water retention.Finally,the application performance of the environmental friendly sand-fixation & dust suppressant and its influence on seed germination were studied.The experimental results show that this XG grafted sand-fixation & dust suppressant with a certain degree of degradation has good water resistance and water erosion resistance.Also,its compressive strength can satisfy the practical requirements of sand control.

A new coordination compound ([Nd(bpdc)(Hsuc)]n) has been synthesized by reaction of Nd2O3,2,2'-bipyridyl-3,3'-dicarboxylic acid (H2 bpdc) and succinic acid (H2 suc) hydrothermal conditions.The products are purple sheet-like crystals.This paper discusses the factors affecting the synthesis,such as the ratio of reactants,the amount of solvent,temperature and cooling rate.Ultimately the optimal synthetic conditions were determined:n(Nd3+):n(bpdc2-):n(suc2-) =2:3:3,5 mL H2O as the solvent,with reaction for 96 h at a constant temperature of 140 ℃ followed by cooling at a rate of 1 ℃/h.The coordination mode,single crystal structure and electrocatalytic properties of the materials were determined by infrared spectroscopy,single crystal X-ray diffraction and linear voltammetry (LSV) respectively.The results show that the crystal is orthorhombic,space group Pbca,and the material has the ORR electrocatalytic activity,showing good potential for application in electrocatalysis.

磺酰氯是重要的有机合成和医药中间体,综述了由烷基异硫脲盐合成磺酰氯的方法和研究进展.烷基异硫脲盐是一类无恶臭味道的固体,容易制备,也是制备硫醇的前体化合物,用其直接合成磺酰氯既节省操作步骤又环保,是合成磺酰氯的有效环保方法.

采用乳液聚合中的预乳化工艺,制备碱玉米秸秆接枝丙烯酸丁酯(BA)/甲基丙烯酸甲酯(MMA)/丙烯酰胺(AM)新型固沙抑尘剂.考察了单体配比、丙烯酰胺用量、乳化剂用量、引发剂过硫酸铵(APS)用量、反应温度以及碱玉米秸秆加入量对合成产物性能的影响;然后采用FT-IR、HPLC、TG-DTA对产物进行表征,并对固沙抑尘剂的表面固沙效果、保水性和抗压强度等应用性能进行了研究.实验结果表明,单体质量配比(mBA∶mMMA)为7∶3、AM质量分数2％、乳化剂质量分数5％、APS质量分数0.6％、碱玉米秸秆质量分数5％、聚合温度为75℃时,固沙抑尘剂乳液的黏度、流动性、稳定性以及产品外观良好,在320℃下热稳定性良好,保水性和压缩强度可满足实际应用需求.

以NdC13·6H20、2,2'-联吡啶-3,3'-二羧酸(H2bpdc)、己二酸(adi)为原料,用水热法合成了一种新型双配体单金属MOFs材料[Nd2(bpdc)2(adi)(H20)6]n,该材料晶体呈粉色片状.讨论了反应物配比、溶剂种类与用量、体系pH、温度与降温速率对MOFs材料合成的影响,最终确定最佳合成条件为:反应物配比n(Nd3+)∶n(bpdc2-)∶n(adi2-) =2∶3∶3,以去离子水为溶剂,溶剂量为8 mL,pH =4,145℃恒温96 h,以1℃/h速度降温.采用红外光谱、X-射线单晶衍射、热重TG和紫外可见漫反射对材料的结构、热稳定性和导电性能进行测试,结果表明:产物晶体为三斜晶系,Pī空间群;在197℃以下材料可以稳定存在;材料具有良好的绝缘特性,可以用作绝缘材料.

Starts from 2012, more than 20 provinces in China present the wide range long-enduring fog haze, affects the crowd to surpass 600 million. In addition to industrial emissions, vehicle exhaust is also a big source of pollution. Automobile exhaust purification catalysts can reduce the content of harmful substances in the exhaust, is the most effective way to deal with exhaust emissions now. Research progress of the three-way-catalyst, single palladium catalyst, perovskite catalysts and molecular sieve catalyst was reviewed, and the prospect of these research areas was put forward.

采用木质素磺酸钠接枝改性技术,合成了具有良好固沙性能的水溶性木质素磺酸钠改性脲醛树脂固沙抑尘剂.采用FT-IR对木质素磺酸钠改性脲醛树脂进行了表征,测试了其黏度,并研究了固沙抑尘剂的表面固沙效果、热稳定性、保水性和抗压强度等固沙性能.实验结果表明,固沙抑尘剂在室温至200℃区间内热稳定性良好;当使用的固沙抑尘剂的固含量(质量分数)为5％时,能够形成有效固结层,可满足室外固沙需要.

采用水热合成法,以NdCl3·6H2O、CoCl2· 6H2O、2,2'-联吡啶-3,3'-二羧酸(H2bpdc)、氢氧化钠和水为原料合成了一种新型3d-4f金属有机框架晶体材料.该晶体呈红色棒状,经X-射线单晶衍射分析,其结构属单斜晶系,P21/n空间群,化学式为{[Nd2Co(bpdc)3 (OH)2(H2O)2]·(H2O)2}n.通过单一变量法确定其最佳合成条件为:n(Nd3+)∶n(Co2+)∶n(bpdc)=1∶1∶1.5,溶于5 mL去离子水,以NaOH调节溶液pH≈5,150℃恒温72h,降温速度1℃/h.热重分析表明该材料具有良好的热稳定性,在340℃以下可以稳定存在;经循环伏安法测试,此晶体材料具有良好的电化学活性.

采用乳液接枝共聚合法制备羟丙基甲基纤维素(HPMC)接枝丙烯酸甲酯(MA)/醋酸乙烯酯(VAc)新型固沙剂.实验考察了单体配比、乳化剂十二烷基苯磺酸钠(SDBS)用量、引发剂过硫酸铵(APS)用量、HPMC用量及聚合温度对合成乳液性能的影响.采用FT-IR、TG对乳液进行表征,并初步研究了固沙剂的表面固沙效果、保水性和抗压强度等固沙性能.实验结果表明,单体质量配比(mMA∶mVAc)3∶5、SDBS质量分数4.5％、APS质量分数0.8％、HPMC质量分数20％、聚合温度为60℃时,固沙剂乳液的黏度、流动性、产品外观和静置稳定性等均较好;固沙剂在240℃下热稳定性良好,保水性和压缩强度能够满足实际固沙应用中的要求.

以SmC13·6H2O、2,2′-联吡啶-3,3′-二羧酸(H2bpdc)、对苯二甲酸(H2bdc)、H2O为原料,采用水热法合成了一种新的双核吡啶羧酸类配位聚合物[Sm2(bpdc)(bdc)2(H2O)2]n,该配合物晶体呈透明片状.讨论了反应物单体配比、溶剂量、不同温度以及体系pH对配合物合成的影响,确定最佳合成条件为:反应物配比SmCl3·6H2O、H2bpdc和H2bdc物质的量之比为2:2∶1,溶剂为5 mL去离子水,pH =5,160℃恒温72 h,降温速度2℃/h.X-射线单晶衍射、TGA及荧光性能测试结果表明:该晶体属于单斜晶系,C2/c空间群;热稳定性较好,骨架在418℃以下可以稳定存在;具有良好的荧光特性,Sm3离子发生高效辐射跃迁.

Two rare earth coordination polymers {[Ln(2) (bpdc)(3) (H2O)(2)]center dot 5H(2)O}(n), (Ln=Nd (1), Eu (2); bpdc=2,2'Bipyridyl-3,3'-dicarboxylic acid) were hydrothermally synthesized. Single-crystal X-ray diffraction shows that 1 and 2 are isomorphic and in the monoclinic system with P2/c group. Crystal unit parameters are a=1.241 00(19) nm,b=0.748 35(59) nm,c=2.060 50(20) nm, beta=94.84(1)degrees and alpha=1.241 00(19)degrees nm,b=0.743 01(20) nm,c=2.052 50 (30) nm beta=94.95(2) respectively. In addition, the complexes afforded a two-dimensional (2D) structure based on the zigzag chains (1D) linked by bpdc ligands and appear 8-coordinated single network structure with topology symbol {3<^>9;4<^>18;5} as well. Interestingly, pentameric water rings were founded between lattice water molecules in 1 and 2. Thermo-gravimetric analyses of 1 and 2 display considerable thermal stability. The complex 2 displays good fluorescence property. CCDC: 925994, 1; 925995, 2.

A novel two-dimensional network complex of europium with 2,2'-bipyridyl-3,3'-dicarboxylate,[Eu2(C12H6N2O4)3(H2O)2·5H2O]n,has been synthesized by a hydrothermal reaction. The crystals were colorless transparent sheets. The effects of varying four experimental conditions were investigated using a single variable method. The optimized reaction conditions were found to be: reaction temperature of 160 ℃; reaction time of 72 h;cooling rate of 2 ℃ / h; pH of 3. 4; 10mL of deionized water as solvent; molar ratio of Eu2O3∶ 2,2'-bipyridyl-3,3'-dicarboxylic acid of 1∶ 3. The compound crystallizes in the monoclinic system,space group P2 / c,is thermally stable up to 390 ℃,and shows intense fluorescence.

A new sand fixing agent has been synthesized by means of graft copolymerization of soluble starch with acrylic acid (AA) and vinyl acetate (VAc). The effects of varying the ratio of monomers, the extent of neutralization of acyclic acid, the initiator dosage, as well as the polymerization temperature on the stability and properties of the resulting emulsions were investigated in detail. The copolymers were characterized by infrared spectroscopy, scanning electron microscopy and thermogravimetric analysis. The crusts formed on shifting sands, viscosities and compressive strengths were studied. The results showed that a sample synthesized with an AA, VAc mass ratio (mAA:mVAc) of 2:1, 25% neutralization of AA, 0.8% initiator and a polymerization temperature of 80°C, had a suitable viscosity, compressive strength and thermostability (under 200°C) to achieve good sand fixing performance for practical applications.

以NdCl3·6H2O、溴化铜、2,5-吡啶二羧酸(物质的量比为1∶1∶3)为原料,采用水热法合成了一种新的具有三维结构的含钕和铜的吡啶羧酸类配位聚合物[Nd2Cu3(C7NO4)6(H2O)10·14H2O]n.该化合物晶体为深蓝紫色颗粒状,最佳合成条件为:反应温度160℃,反应时间3d,pH =6,溶剂为6mL去离子水.XRD和TG测试结果表明,该晶体属于单斜晶系,C2/c空间点群；晶体的光学能隙为1.1398 eV,属于半导体材料；配合物晶体热稳定性较好,骨架在317℃以下可以稳定存在.

The boracic poly-aluminum-ferric-silicate (B-PSAF) coagulant was prepared by water solution co-polymerization method, which was synthesized from sodium silicate, aluminum sulfate, ferric chloride and sodium borate. In addition, the best molar ratio of boron and silicon was determined by single factor process. The micro-morphology and structure of B-PSAF were studied by scanning electronic microscope (SEM) and Fourier transform infrared spectrum (FT-IR). It has been studied the operation of B-PSAF as the flocculating agent, the dosage and its effects on the flocculability. Experiments show that B-PSAF is a good effective flocculant, which can be used to treat alkaline dyeing wastewater and it has the features of less consumption, rapid coagulation and high removal rate of CODCr.