In this study, a zirconium phosphonate, ZrDP, with a rigid multi-nitrogen heterocycle and hierarchical pores in its framework was used to construct a ZnIn2S4@ZrDP composite by in situ surface loading of ZnIn2S4. The multi-nitrogen heterocycle in the carrier promoted light absorption and facilitated energy transfer to ZnIn2S4, thereby accelerating the separation of photogenerated electron-hole pairs in the semiconductor. ZnIn2S4 was uniformly dispersed on the surface of ZrDP, which increased the negative charge density of the composite, enhanced its adsorption capacity toward cationic species and promoted light absorption. Compared with ZnIn2S4, ZnIn2S4@ZrDP exhibited higher catalytic activity and good recyclability in the photodegradation reactions of some cationic dyes, such as methylene blue, rhodamine B, methyl orange and malachite green, and rhodamine B could be completely degraded under mild conditions. (center dot)O2- and h+ produced in the reaction were identified as the main reactive species responsible for the oxidation process.

ZnIn 2 S 4 was prepared and loaded on the surface of hierarchical porous zirconium phosphonate with a rigid multi-nitrogen heterocycle in the framework. The composite was found to exhibit high catalytic activity in the photodegradation of cationic dyes.

Utilizing a ligand-truncation strategy, a hierarchically porous structure was engineered within MOF-808, designated as HP-MOF-808. Furthermore, Mg(OMe)2 2 doping yielded HP-MOF-808@Mg(OMe)2, 2 , materials with both hierarchical porosity and basic character, for decontamination of two types of toxic chemical agents in nonbuffered solutions. In aqueous solution, the HP-808-2 exhibited decontamination rate constants for dimethyl4-nitrophenyl phosphate (DMNP) and the nerve agent soman (GD) that were 3.13 and 1.98 times higher than MOF-808, respectively. The decontamination half-lives of HP-808-2@Mg(OMe)2 2 1:2 for DMNP and GD were further reduced by 13.87 and 36.82 times compared to HP-808-2. The material retains its decontamination efficacy for DMNP even after 60-days exposure in air and maintains structural integrity in solvents devoid of labile hydrogen for at least 24 h. In methanol, HP-808-2@Mg(OMe)2 2 achieved 100% DMNP decontamination in 25 min, outperforming HP-808-2 at 31.8%, marking it as the fastest DMNP decontamination material in methanol. Theoretical simulations confirmed the experimental findings, clearly demonstrating the energy changes during reactions with various nucleophiles and revealing the degradation process and mechanism of DMNP on the active sites of MOFs. Moreover, these materials rapidly degraded 2-chloroethyl ethyl sulfide (CEES) through hydrolysis, dehydrohalogenation, and heterolytic cleavage, demonstrating great potential for dual decontamination of toxic chemical agents in unbuffered systems.

A kind of composite catalyst TTFA@Co2+@ZrDP was prepared by coordination among Co2+,ZrDP(a kind of zirconium phosphonate with 1,4,7,10-tetraazaheterocyclic ring in skeleton)as carrier and TTFA(2-thiophene formyl trifluoroacetone)as chelating ligand.The catalytic activity of the composite was studied in the oxidation degradation reaction of safranin T in the presence of peroxymonosulfate as oxidant.The results indicate that the catalytic activity of TTFA@Co2+@ZrDP is closely related to its particle size,the content and dispersion of Co2+supported,and TTFA is found to promote the transfer of electrons during the catalytic reaction and enhance the catalytic ability of the Co2+.100%of Safranin T could be degraded by TTFA@Co2+@ZrDP under certain conditions in the presence of peroxymonosulfate and the catalyst has good reusability.

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.

Semiconductor quantum dots,composed of elements from groups Ⅱ-Ⅵ(CdSe,CdTe,CdS,ZnTe,ZnO),Ⅲ-Ⅴ(InAs,GaSb,InP)and Ⅳ(Si,Ge),are nanoscale particles attracting significant research interest.The focus of current studies lies predominantly on Ⅱ-Ⅵ group quantum dots like CdS,CdSe,and CdTe,known for their narrow band gaps and exceptional fluorescent properties intrinsically related to quantum size effects.In this study,a straightforward aqueous reflux method was employed,using thioglycolic acid as a stabilizer,and NaHTe as a Te precursor.Over a period of 3 h,CdTe semiconductor quantum dots of various colors were prepared,addressing and mitigating the issue of oxidation susceptibility during NaHTe transfer.The fluorescence luminescence properties of the product were meticulously analyzed,yielding a series of CdTe quantum dots with an impressive quantum efficiency of 48%.This experimental approach is notable for its simplicity,minimal reagent consumption,and distinct fluorescence characteristics,making it highly operable and replicable.It is well-suited for undergraduate education in inorganic chemistry,instrumental analysis,and comprehensive professional experiments.

TpFO-PA, a novel spherical hollow mesoporous polyamide, was firstly synthesized by the reaction among 1,3,5tris(4-aminophenyl)benzene (TAPB), furylamine and oxalyl chloride in using silica-gel nanoparticle as hard template, and the composite Cu(I)@TpFO-PA with high catalytic activities in C-N coupling reactions between (hetero)aryl bromide and (hetero)aryl amines under mild conditions was prepared basing on presence of N in the framework. A maximum activity of the catalyst with yield of C-N coupling product were about 311.9 g(product)/ molCu(I)& sdot;h and 95 % respectively, and the activity could be maintained at least 5 times after the catalyst was reused. The composite Cu(I)@TpFO-PA is a few heterogeneous catalysts reported in catalyzing coupling reaction between aromatic amines and brominated aromatic compounds.

A kind of new zirconium phosphonate material (named as ZrDP) with multilevel porous structure and high surface area (about 408.6 m2/g) was synthesized by the reaction between 1,4,7,10-Tetraazacyclododecane-1,4,7,10-tetrayl- tetrakis(methylphosphonic acid) (DOTMP) and zirconium dichloride oxide octahydrate. Microporous structure (diameter about 0.64 nm) from 1,4,7,10- Tetraazacyclododecane in DOTMP and structural pores with diameter about 1.68 nm were found in the material. A series of metal coordination structures were synthesized basing on the coordination skeleton in ZrDP and Cu@ZrDP (Cu2+ ions coordinated with N atoms in ZrDP) exhibited high catalytic activity in the selective oxidation reaction from benzyl alcohol to benzaldehyde with 90.2% selectivity.

Carbon materials derived from metal-organic frameworks (MOFs) retain the precursor's regular unique morphology and net-like voids, which offers them the advantages of large specific surface area (SSA) and high capacitance for energy storage. In this paper, spherical amorphous porous carbon materials with hierarchical pores (DHTAC-2) were prepared using one-step carbonization of Al-MOF. The carbon has a large SSA (2666 m2 g-1) and a large pore volume (2.35 cm3 g-1). The obtained carbon (DHTAC-2) demonstrates an excellent specific capacitance (298.8 F g-1) at 1 A g-1 and capacitance retentions of 97.3 % and 98.0 % after 120,000 cycles at 50 A g-1 and 100 A g-1, respectively. In addition, Nitrogen-doped carbon (N-DHTAC) has increased pyridine-N, pyrrole-N and graphite-N content. The three types of N significantly improved its wettability, reversible pseu-docapacitance and conductivity, respectively, resulting in a superior capacitance (355.0 F g-1@1 A g-1) and enhanced energy density (17.7 Wh kg-1@350 W kg-1) of the assembled electric double layer capacitor (EDLC) device. The device exhibits an extremely low decline rate of 10.12 % over 10,000 cycles at 10 A g-1, verifying N-DHTAC material is a promising active material for supercapacitors.

A kind of new mesoporous hydroxyapatite (noted as mesoHA) with about 2.4 nm average porous diameter was successfully prepared by casting Ca2+ and H2PO4- ions on the inner channel surface of Si-MCM-41 and dissolving the Si-MCM-41 in alkali soluble, and the porous material was used as a pH-responsive platform to adsorb and release ciprofloxacin molecules. A maximum mass of 0.51 mg of ciprofloxacin (noted as Cip) was loaded on 1.00 mg of the host, and the release rate of the drug was found increasing with the acidic increase of the external solution environment (based on the stability of mesoHA) that simulated basic composition to human plasma. About 88.5% of Cip was released from the platform when environmental pH value was about 4.8, which provides a new method on utilizing antibiotics drugs efficiently, for the host mesoHA is friendly to human body.

侯氏制碱法是中学和大学一个非常重要的无机合成实验,但由于沉淀过程中的包夹和吸附,产物中含有一定量的NaCl杂质,给Na2CO3产率真实性带来一定的假象.本研究使用乙醇洗涤中间产物NaHCO3,实现终产物纯化.通过开展一系列单变量实验,探究了乙醇溶液洗涤NaHCO3去除NaCl的条件,比较了乙醇、甲醇、正丁醇、异丁醇为洗液对产物中NaCl的去除效果;探究了乙醇的回收率及回收的乙醇重复使用情况.在被选择的溶剂当中,甲醇的洗涤效果最好,其次是乙醇(甲醇>乙醇>正丁醇>异丁醇).在室温环境下,用浓度为90 wt.％的乙醇(m乙醇/m反应物=3:1)在3 min内浸润洗涤NaHCO3,经过一次洗涤后,终产物Na2CO3中NaCl杂质含量由11.23 wt.％降到0.12 wt.％.5次重复实验后,乙醇回收率达到87.90 wt.％.本研究结果为侯氏制碱法产物中氯化钠杂质去除难题提供了一个绿色、低成本的解决方案.

采用葡萄糖分子隔离法制备了形貌规整、粒径大约为 0.5 mm的硅胶微球,然后以合成的硅胶微球为载体、乙酸锌为锌源合成了ZnO@硅胶负载型复合催化剂,详细探究了紫外光条件下对藏红T的降解效果.实验发现,当采用相同量(10 mg)ZnO@硅胶催化剂与纯ZnO粒子(粒径大约为 100 nm)分别对藏红T进行催化降解40 min后,ZnO@硅胶催化剂的降解率(约为 91%)远高于纯氧化锌(约为 46%).并且发现负载的ZnO摩尔百分含量为 4.6%时,室温下 20 mg的ZnO@硅胶催化剂在紫外光照射下,40 min内可将 100 mL、10 mg/L的藏红T完全降解,其降解效果要高于目前文献报道的其他催化剂(包括负载型复合催化剂).

This study aimed to investigate the changes in self-esteem levels among Chinese adolescents from 1996 to 2019. In this cross-sectional historical study, 109 articles using the Rosenberg Self-esteem Scale (SES) were selected from three Chinese and five English databases. The results showed that: (1) The self-esteem level of Chinese adolescents was positively correlated with the period, indicating that the self-esteem of Chinese adolescents was gradually increasing. (2) The increase in self-esteem level of girls was higher than that of boys. (3) The increase in the self-esteem level of only child was higher than that of non-only child. (4) The self-esteem level of rural adolescents increased year by year. However, the self-esteem level of urban adolescents was not significantly correlated with the years. (5) The changes in macro social factors can significantly predict the upward trend of the self-esteem level of Chinese adolescents.

We have developed a fluorescent quantification strategy to evaluate the uniformity and the aggregation degree of inorganic particles in polymers. This proposed strategy has been successfully used for investigating the anti-aging behaviors of composites.

化学世界丰富多彩。认识多姿、多彩的材料形成过程，揭示产物生成的奥秘，通过对宏观化学现象的观察，推测产物生长的微观过程，增强学生对化学的学习兴趣，是化学实验教学的主要目的之一。本实验以“界面反应”为切入点，以多彩多姿分子聚集体为目标产物，通过自主设计的反应器，以多孔陶瓷砂芯为隔离层，利用渗透和扩散效应、表面张力及界面反应机理，在砂芯表面可控形成白色、蓝色、绿色、粉色等多彩中空纤维状及珊瑚礁状等多姿的分子聚集体。本科普实验方法安全、新颖、简单，现象明显，具有很高的观赏性，旨在达到在探索微观世界形成过程中发现化学无穷魅力，认识“美丽化学”“奇妙化学”的真实内涵，激发学生对化学学科学习热情之目的。

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.

In this work, we consider the Multi-Agent Pickup-and-Delivery (MAPD) problem, where agents constantly engage with new tasks and need to plan collision-free paths to execute them. To execute a task, an agent needs to visit a pair of goal locations, consisting of a pickup location and a delivery location. We propose two variants of an algorithm that assigns a sequence of tasks to each agent using the anytime algorithm Large Neighborhood Search (LNS) and plans paths using the Multi-Agent Path Finding (MAPF) algorithm Priority-Based Search (PBS). LNS-PBS is complete for well-formed MAPD instances, a realistic subclass of MAPD instances, and empirically more effective than the existing complete MAPD algorithm CENTRAL. LNS-wPBS provides no completeness guarantee but is empirically more efficient and stable than LNS-PBS. It scales to thousands of agents and thousands of tasks in a large warehouse and is empirically more effective than the existing scalable MAPD algorithm HBH+MLA*. LNS-PBS and LNS-wPBS also apply to a more general variant of MAPD, namely the Multi-Goal MAPD (MG-MAPD) problem, where tasks can have different numbers of goal locations.

分别以3-(三乙氧基硅基)丙基异氰酸酯、环己二胺、乙二胺、氨丙基三乙氧基硅烷、草酰氯为原料,通过分子间的加成反应和加成产物在微酸性环境中的水解反应,制备得到三种微形貌和结构差异的硅氧倍半聚合物.将二氯二茂锆(Cp2 ZrCl2)负载于合成的三种硅氧倍半聚合物表面,制备得到三种负载型茂金属催化剂.研究发现,上述三种负载型催化剂对乙烯均聚和乙烯与辛烯共聚均表现出较高的催化活性,尤其是Cp2 ZrCl2负载于螺旋状硅氧倍半聚合物(环己二胺加成并水解的产物)表面催化乙烯聚合产物(聚乙烯)的熔点达到139.2℃,系目前所报道的熔点较高的聚乙烯产品,显示出优异的工业应用价值.

Cp 2 ZrCl 2 , a kind of catalyst for olefin polymerization, was in-situ synthesized on the chain of N 1 ,N 2 -bis(2-(triethoxysilyl)ethyl)oxalamide connected on the surface of spherical silica gel, and the composite catalyst was found to have high catalytic activities in ethylene polymerization (8.46 × 10 6 gPE/Mol(Zr)·h) and in copolymerization between ethylene and 1-octene (9.08 × 10 5 gPE/Mol(Zr)·h) by using methylaluminoxane (MAO) as cocatalyst. The polyethylene synthesized was found with narrow molecular weight distribution (Mw/Mn = 3.33) than the products produced under the existence of Cp 2 ZrCl 2 only supported on the modified and unmodified silica gel surface. The result offers an important method in solving defects of the catalyst that was caused by falling off and crowding on the carrier.

alpha-Ni(OH)(2) nanoparticles with 5 nm average diameter were prepared under the existence of glucose in water solution, and the size of alpha-Ni(OH)(2) nanoparticles was found to be controlled by the concentration of glucose. A possible mechanism of the preparation process was proposed. When the synthesis was processed without existence of the glucose, beta-Ni(OH)(2) was obtained. The super-small alpha-Ni(OH)(2) nanoparticles showed strong adsorption ability to Li+ ions when pH value of the solution was about 7.0 under room temperature. Maximum adsorption capacity of the super-small alpha-Ni(OH)(2) nanoparticles to Li+ was about 214 mg.g(-1); however, the beta-Ni(OH)(2) with diameter above 1.0 mu m was low than 30 mg.g(-1). Freundlich equation analysis and SEM images of the adsorption products indicate multilayers' adsorption process to Li+ of alpha-Ni(OH)(2) nanoparticles.