Observation of Non‐FCC Copper in Alkynyl‐Protected Cu53 Nanoclusters

The only feasible access to non‐face‐centered cubic (FCC) copper was by physical vapor deposition under high vacuum. Now, non‐FCC copper is observed in a series of alkynyl‐protected Cu₅₃ nanoclusters (NCs) obtained from solution‐phase synthesis. Determined by single‐crystal X‐ray crystallography, the structures of Cu₅₃(C≡CPhPh)₉(dppp)₆Cl₃(NO₃)₉ and its two derivatives reveal an ABABC stacking sequence involving 41 Cu atoms. It can be regarded as a mixed FCC and HCP structure, which gives strong evidence that Cu can be arranged in non‐FCC lattice at ambient conditions when proper ligands are provided. Characterization methods including X‐ray absorption fine structure, XPS, ESI‐MS, UV/Vis, Auger spectroscopy, and DFT calculations were carried out. Cu^II was shown to successively coordinate with introduced ligands and changed to Cu^I after bonding with phosphine. The following addition of NaBH₄ and the aging step further reduced it to the Cu₅₃ NC.     

自然灾害区域疏散的预警优化模型研究

在可预知的灾害来临前,交通堵塞问题是影响应急疏散效率的主要因素。在灾前防御阶段,有策略的发布预警消息可以使疏散更加有秩序的进行,从而提高疏散效率。本文为区域应急疏散预案构建了应急疏散预警发布研究框架,首先建立了避难点分配模型,将其结果代入到疏散预警模型,来优化特定地区预警发布时间和类型。其中,预警模型加入了时间成分,构建成了多时段模型,并使用贪婪的启发式搜索过程求解非线性的公式。最后,通过算例分析了模型算法的应用范围及其可行性,并用模拟退火算法进行了计算,验证了本算法的有效性。本研究更改以往在同一时间通过全部渠道发布消息的方式,通过疏散预警信息的发布策略的优化,可以有效避免在区域内大规模人群同时出发所导致的交通拥堵现象,为政府制定科学的应急疏散预案提供理论和技术支持。     

用自组电位差计测干电池电动势和内阻

根据电压补偿原理，设计了自组电位差计的几种实验电路，用于测量干电池的电动势和内阻。     

Synthesis of graphene oxide-poly(2-hydroxyethyl methacrylate) composite by dispersion polymerization in supercritical CO2: adsorption behavior for the removal of organic dye

The use of a biocompatible and thermoresponsive polymer, poly(2-hydroxyethyl methacrylate) (PHEMA) grafted onto the surface of graphene oxide (GO) as an adsorbent for the removal of a cationic dye (methylene blue [MB]) from an aqueous solution is examined in this work. GO–PHEMA forms a hydrogel in water thus overcoming the problem faced by carbon-based adsorbent materials during post-treatment (i.e., separation of adsorbent from the aqueous phase). The GO–PHEMA composite was synthesized using a green approach through dispersion polymerization in supercritical CO₂. The successful preparation of this composite was confirmed by a series of characterization techniques. The adsorption behavior of the composite toward MB such as the effect of the adsorbent dosage, pH, contact time, dye concentration, and recyclability were observed. In addition, the adsorption isotherm, kinetics and thermodynamics were investigated. According to the experimental data, the adsorption parameters were found to fit well into the Freundlich adsorption isotherm with a correlation coefficient of 0.975 and a maximum predicted adsorption capacity of 39.41 mg g^?1 at 25 °C. The adsorption kinetics studies showed that the adsorption behavior followed a pseudo-second-order reaction. On the other hand, the thermodynamics studies showed that the adsorption of MB on GO–PHEMA composite followed spontaneous and endothermic adsorption process with an efficient adsorption temperature at 45 °C. The experimental results also showed that the GO–PHEMA composite could remove 99.8% of the dye in 45 min. Therefore, GO–PHEMA composite is a favorable green adsorbent for environmental applications.     

Synthesis,Crystal Structures and Luminescent Properties of Terbium,Neodymium and Yttrium Complexes with a New Amide Type Ligand

Solid complexes of terbium, neodymium and yttrium nitrates with an amide type ligand, N‐benzyl‐2‐(benzyloxy)benzamide ( L ) have been prepared in ethyl acetate and characterized by elemental analysis and IR spectroscopy. The crystal and molecular structures of the complexes Tb L ₃(NO₃)₃, Nd L ₃(NO₃)₃ and Y L ₃(NO₃)₃ have been determined by single crystal X‐ray diffraction. The crystal structures of the complexes are similar. The structures show that the crystal consists of two similar but independent molecules in the asymmetric unit and the metal ion is coordinated toward nine donor atoms, three of which belong to the oxygen atoms of three monodentate ligands and six oxygen atoms from three bidentate nitrates. Furthermore, the RE L ₃(NO)₃ complex units are linked by the intermolecular hydrogen bonds to form a three‐dimensional net. At the same time, the luminescent properties of the ligand and the complex Tb L ₃(NO₃)₃ were studied as well.     

合成6-氟-2-甲基茚酮的新方法

对氟氯苄与甲基丙二酸二乙酯经缩合、碱性水解、脱羧、SOCl2酰氯化、分子内Friedel-Crafts酰基化等反应合成非甾体抗炎药舒林酸的中间体--6-氟-2-甲基茚酮,总收率57.0%,其结构经1H NMR,GC-MS和元素分析表征.     

Ni2P@CoP3核壳纳米球的制备、表征及其用于超级电容器性能

利用水热技术先后获得Ni纳米球和Ni@Co(OH)_2海胆状核壳纳米球前驱体,通过高温煅烧法获得NiO@CoO核壳纳米球,再以次磷酸钠为原料,通过高温磷化法最终获得Ni_2P@CoP_3核壳纳米球。利用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、高角度环形暗场像扫描透射电子显微镜(HAADF-STEM)、X射线粉末衍射仪(XRD)、能谱仪(EDS)及X射线光电子能谱(XPS)对产物的形貌、结构和组成进行表征。采用循环伏安(CV)、恒电流充放电(GCD)以及循环稳定性实验探索了电极材料的电化学性能。结果表明,Ni_2P@CoP_3核壳纳米球的直径约为400 nm,由六方系Ni_2P纳米核和立方相CoP_3纳米壳构成。相比单纯的Ni_2P或CoP_3纳米球,Ni_2P@CoP_3核壳纳米球发挥了复合结构的协同效应,更加有利于电解液的质子传递,促进了赝电容反应,表现出更高的比容量、稳定性和更长的循环寿命。     

Synthesis,Characterization, and Magnetic Properties of Iron Complexes Bearing Polydentate Nitrogen Ligands

Four iron complexes {[PhN(CH₂)₂NH(SiMe₃)]₄FeLi · Et₂O ( 1 ), [PhN(CH₂)₃NSiMe₃]₂FeLi(Et₂O) ( 2 ), [PhN(CH₂)₂NCH(Ph)NSiMe₃]₂FeLi(Et₂O)₂ ( 3 ), and [PhN(CH₂)₃NCH(Ph)NSiMe₃]₂FeLi(Et₂O)₂ ( 4 )} with polydentate nitrogen ligands were synthesized and structurally characterized by X‐ray crystallography. The X‐ray structures of complexes 1 – 4 show that they crystallize in three different systems. The magnetic properties of 1 – 4 were investigated. The magnetization trends of magnetic field intensity show the curves of Type‐S, illustrating those complexes 1 – 4 are superparamagnetic.     

Organocatalytic Highly Enantioselective Substitution of 3‐(1‐Tosylalkyl)indoles with Oxindoles Enables the First Total Synthesis of (+)‐Trigolutes B

A highly enantioselective organocatalytic substitution of 3‐(1‐tosylalkyl)indoles with oxindoles has been established by using chiral bifunctional organocatalysts, providing an efficient entry to multiply functionalized 3,3′‐disubstituted oxindoles, and was exploited as the key step to enable the first asymmetric total synthesis of optically pure (+)‐trigolutes B to be accomplished in a concise manner, within seven steps with an 18 % overall yield.     

Syntheses,Structures, and Catalytic Properties of Two 2D Manganese(II) Coordination Polymers Containing Flexible Bis(benzimidazole) Ligands

Two Mn^II coordination polymers based on the flexible bis(benzimidazole) and dicarboxylic acids, namely, [Mn(L1)(bpdc)(H₂O)_0.5]_n ( 1 ) and [Mn(L2)(Htbi)₂]_n ( 2 ) [L1 = 1,4‐bis(5,6‐dimethylbenzimidazol‐1‐ylmethyl)benzene, H₂bpdc = 4,4′‐biphenyldicarboxylic acid, L2 = 1,4‐bis(5,6‐dimethylbenzimidazole)butane, H₂tbi = 5‐tert‐butyl isophthalic acid] were hydrothermally synthesized and characterized by elemental analysis, IR spectroscopy, as well as single‐crystal X‐ray diffraction. Both of the complexes crystallize in the triclinic P$\bar{1}$ space group and present distorted octahedral configurations. Complex 1 possesses a 2D binodal (3,5)‐connected 3,5L2 network with the point symbol of (4².6⁷.8)(4².6), whereas 2 features a 2D uninodal 3‐connected hcb topology and the Schläfli symbol is (6³). Complexes 1 and 2 ultimately are extended into 3D supramolecular framework via π–π stacking and O–H ··· O hydrogen bonding interaction, respectively. Moreover, both of the complexes manifest excellent catalytic activities for the degradation of Congo red.