In-situ self-reconstruction of Ni–Fe–Al hybrid phosphides nanosheet arrays enables efficient oxygen evolution in alkaline

Developing efficient oxygen evolution reaction (OER) electrocatalysts with earth-abundant elements is very important for sustainable H₂ generation via electrochemical water splitting. Here we design a crystalline-amorphous Ni–Fe–Al hybrid phosphides nanosheet arrays grown on NiFe foam for efficient OER application. Dynamic surface reorganization of phosphides at anodic/cathodic polarizations is probed by in situ Raman spectroscopy. The reconstructed amorphous Ni(Fe)OOH species are determined as the active phases that facilitate the OER process. This unique electrode shows highly catalytic activity toward water oxidation, achieving the current densities of 10 and 100 mA cm^?2 at 181 and 214 mV in 1 M KOH, respectively. Meanwhile, it also exhibits excellent stability at a large current density of 100 mA cm^?2 for over 60 h. This work reveals the dynamic structural transformation of pre-catalyst in realistic conditions and highlights the important role of oxyhydroxides as real reactive species in OER process with high activity.     

Ti3C2Tx-foam as free-standing electrode for supercapacitor with improved electrochemical performance

To prevent restacking of the Ti₃C₂T_x layers, the Ti₃C₂T_x-foam has been successfully synthesized through thermal treatment of Ti₃C₂T_x-film with the hydrazine monohydrate. The interconnected porous structure of Ti₃C₂T_x-foam could effectively reduce the restacking of the Ti₃C₂T_x sheets and shorten the diffusion path of ions and accelerate the intercalation/de-intercalation of ions. The Ti₃C₂T_x-foam-80 used as free-standing electrode achieves a high areal capacitance of 271.2 mF/cm² (122.7?F/g) at a scan rate of 5?mV/s in 1?M KOH electrolyte. It also exhibited a high capability rate of 65.5% from 5?mV/s to 100?mV/s and good cycle life with 88.7% retention of its initial after 10,000 cycles at a scan rate of 50?mV/s.     

1D ZnFe2O4 nanorods coupled with plasmonic Ag,Ag2S nanoparticles and Co-Pi cocatalysts for efficient photoelectrochemical water splitting

Improving the absorption of visible light, accelerating the separation of carries and reducing the recombination of electron-hole pairs are critical to enhance photoelectrochemical (PEC) performance of ZnFe₂O₄. Herein, the ZnFe₂O₄/Ag/Ag₂S films are firstly prepared with a photocurrent density of 0.91 mA/cm² at 1.23 V vs. RHE, which is 9.10 times higher than that of pristine ZnFe₂O₄ (0.10 mA/cm² at 1.23 V vs. RHE). On the basis, Co-Pi cocatalyst is deposited on ZnFe₂O₄/Ag/Ag₂S to further optimize PEC performance of ZnFe₂O₄, the photocurrent density of ZnFe₂O₄/Ag/Ag₂S/Co-Pi is 1.18 mA/cm² at 1.23 V vs. RHE. The improved PEC performance of ZnFe₂O₄/Ag/Ag₂S/Co-Pi films could be attributed to: (i) fast transmission of electron-hole pairs owing to 1D ZnFe₂O₄ NRs; (ii) surface plasmon resonance (SPR) effect of Ag nanoparticles; (ⅲ) visible light absorption is improved by sensitization of Ag₂S nanoparticles; (ⅳ) Co-Pi cocatalyst decreases the recombination of electron-hole pairs by capturing holes. This work provides new insights for metal plasmas, sensitizers and cocatalysts synergistically modify photoanodes for efficient PEC water splitting.     

从《赞美》一诗看穆旦对自由诗学的实验

穆旦提出自由诗"新的抒情"的诗学主张,在他的早期代表诗歌<赞美>中有充分的体现.通过分析<赞美>诗的节奏韵律特色,从声与意相结合的诗学标准,总结穆旦所提出的"洪大节奏"创作原则,归纳出穆旦诗歌节奏的两个原则:循序渐进原则与对等原则.对穆旦<赞美>的分析,再一次地让人体味到诗人是以自己的方式写自由诗,用自己的"身体"和"头脑"来为自由诗正名.穆旦的诗歌"主要意义在于它的坚韧探索本身与探索所包含的深刻启迪性".     

“双一流”建设背景下硕士研究生培养模式改革探讨——以哈尔滨工业大学桥梁与隧道工程专业为例

基于十九大报告提出的"交通强国"战略需求，结合"双一流"建设的大背景，桥梁与隧道工程专业的硕士研究生培养质量尤为关键。通过对哈尔滨工业大学近10年来的硕士研究生培养状况及培养模式分析，并在培养年限、课程设置和生师比例等方面与其他几所典型高校相比较，提出桥梁与隧道工程专业硕士研究生培养模式的改革建议。学术型硕士与专业型硕士应分类培养，从课程设置、培养年限与考核要求等方面做到真正有所区分；优化课程设置，减少必修课学分，增加选修课学分，实现学生主动学习；继续加强过程管理，完善相应制度，做到导师与学生互相督促，并实行末位淘汰制度。     

TiO_(2-x)N_x/Sr_2MgSi_2O_7:Eu~(2+),Dy~(3+)复合材料制备及光催化性能

采用溶胶-凝胶法将TiO2-x N x包覆在长余辉光致发光材料(Sr2MgSi2O7∶Eu2+,Dy3+)表面制备得到TiO2-x N x/Sr2MgSi2O7∶Eu2+,Dy3+复合材料。利用X-射线衍射(XRD)、扫描电子显微镜(SEM)对TiO2-x N x/Sr2MgSi2O7∶Eu2+,Dy3+复合光催化材料的结构及表面形貌进行表征,并研究了TiO2-x N x/Sr2MgSi2O7∶Eu2+,Dy3+复合光催化材料对甲基橙溶液的降解性能。     

A 3D Porous Coordination Polymer from Tetrazole Ligand and Cd(II): Crystal Structure,Luminescent Property and Adsorption of Methanol and Water

An unusual tetrazole-based Cd(II) coordination polymer, [Cd(4-tzba)(H₂O)]_n (tzba = 4-(tetrazolyl)benzenecarboxylic acid) (1), was synthesized by hydrothermal reaction and structurally characterized by single-crystal X-ray diffraction. The structure of 1 contains distorted octahedral cadmium centers coordinated by four different tzba^2? ligands and a water molecule. All the tzba^2? ligands display coordination of type, μ4-κN1:κN3:κN4:κO1, O2, which connects four Cd(II) atoms to form an intricate 3-D network. There are three kinds of apertures in the structure of 1; two helical channels and a hexagonal aperture are observed along different axes. Polymer 1 exhibits selective gas adsorption behavior for methanol, ethanol and water. In addition, 1 shows blue photoluminescence mainly arising from intraligand transitions of the aromatic rings in the tbza^2? ligand.     

New method in synthesis of nano uranyl(VI) Schiff base complexes: Characterization and electrochemical studies

This study presents a new method in synthesis of nano uranyl Schiff base complexes. In this method slow addition of dilute uranyl(VI) acetate solution to dilute Schiff base solution following the reflux for about 24 h, yields nano uranyl(VI) Schiff base complexes. Characterization of Schiff base ligands and nano uranyl complexes has been done using ¹H NMR, IR, UV–vis spectroscopy, elemental analysis. Schiff base ligands were synthesized by the condensation of one mole 3,4-diaminobenzophenone and two moles salicylaldehyde or substituted salicylaldehyde (3-OMe, 4-OMe, 5-OMe, 5-Br, 5-Cl). The electrochemical properties of the uranyl(IV) complexes were investigated by cyclic voltammetry. A good correlation was observed between the oxidation potentials and the electron withdrawing character of the substituents on the Schiff base ligands, according to the following trend: 5-MeO < H < 5-Br ≈ 5-Cl. Also the effect of the position of the substituted groups of Schiff base on the anodic potentials is as follows: 5-OMe < 3-OMe < 4-OMe.