New approach to environmentally benign epoxidation: the solid-phase-system using urea–H2O2 and recyclable dodecatungstate on apatite

On the basis of new concept using a solid disperse phase we have developed an efficient catalytic solid-phase-system for epoxidations of alkenes using urea–hydrogen peroxide (urea–H₂O₂) complex and cetylpyridinium dodecatungstate ((CetylPy)₁₀[H₂W₁₂O₄₂]) catalyst on fluorapatite (FAp). The recovered solid catalyst phase was reused to keep the catalytic activity after several times. In the conceptual idea it is a key point that in situ solid-phase-activation of the catalyst with urea–H₂O₂ proceeds to form microcrystals of the active species dispersed on the solid phase. The dispersion of the catalyst on FAp in the case of tungstic acid (H₂WO₄) was suggested by EPMA analysis. We proposed the peroxo type of species keeping the parent polyoxometalate framework as novel active species from FT-IR spectroscopic studies. FAp phase plays important roles of dispersing the active species on its surface to have high catalytic activity and of stabilizing the active species to lead to high reusability.     

Advances in Catalyst Systems for the Asymmetric Hydrogenation and Transfer Hydrogenation of Ketones

Hydrogenation of prochiral ketones using chiral transition-metal catalysts represents the cleanest way to access enantiomerically enriched secondary alcohols, which are important building blocks in fine chemicals synthesis. Despite excellent activity, selectivity and compatibility of metal complexes with variety of functional groups, no universal catalysts exist. In this article we summarize the advances in catalyst systems for the asymmetric homogenous and heterogenous hydrogenation of ketones that have been made in past decade. The development of catalysts is oriented in reaching as high as activity with low catalyst loadings, using “greener’’ conditions, and ensuring good recyclability of catalysts. Even though ruthenium complexes represent the largest part of the catalysts, other metals rapidly penetrate this field.     

Lego architecture: Research on a temporary building design method for post-disaster emergency

Disasters are becoming the norm in this world, which also poses challenges to architects. Many needs to build temporary buildings may occur at the same time randomly around all over the world. Constructing an efficient and economical solution is the motivation of this research. Through a comprehensive review of all past related researches and architectural practices, “convenience” and “recyclability” have been identified as two important features of temporary buildings in the post-pandemic era. In this article, we carry on a novel research of discrete architecture. Based on the design paradigm of discrete architecture, this research uses the three main components of S/U/P to develop a Lego Architecture design method by combining with the Grasshopper plug-in under the Rhino platform to write a program that automatically generates the target plan. Then, a typical design scheme for physical construction verification and structural optimization is selected to ensure landing and safety. Originating from the thinking of productization, this research attempts to package the design methods and related knowledge into a systematic solution, relying on an open construction system framework to achieve a rapid, simple and safe construction of temporary buildings after disasters.     

Efficient recyclable organic solar cells on cellulose nanocrystal substrates with a conducting polymer top electrode deposited by film-transfer lamination

We report on efficient solar cells on recyclable cellulose nanocrystal (CNC) substrates with a new device structure wherein polyethylenimine-modified Ag is used as the bottom electron-collecting electrode and high-conductivity poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS, PH1000) is used as the semitransparent top hole-collecting electrode. The PEDOT:PSS top electrode is deposited by a film-transfer lamination technique. This dry process avoids swelling damage to the CNC substrate, which is observed when PEDOT:PSS is directly spin-coated from an aqueous solution. Solar cells on recyclable CNC substrates exhibit a maximum power conversion efficiency of 4.0% with a large fill factor of 0.64 ± 0.02 when illuminated through the top semitransparent PEDOT:PSS electrode. The performance of solar cells on CNC substrates is comparable to that of reference solar cells on polyethersulfone substrates.     

木之建构——关于国际当代木构建筑的发展

当今国际木构建筑的新发展要求我们对世界木建构文化重新认识。事实上，木材作为建材的许多优点我们并没有认识清楚，国际上，尤其是欧洲当代木构建筑的新发展正是以这种思想为基础的，欧洲的木构建筑传统实际上也是很深厚的，并且分布很广，经过社会和理论上的准备，一些具有先进意识的建筑大师们或功地探索了当代木构建筑的发展，主要集中在欧洲的阿尔卑斯山地区和北欧地区。我们在接受潮流影响的同时，有必要理解木建构文化在人类不同文明历史发展阶段的意义。尤其是在现阶段作为后工业文明阶段的木建构文化的特性，以及该建筑潮流的建造规律和造型表现力。     

新型玻璃防霉隔离粉回收的实践探讨

面向循环经济的可回收新型玻璃防霉隔离粉,其配方以隔离树脂为基本骨架,加入流动促进剂,对无机酸和有机酸进行改性处理。对原片玻璃不仅有优良的隔离作用,而且对玻璃表面有非常好的防腐蚀作用,进一步深入研究了与之配套的玻璃防霉隔离粉回收工艺。     

Synthesis of recyclable catalyst-sorbent Fe/CMK-3 for dry oxidation of phenol

The magnetic mesoporous material Fe/CMK-3 acting as a catalyst-sorbent was synthesized by using ordered mesoporous carbon CMK-3 as the supporter, Fe(NO₃)₃ as the iron source, and glycol as the reducing agent. The samples synthesized were characterized by powder X-ray diffraction (XRD), N₂ adsorption-desorption, scanning electron microscope (SEM) and transmission electron microscopy (TEM). The results show that the prepared Fe/CMK-3 preserved the ordered mesoporous structure of CMK-3, and magnetic species was mainly Fe₃O₄, which was dispersed inside channels of CMK-3 as nanoparticles with the diameter of around 10 nm. The adsorption and catalytic dry oxidation efficiency of the prepared Fe/CMK-3 were determined. The results also show that Fe/CMK-3 had good adsorption performance of phenol in aqueous solution and could be easily separated from water and recycled due to its ferromagnetic nature. Iron oxides supported on CMK-3 were excellent catalysts for dry oxidation of phenol. After 15 adsorption-catalytic oxidation cycles, the phenol adsorption capacity of Fe/CMK-3 only decreased a little, suggesting the good practicality. Combined thermogravimetry and mass spectrum (TG-MS) instrument was used to investigate the catalytic oxidation of phenol on Fe/CMK-3 and the ignition characteristics of the catalyst-sorbent. The supported Fe₃O₄ was found to be not only the magnetic component but also the active catalyst for the oxidation of phenol. The adsorbed phenol could be oxidized into CO₂ and H₂O at 220 °C at which no obvious phenol desorption or CMK-3 ignition occurred.     

Vanadomolybdophosphoric acid/fluorapatite solid-phase system for aerobic oxidative dehydrogenation

We developed a solid-phase-oxidation-system using FAp disperse phase and vanadomolybdophosphoric acid (H_3+nPV_nMo_12−nO₄₀: PVn) catalysts with molecular oxygen as a new green reaction system. The PV4/FAp system was an efficient and recyclable solid–catalyst system for solvent-free oxidative dehydrogenation of -terpinene to p-cymene under 1 atm of molecular oxygen at 50 °C. The catalytic activity in the solid-phase system was comparable to that in the homogeneous liquid-phase system with acetonitrile. Even if under air conditions, PV4/FAp system was able to promote the catalytic dehydrogenation at room temperature sufficiently.     

固载型维生素B1模拟物的合成与催化安息香缩合反应研究

以阴离子交换树脂氯球为载体,把4-甲基-5-羟乙基噻唑固载到高分子载体上制成一种VB1模拟物作为安息香缩合催化剂,考察了溶胀方式、温度对4-甲基-5-羟乙基噻唑固载量的影响,探索了固载型VB1模拟物催化安息香缩合反应的最佳反应条件是：三乙胺为辅助催化剂,80℃下反应90min,收率74．7％,催化剂过滤回收可循环套用。     

Tough,transparent, biocompatible and stretchable thermoplastic copolymer with high stability and processability for soft electronics

Materials with a variety of required properties, including stretchability, toughness, optical transparency, biocompatibility, processability, and recyclability are in great demand for soft electronics. Creation of such materials, however, has been hampered due to the challenges of balancing these properties. Herein, we report intrinsically stretchable thermoplastic copolymers with a random sequence of hard and soft domains in the polyimide backbone in which their superior traits are harnessed to enable the properties of the copolymer tunable and balanced. We obtained a tough and stretchable copolymer with high optical transparency, biocompatibility, thermal and chemical stability, and low water vapor transmission rate. In addition, the polymer is recyclable and shows excellent processability, allowing for the fabrication of fibers, thin films, and molded parts for soft electronics. Furthermore, the utility of the copolymer was successfully demonstrated for a wearable temperature sensor on the stretchable copolymer and a copolymer-based fully stretchable sweat collection patch, suggesting that they have great potential in soft electronics.