Zeolite-Encaged Isolated Palladium Redox Centers toward Sustainable Wacker-Type Oxidations.

The selective oxidation of olefins by molecular oxygen holds great importance in the chemical industry due to its remarkable adaptability in constructing carbonyl compounds. Classical homogeneous Wacker oxidation with a complex system of PdCl-CuCl-HO is currently employed in the industrial production of acetaldehyde, which suffers from several key drawbacks. The development of alternative heterogeneous catalytic systems for Wacker-type oxidations has been hotly pursued for decades.

Ni electrodes with 3D-ordered surface structures for boosting bubble releasing toward high current density alkaline water splitting.

The performance of alkaline water electrolysis (AWE) at high current densities is limited by gas bubble generation on the surface of electrodes, which covers active sites and blocks mass transfer, resulting in lower AWE efficiency. Here, we utilize electro-etching to construct Ni electrodes with hydrophilic and aerophobic surfaces to improve the efficiency of AWE. Ni atoms on the Ni surface can be exfoliated orderly along the crystal planes by electro-etching, forming micro-nano-scale rough surfaces with multiple crystal planes exposed.

Direct Propylene Epoxidation with Molecular Oxygen over Cobalt-Containing Zeolites.

Direct propylene epoxidation with molecular oxygen is a dream reaction with 100% atom economy, but aerobic epoxidation is challenging because of the undesired over-oxidation and isomerization of epoxide products. Herein, we report the construction of uniform cobalt ions confined in faujasite zeolite, namely, Co@Y, which exhibits unprecedented catalytic performance in the aerobic epoxidation of propylene. Propylene conversion of 24.

Effect of mesenchymal stem cells on biomechanics of stress fracture rabbit model after healing.

This study aimed to investigate the effects of mesenchymal stem cells (MSCs) on the biomechanics of stress-fractured rabbits after healing. Twenty-Four New Zealand white rabbits were selected to establish a stress fracture model. All rabbits were randomly divided into model group and MSCs group, and another 12 rabbits were chosen as control group.

Relay protection system of transmission line based on AI.

With the development of modern power systems, higher requirements are imposed on relay protection technology. Traditional relay protection and fault diagnosis technologies have been unable to meet the requirements of the continuous development of power systems, and relay protection systems based on artificial intelligence(AI) technology have received increasing attention. Therefore, this document first analyses the weaknesses of traditional broadcast line protection and uses the adaptability and self-learning of artificial intelligence(AI); to propose the concept of protection of a relay line based on AI.

The necessity of treating asymptomatic bacteriuria with antibiotics in the perioperative period of joint arthroplasty: a metaanalysis.

Background/aim: Oral antibiotics are usually used to treat asymptomatic bacteriuria during the perioperative period of joint replacement. However, there is no unified conclusion as to whether asymptomatic bacteriuria causes infection around joint prostheses, and the efficacy of antibiotics is unknown.

Materials And Methods: We systematically searched PubMed, CNKI, Ovid, Cochrane Library, EMBASE, manual research, and references of relevant articles up to January 1, 2020, to identify and compare observational studies.

Ion exchange collaborating coordination substitution: More efficient Cr(VI) removal performance of a water-stable Cu-MOF material.

An unusual water-stable cationic metal-organic framework {[Cu(L)(bpe)(HO)](NO)•(HO)} (1) (HL = bis(3,5-dicarboxypyridinium)-p-xylylene) was synthesized, which was developed into an effective capture material for removal chromate from water. The results show that this material efficiently traps HCrO pollutant ions via single-crystal to single-crystal (SCSC) coordination substitution process. The HCrO uptake capacity of 1 is high to 190 mg/g.

[Regulation effects of irrigation methods and nitrogen application on soil water, nitrate, and wheat growth and development].

Field experiments were conducted to examine the effects of flooding irrigation (FI), micro-sprinkler irrigation (SI), drip irrigation (DI), combined with nitrogen application (N:157.5 kg·hm as basal, 67.5 kg·hm top dressed at jointing stage; N:157.

Efficient Catalytic Performance for Acylation-Nazarov Cyclization Based on an Unusual Postsynthetic Oxidization Strategy in a Fe(II)-MOF.

A rare example of SC-SC triggered by Cu heterogeneous oxidation was demonstrated in a Fe(II)-based MOF {[Fe(L)(HO)]·3HO} (1), which occurred a slow conversion into an oxidized MOF 2 ({[Fe(L)(HO)]·3(OH)} ) with retention of single crystallinity. The Fe → Fe progress of the reaction oxidation was proved by single crystal XRD, PXRD, XPS, Fe Mössbauer spectroscopy, and UV-vis. We used 1 and 2 as catalysts to catalyze the tandem Nazarov cyclization, and the results show that acylation products were only harvested when 1 was a catalyst, while the oxidized transformer 2 lead mainly to the formation of cyclization products under identical conditions.

[Effects of deep plowing time during the fallow period on water storage-consumption characteristics and wheat yield in dry-land soil.].

Through a three-year field trail, effects of deep plowing time during the fallow period on water storage of 0-200 cm soil before sowing, water consumption of growth period, and growth and development of wheat were investigated. Results demonstrated that soil water storage (SWS) of the fallow period was influenced by deep plowing time, precipitation, and rainfall distribution. With postponing the time of deep plowing in the fallow period, SWS was increased firstly, and then decreased.