Cobalt phthalocyanine promoted copper catalysts toward enhanced electro reduction of CO_(2)to C_(2):Synergistic catalysis or tandem catalysis?

The activity and selectivity of electrocatalytic CO_(2)reduction reaction(CO_(2)RR)to C_(2)products on metal catalysts can be regulated by molecular surfactants.However,the mechanism behind it remains elusive and debatable.Herein,copper nanowires(Cu NWs)were fabricated and decorated with cobalt phthalocyanine(CoPc).The electronic interaction between the Cu NWs,CoPc,CO_(2) and CO_(2)RR intermediates were explored by density functional theory(DFT)calculations.It was found that the selectivity and activity of CO_(2)RR towards C_(2)products on Cu NWs were considerably enhanced from 35.2%to 69.9%by surface decoration of CoPc.DFT calculations revealed that CO_(2)RR can proceed in the interphase between Cu substrate and CoPc,and the CO_(2)RR intermediates could synergistically bond with both Cu and Co metal centre in CuNWs-CoPc,which favours the adsorption of CO_(2),CO and CO_(2)RR intermediates,thus reducing the free energy for CO-COcoupling towards C_(2)products.The synergistic interaction was further extended to phthalocyanine(Pc)and other metal phthalocyanine derivatives(MPc),where a relatively weaker synergistic interaction of COintermediates with MPc and Cu substrate and only a slight enhancement of CO_(2)RR towards C_(2) products were observed.This study demonstrates a synergistic catalysis pathway for CO_(2)RR,a novel perspective in interpreting the role of CoPc in enhancing the activity and selectivity of CO_(2)RR on Cu NWs,in contrast to the conventional tandem catalysis mechanism.

Nonlocal multi-target controlled controlled gate using Greenberger–Horne–Zeilinger channel and qutrit catalysis

We present a scheme for implementing locally a nonlocal N-target controlled–controlled gate with unit probability of success by harnessing two（N＋1）-qubit Greenberger–Horne–Zeilinger（GHZ） states as quantum channel and N qutrits as catalyser. The quantum network that implements this nonlocal（N＋2）-body gate is built entirely of local single-body and two-body gates, and has only（3N＋2） two-body gates. This result suggests that both the computational depth of quantum network and the quantum resources required to perform this nonlocal gate might be significantly reduced. This scheme can be generalized straightforwardly to implement a nonlocal N-target and M-control qubits gate.

Is a catalyst always beneficial in plasma catalysis? Insights from the many physical and chemical interactions

Plasma-catalytic dry reforming of CH_(4)(DRM) is promising to convert the greenhouse gasses CH_(4) and CO_(2) into value-added chemicals, thus simultaneously providing an alternative to fossil resources as feedstock for the chemical industry. However, while many experiments have been dedicated to plasma-catalytic DRM, there is no consensus yet in literature on the optimal choice of catalyst for targeted products,because the underlying mechanisms are far from understood. Indeed, plasma catalysis is very complex,as it encompasses various chemical and physical interactions between plasma and catalyst, which depend on many parameters. This complexity hampers the comparison of experimental results from different studies, which, in our opinion, is an important bottleneck in the further development of this promising research field. Hence, in this perspective paper, we describe the important physical and chemical effects that should be accounted for when designing plasma-catalytic experiments in general, high-lighting the need for standardized experimental setups, as well as careful documentation of packing properties and reaction conditions, to further advance this research field. On the other hand, many parameters also create many windows of opportunity for further optimizing plasma-catalytic systems.Finally, various experiments also reveal the lack of improvement in plasma catalysis compared to plasma-only, specifically for DRM, but the underlying mechanisms are unclear. Therefore, we present our newly developed coupled plasma-surface kinetics model for DRM, to provide more insight in the underlying reasons. Our model illustrates that transition metal catalysts can adversely affect plasmacatalytic DRM, if radicals dominate the plasma-catalyst interactions. Thus, we demonstrate that a good understanding of the plasma-catalyst interactions is crucial to avoiding conditions at which these interactions negatively affect the results, and we provide some recommendations for improvement. For instance, we believe that plasma-catalytic DRM may benefit more from higher reaction temperatures,at which vibrational excitation can enhance the surface reactions.

Operational feasibility study of stagnation pressure reaction control for a mid-caliber non-spinning projectile

Controlled,guided munitions can reduce dispersion in the shot,while providing the capability of engaging both stationary and maneuvering targets.The Netherlands Organisation for Applied Scientific Research has developed a fin-less control technology called Stagnation Pressure Reaction Control(SPRC)that takes stagnation pressure air and directs it sideways to control non-spinning projectiles.In a previous study,this technology was demonstrated at Mach 2 wind-tunnel conditions to achieve up to 1.5°controllable angle of incidence for a non-spinning,aerodynamically unstable projectile-like test object.In an operational scenario,the decelerating projectile will experience a decline in control force while the simultaneous forward shift of the center of pressure increases the need for control force.Furthermore,angles of incidence exceeding 1.5°will be experienced under realistic flight conditions,especially against maneuvering targets.This work addresses these challenges and presents an operational feasibility study for a practical application of SPRC in a non-spinning mid-caliber gun-launched projectile,using experiment data on control latency and force of the earlier study.It illustrates the combined effect of the control-and stability dynamics and underlines the potential of an SPRC projectile as a precisionoperation ammunition.This research revealed that SPRC technology can stabilize and control the hypothesized projectile in a direct fire scenario against stationary and maneuvering targets.

Nitrogen-Doped Hierarchical Heterostructured Aerophobic MoS_(x)/Ni_(3)S_(2)Nanowires by One-pot Synthesis:System Engineering and Synergistic Effect in Electrocatalysis of Hydrogen Evolution Reaction

Non-noble metal electrocatalysis has witnessed rapid and profound performance improvements owing to the emergence of advanced nanosynthetic techniques.Integration of these nanotechniques can lead to synergistic performance enhancement,but such system-engineering strategies are difficult to achieve because of the lack of effective synthesis method.We hereby demonstrate an integrated approach that combines most of the existing nanotechniques in a facile one-pot synthesis.Material characterization reveals that the product shows key features intended by techniques including morphological,structural,doping,heterointerface,and surface wetting engineering.The as-obtained nitrogen-doped hierarchical heterostructured MoS_(x)/Ni_(3)S_(2)nanowires show an overpotential that is only50 mV higher than commercial Pt/C for hydrogen evolution reaction over current densities from 10 to 150 mA cm^(-2).Correlations between the adopted nanotechniques and the electrochemical reaction rates are established by evaluating the impacts of individual techniques on the activation energy,pre-exponential factor,and transfer coefficient.This indepth analysis provides a full account of the synergistic effects and the overall improvement in electrocatalytic performance of hydrogen evolution reaction.This work manifests a generic strategy for multipurpose material design in non-noble metal electrocatalysis.

THE REACTION OF AROMATIC ALDEHYDES WITH p-NITROBENZYLLIBUTYLTELLURONIUM BROMIDE BY PHASE TRANSFER CATALYSIS

Under the condition of solid-liquid phase transfer catalysis, olefins were obtained by the reaction of p-nitrobenzyldibutyltelluronium bromide with aromatic aldehyde.Under the condition of liquid-liquid phase transfer catalysis,however,different products were obtained due to the reactivity of different bases or aldehydes.

Efficient oxidation of benzyl alcohol with heteropolytungstate as reaction-controlled phase-transfer catalyst

A series of heteropolytungstates has been synthesized and utilized as catalysts to catalyze oxidation of benzyl alcohol with aqueous hydrogen peroxide. The results indicated that three of these catalysts showed the properties of reaction-controlled phasetransfer catalysis, and they had excellent catalytic ability to the oxidation of benzyl alcohol. No other by-products were detected by gas chromatography. Once the hydrogen peroxide was consumed completely, the catalyst precipitated from solvent, and the results of the catalyst recycle showed that the catalyst had high stability.

KINETIC MODEL FOR DIFFUSION-CONTROLLED INTERMOLECULAR REACTION OF HOMOGENOUS POLYMER UNDER STEADY SHEAR

The kinetic model for diffusion-controlled intermolecular reaction of homogenous polymer under steady shear was theoretically studied. The classic formalism and the concept of conformation ellipsoids were integrated to get a new equation, which directly correlates the rate constant with shear rate. It was found that the rate constant is not monotonic with shear rate. The scale of rate constant is N^-1.5 （N is the length of chains）, which is in consistent with de Gennes＇s result.

A New Reaction-controlled Phase-transfer Catalyst System

A new reaction-controlled phase-transfer catalyst system was designed and synthesized. In this system, heteropolytungstate [C7H7N(CH3)3]9PW9O34 was used for catalytic epoxidation of cyclohexene with H2O2 as the oxidant. The conversion of H2O2 was 100% and the yield of cyclohexene oxide was 87.1% based on cyclohexene. Infrared spectra showed that both fresh catalyst and the recovered catalyst do have completely same absorption peak, indicating the structure of catalyst is very stability and can be recycled.

REACTIONS OF 1-ACETOXY ALLYLIC PHOSPHONATES UNDER PALLADIUM(0) CATALYSIS

l-Acetoxy allylic phosphonates rearrange regioselectively to γ-acetoxy α,β-unsaturated phosphonates under the catalysis of Pd(0). l-Acetoxy allylic phosphonates act as the precursors of phosphonatedπ-allylic cations in palladium(0) catalyzed reactions[1]. The reactions of l-acetoxy allylic phosphonates under palladium(0) catalysis with nucleophiles have been reported. 1-4 These reactions are highly regio- and stereoselective. We wish to report here the palladium(0) catalyzed reaction of l-acetoxy allylic phosphonates in the absence of a nucleophile.

Incidence of adverse reactions to COVID-19 vaccination:A meta-analysis of randomized controlled trials

Objective:To systematically evaluate the incidence of adverse reactions to coronavirus disease 2019(COVID-19)vaccination.Methods:We systematically searched PubMed,Embase,The Cochrane Library,Web of Science,CNKI,WanFang Data,and VIP Database from the inception of each database to August 31,2021.Randomized controlled clinical trials(RCTs)on the safety of different types of COVID-19 vaccines were retrieved and analyzed.A random or fixed-effects model was used with an odds ratio as the effect size.The quality of each reference was evaluated.The incidence of the adverse reactions of the placebo group and the vaccination group was compared.Heterogeneity and publication bias were taken care of by meta-regression and sub-group analyses.Results:A total of 13 articles were included,with 81287 subjects.Compared with the placebo group,the vaccination group showed a higher combined risk ratio(RR)of total adverse reactions(RR=1.67,95%CI:1.46-1.91,P<0.01),local adverse reactions(RR=2.86,95%CI:2.11-3.87,P<0.01),systemic adverse reactions(RR=1.25,95%CI:0.92-1.72,P=0.16),pain(RR=2.55,95%CI:1.75-3.70,P<0.01),swelling(RR=4.16,95%CI:1.71-10.17,P=0.002),fever(RR=2.34,95%CI:1.84-2.97,P<0.01),fatigue(RR=1.36,95%CI:1.32-1.41,P<0.01)and headache(RR=1.22,95%CI:1.18-1.26,P<0.01).The subgroup analysis showed the incidence of adverse reactions of the vaccination group after injection of the three COVID-19 vaccines(inactivated viral vaccines,mRNA vaccines and adenovirus vector vaccines)was higher than that of the placebo group,and the difference between the placebo group and the vaccination group in the mRNA vaccine subgroup and the adenovirus vector vaccine subgroup was statistically significant(P<0.01).The incidence of adverse reactions after injection of COVID-19 vaccine in subgroups of different ages was significantly higher than that in the placebo group(P<0.01).Conclusions:COVID-19 vaccines have a good safety,among which adenovirus vector vaccine has the highest incidence of adverse reactions.Both adolescents and adults vaccinated with novel coronavirus vaccine have a certain proportion of adverse reactions,but the symptoms are mild and can be relieved by themselves.Our meta-analysis can help boost global awareness of vaccine safety,promote mass vaccination,help build regional and global immune barriers and effectively curb the recurrency of COVID-19.

THE SOLID STATE CONTROLLED PHOTOCHEMICAL REACTION OF NITROBENZALDEHYDE WITH INDOLE

The solid state photochemical reaction of nitrobenzaldehyde with indole was investigated. Seven hey products were identified by IR, MS,;H HMR and elemental analysis.

REACTION OF ETHYL N-CYANOMETHYLBENZEHECARBOXIMIDATE WITH ALIPHATIC ALDEHYDES UNDER THE SOLID-LIQUID PHASE TRANSFER CATALYSIS

Ethyl N-cyanomethytbenzenecarboximidate reacted with aliphatic aldehydes under the solid-liquid PTC condition to gire a-ethoxyphenylmethylene- aminoacrylonitrile derivatives and oxazoline derivatives.It is a convenient and new method for synthesis of β,β'-dihyroxy-a-amino acids by hydrolysis of the oxazoline derivatives.

STUDIES ON THE REACTION OF SULFUR,SELENIUM AND TELLURIUM WITH SODIUM HYDROXIDE UNDER PHASE TRANSFER CATALYSIS(Ⅱ).A CONVENIENT METHOD FOR THE SYNTHESIS OF BI(ACYL)DISULFIDES

A simple and general method for the synthesis of bi(acyl)disulfides is reported.Sulfur is allowed to react with sodium hydroxide to give sodium disulfide at 65℃ under PTC,which can react with acyl halides to afford bi(acyl)disulfides in good to excellent isolated yields.The effects of solvents and phase transfer catalysts are discussed.

Heteropolymolybdate as a New Reaction-controlled Phase-transfer Catalyst for Efficient Alcohol Oxidation with Hydrogen Peroxide

A new catalytic process for the synthesis of aldehyde from alcohol by oxidation with H202 with high selectivity, was studied. In this system, heteropolymolybdate [C7H7N（CH3）3]3 {PO4[MoO（O2）2]4} was utilized as the reaction-controlled phase-transfer catalyst to catalyze oxidation of benzyl and aliphatic alcohols. The molar ratio of H2O2 and alcohol was 0.75, no other by-products were detected by gas chromatography, the results of oxidation reaction indicated that the catalyst has high activity and stability.

Light-Controlled Chemical Reaction Pathways in Disulfide-Based Nonequilibrium Systems

Pathway selection in a complex chemical reaction network(CRN)enables organisms to adapt,evolve,and even learn in response to changing environments.Inspired by this,herein we report an artificial system,where light signal was used to manipulate the reaction pathways in a disulfide-based nonequilibrium CRN.By changing the photon energy and irradiation window,the anion or new radical-mediated pathways were selectively triggered,resulting in a user-defined evolution pathway.Additional photodissipative cycles were achieved by UV(365 nm)irradiation,increasing the total number of reactions from 3 to 7.The emerging pathway selection of the CRN is accurately predictable and controllable even in complex organo-hydrogel materials.We demonstrate up to five-state autonomous sol-gel transitions and the formation of fuel-driven dissipative organo-hydrogel through both chemical and light input.This work represents a new approach to allowing CRNs to communicate with the environment that can be used in the development of materials with lifelike behaviors.

Reentry Attitude Tracking Control for Hypersonic Vehicle with Reaction Control Systems via Improved Model Predictive Control Approach

This paper studies the reentry attitude tracking control problem for hypersonic vehicles(HSV)equipped with reaction control systems(RCS)and aerodynamic surfaces.The attitude dynamical model of the hypersonic vehicles is established,and the simplified longitudinal and lateral dynamic models are obtained,respectively.Then,the compound control allocation strategy is provided and the model predictive controller is designed for the pitch channel.Furthermore,considering the complicated jet interaction effect of HSV during RCS is working,an improved model predictive control approach is presented by introducing the online parameter estimation of the jet interaction coefficient for dealing with the uncertainty and disturbance.Moreover,considering the strong coupling effect between the yaw channel and roll channel,a coupled model predictive controller is designed by introducing the feedback of sideslip angle into the roll control channel to eliminate the coupling effect.Finally,the comparison simulations using the classical control method,MPC and IMPC approach are given to demonstrate the effectiveness and efficiency of the presented IMPC scheme.

Enhanced Acid/Base Catalysis in High Temperature Liquid Water

Two novel and environmentally benign solvent systems, organic acids-ennchea high temperature liquid water （HTLW） and NH3-enriched HTLW, were developed, which can enhance the reaction rate of acid/base-catalyzed organic reactions in HTLW. We investigated the decomposition of fructose in organic acids-enriched HTLW, hydrolysis of cinnamaldehyde and aldol condensation of phenylaldehyde with acetaldehyde in NH3-enriched HTLW. The experimental results demonstrated that organic acids-enriched or NH3-enriched HTLW can greatly accelerate acid/base-catalyzed organic reactions in HTLW.