Efficient and stable Ru(Ⅲ)-choline chloride catalyst system with low Ru content for non-mercury acetylene hydrochlorination

Herein,we report an excellent,supported Ru(III)‐ChCl/AC catalyst with lower Ru content,where the ionic complex ChRuCl4 serves as the active component for acetylene hydrochlorination.The prepared heterogeneous Ru‐10%ChCl/AC catalyst shows excellent activity and long‐term stability.In this system,ChCl provides an environment for the ChRuCl4 to be stabilized as Ru(III),thus suppressing the reduction of the active species and the aggregation of ruthenium species during the reaction.The interaction between reactants and catalyst species was investigated by catalyst characterizations in combination with DFT calculations to disclose the effect of the ChRuCl4 complex and ChCl on the catalytic performance.This inexpensive,efficient,and long‐term catalyst is a competitive candidate for application in the hydrochlorination industry.

Fe–Mn/MCM-41: Preparation,Characterization,and Catalytic Activity for Methyl Orange in the Process of Heterogeneous Fenton Reaction

Active Fe-and Mn-loaded MCM-41(Fe–Mn/MCM-41),which was synthesized via a hydrothermal reaction followed by impregnation,is used in the heterogeneous Fenton reaction to degrade methyl orange(MO) in aqueous solution. The synthesized samples were characterized by X-ray diffraction,scanning electron microscopy,transmission electron microscopy,N_2 adsorption–desorption isotherm analysis,Fourier transform infrared spectroscopy,and X-ray photoelectron spectroscopy. Compared with Fe/MCM-41 and Mn/MCM-41,Fe–Mn/MCM-41 showed higher activity for MO degradation and mineralization. Effects of various operating parameters,such as pH,Mn content,and H_2O_2 dosage,on the degradation process were subsequently investigated. Results of experiments on the effect of radical scavengers revealed that the degradation of MO could be attributed to oxidation by HO_·. The synergy of Fe and Mn species in the Fenton oxidation process was also explained.

Analysis of sex pheromone production and field trapping of the Asian corn borer(Ostrinia furnacalis Guenée)in Xinjiang,China

Identifying the sex pheromone systems of local pest populations facilitates their management,especially for moth species that show significant geographic variation in sex pheromone communication.We investigated the pheromone production and behavioral responses of the Asian corn borer(Ostrinia furnacalis Guenée;ACB)in Xinjiang,China.The ACB produces three compounds:(Z)-12-tetradecenyl acetate(Z12-14:Ac)and(E)-12-tetradecenyl acetate(E12-14:Ac)which are two sex pheromone compounds,and n-tetradecyl acetate(14:Ac)which has variable roles in mediating behavioral responses.The ratios of these three compounds produced in female gland are geographically distinct among different populations.Quantitative analysis of pheromone production showed that the proportions of Z12-14:Ac in the E/Z isomers(i.e.,Z and E12-14:Ac)and the proportions of 14:Ac in the ternary blend respectively averaged 60.46%(SD=5.26)and 25.00%(SD=7.37),with their probabilities normally or near-normally distributed.Trapping experiments in a cornfield indicated that deploying the E/Z isomers and the three compounds in rubber septa close to their gland ratios yielded the most captured males,while other ratios that deviated from the gland ratios showed reduced field captures.The ternary blend was significantly more attractive to males than the E/Z isomers in the field,indicating a functional role of 14:Ac as the third pheromone component used by the local population.Additionally,the dose-response test demonstrated that the application of the three compounds at dosages between 200 and 350μg attracted significantly more males compared to other dosages.Therefore,the characterization of this local ACB pheromone system provides additional information about its geographic variation and serves as a basis for optimizing the pheromone-mediated control of this pest in Xinjiang.

CFD simulation study of the effect of baffles on the fluidized bed for hydrogenation of silicon tetrachloride

In this study,the effect of channel baffles and louver baffles on the flow pattern in the large-scale industrial fluidized beds was studied by computational fluid dynamics(CFD)methods.Then,the effect of flow pattern on the chemical reaction performance was studied for the first time.Simulation results showed that the gas velocity distributed more uniformly,solid particles dispersed more homogeneously and aggregation scarcely occurred in the fluidized bed with louver baffles than that with channel baffles.The residence time distribution indicated that louver baffles remarkably suppressed gas back-mixing in comparison with channel baffles.The reasonable agreements of pressure distribution and reaction results between the simulation in the bed with channel baffles and the data on a large-scale industrial apparatus demonstrated the accuracy of the CFD model.The predicted conversion of SiCl_(4) in the bed with louver baffles(27.44%)was higher than that with channel baffles(22.69%),indicating that louver baffles markedly improved the performance of the fluidized bed.This study could provide useful information for future structural improvements of baffles in large-scale fluidized beds.

Preparation of Vitamin E Intermediate from an Inexpensive Substrate by Selective Oxidation of Pseudocumene in HCOOH–H_2O_2 System

In this paper, 2,3,5-trimethyl-1,4-benzoquinone（TMBQ） was synthesized through the direct oxidation of1,2,4-trimethylbenzene（pseudocumene, TMB） in the HCOOH–H2O2 system. The influence ofthree active species was studied, including performic acid（PFA） generated in formic acid, peracetic acid（PAA） generated in acetic acid, and trifluoroperacetic（TFPA） acid generated in trifluoroacetic acid. The effects ofsulfuric acid and sodium formate addition were investigated, the overoxidation ofTMB was discussed, and the main reason for the decreasing selectivity was revealed. The oxidation ofTMB can be controlled and improved through adjusting the reaction temperature, mole ratio ofoxidant to substrate, and reactant concentration. The TMBQ yield of28% was achieved with a TMB concentration of0.2 mol/L, H2O2/TMB mole ratio of6：1, and reaction temperature 37 ℃. The selectivity of72% was obtained with a TMB concentration of0.2 mol/L, H2O2/TMB mole ratio of5：1, and reaction temperature of27 ℃. The reaction mechanisms were proposed and discussed based on the gas chromatography–flame ionization detection（GC–FID） and gas chromatography–mass spectrometer（GC–MS） results.

In Situ Growth of 3D Hierarchical ZnO@Ni_xCo_(1-x)(OH)_y Core/Shell Nanowire/Nanosheet Arrays on Ni Foam for High-Performance Aqueous Hybrid Supercapacitors

In this study, we designed and synthesized a novel battery-type electrode featuring three-dimensional(3D) hierarchical ZnO@Ni_xCo_(1-x)(OH)_y core/shell nanowire/nanosheet arrays arranged on Nifoam substrate via a two-step protocol including a wet chemical process followed by electro-deposition. We then characterized its composition, structure and surface morphology by X-ray diff raction, energy-dispersive X-ray spectrometry(EDS), X-ray photoelectron spectroscopy, scanning electron microscopy(SEM), transmission electron microscopy, EDS elemental mapping. Our electrochemical measurements show that the ZnO@Ni_(0.67)Co_(0.33)(OH)_y electrode material exhibited a noticeably high specific capacity of as much as 255(mA ·h)/g at 1 A/g. Additionally, it demonstrated a superior rate capability, as well as an excellent cycling stability with 81.6% capacity retention over 2000 cycles at 5 A/g. This sample delivered a high energy density of 64 W·h/kg and a power density of 250 W/kg at a current density of 1 A/g. With such remarkable electrochemical properties, we expect the 3D hierarchical hybrid electrode material presented in this work to have promising applications for the next generation of energy storage systems.

Common-anode LED on a Si substrate for beyond 15 Gbit/s underwater visible light communication

Visible light communication based on light-emitting diodes(LEDs) has become a promising candidate by providing high data rates, low latency, and secure communication for underwater environments. In this paper,a self-designed common-anode GaN-based five-primary-color LED(RGBYC LED) on a Si substrate is proposed and fabricated. The design of a common anode is used to mitigate the saturation effect for a low-frequency component. Additionally, compared with commercially available LEDs that suffer from nonlinearity distortion,applying the designed LED can provide much better and broader linearity according to the measurement results.Therefore, the modulation depth and system performance can be further improved to implement a high-speed underwater visible light communication(UVLC) system. There is no nonlinearity compensation algorithm applied due to the good linearity of the proposed LED;thus, the offline digital signal processing is simplified. We experimentally demonstrate 14.81 Gbit/s 64 quadrature amplitude modulation(QAM)-discrete multitone(DMT)and 15.17 Gbit/s bit-loading-DMT transmissions through a 1.2-m-long underwater channel based on the proposed RGBYC LED with an intrasymbol frequency-domain averaging channel estimation and zero-forcing equalization.As far as we know, this is the highest data rate for an LED-based UVLC system.

Directional design and synthesis of high-yield hollow Fe-MFI zeolite encapsulating ultra-small Fe_(2)O_(3) nanoparticles by using mother liquid

How to directionally design the hollow zeolite via a green route is of great significance. Here, we successfully synthesized the hollow Fe-silicate-1 encapsulated ultra-small Fe_(2)O_(3) nanoparticles (2.5 nm) with higher yield (85.2%) by mother liquid than traditional dissolution-recrystallization for the first time, which was achieved by precisely regulating the number and distribution of defects in zeolite and cleverly utilizing the TPAOH and nuclei in mother liquor. The effects of synthetic temperature, synthetic period and addition amount of parent zeolite on the formation of hollow zeolite have been investigated and the effect of synthetic conditions on the defects in parent zeolite has been also firstly quantified. The corresponding formation mechanism has been proposed. The abundant inner defects provided by the zeolite synthesized at 130 °C for 1 day and large amount of TPAOH remaining in mother liquid are conducive to the formation of hollow zeolite. Meanwhile, both parent zeolite and nuclei (4-, 5-member rings and structure units) in mother liquid obtained at 130 °C play the crucial roles in enhancing the zeolite yield. Notably, Fe_(2)O_(3) nanoparticles could decompose into small fragments by the interaction with nuclei in mother liquid. Partial ultra-small Fe_(2)O_(3) nanoparticles would be encapsulated in cavity and the rest could be inserted in the zeolite framework, which is significantly different from the conventional dissolution-recrystallization mechanism. The obtained encapsulated catalyst shows the superior catalytic performance and stability in phenol and tetracycline degradation reactions.

Monitoring nitrogen concentration of oilseed rape from hyperspectral data using radial basis function

Remote sensing technology is the important tool of digital earth,it can facilitate nutrient management in sustainable cropping systems.In the study,two types of radial basis function(RBF)neural network approaches,the standard radial basis function(SRBF)neural networks and the modified type of RBF,generalized regression neural networks(GRNN),were investigated in estimating the nitrogen concentrations of oilseed rape canopy using vegetation indices(VIs)and hyperspectral reflectance.Comparison analyses were performed to the spectral variables and the approaches.The Root Mean Square Error(RMSE)and determination coefficients(R2)were used to assess their predictability of nitrogen concentrations.For all spectral variables(VIs and hyperspectral reflectance),the GRNN method produced more accurate estimates of nitrogen concentrations than did the SRBF method at all ranges of nitrogen concentrations,and the better agreements between the measured and the predicted nitrogen concentration were obtained with the GRNN method.This indicated that the GRNN method is prior to the SRBF method in estimation of nitrogen concentrations.Among the VIs,the Modified Chlorophyll Absorption in Reflectance Index(MCARI),MCARI1510,and Transformed Chlorophyll Absorption in Reflectance Index are better than the others in estimating oilseed rape canopy nitrogen concentrations.Compared to the results from VIs,the hyperspectral reflectance data also gave an acceptable estimation.The study showed that nitrogen concentrations of oilseed rape canopy could be monitored using remotely sensed data and the RBF method,especially the GRNN method,is a useful explorative tool for oilseed rape nitrogen concentration monitoring when applied on hyperspectral data.

Multi-feature weight factor extraction and survival risk assessment of hepatocellular carcinoma based on a clinical missing dataset-independent support vector machine

Background:In clinical datasets,the characteristics of an individual patient vary so much that data loss becomes a normal event,which may be a unignorable dilemma in clinical data analysis.Therefore,the construction of a machine learning model aimed at missing clinical datasets(MCD)is of great clinical importance.Methods:All included patients were divided into two groups according to outcome within a period of up to 36 months or less.The following characteristics(variables)were collected:age,sex,Child-Pugh status,hepatitis status,cirrhosis status,treatment,tumor size,portal vein tumor thrombus,and alpha fetoprotein(μg/mL),and a missing dataset-independent support vector machine(MDI-SVM)independent of missing data was built for the analysis.Results:A MCD-independent SVM was developed based on clinical data from 1334 patients with hepatocellular carcinoma(HCC)at a single center,which had an accuracy of 84.43%in the survival analysis in the presence of 5%missing data.Based on the different combinations of features,our model calculated five features(tumor size,age,treatment,hepatitis status,and alpha fetoprotein)that had the greatest impact on survival in patients with HCC and extracted their weighting factors.Conclusions:A MCD-independent SVM was developed to achieve prognosis prediction for patients with HCC in the absence of first-visit data.