Linear paired electrolysis of furfural to furoic acid at both anode and cathode in a multiple redox mediated system

Implementing a new energy-saving electrochemical synthesis system with high commercial value is a strategy of the sustainable development for upgrading the bulk chemicals preparation technology in the future.Here,we report a multiple redox-mediated linear paired electrolysis system,combining the hydrogen peroxide mediated cathode process with the I2 mediated anode process,and realize the conversion of furfural to furoic acid in both side of the dividedflow cell simultaneously.By reasonably controlling the cathode potential,the undesired water splitting reaction and furfural reduction side reactions are avoided.Under the galvanostatic electrolysis,the two-mediated electrode processes have good compatibility,which reduce the energy consumption by about 22%while improving the electronic efficiency by about 125%.This system provides a green electrochemical synthesis route with commercial prospects.

Detection of wheat seedling lines in the complex environment via deep learning

Wheat seedling line detection is critical for precision agriculture and automatic guidance in early wheat field operation. Aiming at the complex wheat field environment, a method of detecting wheat seedling lines based on deep learning was proposed in this study. Firstly, a rotated bounding box was created to improve the YOLOv3 model to predict the approximate position of the wheat seedling line;Then, according to the rotated bounding region obtained by the model, the wheat seedling line was detected by fitting the extracted center points. Finally, a comprehensive evaluation method combining angle error and distance error was proposed to evaluate the accuracy of the extracted crop line. By testing images of wheat seedlings in different environments, the results showed that the mean angle error and distance error respectively reached 0.75° and 10.84 pixels while the mean running time was 63.83 ms for a 1920×1080 pixels image. And compared to the original model the improved algorithm model improved the mAP value by 13.2%. The angle error and the distance error of the improved algorithm model were reduced by 51.4% and 39.7%, respectively. The method proposed in this study can accurately detect the wheat seedling lines at different stages and it is also suitable for the environments with weeds, shadow, bright light, and dark light. At the same time, it has a certain adaptability to wheat seedling images with a yaw angle in the shooting process. The research results could provide a reference for the automatic guidance of early wheat field machinery.

Highly reversible lead-carbon battery anode with lead grafting on thecarbon surface

A novel C/Pb composite has been successfully prepared by electmless plating to reduce the hydrogenevolution and achieve the high reversibility of the anode of lead-carbon battery （LCB）. The depositedlead on the surface of C/Pb composite was found to be uniform and adherent to carbon surface. Becauselead has been stuck on the surface of C/Pb composite, the embedded structure suppresses the hydrogenevolution of lead-carbon anode and strengthens the connection between carbon additive and sponge lead.Compared with the blank anode, the lead-carbon anode with C/Pb composite displays excellent charge-discharge reversibility, which is attributed to the good connection between carbon additives and leadthat has been stuck on the surface of C/Pb composite during the preparation process. The addition of CIPb composite maintains a solid anode structure with high specific surface area and power volume, andthereby, it plays a significant role in the highly reversible lead-carbon anode.

Purifying chylous plasma by precluding triglyceride via carboxylated polyethersulfone microfiltration membrane

Precluding the excessive lipoproteins from plasma rapidly and effectively is highly needed for biomedical detection and reducing plasma product scrap in blood donation stations.The current centrifugation procedure is high-cost and time-consuming.Herein,we fabricated an anionic microfiltration polyethersulfone(PES)membrane modified by interface swelling and implanting of acrylic acid(AA)for screening out large particle lipoprotein chylomicron(CM)and adsorbing cationic very low-density lipoproteins(VLDL).To improve the separation efficiency,a two-stage filtration through carboxylated polyethersulfone microfiltration membranes with the mean pore size of 0.45 and 0.22μm respectively were conducted.Attenuated total reflection Fourier transform infrared technique(ATR-FTIR),water contact angle(WCA),Zeta potential and scanning electron microscope(SEM)were employed to characterize the modified membrane.To test the effectiveness of this membrane,plasma flux and concentration variation of plasma components were examined to study the purification effectiveness.Furthermore,the hemocompatibility of modified membranes was tested to confirm its practicability on bloodcontacting materials.The carboxylated polyethersulfone microfiltration membrane shows its promising potential application to purify chylous plasma.

Effect of the lead deposition on the performance of the negative electrode in an aqueous lead-carbon hybrid capacitor

Lead-carbon hybrid capacitors are the electrochemical devices between supercapacitors and lead-acid batteries,with low prices,stability in high and low temperature,good security and broad application prospects.This paper introduces an electrodeposition behavior of Pb^(2+)on the negative electrode,which can improve the cycle life of the lead-carbon hybrid capacitor.During the charging process,lead ions in the electrolyte can diffuse from the positive electrode of the lead-carbon hybrid capacitor into the negative electrode.When charging at a low current density,the lead ions around the negative electrode can be reduced to lead,and it is then quickly converted to lead sulfate crystals.With the increase of the number of cycles,the final result is sulfation.Sulfation can reduce the specific surface area of the electric double layer,thereby reducing the capacitance performance of the carbon material.As a result,it reduces the charge-discharge efficiency of the lead-carbon hybrid capacitor.The service life of lead-carbon hybrid capacitor is significantly improved by the inhibition of lead deposition by anion exchange membrane.The capacity retention rate at 5 A/g is improved from 84%after 1000 cycles to 95%after 10,000 cycles.The discovery of lead deposition in the negative electrode is conducive to improving the performance of long-life lead-carbon hybrid capacitors.

Robustness Evaluation of a Novel Proton Beam Geometry for Head and Neck Patients Treated with Pencil Beam Scanning Therapy

Background: To evaluate the robustness of head and neck treatment using proton pencil beam scanning (PBS) technique with respect to range uncertainty (RU) and setup errors (SE), and to establish a robust PBS planning strategy for future treatment. Methods and Materials: Ten consecutive patients were planned with a novel proton field geometry (combination of two posterior oblique fields and one anterior field with gradient dose match) using single-field uniform dose (SFUD) planning technique and the proton plans were dosimetrically compared to two coplanar arc VMAT plans. Robustness of the plans, with respect to range uncertainties (RU = ± 3% for proton) and setup errors (SE = 2.25 mm for proton and VMAT), in terms of deviations to target coverage (CTV D98%) and OAR doses (max/mean), were evaluated and compared for each patient under worst case scenarios. Results: Dosimetrically, PBS plans provided better sparing to larynx (p = 0.005), oral cavity (p < 0.001) and contralateral parotid (p = 0.004) when compared to VMAT. CTV D98% variations were higher from SE than from RU for proton plans (-1.1% ± 1.3 % vs -0.4% ± 0.7% for nodal CTV and -1.4% ± 1.2 vs -0.4% ± 0.5% % for boost CTV). Overall, the magnitudes of variation of CTV D98% to combined SE and RU were found to be similar to the impact of the SE on the VMAT plans (-1.6% ± 1.9% vs -1.7% ± 1.4% for nodal CTV and -1.9% ± 1.6% vs -1.3% ± 1.5% for boost CTV). Compared to VMAT, a larger range of relative dose deviations were found for OARs in proton plans, but safe doses were maintained for cord (41.8 ± 3.6 Gy for PBS and 41.7 ± 3.9 Gy for VMAT) and brainstem (35.2 ± 8.4 Gy for PBS and 36.2 ± 5.1 Gy for VMAT) in worst case scenarios. Conclusions: Compared to VMAT, proton plans containing three SFUD fields with superior-inferior gradient dose matching had improved sparing to larynx, contralateral parotid and oral cavity, while providing similar robustness of target coverage. Evaluation of OAR dose robustness showed higher sensitivities to uncertainties for proton plans, but safe dose levels were maintained for cord and brainstem.

A Multi-feature Fusion Apple Classification Method Based on Image Processing and Improved SVM

In order to achieve accurate classification of apple, a multi-feature fusion classification method based on image processing and improved SVM was proposed in this paper. The method was mainly divided into four parts, including image preprocessing, background segmentation, feature extraction and multi-feature fusion classification with improved SVM. Firstly, the homomorphic filtering algorithm was used to improve the quality of apple images. Secondly, the images were converted to HLS space. The background was segmented by the QTSU algorithm. Morphological processing was employed to remove fruit stem and surface defect areas. And apple contours were extracted with the Canny algorithm. Then, apples’ size, shape, color, defect and texture features were extracted. Finally, the cross verification method was used to optimize the penalty factor in SVM. A multi-feature fusion classification model was established. And the weight of each index was calculated by Fisher. In this study, 146 apple samples were selected for training and 61 apple samples were selected for testing. The test results showed that the accuracy of the classification method proposed in this paper was 96.72%, which can provide a reference for apple automatic classification.

Weighted estimates for iterated commutators of multilinear Calderón-Zygmund operators on non-homogeneous metric measure spaces

Let(X, d, μ) be a non-homogeneous metric measure space satisfying the so-called upper doubling and geometrically doubling conditions, which includes the space of homogeneous type and the Euclidean space with the non-doubling measure as special cases. Let T be a multilinear Calderón-Zygmund operator and b:=(b1,..., bm) be a finite family of RBMO(μ) functions. In this paper, some weak-type multiple weighted estimates for the iterated commutator T∏bgenerated by T and b are obtained.

The Weighted Morrey Boundedness of Multilinear Singular Integral Operators on RD-Spaces

An RD-space X is a space of homogeneous type in the sense of Coifman and Weiss,which is equipped with a measure satisfying an additional reverse doubling property.In this paper we study the boundedness of multilinear singular integral operators in weighted Morrey spaces within the framework of RD-spaces.

Lead‑Carbon Batteries toward Future Energy Storage:From Mechanism and Materials to Applications

The lead acid battery has been a dominant device in large-scale energy storage systems since its invention in 1859.It has been the most successful commercialized aqueous electrochemical energy storage system ever since.In addition,this type of battery has witnessed the emergence and development of modern electricity-powered society.Nevertheless,lead acid batteries have technologically evolved since their invention.Over the past two decades,engineers and scientists have been exploring the applications of lead acid batteries in emerging devices such as hybrid electric vehicles and renewable energy storage;these applications necessitate operation under partial state of charge.Considerable endeavors have been devoted to the development of advanced carbon-enhanced lead acid battery(i.e.,lead-carbon battery)technologies.Achievements have been made in developing advanced lead-carbon negative electrodes.Additionally,there has been significant progress in developing commercially available lead-carbon battery products.Therefore,exploring a durable,long-life,corrosion-resistive lead dioxide positive electrode is of significance.In this review,the possible design strategies for advanced maintenance-free lead-carbon batteries and new rechargeable battery configurations based on lead acid battery technology are critically reviewed.Moreover,a synopsis of the lead-carbon battery is provided from the mechanism,additive manufacturing,electrode fabrication,and full cell evaluation to practical applications.

Preparation of Au nanoparticles modified TiO_2 nanotube array sensor and its application as chemical oxygen demand sensor

Au nanoparticles(AuNPs) were electrodeposited at the highly ordered anatase TiO_2 nanotube array(TiO_2 NA) electrode under sonicating, and the AuNP-TiO_2 NA sensor was characterized by scanning electron microscope(SEM), X-ray photoelectron spectroscopy(XPS), X-ray diffraction(XRD). The photoelectrochemical experiments indicate the AuNP-TiO_2 NA sensor has lower photoelectro-resistance,higher photoelectrocatalytical activity and stability than that of pure TiO_2 NA sensor under the same conditions. The as-prepared sensor can be used for the determination of chemical oxygen demand(COD)in real samples, and the obtained results are comparable well with those of by standard K_2Cr_2O_7 method.The method proposed is simple, fast, cost effective, and environmentally friendly.

Hierarchical porous carbon derived from Allium cepa for supercapacitors through direct carbonization method with the assist of calcium acetate

In this paper, a direction carbonization method was used to prepare porous carbon from Allium cepa for supercapacitor applications. In this method, calcium acetate was used to assist carbonization process. Scanning electron microscope （SEM） and N2 adsorption/desorption method were used to characterize the morphology, Brunauer-Emmett-Teller （BET） specific surface area and pore size distribution of porous carbon derived from Allium cepa （onion derived porous carbon, OPC）. OPC is of hierarchical porous structure with high specific surface area and relatively high specific capacitance. OPC possesses relatively high specific surface area of 533.5 m2Jg. What＇s more, OPC possesses a specific capacitance of 133.5 Fig at scan rate of 5 mV/s.

Electrochemical conversion of furfural to furoic acid:a more stable,efficient and energy-saving system

The paired electrolytic system is constructed by combining the valuable organic electro-oxidation and electro-reduction reactions,which can replace the ineffective water splitting half-reaction.By reducing the energy consumption of the electrolytic cell,the value-added electrolysis is realized.The indirect electrolysis method greatly reduces the dependence of the organic electrolysis reaction on electrode potential by introducing the redox mediators,which solves the problem on the matching of anode and cathode current under potentiostatic conditions.Here,we report a more stable,efficient and energy-saving linear paired electrochemical synthesis system that can simultaneously convert furfural to furoic acid at both the anode and cathode at higher current densities.Stable three-dimensional networked PbO_(2)is used as the anode and the catalytic amount of 2,2,6,6-tetramethyl-1-piperidinyloxy(TEMPO)is used as the mediator to realize the efficient conversion of furfural to furoic acid in a wide potential range.The cathode catalyzes two-electron oxygen reduction to hydrogen peroxide using Pb/RHPC gas-diffusion electrode,which mediates the oxidation of furfural to furoic acid simultaneously.In potentiostatic electrolysis,the selectivity of the furoic acid in the cathode and anode is 33.2%and 99.3%,respectively,and the total electron efficiency is 127.1%.The properties of the cathode and anode remain stable after the long-time electrolysis in a flow cell.By choosing a stable anode with high oxygen evolution overpotential and a gas-diffusion cathode with high hydrogen evolution overpotential,the electrolytic cell can be operated efficiently and stably by introducing reasonable mediated reactions.The two half-reactions have good compatibility during the electrolysis process,saving energy consumption by about 12.3%,for certain industrial application prospects.