Nitrogen‐doped carbon (NC) materials have been proposed as next‐generation oxygen reduction reaction (ORR) catalysts to significantly improve scalability and reduce costs, but these alternatives ...usually exhibit low activity and/or gradual deactivation during use. Here, we develop new 2D sandwich‐like zeolitic imidazolate framework (ZIF) derived graphene‐based nitrogen‐doped porous carbon sheets (GNPCSs) obtained by in situ growing ZIF on graphene oxide (GO). Compared to commercial Pt/C catalyst, the GNPCSs show comparable onset potential, higher current density, and especially an excellent tolerance to methanol and superior durability in the ORR. Those properties might be attributed to a synergistic effect between NC and graphene with regard to structure and composition. Furthermore, higher open‐circuit voltage and power density are obtained in direct methanol fuel cells.
Nitrogen‐doped: A new oxygen reduction reaction electrocatalyst was obtained from ZIF‐derived porous carbon and graphene. The catalyst exhibits high activity, superior tolerance to methanol, and good stability in comparison to commercial Pt/C catalyst.
Due to strong learning ability, convolutional neural networks (CNNs) have been developed in image denoising. However, convolutional operations may change original distributions of noise in corrupted ...images, which may increase training difficulty in image denoising. Using relations of surrounding pixels can effectively resolve this problem. Inspired by that, we propose a robust deformed denoising CNN (RDDCNN) in this paper. The proposed RDDCNN contains three blocks: a deformable block (DB), an enhanced block (EB) and a residual block (RB). The DB can extract more representative noise features via a deformable learnable kernel and stacked convolutional architecture, according to relations of surrounding pixels. The EB can facilitate contextual interaction through a dilated convolution and a novel combination of convolutional layers, batch normalisation (BN) and ReLU, which can enhance the learning ability of the proposed RDDCNN. To address long‐term dependency problem, the RB is used to enhance the memory ability of shallow layer on deep layers and construct a clean image. Besides, we implement a blind denoising model. Experimental results demonstrate that our denoising model outperforms popular denoising methods in terms of qualitative and quantitative analysis. Codes can be obtained at https://github.com/hellloxiaotian/RDDCNN.
Ovarian cancer is the most lethal gynecologic malignancy. Surgery and chemotherapy are the primary treatments for ovarian cancer; however, patients often succumb to recurrence with chemotherapeutic ...resistance within several years after the initial treatment. In the past two decades, immunotherapy has rapidly developed, and has revolutionized the treatment of various types of cancer. Despite the fact that immunotherapy response rates among ovarian cancer patients remain modest, treatment with immune checkpoint inhibitors (ICIs), chimeric antigen receptor (CAR)- and TCR-engineered T cells is rapidly developing. Therapeutic efficiency could be improved significantly if immunotherapy is included as an adjuvant therapy, in combination with chemotherapy, radiation therapy, and the use of anti-angiogenesis drugs, and poly ADP ribose polymerase inhibitors (PARPi). Newly developed technologies that identify therapeutic targets, predict treatment efficacy, rapidly screen potential immunotherapy drugs, provide neoadjuvant immunotherapy, and utilize nanomedicine technology provide new opportunities for the treatment of ovarian cancer, and have the potential to prolong patient survival. However, important issues that may hinder the efficacy of such approaches, including hyperprogressive disease (HPD), immunotherapy-resistance, and toxicity of the treatments, including neurotoxicity, must be taken into account and addressed for these therapies to be effective.
This technical note addresses the problem of global control for a class of time-delay nonlinear systems. Under a smoothness condition on the system nonlinearities, a delay-independent, non-smooth ...dynamic state compensator is constructed by developing a dynamic gain based design method. With the help of appropriate Lyapunov-Krasovskii functionals, it is shown that all the states of the time-delay nonlinear system can be regulated to the origin while maintaining boundedness of the closed-loop system. A benchmark example is given to illustrate the effectiveness of the proposed non-smooth feedback controller.
3D cellular graphene films with open porosity, high electrical conductivity, and good tensile strength, can be synthesized by a method combining freeze‐casting and filtration. The resulting ...supercapacitors based on 3D porous reduced graphene oxide (RGO) film exhibit extremely high specific power densities and high energy densities. The fabrication process provides an effective means for controlling the pore size, electronic conductivity, and loading mass of the electrode materials, toward devices with high energy‐storage performance.
This study attempted to clarify the carrying-over effect of different nitrogen treatments applied to the main crop on the crop population growth and yield formation of ratoon rice under mechanized ...cultivation in Southeast China. Based on the constant total nitrogen application amounts (225.00 kg ha−1) in the main crop, an experiment with different ratios of basal and topdressing nitrogen fertilizer (the ratio of basal fertilizer:primary tillering fertilizer:secondary tillering fertilizer:booting fertilizer at 3:1:2:4 (N1), 3:2:1:4 (N2), 3:3:0:4 (N3), and 4:3:0:3 (N4), respectively, and a control without nitrogen treatment (N0)) was set up across two consecutive years in field using hybrid rice variety Yongyou 1540 as the test materials. The results showed that the total tiller number and effective tillering percentage increased in the main crop under the N1 treatment, more nitrogen fertilizer applied in late growth stage of the main crop, and its effective tillering percentage of the main crop was the highest at up to 70.18%, which was 9.15% higher than that of conventional fertilization treatment (N4), more nitrogen fertilizer applied in early growth stage of the main crop. The same tendency was observed in leaf area index (LAI) value of the main crop and its subsequent ratoon rice, which were 16.52 and 29.87% higher, respectively, in the N1 treatment than that in the N4 treatment at the full heading stage. The same was true in the case of the transport rates of stem and sheath dry mater and the canopy light interception rates in both the main and its ratoon crops. The transport rate of stem and sheath in main crop rice under N1 treatment increased by 50.57% compared with N4 treatment. The canopy light interception rate of N1 treatment increased by 5.07% compared with N4 treatment at the full heading stage of the ratoon crop. Therefore, the total actual yield was the highest in the main and its ratoon crops under N1 treatment, averaging 17 351.23 kg ha−1 in two-year trials, which was 23.00% higher than that in the conventional fertilization treatment (N4). The results showed that appropriate nitrogen treatment was able to produce a good crop stand in the main crop, which was essential for producing a good ratoon crop population and high yield especially under mechanized cultivation with low stubble height of the main crop. The study suggested that shifting the proper nitrogen application amounts to the late growth stage of the main crop, such as N1 treatment, not only had a higher productive effect on ensuring the yield of the main crop, but also had a positive effect on the axillary bud sprouts from the stubbles for ratoon rice, resulting in an increased percentage of productive panicles and achieving the goal of one planting with two good harvests under the conditions of our study.
With the rapidly growing demand for low‐cost and safe energy storage, the advanced battery concepts have triggered strong interests beyond the state‐of‐the‐art Li‐ion batteries (LIBs). Herein, a ...novel hybrid Li/Na‐ion full battery (HLNIB) composed of the high‐energy and lithium‐free Na3V2(PO4)2O2F (NVPOF) cathode and commercial graphite anode mesophase carbon micro beads is for the first time designed. The assembled HLNIBs exhibit two high working voltage at about 4.05 and 3.69 V with a specific capacity of 112.7 mA h g−1. Its energy density can reach up to 328 W h kg−1 calculated from the total mass of both cathode and anode materials. Moreover, the HLNIBs show outstanding high‐rate capability, long‐term cycle life, and excellent low‐temperature performance. In addition, the reaction kinetics and Li/Na‐insertion/extraction mechanism into/out NVPOF is preliminarily investigated by the galvanostatic intermittent titration technique and ex situ X‐ray diffraction. This work provides a new and profound direction to develop advanced hybrid batteries.
A novel Li/Na‐ion hybrid battery with high working voltage and superior electrochemical and low‐temperature properties is designed and assembled by using lithium‐free Na3V2(PO4)2O2F (NVPOF) and commercial graphite as cathode and anode, respectively. The electrode kinetics and Li/Na‐insertion/extraction processes into/out the NVPOF cathode are preliminarily studied by the galvanostatic intermittent titration technique and ex situ X‐ray diffraction.
In order to develop promising anode materials for sodium-ion batteries (SIBs), a novel pie-like FeS@C (P-FeS@C) nanohybrid, in which all ultrasmall FeS nanocrystals (NCs) are completely embedded into ...the carbon network and sealed by a protective carbon shell, has been prepared. The unique pie-like structure can effectively speed up the kinetics of electrode reactions, while the carbon shell stabilizes the FeS NCs inside. Studies show that the electrochemical reaction processes of P-FeS@C electrodes are dominated by the pseudocapacitive behavior, leading to an ultrafast Na+-insertion/extraction reaction. Hence, the prepared P-FeS@C nanohybrid exhibits superior Na-storage properties especially high rate capability in half cells. For example, it can deliver reversible capacities of 555.1 mA h g-1 at 0.2 A g-1 over 150 cycles and about 60.4 mA h g-1 at 80 A g-1 (an ultrahigh current density even higher than that of the capacitor test). Furthermore, an advanced P-FeS@C//Na3V2(PO4)2O2F full cell has been assembled out, which delivers a stable specific capacity of 441.2 mA h g-1 after 80 cycles at 0.5 A g-1 with a capacity retention of 91.8%.
Halide perovskites have gained tremendous attention in the past decade owing to their excellent properties in optoelectronics. Recently, a fascinating property, ferroelectricity, has been discovered ...in halide perovskites and quickly attracted widespread interest. Compared with traditional perovskite oxide ferroelectrics, halide perovskites display natural advantages such as structural softness, low weight, and easy processing, which are highly desirable in applications pursuing miniaturization and flexibility. This review focuses on the current research progress in halide perovskite ferroelectrics, encompassing the emerging materials systems and their potential applications in ferroelectric photovoltaics, self‐powered photodetection, and X‐ray detection. The main challenges and possible solutions in the future development of halide perovskite ferroelectric materials are also attempted to be pointed out.
Halide perovskite ferroelectrics display natural advantages of structural softness and low weight, which are highly desirable in applications pursuing miniaturization and flexibility. This review focuses on the current research progress in halide perovskite ferroelectrics, encompassing the emerging materials systems and their potential applications. The main challenges and possible solutions in the future development of these ferroelectrics are also highlighted.
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