Here, the authors performed density functional theory calculations to study the catalytic performance of the nitric oxide reduction reaction (NORR) via a series of transition metal borides (MBenes). ...This work screened the M2B2 type MBenes from the IVB to V transition metals from the periodic table and systematically probed the catalytic activity and selectivity for the NORR process. It has been reported that Fe2B2, Mn2B2, and Rh2B2 can be high‐performance catalysts for converting NO to NH3 with smaller limiting potentials than other MBenes, and Nb2B2 and Hf2B2 have low limiting potentials of −0.11 V and −0.17 V for the NO production of NH3. The binding energy of ΔG*N can be a good descriptor of catalytic performance and is determined by the volcano plot of the rate‐determining step. The reaction mechanisms for NO reduction to NH3, N2, and N2O have been studied in detail, atomic *N can interact with another *N or one *NO molecule to form N2 and N2O via two successive hydrogenations. In this regard, *NO hydrogenation to *NOH has a lower formation energy than *HNO, and the MBenes have high selectivity for promoting the NORR and suppressing the hydrogen evolution reaction competition process.
Selective nitric oxide electroreduction to ammonia is an efficient pathway to solve the nitrogen oxide air pollution problem; it reveals that highly efficient NORR toward NH3 can be achieved on Ru2B2, Mo2B2, and Cr2B2 MBenes with low limiting potentials. In terms of selectivity, the highly limiting potentials prevent the formation of N2, H2, and N2O.
Over the present material synthesis routes, the sonochemical route is highly efficient and comfortable way to produce nanostructured materials. In this way, the copper sulfide (CuS-covellite) and ...sulfur doped reduced graphene oxide (S-rGO) nanocomposite was prepared by sonochemical method. Interestingly, the structure of the as-prepared S-rGO/CuS was changed from the covellite to digenite phase. Herein, the S-rGO was act as a mild oxidizer and liable for the structural transformations. These structural changes are sequentially studied by various physicochemical characterizations such as Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Transmission electron microscopy (TEM). After scrupulous structural evaluations, the transformation of CuS phase was identified and documented. This oxidized CuS has an excellent electrocatalytic activity when compare to the bulk CuS. This S-rGO/CuS was further used for the determination of glucose and acquired good electrocatalytic performances. This S-rGO/CuS was exhibited a wide linear concentration range, 0.0001-3.88 mM and 3.88-20.17 mM, and a low-level detection limit of 32 nM. Moreover, we have validated the practicability of our developed glucose sensor in real biological samples.
From the formal dialogue between China and ASEAN in 1991 to the establishment of the China–ASEAN FTA in 2010, the economic and trade relations between China and ASEAN countries have developed ...rapidly. With the continuous development of economic and trade relations, the infrastructural level between China and ASEAN has far lagged behind the needs of exchanges and trade. How to promote the development of bilateral trade through infrastructure construction and interconnection has become a concern of governments of all countries. In the context of China’s “Belt and Road” Initiative and the “Master Plan for ASEAN Connectivity”, new ideas and opportunities are provided for ASEAN infrastructure construction and its interconnection with China. Based on panel data from 2004 to 2020, this paper analyzes the impact of ASEAN infrastructure on the China–ASEAN trade volume. The analysis finds that road, port, shipping and communication infrastructure positively impact the bilateral trade volume, among which ports exert the greatest impact on the bilateral trade volume and roads have the least impact. For a more in-depth study, the transportation infrastructures of land and island countries are compared and analyzed separately. The impact of road infrastructure on trade is significant for land countries, while the impact of port infrastructure on trade is more remarkable for island countries. Finally, measures and suggestions on how to promote the development of bilateral trade are proposed on the basis of the above analysis.
The distributed secondary control in a microgrid can be used for complementing the function of the primary droop-based control. However, its dynamic performance may be undesirable and furthermore it ...may introduce new less-damped modes to the system leading to oscillatory responses. Unfortunately, mechanism analysis of the undesirable dynamic performance and the possible oscillations, and more importantly, stabilization of the microgrid with the distributed secondary control have not been reported. To fill this gap, this paper first develops a unified small-signal dynamic model of the microgrid. Based on the developed model, a small-signal stability analysis is utilized to perform the aforementioned mechanism analysis. A distributed optimal controller is thereafter proposed to enhance the system stability and improve the system dynamic performance. The distributed optimal controller can coordinate multiple distributed generation units in the microgrid and exhibits robust performance under a wide range of operating conditions. Finally, theoretical analysis and time-domain simulation results on a benchmark microgrid system are provided to verify the effectiveness of the proposed methods.
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•We proposed a novel electrochemical sensor for the highly selective detection of nitrofurantoin (NFT) in water samples based on lutetium vanadate (LuVO4)/graphene sheet (GRS) ...nanocomposite as an electrocatalyst modified with glassy carbon electrode (GCE).•Results suggested the LuVO4/GRS prepared electrochemical sensor exhibited improved reduction peak current and lower peak potential than the other modified/unmodified GCE for the detection of NFT.•The sensor demonstrated a good working range with low detection limit and excellent sensitivity.
Lutetium vanadate (LuVO4) is a promising material for electrochemical application owing to its good conductivity and electrocatalytic activity. Herein, we demonstrate a facile technique for the synthesis of a LuVO4/ graphene sheet (GRS) nanocomposite where LuVO4 is encapsulated with an ultrathin GRS to form a hierarchical structure (LuVO4/GRS). The resulting hierarchical LuVO4/GRS architecture was characterized by several analytical and spectroscopic techniques. The resultant electrocatalyst shows superior electrochemical sensing for nitrofurantoin (NFT) with a low detection limit (0.001 μM), wide linear range (0.008–256.0 μM) and excellent sensitivity (1.709 μA μM−1 cm-2). It has been demonstrated that the enhanced electrocatalytic performance of LuVO4/GRS nanocomposite is due to their excellent electrical conductivity, suitable surface area, high redox reaction and large number of electron transport. In addition, the LuVO4/GRS nanocomposite exhibited excellent response towards NFT detection with adequate reproducibility, good repeatability, long-term stability and excellent selectivity over its structural analogs and common interferents. Furthermore, the practical applicability of the proposed electrochemical sensor was successfully applied for determination of NFT in environmental samples with satisfactory results. The LuVO4/GRS nanocomposite presented here can serve as a favorable candidate for developing electrochemical sensor and plays an important role in widespread fields.
Irinotecan is one of the main chemotherapeutic agents for colorectal cancer (CRC). MicroRNA‐200 (miR‐200) has been reported to inhibit metastasis in cancer cells. Herein, pH‐sensitive and ...peptide‐modified liposomes and solid lipid nanoparticles (SLN) are designed for encapsulation of irinotecan and miR‐200, respectively. These peptides include one cell‐penetrating peptide, one ligand targeted to tumor neovasculature undergoing angiogenesis, and one mitochondria‐targeting peptide. The peptide‐modified nanoparticles are further coated with a pH‐sensitive PEG‐lipid derivative with an imine bond. These specially‐designed nanoparticles exhibit pH‐responsive release, internalization, and intracellular distribution in acidic pH of colon cancer HCT116 cells. These nanoparticles display low toxicity to blood and noncancerous intestinal cells. Delivery of miR‐200 by SLN further increases the cytotoxicity of irinotecan‐loaded liposomes against CRC cells by triggering apoptosis and suppressing RAS/β‐catenin/ZEB/multiple drug resistance (MDR) pathways. Using CRC‐bearing mice, the in vivo results further indicate that irinotecan and miR‐200 in pH‐responsive targeting nanoparticles exhibit positive therapeutic outcomes by inhibiting colorectal tumor growth and reducing systemic toxicity. Overall, successful delivery of miR and chemotherapy by multifunctional nanoparticles may modulate β‐catenin/MDR/apoptosis/metastasis signaling pathways and induce programmed cancer cell death. Thus, these pH‐responsive targeting nanoparticles may provide a potential regimen for effective treatment of colorectal cancer.
Collectively, successful delivery of miR and chemotherapy by pH‐responsive targeting nanoparticles modulates β‐catenin/multiple drug resistance/apoptosis/metastasis pathways and induces cancer cell death, mainly via apoptosis. These pH‐sensitive targeting nanoparticles carrying chemotherapy and gene therapeutics remarkably enhance anticancer efficacy in tumor‐bearing mice. Thus, these nanoparticles may provide a potential regimen for effective treatment of colorectal cancer.
This paper presents a systematic method to determine the feasible range and optimal value of the virtual impedance of the droop-based control to enhance a microgrid system performance with respect to ...power decoupling, reactive power sharing, system damping, and node voltage profile. A modified power flow analysis and an augmented small-signal dynamic model of the droop-based controlled microgrid, considering the impact of the virtual impedance, are developed. Subsequently, based on the developed methods, the feasible range of the virtual impedance, which can satisfy all the system performances requirements, is determined and presented. Based on a particle swarm optimization technique, an optimization process is introduced to select a virtual impedance value within the feasible range to achieve the overall optimal microgrid performance. Finally, simulation results in the PSCAD/EMTDC platform are provided to validate the feasibility and effectiveness of the proposed methods.
Automatic detection of intact tomatoes on plants is highly expected for low-cost and optimal management in tomato farming. Mature tomato detection has been wildly studied, while immature tomato ...detection, especially when occluded with leaves, is difficult to perform using traditional image analysis, which is more important for long-term yield prediction. Therefore, tomato detection that can generalize well in real tomato cultivation scenes and is robust to issues such as fruit occlusion and variable lighting conditions is highly desired. In this study, we build a tomato detection model to automatically detect intact green tomatoes regardless of occlusions or fruit growth stage using deep learning approaches. The tomato detection model used faster region-based convolutional neural network (R-CNN) with Resnet-101 and transfer learned from the Common Objects in Context (COCO) dataset. The detection on test dataset achieved high average precision of 87.83% (intersection over union ≥ 0.5) and showed a high accuracy of tomato counting (R
= 0.87). In addition, all the detected boxes were merged into one image to compile the tomato location map and estimate their size along one row in the greenhouse. By tomato detection, counting, location and size estimation, this method shows great potential for ripeness and yield prediction.
Digital technology usage has been extensively studied in academic research and industry. A deeper look at firm performance shows that digital transformation strategy and organisational innovation are ...facilitated by digital technology usage. This study further examined the mediating effects of digital transformation strategy and organisational innovation on the relationship between digital technology usage and firm performance. An empirical study was performed based on a survey of supervisors from financial industries in Taiwan. Two hundred twenty-seven companies responded to the questionnaires. The findings indicated that digital technology usage has positive influences on digital transformation strategy and organisational innovation, which in turn influence firm performance. Furthermore, digital transformation strategy and organisational innovation played full mediating roles between digital technology usage and firm performance.
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