In this study, we explore the utilization of inkjet printing technology with liquid ink to fabricate boron-doped polycrystalline silicon (poly-Si)/SiOx passivating contacts. The impacts of substrate ...morphology, baseplate temperature, and surface oxide on the printing performance were investigated to achieve distinct printed patterns. Moreover, a pre-oxidation process at 750 °C for 30 min was conducted as a strategy to prevent dopant spreading from the printed pattern via the gas phase during the high-temperature annealing. Thereafter, the influences of annealing temperature on the formed poly-Si passivating contact quality were studied. By applying optimized process conditions on intrinsic poly-Si(i-poly-Si)/SiOx/p-type crystalline Si (c-Si) substrates, promising surface passivation was achieved with an implied open-circuit voltage (iVoc) of 718 mV and a low contact resistivity (ρc) of 6.1 mΩ cm2 after annealing at 950 °C followed by a hydrogenation treatment. Optical images demonstrate that single-droplet dopant lines with a width of 69 μm could be realized on a mechanically polished substrate by printing with a drop spacing of 40 μm, while the line width expands on rough surfaces or when printing with a reduced drop spacing. Furthermore, high-resolution micro-photoluminescence maps clearly illustrate the localization of the boron-doped regions on polished and planar substrates after annealing. We also realized the formation of localized inkjet-printed phosphorus- and boron-doped poly-Si passivating contacts simultaneously within a single annealing step at 950 °C. These findings underscore the potential of inkjet printing as a promising technique for fabricating localized poly-Si/SiOx passivating contacts in high-efficiency silicon solar cells.
•Application of inkjet printing for localized doping of poly-Si passivating contact.•iVoc of 718 mV and ρc of 6.1 mΩ cm2 were achieved for p-type poly-Si contact.•Pre-oxidation process mitigated unwanted dopant spreading during N2 annealing.•μPL map shows 69 μm wide localized poly-Si passivating contacts.•Simultaneous formation of localized n- and p-type poly-Si passivating contacts.
The emulsification process is an important factor affecting emergency response to oil spills. In this study, the spreading behavior of crude oil and emulsified oils with 20 %, 40 %, and 60 % water ...content on water substrates at 10 °C, 20 °C, 30 °C, and 40 °C was investigated. The oil film was monitored in real time from the side and top view perspectives, and the spreading area, thickness, and angle could be observed. The results show that an increase in water content inhibits spreading, while an increase in temperature promotes spreading. The mechanism affecting oil spreading of temperature and water content is analyzed. The factors are related to the viscosity thus leading to different spreading tendencies and no significant spreading of the oil film occurs when the water temperature is below the pour point. The spreading of emulsified oil on water is not a Newtonian behavior. To elucidate the behavior, a gravity-viscosity model is developed to predict the oil's radius. The contact angle and spreading coefficient of the oil film are calculated by geometrical analysis and Neumann's rule. This study provides valuable theoretical insights for oil spills.
Display omitted
•1. The oil morphology was monitored in real time from the top and side view perspectives.•2. An increase in water content will inhibit oil spreading.•3. The spreading tendency at different temperatures is classified into three modes.•4. The prediction equation of oil radius is established applicable to different oils.•5. The results are of great significance to marine oil spill emergency response.
Competition and cooperation among agents in multiagent systems can be effectively modeled as differential games. One of the typical tasks is capturing the flag, in which the agents can be divided ...into attackers' alliance and defenders' alliance with two-phase competitive behaviors. The attackers' alliance aims to capture flags in the first phase and then return to the safe region in the second phase, while the defenders' alliance aims to protect the flags and apprehend as many attackers as possible. Throughout the interaction, agents are actively involved in perception, cognitive learning, and the formulation of optimal decisions rooted in their acquired knowledge. Consequently, this article delves into the central challenges posed by capture-the-flag differential games, particularly in terms of task allocation and coordinated apprehension strategies among defenders. First, we use the Apollonius circle to transform the multiplayer capture-the-flag problems into one-defense-one or two-defense-one scenarios. By analyzing the advantages of cooperation between defenders, a two-stage joint optimal strategy is obtained. Moreover, we propose an approximation algorithm that achieves optimal task assignment, significantly reducing computational complexity. The performance and effectiveness of the proposed algorithm are demonstrated through numerical simulations.
The density functional theory (DFT) calculations and experiments are combined, and we find that the M1Ag(1 1 1) dilute nanoalloys exhibit high stability when M is on the subsurface of the Ag(1 1 1) ...facet. The overpotential of as-prepared CuMnAg nanoalloy is close to the predicted overpotential and that of the Pt/C catalyst.
Display omitted
•For the first time a new CuMnAg catalyst is developed to exhibit ORR overpotential compared to the commercial Pt/C.•The silver based dilute nanoalloys exhibit high stability when the 3d transition metal atom M is on the subsurface of the Ag(111) facet.
To address the sluggish kinetics of the electrochemical oxygen reduction reaction (ORR), we consider a family of silver-based dilute nanoalloys by alloying the Ag(1 1 1) with one 3d transition metal atom M (M = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn) as ORR catalysts in alkaline media. The M1Ag(1 1 1) dilute nanoalloys exhibit higher stability when M is on the subsurface (2L-M1Ag(1 1 1)) than when M is on the surface (1L-M1Ag(1 1 1)) of the Ag(1 1 1) facet as observed from surface segregation and mixing energies, and this subsurface stability is attributed to the relative positive charge transfer of surface Ag atoms as revealed from atomic charge analysis. Thus, 2L-M1Ag(1 1 1) catalysts are further investigated for their electronic structure and ORR activities. Particularly, 2L-Cu1Ag(1 1 1), 2L-Ni1Ag(1 1 1) and 2L-Zn1Ag(1 1 1) dilute nanoalloys exhibit a free-atom-like d state, and 2L-Mn1Ag(1 1 1) and 2L-Cu1Ag(1 1 1) dilute nanoalloys exhibit an ORR overpotential of 0.459 and 0.468 V, respectively. For the first time, the ternary 2L-Cu1Mn1Ag(1 1 1) is theoretically predicted with an overpotential of 0.450 V. Motivated by this prediction, we prepare a ternary CuMnAg nanoalloy by using the pulse laser deposition method. These ternary CuMnAg and dealloyed DE-CuMnAg catalysts exhibit an ORR overpotential of 0.50 and 0.47 V that is close to the predicted overpotential and that of a commercial Pt/C catalyst.
We developed a Pd-catalyzed decarboxylative cross-coupling of zinc polyfluorobenzoates, which were used as precursors for producing zinc reagents in situ, with aryl bromides and nonaflates, providing ...a mild and efficient pathway for the synthesis of polyfluorinated biaryls. This protocol exhibits a broad substrate scope and excellent functional tolerance. Moreover, the versatility of this approach was demonstrated by the straightforward late-stage modification of drugs, biologically active molecules, and pesticides, indicating its potential significance in drug discovery.
Pythagorean fuzzy sets have higher performance in expressing uncertainty information in multi-attribute group decision-making (MAGDM). The linear programming technique for multidimensional analysis ...of preference (LINMAP) is a prototypical compromising model that adjusts the deviation between objective assessments and subjective preferences on decision alternatives. However, the disadvantages of Pythagorean fuzzy sets in conflict measure and LINMAP model in inconsistent decision information structure have not been solved yet. To solve the problems that incomplete decision information in Pythagorean fuzzy set and inconsistent evaluation structure in LINMAP, the spatial measures and Dempster-Shafer evidence theory are introduced. A new spatial structure conflict measure is thus presented, and the belief structure of Dempster-Shafer evidence theory is used to provide a unified decision-making framework for LINMAP inconsistent evaluation structure. Firstly, a novel spatial distance measurement method is developed. Secondly, comprehensive closeness is introduced to measure individual order consistency and inconsistency between subjective preference and objective evaluation. Thirdly, we define the objective basic probability assignment and subjective basic probability assignment based on Dempster-Shafer belief structure to develop the bi-objective LINMAP of Pythagorean fuzzy sets and add the deviance between individual goodness of fit and poorness of fit is introduced as constraints to obtain the optimal attribution weights. Then, the final order of decision alternatives can be obtained by the fusion rules of Dempster-Shafer. Finally, we verify that the proposed method can improve the alternative discrimination in the case of unstable order, and the result of alternative order total biased of the proposed method is reduced by at least 80% compared with the comparative method.
In this study, 192 diarrheal fecal samples were collected from 2019 to 2021 for monitoring the molecular prevalence of canine parvovirus 2 (CPV-2) among dogs in Southwest China, and 113 samples were ...detected as Carnivore protoparvovirus 1-positive. Surprisingly, 28/113 (24.8%) strains were identified as feline parvovirus (FPV)-like viruses based on the key amino acid (aa) residues in VP2. Further, 6 FPV-like strains were successfully isolated and genome sequenced, and phylogenetic trees based on the genome, VP2 and NS1 sequences showed that the 6 FPV-like strains were most genetically related with FPV instead of CPV-2. Interestingly, the VP2 proteins of the FPV-like virus contained all key aa residues typical for FPV and can be 100% identical to that of FPV, but the VP1 intron and NS1 aa sequences exhibited some unique molecular characteristics. The FPV-like isolate could hemagglutinate swine erythrocyte at pH values between 6 and 8, and replicated efficiently in MDCK cell line; moreover, the virus could cause canine systemic infection via oral administration. Further analysis based on VP2 sequences of FPV and CPV-2 in GenBank revealed that the FPV-like virus had already existed among dogs in 4 Asian countries, and have circulated widely in China. This study first confirmed that the FPV-like isolates could efficiently infect dogs, and has been prevalent among dogs in China. Moreover, this study first reported the genome characteristics of the FPV-like virus in dogs, which may represent a novel evolution pattern involving in the cross-species transmission of the virus from cats to dogs.
•An FPV-like virus was first found to be prevalent among dogs in China.•The genomes and individual proteins of the FPV-like virus are most genetically related with FPV instead of CPV.•The VP2 proteins can be 100% identical to that of FPV, but the VP1 intron and NS1 exhibit some identical mutations.•The FPV-like virus can cause systemic infection in dogsand effectively proliferate in MDCK cells distinguished from FPV.•The FPV-like virus represents a novel CPV originating from FPV through a novel evolutionary pattern.
To overcome the problem that the smoky environment affects the laser detection performance and generates false alarm, this paper proposes a polarization pulse laser target detection method based on ...the difference of the polarization information between the target and the smoke, combining full waveform decomposition and Multiple Scale-Attention convolutional neural network with Focal loss function (MSAFCNN). Optimal parameters of the algorithm are obtained by studying the recognition accuracy of the algorithm with different sampling rates and the number of convolution kernels. The polarization pulse laser detection platform is built and the target detection experiments under five different scenarios using infrared lasers are conducted. The polarization echo signals of the smoke and the targets are collected and the recognition accuracy of the proposed algorithm is calculated. The ablation experiments are carried out and MSAFCNN is compared with several advanced algorithms. The experimental results show that the proposed algorithm has the highest recognition accuracy (99.085% ± 0.249%) compared with other algorithms. According to the ablation experiment, the recognition accuracy can be improved by 1.381% using MSAFCNN. The recognition experiments with different sampling rates and numbers of convolutional kernels are performed, and the accuracy of the proposed algorithm can reach 99.348% ± 0.178% at 1 GHz sampling rate and 98.910% ± 0.297% at 500 MHz sampling rate. The optimal number of convolutional kernels is 16, and the number of the algorithm parameters is only 125.273 KB, which provides the feasibility for the subsequent implementation of the algorithm in hardware.
Typically, robotic dexterous hands are equipped with various sensors to acquire multimodal tactile information, which is an important way for robots to perceive and interact with the environment. ...Vision-based tactile sensors have been widely developed due to their simple structure and high resolution. It adopts a specialized optical design to convert different contact information into different signal responses, such as recognizing contact force information based on the marker-based method, obtaining contact shape information based on the photometric stereo (PS) method, and so on. However, the current mainstream vision-based tactile sensing systems tend to adopt isolated optical design strategies and different data processing methods for different modal tactile information, introducing limitations in system integration. This article proposes a vision-based tactile sensing strategy for multimodal tactile information using only reflected light field information. The specific implementation of the vision-based tactile sensor and the recognition algorithm for sensing multiple tactile information simultaneously are described in detail. The results show that the tactile sensing strategy does not need to design different optical structures for different modal tactile information but only uses a simple reflection layer combined with a neural network to sense multimodal tactile information, which reduces the complexity of the tactile system. In addition, the system achieves a force error of 0.2 N and a pose error of 0.41° and shows excellent precision and recall in localization and classification tasks, demonstrating the potential for multimodal tactile integration in various fields.
