Intracavity frequency doubling acousto-optic Q-switched high repetition rate high-energy Nd:YLF laser.

The ongoing advancement of Ti:sapphire femtosecond laser technology has drawn increasing attention to high repetition rate, high-energy green lasers as ideal pump sources for Ti:sapphire regenerative amplifiers. This study employed a neodymium-doped yttrium lithium fluoride (Nd:YLF) as the gain medium, supplemented with side-pumped laser diodes, acousto-optic Q-switching, and intracavity frequency doubling technologies. The results demonstrated a repetition rate ranging from 1-10 kHz, a pulse width of less than 100 ns, and a single pulse energy exceeding 50 mJ at 527 nm green light output. Furthermore, an operating stability (RMS) of ≤0.15% was maintained for 14 h at a repetition rate of 1 kHz and an output power of 40 W.

Super-resolution reconstruction of underwater polarized images with a fused attention mechanism.

The polarization imaging technique leverages the disparity between target and background polarization information to mitigate the impact of backward scattered light, thereby enhancing image quality. However, the imaging model of this method exhibits limitations in extracting inter-image features, resulting in less-than-optimal outcomes in turbid underwater environments. In recent years, machine learning methodologies, particularly neural networks, have gained traction. These networks, renowned for their superior fitting capabilities, can effectively extract information from multiple images. The incorporation of an attention mechanism significantly augments the capacity of neural networks to extract inter-image correlation attributes, thereby mitigating the constraints of polarization imaging methods to a certain degree. To enhance the efficacy of polarization imaging in complex underwater environments, this paper introduces a super-resolution network with an integrated attention mechanism, termed as SRGAN-DP. This network is a fusion of an enhanced SRGAN network and the high-performance deep pyramidal split attention (DPSA) module, also proposed in this paper. SRGAN-DP is employed to perform high-resolution reconstruction of the underwater polarimetric image dataset, constructed specifically for this study. A comparative analysis with existing algorithms demonstrates that our proposed algorithm not only produces superior images but also exhibits robust performance in real-world environments.

Optical Diffractive Convolutional Neural Networks Implemented in an All-Optical Way.

Optical neural networks can effectively address hardware constraints and parallel computing efficiency issues inherent in electronic neural networks. However, the inability to implement convolutional neural networks at the all-optical level remains a hurdle. In this work, we propose an optical diffractive convolutional neural network (ODCNN) that is capable of performing image processing tasks in computer vision at the speed of light. We explore the application of the 4f system and the diffractive deep neural network (D2NN) in neural networks. ODCNN is then simulated by combining the 4f system as an optical convolutional layer and the diffractive networks. We also examine the potential impact of nonlinear optical materials on this network. Numerical simulation results show that the addition of convolutional layers and nonlinear functions improves the classification accuracy of the network. We believe that the proposed ODCNN model can be the basic architecture for building optical convolutional networks.

Advances in Silicon-Based Integrated Lidar.

Silicon-based Lidar is an ideal way to reduce the volume of the Lidar and realize monolithic integration. It removes the moving parts in the conventional device and realizes solid-state beam steering. The advantages of low cost, small size, and high beam steering speed have attracted the attention of many researchers. In order to facilitate researchers to quickly understand the research progress and direction, this paper mainly describes the research progress of silicon-based integrated Lidar, including silicon-based optical phased array Lidar, silicon-based optical switch array Lidar, and continuous frequency-modulated wave Lidar. In addition, we also introduced the scanning modes and working principles of other kinds of Lidar, such as the Micro-Electro-Mechanical System, mechanical Lidar, etc., and analyzed the characteristics of the Lidars above. Finally, we summarized this paper and put forward the future expectations of silicon-based integrated Lidar.

Wood-Derived Continuously Oriented Three-Phase Interfacial Channels for High-Performance Quasi-Solid-State Alkaline Zinc Batteries.

Although recently developed hybrid zinc (Zn) batteries integrate the benefits of both alkaline Zn and Zn-air batteries, the kinetics of the electrocatalytic oxygen reaction and mass transfer of the electrolyte, which are limited by the mismatched and disordered multiphase reaction's interfacial transfer channels, considerably inhibit the performance of hybrid Zn batteries. In this work, novel, continuously oriented three-phase interfacial channels at the cathode derived from the natural structure of pine wood are developed to address these challenges. A pine wood chip is carbonized and asymmetrically loaded with a hydrophilic active material to achieve the creation of a wood-derived cathode that integrates the active material, current collector, and continuously oriented three-phase reaction interfacial channels, which allows the reaction dynamics to be accelerated. Consequently, the assembled quasi-solid-state hybrid battery performs an extra charge-discharge process beyond that performed by a typical nickel (Ni)-Zn battery, resulting in a wide operating voltage range of 0.6-2.0 V and a superior specific capacity of 656.5 mAh g-1 , in addition to an excellent energy density (644.7 Wh kg-1 ) and good durability. The ≈370% capacity improvement relative to the Ni-Zn battery alone makes the hybrid battery one of the best-performing alkaline Zn batteries.

Rational Design of Ni-Doped V2O5@3D Ni Core/Shell Composites for High-Voltage and High-Rate Aqueous Zinc-Ion Batteries.

Aqueous zinc-ion batteries (ZIBs) have significant potential for large energy storage systems because of their high energy density, cost-effectiveness and environmental friendliness. However, the limited voltage window, poor reaction kinetics and structural instability of cathode materials are current bottlenecks which contain the further development of ZIBs. In this work, we rationally design a Ni-doped V2O5@3D Ni core/shell composite on a carbon cloth electrode (Ni-V2O5@3D Ni@CC) by growing Ni-V2O5 on free-standing 3D Ni metal nanonets for high-voltage and high-capacity ZIBs. Impressively, embedded Ni doping increases the interlayer spacing of V2O5, extending the working voltage and improving the zinc-ion (Zn302+) reaction kinetics of the cathode materials; at the same time, the 3D structure, with its high specific surface area and superior electronic conductivity, aids in fast Zn302+ transport. Consequently, the as-designed Ni-V2O5@3D Ni@CC cathodes can operate within a wide voltage window from 0.3 to 1.8 V vs. Zn30/Zn302+ and deliver a high capacity of 270 mAh g-1 (~1050 mAh cm-3) at a high current density of 0.8 A g-1. In addition, reversible Zn2+ (de)incorporation reaction mechanisms in the Ni-V2O5@3D Ni@CC cathodes are investigated through multiple characterization methods (SEM, TEM, XRD, XPS, etc.). As a result, we achieved significant progress toward practical applications of ZIBs.

Effect of sedentary interval intervention on body composition and blood lipid metabolism of obese female college students / 中国学校卫生

Objective@#To explore the intervention effect of sedentary interval on body composition and blood lipid metabolism of obese female college students, so as to provide reference for health promotion among obese students.@*Methods@#Eighty obese female college students from first and second grades were randomly assigned into three groups, the control group ( n =28), experimental group A ( n =26), and experimental group B ( n =26), between September and November 2022. The participants received appropriate dietary guidance, a 90-minute optional physical education course was offered to control group once a week, on the basis of the control group, experimental group A performed 5-minute-intermittent brisk walking (6 km/h) during each break. Experimental group B performed 5-minute-intermittent brisk walking (6 km/h) during each break for the first 4 weeks, then changed to 4-minute-brisk walking (6 km/h) and 1-minute-rope skipping (60 skips/min) during each break for weeks 5-8, and changed to 4-minute-brisk walking (6 km/h) and 1-minute-rope skipping (80 skips/min) during each break for 9-12 weeks. The intervention was performed 10 times per day, with the interruption time and frequency on weekends remaining the same. Body mass index (BMI), body fat rate (BFR), waist hip ratio (WHR), visceral fat index (VFI), total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) were measured before and after the experiment.@*Results@#After 12 weeks intervention, there were no significant differences in body composition and blood lipids in control group ( P >0.05), BMI, BFR, VFI and TG in Group A were lower than those before intervention ( t=3.20, 2.80, 8.19, 2.21, P <0.05), BMI, BFR, WHR, VFI, TG, TC, LDL-C were lower and HDL-C in group B were higher than those before intervention ( t=6.27, 5.85, 10.82 , 19.91, 3.86, 3.29, 7.20, -4.93, P <0.01). There were significant differences in BMI, BFR, WHR, VFI and HDL-C among the three groups ( F=24.01, 23.77, 10.00, 15.28, 6.72, P <0.01), and the intervention effects of BMI, BFR and HDL-C in group B were better than those in group A and control group ( P <0.01).@*Conclusion@#The intervention of brisk walking and rope skipping had a good effect on improving body composition and blood lipid metabolism of obese female college students. Schools should make good use of the time between classes and adopt short-time and high-intensity exercise intervention to improve the body composition and blood lipid metabolism of obese students.

Application of Image Mosaic Technology in Tai Chi Animation Creation.

Panorama can reflect the image seen at any angle of view at a certain point of view. How to improve the quality of panorama stitching and use it as a data foundation in the "smart tourism" system has become a research hotspot in recent years. Image stitching means to use the overlapping area between the images to be stitched for registration and fusion to generate a new image with a wider viewing angle. This article takes the production of "Tai Chi" animation as an example to apply image stitching technology to the production of realistic 3D model textures to simplify the production of animation textures. A handheld camera is used to collect images in a certain overlapping area. After cylindrical projection, the Harris algorithm based on scale space is adopted to detect image feature points, the two-way normalized cross-correlation algorithm matches the feature points, and the algorithm to extract the threshold T iteratively removes mismatches. The transformation parameter model is quickly estimated through the improved RANSAC algorithm, and the spliced image is projected and transformed. The Szeliski grayscale fusion method directly calculates the grayscale average of the matching points to fuse the image, and finally, the best stitching method is used to eliminate the ghosting at the image mosaic. Data experiments based on Matlab show that the proposed image splicing technology has the advantages of high efficiency and clear spliced images and a more satisfactory panoramic image visual effect can be achieved.

Development and validation of radiologic scores for guiding individualized induction chemotherapy in T3N1M0 nasopharyngeal carcinoma.

OBJECTIVES: We aimed to develop and validate radiologic scores from [18F]FDG PET/CT and MRI to guide individualized induction chemotherapy (IC) for patients with T3N1M0 nasopharyngeal carcinoma (NPC). METHODS: A total of 542 T3N1M0 patients who underwent pretreatment [18F]FDG PET/CT and MRI were enrolled in the training cohort. A total of 174 patients underwent biopsy of one or more cervical lymph nodes. Failure-free survival (FFS) was the primary endpoint. The radiologic score, which was calculated according to the number of risk factors from the multivariate model, was used for risk stratification. The survival difference of patients undergoing concurrent chemoradiotherapy (CCRT) with or without IC was then compared in risk-stratified subgroups. Another cohort from our prospective clinical trial (N = 353, NCT03003182) was applied for validation. RESULTS: The sensitivity of [18F]FDG PET/CT was better than that of MRI (97.7% vs. 87.1%, p < 0.001) for diagnosing histologically proven metastatic cervical lymph nodes. Radiologic lymph node characteristics were independent risk factors for FFS (all p < 0.05). High-risk patients (n = 329) stratified by radiologic score benefited from IC (5-year FFS: IC + CCRT 83.5% vs. CCRT 70.5%; p = 0.0044), while low-risk patients (n = 213) did not. These results were verified again in the validation cohort. CONCLUSIONS: T3N1M0 patients were accurately staged by both [18F]FDG PET/CT and MRI. The radiologic score can correctly identify high-risk patients who can gain additional survival benefit from IC and it can be used to guide individualized treatment of T3N1M0 NPC. KEY POINTS: • [18F]FDG PET/CT was more accurate than MRI in diagnosing histologically proven cervical lymph nodes. • Radiologic lymph node characteristics were reliable independent risk factors for FFS in T3N1M0 nasopharyngeal carcinoma patients. • High-risk patients identified by the radiologic score based on [18F]FDG PET/CT and MRI could benefit from the addition of induction chemotherapy.

Quench-Induced Surface Engineering Boosts Alkaline Freshwater and Seawater Oxygen Evolution Reaction of Porous NiCo2 O4 Nanowires.

The electrochemical oxygen evolution reaction (OER) by efficient catalysts is a crucial step for the conversion of renewable energy into hydrogen fuel, in which surface/near-surface engineering has been recognized as an effective strategy for enhancing the intrinsic activities of the OER electrocatalysts. Herein, a facile quenching approach is demonstrated that can simultaneously enable the required surface metal doping and vacancy generation in reconfiguring the desired surface of the NiCo2 O4 catalyst, giving rise to greatly enhanced OER activities in both alkaline freshwater and seawater electrolytes. As a result, the quenched-engineered NiCo2 O4 nanowire electrode achieves a current density of 10 mA cm-2 at a low overpotential of 258 mV in 1 m KOH electrolyte, showing the remarkable catalytic performance towards OER. More impressively, the same electrode also displays extraordinary activity in an alkaline seawater environment and only needs 293 mV to reach 10 mA cm-2 . Density functional theory (DFT) calculations reveal the strong electronic synergies among the metal cations in the quench-derived catalyst, where the metal doping regulates the electronic structure, thereby yielding near-optimal adsorption energies for OER intermediates and giving rise to superior activity. This study provides a new quenching method to obtain high-performance transition metal oxide catalysts for freshwater/seawater electrocatalysis.

Development and prospective validation of a risk score model in guiding individualized concurrent chemoradiotherapy in stage II nasopharyngeal carcinoma in intensity-modulated radiotherapy era.

PURPOSE: We aimed to develop and prospectively validate a risk score model to guide individualized concurrent chemoradiotherapy (CCRT) for patients with stage II nasopharyngeal carcinoma (NPC) in intensity-modulated radiotherapy (IMRT) era. MATERIALS AND METHODS: In total, 1220 patients who received CCRT or IMRT alone were enrolled in this study, including a training cohort (n = 719), a validation cohort (n = 307), and a prospective test cohort (n = 194). Patients were stratified into different risk groups by a risk score model based on independent prognostic factors, which were developed in the training cohort. Survival rates were compared by the log-rank test. The validation and prospective test cohorts were used for validation. RESULTS: Total tumor volume, Epstein-Barr virus DNA, and lactate dehydrogenase were independent risk factors for failure-free survival (FFS, all p < 0.05). A risk score model based on these three risk factors was developed to classify patients into low-risk group (no risk factor, n = 337) and high-risk group (one or more factors, n = 382) in the training cohort. In the high-risk group, CCRT had better survival rates than IMRT alone (5-year FFS: 82.6% vs. 74.0%, p = 0.028). However, there was no survival difference between CCRT and IMRT alone either in the whole training cohort (p = 0.15) or in the low-risk group (p = 0.15). The results were verified in the validation and prospective test cohorts. CONCLUSION: A risk score model was developed and prospectively validated to precisely select high-risk stage II NPC patients who can benefit from CCRT, and thus guided individualized treatment in IMRT era.

Surfactant-Induced Reconfiguration of Urea-Formaldehyde Resins Enables Improved Surface Properties and Gluability of Bamboo.

The high-efficiency development and utilization of bamboo resources can greatly alleviate the current shortage of wood and promote the neutralization of CO2. However, the wide application of bamboo-derived products is largely limited by their unideal surface properties with adhesive as well as poor gluability. Herein, a facile strategy using the surfactant-induced reconfiguration of urea-formaldehyde (UF) resins was proposed to enhance the interface with bamboo and significantly improve its gluability. Specifically, through the coupling of a variety of surfactants, the viscosity and surface tension of the UF resins were properly regulated. Therefore, the resultant surfactant reconfigured UF resin showed much-improved wettability and spreading performance to the surface of both bamboo green and bamboo yellow. Specifically, the contact angle (CA) values of the bamboo green and bamboo yellow decreased from 79.6° to 30.5° and from 57.5° to 28.2°, respectively, with the corresponding resin spreading area increasing from 0.2 mm2 to 7.6 mm2 and from 0.1 mm2 to 5.6 mm2. Moreover, our reconfigured UF resin can reduce the amount of glue spread applied to bond the laminated commercial bamboo veneer products to 60 g m-2, while the products prepared by the initial UF resin are unable to meet the requirements of the test standard, suggesting that this facile method is an effective way to decrease the application of petroleum-based resins and production costs. More broadly, this surfactant reconfigured strategy can also be performed to regulate the wettability between UF resin and other materials (such as polypropylene board and tinplate), expanding the application fields of UF resin.

Boosting supercapacitive performance of flexible carbon via surface engineering.

The relatively low specific capacitance of flexible carbons hinders their practical application for fabricating high-performance flexible supercapacitors. In this work, a surface engineering method is proposed to boost the supercapacitive performance of the flexible carbon. In this method, a flexible carbon was fabricated from carbon felt via co-activation with potassium argininate and potassium hydroxide (KOH) as activators, and the resulting material is abbreviated as AKCF. Unlike traditional KOH activation processes, the addition of potassium argininate can produce a micro-graphitized carbon layer to be the outer layer of AKCF fibers for achieving better electronic transfer. Due to the improved conductivity and lower charge transfer resistance endowed by a thin micro-graphitized carbon layer, the capacitance of the AKCF-0.1 (0.1 M arginine was used) electrode obtained by the co-activation process is elevated to a 1.8-fold higher value of 403 C·g-1 (2583 mC·cm-2) relative to the AKCF-0 (0 M arginine was used) electrode prepared by KOH activation alone (222 C·g-1 or 1369 mC·cm-2). Moreover, this AKCF-0.1 electrode also displays satisfactory rate capability (66% capacitance retention after a 20-fold current increase) and highly stable cycling performance (no capacitance decline after 20,000 cycles). In addition, the asymmetric supercapacitors constructed with this AKCF-0.1 electrode as the flexible negative electrode expresses high energy densities of 68.4 Wh·kg-1 and 0.139 mWh·cm-2 in aqueous and gel electrolytes, respectively.

Gentle fabrication of colorful superhydrophobic bamboo based on metal-organic framework.

The efficient use of abundant renewable bamboo as high value-added decoration and building materials is of great significance for mitigating carbon dioxide emissions and maintaining sustainable development. The key challenge is to explore efficient and gentle methods to improve the undesirable surface properties of bamboo. Herein, a colorful and superhydrophobic bamboo is gently fabricated by a facile in-situ growth and conversion method based on metal-organic framework (for constructing micro-nano composite structures) and subsequent coating of sodium laurate (for reducing surface energy) at room temperature. The resulting sodium laurate-coated cobalt-nickel double hydroxide layer (CoNi-DH-La) is demonstrated as an efficient superhydrophobic layer to exhibit excellent chemical and mechanical stability. Impressively, the as-obtained CoNi-DH-La-coated bamboo sheet (BS-CoNi-DH-La) shows positive performances in terms of mildew resistance, flame retardancy, and self-cleaning. More importantly, this gentle method can endow bamboo with multiple unfading colors by changing the type of inorganic salts during the preparation process and display good potential for large-scale production.

Aluminum-doping-based method for the improvement of the cycle life of cobalt-nickel hydroxides for nickel-zinc batteries.

The unsatisfactory cycle life of nickel-based cathodes hinders the widespread commercial usage of nickel-zinc (Ni-Zn) batteries. The most frequently used methods to improve the cycle life of Ni-based cathodes are usually complicated and/or involve using organic solvents and high energy consumption. A facile process based on the hydrolysis-induced exchange of the cobalt-based metal-organic framework (Co-MOF) was developed to prepare aluminum (Al)-doped cobalt-nickel double hydroxides (Al-CoNiDH) on a carbon cloth (CC). The entire synthesis process is highly efficient, energy-saving, and has a low negative impact on the environment. Compared to undoped cobalt-nickel double hydroxide (Al-CoNiDH-0%), the as-prepared Al-CoNiDH as the electrode material displays a remarkably improved cycling stability because the Al-doping successfully depresses the transition in the crystal phase and microstructure during the long cycling. Benefiting from the improved performance of the optimal Al-CoNiDH electrode (Al-CoNiDH-5% electrode), the as-constructed aqueous Ni-Zn battery with Al-CoNiDH-5% as the cathode (Al-CoNiDH-5%//Zn) displays more than 14% improvement in the cycle life relative to the Al-CoNiDH-0%//Zn battery. Moreover, this Al-CoNiDH-5%//Zn battery achieves a high specific capacity (264 mAh g-1), good rate capability (72.4% retention at a 30-fold higher current), high electrochemical energy conversion efficiency, superior fast-charging ability, and strong capability of reversible switching between fast charging and slow charging. Furthermore, the as-assembled quasi-solid-state Al-CoNiDH-5%//Zn battery exhibits a decent electrochemical performance and satisfactory flexibility.

Rational Regulation of Surface Free Radicals on TiO2 Nanotube Arrays via Ag2O-AgBiO3 towards Enhanced Selective Photoelectrochemical Detection.

Due to integrated advances in photoelectrochemical (PEC) functionalities for environment detection applications, one-dimensional (1D) TiO2 nanostructures provide a new strategy (PEC sensors) towards organics detection in wastewater. However, the unidealized selectivity to the oxidation of water and organics limits the PEC detection performance. Herein, we designed a ternary photoanode consisting of Ag2O-AgBiO3/TiO2 nanotube arrays (NTAs) to solve this issue by using a facile one-step precipitation reaction. High oxidation capacity for organics is achieved by regulating the surface free radicals properly through the heterostructure formed between the interface of TiO2 and AgBiO3. More importantly, as a trap for electron capture, Ag2O in this ternary system could not only further improve the separation efficiency of charge carriers, but also capture electrons transferred to the TiO2 conduction band, thus reducing the electrons transferred to the external circuit and the corresponding background photocurrent when detecting organics. As a result, the reconstructed TiO2 NTAs decrease their photocurrent response to water and enhance their response to organics, thus presenting lower oxidation activity to water and higher activity to organics, that is, highly selective oxidation characteristics. This work provides more insights into the impact of charge transfer and surface free radicals on developing promising and efficient PEC sensors for organics.

Assembling of Bi atoms on TiO2 nanorods boosts photoelectrochemical water splitting of semiconductors.

Low photoconversion efficiency, high charge transfer resistance and fast recombination rate are the bottlenecks of semiconductor nanomaterials in photoelectrochemical (PEC) water splitting, where the introduction of an appropriate co-catalyst is an effective strategy to improve their performance. In the present study, we have purposely designed atomic-scale dispersed bismuth (Bi) assembled on titanium dioxide nanorods (TiO2), and demonstrated its effective role as a co-catalyst in enhancing the PEC water splitting performance of TiO2. As a result, functionalized Bi/TiO2 generates a high photocurrent intensity at 1.23 VRHE under simulated solar light irradiation, which is 4-fold higher than that of pristine TiO2, exhibiting a significantly improved PEC performance for water splitting. The strategy presented in this study opens a new window for the construction of non-precious metals dispersed at atomic scales as efficient co-catalysts for realizing sustainable solar energy-driven energy conversion and storage.

Relation between lifestyle, negative emotions and obesity of female college students / 中国学校卫生

Objective@#Exploring the relation between lifestyle, negative emotions and obesity of female college students,and to provide references for controlling obesity improving life style and promoting physical and mental health.@*Methods@#A random sample survey of 2 044 female college students in Henan Province was conducted using height and weight tester, body composition analyzer, the Depression-Anxiety-Stress Scale and College Students’ Healthy Lifestyle Scale. SPSS 17.0 and AMOS 20.0 were used for statistical analysis.@*Results@#The detection rates of recessive obesity, overweight and dominant obesity among female college students were 28.6%, 6.5% and 4.2% respectively. Exercise behavior, dietary nutrition behavior and stress management behavior of female college students’ lifestyle could predict the degree of obesity positively, and negative emotions could predict the degree of obesity positively( r =-0.23, -0.22, -0.21, 0.26, P <0.01). The proportion of negative emotions explained in the associations between exercise, dietary behavior and stress management with obesity was 22.1%, 25.9% and 42.5%, respectively, between the negative emotions of exercise behavior and obesity, dietary nutrition behavior and obesity, stress management behavior and obesity.@*Conclusion@#Negative emotions played an intermediary role between exercise behavior and obesity, dietary nutrition behavior and obesity, stress management behavior and obesity.

CuCo2S4 Nanosheets@N-Doped Carbon Nanofibers by Sulfurization at Room Temperature as Bifunctional Electrocatalysts in Flexible Quasi-Solid-State Zn-Air Batteries.

The performance of quasi-solid-state flexible zinc-air batteries (ZABs) is critically dependent on the advancement of air electrodes with outstanding bifunctional electrocatalysis for both the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), together with the desired mechanical flexibility and robustness. The currently available synthesis processes for high-efficiency bifunctional bimetallic sulfide electrodes typically require high-temperature hydrothermal or chemical vapor deposition, which is undesirable in terms of the complexity in experimental procedure and the damage of flexibility in the resultant electrode. Herein, a scalable fabrication process is reported by combining electrospinning with in situ sulfurization at room temperature to successfully obtain CuCo2S4 nanosheets@N-doped carbon nanofiber (CuCo2S4 NSs@N-CNFs) films, which show remarkable bifunctional catalytic performance (Ej = 10 (OER) - E 1/2 (ORR) = 0.751 V) with excellent mechanical flexibility. Furthermore, the CuCo2S4 NSs@N-CNFs cathode delivers a high open-circuit potential of 1.46 V, an outstanding specific capacity of 896 mA h g-1, when assembled into a quasi-solid-state flexible ZAB together with Zn NSs@carbon nanotubes (CNTs) film (electrodeposited Zn nanosheets on CNTs film) as the anode. The ZAB also shows a good flexibility and capacity stability with 93.62% capacity retention (bending 1000 cycles from 0° to 180°), making it an excellent power source for portable and wearable electronic devices.

In situ electrochemical oxidation of electrodeposited Ni-based nanostructure promotes alkaline hydrogen production.

Highly active and stable electrocatalysts based on non-precious metals for hydrogen evolution reaction (HER) in alkaline solution are urgently required for enabling mass production of clean hydrogen in industry. Herein, core-shell NiOOH/Ni nanoarchitectures supported on the conductive carbon cloth have been successfully prepared by a facile electrodeposition process of Ni, and a subsequent in situ electrochemical oxidation. When explored as an alkaline HER electrocatalyst, the as-synthesized NiOOH/Ni nanoarchitecture requires only a low overpotential of ∼111 mV to attain a current density of -10 mA cm-2, demonstrating its strong catalytic capability of hydrogeneration. The excellent HER activity could well be attributed to the decreasing charge transfer resistance and competitive electrochemical active area of the amorphous NiOOH, compared with inactive Ni substrate. The feasible methodology established in this study can be easily expanded to obtain a series of nano-sized metal oxyhydroxide materials for various energy conversion and storage applications, where Ni-based nanomaterials are among the highly active ones.