Performance Characteristics Research Articles

Miniaturized Substrate-Integrated Waveguide Bandpass Filter Using Symmetric Vertical Slots

A substrate-integrated waveguide (SIW) bandpass filter designed by introducing a vertical slot in the central metallic septum of the SIW is proposed in this paper. The input/output arrangement analysis and the stub variation in the port termination are also demonstrated, resulting in a wider bandwidth and better performance characteristics. The SIW bandpass filter (BPF) has a passband in the range of 18.23 GHz - 28.74 GHz depending on the stub variation arrangement with the central symmetric slot synthesized on a 0.5 mm thick planar RO 3003 substrate using a periodically arranged metal via holes. The proposed filter has excellent wide stopband rejection characteristics of -16 dB from 30 GHz to 40 GHz. Furthermore, the experimentally measured S-parameters of the filter are in good agreement with the simulated results; thus, the performance of the filter is validated.

The Effect of Dry Immersion on the Characteristics of Joystick Control during the Performance of a Visual-Motor Task in Men and Women

A study of the effect of Dry Immersion (DI) on the characteristics of joystick control during a visual-motor task in men and women was conducted. It is shown that in the first days of DI there is a deterioration in the performance of the visual-motor task – an increase in time indicators and a decrease in movement accuracy. By the end of DI, most of the parameters returned to the control level indicating the adaptation of the hand movement control mechanisms to immersion conditions. However, despite the similarity of the effect of DI on changes in the parameters of movement trajectories in men and women, it was shown that both in control and in DI, women performed the presented visual-motor task faster and more accurately due to a longer latency time. In the early days of DI, the characteristics of task performance in women changed less than in men, which indicated a better adaptation of women to the conditions of DI. In the process of adaptation to DI factors, men and women had different strategies for performing visual-motor tasks.

Characteristics Of Organizational Culture, Adaptation Ability, And Performance Of Micro, Small And Medium Enterprises

This study investigates the role of organizational culture, adaptability, and performance of micro, small, and medium enterprises (MSMEs) in facing market dynamics and technological developments. Micro, Small, and Medium Enterprises (MSMEs) have a very important role in the economy, but often experience challenges in the adaptation process due to the lack of support from the right organizational culture. This study aims to explore the characteristics of organizational culture and adaptability in improving the performance of Micro, Small, and Medium Enterprises (MSMEs). The results of the study show that an organizational culture that supports adaptation and innovation can significantly improve the performance of micro, small and medium enterprises (MSMEs). The ability to adapt helps MSMEs respond to change and strengthens an organizational culture that is sensitive to needs. The results of this study indicate that the Micro, Small, and Medium Enterprises (MSMEs) sector needs to implement an adaptive organizational culture to increase competitiveness and ensure survival in an ever-changing market.

Allelopathic Effects of Soil Extracts from Rhus typhina Plantations on Common Turfgrass Species in Northern China

The allelopathic plant Rhus typhina (Rt) has a shallowly distributed root system with a high density of secretory canals, which may allow it to exhibit indirect allelopathic effects through the soil on an understory turf species in a plantation. However, how these effects occur is still not well understood. For this study, the soil from the root zone of Rt was extracted via distilled water, and extracts at different concentrations (25, 50, and 100 g L−1) were used to treat six commonly planted turfgrass species, including Medicago sativa (Ms), Lolium perenne (Lp), Trifolium repens (Tr), Medicago falcata (Mf), Festuca arundinacea (Fa) and Coronilla varia (Cv), during a continuous germination–seedling culture experiment via the sand culture method. The germination, physiological, and growth indicators of the turfgrass seedlings were analyzed. The allelopathic effects of the soil extract at different concentrations on the six receivers were evaluated to provide a scientific basis for managing plantations with multilayer structures. The results indicated that, in general, the extracts of the soil from the root zone of Rt inhibited the germination and seedling growth performance characteristics of the mentioned turfgrasses; the inhibitory effects on Ms, Lp, and Mf increased with increasing concentrations of the Rt soil extracts, whereas those on Fa tended to decrease. In addition, the inhibitory effect on Tr obviously weakened at 50 g·L−1 relative to that at 25 g·L−1, whereas it became more obvious at 100 g·L−1; however, it exhibited the opposite trend for Cv. Generally, Mf and Cv were more sensitive to Rt allelochemicals at relatively low concentrations, and these species should be avoided when planting in Rt plantations at low densities. In contrast, Lp and Tr were more sensitive than those at relatively high concentrations and should be avoided when planting in Rt plantations at high densities.

The effect of administering aqueous extract of fermented Moringa oleifera leaves via drinking water on performance and carcass characteristics of broilers

The need to adopt natural herbal plants as feed additives in poultry production has received attention among poultry nutrition and production experts in recent years. Herbal plants have few or no side effects, unlike synthetic additives. The aim of the research was to examine the effect of fermented Moringa oleifera leaf aqueous extract (FMLAE) on growth performance and broiler carcass characteristics. A total of 240 healthy day-old-chick broilers with homogeneous average body weight were randomly divided into 4 treatments and 6 replications with 10 heads per cage in a completely randomized design. Fermented Moringa leaf aqueous extract (FMLAE) treatment was given through drinking water at levels: 0% as control (A); 2% (B), 4% (C), and 6% (D), respectively. The results showed that FMLAE supplementation in drinking water had a significant increase (P<0.05) in body weight gain, carcass weight, carcass percentage, feed consumption and feed efficiency. It can be concluded that the addition of 2-6% fermented Moringa leaf aqueous extract (FMLAE) to the drinking water of broilers aged 0-4 weeks significantly increases growth, carcass and feed efficiency.

Comparison of 2 Sets of Immunoassays Used in Modified 2-Tiered Testing Algorithms for the Diagnosis of Lyme Disease.

Since 2019, modified 2-tiered testing (MTTT) algorithms have been available for the diagnosis of Lyme disease. MTTTs replaced the standard algorithms that utilized enzyme immunoassays and immunoblots with sequential enzyme immunoassays that detect different antigens. We compared the performance of serological assays from ZEUS Scientific Inc. and DiaSorin Inc. that are used for the diagnosis of Lyme disease. Serological results were compared with clinical information gathered by chart review. Percent positive agreement (PPA) and percent negative agreement (PNA) for total immunoglobulin G (IgG)/immunoglogulin M (IgM) (n = 120) were 64% (95% confidence interval 54% to 73%) and 100% (87% to 100%), respectively. PPA and PNA for IgG (n = 93) were 91% (80% to 97%) and 66% (52% to 78%), respectively. PPA and PNA for IgM (n = 93) were 75% (62% to 85%) and 95% (82% to 99%), respectively. Fewer positive total IgG/IgM results confirmed positive for either IgG or IgM for ZEUS compared to DiaSorin. Overall MTTT algorithm interpretation was concordant in 58% (55/95) of samples, and concordance improved when the results were limited to IgM in patients with symptom duration <30 days. Treatment with antibiotics was most strongly associated with IgM positivity. This analysis highlights differences in the performance characteristics between commercially available diagnostic assays for Lyme disease. Our data suggest that the DiaSorin assays would result in fewer positive total IgG/IgM tests, decreasing the required number of confirmatory IgG and IgM tests. This would potentially lead to fewer patients treated with antibiotics.

Investigation into the impact of acetylene on performance and emission characteristics of a compression ignition engine using a blended biodiesel of ethanol and tamanu oil.

Due to the significant increase in transportation, traditional fossil fuels utilised in internal combustion engines will only be accessible for a limited duration. Additionally, the harmful pollutants produced by these fuels, including CO, NOx, unburned hydrocarbons, smoke, and a small amount of particulate matter, have a severe negative impact on the environment. Although biodiesel proves efficient without necessitating engine modifications, its performance is hindered by its higher viscosity. Consequently, this research aims to enhance performance by introducing acetylene alongside tamanu methyl ester (biodiesel); however, this approach results in elevated NOx levels. To mitigate NOx emissions, a combination of ethanol and biodiesel is employed. This study investigates the performance and emission attributes of Acetylene + TME90E10 as the fuel. The combustion pressure and heat release rate of TME90E10 with 6 lpm, improved by 5.41% and 9.1% than diesel. When compared to regular diesel fuel, the introduction of 6l per minute of acetylene with TME90E10 yields a substantial 24.4% decrease in hydrocarbon (HC) emissions. Furthermore, employing TME90E10 at the same acetylene flow rate demonstrates the lowest carbon monoxide (CO) emissions, registering at 0.07%, in contrast to the 0.13% emissions observed throughout the exhaust cycle when using pure diesel fuel.

Experimental study of ammonia energy ratio on combustion and emissions from ammonia-gasoline dual-fuel engine at various load conditions

Achieving carbon neutrality necessitates the adoption of zero-carbon fuels in engine applications, with ammonia emerging as an up-and-coming candidate due to its favorable safety profile and advantages in storage and transportation. This study experimentally investigated the feasibility of an ammonia-gasoline dual-fuel (AGDF) engine to achieve comparable power output and satisfactory carbon reduction without changing the main structural parameters of the engine. A four-cylinder, naturally aspirated, spark ignition engine was used to investigate the impact of ammonia energy ratio (AER), engine base torque and engine speed on the engine performance, combustion evolution and emission characteristics. The findings reveal that the brake thermal efficiency (BTE) in AGDF mode is lower than in gasoline-only mode, primarily due to the reduced combustion activity. However, this efficiency decline becomes noticeable only when the AER exceeds 15 %. Additionally, at high AERs and high engine base torques, the delayed effect of ammonia fuel on the main combustion period results in a double-peak pattern, which limits the energy output but presents opportunities for phase optimization. The study also examined three incomplete combustion emissions, each exhibiting distinct behaviors. Except for ammonia slip, adding ammonia fuel does not significantly affect carbon monoxide (CO) and unburned hydrocarbons (UHC) emissions, particularly at AERs below 25 %. Nevertheless, nitrogen oxide (NOx) emissions under AGDF combustion are significantly higher than under gasoline alone in most instances. Crucially, the study demonstrates the carbon reduction potential of ammonia fuel across different engine loads, with a maximum carbon dioxide (CO2) reduction of 46.8 % at a 35 % AER. It is anticipated that further optimization of the combustion phase will improve the capability for carbon reduction.

Evaluation of Impact of Additive-Blended Biofuels (ABFs) on Single-Cylinder Motorcycle Engines

The elimination of subsidies for conventional gasoline (E0) in Nigeria has led to a surge in fuel prices, prompting researchers to explore alternative automotive biofuels. Among the promising options are additive-blended biofuels, which can be used in spark ignition engines (S.I.E.). However, biofuels have limitations, such as lower energy density, compatibility issues, and potential infrastructure degradation. Additive-blended biofuels (ABFs) represent an advanced technology that can address these shortcomings and enhance the performance of blended biofuels in automotive engines. In this study, additives were prepared and added to ethanol-gasoline blends, which are referred to as additive-blended biofuels (ABFs). E0 and ABFs were then tested in a single-cylinder motorcycle engine on a chassis dynamometer to evaluate the performance and emission characteristics of ABFs at partial and full load respectively. It was found that ABFs exhibited an increase in engine torque (T), brake power (BP) and brake mean effective pressure (BMEP) by 42.3%, 25.2% and 48.3%, respectively over E0. In addition, ABFs showed a 40% reduction in brake specific fuel consumption (BSFC) compared to E0. On the other hand, the emission measurements showed that NOX and HC emissions were reduced by 76 % and 35.3 % respectively for ABFs compared to E0.

Partial or complete replacement of soybean meal with black soldier fly larvae meal improves feed efficiency in laying hens between 22 to 30 weeks of age

Abstract The European Commission recently authorised the inclusion of insect meal in poultry feed. Black soldier fly larvae meal (BSF) has comparable nutritional value to soybean meal (SBM) and higher calcium content, making it an attractive alternative protein source for laying hens While a few studies have explored this objective, inconsistent results have been reported, likely due to variations in hen age, breed, husbandry systems, and sunflower meal composition across studies, making it difficult to draw clear conclusions. We hypothesised that partial or complete replacement of SBM with BSF has no adverse effects on egg production and quality in laying hens at the initiation of laying (22-30 weeks of age). This study consisted of three dietary treatments and nine replicates per treatment. Diets were a control diet, and two diets containing 5% (BSF5%) and 10% (BSF10%). The experimental unit was a pen (100 × 200 × 200 cm) of 14 Brown Nick laying hens resembling an aviary setting. We found that complete replacement of SBM with BSF10% in the diet of laying hens improved feed efficiency attributed to a lower feed intake in comparison to laying hens fed the BSF5% or the control diets, while production performance, body weight, and egg quality were maintained and the colour of the egg yolk increased. Therefore, replacing SBM with up to 10% BSF in brown laying hens in aviary pens at the initiation of laying had no adverse effects on production performance, chemical and physical characteristics, and sensory attributes of eggs. Maintaining production and egg quality with a lower intake of nutrients requires further investigation.

A Review of Intelligent Depth Distance Perception Research for Power Transmission Line Corridor Scenarios

Transmission lines are essential carriers for the transmission of electrical energy, and their safe operation is fundamental to ensuring reliable power supply. However, the environment of transmission line corridors is complex and variable, posing numerous risks of external damage. With the development of smart power systems, information technologies such as video monitoring provide effective means for monitoring and managing external damage to transmission lines. Nonetheless, the current technology for identifying external damage and safe distances for transmission lines is weak, leading to frequent false alarms and low efficiency in practical applications. To address this issue, this paper systematically reviews and summarizes the progress of distance recognition technology in power systems. First, it outlines the spatial distance perception performance requirements for models in transmission line corridor scenarios and summarizes the spatial distance data characteristics of these corridors. Second, the paper categorizes existing common safety distance recognition methods from the perspectives of active and passive ranging, analyzing their advantages and disadvantages in the context of transmission line corridors. Finally, this paper summarizes the types and performance characteristics of current deep learning-based distance recognition methods and proposes a potential application framework for these methods in transmission line corridor scenarios. It also discusses the future application prospects and challenges faced by this framework.

Model-based design of a mechanically intelligent shape-morphing structure

Soft robotics has significant interest within the industrial applications due to its advantages in flexibility and adaptability. Nevertheless, its potential is challenged by low stiffness and limited deformability, particularly in large-scale application scenarios such as underwater and offshore engineering. The integration of smart materials and morphing structures presents a promising avenue for enhancing the capabilities of soft robotic systems, especially in large deformation and variations in stiffness. In this study, we propose a multiple smart materials based mechanically intelligent structure devised through a model-based design framework. Specifically, the intelligent structure incorporates smart hydrogel and shape memory polymer (SMP). Employing the finite element method (FEM), we simulated the complex interactions among smart material to analyze the performance characteristics of the intelligent structure. The results demonstrate that, utilizing smart hydrogel and shape memory polymer (SMP) can effectively attain large deformation and exhibit variable stiffness due to the shape memory effect. Besides, the shape-morphing structures exhibit customized behaviours including bending, curling, and elongation, all while reducing reliance on external power sources. In conclusion, utilizing multiple smart materials within the model-based design framework offers an efficient approach for developing mechanically intelligent structure capable of complex deformations and variable stiffness, thereby providing support for underwater or offshore engineering applications.

Eкспериментально-розрахункове визначення коефіцієнтів гідродинамічної моделі кавітуючих насосів рідинних ракетних двигунів

Cavitation phenomena in liquid-propellant rocket engine (LPRE) pumps not only affect the power performance characteristics of the pumps, but they also affect the pump dynamics and pogo vibrations. The theoretical characterization of cavitation phenomena in LPRE pumps is not a widely used practice because theoretical and experimental data are in unsatisfactory agreement. Because of this, use is made of approaches that employ experimental data. The goal of this work is to determine the coefficients of a hydrodynamic model of cavitating LPRE pumps throughout the cavity existence region based on the experimental frequencies of cavitation oscillations and cavitation self-oscillation boundaries. In determining the cavity elasticity and negative resistance, use was made of the experimental cavitation oscillation frequencies of 26 LPRE pumps differing in dimensions and capacity. In determining the cavitation resistance distribution coefficient and the cavity-due disturbance transfer time, the experimental cavitation self-oscillation boundaries of 14 more pumps were used. To extend the cavity elasticity determination region, the extrapolation dependence of the cavity elasticity in cavitation stall regimes was updated. To make the stratification of the cavity resistance dependence more uniform in the range of large discharge coefficients, incipient cavitation numbers were refined. Using he qualitative dependence of the cavitation resistance distribution coefficient obtained from theoretical transfer matrices of cavitating pumps and its lower estimate (at zero disturbance transfer time) and upper estimate (for a uniform stratification of pump transfer matrix determinants), its analytical dependence was found. Using it and the coefficients of a mathematical model of cavitation oscillations on the cavitation-self oscillation boundary, disturbance transfer times were found and approximated.

Preparation, optimization, and modification of urea‐formaldehyde resin for used as a plugging agent in fractured and caved oil and gas reservoirs

AbstractBased on the requirements of resin‐based plugging agents on initial viscosity, gel time and cost, the urea‐formaldehyde resin Poly‐UF was synthesized via aqueous solution polymerization. Subsequently, the Poly‐UF was further modified by using melamine, polyvinyl alcohol (PVA), and oxidized starch to enhance its application performances, which were marked by Poly‐UF‐M, Poly‐UF‐PVA and Poly‐UF‐OS, respectively. Simultaneously, the relationship between the preparation process, structural, and performance characteristics of the different resin types was investigated using a single‐factor experimental approach, specifically, the solid content, viscosity, and free formaldehyde content were evaluated to gauge its application performance. In this study, the chemical structure, thermal stability and microscopic morphology of Poly‐UF‐M, Poly‐UF‐PVA and Poly‐UF‐OS were studied by using FTIR, TG‐DTG and SEM. As a result, it was confirmed that the Poly‐UF was successfully modified, and the thermal stability was obviously improved, and the microstructure was further enhanced by melamine, PVA and oxidized starch. The outcomes revealed a notable reduction in free formaldehyde content and a significant increase in solid content for Poly‐UF‐M, Poly‐UF‐PVA, and Poly‐UF‐OS, specifically, the free formaldehyde content decreased by 47.15%, 36.59%, and 32.52%, respectively, while the solid content increased by 3.47%, 1.62%, and 1.39%, respectively. Moreover, the acid and alkali solubility, mechanical strength of cured Poly‐UF‐M, Poly‐UF‐PVA and Poly‐UF‐OS were improved attribute to excellent membrane‐forming performance. The innovation of this study is that the systematic investigation and optimization of urea‐formaldehyde resin are presented, providing technical insights on its utilization as a plugging agent in fractured and caved oil and gas reservoirs.

Comparison of composition, properties and modifying effect in epoxy compositions of natural and synthetic diopside-containing fillers

Diopside is one of the key components in various construction materials and can also be used as a filler for epoxy compositions. However, due to the complexity and labor intensity of developing domestic deposits of this calcium magnesium silicate, it is rational to synthesize diopside based on rice husk ash and dolomite and compare its phase composition and properties with diopside concentrate mined in nature.It has been established that the synthesized calcium-magnesium silicate, compared to the natural mineral, contains 10 times more diopside, has a 3 times smaller pore volume and an almost 5 times smaller average particle size, i.e. they differ significantly in both phase and granulometric composition, as well as in porosity.At the same time, both natural and synthetic diopside-containing fillers increase the hardness, wear resistance and viability of epoxy compositions. A filler synthesized on the basis of rice husk ash is more effective in terms of increasing the performance characteristics of epoxy materials.

Mechanical behavior analysis of sandwich composite structures with different core geometries under three-point bending

This study presents a comprehensive investigation into the mechanical behavior of sandwich composite structures featuring six distinct core geometries under three-point bending conditions. Through detailed finite element analysis (FEA), the research examines the performance characteristics of I-shaped, traditional honeycomb (NIDA), O-shaped, X-shaped, semi-circular, and modified core geometries. The analysis focused on stress distribution patterns, displacement responses, and overall structural integrity. Results demonstrate that the semi-circular core geometry exhibits superior mechanical properties, achieving an 84.66% improvement in positive stress resistance and 74.79% enhancement in negative stress resistance compared to the traditional honeycomb reference model. The study revealed consistent linear elastic behavior across all models within the tested displacement range, with the semi-circular configuration showing optimal stress distribution and minimal core deformation. Using aluminum for facings and core materials, the research evaluated mechanical responses through displacement-controlled loading conditions, measuring stress concentrations at critical points and analyzing deformation patterns. This research provides valuable insights into the relationship between core geometry and mechanical performance, offering practical implications for engineering applications requiring high strength-to-weight ratios and enhanced flexural resistance in modern structural design.

CPW fed optically transparent ultrawideband fractal MIMO terahertz antenna with meshed ground plane

Abstract An optically transparent UWB antenna element and its two-element pattern diversity MIMO configurations are presented in this paper. Three iterations of the quarter elliptical coplanar waveguide ground plane, rectangular microstrip feedline, and octagonal annular rings make up the antenna element. By metal meshing the ground planes and loading the radiator with several octagonal slots, the optical transparency is improved. It has a maximal achieved gain of 6.78 dBi and operates with steady radiation characteristics over the frequency spectrum of 4.52–28.64 THz (145.48%). The dimensions of the antenna element are 18 × 20.5 μm2. A metallic stub is positioned between two identical antenna components that are positioned orthogonally to one another to create a two-element pattern diversity MIMO antenna arrangement. The MIMO antenna is 20.5 × 42.5 μm2 in total. Its impedance bandwidth is 23.72 THz for port 2 and 22.68 THz for port 1. Using a rectangular stub results in an intraport isolation of &gt;19 dB. Between the two ports, the planes in the radiation patterns have switched places. The diversity performance characteristics, which are considerably below the permissible limitations, are as follows: ECC &gt; 0.01, CCL &lt; 0.3 b/s/Hz, DG ∼ 10, TARC &lt; 0 dB, MEG ∼ −3 dB, and 1≤VSWR_MIMO≤2. Compared to previously published structures, the suggested antenna structures have the advantages of smaller dimensions, a larger bandwidth, and improved optical transparency.

Mechanical and micro-structural characterization of biodegradable coir fiber–glass sheet–charcoal reinforced polymer composite: an experimental approach

In the present investigation, the combined influence of coir, glass fibers and charcoal content on the mechanical properties of epoxy-based hybrid composites has been explored, providing insights for the potential development of advanced materials with tailored performance characteristics. Through a systematic analysis of the mechanical properties (tensile strength, Young's modulus, flexural strength, flexural modulus, and Brinell hardness number), various composite formulations were evaluated to discern their performance characteristics. The study reveals significant variations in mechanical properties across different composite configurations, highlighting the critical role of fiber type and charcoal content in determining the materials’ performance. Notably, composites featuring alternating layers of glass and coir fibers exhibit superior tensile and flexural strengths, underscoring the synergistic effects of hybridization. Conversely, the introduction of charcoal as a reinforcement agent leads to deterioration in the mechanical properties, indicating a trade-off between the reinforcement and other desirable attributes. These findings offer valuable insights for the strategic design and engineering of advanced materials tailored to specific applications, paving the way for the development of high-performance epoxy-based hybrid composites with enhanced mechanical properties and durability.

Innovations in Biodegradable Batteries: A Sustainable Future

The increasing demand for batteries in several industries such as medical and electric car (EV) Industry has led to significant environmental challenges due to the production and disposal of traditional batteries, which are nonbiodegradable and pose risks to ecosystems. This report investigates the potential of biodegradable batteries as a sustainable alternative to traditional batteries, aiming to minimize environmental impact. This study analyzing and comparing the fiber batteries, zinc-molybdenum batteries, plant-based batteries (Flower battery), crab shell battery as well as algal biopolymers battery. It also highlights the key materials, methods for manufacture, and performance characteristics (biodegradability, energy capacity, degradation time) of each type of biodegradable batteries. The findings suggest that biodegradable batteries offer promising solutions for specific applications, such as in biomedical devices, wearable electronics, and precision agriculture, where their biocompatibility and environmental safety are crucial. Future development should focus on enhancing energy density, optimizing degradation timelines, and reducing costs to make these batteries more competitive with traditional options.

Zn-doped hollow cubic MnO2 as a high-performance cathode material for Zn ion batteries.

Manganese-based compounds have the characteristics of high theoretical capacity, low cost and stable performance, thus become a research hotspot for cathode materials of zinc-ion batteries (ZIBs). However, in the process of charging and discharging, it is accompanied by problems such as structural collapse and low conductivity, which resulted in severe capacity degration during cycles. In this paper, a kind of Zn2+ doped MnO2 hollow cube cathode material (Zn-MnO2) was prepared by self-sacrificing template method. The Zn2+ doped in MnO2 crystals can induce oxygen vacancies in the structure, thereby improving the structural stability ion diffusion coefficient and electrical conductivity of the material. After 100 cycles at 0.3 A g-1, the high specific capacity of 281.2 mA h g-1 is still maintained. Through ex-situ XPS and ex-situ XRD tests, the mechanism of charge-discharge process was discussed. The results show that the storage mechanism of Zn-MnO2 is H+ and Zn2+ insertion/removal and Mn3+/Mn2+ two-electron reaction pathway. The total state density (TDOS) and partial state density (PDOS) of Zn-MnO2 and MnO2 further demonstrated that the doping of Zn2+ enhanced the electron conductivity and is beneficial to the electron transfer during the electrochemical reaction.