16 research outputs found

    Facile synthesis of Co2P2O7 nanorods as a promising pseudocapacitive material towards high-performance electrochemical capacitors

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    National Natural Science Foundation of China [51202004]; Natural Science Foundation of Anhui Province [KJ2013A051]In the present work, we developed an efficient one-step template-free strategy to fabricate intriguing one-dimensional (1D) Co2P2O7 nanorods (NRs) at room temperature, and utilized the unique monoclinic Co2P2O7 NRs as an excellent electrode material for high-performance pseudocapacitors using 3 M KOH as an electrolyte. Strikingly, the as-synthesized 1D Co2P2O7 NR electrode delivered a specific capacitance (SC) of 483 F g(-1) at 1 A g(-1), and even at 402 F g(-1) a high current loading of 10 A g(-1). And the SC retention of similar to 90% over continuous 3000 charge-discharge cycles at a current density of 6 A g(-1) confirmed its stable long-term cycling ability at high current density. More significantly, the underlying electrochemical energy-storage mechanism of the Co2P2O7 NR electrode in alkaline KOH aqueous solution was tentatively proposed. And the appealing strategy was proposed for future exploration and development of other low-cost pseudocapacitive materials for next-generation ECs

    Comparison Study of Perceived Neighborhood-Built Environment and Elderly Leisure-Time Physical Activity between Hangzhou and Wenzhou, China

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    Physical activity and health are of significant importance for the rapid aging population in China. Built environment has been suggested to be associated with elderly physical activity and health. However, the association differences between cities remain unclear. Perceived built environment scores and elderly leisure-time physical activity (LTPA) of 308 elderly in Hangzhou and 304 elderly in Wenzhou were collected using Neighborhood Environment Walkability Scale and International Physical Activity Questionnaire, respectively. A multivariate linear regression method and T-test were used to analyze of the associations between elderly LTPA and built environment and the differences between the two cities, respectively. The results showed that LTPA was positively associated with walking/cycling facilities and crime safety in both cities. LTPA was positively correlated with residential density, aesthetics, pedestrian/traffic safety in Wenzhou and negatively correlated with access to services in Hangzhou. The perceived scores of aesthetics (2.71 vs. 2.45) and pedestrian/traffic safety (2.11 vs. 1.71) in Hangzhou were significantly higher than those in Wenzhou. The results suggested that built environment elements like higher walking/cycling facilities and crime safety may motivate elderly engaging LTPA in both cities. However, LTPA was affected by different factors in these two cities. In the urban redevelopment, survey conducted in its own city would provide meaningful information and cannot be neglected

    Study of Key Non-dimensional Parameters for Wave Drag Reduction with High-Frequency Repetitive Laser Pulse Energy Depositions

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    The problem of wave drag reduction with high-frequency repetitive laser pulse energy depositions is multivariable. Three key non-dimensional parameters, non-dimensional energy, non-dimensional depositing position and Mach number, were constructed from a number of original variables by using Buckingham pi theorem. Influences of these non-dimensional parameters on energy deposition performance, namely drag reduction and energy deposition efficiency, were investigated numerically by solving three-dimensional Navier-Stokes equations with an upwind scheme. Optimizing method of non-dimensional energy and non-dimensional depositing position is proposed. Drag reduction and energy deposition efficiency have exponential relationships with non-dimensional energy; Drag reduction and energy deposition efficiency have quadratic relationships with non-dimensional depositing position. Drag reduction has exponential relationship with freestream Mach number and energy deposition efficiency has quadratic relationship with Mach number. Non-dimensional laser energy and non-dimensional depositing position should be optimized synthetically for a given freestream

    Study of Key Non-dimensional Parameters for Wave Drag Reduction with High-Frequency Repetitive Laser Pulse Energy Depositions

    No full text
    The problem of wave drag reduction with high-frequency repetitive laser pulse energy depositions is multivariable. Three key non-dimensional parameters, non-dimensional energy, non-dimensional depositing position and Mach number, were constructed from a number of original variables by using Buckingham pi theorem. Influences of these non-dimensional parameters on energy deposition performance, namely drag reduction and energy deposition efficiency, were investigated numerically by solving three-dimensional Navier-Stokes equations with an upwind scheme. Optimizing method of non-dimensional energy and non-dimensional depositing position is proposed. Drag reduction and energy deposition efficiency have exponential relationships with non-dimensional energy; Drag reduction and energy deposition efficiency have quadratic relationships with non-dimensional depositing position. Drag reduction has exponential relationship with freestream Mach number and energy deposition efficiency has quadratic relationship with Mach number. Non-dimensional laser energy and non-dimensional depositing position should be optimized synthetically for a given freestream

    Microstructure Evolution and Orientation Relationship of Reverted Austenite in 13Cr Supermartensitic Stainless Steel During the Tempering Process

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    The transformation mechanism of reverted austenite and the amount of reverted austenite during the tempering process in supermartensitic stainless steel have been investigated by X-ray diffraction (XRD), electron backscattered diffraction (EBSD), and a high-temperature laser scanning confocal microscope (HTLSCM). The results indicate that the microstructure mainly consists of tempered martensite and reverted austenite. The reverted austenite nucleates uniformly at the sub-block boundary and prior grain austenite boundary. The amount of reverted austenite strongly relies on the tempering time, showing a positive correlation in the supermartensitic stainless steel. The crystallographic orientation relationship between reverted austenite and martensite meets the Kurdjumov-Sachs(K-S) relationship and the deviation angle is mainly concentrated at about 2 degrees. The mechanism of reverted austenite transformed from martensite is a diffusion mechanism. The growth kinetics of the reverted austenite are dominated by diffusion of the Ni element and there is no shear deformation of the martensite matrix in the in situ observation. It can be deduced that the reverted austenite is formed by nickel diffusion during tempering at 620 °C for different tempering times

    The Effect of the Built Environment on Older Men′s and Women′s Leisure-Time Physical Activity in the Mid-Scale City of Jinhua, China

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    Physical activity has been suggested to be beneficial in preventing disease and improving body function in older people. Older people’s leisure-time physical activity (LTPA) is affected by various factors, especially environmental factors. However, the differences in the association between older people’s LTPA and the built environment in different sex groups remain unclear. Perceived built environment scores and older people’s LTPA were collected for 240 older people in Jinhua using the Neighborhood Environment Walkability Scale and International Physical Activity Questionnaire, respectively. A linear regression method was used to analyze the associations between older people’s LTPA and the built environment in men, women, and all participants. The results showed that land use mix diversity was associated with LTPA in older people for both sexes. In men, LTPA was also associated with access to services. However, in women, LTPA was associated with residential density, street connectivity, and crime safety. The relationship varied when demographic variables were incorporated into the regression analysis. Those results indicated that a shorter perceived distance from home to destination would motivate older people to engage more in LTPA. Older people’s LTPA was affected by various built environment factors according to different sex groups. Women’s LTPA was generally more sensitive to the built environment. More studies are needed to confirm the association between LTPA in older people and the built environment in men and women in mid- or small-sized Chinese cities in the future

    Understanding of Hormonal Regulation in Rice Seed Germination

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    Seed germination is a critical stage during the life cycle of plants. It is well known that germination is regulated by a series of internal and external factors, especially plant hormones. In Arabidopsis, many germination-related factors have been identified, while in rice, the important crop and monocot model species and the further molecular mechanisms and regulatory networks controlling germination still need to be elucidated. Hormonal signals, especially those of abscisic acid (ABA) and gibberellin (GA), play a dominant role in determining whether a seed germinates or not. The balance between the content and sensitivity of these two hormones is the key to the regulation of germination. In this review, we present the foundational knowledge of ABA and GA pathways obtained from germination research in Arabidopsis. Then, we highlight the current advances in the identification of the regulatory genes involved in ABA- or GA-mediated germination in rice. Furthermore, other plant hormones regulate seed germination, most likely by participating in the ABA or GA pathways. Finally, the results from some regulatory layers, including transcription factors, post-transcriptional regulations, and reactive oxygen species, are also discussed. This review aims to summarize our current understanding of the complex molecular networks involving the key roles of plant hormones in regulating the seed germination of rice

    Synergistic effects of bast fiber seedling film and nano-silicon fertilizer to increase the lodging resistance and yield of rice

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    Abstract The use of bast fiber film can improve rice seedling quality, and nano-silicon fertilizer can increase rice yields. This study aimed to compare the effects of using bast fiber film, nano-silicon fertilizer, and both treatments on rice yield and lodging resistance. A 2-year field experiment was conducted in 2017 and 2018, in Liaoning, China. The experiment comprised a control (no-bast fiber film, no nano-silicon fertilizer; CK), and three treatments: seedlings cultivated with bast film (FM), single nano-silicon fertilization (SF), and bast fiber film seedlings + nano-silicon fertilization (FM + SF). The japonica rice (Oryza sativa L.) cultivar Liaojing 371 was used. Compared with the plants in CK, those in the FM treatment showed greater average root diameter, root volume and root dry weight. The SF treatment increased the single stem flexural strength, increased the contents of silicon, lignin, and cellulose in the rice plant stalk, and reduced the lodging index, thereby increasing lodging resistance. The SF treatment resulted in increased leaf chlorophyll content at late growth stage and a higher net photosynthetic rate, which increased plant dry matter accumulation. In the FM + SF treatment, plant growth was enhanced during the whole growth period, which resulted in an increased number of effective panicles and an increased grain yield. The results show that the combination of FM and SF synergistically improves rice lodging resistance and grain yield. This low-cost, high-efficiency system is of great significance for improving the stability and lodging resistance of rice plants, thereby increasing yields
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