A High Capacity and Working Voltage Potassium-Based Dual Ion Batteries

Potassium-based dual ion batteries(KDIBs)have attracted significant attention owing to high working voltage,high safety,low processing cost,and environmental friendliness.Nevertheless,one great challenge for practical KDIBs is to develop suitable anode materials with high specific capacity.Herein,we report an architecture of hierarchically porous antimony nanoparticles/carbon nanofibers(HPSb CNFs)as flexible,free-standing anode for high-performance KDIBs.The HPSb CNFs with hierarchically porous structure,and high-content nitrogen doping,not only offer sufficient free space to tolerate the repetitive volume expansion of Sb nanoparticles during long-term cycling,but also greatly facilitate the transport of electrons and ions within electrode,ensuring high material utilization ratio.Thus,the KDIBs,constituted by HPSb CNFs-700(calcined at 700°C)anode and graphite cathode,exhibited a high reversible capacity of 440 m Ah g^(-1)with high discharge medium voltage of 4.5 V at a specific current of 200 m A g^(-1)(the highest capacity for all KDIBs normalized by the mass of the anode),and excellent cyclic life.Outstanding electrochemical reversibility of the KDIBs was further demonstrated by ex situ XRD,ex situ Raman spectrum,and HRTEM.These results suggest the as-designed HPSb CNFs-700 with highcapacity and long-term cycling stability is a promising anode material for high-performance KDIBs.

Examining the Interplay between Trait Mindfulness and Thriving at Work among Teachers in Western China:The Mediating Role of General Self-Efficacy

This study explores the nuanced relationship between trait mindfulness and thriving at work among educators in Western China,emphasizing the mediating role of general self-efficacy.Employing a sample of 378 primary and secondary school teachers,this research utilizes the Five Facet Mindfulness Questionnaire(FFMQ),Thriving at Work Scale(TWS),and the General Self-Efficacy Scale(GSES)to conduct a thorough investigation.The findings indicate a significant positive correlation between trait mindfulness and thriving at work,between trait mindfulness and general self-efficacy,and between general self-efficacy and thriving at work.Additionally,trait mindfulness was found to have a positive predictive effect on both thriving at work and general self-efficacy,with general self-efficacy also showing a positive predictive effect on thriving at work.Importantly,general self-efficacy was identified as playing a partial mediating role in the relationship between trait mindfulness and thriving at work.These results underscore the importance of cultivating mindfulness and self-efficacy among teachers to enhance their enthusiasm for work,suggesting potential pathways for professional development and well-being in the educational sector.

Supercritical carbon dioxide as a new working medium for pneumatic launch:A theoretical study

Compared with the conventionally gaseous or liquid working media,the specific internal energy of supercritical carbon dioxide(SCD)is higher at the same temperature and pressure,and the critical temperature of carbon dioxide is close to room temperature,making SCD a potential new working medium for pneumatic launch.To analyze the feasibility of this conception,an analytical model of a pneumatic catapult is established on basis of the conservations of mass and energy.The model consists of a high-pressure chamber and a low-pressure chamber connected by multiple valves,and there is a movable piston in the low-pressure chamber that can push an aircraft to accelerate.The effects of the launch readiness state of SCD in the high-pressure chamber,the initial volume of the low-pressure chamber and the valve control on the movement of the aircraft are analyzed.It is found that there is a restrictive relation between the temperature and pressure of the launch readiness state of SCD,i.e.,there is a maximum allowable launch readiness pressure when the launch readiness temperature is fixed.If this restrictive relation is not satisfied,the working medium in the low-pressure chamber will drop to its triple point within a few milliseconds,leading to a launch failure.Owing to this restrictive relation,there is an optimal launch readiness state of SCD with the highest working capacity for any allowable launch readiness temperature.The pressure of the low-pressure chamber will decrease significantly as the initial volume increases,leading to a decreased acceleration of the aircraft.The acceleration can be controlled below a critical value by a designed sequential blasting technique of multiple valves.The calculated results show that a 500 kg aircraft can be accelerated from 0 to 58 m/s in 0.9 s with 36 kg of carbon dioxide.This research provides a new technique for the controllable cold launch of an aircraft.

LaB6 Work Function and Structural Stability under High Pressure

The work functions of the （110） and （10（3） surfaces of LaB6 are determined from ambient pressure to 39.1 GPa. The work function of the （110） surface slowly decreases but that of the （100） surface remains at a relatively constant value. To determine the reason for this difference, the electron density distribution （EDD） is determined from high-pressure single-crystal x-ray diffraction data by the maximum entropy method. The EDD results show that the chemical bond properties in LaB6 play a key role also investigated by single-crystal x-ray diffraction. In observed from ambient pressure to 39.1 GPa. The structural stability of LaB6 under high pressure is this study, no structural or electronic phase transition is

Investigation into microstructure of spray formed V4 cold working mould steel and its roiling and annealing

The material selected for this work was the spray formed Vanadis4 high alloy cold working mould steel （abbreviated to V4 steel）. Its microstructure, hot rolling process, and annealing treatment have been investigated. Observed from the optical and electron microscopes, the as-sprayed V4 steel had the finer microstructure of uniform and equiaxial grains ,while after hot rolling for densification and spheroidized annealing, the V4 steel obtained an excellent spheroidized structure that is favorable to subsequent quenching and tempering treatment. The spheroidized structure and level of annealed hardness of the V4 steel are almost the same as expensive imported powder metallurgy the V4 steel. It is difficult to produce V4 steel with the conventional ingot metallurgical technique, so the multi-step and high-cost powder metallurgy method is generally used at present. Compared to the powder metallurgy technique, using the spray forming technique to produce the V4 steel has obvious advantages and potential market competitiveness in reducing production costs, simplifying working process, and shortening the production cycle.

Best Practice Standards and Methodology for Crane Operator Training—A Global Perspective

Crane operators control mobile or stationary cranes to lift, move and place objects at locations such as building and construction sites, wharves and shipyards. This activity occurs all over the world and is a high risk task with many noted examples of serious incidents and accidents. There are identifiable key causes that have been noted through analysis of the well documented cases and many of these causes are preventable through effective training programs. Internationally, there are not currently consistent approaches to crane operator training program content or duration. Leading causes of crane accidents are firstly discussed and identified as areas for inclusion in training programs. A number of current training approaches from a range of countries are then considered and these are used to outline the basis of a generic competency standard for crane operation, as it was found that there are not common standards in place. The proposed competency standard can be adapted by training regulators, training providers, government agencies, industry bodies and enterprises as a benchmark for the development of effective training programs.

High performance work systems and corporate performance： the influence of entrepreneurial orientation and organizational learning

This study investigates the functioning mechanisms of how high performance work systems （HPWS） affect organizational performance. We propose that （HPWS） can positively affect organizational performance through the mediating role of entrepreneurial orientation. An organization with high performance work systems can perform better if it enjoys high level of organizational learning. We design and administer a survey questionnaire to high-level executives or founders of companies from manufacturing and service industries and receive 176 valid responses. The results of the empirical data indicate that the relationship between high performance work systems and corporate performance is more positive when organizational learning is stronger. Entrepreneurial orientation partially mediates the relationship between high performance work systems and organizational performance. This study opens new research avenues by extending and incorporating explanations and predictions of HPWS and entrepreneurial orientation, two areas that largely have been considered independently of each other. Implications for practice and directions for future research are provided.

High Performance Work Systems and Employee Creativity： The Mediating Effect of Knowledge Sharing

Employee creativity is both the core element of a firm＇s innovation capabilities and the sources for its growth. To improve an organization＇s ability to innovate, it is necessary to improve the creativity of its employees. Based on theories from strategic human resource management, creativity and organizational learning, this paper investigates the relationship between high performance work systems and employee creativity and explores the role knowledge sharing plays in their relationship. A questionnaire is designed and administered to a group of part-time executive students in the winter of 2012. Two hundred students are invited to answer the survey questions with 117 valid responses. Data are collected and processed by using statistical regressions. The empirical findings reveal that high performance work systems positively affect knowledge sharing and employee creativity. Knowledge sharing plays a mediating role in the relationship between high performance work systems and employee creativity. Implications for practice and future research are discussed.

Volunteer High Performance Work Systems and Service Performance： An Empirical Study of Beijing Olympic Volunteers

This study examines the key human resources factors that affect volunteers＇ service performance from the perspectives of volunteers and managers in the Beijing Summer Olympic Games of 2008. Survey data were collected from 1,727 volunteers and 243 managers at the Beijing Olympics test events held at 10 venues between November 2007 and April 2008. Regression analyses and a moderation test were combined to test the hypotheses. A set of high performance work systems （HPWS） for volunteers in the Beijing Summer Olympic Games were developed which include performance management, training, recognition, teamwork and volunteer participation. Volunteer HPWS were positively related to psychological empowerment, which was in turn positively related to service recovery performance. Moreover, transformational leadership moderates the relationship between volunteer HPWS and psychological empowerment in such a way that the relationship is stronger when transformational leadership is at a higher level than when it is at a lower level.Implications and limitations were also discussed.

N,O co-doped porous carbon with rich pseudocapacitive groups exhibiting superior energy density in an acidic 2.4 V Li_(2)SO_(4)electrolyte

Designing a carbon material with a unique composition and surface functional groups for offering high specific capacity in a wide voltage window is of great significance to improve the energy density for the supercapacitor in a cheap and eco-friendly aqueous electrolyte.Herein,we develop an efficient strategy to synthesize a N,O co-doped hierarchically porous carbon(NODPC-1.0)with moderate specific surface area and pore volume as well as rich heteroatoms using a deep eutectic solvent(DES)as an activator.It is found that NODPC-1.0 with a large proportion of pseudocapacitive functional groups(pyrrole-N,pyridineN and carbonyl-quinone)can work stable in an acidic 2 mol/L Li_(2)SO_(4)(pH 2.5)electrolyte,exhibiting specific capacities of 375 and 186 F/g at the current densities of 1.0 and 100 A/g,respectively.Also,the assembled symmetric capacitor using the NODPC-1.0 as the active material and 2 mol/L acidic Li_(2)SO_(4)(pH 2.5)as the electrolyte shows an outstanding energy density of 74.4 Wh/kg at a high power density of 1.44 k W/kg under a broad voltage window(2.4 V).Relevant comparative experiments indicate that H+of the acidic aqueous electrolyte plays a crucial part in enhancement the specific capacity,and the abundant pseudocapacitive functional groups on the surface of the NODPC-1.0 sample play the key role in the improvement of electrochemical cycle stability under a broad voltage window.