Rare earths,as a strategic mineral resource,play a vital role in high-tech industries such as aerospace,national defense and military,electronic information,and new energy.With the accelerated evolution of the new rou...Rare earths,as a strategic mineral resource,play a vital role in high-tech industries such as aerospace,national defense and military,electronic information,and new energy.With the accelerated evolution of the new round of technological revolution and industrial transformation,global supply chain security risks have become more prominent.The focus of major countries'resource security assurance has also shifted from bulk minerals to critical minerals.展开更多
To meet the intelligent detection needs of underwater defects in large hydropower stations,the hydrodynamic performance of a bionic streamlined remotely operated vehicle containing a thruster protective net structure ...To meet the intelligent detection needs of underwater defects in large hydropower stations,the hydrodynamic performance of a bionic streamlined remotely operated vehicle containing a thruster protective net structure is numerically simulated via computational fluid dynamics and overlapping mesh technology.The results show that the entity model generates greater hydrodynamic force during steady motion,whereas the square net model experiences greater force and moment during unsteady motion.The lateral and vertical force coefficients of the entity model are 4.32 and 3.13 times greater than those of the square net model in the oblique towing test simulation.The square net model also offers better static and dynamic stability,with a 24.5%increase in dynamic stability,achieving the highest lift-to-drag ratio at attack angles of 6°∼8°.This research provides valuable insights for designing and controlling underwater defect detection vehicles for large hydropower stations.展开更多
FeS_(2) shows significant potential as cathode material for all-solid-state lithium batteries(ASSLBs)due to its high theoretical specific capacity,low cost,and environmental friendliness.However,the poor ion/electron ...FeS_(2) shows significant potential as cathode material for all-solid-state lithium batteries(ASSLBs)due to its high theoretical specific capacity,low cost,and environmental friendliness.However,the poor ion/electron conductivity and large volume variation effect of FeS_(2) inhibit its practical applications.Here,the influence of particle size of FeS_(2) on the corresponding sulfide-based solid-state batteries is carefully investigated by tuning FeS_(2) size.Moreover,low operating temperature is chosen to mitigate the large volume changes during cycling in the battery.S-FeS_(2) with smaller particle sizes delivers superior electrochemical performances than that of the larger L-FeS_(2) in Li_(5.5)PS_(4.5)Cl_(1.5)-based ASSLBs under different operating temperatures.S-FeS_(2) shows stable discharge capacities during 50 cycles with a current density of 0.1 m A/cm^(2)under -20℃.When the current density rises to 1.0 m A/cm^(2),it delivers an initial discharge capacity of 146.9 m Ah/g and maintains 63% of the capacity after 100 cycles.This work contributes to constructing ASSLBs enables excellent electrochemical performances under extreme operating temperatures.展开更多
The banking industry is placing increasing emphasis on green finance to address climate change,support sustainable development,and align with environmental,social,and governance(ESG)goals,as well as sustainable invest...The banking industry is placing increasing emphasis on green finance to address climate change,support sustainable development,and align with environmental,social,and governance(ESG)goals,as well as sustainable investments to fund environmentally friendly projects.In an era of growing regulatory pressure and rising demand for sustainability from investors and stakeholders,green finance has become a vital tool for banks to enhance operational efficiency.It can reduce operational costs by financing energy-saving projects,improve asset quality by funding low-risk sustainable projects,and even attract capital from environmentally responsible capital markets.Additionally,green finance helps improve risk management frameworks by financing projects that align with long-term sustainable development objectives.This paper explores the relationship between green finance and the operational efficiency of three major banks—RHB Bank,Industrial and Commercial Bank of China(ICBC),and Deutsche Bank.The article focuses on analyzing how these banks integrate green finance into their strategies and the overall impact of these initiatives on operational performance,primarily cost reduction.展开更多
Enhancing the efficiency of Rankine cycles is crucial for improving the performance of thermal power plants,as it directly impacts operational costs and emissions in light of energy transition goals.This study sets it...Enhancing the efficiency of Rankine cycles is crucial for improving the performance of thermal power plants,as it directly impacts operational costs and emissions in light of energy transition goals.This study sets itself apart from existing research by applying a novel optimization technique to a basic ideal Rankine cycle,focusing on a specific power plant that has not been previously analyzed.Currently,this cycle operates at 41%efficiency and a steam quality of 76%,constrained by fixed operational parameters.The primary objectives are to increase thermal efficiency beyond 46%and raise steam quality above 85%,while adhering to operational limits:a boiler pressure not exceeding 15 MPa,condenser pressure not dropping below 10 kPa,and turbine temperature not surpassing 500℃.This study utilizes numerical simulations to model the effects of varying boiler pressure(Pb)and condenser pressure(Pc)within the ranges of 12MPa<Pb<15 MPa and 5 kPa<Pc<10 kPa.By systematically adjusting these parameters,the proposed aimto identify optimal conditions that maximize efficiency and performance within specified constraints.The findings will provide valuable insights for power plant operators seeking to optimize performance under real-world conditions,contributing to more efficient and sustainable power generation.展开更多
Currently,the operational performance assessment system in the power market primarily focuses on power generation and electricity retail companies,lacking a system tailored to the operational characteristics of power ...Currently,the operational performance assessment system in the power market primarily focuses on power generation and electricity retail companies,lacking a system tailored to the operational characteristics of power generation/selling integrated companies.Therefore,this article proposes an assessment index system for assessing the operational performance of a power generation/selling integrated company,encompassing three dimensions:basic capacity,development potential,and external environment.A dynamic proportional adjustment coefficient is designed,along with a subjective and objective weighting model for assessment indexes based on a combined weightingmethod.Subsequently,the operational performance of an integrated company is assessed using extension theory.The results in the case study demonstrate the feasibility and effectiveness of the proposed dynamic proportional adjustment coefficient.展开更多
In this work,n-pentane catalytic cracking over HZSM-5 zeolites was studied at 650°C under atmosphere pressure.A particular attention was paid to the measurement of n-pentane conversion,light olefins production,pr...In this work,n-pentane catalytic cracking over HZSM-5 zeolites was studied at 650°C under atmosphere pressure.A particular attention was paid to the measurement of n-pentane conversion,light olefins production,product distribution,coke deposit,etc.Several indexes were defined to evaluate the effects of operating conditions on the catalytic performance of HZSM-5 zeolites.It was found that decreasing the weight hourly space velocity,increasing the reactant partial pressure,and increasing the carrier gas flow rate could inhibit C-H bond breaking and enhance the C-C bond breaking and hydride transfer reactions,leading to reduced alkenes selectivity,which suppressed the formation of external coke and alleviated the deactivation of HZSM-5 zeolites.It was deduced that the catalytic stability of HZSM-5 zeolites was improved at the cost of alkenes selectivity.Compared with decreasing the weight hourly space velocity and increasing the reactant partial pressure,increasing the carrier gas flow rate could enhance the diffusion process and protect alkenes from being consumed in coke formation in order to improve the catalytic stability of HZSM-5 zeolites with less reduction of alkenes selectivity.展开更多
This study investigates the earnings performance of 418 initial public offerings （IPOs） listed on the stock exchange of Hong Kong. By analyzing several profitability measures of these 1PO companies from the third ye...This study investigates the earnings performance of 418 initial public offerings （IPOs） listed on the stock exchange of Hong Kong. By analyzing several profitability measures of these 1PO companies from the third year prior to listing up to the fifth year post-listing, it is found that IPO companies＇ operating performances as a whole peak in the year of listing or the year preceding the listing, but exhibit a fall in post-issue profitability with the decline being most pronounced in the first financial year following the year in which the listing take place. Over 30% of these IPOs suffer a loss three years after the offerings. Deterioration of post-issue performance is found to be more severe for smaller finns, highly-geared companies, fast-growing enterprises, companies with lower ownership retention by original shareholders, and companies which have managed earnings upwards at the time of listing. These observations are consistent with the higher agency costs when firms go public and that managers have timed the issue at the peak of the companies＇ long-run performance. Further investigation confirms that IPO companies in general make use of income-increasing accruals to manage their earnings upwards in the year when they go public. The reversal of the accruals in post-issue years further exaggerates the decline in their profitability.展开更多
78Li_(2)S-22P_(2)S_(5) are sulfide electrolytes with high lithium-ion conductivity and wide electrochemical windows in the Li_(2)S-P_(2)S_(5) system,making them attractive solid electrolytes for ASSLBs.However,the rol...78Li_(2)S-22P_(2)S_(5) are sulfide electrolytes with high lithium-ion conductivity and wide electrochemical windows in the Li_(2)S-P_(2)S_(5) system,making them attractive solid electrolytes for ASSLBs.However,the role and potential of 78Li_(2)S-22P_(2)S_(5) solid electrolytes over a wide temperature range are still not fully understood.Therefore,we constructed solid-state batteries with NCM622 as the positive electrode and 78Li_(2)S-22P_(2)S_(5) glass-ceramics as the electrolyte to investigate in depth the differences in battery performance over a wide temperature range and their intrinsic mechanisms.The in-situ impedance and relaxation time distribution (DRT) demonstrated the electrochemical stability of the electrolyte over a wide temperature range,while the in-situ stacking pressure observed a large volume change during cycling at 60℃,leading to local solid-solid contact failure and poor cycling stability.This study provides insight into the advantages and problems of 78Li_(2)S-22P_(2)S_(5) in the wide temperature range as well as a basis for the construction of ASSLBs with high energy density and long cycle life.展开更多
A theoretical analysis of the effects of flow and mixing on the operating features of astirred column reactor(SCR)with multistage mixers and cooling partition plates was conducted.Amethod for calculating the concentra...A theoretical analysis of the effects of flow and mixing on the operating features of astirred column reactor(SCR)with multistage mixers and cooling partition plates was conducted.Amethod for calculating the concentration reduction for a second order chemical reaction in a SCRwas proposed.The reactants concerned were pre-mixed before feeding into the SCR.The SCR wascomposed of a number of stages with interstage backmixing.Experimental investigation with variousreaction media were carried out in order to study the effect of mixing on the operational performanceof the SCR.The experimental data were compared with the theoretical results.展开更多
By establishing the theoretical model of " strategic network cooperation-relational capability-operating performance" and structural equation,we conduct a sampling survey on 208 agricultural enterprises,and ...By establishing the theoretical model of " strategic network cooperation-relational capability-operating performance" and structural equation,we conduct a sampling survey on 208 agricultural enterprises,and use Spss21. 0 and Amos21. 0 for empirical analysis of influence of three factors in strategic network cooperation( market futurity,trusting relationship and business networks) on market relational capability and operating performance of agricultural enterprises. The results show that the establishment of trusting relationship and business networks in strategic networks has a positive impact on the operating performance of agricultural enterprises,and relational capability plays a fully mediating role while relational capability has not mediating effect on market futurity. This study provides a meaningful reference for the follow-up studies on relational capability and operating performance of agricultural enterprises,to further enhance the operating performance of agricultural enterprises and effectively improve farmers' income.展开更多
As an important part of the pharmaceutical industry, the pharmaceutical manufacturing industry is always at the battlefield of the international public health and health industry. At the same time, as a basic and stra...As an important part of the pharmaceutical industry, the pharmaceutical manufacturing industry is always at the battlefield of the international public health and health industry. At the same time, as a basic and strategic sub-industry in China's manufacturing industry, the medical manufacturing industry closely related to people’s livelihood which is not only related to social Responsibility but also plays a key role in China's economy today. For the Chinese people, the new medical reforms and the irreversible aging of the population have increased the nation’s total expenditure on health care. From January to October 2017, the pharmaceutical industry’s main business income was RMB 2,410.29 billion, a year-on-year increase of 13.10%. This is a 4.50 percentage point higher than the 10.30% growth rate in 2016. However, even if the circumstance of this industry is getting better, high growth also has a drag on the national health insurance system and the standard of living of the people. This article chooses to analyze the financial and operating-level factors of China's pharmaceutical manufacturing listed companies such as Inventory turnover rate and operating rate. Study the impact on the performance of China's pharmaceutical manufacturing listed companies. The results of the study will fill gaps in the research of this industry and help pharmaceutical manufacturing listed companies choose the right capital size, liabilities, and expansion strategies, and more effectively absorb the current development dividends of China’s “four new economy”, and use them rationally and effectively. Markets and complex and limited capital and resources of enterprises, as China's industry benchmarks continue to guide the rapid growth of the market. on the other hand, to help investor the empirical point of view better choice of investment targets. This paper uses data from 2007-2016 for randomly selecting 19 companies from 118 medical manufacturing listed companies classified by China Securities Regulatory Commission. After dealing with panel data, multiple inspections are performed on panel data. To avoid the deviation from the actual level of the regression results, the panel-corrected standard deviation model was used to derive the relationship between the operating-level factors of pharmaceutical manufacturing listed companies and their performance. The results of the study indicate that there is a positive correlation between Inventory turnover rate, operating rate and performance, which fills the domestic empirical research on this issue. This area of industry company performance is blank.展开更多
As the development of economy, the corporate social responsibility （CSR） received more and more recognition from academic and business. The traditional economy with only goal of pursuing the wealth is changing rapi...As the development of economy, the corporate social responsibility （CSR） received more and more recognition from academic and business. The traditional economy with only goal of pursuing the wealth is changing rapidly. Chinese corporations realize that it is important and urgent to value the social responsibility, search for effective means to balance the relationship between CSR and COP （corporate operating performance）. Meanwhile, it is helpful and meaningful for the society to build up a healthy and appropriate operating value for corporations. However, there is always a debate of how many social responsibilities a corporation should take in order to satisfy the corporate development and the relationship between CSR and profit, and previous researches on corporate social responsibility mainly focused on all stakeholders of a company. As more and more corporations are aware of the importance of their employee, this study specifically selects employee, one of the most important stakeholders, as the subject investigated. Meanwhile, it chooses New Era Health Industry （Group） Co., Ltd as the target enterprise, which is the only state-owned key enterprises in health industry and the leading corporation in directselling industry in China's Mainland. In order to research the relationship between corporate operating performance and the satisfaction of employees’ material needs and psychological needs, this study plans to complete it by combining the theoretical and empirical study, qualitative analysis and quantitative analysis research methods. Based on a questionnaire of 200 employees in New Era, this study analyzes the situation of CSR to employees for New Era and comes to the conclusion of the relationship between the CSR and COP. According to the research result, this study may give some suggestions for Chinese corporations to fulfill their socialresponsibility system and to improve the situation of the lack of CSR to employees.展开更多
Due to the pressure gain combustion characteristics,the rotating detonation combustor(RDC)can enhance thermodynamic cycle efficiency.Therefore,the performance of gas-turbine engine can be further improved with this co...Due to the pressure gain combustion characteristics,the rotating detonation combustor(RDC)can enhance thermodynamic cycle efficiency.Therefore,the performance of gas-turbine engine can be further improved with this combustion technology.In the present study,the RDC operation performance with a turbine guide vane(TGV)is experimentally investigated.Hydrogen and air are used as propellants while hydrogen and air mass flow rate are about 16.1 g/s and 500 g/s and the equivalence ratio is about 1.0.A pre-detonator is used to ignite the mixture.High-frequency dynamic pressure transducers and silicon pressure sensors are employed to measure pressure oscillations and static pressure in the combustion chamber.The experimental results show that the steady propagation of rotating detonation wave(RDW)is observed in the combustion chamber and the mean propagation velocity is above 1650 m/s,reaching over 84%of theoretical Chapman-Jouguet detonation velocity.Clockwise and counterclockwise propagation directions of RDW are obtained.For clockwise propagation direction,the static pressure is about 15%higher in the combustor compared with counterclockwise propagation direction,but the RDW dominant frequency is lower.When the oblique shock wave propagates across the TGV,the pressure oscillations reduces significantly.In addition,as the detonation products flow through the TGV,the static pressure drops up to 32%and 43%for clockwise and counterclockwise propagation process respectively.展开更多
Currently,developing supercapacitors with robust cycle stability and suitability for wide-temperature-range operations is still a huge challenge.In the present work,few-layer hexagonal boron nitride nanosheets(h-BNNSs...Currently,developing supercapacitors with robust cycle stability and suitability for wide-temperature-range operations is still a huge challenge.In the present work,few-layer hexagonal boron nitride nanosheets(h-BNNSs)with a thickness of 2−4 atomic layers were fabricated via vacuum freeze-drying and nitridation.Then,the h-BNNSs/reduced graphene oxide(rGO)composite were further prepared using a hydrothermal method.Due to the combination of two two-dimensional(2D)van der Waals-bonded materials,the as-prepared h-BNNSs/rGO electrode exhibited robustness to wide-temperature-range operations from−10 to 50℃.When the electrodes worked in a neutral aqueous electrolyte(1 M Na2SO4),they showed a great stable cycling performance with almost 107%reservation of the initial capacitance at 0℃ and 111% at 50℃ for 5000 charge−discharge cycles.展开更多
Operation optimization is an effective method to explore potential economic benefits for existing plants. The m.aximum potential benefit from operationoptimization is determined by the distances between current operat...Operation optimization is an effective method to explore potential economic benefits for existing plants. The m.aximum potential benefit from operationoptimization is determined by the distances between current operating point and process constraints, which is related to the margins of design variables. Because of various ciisturbances in chemical processes, some distances must be reserved for fluctuations of process variables and the optimum operating point is not on some process constraints. Thus the benefit of steady-state optimization can not be fully achied（ed while that of dynamic optimization can be really achieved. In this study, the steady-state optimizationand dynamic optimization are used, and the potential benefit-is divided into achievable benefit for profit and unachievable benefit for control. The fluid catalytic cracking unit （FCCU） is used for case study. With the analysis on how the margins of design variables influence the economic benefit and control performance, the bottlenecks of process design are found and appropriate control structure can be selected.展开更多
The determination of source-side extracted heating parameters is of great significance to the economic operation of cogeneration systems.This paper investigated the coupling performance of a cogeneration heating and p...The determination of source-side extracted heating parameters is of great significance to the economic operation of cogeneration systems.This paper investigated the coupling performance of a cogeneration heating and power system multidimensionally based on the operating characteristics of the cogeneration units,the hydraulic and thermodynamic characteristics of the heating network,and the energy loads.Taking a steam network supported by a gas-steam combined cycle cogeneration system as the research case,the interaction effect among the source-side prime movers,the heating networks,and the terminal demand thermal parameters were investigated based on the designed values,the plant testing data,and the validated simulation.The operating maps of the gas-steam combined cycle cogeneration units were obtained using THERMOFLEX,and the minimum source-side steam parameters of the steam network were solved using an inverse solution procedure based on the hydro-thermodynamic coupling model.The cogeneration operating maps indicate that the available operating domain considerably narrows with the rise of the extraction steam pressure and flow rate.The heating network inverse solution demonstrates that the source-side steam pressure and temperature can be optimized from the originally designed 1.11 MPa and 238.8°C to 1.074 MPa and 191.15°C,respectively.Under the operating strategy with the minimum source-side heating parameters,the power peak regulation depth remarkably increases to 18.30%whereas the comprehensive thermal efficiency decreases.The operation under the minimum source-side heating steam parameters can be superior to the originally designed one in the economy at a higher price of the heating steam.At a fuel price of$0.38/kg and the power to fuel price of 0.18 kg/(kW·h),the critical price ratio of heating steam to fuel is 119.1 kg/t.The influence of the power-fuel price ratio on the economic deviation appears relatively weak.展开更多
In situations where discontinuity in operation occurs, specifically in a country where coontractualization has an increasing trend, the performance level of operators after the work break is of great interest. Existin...In situations where discontinuity in operation occurs, specifically in a country where coontractualization has an increasing trend, the performance level of operators after the work break is of great interest. Existing studies have found that the performance of an operator declines after her operation is completely stopped. However, when the operator performed other tasks （may it be similar or not from her previous task） during the work break, the performance after the work break seems to be affected at different level. Contractual and regular operators from a semiconductor and textile company were considered to replicate a discontinuous and continuous operation. The processing times of contractual workers before and after several months of work break were compared. Two types of work break were seen to have significant effect on an operator＇s performance after the work break, Type 1： 0% to 40% similarity from previous task and Type 2： 40% to 97% similarity from previous task. One can find that when 21% of tasks performed during the work break are similar to the operator＇s previous task, there would be no change in her performance upon returning. On the other hand, a 5% decline in performance was observed after work break type 1 and an 8.54% improvement after work break type 2. Also, a remission rate of 18% from end of stint 1 to start of stint 2 under work break type 1 was seen, while 8% for work break type 2. This may also be true to other industries. Thus, further study is suggested.展开更多
文摘Rare earths,as a strategic mineral resource,play a vital role in high-tech industries such as aerospace,national defense and military,electronic information,and new energy.With the accelerated evolution of the new round of technological revolution and industrial transformation,global supply chain security risks have become more prominent.The focus of major countries'resource security assurance has also shifted from bulk minerals to critical minerals.
基金supported by the National Key R&D Program of China(Grant No.2022YFB4703401).
文摘To meet the intelligent detection needs of underwater defects in large hydropower stations,the hydrodynamic performance of a bionic streamlined remotely operated vehicle containing a thruster protective net structure is numerically simulated via computational fluid dynamics and overlapping mesh technology.The results show that the entity model generates greater hydrodynamic force during steady motion,whereas the square net model experiences greater force and moment during unsteady motion.The lateral and vertical force coefficients of the entity model are 4.32 and 3.13 times greater than those of the square net model in the oblique towing test simulation.The square net model also offers better static and dynamic stability,with a 24.5%increase in dynamic stability,achieving the highest lift-to-drag ratio at attack angles of 6°∼8°.This research provides valuable insights for designing and controlling underwater defect detection vehicles for large hydropower stations.
基金supported by the National Key Research and Development Program(No.2021YFB2400300)the National Natural Science Foundation of China(No.52177214)supported by China Fujian Energy Devices Science and Technology Innovation Laboratory Open Fund(No.21C-OP202211)。
文摘FeS_(2) shows significant potential as cathode material for all-solid-state lithium batteries(ASSLBs)due to its high theoretical specific capacity,low cost,and environmental friendliness.However,the poor ion/electron conductivity and large volume variation effect of FeS_(2) inhibit its practical applications.Here,the influence of particle size of FeS_(2) on the corresponding sulfide-based solid-state batteries is carefully investigated by tuning FeS_(2) size.Moreover,low operating temperature is chosen to mitigate the large volume changes during cycling in the battery.S-FeS_(2) with smaller particle sizes delivers superior electrochemical performances than that of the larger L-FeS_(2) in Li_(5.5)PS_(4.5)Cl_(1.5)-based ASSLBs under different operating temperatures.S-FeS_(2) shows stable discharge capacities during 50 cycles with a current density of 0.1 m A/cm^(2)under -20℃.When the current density rises to 1.0 m A/cm^(2),it delivers an initial discharge capacity of 146.9 m Ah/g and maintains 63% of the capacity after 100 cycles.This work contributes to constructing ASSLBs enables excellent electrochemical performances under extreme operating temperatures.
文摘The banking industry is placing increasing emphasis on green finance to address climate change,support sustainable development,and align with environmental,social,and governance(ESG)goals,as well as sustainable investments to fund environmentally friendly projects.In an era of growing regulatory pressure and rising demand for sustainability from investors and stakeholders,green finance has become a vital tool for banks to enhance operational efficiency.It can reduce operational costs by financing energy-saving projects,improve asset quality by funding low-risk sustainable projects,and even attract capital from environmentally responsible capital markets.Additionally,green finance helps improve risk management frameworks by financing projects that align with long-term sustainable development objectives.This paper explores the relationship between green finance and the operational efficiency of three major banks—RHB Bank,Industrial and Commercial Bank of China(ICBC),and Deutsche Bank.The article focuses on analyzing how these banks integrate green finance into their strategies and the overall impact of these initiatives on operational performance,primarily cost reduction.
文摘Enhancing the efficiency of Rankine cycles is crucial for improving the performance of thermal power plants,as it directly impacts operational costs and emissions in light of energy transition goals.This study sets itself apart from existing research by applying a novel optimization technique to a basic ideal Rankine cycle,focusing on a specific power plant that has not been previously analyzed.Currently,this cycle operates at 41%efficiency and a steam quality of 76%,constrained by fixed operational parameters.The primary objectives are to increase thermal efficiency beyond 46%and raise steam quality above 85%,while adhering to operational limits:a boiler pressure not exceeding 15 MPa,condenser pressure not dropping below 10 kPa,and turbine temperature not surpassing 500℃.This study utilizes numerical simulations to model the effects of varying boiler pressure(Pb)and condenser pressure(Pc)within the ranges of 12MPa<Pb<15 MPa and 5 kPa<Pc<10 kPa.By systematically adjusting these parameters,the proposed aimto identify optimal conditions that maximize efficiency and performance within specified constraints.The findings will provide valuable insights for power plant operators seeking to optimize performance under real-world conditions,contributing to more efficient and sustainable power generation.
基金supported in part by the Science and Technology Innovation Program of Hunan Province under Grants 2023JJ40046 and 2023JJ30049.
文摘Currently,the operational performance assessment system in the power market primarily focuses on power generation and electricity retail companies,lacking a system tailored to the operational characteristics of power generation/selling integrated companies.Therefore,this article proposes an assessment index system for assessing the operational performance of a power generation/selling integrated company,encompassing three dimensions:basic capacity,development potential,and external environment.A dynamic proportional adjustment coefficient is designed,along with a subjective and objective weighting model for assessment indexes based on a combined weightingmethod.Subsequently,the operational performance of an integrated company is assessed using extension theory.The results in the case study demonstrate the feasibility and effectiveness of the proposed dynamic proportional adjustment coefficient.
基金The authors gratefully acknowledge the financial support from the National Natural Science Foundation of China(Grant No.21908010)the Education Department of Jilin Province(Grant No.JJKH20191314KJ)the Changchun University of Technology.
文摘In this work,n-pentane catalytic cracking over HZSM-5 zeolites was studied at 650°C under atmosphere pressure.A particular attention was paid to the measurement of n-pentane conversion,light olefins production,product distribution,coke deposit,etc.Several indexes were defined to evaluate the effects of operating conditions on the catalytic performance of HZSM-5 zeolites.It was found that decreasing the weight hourly space velocity,increasing the reactant partial pressure,and increasing the carrier gas flow rate could inhibit C-H bond breaking and enhance the C-C bond breaking and hydride transfer reactions,leading to reduced alkenes selectivity,which suppressed the formation of external coke and alleviated the deactivation of HZSM-5 zeolites.It was deduced that the catalytic stability of HZSM-5 zeolites was improved at the cost of alkenes selectivity.Compared with decreasing the weight hourly space velocity and increasing the reactant partial pressure,increasing the carrier gas flow rate could enhance the diffusion process and protect alkenes from being consumed in coke formation in order to improve the catalytic stability of HZSM-5 zeolites with less reduction of alkenes selectivity.
文摘This study investigates the earnings performance of 418 initial public offerings （IPOs） listed on the stock exchange of Hong Kong. By analyzing several profitability measures of these 1PO companies from the third year prior to listing up to the fifth year post-listing, it is found that IPO companies＇ operating performances as a whole peak in the year of listing or the year preceding the listing, but exhibit a fall in post-issue profitability with the decline being most pronounced in the first financial year following the year in which the listing take place. Over 30% of these IPOs suffer a loss three years after the offerings. Deterioration of post-issue performance is found to be more severe for smaller finns, highly-geared companies, fast-growing enterprises, companies with lower ownership retention by original shareholders, and companies which have managed earnings upwards at the time of listing. These observations are consistent with the higher agency costs when firms go public and that managers have timed the issue at the peak of the companies＇ long-run performance. Further investigation confirms that IPO companies in general make use of income-increasing accruals to manage their earnings upwards in the year when they go public. The reversal of the accruals in post-issue years further exaggerates the decline in their profitability.
基金supported by the National Key Research and Development Program (No. 2021YFB2400300)the National Natural Science Foundation of China (No. 52177214)。
文摘78Li_(2)S-22P_(2)S_(5) are sulfide electrolytes with high lithium-ion conductivity and wide electrochemical windows in the Li_(2)S-P_(2)S_(5) system,making them attractive solid electrolytes for ASSLBs.However,the role and potential of 78Li_(2)S-22P_(2)S_(5) solid electrolytes over a wide temperature range are still not fully understood.Therefore,we constructed solid-state batteries with NCM622 as the positive electrode and 78Li_(2)S-22P_(2)S_(5) glass-ceramics as the electrolyte to investigate in depth the differences in battery performance over a wide temperature range and their intrinsic mechanisms.The in-situ impedance and relaxation time distribution (DRT) demonstrated the electrochemical stability of the electrolyte over a wide temperature range,while the in-situ stacking pressure observed a large volume change during cycling at 60℃,leading to local solid-solid contact failure and poor cycling stability.This study provides insight into the advantages and problems of 78Li_(2)S-22P_(2)S_(5) in the wide temperature range as well as a basis for the construction of ASSLBs with high energy density and long cycle life.
基金Supported by the National Natural Science Fundation of China.
文摘A theoretical analysis of the effects of flow and mixing on the operating features of astirred column reactor(SCR)with multistage mixers and cooling partition plates was conducted.Amethod for calculating the concentration reduction for a second order chemical reaction in a SCRwas proposed.The reactants concerned were pre-mixed before feeding into the SCR.The SCR wascomposed of a number of stages with interstage backmixing.Experimental investigation with variousreaction media were carried out in order to study the effect of mixing on the operational performanceof the SCR.The experimental data were compared with the theoretical results.
基金Supported by The"Twelfth Five-Year Plan"Philosophy and Social Sciences Planning Project in Guangdong Province(GD11CGL15)Humanities and Social Sciences Foundation of the Ministry of Education(13YJA840024)
文摘By establishing the theoretical model of " strategic network cooperation-relational capability-operating performance" and structural equation,we conduct a sampling survey on 208 agricultural enterprises,and use Spss21. 0 and Amos21. 0 for empirical analysis of influence of three factors in strategic network cooperation( market futurity,trusting relationship and business networks) on market relational capability and operating performance of agricultural enterprises. The results show that the establishment of trusting relationship and business networks in strategic networks has a positive impact on the operating performance of agricultural enterprises,and relational capability plays a fully mediating role while relational capability has not mediating effect on market futurity. This study provides a meaningful reference for the follow-up studies on relational capability and operating performance of agricultural enterprises,to further enhance the operating performance of agricultural enterprises and effectively improve farmers' income.
文摘As an important part of the pharmaceutical industry, the pharmaceutical manufacturing industry is always at the battlefield of the international public health and health industry. At the same time, as a basic and strategic sub-industry in China's manufacturing industry, the medical manufacturing industry closely related to people’s livelihood which is not only related to social Responsibility but also plays a key role in China's economy today. For the Chinese people, the new medical reforms and the irreversible aging of the population have increased the nation’s total expenditure on health care. From January to October 2017, the pharmaceutical industry’s main business income was RMB 2,410.29 billion, a year-on-year increase of 13.10%. This is a 4.50 percentage point higher than the 10.30% growth rate in 2016. However, even if the circumstance of this industry is getting better, high growth also has a drag on the national health insurance system and the standard of living of the people. This article chooses to analyze the financial and operating-level factors of China's pharmaceutical manufacturing listed companies such as Inventory turnover rate and operating rate. Study the impact on the performance of China's pharmaceutical manufacturing listed companies. The results of the study will fill gaps in the research of this industry and help pharmaceutical manufacturing listed companies choose the right capital size, liabilities, and expansion strategies, and more effectively absorb the current development dividends of China’s “four new economy”, and use them rationally and effectively. Markets and complex and limited capital and resources of enterprises, as China's industry benchmarks continue to guide the rapid growth of the market. on the other hand, to help investor the empirical point of view better choice of investment targets. This paper uses data from 2007-2016 for randomly selecting 19 companies from 118 medical manufacturing listed companies classified by China Securities Regulatory Commission. After dealing with panel data, multiple inspections are performed on panel data. To avoid the deviation from the actual level of the regression results, the panel-corrected standard deviation model was used to derive the relationship between the operating-level factors of pharmaceutical manufacturing listed companies and their performance. The results of the study indicate that there is a positive correlation between Inventory turnover rate, operating rate and performance, which fills the domestic empirical research on this issue. This area of industry company performance is blank.
文摘As the development of economy, the corporate social responsibility （CSR） received more and more recognition from academic and business. The traditional economy with only goal of pursuing the wealth is changing rapidly. Chinese corporations realize that it is important and urgent to value the social responsibility, search for effective means to balance the relationship between CSR and COP （corporate operating performance）. Meanwhile, it is helpful and meaningful for the society to build up a healthy and appropriate operating value for corporations. However, there is always a debate of how many social responsibilities a corporation should take in order to satisfy the corporate development and the relationship between CSR and profit, and previous researches on corporate social responsibility mainly focused on all stakeholders of a company. As more and more corporations are aware of the importance of their employee, this study specifically selects employee, one of the most important stakeholders, as the subject investigated. Meanwhile, it chooses New Era Health Industry （Group） Co., Ltd as the target enterprise, which is the only state-owned key enterprises in health industry and the leading corporation in directselling industry in China's Mainland. In order to research the relationship between corporate operating performance and the satisfaction of employees’ material needs and psychological needs, this study plans to complete it by combining the theoretical and empirical study, qualitative analysis and quantitative analysis research methods. Based on a questionnaire of 200 employees in New Era, this study analyzes the situation of CSR to employees for New Era and comes to the conclusion of the relationship between the CSR and COP. According to the research result, this study may give some suggestions for Chinese corporations to fulfill their socialresponsibility system and to improve the situation of the lack of CSR to employees.
基金the National Natural Science Foundation of China(No.11702143 and 11802137)the Fundamental Research Funds for the Central Universities(No.30918011343 and 30919011259).
文摘Due to the pressure gain combustion characteristics,the rotating detonation combustor(RDC)can enhance thermodynamic cycle efficiency.Therefore,the performance of gas-turbine engine can be further improved with this combustion technology.In the present study,the RDC operation performance with a turbine guide vane(TGV)is experimentally investigated.Hydrogen and air are used as propellants while hydrogen and air mass flow rate are about 16.1 g/s and 500 g/s and the equivalence ratio is about 1.0.A pre-detonator is used to ignite the mixture.High-frequency dynamic pressure transducers and silicon pressure sensors are employed to measure pressure oscillations and static pressure in the combustion chamber.The experimental results show that the steady propagation of rotating detonation wave(RDW)is observed in the combustion chamber and the mean propagation velocity is above 1650 m/s,reaching over 84%of theoretical Chapman-Jouguet detonation velocity.Clockwise and counterclockwise propagation directions of RDW are obtained.For clockwise propagation direction,the static pressure is about 15%higher in the combustor compared with counterclockwise propagation direction,but the RDW dominant frequency is lower.When the oblique shock wave propagates across the TGV,the pressure oscillations reduces significantly.In addition,as the detonation products flow through the TGV,the static pressure drops up to 32%and 43%for clockwise and counterclockwise propagation process respectively.
基金financially supported by the National Natural Science Foundation for Excellent Young Scholars of China (No. 51522402)the National Postdoctoral Program for Innovative Talents of China (No. BX20180034)+2 种基金the National Natural Science Foundation of China (No. 51902020)the Fundamental Research Funds for the Central Universities (No. FRF-TP-18-045A1)the China Postdoctoral Science Foundation (No. 2018M641192)
文摘Currently,developing supercapacitors with robust cycle stability and suitability for wide-temperature-range operations is still a huge challenge.In the present work,few-layer hexagonal boron nitride nanosheets(h-BNNSs)with a thickness of 2−4 atomic layers were fabricated via vacuum freeze-drying and nitridation.Then,the h-BNNSs/reduced graphene oxide(rGO)composite were further prepared using a hydrothermal method.Due to the combination of two two-dimensional(2D)van der Waals-bonded materials,the as-prepared h-BNNSs/rGO electrode exhibited robustness to wide-temperature-range operations from−10 to 50℃.When the electrodes worked in a neutral aqueous electrolyte(1 M Na2SO4),they showed a great stable cycling performance with almost 107%reservation of the initial capacitance at 0℃ and 111% at 50℃ for 5000 charge−discharge cycles.
基金Supported by the National Natural Science Foundation of China(21006127)the National Basic Research Program of China(2012CB720500)the Science Foundation of China University of Petroleum(KYJJ2012-05-28)
文摘Operation optimization is an effective method to explore potential economic benefits for existing plants. The m.aximum potential benefit from operationoptimization is determined by the distances between current operating point and process constraints, which is related to the margins of design variables. Because of various ciisturbances in chemical processes, some distances must be reserved for fluctuations of process variables and the optimum operating point is not on some process constraints. Thus the benefit of steady-state optimization can not be fully achied（ed while that of dynamic optimization can be really achieved. In this study, the steady-state optimizationand dynamic optimization are used, and the potential benefit-is divided into achievable benefit for profit and unachievable benefit for control. The fluid catalytic cracking unit （FCCU） is used for case study. With the analysis on how the margins of design variables influence the economic benefit and control performance, the bottlenecks of process design are found and appropriate control structure can be selected.
基金Guangdong Province Key Laboratory of Efficient and Clean Energy Utilization(South China University of Technology)(2013A061401005)Research Fund(JMSWFW-2110-044)from Zhongshan Jiaming Electric Power Co.,Ltd.
文摘The determination of source-side extracted heating parameters is of great significance to the economic operation of cogeneration systems.This paper investigated the coupling performance of a cogeneration heating and power system multidimensionally based on the operating characteristics of the cogeneration units,the hydraulic and thermodynamic characteristics of the heating network,and the energy loads.Taking a steam network supported by a gas-steam combined cycle cogeneration system as the research case,the interaction effect among the source-side prime movers,the heating networks,and the terminal demand thermal parameters were investigated based on the designed values,the plant testing data,and the validated simulation.The operating maps of the gas-steam combined cycle cogeneration units were obtained using THERMOFLEX,and the minimum source-side steam parameters of the steam network were solved using an inverse solution procedure based on the hydro-thermodynamic coupling model.The cogeneration operating maps indicate that the available operating domain considerably narrows with the rise of the extraction steam pressure and flow rate.The heating network inverse solution demonstrates that the source-side steam pressure and temperature can be optimized from the originally designed 1.11 MPa and 238.8°C to 1.074 MPa and 191.15°C,respectively.Under the operating strategy with the minimum source-side heating parameters,the power peak regulation depth remarkably increases to 18.30%whereas the comprehensive thermal efficiency decreases.The operation under the minimum source-side heating steam parameters can be superior to the originally designed one in the economy at a higher price of the heating steam.At a fuel price of$0.38/kg and the power to fuel price of 0.18 kg/(kW·h),the critical price ratio of heating steam to fuel is 119.1 kg/t.The influence of the power-fuel price ratio on the economic deviation appears relatively weak.
文摘In situations where discontinuity in operation occurs, specifically in a country where coontractualization has an increasing trend, the performance level of operators after the work break is of great interest. Existing studies have found that the performance of an operator declines after her operation is completely stopped. However, when the operator performed other tasks （may it be similar or not from her previous task） during the work break, the performance after the work break seems to be affected at different level. Contractual and regular operators from a semiconductor and textile company were considered to replicate a discontinuous and continuous operation. The processing times of contractual workers before and after several months of work break were compared. Two types of work break were seen to have significant effect on an operator＇s performance after the work break, Type 1： 0% to 40% similarity from previous task and Type 2： 40% to 97% similarity from previous task. One can find that when 21% of tasks performed during the work break are similar to the operator＇s previous task, there would be no change in her performance upon returning. On the other hand, a 5% decline in performance was observed after work break type 1 and an 8.54% improvement after work break type 2. Also, a remission rate of 18% from end of stint 1 to start of stint 2 under work break type 1 was seen, while 8% for work break type 2. This may also be true to other industries. Thus, further study is suggested.
