Hydrogen production at intermediate temperatures with proton conducting ceramic cells:Electrocatalytic activity,durability and energy efficiency

Proton conducting ceramic cells(PCCs)are an attractive emerging technology operating in the intermediate temperature range of 500 to 700℃.In this work,we evaluate the production of hydrogen at intermediate temperatures by proton conducting ceramic cell electrolysis(PCCEL).We demonstrate a highperformance steam electrolysis owing to a composite positrode based on BaGd_(0.8)La_(0.2)Co_(2)O_(6-δ)(BGLC1082)and BaZr0.5Ce0.4Y0.1O3-δ(BZCY541).The high reliability of PCCEL is demonstrated for 1680 h at a current density as high as-0.8 A cm^(-2)close to the thermoneutral cell voltage at 600℃.The electrolysis cell showed a specific energy consumption ranging from 54 to 66 kW h kg^(-1)that is comparable to state-of-the-art low temperature electrolysis technologies,while showing hydrogen production rates systematically higher than commercial solid oxide ceramic cells(SOCs).Compared to SOCs,the results verified the higher performances of PCCs at the relevant operating temperatures,due to the lower activation energy for proton transfer comparing with oxygen ion conduction.However,because of the p-type electronic conduction in protonic ceramics,the energy conversion rate of PCCs is relatively lower in steam electrolysis.The faradaic efficiency of the PCC in electrolysis mode can be increased at lower operating temperatures and in endothermic conditions,making PCCEL a technology of choice to valorize high temperature waste heat from industrial processes into hydrogen.To increase the faradaic efficiency by optimizing the materials,the cell design,or the operating strategy is a key challenge to address for future developments of PCCEL in order to achieve even more superior techno-economic merits.

Heterosis Analysis of Nitrogen Use Efficiency for Grain Production of Brassica napus L.

[Objective]The aim was to study heterosis of N use efficiency for grain production （NUEg） of Brassica napus L. and provide theoretical basis for breeding N-efficient cultivars. [Method]Dry matter production and N content of six B.napus parents （Zheshuang 3,Yangyou 7,ZJ1,Shilijia,Ningyou 14 and Huyou 16） and their F1 combinations from 6 × 6 complete diallel cross in maturity stage under two N levels were measured; heterosis of NUEg,combining ability and heritability size were analyzed and calculated. [Result]The results showed that NUEg has obvious heterosis; combining ability variance analysis indicated that NUEg was mainly controlled by additive,dominant and cytoplasmic effects; genetic variance analysis showed that additive effects and dominance effects were all significant in low nitrogen fertilizer and dominance effects were significant in high nitrogen fertilizer. [Conclusion]NUEg of B.napus has obvious heterosis.

Research on the Production Efficiency and Utilizing Rate of Potassium Fertilizer for Rape in Yunnan Province

[Objective] This study aimed at investigating the effects of consumption of potassium fertilizer on production and biological characteristics of rape and utilizing efficiency of potassium fertilizer.[Method] Taking 0 kg/hm2 as control,nine consumptions of potassium fertilizer were designed for the experiment using single factor randomized block design with three replications and field experiment in nine rape-producing areas with different ecological types in Yunnan Province.[Result] Appropriately applying potassium fertilizer in Yunnan Province could improve the rapeseed production,the rape production could achieve 3 983-4 151 kg when applied 150-180 kg/hm2 of K2O,which had increased by 4.7-9.1% compared with the control and attained the peak in K165 treatment.When applied 1 kg of K2O,the rapeseed production could enhance 559 kg,the net profit could reach 1 229 yuan/hm2 and the partial productivity of potassium fertilizer could attain 31.32 kg/kg K2O and 3.7 kg/kg K2O,respectively.Applying potassium fertilizer could promote the growth of rape and increase rapeseed production.[Conclusion] The recommended optimal consumptions of potassium fertilizer with high production and high efficiency for rape in Yunnan Province were ranged between 150 and 180 kg K2O/hm2.However,comprehensively considering production and efficiency factors,the consumption of potassium fertilizer in Yunnan Province was around 73.9 kg/hm2,which should be appropriately increased to around 100.0 kg/hm2 in Longchuan,Yulong,Linxiang and other producing areas with similar conditions.

Production Efficiency of Four Main Crops in the Decade in Hunan Province

The research explored productive efficiencies of main crops in the decade in Hunan by nonparametric DEA method and the results showed that net output value and net-profit rate of potato and sweet potato were extremely higher than those of rice and maize, and comprehensive efficiencies from high to low were potato, rice, sweet potato and maize. It is recommended that scales of rice, maize, and sweet potato should be reduced to certain extent and the scale of potato pro- duction extended. Besides, direct fee and labor cost should be lowered as much as possible to improve net-profit rate, accelerate crop S＆T development and improve grain productive efficiency.

Technical efficiency of cocoa farms at varying elevation levels in Davao City, Philippines: implications to sustainable upland farming systems

Elevation is one of many components that influence agriculture, and this in turn affects the level of both inputs and outputs of farmers. This article focuses on the productivity and technical efficiency of 100 cocoa farms using cross-sectional data from areas ranging from 190 to 1021 m above sea level which were classified as low, medium, and high elevation in Davao City, considered as the chocolate capital of the Philippines. Using stochastic frontier analysis, the results showed that the cost of inputs per ha and the number of cocoa trees per ha significantly increase yield. Farms at high elevations were less technically efficient, as this entails lower temperatures and increased rainfall, and cocoa farming in those areas and conditions can be more challenging, especially with changes in farming practices, terrain, and distance to markets. Other significant variables were age of cocoa farms, married farmers, and age of the farmers. Older farms may be more developed, farmers who are married benefit from their spouses being able to readily contribute as farm labor, and lastly, older farmers' inefficiency may likely stem from nonadaptation of newer farming practices. With an average technical efficiency of 0.61, 0.63, and 0.26 in low, medium, and high elevation areas, respectively, farmers therefore have an incentive to improve farm practices and consider topographical variations found in high elevation areas. Recommendations for the improvement of technical efficiency of cocoa farms are better connectivity to markets, enhancing farm practices, and continuation and improvement of government programs on cocoa with an added emphasis on research. For farmers in high elevation areas, mitigating solutions such as sustainable agriculture practices and ecolabelling are key to improving efficiency and minimizing the potential negative impact on upland farming systems. Moreover, such adaptation measures may also contribute to sustainability of cocoa farming in high elevation areas.

Potentials and Challenges of Carbon Knowledge Graph in Sustainable Textile Production for Carbon Traceability:A Review

Textile production has received considerable attention owing to its significance in production value,the complexity of its manufacturing processes and the extensive reach of its supply chains.However,textile industry consumes substantial energy and materials and emits greenhouse gases that severely harm the environment.In addressing this challenge,the concept of sustainable production offers crucial guidance for the sustainable development of the textile industry.Low-carbon manufacturing technologies provide robust technical support for the textile industry to transition to a low-carbon model by optimizing production processes,enhancing energy efficiency and minimizing material waste.Consequently,low-carbon manufacturing technologies have gradually been implemented in sustainable textile production scenarios.However,while research on low-carbon manufacturing technologies for textile production has advanced,these studies predominantly concentrate on theoretical methods,with relatively limited exploration of practical applications.To address this gap,a thorough overview of carbon emission management methods and tools in textile production,as well as the characteristics and influencing factors of carbon emissions in key textile manufacturing processes is presented to identify common issues.Additionally,two new concepts,carbon knowledge graph and carbon traceability,are introduced,offering strategic recommendations and application directions for the low-carbon development of sustainable textile production.Beginning with seven key aspects of sustainable textile production,the characteristics of carbon emissions and their influencing factors in key textile manufacturing process are systematically summarized.The aim is to provide guidance and optimization strategies for future emission reduction efforts by exploring the carbon emission situations and influencing factors at each stage.Furthermore,the potential and challenges of carbon knowledge graph technology are summarized in achieving carbon traceability,and several research ideas and suggestions are proposed.

Do smart city policies improve energy efficiency?Evidence from China

To address air pollution and offer a convenient and comfortable living environment,the Chinese government launched a smart city pilot(SCP)project in 2012,accompanied by a comprehensive set of environmental and energy-related laws and regulations.Although academic interest in smart cities has surged,there remains a notable gap in empirical research exploring the economic,environmental,and energy effects of such initiatives.Taking 232 prefecture-level cities from 2003 to 2017 as research subjects,this study measures energy effi‐ciency by using energy consumption per unit of GDP and adopts a difference-in-differences(DID)analysis to investigate the impact of SCPs on energy efficiency.The empirical results indicate that SCPs improved energy efficiency by promoting urban technological innovation capabilities and green total factor productivity,and this effect was more pronounced in cities that were more dependent on traditional fossil fuel energy sources and had more developed fiscal and financial levels.Studying the impact of smart city construction on energy utilization efficiency in developing countries,such as China,is not only significantly enlightening for China’s green and low-carbon transition but also provides reference opinions for constructing smart cities and the path to enhancing energy efficiency in other developing countries.The findings provide valuable insights into the global development of smart cities,urban sustainability,and high-quality economic growth.

Environmental Efficiency Analysis of China’s Vegetable Production

To analyze and estimate the environmental efficiency of China’s vegetable production. Methods The stochastic translog frontier model was used to estimate the technical efficiency of vegetable production. Based on the estimated frontier and technical inefficiency levels, we used the method developed by Reinhard, et al.[1] to estimate the environmental efficiency. Pesticide and chemical fertilizer inputs were treated as environmentally detrimental inputs. Results From estimated results, the mean environmental efficiency for pesticide input was 69.7%, indicating a great potential for reducing pesticide use in China’s vegetable production. In addition, substitution and output elasticities for vegetable farms were estimated to provide farmers with helpful information on how to reallocate input resources and improve efficiency. Conclusion There exists a great potential for reducing pesticide use in China’s vegetable production.

Evaluation for Use Efficiency of Agricultural Resources in Grain Production:A Case Study of Changshu,Taihe and Ansai in China

This paper aims to establish an index system for evaluation of agricultural resources use efficiency(ARUE) in grain production and discuss the causes of low efficiency and high consumption of agricultural resources in Changshu of Jiangsu Province,Taihe of Jiangxi Province and Ansai of Shaanxi Province in China by analyzing the data about meteorology,soil,water consumption and grain production. Agro-ecological Zone(AEZ) method was adopted to calculate the potential productivity,and synthetically multivariate equation was used to evaluate the ARUE of study areas. This paper can be concluded as:1) the agricultural resources in grain production can be classified into five categories,i.e.,climatic resources,water resources,land resources,biological resources and assistant resources,and 15 indexes were selected to evaluate their use efficiency in grain production;2) the values of ARUE in grain production are 0.5868,0.6368 and 0.5390 respectively in Changshu,Taihe and Ansai;and 3) Changshu ranks the highest among the three study areas in terms of the use efficiency of climatic resources and biological resources(evaluation values are 0.0277 and 0.1530) ,but Taihe tops the three in terms of the use efficiency of water resources,land resources and assistant resources(evaluation values are 0.0502,0.2945 and 0.1379 respectively) . However,the ARUE remains always low in Ansai for all the resources. The inefficiencies are caused by poor grain revenue in Changshu,deficient agriculture investments in Taihe and unfavorable natural conditions in Ansai.

Global patterns in above-ground net primary production and precipitation-use efficiency in grasslands

The above-ground net primary production(ANPP) and the precipitation-use efficiency(PUE) regulate the carbon and water cycles in grassland ecosystems, but the relationships among the ANPP, PUE and precipitation are still controversial. We selected 717 grassland sites with ANPP and mean annual precipitation(MAP) data from 40 publications to characterize the relationships ANPP–MAP and PUE–MAP across different grassland types. The MAP and ANPP showed large variations across all grassland types, ranging from 69 to 2335 mm and 4.3 to 1706 g m^(-2), respectively. The global maximum PUE ranged from 0.19 to 1.49 g m^(-2) mm^(-1) with a unimodal pattern. Analysis using the sigmoid function explained the ANPP–MAP relationship best at the global scale. The gradient of the ANPP–MAP graph was small for arid and semi-arid sites(MAP <400 mm). This study improves our understanding of the relationship between ANPP and MAP across dry grassland ecosystems. It provides new perspectives on the prediction and modeling of variations in the ANPP for different grassland types along precipitation gradients.

Energy Efficiency Evaluation Based on Data Envelopment Analysis Integrated Analytic Hierarchy Process in Ethylene Production

Energy efficiency data from ethylene production equipment are of high dimension, dynamic and time sequential, so their evaluation is affected by many factors. Abnormal data from ethylene production are eliminated through consistency test, making the data consumption uniform to improve the comparability of data. Due to the limit of input and output data of decision making unit in data envelopment analysis(DEA), the energy efficiency data from the same technology in a certain year are disposed monthly using DEA. The DEA data of energy efficiency from the same technology are weighted and fused using analytic hierarchy process. The energy efficiency data from different technologies are evaluated by their relative effectiveness to find the direction of energy saving and consumption reduction.

Production Efficiency Change and Convergence Analysis of Japonica Rice in China

Using DEA- Malmquist index method,we perform an empirical analysis of Japonica rice production input- output panel data in 12China's major Japonica rice producing areas during 2001- 2012,calculate the total factor input- output efficiency of China's major Japonica rice producing areas,and analyze TFP change and convergence of Japonica rice. It is found that from 2001 to 2012,the average growth rate of total factor productivity( TFP) was- 2. 3% and the technological progress was- 2. 2%,and the decline of technical progress was the main cause of the decrease of TFP. Moreover,significant differences exist between the TFP of these provinces,and the TFP of Heilongjiang and Jiangsu is higher than that of other provinces. Further convergence test indicates that TFP of the main producing areas shows σ convergence trend.

Analysis on Technical Efficiency and Influencing Factors of Rapeseed Production

Based on micro survey data of 344 rapeseed farmers in 19 rapeseed counties of Hubei Province,with the aid of stochastic frontier production function model and efficiency loss model,this paper analyzed basic production situations,demographic characteristics of rapeseed farmers,technical efficiency loss,and main influencing factors. In Hubei Province,there are mainly following problems in rapeseed production: serious aging of rapeseed farmers; relatively scarce labors; the middle-aged and old farmers have higher technical efficiency level; with increase in farmer age,their technical efficiency firstly declines and then rises. In view of these situations,it came up with recommendations including raising educational level of rapeseed farmers to realize large scale economy and effectively reduce technical efficiency loss,and local government,specialized associations and agricultural machinery extension departments should provide proper technical guidance according to demands of farmers to reduce technical efficiency loss.

Energy efficiency evaluation based on DEA integrated factor analysis in ethylene production

Energy efficiency evaluation plays an important role in energy efficiency improvement of the ethylene production. It is observed from the actual production data that the ethylene production energy efficiency often varies with the complex production working conditions. In the favored methods for energy efficiency evaluation,DEA models may show poor resolution when directly used to evaluate the efficiency values. Therefore, a new energy efficiency evaluation method for ethylene production is proposed based on DEA integrated factor analysis with respect to operation classification. Three key factors, including raw material composition, cracking depth and load rate, are taken into account in determining the production working conditions by means of k-means algorithm. Based on the multi-working conditions mode the energy efficiency evaluation of the ethylene production is made by using DEA model, where the most related energy data are screened by factor analysis.Furthermore, the supporting decision of energy efficiency improvement is provided to the operators. The accuracy and effectiveness of the proposed method are illustrated by applying in a practical ethylene production,which gives more effective energy efficiency evaluation in the complicated working conditions of ethylene production with declined dimension of input indicators.

An Analysis of Pig Production Efficiency and Regional Differences in China Based on Malmquist-DEA Model and Inter-provincial Panel Data

Pig production efficiency and its regional differences in China have strategic importance to the transformation of pig production mode and optimization of pig production layout in China. In this paper,Malmquist-DEA model is adopted to analyze the statistical data; TFP and its decomposition indicators of different pig breeding scale among the top ten pig producing provinces are calculated; both horizontal and longitudinal comparisons are made. Results show that among different pig breeding scales,free-range breeding scale is dominant in Hunan,small breeding scale is dominant in Sichuan,medium breeding scale is dominant in Sichuan and Hunan,and large breeding scale is dominant in Sichuan,Shandong and Jiangsu; among the provinces,pig production efficiency varies with breeding scale,and small-scale pig breeding in Sichuan,Guangdong and Hebei,free-range and medium-scale pig breeding in Hunan,medium-scale pig breeding in Henan and Yunnan,largescale pig breeding in the rest of the provinces,have significant efficiency advantage.

DEA Analysis of Agricultural Production Efficiency in Hainan Province

On the basis of summarizing some literatures regarding research of agricultural production efficiency by using DEA at home,we conduct empirical analysis on agricultural production efficiency in 18 cities or counties of Hainan Province in the year 2002,2005 and 2008 by using DEA model.The results show that in 2005 Hainan Province suffered from unusual drought and windstorm,which made the effective value of agricultural production in all cities or counties relatively low;the regions with DEA effectiveness of agricultural production in the year 2002,2005 and 2008 were Qionghai City,Tunchang County,Lingao County,Danzhou City,Qiongzhong County and Baisha County.Haikou City,Wuzhishan City and Baoting County in the year 2002,Lingshui County in the year 2005,and Sanya City and Dongfang County in the year 2008 were also regions with DEA effectiveness,indicating that the input-output of these regions in the corresponding years is in optimal state.Finally,we conduct projection analysis on six cities and counties with non-DEA effectiveness in the year 2008 in Hainan Province,and based on this,find out the approach of improving agricultural production efficiency in these regions.

Efficiency Evaluation of Effect of Direct Grain Subsidy Policy on Performance of Rice Production

Using the DEA analysis method,on the basis of the national panel data from 2002 to 2014,this paper made a comparative analysis on the rice production performance before and after the implementation of direct grain subsidy policy,and made an empirical analysis on the relationship between the direct grain subsidy policy and the changes in the rice production performance. The results showed that the effect of the direct grain subsidy policy on promoting the rice production performance is declining year by year,largely because drop of scale efficiency. Besides,there are problems of serious redundancy in agricultural subsidy,unreasonable resource allocation,leading to low performance and resource waste of rice production.

The Effect of Nitrogen Gas Cooling Which Is Used in Aluminium Extrusion Mold on Production Efficiency

It is aimed to investigate the efficiency of nitrogen gas cooling which is used in aluminium extrusion mold in this study. The exit temperature of extrusion profile increases depending on heat generated by friction and forming. This situation can cause to surface defects such as hot cracks and grain thickening after extrusion process. Cooling of the mold has a critical role in terms of dissipating heat close to the forming zone. Local internal cooling experiments were performed in the hot aluminium extrusion mold within the scope of this study. It has been obtained that exit temperature of the aluminium extrusion profile can be significantly reduced in experimental results. Also it was found that the reduction of press time (s) and increase of press speed (mm/s). This paper focuses the effect of nitrogen gas cooling on extrusion mold for process efficiency. The extrusion parameters were performed for comparative analysis. Its obtained that process ensures efficiency.

Measurement and Analysis of Agricultural Production Efficiency in Taiwan of China Based on Three-stage DEA Model

Agricultural production efficiency in Taiwan of China in 2015 is studied by using three-stage DEA model. The results show that total output value of agriculture,forestry,animal husbandry and fishery is taken as output index,while employees of agriculture,forestry,animal husbandry and fishery,number of tractors,investment in dry land and paddy field are taken as input indexes,which meets " isotropic" condition assumption of model application. Natural disaster,number of workers in agricultural production and marketing class,expenditure on farmland water conservancy are not favorable for the promotion of agricultural production efficiency,while multiple cropping index is favorable for promoting agricultural production efficiency. Three-stage DEA model effectively eliminates the influences of environmental and random factors on agricultural production efficiency. After environmental and random factors are eliminated,comprehensive technical efficiency in Taiwan of China declines because of the decline of pure technical efficiency. Each county and city of Taiwan could be divided into different types according to pure technical efficiency and scale efficiency,and it can have some emphasis in improving agricultural production efficiency according to their own efficiency characteristics.

Agricultural Production Efficiency of Chongqing Based on DEA

Literatures about agricultural production efficiency are reviewed.Concept of DEA Method,as well as the definition methods of effective DEA and scale efficiency increase are introduced.According to the relevant statistical data in the years 1997-2007 in Chongqing Municipality,efficiency of agricultural economy is calculated from the year 1997 to 2007 by DEA method and the scale efficiency is also analyzed by taking the total output of agriculture,forestry,animal husbandry and fishery industry as the output index.And the input index includes total workforce in agriculture,forestry,animal husbandry and fishery,the total sown area of crops,the total power of agricultural machinery,chemical fertilizer application,the draft animal,and the effective irrigation area.Result shows that Chongqing City became a municipality directly under the central government;its agricultural production efficiency is still low.And the sustainable development capacity of agricultural is weak in Chongqing,and the agricultural resources are not fully used.Based on this,related suggestions are put forward to improve the agricultural production efficiency of Chongqing,such as implementing an appropriate management scale of land,improving the organization degree of peasant households and the rate of industrialization management,enhancing the quality of the rural labor force,strengthening the agricultural science and technology input and extension,perfecting the construction of rural infrastructure,and improving the rate of resource utilization.