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31.
《Energy Policy》2005,33(3):279-287
Eastern Coastal areas of China have been developing rapidly since the implementation of reforms and the opening of China's economic markets in 1978. As in most areas of the world, this rapid economic growth has been accompanied by large increases in energy consumption. China's coal-dominated energy structure has resulted in serious ecological and environmental problems. Exploiting renewable energy resources and introducing Renewables Portfolio Standard (RPS) are some of the most important approaches towards optimising and sustaining the energy structure of China. This paper discusses international experiences in the implementation of RPS policies and prospects for using these policies to encourage renewable energy development in China, establishes a concise definition of renewable resources, differentiating between the broad definition (which includes hydro over 25 MW in size) from the narrow definition (which limits the eligibility of hydro to below 25 MW in size), and quantitatively analyses the potential renewable energy target. The research shows that: (1) Under the narrow hydro definition the renewable energy target would be 5.1% and under the broad hydro definition it would be 18.4%. (2) Western China has contributed 90.2% of the total renewable electricity generation in the country (if big and medium hydropowers are not included). Including big and medium hydropower, the figure is 63.8%. (3) Eastern electricity companies can achieve their quota by buying Tradable Renewable Energy Certificates (TRCs or Green Certificates) and by exploiting renewable energy resources in Western China. The successful implementation of the RPS policy will achieve the goal of sharing the benefits and responsibilities of energy production between the different regions of China. 相似文献
32.
《Food Control》2016
Both global and domestic markets place increasing importance on the quality and safety of food products that are produced in China. The presence of microbial agents, toxic animal and plant products and chemical contamination remain because of the existence of small and dispersed farmers, who are not educated to use agricultural inputs correctly. This inability raises the issue of safety control in the agricultural sector. This study proposes that cooperatives' self-inspection of agricultural products before they enter the market can better organize small farmers to utilize a standardized production and safety management system. Therefore, we attempt to explore the factors that influence farmer cooperatives' self-inspection behavior. An Ordered Logistic Regression Model is employed to estimate the factors that influence cooperatives' choices of inspection frequency. The results show that the respondents expressed a medium to high level of implementing self-inspection but a lower level of concern in testing products by batch. The regression results indicate that subjective norms from the social environment, the perceived behavioral control of managers, ability and rules including input management, production documentation, and social demographic variables, significantly affect cooperatives' self-inspection behavior. The future implementation of safety inspection depends on the extent to which subjective norms, ability, and internal rules can improve agri-product safety in China. 相似文献
33.
《Food Control》2015
An event-specific multiplex polymerase chain reaction (PCR) detection method was developed to simultaneously detect eight genetically modified (GM) canola events (GT73, MS1, MS8, RF1, RF2, RF3, T45, and Topas 19/2). For a successful multiplex PCR assay, the eight GM canola events were divided into groups 1 and 2 in consideration of their amplicon sizes, primer efficiencies, and target sequences. In addition to the canola endogenous reference gene, FatA, the two pentaplex PCR assays targeted group 1, containing GT73, MS8, RF3, and T45, and group 2, including MS1, RF1, RF2, and Topas 19/2. Event-specific primers targeting the eight GM canola events were designed, and their specificities were confirmed using 14 GM events of maize, soybean, cotton, and canola. After optimizing the reaction conditions, the limits of detection of these two assays were approximately 0.025% for group 1 and 0.0125% for group 2. This multiplex PCR method for eight GM canola events was validated by two operators, and the data confirmed the reliability of the developed assays. The method was used to test commercially available canola seed (eight samples) and meal (one sample) produced in South Korea, China, Canada, and Australia, and the results revealed one or more GM canola events in seven of the nine samples tested. These results show that the developed multiplex system is applicable for use in the specific testing of eight commercially available GM canola events. 相似文献
34.
A statistical method is presented for the determination of the global solar radiation at ground level. It makes use of data from the meteorological satellites, which provide extensive coverage as well as adequante ground resolution. In the first step, a reference map of ground albedo is deduced from the time-sequence of satellite images. Then, by comparing the satellite data with the computed albedo map, a cloud coverage index is determined for each ground point of 5 km × 5 km. This index is linearly correlated to the atmospheric transiission factor. The regression parameters are estimated using a training set provided by ground pyranometers. Tests for two different time periods show a good agreement between the actual and model-derived hourly global radiation. 相似文献
35.
《International Journal of Hydrogen Energy》2023,48(47):17983-17994
Stainless steels play an extremely vital role in the field of marine engineering equipment. However, stainless steel products in service are still subject to corrosion from severe environments such as alternating dry/wet condition and damage caused by hydrogen introduced during heat treatment or cathodic protection. Under alternating dry/wet marine environment, the synergistic effect of hydrogen and corrosion can influence the corrosion resistance of stainless steels dramatically. In this work, the corrosion behavior and mechanism of 2205 duplex stainless steel under alternating dry/wet marine environment are investigated before and after hydrogen charging using electrochemical testing, component characterization and morphological observation. The results show that the open circuit potential, film resistance and breakdown potential all reduce and the passive current density increases after 12 h hydrogen charging. The ratio of Fe3+ and O2−/OH− decreases. The components of the hydrogen charged passive film alter and the performance deteriorates. The number of surface pits increases after 12 h hydrogen charging and additional 10 d alternating dry/wet corrosion. The pitting potential drops much lower. Consequently, The synergistic effect of high concentrations of Cl− in the thin liquid film and hydrogen accelerates the destruction of the passive film, further reducing the corrosion resistance of stainless steels. 相似文献
36.
《International Journal of Hydrogen Energy》2023,48(47):17783-17800
Seawater electrolysis has become an efficient method which makes full use of natural resources to produce hydrogen. However, it suffers high energy cost and chloride corrosion. Herein, we first present a Ni2P/Co(PO3)2/NF heterostructure in which Co(PO3)2 with the nano-rose morphology in-situ grown on the rough Ni2P/NF. The unique 3D nano-rose structure and the optimized electronic structure of the heterostructure enable Ni2P/Co(PO3)2/NF super-hydrophilic and super-aerophobic characteristics, and highly facilitate hydrogen evolution reaction (HER) kinetics in alkaline fresh water, alkaline seawater and even industrial wastewater at large current density, which is rarely reported. Significantly, at large current densities, Ni2P/Co(PO3)2/NF only requires overpotentials of 217 and 307 mV for HER to achieve 1000 mA cm−2 in alkaline fresh water and alkaline seawater, respectively, and requires an overpotential of 469 mV for HER to deliver 500 mA cm−2 in industrial wastewater. Furthermore, the overall seawater splitting system in the two-electrode electrolyzer only requires voltage of 1.98 V to drive 1000 mA cm−2, which also demonstrates significant durability to keep 600 mA cm−2 for at least 60 h. This study opens a new avenue of designing high efficiency electrocatalysts for hydrogen production at large current densities in alkaline seawater and industrial wastewater. 相似文献
37.
《International Journal of Hydrogen Energy》2023,48(47):17827-17837
A novel Pd/PdO and hydrous RuO2 difunction-modified SiO2@TaON@Ta3N5 core-shell structured nano-photocatalyst was synthesized successfully, which displayed excellent photocatalytic activity for overall water splitting into H2 (473.52 μmol−1·g−1·h−1), about 2.86 times higher than unmodified SiO2@TaON@Ta3N5 (165.74 μmol−1·g−1·h−1), under the visible-light irradiation with the wavelength ≥420 nm, without any sacrificial agent, as well as excellent stability against photocorrosion. The apparent quantum yield (AQY) reaches to 0.253% under irradiation intensity of 12 mW cm−2 at 420 nm. The spatially separated Pd, PdO and RuO2 clusters were decorated on the Ta3N5 surface to construct local multi-heterojunctions, which were confirmed to enhance the light absorption capability, drive efficient separation of charge carriers and directional transfer, and promote surface redox reaction kinetics of HER and OER. The trace modification of metallic Pd clusters and TaN could mainly contribute to the significant decrease in the HER overpotential, while PdO exhibited a stronger contribution than RuO2 for OER catalytic activity. The synergetic mechanism of enhanced photocatalytic overall water splitting for hydrogen production was discussed in detail. Thus the combination of core-shell heterojunction construction and surface difunction modification provides a promising strategy for develop efficient all-in-one photocatalysts for solar overall water splitting. 相似文献
38.
《Cities》2019
While many publications predict future urban scenarios, few have deliberated the impact of issued urban planning on scenario prediction. We propose a planning-constrained model (named PCGA-CA) that integrates cellular automata (CA) and genetic algorithm (GA) to simulate current and future urban patterns under the spatial constraints of urban planning. The planning regulations include three types: fully allowed area (FAA), partially allowed area (PAA), and strictly prohibited area (SPA), where we propose a planning implementation parameter (PIP) to represent the stringency in PAA. Under different PIPs, we apply the PCGA-CA model to simulate the 2015 urban patterns and predict the 2030 and 2045 scenarios for Ningbo city, China. The results show that the regulations substantially affect the simulation accuracy and urban pattern. As the planning regulations become less stringent, the accuracy decreases from 90.3% to 89.4% and the urban pattern becomes less compact. In particular, the urban pattern is the most compact when the regulations are not imposed. The PCGA-CA predicts the quantity and location of illegal urban development, and identifies spatially varying urban growth across planning regulations. For the same year, the urban patterns with different PIPs illustrate substantial differences in landscape metrics. The simulations of the current urban pattern should help urban planners and local authorities assess past implementations of urban planning, while the scenario predictions can offer a view of the future by evaluating the consequences of different planning regulations. 相似文献
39.
《Cities》2019
This is a pioneering research linking two areas of knowledge which attract great attention from academia, industry, and governments: business incubation and smart cities. It is a quantitative exploratory study, whose purpose is to investigate the relationship between incubation mechanisms and local urban development according to the concept of Smart City. Methodologically, canonical correlation analysis was applied between two sets of elements: variables associated to business incubation and variables related to smart city characteristics. The research was concentrated on 157 medium- and large-sized cities from 25 European countries. Based on the findings, clusters analysis was also performed. The article presents, among the main results: (1) evidence of correlation between business incubation and smart urban development, and (2) visual classification of these cities into four clusters, according to their urban development and incubation activity. 相似文献
40.
《Cities》2019
Drawing on an agency theory approach, this paper examines conflict of interests and the resulting agency costs in the provision of urban public transport services in Istanbul's public transport system, particularly the private bus and minibus operators' relationship with local government. The agency problem in Istanbul's urban mobility system shows itself most explicitly in private bus and minibus operators because of the net-cost (NC) contract model in place. The private bus and minibus operators' relationship with local government is examined as a case study of agency relationships. Conceptually, government transport authorities and transport operators, together with the passengers, are the main actors of this urban public transport system. They all have distinct needs, interests and requirements and interact with each other, all embedded in a specific institutional environment. Service quality provided by public transport operators depends on the positive interactions between these actors. Whereas passengers demand reliable, affordable, safe and comfortable mobility services, private bus and minibus operators aim to increase their revenue and maximise their profits. In contrast to this, government bus operators provide in-house bus services without much concern for profitability. Regulators or local authorities, on the other hand, are expected to set up an institutional environment where passengers' and operators' expectations are met in a satisfactory manner. Empirical analyses and interviews with key agents demonstrate that agency costs are shown to be the result of misaligned interests between the government transport authority and private operators that lead to reduced service quality in terms of safety, comfort, reliability and affordability. We conclude that the agency costs of current NC contracting on passengers in Istanbul has deficiencies and propose instead a performance-based gross-cost (PrGC) contracting model. PrGC contracting can alleviate agency costs by changing the incentives of operators where regulatory and financing mechanisms are not enough to handle NC contracting. Istanbul represents some transferable lessons and implications, especially for developing cities around the world. 相似文献