Analysis on the changes of fertilization intensity and efficiency in China's grain production from 1980 to 2019.

BACKGROUND: Relieving serious non-point source pollution of nitrogen (N), phosphorus (P), and potassium (K) is an urgent task in China. It is necessary to explore the changing characteristics of chemical fertilization intensity (FI) and efficiency to provide references. A new method of 'relative productivity proportion weight', which was simpler than data envelope analysis, was proposed to construct models of fertilizer allocation efficiency (FAE) and chemical fertilizer integrated efficiency (FIE) by considering NPK multi-inputs and the grain output scale, respectively. RESULTS: During 1980-2014, the FIs of NPK chemical fertilizers in China showed a significant growing trend. After reaching the highest value of 339 kg ha-1 in 2014, FIs were reduced to 303 kg ha-1 in 2019, higher than the 225 kg ha-1 maximum safe usage internationally recognized. Meanwhile, the pattern of change of FAE was one of 'decreasing to increasing', with values of 1 in 1980, 0.66 in 2003, and 0.80 in 2019. FIE basically showed an increasing trend, which could be divided into three stages: the first stage of low efficiency during 1980-2009, the second stage of medium efficiency after 2010, and the third stage of high efficiency after 2018. CONCLUSION: From 1980 until 2019, a reduction of FAE from 1 to 0.80 with an average of 0.75 was observed in China. FIE was found between 0.65 and 0.85 and had the potential of upgrading by 15-35%. Therefore, China needs to improve the fertilizer use efficiency in order to strive for negative growth of chemical fertilizer intensity and ecological agriculture construction. © 2022 Society of Chemical Industry.

Regional differences of individual and allocation efficiencies of health resources in China.

Background: The existing health resources and services are difficult to meet the needs of rapid economic development and the aging population in China. This paper evaluates the regional differences of individual and allocation efficiencies of health resources in China to explore ways to change the current situation. Methods: The models of single-input single-output efficiency (SISOE), single-input multi-output efficiency (SIMOE), multi-input single-output efficiency (MISOE), and multi-input multi-output efficiency (MIMOE) were developed to calculate the individual and allocation efficiencies of health resources of China in this study. Results: It was found that the efficiencies of the number of health institutions (NHI) in the eastern and western regions of China were relatively close, with values of 0.61 and 0.59, respectively, significantly higher than 0.49 in the middle region. The efficiencies of the number of health personnel (NHP) in the eastern, middle, and western regions were closer, with values of 0.77, 0.75, and 0.79, respectively. The efficiencies of the number of health institution beds (NHIB) in the eastern and western regions were very close, with values of 0.79 and 0.78, respectively, while that in the middle region was 0.72. The efficiencies of the total health expenditure (THE) were 0.72, 0.76, and 0.79 in the east, middle, and western regions, respectively. The efficiencies of the number of diagnosis and treatment persons (NDTP) were 0.81, 0.70, and 0.71 in the eastern, middle, and western regions, respectively, while the efficiencies of the number of inpatients (NI) were 0.75, 0.79, and 0.81, respectively. The efficiencies of the utilization rate of beds (URB) and the average days of hospitalization (ADH) in the three regions were below 0.51. The health resources allocation efficiencies (HRAEs) were 0.86, 0.83, and 0.87 in the eastern, middle, and western regions, respectively. Conclusion: There were obvious regional differences in HRAE in China with the situation of "Middle Collapse." The main direct reason for the low HRAE in the middle region was the lower efficiencies of NHI, NHIB, URB, and ADH. It revealed that there was relatively blind expansion of health institutions and beds with lower health service quality in the middle region. Governments should make strategic adjustments to public health resources and increase the investment in medical technology and manpower in the middle region. Hospitals in the eastern region should strengthen inter-regional medical and health technical cooperation with partners in the middle region by establishing a tele-medical network. The models of SISOE, SIMOE, MISOE, and MIMOE put forward in this study are simple, reasonable, and useful for resource efficiency analysis, which makes it convenient to adopt targeted measures to upgrade the efficiency of resource allocation. This study provides a new perspective and method to understand the mechanism of regional differences in China's health resource allocation efficiency.

Comparison of fertilizer use efficiency in grain production between developing countries and developed countries.

BACKGROUND: The investigation of chemical fertilization intensity (FI) and efficiency can provide basal data for decision-making in food production and environmental impact assessments of fertilization. The present study aimed to compare trends of the FI and efficiency during 1961-2018 in developed and developing countries using a simple method. RESULTS: The FI in China increased rapidly from approximately 5 kg ha-1 in 1961 to the highest value of 282 kg ha-1 in 2014, and then decreased to approximately 231 kg ha-1 in 2018. Although the fertilizer allocation efficiency (FAE) showed a slight downward trend, a slight upward trend was observed for fertilizer integrated efficiency (FIE). FIs in India, Iran and Turkey continuously increased from 5 kg ha-1 in 1961 to 116, 49(148 in 2006),120 kg ha-1 in 2018, respectively, whereas FAEs showed a significant fluctuation around horizontal direction or downward trends and their FIEs showed a slight fluctuation downward. The FIs of Britain, Germany and France, excluding USA, increased rapidly from approximately 200-400 kg ha-1 in 1960s to peaks of 430-530 kg ha-1 in 1980s, decreasing to 150-340 kg ha-1 around 2010, and then increased to the current level of 200-350 kg ha-1 , whereas FAEs and FIEs increased rapidly. CONCLUSION: France and Germany were found to have moderate chemical fertilizer input and the highest FIE. Thus, their experiences of ecological agricultures in both countries could provide good examples for developing countries to follow. In brief, models of FAE and FIE are an easier way of reflecting fertilizer efficiencies in developed and developing countries. © 2021 Society of Chemical Industry.

Carbon doped honeycomb-like graphitic carbon nitride for photocatalytic hydrogen production.

Carbon doped honeycomb-like graphitic carbon nitride (g-C3N4) was prepared by one-step thermal polymerization, which derived from chitosan as a carbon source together with the melamine-cyanuric acid complex as a supramolecular precursor. Interestingly, the carbon doped g-C3N4 displayed an increased specific surface area and a more negative conduction band energy level, which not only provided a large number of reaction sites for the photocatalytic hydrogen production, but also effectively enhances the separation of photogenerated electrons-holes. And the experimental results showed that the hydrogen evolution rate of the optimal sample was as high as 320 µmol·h-1, which is 29.10 times than that of bulk g-C3N4 (11 µmol·h-1). More importantly, this work may provide a promising idea for the design of efficient g-C3N4 by controlling the material morphology and combining the electronic modulation strategy.

Ru decorated with NiCoP: an efficient and durable hydrogen evolution reaction electrocatalyst in both acidic and alkaline conditions.

The construction of a high efficiency and stable catalyst for use in electrochemical hydrogen generation has great significance for renewable energy technologies. Herein, we show for the first time that Ru decorated with NiCoP is an excellent hydrogen evolving catalyst in both acidic and alkaline conditions, close in performance to that of Pt/C.

Linear-dendritic block copolymers as a green scale inhibitor for calcium carbonate in cooling water systems.

Water-soluble monomer APEG-PG-(OH)n were produced and the Structure of APEG-PG-(OH)5 were identified by 1H-NMR. APEG-PG-(OH)n were copolymerized with maleic anhydride (MA) to synthesize no phosphate and nitrogen free calcium carbonate inhibitor MA/APEG-PG-(OH)n. The structure and thermal property of MA/APEG-PG-(OH)5 were characterized and measured by 1H-NMR, GPC and TGA. The observation shows that the dosage and n value of MA/APEG-PG-(OH)n plays an important role on CaCO3 inhibition. MA/APEG-PG-(OH)5 displays superior ability to inhibit the precipitation of calcium carbonate, with approximately 97% inhibition at a level of 8 mg/L. The effect on formation of CaCO3 was investigated with combination of SEM and XRD analysis.

[Regional difference of NPK fertilizers application and environmental risk assessment in Jiangsu Province, China].

It is of great importance to have a deep understanding of the spatial distribution of NPK fertilizers application and the potential threat to the ecological environment in Jiangsu Province, which is helpful for regulating the rational fertilization, strengthening the fertilizer use risk management and guidance, and preventing agricultural non-point pollution. Based on the environmental risk assessment model with consideration of different impacts of N, P, K fertilizers on environment, this paper researched the regional differentiation characteristic and environmental risk of intensity of NPK fertilizer usages in Jiangsu. Analystic hierarchy process ( AHP) was used to determine the weithts of N, P, K. The environmental safety thresholds of N, P, K were made according to the standard of 250 kg · hm(-2) for the construction of ecological counties sponsered by Chinese government and the proportion of 1:0.5:0.5 for N:P:K surposed by some developed countries. The results showed that the intensity of NPK fertilizer application currently presented a gradually increasing trend from south to north of Jiangsu, with the extremum ratio of 3.3, and the extremum ratios of nitrogen fertilizer, phosphorus fertilizer and potassium fertilizer were 3.3, 4.5 and 4.4, respectively. The average proportion of nitrogen fertilizer, phosphorus fertilizer and potassium fertilizer of 13 cities in Jiangsu was 1:0.39:0.26. Their proportion was relatively in equilibrium in southern Jiangsu, but the nutrient structure disorder was serious in northern Jiangsu. In Jiangsu, the environmental risk index of fertilization averaged at 0.69 and in the middle-range of environmental risk. The environmental risk index of fertilizer application in southern and central Jiangsu was respectively at the low and moderate levels, while that of cities in northern Jiangsu was at the moderate, serious or severe level. In Jiangsu, the regional difference of fertilizer application and environmental risk assessment were affected by many factors, including physical and economic conditions, government policy, management system, technology, and management methods.