通讯机构:
[Weikun Zhang] S;School of Social and Public Administration, Lingnan Normal University, Zhanjiang 524088, China
关键词:
agricultural green production;green total factor productivity;spillover effect;technological progress;threshold effect
摘要:
Abstract: This study performs the spatial Durbin model (SDM) and threshold model to analyze the efficiency of agricultural green production following technological progress from 1998 through 2019. The SDM supports a nonlinear contribution of technological progress spillover to agricultural green total factor productivity (GTFP), exacerbated by upgrading agricultural structure. Moreover, the threshold model confirms that technological progress has a single threshold effect on agricultural GTFP with the rationalization of the agrarian system as a threshold variable; meanwhile, the contribution of technological progress to agricultural GTFP is less than that of agricultural total factor productivity. Out of the expanded application of dissipative structure theory in agricultural GTFP systems innovatively, this study reveals the urgency to strengthen the innovation of independent technology, lower the threshold for introducing technology, and optimize the agrarian structure in the long-term sustainable agriculture for the economies that are undergoing a similar development stage as China. Keywords: agricultural green production; technological progress; green total factor productivity; spillover effect; threshold effect
关键词:
Trade policy uncertainty;Precious metal markets;China-US trade Conflict;Time-varying spillovers
摘要:
Using a time-varying vector autoregressive (TVP-VAR) model combined with a spillover index, we study the dynamic spillovers between trade policy uncertainty (TPU) and precious metal markets during the Sino-US trade war. The results show obvious spillover effects between the Chinese TPU and American TPU and the precious metal markets, and the strength and direction of the spillover effects are time-varying and asymmetrical. The uncertainty of the Sino-US trade policy has a heterogeneous impact on the precious metal markets. American TPU dominates the markets, followed by Chinese TPU. In the face of trade war conflict, the spillover fluctuation of American TPU to Chinese TPU is very significant. In addition, in the face of trade policy uncertainty, gold and silver have strong self-adjustment abilities and stabilities, making them highly suitable for hedging investments. International investors and policymakers should consider the impacts of international trade policy uncertainty when conducting risk monitoring and building portfolios in precious metal markets.
作者机构:
[Wu, Liang; Peng, Yuting; Li, Zhijuan] Wuhan Univ, Dept Econ & Management, Wuhan 430072, Peoples R China.;[Zhang, Zemin; Chen, Rui] Wuhan Univ, Dong FuReng Econ & Social Dev Sch, Wuhan 430072, Peoples R China.;[Jiang, Wen; Jiang, Yinjuan] Hunan Agr Univ, Econ Coll, Changsha 410125, Peoples R China.;[Zheng, Kaixin] Wuhan Univ, Acad Dev, Wuhan 430072, Peoples R China.
关键词:
carbon emission;construction sector;green development;industrial green transformation;entropy method
摘要:
In the context of the commitment to peak carbon emissions by 2030, specific sectors in China should take responsibility to change their energy consumption patterns. In China and across the globe, the construction sector is a major source of carbon dioxide emissions, as well as an indicator of economic growth and structural transformation. In this study, we examine panel data for 30 provinces or regions from 2008 to 2019 to dissect which macro-factors contribute to growth in carbon emissions, and which will lead to carbon emission reductions. Derived by the entropy method, the Green Finance Index is a comprehensive environmental regulation index related to reduction in emissions in each province. It presents an N shape for construction emissions, and provinces are currently striving to cross the first inflection point, which will help to curb emissions. Judging from the combined effects of this and other structural factors, the Green Finance Index can promote the decarbonization of production by playing the role of guiding and screening capital allocation. Population expansion, income levels, and financial development initially stimulate demand for construction, but their effects eventually level off. This paper can serve as a reference for developing countries that are experiencing industrialization and urbanization processes and handling gas discharge pressure at the same time.
摘要:
Abstract: Long-term of excessive fertilization using nitrogen (N) chemical fertilizer caused the acidification of paddy soils. Presently, the impacts of soil acidification on physiological characteristics of diazotrophic cyanobacteria remain unknown. In order to elucidate this issue, the effects of paddy floodwater acidification on activities of respiration, photosynthetic oxygen evolution, and N2 fixation of a paddy diazotrophic cyanobacterium Aliinostoc sp. YYLX235 were investigated in this study. In addition, the origination and quenching of intracellular reactive oxygen species (ROS) were analyzed. The acidification of paddy floodwater decreased intracellular pH and interfered in energy flux from light-harvesting chlorophyll antenna to the reaction center of photosystem II (PS II). Activities of respiration, photosynthetic oxygen evolution, and N2 fixation were decreased by the acidification of paddy floodwater. Accompanied with an increase in ROS, the level of antioxidative system increased. Superoxide dismutase (SOD) and catalase (CAT) were the main enzymatic ROS scavengers in the cells of YYLX235; reduced glutathione (GSH) was the main non-enzymatic antioxidant. Antioxidants and oxidants in the cells of YYLX235 lost balance when the pH of paddy floodwater fell to 5.0 and 4.0, and lipid oxidative damage happened. The results presented in this study suggest that the acidification of paddy soil severely interfered in the photosynthesis of diazotrophic cyanobacteria and induced the production of ROS, which in turn resulted in oxidative damage on diazotrophic cyanobacteria and a decrease in cell vitality. Keywords: acidification; diazotrophic cyanobacteria; photosynthesis; reactive oxygen species; antioxidants
通讯机构:
[Xin Liu] C;[Yulin Liao] S;College of Resources and Environment, Hunan Agricultural University, Changsha 410128, China<&wdkj&>Soil and Fertilizer Institute of Hunan Province, Hunan Academy of Agricultural Sciences, Changsha 410125, China
摘要:
Abstract: In this study, we conducted field experiments to assess the effects of the combined application of Chinese milk vetch (Astragalus sinicus L., CMV) and red mud (RM) to remediate the cadmium-polluted acidic paddy soil. The results showed that the combined application increased the yield component index and improved the grain yields, compared with the control, RM1, RM2, and CMV treatments. However, the increased range of soil pH values in the CMV-RM1 and CMV-RM2 treatments was smaller than that of the RM1 and RM2 treatments at the different rice growth stages. The soil organic matter (SOM) contents of the RM-only treatments did not differ throughout the whole period, but were significantly different (p < 0.05) between CMV-RM2 and the control. Compared with the control, the combined application decreased the concentration of exchangeable Cd in the early rice soil. The combined application of CMV and RM substantially decreased the rice uptake of Cd. However, we found no significant difference (p < 0.05) between the CMV-RM1 and CMV-RM2 treatments. Therefore, compared with remediation with RM or CMV alone, we recommend the combined application of CMV and RM as an economical, highly effective, and replicable amendment for remediating acidic, Cd-polluted paddy soil. Considering the restorative effect and proper use of RM, we recommend CMV-RM1 treatment. Keywords: cadmium; contamination; red mud; Chinese milk vetch; rice; paddy soil
通讯机构:
[Lijuan Zhou] S;School of Public Management and Law, Hunan Agricultural University, Changsha 410128, China
关键词:
internet use;social safety perception;China;CSS2017
摘要:
Abstract: Since the advent of the Internet has changed how risk information develops and disseminates, citizens’ risk perception alters correspondingly. Although extant studies have explored the impacts of Internet use on citizens, only a few have focused on citizens’ perception of social safety exclusively. This study examined the effect of Internet use and Internet use frequency on citizens’ perception of social safety with 2017 China Social Survey data. It found that Internet use and Internet use frequency have a significant negative impact on citizens’ social safety perception. Compared to non-users, the probability of perceiving society as very safe decreases significantly by 2.3% for Internet users. Subsequently, this study avoided the endogeneity issues by employing the Bioprobit and CMP methods, and the robustness check adopted propensity score matching methods. In general, it supported results in benchmark regression. The heterogeneity analysis indicated that Internet use had a higher negative impact on citizens in the western region, rural household registration, and middle-aged groups. It suggests that the establishment of a comprehensive mechanism to regulate online information involving governments, Internet industrial organizations, and Internet users may improve governance effectiveness. In addition, education targeting Internet literacy is required to enable a more rational citizen participation on the Internet. Keywords: internet use; social safety perception; China; CSS2017
摘要:
Abstract: Developing countries with small-scale agriculture have yet to exploit the untapped potential of agricultural mechanization. This is because of the misconception that mechanization is often seen as unworthy in small-scale agriculture. The purpose of this paper is to examine the development of agricultural mechanization in China and to provide evidence on how smallholder farmers can access agricultural machinery. A narrative approach was employed to conduct an in-depth analysis of the policies, strategies, and trends associated with agricultural mechanization development. The findings showed that: (1) the establishment and development of mechanization for smallholder agriculture is an evolutionary process that strongly opposes leapfrogging (technocratic behavior) and making large jumps; (2) the foundation of mechanization development should rely on a self-reliance system; (3) an appropriate mechanization theory is the key to inducing the rapid growth of mechanization in small-scale agriculture; (4) the successful application of agricultural machinery requires strong, target-oriented, and pro-farmer policies with effective leadership strategies. We present the key lessons on policy and institutional aspects for countries with small-scale agriculture and who are in the initial stages of agricultural mechanization. Keywords: agricultural mechanization; small-scale agriculture; smallholder farmers
通讯机构:
[Gong Rengui] C;College of Public Administration and Law, Hunan Agricultural University, Changsha, China
关键词:
Elderly people;Physical health;Neighborhood health effects;Mechanism of function
摘要:
BACKGROUND: There are more than 26 million elderly people in China, and due to the Health China strategy proposed in 2020, "Elderly Health" has become an important topic of concern for all sectors of society. Neighborhoods provide important social relationships. However, Chinese researchers have not extensively explored the impact of these relationships on the physical health of the elderly. METHODS: Based on the data from the 2018 China Health and Retirement Longitudinal Study (CHARLS), we constructed a comprehensive research framework integrating ordinary least square (OLS) regression, heterogeneity analysis, IV-2SLS, robustness testing, and Karlson-Holm-Breen (KHB) mediating effect analysis, which can be used to thoroughly examine neighborhood health effects (NHEs) in relation to the physical health of the elderly. RESULTS: The OLS results showed that the NHEs (B=0.4689, p<0.01) had a positive influence on the physical health of the elderly, and were lower than the NHEs estimated by IV-2SLS (B=0.5018, p<0.01). The mediating effects of social networks and social relationships were analyzed using KHB, and both the total (B=0.6056, p<0.01) and indirect (B=0.0800, p<0.01) effects on neighborhood health were significant, with the total effect being 10 times larger than the direct effect and 13.24% of the total effect coming from the mediating variable. CONCLUSIONS: Firstly, the NHEs positively influence the physical health of elderly persons, but there are heterogeneous differences. Secondly, the IV-2SLS estimation results suggest that not controlling for endogeneity leads to underestimation of the role of the NHEs. Thirdly, using the county-level NHEs, self-rated health, and health changes to replace variables, and grouping by smokers (small sample) and never smoked (large sample), the influence of the NHEs on the physical health of the elderly is robust. Finally, social networks and social relationships are important transmission mechanisms of the NHEs when it comes to the physical health of the elderly.
通讯机构:
[Chunyun Guan; Mei Guan] C;College of Agriculture, Hunan Agricultural University, Changsha 410128, China<&wdkj&>Hunan Branch of National Oilseed Crops Improvement Center, Changsha 410128, China<&wdkj&>Southern Regional Collaborative Innovation Center for Grain and Oil Crops in China, Changsha 410128, China
摘要:
Abstract: The overuse of chemical fertilizers has caused various ecological problems in China, necessitating the development of organic alternative fertilizers. There are few studies on the rapidly emerging organic fertilizer rapeseed green manure, despite the importance of understanding its decomposition efficiency and impact on soil. In this study, using plant residue from 14 rapeseed cultivars, we examined the 30-day decomposition changes under conditions A and B (150 and 300 g of plant residue returned, respectively) and detected the effects of their decomposition on soil nitrogen, phosphorus, potassium, and microorganisms. Under condition B, the 30-day cumulative decomposition and nutrient release rates of rapeseed were higher than those under condition A, and the rapeseed decomposition rate exceeded 50% under both conditions, which is similar to results in legume green fertilizers. Moreover, the decomposition of rapeseed green manure significantly increased the soil nutrient content and effectively improved the soil bacterial community structure and diversity relative to the original soil, especially under condition B. Thiobacillus, Azotobacter, and Pseudomonas are bacteria that responded to plant decomposition, and the abundance of the three bacterial genera after plant decomposition was significantly correlated with the plant decomposition traits and soil nutrient content. In conclusion, rapeseed green manure has potential to offset the use of chemical fertilizers, promoting sustainable agricultural development, and this study provides a reference for such green fertilization measures. Keywords: rapeseed; organic fertilizer; nutrients; soil microorganism
摘要:
Irrigation with treated domestic wastewater (TWW) affects the physicochemical properties of soils, but little research has been conducted for different soils in subtropical regions. Consequently, in order to evaluate the effects of domestic wastewater (treated by A2/O process) irrigation on the hydraulic properties, soil salinity and sodicity of four typical subtropical agricultural soils, a soil-column experiment was conducted for one year with eight cycles of wetting and drying. A clay soil (red soil), a silty clay soil (aquic soil), a loamy clay soil (purple soil), and a silty clay loam soil (paddy soil) were subjected to three irrigation modes: (a) cyclic irrigation with TWW (W1), (b) alternating irrigations with TWW and distilled water (W2), and (c) irrigation with distilled water as a control (CK). Our results indicated that EC values increased significantly (p < 0.05) with TWW irrigation for all the soils. TWW irrigation increased the concentrations of Na+, K+, Ca2+, Mg2+, and SAR, ESP values in the red soil, for the W2 treatment especially. In contrast, it decreased Na+, K+, Ca2+, Mg2+ accumulation and ESP values in the aquic soil. Moreover, the soil physical properties exhibited correlations with soil salinity. The saturated hydraulic conductivity (Ks) of the red soil, purple soil, and paddy soil were lower under the W1 and W2 treatments than CK, but the Ks of the aquic soil for W1 were 183.7% higher than that under CK. The unsaturated hydraulic conductivity (Kψ) of the purple soil and paddy soil decreased after TWW irrigation, but those of the aquic soil increased. The water-retention capacities (WRCs) of the TWW-irrigated red soil and aquic soil decreased as a consequence of a shift in the pore-size distribution toward wider pores, but the those of the purple soil and paddy soil improved, associated with narrower pores. The W2 treatment alleviated the impact of TWW on the aquic soil, purple soil, and paddy soil but negatively affected the physical properties, salinity, and sodicity of the red soil. Our results will provide useful information for managing soil and water under TWW irrigation in subtropical regions.
作者机构:
[Gu, Shengbo; Zhuang, Xiaojie; Qiu, Jinsheng] Power China Zhongnan Engn Corp Ltd, Changsha 410014, Peoples R China.;[Liu, Leibin] Beijing Gen Municipal Engn Design & Res Inst Corp, Beijing 100082, Peoples R China.;[Zhou, Zhi] Hunan Agr Univ, Sch Chem & Mat Sci, Changsha 410128, Peoples R China.
通讯机构:
[Shengbo Gu] P;Power China Zhongnan Engineering Corporation Limited, Changsha 410014, China
关键词:
domestic wastewater;enhanced treatment capacity;microbial community shift;nitrifying bacteria carriers;nitrogen removal
摘要:
Abstract: Integrated fixed-film activated sludge technology (IFAS) has a great advantage in improving nitrogen removal performance and increasing treatment capacity of municipal wastewater treatment plants with limited land for upgrading and reconstruction. This research aims at investigating the enhancing effects of polyethylene (PE) carrier and nitrifying bacteria PE (NBPE) carrier on nitrogen removal efficiency of an anoxic/aerobic (A/O) system from municipal wastewater and revealing temporal changes in microbial community evolution. A pilot-scale A/O system and a pilot-scale IFAS system were operated for nearly 200 days, respectively. Traditional PE and NBPE carriers were added to the IFAS system at different operating phases. Results showed that the treatment capacity of the IFAS system was enhanced by almost 50% and 100% by coupling the PE carrier and NBPE carrier, respectively. For the PE carrier, nitrifying bacteria abundance was maintained at 7.05%. In contrast, the nitrifying bacteria on the NBPE carrier was enriched from 6.66% to 23.17%, which could improve the nitrogen removal and treating capacity of the IFAS system. Finally, the ammonia efficiency of the IFAS system with NBPE carrier reached 73.0 ± 7.9% under 400% influent shock load and hydraulic retention time of 1.8 h. The study supplies a suitable nitrifying bacteria enrichment method that can be used to help enhance the nitrogen removal performance of municipal wastewater treatment plants. The study’s results advance the understanding of this enrichment method that effectively improves nitrogen removal and anti-resistance shock-load capacity. Keywords: enhanced treatment capacity; domestic wastewater; nitrifying bacteria carriers; microbial community shift; nitrogen removal
摘要:
Abstract: This study investigates how environmental regulations and social norms affect farmers’ chemical fertilizer reduction behaviors (CFRBs) and investigates the mediating role played by social norms and the moderating role played by social networks. As the analysis tool, a structural equation model is employed to analyze the data collected from a questionnaire survey with 402 valid samples of Chinese citrus growers. This study reveals that (1) environmental regulations and social norms have a significant effect on farmers’ CFRBs; (2) injunctive social norms are a partial mediator of the relationship between incentive-based environmental regulations and farmers’ CFRBs; (3) social networks play a positive moderating role in the relationship between injunctive social norms and farmers’ CFRBs; and (4) large-scale farmers’ CFRBs are more susceptible to the impact of environmental regulations and social norms than small-scale farmers. The result of this study provides a significant scientific foundation for the Chinese agricultural sector to develop policies to combat soil pollution in agriculture. Keywords: agricultural soil pollution; chemical fertilizer reduction behaviors (CFRBs); citrus growers; environmental regulations; social norms; social networks
通讯机构:
[Chen, A.] C;[Li, F.] S;College of Resources and Environment, China;School of Information and Safety Engineering, China
关键词:
Cumulative frequency curve method;PM2.5 baseline;hierarchical management strategy;China;Air Quality
摘要:
Provincial PM2.5 pollution management in China is facing great challenges, which is necessary to formulate hierarchical management strategies according to the specific situation of each province to achieve environmental equity management. This work calculates and analyzes the baseline value of PM2.5 in 31 provinces in China from 2018 to 2019 using the cumulative frequency curve method. Results showed that 93% of the provinces have two inflection points in the cumulative frequency curve, indicating that human activities showed a significant impact on PM2.5. The obtained baselines were assuredly lower than the corresponding monitoring values, which represented upper limits of PM2.5 in a certain area under low human activities. According to the relative size of baseline values, monitoring values, and national standard values, the following three types of results were obtained. Category I was classified as the standard value > monitoring values > baseline value. Category II was classified as the monitoring values > baseline value > standard value. Category III is the monitoring values > standard value > baseline value. A more practical hierarchical management strategy is formulated according to the relationship between baseline, monitoring, and standard values. Category I keeps the current status while striving to bring PM2.5 emissions closer to the baseline value. Category II implements the ‘step-by-step’ measures of reducing to the baseline value and then to the standard val...
关键词:
Introduction;Materials and Methods;Results;Discussion;Conclusion;Abstract;Data Availability;Additional Points;Ethical Approval;Consent;Disclosure;Conflicts of Interests;Authors’ Contributions;Funding Statement;Acknowledgements;Acknowledgments;Supplementary Materials;Reference;Dataset Description;Dataset Files;Abstract;Introduction;Introduction and Materials;Introduction and Methods;Materials;Materials and Methods;Methods;Results;Discussion;Results and Discussion;Discussion and Conclusion;Results and Conclusion;Conclusion;Conclusions;Data Availability;Additional Points;Ethical Approval;Consent;Disclosure;Conflicts of Interest;Authors’ Contributions;Funding Statement;Acknowledgements;Supplementary Materials;References;Appendix;Abbreviations;Preliminaries;Introduction and Preliminaries;Notation;Proof of Theorem;Proofs;Analysis of Results;Examples;Numerical Example;Applications;Numerical Simulation;Model;Model Formulation;Systematic Palaeontology;Nomenclatural Acts;Taxonomic Implications;Experimental;Synthesis;Overview;Characterization;Background;Experimental;Theories;Calculations;Model Verification;Model Implementation;Geographic location;Study Area;Geological setting;Data Collection;Field Testing;Data and Sampling;Dataset;Literature Review;Related Works;Related Work;System Model;Methods and Data;Experimental Results;Results and Analysis;Evaluation;Implementation;Case Presentation;Case Report;Search Terms;Case Description;Case Series;Background;Limitations;Additional Points;Case;Case 1;Case 2 etc.;Concern Details;Retraction Details;Copyright;Related Articles
摘要:
In order to solve the problem of resource ecological compensation, this paper proposed a model of resource ecological compensation mechanism based on a rural leisure sports environment. The model is carried out in many places in China. The survey data involves 31 provinces, 10 years, and 43 indicators, with a total of 43 x 10 x 31 = 13,330 data. The preliminary basis of mechanism construction is summarized from four aspects. Finally, make full use of modern information technology to improve the network platform of the compensation mechanism, promote the efficient allocation and comprehensive utilization of ecotourism resources, and lay a solid foundation for establishing a reasonable and perfect resource ecological compensation mechanism and ensuring the long-term and stable operation of the mechanism. Through the experiment, it is found that the timely and effective publication of information can eliminate the inner estrangement between the two sides, so as to make the behavior of both sides more rational. A special information feedback department is established to deal with the opinions put forward by all compensation parties in tourism development, extract effective information, summarize and publish reasonable guidance information, and guide the compensation of both sides to an ideal balance through the feedback of this information. The effectiveness of the experiment is verified.
期刊:
International Journal of Environmental Research and Public Health,2022年19(22) ISSN:1661-7827
通讯作者:
Jie Xu<&wdkj&>Yong Zhou
作者机构:
[Li, Xigui] Hunan Agr Univ, Coll Landscape Architecture & Art Design, Changsha 410128, Peoples R China.;[Xiao, Pengnan; Zhou, Yong] Cent China Normal Univ, Coll Urban & Environm Sci, Wuhan 430079, Peoples R China.;[Xu, Jie] Hubei Univ, Fac Resources & Environm Sci, Wuhan 430062, Peoples R China.;[Wu, Qing] Zhaoqing Univ, Tourism & Hist Culture Coll, Zhaoqing 526061, Peoples R China.
通讯机构:
[Jie Xu] F;[Yong Zhou] T;The College of Urban & Environmental Sciences, Central China Normal University, Wuhan 430079, China<&wdkj&>Faculty of Resources and Environmental Science, Hubei University, Wuhan 430062, China
关键词:
cultivated land multifunction;trade-off and synergy;function zoning;Jianghan and Dongting Lake Plain
摘要:
Abstract: The material foundation of sustainable agricultural development is cultivated land resources, and their sustainable use is critical to fostering agricultural sustainability and guaranteeing national food security. In this paper, the multifunctional evaluation framework of the cultivated land system based on the “GESEL” model at the grid scale (5 km × 5 km) is constructed to explore the spatiotemporal evolution characteristics of a multifunctional cultivated land system in two lake plains and the trade-off and synergy between the functions. The five functions are all unstable in time scales, and their spatial distribution characteristics are also different. The trade-off and synergy between the multiple functions of the cultivated land system in the two lake plains from 2000 to 2019 showed significant spatial heterogeneity. Most of the functions were mainly collaborative, and a few were trade-offs. The two lake plains can be divided into four multi-functional cultivated land zones: a grain production leading zone, a distinctive agricultural planting zone, a high-efficiency agricultural development zone, and an ecological agricultural construction zone. This research puts forward some countermeasures and suggestions to promote the sustainable utilization of cultivated land resources. Keywords: cultivated land multifunction; trade-off and synergy; function zoning; Jianghan and Dongting Lake Plain