41 results
Search Results
2. Global Progress in Oil and Gas Well Research Using Bibliometric Analysis Based on VOSviewer and CiteSpace.
- Author
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Zhang, Pan, Du, Yongjun, Han, Sijie, and Qiu, Qingan
- Subjects
PETROLEUM industry ,GAS wells ,OIL well cementing ,ENVIRONMENTAL sciences ,MATERIALS science ,ENVIRONMENTAL protection ,OIL wells - Abstract
Studies related to oil and gas wells have attracted worldwide interest due to the increasing energy shortfall and the requirement of sustainable development and environmental protection. However, the state of oil and gas wells in terms of research characteristics, technological megatrends, article-produced patterns, leading study items, hot topics, and frontiers is unclear. This work is aimed at filling the research gaps by performing a comprehensive bibliometric analysis of 6197 articles related to oil and gas wells published between 1900 and 2021. VOSviewer and CiteSpace software were used as the main data analysis and visualization tools. The analysis shows that the annual variation of article numbers, interdisciplinary numbers, and cumulative citations followed exponential growth. Oil and gas well research has promoted the expansion of research fields such as engineering, energy and fuels, geology, environmental sciences and ecology, materials science, and chemistry. The top 10 influential studies mainly focused on shale gas extraction and its impact on the environment. More studies were produced by larger author teams and inter-institution collaborations. Elkatatny and Guo have greatly contributed to the application of artificial intelligence in oil and gas wells. The two most contributing institutions were the Southwest Petr Univ and China Univ Petr from China. The People's Republic of China, the US, and Canada were the countries with the most contributions to the development of oil and gas wells. The authoritative journal in engineering technology was J Petrol Sci Eng, in environment technology was Environ Sci Technol, in geology was Aapg Bull, and in materials was Cement Concrete Res. The keyword co-occurrence network cluster analysis indicated that oil well cement, new energy development, machine learning, hydraulic fracturing, and natural gas and oil wells are the predominant research topics. The research frontiers were oil extraction and its harmful components (1992–2016), oil and gas wells (1997–2016), porous media (2007–2016), and hydrogen and shale gas (2012–2021). This paper comprehensively and quantitatively analyzes all aspects of oil and gas well research for the first time and presents valuable information about active and authoritative research entities, cooperation patterns, technology trends, hotspots, and frontiers. Therefore, it can help governments, policymakers, related companies, and the scientific community understand the global progress in oil and gas well research and provide a reference for technology development and application. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
3. How does vertical integration promote innovation corporate social responsibility (ICSR) in the coal industry? A multiple-step multiple mediator model.
- Author
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Sun, Ziyuan, Li, Yanli, Wang, Man, Wang, Xiaoping, Pan, Yiwen, and Dong, Feng
- Subjects
VERTICAL integration ,SOCIAL responsibility of business ,SOCIAL innovation ,COAL industry ,CORPORATE reform ,MIMO radar - Abstract
This paper aims to demonstrate the impact of coal enterprises’ vertical integration on the performance of innovation corporate social responsibility (ICSR) and to elaborate its specific transmission path through financing structure and market power. This paper takes the data of A-share listed coal company from 2008 to 2017 as samples, uses input-output table method to measure the degree of vertical integration, and explores the relationship between the four factors through multiple linear regression and Bootstrap method. We found that: (1) the vertical integration of coal enterprises has positive incentives for the promotion of ICSR. (2) Financing structure and market power play a chain intermediary role in this process of incentive. (3) In areas with high marketization process, vertical integration has more significant incentive effect on ICSR. The paper extends the research on the relationship between vertical integration and innovation, which provides a reference for the improvement of China’s supply-side reform and corporate social responsibility (CSR) fulfillment policy. It is helpful to promote the sustainable development of the coal industry, stimulate the innovation vitality of enterprises, and improve the fulfillment of CSR. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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4. Energy Storage Ceramics: A Bibliometric Review of Literature.
- Author
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Hu, Haiyan, Liu, Aiping, Wan, Yuehua, and Jing, Yuan
- Subjects
ENERGY storage ,LEAD-free ceramics ,LITERATURE reviews ,MATERIALS science ,BIBLIOMETRICS ,PIEZOELECTRIC ceramics - Abstract
Energy storage ceramics is among the most discussed topics in the field of energy research. A bibliometric analysis was carried out to evaluate energy storage ceramic publications between 2000 and 2020, based on the Web of Science (WOS) databases. This paper presents a detailed overview of energy storage ceramics research from aspects of document types, paper citations, h-indices, publish time, publications, institutions, countries/regions, research areas, highly cited papers, and keywords. A total of 3177 publications were identified after retrieval in WOS. The results show that China takes the leading position in this research field, followed by the USA and India. Xi An Jiao Tong Univ has the most publications, with the highest h-index. J.W. Zhai is the most productive author in energy storage ceramics research. Ceramics International, Journal of Materials Science-Materials in Electronics, and the Journal of Alloys and Compounds are the most productive journals in this field, and materials science—multidisciplinary is the most frequently used subject category. Keywords, highly cited papers, and the analysis of popular papers indicate that, in recent years, lead-free ceramics are prevalent, and researchers focus on fields such as the microstructure, thin films, and phase transition of ceramics. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
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5. Carbon emissions tax policy of urban road traffic and its application in Panjin, China.
- Author
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Yang, Longhai, Hu, Xiaowei, and Fang, Lin
- Subjects
TRAFFIC congestion ,GOVERNMENT policy ,EMISSIONS (Air pollution) ,TRANSPORTATION management ,URBANIZATION ,ROADS - Abstract
How to effectively solve traffic congestion and transportation pollution in urban development is a main research emphasis for transportation management agencies. A carbon emissions tax can affect travelers’ generalized costs and will lead to changes in passenger demand, mode choice and traffic flow equilibrium in road networks, which are of significance in green travel and low-carbon transportation management. This paper first established a mesoscopic model to calculate the carbon emissions tax and determined the value of this charge in China, which was based on road traffic flow, vehicle speed, and carbon emissions. Referring to existing research results to calibrate the value of time, this paper modified the traveler’s generalized cost function, including the carbon emissions tax, fuel surcharge and travel time cost, which can be used in the travel impedance model with the consideration of the carbon emissions tax. Then, a method for analyzing urban road network traffic flow distribution was put forward, and a joint traffic distribution model was established, which considered the relationship between private cars and taxis. Finally, this paper took the city of Panjin as an example to analyze the road traffic carbon emissions tax’s impact. The results illustrated that the carbon emissions tax has a positive effect on road network flow equilibrium and carbon emission reduction. This paper will have good reference value and practical significance for the calculation and implementation of urban traffic carbon emissions taxes in China. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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6. Mapping knowledge landscapes and emerging trends of sonodynamic therapy: A bibliometric and visualized study.
- Author
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Zhenjiang Wu, Kunming Cheng, Zefeng Shen, Yanqiu Lu, Hongtao Wang, Guolei Wang, Yulin Wang, Weiguang Yang, Zaijie Sun, Qiang Guo, and Haiyang Wu
- Subjects
MICROBUBBLE diagnosis ,MATERIALS science ,SILICA nanoparticles ,MESOPOROUS silica ,BIBLIOMETRICS ,NANOTECHNOLOGY ,NANOPARTICLES - Abstract
Background: Ultrasound-triggered sonodynamic therapy (SDT), as a noninvasive approach, has attracted considerable attention in a wide variety of malignant tumors and other diseases. Over the past 2 decades, the number of scientific publications on SDT has increased rapidly. However, there is still a lack of one comprehensive report that summarizes the global research trends and knowledge landscapes in the field of SDT in detail. Thus, we performed a bibliometric analysis on SDT from 2000 to 2021 to track the current hotspots and highlight future directions. Methods: We collected publications on SDT research from the Web of Science Core Collection database. The annual number of publications and citations, major contributors, popular journals, international collaborations, co-cited references and co-occurrence keywords were analyzed and visualized with CiteSpace, VOSviewer, and R-bibliometrix. Results: A total of 701 publications were included. The annual publication output increased from 5 in 2000 to 175 in 2021, and the average growth rate was 18.4%. China was the most productive country with 463 documents (66.05%), and Harbin Medical University was the most prolific institution (N = 73). Ultrasound in Medicine and Biology published the most papers related to SDT. Materials Science, and Chemistry were the research areas receiving the most interest. All the keywords were divided into four different clusters including studies on mechanisms, studies on drug delivery and nanoparticles, studies on cancer therapy, as well as studies on ultrasound and sonosensitizers. In addition to nanomaterials-related studies including nanoparticles, mesoporous silica nanoparticles, nanosheets, liposomes, microbubble and TiO2 nanoparticle, the following research directions such as immunogenic cell death, metal-organic framework, photothermal therapy, hypoxia, tumor microenvironment, chemodynamic therapy, combination therapy, tumor resistance, intensity focused ultrasound, drug delivery, and Staphylococcus aureus also deserve further attention and may continue to explode in the future. Conclusion: SDT has a bright future in the field of cancer treatment, and nanomaterials have increasingly influenced the SDT field with the development of nano-technology. Overall, this comprehensive bibliometric study was the first attempt to analyze the field of SDT, which could provide valuable references for later researchers to better understand the global research trends, hotspots and frontiers in this domain. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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7. Status of the high-intensity heavy-ion accelerator facility in China.
- Author
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Zhou, Xiaohong and Yang, Jiancheng
- Subjects
LIFE sciences ,MATERIALS science ,SPACE sciences ,NUCLEAR physics ,ION beams ,RADIOACTIVE nuclear beams ,EXOTIC nuclei - Abstract
Nuclear physics has been aiming at understanding of the origin, structure, and property of strongly interacting matters, which constitute nearly all visible matter in the universe. Despite tremendous breakthroughs and achievements over the past century, there still exists overarching questions that animate nuclear physics today and incite constructing next-generation heavy-ion accelerator complexes worldwide. In order to promote the national development of heavy-ion science and technology, China government approved the high-intensity heavy-ion accelerator facility (HIAF) in 2015, proposed by the Institute of Modern Physics, Chinese Academy of Sciences. HIAF is composed of a superconducting ion linear accelerator, a high-energy synchrotron booster, a high-energy radioactive isotope beam line, an experimental storage ring, and a few experimental setups. By using HIAF characterized with unprecedented intense ion beams from hydrogen through uranium, we can produce a large variety of exotic nuclear matters not normally found on the Earth, including super-heavy nuclides, short-lived extremely neutron-rich and proton-rich nuclides, finite nuclear matters in the quantum chromodynamics phase diagram, exotic nuclides containing hyperons, meson-nucleus-bound systems, and highly charged ions. Therefore, HIAF will bring researchers to the forefront of promoting the most vigorous and fascinating fields in nuclear physics, such as to explore the limits to the existence of nuclides in terms of proton and neutron numbers, to discover exotic nuclear structure and properties and then to study the physics behind, to understand the origin of heavy elements in the cosmos, to depict the phase diagram of strongly interacting matter, etc. In addition, HIAF will provide an excellent platform to develop heavy-ion applications in life science, space science, and material science. The construction of HIAF started up in December of 2018 and takes 7 years. The civil engineering and infrastructure are being constructed on time schedule and will be completed in July, 2023. R&D on key accelerator techniques are going on successfully, and prototypes of core devices are fabricated in collaboration with home and abroad universities, institutes, and companies. Presently, we come to the stage of invitation for bids and volume production of various apparatuses. We plan to start facility installation in summer of 2023. As a scientific user facility opening to domestic and oversea researchers, HIAF user community plays key roles in defining research programs and raising requirements. We call upon expertise, aspirations, and resources of a host of collaborators. Collaborations, dedicated to specific research subjects, are established and will be established. These collaborations develop new experimental techniques and methods and take responsibility for design and building of measurement systems. We have completed the design of experimental setups. A new gas-filled recoil separator and a novel storage-ring-based isochronous mass spectrometer are already built, and other measurement systems are under construction. The facility commissioning is scheduled at the end in the year of 2025. After into operation of the 2.5 billion Chinese yuan HIAF, this world-class facility will ensure the nation's continued competitiveness in heavy-ion physics and technology through provision of outstanding discovery potential. Based on HIAF, we aim at establishing a world's leading laboratory for research and education in nuclear science, accelerator physics and technology, and applications of energetic heavy ions to meet societal needs. In this paper, progress and status of civil engineering and infrastructure construction of HIAF are introduced, R&D on critical accelerator techniques and prototypes of core devices as well as development of new experimental techniques and methods are presented, and design and construction of experimental setups and the associated physics research programs are briefly depicted. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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8. Bibliometric Analysis of Artificial Intelligence in Textiles.
- Author
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Halepoto, Habiba, Gong, Tao, Noor, Saleha, and Memon, Hafeezullah
- Subjects
ARTIFICIAL intelligence ,BIBLIOMETRICS ,TEXTILE technology ,TECHNICAL textiles ,CHINA-United States relations ,MATERIALS science ,TEXTILES - Abstract
Generally, comprehensive documents are needed to provide the research community with relevant details of any research direction. This study conducted the first descriptive bibliometric analysis to examine the most influential journals, institutions, and countries in the field of artificial intelligence in textiles. Furthermore, bibliometric mapping analysis was also used to examine diverse research topics of artificial intelligence in textiles. VOSviewer was used to process 996 articles retrieved from Web of Science—Core Collection from 2007 to 2020. The results show that China and the United States have the largest number of publications, while Donghua University and Jiangnan University have the highest output. These three themes have also appeared in textile artificial intelligence publications and played a significant role in the textile structure, textile inspection, and textile clothing production. The authors believe that this research will unfold new research domains for researchers in computer science, electronics, material science, imaging science, and optics and will benefit academic and industrial circles. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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9. The heterogeneous effects of exchange rate and stock market on CO2 emission allowance price in China: A panel quantile regression approach.
- Author
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Su, Xiaojian and Deng, Chao
- Subjects
STOCK exchanges ,FOREIGN exchange rates ,QUANTILE regression ,MARKETING ,EMISSIONS trading ,PRICES - Abstract
This paper studies the heterogeneous effects of exchange rate and stock market on carbon emission allowance price in four emissions trading scheme pilots in China. We employ a panel quantile regression model, which can describe both individual and distributional heterogeneity. The empirical results illustrate that the effects of explanatory variables on carbon emission allowance price is heterogeneous along the whole quantiles. Specifically, exchange rate has a negative effect on carbon emission allowance price at lower quantiles, while becomes a positive effect at higher quantiles. In addition, a negative effect exists between domestic stock market and carbon emission allowance price, and the intensity decreasing along with the increase of quantile. By contrast, an increasing positive effect is discovered between European stock market and domestic carbon emission allowance prices. Finally, heterogeneous effects on carbon emission allowance price can also be proved in European Union Emission Trading Scheme (EU-ETS). [ABSTRACT FROM AUTHOR]
- Published
- 2019
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10. Examining seasonal effect of urban heat island in a coastal city.
- Author
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Wu, Xiangli, Zhang, Lin, and Zang, Shuying
- Subjects
URBAN heat islands ,LAND surface temperature ,DIGITAL elevation models ,HUMAN ecology ,MATERIALS science ,ENVIRONMENTAL sciences - Abstract
Urban heat islands (UHIs) have a significant and negative impact on the urban ecological environment and on human health, and it is imperative to examine factors that lead to UHIs. Although numerous studies have been conducted in this field, little research has considered seasonal variations in UHIs in coastal cities. Moreover, parametric statistical analyses, such as regression and correlation analyses, have been typically applied to examine the influential factors. Such analyses are flawed because they cannot uncover the complicated relationships between UHIs and their factors. Taking Dalian, a coastal city in China, as an example, this paper reveals the dynamic mechanism of the UHI effect for different seasons using the cubist regression tree algorithm. Analyses suggest that the UHI effect only exists in spring and summer, and no obvious UHIs can be found in autumn and winter. The adjacency to the sea leads to moderate UHI effects in spring and summer and no UHI or urban cooling island (UCI) effects in autumn and winter. The distance to the coastline, however, does not play a role in the UHI effect. Furthermore, as one of the most important factors, the vegetation coverage plays a significant role in the UHI effect in spring and summer and significantly mediates the UHI in autumn and winter. Comparatively, the elevation (e.g., digital elevation models (DEMs)) is consistently negatively associated with the land surface temperature in all seasons, although a stronger relationship was found in spring and summer. In addition, the surface slope is also a significant factor in spring and winter, and the population density impacts the UHI distribution in summer as well. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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11. Research on desert water management and desert control.
- Author
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Wang, Zhiyong
- Subjects
WATER management ,MATERIALS science ,MANAGEMENT controls ,DESERTS ,WATER use ,WATER storage ,IRRIGATION water - Abstract
Ecological restoration in desertified areas is a worldwide problem. Vegetation restoration is the most sustainable method. But vegetation restoration is facing the challenge of scientific water use. The most effective method of scientific water use is to introduce new material technologies and scientific water management. In this paper, the principles and characteristics of water science materials in recent years are comprehensively analyzed, which includes the interfacial structure water transport mechanism and water droplet formation principle of structural micro-water irrigation technology, the structure self-differential dynamic principle and water transfer dynamics of water molecule infiltrated Irrigation Materials for Self-regulating soil moisture, preliminary scientific analysis and biomimetic structure test of biomimetic gel, water storage principle and characteristics of sand surface crust biomaterials. In addition, according to the characteristics of desert water resources, future research fields and characteristics of desert water science materials are inferred, and the new material technology of "smart irrigation" and "waterless irrigation" will be the leading direction for future development is put forward. However, sand control is the most fundamental solution. Combined with the experience of sand control in the non-Kubuqi desert in China, specific sand prevention plan is put forward. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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12. Transport oil product consumption and GHG emission reduction potential in China: An electric vehicle-based scenario analysis.
- Author
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Zheng, Yuhua, Li, Shiqi, and Xu, Shuangshuang
- Subjects
ELECTRIC potential ,OIL consumption ,REDUCTION potential ,INTERNAL combustion engines ,DIESEL motor exhaust gas ,AUTOMOBILE emissions ,GASOLINE ,HYBRID electric vehicles - Abstract
China’s transport sector is facing enormous challenges from soaring energy consumption and greenhouse gas (GHG) emissions. Transport electrification has been viewed as a major solution to transportation decarbonization, and electric vehicles (EVs) have attracted considerable attention from policymakers. This paper analyzes the effects of the introduction of EVs in China. A system dynamics model is developed and applied to assess the energy-saving and emission-reducing impacts of the projected penetration of EVs until the year 2030. Five types of scenarios of various EV penetration rates, electricity generation mixes, and the speed of technological improvement are discussed. Results confirm that reductions in transport GHG emissions and gasoline and diesel consumption by 3.0%–16.2%, 4.4%–16.1%, and 15.8%–34.3%, respectively, will be achieved by 2030 under China’s projected EV penetration scenarios. Results also confirm that if EV penetration is accompanied by decarbonized electricity generation, that is, the use of 55% coal by 2030, then total transport GHG emissions will be further reduced by 0.8%–4.4%. Moreover, further reductions of GHG emissions of up to 5.6% could be achieved through technological improvement. The promotion of EVs could substantially affect the reduction of transport GHG emissions in China, despite the uncertainty of the influence intensity, which is dependent on the penetration rate of EVs, the decarbonization of the power sector, and the technological improvement efficiency of EVs and internal combustion engine vehicles. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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13. Oil price shocks, economic policy uncertainty and industrial economic growth in China.
- Author
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Chen, Jingyu, Jin, Faqi, Ouyang, Guangda, Ouyang, Jian, and Wen, Fenghua
- Subjects
ECONOMIC policy ,PETROLEUM sales & prices ,ECONOMIC development ,INDUSTRIAL policy ,GRANGER causality test - Abstract
This paper combines a Granger causality test and a VAR model to investigate the relationships among oil price shocks, global economic policy uncertainty (GEPU), and China’s industrial economic growth. Based on monthly data from 2000 to 2017, we reveal that GEPU and world oil prices jointly Granger cause China's industrial economic growth; world oil prices have a positive effect on China's industrial economic growth, while GEPU has a negative effect. Further analyses investigate the asymmetry effect of oil prices and find that the negative component shows a more significant impact on China's industrial economic growth. The results are robust to different oil price and EPU proxies. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
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14. Effect of cutting tool with micro-pits texture on wood cutting performance.
- Author
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Li, Weiguang and Zhang, Zhankuan
- Subjects
WOODCUTTING (Printmaking) ,CUTTING tools ,CARBIDE cutting tools ,CUTTING (Materials) ,LIQUID films ,TEXTURES ,CUTTING force - Abstract
A reasonable micro-pits texture has been initially proved that it can improve friction characteristics between wood and cemented carbide surface and reduce surface friction coefficient. In order to study the cutting performance of the micro-texture when it is applied to the cutting tool for cutting wood more effectively, this paper selected micro-pit texture for studying influence of surface micro-texture cutting tool on wood cutting performance and cutting temperature, finding that when micro-pit cemented carbide cutting tool is adopted for turning the northeast China ash (Fraxinus spp.), it can reduce cutting force of turning and surface friction coefficient between rake face and cuttings. Moreover, for type A and type B cutting tools, when the texture parameters are that the diameter of the micro-pit is 80μm, the depth of the micro pit is: 10μm, area occupancy is 20% and the diameter of the micro-pit is 120μm, the depth of the micro-pit is 10μm and the area occupancy is 20%, the effect generated is the best. When a texture cutting tool is used for cutting, the decrease of the highest temperature in the cutting area is not very great, but the average temperature in the cutting area changes a lot, which is mainly caused by that micro-texture is processed at a position of the rake face close to the main cutting edge and that the highest temperature of cutting is mainly generated on the contact point between tool tip and wood. A reasonable micro-texture parameter can form a layer of liquid lubricating film on the up and down contact surfaces such that the direct contact between cemented carbide and northeast China ash is changed into indirect contact between lubricating films formed by the liquid so as to reduce the surface friction coefficient. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
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15. Application of MIKE SHE to study the impact of coal mining on river runoff in Gujiao mining area, Shanxi, China.
- Author
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Ping, Jianhua, Yan, Shiyan, Gu, Pan, Wu, Zening, and Hu, Caihong
- Subjects
COAL mining ,ECONOMIC development ,ENVIRONMENTAL degradation ,HYDROLOGIC cycle ,HYDROLOGIC models - Abstract
Coal mining is one of the core industries that contribute to the economic development of a country but deteriorate the environment. Being the primary source of energy, coal has become essential to meet the energy demand of a country. It is excavated by both opencast and underground mining methods and affects the environment, especially hydrological cycle, by discharging huge amounts of mine water. Natural hydrological processes have been well known to be vulnerable to human activities, especially large scale mining activities, which inevitably generate surface cracks and subsidence. It is therefore valuable to assess the impact of mining on river runoff for the sustainable development of regional economy. In this paper, the impact of coal mining on river runoff is assessed in one of the national key coal mining sites, Gujiao mining area, Shanxi Province, China. The characteristics of water cycle are described, the similarities and differences of runoff formation are analyzed in both coal mining and pre-mining periods. The integrated distributed hydrological model named MIKE SHE is employed to simulate and evaluate the influence of coal mining on river runoff. The study shows that mining one ton of raw coal leads to the reduction of river runoff by 2.87 m
3 between 1981 and 2008, of which the surface runoff decreases by 0.24 m3 and the baseflow by 2.63 m3 . The reduction degree of river runoff for mining one ton of raw coal shows an increasing trend over years. The current study also reveals that large scale coal mining initiates the formation of surface cracks and subsidence, which intercepts overland flow and enhances precipitation infiltration. Together with mine drainage, the natural hydrological processes and the stream flows have been altered and the river run off has been greatly reduced. [ABSTRACT FROM AUTHOR]- Published
- 2017
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16. Assessment of durability of recycled aggregate concrete produced by two-stage mixing approach.
- Author
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Tam, Vivian W. Y. and Tam, C. M.
- Subjects
CONCRETE ,MINERAL aggregates ,CONSTRUCTION materials ,MATERIALS science - Abstract
As more than 50% construction and demolition (C&D) wastes are composed of concrete debris in Hong Kong, recycling this debris into Recycled Aggregate (RA) for production of Recycled Aggregate Concrete (RAC) is an efficient way to alleviate the burden on landfill areas. Since RA is generated from concrete debris which has undergone years of services, the resulting RAC bears the weaknesses of lower density, higher water absorption, and higher porosity that limit them to lower-grade applications. Pinpointing to these weaknesses, Tam et al . [2005, Cement Concrete Res 35(6):1195–1203] developed the Two-Stage Mixing Approach (TSMA) for improving the strength of RAC, leading to the possibility in applying RAC for higher-grade applications. While the improvement in strength by TSMA has been proven in Tam et al.’s work [2005, Cement Concrete Res 35(6):1195–1203], the durability, in terms of deformation (shrinkage and creep) and permeability (water, air and chloride permeability), remains to be verified. In this paper, 0%, 20% and 100% of RA substitutions have been experimented to compare the durability performance of the Normal Mixing Approach (NMA) and the TSMA. Experiment results highlight that: (i) the higher the substitutions of RA, the weaker the performance of RAC; and (ii) the deformation and permeability of RAC can be enhanced when adopting TSMA. Therefore, it demonstrates that TSMA can help to improve the durability of RAC, on top of the previously verified strength improvement, and thus opening up wider applications of RAC. [ABSTRACT FROM AUTHOR]
- Published
- 2007
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17. Characteristics and origin of the relatively high-quality tight reservoir in the Silurian Xiaoheba Formation in the southeastern Sichuan Basin.
- Author
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Gong, Xiaoxing, Shi, Zejin, Wang, Yong, Tian, Yaming, Li, Wenjie, and Liu, Lei
- Subjects
- *
RESERVOIRS , *SCANNING electron microscopy , *SANDSTONE , *POROSITY - Abstract
A mature understanding of the sandstone gas reservoir in the Xiaoheba Formation in the southeastern Sichuan Basin remains lacking. To assess the reservoir characteristics and the origin of the high-quality reservoir in the Xiaoheba Formation, this paper uses systematic field investigations, physical property analysis, thin section identification, scanning electron microscopy and electron microprobe methods. The results indicate that the Xiaoheba sandstone is an ultra-tight and ultra-low permeability reservoir, with an average porosity of 2.97% and an average permeability of 0.56×10−3 μm2. This promising reservoir is mainly distributed in the Lengshuixi and Shuangliuba regions and the latter has a relatively high-quality reservoir with an average porosity of 5.28% and average permeability of 0.53×10−3 μm2. The reservoir space comprises secondary intergranular dissolved pores, moldic pores and fractures. Microfacies, feldspar dissolution and fracture connectivity control the quality of this reservoir. The relatively weak compaction and cementation in the interbedded delta front distal bar and interdistributary bay microfacies indirectly protected the primary intergranular pores and enhanced late-stage dissolution. Late-stage potassium feldspar dissolution was controlled by the early-stage organic acid dissolution intensity and the distance from the hydrocarbon generation center. Early-stage fractures acted as pathways for organic acid migration and were therefore important factors in the formation of the reservoir. Based on these observations, the area to the west of the Shuangliuba and Lengshuixi regions has potential for gas exploration. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
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18. A Bibliometric Analysis of Electrospun Nanofibers for Dentistry.
- Author
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Jin, Shixin, Yeung, Andy Wai Kan, Zhang, Chengfei, and Tsoi, James Kit-Hon
- Subjects
NANOFIBERS ,BIOENGINEERING ,DENTAL materials ,BONE regeneration ,POLYCAPROLACTONE ,BIBLIOMETRICS ,MATERIALS science - Abstract
Electrospun nanofibers have been widely used in dentistry due to their excellent properties, such as high surface area and high porosity, this bibliometric study aimed to review the application fields, research status, and development trends of electrospun nanofibers in different fields of dentistry in recent years. All of the data were obtained from the Web of Science from 2004 to 2021. Origin, Microsoft Excel, VOSviewer, and Carrot
2 were used to process, analyze, and evaluate the publication year, countries/region, affiliations, authors, citations, keywords, and journal data. After being refined by the year of publication, document types and research fields, a total of 378 publications were included in this study, and an increasing number of publications was evident. Through linear regression calculations, it is predicted that the number of published articles in 2022 will be 66. The most published journal about electrospun dental materials is Materials Science & Engineering C-Materials for Biological Applications, among the six core journals identified, the percent of journals with Journal Citation Reports (JCR) Q1 was 60%. A total of 17.60% of the publications originated from China, and the most productive institution was the University of Sheffield. Among all the 1949 authors, the most productive author was Marco C. Bottino. Most electrospun dental nanofibers are used in periodontal regeneration, and Polycaprolactone (PCL) is the most frequently used material in all studies. With the global upsurge in research on electrospun dental materials, bone regeneration, tissue regeneration, and cell differentiation and proliferation will still be the research hotspots of electrospun dental materials in recent years. Extensive collaboration and citations among authors, institutions and countries will also reach a new level. [ABSTRACT FROM AUTHOR]- Published
- 2022
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- View/download PDF
19. Academic spin-off activities and research performance: the mediating role of research collaboration.
- Author
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Li, Huan, Yang, Xi, and Cai, Xinlan
- Subjects
BUSINESSPEOPLE ,MATERIALS science ,ENTREPRENEURSHIP - Abstract
Studies on the effect of entrepreneurial activities on scientists' subsequent research performance have reported mixed findings. Given the misalignment between spin-off involvement and research activity, our study aims to add to the literature on academic entrepreneurship by examining this effect in a new context and testing the mediating role of research collaboration. We hypothesize that spin-off involvement fosters research collaboration between entrepreneurs and external researchers, which in turn is conducive to research performance. The empirical exercise is based on a sample of 945 scientists at 11 leading material sciences faculties in China, focusing on their spin-off involvement from 2012 to 2014 and their publication records in the following 5-year period. We find that spin-off involvement has a positive effect on individual scientists' subsequent research excellence but does not significantly increase their research productivity. Our findings also confirm the mediating role of research collaboration (both academic–corporate and domestic cross-institutional) in the association between spin-off involvement and research performance. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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20. Changes in orientation.
- Author
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Redahan, Eoin
- Subjects
- *
MATERIALS science , *PHYSICAL sciences research , *INDUSTRIAL processing equipment , *NEW product development - Abstract
The article discusses developments in materials science research in China in 2012. A report says China may be the most prolific producer of materials science research papers, but their impact is less profound. Particular focus is given to the government's involvement in addressing the educational landscape. Premier Wen Jibao addresses development in areas like new materials and advanced equipment manufacturing. The study of specific materials is also mentioned in a Reuters report.
- Published
- 2012
21. HPC software capability landscape in China.
- Subjects
SOFTWARE frameworks ,MATERIALS science ,APPLICATION software ,MIDDLEWARE ,SCIENTISTS ,ARTIFICIAL intelligence ,HIGH performance computing - Abstract
Hardware, applications, and software are equally important to the comprehensive strength of a country in the high-performance computing (HPC) arena. China has made significant progress in developing HPC systems in recent years. The nation's first win of the Gordon Bell Prize at Supercomputing 2016 (SC16) also represents an accomplishment in HPC applications. China's subsequent win in 2017 shows that the 2016 accomplishment was no accident. However, lacking adequately reliable and scalable application software remains the biggest challenge for China. Scientists and engineers who can develop algorithms and software to effectively use supercomputers are in short supply. The present report describes the current HPC software development landscape in China, including government projects and leading universities/research organizations/companies in terms of developing application software and programming frameworks (middleware), as well as examples of self-developed software in the application areas of energy and physics, aerospace, manufacturing, weather and climate, biotechnology (biotech), material science, artificial intelligence (AI), and data analytics. In addition, China's demand and supply of HPC experts are analyzed. Data for this report were generated during the first half of 2017. Some modifications to the text have been added to account for new information through the end of 2017. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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22. Practice pattern of aerosol therapy among patients undergoing mechanical ventilation in mainland China: A web-based survey involving 447 hospitals.
- Author
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Zhang, Zhongheng, Xu, Peifeng, Fang, Qiang, Ma, Penglin, Lin, Huiling, Fink, Jim B., Liang, Zongan, Chen, Rongchang, Ge, Huiqing, and null, null
- Subjects
INHALATION administration ,AEROSOLS ,METERED-dose inhalers ,INTENSIVE care units ,ARTIFICIAL respiration ,NONINVASIVE ventilation - Abstract
Background and objective: Aerosol therapies are widely used for mechanically ventilated patients. However, the practice pattern of aerosol therapy in mainland China remains unknown. This study aimed to determine the current practice of aerosol therapy in mainland China. Methods: A web-based survey was conducted by the China Union of Respiratory Care (CURC) from August 2018 to January 2019. The survey was disseminated via Email or WeChat to members of CURC. A questionnaire comprising 16 questions related to hospital information and 12 questions related to the practice of aerosol therapy. Latent class analysis was employed to identify the distinct classes of aerosol therapy practice. Main results: A total of 693 valid questionnaires were returned by respiratory care practitioners from 447 hospitals. Most of the practitioners used aerosol therapy for both invasive mechanical ventilation (90.8%) and non-invasive mechanical ventilation (91.3%). Practitioners from tertiary care centers were more likely to use aerosol therapy compared with those from non-tertiary care centers (91.9% vs. 85.4%, respectively; p = 0.035). The most commonly used drugs for aerosol therapy were bronchodilators (64.8%) followed by mucolytic agents (44.2%), topical corticosteroids (43.4%) and antibiotics (16.5%). The ultrasonic nebulizer (48.3%) was the most commonly used followed by the jet nebulizer (39.2%), the metered dose inhaler (15.4%) and the vibrating mesh nebulizer (14.6%). Six latent classes were identified via latent class analysis. Class 1 was characterized by the aggressive use of aerosol therapy without a standard protocol, while class 3 was characterized by the absence of aerosol therapy. Conclusions: Substantial heterogeneity among institutions with regard to the use of aerosol therapy was noted. The implementation of aerosol therapy during mechanical ventilation was inconsistent in light of recent practice guidelines. Additional efforts by the CURC to improve the implementation of aerosol therapy in mainland China are warranted. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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23. A technological combination of lead-glaze and calcium-glaze recently found in China: Scientific comparative analysis of glazed ceramics from Shangyu, Zhejiang Province.
- Author
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Wang, Yue, Zhou, Yihang, Yang, Zhefeng, and Cui, Jianfeng
- Subjects
GLAZES ,CERAMICS ,HAN dynasty, China, 202 B.C.-220 A.D. ,COMPARATIVE studies ,CHINESE pottery ,MANUFACTURING processes - Abstract
To study the relationship between the glazed pottery from southern China and the lead-glazed pottery in northern China in the Han Dynasty (202BC-220AD), 34 samples unearthed from Shangyu(上虞), Zhejiang Province have been studied by LA-ICP-AES, SEM/EDS and XRD. The results showed that these samples included the typical lead-glazed pottery, the proto-porcelain and the glazed pottery using both lead and calcium as glaze fluxing agents. Previously, the lead-glazed pottery type was considered as the main northern products during the Han dynasty while the calcium-glazed pottery type or the proto-porcelain was the representative of the south of China. However, apart from the two typical types above, a new variety of glaze categorized as the calcium-lead glaze was discovered in the samples from Shangyu. This indicates that there were technology exchanges and amalgamation of lead-glaze and calcium-glaze between the south and the north during the Han Dynasty. As a result, a new type of glazed potteries with both features was created, which had a more beautiful appearance than the proto-porcelain but perhaps had some undesirable aspects. The manufacturing process of the new variety might also lay foundations for the invention of celadon. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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- View/download PDF
24. Laboratory study on nitrate removal and nitrous oxide emission in intact soil columns collected from nitrogenous loaded riparian wetland, Northeast China.
- Author
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Mwagona, Patteson Chula, Yao, Yunlong, Yuanqi, Shan, and Yu, Hongxian
- Subjects
WETLAND soils ,WETLANDS ,NITROUS oxide ,AGRICULTURAL pollution ,GROUNDWATER pollution ,SOIL science ,AQUATIC sciences - Abstract
Nitrate pollution of surface and groundwater systems is a major problem globally. For some time now wetlands have been considered potential systems for improving water quality. Nitrate dissolved in water moving through wetlands can be removed through different processes, such as the denitrification process, where heterotrophic facultative anaerobic bacteria use for respiration, leading to the production of nitrogen (N
2 ) and nitrous oxide (N2 O) gases. Nitrate removal and emission of N2 O in wetlands can vary spatially, depending on factors such as vegetation, hydrology and soil structure. This study intended to provide a better understanding of the spatial variability and processes involved in removal and emission of N2 O in riparian wetland soils. We designed a laboratory experiment simulating surface water flow through soil columns collected from different sites dominated by different plant species within a wetland. Water and gas samples for and N2 O analyses were collected every 5 days for a period of 30 days. The results revealed significant removal of in all the soil columns, supporting the role of riparian wetland soils in removing nitrogen from surface runoff. Nitrate removal at 0 and 10cm depths in sites dominated by Phragmites australis and Carex schnimdtii was significantly higher than in the site dominated by Calamagrostis epigeio. Nitrous oxide emissions varied spatially and temporally with negative flux observed in sites dominated by P. australis and C. schnimdtii. These results reveal that in addition to the ability of wetlands to remove , some sites within wetlands are also capable of consuming N2 O, hence mitigating not only agricultural nitrate pollution but also climate change. [ABSTRACT FROM AUTHOR]- Published
- 2019
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25. The analysis and application of granular backfill material to reduce surface subsidence in China’s northwest coal mining area.
- Author
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Bai, Erhu, Guo, Wenbing, Tan, Yi, and Yang, Daming
- Subjects
COAL mining ,LANDFILLS ,LAND subsidence ,GROUNDWATER analysis ,SLURRY - Abstract
In China’s northwest coal mining area, the excavation of shallow buried thick coal seams has caused serious damage to the phreatic water layer and induced deterioration of the ecological environment. Backfilling is a basic method of controlling the loss of groundwater and reducing surface subsidence. In order to reduce the porosity of the backfill material and control the compression ratio of the backfill body, the grain gradation of the local aeolian sand was studied based on the geological conditions of the shallow buried coal seam in the Yulin mining area, Shaanxi province. Subsequently, aeolian sand was selected as the backfilling aggregate, and tests were implemented. The optimum proportion and slurry concentration of the backfill material were then obtained. The engineering application shows that the strength and stability of the backfill body based on the close packing theory can satisfy the requirements of supporting the overlying strata, and the integrity of overburden strata is competent. The maximum accumulated surface subsidence was measured to be 38mm, indicating that the aeolian sand-based backfill material in shallow and thick underground coal seam mining is able to protect the eco-environment and control the geo-environmental hazards, which are critical for the sustainable development of the mining industry and economic growth. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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26. Relationship between fine particulate matter, weather condition and daily non-accidental mortality in Shanghai, China: A Bayesian approach.
- Author
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Fang, Xin, Fang, Bo, Wang, Chunfang, Xia, Tian, Bottai, Matteo, Fang, Fang, and Cao, Yang
- Subjects
PARTICULATE matter ,MORTALITY ,ENVIRONMENTAL policy ,METEOROLOGY ,BAYESIAN analysis - Abstract
There are concerns that the reported association of ambient fine particulate matter (PM
2.5 ) with mortality might be a mixture of PM2.5 and weather conditions. We evaluated the effects of extreme weather conditions and weather types on mortality as well as their interactions with PM2.5 concentrations in a time series study. Daily non-accidental deaths, individual demographic information, daily average PM2.5 concentrations and meteorological data between 2012 and 2014 were obtained from Shanghai, China. Days with extreme weather conditions were identified. Six synoptic weather types (SWTs) were generated. The generalized additive model was set up to link the mortality with PM2.5 and weather conditions. Parameter estimation was based on Bayesian methods using both the Jeffreys’ prior and an informative normal prior in a sensitivity analysis. We estimate the percent increase in non-accidental mortality per 10 μg/m3 increase in PM2.5 concentration and constructed corresponding 95% credible interval (CrI). In total, 336,379 non-accidental deaths occurred during the study period. Average daily deaths were 307. The results indicated that per 10 μg/m3 increase in daily average PM2.5 concentration alone corresponded to 0.26–0.35% increase in daily non-accidental mortality in Shanghai. Statistically significant positive associations between PM2.5 and mortality were found for favorable SWTs when considering the interaction between PM2.5 and SWTs. The greatest effect was found in hot dry SWT (percent increase = 1.28, 95% CrI: 0.72, 1.83), followed by warm humid SWT (percent increase = 0.64, 95% CrI: 0.15, 1.13). The effect of PM2.5 on non-accidental mortality differed under specific extreme weather conditions and SWTs. Environmental policies and actions should take into account the interrelationship between the two hazardous exposures. [ABSTRACT FROM AUTHOR]- Published
- 2017
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- View/download PDF
27. Identification of low-overpressure interval and its implication to hydrocarbon migration: Case study in the Yanan sag of the Qiongdongnan Basin, South China Sea.
- Author
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Xu, Qinghai, Shi, Wanzhong, Xie, Yuhong, Wang, Zhenfeng, Li, Xusheng, and Tong, Chuanxin
- Subjects
HYDROCARBONS ,GAS migration ,HYDROSTATIC pressure ,GEOLOGICAL basins - Abstract
The Qiongdongnan Basin is a strongly overpressured basin with the maximum pressure coefficient (the ratio of the actual pore pressure versus hydrostatic pressure at the same depth) over 2.27. However, there exists a widespread low-overpressure interval between the strong overpressure intervals in the Yanan Sag of western basin. The mechanisms of the low-overpressure interval are not well understood. Three main approaches, pore pressure test data and well-log analysis, pressure prediction based on the relationship between the deviation of the velocity and the pressure coefficients, and numerical modeling, were employed to illustrate the distribution and evolution of the low-overpressure interval. And we analyzed and explained the phenomenon of the low-overpressure interval that is both underlain and overlain by high overpressure internal. The low-overpressure interval between the strong overpressure intervals can be identified and modelled by drilling data of P-wave sonic and the mud weight, and the numerical modeling using the PetroMod software. Results show that the low-overpressure interval is mainly composed of sandstone sediments. The porosities of sandstone in the low-overpressure interval primarily range from 15%-20%, and the permeabilities range from 10–100 md. Analysis of the geochemical parameters of C1, iC4/nC4, ΔR3, and numerical modeling shows that oil and gas migrated upward into the sandstone in the low-overpressure interval, and then migrated along the sandstone of low-overpressure interval into the Yacheng uplift. The low-overpressure both underlain and overlain by overpressure resulted from the fluids migrating along the sandstones in the low-overpressure interval into the Yacheng uplift since 1.9Ma. The mudstone in the strong overpressure interval is good cap overlain the sandstone of low-overpressure interval, therefore up-dip pinchouts or isolated sandstone in the low-overpressure interval locating the migration path of oil and gas are good plays for hydrocarbon exploration. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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- View/download PDF
28. Bio-inspired superwettable materials: an interview with Lei Jiang.
- Author
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Weijie Zhao
- Subjects
SCIENTISTS ,MATERIALS science - Published
- 2017
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29. Dust-concentration measurement based on Mie scattering of a laser beam.
- Author
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Yu, Xiaoyu, Shi, Yunbo, Wang, Tian, and Sun, Xu
- Subjects
ECONOMIC conditions in China, 2000- ,URBANIZATION ,URBANIZATION & the environment ,AEROSOLS & the environment ,FOG - Abstract
To realize automatic measurement of the concentration of dust particles in the air, a theory for dust concentration measurement was developed, and a system was designed to implement the dust concentration measurement method based on laser scattering. In the study, the principle of dust concentration detection using laser scattering is studied, and the detection basis of Mie scattering theory is determined. Through simulation, the influence of the incident laser wavelength, dust particle diameter, and refractive index of dust particles on the scattered light intensity distribution are obtained for determining the scattered light intensity curves of single suspended dust particles under different characteristic parameters. A genetic algorithm was used to study the inverse particle size distribution, and the reliability of the measurement system design is proven theoretically. The dust concentration detection system, which includes a laser system, computer circuitry, air flow system, and control system, was then implemented according to the parameters obtained from the theoretical analysis. The performance of the designed system was evaluated. Experimental results show that the system performance was stable and reliable, resulting in high-precision automatic dust concentration measurement with strong anti-interference ability. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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30. Factor contribution to fire occurrence, size, and burn probability in a subtropical coniferous forest in East China.
- Author
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Ye, Tao, Wang, Yao, Guo, Zhixing, and Li, Yijia
- Subjects
CONIFEROUS forests ,FORESTS & forestry ,FOREST fires ,SIMULATION methods & models ,PROBABILITY theory - Abstract
The contribution of factors including fuel type, fire-weather conditions, topography and human activity to fire regime attributes (e.g. fire occurrence, size distribution and severity) has been intensively discussed. The relative importance of those factors in explaining the burn probability (BP), which is critical in terms of fire risk management, has been insufficiently addressed. Focusing on a subtropical coniferous forest with strong human disturbance in East China, our main objective was to evaluate and compare the relative importance of fuel composition, topography, and human activity for fire occurrence, size and BP. Local BP distribution was derived with stochastic fire simulation approach using detailed historical fire data (1990–2010) and forest-resource survey results, based on which our factor contribution analysis was carried out. Our results indicated that fuel composition had the greatest relative importance in explaining fire occurrence and size, but human activity explained most of the variance in BP. This implies that the influence of human activity is amplified through the process of overlapping repeated ignition and spreading events. This result emphasizes the status of strong human disturbance in local fire processes. It further confirms the need for a holistic perspective on factor contribution to fire likelihood, rather than focusing on individual fire regime attributes, for the purpose of fire risk management. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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- View/download PDF
31. Effect of Waterlogging Duration at Different Growth Stages on the Growth, Yield and Quality of Cotton.
- Author
-
Wang, Xiaosen, Deng, Zhong, Zhang, Wenzheng, Meng, Zhaojiang, Chang, Xiao, and Lv, Mouchao
- Subjects
MALVACEAE ,WATERLOGGING (Soils) ,COTTON quality ,AGRICULTURE ,SEEDLINGS - Abstract
In this study, a soil culture experiment was set up in barrels to investigate the effect of waterlogging duration at different growth stages on the growth, yield, and quality of cotton in the Huang-Huai Region of China during summer. The experiment was conducted at four growth stages of cotton (seedling, squaring, flowering, and boll opening), and the waterlogging duration at each stage was set to five levels (2, 4, 6, 8, and 10 d) and the waterlogging depth was 5cm. Twenty different treatment combinations were established, and one group without waterlogging throughout the whole growth period was used as the control (CK). The results showed that the waterlogging treatments at the different growth stages reduced the morphological and yield parameters of the cotton plants as well as the physiological parameters of the cotton leaves, and the extent of the reduction in these parameters increased with the extension of the waterlogging duration. The effect of waterlogging at different growth stages on the cotton decreased in the order of the flowering, squaring, seedling, and boll-opening stages, and the highest yield reduction rates for the four stages were 38.8%, 27.9%, 18.3%, and 7.6% respectively. Additionally, waterlogging decreased the quality parameters of cotton such as the upper-half mean length, uniformity index, micronaire value, elongation, yellowness, and lint percentage at the squaring, flowering, and boll-opening stages. Furthermore, at the seedling stage waterlogging for no more than 6 d allowed the morphological and yield parameters to recover in the boll-opening stage upon timely drainage, and these parameters showed no significant decreases compared with the CK level. The critical duration of waterlogging at the squaring stage was 4 d. However, at the flowering stage, even 2 d of waterlogging could lead to the stagnation of morphological development and prevent the recovery of the cotton yield to the CK level. Therefore, when waterlogging disasters occur in cotton fields, the implementation of appropriate surface and subsurface drainage schemes for the different growth stages is needed as soon as possible to mitigate the damage. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
32. Tracing Sources and Contamination Assessments of Heavy Metals in Road and Foliar Dusts in a Typical Mining City, China.
- Author
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Yang, Jie, Teng, Yanguo, Song, Liuting, and Zuo, Rui
- Subjects
HEAVY metals & the environment ,ROADS ,DUST ,MINERAL industries ,MAGNETITE ,POLLUTION - Abstract
Road and foliar dust samples from four land-use districts of Panzhihua City, a famous V-Ti magnetite production area of China, were collected to investigate the sources and distribution characteristics of 9 heavy metals (V, Pb, Cd, Cu, Zn, Ni, Cr, Fe, and Mn). The results suggest that foliar samples had smaller particle size and higher heavy metal contents than road dusts. The contamination assessments of heavy metals were as follows: Pb and V (significant enrichment) > Zn, Ni, Cr, Fe, and Mn (moderate enrichment) > Cd and Ni (minimal enrichment). Statistical analyses showed Pb, as the primary pollution element, originated from waste incineration and lead-fuel combustion. The sources of Zn, Ni, Cr, Fe, V, and Mn were fugitive dust and traffic activities. Potential origins of Cu were corrosion of alloys used in vehicle components, vehicle covers, or other metallic surfaces and materials. The sources of Cd were different from any other heavy metals. Traffic and industrial activities were the main anthropogenic origins of heavy metals in dusts of Panzhihua, and more attention should be paid to heavy metal pollution in agricultural area. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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- View/download PDF
33. Effects of Heavy Metals from Soil and Dust Source on DNA Damage of the Leymus chinensis Leaves in Coal-Mining Area in Northwest China.
- Author
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Li, Tianxin, Zhang, Minjie, Lu, Zhongming, Herman, Uwizeyimana, Mumbengegwi, Dzivaidzo, and Crittenden, John
- Subjects
HEAVY metals ,SOIL composition ,DNA damage ,COAL mining ,PARTICULATE matter ,HEAVY metal toxicology - Abstract
Air and soil pollution from mining activities has been considered as a critical issue to the health of living organisms. However, few efforts have been made in distinguishing the main pathway of organism genetic damage by heavy metals related to mining activities. Therefore, we investigated the genetic damage of Leymus chinensis leaf cells, the air particulate matter (PM) contents, and concentrations of the main heavy metals (Pb, Cd, Cr, Hg) in soil and foliar dust samples collected from seven experiment points at the core mining area and one control point 20 kilometers away from the core mining area in Inner Mongolia in 2013. Comet assay was used to test the genetic damage of the Leymus chinensis leaf cells; the Tail DNA% and Tail Moment were used to characterize the genetic damage degree of the plant cells. The comet assay results showed that the cell genetic damage ratio was up to 77.0% in experiment points but was only 35.0% in control point. The control point also had the slight Tail DNA% and Tail Moment values than other experiment groups. The cell damage degree of the control group was 0.935 and experiment groups were 1.299–1.815. The geo-accumulation index and comperehensive pollution index(CPI) were used to characterize heavy metal pollution in foliar dust samples, and single factor pollution index and CPI were used to characterize the heavy metal pollution in soil samples. The CPI
foliar dust of control group was 0.36 and experiment groups were 1.45–2.57; the CPIsoil of control group was 0.04 and experiment groups were 0.07–0.12. The results of correlation analyze showed that Air Quality Index (AQI) -CPIfoliar dust (r = 0.955**)>Damage degree-CPIfoliar dust (r = 0.923**)>Damage degree-AQI(r = 0.908**)>Damage degree-CPIsoil (r = 0.824*). The present research proved that mining activity had a high level of positive correlation with organism genetic damage caused by heavy metals through comparing with the control point; soil and atmosphere were both the important action pathway for heavy metal induced genetic damage in mining area. Furthermore, heavy metal contents in foliar dust showed a higher positive correlation with genetic damage than when compared with soil. This means the heavy metal contents that L.chinensis absorbed through respiration from the atmosphere could make more serious genetic damage than when absorbed by root systems from soil in the mining area. This study can provide theoretical support for research on plant genetic damage mechanisms and exposure pathways induced by environmental pollution. [ABSTRACT FROM AUTHOR]- Published
- 2016
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34. Effects of Long-Term Periodic Submergence on Photosynthesis and Growth of Taxodium distichum and Taxodium ascendens Saplings in the Hydro-Fluctuation Zone of the Three Gorges Reservoir of China.
- Author
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Wang, Chaoying, Li, Changxiao, Wei, Hong, Xie, Yingzan, and Han, Wenjiao
- Subjects
BALDCYPRESS ,PHOTOSYNTHESIS ,PLANT growth ,WATER purification ,PONDCYPRESS - Abstract
Responses of bald cypress (Taxodium distichum) and pond cypress (Taxodium ascendens) saplings in photosynthesis and growth to long-term periodic submergence in situ in the hydro-fluctuation zone of the Three Gorges Dam Reservoir (TGDR) were studied. Water treatments of periodic deep submergence (DS) and moderate submergence (MS) in situ were imposed on 2-year-old bald cypress and pond cypress saplings. The effects of periodic submergence on photosynthesis and growth were investigated after 3 years (i.e. 3 cycles) compared to a control (i.e. shallow submergence, abbreviated as SS). Results showed that pond cypress had no significant change in net photosynthetic rate (P
n ) in response to periodic moderate and deep submergence in contrast to a significant decrease in Pn of bald cypress under both submergence treatments, when compared to that of SS. Ratios of Chlorophyll a/b and Chlorophylls/Carotenoid of pond cypress were significantly increased in periodic moderate submergence and deep submergence, while bald cypress showed no significant change. Diameter at breast height (DBH) and tree height of both species were significantly reduced along with submergence depth. Relative diameter and height growth rates of the two species were also reduced under deeper submergence. Moreover, bald cypress displayed higher relative diameter growth rate than pond cypress under deep submergence mainly attributed to higher productivity of the larger crown area of bald cypress. When subjected to deep subergence, both species showed significant reduction in primary branch number, while in moderate submergence, bald cypress but not pond cypress showed significant reduction in primary branch number. These results indicate that both bald cypress and pond cypress are suitbale candidates for reforestation in the TGDR region thanks to their submergence tolerance characteristics, but bald cypress can grow better than pond cypress under deep submergence overall. [ABSTRACT FROM AUTHOR]- Published
- 2016
- Full Text
- View/download PDF
35. Temperature-Related Yield Constraints of Early-Rice in South China: A Cross-Location Analysis.
- Author
-
Huang, Min, Zhang, Ruichun, Jiang, Peng, Xie, Xiaobing, Zhou, Xuefeng, Cao, Fangbo, and Zou, Yingbin
- Subjects
RICE yields ,RICE varieties ,EFFECT of temperature on crops ,AGING in plants ,EXPERIMENTAL agriculture - Abstract
Warm temperature during post-heading is generally hypothesized to be the critical factor limiting grain yield of early-rice in South China. However, there is no direct evidence to confirm this hypothesis in the field. This study was conducted to determine the temperature-related yield constraints of early-rice in South China. Field experiments were carried out in Huaiji (a location in South China) and Changsha (a location in the Yangtze River basin) in 2011–2013. In each year, two rice cultivars were grown in early-rice growing season in Huaiji and in single-rice growing season in Changsha. Huaiji had higher average daily maximum temperature during post-heading than Changsha. The higher temperature during post-heading induced early plant senescence (slower crop growth rate and shorter grain filling duration), but grain weight did not reduce because it was compensated for by increased translocation of pre-heading biomass. The higher temperature during post-heading also did not cause a reduction in grain filling percentage. Huaiji had lower temperature during pre-heading than Changsha, which to some extent resulted in slower crop growth rate and consequently lower biomass production and smaller sink size in Huaiji than in Changsha. As a result, grain yield was about 30% lower in Huaiji than in Changsha. Our results indicate that grain yield of early-rice in South China is limited not by warm temperature during post-heading but partially by cool temperature during pre-heading, and suggest that enhancing sink size and meanwhile maintaining good translocation of pre-heading biomass may be an effective way to achieve high yield for early-rice in South China. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
36. Prevalence and Fate of Carbapenemase Genes in a Wastewater Treatment Plant in Northern China.
- Author
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Yang, Fengxia, Mao, Daqing, Zhou, Hao, and Luo, Yi
- Subjects
CARBAPENEMASE ,SEWAGE disposal plants ,PUBLIC health ,DISEASE prevalence ,POLYMERASE chain reaction - Abstract
Carbapenemase-producing strains of bacteria, which were primarily found in the medical field, have increasingly been found in the environment, thus posing potential risks to public health. One possible way for carbapenemase genes to enter the environment is via wastewater. Therefore, the goal of this study was to determine the occurrence and fate of five high-risk carbapenemase genes in a wastewater treatment plant (WWTP) in northern China using real-time qPCR. Results showed that the bla
KPC-2 , blaGES-1 , and blaIMP-1 genes prevailed throughout all processing stages (even in the chlorination disinfection unit) in the WWTP, whereas the blaVIM-2 and blaOXA-48 genes were not detected in all samples. Worryingly, considerable amounts of carbapenemase genes ((1.54 ± 0.61) × 103 copies/mL to (2.14± 0.41) × 105 copies/mL) were detected in WWTP effluent samples, while the majority of the carbapenemase genes were transported to the dewatered sludge with concentrations from (6.51 ± 0.14) × 109 copies/g to (6.18 ± 0.63) × 1010 copies/g dry weight. Furthermore, a total of 97 KPC-2-producing strains, belonging to 8 bacterial genera, were isolated from the WWTP. Sequencing of 16S rRNA revealed that most of KPC-2 producing isolates were opportunistic pathogens, including Klebsiella spp. (10.3%), Enterococcus spp. (11.3%), Acinetobacter spp. (19.6%), Escherichia spp. (12.4%), Shigella spp. (17.5%), Stenotrophomonas spp. (10.3%) and Wautersiella spp. (9.3%). Moreover, blaKPC-2 genes were identified for the first time in Paenibacillus spp. isolates (an indigenous bacteria), indicating an increased risk of horizontal transfer between clinical pathogens and environmental bacteria. Indeed, a conjugation experiment demonstrated transfer of the blaKPC-2 gene to an E.coli J53 strain from a Klebsiella strain isolated from the WWTP. To our knowledge, this is the first study to obtain Paenibacillus spp. isolates carrying the carbapenemase gene and to quantify the abundance of carbapenemase genes in the environment. [ABSTRACT FROM AUTHOR]- Published
- 2016
- Full Text
- View/download PDF
37. Estimating and Predicting Metal Concentration Using Online Turbidity Values and Water Quality Models in Two Rivers of the Taihu Basin, Eastern China.
- Author
-
Yao, Hong, Zhuang, Wei, Qian, Yu, Xia, Bisheng, Yang, Yang, and Qian, Xin
- Subjects
MATHEMATICAL models ,WATER quality ,TURBIDITY ,WATERSHEDS ,METAL content of water ,WATER pollution - Abstract
Turbidity (T) has been widely used to detect the occurrence of pollutants in surface water. Using data collected from January 2013 to June 2014 at eleven sites along two rivers feeding the Taihu Basin, China, the relationship between the concentration of five metals (aluminum (Al), titanium (Ti), nickel (Ni), vanadium (V), lead (Pb)) and turbidity was investigated. Metal concentration was determined using inductively coupled plasma mass spectrometry (ICP-MS). The linear regression of metal concentration and turbidity provided a good fit, with R
2 = 0.86–0.93 for 72 data sets collected in the industrial river and R2 = 0.60–0.85 for 60 data sets collected in the cleaner river. All the regression presented good linear relationship, leading to the conclusion that the occurrence of the five metals are directly related to suspended solids, and these metal concentration could be approximated using these regression equations. Thus, the linear regression equations were applied to estimate the metal concentration using online turbidity data from January 1 to June 30 in 2014. In the prediction, the WASP 7.5.2 (Water Quality Analysis Simulation Program) model was introduced to interpret the transport and fates of total suspended solids; in addition, metal concentration downstream of the two rivers was predicted. All the relative errors between the estimated and measured metal concentration were within 30%, and those between the predicted and measured values were within 40%. The estimation and prediction process of metals’ concentration indicated that exploring the relationship between metals and turbidity values might be one effective technique for efficient estimation and prediction of metal concentration to facilitate better long-term monitoring with high temporal and spatial density. [ABSTRACT FROM AUTHOR]- Published
- 2016
- Full Text
- View/download PDF
38. Estimates and Predictions of Coal Workers’ Pneumoconiosis Cases among Redeployed Coal Workers of the Fuxin Mining Industry Group in China: A Historical Cohort Study.
- Author
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Han, Bing, Liu, Hongbo, Zhai, Guojiang, Wang, Qun, Liang, Jie, Zhang, Mengcang, Cui, Kai, Shen, Fuhai, Yi, Hongbo, Li, Yuting, Zhai, Yuhan, Sheng, Yang, and Chen, Jie
- Subjects
DUST diseases ,MINERAL industries ,DISEASE incidence ,PARAMETER estimation ,COHORT analysis ,THERAPEUTICS - Abstract
This research was aimed at estimating possible Coal workers’ pneumoconiosis (CWP) cases as of 2012, and predicting future CWP cases among redeployed coal workers from the Fuxin Mining Industry Group. This study provided the scientific basis for regulations on CWP screening and diagnosis and labor insurance policies for redeployed coal workers of resource-exhausted mines. The study cohort included 19,116 coal workers. The cumulative incidence of CWP was calculated by the life-table method. Possible CWP cases by occupational category were estimated through the average annual incidence rate of CWP and males’ life expectancy. It was estimated that 141 redeployed coal workers might have suffered from CWP as of 2012, and 221 redeployed coal workers could suffer from CWP in the future. It is crucial to establish a set of feasible and affordable regulations on CWP screening and diagnosis as well as labor insurance policies for redeployed coal workers of resource-exhausted coal mines in China. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
39. International collaboration in science: a Chinese perspective.
- Author
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Qiu, Jane
- Subjects
SCIENCE ,RESEARCH ,PARTICLE physics ,MATERIALS science ,MEDICAL research - Abstract
The article presents a discussion on the perspective of Chinese researchers on the issue of global collaboration in science, organized by the journal "National Science Review" in 2014. Topics discussed include experimental particle physics, capacity building, and the strength of China in material science. Also mentioned are the position of China in medical research, the role of China in international programs, and the need for China to develop its strength in international collaboration.
- Published
- 2014
- Full Text
- View/download PDF
40. Development of Rapid Immunochromatographic Test for Hemagglutinin Antigen of H7 Subtype in Patients Infected with Novel Avian Influenza A (H7N9) Virus.
- Author
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Kang, Keren, Chen, Li, Zhao, Xiang, Qin, Chengfeng, Zhan, Zanwu, Wang, Jihua, Li, Wenmei, Dzakah, Emmanuel E., Huang, Weijuang, Shu, Yuelong, Jiang, Tao, Cao, Wuchun, Xie, Mingquan, Luo, Xiaochun, and Tang, Shixing
- Subjects
HEMAGGLUTININ ,ANTIGENS ,CHROMATOGRAPHIC analysis ,H7N9 Influenza ,DEATH rate - Abstract
Background: Since human infection with the novel H7N9 avian influenza virus was identified in China in March 2013, the relatively high mortality rate and possibility of human-to-human transmission have highlighted the urgent need for sensitive and specific assays for diagnosis of H7N9 infection. Methodology/Principal Findings: We developed a rapid diagnostic test for the novel avian influenza A (H7N9) virus using anti-hemagglutinin (HA) monoclonal antibodies specifically targeting H7 in an immunochromatographic assay system. The assay limit of detection was 10
3.5 pfu/ml or 103 TCID50 of H7N9 virus. The assay specifically detected H7N9 viral isolates and recombinant HA proteins of H7 subtypes including H7N7 and H7N9, but did not react with non-H7 subtypes including H1N1, H3N2, H5N1, H5N9, and H9N2. The detection sensitivity was 59.4% (19/32) for H7N9 patients confirmed by RT-PCR. Moreover, the highest sensitivity of 61.5% (16/26) was obtained when testing H7N9 positive sputum samples while 35.7% (5/14) of nasopharyngeal swabs and 20% (2/10) of fecal samples tested positive. No false positive detection was found when testing 180 H7N9 negative samples. Conclusions/Significance: Our novel rapid assay can specifically detect H7 HA antigen, facilitating rapid diagnosis for prevention and control of the on-going H7N9 epidemic. [ABSTRACT FROM AUTHOR]- Published
- 2014
- Full Text
- View/download PDF
41. Sclerotial Formation of Polyporus umbellatus by Low Temperature Treatment under Artificial Conditions.
- Author
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Xing, Yong-Mei, Zhang, Li-Chun, Liang, Han-Qiao, Lv, Jing, Song, Chao, Guo, Shun-Xing, Wang, Chun-Lan, Lee, Tae-Soo, and Lee, Min-Woong
- Subjects
SCLEROTIUM (Mycelium) ,POLYPORUS ,TEMPERATURE ,DIURETICS ,DIPHENYLENEIODONIUM ,ANTIOXIDANTS ,CELL physiology ,BIOTECHNOLOGY - Abstract
Background: Polyporus umbellatus sclerotia have been used as a diuretic agent in China for over two thousand years. A shortage of the natural P. umbellatus has prompted researchers to induce sclerotial formation in the laboratory. Methodology/Principal Finding: P. umbellatus cultivation in a sawdust-based substrate was investigated to evaluate the effect of low temperature conditions on sclerotial formation. A phenol-sulfuric acid method was employed to determine the polysaccharide content of wild P. umbellatus sclerotia and mycelia and sclerotia grown in low-temperature treatments. In addition, reactive oxygen species (ROS) content, expressed as the fluorescence intensity of mycelia during sclerotial differentiation was determined. Analysis of ROS generation and sclerotial formation in mycelia after treatment with the antioxidants such as diphenyleneiodonium chloride (DPI), apocynin (Apo), or vitamin C were studied. Furthermore, macroscopic and microscopic characteristics of sclerotial differentiation were observed. Sclerotia were not induced by continuous cultivation at 25°C. The polysaccharide content of the artificial sclerotia is 78% of that of wild sclerotia. In the low-temperature treatment group, the fluorescent intensity of ROS was higher than that of the room temperature (25°C) group which did not induce sclerotial formation all through the cultivation. The antioxidants DPI and Apo reduced ROS levels and did not induce sclerotial formation. Although the concentration-dependent effects of vitamin C (5–15 mg mL
−1 ) also reduced ROS generation and inhibited sclerotial formation, using a low concentration of vitamin C (1 mg mL−1 ) successfully induced sclerotial differentiation and increased ROS production. Conclusions/Significance: Exposure to low temperatures induced P. umbellatus sclerotial morphogenesis during cultivation. Low temperature treatment enhanced ROS in mycelia, which may be important in triggering sclerotial differentiation in P. umbellatus. Moreover, the application of antioxidants impaired ROS generation and inhibited sclerotial formation. Our findings may help to provide new insights into the biological mechanisms underlying sclerotial morphogenesis in P. umbellatus. [ABSTRACT FROM AUTHOR]- Published
- 2013
- Full Text
- View/download PDF
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