150 research outputs found
A Tale of Two Counties: How Two School Libraries in Rural Western China Serve Local Needs
This report presents a case study of school library programs in two rural counties in Western China. Since 2002, the libraries of Tianzhu and Tongwei high schools have undertaken a series of outreach initiatives to improve local residents’ access to information and to address their cultural and educational needs. Over the past decade, both school libraries have played a leading role in improving the quality of life and enhancing the information literacy of local residents. Tianzhu No. 1 High School Library 天祝一中图书馆—which serves a large Tibetan and other minority populations—has gained a reputation for its oral history of local culture program. This program trains students to conduct interviews with folk artists and scholars and then post their audiovisual recordings on websites. Tongwei No. 1 High School Library 通渭一中图书馆 is known for providing health care information through both in-person workshops and online. Recently, it implemented a tutoring service aimed at teaching residents to use online resources. These programs have been successful and sustainable in part because of the sponsorship and funding of the U.S.-based Evergreen Education Foundation (EEF) 美国青树教育基 金会. This report analyzes the results of these major initiatives, both of which do a great deal to reach out to rural residents, particularly farmers and the elderly
A Tale of Two Counties: How Two School Libraries in Rural Western China Serve Local Needs
This report presents a case study of school library programs in two rural counties in Western China. Since 2002, the libraries of Tianzhu and Tongwei high schools have undertaken a series of outreach initiatives to improve local residents’ access to information and to address their cultural and educational needs. Over the past decade, both school libraries have played a leading role in improving the quality of life and enhancing the information literacy of local residents. Tianzhu No. 1 High School Library 天祝一中图书馆—which serves a large Tibetan and other minority populations—has gained a reputation for its oral history of local culture program. This program trains students to conduct interviews with folk artists and scholars and then post their audiovisual recordings on websites. Tongwei No. 1 High School Library 通渭一中图书馆 is known for providing health care information through both in-person workshops and online. Recently, it implemented a tutoring service aimed at teaching residents to use online resources. These programs have been successful and sustainable in part because of the sponsorship and funding of the U.S.-based Evergreen Education Foundation (EEF) 美国青树教育基 金会. This report analyzes the results of these major initiatives, both of which do a great deal to reach out to rural residents, particularly farmers and the elderly
Effect of dynamic threshold pressure gradient on production performance in water-bearing tight gas reservoir
AbstractWater content and distribution have important impacts on gas production in water-bearing tight gas reservoirs. However, due to the structural and chemical heterogeneity of tight reservoirs, the water phase exists in various states, which has complicated the analyses of the effects of water characteristics on tight gas production performance. In this work, the water phase is distinguished from immobile to mobile states and the term of constrained water saturation is proposed. It is established that water can flow when the driving pressure difference is larger than the critical driving pressure difference. A new theoretical model of threshold pressure gradient is derived to incorporate the influences of constrained water saturation and permeability. On this basis, a new prediction model considering the varied threshold pressure gradient is obtained, and the result indicates that when threshold pressure gradient is constant, the real gas production capacity of the reservoir will be weakened. Meanwhile, a dynamic supply boundary model is presented, which indicates that the permeability has a strong influence on the dynamic supply boundary, whereas the impact of initial water saturation is negligible. These findings provide insights into the understanding of the effects of water state and saturation on the threshold pressure gradient and gas production rate in tight gas reservoirs. Furthermore, this study provides useful guidance on the prediction of field-scale gas production.Cited as: Zhu, W., Liu, Y., Shi, Y., Zou, G., Zhang, Q., Kong, D. Effect of dynamic threshold pressure gradient on production performance in water-bearing tight gas reservoir. Advances in Geo-Energy Research, 2022, 6(4): 286-295. https://doi.org/10.46690/ager.2022.04.0
Agricultural land use regulates the fate of soil phosphorus fractions following the reclamation of wetlands
Over half of the Earth's wetlands have been reclaimed for agriculture, leading to significant soil P destabilization and leaching risks. To evaluate the effects of agricultural land use on soil P stability, we used sequential P extraction to investigate the long-term effects of wetland cultivation for rice and soybean on soil P fractions, including labile and moderately labile inorganic/organic P (LPi, LPo, MPi, and MPo), and stable P in Northeast China. The results showed that soybean cultivation decreased the total P by 35.9 %, whereas rice cultivation did not influence the total P content (p < 0.05). Both the soybean and rice cultivations significantly increased LPi (p < 0.05). Soybean cultivation significantly decreased the LPo and MPo compared to rice cultivation, and the latter increased MPi by 309.28 % compared with the reference wetlands (p < 0.05). Redundancy analysis indicated that pH, poorly crystalline Fe (Feca), crystalline Fe (Fec), and total organic carbon (TOC) explained similar variations in P fractions during soybean and rice cultivation (54.9 % and 49.7 %, respectively). Similarly, during soybean or rice cultivation, pH negatively influenced LPo and MPo, while Feca positively influenced MPi and LPi. Furthermore, TOC showed a positive role in LPo, and MPo, but a negative effect on LPi and MPi during rice cultivation. Hence, we concluded that the cultivation of soybean or rice create contrasting modifications to wetland soil P fractionation by altering TOC, Feca, Fec, and pH. Our study indicates that agricultural land use can regulate the fate of wetland soil P fractionation, with potential benefits to both i) P risk management in cultivated wetlands and ii) potential approaches for future wetland restoration.</p
Number 2 Feibi Recipe Reduces PM2.5-Induced Lung Injury in Rats
Air pollution is the main cause of respiratory diseases. Fine particulates with the diameter below 2.5 μm can get into the alveoli and then enter the blood circulation through the lung tissue ventilation function and cause multiple systemic diseases especially the respiratory diseases. This study investigated the pathological mechanism of the lungs injury in rats induced by PM2.5 and the effect and mechanism of the Chinese herbal medicine number 2 Feibi Recipe (number 2 FBR) on lungs injury. In this experiment, Wistar rats were used. Lungs injury was induced by PM2.5. Number 2 FBR was used to treat the rats. The result showed that number 2 FBR could improve the lung injury in the rats. Meanwhile, it significantly reduced pathological response and inflammatory mediators including interleukin-6 (IL-6), interleukin-13 (IL-13), interleukin-17 (IL17), monocyte chemotactic protein-1 (MCP-1), and transforming growth factor-α (TNF-α) and upregulated glutathione peroxidase (GSH-Px) in the PM2.5 induced lung injury in the rats. Collectively, number 2 FBR appears to attenuate the lungs injury in rats induced by PM2.5
Self-reductive synthesis of MXene/Na0.55Mn1.4Ti0.6O4 hybrids for high-performance symmetric lithium ion batteries.
Increasing environmental problems and energy challenges have created an urgent demand for the development of green and efficient energy-storage systems. The search for new materials that could improve the performance of Li-ion batteries (LIBs) is one of today's most challenging tasks. Herein, a stable symmetric LIB based on the bipolar material-MXene/Na0.55Mn1.4Ti0.6O4 was developed. This bipolar hybrid material showed a typical MXene-type layered structure with high conductivity, containing two electrochemically active redox couples, namely, Mn4+/Mn3+ (3.06 V) and Mn2+/Mn (0.25 V). This MXene/Na0.55Mn2O4-based symmetric full cell exhibited the highest energy density of 393.4 W h kg−1 among all symmetric full cells reported so far, wherein it is bestowed with a high average voltage of 2.81 V and a reversible capacity of 140 mA h g−1 at a current density of 100 mA g−1. In addition, it offers a capacity retention of 79.4% after 200 cycles at a current density of 500 mA g−1. This symmetric lithium ion full battery will stimulate further research on new LIBs using the same active materials with improved safety, lower costs and a long life-span
Identification of random amplified polymorphic DNA (RAPD) marker of Ph-3 gene for late blight resistance in tomato
Late blight is a highly destructive disease of tomato worldwide. Host resistance is the most effective method for disease control. The application of molecular markers is an efficient way to identify host resistance for breeding programs. In this study, bulked segregant analysis (BSA) was used to search for random amplified polymorphic DNA (RAPD) markers linked to the late blight resistance gene Ph-3, using an F2 population (147 individuals) derived from a cross of tomato lines CLN2037 (resistant) and T2-03 (susceptible). Two hundred and thirty decamer primers with arbitrary sequences were chosen for polymerase chain reaction amplification. One RAPD marker CCPB272-03740 (primer sequence GGTCGATCTG) was found to be tightly linked to the resistance gene Ph-3 and was located 5.8 cm from the resistance gene. Marker CCPB272-03740 is the first marker of gene Ph-3 based on PCR reaction.Key words: Tomato, late blight, random amplified polymorphic DNA (RAPD) marker, gene Ph-3
Atomically dispersed quintuple nitrogen and oxygen co-coordinated zirconium on graphene-type substrate for highly efficient oxygen reduction reaction.
A cost-effective and long stability catalyst with decent electrochemical activity would play a crucial role in accelerating applications of metal-air batteries. Here, we report quintuple nitrogen and oxygen co-coordinated Zr sites on graphene (Zr-N/O-C) by using a ball-milling, solid-solution-assisted pyrolysis method. The as-prepared Zr-N/O-C catalyst with 2.93 wt % Zr shows a half-wave potential of 0.910 V, an onset potential of 1.000 V in 0.1 M KOH, impressive durability (95.1% remains after 16,000 s), and long-term stability (5 mV loss over 10,000 cycles). Zn-air batteries with the Zr-N/O-C electrode exhibit a maximum power density of 217.9 mW cm−2 and a high cycling life of over 1,000 h, exceeding the counterpart equipped with a Pt/C benchmark. Theoretical simulations demonstrate that nitrogen and oxygen dual-ligand confinement effectively tunes the d-band center and balances key intermediates binding energy of intrinsic quintuple coordination Zr sites
High-strong-ductile magnesium alloys by interactions of nanoscale quasi-long period stacking order unit with twin.
Magnesium alloys with high strength in combination of good ductility are especially desirable for applications in transportation, aerospace and bio-implants owing to their high stiffness, abundant raw materials, and environmental friendliness. However, the majority of traditional strengthening approaches including grain refining and precipitate strengthening can usually prohibit dislocation movement at the expense of ductility invariably. Herein, we report an effective strategy for simultaneously enhancing yield strength (205 MPa, 2.41 times) and elongation (23%, 1.54 times) in a Mg-0.2Zn-0.6Y (at.%) alloy at room temperature, based on the formation of a nanosized quasi-long period stacking order unit (QLPSO)-twin structure by ultrahigh-pressure treatment followed by annealing. The formation reason and strong-ductile mechanism of the unique QLPSO-twin structure have been clarified by transmission electron microscopy observations and molecule dynamics simulations. The improved strength is mainly associated with the presence of nanosized QLPSO and the modified <86.3o QLPSO-twin boundary (TB) interface, effectively pinning dislocation movement. Comparatively, the enhanced ductility is related to the <3.7o QLPSO-TB interface and micro-kinks of nanoscale QLPSO, providing some paths for plastic deformation. This strategy on the QLPSO-twin structure might provide an alternative perspective for designing innovative hexagonal close-packed structural materials with superior mechanical properties
Heterogeneous Ti3SiC2@C-containing Na2Ti7O15 architecture for high-performance sodium storage at elevated temperatures.
Rational design of heterogeneous electrode materials with hierarchical architecture is a potential approach to significantly improve their energy densities. Herein, we report a tailored microwave-assisted synthetic strategy to create heterogeneous hierarchical Ti3SiC2@C-containing Na2Ti7O15 (MAX@C-NTO) composites as potential anode materials for high-performance sodium storage in a wide temperature range from 25 to 80 {deg}C. This composite delivers first reversible capacities of 230 mAh g-1 at 200 mA g-1 and 149 mAh g-1 at 3000 mA g-1 at 25 {deg}C. A high capacity of ~93 mAh g-1 without any apparent decay even after more than 10 000 cycles is obtained at an ultrahigh current density of 10 000 mA g-1. Moreover, both a high reversible capacity and an ultralong durable stability are achieved below 60 {deg}C for the same composites, wherein a 75.2% capacity retention (~120 mAh g-1 at 10 000 mA g-1) is achieved after 3000 cycles at 60 {deg}C. To the best of our knowledge, both the sodium storage performances and the temperature tolerances outperform those of all the Ti-based sodium storage materials reported so far. The superior sodium storage performances of the as-synthesized composites are attributed to the heterogeneous core'shell architecture, which not only provides fast kinetics by high pseudocapacitance but also prolongs cycling life by preventing particle agglomeration and facilitates the transportation of electrons and sodium ions by large micro/mesopore structure
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