Journal of Chemistry
·
2010
·Vol. 9
·期 1
·435-442
·
IF 0
Yabin Wang,Yanni Li,Fang Wang
The protective performances of coating formed by organo-silane with a linear alkyl chain for promoting aluminum alloy corrosion protection were evaluated by electrochemical techniques. The coatings were self-assembled in the hydrolyzed hydroalcoholic bath of n -octyltriethoxysilane (OS) and cured at hot air oven by different time. The coatings prepared by the less self-assembled number and shorter cured time, were always porous and scarcely protective. On the contrary, those built by the more self-assembled number and the longer cured time had higher coverage on aluminum surface and favorable corrosion resistant property. The best results were obtained when n -octyltri-ethoxysilane (OS) was hydrolyzed 25 h, self-assembling of OS was conducted for five times and the multi-layers were cured at 120 for 1∼2 hours. In this case, the thicker, high cross-linked and more scarcely defective layer was formed on aluminum alloy surface.
研究领域:
材料科学
·
表面工程
·
腐蚀与防护
·
高分子化学
·
电化学
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DOI
BMC PUBLIC HEALTH
·
2021
·Vol. 21
·期 1
·2001
·
IF 3.295
Mao Zijun,Zou Qi,Yao Hong,Wu Jingyi
Background As COVID-19 continues to spread globally, traditional emergency management measures are facing many practical limitations. The application of big data analysis technology provides an opportunity for local governments to conduct the COVID-19 epidemic emergency management more scientifically. The present study, based on emergency management lifecycle theory, includes a comprehensive analysis of the application framework of China’s SARS epidemic emergency management lacked the support of big data technology in 2003. In contrast, this study first proposes a more agile and efficient application framework, supported by big data technology, for the COVID-19 epidemic emergency management and then analyses the differences between the two frameworks. Methods This study takes Hainan Province, China as its case study by using a file content analysis and semistructured interviews to systematically comprehend the strategy and mechanism of Hainan’s application of big data technology in its COVID-19 epidemic emergency management. Results Hainan Province adopted big data technology during the four stages, i.e., migration, preparedness, response, and recovery, of its COVID-19 epidemic emergency management. Hainan Province developed advanced big data management mechanisms and technologies for practical epidemic emergency management, thereby verifying the feasibility and value of the big data technology application framework we propose. Conclusions This study provides empirical evidence for certain aspects of the theory, mechanism, and technology for local governments in different countries and regions to apply, in a precise, agile, and evidence-based manner, big data technology in their formulations of comprehensive COVID-19 epidemic emergency management strategies.
研究领域:
公共卫生
·
应急管理体系
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信息科学
·
流行病学
·
数据驱动决策
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DOI
高影响因子
Journal of Hospitality and Tourism Management
·
2021
·
IF 5.959
Mohamed E. Mohamed,Xinran Lehto,Mahmoud Hewedi,Carl A. Behnke
The study provides a much-needed understanding of how non-visitors form naive destination food images. Specifically, it uses Projective Techniques to identify Egyptian food perceptions held by Americans who never visited Egypt nor tried Egyptian food. Nine food image dimensions were identified: health and nutrition , food culture and heritage, distinctiveness, food quality and variety, flavor profile, cooking methods and ingredients, price and informality, dining places, and table manners. The study showed that non-visitors visualize a destination's food and cuisine based on its cultural and environmental features. It also shows that non-visitors derive their naïve destination food images in part from their home country food experiences and places they have visited. Although this study is based on individuals with no Egyptian food experience, it suggests that many secondary experiences influence food images formation .
研究领域:
旅游心理学
·
跨文化研究
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消费者行为
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饮食人类学
·
目的地营销
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DOI
高影响因子
COLLOIDS AND SURFACES B-BIOINTERFACES
·
2011
·Vol. 86
·期 2
·345-352
·
IF 2.78
Xianfeng Wang,Bin Ding,Jianyong Yu,Jianmao Yang
For the first time, two-dimensional (2D) gelatin nano-nets are fabricated by regulating the solution properties and several process parameters during electrospinning/electro-netting. The spider-web-like nano-nets that comprise interlinked one-dimensional (1D) ultrathin nanowires (10–35 nm) are stacked layer-by-layer and widely distributed in the three-dimensional (3D) porous membranes. The final morphology of the gelatin nano-nets, including nanowire diameter, area density and pore-width of the nano-nets, is highly dependent on the solution concentration, salt concentration, kinds of solvents, applied voltage, ambient temperature and relative humidity (RH). The occurrence of rapid phase separation on the splitting-film and the formation of hydrogen bond among gelatin molecules during electro-netting are proposed as the possible mechanisms for the formation of these spider-web-like nano-nets.
研究领域:
生物材料
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纳米医学
·
组织工程
·
再生医学
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药物递送
·
生物制造
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DOI
高影响因子
Laser & Photonics Reviews
·
2024
·Vol. 18
·期 12
·2400812
·
IF 9.8
Guangyin Qu,Xiaojuan Zhang,Siqi Li,Yan Kuai,Feng Xu,Liang Lu,Yu Liu,Zhigang Cao,Benli Yu,Anderson S. L. Gomes,Zhijia Hu
In contrast to conventional anti-counterfeiting technologies, which are susceptible to decryption and exhibit limited effectiveness, the utilization of light to dynamically configure soft materials in a fully reversible and programmable manner not only enhances data security but also improves anti-counterfeiting performance. However, achieving precise control over reflection structural colors and laser wavelengths within a broad dynamic range remains a challenge. In this study, a UV-responsive soft helical superstructure is established by combining a photochromic compound with chiral liquid crystals (LCs). By manipulating the Bragg reflection angle, structural reflection colors ranging from red to cyan are successfully achieved. The introduction of an anti-counterfeiting technique that embeds diverse micro-structures provides features such as color adjustability, erasability, and angle-dependent stability. Using the unique properties of this soft helical superstructure, the implementation of a wavelength-tunable LC bandgap laser through optically reconfigurable Förster resonance energy transfer processes is showcased. Furthermore, a straightforward prototype information encoder is developed to mimic the processes of information encoding and decoding, bypassing the need for complex algorithm design. This research underscores the practicality of LC helical soft systems, emphasizing their distinctive responsiveness to light and their applicability in optical programming photonics.
研究领域:
光学材料
·
软物质物理
·
光子学
·
信息安全
·
功能材料
·
分子光化学
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DOI
高影响因子
ANALYTICA CHIMICA ACTA
·
2018
·
IF 5.123
Feng Tan,Xiao Jiang,Xianliang Qiao,Daming Sun,Jinsuo Gao,Xie Quan,Jingwen Chen,Suyu Ren,Yi Wang
A diffusive gradients in thin films (DGT) method using a new high-capacity cerium oxide (CeO 2 ) binding gel, for the first time, was developed for measuring dissolved inorganic arsenic in freshwater and seawater . The capacities of the new CeO 2 binding gel were 682 μg and 375 μg for As III and As V , respectively. The masses of As III and As V accumulated by CeO 2 -DGT device increased linearly with time and agreed well with the theoretical value calculated by DGT equation. The arsenic accumulation by CeO 2 -DGT was independent of pH (4.05–9.04) and ionic strength (0.1–750 mM), and common anions including CO 3 2− , SO 4 2− , Cl − and PO 4 3− had no obvious interference. CeO 2 -DGT showed excellent long-term deployment performance in freshwater and synthetic seawater . Field trials with CeO 2 -DGT achieved successfully the time-weighted-average concentrations of total inorganic arsenic in reservoir water (1.38 ± 0.09 μg/L) and coastal seawater (0.45 ± 0.06 μg/L). The results were comparable to those measured by grab sampling. The proposed method was reliable and robust for in-situ measurements of dissolved inorganic arsenic in environmental waters.
研究领域:
环境化学
·
分析化学
·
水环境监测
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环境地球化学
·
污染生态学
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DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2023
·
IF 13.6
Kang Liu,Mengmeng Wang,Qiaozhi Zhang,Shanta Dutta,Tianle Zheng,Marjorie Valix,Daniel C.W. Tsang
Copper plays a crucial role in the low-carbon transformation of global communities with prevalent use of electric vehicles. This study proposed an environmentally friendly approach that utilizes a deep eutectic solvent (DES), choline chloride-ethylene glycol (ChCl-EG), as green solvent for the selective extraction of copper from scrap materials . With hydrogen peroxide as an oxidizing agent , the copper species from the printed circuit boards (PCBs) scraps were efficiently leached by the DES through oxidation-complexation reactions (conditions: 25 min, 20 °C, and 5 wt% H 2 O 2 ). Molecular dynamics and density functional theory were performed to simulate the intricate cascade of interactions between copper species and hydrogen bond donors/acceptors of DES, providing insights into the mechanistic processes involved. Copper was selectively recovered from the DES leachate containing impurities (e.g. , Pb 2+ , Sn 2+ , and Al 3+ ) through electrodeposition via a diffusion-controlled reaction under a constant potential mode. A comprehensive life cycle assessment of the process demonstrated that the utilisation of DES in the extraction of copper from waste PCBs could result in significant reduction in carbon dioxide emissions (−93.6 kg CO 2 eq of 1000 kg waste PCBs), thus mitigating the carbon footprint of global copper use through the proposed solvometallurgical recycling process of secondary resources.
研究领域:
环境科学
·
冶金工程
·
绿色化学
·
资源循环利用
·
可持续材料
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Yiheng Yue,Guocheng Pan,Jun Wan,Zhen Xiao,Yang Zhang,Shiqing Xu,Gongxun Bai
Mechanoluminescent (ML) materials offer significant potential for remote stress sensing and distribution. However, creating highly sensitive and responsive ML materials remains a challenge. In this study, mechanoluminescent semiconductor materials have been successfully prepared as Mn 2+ doped ZnS-SrZnOS heterojunction composites. These materials exhibit high-resolution stress distribution visualization and rapid response, captured via camera recording. Notably, they possess a low stress triggering threshold, reaching the KPa level, and respond within milliseconds. Furthermore, it was found that by adjusting the doping concentration of Mn 2+ within the heterojunction, the material utilizes its bimodal emission capability to manipulate the fluorescence shift and achieve optical anti-counterfeiting. The synthesis of smart films by combining the material with polydimethylsiloxane matrix had enabled the achievement of collision detection, information hiding and optical anti-counterfeiting. These results suggest that the prepared smart films have wide range of optical sensing applications.
研究领域:
材料科学
·
纳米科技
·
光学传感
·
功能材料
·
固态物理
·
表面与界面科学
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DOI
高影响因子
POLYMER TESTING
·
2020
·
IF 3.275
Rui Wang,Congzhen Xie,Bin Gou,Huasong Xu,Shoukang Luo,Jiangang Zhou,Leilei Zeng
Dielectric polymers with high thermal conductivity are very promising in the fields of aerospace and electronic device packaging. However, composites with excellent dielectric properties usually have low thermal conductivity. It is usually to fill the polymer with thermal conductivity particles to improve the thermal conductivity, but the high content of filler often reduces the mechanical properties of the polymer. In this paper, the traditional insulating polymer epoxy resin was used as the matrix, by covering the surface of silicon carbide with graphene to form a core-shell structure and co-filled with nano diamonds to achieve the preparation of high-performance epoxy resin at low content. The results showed that at the filling content of 30 wt%, the thermal conductivity of epoxy nanocomposites showed a dramatic thermal conductivity enhancement of 1263%, the energy storage modulus increased by 1.1 GPa, and the dielectric loss remained unchanged at 50 Hz. The advantages of the composite are the structural design and surface modification of the filler, which not only take advantage of its inherent advantages, but also improve the interface area with the epoxy matrix. The composite materials with excellent properties are expected to provide theoretical guidance for the application of high thermal conductivity dielectric materials.
研究领域:
材料科学
·
高分子化学
·
复合材料工程
·
电子封装材料
·
介电材料
·
热管理材料
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DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2023
·
IF 9.2
Tianyao Ding,Dong Zheng,Huainan Qu,Weixiao Ji,Xiaoxiao Zhang,Dongping Lu,Gongwei Wang,Deyang Qu
An in-situ electrochemical optical diagnosis is the key to the investigation of electrode interface during a redox reaction . Because the morphology changes particularly, dendrite formation, dendrite shapes, solid electrolyte interface formation and gas generation can be revealed visually. The challenge of ensuring uniform current density on a flat Li anode in a liquid electrolyte is addressed and uniform Li plating is demonstrated. The dendrite shape change under different reduction current density is discussed. The Li dendrite shape change and the performance of Li anodes with a surface lamination of graphite and red phosphate are used as examples to demonstrate the capability of the in-situ optical cell. An in-situ electrochemical optical cell used in the investigation of the increasingly popular solid-state Li batteries has its own challenges. Due to the untransparent nature of a solid-state electrolyte, an optical investigation on a solid-state electrolyte Li battery needs to be done by exposing the cross-section of the cell. In addition, it is very difficult to assemble an optical cell with a brittle and fragile solid-state electrolyte in a glove box. A set of formation and transfer dies, and an optical cell are introduced. The Li dendrite growth at the interface can be observed in a solid-state Li cell.
研究领域:
电化学
·
材料科学
·
能源存储
·
固态电池
·
界面科学
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DOI
高影响因子
Early Childhood Education Journal
·
2024
·
IF 2.3
Li Hui,He Huihua,Luo Wenwei,Li Hui
Early childhood digital pedagogy (ECDP) has been widely implemented and studied, but the empirical evidence has not been systematically reviewed. This scoping review aimed to synthesize the existing studies to understand the practices and profiles of ECDP and the redefined roles of teacher, child, and technology. Thirty-eight studies on ECDP published from January 2010 to October 2024 were collected from three academic databases: EBSCO, Web of Science, and ProQuest. Synthesis of the findings of these studies revealed that: Firstly, digital technologies increasingly hold transformative potential for instructional practices at the level of modification and redefinition based on the SAMR framework. Secondly, play-based, project-based, problem-based, and co-operative and collaborative pedagogy with constructivist tendencies are the trademarks of ECDP. Lastly, in pedagogical interactions, teachers, children, and digital technologies each play diverse roles. This review study sheds some light on the practical characteristics of ECDP, which can inspire the effective designs and implementation of ECDP in the future.
研究领域:
教育学
·
学前教育
·
教育技术
·
数字化学习
·
教学设计
·
发展心理学
·
课程与教学论
·
学习科学
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DOI
高影响因子
JOURNAL OF CRYSTAL GROWTH
·
2018
·
IF 1.742
Xuehua Zhang,Liang Yu,Wei Zhang,Fangren Hu,Yongjin Wang
PS microspheres emulsions with different PS diameters of 207 and 378 nm were prepared by using an emulsifier-free polymerization method. A novel secondary self-assembly method which combined the spin coating and the lifting-up method was used to prepare the close-packed PS MCC films. During the process, the PS MCC film was firstly assembled on a glass substrate by a spin coating technique. Secondly, the obtained PS MCC film was transferred on the air-water interface by immersing the PS glass substrate in water using a dip-coater. Thirdly, the floating close-packed PS MCC films on the air-water interface was transferred to a new glass substrate by using a lifting-up method. During the spin-coating and the self-assembly process, some SDS solution was added in the PS films to improve the uniformity of the PS layer. Effects of the spin-coating speeds, the SDS solution concentration and the lifting-up rates on the morphology of PS MCC films have been discussed. Scanning electron microscopy was used to observe the morphological properties of the PS colloidal crystal films. Results indicate that a relatively close-packed and large scale PS MCC films can be obtained when the spinning speed is 2000 rpm for 60 s, the SDS solution concentration is 2 wt% and the lifting-up rate is 2 mm/min. Furthermore, the polydimethylsiloxane soft mold was replicated from the-fabricated PS MCC films and was then imprinted onto the photosensitive hybrid film under UV-irradiation and thus the micro-lens arrays built in the photosensitive hybrid sol–gel film were obtained.
研究领域:
材料科学
·
纳米技术
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）