464 results on '"Zhou, Haiping"'
Search Results
202. Susceptible-Infected-Susceptible Virus Spread Model in 2-Dimension Regular Network under Local Area Control
- Author
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Guo, ChangRui, primary, Cai, ShaoHong, additional, Zhou, HaiPing, additional, and Zhang, DaMin, additional
- Published
- 2009
- Full Text
- View/download PDF
203. Nanofabrication of two‐dimensional arrays of magnetite particles for fundamental rock magnetic studies
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Krása, David, primary, Wilkinson, Chris D. W., additional, Gadegaard, Nikolaj, additional, Kong, Xiang, additional, Zhou, Haiping, additional, Roberts, Andrew P., additional, Muxworthy, Adrian R., additional, and Williams, Wyn, additional
- Published
- 2009
- Full Text
- View/download PDF
204. Fully self-aligned process for fabricating 100 nm gate length enhancement mode GaAs metal-oxide-semiconductor field-effect transistors
- Author
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Li, Xu, primary, Hill, Richard J. W., additional, Longo, Paolo, additional, Holland, Martin C., additional, Zhou, Haiping, additional, Thoms, Stephen, additional, Macintyre, Douglas S., additional, and Thayne, Iain G., additional
- Published
- 2009
- Full Text
- View/download PDF
205. The fluorescence enhancement of quercetin-nucleic acid system and the analytical application
- Author
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Liu, Yuan, primary, Wu, Xia, additional, Zhou, Haiping, additional, Liu, Xiaoyu, additional, Zhang, Fengju, additional, and Yang, Jinghe, additional
- Published
- 2009
- Full Text
- View/download PDF
206. FIRST-PRINCIPLES STUDY OF GAMMA-Si3N4 WITH GENERALIZED GRADIENT APPROXIMATION AND LOCAL DENSITY APPROXIMATION
- Author
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DING, YINGCHUN, primary, ZHOU, HAIPING, additional, XU, MING, additional, SHEN, YIBING, additional, CHEN, QINGYUN, additional, ZHU, WEN-JUN, additional, and HE, HONGLIANG, additional
- Published
- 2008
- Full Text
- View/download PDF
207. Susceptible-Infected-Susceptible Virus Spread Model Based on Sparsely Distributed Crowd
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Zhou, HaiPing, primary and Cai, ShaoHong, additional
- Published
- 2008
- Full Text
- View/download PDF
208. Asphalt Rubber and Its Potential Use in China
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Bressette, Terrie, primary, Zhou, Haiping, additional, Stonex, Anne, additional, and Hicks, R. Gary, additional
- Published
- 2008
- Full Text
- View/download PDF
209. Enhancement-Mode GaAs MOSFETs With an $\hbox{In}_{0.3} \hbox{Ga}_{0.7}\hbox{As}$ Channel, a Mobility of Over 5000 $ \hbox{cm}^{2}/\hbox{V} \cdot \hbox{s}$, and Transconductance of Over 475 $\mu\hbox{S}/\mu\hbox{m}$
- Author
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Hill, Richard J. W., primary, Moran, David A. J., additional, Li, Xu, additional, Zhou, Haiping, additional, Macintyre, Douglas, additional, Thoms, Stephen, additional, Asenov, Asen, additional, Zurcher, Peter, additional, Rajagopalan, Karthik, additional, Abrokwah, Jonathan, additional, Droopad, Ravi, additional, Passlack, Matthias, additional, and Thayne, Iain G., additional
- Published
- 2007
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- View/download PDF
210. Determining the Electronic Performance Limitationsin Top-Down-Fabricated Si Nanowires with Mean Widths Down to 4 nm.
- Author
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Mirza, Muhammad M., MacLaren, Donald A., Samarelli, Antonio, Holmes, Barry M., Zhou, Haiping, Thoms, Stephen, MacIntyre, Douglas, and Paul, Douglas J.
- Published
- 2014
- Full Text
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211. Optical Emission Spectrometry of Plasma in Low-Damage Sub-100 nm Tungsten Gate Reactive Ion Etching Process for Compound Semiconductor Transistors
- Author
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Li, Xu, primary, Zhou, Haiping, additional, Wilkinson, Chris D. W., additional, and Thayne, Iain G., additional
- Published
- 2006
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212. Low-Hydrogen-Content Silicon Nitride Deposited at Room Temperature by Inductively Coupled Plasma Deposition
- Author
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Zhou, Haiping, primary, Elgaid, Khaled, additional, Wilkinson, Chris, additional, and Thayne, Iain, additional
- Published
- 2006
- Full Text
- View/download PDF
213. Metal-Ion-Dependent Catalysis and Specificity of CCA-Adding Enzymes: A Comparison of Two Classes
- Author
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Hou, Ya-Ming, primary, Gu, Shan-Qing, additional, Zhou, Haiping, additional, and Ingerman, Lindsey, additional
- Published
- 2005
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- View/download PDF
214. Chaperone characteristics of PDI-related protein A from Aspergillus niger
- Author
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Zhou, Haiping, primary, Zhang, Yuying, additional, Jia, Cuijuan, additional, and Yang, Kaiyu, additional
- Published
- 2004
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215. Guide for Investigating and Remediating Distress in Flexible Pavements: California Department of Transportation's New Procedure
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Cook, Mike C., primary, Seeds, Stephen B., additional, Zhou, Haiping, additional, and Hicks, R. Gary, additional
- Published
- 2004
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216. Investigation of Backcalculated Moduli Using Deflections Obtained at Various Locations in a Pavement Structure
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Zhou, Haiping, primary, Rada, Gonzalo R., additional, and Elkins, Gary E., additional
- Published
- 1997
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217. Low-infrared-emissivity Al@SiO2/EPDM composite coating compatible with low dielectric loss and antistatic property.
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Wang, Yanjun, Zhou, Haiping, Gao, Yuexin, Zhang, Ze, Liu, Siyu, Zhong, Sijia, Yu, Meijie, Liu, Jianjun, and Wang, Chengguo
- Subjects
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DIELECTRIC loss , *ALUMINUM powder , *COMPOSITE coating , *SOL-gel materials , *PERMITTIVITY , *INFRARED absorption , *DIELECTRIC films - Abstract
• Floating aluminum powder coated with SiO 2 was prepared using tetraethyl orthosilicate (TEOS) as raw material by sol-gel method. • The composite coating was prepared using modified Al powder and antistatic carbonaceous fiber (CF) as filler, EPDM as binder. • The composite coating that we prepared has low infrared emissivity compatible with high radar wave transmittance. Low infrared emissivity coatings have been widely used in many fields. At present, there are few researches on coatings that are compatible with low infrared emissivity and high radar wave transmittance. In this paper, floating aluminum (Al) powder coated with SiO 2 was prepared using tetraethyl orthosilicate (TEOS) as raw material by sol-gel method. The composite coating was prepared using modified Al powder and antistatic carbonaceous fiber (CF) as filler, EPDM as binder. The surface morphology, infrared absorption properties of the modified Al powder and the infrared emissivity, surface resistivity, electromagnetic properties and mechanical properties of the composite coating were analyzed. The results show that with the increase of TEOS addition amount, more SiO 2 was covered to the surface of floating Al powder. By adjusting the thickness of the surface modification layer of floating Al powder, the dielectric constant (ε) and dielectric loss tangent values (tanδ) of the composite coating were significantly reduced. When the addition amount of TEOS is 1 g for Al@SiO 2 , the ε and tanδ can be significantly reduced, and the infrared emissivity was less than 0.6, the tensile strength (σ b) and elongation rate at break (e) decreased slightly. This suggests that the composite coating has low infrared emissivity compatible with high radar wave transmittance was obtained, which is expected to be applied to the surface of aircraft radome. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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218. Nucleic acids determination using the complex of eriochrome black T and silver nanoparticles in a resonance light scattering technique
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Zhou, Haiping, Wu, Xia, Meng, Fanhui, Yang, Jinghe, and Wang, Minqin
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NUCLEIC acids , *NANOPARTICLES , *COLLOIDAL silver , *LIGHT scattering , *DNA , *SPERMATOZOA , *NUCLEIC acid probes - Abstract
Abstract: A novel method for the determination of nucleic acids by using silver nanoparticle (AgNPs)–eriochrome black T (EBT) as a resonance light scattering (RLS) probe has been developed. Under optimum conditions, there are linear relationships between the quenching extent of RLS intensity and the concentration of nucleic acids in the range of 4.0×10−9–4.0×10−7, 4.0×10−7–1.6×10−6 gmL−1 for fish sperm DNA (fsDNA) and 4.0×10−8–2.0×10−6 gmL−1 for yeast RNA (yRNA). Their detection limits (S/N=3) are 2.0ngmL−1 and 21ngmL−1, respectively. The results indicate that AgNPs can form wirelike aggregates and nanoslices in the presence of the EBT. Whereas, when nucleic acids are added into the AgNPs–EBT system, the dynamic balance of AgNPs–EBT system is destroyed and the nanoparticles undergo dispersion again, leading to the RLS intensity of AgNPs–EBT system quenching. Meanwhile, the conformation of fsDNA is changed by the synergistic effect of AgNPs and EBT. [ABSTRACT FROM AUTHOR]
- Published
- 2011
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219. Fully self-aligned process for fabricating 100 nm gate length enhancement mode GaAs metal-oxide-semiconductor field-effect transistors.
- Author
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Xu Li, Hill, Richard J. W., Longo, Paolo, Holland, Martin C., Zhou, Haiping, Thoms, Stephen, Macintyre, Douglas S., and Thayne, Iain G.
- Subjects
METAL oxide semiconductor field-effect transistors ,SEMICONDUCTORS ,GALLIUM arsenide ,SILICON ,PLASMA etching - Abstract
This article describes a process flow that has enabled the first demonstration of functional, fully self-aligned 100 nm enhancement mode GaAs metal-oxide-semiconductor field-effect transistors (MOSFETs) with Ga
x Gdy Oz as high-κ dielectric, Pt/W as metal gate stack, and SiN as sidewall spacers. The flow uses blanket metal and dielectric deposition and low damage dry etch modules. As a consequence, no critical dimension lift-off processes are required. Encouraging data are presented for 100 nm gate length devices including threshold voltage of 0.32 V, making these the shortest, fully self-aligned gate length enhancement mode III-V MOSFETs reported to date. This work is a significant step forward to the demonstration of high performance “siliconlike” III-V MOSFETs. [ABSTRACT FROM AUTHOR]- Published
- 2009
- Full Text
- View/download PDF
220. Development of Prototype Expert System for Roadside Safety
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Zhou, Haiping, primary and Layton, Robert D., additional
- Published
- 1991
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221. Caltrans use of scrap tires in asphalt rubber products: a comprehensive review
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Zhou, Haiping, Holikatti, Sri, and Vacura, Peter
- Abstract
The California Department of Transportation (Caltrans) has been using scrap tire rubber in asphalt pavements since the 1970s in chip seals and the 1980s in rubberized hot mix asphalt(RHMA). Both the wet (field blend) and dry processes were used in early trials. Caltrans has also used rubber modified binders containing both crumb rubber modifier and polymer modifier that could be manufactured at a refinery facility, a terminal blend wet process. Since the beginning of this century, Caltrans increased the use of scrap tire rubber in paving projects and invested considerable resources in developing technically sound, cost effective, and environmentally friendly strategies for using scrap tire rubber in roadway applications. By the end of year 2010, approximately 31%of all hot mix asphalt (HMA) placed by Caltrans was rubberized HMA, roughly 1.2 million tons. Caltrans efforts in using asphalt rubber products were also demonstrated in its research and technology development. These included the construction of two full-scale field experiments, five warranty projects, and an accelerated pavement study using a heavy vehicle simulator. Additionally, terminal blend asphalt rubber and rubberized warm mix asphalts began to be experimented on trial basis. This paper provides a comprehensive review of Caltrans experience over four decades with asphalt rubber products. Current practices and future outlook are also discussed.
- Published
- 2014
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222. Dual-heterostructures decorated interweaved carbon nanofibers sulfur host for high performance lithium-sulfur batteries.
- Author
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Song, Yaochen, Zhou, Haiping, Long, Xin, Xiao, Jisheng, Yang, Jian, Wu, Ningning, Chen, Zhi, Li, Pengyu, Chen, Cheng, Liao, Jiaxuan, and Wu, Mengqiang
- Subjects
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CARBON nanofibers , *LITHIUM cells , *LITHIUM sulfur batteries , *SULFUR , *X-ray photoelectron spectroscopy , *ENERGY storage - Abstract
• Sulfur host prepared by a unique dual-channel electrospinning method. • WS 2 /WO 3 and MoS 2 /MoO 3 heterostructures enabling anchor of LiPSs. • WX 2 and MoX 2 realized LiPSs adsorption and catalytic conversion. • Excellent energy storage performance is in both coin cell and pouch cell. Due to the dissolution of Lithium polysulfides (LiPSs), the volume expansion, and poor conductivity, practical applications of Lithium-sulfur batteries (LSBs) are not satisfactory. Herein, dual-heterostructure decorated interweaved carbon nanofibers are proposed as sulfur hosts to significantly improve the energy storage behavior of LSBs. The unique structure of the interweaved carbon nanofibers and heterostructures provides more transmission channels for electrons and ions while also accelerating the process. Moreover, the heterostructures induce chemical anchoring and catalytic conversion of LiPSs. As a result, the cathode in the coin cell delivers an initial capacity of 777.9 mAh g−1 at 1C and high retention of 68.59% after 600 cycles. In the pouch cell, the cathode delivers a discharge capacity of 907.8 mAh g−1 and a reversible charging capacity of 913.1 mAh g−1 for the first cycle with an ultra-high sulfur loading up to 9.136 mg cm−2. Beyond that, density functional theory calculations, X-ray photoelectron spectroscopy, symmetric cell, and Li 2 S nucleation tests were adopted to verify the adsorption and catalytic conversion mechanisms of the cathode. This excellent interweaved dual-heterostructure sulfur host provides a novel structural design strategy for efficient chemical adsorption and catalytic conversion of LiPSs, as well as more opportunities for the commercial application of LSBs. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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- View/download PDF
223. Review of Current Status of III-V MOSFETs
- Author
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Thayne, Iain, Hill, Richard, Holland, Martin, Li, Xi, Zhou, Haiping, Macintyre, Douglas, Thoms, Stephen, Kalna, Karol, Stanley, Colin, Asenov, Asen, Droopad, Ravi, and Passlack, Matthias
- Abstract
To address issues associated with continual scaling of the International Technology Roadmap for Semiconductors (ITRS) (1) to follow Moore's Law, MOSFETs with high mobility channel materials are now being seriously considered. As a result, there has been a significant expansion in research into III-V MOSFETs as a potential n-channel device solution. A wide range of high electron mobility channel materials, device architectures and gate oxides are currently being considered, and in this review, key performance metrics of III-V MOSFETs will be compared.
- Published
- 2009
224. Redox/NIR dual-responsive PEG-betulinic acid/pluronic-cypate prodrug micelles for chemophotothermal therapy.
- Author
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Zhang, Yunran, Zhou, Haiping, Zhang, Zhe, Zhu, Yijun, Wang, Tao, Yu, Liguo, and Song, Hongrui
- Subjects
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MICELLES , *PHOTOTHERMAL effect , *TREATMENT effectiveness , *OXIDATION-reduction reaction , *ANTINEOPLASTIC agents , *POLYETHYLENE glycol , *REDOX polymers , *BETULINIC acid - Abstract
Betulinic acid (BA) is a new class of anticancer drug, but its relatively short half-life and poor water solubility limit its therapeutic effect and clinical application. Herein, to tackle the dilemma, BA prodrugs were prepared by conjugating BA onto the polyethylene glycol (PEG) polymer via cleavable disulfide bonds. The prodrugs exhibited high water solubility (270-fold of free BA) and a relatively high drug-loading efficiency of 14.2 %. To further endow the BA prodrugs with a photothermal therapeutic effect, the near-infrared (NIR) agent Cypate was grafted on the Pluronic triblock copolymer. The different PEG polymers and different Pluronic polymers were chosen to obtain the optimal drug loading efficiency and the photothermal generation effect. The P-SS-BA/F68-Cy prodrug micelles integrate the redox-responsive BA prodrugs and the NIR-responsive amphiphilic triblock polymer into one single nanocomposite. The release of BA was less than 20 % in pH 7.4 PBS in the absence of glutathione (GSH), whereas the release of BA was obviously accelerated in pH 5.0 PBS with 10 mM GSH. In addition, the release of BA was further accelerated under the NIR irradiation. The P-SS-BA/F68-Cy micelles showed an excellent photothermal heating effect under NIR irradiation. The prepared P-SS-BA/F68-Cy micelles showed the synergistic thermochemotherapeutic effect on tumors both in vitro and in vivo. Therefore, the present study shows the great potential of dual-triggered drug delivery and thermochemotherapy for combination therapy. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
225. Electron Mobility in Surface- and Buried-Channel Flatband \In0.53\Ga0.47\As MOSFETs With ALD \Al2\O3 Gate Dielectric.
- Author
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Bentley, Steven J., Holland, Martin, Li, Xu, Paterson, Gary W., Zhou, Haiping, Ignatova, Olesya, Macintyre, Douglas, Thoms, Stephen, Asenov, Asen, Shin, Byungha, Ahn, Jaesoo, McIntyre, Paul C., and Thayne, Iain G.
- Subjects
ELECTRON mobility ,DIELECTRICS ,HETEROSTRUCTURES ,ELECTRON distribution ,METAL oxide semiconductor field-effect transistors ,ALUMINUM oxide ,ELECTRIC currents ,COMPLEMENTARY metal oxide semiconductors - Abstract
In this letter, we investigate the scaling potential of flatband III–V MOSFETs by comparing the mobility of surface- and buried-channel \In0.53\Ga0.47\As devices employing an atomic-layer-deposited \Al2 \O3 gate dielectric and a delta-doped InGaAs/InAlAs/InP heterostructure. Peak electron mobilities of 4300 \cm^2/\V\cdot \s and 6600 \cm^2/\V\cdot \s at a carrier density of \3 \times \10^12\ \cm^-2 were determined for the surface- and buried-channel structures, respectively. In contrast to similarly scaled inversion-channel devices, we find that the mobility in surface-channel flatband structures does not drop rapidly with the electron density, but rather high mobility is maintained up to carrier concentrations around \4 \times \10^12\ \cm^-2 before slowly dropping to around 2000 \cm^2/\V \cdot \s at \1 \times \10^13\ \cm^-2. We believe these to be world leading metrics for this material system and an important development in informing the III–V MOSFET device architecture selection process for the future low-power highly scaled CMOS. [ABSTRACT FROM AUTHOR]
- Published
- 2011
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- View/download PDF
226. Modulation of the electronic states of perovskite SrCrO3 thin films through protonation via low-energy hydrogen plasma implantation approaches.
- Author
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Wu, Meng, Chen, Shanquan, Huang, Chuanwei, Ye, Xing, Zhou, Haiping, Huang, Xiaochun, Zhang, Kelvin H. L., Yan, Wensheng, Zhang, Lihua, Kim, Kisslinger, Du, Yingge, Chambers, Scott, Zheng, Jin-Cheng, and Wang, Hui-Qiong
- Abstract
Hydrogenation of transition metal oxides offers a powerful platform to tailor physical functionalities as well as for potential applications in modern electronic technologies. An ideal nondestructive and efficient hydrogen incorporation approach is important for the realistic technological applications. We demonstrate the proton injection on SrCrO
3 thin films via an efficient low-energy hydrogen plasma implantation experiments, without destroying the original lattice framework. Hydrogen ions accumulate largely at the interfacial regions with amorphous character which extend about one-third of the total thickness. The Hx SrCrO3 (HSCO) thin films appear like exfoliated layers which however retain the fully strained state with distorted perovskite structure. Proton doping induces the change of Cr oxidation state from Cr4+ to Cr3+ in HSCO thin films and a transition from metallic to insulating phase. Our investigations suggest an attractive platform in manipulating the electronic phases in proton-based approaches and may offer a potential peeling off strategy for nanoscale devices through low-energy hydrogen plasma implantation approaches. [ABSTRACT FROM AUTHOR]- Published
- 2020
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- View/download PDF
227. Versatile and Highly Efficient Controls of Reversible Topotactic Metal–Insulator Transitions through Proton Intercalation.
- Author
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Chen, Shanquan, Zhou, Haiping, Ye, Xing, Chen, Zuhuang, Zhao, Jinzhu, Das, Sujit, Klewe, Christoph, Zhang, Lei, Lupi, Eduardo, Shafer, Padraic, Arenholz, Elke, Jin, Dun, Huang, Haoliang, Lu, Yalin, Li, Xiaowen, Wu, Meng, Ke, Shanming, Xu, Hu, Zeng, Xierong, and Huang, Chuanwei
- Subjects
- *
METAL-insulator transitions , *NONMETALS , *FERROMAGNETIC materials , *REVERSIBLE phase transitions , *METALLIC films , *CRYSTAL structure - Abstract
The ability to tailor a new crystalline structure and associated functionalities with a variety of stimuli is one of the key issues in material design. Developing synthetic routes to functional materials with partially absorbed nonmetallic elements (i.e., hydrogen and nitrogen) can open up more possibilities for preparing novel families of electronically active oxide compounds. Fast and reversible uptake and release of hydrogen in epitaxial ABO3 manganite films through an adapted low‐frequency inductively coupled plasma technology is introduced. Compared with traditional dopants of metallic cations, the plasma‐assisted hydrogen implantations not only produce reversibly structural transformations from pristine perovskite (PV) phase to a newly found protonation‐driven brownmillerite one but also regulate remarkably different electronic properties driving the material from a ferromagnetic metal to a weakly ferromagnetic insulator for a range of manganite (La1−xSrxMnO3) thin films. Moreover, a reversible perovskite‐brownmillerite‐perovskite transition is achieved at a relatively low temperature (T ≤ 350 °C), enabling multifunctional modulations for integrated electronic systems. The fast, low‐temperature control of structural and electronic properties by the facile hydrogenation/dehydrogenation treatment substantially widens the space for exploring new possibilities of novel properties in proton‐based multifunctional materials. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
228. Pavement Maintenance and Rehabilitation Practices in California: A Study of 35-year As-built Data in PaveM
- Author
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Wang, Zhongren, Zhou, Haiping, Mandapaka, Venkata, and Nguyen, Lan
- Abstract
In this paper, the pavement maintenance and rehabilitation practices are presented based on the analysis of as-built data housed in PaveM—the pavement management system for the California Department of Transportation (Caltrans). A 35-year period of as-built data from 1983 to 2017 was analyzed, involving 37 treatment strategies with 17 for asphalt and 20 for Portland Cement Concrete (PCC) pavements. The top ten treatment strategies, geographical and temporal variation of treated mileage, together with treatment costs and corresponding network condition were presented. It was found that: (1) The top 10 strategies are, in descending order: “Chip Seal”, “Hot Mix Asphalt (HMA) Thin Overlay”, “HMA Medium Overlay”, “HMA Thick Overlay”, “Mill and Fill”, “Grind/Replace Slabs”, “Slab Replacement”, “Crack Seat and Overlay”, “HMA Lane Replacement”, and “PCC Lane Replacement”. The top 10 strategies accounted for about 84% of the total treated lane kilometers. (2) On average, about 12.4% of the total network inventory (both asphalt and concrete pavements) was treated each year. This is equivalent to treat the entire network once every eight years. (3) About 18.3% of AC and 35.1% of PCC rehabilitation mileage was found applied on a lane-by-lane basis, instead of across all lanes. This finding solidified the necessity of a lane-based pavement management system in California. (4) The average annual weighted maintenance and rehabilitation cost per lane kilometer is about $192,248 for asphalt and $366,804 for PCC pavements. Due to the lack of preventive types of treatments for PCC pavement, the per lane kilometer cost is almost twice as high as that for its asphalt counterpart. It is suggested that more preventive type of treatments be implemented for PCC pavements.
- Published
- 2021
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- View/download PDF
229. Coexistence of bipolar non-volatile and threshold volatile resistive switching in MoS2nanosheets treated by soft nitrogen plasma
- Author
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Ke, Yizhen, Zhang, Zidong, Guo, Junxiong, Mao, Linna, Cheng, Tiedong, Zhou, Haiping, Lin, Yuan, Gong, Tianxun, Huang, Wen, and Zhang, Xiaosheng
- Abstract
Coexistence of non-volatile and volatile resistive switching on the same device are of interest in memory devices for weight storage applications. In this work, stacked MoS2nanosheet thin film was modified using soft nitrogen plasma treatment (NPT). Compared to pristine MoS2-based counterparts, the fabricated Ag/NPT-MoS2/indium tin oxide (ITO) structure exhibited both an enhanced ratio of 104and lowered threshold voltage of 0.1 V. The distinction might be attributed to the introduced carbonitride between Ag and MoS2, where the conductive filaments and interface barrier altogether affect the switching. The observation suggested a possibility of programming on a single two-terminal device.
- Published
- 2019
- Full Text
- View/download PDF
230. The microstructure evolution and strength mechanism of Ni3(Al, Ti)-type multicomponent alloy with superior mechanical property by laser melting disposition.
- Author
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Han, Zhihao, Zhao, Ling, Zhou, Haiping, Zhang, Hongbin, and Liu, Xue
- Subjects
- *
MECHANICAL alloying , *SOLUTION strengthening , *ALLOYS , *MICROSTRUCTURE , *HIGH temperatures , *LASER deposition - Abstract
By introducing nanoscale disordered interfaces into the ordered superlattice grains can achieved a combination of ultra-high strength and excellent ductility in Ni 3 Al-type high-temperature alloys, but limited by the complex preparation process. In the present work, a Ni 3 (Al, Ti)-type multicomponent alloy of Ni 43.9 Co 22.4 Fe 8.8 Al 10.7 Ti 11.7 B 2.5 was successfully fabricated using laser metal deposition (LMD) technique. The microstructural evolution, tensile properties and strengthening mechanism were investigated. Microstructural and phase analyses of the sample reveale the presence of dendritic γ + γ′ phases, γ′ envelopes and interdendritic γ + γ′ phases in the alloy. The LMD prepared Ni 43.9 Co 22.4 Fe 8.8 Al 10.7 Ti 11.7 B 2.5 alloy exhibits superior mechanical property at both room temperature and elevated temperature. Compared to Ni 3 Al-type intermetallic alloys, the alloy exhibited excellent strength-ductility synergy at room temperature. In addition, the alloy's yield strength rises as temperature rises from 298 K to 973 K, reaching a maximum value of 1043 MPa at 973 K. The strength of the prepared Ni 43.9 Co 22.4 Fe 8.8 Al 10.7 Ti 11.7 B 2.5 alloy is mainly contributed by lattice friction strengthening, solid solution strengthening, precipitation strengthening and the inherent yield strength of γ′ envelopes with precipitation strengthening, and the inherent yield strength is the key factor. This work provides insight into the preparation of Ni 3 (Al, Ti)-type multicomponent alloy with superior mechanical property at both room temperature and elevated temperature by LMD. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
231. Plasma-induced oxygen defects in titanium dioxide to address the long-term stability of pseudocapacitive MnO2 anode for lithium ion batteries.
- Author
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Zhang, Zidong, Ran, Ke, Wang, Wenjian, Cao, Shengling, Zhao, Rui, Zhou, Haiping, Xue, Weidong, Li, Haomiao, Wang, Wei, Min, Zhou, Jiang, Kai, and Wang, Kangli
- Subjects
- *
LITHIUM-ion batteries , *OXYGEN plasmas , *TITANIUM dioxide , *LITHIUM titanate , *ANODES , *ACTIVATION energy , *ELECTRIC conductivity - Abstract
[Display omitted] • The structure of MnOx@aTiOy showed the increasing capacity being activated to maintain for a long-term cycling (829.5 mAh g−1 at 1 A g−1 after 2000 cycles). • The oxygen defects in the coating layer of modified TiO 2 boosted the pseudocapacitance effect for electrochemical performance. • The DFT calculations reveals the oxygen defects, the transformation of α-MnO 2 into Bixbyite-O Mn 2 O 3 , would decrease the kinetics of Li+ on lithium migrating paths and energy barriers. In this work, we developed Manganese and Titanium based oxide composites with oxygen defects (MnO x @aTiO y) via plasma processing as anodes of lithium ion batteries. By appropriately adjusting the defect concentration, the ion transport kinetics and electrical conductivity of the electrodes are significantly improved, showing stable capacity retention. Furthermore, the incremental capacity is further activated and long-term stable cycling performance is achieved, with a specific capacity of 829.5 mAh/g at 1 A/g after 2000 cycles. To scrutinize the lithium migration paths and energy barriers in MnO 2 and Mn 2 O 3 , the density functional theory (DFT) calculations is performed to explore the lithium migration paths and energy barriers. Although the transformation of MnO 2 into Mn 2 O 3 through oxygen defects was initially surmised to inhibit Li ions along their standard routes, our results indicate quite the contrary. In fact, the composite's lithium diffusion rate saw a substantial increase. This can be accredited to the pronounced enhancement of conductivity and ion transport efficiency in the amorphous and porous TiO y. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
232. Enhanced photocatalytic hydrogen production activity of Ni modified TiO2/GO nanosheet composites.
- Author
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Liu, Faxing, Xiang, Quanjun, Zhang, Xigui, and Zhou, Haiping
- Subjects
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HYDROGEN production , *SILVER , *INTERSTITIAL hydrogen generation , *HYDROGEN evolution reactions , *ATOMIC hydrogen , *VISIBLE spectra , *PHOTOELECTROCHEMICAL cells , *LIGHT absorption , *RAMAN spectroscopy - Abstract
Solar-driven photocatalytic hydrogen generation via splitting water requires an efficient visible light active photocatalyst. In this work, Ni cocatalysts on a TiO2 composite photocatalyst with different graphene oxide (GO) contents were prepared using a hydrothermal method and characterized by TEM, XRD, UV-vis, Raman and PL spectra. The results show that the synthesized TiO2/GO/Ni nanosheet composites have a large specific surface area and can provide a large number of active sites for a photocatalytic hydrogen production reaction. GO can broaden the optical absorption range of TiO2 and absorb more visible light, thus stimulating more photogenerated electron–hole pairs. At the same time, GO can collect electrons and promote the separation of photogenerated electron–hole pairs. Ni, as a cocatalyst, can be used as an active site for hydrogen ion adsorption, which is conducive to promoting the migration of photogenerated electrons in the system and prolonging the life of photogenerated electrons and holes, thus ensuring the high efficiency of the photocatalytic reaction. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
233. Highly reversible aqueous zinc-ion battery using the chelating agent triethanolamine as an electrolyte additive.
- Author
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Lin, Yunhui, Hu, Youzuo, Zhang, Shu, Xu, Ziqiang, Feng, Tingting, Zhou, Haiping, and Wu, Mengqiang
- Subjects
- *
ELECTROLYTES , *CHELATING agents , *LITHIUM cells , *SOLVATION , *ELECTRIC batteries , *CATHODES , *ADDITIVES - Abstract
Aqueous zinc-ion batteries (AZIBs) have received great attention owing to the increasing demand for safe and inexpensive batteries. However, their poor cycling issue hinders their commercialization and further application, resulting from the zinc dendrite growth, corrosion, and passivation that occur on the Zn anode, as well as the dissolution and cracking issue of active materials on the cathode. Herein, we introduce the use of a chelating agent triethanolamine (TEA) as an additive in the electrolyte to enhance the cycling stability of AZIBs. TEA molecules preferentially coordinate with Zn2+, replacing water molecules in the solvation sheath of Zn2+, thereby reducing the solvation effect in the electrolyte. Moreover the adsorbed interface layer on the anode Zn surface forms a stable solid–electrolyte interphase (SEI) while the cathode forms a cathode–electrolyte interphase (CEI), suppressing the side reactions and dendrite growth of metallic Zn and protecting the cathode from dissolution while increasing the diffusion rate of Zn2+. The Zn‖MnO2@CNT cell showed reversible and durable performance with 78% retention after 2000 cycles at 0.5 A g−1. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
234. Hot deformation behavior and processing map of vanadium particles reinforced AZ31 composite.
- Author
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Zhang, Hongbin, Chen, Shengchao, Huang, Yilin, Zhou, Haiping, Qin, Shengxue, and Liu, Jie
- Subjects
- *
VANADIUM , *DEFORMATIONS (Mechanics) , *ACTIVATION energy , *POWDER metallurgy , *MODEL theory - Abstract
The vanadium particles reinforced AZ31 matrix composite (V P /AZ31) was prepared using the powder metallurgy method. Subsequently, hot deformation behavior of V P /AZ31 composite was studied through hot compression trials. The experimental parameters were set in a temperature range of 250–400 °C and a strain rate range of 0.001–1 s−1. Based on the experimental results, a strain-compensated Arrhenius constitutive model was developed to accurately forecast the flow behavior of V P /AZ31 composite. Moreover, the thermal activation energy was calculated to be 138.605 kJ/mol and the processing map was delineated according to the dynamic material model theory. The processing map revealed that the optimal processing area existed under 363–400 °C/0.001–0.004 s−1, where the efficiency of power dissipation exceeded 23 %. Notably, the highest efficiency of power dissipation occurred at 400 °C/1 s−1, which exceeded 30 %. Under these conditions, dynamic recrystallization (DRX) was sufficiently developed, indicating the enhancement of workability. It is estimated that the instability region for V P /AZ31 composites occurred within the conditions of 250–325 °C/0.16–1 s−1, characterized by crack formation. The DRX of V P /AZ31 composite is predominantly governed through the mechanism of discontinuous DRX (DDRX). • A strain-compensated Arrhenius constitutive model was developed to forecast the flow behavior of V P /AZ31 composite. • The thermal activation energy of V P /AZ31 composite is approximately 138.605 kJ/mol. • The processing map revealed that a safe processing range exists under 363–400 °C/0.004–0.001 s−1. • It is estimated that the instability region for V P /AZ31 composites occurs within the condition of 250–325 °C/0.16–1 s−1. • The dynamic recrystallization of V P /AZ31 composite is predominantly governed by discontinuous dynamic recrystallization. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
235. High pressure optical studies of semiconductors
- Author
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Zhou, Haiping
- Subjects
- 621.3815
- Abstract
Until this work was completed no detailed studies of the low-temperature emission of A10.48gIn0.52As under high pressures were available to the best of our knowledge. We investigated the low-temperature emission of Al0.48gIn0.52AS under high pressures from 1 bar up to 92 kbar, especially with respect to the changes in luminescence mechanisms that occur concurrently with the crossover between the direct- and indirect-related bands.
- Published
- 1992
236. Effect of strain rate on microstructure evolution of a nickel-based superalloy during hot deformation.
- Author
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Zhang, Hongbin, Zhang, Kaifeng, Zhou, Haiping, Lu, Zhen, Zhao, Changhong, and Yang, Xiaoli
- Subjects
- *
STRAIN rate , *MICROSTRUCTURE , *NICKEL compounds , *HEAT resistant alloys , *DEFORMATIONS (Mechanics) , *RECRYSTALLIZATION (Metallurgy) - Abstract
The hot deformation behavior of a nickel-based superalloy was investigated by means of isothermal compression tests in the strain rate range of 0.001–10 s −1 at 1110 °C. Transmission electron microscope (TEM) and electron backscatter diffraction (EBSD) technique were used to study the effect of strain rate on the microstructure evolution of the alloy during hot deformation. The results revealed that the dynamic recrystallization (DRX) process was stimulated at high strain rates ( ε ̇ ⩾ 5 s - 1 ) due to the high dislocation density and adiabatic temperature rise. Meanwhile, high nucleation of DRX and low grain growth led to the fine DRX grains. In the strain rate rage of 0.001–1 s −1 , the volume fraction of DRX grains increased with the decreasing strain rate, and the grain growth gradually governed the DRX process. Moreover, the strain rate has an important effect on DDRX and CDRX during hot deformation. On the other hand, particular attention was also paid to the evolution of twin boundaries during hot deformation. It was found that there was a lower fraction of Σ 3 boundaries at the intermediate strain rate of 1 s −1 , while the fractions of Σ 3 boundaries were much higher at both the lower strain rates ( ε ̇ ⩽ 0.1 s - 1 ) and higher strain rates ( ε ̇ ⩾ 5 s - 1 ). [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
237. Zn-doping Effects of Na-rich Na3+xV2-xZnx(PO4)3/C cathodes for Na-Ion Batteries: Lattice distortion induced by doping site and enhanced electrochemical performance.
- Author
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Li, Xinran, Chen, Cheng, Yang, Jian, Fang, Zixuan, Zeng, Shumao, Feng, Tingting, Zhou, Haiping, Zhang, Shu, and Wu, Mengqiang
- Subjects
- *
CATHODES , *ANCHORING effect , *STRUCTURAL stability , *SODIUM ions , *STORAGE batteries , *DOPING agents (Chemistry) - Abstract
[Display omitted] To tackle the intrinsic inferior conductivity of the sodium ion batteries (SIBs) cathode Na 3 V 2 (PO 4) 3, transitional metal cation doping, and carbon frame design are employed for NASICON structural modification. Herein, a hard carbon skeleton Na 3+x V 2−x Zn x (PO 4) 3 NASICON structure is proposed resorting to the combination of flimsy hard carbon slices coating and Zn2+ doping along with the introduction of spare Na+. The structural distortion caused by the insertion of Zn2+ and Na+ broadens the transfer channels and increases diffusion routes for Na+. At the same time, the anchoring effect for Na 3+x V 2−x Zn x (PO 4) 3 nanoparticles brought by external hard carbon layers and pillar effect aroused by Zn2+ provide a stable and firm skeleton, which is conducive to structural stability and reversibility at high current density. Among various doping concentrations, Na 3.03 V 1.97 Zn 0.03 (PO 4) 3 performs a significantly enhanced rate performance with a reversible capacity up to 60 mAh·g−1 (40C) and ultra-long cycle life of 1000 cycles with a capacity retention of 92.6% at 5C. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
238. Multilevel-teaching/training practice on GNSS principle and application for undergraduate educations: A case study in China.
- Author
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He, Xiaoxing, Yu, Kegen, Huang, Zhengkai, Montillet, Jean-Philippe, Lu, Tieding, Lan, Xiaoji, Xiao, Genru, Ma, Xiaping, Zhou, Haiping, and Chen, Yilin
- Subjects
- *
REMOTE sensing , *TEACHING methods , *DISTANCE education , *BACK to basics (Education) , *USER-generated content ,UNDERGRADUATE education - Abstract
This work discusses a Multilevel-Teaching Practice on GNSS Principle and Application for Undergraduates of Surveying and Mapping in China, underlining the fast development of remote sensing technology. We explore i) the multidisciplinary cross-combination transformation of the traditional GNSS education of remote sensing; ii) we combine theoretical knowledge and practical results in the field of navigation and positioning; iii) we highlight the cutting-edge, intersecting and comprehensive teaching content; innovate the construction of a practical teaching platform for GNSS theory, practice and innovation ability training. A multi-level theoretical and practical curriculum system has been established to strengthen the foundation and professional skills, and cultivate scientific and technological innovation. We propose a teaching method of "Hybrid Online/Offline Teaching", which makes use of the advantages of online/offline teaching form, effectively improving the quality of undergraduate teaching. In terms of practice and innovation ability training, we establish an open, diversified, research-based practice innovation-education platform based on virtual simulated experiments. The implementation of this teaching approach has achieved remarkable results on undergraduate training for GNSS education. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
239. Bimetallic composite induced ultra-stable solid electrolyte interphase for dendrite-free lithium metal anode.
- Author
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Yang, Jian, Feng, Tingting, Zhi, Chen, Li, Jingzhu, Zhou, Haiping, Chen, Cheng, Song, Yaochen, and Wu, Mengqiang
- Subjects
- *
SOLID electrolytes , *SUPERIONIC conductors , *LITHIUM-ion batteries , *METALLIC composites , *ANODES , *HIGHWAY engineering - Abstract
The NiLi-BC electrode forms regular interfacial electric field near the electrode surface, which is favorable to eliminate the local concentration polarization and induce the generation of the stable and long-term effective SEI during the Li plating and striping processes. As a result, the NiLi-BC electrode exhibits a Li dendrite-free feature and ultra-stable cycling performance with a low overpotential. [Display omitted] • Bimetallic composite induced ultra-stable solid electrolyte interphase on the surface of the electrode. • The bimetallic composite is contributed to uniform Li deposition. • The strategy is facile and effective enough to provide a feasible road for the engineering application of Li metal anode. Lithium metal is the most promising anode materials for the next generation lithium ion battery. However, the electrode polarization leads to the formation of dendrites and "dead lithium", which degrades the performance of lithium metal batteries and induce a variety of security risk. The electrode polarization and lithium dendrites can be suppressed by lithium metal composite electrode. Herein, a simple and effective strategy is adopted to construct nickel and lithium bimetallic composite (NiLi-BC) electrode by a double roll process. The Ni framework inside the electrode can optimize the electric field and Li+ distribution at the electrode/electrolyte interface and induce the uniform lithium deposition. As a result, the NiLi-BC exhibits a lithium dendrite-free feature and stable cycling performance under a low overpotential (<15 mV throughout 2180 h at 1 mA cm−2 with a deposition capacity of 1 mAh cm−2). Moreover, the assembled NiLi-BC||LiFePO 4 coin cell and pouch cell exhibit improved capability and stable cycling performance. Finally, the in-situ optical microscopy and in-situ Raman spectroscopy are employed to obtain a better understanding of the interfacial structure and chemical component during the Li plating and striping processes. The scheme of this study of the NiLi electrode has great practical application value. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
240. An effective approach for the protection of user commodity viewing privacy in e-commerce website.
- Author
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Wu, Zongda, Shen, Shigen, Zhou, Haiping, Li, Huxiong, Lu, Chenglang, and Zou, Dongdong
- Subjects
- *
ELECTRONIC commerce , *PRIVACY , *COMMERCIAL products , *PROBABILITY measures , *INTERNET privacy - Abstract
Along with the rapid development of network technologies, the server-side of an e-commerce website is becoming more and more untrustworthy. Thus, how to prevent the disclosure of users' behavior privacy in online business activities has attracted people's wide attention. Aiming at the protection of users' commodity viewing privacy in a commercial website, this paper proposes to construct a group of dummy requests on a trusted client, then, which are submitted together with a user commodity viewing request to the untrusted server-side, so as to confuse and cover up the user preferences. First, we define a privacy model for a user commodity viewing service, in which we introduce a concept called entropy for commodity viewing probability to measure the confusion effect of dummy requests on user requests, and we introduce a concept called regional distance among commodity categories to measure the cover-up effect of dummy requests on users' commodity viewing preferences. Second, we design an implementation algorithm to generate a group of ideal dummy requests that can meet the constraints formulated in the privacy model. Finally, both theoretical analysis and experimental evaluation demonstrate the effectiveness of the proposed approach, i.e., which can improve the security of users' commodity viewing privacy on the untrusted server-side, without compromising the availability of an e-commerce website. In this paper, we present a valuable research attempt to the protection of users' behavior privacy in a commercial website, which is of positive significance for building a privacy-preserving e-commerce platform. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
241. Rational construction Ag/LiF/sulfide rich protective layer for remarkably enhancing the stability of Li metal anodes.
- Author
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Xu, Caili, Zhang, Shu, Chen, Cheng, Lin, Yunhui, Qu, Bing, Zhou, Haiping, and Wu, Mengqiang
- Subjects
- *
SILVER alloys , *SILVER sulfide , *METALS , *ANODES , *LITHIUM fluoride , *ELECTROCHEMICAL electrodes , *SULFIDES , *ENERGY density , *SOLID electrolytes - Abstract
Li anode with a multicomponent protective layer (Ag/F/S-Li) protective layer at molecular level are designed and prepared. The Ag0 in Ag/F/S-Li has the ability to induce uniform Li+ distribution, while LiF/sulfide layer enable to reduce the side reaction between electrolyte and Li metal. This Ag/F/S-Li anode can cycle stably for 2000h. [Display omitted] • Rational construction of Ag0, LiF/sulfide enriched composition protection layer at molecular level for Li metal anode. • Ag0, LiF and sulfide in the layer are uniformy distributed. • The stability of Ag/F/S-Li anode is significantly enhanced and can be stably cycled for 2000 h. • Ag/F/S-Li||LFP, Ag/F/S-Li||LCO full cells and Ag/F/S-Li(or LiB)||MnO 2 primary cell exhibit excellent performance. Li metal is a promising anode material for high-energy–density batteries due to its high theoretical capacity and low redox potential. However, both the uncontrolled Li dendrite growth and unstable solid electrolyte interphase (SEI) layer restricts its large-scale practical applications. Herein, an artificial protective layer consisting of Ag nanoparticles, lithium fluoride (LiF) and sulfide are innovatively designed and fabricated via the in-situ chemical reaction between Ag(I) trifluoromethylthiolate (AgSCF 3) and Li metal. Density functional theory (DFT) results indicate that Ag nanoparticles have a high binding energy with Li atom and LiF/sulfide have wide band gap, which would provide plenty of nucleation sites for Li+ and reduce the direct contact between inner Li metal and the electrolyte. The co-existence of Ag and LiF/sulfide results in a strong synergistic effect, and this is confirmed by the systematical comparison with single modified Ag-Li and double modified F/S-Li anodes. Benefitting from this synergistic effect, the Ag/F/S-Li symmetrical cells can stably work for 2000 h with low-voltage hysteresis at current density of 1 mA cm−2. Full cells assembled with LiCoO 2 (LCO) and LiFePO 4 (LFP) cathodes displays much better long‐term cycle performance when the Ag/F/S-Li anode is applied. Furthermore, this Ag/F/S-Li modification can significantly enhance discharge capacity, rate performance, as well as energy density of Li(or LiB alloy)||MnO 2 primary cells. This promising work promotes the practical application of Li metal and provides new insight into the protective layer design in stable Li metal batteries. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
242. Infrared emission characteristic and microwave loss property of aluminum doped zinc oxide nanoparticles.
- Author
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Wang, Yanjun, Yu, Meijie, Huang, Chaohui, Zheng, Qi, Zhou, Haiping, Zhang, Ze, and Zhao, Shengyao
- Subjects
- *
ZINC oxide , *NANOPARTICLES , *DIELECTRIC loss , *DOPING agents (Chemistry) , *ALUMINUM - Abstract
Aluminum doped zinc oxide (AZO) nanoparticles with different doping concentrations were prepared by a simple one-step hydrothermal synthesis method. The crystal structure, morphology, infrared absorption, infrared emission and microwave loss properties of the AZO nanoparticles were analyzed in detail. With the increase of the aluminum doping concentration, the crystal plane spacing does not change much, while the grain size increases gradually, and the thickness of the flakes and the average size of the particles have no significant change. With the increase of the Al doping concentration, the infrared emissivity of AZO tends to decrease first and then increase, among which the AZO infrared emissivity with Zn-ion ratio of 95:5 is the lowest. The electromagnetic parameters of AZO with a mole doping ratio of 93:7 were carried out at a frequency range of 2–18 GHz, the real part (ε′) and imaginary part (ε″) of the complex permittivity varies between 4.3-4.5 and 0.2–0.4, respectively, the dielectric loss tangent (tan δ) varies between 0.04 and 0.09. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
243. Enhanced microwave absorption performance of Fe/C nanofibers by adjusting the magnetic particle size using different electrospinning solvents.
- Author
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Zheng, Qi, Yu, Meijie, Wang, Wen, Wang, Yanjun, Zhang, Ze, Zhou, Haiping, Dai, Youyong, Wang, Chengguo, and Xu, Yong
- Subjects
- *
MAGNETIC particles , *NANOFIBERS , *SOLVENTS , *ETHANOL , *NANOPARTICLES , *CALCINATION (Heat treatment) , *CARBON nanofibers - Abstract
Two kinds of Fe/C nanofibers were prepared by electrospinning and calcination under the same process conditions. A simple way was used to adjust the size of the Fe nanoparticles by using different spinning solvents. The one was prepared by a mixture of water and anhydrous alcohol as solvents (named as CNF water) and the other by N,N-Dimethylformamide and anhydrous alcohol (named as CNF DMF). Due to the higher solubility to iron salts and larger surface tension of water, CNF water gained a larger size of Fe nanoparticles and average diameter. In addition, the graphite layers wrapped on Fe nanoparticles which were formed during calcination were thinner in CNF water than CNF DMF. These factors endowed CNF water better microwave absorption performance. The results of XRD, SEM, HRTEM, Raman, magnetostatic and electromagnetic properties analysis revealed the influence mechanisms of solvents on the formation, microstructure and properties of Fe/C nanofibers. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
244. Interfacial modification of titanium dioxide to enhance photocatalytic efficiency towards H2 production.
- Author
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Xiang, Quanjun, Ma, Xiyang, Zhang, Dainan, Zhou, Haiping, Liao, Yulong, Zhang, Huaiwu, Xu, Shuyan, Levchenko, Igor, and Bazaka, Kateryna
- Subjects
- *
TITANIUM dioxide , *SPACE flight propulsion systems , *CLEAN energy , *SOLAR wind , *INTERSTITIAL hydrogen generation - Abstract
Strong demand for affordable clean energy to support applications ranging from conventional energy supply to space propulsion places spotlight on advanced energy generation using photovoltaic and wind power. Yet, the intermittent nature of solar and wind sources drives the search for energy storage solutions that would permit the needed level of resilience and support further growth in the use of renewable sources of power. Hydrogen generation using sunlight is a promising pathway to decouple demand from supply. Herein, we show how exposure to reactive Ar-H 2 , Ar-H 2 -N 2 , and Ar-O 2 plasma environments can notably enhance surface properties of photocatalytic TiO 2 nanosheets used in advanced energy generation systems. Treatment using Ar-H 2 plasmas produced highly hydrogenated, surface-disordered TiO 2 nanosheets with oxygen vacancies, whereas exposure to Ar-H 2 -N 2 plasmas resulted in N doping. Surprisingly, Ar-O 2 plasma treatment did not change surface properties of TiO 2. Optical emission spectroscopy was used to monitor transient species to further understand surface modification in plasma. Direct measurements demonstrated that among thus-produced samples, hydrogenated TiO 2 nanosheets exhibit the highest photocatalytic H 2 -generation activity under visible-light irradiation, which is also greater than the activity of pure, untreated nanosheets. The mechanism of enhancing the visible-light photocatalytic H 2 -generation activity on hydrogenated TiO 2 nanosheets is also proposed. The level of surface disorder and oxygen vacancies plays an important role in enhancing visible-light absorption and reducing the recombination of photogenerated electrons and holes. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
245. Complex phase transition of DNA condensation under crowding confinement conditions.
- Author
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Zhou, Qian, Gao, Qingqing, Peng, Yixue, Song, Xiaoyi, Liu, Yong, Liu, Yanhui, Gu, Lingyun, Zhou, Xun, and Zhou, Haiping
- Subjects
- *
DNA condensation , *PHASE transitions , *MONTE Carlo method , *CONFINEMENT farms , *TOROIDAL magnetic circuits - Abstract
The mechanism underlying the crowding effects that assist the condensation process by multivalent cations under confinement is not yet reported. Based on the strong correlation model, Monte Carlo simulation was implemented to detect the crowding effects on DNA condensation within a capsule-like space, and its geometry controlled by the aspect ratio. With the addition of crowders, the condensed conformations confined within the spherical space (aspect ratio is 1) become more compact than those without crowders. The DNA-condensed conformations undergo a transition from the initial random coil structure to toroid structure, followed by the extended rod-like structure, and finally to totally compacted structure. The critical volume fraction corresponding to the transition from the rod-like structure to totally compacted structure pertained to the crowder size proportionally. Moreover, the critical volume fraction corresponding to the phase transition strongly depends on the confinement geometry, the critical volume fraction for the case with constant radius is inversely proportional to the aspect ratio. Conversely, the case with constant cylinder length showed that the critical volume fraction is proportional to the aspect ratio. These phenomena are consistent with their corresponding phase diagram re-expressed in the space of volume fraction and aspect ratio. The effects of confinement geometry and crowder size on the response of DNA condensation to crowding are elucidated and generalized into the space diagram in the space of aspect ratio and crowder size. When the aspect ratio less than 1.6 and the crowder size larger than 2.0 nm or when the aspect ratio ≥ 1.6 and the crowder size larger than the critical d c ∗ , the DNA conformation undergo the transition from the initial random coil structure to toroid structure, followed by totally compacted structure; when the aspect ratio ≥ 1.6 and the crowder size ≤ d c ∗ , the DNA condensed conformations will be condensed further from the totally compacted structure to the extended rod-like structure. Furthermore, the transition from the totally compacted structure to the extended rod-like structure is entirely due to the crowder size and the confinement geometry between the de Gennes and Odijk regimes. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
246. Nitrogen-doped carbon coated zinc as powder-based anode with PVA-gel electrolyte enhancing cycling performance for zinc-ion batteries.
- Author
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Lin, Yunhui, Zhang, Ming, Hu, Youzuo, Zhang, Shu, Xu, Ziqiang, Feng, Tingting, Zhou, Haiping, and Wu, Mengqiang
- Subjects
- *
ELECTROLYTES , *DOPING agents (Chemistry) , *ANODES , *POWDERS , *DENDRITIC crystals - Abstract
• N-doped carbon coating of Zn powder increases the conductivity and zincophilic sites. • PVA-gel based electrolyte effectively eliminates side reactions on Zn anode. • Symmetric cell of Zn-NC in PVA-gel electrolyte achieves ultralong lifespan. • Full cell Zn-NC||MnO 2 in PVA-gel electrolyte achieves highly reversible capacity. • This work provides a promising pathway for flexible Zn-powder based batteries. Zn-powder based anodes are considered as candidates for Zn-based batteries in practical industrial applications in terms of cost, large-scale processing, versatility and tunability. However, Zn-P-based anodes suffer from even more severe side effects including corrosion, passivation, and uncontrolled dendrite growth. Herein, we successfully fabricated nitrogen-doped carbon coating layer on Zn particles (Zn-NC) as anode material for more homogeneous Zn deposition by inducing more zincophilic site on N-doped carbon layers and enhanced electrical connection with carbon networks on Zn-NC particle surface. Nevertheless, metallic Zn deposited on Zn-NC surface still suffers from unavoidable side effects with continuous cycling, even though the dendrite growth was suppressed. It is worth mentioned that PVA-gel electrolyte greatly improves the cycling performance of Zn-NC with limited water content, which can alleviate side reactions. Experiments and simulations address the importance of NC layers with higher electricity, chemical stability, and zincophilic property, as well as the role that PVA-gel electrolyte plays for the further improved cycling performance. Zn-NC with PVA-gel electrolyte achieves ultra-long cycling hours with over 3500 h at 1 mA cm−2 and 850 h at 5 mA cm−2 in symmetrical cells. This study provides a promising pathway and in-depth mechanistic analysis for Zn-powder based anode in versatile applications especially for flexible energy-storage devices. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
247. Optimal privacy preservation strategies with signaling Q-learning for edge-computing-based IoT resource grant systems.
- Author
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Shen, Shigen, Wu, Xiaoping, Sun, Panjun, Zhou, Haiping, Wu, Zongda, and Yu, Shui
- Subjects
- *
DATA privacy , *INTERNET of things , *CLOUD storage , *PRIVACY , *COMPUTATIONAL complexity , *EDGE computing - Abstract
• Propose a privacy-preservation signaling game for edge-based IoT networks. • Obtain optimal privacy preservation strategies from theoretical and practical views. • Address the problem of obtaining the convergent game equilibrium in practice. • Have a lower computational complexity available to real-life implementation. Data privacy leakage can be severe when a malicious Internet of Things (IoT) node sends requests to gather private data from an edge-computing-based IoT cloud storage system across the edge nodes. To solve this problem, a privacy-preservation signaling game for edge-computing-based IoT networks is proposed to characterize the interactions between an IoT node and its corresponding edge node when managing an IoT resource-grant system. Optimal privacy preservation strategies for edge nodes are then theoretically derived. A signaling Q-learning algorithm is then designed to address the problem of achieving convergent equilibrium and game parameters from a practical perspective. The theoretical results are validated using simulations that focus on two statistical points (i.e., the optimal probability of an IoT node requesting maliciously and the posterior probability of an IoT node being malicious). By comparing the proposed signaling Q-learning algorithm with the greedy algorithm benchmark, the proposed algorithm is shown to more effectively decrease the optimal probability of an IoT node sending malicious requests. Thus, privacy preservation for edge-computing-based IoT cloud storage systems can be strengthened. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
248. Comprehensive analysis of hub biomarkers associated with immune and oxidative stress in Hashimoto's thyroiditis.
- Author
-
Xu, Bojin, Huang, Shan, Peng, Wenfang, Cai, Guanjun, Zhou, Haiping, Guo, Yiming, Du, Juan, Ge, Xiaoxu, and Wu, Xiaohong
- Subjects
- *
AUTOIMMUNE thyroiditis , *OXIDATIVE stress , *BIOINFORMATICS , *IMMUNOLOGIC memory , *THYROTROPIN receptors , *GENE expression , *GENE regulatory networks - Abstract
Hashimoto's thyroiditis (HT) is a type of autoimmune disorder with a complex interplay between immune disorder and oxidative stress (OS). This research aimed to discover biomarkers and potential treatment targets associated with immune and OS dysregulation in HT through integrated bioinformatics analysis and clinical validations. Differential gene expression analysis of GSE138198 dataset from the GEO database identified 1490 differentially expressed genes (DEGs) in HT, including 883 upregulated and 607 downregulated genes. Weighted gene co-expression network analysis explored module genes associated with HT. Overlapping the differentially expressed module genes with immune-related and OS-related genes identified eight differentially expressed module genes associated with immune and OS (DEIOGs) in HT. Protein-protein interaction network analysis identified five hub genes (TNFAIP3, FOS, PTK2B, STAT1, and MMP9). We confirmed four hub genes (TNFAIP3, PTK2B, STAT1 and MMP9) in GSE29315 dataset and clinical thyroid samples, which showed high diagnostic accuracy (AUC >0.7) for HT. The expression of these four genes was positively correlated with serum thyroid peroxidase antibody, thyroglobulin antibody levels, and inflammatory infiltration scores in clinical thyroid samples. Immune profiling revealed distinct profiles in HT, such as B cells memory, monocytes and macrophages. Additionally, all hub genes were inversely associated with monocytes. Further, miRNA-mRNA network analysis was conducted, and a regulatory network comprising four hub genes, 238 miRNAs and 32 TFs was established. These findings suggest that immune cells play a crucial role in the development of HT, and the hub genes TNFAIP3, PTK2B, STAT1, and MMP9 may be key players in HT through immune- and OS-related signaling pathways. Our results may provide valuable insights into the pathogenesis and therapeutic monitoring of HT. [Display omitted] • Four hub genes associated with immunity and oxidative stress were identified in Hashimoto's thyroiditis (HT). • The expression of TNFAIP3, PTK2B, STAT1, and MMP9 was correlated with clinical characteristics of HT. • Immune profiling showed distinct immune cells in HT versus controls, with hub genes correlated to specific immune cells. • A gene-miRNA-TF regulatory network analysis identified 238 miRNAs and 32 TFs regulating the four hub genes. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
249. Orbital polarization change and magnetic enhancement in rutile MnO2-δ epitaxial films.
- Author
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Liu, Wenyi, Huang, Haoliang, Zeng, Shuming, Zhou, Haiping, Xie, Liang, Jiang, Zhongyuan, Zhang, Jian, Wang, Lenan, Wang, Jianlin, Huang, Qiuping, Fu, Zhengping, Tu, Yusong, and Lu, Yalin
- Subjects
- *
RUTILE , *LINEAR dichroism , *MAGNETIC films , *OXIDE coating , *MAGNETIC moments - Abstract
[Display omitted] • Rutile MnO 2-δ film is used to demonstrate the regulation of the orbital occupation. • Orbital polarization change in MnO 2-δ films is obtained by reductvie annealing. • Significant enhanced magnetic moments in MnO 2-δ films can be detected below 50 K. Effectively manipulating the orbital configuration is an emerging method to design quantum functional materials with novel electronic ground states. Here, we report the realization of orbital polarization change in rutile MnO 2-δ epitaxial thin films by reductive treatments such as CaH 2 coating annealing and hydrogen atmosphere annealing. These treated samples show significant lattice expansion due to the generation of oxygen vacancies and incorporation of H, and the mixed valence states of Mn2+ and Mn3+ are formed with the decrease in the Mn valence state. The X-ray linear dichroism results show that the electron occupied state of Mn in the treated film samples changes from 3d 3z 2 -r 2 to 3d x 2 -y 2, which means that the deprivation of oxygen atoms in the oxygen octahedron of MnO 6 causes a change of orbital polarization. The resulting high spin state in the treated MnO 2-δ films greatly enhances the magnetic properties of the films. This work not only demonstrates how the oxygen atoms in the edge-shared oxygen octahedron of rutile structures are replaced by reduction but also extends the study of orbital polarization and magnetic ground state control in oxide epitaxial films. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
250. Dual-functionally modified N/S doped hierarchical porous carbon and glycerol-engineered polyacrylonitrile carbon nanofibers combine for high-performance lithium-ion capacitors.
- Author
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Hu, Shun, Ge, Zhen, Tan, Jie, Lai, Haoran, Feng, Tingting, Zhang, Shu, Xu, Ziqiang, Zhou, Haiping, Cao, Xiuhua, Zhu, Guisheng, and Wu, Mengqiang
- Subjects
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CARBON nanofibers , *POLYACRYLONITRILES , *ENERGY density , *CAPACITORS , *NANOFIBERS , *ELECTRIC conductivity , *POWER density , *CATHODES - Abstract
Designing cathode and anode materials that can accommodate capacity and rate performance is a significant challenge in developing lithium-ion capacitors (LICs). Herein, we synthesize a unique N/S dual-doped hierarchical porous carbon (NSC) under the effect of pore distribution modification and heteroatom doping. The nanosheet shape and pore distribution of NSC are highly adjustable, while it demonstrates a reversible capacity that is tens of times more than that of unaltered pristine active carbon. Meanwhile, the prepared glycerol-engineered polyacrylonitrile nanofiber (GPN) form a fast conducting network in the presence of glycerol and carbon nanotubes (CNTs) and exhibit a 300% higher capacity compared to pure polyacrylonitrile nanofibers at 5 A g−1. On this premise, the constructed highly stable LIC (NSC//GPN x @CNTs) can achieve an energy density of 131.48 Wh kg−1 and have an excellent capacity retention rate (93.5%) over 10,000 cycles at a high current density (5 A g−1). This work may lead to new avenues for the preparation of heteroatom-doped porous carbon and redefine the electrode matching of highly stable LICs. [Display omitted] • Highly tunable pore distribution and nanosheet shape of porous carbon. • The cathode nanofibers exhibit high electrical conductivity. • The LIC achieves high energy density and high power density simultaneously. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
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