20 results on '"Fan, Chunlei"'
Search Results
2. The impacts of recycled concrete aggregate (RCA) on epifaunal community structure and eastern oyster recruitment: Implication of using RCA as bottom conditioning material for oyster restoration and aquaculture
- Author
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Fan, Chunlei, Clark, Kelton, Mclean, Nikelene, and Bundy, Mark
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- 2020
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3. Regulation of Lipoprotein Lipase Expression by Effect of Hawthorn Flavonoids on Peroxisome Proliferator Response Element Pathway
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Fan, Chunlei, Yan, Jin, Qian, Ying, Wo, Xingde, and Gao, Liping
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- 2006
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4. Design and FPGA implementation of a high-speed PRNG based on an n-D non-degenerate chaotic system.
- Author
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Luo, Yuyao, Fan, Chunlei, Xu, Chengbin, and Li, Xinyu
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LYAPUNOV exponents , *IMAGE encryption , *PERMUTATIONS , *ENTROPY , *DESIGN - Abstract
Currently, low-dimensional chaotic maps have many disadvantages, such as narrow chaotic regions, numerous cycle windows, and weak chaotic representations. Based on this issue, an n -dimensional non-degenerate chaotic system (n D - NDCS) is constructed. By setting the control parameters of the system, we can obtain dimensionally adjustable non-degenerate chaotic systems with desired Lyapunov exponents. Compared with existing methods, the proposed n D - NDCS has a simple structure with few control parameters, which is suitable for resource-constrained scenarios, such as small embedded devices and mobile devices. To demonstrate the practicality of the proposed method, we construct a 3D - NDCS and a 4D - NDCS as two examples. Performance evaluations show better randomness and complexity than other methods in terms of sample entropy, permutation entropy and other indicators. Since both chaotic systems can produce pseudo-random sequences with sensitive initial values and strong randomness, we further design an efficient pseudo-random number generator (PRNG) on the FPGA. The experiment results show that the proposed PRNG occupies merely 3.13 % of the effective resources of the target FPGA. In addition, the throughput of the PRNG which obtained from post-processing is up to 15 Gb/s, and successfully passed the NIST SP800-22 test. Finally, an FPGA-based hardware implementation platform is developed to realize the proposed PRNG. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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5. Constructing n-dimensional discrete non-degenerate hyperchaotic maps using QR decomposition.
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Fan, Chunlei and Ding, Qun
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LYAPUNOV exponents , *PHASE space , *ORBITS (Astronomy) , *BOOSTING algorithms , *EXPERIMENTAL design , *CRYPTOGRAPHY - Abstract
Lyapunov exponents (LEs) characterize the average exponential rate of convergence or divergence between adjacent orbits in phase space. Thus, the number of positive LEs can reflect the complexity of chaotic systems from a certain point of view. To resist the dynamic degradation of digital chaos, we propose a novel universal method that is based on QR decomposition for constructing non-degenerate hyperchaotic maps. A large number of positive LEs can be generated to increase the complexity of chaotic systems. Furthermore, we construct a 4-D discrete non-degenerate hyperchaotic map as an example to demonstrate the adaptability and efficacy of the proposed scheme. For the proposed method, the related control parameters can not only effectively adjust Lyapunov exponents, but also carry out chaotic regulation on the discrete map, such as amplitude control and offset boosting. In addition, a pseudorandom number generator (PRNG) is designed with desirable statistical properties. Then, a microcontroller-based platform was developed to implement the proposed chaotic map. This study is interesting and has a potential for real-world applications, such as secure communication and cryptography. [ABSTRACT FROM AUTHOR]
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- 2023
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6. Design and geometric control of polynomial chaotic maps with any desired positive Lyapunov exponents.
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Fan, Chunlei and Ding, Qun
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LYAPUNOV exponents , *DISCRETE Fourier transforms , *DIGITAL maps , *INFORMATION assurance , *POLYNOMIALS , *CRYPTOGRAPHY - Abstract
Digital chaotic maps are severely hampered by the finite calculation accuracy of the hardware device that is used to implement them, and their applications in cryptography and information assurance are seriously degraded. To resolve this issue, we put forward a universal iterative model to construct non-degenerate polynomial chaotic maps with any desired number of positive Lyapunov exponents. In addition, we innovatively propose the geometric control methods of polynomial chaotic maps, including amplitude control, offset boosting, plane rotation, shape control, and combined regulation. Furthermore, to assess the effectiveness and feasibility of the proposed method, a microcontroller-based platform was developed to demonstrate the hardware implementation and geometric control of the proposed polynomial chaotic map. Finally, a PRNG is constructed by interval quantization. Numerical experiments are performed to verify the desirable statistical properties of the PRNG in terms of local weak random test, discrete Fourier transform test, linear complexity and NIST SP800-22 test. [ABSTRACT FROM AUTHOR]
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- 2023
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7. A universal method for constructing non-degenerate hyperchaotic systems with any desired number of positive Lyapunov exponents.
- Author
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Fan, Chunlei and Ding, Qun
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IMAGE encryption , *LYAPUNOV exponents , *SINGULAR value decomposition , *DATA encryption , *INFORMATION technology security , *ENTROPY (Information theory) - Abstract
Due to the limited machine word length of hardware devices, the dynamics of digital chaotic systems will degenerate. To combat this issue, we proposed a universal method that is based on singular value decomposition (SVD), which can reversely construct non-degenerate hyperchaotic systems with any desired number of positive Lyapunov exponents by controlling pre-specified singular values. To assess the practicability and effectiveness of the method, we construct a 6-dimensional non-degenerate hyperchaotic system as an example. Furthermore, based on the hyperchaotic system, a pseudorandom number generator (PRNG) with desirable statistical characteristics is designed for image encryption. Numerical simulations were performed to evaluate the security of the image encryption algorithm in terms of histogram, information entropy, differential attack test, etc. The proposed non-degenerate hyperchaotic system can be effectively applied in the field of multimedia data encryption and information security. [ABSTRACT FROM AUTHOR]
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- 2022
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8. Effect of curcumin on the expression of LDL receptor in mouse macrophages
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Fan, Chunlei, Wo, Xingde, Qian, Ying, Yin, Jin, and Gao, Liping
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MACROPHAGES , *LABORATORY mice , *DRUGS , *ALCOHOL - Abstract
Abstract: To investigate the molecular mechanisms of lipid-lowering drug, Rhizoma Curcumae Longae, we treated the mouse macrophages with curcumin, which was purified from the ethanol extraction of Rhizoma Curcumae Longae. The LDL receptors expressed in the macrophages were determined by ELISA, FLISA and assay of LDL uptake. Here for the first time, we found that curcumin obviously up-regulated the expression of LDL receptor in mouse macrophages, and the dose–effect relationship was demonstrated. [Copyright &y& Elsevier]
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- 2006
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9. Effects of light on nitrogen and carbon uptake during a Prorocentrum minimum bloom
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Fan, Chunlei and Glibert, Patricia M.
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DINOFLAGELLATE blooms , *ALGAL blooms , *DINOFLAGELLATES , *NITROGEN excretion , *CARBON , *GASES from plants - Abstract
Abstract: During a 4-week period in late spring 1998 an extensive Prorocentrum minimum (Pavillard) Schiller bloom developed in several tributaries of the Chesapeake Bay. Experiments were carried out in one of these tributaries using 13C and 15N isotopic techniques to characterize C and N uptake as a function of irradiance during the course of this bloom. Uptake rates of N substrates (NO3-, NH4+, urea, and an amino acid mixture) and C substrates (bicarbonate and urea) were measured. For each N substrate, short-term uptake rates (0.5h) were not substantially different over the irradiance range measured, suggesting that N uptake of this dinoflagellate was not strongly light-dependent over this time scale. Dark uptake rates of all N substrates ranged between 35 and 113% of light uptake rates. Over the duration of the P. minimum bloom, however, total ambient N uptake rates increased with increasing natural irradiance. Uptake of bicarbonate showed typical light-dependent photosynthetic characteristics and the measured photosynthetic parameters suggested that at least on the short time scale (0.5h), P. minimum cells were adapted to high light. Rates of C uptake from the substrate urea were minimal, <1% of total C uptake from photosynthesis, but doubled over the course of the bloom, and like N uptake, were not strongly light-dependent on the short time scale (0.5h). Significant N dark uptake by P. minimum was likely to have been important by providing N sources over the daily scale to sustain the bloom. [Copyright &y& Elsevier]
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- 2005
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10. Characterization of the affinity for nitrogen, uptake kinetics, and environmental relationships for Prorocentrum minimum in natural blooms and laboratory cultures
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Fan, Chunlei, Glibert, Patricia M., and Burkholder, JoAnn M.
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DINOFLAGELLATES , *NITROGEN , *UREA , *URINALYSIS , *AMINO acids - Abstract
During the late spring and early summer of 1998, an extensive bloom of the dinoflagellate Prorocentrum minimum (>93% of phytoplankton cell density) developed in several tributaries of the Chesapeake Bay, USA. In January 1999, a bloom of mixed dinoflagellates (Heterocapsa rotundata, H. triquetra and P. minimum, with P. minimum forming 21% of total phytoplankton cells and 39% of the total biovolume) developed in the mesohaline Neuse Estuary, North Carolina, USA. During these blooms, experiments were carried out to characterize the nitrogen uptake kinetics of these assemblages with
15N isotopic techniques. Four nitrogenous substrates (NO3−, NH4+, urea, and a mixed amino acids substrate) were used to determine uptake rate and substrate preference. Rates of nitrogen uptake were also measured in P. minimum cultures grown on varying growth nitrogen substrates. The calculated kinetic parameters determined for the P. minimum-dominated field assemblages and the cultures indicated a preference for NH4+. NH4+ was also the primary nitrogen source supporting the blooms. In addition, a high affinity for urea was also found, and urea contributed significantly to the Neuse Estuary bloom. Furthermore, results showed that the regulation of uptake for each of the substrates was different: strong positive relationships between affinity and temperature were found for NH4+ and amino acids, while a negative response was found for NO3−, and very little response to temperature was noted for urea. These differences suggest that a diversity of nitrogen uptake mechanisms may aid the development and maintenance of P. minimum blooms. [Copyright &y& Elsevier]- Published
- 2003
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11. Experimental study on deformation and fracture of resistance-spot-welded (RSW) overlapping plates impacted at RSW joint by round-nosed bullet.
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Ma, Bohan, Fan, Chunlei, Chen, Danian, Wang, Huanran, Ma, Dongfang, and Zhou, Fenghua
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BOLTED joints , *STRESS waves , *BULLETS , *FREE surfaces , *LASER interferometers , *IMPACT loads , *FRACTOGRAPHY , *SCANNING electron microscopes - Abstract
• The ballistic tests of RSW specimens are performed on gas gun system with VISAR. • The shearing near notch tip and partial opening of RSW specimens are found. • The through-thickness fracture and interfacial fracture of RSW specimens are revealed. • The crack propagation of corona bond and pre-crack of RSW specimens is investigated. The ballistic tests of Q&P980 resistance-spot-welded (RSW) overlapping plates impacted at RSW joint by round-nosed bullet were performed using a single-stage gas gun system with a laser velocity interferometer system for any reflector (VISAR). The deformation and fracture mechanism of the RSW specimens were investigated by using the VISAR measured results, the metallographic cross-section observation and the scanning electron microscope (SEM) analysis of the recovered RSW specimens. The dynamic response of the RSW specimens was related to the reflection and refraction of the impact stress waves on the material interfaces and the free surfaces in the RSW specimens. The bulging, dishing, shearing near the notch tip and partial opening of the RSW specimens were discussed. With the range of loading speed and the joint configuration (overlap structure, nugget size, etc.) studied in this work, the plugging fracture should be a prevailing mode. The crack propagation of the corona bond and pre-crack of the RSW specimens under impact loading was found to affect the dynamic fracture process of the RSW specimens under bullet impact. [ABSTRACT FROM AUTHOR]
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- 2020
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12. A field scale evaluation of Gracilaria lemaneiformis co-cultured with Crassostrea gigas as a nutrient bioextraction strategy in Yantian Bay, China.
- Author
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Wei, Zhangliang, Huo, Yuanzi, Liu, Qiao, Yang, Fangfang, Long, Lijuan, Bi, Hongsheng, Fan, Chunlei, and He, Peimin
- Abstract
Abstract Nutrient bioextraction using Gracilaria lemaneiformis co-cultured with Crassostrea gigas in a eutrophic, intensive mariculture area was evaluated over 49 days in Yantian Bay, which is an enclosed bay within Sansha Bay, China. The amount of nitrogen removed by G. lemaneiformis was 4.07 ± 0.25 kg and 4.49 ± 0.57 kg per ton (FW) at depths of 0.4–0.8 m and 1.0–1.2 m, respectively. The ranges of ammonium-nitrogen (NH 4 -N), nitrite-nitrogen (NO 2 -N), nitrate-nitrogen (NO 3 -N), and inorganic phosphate (PO 4 -P) reduction efficiencies in the co-cultured area were 39.22–80.34%, 4.70–26.14%, 13.42–48.84%, and 25.33–41.36%, respectively. The total wet weight of harvested G. lemaneiformis was 5.44 and 3.92 times greater than the initial mass (500 g FW/m), with highest specific growth rates (SGR) of 4.67 ± 0.21%/d and 3.44 ± 0.18%/d at 0.4–0.8 m and 1.0–1.2 m, respectively. A total of 3.11 kg of nitrogen could be removed from the co-cultured area per ton of C. gigas harvested with a total length (TL) of 80 ± 12 mm. Based on the nitrogen balance in this co-cultured system, the largest proportion of nitrogen removal from the co-cultured system was the harvest production of G. lemaneiformis (25.44%), followed by C. gigas (8.27%). The quantity of nitrogen excreted and metabolized by C. gigas was 33.40 kg, which could be entirely assimilated by the G. lemaneiformis during the experimental period. Based on these results, at least 6.76 tons of G. lemaneiformis should be co-cultured per ton of C. gigas (77–80 mm TL) to remove the nitrogen produced by C. gigas in this mariculture area. The results of this study indicate that the co-culture G. lemaneiformis with C. gigas is an environmentally-friendly mariculture method which could effectively remove surplus nutrients and reduce the environmental impact of mariculture areas. Highlights • It is environmentally advantageous to co-culture Gracilaria lemaneiformis with Crassostrea gigas in an enclosed bay. • Nutrients flux of the co-cultured system was determined. • A field scale evaluation of G. lemaneiformis in the co-cultured system as a bioextraction strategy was given. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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13. The Efficacy of Defocus Incorporated Multiple Segments Lenses in Slowing Myopia Progression: Results from Diverse Clinical Circumstances.
- Author
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Liu, Jiaxin, Lu, Yiqiu, Huang, Dan, Yang, Jiwen, Fan, Chunlei, Chen, Chunmei, Li, Jianhua, Wang, Qinqin, Li, Shan, Jiang, Baolin, Jiang, Hongyan, Li, Xiaoning, Yang, Zhikuan, and Lan, Weizhong
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MYOPIA , *PROPENSITY score matching , *EYEGLASSES , *RANDOMIZED controlled trials - Abstract
Defocus incorporated multiple segments (DIMS) spectacle lenses were reported to slow myopia progression significantly in a randomized controlled trial (RCT). The study evaluated their effectiveness in clinical settings. Retrospective study. Patient records involving use of DIMS and single-vision (SV) spectacle lenses were collected from subsidiary hospitals of Aier Eye Hospital Group. The spherical equivalent (SE), determined by subjective refraction, was adopted to assess the myopia progression. The strategy of propensity score matching (PSM) was applied to match the confounding baseline characteristics between the 2 groups. The effectiveness was calculated based on the difference of myopia progression of these 2 approaches. Change in SE. Three thousand six hundred thirty-nine patients with DIMS and 6838 patients with SV spectacles were included. The age of the patients was 6 to 16 years (mean ± standard deviation: 11.02 ± 2.53 years). The baseline SE was between 0.00 and –10.00 diopters (D) (mean ± standard deviation: –2.78 ± 1.74 D). After the PSM, data on 2240 pairs with 1-year follow-up and on 735 pairs with 2-year follow-up were obtained. Significantly slower progression was seen in the DIMS group at both the 1-year (DIMS, –0.50 ± 0.43 D; SV, –0.77 ± 0.58 D; P < 0.001) and 2-year (DIMS, –0.88 ± 0.62 D; SV, –1.23 ± 0.76 D; P < 0. 001) subdataset. In the 1-year subdataset, 40% and 19% showed myopia progression of no more than 0.25 D for the DIMS and SV groups, respectively (chi-square, 223.43; P < 0.001), whereas 9% and 22% showed myopia progression of more than 1.00 D for the DIMS and SV groups, respectively (chi-square, 163.38; P < 0.001). In the 2-year subdataset, 33% and 20% showed myopia progression of no more than 0.50 D for the DIMS and SV groups, respectively (chi-square, 31.15; P < 0.001), whereas 12% and 29% showed myopia progression of more than 1.50 D for the DIMS and SV groups (chi-square, 65.60; P < 0.001). Although the magnitude was lower than that reported in the previous RCT, this large-scale study with diversity of the data sources confirmed the effectiveness of DIMS spectacles to slow myopia progression in clinical practice. Proprietary or commercial disclosure may be found after the references. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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14. Effect of internal axial loads on the stability of sway-permitted prismatic columns.
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Tian, Weifeng, Zhou, Xuhong, and Fan, Chunlei
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AXIAL loads , *STABILITY (Mechanics) , *STIFFNESS (Mechanics) , *EULER method , *ELASTICITY - Abstract
The stability of prismatic columns subjected to internal axial loads is a common issue during engineering analysis and design. Because of the big difference between the effects of internal loads and end loads, the traditional effective length method is not applicable. Current codes do not provide design method for this issue and engineers require the ability to analysis and design this kind of columns efficiently. Using the concept of negative stiffness, a relationship between end loads and internal axial loads applied on sway-permitted prismatic columns is established so that the internal loads can be considered equivalent to end loads and the critical value can be obtained easily by Euler formula. A practical method to determine the second-order effect is also developed. Eigenvalue buckling and elastic nonlinear analyses are performed to examine the proposed method and the comparison results indicate it has high accuracy. [ABSTRACT FROM AUTHOR]
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- 2017
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15. Prorocentrum minimum (Pavillard) Schiller: A review of a harmful algal bloom species of growing worldwide importance
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Heil, Cynthia A., Glibert, Patricia M., and Fan, Chunlei
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ALGAL blooms , *DINOFLAGELLATES , *MICROALGAE , *ESTUARINE ecology , *ESTUARINE biology , *EUTROPHICATION - Abstract
Abstract: Prorocentrum minimum (Pavillard) Schiller, a common, neritic, bloom-forming dinoflagellate, is the cause of harmful blooms in many estuarine and coastal environments. Among harmful algal bloom species, P. minimum is important for the following reasons: it is widely distributed geographically in temperate and subtropical waters; it is potentially harmful to humans via shellfish poisoning; it has detrimental effects at both the organismal and environmental levels; blooms appear to be undergoing a geographical expansion over the past several decades; and, a relationship appears to exist between blooms of this species and increasing coastal eutrophication. Although shellfish toxicity with associated human impacts has been attributed to P. minimum blooms from a variety of coastal environments (Japan; France; Norway; Netherlands; New York, USA), only clones isolated from the Mediterranean coast of France, and shellfish exposed to P. minimum blooms in this area, have been shown to contain a water soluble neurotoxic component which killed mice. Detrimental ecosystem effects associated with blooms range from fish and zoobenthic mortalities to shellfish aquaculture mortalities, attributable to both indirect biomass effects (e.g., low dissolved oxygen) and toxic effects. P. minimum blooms generally occur under conditions of high temperatures and incident irradiances and low to moderate salinities in coastal and estuarine environments often characterized as eutrophic, although they have been found under widely varying salinities and temperatures if other factors are conducive for growth. The physiological flexibility of P. minimum in response to changing environmental parameters (e.g., light, temperature, salinity) as well as its ability to utilize both inorganic and organic nitrogen, phosphorus, and carbon nutrient sources, suggest that increasing blooms of this species are a response to increasing coastal eutrophication. [Copyright &y& Elsevier]
- Published
- 2005
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16. Cyclic behavior of sandwich steel plate shear wall with embedded corrugated plate.
- Author
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Hui, Fan, Hao, Jiping, Xue, Qiang, Sun, Xiaoling, and Fan, Chunlei
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SHEAR walls , *IRON & steel plates , *SANDWICH construction (Materials) , *ENERGY dissipation , *WALLS - Abstract
The sandwich structure has superior properties. To explore the application of sandwich structures in steel plate shear walls, this study presents a sandwich steel plate shear wall with embedded corrugated plate (ECSSW). The proposed wall is composed of two flat plates and a corrugated plate embedded between them. The flat and corrugated plates are joined by connectors. To study the cyclic behavior of the ECSSW, a quasi-static test and a numerical simulation of two specimens were conducted. In addition, a parametric assessment was conducted on the ECSSW with different connector horizontal spacings and strengths. The results showed that the ECSSW provides satisfactory seismic performance, does not produce significant noise, and can effectively delay the occurrence and development of infill plate buckling. With a small-wavelength embedded corrugated plate, the ECSSW can increase the yield load and yield displacement. The ECSSW with a large-wavelength embedded corrugated plate can reduce stiffness degradation and increase ductility and energy dissipation. When the strength of the connector is low, its horizontal spacing has minimal effect on the cyclic behavior of the ECSSW. The strength of the connector significantly affects the out-of-plane deformation of the ECSSW. • Application of sandwich structures in realm of steel-plate shear walls was explored. • A sandwich steel plate shear wall with embedded corrugated plate was proposed. • Seismic performance of the proposed shear wall was studied. • The proposed shear wall has three ductile fuses, namely flat plate, embedded corrugated plate, and frame. • Strength of the connectors significantly affects the proposed shear wall out-of-plane deformation. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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17. Seismic behavior of wall-type spiral stirrups-confined RC column to steel beam joint.
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Cao, Jiahao, Hao, Jiping, Xue, Qiang, Fan, Chunlei, and Sun, Xiaoling
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TRANSVERSE reinforcements , *WALL panels , *CONCRETE columns , *REINFORCED concrete , *STEEL framing , *ENGINEERING design , *FINITE element method , *LATERAL loads , *CONCRETE beams - Abstract
This study proposes a new interior diaphragm joint between wall-type reinforced concrete column with high-strength spiral stirrups and steel beams, and the quasi-static test was conducted to investigate the seismic performance of the new joint under cyclic lateral force. Finite element model (FEM) simulation was carried out using the software ABAQUS, and the correctness of the FEM was verified by the results of the test. Additionally, the effect of parameters including the strength of concrete, thickness of the beam flange, interior diaphragm, joint flange, and joint web on the seismic performances of the joint was analyzed. Based on the parametric analysis and existing codes, a shear capacity formula was determined with the consideration of the shear capacity of the joint web and flange, and concrete. The comparison between the calculated and FEM results indicates that this formula could be regarded as an accurate calculation method for the shear-bearing capacity of different joint types in engineering design. • A new type of joint connecting steel beams and wall-type RC columns with high-strength spiral stirrups was proposed. • The seismic performance of the connection was studied using quasi-static tests. • The two compressive diagonal struts mechanism was used in the shear capacity of the concrete. • The shear capacity of the joint core area was analyzed. • The simplified nonlinear model and boundary condition save time cost. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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18. Numerical simulation on dense phase pneumatic conveying of pulverized coal in horizontal pipe at high pressure
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Pu, Wenhao, Zhao, Changsui, Xiong, Yuanquan, Liang, Cai, Chen, Xiaoping, Lu, Peng, and Fan, Chunlei
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PULVERIZED coal , *PIPE , *HIGH pressure (Technology) , *PNEUMATIC-tube transportation , *STRAINS & stresses (Mechanics) , *FRICTION , *KINETIC theory of liquids , *COMPUTER simulation - Abstract
Abstract: A kinetic–frictional model, which treats the kinetic and frictional stresses in an additive manner, was incorporated into the two fluid model based on the kinetic theory of granular flow to simulate three dimensional flow behaviors of dense phase pneumatic conveying of pulverized coal in horizontal pipe. The kinetic stress was modeled by the kinetic theory of granular flow, while the friction stress is from the combination of the normal frictional stress model proposed by Johnson and Jackson [1987. Frictional–collisional constitutive relations for granular materials, with application to plane shearing. Journal of Fluid Mechanics 176, 67–93] and the modeled frictional shear viscosity model proposed by Syamlal et al. [1993. MFIX documentation and theory guide, DOE/METC94/1004, NTIS/DE94000087. Electronically available from http://www.mfix.org], which was modified to fit experimental data. For the solid concentration and gas phase Reynolds number was high, the gas phase and particle phase were all treated as turbulent flow. The experiment was carried out to validate the prediction results by three kinds of measurement methods. The predicted pressure gradients were in good agreement with experimental data. The predicted solid concentration distribution at cross section agreed well with electrical capacitance tomography (ECT) image, and the effects of superficial velocity on solid concentration distribution were discussed. The formation and motion process of slug flow was demonstrated, which is similar to the visualization photographs by high speed video camera. [Copyright &y& Elsevier]
- Published
- 2010
- Full Text
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19. Sonar imaging surveys fill data gaps in forage fish populations in shallow estuarine tributaries.
- Author
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Lankowicz, Katelynn M., Bi, Hongsheng, Liang, Dong, and Fan, Chunlei
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FORAGE fishes , *SONAR imaging , *FISH populations , *WATER depth , *FISH surveys - Abstract
• Traditional surveys do not efficiently sample forage fish in shallow estuaries. • Sonar imaging produces high-resolution, fine-scale forage fish distribution data. • Forage fish mostly aggregate in shallow water creeks. • We recommend sonar imaging be used to supplement traditional sampling approaches. Forage fish are economically and ecologically important to many coastal marine ecosystems, but most forage fish species are not targeted in species-specific abundance surveys. In the Chesapeake Bay, Atlantic menhaden (Brevoortia tyrannus), an important forage species for many upper-trophic level consumers, are sampled with beach seines and midwater trawls. There is evidence that these traditional fish sampling gears are insufficient for observing menhaden abundance and distribution, which may lead to biased and inaccurate indices of abundance. We suggest this is due to omitting or under-sampling shallow estuarine creeks and nearshore areas. We tested this hypothesis in the Patuxent River, Maryland and its surrounding shallow-water creeks, which are representative of many estuarine tributaries with varied bathymetry. Sonar imaging surveys were conducted using Adaptive Resolution Imaging Sonars (ARIS 1800 and 3000) and a generalized additive model was fit to the resulting data to model forage fish density. Results indicated that menhaden and other forage fish were present at significantly higher densities in shallow-water creeks than in deeper-water areas. Further, many forage fish were observed in creek habitats frequently omitted by both seines and trawls, suggesting that these survey designs may result in biased forage fish indices of abundance. Therefore, we recommend current forage fish surveys in the Chesapeake Bay, especially those with the intent of developing juvenile menhaden indices of abundance, be supplemented with hydroacoustic surveys in shallow waters to improve accuracy and reduce bias. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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20. Early warning of Noctiluca scintillans blooms using in-situ plankton imaging system: An example from Dapeng Bay, P.R. China.
- Author
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Song, Junting, Bi, Hongsheng, Cai, Zhonghua, Cheng, Xuemin, He, Yonghong, Benfield, Mark C., and Fan, Chunlei
- Subjects
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IMAGING systems , *PLANKTON , *ALGAL blooms , *IMAGE processing , *BAYS , *CLIMATE change - Abstract
• An in-situ imaging system captured Noctiluca bloom in Dapeng Bay, P.R. China. • A logistic growth model was applied to simulate the growth and decay of Noctiluca. • We demonstrated an early warning framework using the in-situ observations and model. The frequency and intensity of harmful algal blooms (HABs) are likely to increase with climate change and increases in nutrients due to anthropogenic activities. To manage the environment and health threats to surrounding organisms, it is essential to improve our capability to provide early warning of harmful species. Using Noctiluca scintillans as example, a dinoflagellate that often blooms in Asia and whose presence is rapidly expanding worldwide, we demonstrate a potential way to predict N. scintillans blooms by deploying an in-situ plankton imaging system: PlanktonScope. PlanktonScope is a shadowgraph imaging system and capable of imaging organisms 40 µm – 5 cm. This system was deployed in Shenzhen Bay, China, recording images at 0.5 Hz in April 2016. Using the automated image processing procedure, we found that PlanktonScope recorded nearly a full cycle of a N. scintillans bloom. A simple resource-limited logistic population growth model was then applied to develop a predictive framework for the outburst of N. scintillans. Environmental changes could explain the observed dynamics of N. scintillans ; however, it was difficult to quantify the relationship between the dynamics of N. scintillans and environmental variables. Our study demonstrated that a camera system like PlanktonScope could be useful in developing an early warning system for N. scintillans blooms, which could be applicable to other HAB species for proactive management. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
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