34 results on '"Haibo Hu"'
Search Results
2. Predicting the strut forces of the steel supporting structure of deep excavation considering various factors by machine learning methods.
- Author
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Haibo Hu, Xunjian Hu, and Xiaonan Gong
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EXCAVATION , *MACHINE learning , *BACK propagation , *SUPPORT vector machines , *COHESION - Abstract
The application of steel strut force servo systems in deep excavation engineering is not widespread, and there is a notable scarcity of in-situ measured datasets. This presents a significant research gap in the field. Addressing this, our study introduces a valuable dataset and application scenarios, serving as a reference point for future research. The main objective of this study is to use machine learning (ML) methods for accurately predicting strut forces in steel supporting structures, a crucial aspect for the safety and stability of deep excavation projects. We employed five different ML methods: radial basis function neural network (RBFNN), back propagation neural network (BPNN), K-Nearest Neighbor (KNN), support vector machine (SVM), and random forest (RF), utilizing a dataset of 2208 measured points. These points included one output parameter (strut forces) and seven input parameters (vertical position of strut, plane position of strut, time, temperature, unit weight, cohesion, and internal frictional angle). The effectiveness of these methods was assessed using root mean square error (RMSE), correlation coefficient (R), and mean absolute error (MAE). Our findings indicate that the BPNN method outperforms others, with RMSE, R, and MAE values of 72.1 kN, 0.9931, and 57.4 kN, respectively, on the testing dataset. This study underscores the potential of ML methods in precisely predicting strut forces in deep excavation engineering, contributing to enhanced safety measures and project planning. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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3. Transthoracic echocardiography-guided PBMV for severe rheumatic mitral stenosis with pregnancy.
- Author
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Xiao, Hao, Xiangbin, Pan, and Haibo, Hu
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MEDICAL personnel , *MITRAL stenosis , *MITRAL valve , *ATRIAL septal defects , *INFORMED consent (Medical law) , *PERCUTANEOUS balloon valvuloplasty , *TRANSESOPHAGEAL echocardiography , *VENTRICULAR septal defects - Abstract
This article discusses the use of transthoracic echocardiography (TTE) as a guiding method for percutaneous balloon mitral valvuloplasty (PBMV) in patients with severe rheumatic mitral stenosis, particularly in cases involving pregnancy. The traditional method of guiding PBMV is fluoroscopy, which involves the use of radiation and may have negative effects on the fetus. The case study presented in the article demonstrates the successful use of TTE-guided PBMV in a pregnant patient, resulting in improved mitral valve opening and decreased pulmonary artery pressure. The article suggests that TTE-guided PBMV may be a preferred method due to its effectiveness and reduced radiation-related risks. [Extracted from the article]
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- 2024
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4. Reactive Behavior of Explosive Billets in Deflagration Tube of Varied Confinements.
- Author
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Haibo Hu, Yingwen Guo, Tao Li, Hua Fu, Hailin Shang, Shanggang Wen, Tian Qiu, and Hong Yu
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MILITARY billets , *FRACTURE mechanics , *EXPLOSIVES , *VELOCIMETERS , *COMBUSTION - Abstract
The deflagration process of pressed HMX-based PBX cylindrical billets confined in metal tube is diagnosed by combined pressure, velocity-meter, high-speed frame photographic and radiographic diagnostic system. The reaction violence evolution is analyzed with consideration of convective flame propagation along the seam between explosive billet and tube wall, the follow-up conductive reaction on the side surface and between the end faces of explosive billets based on the observation on radical expansion and fracture of tube wall, axial length stretching and pullback to negative less than initial length which leads to the breakup of explosive column and final extinguishment of combustion after fracture. In the relatively light confinement of deflagration tube, the reaction violence growth is deformation and following fracture of tube wall. Only few cracks inside explosive billets with convective burning are observed before tube fracture. The blast overpressure record and post experiment recovery explosive specimens suggest that only few percentage of explosive mass is consumed during lightly confined deflagration. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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5. Experimental Study on Colliding Shock Waves and Mach Stem Formation in Metals.
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Haibo Hu, Chongyu Zhang, Xiang Wang, Yongtao Chen, Tiegang Tang, and Ningwen Liu
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ACOUSTIC phenomena in nature , *SHOCK waves , *FREE surfaces , *HYDRODYNAMICS , *COLLISIONS (Physics) - Abstract
A multi-channel PDV probe is designed to diagnose quantitatively the dynamic response of metal flyers in the collision region of two head-on sliding detonation waves by measuring the free surface velocity of particles normal to free surface near the collision plane. The results show typical regular reflection for W, Cu and Mach stem configuration for Sn, Pb, Ce in result of oblique colliding of two shock waves. These high spatial and time resolution velocity profiles can be used as early time stage benchmark for the validation of hydrodynamic codes and digital clue to retrace the kinetics leading to the formation of low density jet-like spiking in the collision region at late stage after colliding event. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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6. A Numerical Study of Multiple Adiabatic Shear Bands Evolution in a 304LSS Thick-Walled Cylinder.
- Author
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Mingtao Liu, Haibo Hu, Cheng Fan, and Tiegang Tang
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METAL analysis , *STAINLESS steel , *LOCALIZATION theory , *GAUSSIAN distribution , *MICROSTRUCTURE , *YIELD stress - Abstract
The self-organization of multiple shear bands in a 304L stainless steel(304LSS) thick-walled cylinder (TWC) was numerically studied. The microstructures of material lead to the non-uniform distribution of the local yield stress, which play a key role in the formation of spontaneous shear localization. We introduced a probability factor satisfied the Gaussian distribution into the macroscopic constitutive relationship to describe the non-uniformity of local yield stress. Using the probability factor, the initiation and propagation of multiple shear bands in TWC were numerically replicated in our 2D FEM simulation. Experimental results in the literature indicated that the machined surface at the internal boundary of a 304L stainless steel cylinder provides a work-hardened layer (about 20~30μm) which has significantly different microstructures from the base material. The work-hardened layer leads to the phenomenon that most shear bands propagate along a given direction, clockwise or counterclockwise. In our simulation, periodical single direction spiral perturbations were applied to describe the grain orientation in the work-hardened layer, and the single direction spiral pattern of shear bands was successfully replicated. [ABSTRACT FROM AUTHOR]
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- 2017
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7. Improving Satellite-Driven PM2.5 Models with VIIRS Nighttime Light Data in the Beijing-Tianjin-Hebei Region, China.
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Xiya Zhang and Haibo Hu
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PARTICULATE matter , *LAND use , *URBANIZATION , *AIR pollution , *SEASONAL temperature variations , *REMOTE-sensing images - Abstract
Previous studies have estimated ground-level concentrations of particulate matter 2.5 (PM2.5) using satellite-derived aerosol optical depth (AOD) in conjunction with meteorological and land use variables. However, the impacts of urbanization on air pollution for predicting PM2.5 are seldom considered. Nighttime light (NTL) data, acquired with the Visible Infrared Imaging Radiometer Suite (VIIRS) aboard the Suomi National Polar-orbiting Partnership (S-NPP) satellite, could be useful for predictions because they have been shown to be good indicators of the urbanization and human activity that can affect PM2.5 concentrations. This study investigated the potential of incorporating VIIRS NTL data in statistical models for PM2.5 concentration predictions. We developed a mixed-effects model to derive daily estimations of surface PM2.5 levels in the Beijing-Tianjin-Hebei region using 3 km resolution satellite AOD and VIIRS NTL data. The results showed the addition of NTL information could improve the performance of the PM2.5 prediction model. The NTL data revealed additional details for predication results in areas with low PM2.5 concentrations and greater apparent seasonal variation due to the seasonal variability of human activity. Comparison showed prediction accuracy was improved more substantially for the model using NTL directly than for the model using the vegetation-adjusted NTL urban index that included NTL. Our findings indicate that VIIRS NTL data have potential for predicting PM2.5 and that they could constitute a useful supplemental data source for estimating ground-level PM2.5 distributions. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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8. Fabrication of Orientation-Tunable Si Nanowires on Silicon Pyramids with Omnidirectional Light Absorption.
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Zhibin Pei, Haibo Hu, Shuxin Li, and Changhui Ye
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SILICON nanowire manufacturing , *LIGHT absorption , *FREQUENCY tuning , *SILVER catalysts , *CHEMICAL milling , *OPTOELECTRONIC devices - Abstract
In this work, the different orientation of SiNWs on Si pyramids by a two step MACE method have been fabricated. By tuning the structure of Ag catalyst film and controlling the concentration of H2O2 or the etching temperature, the tunability of the orientation of SiNWs from <111> to <100> on Si pyramids was realized. Si structures composed of Si pyramids and SiNWs exhibit better omnidirectional light-trapping ability by multiple reflections. Si structures with structural tunability and enhanced light harvesting performance will find a wide variety of significant applications in solar cells, photodetectors, and optoelectronic devices. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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9. High expression of lncRNA PVT1 promotes invasion by inducing epithelial-to-mesenchymal transition in esophageal cancer.
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XIANGXIANG ZHENG, HAIBO HU, and SHITING LI
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NON-coding RNA , *PLASMACYTOMA , *ONCOGENES , *METASTASIS , *ESOPHAGEAL cancer - Abstract
The long non-coding RNA (lncRNA) plasmacytoma variant translocation 1 (PVT1) has been identified as an oncogene in numerous diseases, and aberrant lncRNA PVT1 expression has been associated with the development of cancer. However, the underlying mechanism by which lncRNA PVT1 affects cell invasion in esophageal cancer has been not demonstrated. In the current study, the expression of lncRNA PVT1 was found to be increased in esophageal cancer specimens (n=77) by reverse transcription-quantitative polymerase chain reaction, and was correlated with tumor stage (P=0.009) and metastasis (P<0.001). In vitro, by using transwell assay, upregulation of lncRNA PVT1 promoted the invasion of TE-1 esophageal cancer cells; while downregulation of lncRNA PVT1 inhibited Eca-109 cell invasion. In addition, western blot analysis indicated that upregulation of lncRNA PVT1 may induce epithelial-to-mesenchymal transition (EMT) by regulating the expression levels of EMT markers (E-cadherin, N-cadherin and vimentin). In conclusion, lncRNA PVT1 is able to regulate the invasion of esophageal cancer cells by inducing EMT. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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10. EXPERIMENTAL STUDY OF EJECTA ON LEAD SURFACE AT DIFFERENT LOADING RATES AND AMPLITUDES.
- Author
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Yongtao Chen, Haibo Hu, Qingzhong Li, Rongbo Wang, and Tiegang Tang
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MECHANICAL loads , *PIEZOELECTRIC devices , *HIGH-speed photography , *LASER Doppler velocimetry , *SENSITIVITY analysis , *VELOCITY distribution (Statistical mechanics) - Abstract
We conducted experiments to study the ejecta from explosively shocked Pb targets. In the experiments we diagnose the ejected mass and dynamic system through use of piezoelectric pins, optical fiber probes, Asay foils, Asay windows, laser Doppler velocimetry, and high speed photography. The mass, the density distribution and the corresponding velocity distribution of micro-spall fragments of the Pb target are presented. We also study the sensitivity of Pb ejecta production to the loading rate and the peak shock stress. [ABSTRACT FROM AUTHOR]
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- 2012
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11. Multi-state voter model on weighted social networks with committed agents.
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Saijun Chen, Haibo Hu, Jun Chen, and Zhigao Chen
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SOCIAL networks , *STATISTICAL correlation , *PREDICTION models , *COMPUTER simulation , *CONSENSUS (Social sciences) , *SIMULATION methods & models - Abstract
There exist scaling correlations between the edge weights and the nodes' degrees in weighted social networks. Based on the empirical findings, we study a multi-state voter model on weighted social networks where the weight is given by the product of agents' degrees raised to a power θ and there exist persistent individuals whose opinions are independent of those of their friends. We find that the fraction of each opinion will converge to a value which only relates to the degrees of initial committed agents and the scaling exponent θ. The analytical predictions are verified by numerical simulations. The model indicates that agents' degrees and scaling exponent can significantly influence the final coexistence or consensus state of opinions. We also study the influence of degree mixing characteristics on the dynamics model by numerical simulations and discuss the relation between the model and the other related opinion dynamics models on social networks with different topological structures and initial configurations. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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12. One for Two: Conversion of Waste Chicken Feathers to Carbon Microspheres and (NH4)HCO3.
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Lei Gao, Haibo Hu, Xuelin Sui, Changle Chen, and Qianwang Chen
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FEATHERS , *BIOCONVERSION , *PYROLYSIS , *MICROFABRICATION , *AMMONIUM bicarbonate , *MICROSPHERES , *ORGANIC waste recycling - Abstract
Pyrolysis of 1 g of waste chicken feathers (quills and barbs) in supercritical carbon dioxide (sc-CO2) system at 600 °C for 3 h leads to the formation of 0.25 g well-shaped carbon microspheres with diameters of 1-5 μm and 0.26 g ammonium bicarbonate ((NH4)HCO3). The products were characterized by powder X-ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM), Raman spectroscopic, FT-IR spectrum, X-ray electron spectroscopy (XPS), and N2 adsorption/desorption measurements. The obtained carbon microspheres displayed great superhydrophobicity as fabric coatings materials, with the water contact angle of up to 165.2 ± 2.5°. The strategy is simple, efficient, does not require any toxic chemicals or catalysts, and generates two valuable materials at the same time. Moreover, other nitrogen-containing materials (such as nylon and amino acids) can also be converted to carbon microspheres and (NH4)HCO3 in the sc-CO2 system. This provides a simple strategy to extract the nitrogen content from natural and man-made waste materials and generate (NH4)HCO3 as fertilizer. [ABSTRACT FROM AUTHOR]
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- 2014
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13. Preparation of γ-Fe2O3@C@MoO3 core/shell nanocomposites as magnetically recyclable catalysts for efficient and selective epoxidation of olefins.
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Fushan Zhang, Haibo Hu, Hao Zhong, Nan Yan, and Qianwang Chen
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NANOCOMPOSITE materials , *IRON compounds , *EPOXIDATION , *ALKENES , *HYDROPEROXIDES , *FOURIER transform infrared spectroscopy , *X-ray photoelectron spectra ,CATALYSTS recycling - Abstract
Magnetic γ-Fe2O3@C@MoO3 core–shell structures were fabricated via a general approach and characterized by several techniques such as XRD, XPS, ICP-AES, Raman etc. The catalytic performance of them has been demonstrated in heterogeneously catalyzed oxidation of cyclooctene with tert-butyl hydroperoxide (tBuOOH) as an oxidant, and high conversion (100%) and selectivity (over 99%) were achieved with relatively low catalyst dosage under mild conditions. It should be emphasized that the hybrid catalyst could be easily separated by an external magnet and reused up to 9 times with no significant loss of activity and selectivity. The reaction mechanism over MoO3 is also discussed on the basis of the FTIR and XPS measurements. It is suggested that the high catalytic activity is related to the formation of the transition state, a Mo-alkyl peroxide and olefin complex, which is beneficial for an efficient oxygen atom transfer by converting the intermolecular process directly into an intramolecular process. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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14. Low-Cost, Acid/Alkaline-Resistant, and Fluorine-Free Superhydrophobic Fabric Coating from Onionlike Carbon Microspheres Converted from Waste Polyethylene Terephthalate.
- Author
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Haibo Hu, Lei Gao, Changle Chen, and Qianwang Chen
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CARBON , *MICROSPHERES , *POLYETHYLENE terephthalate , *CARBON dioxide , *POLYDIMETHYLSILOXANE , *SOLID waste management - Abstract
Onionlike carbon microspheres composed of many nanoflakes have been prepared by pyrolyzing waste polyethylene terephthalate in supercritical carbon dioxide at 650 °C for 3 h followed by subsequent vacuum annealing at 1500 °C for 0.5 h. The obtained onionlike carbon microspheres have very high surface roughness and exhibit unique hydrophobic properties. Considering their structural similarities with a lotus leaf, we further developed a low-cost, acid/alkaline-resistant, and fluorine-free superhydrophobic coating strategy on fabrics by employing the onionlike carbon microspheres and polydimethylsiloxane as raw materials. This provides a novel technique to convert waste polyethylene terephthalate to valuable carbon materials. At the same time, we demonstrate a novel application direction of carbon materials by taking advantage of their unique structural properties. The combination of recycling waste solid materials as carbon feedstock for valuable carbon material production, with the generation of highly value-added products such as superhydrophobic fabrics, may provide a feasible solution for sustainable solid waste treatment. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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15. Molecular dynamics simulations of micro-spallation of single crystal lead.
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Meizhen Xiang, Haibo Hu, Jun Chen, and Yao Long
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SPALLATION (Nuclear physics) , *LEAD , *SHOCK wave effects , *FREE surfaces (Crystallography) , *SIMULATION methods & models , *CAVITATION - Abstract
We present a molecular dynamics (MD) study of the micro-spallation of lead (Pb), which corresponds to damage and liquid fragment ejection following the reflection of a strong shock wave on the free surface of the target. First, the Hugoniot and melting curves of Pb are derived by equilibrium MD simulations, and the potential function is validated by comparing these curves with experimental results. Then nonequilibrium MD simulations are conducted to study the dynamical processes of micro-spallation. Damage and ejection processes are analyzed by a binning analysis and direct observations of atom configurations. Comparisons with classical spallation simulations or experiments are made where necessary. It is found that damages in classical spallation and micro-spallation are both dominated by cavitation, i.e. nucleation and the growth and coalescence of voids. The main difference in the cavitation process of classical and micro-spallation lies in the amount and spatial distribution of void nucleation sites. Different properties in dynamical stress evolutions between micro-spallation and classical spallation are also discussed. In addition, the properties of the surface micro-spall are found to be different from those of interior micro-spall particles in some shock intensity regimes. Factors that cause such differences are studied by analyzing in detail the thermodynamics paths of different parts of the shocked target. [ABSTRACT FROM AUTHOR]
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- 2013
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16. MEASUREMENT AND INTERNALIZATION OF SYSTEMIC RISK IN A GLOBAL BANKING NETWORK.
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XIAOBING FENG and HAIBO HU
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BANKING industry , *GLOBALIZATION , *BUSINESS failures , *BANK management , *BANK failures - Abstract
The negative externalities from an individual bank failure to the whole system can be huge. One of the key purposes of bank regulation is to internalize the social costs of potential bank failures via capital charges. This study proposes a method to evaluate and allocate the systemic risk to different countries/regions using a Susceptible-Infected-Removable (SIR) type of epidemic spreading model and the Shapley value (SV) in game theory. The paper also explores features of a constructed bank network using real globe-wide banking data. [ABSTRACT FROM AUTHOR]
- Published
- 2013
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17. Observed Influences of Autumn--Early Winter Eurasian Snow Cover Anomalies on the Hemispheric PNA-like Variability in Winter.
- Author
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Qigang Wu, Haibo Hu, and Lujun Zhang
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SNOW , *SNOW cover , *WINTER , *ANALYSIS of covariance - Abstract
The impact of the Eurasian snow cover extent on the Northern Hemisphere (NH) circulation is investigated by applying a lagged maximum covariance analysis (MCA) to monthly satellite-derived snow cover and NCEP reanalysis data. Wintertime atmospheric signals significantly correlated with persistently autumn--early winter snow cover anomalies are found in the leading two MCA modes. The first MCA mode indicates the effect of Eurasian snow cover anomalies on the Arctic Oscillation/North Atlantic Oscillation (AO/NAO). The second MCA mode corresponds with the forcing of Eurasian snow cover anomalies on the hemispheric Pacific--North America (PNA)-like atmospheric variations. This snow--atmosphere relationship may present a significant potential for wintertime predictability. [ABSTRACT FROM AUTHOR]
- Published
- 2011
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18. Privacy-Aware Location Data Publishing.
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Haibo Hu, Jianliang Xu, Sai Tung On, Jing Du, and Joseph Kee-Yin Ng
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DATABASE security , *DATABASE management , *SPATIAL data infrastructures , *DATABASE design , *ALGORITHMS , *EXPERIMENTS , *ONLINE databases , *MATHEMATICAL analysis , *PRIVACY - Abstract
This article examines a new problem of k-anonymity with respect to a reference dataset in privacyaware location data publishing: given a user dataset and a sensitive event dataset, we want to generalize the user dataset such that by joining it with the event dataset through location, each event is covered by at least k users. Existing k-anonymity algorithms generalize every k user locations to the same vague value, regardless of the events. Therefore, they tend to overprotect against the privacy compromise and make the published data less useful. In this article, we propose a new generalization paradigm called local enlargement, as opposed to conventional hierarchy- or partition-based generalization. Local enlargement guarantees that user locations are enlarged just enough to cover all events k times, and thus maximize the usefulness of the published data. We develop an O(Hn)-approximate algorithm under the local enlargement paradigm, where n is the maximum number of events a user could possibly cover and Hn is the Harmonic number of n. With strong pruning techniques and mathematical analysis, we show that it runs efficiently and that the generalized user locations are up to several orders of magnitude smaller than those by the existing algorithms. In addition, it is robust enough to protect against various privacy attacks. [ABSTRACT FROM AUTHOR]
- Published
- 2010
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19. Asiatic Acid (AA) Sensitizes Multidrug- Resistant Human Lung Adenocarcinoma A549/DDP Cells to Cisplatin (DDP) via Downregulation of P-Glycoprotein (MDR1) and Its Targets.
- Author
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Qilai Cheng, Meixiang Liao, Haibo Hu, Hongliang Li, and Longhuo Wu
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CISPLATIN , *LUNG cancer , *MULTIDRUG resistance , *P-glycoprotein , *ADENOCARCINOMA , *CANCER chemotherapy , *DOWNREGULATION - Abstract
Background/Aims: P-glycoprotein (P-gp, i.e., MDR1) is associated with the phenotype of multidrug resistance (MDR) and causes chemotherapy failure in the management of cancers. Searching for effective MDR modulators and combining them with anticancer drugs is a promising strategy against MDR. Asiatic acid (AA), a natural triterpene isolated from the plant Centella asiatica, may have an antitumor activity. The present study assessed the reversing effect of AA on MDR and possible molecular mechanisms of AA action in MDR1- overexpressing cisplatin (DDP)-resistant lung cancer cells, A549/DDP. Methods: Human lung adenocarcinoma A549/DDP cells were either exposed to different concentrations of AA or treated with DDP, and their viability was measured by the MTT assay. A Rhodamine 123 efflux assay, immunofluorescent staining, ATPase assay, reverse-transcription PCR (RT-PCR), and western blot analysis were conducted to elucidate the mechanisms of action of AA on MDR. Results: Our results showed that AA significantly enhanced the cytotoxicity of DDP toward A549/DDP cells but not its parental A549 cells. Furthermore, AA strongly inhibited P-gp expression by blocking MDR1 gene transcription and increased the intracellular accumulation of the P-gp substrate Rhodamine 123 in A549/DDP cells. Nuclear factor (NF)-kB (p65) activity, IkB degradation, and NF-kB/p65 nuclear translocation were markedly inhibited by pretreatment with AA. Additionally, AA inhibited the MAPK-ERK pathway, as indicated by decreased phosphorylation of ERK1 and -2, AKT, p38, and JNK, thus resulting in reduced activity of the Y-box binding protein 1 (YB1) via blockage of its nuclear translocation. Conclusions: AA reversed P-gp-mediated MDR by inhibition of P-gp expression. This effect was likely related to downregulation of YB1, and this effect was mediated by the NF-kB and MAPK-ERK pathways. AA may be useful as an MDR reversal agent for combination therapy in clinical trials. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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20. Wearable Sensor-Based Human Activity Recognition Method with Multi-Features Extracted from Hilbert-Huang Transform.
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Huile Xu, Jinyi Liu, Haibo Hu, and Yi Zhang
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WEARABLE technology , *HUMAN activity recognition , *HILBERT-Huang transform , *MEDICAL care , *MEDICAL rehabilitation , *SOCIAL interaction - Abstract
Wearable sensors-based human activity recognition introduces many useful applications and services in health care, rehabilitation training, elderly monitoring and many other areas of human interaction. Existing works in this field mainly focus on recognizing activities by using traditional features extracted from Fourier transform (FT) or wavelet transform (WT). However, these signal processing approaches are suitable for a linear signal but not for a nonlinear signal. In this paper, we investigate the characteristics of the Hilbert-Huang transform (HHT) for dealing with activity data with properties such as nonlinearity and non-stationarity. A multi-features extraction method based on HHT is then proposed to improve the effect of activity recognition. The extracted multi-features include instantaneous amplitude (IA) and instantaneous frequency (IF) by means of empirical mode decomposition (EMD), as well as instantaneous energy density (IE) and marginal spectrum (MS) derived from Hilbert spectral analysis. Experimental studies are performed to verify the proposed approach by using the PAMAP2 dataset from the University of California, Irvine for wearable sensors-based activity recognition. Moreover, the effect of combining multi-features vs. a single-feature are investigated and discussed in the scenario of a dependent subject. The experimental results show that multi-features combination can further improve the performance measures. Finally, we test the effect of multi-features combination in the scenario of an independent subject. Our experimental results show that we achieve four performance indexes: recall, precision, F-measure, and accuracy to 0.9337, 0.9417, 0.9353, and 0.9377 respectively, which are all better than the achievements of related works. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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21. 2PASS: Bandwidth-Optimized Location Cloaking for Anonymous Location-Based Services.
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Haibo Hu and Jianliang Xu
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LOCATION-based services , *BANDWIDTHS , *MOBILE communication systems , *DISTRIBUTED computing , *COMPUTER security , *DATA protection - Abstract
Protection of users' location privacy is a critical issue for location-based services. Location cloaking has been proposed to blur users' accurate locations with cloaked regions. Although various cloaking algorithms have been studied, none of the prior work has explored the impact of cloaking on the bandwidth usage of requested services. In this paper, we develop an innovative result-aware location cloaking approach, called 2PASS. Based on the notion of Voronoi cells, 2PASS minimizes the number of objects to request, and hence, the bandwidth while meeting the same privacy requirement. The core component of 2PASS is a lightweight WAG-tree index, based on which efficient and secure client and server procedures are designed. Through threat analysis and experimental results, we argue that 2PASS is robust and outperforms state-of-the-art approaches in terms of various metrics, such as query response time and bandwidth consumption. We also enclose a case study of 2PASS in a real-life application. [ABSTRACT FROM AUTHOR]
- Published
- 2010
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22. Expanding dictionary for robust face recognition: pixel is not necessary while sparsity is.
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Zhong-Qiu Zhao, Yiu-ming Cheung, Haibo Hu, and Xindong Wu
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ROBUST control , *HUMAN facial recognition software , *PIXELS , *COMPUTATIONAL complexity , *COMPUTER algorithms - Abstract
Since sparse representation (SR) was first introduced into robust face recognition, the argument has lasted for several years about whether sparsity can improve robust face recognition or not. Some work argued that the robust sparse representation (RSR) model has a similar recognition rate as non-sparse solution, while it needs a much higher computational cost due to the larger feature dimensionality in the pixel space. In this study, the authors reveal that the standard RSR model, which expands the dictionary with the identity matrix to reconstruct corruption or occlusion in face images, is essentially a non-sparse solution with a relatively large residual. The reason why the RSR model underperforms may be its inappropriately expanded bases rather than the sparsity itself. Thereby, this study proposes to design a dictionary with an expanded noise bases set which can precisely reconstructs any corruption or occlusion in face images in a subspace. Experimental results show that the algorithm can greatly improve recognition rates for robust face recognition. In addition, the algorithm can be simply performed in a subspace with a small feature dimensionality, thus efficient enough for real systems. This study makes us come to the conclusion that solving the approximation problem in raw pixel space is not necessary for robust face recognition, while solving in a subspace with a much smaller feature dimensionality is enough when the dictionary is well expanded. Finally, this study also confirms that the sparsity plays an important role in SR based classification. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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23. Study of silver aerosol source term at different specific internal energy input from HE detonation devices.
- Author
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Kefeng, Song, Yaqin, Shi, Kun, Liu, Luochuan, Su, Bo, Li, Wei, Liu, Penglai, Wang, Chenhong, Yi, Yajun, Zhang, Qingpeng, Ma, Haibo, Hu, and Wenjie, Liu
- Subjects
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AEROSOLS , *RADIOACTIVE aerosols , *SILVER , *PARTICLE size distribution , *NUCLEAR accidents - Abstract
Radioactive aerosols harmful to humans are often produced in nuclear accidents, and their source term characteristics (total volume and particle size distribution) and dispersion patterns have important implications for accident response and hazard assessment. However, experimental studies of radioactive aerosols cannot be directly conducted in open space due to the hazardous nature of radioactive aerosols. In this study, silver was used instead of plutonium to study the aerosol source term under different specific internal energy inputs (SIEI) to simulate a low order explosion in an accident. Results show that aerosol release fraction (ARF) and respirable release fraction (RRF) of silver increase linearly with SIEI first, then varies in a range of 8% ~ 19%, with a turning point at SIEI of 1.4 MJ/kg. Analysis suggests an increase of difference between ARF and RRF with respect to SIEI. The size distribution of silver aerosol around 10 µm is influenced by SIEI significantly, which could be possibly attributed to the interactions between silver aerosol and ambient aerosol (solid HE products or rust). Comparison between the source term of silver and plutonium suggests that silver is a good surrogate of plutonium in studying aerosol for SIEI of MJ/kg level. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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24. Co9S8nanotubes synthesized on the basis of nanoscale Kirkendall effect and their magnetic and electrochemical propertiesElectronic supplementary information (ESI) available: Diagram of charge-discharge capacity vs.cycle numbers. See DOI: 10.1039/b923206k.
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Zhenghua Wang, Ling Pan, Haibo Hu, and Suping Zhao
- Subjects
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COBALT sulfide , *NANOTUBES , *KIRKENDALL effect , *MAGNETIC fields , *ELECTROCHEMICAL analysis , *MICROFABRICATION , *CHEMICAL templates , *LITHIUM-ion batteries - Abstract
Polycrystalline Co9S8nanotubes were successfully fabricated by using Co(CO3)0.35Cl0.20(OH)1.10nanorod bunches as sacrificial hard templates through a hydrothermal route. The samples were characterized by means of XRD, XPS, SEM and TEM. The Co9S8nanotubes were formed due to the nanoscale Kirkendall effect, which can be explained by the difference in diffusion rates between the cobalt source and the sulfur ion. Magnetic measurements indicate that the Co9S8nanotubes show a paramagnetic property instead of a ferromagnetic property, which can be attributed to the tiny sizes of the component nanoparticles. The electrochemical properties of the Co9S8nanotubes demonstrate that they deliver a large discharge capacity, which might find possible applications as an electrode material in lithium batteries. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
- View/download PDF
25. Modeled Climate Responses to Realistic Extremes of Northern Hemisphere Spring and Summer Snow Anomalies.
- Author
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SHIZUO LIU, QIGANG WU, LIN WANG, SCHROEDER, STEVEN R., YANG ZHANG, YONGHONG YAO, and HAIBO HU
- Subjects
- *
SNOWMELT , *SNOW , *ATMOSPHERIC temperature , *CLIMATOLOGY , *STANDING waves - Abstract
Northern Hemisphere (NH) snow cover extent (SCE) has diminished in spring and early summer since the 1960s. Historical simulations from phase 5 of the Coupled Model Intercomparison Project (CMIP5) estimated about half as much NH SCE reduction as observed, and thus underestimated the associated climate responses. This study investigates atmospheric responses to realistic decreasing snow anomalies using multiple ensemble transient integrations of climate models forced by observed light and heavyNHsnow cover years, specifically satellite-based observations ofNHSCE and snow water equivalent from March to August in 1990 (light snow) and 1985 (heavy snow), as a proxy for the trend. The primary atmospheric responses to March-August NH snow reduction are decreased soil moisture, increased surface air temperature, general tropospheric warming in the extratropics and the Arctic, increased geopotential heights, and weakening of the midlatitude jet stream and eddy kinetic energy. The localized response is maintained by persistent increased diabatic heating due to reduced snow anomalies and resulting soilmoisture drying, and the remote atmospheric response results partly from horizontal propagation of stationary Rossby wave energy and also from a transient eddy feedback mechanism. In summer, atmospheric responses are significant in both the Arctic and the tropics and are mostly induced by contemporaneous snow forcing, but also by the summer soil moisture dry anomaly associated with early snow melting. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
26. Kirigami Patterning of MXene/Bacterial Cellulose Composite Paper for All-Solid-State Stretchable Micro-Supercapacitor Arrays.
- Author
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Shangqing Jiao, Aiguo Zhou, Mingzai Wu, and Haibo Hu
- Subjects
- *
CELLULOSE , *PAPER , *ENERGY density , *STRUCTURAL design , *KEY performance indicators (Management) , *MICROELECTRONICS - Abstract
Stretchable micropower sources with high energy density and stability under repeated tensile deformation are key components of flexible/wearable microelectronics. Herein, through the combination of strain engineering and modulation of the interlayer spacing, freestanding and lightweight MXene/bacterial cellulose (BC) composite papers with excellent mechanical stability and a high electrochemical performance are first designed and prepared via a facile all-solution-based paper-making process. Following a simple laser-cutting kirigami patterning process, bendable, twistable, and stretchable all-solid-state micro-supercapacitor arrays (MSCAs) are further fabricated. As expected, benefiting from the high-performance MXene/BC composite electrodes and rational sectional structural design, the resulting kirigami MSCAs exhibit a high areal capacitance of 111.5 mF cm−2, and are stable upon stretching of up to 100% elongation, and in bent or twisted states. The demonstrated combination of an all-solution-based MXene/BC composite paper-making method and an easily manipulated laser-cutting kirigami patterning technique enables the fabrication of MXene-based deformableall-solid-state planar MSCAs in a simple and efficient manner while achieving excellent areal performance metrics and high stretchability, making them promising micropower sources that are compatible with flexible/wearable microelectronics. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
27. Inhibition of LHX2 by miR-124 suppresses cellular migration and invasion in non-small cell lung cancer.
- Author
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Qinghui Yang, Liang Wan, Can Xiao, Haibo Hu, Longqiang Wang, Jun Zhao, Zhe Lei, and Hong-Tao Zhang
- Subjects
- *
MICRORNA genetics , *NON-small-cell lung carcinoma , *HOMEOBOX genes , *GROWTH factors , *INVASIVE diagnosis , *DIAGNOSIS - Abstract
Downregulated microRNA (miR)-124 is common in numerous types of cancer, including non-small cell lung cancer (NSCLC). A previous study by the authors demonstrated that LIM-homeobox domain 2 (LHX2) was upregulated and promoted cell growth in NSCLC. However, whether LHX2 affects the migratory and invasive abilities of NSCLC cells and the association of LHX2 with miR-124 remains unclear. The present study revealed that miR-124 expression was frequently decreased in human NSCLC cells and tissues and negatively correlated with LHX2 expression, which was increased in NSCLC cells and tissues. Furthermore, the transfection of miR-124 mimic significantly inhibited endogenous expression of LHX2 mRNA and protein in A549 and H1299 cells, and miR-124 inhibitor promoted LHX2 expression. Of note, overexpression of miR-124 in A549 and H1299 cells attenuated cellular migratory and invasive abilities, and this was observed in LHX2-silenced A549 and H1299 cells. Knockdown of miR-124 augmented the migratory and invasive abilities in A549 and H1299 cells. The 3'-untranslated region of LHX2 transcript has also been identified to be a putative target of miR-124. Taken together, the results revealed that miR-124 may inhibit migration and invasion by repressing LHX2 expression in NSCLC cells. The findings of the present study suggested that overexpression of miR-124 or silencing of LHX2 may provide a therapeutic strategy for advanced NSCLC. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
28. Abnormal Spall Behavior Observed in Pure Iron and FeMnNi Alloy Undergoing α-[variant_greek_epsilon] Phase Transition.
- Author
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Zhiping Tang, Xiaojun Tang, Xinhua Zhang, Haibo Hu, and Weiwei Xu
- Subjects
- *
IRON alloys , *IMPACT (Mechanics) , *PHASE transitions , *STRUCTURAL plates , *IRON-nickel alloys - Abstract
The spall behaviors of pure iron DT2 and FeMnNi alloy are investigated experimentally. The impacts for DT2 are symmetric and with same thickness for both flyer and target plates. It is found a multiple spalling happened as the pressure exceeds the α-[variant_greek_epsilon] transition threshold (13GPa). In the asymmetrical experiments of FeMnNi alloy, a shallow spalling occurs when the impact pressure exceeds the transition pressure of 6.9GPa. Such abnormal spalling phenomena are believed to relate to the α-[variant_greek_epsilon] phase transition of iron. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]
- Published
- 2006
- Full Text
- View/download PDF
29. Spatial-Temporal Correlative Fault Detection in Wireless Sensor Networks.
- Author
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Zhiping Kang, Honglin Yu, Qingyu Xiong, and Haibo Hu
- Subjects
- *
FAULT location (Engineering) , *WIRELESS sensor networks , *DATA quality , *REAL-time computing , *DECISION making - Abstract
Wireless sensor networks (WSNs) have been used extensively in a range of applications to facilitate real-time critical decision-making and situation monitoring. Accurate data analysis and decision-making rely on the quality of the WSN data that have been gathered. However, sensor nodes are prone to faults and are often unreliable because of their intrinsic natures or the harsh environments in which they are used. Using dust data from faulty sensors not only has negative effects on the analysis results and the decisions made but also shortens the network lifetime and can waste huge amounts of limited valuable resources. In this paper, the quality of a WSN service is assessed, focusing on abnormal data derived from faulty sensors. The aim was to develop an effective strategy for locating faulty sensor nodes in WSNs. The proposed fault detection strategy is decentralized, coordinate-free, and node-based, and it uses time series analysis and spatial correlations in the collected data. Experiments using a real dataset from the Intel Berkeley Research Laboratory showed that the algorithm can give a high level of accuracy and a low false alarm rate when detecting faults even when there are many faulty sensors. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
30. Chondroprotective Activity of Murraya exotica through Inhibiting β-Catenin Signaling Pathway.
- Author
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Longhuo Wu, Haiqing Liu, Rui Zhang, Linfu Li, Jialin Li, Haibo Hu, and Hao Huang
- Subjects
- *
BIOTHERAPY , *PHYTOTHERAPY , *OSTEOARTHRITIS , *ACADEMIC medical centers , *ANIMAL experimentation , *APOPTOSIS , *FLOW cytometry , *POLYMERASE chain reaction , *RATS , *RESEARCH funding , *T-test (Statistics) , *WESTERN immunoblotting , *REVERSE transcriptase polymerase chain reaction , *GENE expression profiling , *PREVENTION - Abstract
Osteoarthritis (OA) is a degenerative joint disease that affects millions of people. Currently, there is no effective drug treatment for it. The purpose of this study is to investigate the chondroprotective effects of Murraya exotica (L.) on OA. The rat OA models were duplicated to prepare for separating OA chondrocytes, synovial fluid (SF), and serum containing M. exotica (50mg/kg, 100mg/kg, and 200 mg/kg), M. exotica showed the activity of decreasing the contents of TNF-β and IL-1β in SF and the chondrocyte apoptosis in a dose-dependent manner. To investigate the probable mechanism, quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting were used to determine gene expression and protein profiles, respectively. The results reveal that M. exotica can downregulate mRNA and protein expressions of β-catenin and COX-2 and reporter activity significantly. Conclusively, M. exotica exhibits antiapoptotic chondroprotective activity probably through inhibiting β-catenin signaling. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
31. QTL underlying resistance to two HG types of Heterodera glycines found in soybean cultivar 'L-10'
- Author
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Wei Chang, Limin Dong, Zizhen Wang, Haibo Hu, Yingpeng Han, Weili Teng, Hongxia Zhang, Maozu Guo, and Wenbin Li
- Subjects
- *
SOYBEAN cyst nematode , *HETERODERA , *CELL lines , *GENETIC transcription , *GENOMICS - Abstract
Background: Resistance of soybean (Glycine max L. Merr.) cultivars to populations of cyst nematode (SCN; Heterodera glycines I.) was complicated by the diversity of HG Types (biotypes), the multigenic nature of resistance and the temperature dependence of resistance to biotypes. The objective here was to identify QTL for broad-spectrum resistance to SCN and examine the transcript abundances of some genes within the QTL. Results: A Total of 140 F5 derived F7 recombinant inbred lines (RILs) were advanced by single-seed-descent from a cross between 'L-10' (a soybean cultivar broadly resistant to SCN) and 'Heinong 37' (a SCN susceptible cultivar). Associated QTL were identified by WinQTL2.1. QTL Qscn3-1 on linkage group (LG) E, Qscn3-2 on LG G, Qscn3-3 on LG J and Qscn14-1 on LG O were associated with SCN resistance in both year data (2007 and 2008). Qscn14-2 on LG O was identified to be associated with SCN resistance in 2007. Qscn14-3 on LG D2 was identified to be associated with SCN resistance in 2008. Qscn14-4 on LG J was identified to be associated with SCN resistance in 2008. The Qscn3-2 on LG G was linked to Satt309 (less than 4 cM), and explained 19.7% and 23.4% of the phenotypic variation in 2007 and 2008 respectively. Qscn3-3 was less than 5 cM from Satt244 on LG J, and explained 19.3% and 17.95% of the phenotypic variations in 2007 and 2008 respectively. Qscn14-4 could explain 12.6% of the phenotypic variation for the SCN race 14 resistance in 2008 and was located in the same region as Qscn3-3. The total phenotypic variation explained by Qscn3-2 and Qscn3-3 together was 39.0% and 41.3% in 2007 and 2008, respectively. Further, the flanking markers Satt275, Satt309, Sat_350 and Satt244 were used for the selection of resistant lines to SCN race 3, and the accuracy of selection was about 73% in this RIL population. Four genes in the predicted resistance gene cluster of LG J (chromosome 16) were successfully cloned by RT-PCR. The transcript encoded by the gene Glyma16g30760.1 was abundant in the SCN resistant cultivar 'L-10' but absent in susceptible cultivar 'Heinong 37'. Further, the abundance was higher in root than in leaf for 'L-10'. Therefore, the gene was a strong candidate to underlie part of the resistance to SCN. Conclusions: Satt275, Satt309, Sat_305 and Satt244, which were tightly linked to the major QTL for resistance to SCN on LG G and J, would be candidates for marker-assisted selection of lines resistant to the SCN race 3. Among the six RLK genes, Glyma16g30760.1 was found to accumulate transcripts in the SCN resistance cultivar 'L-10' but not in 'Heinong 37'. The transcript abundance was higher in root than in leaf for L-10. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
32. Pressure dynamics during shock loading of aqueous foams.
- Author
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Vasil’ev, E. I., Mitichkin, S. Yu., Testov, V. G., and Haibo, Hu
- Subjects
- *
SHOCK waves , *FOAM - Abstract
The interaction of shock waves with aqueous foams has been numerically modeling on the basis of a gas–drop model. A modified Godunov scheme of second-order accuracy has been used to solve the gas-dynamics equations. The measured density distributions of the foam over height and the results of calculational modeling of the foam structure were used as starting data. The results of the pressure calculations are compared with experimental oscilloscope traces. © 1998 American Institute of Physics. [ABSTRACT FROM AUTHOR]
- Published
- 1998
33. Facile fabrication and configuration design of Co3O4 porous acicular nanorod arrays on Ni foam for supercapacitors.
- Author
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Tongtong Jiang, Siyu Yang, Zhiman Bai, Peng Dai, Xinxin Yu, Mingzai Wu, and Haibo Hu
- Subjects
- *
POROUS materials , *NANORODS , *SUPERCAPACITORS - Abstract
The configuration of electrode materials is of great significance to the performance of supercapacitors (SCs) because of its direct effects on specific surface area and electron transfer path. Given this, herein, a series of Co3O4 hierarchical configurations composed of porous acicular nanorods are designedly synthesized on Ni foam with in-site self-organization method depending on the addition of NH4F. In the absence of NH4F, Co3O4 nanorods self-assemble into porous urchin-like structure (PULS), while the introduction of NH4F can induce the vertical growth of Co3O4 acicular nanorods, forming porous acicular nanorod arrays (PANRAs). By simply tuning the concentration of NH4F, the Co3O4 PANRAs with different specific surface area can be obtained. As expected, Co3O4 PANRAs electrode for SCs (using 1 mmol of NH4F) exhibits high specific capacitance (1486 F g−1 at 1 A g−1) and excellent cycling stability (98.8% retention after 5000 continuous charge–discharge cycles), which are better than those of Co3O4 PULS electrode (658.2 F g−1 at 1 A g−1, 90.4%). Corresponding solid-state symmetric SC achieves a high energy density of 48.63 Wh kg−1 at power density of 600 W kg−1. Such superior performance is attributed to fast charge transfer kinetics, facile electron transport and ions diffusion rate resulting from porous array structure, indicating the importance of configuration design of electrode materials for high performance SCs. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
34. Building Biomedical Imaging and Informatics e-Science platform for translational medical research.
- Author
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Jianguo Zhang, Kai Zhang, Tusheng Wang, Yuanyuan Yang, Haibo Hu, and Lisa Xu
- Subjects
- *
TRANSLATIONAL research , *ELECTRONIC health records - Abstract
An abstract of the article "Building Biomedical Imaging and Informatics e-Science platform for translational medical research," by Jianguo Zhang, Kai Zhang, Tusheng Wang, Yuanyuan Yang, Haibo Hu, and Lisa Xu is presented.
- Published
- 2012
- Full Text
- View/download PDF
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