The (signless) Laplacian spectral radii of c-cyclic graphs with n vertices, girth g and k pendant vertices

Liu, Muhuo,Das, Kinkar Ch.,Lai, Hong-Jian Gordon and Breach 2017 Linear & multilinear algebra Vol.65 No.5

Spectral results on Hamiltonian problem

Liu, Muhuo,Lai, Hong-Jian,Das, Kinkar Ch. Elsevier 2019 Discrete mathematics Vol.342 No.6

<P><B>Abstract</B></P> <P>Let α be a non-negative real number, and let Θ ( G , α ) be the largest eigenvalue of A ( G ) + α D ( G ) . Specially, Θ ( G , 0 ) and Θ ( G , 1 ) are called the spectral radius and signless Laplacian spectral radius of G , respectively. A graph G is said to be Hamiltonian (traceable) if it contains a Hamiltonian cycle (path), and a graph G is called Hamilton-connected if any two vertices are connected by a Hamiltonian path in G . The number of edges of G is denoted by e ( G ) . Recently, the (signless Laplacian) spectral property of Hamiltonian (traceable, Hamilton-connected) graphs received much attention. In this paper, we shall give a general result for all these existed results. To do this, we first generalize the concept of Hamiltonian, traceable, and Hamilton-connected to s -suitable, and we secondly present a lower bound for e ( G ) to confirm the existence of s -suitable graphs. Thirdly, when 0 ≤ α ≤ 1 , we obtain a lower bound for Θ ( G , α ) to confirm the existence of s -suitable graphs. Consequently, our results generalize and improve all these existed results in this field, including the main results of Chen et al. (2018), Feng et al. (2017), Füredi et al. (2017), Ge et al. (2016), Li et al. (2016), Nikiforov et al. (2016), Wei et al. (2019) and Yu et al. (2013, 2014).</P>

Quantitative Observation of Threshold Defect Behavior in Memristive Devices with <i>Operando</i> X-ray Microscopy

Liu, Huajun,Dong, Yongqi,Cherukara, Mathew J.,Sasikumar, Kiran,Narayanan, Badri,Cai, Zhonghou,Lai, Barry,Stan, Liliana,Hong, Seungbum,Chan, Maria K. Y.,Sankaranarayanan, Subramanian K. R. S.,Zhou, Hua American Chemical Society 2018 ACS NANO Vol.12 No.5

<P>Memristive devices are an emerging technology that enables both rich interdisciplinary science and novel device functionalities, such as nonvolatile memories and nanoionics-based synaptic electronics. Recent work has shown that the reproducibility and variability of the devices depend sensitively on the defect structures created during electroforming as well as their continued evolution under dynamic electric fields. However, a fundamental principle guiding the material design of defect structures is still lacking due to the difficulty in understanding dynamic defect behavior under different resistance states. Here, we unravel the existence of threshold behavior by studying model, single-crystal devices: resistive switching requires that the pristine oxygen vacancy concentration reside near a critical value. Theoretical calculations show that the threshold oxygen vacancy concentration lies at the boundary for both electronic and atomic phase transitions. Through <I>operando</I>, multimodal X-ray imaging, we show that field tuning of the local oxygen vacancy concentration below or above the threshold value is responsible for switching between different electrical states. These results provide a general strategy for designing functional defect structures around threshold concentrations to create dynamic, field-controlled phases for memristive devices.</P> [FIG OMISSION]</BR>

Developmental competence of porcine parthenogenetic embryos relative to embryonic chromosomal abnormalities

Hao, Yan-Hong,Lai, Liang-Xue,Liu, Zhong-Hua,Im, Gi-Sun,Wax, David,Samuel, Melissa,Murphy, Clifton N.,Sutovsky, Peter,Prather, Randall S. Wiley Subscription Services, Inc., A Wiley Company 2006 Molecular reproduction and development Vol.73 No.1

<P>Parthenogenetically activated (PA) embryos exhibit delayed development, a lower blastocyst rate, and less successful development in vitro compared to in vitro fertilized (IVF) embryos. To investigate the possible mechanisms for unsuccessful parthenogenetic development, this study analyzed the chromosome abnormalities and developmental potential of porcine PA embryos. Mature oocytes were electrically activated and cultured in Porcine Zygote Medium-3 (PZM<SUB>3</SUB>) supplemented with 3 mg/ml BSA for 6, 7, or 8 days. The percentage of PA blastocysts was lower than that of IVF embryos on days 6 and 7 (16.4 ± 7.4 vs. 28.7 ± 3.7; 10.9 ± 2.8 vs. 21.5 ± 4.7, P < 0.05; respectively), and the PA blastocysts had significantly fewer nuclei than IVF blastocysts (23.2 ± 1.8 vs. 29.7 ± 0.8; 29.7 ± 3.3 vs. 32.0 ± 2.4, P < 0.05). The percentage of abnormal PA embryos (including embryos with condensed nuclei, arrested embryos and fragmented embryos) was higher than that of IVF embryos (PA: 52.9 ± 12.8 vs. 16.4 ± 7.4 on day 6), and increased with culture time (71.9 ± 12.1 vs. 10.9 ± 2.8. on day 7,and 75.0 ± 22.6 vs. 12.1 ± 2.3 on day 8, P < 0.05). The Day-6 PA blastocysts (n = 147) were divided into three classes according to the total number of nuclei (<20, 20–39, >40) and into three groups according to the morphological diameter (<150, 150–180, >180 µm). Of the haploid blastocysts, 56.1% had less than 20 nuclei, and 71.5% were less than 150 µm in diameter. Of all (114) blastocysts suitable for analysis, 55.5% displayed chromosomal abnormalities. Among chromosomal abnormalities in PA blastocysts, haploid blastocysts were most prevalent (43.6%), while polyploidy (4.4%) and mixoploidy (7.7%) embryos were less prevalent. Chromosomal abnormalities of porcine PA embryos might contribute to a higher rate of abnormal embryonic development. We suggest that a careful consideration should be given when using the blastocysts with smaller size, and establishing the optimum culture condition for PA embryos development in vitro. Mol. Reprod. Dev. © 2005 Wiley-Liss, Inc.</P>

Breastfeeding and the Risk of Childhood Hodgkin Lymphoma: A Systematic Review and Meta-analysis

Wang, Ke-Lai,Liu, Chun-Lan,Zhuang, Yan,Qu, Hong-Yi Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.8

Purpose: Numerous observational epidemiological studies have evaluated associations between breastfeeding and the risk of childhood Hodgkin lymphoma; however, the existing results are inconsistent. We therefore conducted a systematic review and meta-analysis. Methods: Medical literature was searched in the Pubmed and Embase databases to identify all English-language relevant studies up to April 10, 2013. Reference lists were thereafter hand-searched for additional articles. Studies that reported relative risk ratios (RRs) or odds ratios (ORs) with 95% confidence intervals (CIs) were included. This meta-analysis was conducted in accordance with the guidelines for the meta-analysis of observational studies in epidemiology. Results: We finally included 10 case-control studies in our meta-analysis, involving 1,618 childhood Hodgkin lymphoma cases and 8,181 controls. Overall, we did found a borderline significant association between breastfeeding and reduced risk of childhood Hodgkin lymphoma comparing ever breastfed children to never breastfed children (pooled OR =0.79; 95%CI, 0.58-1.08; P=0.13), with limited evidence for between-study heterogeneity (P =0.12, $I^2$ = 35.70%). Conclusion: There is limited evidence for an inverse association between breastfeeding and risk of childhood Hodgkin lymphoma.

A Modified Enskog-Like Equation of Self-Diffusion Coefficients for Penetrable-Sphere Model Fluids

Suh, Soong-Hyuck,Liu, Hong-Lai Korean Chemical Society 2011 Bulletin of the Korean Chemical Society Vol.32 No.4

Molecular dynamics simulations have been performed to investigate the transport properties of self-diffusion coefficients in the penetrable-sphere model system. The resulting simulation data for the product of the packing fraction and the self-diffusion coefficient exhibit a transition from an increasing function of density in lower repulsive systems, where the soft-type collisions are dominant, to a decreasing function in higher repulsive systems, where most particle collisions are the hard-type reflections due to the low-penetrability effects. A modified Enskog-like equation implemented by the effective packing fraction with the mean-field energy correction is also proposed, and this heuristic approximation yields a reasonably good result even in systems of high densities and high repulsive energy barriers.

A Modified Enskog-Like Equation of Self-Diffusion Coefficients for Penetrable-Sphere Model Fluids

Soong-Hyuck Suh,Hong-Lai Liu 대한화학회 2011 Bulletin of the Korean Chemical Society Vol.32 No.4

Molecular dynamics simulations have been performed to investigate the transport properties of self-diffusion coefficients in the penetrable-sphere model system. The resulting simulation data for the product of the packing fraction and the self-diffusion coefficient exhibit a transition from an increasing function of density in lower repulsive systems, where the soft-type collisions are dominant, to a decreasing function in higher repulsive systems, where most particle collisions are the hard-type reflections due to the low-penetrability effects. A modified Enskog-like equation implemented by the effective packing fraction with the mean-field energy correction is also proposed, and this heuristic approximation yields a reasonably good result even in systems of high densities and high repulsive energy barriers.

Weight Gain in Pregnancy, Maternal Age and Gestational Age in Relation to Fetal Macrosomia

( Yi Li ),( Qi-fei Liu ),( Dan Zhang ),( Ying Shen ),( Kui Ye ),( Han-lin Lai ),( Hai-qing Wang ),( Chuan-lai Hu ),( Qi-hong Zhao ),( Li Li ) 한국임상영양학회 2015 Clinical Nutrition Research Vol.4 No.2

To investigate the possible risk factors related to macrosomia. Pregnant women and their newborns (n = 1041) were recruited from a cohort study in Maternal and Child Care Center of Hefei from January 2011 to July 2012. Questionnaires were applied to collect the demographic data besides the medical records. Detailed health records of the entire pregnancy were obtained using retrospective study. Meanwhile the data of neonatal outcomes was prospectively tracked. Associations between exposure risk factors and macrosomia were analyzed using Pearson’s chi squared test. Logistic regression models were used to assess the independent association between these potential predictors and macrosomia. The incidence of macrosomia of this cohort was 11.24% of which male: female = 2.55:1. Male incidence (8.07%) of macrosomia was higher than female (3.17%), p < 0.001. Body mass index (BMI) before pregnancy (pre-BMI), maternal height, parity were not independently associated with macrosomia; multiple logistic regression analysis indicated that macrosomia was mainly independently associated with weight gain in pregnancy (OR=1.14,95% CI [1.10-1.19]), maternal age (OR = 1.09,95% CI [1.03-1.15]) and gestational age (OR = 1.62,95% CI [1.31-1.99]), respectively. Our findings indicate that weight gain in pregnancy, maternal age and gestational age should be considered as independent risk factors for macrosomia.

Size-Controlled Silver Nanoparticles Confined in Ordered Mesoporous Silica and Their Enhanced Catalytic Activities

Xiaofei Zhou,Jiawei Wan,Yefeng Liu,Di Liu,Hong Wang,Xiaoyong Lai,Yanzhao Zou,Guo Lin,Jian Chen 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2017 NANO Vol.12 No.9

A cooperative assembly route has been developed, by which silver nanoparticles with controlled sizes are incorporated into the channels of ordered cubic mesoporous silica (KIT-6) with different pore sizes (4.3–6.4 nm). The samples were characterized by XRD, TEM, FT-IR, UV-Vis and N2 physisorption. The pore wall of mesoporous silica can efficiently confine the growth of silver nanoparticles within the channels and their average sizes decreased with the pore size reduction of KIT-6. Catalytic activities of the resultant Ag/KIT-6-x (x stands for hydrothermal temperature) composite for reducing harmful organic dye Rhodamine B (Rh B) by sodium borohydride (NaBH4) were investigated. All the Ag/KIT-6 composite samples show great catalytic activities, among which Ag/KIT-6-80 with higher loading and smaller size of Ag nanoparticles exhibits higher catalytic activity than those of Ag/KIT-6-60 and Ag/KIT-6-100.

A Modifi ed Virtual Generator Control for DC Microgrid with Improved Dynamic Characteristics of DC Bus Voltage and Enhanced current Sharing Effect

Zhang Han-Wen,Zhang Qin-Jin,Liu Yan-Cheng,Wang Hong-Lai,Hu Wang-Bao 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.6

Traditional virtual DC motor control can suppress the bus voltage fl uctuations caused by load power mutations and distributed generation fl uctuations. However, the dynamic response is poor and the load current sharing cannot be adjusted. Thus, a modifi ed virtual DC generator control strategy is proposed, which combines the average current controller with the virtual DC generator to enhance current sharing eff ect. The adaptive regulation equations of inertia coeffi cient and damping coeffi cient are elaborated simultaneously to improve the system dynamic characteristics. Then the infl uence of key control parameters on system stability is analyzed by establishing the small signal model. Finally, simulations and a StarSim HIL experimental platform of DC microgrid are built. The results show that the proposed method can eff ectively suppress the DC bus voltage fl uctuations and enable them to have a better dynamic response, while realizing the accurate current sharing.