Prestressed concrete bridges with corrugated steel webs: Nonlinear analysis and experimental investigation

Xia-chun Chen,Zhi-zhou Bai,Yu Zeng,Rui-juan Jiang,Francis T.K. Au 국제구조공학회 2016 Steel and Composite Structures, An International J Vol.21 No.5

Concrete bridges with corrugated steel webs and prestressed by both internal and external tendons have emerged as one of the promising bridge forms. In view of the different behaviour of components and the large shear deformation of webs with negligible flexural stiffness, the assumption that plane sections remain plane may no longer be valid, and therefore the classical Euler-Bernoulli and Timoshenko beam models may not be applicable. In the design of this type of bridges, both the ultimate load and ductility should be examined, which requires the estimation of full-range behaviour. An analytical sandwich beam model and its corresponding beam finite element model for geometric and material nonlinear analysis are developed for this type of bridges considering the diaphragm effects. Different rotations are assigned to the flanges and corrugated steel webs to describe the displacements. The model accounts for the interaction between the axial and flexural deformations of the beam, and uses the actual stress-strain curves of materials considering their stress path-dependence. With a nonlinear kinematical theory, complete description of the nonlinear interaction between the external tendons and the beam is obtained. The numerical model proposed is verified by experiments.

State Estimation for Coupled Output Discrete-time Complex Network with Stochastic Measurements and Different Inner Coupling Matrices

Chun-Xia Fan,Fuwen Yang,Ying Zhou 제어·로봇·시스템학회 2012 International Journal of Control, Automation, and Vol.10 No.3

A state estimation problem is studied for a class of coupled outputs discrete-time networks with stochastic measurements, i.e., the measurements are missing and disturbed with stochastic noise. The considered networks are coupled with outputs rather than states, are coupled with different inner coupling matrices rather than identical inner ones. By using Lyapunov stability theory combined with stochastic analysis, a novel state estimation scheme is proposed to estimate the states of discrete-time complex networks through the available output measurements, where the measurements are stochastic missing and are disturbed with Brownian motions which are caused by data transmission among nodes due to communication unreliability. State estimation conditions are derived in terms of linear matrix inequalities (LMIs). A numerical example is provided to demonstrate the validity of the proposed scheme.

Comparative Genomic Analysis Reveals That the 20K and 38K Prophages in Listeria monocytogenes Serovar 4a Strains Lm850658 and M7 Contribute to Genetic Diversity but Not to Virulence

( Chun Fang ),( Tong Cao ),( Ying Shan ),( Ye Xia ),( Yong Ping Xin ),( Chang Yong Cheng ),( Houhui Song ),( John Bowman ),( Xiao Liang Li ),( Xiang Yang Zhou ),( Wei Huan Fang ) 한국미생물 · 생명공학회 2016 Journal of microbiology and biotechnology Vol.26 No.1

Listeria monocytogenes is a foodborne pathogen of considerable genetic diversity with varying pathogenicity. Initially, we found that the strain M7 was far less pathogenic than the strain Lm850658 though both are serovar 4a strains belonging to the lineage III. Comparative genomic approaches were then attempted to decipher the genetic basis that might govern the strain-dependent pathotypes. There are 2,761 coding sequences of 100% nucleotide identity between the two strains, accounting for 95.7% of the total genes in Lm850658 and 92.7% in M7. Lm850658 contains 33 specific genes, including a novel 20K prophage whereas strain M7 has 130 specific genes, including two large prophages (38K and 44K). To examine the roles of these specific prophages in pathogenicity, the 20K and 38K prophages were deleted from their respective strains. There were virtually no differences of pathogenicity between the deletion mutants and their parent strains, although some putative virulent factors like VirB4 are present in the 20K region or holin-lysin in the 38K region. In silico PCR analysis of 29 listeria genomes show that only strain SLCC2540 has the same 18 bp integration hotspot as Lm850658, whereas the sequence identity of their 20K prophages is very low (21.3%). The 38K and 44K prophages are located in two other different hotspots and are conserved in low virulent strains M7, HCC23, and L99. In conclusion, the 20K and 38K prophages of L. monocytogenes serovar 4a strains Lm850658 and M7 are not related to virulence but contribute to genetic diversity.

Automatic Detection and Classification of Rib Fractures on Thoracic CT Using Convolutional Neural Network: Accuracy and Feasibility

Zhou Qing-Qing,Wang Jiashuo,Tang Wen,Hu Zhang-Chun,Xia Zi-Yi,Xue-Song Li,Zhang Rongguo,Yin Xindao,Zhang Bing,Zhang Hong 대한영상의학회 2020 Korean Journal of Radiology Vol.21 No.7

Objective: To evaluate the performance of a convolutional neural network (CNN) model that can automatically detect and classify rib fractures, and output structured reports from computed tomography (CT) images. Materials and Methods: This study included 1079 patients (median age, 55 years; men, 718) from three hospitals, between January 2011 and January 2019, who were divided into a monocentric training set (n = 876; median age, 55 years; men, 582), five multicenter/multiparameter validation sets (n = 173; median age, 59 years; men, 118) with different slice thicknesses and image pixels, and a normal control set (n = 30; median age, 53 years; men, 18). Three classifications (fresh, healing, and old fracture) combined with fracture location (corresponding CT layers) were detected automatically and delivered in a structured report. Precision, recall, and F1-score were selected as metrics to measure the optimum CNN model. Detection/diagnosis time, precision, and sensitivity were employed to compare the diagnostic efficiency of the structured report and that of experienced radiologists. Results: A total of 25054 annotations (fresh fracture, 10089; healing fracture, 10922; old fracture, 4043) were labelled for training (18584) and validation (6470). The detection efficiency was higher for fresh fractures and healing fractures than for old fractures (F1-scores, 0.849, 0.856, 0.770, respectively, p = 0.023 for each), and the robustness of the model was good in the five multicenter/multiparameter validation sets (all mean F1-scores > 0.8 except validation set 5 [512 x 512 pixels; F1-score = 0.757]). The precision of the five radiologists improved from 80.3% to 91.1%, and the sensitivity increased from 62.4% to 86.3% with artificial intelligence-assisted diagnosis. On average, the diagnosis time of the radiologists was reduced by 73.9 seconds. Conclusion: Our CNN model for automatic rib fracture detection could assist radiologists in improving diagnostic efficiency, reducing diagnosis time and radiologists’ workload.

Flavones from the Bark of Lindera caudata and Their Anti-Tobacco Mosaic Virus Activity

Yu-Chun Yang,Ying Qin,Xian-Xue Wu,Cong-Fang Xia,Yan-Lin Meng,Bin Zhou,Yan-Qing Ye,Xue-Mei Gao,Yin-Ke Li,Qiu-Fen Hu 대한화학회 2015 Bulletin of the Korean Chemical Society Vol.36 No.4

Two new flavones, 5-hydroxy-8-hydroxymethyl-7,4′-dimethoxy-flavone (1) and 6-hydroxy-8-hydroxymethyl-7,4′-dimethoxy-flavone (2), together with six known flavones (3–8), were isolated from the bark of Lindera caudata. The structures of 1–8 were elucidated by spectroscopic methods including extensive 1D and 2D NMR techniques. Compounds 1–8 were evaluated for their anti-tobacco mosaic virus (anti-TMV) activity. The results showed that Compounds 1 and 2 showed high anti-TMV activity with inhibition rates of 31.2 and 28.8%, respectively. These values are close to those of positive control.

Balloon dilation of epidermolysis bullosa-related esophageal strictures: A report of two cases

Wei-Zhong Zhou,Jing-Guo Xia,Zheng-Qiang Yang,Chun-Gao Zhou,Lin-Bo Zhao,Sheng Liu,Hai Bin Shi 소화기인터벤션의학회 2018 Gastrointestinal Intervention Vol.7 No.3

Epidermolysis bullosa (EB) is a very rare inherited disease featured with skin blistering resulting from minor trauma. Sometimes the esophageal mucosa could also be involved, which leads to esophageal strictures. Here we report two cases of EB-related esophageal strictures who were successfully treated with esophageal balloon dilations. The two cases with EB had severe dysphagia. Clinical examination showed signs of malnutrition, skin blisters and loss of toenails due to EB. They underwent careful fluoroscopic balloon dilation with 10- and 16-mm-sized balloon catheters, respectively. They could ingest soft and some solid foods after the procedure and maintained during the 20 months and 16 months follow-up periods.

Balloon dilation of epidermolysis bullosa-related esophageal strictures: A report of two cases

Wei-Zhong Zhou,Jing-Guo Xia,Zheng-Qiang Yang,Chun-Gao Zhou,Lin-Bo Zhao,Sheng Liu,Hai Bin Shi 소화기인터벤션의학회 2018 International journal of gastrointestinal interven Vol.7 No.3

Epidermolysis bullosa (EB) is a very rare inherited disease featured with skin blistering resulting from minor trauma. Sometimes the esophageal mucosa could also be involved, which leads to esophageal strictures. Here we report two cases of EB-related esophageal strictures who were successfully treated with esophageal balloon dilations. The two cases with EB had severe dysphagia. Clinical examination showed signs of malnutrition, skin blisters and loss of toenails due to EB. They underwent careful fluoroscopic balloon dilation with 10- and 16-mm-sized balloon catheters, respectively. They could ingest soft and some solid foods after the procedure and maintained during the 20 months and 16 months follow-up periods.

Influence of synthetic polymers on the mechanical properties of hardened b-calcium sulfate hemihydrate plasters

Ping-ping Zhou,Hua-chun Wu,Yong-Mei Xia 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.33 No.-

Polymers have been used to modulate mechanical strengths and water absorption of construction ormodeling materials as like gypsum. To understand the structure–performance relationship of polymersin hydration and properties of gypsum plaster, several designed carboxyl polyether sulfonates wereinvestigated with comparison of some commercial polymers. It is found that bending strength of thehardened b-hemihydrate plaster is inversely proportional to number of carboxyl groups in the polymerthat retards hydration. The mechanical strengths enhancement is coincident with acceleration of initialhydration, while decrease of mechanical strengths happened with retard of the hydration.

Overview of research on three pine species in Jiangxi province, China

Wei Ding,Cheng Zhou,Chun-Xia Yang 강원대학교 산림과학연구소 2018 강원대학교 산림과학연구소 학술대회 Vol.2018 No.09

Masson pine (Pinus massoniana) is a native tree species unique to south China. It has the advantages of fast growth, high yield, strong adaptability and leanness-resistant, and it is an important tree species for timber and rosin. In the aspect of tree breeding, our institute has carried out studies on provenance, genetic variation of forest stand and individual plant at different levels, interaction between provenance and environment, stability and adaptability of provenance, and selected a series of superior varieties suitable for paper making, rosin tapping and insect resistance. In the aspect of forest cultivation, the study on reforming low efficiency stands of masson pine in red soil low hilly areas and the cultivation model of combination of wood and rosin using was carried out. In the aspect of disease and insect control, the method of inducing wood and injecting dry drug and releasing natural enemy insects was developed to control pine wilt disease, and the prevention rate has reached more than 90%. Both of slash pine (Pinus elliottii) and loblolly pine (Pinus taeda) were successful species introduced from abroad, especially the species of slash pine, which is widely planted and promoted in our province. Like the masson pine, slash pine and loblolly pine are both important tree species for timber and rosin with high economic benefits. In our institute, we have carried out research on the breeding of slash pine and loblolly pine building materials, and explored the suitable cultivation mode of building materials. The selection of the improved varieties on high-yield rosin and high-yield wood & rosin of slash pine and loblolly pine was carried out, and the second-generation seed orchard of high-yield rosin was established, and the seed orchard was successfully dwarfed. Since 2015, our institute has introduced more than 100 superior families of slash pine and loblolly pine from the United States, and collected more than 200 high-generation genetic resources of slash pine and loblolly pine from inside and outside the province, and built testing forests from different families and resource collection fields. Research on asexual reproduction techniques of slash pine and loblolly pine such as cutting, grafting and somatic embryo induction has been carried out, and some phased research results have been obtained.

Geometrical and Magnetic Properties of Vanadium Clusters Supported on Graphene

Yu Zou,Chang Yong Zhan,Jian-Chun Wu,Li-Ping Zhou,Hai-Xia Da 한국물리학회 2013 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.63 No.2

We report ab-initio calculations of vanadium-cluster Vn(n = 2−5) adsorption on graphene sheets. Geometrical and magnetic properties of various adsorption configurations are studied using firstprinciples density-functional theory with the generalized gradient approximation. The geometrical and magnetic properties of vanadium clusters are found to be size-dependent, and the supported graphene sheet could influence the formation of the vanadium clusters. Low-dimensional Vn cluster configurations could be easily formed when they are absorbed on a graphene sheet, and the combined Vn-graphene systems exhibit a nonmagnetic state, which is the most stable magnetic configuration. Our calculations for the geometrical and the magnetic moment properties of Vn-graphene systems may be of interest for some nanotechnological applications.