• Title/Summary/Keyword: Liang-Zhi

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Dynamic response of pipe pile embedded in layered visco-elastic media with radial inhomogeneity under vertical excitation

  • Cui, Chun Y.;Meng, Kun;Wu, Ya J.;Chapman, David;Liang, Zhi M.
    • Geomechanics and Engineering
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    • v.16 no.6
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    • pp.609-618
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    • 2018
  • A new mechanical model for predicting the vibration of a pipe pile embedded in longitudinally layered visco-elastic media with radial inhomogeneity is proposed by extending Novak's plain-strain model and complex stiffness method to consider viscous-type damping. The analytical solutions for the dynamic impedance, the velocity admittance and the reflected signal of wave velocity at the pile head are also derived and subsequently verified by comparison with existing solutions. An extensive parametric analysis is further performed to examine the effects of shear modulus, viscous damping coefficient, coefficient of disturbance degree, weakening or strengthening range of surrounding soil and longitudinal soft or hard interbedded layer on the velocity admittance and the reflected signal of wave velocity at the pile head. It is demonstrated that the proposed model and the obtained solutions provide extensive possibilities for practical application compared with previous related studies.

Analysis of DDS Sampling Method and Harmonic Composition

  • Zhi-lai Zhang;Shao-jun Jiang;Li-li Liang
    • Journal of Information Processing Systems
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    • v.19 no.2
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    • pp.164-172
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    • 2023
  • Through theoretical proof and algorithm design, this paper numerically demonstrates that the three sampling methods of DDS are equivalent in amplitude-frequency characteristics. Depending on theoretical analysis, the article obtains the conclusion that 2 points are optimal when sampling at 2, 3, and 4 points. Built on the data results, this paper obtains the fractional form of the amplitude and phase of the DDS sampled signal; in addition, this paper also obtains the design parameters of the DDS post-stage filter. It also gives a control method for the calculation error when addressing this issue.

Clinical Efficacy of Bevacizumab Concomitant with Pemetrexed in Patients with Advanced Non-small Cell Lung Cancer

  • Zhang, Yu-Mei;Li, Yong-Qiang;Liu, Zhi-Hui;Liao, Xiao-Li;Liang, Rong;Lin, Yan;Yuan, Chun-Ling;Liao, Si-Na;Liang, Chao-Yong;Li, Qian;Li, Le-Qun
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.8
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    • pp.3447-3450
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    • 2014
  • Objective: To observe the clinical efficacy of bevacizumab concomitant with pemetrexed in patients with advanced non-small cell lung cancer (NSCLC). Materials and Methods: A total of 72 patients were randomly divided into a combination group (pemetrexed+bevacizumab, n=36) and a pemetrexed group (n=36) and assessed for disease control (CR+PR+SD) after 4-cycles of first-line GP chemotherapy (gemcitabine+cisplatin). Clinical efficacy, progression-free survival time (PFS), overall survival time (OS), overall response rate (ORR), disease control rate (DCR) and rate of adverse responses between two groups were observed and compared. Results: ORR and DCR were 27.8% and 83.4% in combination group, and 16.7% and 69.5% in the pemetrexed group, respectively, but there were no significant differences (P>0.05). PFS in combination group and pemetrexed group were 4.6 months and 3.9 months respectively (P=0.09), whereas OS in the combination group was 14 months, evidently higher than in the pemetrexed group (11 months, P=0.004). Adverse responses in both groups included high blood pressure, bleeding, thrombocytopenia, anemia, elevated transaminase, diarrhea, vomiting and proteinuria, but there were no significant differences (P>0.05). Conclusions: Bevacizumab concomitant with pemetrexed has better clinical efficacy and safety, giving rise to prolonged survival time in patients with advanced NSCLC.

Kinetic Study of Cyclization of High-Tacticity Polyacrylonitrile Heat-Treated under Air Atmosphere via XRD (공기분위기 하에서 열처리된 고입체 규칙성 폴리아크릴로니트릴의 XRD에 의한 환화반응 속도 연구)

  • Xu, Zhi-Xian;Xu, Jing;Xu, Liang-Hua;Dai, Yong-Qiang;Xue, Li-Wei;Jin, Ri-Guang
    • Polymer(Korea)
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    • v.32 no.2
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    • pp.150-156
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    • 2008
  • Two different polyacrylonitrile samples (PANs, triad tacticity fraction is 0.25 and 0.64) were synthesized and used to study the kinetics of cyclization. Polymers were treated at different temperatures between 250 to $300^{\circ}C$ under air atmosphere, and analyzed by X-ray diffractometer. The sharp and strong peak at $2{\theta}=16.5^{\circ}$ corresponds to a lateral repeat distance that is the (100) diffraction in hexagonal lattice, while the peak at $2{\theta}=25.5^{\circ}$ reflects the (101) diffraction. In comparing their areas of different heat treated samples, the cyclization of both PANs was identified as a first-order reaction. The rate constants of cyclization reaction at different temperatures and the active energy parameter were obtained. This results might provide an important effect on pre-oxidation of polyacrylonitrile fiber.

Mechanical behavior of stud shear connectors embedded in HFRC

  • He, Yu-Liang;Wu, Xu-Dong;Xiang, Yi-Qiang;Wang, Yu-Hang;Liu, Li-Si;He, Zhi-Hai
    • Steel and Composite Structures
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    • v.24 no.2
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    • pp.177-189
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    • 2017
  • Hybrid-fiber reinforced concrete (HFRC) may provide much higher tensile and flexural strengths, tensile ductility, and flexural toughness than normal concrete (NC). HFRC slab has outstanding advantages for use as a composite bridge potential deck slab owing to higher tensile strength, ductility and crack resistance. However, there is little information on shear connector associated with HFRC slabs. To investigate the mechanical behavior of the stud shear connectors embedded in HFRC slab, 14 push-out tests (five batches) in HFRC and NC were conducted. It was found that the stud shear connector embedded in HFRC had a better ductility, higher stiffness and a slightly larger shear bearing capacity than those in NC. The experimentally obtained ultimate resistances of the stud shear connectors were also compared against the equations provided by GB50017 2003, ACI 318-112011, AISC 2011, AASHTO LRFD 2010, PCI 2004, and EN 1994-1-1 (2004), and an empirical equation to predict the ultimate shear connector resistance considering the effect of the HFRC slabs was proposed and validated by the experimental data. Curve fitting was performed to find fitting parameters for all tested specimens and idealized load-slip models were obtained for the specimens with HFRC slabs.

Expression of yeast Hem1 gene controlled by Arabidopsis HemA1 promoter improves salt tolerance in Arabidopsis plants

  • Zhang, Zhi-Ping;Yao, Quan-Hong;Wang, Liang-Ju
    • BMB Reports
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    • v.43 no.5
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    • pp.330-336
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    • 2010
  • 5-Aminolevulinate (ALA) is well-known as an essential biosynthetic precursor of all tetrapyrrole compounds, which has been suggested to improve plant salt tolerance by exogenous application. In this work, the gene encoding aminolevulinate synthase (ALA-S) in yeast (Saccharomyces cerevisiae Hem1) was introduced into the genome of Arabidopsis controlled by the Arabidopsis thaliana HemA1 gene promoter. All transgenic lines were able to transcribe the YHem1 gene, especially under light condition. The chimeric protein (YHem1-EGFP) was found co-localizing with the mitochondria in onion epidermal cells. The transgenic Arabidopsis plants could synthesize more endogenous ALA with higher levels of metabolites including chlorophyll and heme. When the $T_2$ homozygous seeds were cultured under NaCl stress, their germination and seedling growth were much better than the wild type. Therefore, introduction of ALA-S gene led to higher level of ALA metabolism with more salt tolerance in higher plants.

Inhibition of the Aspergillus flavus Growth and Aflatoxin B1 Contamination on Pistachio Nut by Fengycin and Surfactin-Producing Bacillus subtilis UTBSP1

  • Farzaneh, Mohsen;Shi, Zhi-Qi;Ahmadzadeh, Masoud;Hu, Liang-Bin;Ghassempour, Alireza
    • The Plant Pathology Journal
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    • v.32 no.3
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    • pp.209-215
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    • 2016
  • In this study, the treatment of pistachio nuts by Bacillus subtilis UTBSP1, a promising isolate to degrade aflatoxin B1 (AFB1), caused to reduce the growth of Aspergillus flavus R5 and AFB1 content on pistachio nuts. Fluorescence probes revealed that the cell free supernatant fluid from UTBSP1 affects spore viability considerably. Using high-performance liquid chromatographic (HPLC) method, 10 fractions were separated and collected from methanol extract of cell free supernatant fluid. Two fractions showed inhibition zones against A. flavus. Mass spectrometric analysis of the both antifungal fractions revealed a high similarity between these anti-A. flavus compounds and cyclic-lipopeptides of surfactin, and fengycin families. Coproduction of surfactin and fengycin acted in a synergistic manner and consequently caused a strong antifungal activity against A. flavus R5. There was a positive significant correlation between the reduction of A. flavus growth and the reduction of AFB1 contamination on pistachio nut by UTBSP1. The results indicated that fengycin and surfactin-producing B. subtilis UTBSP1 can potentially reduce A. flavus growth and AFB1 content in pistachio nut.

Size Effect of Axial Compressive Strength of CFRP Confined Concrete Cylinders

  • Akogbe, Romuald-Kokou;Liang, Meng;Wu, Zhi-Min
    • International Journal of Concrete Structures and Materials
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    • v.5 no.1
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    • pp.49-55
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    • 2011
  • The main objective of this investigation is to study size effect on compressive strength of CFRP confined concrete cylinders subjected to axial compressive loading. In total 24 concrete cylinders with different sizes were tested, small specimens with a diameter of 100 mm and a height of 200 mm, medium specimens with a diameter of 200 mm and a height of 400 mm, and big specimens with a diameter of 300 mm and a height of 600 mm. The lateral confining pressure of each specimen is the same and from that hypothesis the small specimens were confined with one layer of CFRP, medium and big specimens were performed by two and three layers of CFRP respectively. Test results indicate a significant enhancement in compressive strength for all confined specimens, and moreover, the compressive strengths of small and medium specimens are almost the same while a bit lower for big specimens. These results permit to conclude that there is no size effect on compressive strength of confined specimens regardless of cylinder dimension.

Effect of PTMGDA-PEGMA dopant on PVDF ultrafiltration membrane

  • Chen, Gui-E.;Huang, Hui-Hong;Xu, Zhen-Liang;Zhang, Ping-Yun;Wu, Wen-Zhi;Sun, Li;Liu, Yan-Jun
    • Membrane and Water Treatment
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    • v.7 no.6
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    • pp.539-553
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    • 2016
  • As a novel hydrophobic monomer, polytetrahydrofuran diacrylate (PTMGDA) was synthesized by the esterification reaction between polyethylene tetrahydrofuran (PTMG) and acryloyl chloride (AC). In situ free radical polymerization reaction method was utilized to fabricate poly (vinylidene fluoride) (PVDF)-PTMGDA-poly(ethylene oxide) dimethacrylate (PEGMA) ulrafiltration (UF) membranes. The performances of PVDF-PTMGDA-PEGMA UF membranes in terms of morphologies, mechanical properties, separation properties and hydrophilicities were investigated. The introduction of the PTMGDA-PEGMA dopants not only increased the membranes' pure water flux, but also improved their mechanical properties and the dynamic contact angles. The addition of the PTMGDA/PEGMA dopants led to the formation of the finger-like structure in the membrane bulk. With the increase concentration of PTMGDA/PEGMA dopants, the porosity and the mean effective pore size increased. Those performances were coincide with the physicochemical properties of the casting solutions.

New Safrole Oxide Derivatives: Synthesis and in vitro Antiproliferative Activities on A549 Human Lung Cancer Cells

  • Wang, Li-Ying;Wang, Xiu-Hua;Tan, Jia-Lian;Xia, Shuai;Sun, Heng-Zhi;Shi, Jin-Wen;Jiang, Ming-Dong;Fang, Liang;Zuo, Hua;Dupati, Gautam;Jang, Kiwan;Shin, Dong-Soo
    • Bulletin of the Korean Chemical Society
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    • v.33 no.11
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    • pp.3571-3575
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    • 2012
  • A number of novel small molecules, safrole oxide derivatives 4a-c, 6a-c, 9a-h, were synthesized by the reaction of safrole oxide with anilines 3 and 5, or its alkyl allyl ether derivative 7 with alkyl bromide 8 in moderate yields. The antiproliferative effects of all the target molecules on A549 cell growth were investigated and it was found that the 14 novel compounds could suppress A549 lung cancer cell growth. Among them, compound 6b was the most effective compound in inhibiting the proliferation of A549 cells.