Blast vibration of a large-span high-speed railway tunnel based on microseismic monitoring

Li, Ao,Fang, Qian,Zhang, Dingli,Luo, Jiwei,Hong, Xuefei Techno-Press 2018 Smart Structures and Systems, An International Jou Vol.21 No.5

Ground vibration is one of the most undesirable effects induced by blast operation in mountain tunnels, which could cause negative impacts on the residents living nearby and adjacent structures. The ground vibration effects can be well represented by peak particle velocity (PPV) and corner frequency ($f_c$) on the ground. In this research, the PPV and the corner frequency of the mountain surface above the large-span tunnel of the new Badaling tunnel are observed by using the microseismic monitoring technique. A total of 53 sets of monitoring results caused by the blast inside tunnel are recorded. It is found that the measured values of PPV are lower than the allowable value. The measured values of corner frequency are greater than the natural frequencies of the Great Wall, which will not produce resonant vibration of the Great Wall. The vibration effects of associated parameters on the PPV and corner frequency which include blast charge, rock mass condition, and distance from the blast point to mountain surface, are studied by regression analysis. Empirical formulas are proposed to predict the PPV and the corner frequency of the Great Wall and surface structures due to blast, which can be used to determine the suitable blast charge inside the tunnel.

북경의 성곽역사공원 조성방식 연구

리아오페이 ( Ao Fei Li ),강태호 ( Tai Ho Kang ) 한국전통조경학회 2015 한국전통조경학회지 Vol.33 No.4

본 연구는 중국 북경시의 대표적인 성곽역사공원인 황성근성곽역사공원(皇城根城墻遺址公園), 명성곽역사공원(明城墻遺址公園), 원대도성곽역사공원(元大都城墻遺址公園)을 중심으로 성곽 역사공원의 조성방식을 분석하여 문제점과 시사점을 찾는데 목적이 있다. 이를 위해 문헌과 현장조사를 통해 성곽 역사공원의 일반적 개념을 정의하고 북경성의 변천과정을 규명하여 북경시 성곽역사공원의 조성방식을 분석하였다. 그리고 각 공원의 구체적인 정책, 조성과정, 공간계획, 경관구 테마설정, 식재 등을 분석한 결과 성곽역사공원의 조성에 있어 입지 환경을 적절히 활용하지 못하였으며 테마경관구 역시 성곽유적의 역사성과 적합하게 조성되지 못하는 등 문제점이 도출되었다. 연구 결과 성곽역사공원의 조성은 성곽 유적을 대상으로 하는 유적에 관한 보호 및 관리계획, 역사공원에 관한 활용 및 운영계획 등 전문적이고 다차원적인 제도가 필요하며 성곽의 특성상 타 문화재에 비해 조성 면적이 넓기 때문에 공원조성을 위한 토지매입비용 등 사업비가 많이 드는 특징을 갖고 있어서 정부의 적극적인 재정 지원이 필요하다. 또한, 성곽역사공원의 계획을 수립하기 전에 대상지의 자연환경 및 시설현황을 면밀히 분석하여 최대한 활용하고 공간간의 원활한 연결을 통한 공간이용의 효율성을 제고하여야 한다. 아울러 타 시설과의 조화 및 시설물 상호간의 연계성을 가지도록 하여야 하며 형태 및 색채, 재료 등을 고려하여 계획하여야 한다. 그리고 성곽역사공원 조성 계획 수립 후 향후 개발여건 변화에 능동적인 대처가 가능하도록 고려되어야 한다. Parks in order to find the inspiration and implication from their construction. The research is focused on a few cross-sectional city wall parks, which are Huangchenggen city wall park, Ming city wall park and Yuandadu city wall park. to come to the conclusion, it defines the generic concept of city wall park, clarifies the transitional process of the city of Beijing, organize the current situation and basis of the construction of the Beijing city wall parks. besides, by analyzing the Beijing city wall parks`` specific construction manners including the basis of their planning, the support by government, planning functionality, landscape theme arrangement and gardening arrangement, the research puts forwards their construction characters and drawbacks. through comprehensive analysis on the aspects above, a series of inspirations are obtained for the construction of city wall parks. these include: specialized and legally valid regulation systems need to be setup before planning; government and citizens`` proactive support is necessary for the protection of ancient city wall ruins and the construction of the city wall parks; when planning, existing situation should be utilized to the maximum extent, efficiency of space usage should be improved through smooth connection between different spacial locations.

Phospholipid and Fatty Acid Composition in Leaves and Roots of Ten Autumn Chrysanthemum Cultivars Grown at Low Temperature

Yan Li,Yonghua Li,Pan Yang,Hua’ao Zhang,Dan He 한국원예학회 2017 Horticulture, Environment, and Biotechnology Vol.58 No.4

The objective of this study was to evaluate the relationship between cold hardiness and phospholipid andfatty acid content in leaves and roots of chrysanthemum, and to explore cold resistance mechanisms of chrysanthemumin order to provide a theoretical basis for selecting and breeding a new cold-resistant cultivar. We analyzed thephospholipid and fatty acid components in leaves and roots of 10 autumn chrysanthemum cultivars including sixearly-flowering cultivars and four late-flowering cultivars. We determined the content of phosphatidyl ethanolamine(PE), phosphatidyl choline (PC), phosphatidyl serine (PS), phosphatidyl glycerol (PG), myristic acid (C14:0), palmiticacid (C16:0), stearic acid (C18:0), docosanoic acid (C22:0), oleic acid (C18:1), linoleic acid (C18:2), and linolenic acid(C18:3) in leaves and roots of chrysanthemum seedlings grown at 16C and 5C. The cultivars had different responsesto low temperature that included changes in the cell membrane composition in leaves and roots. The main phospholipidin leaves and roots of chrysanthemum was PE, and the main saturated fatty acid was palmitic acid. Amongunsaturated fatty acids, linolenic acid was found in leaves, whereas oleic acid and linoleic acid were present in theroots. Based on the unsaturated fatty acid content and the ratio of unsaturated to saturated fatty acids in leaves, theearly-flowering cultivars ‘Tan Xiang Shi Zi’ and ‘Tong Que Chun Shen’ and the late-flowering cultivars ‘Guan DongXin Xia’ and ‘Yun Long Feng Wu’ were classified as strongly cold tolerant, while the early-flowering cultivar ‘JinFeng Ling’ and the late-flowering cultivar ‘Mo Bao’ were weakly cold tolerant.

Prognostic value of preoperative neutrophil-to-lymphocyte ratio in histological variants of non-muscle-invasive bladder cancer

Deng-xiong Li,Xiao-ming Wang,Yin Tang,Yu-bo Yang,Dechao Feng,Ao Li,Fa-cai Zhang,Yun-jin Bai,Ping Han 대한비뇨의학회 2021 Investigative and Clinical Urology Vol.62 No.6

Purpose: Many studies identified that the preoperative neutrophil-to-lymphocyte ratio (PNLR) was associated with patient prognosis in non-muscle-invasive bladder cancer (NMIBC). We hypothesized that PNLR could be prognostic in patients with histological variants of NMIBC (VH-NMIBC). Materials and Methods: This retrospective study included patients with VH-NMIBC admitted at our center between January 2009 and May 2019. The best cut-off value of NLR was measured by the receiver operating characteristic curve and Youden index. The Kaplan-Meier method and Cox proportional hazard regression models were employed to evaluate the association between PNLR and disease prognosis, including recurrence-free survival (RFS), progression-free survival (PFS), cancer-specific survival (CSS), and overall survival (OS). Results: A total of 243 patients with VH-NMIBC were enrolled in our study. According to the Kaplan-Meier method results, patients with PNLR ≥2.2 were associated with poor RFS (p<0.001), PFS (p<0.001), CSS (p<0.001), and OS (p<0.001). Multivariable analyses indicated that PNLR ≥ 2.2 was an independent prognostic factor of RFS (hazard ratio [HR], 2.11; 95% confidence interval [CI, 1.57–1.83; p<0.001), PFS (HR, 2.34; 95% CI, 1.70–3.21; p<0.001), CCS (HR, 2.87; 95% CI, 1.96–4.18; p< 0.001), and OS (HR, 2.83; 95% CI, 1.96–4.07; p<0.001). Conclusions: This study identified that PNLR ≥2.2 was usually associated with a poor prognosis for patients with VH-NMIBC.

발 ( 跋 ) 「 일명구화파열지전말 」

이광도 ( Kuang T'ao Li ) 한국중국학회 1967 중국학보 Vol.7 No.1

Two New Natural Products from the Fruits of Alpinia oxyphylla with Inhibitory Effects on Nitric Oxide Production in Lipopolysaccharide- Activated RAW264.7 Macrophage Cells

Zhang Jun Qing,Duan Jin Ao,Wang Yong,Li Yong Hui,Lai Wei Yong,Li Hai Long,Pei Li Xia 대한약학회 2012 Archives of Pharmacal Research Vol.35 No.12

Chemical investigation of the fruits of Alpinia oxyphylla led to an isolation of the two new natural products, 9-hydroxy epinootkatol (1) and (S)-2-pentanol-2-O-β-D-glucopyranoside (2), in addition to the nine known compounds, pinocembrin (3), tectochrysin (4), izalpinin (5), nookatone (6), yakuchinone A (7), protocatechuic acid (8), β-sitosterol (9), daucosterol (10) and β-sitosterol palmitate (11). Their structures were elucidated on the basis of physicochemical constants and NMR spectral data analysis. The effects of the isolated components on nitric oxide production in LPS-induced RAW 264.7 macrophages were examined. The two new natural compounds showed inhibitory activities with IC50 values of 21.8 and 32.8 μg/mL, respectively.

Structurally ordered nanofiltration membranes prepared by spatially anchoring interfacial polymerization for highly efficient separation properties

Ao Sheng,Hao Wang,Haoji Jiang,Yaxin Zhao,Hao Li,Hao Jia,Zhong Wei,Heyun Wang 한국화학공학회 2021 Korean Journal of Chemical Engineering Vol.38 No.9

The incorporation of various nanofillers into the interfacial polymerization (IP) process is widely applied to prepare higher performance NF membranes. However, few studies have reported the influence of nanofillers on nanocomposite membrane formation in the IP process. Here, an optical microscope was employed to study the change rule in the 8-NH2-POSS/PSA nanocomposite membrane formation process due to the addition of 8-NH2-POSS nanoparticles. First, the addition of 8-NH2-POSS reduced the diffusion rate of the polyacrylamide hydrochloride (PAH) water phase on the surface against the oil phase because of the interaction with the PAH molecules. Furthermore, the 8-NH2- POSS/PSA nanocomposite membrane structure was more homogeneous and exhibited uniform pinhole defects distribution due to the interaction of the 8-NH2-POSS nanoparticles to the PAH segment. A significant separation performance was observed in the 8-NH2-POSS/PSA nanocomposite membrane due to the hydrophilicity and positive charge of the 8-NH2-POSS nanoparticles. The permeation flux and MgCl2 rejection of the 8-NH2-POSS/PSA nanocomposite membrane increased up to 50.5 L/m2 h at 0.5MPa and 94.8%, respectively, which corresponded to increases of 73.5% and 8.7% as compared to the pristine PSA membrane. 8-NH2-POSS/PSA nanocomposite membranes have great application potential in the water softening and treatment of divalent metals ions under acidic conditions.

Endophytic Fungal strains Specifically Modified the Biochemical Status of Grape Cells

Li-Hua Huang,Ming-Zhi Yang,Xiu-Jin Ao,An-Yun Ren,Ming-Quan Yuan,Han-Bo Zhang 한국식물학회 2018 Journal of Plant Biology Vol.61 No.4

Previously, specific interactions in morphologywere observed between grape cells and endophytic fungalstrains during a dual culture experiment. However, thebiochemical impacts of these fungal endophytes on grapecells is also expected due to their potential application in grapequality management. After assessed multiple physiochemicaltraits to those grape cells which have co-cultured with differentendophytic fungal strains in this study, and found the presenceof fungal endophytes obviously triggered ROS stress responsesin grape cells, and the biochemical status in grape cells weredifferentially modified by different fungal strains. In thosetested endophytic fungal strains, RH37 (Epicoccum sp.),RH6 (Alternaria sp.), RH32 (Alternaria sp.) and RH34(Trichothecium sp.) conferred greater metabolic impacts ongrape cells. And soluble protein (SPr), total flavonoids (TF),total phenols (TPh) and malondialdehyde (MDA) on the otherhand, were sensitive biochemical parameters which can beinfluenced in greater ranges than other detected parameters. Most interestedly, fungal endophytes shaped metabolitespatterns in grape cells during the dual culture appeared fungalgenus/species/strain-specificity. The work confirmed thesignificance of fungal endophytes in grape metabolic regulationand elucidated the possibility to purposely manage grapequality using tool of fungal endophytes.

Multiple Large Shareholders and Firm Performance: Evidence from China

Juan Li,Caiyu Yan,Xuefei He,Hongqu He,Tianping Ao 한국증권학회 2023 Asia-Pacific Journal of Financial Studies Vol.52 No.3

Agency theory has shown that multiple large shareholders have competing monitoring and entrenchment governance effects. Therefore, this paper studies the governance effects of multiple large shareholders to determine the dominant effect in the Chinese setting. A panel data model and F-test demonstrate that a significant positive relationship exists between multiple large shareholders and firm performance, but the positive relationship between multiple large shareholders and firm performance will be weakened by state-owned enterprises and politically connected enterprises. Furthermore, our findings suggest that multiple large shareholders can enhance firm performance by mitigating the agent–principal problem and the principal–principal problem. Additionally, a threshold model is introduced to explore the impact of other governance mechanisms on multiple large shareholders’ governance, and our findings show that enhancing controlling shareholder governance and board size significantly weakens multiple large shareholders governance, but increasing the proportion of independent directors strengthens the positive relationship between multiple large shareholders and Tobin’s Q and weakens the positive relationship between multiple large shareholders and ROA.

A Dual Functional Ti-Ga Alloy: Inhibiting Biofilm Formation and Osteoclastogenesis Differentiation via Disturbing Iron Metabolism

Fupeng Li,Kai Huang,Jinbing Wang,Kai Yuan,Yiqi Yang,Yihao Liu,Xianhao Zhou,Keyu Kong,Tao Yang,Jian He,Chunjie Liu,Haiyong Ao,Fengxiang Liu,Qian Liu,Tingting Tang,Shengbing Yang 한국생체재료학회 2023 생체재료학회지 Vol.27 No.00

Background Although biomedical implants have been widely used in orthopedic treatments, two major clinical challenges remain to be solved, one is the bacterial infection resulting in biofilm formation, and the other is aseptic loosening during implantation due to over-activated osteoclastogenesis. These factors can cause many clinical issues and even lead to implant failure. Thus, it is necessary to endow implants with antibiofilm and aseptic looseningprevention properties, to facilitate the integration between implants and bone tissues for successful implantation. To achieve this goal, this study aimed to develop a biocompatible titanium alloy with antibiofilm and anti-aseptic loosening dual function by utilizing gallium (Ga) as a component. Methods A series of Ti-Ga alloys were prepared. We examined the Ga content, Ga distribution, hardness, tensile strength, biocompatibility, and anti-biofilm performance in vitro and in vivo. We also explored how Ga3+ ions inhibited the biofilm formation of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) and osteoclast differentiation. Results The alloy exhibited outstanding antibiofilm properties against both S. aureus and E. coli in vitro and decent antibiofilm performance against S. aureus in vivo. The proteomics results demonstrated that Ga3+ ions could disturb the bacterial Fe metabolism of both S. aureus and E. coli, inhibiting bacterial biofilm formation. In addition, Ti-Ga alloys could inhibit receptor activator of nuclear factor-κB ligand (RANKL)-dependent osteoclast differentiation and function by targeting iron metabolism, then suppressing the activation of the NF-κB signaling pathway, thus, showing their potential to prevent aseptic loosening. Conclusion This study provides an advanced Ti-Ga alloy that can be used as a promising orthopedic implant raw material for various clinical scenarios. This work also revealed that iron metabolism is the common target of Ga3+ ions to inhibit biofilm formation and osteoclast differentiation.