Influence of the camber trailing-edge wings on the motion performance of underwater gliders

Liu Yuhong,Xu Shixun,Tian Shan,Lan Shiquan,Deng Shihan,Liu Shuhe,Feng Dengxue 대한조선학회 2022 International Journal of Naval Architecture and Oc Vol.14 No.1

Wings are the main source of lift for Underwater Gliders (UGs) and play a decisive role in their motion performance. The wings of UGs are generally rectangular and symmetrical airfoils. In this study, a mini- UG with flexible camber trailing-edge wings was proposed and developed to investigate the influence of the trailing edge of the wings on the motion performance of UGs. Flexible deformation of the trailing edge was realized using a steer-by-wire actuator. The test results showed that the trailing edge of the wing could realize maximum upward/downward sloping angles of þ16/16. By combining computational fluid dynamics simulations and tank experiments, this study obtained the glide efficiency (in liftdrag ratio) and stable margins of a mini-UG with variable camber trailing-edge wings. The results showed that the angles of attack corresponding to the minimum lift-to-drag ratio were all negative in cases of downward sloping and positive in cases of upward sloping. Moreover, the suitable camber of the trailing edge, that is, downward-sloping trailing edge on descending glides and upward-sloping trailing edge on ascending glides, can not only greatly improve glide efficiency but also benefit flight stability. Tank experiments showed that the lift-to-drag ratio of the mini-UG with appropriate variable camber trailing-edge wings can be increased by at least 25% compared to those with a symmetrical airfoil.

A wavelet based distributed ID model

Lan Liu,Zhitang Li,Yong Xu,Chenggang Mei,Xiaoling Tan 한국통신학회 2005 한국통신학회 학술대회 및 강연회 Vol.2005 No.4

Two 3D Cd^II and Zn^II Complexes Based on Flexible Dicarboxylate Ligand and Nitrogen-containing Pillar: Synthesis, Structure, and Luminescent Properties

Liu, Liu,Fan, Yan-Hua,Wu, Lan-Zhi,Zhang, Huai-Min,Yang, Li-Rong Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.12

Two 3D isomorphous and isostructural complexes, namely, $[Zn(BDOA)(bpy)(H_2O)_2]_n$ (1) and $[Cd(BDOA)-(bpy)(H_2O)_2]_n$ (2); (BDOA = Benzene-1,4-dioxyacetic acid, bpy = 4,4'-bipyridine) were synthesized under hydrothermal conditions and characterized by means of elemental analyses, thermogravimetric (TG), infrared spectrometry, and single crystal X-ray diffraction. Complexes 1 and 2 crystallize in the triclinic system, space group P-1 and each metal ion in the complexes are six-coordinated with the same coordination environment. In the as-synthesized complexes, $BDOA^{2-}$ anions link central metal ions to form a 1D zigzag chain $[-BDOA^{2-}-Zn(Cd)-BDOA^{2-}-Zn(Cd)-]_{\infty}$, whereas bpy pillars connect metal ions to generate a 1D linear chain $[-bpy-Zn(Cd)-bpy-Zn(Cd)-]_{\infty}$. Both infinite chains are interweaved into 2D grid-like layers which are further constructed into a 3D open framework, where hydrogen bonds play as the bridges between the adjacent 2D layers. Luminescent properties of complex 1 showed selectivity for $Hg^{2+}$ ion.

Discrimination of neutrons and gamma-rays in plastic scintillator based on spiking cortical model

Liu Bing-Qi,Liu Hao-Ran,Chang Lan,Cheng Yu-Xin,Zuo Zhuo,Li Peng 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.9

In this study, a spiking cortical model (SCM) based n-g discrimination method is proposed. The SCMbased algorithm is compared with three other methods, namely: (i) the pulse-coupled neural network (PCNN), (ii) the charge comparison, and (iii) the zero-crossing. The objective evaluation criteria used for the comparison are the FoM-value and the time consumption of discrimination. Experimental results demonstrated that our proposed method outperforms the other methods significantly with the highest FoM-value. Specifically, the proposed method exhibits a 34.81% improvement compared with the PCNN, a 50.29% improvement compared with the charge comparison, and a 110.02% improvement compared with the zero-crossing. Additionally, the proposed method features the second-fastest discrimination time, where it is 75.67% faster than the PCNN, 70.65% faster than the charge comparison and 38.4% slower than the zero-crossing. Our study also discusses the role and change pattern of each parameter of the SCM to guide the selection process. It concludes that the SCM's outstanding ability to recognize the dynamic information in the pulse signal, improved accuracy when compared to the PCNN, and better computational complexity enables the SCM to exhibit excellent n-g discrimination performance while consuming less time.

p38 MAPK Signaling Mediates Mitochondrial Apoptosis in Cancer Cells Induced by Oleanolic Acid

Liu, Jia,Wu, Ning,Ma, Lei-Na,Zhong, Jia-Teng,Liu, Ge,Zheng, Lan-Hong,Lin, Xiu-Kun Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.11

Oleanolic acid (OA) is a nutritional component widely distributed in various vegetables. Although it has been well recognized for decades that OA exerts certain anti-tumor activity by inducing mitochondria-dependent apoptosis, it is still unclear that what molecular signaling is responsible for this effect. In this study, we employed cancer cell lines, A549, BXPC-3, PANC-1 and U2OS to elucidate the molecular mechanisms underlying OA anti-tumor activity. We found that activation of MAPK pathways, including p-38 MAPK, JNK and ERK, was triggered by OA in both a dose and time-dependent fashion in all the tested cancer cells. Activation was accompanied by cleavage of caspases and PARP as well as cytochrome C release. SB203580 (p38 MAPK inhibitor), but not SP600125 (JNK inhibitor) and U0126 (ERK inhibitor), rescued the pro-apoptotic effect of OA on A549 and BXPC-3 cells. OA induced p38 MAPK activation promoted mitochondrial translocation of Bax and Bim, and inhibited Bcl-2 function by enhancing their phosphorylation. OA can induce reactive oxygen species (ROS)-dependent ASK1 activation, and this event was indispensable for p38 MAPK-dependent apoptosis in cancer cells. In vivo, p38 MAPK knockdown A549 tumors proved resistant to the growth-inhibitory effect of OA. Collectively, we elucidated that activation of ROS/ASK1/p38 MAPK pathways is responsible for the apoptosis stimulated by OA in cancer cells. Our finding can contribute to a better understanding of molecular mechanisms underlying the antitumor activity of nutritional components.

New Insights into mTOR Signal Pathways in Ovarian-Related Diseases: Polycystic Ovary Syndrome and Ovarian Cancer

Liu, Ai Ling,Liao, Hong Qing,Li, Zhi Liang,Liu, Jun,Zhou, Cui Lan,Guo, Zi Fen,Xie, Hong Yan,Peng, Cui Ying Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.12

mTOR, the mammalian target of rapamycin, is a conserved serine/threonine kinase which belongs to the phosphatidyl-linositol kinase-related kinase (PIKK) family. It has two complexes called mTORC1 and mTORC2. It is well established that mTOR plays important roles in cell growth, proliferation and differentiation. Over-activation of the mTOR pathway is considered to have a relationship with the development of many types of diseases, including polycystic ovary syndrome (PCOS) and ovarian cancer (OC). mTOR pathway inhibitors, such as rapamycin and its derivatives, can directly or indirectly treat or relieve the symptoms of patients suffering from PCOS or OC. Moreover, mTOR inhibitors in combination with other chemical-molecular agents may have extraordinary efficacy. This paper will discuss links between mTOR signaling and PCOS and OC, and explore the mechanisms of mTOR inhibitors in treating these two diseases, with conclusions regarding the most effective therapeutic approaches.

Two 3D CdII and ZnII Complexes Based on Flexible Dicarboxylate Ligand and Nitrogen-containing Pillar: Synthesis, Structure, and Luminescent Properties

Liu Liu,Yan-hua Fan,Lan-zhi Wu,Huai-min Zhang,Li-rong Yang 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.12

Two 3D isomorphous and isostructural complexes, namely, [Zn(BDOA)(bpy)(H2O)2]n (1) and [Cd(BDOA)- (bpy)(H2O)2]n (2); (BDOA = Benzene-1,4-dioxyacetic acid, bpy = 4,4'-bipyridine) were synthesized under hydrothermal conditions and characterized by means of elemental analyses, thermogravimetric (TG), infrared spectrometry, and single crystal X-ray diffraction. Complexes 1 and 2 crystallize in the triclinic system, space group P-1 and each metal ion in the complexes are six-coordinated with the same coordination environment. In the as-synthesized complexes, BDOA2− anions link central metal ions to form a 1D zigzag chain [-BDOA2− -Zn(Cd)-BDOA2−-Zn(Cd)-]∞, whereas bpy pillars connect metal ions to generate a 1D linear chain [-bpy- Zn(Cd)-bpy-Zn(Cd)-]∞. Both infinite chains are interweaved into 2D grid-like layers which are further constructed into a 3D open framework, where hydrogen bonds play as the bridges between the adjacent 2D layers. Luminescent properties of complex 1 showed selectivity for Hg2+ ion.

Kinetic Resolution of Allylic Alcohol with Chiral BINOL-Based Alkoxides: A Combination of Experimental and Theoretical Studies

Liu, Yidong,Liu, Song,Li, Dongmei,Zhang, Nan,Peng, Lei,Ao, Jun,Song, Choong Eui,Lan, Yu,Yan, Hailong American Chemical Society 2019 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.141 No.2

<P>The development and characterization of enantioselective catalytic kinetic resolution of allylic alcohols through asymmetric isomerization with chiral BINOL derivatives-based alkoxides as bifunctional Brønsted base catalysts were described in the study. A number of chiral BINOL derivatives-based alkoxides were synthesized, and their structure-enantioselectivity correlation study in asymmetric isomerization identified a promising chiral Brønsted base catalyst, which afforded various chiral secondary allylic alcohols (ee up to 99%, <I>S</I> factor up to >200). In the mechanistic study, alkoxide species were identified as active species and the phenol group of BINOL largely affected the high reactivity and enantioselectivity via hydrogen bonding between the chiral Brønsted base catalyst and substrates. The strategy is the first successful synthesis strategy of various chiral secondary allylic alcohols through enantioselective transition-metal-free base-catalyzed isomerization. The applicability of the strategy had been demonstrated by the synthesis of the bioactive natural product (+)-veraguensin.</P> [FIG OMISSION]</BR>

Diverging from the normal path : The life course of an elderly woman in Kinmen county

Hsiang Lan LIU Asian Center for Women's Studies : Ewha Womans Uni 2020 Asian Journal of Women's Studies(AJWS) Vol.26 No.4

Kinmen, also known as Quemoy, is a unique offshore island of the Republic of China (ROC) that had an unusual and strategic position during the Cold War from 1946 to 1992. After 1949, Kinmen was forced to become involved in the military standoff between Chiang Kai-shek’s Republic of China in Taiwan(ROC) and Mao Zedong’s People’s Republic of China (PRC) during the cold war. Kinmen was under martial law for nearly 50 years from 1946 to 1992. The martial law was lifted in 1992 and Kinmen has become the frontline for cross-strait exchanges between the ROC and mainland China. Men’s heroic stories during the war have been studied and published, while women’s voices are systematically ignored. In order to examine the roles and value of women in Kinmen’s history, a case study methodology was used here. Su was one such unique woman, whose life story is investigated here. My main findings were about how she, as an active agent, used opportunities in order to overcome the major structural pressures of her life, while Kinmen underwent some major transitions. This paper is based on an account of this woman’s extraordinary struggles in different periods of time. 金門是中華民國相當獨特的離島,其特殊性在於冷戰從1946年到1992年間,她被迫成為冷戰戰場,捲進了中國國民黨蔣介石與中國共產黨毛澤東間的衝突。 從1946年到1992年,金門進入到軍事統治近50年,直到1992年解除戒嚴,轉型為中國與中華民國兩岸交流的前線。金門男性在戰爭時期的英勇事蹟已被記載與發表,但女性的聲音受系統性地忽略。為檢視金門女性位置和金門歷史的關係,本文採用個案研究方法,呈現一位女性的生命位置與金門史的關聯。主要發現是女性是一個積極的主體能動者,在不同金門重大變遷時運用機會超越結構性的壓力,此作為一個證據呈現金門女性在冷戰時期的不凡。

A Fractal-Interpolation Model for Diagnosing Spalling Risk in Concrete at Elevated Temperatures

Caiwei Liu,Chaofeng Liu,Wenlong Xu,Xiaobo Zhang,Yue Lan 대한토목학회 2018 KSCE Journal of Civil Engineering Vol.22 No.12

Spalling risk analysis and assessment of fire-loaded concrete structures is an essential part of research on fire-resistant behavior of concrete structures. In this work, the authors developed a stochastic interpolation-based fractal model capable of quickly assessing spalling risk in concrete at high temperatures based on mainly factors affecting explosive spalling. The preliminary grading standard of the factors elected in the study was established based on the data from literature. Test samples were then generated by the stochastic interpolation method according to uniform distribution. A spalling risk diagnosis model was built based on fractal dimension weights. In addition, 10 specimens were assessed with the presented model. The evaluation results obtained by the model in this study were in good agreement with those obtained by the fuzzy pattern recognition approach and coincided well with the actual fire test results. The applicability and reliability of the proposed model were verified and can provide theoretical support for identification of the spalling risk of concrete at elevated temperatures.