Experimental investigations on the resistance performance of a high-speed partial air cushion supported catamaran

Yang, Jinglei,Lin, Zhuang,Li, Ping,Guo, Zhiqun,Sun, Hanbing,Yang, Dongmei The Society of Naval Architects of Korea 2020 International Journal of Naval Architecture and Oc Vol.12 No.-

The partial air cushion supported catamaran (PACSCAT) is a novel Surface Effect Ship (SES) and possesses distinctive resistance performance due to the presence of planing bottom. In this paper, the design of PACSCAT and air cushion system are described in detail. Model tests were carried out for Froude numbers ranging from 0.1 to 1.11, the focus is on the influence of air cushion system on resistance characteristics. Drag-reducing effect of air cushion system was proved by means of contrast tests in cuhionborne and non-cushionborne mode. Wave-making characteristics reflect that the PACSCAT would eventually enter planing regime, in which the air could just escape under the seals and the hull body could operate in a steady state. To acquire different air cushion pressure, air flow rate and leakage height were adjusted during tests. Experimental results show that the resistance performance in planing regime would decrease evidently as the increased air flow rate, however, the scheme with medium leakage height presents the best resistance performance in the hump region.

Two-dimensional multiple-snapshot grid-free compressive beamforming

Yang, Yang,Chu, Zhigang,Ping, Guoli Elsevier 2019 Mechanical systems and signal processing Vol.124 No.-

<P><B>Abstract</B></P> <P>Compressive beamforming with planar microphone arrays can effectively achieve the two-dimensional direction-of-arrival (DOA) estimation and strength quantification of acoustic sources. This paper focuses on developing a multiple-snapshot grid-free method and comparing it against the existing grid-based and single-snapshot grid-free ones. The minimization of the atomic norm of multiple-snapshot microphone pressure induced by acoustic sources and the matrix pencil and pairing method are utilized jointly. The former is utilized to denoise the measured pressure and therefore obtain the pressure from acoustic sources. The latter is utilized to estimate DOAs and quantify strengths. Both simulations and experiments demonstrate the advantages of the developed method. For sources that are active across multiple snapshots, it can overcome the basis mismatch conundrum of the grid-based compressive beamforming. When the sources are uncorrelated or partially correlated in both spatial and temporal dimensions, it outperforms the single-snapshot grid-free compressive beamforming in terms of denoising, DOA estimation and strength quantification accuracy and resolution. These advantages stand up whether a standard uniform rectangular array or a non-uniform array constituted by a small number of microphones is utilized.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A two-dimensional multiple-snapshot grid-free compressive beamforming method is proposed. </LI> <LI> It can overcome the basis mismatch conundrum of the grid-based method. </LI> <LI> It enjoys obvious advantages over the single-snapshot grid-free method. </LI> </UL> </P>

Au/Co3O4/CeO2 heterostructures: Morphology controlling, junction formation and enhanced catalysis performance

Ping Yang,Yunshi Liu 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.53 No.-

Co3O4 nanochain and Co3O4/CeO2 heterostructures were prepared via an electrospinning process and subsequent calcination. The formation and shape evolution from Co3O4 nanochains to Co3O4/CeO2 composite nanobelts were investigated, suggesting that both components and preparation parameters play important roles in resulted morphology and properties. Homogeneous Co3O4/CeO2 junctions in belt samples were formed towards enhanced catalysis performance. Well-dispersed Au nanoparticles were deposited on Co3O4/CeO2 composite nanostructures or doped inside through reduction and direct calcination route method, respectively. The loading of Au nanoparticles significantly enhanced catalytic performance with onset CO conversion at 100 C and resulted in CO conversion over at 127 C.

Biomechanical Evaluation of 2 Endoscopic Spine Surgery Methods for Treating Lumbar Disc Herniation: A Finite Element Study

Yang Zou,Shuo Ji,Hui Wen Yang,Tao Ma,Yue Kun Fang,Zhi Cheng Wang,Miao Miao Liu,Ping Hui Zhou,Zheng Qi Bao,Chang Chun Zhang,Yu Chen Ye 대한척추신경외과학회 2024 Neurospine Vol.21 No.1

Objective: This study aimed to evaluate the effects of 2 endoscopic spine surgeries on the biomechanical properties of normal and osteoporotic spines. Methods: Based on computed tomography images of a healthy adult volunteer, 6 finite element models were created. After validating the normal intact model, a concentrated force of 400 N and a moment of 7.5 Nm were exerted on the upper surface of L3 to simulate 6 physiological activities of the spine. Five types of indices were used to assess the biomechanical properties of the 6 models, range of motion (ROM), maximum displacement value, intervertebral disc stress, maximum stress value, and articular protrusion stress, and by combining them with finite element stress cloud. Results: In normal and osteoporotic spines, there was no meaningful change in ROM or disc stress in the 2 surgical models for the 6 motion states. Model N1 (osteoporotic percutaneous transforaminal endoscopic discectomy model) showed a decrease in maximum displacement value of 20.28% in right lateral bending. Model M2 (unilateral biportal endoscopic model) increased maximum displacement values of 16.88% and 17.82% during left and right lateral bending, respectively. The maximum stress value of L4–5 increased by 11.72% for model M2 during left rotation. In addition, using the same surgical approach, ROM, maximum displacement values, disc stress, and maximum stress values were more significant in the osteoporotic model than in the normal model. Conclusion: In both normal and osteoporotic spines, both surgical approaches were less disruptive to the physiologic structure of the spine. Furthermore, using the same endoscopic spine surgery, normal spine biomechanical properties are superior to osteoporotic spines.

The Cancer/Testis Antigen CT45A1 Promotes Transcription of Oncogenic Sulfatase-2 Gene in Breast Cancer Cells and Is Sensible Targets for Cancer Therapy

Ping Yang,Yingnan Qiao,Huaidong Liao,Yizheng Huang,Mei Meng,Yu Chen,Quansheng Zhou 한국유방암학회 2023 Journal of breast cancer Vol.26 No.2

Purpose: Invasive breast carcinomas (BRCAs) are highly lethal. The molecular mechanisms underlying progression of invasive BRCAs are unclear, and effective therapies are highly desired. The cancer-testis antigen CT45A1 promotes overexpression of pro-metastatic sulfatase-2 (SULF2) and breast cancer metastasis to the lungs, but its mechanisms are largely unknown. In this study, we aimed to elucidate the mechanism of CT45A1-induced SULF2 overexpression and provide evidence for targeting CT45A1 and SULF2 for breast cancer therapy. Methods: The effect of CT45A1 on SULF2 expression was assessed using reverse transcription polymerase chain reaction and western blot. The mechanism of CT45A1-induced SULF2 gene transcription was studied using protein-DNA binding assay and a luciferase activity reporter system. The interaction between CT45A1 and SP1 proteins was assessed using immunoprecipitation and western blot. Additionally, the suppression of breast cancer cell motility by SP1 and SULF2 inhibitors was measured using cell migration and invasion assays. Results: CT45A1 and SULF2 are aberrantly overexpressed in patients with BRCA; importantly, overexpression of CT45A1 is closely associated with poor prognosis. Mechanistically, gene promoter demethylation results in overexpression of both CT45A1 and SULF2. CT45A1 binds directly to the core sequence GCCCCC in the promoter region of SULF2 gene and activates the promoter. Additionally, CT45A1 interacts with the oncogenic master transcription factor SP1 to drive SULF2 gene transcription. Interestingly, SP1 and SULF2 inhibitors suppress breast cancer cell migration, invasion, and tumorigenicity. Conclusion: Overexpression of CT45A1 is associated with poor prognosis in patients with BRCA. CT45A1 promotes SULF2 overexpression by activating the promoter and interacting with SP1. Additionally, SP1 and SULF2 inhibitors suppress breast cancer cell migration, invasion, and tumorigenesis. Our findings provide new insight into the mechanisms of breast cancer metastasis and highlight CT45A1 and SULF2 as sensible targets for developing novel therapeutics against metastatic breast cancer.

Effects of Ga-doping on the microstructure and magnetic properties of MnBi alloys

Yang, Yang,Kim, Jong-Woo,Si, Ping-Zhan,Qian, Hui-Dong,Shin, Yongho,Wang, Xinyou,Park, Jihoon,Li, Oi Lun,Wu, Qiong,Ge, Hongliang,Choi, Chul-Jin Elsevier 2018 JOURNAL OF ALLOYS AND COMPOUNDS Vol.769 No.-

<P><B>Abstract</B></P> <P>The low temperature phase Mn<SUB>55</SUB>Bi<SUB>45-<I>x</I> </SUB>Ga<SUB> <I>x</I> </SUB> (<I>x</I> = 0, 1, 3, 5, and 10) alloys were prepared by induction melting process with subsequent low temperature annealing. The effects of Ga-doping on the crystal structure and magnetic properties of the alloys were systematically studied. The room temperature coercivities of Mn<SUB>55</SUB>Bi<SUB>45-<I>x</I> </SUB>Ga<SUB> <I>x</I> </SUB> after ball milling increased from 1.43 T for <I>x</I> = 0 to 1.66 T for <I>x</I> = 5, while the saturation magnetization decreased from 60.7 Am<SUP>2</SUP>/kg (<I>x</I> = 0) to 45.1 Am<SUP>2</SUP>/kg (<I>x</I> = 5). The maximum energy product (<I>BH</I>)<SUB>max</SUB> of Mn<SUB>55</SUB>Bi<SUB>44</SUB>Ga powders reached 7.87 MGOe. The Curie temperature of the Mn<SUB>55</SUB>Bi<SUB>45-<I>x</I> </SUB>Ga<SUB> <I>x</I> </SUB> alloys increased from 633 K to 658 K with increasing Ga concentration in the range of 0 ≤ <I>x</I> ≤ 5.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Effects of doping Ga on the microstructural and magnetic properties of MnBi alloy. </LI> <LI> The MnBi-Ga powders are achieved by surfactant assisted high energy ball milling. </LI> <LI> The maximum energy produce (<I>BH</I>)<SUB>max</SUB> shows 7.87 MGOe for Mn<SUB>55</SUB>Bi<SUB>44</SUB>Ga sample. </LI> <LI> The coercivity of Mn<SUB>55</SUB>Bi<SUB>40</SUB>Ga<SUB>5</SUB> after ball milling reached 1.66 T at room temperature. </LI> <LI> The elevated curie temperature (<I>T</I> <SUB>c</SUB>) by doping Ga makes it a possible candidate for high temperature applications. </LI> </UL> </P>

IWApriori: An Association Rule Mining and Self-updating Method Based on Weighted Increment

Yang Yang,Na An,Ping Xie,Zhongdi Ge,Jing Dong,Yonghua Huo 한국통신학회 2020 한국통신학회 APNOMS Vol.2020 No.09

The mining of association rules plays an important role in fault prediction. Many studies have shown that there is an obvious temporal and spatial correlation between the failure records of the cluster system. Therefore, most cluster system failure prediction engines are built based on causal correlation analysis between log events. However, the original system log file usually contains a large number of invalid records (duplicate or non-fault related records), which makes the mining of event correlation extremely difficult and seriously affects the efficiency and accuracy of fault prediction. Therefore, this paper proposes an association rule mining and self-updating method based on weighted increment, named IWApriori (improved weighted Apriori algorithm). The method includes two important steps: 1) log preprocessing; 2) mining and updating of association rules based on improved algorithm IWApriori. This method can effectively improve the rule completeness and realize the efficient mining and updating of rules in the whole life cycle of the system. In addition, we used the real log data set Blue Gene/L to validate our method. The results show that our association rule mining method is better than other methods in terms of time performance, space performance and the effectiveness of mining rules.

Magnetoelectric characteristics around resonance frequency under magnetic field in Pb(Zr, Ti)O3/Terfenol-D laminate composite

Yang-Yang Guo,Jian-Ping Zhou,Peng Liu 한국물리학회 2010 Current Applied Physics Vol.10 No.4

Dependence of magnetoelectric modulus and phasic difference on the bias magnetic field was studied in a magnetoelectric Pb(Zr, Ti)O3/Terfenol-D laminate composite. The shifts of both magnetoelectric resonant peak and phasic bounce under the bias magnetic field lead to a nonlinear relationship between them. The acoustic velocity of Terfenol-D has a nonlinear dependence on magnetic field, resulting in a similar relationship between the acoustic velocity of the composite and magnetic field. As a result, the magnetoelectric modulus and phase around the resonance frequency exhibit very sensitive dependences on the bias magnetic field.

An Artificial Freezing Technique to Facilitate Shield Tail Brush Replacement under High Pore-Water Pressure Using Liquid Nitrogen

Ping Yang,Jiling Zhao,Lin Li 대한토목학회 2021 KSCE JOURNAL OF CIVIL ENGINEERING Vol.25 No.4

During tunnelling, with the progression of the shield tunnelling machine, the shield tail brush, which is an important accessory required to seal the shield tail and prevent the tunnel from ground water or grouting fluid discharging, will gradually be worn-out/damaged and inevitably lead to safety problems. As a result, problematic tail brush needs to be replaced to prevent more serious problems from happening before any further tunnelling. The replacement of this shield tail brush can be very risky, especially when the shield tunnelling machine is located at a soil layer under high pore-water pressure. This study introduces an engineering practice to facilitate the shield tail brush replacement under high pore-water pressure through the development of a frozen soil wall with the help of an artificial freezing technique using liquid nitrogen. A case study is adopted to demonstrate the implementation of this technique. For the specific site condition, a numerical simulation is usually performed first to determine the design parameters (e.g., liquid nitrogen temperature, length and spacing of the freezing pipes) required for artificial freezing process. Several holes along the radial direction of the tunnel were then made to monitor the temperature of the soil around the tunnel. Subsequently, the artificial freezing process was performed according to the design. The replacement of the tail brush was initiated when the frozen soil wall developed during freezing met the requirements for tail brush replacement. The artificial freezing technique using liquid nitrogen proved to be a reliable and time-effective option to facilitate the tail brush replacement under high pore-water pressure.

Enhanced CO2/N2 separation performance in HP-Cu-BTCs by modifying the open-metal sites and porosity using added templates

Ping Yang,Rujin Zhou,Youhua Zhang,Shui Cao,Dan Zhang,Hongbing Ji,Linhai Duan,Xiuhong Meng 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.3

HP-Cu-BTCs (CTAB), HP-Cu-BTC(N,N), HP-Cu-BTC(SDBS) series with open metal coordination site Cu(I), cage window sites, tunable porosity, high specific surface area, cavity, etc., were synthesized using cationic surfactant (cetyltrimethylammonium bromide, neutral organic amine, and an anionic surfactant as templates, respectively, A variety of techniques were used to analyze the materials before and after CO2 cycle adsorption at 303K. A high BET specific surface area (1,194.06 m2/g) and total pore volume (0.63 cm3/g) were found in the synthesized HP-Cu-BTC(NN). The synthesized HP-Cu-BTC(N,N) not only has high CO2 adsorption capacity (7.4293 mmol/g) but also good selectivity (37.20) for adsorption separation of CO2/N2. Besides, FT-IR spectroscopy, CO2-TPD curves and adsorption kinetic curve demonstrated that the adsorption mechanism of synthesized HP-Cu-BTC(N,N) was mainly attributable to physisorption and it could be regenerated at relatively low temperature. The mesoporous structure not only improves the uptake capacity but also improves the diffusion and mass transfer of CO2. At the same time, the CO2-TPD showed that the HP-Cu-BTCs may have two major adsorption sites. One is to absorb CO2 molecules through van der Waals forces. The other is the electrostatic interaction of the open Cu sites with CO2. Therefore, the CO2/N2 adsorption selectivity of HP-Cu-BTC(N,N) is significantly higher than that of conventional Cu-BTC. After five consecutive adsorption/desorption cycles, the adsorbents retained an excellent adsorption property. Thus, it is a very good adsorbent for the CO2 capture.