ANALYSIS AND OPTIMIZATION OF AN EXPANDING ENERGY ABSORBER WITH VARIABLE THICKNESS DISTRIBUTION TUBE UNDER AXIAL DYNAMIC LOADING

Yanqing Wang,Shiming Wang,Lin Hou,Yong Peng 한국자동차공학회 2022 International journal of automotive technology Vol.23 No.6

An expanding energy absorber with variable thickness distribution tube is proposed and studied in this work. At first, a uniform thickness tube structure finite element (FE) model was developed and then verified by the results of an impact test. The parametric study found that outer obliquity angle β and inner obliquity angle γ have positive influence on initial peak force (Fp). While as axial distribution ratio l less than 0.1, the l has significant positive effect on Fp. The non-monotonicity of specific energy absorption (SEA) with design parameters of β and γ was found. Increasing the parameter l could obviously improve the SEA. To obtain the optimal design, an integrated optimization methodology was applied. The Pareto fronts show that there is a lot of room for improvement of original design. The optimal compromising solution increased the SEA by 12.60 % with Fp decreased by 14.24 kN comparing with that of original design. At last, the optimization result were verified. The study stated that the proposed variable thickness distribution tube of expanding energy absorber is conducive to improving the crashworthiness of rail vehicles.

Institute-industry interoperation model: an industry-oriented engineering education strategy in China

Yanqing Wang,Zhongying Qi,Ziru Li,Lijie Zhang 서울대학교 교육연구소 2011 Asia Pacific Education Review Vol.12 No.4

Engineering education has been well implemented in the majority of developed countries such as the USA, Germany, and the United Kingdom so that the gap between engineering science and engineering practice is greatly bridged. However, in China, the gap still exists, and some attempts by Chinese government, even though having made obvious progress, are not very satisfactory yet. Thus, the research on feasible engineering education strategy has drawn our pressing concerns. Based on the analyses of participants' motivation and value chain, an evolutionary model of institute-industry interoperation is proposed, which includes isolated stage, orienting stage, interacting stage, interoperating stage, and convergence stage. The case of one school of software in China is analyzed to support and clarify this model. This institute-industry interoperation model is showing considerable vitality in the development of engineering education, and it can present reference value not only to China but to other countries as well.

PPV/PVA/ZnO nanocomposite prepared by complex precursor method and its photovoltaic application

Mingqing Wang,Yanqing Lian,Xiaogong Wang 한국물리학회 2009 Current Applied Physics Vol.9 No.1

In this article, we describe a new method to prepare a ZnO and conjugated polymer nanocomposite and its application in bulk-heterojunction solar cells. The composite was composed of zinc oxide (ZnO) and poly(phenylene vinylene)/poly(vinyl alcohol) (PPV/PVA). For the preparation, the composite was prepared first through the complex reaction between Zn2+ ion and –OH of the PVA–PPV precursor by simply mixing zinc salts and a PVA–PPV precursor aqueous solution at 70℃. By addition of a concentrated aqueous ammonia into the system, highly regular Zn(OH)2 nanodots were formed and dispersed in the PVA/PPV precusor mixed solution. The PVA/PPV precursor can well bind Zn2+ ion through complex interaction, so act as a template to direct the distribution of ZnO in the process. The nanocomposite films were finally obtained by solution casting and subsequently treated by heating samples at 160 ℃ for 6 h. TEM observations showed that ZnO nanodots uniformly dispersed in PVA–PPV mixtures. The resulting nanocomposite films possess a large interfacial area between the electron donor and acceptor of the bulk-heterojunction. Improved charge seperation and collection are evidenced by the large photoluminescence intensity difference between pure PPV and composites films, which result in the increase in both open circuit voltage and short circuit current of the hybrid solar cells. In this article, we describe a new method to prepare a ZnO and conjugated polymer nanocomposite and its application in bulk-heterojunction solar cells. The composite was composed of zinc oxide (ZnO) and poly(phenylene vinylene)/poly(vinyl alcohol) (PPV/PVA). For the preparation, the composite was prepared first through the complex reaction between Zn2+ ion and –OH of the PVA–PPV precursor by simply mixing zinc salts and a PVA–PPV precursor aqueous solution at 70℃. By addition of a concentrated aqueous ammonia into the system, highly regular Zn(OH)2 nanodots were formed and dispersed in the PVA/PPV precusor mixed solution. The PVA/PPV precursor can well bind Zn2+ ion through complex interaction, so act as a template to direct the distribution of ZnO in the process. The nanocomposite films were finally obtained by solution casting and subsequently treated by heating samples at 160 ℃ for 6 h. TEM observations showed that ZnO nanodots uniformly dispersed in PVA–PPV mixtures. The resulting nanocomposite films possess a large interfacial area between the electron donor and acceptor of the bulk-heterojunction. Improved charge seperation and collection are evidenced by the large photoluminescence intensity difference between pure PPV and composites films, which result in the increase in both open circuit voltage and short circuit current of the hybrid solar cells.

Efficacy of nano-drugs in muscle injury rehabilitation and fatigue relief

Zicheng Wang,Yanqing Liu,Haibo Wang,Dai Liu,Niuniu Yang,Mengying Lv Techno-Press 2023 Advances in nano research Vol.14 No.1

Gold nanoparticles have recognized a promising drug carriers in many diseases. These nanoparticles could carry anti-inflammatory drugs in the case of muscle injury and for fatigue relief. On the other hand, specific surface of this kind of nanoparticles could be critical in amount of drug they could carry. Therefore, in this study, we explore different methodology and influencing parameters on the specific surface of gold nanoparticles. After specifying the main parameters, different machine learning and artificial neural network are adopted to model the effects of different parameters. Furthermore, response surface methodology is utilized to obtain a quadrilateral relationship between different parameters and specific surface. The results indicate that concentration of the gold salt solution is the most important parameter in increasing the size of gold nanoparticle and, as a consequence, increasing specific surface. Moreover, the ability of gold nanoparticles in prolonging retention of the drugs is discussed in detail.

Statics variation analysis due to spatially moving of a full ocean depth autonomous underwater vehicle

Yanqing Jiang,Ye Li,Yumin Su,Jian Cao,Yueming Li,Youkang Wang,Yeyi Sun 대한조선학회 2019 International Journal of Naval Architecture and Oc Vol.11 No.1

Changes in gravity and buoyancy of a Full Ocean Depth Autonomous Underwater Vehicle (FOD-AUV) during its descending and ascending process must be considered very carefully compared with a Human Occupied Vehicle (HOV) or a Remotely Pperated Vehicle (ROV) whose activities rely on human decision. We firstly designed a two-step weight dropping pattern to achieve a high descending and ascending efficiency and a gravity-buoyancy balance at designed depth. The static equations showed that gravity acceleration, seawater density and displacement are three key aspects affecting the balance. Secondly, we try our best to analysis the gravity and buoyancy changing according to the previous known scientific information, such as anomaly of gravity acceleration, changing of seawater states. Finally, we drew conclusion that gravity changes little (no more than 0.1kgf, it is impossible to give a accurate value). A density-depth relationship at the Challenger Deep was acquired and the displacement changing of the FOD-AUV was calculated preciously.

Antifouling Activity towards Mussel by Small-Molecule Compounds from a Strain of Vibrio alginolyticus Bacterium Associated with Sea Anemone Haliplanella sp.

( Xiang Wang ),( Yanqiu Huang ),( Yanqing Sheng ),( Pei Su ),( Yan Qiu ),( Caihuan Ke ),( Danqing Feng ) 한국미생물 · 생명공학회 2017 Journal of microbiology and biotechnology Vol.27 No.3

Mussels are major fouling organisms causing serious technical and economic problems. In this study, antifouling activity towards mussel was found in three compounds isolated from a marine bacterium associated with the sea anemone Haliplanella sp. This bacterial strain, called PE2, was identified as Vibrio alginolyticus using morphology, biochemical tests, and phylogenetic analysis based on sequences of 16S rRNA and four housekeeping genes (rpoD, gyrB, rctB, and toxR). Three small-molecule compounds (indole, 3-formylindole, and cyclo (Pro-Leu)) were purified from the ethyl acetate extract of V. alginolyticus PE2 using column chromatography techniques. They all significantly inhibited byssal thread production of the green mussel Perna viridis, with EC₅₀ values of 24.45 μg/ml for indole, 50.07 μg/ml for 3-formylindole, and 49.24 μg/ml for cyclo (Pro-Leu). Previous research on the antifouling activity of metabolites from marine bacteria towards mussels is scarce. Indole, 3-formylindole and cyclo (Pro-Leu) also exhibited antifouling activity against settlement of the barnacle Balanus albicostatus (EC₅₀ values of 8.84, 0.43, and 11.35 μg/ml, respectively) and the marine bacterium Pseudomonas sp. (EC₅₀ values of 42.68, 69.68, and 39.05 μg/ml, respectively). These results suggested that the three compounds are potentially useful for environmentally friendly mussel control and/or the development of new antifouling additives that are effective against several biofoulers.

Effects of echinomycin on endothelin-2 expression and ovulation in immature rats primed with gonadotropins

Zhengchao Wang,Yanqing Wu,Liyun Chen,Qianping Luo,Jisen Zhang,Jiajie Chen,Zimiao Luo,Xiaohong Huang,Yong Cheng,Zhenghong Zhang 생화학분자생물학회 2012 Experimental and molecular medicine Vol.44 No.10

Echinomycin is a small-molecule inhibitor of hypoxia- inducible factor-1 DNA-binding activity, which plays a crucial role in ovarian ovulation in mammalians. The present study was designed to test the hypothesis that hypoxia-inducible factor (HIF)-1α-mediated endothelin (ET)-2 expressions contributed to ovarian ovulation in response to human chorionic gonadotropin (hCG) during gonadotropin-induced superuvulation. By real-time RT-PCR analysis, ET-2 mRNA level was found to significantly decrease in the ovaries after chinomycin treatment, while HIF-1α mRNA and protein expression was not obviously changed. Further analysis also showed that these changes of ET-2 mRNA were consistent with HIF-1 activity in the ovaires, which is similar with HIF-1α and ET-2 expression in the granulosa cells with gonadotropin and echinomycin treatments. The results of HIF-1α and ET-2 expression in the granulosa cells transfected with cis-element oligodeoxynucleotide (dsODN) under gonadotropin treatment further indicated HIF-1α directly mediated the transcriptional activation of ET-2 during gonadotropin- induced superuvulation. Taken together, these results demonstrated that HIF-1α-mediated ET-2 transcriptional activation is one of the important mechanisms regulating gonadotropin-induced mammalian ovulatory precess in vivo. Echinomycin is a small-molecule inhibitor of hypoxia- inducible factor-1 DNA-binding activity, which plays a crucial role in ovarian ovulation in mammalians. The present study was designed to test the hypothesis that hypoxia-inducible factor (HIF)-1α-mediated endothelin (ET)-2 expressions contributed to ovarian ovulation in response to human chorionic gonadotropin (hCG) during gonadotropin-induced superuvulation. By real-time RT-PCR analysis, ET-2 mRNA level was found to significantly decrease in the ovaries after chinomycin treatment, while HIF-1α mRNA and protein expression was not obviously changed. Further analysis also showed that these changes of ET-2 mRNA were consistent with HIF-1 activity in the ovaires, which is similar with HIF-1α and ET-2 expression in the granulosa cells with gonadotropin and echinomycin treatments. The results of HIF-1α and ET-2 expression in the granulosa cells transfected with cis-element oligodeoxynucleotide (dsODN) under gonadotropin treatment further indicated HIF-1α directly mediated the transcriptional activation of ET-2 during gonadotropin- induced superuvulation. Taken together, these results demonstrated that HIF-1α-mediated ET-2 transcriptional activation is one of the important mechanisms regulating gonadotropin-induced mammalian ovulatory precess in vivo.

Classifier Combination Based Source Identification for Cell Phone Images

( Bo Wang ),( Yue Tan ),( Meijuan Zhao ),( Yanqing Guo ),( Xiangwei Kong ) 한국인터넷정보학회 2015 KSII Transactions on Internet and Information Syst Vol.9 No.12

Rapid popularization of smart cell phone equipped with camera has led to a number of new legal and criminal problems related to multimedia such as digital image, which makes cell phone source identification an important branch of digital image forensics. This paper proposes a classifier combination based source identification strategy for cell phone images. To identify the outlier cell phone models of the training sets in multi-class classifier, a one-class classifier is orderly used in the framework. Feature vectors including color filter array (CFA) interpolation coefficients estimation and multi-feature fusion is employed to verify the effectiveness of the classifier combination strategy. Experimental results demonstrate that for different feature sets, our method presents high accuracy of source identification both for the cell phone in the training sets and the outliers.

Statics variation analysis due to spatially moving of a full ocean depth autonomous underwater vehicle

Jiang, Yanqing,Li, Ye,Su, Yumin,Cao, Jian,Li, Yueming,Wang, Youkang,Sun, Yeyi The Society of Naval Architects of Korea 2019 International Journal of Naval Architecture and Oc Vol.11 No.1

Changes in gravity and buoyancy of a Full Ocean Depth Autonomous Underwater Vehicle (FOD-AUV) during its descending and ascending process must be considered very carefully compared with a Human Occupied Vehicle (HOV) or a Remotely Pperated Vehicle (ROV) whose activities rely on human decision. We firstly designed a two-step weight dropping pattern to achieve a high descending and ascending efficiency and a gravity-buoyancy balance at designed depth. The static equations showed that gravity acceleration, seawater density and displacement are three key aspects affecting the balance. Secondly, we try our best to analysis the gravity and buoyancy changing according to the previous known scientific information, such as anomaly of gravity acceleration, changing of seawater states. Finally, we drew conclusion that gravity changes little (no more than 0.1kgf, it is impossible to give a accurate value). A density-depth relationship at the Challenger Deep was acquired and the displacement changing of the FOD-AUV was calculated preciously.

Mechanical properties of reinforced-concrete rocking columns based on damage resistance

Chunyang Zhu,Yanqing Cui,Li Sun,Shiwei Du,Xinhui Wang,Haochuan Yu 국제구조공학회 2021 Structural Engineering and Mechanics, An Int'l Jou Vol.80 No.6

The objective of seismic resilience is to maintain or rapidly restore the function of a building after an earthquake. An efficient tilt mechanism at the member level is crucial for the restoration of the main structure function; however, the damage resistance of the members should be the main focus. In this study, through a comparison with the classical Flamant theory of local loading in the elastic half-space, an elastomechanical solution for the axial-stress distribution of a reinforced-concrete (RC) rocking column was derived. Furthermore, assuming that the lateral displacement of the rocking column is determined by the contact surface rotation angle of the column end and bending and shear deformation of the column body, the load–lateral displacement mechanical model of the RC rocking column was established and validated through a comparison with finiteelement simulation results. The axial-compression ratio and column-end strength were analyzed, and the results indicated that on the premise of column damage resistance, simply increasing the axial-compression ratio increases the lateral loading capacity of the column but is ineffective for improving the lateral-displacement capacity. The lateral loading and displacement of the column are significantly improved as the strength of the column end material increases. Therefore, it is feasible to improve the working performance of RC rocking columns via local reinforcement of the column end.