CONTROL OF DPPS IN VEHICLE USING FEED-FORWARD DECOUPLING

Hao Chen,Chao Wang,Xi Chen,Xiaomin Lian 한국자동차공학회 2020 International journal of automotive technology Vol.21 No.4

To solve the contradiction between interior space and demand for electricity of vehicle, this paper brings forward the dual-generator parallel power system (DPPS). However, it is difficult to control the voltage and balance output power between two different types of generators simultaneously. Thus, feed-forward control has been developed to accomplish decoupling the target current of two generators, and proportional-integral differential (PID) controllers, with its stability being discussed, are also designed to track desired values. Based on structural analysis of DDPS, the simulation model is built in MATLAB/Simulink to prove the preliminary feasibility of the scheme and provide a reference for the real system. Finally, bench tests have been performed involving the dynamic change in the reference voltage, engine rotating speed, and load, to verify the effectiveness of the proposed method. The results show that it can achieve synchronous control of the output voltage and current ratio of two generators in DPPS.

Finite element analysis for the seismic performance of steel frame-tube structures with replaceable shear links

Ming Lian,Hao Zhang,Qianqian Cheng,Mingzhou Su 국제구조공학회 2019 Steel and Composite Structures, An International J Vol.30 No.4

In steel frame-tube structures (SFTSs) the application of flexural beam is not suitable for the beam with span-to-depth ratio lower than five because the plastic hinges at beam-ends can not be developed properly. This can lead to lower ductility and energy dissipation capacity of the SFTS. To address this problem, a replaceable shear link, acting as a ductile fuse at the mid length of deep beams, is proposed. SFTS with replaceable shear links (SFTS-RSLs) dissipate seismic energy through shear deformation of the link. In order to evaluate this proposal, buildings were designed to compare the seismic performance of SFTS-RSLs and SFTSs. Several sub-structures were selected from the design buildings and finite element models (FEMs) were established to study their hysteretic behavior. Static pushover and dynamic analyses were undertaken in comparing seismic performance of the FEMs for each building. The results indicated that the SFTS-RSL and SFTS had similar initial lateral stiffness. Compared with SFTS, SFTS-RSL had lower yield strength and maximum strength, but higher ductility and energy dissipation capacity. During earthquakes, SFTS-RSL had lower interstory drift, maximum base shear force and story shear force compared with the SFTS. Placing a shear link at the beam mid-span did not increase shear lag effects for the structure. The SFTS-RSL concentrates plasticity on the shear link. Other structural components remain elastic during seismic loading. It is expected that the SFTS-RSL will be a reliable dual resistant system. It offers the benefit of being able to repair the structure by replacing damaged shear links after earthquakes.

Seismic performance of high-strength steel framed-tube structures with bolted web-connected replaceable shear links

Ming Lian,Qianqian Cheng,Binlin Guan,Hao Zhang,Mingzhou Su 국제구조공학회 2020 Steel and Composite Structures, An International J Vol.37 No.3

In steel framed-tube structures (SFTSs), the plastic hinges at beam-ends cannot be adequately improved because of the large cross sections of spandrel beams, which results in the lower ductility and energy dissipation capacities of traditional SFTSs. To address this drawback, high-strength steel fabricated SFTSs with bolted web-connected replaceable shear links (HSFTS-SLs) have been proposed. In this system, shear links use conventional steel and are placed in the middle of the deep spandrel beams to act as energy dissipative components. In this study, 2/3-scaled HSFTS-SL specimens were fabricated, and cyclic loading tests were carried out to study the seismic performance of both specimens. The finite element models (FEMs) of the two specimens were established and the numerical results were compared with the test results. The results showed that the specimens had good ductility and energy dissipation capacities due to the reliable deformation capacities. The specimens presented the expected failure modes. Using a shorter shear link can provide a higher load-carrying capacity and initial elastic lateral stiffness but induces lower ductility and energy dissipation capacity in HSFTS-SLs. The performance of the specimens was comparable to that of the original sub-structure specimens after replacing shear links. Additionally, the expected post-earthquake recoverability and resilience of the structures could be achieved by replacing shear links. The acceptable residual interstory drift that allows for easy replacement of the bolted web-connected shear link was 0.23%. The bolted web-connected shear links had reliable hysteretic responses and deformation capacities. The connection rotation had a notable contribution to total link rotation. The results of the numerical analysis run for the proposed FEMs were consistent with the test results. It showed that the proposed FEMs could be used to investigate the seismic performance of the HSFTS-SL.

EFFECT OF CARBONIZATION TEMPERATURE ON DIELECTRIC AND MICROWAVE ABSORBING PROPERTIES OF COBALT DOPED MESOPOROUS CARBON COMPOSITES

QIAN LIAN,HONGJING WU,LIUDING WANG,HAO WU 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2014 NANO Vol.9 No.3

Co doped mesoporous carbon composites (MC – Co) have been synthesized at di®erent carbon-ization temperatures via evaporation-induced multicomponent co-assembly strategy. Thenanostructures and chemical compositions of MC – Co composites were characterized by trans-mission electron microscope (TEM), scanning electron microscope (SEM) and X-ray di®ractionanalysis (XRD), etc. Their electromagnetic and microwave absorption properties were investi-gated in the frequency ranging from 2 GHz to 18 GHz. By the measurement of electromagneticparameters and theoretical simulation of re°ection loss (RL), the results showed that the mini-mum RL value of the optimum composite MC – Co-800 reached up to ? 41.9 dB at 13.5 GHz with athickness of only 1.80 mm, and the e®ective absorption bandwidth ( < ? 10 dB) is 4.4 GHz (from11.4 GHz to 15.8 GHz). This work demonstrated that the optimum carbonization temperature ofthe obtained composites is 800?C, which is critical to its electromagnetic properties. The excellentmicrowave absorption properties can be attributed to dielectric loss, Ohmic loss, and charac-teristic impedance matching. Therefore, the as-synthesized composites could be acted as a can-didate of microwave absorber, especially for the light weight demand.

Numerical study of the seismic behavior of steel frame-tube structures with bolted web-connected replaceable shear links

Ming Lian,Qianqian Cheng,Hao Zhang,Mingzhou Su 국제구조공학회 2020 Steel and Composite Structures, An International J Vol.35 No.3

Beams of steel frame-tube structures (SFTSs) typically have span-to-depth ratios of less than five. This makes a flexural beam unsuitable for such an application because the plastic hinges at the beam-ends cannot be adequately developed. This leads to lower ductility and energy dissipation capacities of SFTSs. To address this, SFTSs with bolted web-connected replaceable shear links (SFTS-BWSLs) are proposed. In this structural system, a web-connected replaceable shear link with a back-to-back double channel section is placed at the mid-length of the deep beam to act as a ductile fuse. This allows energy from earthquakes to be dissipated through link shear deformation. SFTS and SFTS-BWSL buildings were examined in this study. Several sub-structures were selected from each designed building and finite element models were established to study their respective hysteretic performance. The seismic behavior of each designed building was observed through static and dynamic analyses. The results indicate that the SFTS-BWSL and SFTS have similar initial lateral stiffness and shear leg properties. The SFTS-BWSL had lower strength, but higher ductility and energy dissipation capacities. Compared to the SFTS, the SFTS-BWSL had lower interstory drift, base shear force, and story shear force during earthquakes. This design approach could concentrate plasticity on the shear link while maintaining the residual interstory drift at less than 0.5%. The SFTS-BWSL is a reliable resistant system that can be repaired by replacing shear links damaged due to earthquakes.

Expression, Purification and Properties of Shikimate Dehydrogenase from Mycobacterium Tuberculosis

Xue Lian Zhang,Shun Bao Zhang,Fang Hao,Xu Hui Lai,Hai Dong Yu,Yi Shu Huang,Hong Hai Wang 한국생활환경학회 2005 BMB Reports Vol.38 No.5

Effects of maternal dietary energy restriction on laying performance, embryonic development, and lipid metabolism in broilers

Sun, Hao,Chen, Zhihui,Ma, Chengzhan,Lian, Lina,Zhao, Zeyu,Niu, Shupeng,Xu, Liangmei,Sun, Jinhua Asian Australasian Association of Animal Productio 2022 Animal Bioscience Vol.35 No.5

Objective: The objective of this study was to investigate the effects of different degrees of maternal dietary energy restriction on lipid deposition in embryonic tissues during the medium laying period (37 to 39 weeks) in Arbor Acres (AA) broiler breeders. Methods: A single factor design was adopted, and 400 AA broiler breeders (20 weeks of age) with a similar weight were randomly allocated into four groups. The birds in the control group were fed a corn-soybean meal based diet, and those in trial groups were fed diets with 80%, 70%, and 50% energy levels of the basal diet. Incubated eggs from the medium laying period were collected. Samples of developing embryos at various stages were prepared for composition analysis. Results: The embryo weight in the 80% energy group was higher than those of the other groups on embryonic day (E) 13, but at 21 E, they were significantly decreased with decreasing energy intake of the broiler breeders (p<0.05). Additionally, the levels of crude fat in tissues in the restriction groups were significantly decreased (p<0.05). The long axis and area of adipocytes in breast muscle, thigh muscle and the liver were significantly decreased (p<0.05) at 21 E in the 80%, 70%, and 50% energy groups. Conclusion: The effects of the 80% maternal dietary energy restriction energy affects egg production performance, egg quality, and nutrient deposition in egg weights, which then directly impacts on the developmental process of embryos, especially on fat utilization and deposition.

Traffic-load-induced dynamic stress accumulation in subgrade and subsoil using small scale model tests

Tang, Lian Sheng,Chen, Hao Kun,Sun, Yin Lei,Zhang, Qing Hua,Liao, Hua Rong Techno-Press 2018 Geomechanics & engineering Vol.16 No.2

Under repeated loading, the residual stresses within the subgrade and subsoil can accelerate the deformation of the road structures. In this paper, a series of laboratory cyclic loading model tests and small-scale model tests were conducted to investigate the dynamic stress response within soils under different loading conditions. The experimental results showed that a dynamic stress accumulation effect occurred if the soil showed cumulative deformation: (1) the residual stress increased and accumulated with an increasing number of loading cycles, and (2) the residual stress was superimposed on the stress response of the subsequent loading cycles, inducing a greater peak stress response. There are two conditions that must be met for the dynamic stress accumulation effect to occur. A threshold state exists only if the external load exceeds the cyclic threshold stress. Then, the stress accumulation effect occurs. A higher loading frequency results in a higher rate of increase for the residual stress. In addition to the superposition of the increasing residual stress, soil densification might contribute to the increasing peak stress during cyclic loading. An increase in soil stiffness and a decrease in dissipative energy induce a greater stress transmission within the material.

Early Diagnosis and Management of Cerebral Venous Flow Obstruction Secondary to Transsinus Fracture after Traumatic Brain Injury

Wen-hao Wang,Jun-ming Lin,Fei Luo,Lian-shui Hu,Jun Li,Wei Huang 대한신경과학회 2013 Journal of Clinical Neurology Vol.9 No.4

Background and Purpose Cerebral venous flow obstruction (CVFO) is a fatal complication of traumatic brain injury. To compare the outcomes of patients with CVFO secondary to traumatic-brain-injury-induced transsinus fracture who were diagnosed early versus those diagnosed late in the therapeutic course. Methods In total, 403 patients with transsinus fracture were reviewed retrospectively. The patients were divided into an early-diagnosis group (n=338) and a delayed-diagnosis group (n=65).The patients submitted to 2D time-of-flight magnetic resonance venography (2D-TOF MRV) and/or CT venography (CTV), depending upon the findings of intracranial pressure monitoring, in order to identify potentially complicated CVFO. These examinations took place within 3 days of the onset of malignant intracranial hypertension symptoms in the early-diagnosis group, and after an average of 7 days in the delayed-diagnosis group. Once diagnosed, patients received intravenous thrombolytic therapy with low-dose urokinase. Patients with massive transsinus epidural hematoma, depressed fracture, or cerebral hernia were treated surgically to relieve the compression and repair any damage to the venous sinuses. Results Cerebral venous flow obstruction was much more severe in the delayed-diagnosis group than in the early-diagnosis group (p<0.001), and hence patients in the former group were given a higher dose of urokinase (p<0.001) for thrombolytic therapy. They were also significantly more likely to need surgery (48.1% vs. 20.6%, p=0.003) and had a higher mortality rate (37.0%vs. 4.1%, p<0.001). However, patients in both groups experienced a similarly favorable prognosis, not only with regard to functional outcome but also with respect to neuroradiological improvement, as evaluated by 2D-TOF MRV/CTV at the final follow-up (p=0.218). Conclusions Delayed diagnosis can result in increased risk of surgery and death in the acute phase. Thrombolytic therapy with low-dose urokinase resulted in promising improvements in both functional and neuroradiological outcomes in all of the patients in this study, regardless of the time to diagnosis. J Clin Neurol 2013;9:259-268

Regulatory effect of peroxiredoxin 1 (PRDX1) on doxorubicin-induced apoptosis in triple negative breast cancer cells

Han Ying-Hao,Lian Xu-Dong,Lee Seung-Jae,Li Wei-Long,Sun Hu-Nan,Jin Mei-Hua,Kwon Taeho 한국응용생명화학회 2022 Applied Biological Chemistry (Appl Biol Chem) Vol.65 No.5

Patients with triple negative breast cancer (TNBC) lack the estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2; thus, conventional hormone and targeted therapies have minimal effect on them. Therefore, clinical treatment of TNBC is still based on chemotherapy and supplemented by other methods. Doxorubicin (DOX), a common drug used in TNBC chemotherapy, has high affinity for cardiolipin, and the nematosomes are rich in cardiolipin; therefore, DOX has high mitochondria-targeting ability. DOX accumulates and plunders the electrons of nicotinamide adenine dinucleotide phosphate (NADPH) and cytochrome C in mitochondria to produce semiquinone DOX. Under the action of oxygen molecules, semiquinone DOX is reduced to DOX and reactive oxygen species (ROS) are generated. The accumulation of ROS can cause mitochondrial dysfunction and lead to mitochondrial dependent apoptosis. Bioinformatic analysis of samples from TNBC patients revealed that peroxiredoxin 1 (PRDX1) was highly expressed in TNBC tissues, and the poor prognosis of patients with high PRDX1 expression was considerably increased. Previous studies determined that DOX can upregulate the expression of the PRDX1 protein in the human TNBC cell line (MDA-MB-231). Thus, we speculate that PRDX1 plays an important role in the process of DOX-induced TNBC cell apoptosis. In this study, we aimed to explore the role of PRDX1 in the process of DOX-induced TNBC cell apoptosis. We found that PRDX1 deletion increased the sensitivity of MDA-MB-231 cells to DOX, which was mainly due to mitochondrial oxidative stress caused by intracellular ROS accumulation, leading to mitochondriadependent apoptosis. Deletion of PRDX1 promotes the PI3K/Akt signaling pathway to mediate the expression of GSK3β. Gsk3β is an upstream signal of mitochondria-dependent apoptosis, and is also an important target of ROS. PRDX1 participates in adriamycin-induced apoptosis of TNBC cells by regulating the expression level of GSK3β. Our findings present new insights to treat breast cancer and TNBC, outlines the clinical use of DOX, and provides a basic theory to develop PRDX1 gene function.