Vibration control of high-speed trains self-excitation under-chassis equipment by HSLDS vibration isolators

Yu Sun,Jinsong Zhou,Dao Gong,Wenjing Sun,Zhanghui Xia 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.1

To minimize the self-excitation effects of the equipment on the carbody, a high static and low dynamic stiffness (HSLDS) vibration isolator is proposed by connecting a negative stiffness unit and a positive linear stiffness spring in parallel. The nonlinear stiffness of the HSLDS isolator can be designed according to the needs of any target stiffness curve. A vibration test is applied to obtain the vibration acceleration of the under-chassis equipment. A rigid-flexible coupling multi-body dynamic model of a high-speed train is established which considers the elastic vibration of the carbody and the self-excitation of the under-chassis equipment based on the tested result. Different connection methods of the under-chassis equipment including rigid hanging, vibration isolation theory (VIT) hanging, dynamic vibration absorber (DVA) hanging and HSLDS hanging are applied and their effects on the carbody vibration and ride quality are investigated. The simulation results reveal that the proposed HSLDS vibration isolator can effectively isolate the self-excitation of the under-chassis equipment from the carbody and enhance the ride quality of the high-speed train.

Development of EST-SSRs from the ark shell (Scapharca broughtonii) transcriptome and their application in genetic analysis of four populations

Wenjing Wang,Biao Wu,Zhihong Liu,Liqing Zhou,Xiujun Sun,Jiteng Tian,Aiguo Yang 한국유전학회 2021 Genes & Genomics Vol.43 No.6

Background The ark shell (Scapharca broughtonii) is one of the most economically important mollusks in the Bohai Sea and Yellow Sea of China. In recent years, ark shells from the Korean population were introduced to China for seed propagation and culture. Objective To explore the impact of the introduction of Korean ark shell on the genetic diversity of native population in China. Methods Simple sequence repeat (SSR) is efective and widely used tool for genetic analysis. In this study, 180 EST-SSRs were selected and verifed by polymerase chain reaction and polyacrylamide gel electrophoresis. Subsequently, fve polymorphic EST-SSRs were screened and their primers were modifed by fuorescein for use in the genetic analysis of four populations. Results Genetic analysis showed that 361 alleles amplifed by fve SSR loci were detected in the four populations. The number of alleles for the fve SSRs ranged from 8 to 30, with a mean of 18.05 (standard deviation, SD=6.492). The efective number of alleles varied from 2.253 to 22.222, with a mean of 10.596 (SD=4.713). Observed heterozygosity and expected heterozygosity were 0.167–0.833 and 0.566–0.971, with average values of 0.520 (SD=0.177) and 0.891 (SD =0.062), respectively. Polymorphic information content ranged from 0.521 to 0.953, with a mean of 0.865 (SD=0.070). The pairwise genetic diferentiation coefcient (FST) of the four populations ranged from 0.0267 to 0.0477, showing low genetic diferentiation. The phylogenetic tree constructed by neighbor-joining method showed that the genetic distance between the Chinese Dalian native population and three Korean populations was relatively more far than that among those Korean populations. Conclusion The results indicated that the genetic structure of the Dalian wild population was less afected by the introduced Korean wild populations.

Shikonin ameliorates salivary gland damage and inflammation in a mouse model of Sjögren's syndrome by modulating MAPK signaling pathway

Wenjing Guo,Xin Wang,Chao Sun,Jian Wang,Tao Wang The Korean Society of Pharmacology 2023 The Korean Journal of Physiology & Pharmacology Vol.27 No.4

Sjögren syndrome (SS) is a systemic inflammatory autoimmune disease that involves exocrine glands. Shikonin is extracted from comfrey, which is conventionally used as an anti-tumor, antibacterial, and antiviral drug in China. However, the application of Shikonin in SS remains unreported. This study aimed to verify the potential functions of Shikonin in SS progression. Firstly, non-obese diabetic mice were used as the SS mouse model, with C57BL/6 mice serving as the healthy control. It was demonstrated that the salivary gland damage and inflammation were aggravated in the SS mouse model. Shikonin improved salivary gland function decline and injury in the SS mouse model. Moreover, Shikonin reduced inflammatory cytokines and immune infiltration in the SS mouse model. Further experiments discovered that Shikonin attenuated the MAPK signaling pathway in the SS mouse model. Lastly, inhibition of the MAPK signaling pathway combined with Shikonin treatment further alleviated the symptoms of SS. In conclusion, Shikonin ameliorated salivary gland damage and inflammation in a mouse model of SS by modulating the MAPK signaling pathway. Our findings indicate that Shikonin may be a useful drug for SS treatment.

Type I Lepra Reaction as the Presenting Sign of Histoid Leprosy

( Jingru Sun ),( Ping Tu ),( Shengguo Yi ),( Wenjing Fu ),( Yang Wang ) 대한피부과학회 2017 Annals of Dermatology Vol.29 No.5

Improved Adaptive Compensation of Variant Fighter With Multiple Faults via Extended Observer

Kaiyu Hu,Wenjing Sun,Zian Cheng 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.7

This research is devoted to devising a fault-tolerant control system to resolve the challenge of multi-fault automatic repair in variable-structure flight conditions of fighters. In the classical fighter system, the increment of the state parameter is used to represent the variable structure parameter. To illustrate the broad applicability of the following technique, Rudder and Sensor Gain Loss and Bias Faults are constructed. The Extended Observer is designed to simultaneously gauge faults, states, and disturbances. Furthermore, the harmonic functions is designed to quickly adapt to fighter configuration changes, time-varying disturbances, and to estimate all failures. Similar harmonic functions also appear in the design of fault self-healing algorithms, i.e., adaptive fault-tolerant controllers with variable-structure harmonic functions, simultaneously repairing gain loss and bias faults of rudder and sensors. Verification of the method’s effectiveness is achieved through semi-physical simulations, while the Lyapunov function function demonstrates the system’s stability.

Insights into chlorantraniliprole resistance of Chilo suppressalis: Expression profiles of ATP-binding cassette transporter genes in strains ranging from low- to high-level resistance

Peng Yingchuan,Zhao Jun,Sun Yang,Wan Peng,Hu Yanyue,Luo Guanghua,Qin Wenjing,Huang Shuijin 한국응용곤충학회 2021 Journal of Asia-Pacific Entomology Vol.24 No.2

The ATP-binding cassette (ABC) proteins are involved in trans-cellular transport of substances at inverse con centrations. After ABC genes were discovered to be involved in multidrug resistance in humans, increased attention was paid to the role of insect ABC genes in pesticide resistance. Chilo suppressalis, the most important Lepidopteran pest in rice production, has developed resistance to the insecticide chlorantraniliprole. However, few of the ABC genes that contribute to chlorantraniliprole resistance have been studied. Here, 47 genes encoding ABC transporters were identified, including five CsABCA, seven CsABCB, ten CsABCC, two CsABCD, one CsABCE, three CsABCF, 15 CsABCG, and four CsABCH genes. The expression profiles of these transporter genes were determined in three chlorantraniliprole-resistant strains: R1, R2, and HR, with a resistance ratio of 38.8, 110.4, and 249.6, respectively. CsABCA1, -D2, and -H2 were up-regulated in all resistant strains, and the trend in the transcript levels of all 47 CsABC genes fitted a descending curve from R1 to HR. Unexpectedly, CsABCF1, -G11 and -G12 were significantly down-regulated in HR. These results provide new insights into the roles of ABC transporters in chlorantraniliprole resistance in C. suppressalis.

Passive control of railway vehicle car body flexural vibration by means of underframe dampers

Dao Gong,Jinsong Zhou,Wenjing Sun 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.2

To suppress vertical flexural vibration of a railway vehicle car body, a new passive control method by mounting dampers on the longitudinal beams of the car body underframe is proposed. The method is firstly studied by an Euler-Bernoulli beam model using Green’s functions, then it is further verified by a nonlinear dynamic model of the vehicle. Results show that the car body flexural vibration can be noticeably reduced by this method. It is better to mount the damper near the car body centre. The higher damping coefficient of the damper, the more effective in decreasing the car body first vertical bending vibration. The higher the rigidity of the damper bracket and rubber bush, the better performance of the damper. It is found that when mounting six dampers at proper positions, the damping coefficient of each damper is 1.33×10 7 N·s/m, even if the first vertical bending frequency of the studied car body is only 7.2 Hz, a very good ride quality will be achieved when the vehicle runs at 250 km/h.

A High-Efficiency Bidirectional AC/DC Topology for V2G Applications

Su, Mei,Li, Hua,Sun, Yao,Xiong, Wenjing The Korean Institute of Power Electronics 2014 JOURNAL OF POWER ELECTRONICS Vol.14 No.5

This paper proposes a single-phase bidirectional AC/DC converter topology applied in V2G systems, which consists of an inverter and a bidirectional non-inverting buck-boost converter. This topology can operate in four modes: buck charging, boost charging, buck discharging and boost discharging with high input current quality and unity input power factor. The inverter switches at line frequency, which is different from conventional voltage source inverters. A bidirectional buck-boost converter is utilized to adapt to a wider charging voltage range. The modulation and control strategy is introduced in detail, and the switching patterns are optimized to reduce the current ripple. In addition, the semiconductor losses are analyzed. Simulation and experimental results demonstrate the validity and effectiveness of the proposed topology.

Black box-assisted fine-grained hierarchical access control scheme for epidemiological survey data

Xueyan Liu,Ruirui Sun,Linpeng Li,Wenjing Li,Tao Liu 한국인터넷정보학회 2023 KSII Transactions on Internet and Information Syst Vol.17 No.9

Epidemiological survey is an important means for the prevention and control of infectious diseases. Due to the particularity of the epidemic survey, 1) epidemiological survey in epidemic prevention and control has a wide range of people involved, a large number of data collected, strong requirements for information disclosure and high timeliness of data processing; 2) the epidemiological survey data need to be disclosed at different institutions and the use of data has different permission requirements. As a result, it easily causes personal privacy disclosure. Therefore, traditional access control technologies are unsuitable for the privacy protection of epidemiological survey data. In view of these situations, we propose a black box-assisted fine-grained hierarchical access control scheme for epidemiological survey data. Firstly, a black box-assisted multi-attribute authority management mechanism without a trusted center is established to avoid authority deception. Meanwhile, the establishment of a master key-free system not only reduces the storage load but also prevents the risk of master key disclosure. Secondly, a sensitivity classification method is proposed according to the confidentiality degree of the institution to which the data belong and the importance of the data properties to set fine-grained access permission. Thirdly, a hierarchical authorization algorithm combined with data sensitivity and hierarchical attribute-based encryption (ABE) technology is proposed to achieve hierarchical access control of epidemiological survey data. Efficiency analysis and experiments show that the scheme meets the security requirements of privacy protection and key management in epidemiological survey.

Study on pharmacokinetics and tissue distribution of single dose oral tryptanthrin in Kunming mice by validated reversed-phase high-performance liquid chromatography with ultraviolet detection

Xiaoyan Zhang,Jie Xia,Wenjing Zhang,Yao Luo,Wenbo Sun,Wei Zhou 한국한의학연구원 2017 Integrative Medicine Research Vol.6 No.3

Background: Tryptanthrin is a major active constituent of several Chinese herbal plants, such as Isatidis radix. Tryptanthrin had been demonstrated to have several beneficial pharmacological effects in vitro for human diseases, including antitumor, anti-inflammatory and antibacteria activities. In contrast to the extensive in vitro investigations, the in vivo disposition process of tryptanthrin was explored limitedly. Methods: In this study, the pharmacokinetics (PK) and tissue distribution of tryptanthrin in Kunming mice following a single oral dose of 80 mg/kg tryptanthrin were investigated for the first time. Mouse plasma, liver, heart, spleen, lung, kidney and brain were collected and analyzed using a validated reversed-phase high-performance liquid chromatography with ultraviolet detection (RP-HPLC–UV) method after biological sample preparation by a simple liquid–liquid extraction. Results: The chromatographic analysis was performed on a Diamonsil C18 column (5 μm, 250 mm × 4.6 mm) and ultraviolet detection was set at a wavelength of 251 nm. The analysis was achieved with a mobile phase of methanol (A) and water (B) (60:40, v/v) at a flow rate of 1.0 mL/min. The method was linear over the concentration range of 4.0–400.0 μg/mL with a lower limit of quantification of 0.10–0.30 μg/mL. Inter- and intraday precisions (relative standard deviations %) were all within 2.93%. Recoveries of tryptanthrin were more than 86.44%. Maximal tryptanthrin concentrations in plasma and tissues of mice were reached within 2.5 hours. The actual highest concentration (Cmax) in mouse plasma was 3.13 μg/mL, the area under the curve (AUC0–t) was 9.38 h μg/mL, and the terminal half-life was 2.27 hours. The volume of distribution was 343.89 mL, the clearance rate was 204.58 mL/h, and the PK of tryptanthrin in mice after oral administration was fit to 2 compartment 1 st Order. After oral dosing of tryptanthrin to Kunming mice, the analyte was well distributed to the plasma and main tissues. Cmax was found in the liver with a mean value of 3.54 μg/g, followed by that in the kidney, lung, spleen, heart, and brain. Conclusion: In this study, a validated RP-HPLC–UV method was developed and successfully applied to PK and tissue distribution of oral tryptanthrin in mice. We confirmed that tryptanthrin was closely related and targeted to plasma, liver, kidney, and lung. These results indicate that tryptanthrin will have a good clinical application in the liver, kidney, or lung. The clinical use of tryptanthrin should focus on its pharmacodynamics and safety study in these tissues.