A Study on the Optimization of Anisotropic Conductive Films for Sn-3Ag-0.5Cu-Based Flex-on-Board Application at a 250 °C Bonding Temperature

Zhang, Shuye,Yang, Ming,Wu, Yang,Du, Jikun,Lin, Tiesong,He, Peng,Huang, Mingliang,Paik, Kyung-Wook IEEE 2018 IEEE transactions on components, packaging, and ma Vol.8 No.3

<P>Although cationic epoxy was optimized for low-melting SnBi58 solder ACF joints with the lowest coefficient of thermal expansion (CTE) in terms of reliability, cationic epoxy also showed a faster curing property than any other types of adhesives. In fact, solder joint shapes at 250 °C bonding are very different from those shapes at 200 °C bonding. In this paper, four adhesive film types were investigated in terms of Sn-3Ag-0.5Cu solder ACF joint shapes on the electrical performances and reliability in a pressure cooker test (PCT). Thermal stability of adhesive films was tested to be first. Resin curing speeds were measured in a 250 °C isothermal mode differential scanning calorimetry, resin viscosities were checked by a parallel-plate rheometer, and adhesive thermomechanical properties, such as modulus and CTE, were characterized. Then, four different types of ACF resins containing the same weight percentages of Sn-3Ag-0.5Cu solders were assembled by the same thermocompression bonding parameter (250 °C 10s 2MPa on bump) on a 500- <TEX>$\mu \text{m}$</TEX>-pitch flex-on-board (FOB) application, and different solder joint morphologies were verified. Various bonded solder ACFs joints were compared in terms of solder wetting areas, electrical performances by a four-point-probe method, and the reliability of PCT (121 °C 100% humidity 2atm) for 120 h. This paper aims at optimizing the best adhesive film candidate for SAC305 solder ACF joints of FOB application.</P>

Macroscopic Zn-doped a-Fe2O3/graphene aerogel mediated persulfate activation for heterogeneous catalytic degradation of sulfamonomethoxine wastewater

Shuying Dong,Xuanxuan Yan,Wenli Li,Yafei Liu,Xiaoxu Han,Xiaodan Liu,Jinglan Feng,Chongfei Yu,Chunyan Zhang,Jianhui Sun 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.108 No.-

In order to obtain a robust, durable and efficient heterogeneous catalyst, macroscopic monolithic Zndopeda-Fe2O3/graphene aerogel (GA) hybrid architecture with integrated morphology and hierarchicallyporous structure were controllably synthesized via a facile in-situ hydrothermal method and then used aspersulfate (PS) activator for sulfamonomethoxine (SMM) wastewater purification. Several key reactionparameters including the initial SMM concentration, reaction temperature, coexisting inorganic anionsand SMM in real natural water samples had different influence on the SMM removal efficiency. The catalyticefficiency of Zn-doped a-Fe2O3/GA with the molar ratio of Fe/Zn = 2:1.5 was about 66%, 62%, 66%and 11%33% higher than that of GA, a-Fe2O3/GA, Zn/GA and other Fe/Zn molar ratio. The improvedactivity of Fe/Zn = 2:1.5 benefits from the synergistic effects of the sp2 hybridized carbon and porousframework, as well as the surface oxygenic functional groups, which accelerate the pollutant/oxidant dispersionand electron transfer. Electron paramagnetic resonance results indicate that OH, 1O2 and SO4radicals account for the catalytic degradation of SMM and the activation of PS in present system is differentfrom conventional homogeneous systems, and speculate mechanism was proposed based on theobtained data.

Fault-Tolerant Control of Nonlinear System

Yingwei Zhang,Shuying Wu,Yuan Wei 제어·로봇·시스템학회 2011 International Journal of Control, Automation, and Vol.9 No.6

The design strategies of fault-tolerant control system (FTCS) are developed, which are categorized into two types: redundant design and fault compensation. In the first type, a certain degree of redundancy is introduced to controller. The resulting closed-loop system is stable not only when all actuators are operational but also only when one actuator experiences fault. In the second type, the on-line fault-tolerant control (FTC) scheme is developed based on the fuzzy logic system. The closed-loop stability is established based on Lyapunov’s sense. The resulting closed-loop system is stable by using the corrective control law. Compared with the existing results, the fault is accommodated by the fault compensator. The updating control law is so derived that all the parameters of the closed-loop system are bounded. The advantage of redundant design is that it is unnecessary to know the position and magnitude of the fault and is performed without FDI, which reduce the computing time and avoid the false alarms, non-detection and delay due to FDI. The advantage of fault compensation is the dynamics caused by faults that can be accommodated online. Examples of the proposed design indicate that the approaches are effective.

circSPG21 protects against intervertebral disc disease by targeting miR-1197/ATP1B3

Huang Yizhen,Zhang Zhenlei,Wang Jianle,Shen Shuying,Yao Teng,Xu Yining,Chen Zizheng,Fang Bin,Ma Jianjun 생화학분자생물학회 2021 Experimental and molecular medicine Vol.53 No.-

The abnormal expression of circular RNAs (circRNAs) is associated with numerous human diseases. This study investigated the mechanism by which circRNA acts as competitive endogenous RNA in the regulation of degenerative intervertebral disc disease (IVDD). Decreased expression of circSPG21 was detected in degenerated nucleus pulposus cells (NPCs), the function of circSPG21 in NPCs was explored and verified, and the downstream target of circSPG21 was investigated. The interaction between circSPG21 and miR-1197 and its target gene ( ATP1B3 ) was studied by online database prediction and molecular biological verification. Finally, the circSPG21/miR-1197/ATP1B3 axis was verified in the mouse tail-looping model. The expression of circSPG21 in the nucleus pulposus in IVDD was directly related to an imbalance of anabolic and catabolic factors, which affected cell senescence. circSPG21 was found to play a role in human NPCs by acting as a sponge of miR-1197 and thereby affecting ATP1B3 . The regulation of circSPG21 provides a potentially effective therapeutic strategy for IVDD.

Next-generation sequencing for the genetic characterization of Maedi/Visna virus isolated from the northwest of China

Ling Zhao,Liang Zhang,Xiaona Shi,Xujie Duan,Huiping Li,Shuying Liu 대한수의학회 2021 Journal of Veterinary Science Vol.22 No.6

Background: Maedi/Visna virus (MVV) is a contagious viral pathogen that causes considerable economic losses to the sheep industry worldwide. Objectives: In China, MVV has been detected in several regions, but its molecular characteristics and genetic variations were not thoroughly investigated. Methods: Therefore, in this study, we conducted next-generation sequencing on an MVV strain obtained from northwest China to reveal its genetic evolution via phylogenetic analysis. Results: A MVV strain obtained from Inner Mongolia (NM) of China was identified. Sequence analysis indicated that its whole-genome length is 9193 bp. Homology comparison of nucleotides between the NM strain and reference strains showed that the sequence homology of gag and env were 77.1%–86.8% and 67.7%–75.5%, respectively. Phylogenetic analysis revealed that the NM strain was closely related to the reference strains isolated from America, which belong to the A2 type. Notably, there were 5 amino acid insertions in variable region 4 and a highly variable motif at the C-terminal of the surface glycoprotein (SU5). Conclusions: The present study is the first to show the whole-genome sequence of an MVV obtained from China. The detailed analyses provide essential information for understanding the genetic characteristics of MVV, and the results enrich the MVV library.

Compositional Dependence of the Recrystallization and Grain Growth in Strongly-distorted Pd-containing Multi-Component Equiatomic Alloys

Jingbo Qiao,Hongmin Zhang,Haoyan Meng,Fanchao Meng,Yang Tong,Daiyi Chao,Peter K. Liaw,Shuying Chen 대한금속·재료학회 2024 METALS AND MATERIALS International Vol.30 No.2

The equiatomic high entropy alloy (HEA) NiCoCrFePd crystalizes as a single face-centered cubic (FCC) phase with stronglocal lattice distortion due to large atomic size mismatch between Pd element and other constitute elements. To betterunderstand this quinary alloy, a family of single FCC phase equiatomic alloys made from the constituent elements of theNiCoCrFePd HEA, including the binary NiPd alloy, medium entropy alloys (MEAs) of NiCoPd, NiCrPd, and NiFePd, andthe quinary NiCoCrFePd HEA with fully-recrystallized microstructure was experimentally investigated to understand thechemical effects on grain growth kinetics and solid solution hardening. With the principal elements increasing from two tofive, the grain growth was increasingly inhibited in the annealing temperature range of 800–900 °C, while at 1000 °C andabove, the NiCrPd MEA showed the slowest grain growth, which may attribute to the higher melting temperature of Crand negative mixing enthalpy between Cr and other constituent elements, increasing the activation energy of grain growth. Moreover, the hardness depending on the grain size complied with the Hall-Petch relationship, in which NiCoPd exhibitedthe lowest hardness, while NiPd had a comparable hardness with NiCrPd and NiFePd. The above results suggested thatthe number of alloying elements was not the sole factor determining the sluggish diffusion and hardness. Instead, thetype of constituent elements in the Pd-containing multicomponent alloys played more critical role. Furthermore, it wasconcluded that the strength of MEAs and HEA should depend on the combination of atomic size and modulus mismatchand electronegativity difference.

A Bama Minipig Model of Laryngopharyngeal Reflux and the Change of Laryngopharyngeal Mucosal Ultrastructure

( Guijian Feng ),( Zhenyu Zhang ),( Chunyan Diao ),( Jun Jiang ),( Shuying Zheng ),( Yulan Liu ) 대한소화기기능성질환·운동학회 2015 Journal of Neurogastroenterology and Motility (JNM Vol.21 No.2

Background/Aims To establish an animal model of laryngopharyngeal reflux (LPR) and study the effect of LPR on the laryngopharyngeal mucosal ultrastructure. Methods Ten Bama minipigs were randomly divided into control group and stent group. Every pig underwent endoscope, and baseline pH was monitored for 4 hours at laryngopharynx and distal esophagus, then specimens from laryngopharyngeal mucosa were biopsied. For the control group, these procedures were repeated on the 14th day. In the stent group, a custom-designed esophageal stent suit was implanted into esophagus, laryngopharyngeal and distal esophageal pH monitoring lasted for 2 hours, then stent suit was removed 3 days later. At last, the same procedures were done as the control group on the 14th day. Specimens were observed under transmission electron microscope to measure the intercellular space and desmosome number. Results In the control group, there was no laryngopharyngeal reflux on the first day and 14th day. Before the stent was implanted, there was also no laryngopharyngeal reflux in the stent group. In both 2 hours and 14 days after stent implantation, the num - ber of reflux, reflux time, and percentage time of pH < 4.0 were significantly increased (P < 0.05) in the stent group. There was no difference in intercellular space and desmosomes in the control group between baseline and 14th day. In the stent group, intercellular space of laryngopharyngeal mucosa was significantly increased (0.37 μm vs 0.96 μm, P = 0.008), and the number of desmosomes was significantly decreased (20.25 vs 9.5, P = 0.003). Conclusions A Bama minipig model of LPR was established by implanting a custom-designed stent suit. LPR might destroy the laryngophar yngeal mucosal barrier. (J Neurogastroenterol Motil 2015;21:182-188)

Studies on Shoot Regeneration from Leaf Pieces of Rubus in Vitro

Yadong Li,Wei An,Shuying Liu,Zhidong Zhang,Lin Wu 한국원예학회 2006 한국원예학회 기타간행물 Vol.- No.-

Highly Reliable Solder ACFs FOB (Flex-on-Board) Interconnection Using Ultrasonic Bonding

Kim, Yoo-Sun,Zhang, Shuye,Paik, Kyung-Wook The Korean Microelectronics and Packaging Society 2015 마이크로전자 및 패키징학회지 Vol.22 No.1

In this study, in order to improve the reliability of ACF interconnections, solder ACF joints were investigated interms of solder joint morphology and solder wetting areas, and evaluated the electrical properties of Flex-on-Board (FOB) interconncections. Solder ACF joints with the ultrasonic bonding method showed excellent solder wetting by broken solder oxide layers on solder surfaces compared with solder joints with remaining solder oxide layer bonded by the conventional thermo-compression (TC) bonding method. When higher target temperature was used, Sn58Bi solder joints showed concave shape due to lower degree of cure of resin at solder MP by higher heating rate. ACFs with epoxy resins and SAC305 solders showed lower degree of resin cure at solder MP due to the slow curing rate resulting in concave shaped solder joints. In terms of solder wetting area, solder ACFs with $25-32{\mu}m$ diameters and 30-40 wt% showed highest wetted solder areas. Solder ACF joints with the concave shape and the highest wetting area showed lower contact resistances and higher reliability in PCT results than conventional ACF joints. These results indicate that solder morphologies and wetting areas of solder ACF joints can be controlled by adjustment of bonding conditions and material properties of solder and polymer resin to improve reliability of ACF joints.

Super-Twisting Sliding Mode Observer Based Speed Sensorless Torque Control for PMSG Used in Wind Turbines

Leilei Guo,Xing Zhang,Shuying Yang,Zhen Xie,Lifeng Qi,Lingxiang Wang 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

A speed sensorless torque control method for permanent magnet synchronous generator (PMSG) based on super-twisting sliding mode observer (STSMO) is proposed in this paper. Active back electromotive force (BEMF) can be obtained based on the STSMO. With the observed active BEMF, the rotor position angle and the speed are estimated by a phase-locked loop. Besides, a stator flux and electromagnetic torque (EMT) observation method is proposed based on the observed active BEMF. Compared to the traditional method, the robustness of the proposed one to the parameters of PMSG is improved. Then a speed sensorless EMT closed-loop control system is established. The simulation and experimental results verify the effectiveness of the proposed algorithm.