A Complex Reinforced Polymer Interposer with Ordered Ni Grid and SiC Nano-whiskers Polyimide Composite Based on Micromachining Technology

Yanmei Liu,Yunna Sun,Yan Wang,Guifu Ding,Bin Sun,Xiaolin Zhao 대한금속·재료학회 2017 ELECTRONIC MATERIALS LETTERS Vol.13 No.1

A complex reinforced polymer interposer comprised with conductive Nicylinders, ordered Ni grid and SiC nano-whiskers/Polyimide (PI)composite was proposed. The conductive Ni cylinders distributing in themiddle of each Ni grid unite designed as the supporting structure wereused as electric connecting component for the interposer and wereinsulated by the SiC nano-whiskers/PI composite. The comprehensiveproperties of the complex reinforced polymer interposer were improvedby a complex reinforced mechanism: the improved thermal conductivityand mechanical strength by the Ni supporting structure and the reducedmetal/polymer interfacial mismatch due to the SiC nano-whiskers/PIcomposite with the optimized mixture ratio. The above complexreinforced polymer interposer and a traditional reinforced polymerinterposer only with Ni grid were fabricated using micro-machiningtechnology for comparative analysis. The comprehensive properties ofthese two polymer interposers were analyzed respectively. Comparedwith the traditional design, the comprehensive properties of the proposedcomplex reinforced polymer interposer were improved further, such as,21.3% increase for the Young modulus, 10.1% decrease for thecoefficient of thermal expansion (CTE) and 54.9% increase for thethermal conductivity. Such complex reinforced mechanism based on themetal ordered grid and random nano-whiskers has potential to expandthe applications of the polymer interposer.

Ternary Resistive Switching Memory Behavior in Graphene Oxide Layer

Junguo Lu,Yanmei Sun,Dianzhong Wen 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2018 NANO Vol.13 No.7

We report the application of graphene oxide (GO) as the active layer of memory devices. The indium-tin-oxide/GO/Al devices present the ternary write-once-read-many times resistive switching memory, and retain the data information for 3 X 10 5 s. In the OFF states, the I–V characteristics in the applied voltage dominantly followed the space-charge-limited-current behaviors. The intermediate resistance state was attributed to the thermionic emission mechanism. In the ON state, the curve in the applied voltage range was related to an Ohmic mechanism.

Influence of dragon bamboo with different planting patterns on microbial community and physicochemical property of soil on sunny and shady slopes

Liu Weiyi,Wang Fang,Sun Yanmei,Yang Lei,Chen Huihai,Liu Weijie,Zhu Bin,Hui Chaomao,Wang Shiwei 한국미생물학회 2020 The journal of microbiology Vol.58 No.11

Dragon bamboo (Dendrocalamus giganteus) is a giant sympodial bamboo species widely distributed in Asia. However, it remains unclear how dragon bamboo and soil microbes interact to affect soil properties. In this study, we investigated the planting patterns (semi-natural and artificial) on different slopes (sunny and shady) to determine the effects on soil properties and microbial community. The results showed that the soil in which dragon bamboo was grown was acidic, with a pH value of ~5. Also, the soil organic matter content, nitrogen hydrolysate concentration, total nitrogen, available potassium, and total potassium of the dragon bamboo seminatural forest significantly improved, especially on the sunny slope. In contrast, the available phosphorus level was higher in the artificial bamboo forest, probably owing to the phosphate fertilizer application. The bacterial and fungal diversity and the bacterial abundance were all higher on the sunny slope of the semi-natural forest than those in the other samples. The microbial operational taxonomic units (OTUs) shared between the shady and sunny slopes accounted for 47.8–62.2%, but the core OTUs of all samples were only 24.4– 30.4% of each sample, suggesting that the slope type had a significant effect on the microbial community. Some acidophilic microbes, such as Acidobacteria groups, Streptomyces and Mortierella, became dominant in dragon bamboo forest soil. A PICRUSt analysis of the bacterial functional groups revealed that post-translational modification, cell division, and coenzyme transport and metabolism were abundant in the semi-natural forest. However, some microorganisms with strong stress resistance might be activated in the artificial forest. Taken together, these results illustrated the influence of dragon bamboo growth on soil physicochemical property and microbial community, which might help understand the growth status of dragon bamboo under different planting patterns.

Epoxyeicosatrienoic Acid Inhibits the Apoptosis of Cerebral Microvascular Smooth Muscle Cells by Oxygen Glucose Deprivation via Targeting the JNK/c-Jun and mTOR Signaling Pathways

Youyang Qu,Yu Liu,Yanmei Zhu,Li Chen,Wei Sun,Yulan Zhu 한국분자세포생물학회 2017 Molecules and cells Vol.40 No.11

As a component of the neurovascular unit, cerebral smooth muscle cells (CSMCs) are an important mediator in the development of cerebral vascular diseases such as stroke. Epoxye-icosatrienoic acids (EETs) are the products of ara-chidonic acid catalyzed by cytochrome P450 epoxygenase. EETs are shown to exert neuroprotective effects. In this article, the role of EET in the growth and apoptosis of CSMCs and the underlying mechanisms under oxygen glucose deprivation (OGD) conditions were addressed. The viability of CMSCs was decreased significantly in the OGD group, while different subtypes of EETs, especially 14,15-EET, could increase the viability of CSMCs under OGD conditions. RAPA (serine/threonine kinase Mammalian Target of Rapamycin), a specific mTOR inhibitor, could elevate the level of oxygen free radicals in CSMCs as well as the anti-apoptotic effects of 14,15-EET under OGD conditions. However, SP600125, a specific JNK (c-Jun N-terminal protein kinase) pathway inhibitor, could attenuate oxygen free radicals levels in CSMCs as well as the anti-apoptotic effects of 14,15-EET under OGD conditions. These results strongly suggest that EETs exert protective functions during the growth and apoptosis of CSMCs, via the JNK/c-Jun and mTOR signaling pathways in vitro. We are the first to disclose the beneficial roles and underlying mechanism of 14,15-EET in CSMC under OGD conditions.

Nonvolatile Bistable Resistive Switching in Polyimide Bearing Trifluoromethyl Film

Enming Zhao,Hui Li,Fengjuan Miao,Yanmei Sun 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2017 NANO Vol.12 No.5

A functional polyimide (CF3 PI) was used as the active layer in our present work for electrical resistive memory device applications. Current–voltage (I–V ) characteristics analysis on the polyimide memory devices indicates that the polyimide possesses a nonvolatile rewritable flash characteristic with an ON/OFF current ratio of about 104 at the threshold voltage of around -1.2 V and 3.8 V. In addition, the device using the CF3 PI as the active layer reveals excellent long-term operation stability with the endurance of reading cycles up to 10 8 under a voltage pulse and retention times for at least 10 6 s under constant voltage stress (1 V). The conduction mechanisms are elucidated on the basis of the thermionic emission theory and filament conduction.

Dynamic load sharing characteristics of a dual-branch transmission system with offset nonorthogonal spur face gear pairs

Xuezhong Fu,Yuanxing Huang,Zongde Fang,Yanmei Cui,Jie Sun 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.7

According to the lumped mass method, this study presents a bending axial– torsional coupled dynamic model of a dual-branch transmission system with offset nonorthogonal spur (ONS) face gear pairs. The common form and force of the ONS face gear pair, the layout form of the dual-branch transmission system, and meshing phase differences are investigated in detail. The dynamic model considers factors, such as meshing phase differences, meshing stiffness, installation errors, damping, and elastic deformations. Results show that the dynamic uneven load of the system is affected by the meshing phase differences and gear vibrations when no installation error occurs. The input load and torsional stiffness have a crucial effect on the dynamic load sharing coefficients when installation errors exist. Moreover, the support stiffness of the spur cylindrical pinion 1 and the meshing stiffness fluctuation amplitude of each gear pair should be smaller.

Epoxyeicosatrienoic Acid Inhibits the Apoptosis of Cerebral Microvascular Smooth Muscle Cells by Oxygen Glucose Deprivation via Targeting the JNK/c-Jun and mTOR Signaling Pathways

Qu, Youyang,Liu, Yu,Zhu, Yanmei,Chen, Li,Sun, Wei,Zhu, Yulan Korean Society for Molecular and Cellular Biology 2017 Molecules and cells Vol.40 No.11

As a component of the neurovascular unit, cerebral smooth muscle cells (CSMCs) are an important mediator in the development of cerebral vascular diseases such as stroke. Epoxyeicosatrienoic acids (EETs) are the products of arachidonic acid catalyzed by cytochrome P450 epoxygenase. EETs are shown to exert neuroprotective effects. In this article, the role of EET in the growth and apoptosis of CSMCs and the underlying mechanisms under oxygen glucose deprivation (OGD) conditions were addressed. The viability of CMSCs was decreased significantly in the OGD group, while different subtypes of EETs, especially 14,15-EET, could increase the viability of CSMCs under OGD conditions. RAPA (serine/threonine kinase Mammalian Target of Rapamycin), a specific mTOR inhibitor, could elevate the level of oxygen free radicals in CSMCs as well as the anti-apoptotic effects of 14,15-EET under OGD conditions. However, SP600125, a specific JNK (c-Jun N-terminal protein kinase) pathway inhibitor, could attenuate oxygen free radicals levels in CSMCs as well as the anti-apoptotic effects of 14,15-EET under OGD conditions. These results strongly suggest that EETs exert protective functions during the growth and apoptosis of CSMCs, via the JNK/c-Jun and mTOR signaling pathways in vitro. We are the first to disclose the beneficial roles and underlying mechanism of 14,15-EET in CSMC under OGD conditions.

Deficit irrigation and silicate spray applied since blooming period improved strawberry fruit quality without reducing fruit size

Xu Xiangnan,Lei Xihong,Zou Guoyuan,Liao Shangqiang,Sun Na,Sun Yanxin,Li Yanmei 한국원예학회 2024 Horticulture, Environment, and Biotechnology Vol.65 No.1

The drought stress created by defi cit irrigation has been widely introduced into production for fruit quality improvement, whilst silicon is considered as a functional element in plant antistress process. To explore the infl uence of defi cit irrigation and silicon application on the strawberry fruit quality and the plant’s response to drought stress, a split-plot experiment was conducted. The impacts of the treatments start-time was also evaluated. The plants were subjected to two irrigation regimes, defi cit irrigation (DI) or full irrigation, and two foliar sprays, 0.01 mol L − 1 Na 2 SiO 3 (Si) or water, with two treatment start-time, as after fi rst bloom (Fr) or after transplanting. Therefore, there were 6 diff erent treatments (consider ing treatment start-time) and a control group, which were DI, FrDI, Si, FrSi, DISi, FrDISi and CK. As a result, the DI signifi cantly increased the leaf ascorbate, leaf anthocyanins and specifi c leaf weight by 93.5%, 109.9% and 24.5%, but it also reduced fruit reducing sugars concentration and single fruit mass by 25.1% and 12.6%, respectively. Whilst the FrDI increased specifi c leaf weight by 27.9% and had no negative eff ect on fruit quality. The timing of starting silicate spray didn’t infl uence leaf morphology or fruit quality, but the FrSi signifi cantly increased the percentage of leaf sucrose to total sugars by 9.0%, and the Si didn’t. The DISi and FrDISi tended to increase the concentration of fruit sugars, glutamate, polyphenols, and organic acids. Although the DISi showed more obvious eff ect on improving the fruit nutritive values, the FrDISi tended to have lighter negative impact on fruit size, compared to CK. We concluded that the combination of defi cit irrigation and silicate spray started after the fi rst bloom could eff ectively improve the fruit sugars, glutamate and polyphenols, without reducing the fruit size, due to the mitigation of plant antistress response.

Low-temperature strategy for vapor phase hydrothermal synthesis of C\N\S-doped TiO2 nanorod arrays with enhanced photoelectrochemical and photocatalytic activity

Hai Yu,Miao Zhang,Yanfen Wang,Janguo Lv,Yanmei Liu,Gang He,Zhaoqi Sun 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.98 No.-

In this study, a material with high photocatalytic activity was synthesized using ternary C/N/S-dopedTiO2 nanorod array (TiO2); this was done using a practical and straightforward vapor-phase hydrothermal(VPH) method at a low temperature. The effect of C/N/S content on TiO2 morphology, optical,photocatalytic and photoelectrochemical (PCE) properties of the material was investigated by varying thequality of thiourea. C/N/S-TiO2 reduced the bonding rate of electron-hole pairs and enhances visible lightabsorption, photocatalytic, and PCE properties. The C/N/S doping could significantly adjust theabsorption cut-off wavelengths (407 602 nm) and shorten the bandgap (3.04 2.18 eV) of TiO2. Undersimulated sunlight, 8-C/N/S-TiO2 had the highest photocatalytic efficiency of 97.6% for methylene blue(MB) in 150 min with a rate constant of 0.0192 min 1, which is approximately four times that of TiO2(0.005 min 1). The 8-C/N/S-TiO2 photoelectrode had the lowest transfer resistance for interfacial chargesand highest transient photocurrent of 33.5 mA/cm2, which isfive times higher than that of TiO2 (6.6 mA/cm2). The 8-C/N/S-TiO2 exhibits the most extensive PCE behavior as a photoelectrode, and has a currentdensity of 38.2 mA/cm2 at 2.5VRHE, which is about two times higher than TiO2 (19.1 mA/cm2). Thefavorable sunlight-driven photocatalytic activity is probably due to the synergistic effect of C/N/S-doping,which shifts the valence band maximum of TiO2 upward. This provides new ideas for future solar cellsthat can use dye-sensitized TiO2 nanorod arrays as photoanodes. It is noteworthy that VPH is a veryeffective strategy for fabricating semiconductors doped with multiple nonmetallic elements.