ZnO/TiO2 core–shell heterojunction for CdS and PbS quantum dot-cosensitized solar cells

Fangfang Gao,Qian Chen,Xiaoshan Zhang,Huan Wang,Tianjiao Huang,Liya Zhou 한국물리학회 2018 Current Applied Physics Vol.18 No.5

ZnO nanorods (NRs) with regular morphology were prepared through hydrothermal method, and the TiO2 shell was assembled onto the surface of ZnO NRs by spin coating to the ZnO/TiO2 core–shell heterojunction. CdS and PbS quantum dots (QDs) were used to cosensitize the ZnO/TiO2 nanostructure by direct adsorption (DA) and successive ionic layer adsorption and reaction, respectively. SEM, TEM, and HRTEM images show that the samples possessed a rough surface and four lattice fringes indicating the successful synthesis of the ZnO/TiO2/ CdS/PbS composite structure. The ZnO/TiO2(10T)/CdS/PbS sample showed a high absorption intensity at a broad range of wavelength to visible light region. The ZnO/TiO2(10T)/CdS/PbS photoelectrode with QDSSCs showed the highest IPCE of 36.04% and photoelectric efficiency (η) of 1.59%; these values increased by approximately 550% and 150% compared with those of unsensitized ZnO (0.29%) and ZnO/TiO2(10T) (1.04%) and about 146% and 120% compared with those of ZnO/TiO2(10T)/CdS and ZnO/TiO2(10T)/PbS, respectively. The fill factor was 0.36, and the photocurrent density (Jsc) and open circuit voltage (Voc) reached the maximum values of 9.73 mA cm−2 and 0.46 V, respectively.

A New Approach to Distributed Control for Multi-agent Systems Based on Approximate Upper and Lower Bounds

Fangfang Zhang,Jinfeng Gao,Huanshui Zhang,Cheng Tan,Wei Wang 제어·로봇·시스템학회 2017 International Journal of Control, Automation, and Vol.15 No.6

In this paper, the distributed control of the LQR problem for continuous-time multi-agent systems isconsidered. Based on the centralized optimal control, we prove that the solution of the algebraic Riccati equationis the maximal solution of the algebraic Riccati inequality. The algebraic relations of the solutions of the algebraicRiccati equations for different weighted matrices are shown and two distributed controllers are designed: the fullydistributed one and the interconnected distributed one. They can provide an upper bounds and a lower bounds ofthe centralized optimal cost function. The optimal closed-loop feedback control systems for the two distributedcontrollers are also asymptotically stable. Some examples are given to show the correctness of the proposed results.

Highly Efficient Photocatalysts Based on Lamellar-Shaped Bi2S3 Grown on TiO2 Monolith

Kaidi Li,Fangfang Zhang,Huiming Wang,Yalan Zhou,Lixin Zhao,Jimin Du,Yating Gao,Weimin Wang,강대준 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2018 NANO Vol.13 No.09

Here, the lamellar-shaped Bi2S3 grown on a porous TiO2 monolith was obtained by a two-step method including a sol–gel route and hydrothermal treatment. The photocatalytic activity of the as-synthesized Bi2S3/TiO2 composites was evaluated for photodegradation of methylene blue (MB) dye in aqueous solution under the visible-light irradiation. Based on our experimental results, 5% (molar ratio of Bi2S3 to TiO2) Bi2S3/TiO2 photocatalysts exhibited a maximum photodegradation rate of MB up to 96.9% under visible-light irradiation for 120 min. Our findings indicated that the lamellar-shaped Bi2S3 can extend the light absorption up to visible areas, and porous TiO2 can provide enhanced specific surface area and more mass transfer pathway to enhance the photodegradation efficiency. Furthermore, porous TiO2 can accept the electrons from the Bi2S3 conduction band due to the relatively positive electrode potential to impede the photoproduced electron and hole combination to result in advanced photocatalytic performance.

Energy Harvest System Research for High Precision Electronic Voltage Transformer based on Coupling Capacitance

Liu Ying,Li Bing,Song FangFang,Gao HanYu,Huang LiangDong,Chen XuXuan 한국전기전자재료학회 2022 Transactions on Electrical and Electronic Material Vol.23 No.6

High quality power is the prerequisite for high precision measurement of an electronic voltage transformer. In order to ensure a compact structure and stable operation of the transformer, this paper proposes a circuit and high voltage energy harvest of high precision electronic voltage transformer based on coupling capacitance. The energy extraction circuit is directly connected with the high voltage terminal through a capacitor, and the low DC voltage is obtained through the diode rectifier bridge. A self-holding duty cycle regulating circuit is installed on the DC side, and the power required by the load can be automatically adjusted to match the load. Because the overall load of the power extraction circuit is capacitive, there is no ferro-resonance problem. Furthermore, there is also no MCU in the device, so that the whole circuit has the advantages of small power loss, small volume, strong anti-interference ability, and can provide a stable DC power for the metering device. The proposed method is verifi ed in simulations using PSCAD/EMTDC.

Maintaining Drosha expression with Cdk5 inhibitors as a potential therapeutic strategy for early intervention after TBI

Huang Lu,Xia Li,Nie Tiejian,Cui Bozhou,Lu Jianjun,Lu Fangfang,Fan Feiyan,Ren Dongni,Lu Yuan,Gao Guodong,Yang Qian 생화학분자생물학회 2024 Experimental and molecular medicine Vol.56 No.-

Traumatic brain injury (TBI) is a major cause of death and disability in adults. The pathological process of TBI involves a multifactorial cascade in which kinases have been proven contribute to interactions between relevant factors and amplification of signaling cascades. Cyclin-dependent kinase 5 (Cdk5) is a promising kinase that has been implicated in various brain disorders, including TBI. However, the mechanism by which Cdk5 induces neuronal damage remains unclear. Here, we show for the first time that Drosha, a key enzyme in microRNA biogenesis, is a pivotal substrate of abnormally activated Cdk5. Cdk5-mediated phosphorylation decreases Drosha expression and exacerbates nerve injury in TBI. We proved that maintaining Drosha expression via the administration of repurposed Cdk5 inhibitors that were previously studied in clinical trials is a promising approach for the early treatment of TBI. Together, our work identifies Drosha as a novel target for neuroprotective strategies after TBI and suggests Cdk5-mediated regulation of Drosha expression as a potential therapeutic strategy for early TBI intervention.

Histone demethylase KDM4A plays an oncogenic role in nasopharyngeal carcinoma by promoting cell migration and invasion

Zhao Jingyi,Li Bingyan,Ren Yongxia,Liang Tiansong,Wang Juan,Zhai Suna,Zhang Xiqian,Zhou Pengcheng,Zhang Xiangxian,Pan Yuanyuan,Gao Fangfang,Zhang Sulan,Li Liming,Yang Yongqiang,Deng Xiaoyu,Li Xiaole,C 생화학분자생물학회 2021 Experimental and molecular medicine Vol.53 No.-

Compelling evidence has indicated the vital role of lysine-specific demethylase 4 A (KDM4A), hypoxia-inducible factor-1α (HIF1α) and the mechanistic target of rapamycin (mTOR) signaling pathway in nasopharyngeal carcinoma (NPC). Therefore, we aimed to investigate whether KDM4A affects NPC progression by regulating the HIF1α/DDIT4/mTOR signaling pathway. First, NPC and adjacent tissue samples were collected, and KDM4A protein expression was examined by immunohistochemistry. Then, the interactions among KDM4A, HIF1α and DDIT4 were assessed. Gain- and loss-of-function approaches were used to alter KDM4A, HIF1α and DDIT4 expression in NPC cells. The mechanism of KDM4A in NPC was evaluated both in vivo and in vitro via RT-qPCR, Western blot analysis, MTT assay, Transwell assay, flow cytometry and tumor formation experiments. KDM4A, HIF1α, and DDIT4 were highly expressed in NPC tissues and cells. Mechanistically, KDM4A inhibited the enrichment of histone H3 lysine 9 trimethylation (H3K9me3) in the HIF1α promoter region and thus inhibited the methylation of HIF1α to promote HIF1α expression, thus upregulating DDIT4 and activating the mTOR signaling pathway. Overexpression of KDM4A, HIF1α, or DDIT4 or activation of the mTOR signaling pathway promoted SUNE1 cell proliferation, migration, and invasion but inhibited apoptosis. KDM4A silencing blocked the mTOR signaling pathway by inhibiting the HIF1α/DDIT4 axis to inhibit the growth of SUNE1 cells in vivo. Collectively, KDM4A silencing could inhibit NPC progression by blocking the activation of the HIF1α/DDIT4/mTOR signaling pathway by increasing H3K9me3, highlighting a promising therapeutic target for NPC.