SiO2-Encapsulated ZnO@ZIF-8 Coated Fabric for Passive Radiative Cooling

Jianhua Zhou,Zhuanli Niu,Anguo Xiao,Xiang Li 한국섬유공학회 2023 Fibers and polymers Vol.24 No.12

Materials with passive daytime radiative cooling (PDRC) have drawn more attention as a result of their potential for energy savings. We prepared SiO2-encapsulated ZnO@ZIF-8 (ZZS) particles and a radiative cooling coating containing ZZS particles. Owing to the polyhedron structure and the phonon-polarization resonance of ZZS particles, the ZZS fabric coating could reflect sunlight with 83% and radiate heat to outer space with 0.96. Compared with the ambient air, its average temperature decreased by 6.4 °C, and the human body under direct sunlight could avoid overheating 3.9 °C. In addition, the ZZS coated fabric after rubbing still had good PDRC and its average temperature increased by 1.38℃ higher than the original ZZS coated fabric. Owing to good PDRC property, hydrophobicity, mechanical properties and simple methods, the widespread usage of ZZS coated fabric for personal thermal management appears to be promising.

Targeting RNA-splicing for SMA treatment

Zhou, Jianhua,Zheng, Xuexiu,Shen, Haihong Springer-Verlag 2012 Molecules and cells Vol.33 No.3

Targeting RNA-Splicing for SMA Treatment

Jianhua Zhou,심해홍,정학수 한국분자세포생물학회 2012 Molecules and cells Vol.33 No.3

The central dogma of DNA-RNA-protein was established more than 40 years ago. However, important biological processes have been identified since the central dogma was developed. For example, methylation is important in the regulation of transcription. In contrast, proteins, are more complex due to modifications such as phosphorylation, glycosylation, ubiquitination, or cleavage. RNA is the mediator between DNA and protein, but it can also be modulated at several levels. Among the most profound discoveries of RNA regulation is RNA splicing. It has been estimated that 80% of pre-mRNA undergo alternative splicing, which exponentially increases biological information flow in cellular processes. However, an increased number of regulated steps inevitably accompanies an increased number of errors. Abnormal splicing is often found in cells, resulting in protein dysfunction that causes disease. Splicing of the survival motor neuron (SMN) gene has been extensively studied during the last two decades. Accumulating knowledge on SMN splicing has led to speculation and search for spinal muscular atrophy (SMA) treatment by stimulating the inclusion of exon 7 into SMN mRNA. This mini-review summaries the latest progress on SMN splicing research as a potential treatment for SMA disease.

Optimal Duty Cycle Method to Suppress the Commutation Torque Ripple of Brushless DC Motor in Braking Mode

Zhou Qixun,Shu Jianhua,Cai Ziwei,Han Chenyang,Zhang Yufeng 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.3

This paper proposes an optimal duty cycle method to suppress the commutation torque ripple under the braking condition of the brushless DC motor (BLDCM). The commutation torque will also fl uctuate in the braking process, but the current loop and change trend are diff erent from that of electric operation. Therefore, it is necessary to study the commutation torque ripple under braking. To directly analyze the interfering factors of commutation torque ripple, the formulas of commutation torque ripple under the standard brake modulation mode are derived in this paper. Based on the mathematical analysis, an optimized duty cycle method is proposed to suppress the commutation torque ripple by dynamically adjusting the duty cycle during commutation period to make the target formula of torque ripple zero. The simulation and experimental results show that this method can eff ectively reduce the commutation torque ripple, and it is helpful for the promotion of the braking performance and the scope of application of the brushless DC motor

Fatigue Life Analysis and Experimental Study of the Input Shaft of 6-Speed Automatic Transmission

려건화(Jianhua Lv),종흥(Xing Zhong),주서(Rui Zhou),진진(Zhen Qin),장기(Qi Zhang),류성기(Sungki Lyu) Korean Society for Precision Engineering 2020 한국정밀공학회지 Vol.37 No.8

The input shaft of gearbox usually bears a cyclic variation of torque, which may lead to the risk of experiencing a fatigue fracture. To evaluate the fatigue life accurately and identify the weak parts, the ANSYS is used to simulate the torsional fatigue of the input shaft for the gearbox, and the fatigue life of the weak part is obtained, which is then tested and verified by the torsional fatigue testing in the MTS torsional fatigue test rig. The test results show that the maximum difference is 14% between the calculated life and the testing results, indicating that the simulation value can reflect the actual fatigue life accurately. Notably, the cracks appear in the large oil holes, and its life is mainly concentrated in the crack initiation stage, accounting for 99.2% of the total life. The analysis results show that the fatigue life of the software simulation has the guiding significance for the life evaluation. The fatigue life of the shaft can be quickly calculated by the simulation to reduce the number of fatigue tests and achieve cost-effectiveness.

Experimental Investigation of the Hydraulic Performance of a Hydraulic-Jump-Stepped Spillway

Yu Zhou,Jianhua Wu,Fei Ma,Shangtuo Qian 대한토목학회 2021 KSCE Journal of Civil Engineering Vol.25 No.10

For a traditional stepped spillway, low energy dissipation and cavitation damage may occur when the unit discharge is larger than a limit due to reduced air entrainment in the flow. In the present work, a new type of stepped spillway called hydraulic-jump-stepped spillway (HJSS) was developed, and the air was efficiently entrained into the flow by means of a hydraulic jump in the aeration basin, which was an aeration element of this stepped spillway. Compared with the traditional stepped spillway, various aspects of the hydraulic performance of the HJSS were experimentally investigated, including the flow pattern, energy dissipation, air entrainment characteristics and time-averaged pressure. Physical model results demonstrated that the HJSS achieved a higher energy dissipation, a more favorable air entrainment performance, and a more reasonable pressure distribution. The HJSS successfully increased the unit discharge from 50 – 60 m2/s for a traditional stepped spillway to 101.47 m2/s.

1,4-Di(3-alkoxy-2-thienyl)-2,5-difluorophenylene: A Building Block Enabling High-Performance Polymer Semiconductors with Increased Open-Circuit Voltages

Chen, Jianhua,Yan, Zhenglong,Tang, Linjing,Uddin, Mohammad Afsar,Yu, Jianwei,Zhou, Xin,Yang, Kun,Tang, Yumin,Shin, Tae Joo,Woo, Han Young,Guo, Xugang American Chemical Society 2018 Macromolecules Vol.51 No.14

<P>A new building block, 1,4-di(3-alkoxy-2-thienyl)-2,5-difluorophenylene (DOTFP) with several desirable features such as high backbone planarity, suitably lying highest occupied molecular orbital (HOMO), and good solubility, was developed by inserting an electron-deficient difluorophenylene into the 3,3′-dialkoxy-2,2′-bithiophene (BTOR) unit. Three regioregular D-A<SUB>1</SUB>-D-A<SUB>2</SUB> type polymers based on DOTFP and benzothiadiazole (BT) derivatives were synthesized and characterized by comparing with a D-A type BTOR-based polymer. The content of highly electron-rich alkoxythiophene is reduced by half in the DOTFP-based polymers versus that of the BTOR-based polymer analogue, which results in a deeper HOMO level and benefits high open-circuit voltage (<I>V</I><SUB>oc</SUB>) in polymer solar cells (PSCs). Consequently, the DOTFP-ffBT-based solar cells exhibited a significantly improved power conversion efficiency (PCE) of 8.7% and an increased <I>V</I><SUB>oc</SUB> of 0.84 V compared to the BTOR-ffBT-based solar cells with a PCE of 2.6% and a <I>V</I><SUB>oc</SUB> of 0.49 V. Additionally, the DOTFP-based polymers showed improved charge transport properties and film morphology than the BTOR-based polymer BTOR-ffBT, resulting in simultaneous enhancement of the short-circuit current (<I>J</I><SUB>sc</SUB>) and fill factor (FF) in PSCs. These results demonstrate the great promise of the DOTFP building block for the construction of high-performance photovoltaic polymer semiconductors with increased <I>V</I><SUB>oc</SUB>s.</P> [FIG OMISSION]</BR>

Backbone Conformation Tuning of Carboxylate-Functionalized Wide Band Gap Polymers for Efficient Non-Fullerene Organic Solar Cells

Chen, Jianhua,Wang, Lei,Yang, Jie,Yang, Kun,Uddin, Mohammad Afsar,Tang, Yumin,Zhou, Xin,Liao, Qiaogan,Yu, Jianwei,Liu, Bin,Woo, Han Young,Guo, Xugang American Chemical Society 2019 Macromolecules Vol.52 No.1

<P>Two carboxylate-functionalized wide band gap polymers, 2TC-TT-BDTFT and 2T-TTC-BDTFT, which feature a fluorinated benzodithiophene (BDTFT)-<I>alt</I>-2,5-di(thiophen-2-yl)thieno[3,2-<I>b</I>]thiophene (2T-TT) backbone having different carboxylate attaching positions, were designed and synthesized. By variation of the substitution position of carboxylate groups on the 2T-TT unit, the backbone conformation of the designed building blocks 2TC-TT and 2T-TTC and their corresponding donor-acceptor polymers was fine-tuned as demonstrated by single crystal study and DFT calculation, thus yielding a large device performance difference in organic solar cells. As a result of the relatively higher planarity of the 2T-TTC unit in which the two carboxylate groups were attached on the inner thieno[3,2-<I>b</I>]thiophene moiety, the 2T-TTC-BDTFT polymer exhibited a red-shifted UV-vis absorption, stronger aggregation, and improved charge transport property than its polymer analogue 2TC-TT-BDTFT, in which the two outer thiophene rings were functionalized with carboxylate groups. Benefiting from the improved exciton dissociation and charge collection efficiency, better film morphology, and higher photoresponse, non-fullerene organic solar cells based on 2T-TTC-BDTFT:m-ITIC achieved a power conversion efficiency (PCE) of 11.15% with a fill factor (FF) of ∼70%, while the 2TC-TT-BDTFT:m-ITIC cells showed a relatively lower PCE of 9.65% and FF of 59.31%. The much higher FF of 2T-TTC-BDTFT-based solar cells reflects the great merit of the carboxylation on thienothiophene moiety rather than the outer thiophene counterpart. Therefore, the modulation of the carboxylate position on polymer backbones is an efficient strategy to tune the backbone conformation, interchain packing, film morphology, and the resulting optical, electrical, and photovoltaic properties. Moreover, both the 2T-TTC-BDTFT:m-ITIC and 2TC-TT-BDTFT:m-ITIC solar cells showed excellent stability during annealing and long-term storage. These results demonstrate that carboxylate-functionalized 2T-TTC and 2TC-TT have great potentials as a weak electron-accepting building block for wide band gap polymers for high-performance non-fullerene organic solar cells, and the carboxylate position on the polymer backbones is critical for performance improvement of organic photovoltaic devices.</P> [FIG OMISSION]</BR>

Path Optimization Algorithms Based on Graph Theory

Biyuan Yao,Jianhua Yin,Hui Zhou,Wei Wu 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.6

Transport with minimum time cost and distance remains to be an important research area in intelligent transport systems. Shortest path algorithms are primary methods to address simplified problems, which could not be well applied in high-dimensional real situations. We realized the minimum cost and maximum flow result via classical iterative algorithm based on graph theory, adjacency matrix is well applied to express the relationship between transport nodes, a topological sorting transport map is adopted to verify these approaches.

Atomic layer deposited ZrxAl1-xOy film as high κ gate insulator for high performance ZnSnO thin film transistor

Jun Li,You-Hang Zhou,De-Yao Zhong,Chuanxin Huang,Jian Huang,Jianhua Zhang 대한금속·재료학회 2018 ELECTRONIC MATERIALS LETTERS Vol.14 No.6

In this work, the high κ Zr x Al 1−x O y fi lms with a diff erent Zr concentration have been deposited by atomic layer deposition,and the eff ect of Zr concentrations on the structure, chemical composition, surface morphology and dielectric propertiesof Zr x Al 1−x O y fi lms is analyzed by Atomic force microscopy, X-ray diff raction, X-ray photoelectron spectroscopy andcapacitance-frequency measurement. The eff ect of Zr concentrations of Zr x Al 1-x O y gate insulator on the electrical propertyand stability under negative bias illumination stress (NBIS) or temperature stress (TS) of ZnSnO (ZTO) TFTs is fi rstlyinvestigated. Under NBIS and TS, the much better stability of ZTO TFTs with Zr x Al 1−x O y fi lm as a gate insulator is due tothe suppression of oxygen vacancy in ZTO channel layer and the decreased trap states originating from the Zr atom permeationat the ZTO/Zr x Al 1−x O y interface. It provides a new strategy to fabricate the low consumption and high stability ZTOTFTs for application.