2,1,3-Benzothiadiazole-5,6-dicarboxylicimide-Based Polymer Semiconductors for Organic Thin-Film Transistors and Polymer Solar Cells

Yu, Jianwei,Ornelas, Joshua Loroñ,a,Tang, Yumin,Uddin, Mohammad Afsar,Guo, Han,Yu, Simiao,Wang, Yulun,Woo, Han Young,Zhang, Shiming,Xing, Guichuan,Guo, Xugang,Huang, Wei American Chemical Society 2017 ACS APPLIED MATERIALS & INTERFACES Vol.9 No.48

<P>A series of polymer semiconductors incorporating 2,1,3-benzothiadiazole-5,6-dicarboxylicimide (BTZI) as strong electron-withdrawing unit and an alkoxy-functionalized head-to-head linkage containing bithiophene or bithiazole as highly electron-rich co-unit are designed and synthesized. Because of the strong intramolecular charge transfer characteristics, all three polymers BTZI-TRTOR (P1), BTZI-BTOR (P2), and BTZI-BTzOR (P3) exhibit narrow bandgaps of 1.13, 1.05, and 0.92 eV, respectively, resulting in a very broad absorption ranging from 350 to 1400 nm. The highly electron-deficient 2,1,3-benzothiadiazole-5,6-dicarboxylicimide and alkoxy-functionalized bithiophene (or thiazole) lead to polymers with low-lying lowest unoccupied molecular orbitals (-3.96 to -4.28 eV) and high-lying highest occupied molecular orbitals (-5.01 to -5.20 eV). Hence, P1 and P3 show substantial and balanced ambipolar transport with electron mobilities/hole mobilities of up to 0.86/0.51 and 0.95/0.50 cm(2) V-1 s(-1), respectively, and polymer P2 containing the strongest donor unit exhibited unipolar p-type performance with an average hole mobility of 0.40 cm(2) V-1 s(-1) in top-gate/bottom-contact thin-film transistors with gold as the source and drain electrodes. When incorporated into bulk heterojunction polymer solar cells, the narrow bandgap (1.13 eV) polymer P1 shows an encouraging power conversion efficiency of 4.15% with a relatively large open-circuit voltage of 0.69 V, which corresponds to a remarkably small energy loss of 0.44 eV. The power conversion efficiency of P1 is among the highest reported to date with such a small energy loss in polymer:fullerene solar cells.</P>

Microwave-assisted low-temperature hydrothermal treatment of red seaweed (<i>Gracilaria lemaneiformis</i>) for production of levulinic acid and algae hydrochar

Cao, Leichang,Yu, Iris K.M.,Cho, Dong-Wan,Wang, Di,Tsang, Daniel C.W.,Zhang, Shicheng,Ding, Shiming,Wang, Linling,Ok, Yong Sik Elsevier 2019 Bioresource technology Vol.273 No.-

<P><B>Abstract</B></P> <P>In this study, red seaweed (<I>Gracilaria lemaneiformis</I>) food waste with high carbohydrate content was valorized into levulinic acid (LA) and algae hydrochar through microwave-assisted low-temperature hydrothermal treatment in dilute acid solution. Various parameters including treatment temperature (160–200 °C), reaction time (1–40 min), acid concentration (0–0.6 M), and biomass-to-liquid ratio (1%–10%, w/v) were examined. The energy efficiency and carbon recovery of the proposed process were investigated. Under the experimental conditions of 5% (w/v) biomass loading, 0.2 M H<SUB>2</SUB>SO<SUB>4,</SUB> 180 °C, and 20 min, the highest levulinic acid yield of 16.3 wt% was produced. The resulting hydrochar showed approximately 45–55% energy yield and higher heating values of 19–25 MJ kg<SUP>−1</SUP>. The energy efficiency of the present study (1.31 × 10<SUP>−6</SUP> g LA/J) was comparable to those of the conventional hydrothermal treatment of lignocellulosic biomass, while the reaction time (20 min) was much shorter with a high carbon recovery (73.3%).</P> <P><B>Highlights</B></P> <P> <UL> <LI> Red seaweed food waste was used as a sustainable feedstock for LA production. </LI> <LI> Microwave-assisted hydrothermal treatment facilitated fast red seaweed conversion. </LI> <LI> High LA yield of 16.3 wt% was obtained from <I>Gracilaria lemaneiformis</I>. </LI> <LI> Algae hydrochar recovered can serve as a potential solid fuel. </LI> <LI> Energy efficiency of 1.31 × 10<SUP>−6</SUP> g LA/J and high carbon recovery of 73.3% were achieved. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Redundant rule Detection for Software-Defined Networking

( Jian Su ),( Ruoyu Xu ),( Shiming Yu ),( Baowei Wang ),( Jiuru Wang ) 한국인터넷정보학회 2020 KSII Transactions on Internet and Information Syst Vol.14 No.6

The emergence of Software Defined Networking (SDN) overcomes the limitations of traditional networking architectures. There are some advantages in SDN which are centralized global network view, programmability, and separation of the data plane and control plane. Due to the limitation of data plane storage capacity in SDN, it is necessary to process the redundancy rules of switch. In this paper, we propose a method for active detection and processing of redundant rules. We use the result generated by the customized probe package to detect redundant rules. And by checking the forwarding behavior of probe packets in the data plane, the redundancy rules are further processed. Furthermore, in order to quickly check the dynamic networks, we propose an incremental algorithms for rapidly evolve the network strategies. We conduct simulation experiments on Matlab to verify the feasibility of the algorithm. The influence of some parameters on the result are discussed.

Lightweight Single Image Super-Resolution Convolution Neural Network in Portable Device

( Jin Wang ),( Yiming Wu ),( Shiming He ),( Pradip Kumar Sharma ),( Xiaofeng Yu ),( Osama Alfarraj ),( Amr Tolba ) 한국인터넷정보학회 2021 KSII Transactions on Internet and Information Syst Vol.15 No.11

Super-resolution can improve the clarity of low-resolution (LR) images, which can increase the accuracy of high-level compute vision tasks. Portable devices have low computing power and storage performance. Large-scale neural network super-resolution methods are not suitable for portable devices. In order to save the computational cost and the number of parameters, Lightweight image processing method can improve the processing speed of portable devices. Therefore, we propose the Enhanced Information Multiple Distillation Network (EIMDN) to adapt lower delay and cost. The EIMDN takes feedback mechanism as the framework and obtains low level features through high level features. Further, we replace the feature extraction convolution operation in Information Multiple Distillation Block (IMDB), with Ghost module, and propose the Enhanced Information Multiple Distillation Block (EIMDB) to reduce the amount of calculation and the number of parameters. Finally, coordinate attention (CA) is used at the end of IMDB and EIMDB to enhance the important information extraction from Spaces and channels. Experimental results show that our proposed can achieve convergence faster with fewer parameters and computation, compared with other lightweight super-resolution methods. Under the condition of higher peak signal-to-noise ratio (PSNR) and higher structural similarity (SSIM), the performance of network reconstruction image texture and target contour is significantly improved.

Idle Slots Skipped Mechanism based Tag Identification Algorithm with Enhanced Collision Detection

( Jian Su ),( Ruoyu Xu ),( Shiming Yu ),( Baowei Wang ),( Jiuru Wang ) 한국인터넷정보학회 2020 KSII Transactions on Internet and Information Syst Vol.14 No.5

In this article, a new Aloha-based tag identification protocol is presented to improve the reading efficiency of the EPC C1 Gen2-based UHF RFID system. Collision detection (CD) plays a vital role in tag identification process which determines the efficiency of anti-collision protocols since most Aloha-based protocols optimize the incoming frame length based on the collisions in current frame. Existing CD methods are ineffective in identifying collision, resulting in a degradation of identification performance. Our proposed algorithm adopts an enhanced CD (ECD) scheme based on the EPC C1 Gen2 standard to optimize identification performance. The ECD method can realize timely and effective CD by detecting the pulse width of the randomly sent by tags. According to the ECD, the reader detects the slot distribution and predicts tag cardinality in every collision slot. The tags involved in each collision slot are identified by independently assigned sub-frames. A large number of numerical results show that the proposed solution is superior to other existing anti-collision protocols in various performance evaluation metrics.

Deformation research of Silty Clay Under Freeze-Thaw Cycles

Lihui Tian,Liangliang Yu,Shiming Liu,Bo Zhang 대한토목학회 2020 KSCE Journal of Civil Engineering Vol.24 No.2

To explore the dynamic properties of silty clay in seasonally frozen ground under repeated freeze-thaw cycles, an unconsolidated undrained dynamic triaxial test was conducted on such properties under various confining pressures, number of freeze-thaw cycles, and dynamic stress amplitudes. The test results showed that due to the impact of freeze-thaw cycles, the inherent structure of the soil underwent some major changes, in which the resilient strain increased and the resilient modulus decreased. However, as the number of freeze-thaw cycles increased, the effect was reduced and eventually tended to be stable. As the number of freeze-thaw cycles increased, the cumulative plastic strain of the soil rose rapidly, and the soil samples became more prone to fracture at low stress amplitudes and small number of vibrations. The more the number of freeze-thaw cycles, the higher the cumulative plastic strain rate generated under a single dynamic stress amplitude. Moreover, with the increase in the confining pressure, the failure form of the thawed silty clay gradually evolved from a plastic fracture to a brittle one. The research results of this paper were helpful to further understand the influence of freeze-thaw cycle on the dynamic properties of silty clay, and provide data support for the subsequent research on the mechanism of roadbed diseases under the load in seasonally frozen ground.