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981.
ZHANG Ziwei XIA Dongdong XIE Qian ZHAO Chaowei FANG Jie WU Yonggang LI Weiwei 《高等学校化学研究》2023,39(2):213-218
By combining stable radical tetramethylpiperidine nitrogen oxide(TEMPO) as end groups and perylene bisimide(PBI) as the core, a small molecular cathode interlayer(CIL) (PBI-TEMPO) was synthesized. Detailed physical-chemical characterizations indicate that PBI-TEMPO can form smooth film, owns low unoccupied molecular orbital(LUMO) level of –3.67 eV and can reduce the work function of silver electrode. When using PBI-TEMPO as CIL in non-fullerene organic solar cells(OSCs), the PM6:BTP-4Cl based OSCs delivered high power conversion efficiencies(PCEs) up to 17.37%, higher than those using commercial PDINO CIL with PCEs of 16.95%. Further device characterizations indicate that PBI-TEMPO can facilitate more efficient exciton dissociation and reduce charge recombination, resulting in enhanced current density and fill factor. Moreover, PBI-TEMPO displays higher thermal stability than PDINO in solution. When PBI-TEMPO and PDINO solution were heated at 150 ℃ for 2 h and then were used as CIL in solar cells, PBI-TEMPO-based OSCs provided a PCE of 15%, while PDINO-based OSCs only showed a PCE of 10%. These results demonstrate that incorporating TEMPO into conjugated materials is a useful strategy to create new organic semiconductors for application in OSCs. 相似文献
982.
Kean Chen Xiaohui Shen Laibing Luo Hui Chen Ruoyu Cao Prof. Xiangming Feng Prof. Weihua Chen Prof. Yongjin Fang Prof. Yuliang Cao 《Angewandte Chemie (International ed. in English)》2023,62(47):e202312373
The solvation structure of Li+ plays a significant role in determining the physicochemical properties of electrolytes. However, to date, there is still no clear definition of the solvating power of different electrolyte solvents, and even the solvents that preferentially participate in the solvation structure remain controversial. In this study, we comprehensively discuss the solvating power and solvation process of Li+ ions using both experimental characterizations and theoretical calculations. Our findings reveal that the solvating power is dependent on the strength of the Li+-solvent (ion-dipole) interaction. Additionally, we uncover that the anions tend to enter the solvation sheath in most electrolyte systems through Li+-anion (ion-ion) interaction, which is weakened by the shielding effect of solvents. The competition between the Li+-solvent and Li+-anion interactions ultimately determines the final solvation structures. This insight into the fundamental understanding of the solvation structure of Li+ provides inspiration for the design of multifunctional mixed-solvent electrolytes for advanced batteries. 相似文献
983.
在无水无氧、超声辐射下, N-取代苄基脯氨酸苄基酯与取代苯基溴化镁反应合成了7个未见文献报道的N-苄 基-α,α-二苯基-2-吡咯烷甲醇衍生物, 其结构经IR, 1H NMR和元素分析测试确证, 并且初步生物活性测定结果表明目标化合物均有较好的杀虫活性. 相似文献
984.
As an important part of the intelligent transportation system (ITS), vehicular networks can provide drivers and passengers with more comfortable and convenient services such as efficient traffic management and infotainment. However, the security threats on data exchanges over vehicular networks have become increasingly severe. Different from conventional cryptographic technologies, the application of physical layer security (PLS) to vehicular networks has been investigated to prevent the security of exchanging data from the eavesdropper and measure precisely the leaked information to the eavesdropper, due to its low complexity and communication overhead. In this work, we are concerned with the PLS of cooperative vehicular networks consisting of a source vehicle, a destination vehicle, an eavesdropping vehicle and a cooperative jamming vehicle. First, to improve the secrecy performance, the cooperative jamming helper emits jamming signals to degrade the eavesdropping channel without harming the legitimate channel. Then, based on the Rayleigh fading channel models and the traffic models, the closed-form expressions of the secrecy outage probability (SOP) and the average secrecy capacity (ASC) of the considered vehicular networks are derived, which deliver more implications of various system parameters on SOP and ASC performances and can be computed without simulations at a lower complexity. Second, a definition of the optimal jamming vehicle is introduced and then the cooperative jamming vehicle selection strategy is presented. The existence of the optimal jamming vehicle is measured in probability, which is explored analytically. Third, the optimal power allocation that maximizes the secrecy capacity is found analytically for the source vehicle and the cooperative jamming helper. Finally, simulations are also presented to demonstrate the validation of these analytical results and confirm the advantages of the cooperative jamming strategy and the optimal power allocation. From the numerical results, more observations on the effects of the main system parameters on secrecy performances are obtained, which provides some useful guides for practice. 相似文献
985.
In this paper, we report a feasible protocol for the preparation of [1]benzopyranopyrido[d]pyrimidines via expeditious sonochemical route. The reaction efficiency was evaluated by influence of several parameters including sonication power, sonication time, different solvents, and using porous graphene/MoO3 nanocomposite as catalyst, for the first time. The effect of the ultrasonication comparing with the conventional heating on the synthesis of the titled compounds shows that the ultrasonic irradiation is required to rich the cyclized products. The structural properties of porous graphene/MoO3 nanocomposite were determined by Fourier transform infrared spectroscopy (FT‐IR), powder X‐ray diffractometry (XRD), scanning electron microscope (SEM), Raman spectroscopy, and also by TGA analysis. Confirmation of the structures of compounds 4a – 4h were also established with IR, 1H NMR, and 13C NMR spectroscopic data and also by elemental analyses. 相似文献
986.
Device-to-device (D2D) communications and non-orthogonal multiple access (NOMA) are promising technologies to meet the growing demand for IoT-connected devices. However, they bring about new challenges including the co-channel interference, that can limit the performance improvement. To manage the co-channel interference, we address the problem of joint power allocation and sub-channel assignment for D2D-enabled IoT devices (IoTDs) underlaying a NOMA-based cellular network, in which the successive interference cancellation (SIC) decoding is enabled at the level of IoTDs and cellular user equipment (CUE)to increase the number of connected devices and the capacity. This problem is modeled as a mixed-integer nonconvex optimization problem which includes the concept of fairness with respect to the data rates of IoTDs. To solve the problem, a semi-distributed algorithm is developed, which is of polynomial time complexity. The proposed algorithm leverages the successive convex approximation and a heuristic approach. Evaluation results demonstrate the efficiency of the proposed scheme with respect to the sum rate, fairness, access rate and computational complexity. 相似文献
987.
988.
《Discrete Mathematics》2022,345(11):113113
989.
990.