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61.
Hao Zhang Dr. Xu Liu Ting-Ting Lu Peng Lv Prof. Wen-Yong Lai 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(15):3909-3917
A series of monodisperse six-armed conjugated starbursts ( Tr1F , Tr2F , and Tr3F ) containing a truxene core and multibranched oligofluorene bridges capped with diphenylamine (DPA) units has been designed, synthesized, and investigated as robust gain media for organic semiconductor lasers (OSLs). The influence of electron-rich DPA end groups on their optoelectronic characteristics has been discussed at length. DPA cappers effectively raise HOMO levels of the starbursts, thus enhancing the hole injection and transport ability. Solution-processed electroluminescence devices based on the resulting six-armed starbursts exhibited efficient deep-blue electroluminescence with clear reduced turn-on voltages (3.2–3.5 V). Moreover, the resulting six-armed molecules showed stabilized electroluminescence and amplified spontaneous emission with low thresholds (27.4–63.9 nJ pulse−1), high net gain coefficients (80.1–101.3 cm−1), and small optical loss (2.6–4.4 cm−1). Distributed feedback OSLs made from Tr3F exhibited a low lasing threshold of 0.31 kW cm−2 (at 465 nm). The results suggest that the construction of truxene-centered six-armed conjugated starbursts with the incorporation of DPA units can effectively enhance EL properties by precisely regulating the HOMO energy levels, and further optimizing their optical gain properties. 相似文献
62.
Chenyang Fan Chonglin Song Gang Lv Jiangjun Wei Xuyang Zhang Yuehan Qiao Ye Liu 《Proceedings of the Combustion Institute》2019,37(4):4821-4829
Post injection has significant benefit in the reduction of diesel soot emissions. Therefore, there is a need to understand the effect of post-injection strategy on soot physicochemical properties and reactivity because they play an important role in soot oxidation process that governs the final soot emissions. This work focuses on the impact of post injection on the physicochemical properties and reactivity of diesel in-cylinder soot using a main plus post injection (M*P) and a single injection (M) strategy. The soot was sampled by a developed total cylinder sampling system, and the dividing points of soot formation-dominant and oxidation-dominant phases were used for studying the impacts of post injection on the characteristics of in-cylinder soot. The physicochemical properties of the soot samples, including primary particle size, nanostructure, carbon chemical state and surface functional groups, were characterized. The soot reactivity was evaluated in terms of peak temperature, burnout temperature and apparent activation energy. In the oxidation-dominant phase, the M*P soot initially possesses smaller primary particle size, shorter fringe length, larger tortuosity, lower sp2/sp3 hybridization ratio of carbon atoms and higher content of aliphatic CH groups than the M soot. The beneficial influence of physicochemical properties on soot reactivity when using post injection is validated by the thermogravimetric data, which shows that the M*P soot is more reactive than the M soot at the onset of the oxidation-dominant phase. In the M*P case, the soot generated from the main-injection combustion has lower reactivity than the soot from the post-injection combustion after they experience the soot formation-dominant phase. The results indicate that the use of post injection leads to in-cylinder soot with physicochemical properties that favor reactivity. The enhancement of reactivity means that the soot will be more readily oxidized in the subsequent combustion process, and consequently contributes to a reduction in final soot emissions. 相似文献
63.
Catalytic activities of NHC‐PdCl2 species based on functionalized tetradentate imidazolium salt in three types of C‐C coupling reactions
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A functionalized tetradentate imidazolium salt 9,10‐bis{di[2′‐(N‐ethylimidazolium‐1‐yl)ethyl]aminomethyl}anthracene tetrakis(hexafluorophosphate) ( 1 ) has been synthesized and characterized. The catalytic activity of the NHC‐PdCl2 species formed by compound 1 and PdCl2 was tested in Suzuki‐Miyaura, Heck‐Mizoroki and Sonogashira reactions. The results showed that this catalytic system was effective for above three types of C‐C coupling reactions. 相似文献
64.
Dr. Xiaopeng Xu Prof. Qiang Peng 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(25):e202104453
Nonfullerene acceptor based organic solar cells (NF-OSCs) have witnessed rapid progress over the past few years owing to the intensive research efforts on novel electron donor and nonfullerene acceptor (NFA) materials, interfacial engineering, and device processing techniques. Interfacial layers including electron transporting layers (ETL) and hole transporting layers (HTLs) are crucially important in the OSCs for facilitating electron and hole extraction from the photoactive blend to the respective electrodes. In this review, the lates progress in both ETLs and HTLs for the currently prevailing NF-OSCs are discussed, in which the ETLs are summarized from the categories of metal oxides, metal chelates, non-conjugated electrolytes and conjugated electrolytes, and the HTLs are summarized from the categories of inorganic and organic materials. In addition, some bifunctional interlayer materials served as both ETLs and HTLs are also introduced. Finally, the prospects of ETL/HTL materials for NF-OSCs are provided. 相似文献
65.
Kezhen Yang Taotao Lv Jiaojuan Wu Xudong Zhang Yanjun Xue Pengcheng Yu Qingguo Liu 《Biomedical chromatography : BMC》2022,36(5):e5338
Hypertension affects multiple organs in the body during the development of the disease. The antihypertensive effect of acupuncture has been confirmed. How the protective effect of electroacupuncture on the renal cortex of the spontaneously hypertensive rat (SHR) is achieved has not yet been determined. The purpose of this study was to understand the impact of electroacupuncture on the blood pressure of SHRs and the impact on metabolites in the renal cortex, looking for potential differential metabolites and then proceeding to the next step of exploratory research. The experimental animals were divided into four groups: control group, model group, electroacupuncture group and losartan potassium group. Electroacupuncture on bilateral Taichong (LR3) and Zusanli (ST36) lasted for 3 weeks, and the renal cortex was collected for metabonomics research. UHPLC–MS was used to analyze the changes in the metabolic spectrum of renal cortex tissue. The results showed that electroacupuncture can significantly reduce the blood pressure of SHRs. A total of 12 metabolites changed significantly in the comparison between each group and the model group.The possible mechanism is that the primary bile acid biosynthesis, bile secretion, tryptophan metabolism and other metabolic pathways affect the renal cortex. 相似文献
66.
Rongrong Wang Yidan Duan Xiaopeng Xiong 《Journal of polymer science. Part A, Polymer chemistry》2021,59(20):2284-2294
Increasing hydrophilicity of hydrophobic membrane is one of the strategies to improve its antifouling performance. Herein we report a procedure of reactive-vapor induced phase separation to prepare an N-vinyl pyrrolidone (NVP) modified poly(vinylidene fluoride) (PVDF) membrane to improve its hydrophilicity. PVDF solution containing NVP monomer was cast in ammonia water vapor atmosphere to prepare the modified membrane. During the process, PVDF was dehydrofluorinated by the reactive vapor of ammonia water to generate double bond of FC═CH, and then NVP was grafted. The degree of grafting modification and the microstructure evolution of the membrane were studied by adjusting the amount of NVP addition. A possible mechanism of membrane formation from crystallization gelling to non-crystallization gelling has been proposed to understand the morphology change from nodular sphere to bi-continuous microstructure with fibril matrix. It has been found that rising the degree of modification has changed the polymorph of PVDF from β to α crystalline phase, as well as turned the hydrophobic PVDF membrane into hydrophilic. Moreover, the modified membrane displayed obvious reduction in bovine serum albumin adsorption, suggesting improvement in anti-fouling performance. Therefore, our work provides an easy strategy to prepare hydrophilic PVDF membrane, which may have promising potential applications. 相似文献
67.
Ping Lv Xin Shen Zhiliyu Cui Bo Li Qiangqiang Xu Zhuo Yu Weijie Lu Haonan Shao Yan Ge Zhenhui Qi 《Journal of polymer science. Part A, Polymer chemistry》2021,59(23):3001-3008
Fiber-reinforced-concrete (FRC) mechanism refers short discrete fibers that are uniformly distributed and randomly oriented, which offers an effective way to improve the mechanical performance of concrete. In the design of supramolecular polymers, an analogous concept of FRC appears to have been considered very rarely-although fibrous structure has been frequently observed/generated during the supramolecular polymerization. In this work, we apply the alkane thermosets, octadecane (C18H38) and tetracosane (C24H50), taking the role of “concrete”, and the low-molecular-weight monomer with long alkyl chains as the essential “fiber” component, to fabricate the “fiber reinforced supramolecular polymer”. Very much like FRC mechanism in material science, the resulting fiber reinforced supramolecular polymer thus exhibit unusually high mechanical strength and stiffness, which is unprecedented in the conventional supramolecular strategy. 相似文献
68.
Lv Xinrong Wang Yanfang Wang Ying-ao Lin Xiaoyun Ni Yongnian 《Journal of Solid State Electrochemistry》2021,25(6):1871-1880
Journal of Solid State Electrochemistry - In this work, the binary nanocomposite of crosslinked polyaniline nanorods (CPANINRs) and molybdenum disulfide (MoS2) is first synthesized by in situ... 相似文献
69.
Dr. Naixia Lv Jie Yin Wendi Fu Jinrui Zhang Yujun Li Dr. Ding Jiang Dr. Hongping Li Prof. Wenshuai Zhu 《Chemphyschem》2021,22(2):168-177
The rational design of highly active hexagonal boron nitride (h-BN) catalysts at the atomic level is urgent for aerobic reactions. Herein, a doping impurity atom strategy is adopted to increase its catalytic activities. A series of doping systems involving O, C impurities and B, N antisites are constructed and their catalytic activities for molecular O2 have been studied by density functional theory (DFT) calculations. It is demonstrated that O2 is highly activated on ON and BN defects, and moderately activated on CB and CN defects, however, it is not stable on NB and OB defects. The subsequent application in oxidative desulfurization (ODS) reactions proves the ON and C-doped (CB, CN) systems to be good choice for sulfocompounds oxidization, especially for dibenzothiophene (DBT). While the BN antisite is not suitable for such aerobic reaction due to the extremely stable B−O*−B species formed during the oxidation process. 相似文献
70.
Based on previous works, most of the transition metal phosphides (TMPs) were directly prepared by decomposing NaH2PO2 with the precursors at high temperatures, which resulted in different degrees of phosphidation in the final product. Therefore, it is necessary to design an innovative approach to enhance the degree of phosphidation in the material using crystal defects. Here, oxygen-vacancy iron oxide/iron foam (Ov-Fe2O3/IF) was firstly prepared by generating oxygen vacancy in situ in an iron foam through heating in vacuum conditions. Subsequently, FeP/IF was formed by phosphating Ov-Fe2O3/IF. Under the effects of oxygen vacancies, oxygen-vacancy iron oxide could be completely phosphatized to produce more active sites on the surface of the material. This, in turn, could result in a catalyst with exceptional hydrogen evolution activity. Thus, the successful fabrication of FeP/IF demonstrated in this work provides an effective and feasible way for the preparation of other high-efficiency catalysts. 相似文献