A robust hole transporting layer (HTL), using the cost‐effective Cobalt(II) acetate tetrahydrate (Co(OAc)2⋅4 H2O) as the precursor, was simply processed from its aqueous solution followed by thermal annealing (TA) and UV‐ozone (UVO) treatments. The TA treatment induced the loss of crystal water followed by oxidization of Co(OAc)2⋅4 H2O precursor, which increased the work function. However, TA treatment differently realize a high work function and ideal morphology for charge extraction. The resulting problems could be circumvented easily by additional UVO treatment, which also enhanced the conductivity and lowered the resistance for charge transport. The optimal condition was found to be a low temperature TA (150 °C) followed by simple UVO, where the crystal water in Co(OAc)2⋅4 H2O was removed fully and the HTL surface was anchored by substantial hydroxy groups. Using PM6 as the polymer donor and L8‐BO as the electron acceptor, a record high PCE of 18.77 % of the binary blend OSCs was achieved, higher than the common PEDOT:PSS‐based solar cell devices (18.02 %).
On the basis of the inhibition of double strand DNA (dsDNA)-templated fluorescent copper nanoparticles (CuNPs) by pyrophosphate (PPi), a novel label-free turn-on fluorescent strategy to detect alkaline phosphatase (ALP) under physiological conditions has been developed. This method relies on the strong interaction between PPi and Cu(2+), which would hamper the effective formation of fluorescent CuNPs, leading to low fluorescence intensity. The ALP-catalyzed PPi hydrolysis would disable the complexation between Cu(2+) and PPi, facilitating the formation of fluorescent CuNPs through the reduction by ascorbate in the presence of dsDNA templates. Thus, the fluorescence intensity was recovered, and the fluorescence enhancement was related to the concentration of ALP. This method is cost-effective and convenient without any labels or complicated operations. The present strategy exhibits a high sensitivity and the turn-on mode provides a high selectivity for the ALP assay. Additionally, the inhibition effect of phosphate on the ALP activity was also studied. The proposed method using a PPi substrate may hold a potential application in diagnosis of ALP-related diseases or evaluation of ALP functions in biological systems.
Abstract-Large-scale wireless sensor networks are expected to play an increasingly important role in future civilian and military settings. Collaborative microsensors could be very effective in monitoring their operations. However, low power and in-network data processing make data-centric routing in wireless sensor networks a challenging problem. In this paper we propose heuristics to construct and maintain an aggregation tree in sensor networks. This aggregation tree can be used to facilitate data-centric routing. The main idea is to turn off the radio of all leaf nodes to save power, and thereby extending the network lifetime. Therefore, in order to save the number of broadcasting messages, only the non-leaf nodes in the tree are in charge of data aggregation and traffic relaying.In this paper, we propose an efficient energy-aware distributed heuristic to generate the aggregation tree, which we refer to as EADAT. Our EADAT algorithm makes no assumption on local network topology, and is based on residual power. It makes use of neighboring broadcast scheduling and distributed competition among neighbors. These novel concepts make EADAT very efficient and effective, as demonstrated by our simulation experiments with NS2.
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