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This paper summarizes the community where people live development laws and proposes a novel meta-heuristic called community development algorithm (CDA). To enhance the optimization process, CDA innovatively designed two unique attraction effects based on the degree of people's direct contribution to society and abstracted four novel inter-particle learning ways based on people's four social activities: Marriage, Entrepreneurship, Working, and University. Theoretically, it is demonstrated that CDA can satisfactorily balance the exploration and the exploitation stages, and necessary and sufficient conditions for CDA convergence are derived. The 59 functions of Congress on Evolutionary Computation 2014 and 2017 are introduced as the benchmark. Under the pressure of other 32 well-known meta-heuristics, statistical results, including averages, standard deviations, rank-sum tests, and sign-rank tests, as well as graphical results, including convergence curves and box plots, confirm that CDA is competent for solving numerical optimization problems with efficiency and reliability. Significantly, the quantitative analysis demonstrated that CDA's average ranking is ahead of the emperor penguin optimizer by 73.5% while ahead of the fully informed search algorithm by 62.1%, respectively. Additionally, the scalability and fastness of CDA are validated by scalability and wall clock time analysis, and the classical application of Congress on Evolutionary Computation 2011 demonstrates the outstanding accuracy and stability of CDA. Finally, CDA is utilized to optimize the controller parameter in the main steam temperature control system of the supercritical unit. The control response curves show that CDA generally provides better parameters than compared algorithms, demonstrating the merits and potential to solve complex real-world engineering problems. [ABSTRACT FROM AUTHOR]

Most high-performance organic solar cells (OSCs) are so far fabricated using halogenated solvents, which are environmentally hazardous. Therefore, it is imperative to develop high-efficiency OSCs processed by more environmentally friendly solvents. Perylene diimides (PDIs) based acceptors have become one of the most promising candidates for nonfullerene OSCs owing to their outstanding optoelectronic properties. However, PDIs-based ternary OSCs are rarely investigated, let alone the green-solvent processed ones. In this study, non-halogenated solvent processed ternary OSCs using a star-shaped helical perylene diimide (TPDI2) and ITIC as acceptors, PTB7-Th as donor, were fabricated and characterized. The best power conversion efficiency (PCE) of the ternary OSCs were 8.22%, which showed a PCE improvement over 18% comparing to the reference binary blend devices (6.95%). The PCE of 8.22% is among the highest performance reported to date for PDIs-based OSCs devices processed using non-halogenated solvent (without additives). Image 1 • Efficient helical perylene diimide based ternary organic solar cells processed with single non-halogenated solvent. • ITIC plays a vital role in improving the charge transport properties of the ternary blends. • The PCE of PDIs-based ternary OSCs processing by non-halogenated solvents achieved 8.22%. [ABSTRACT FROM AUTHOR]

Multifunctional and easily-controlled self-healing rubbers with high performance are booming and have great potential in a wide range of applications. In this paper, natural rubber/zinc dimethacrylate/carbon nanotube (NR/ZDMA/CNT) composites with satisfactory mechanical strength, photothermal conversion and accurate self-healing were developed. CNC is used to assist the dispersion of CNT into NR and ZDMA is generated in situ reaction of ZnO and MAA. The self-healing capacity of the composites is realized through ionic supramolecular network constructed by regulating the DCP-induced vulcanization of NR/ZDMA. The compatibility between CNT and NR matrix is enhanced by establishing non-covalent interactions through ionic clusters of the supramolecular network, thus, the mechanical properties of composites are significantly improved. As a result, the tensile strength of NR/ZDMA/CNT-7 reaches ∼7.8 MPa, and it can recover tensile strength of ∼65% at room temperature. The photothermal effect of CNT can effectively promote the self-healing process, and also endow the composites with NIR-actuated accurate self-healing. After activated by NIR laser for 60 min, the healing efficiency of NR/ZDMA/CNT-7 can reach 90%. Furthermore, the composites have great potential application in thermoelectric conversion. Therefore, this kind of high-performance self-healing rubber with photothermal conversion and accurate self-healing has broader application prospect in various scenarios. [Display omitted] • Non-covalent interaction is constructed between natural rubber and fillers. • The contradiction between mechanical properties and self-healing is reconciled. • NR composites with photothermal conversion apply in thermoelectric conversion. • The composites show accurate self-healing performance under NIR light. [ABSTRACT FROM AUTHOR]

To achieve self-healing for commercial rubbers, the current mainstream strategy is to equip rubber molecules with essential functional groups by chemical modifications. However, different structure of rubber molecules determines a disparate optimal self-healing mechanism, which turns out a consequent complex and multifarious chemical modifications for them. In other words, the same modification method cannot be applied to various rubbers, which is partly a limitation on the preparation of self-healing rubbers. Herein, we propose a concept of self-healing masterbatch which can effectively endow rubber matrix with self-healing ability via a facile processing method. We design this rubber masterbatch equipped with a mass of carboxyl groups by the grafting reaction between natural rubber and 2-methacrylic acid. Then the rubber masterbatch can be mixed with rubber matrix and simultaneously ZnO must be added to introduce Zn2+ via its neutralization reaction with the masterbatch. After a controlled peroxide-induced vulcanization, the chains of masterbatch are grafted onto the chains of rubber matrix and then a reversible Zn2+ crosslinking network is generated. Based on above method, natural rubber, styrene butadiene rubber and cis -polybutadiene rubber successfully earn considerable self-healing ability, showing a self-healing efficiency of >90%. Furthermore, based on the reversible non-covalent interactions between the carboxyl groups of the self-healing masterbatch and inorganic substrates, the self-healing masterbatch can recover its adhesion and reuse to bond the cements together, showing a "dynamic reversible adhesion". We hope this concept of self-healing masterbatch could open up a feasible and versatile avenue to prepare self-healing rubbers based on reversible non-covalent interactions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Covalent crosslinks were introduced into ionic supramolecular network. • Permanent covalent crosslinks effectively enhance natural rubber. • The effects of covalent crosslinks on the self-healing were studied systematiclly. • Mechanical properties and self-healing effect of natural rubber was balanced. Introducing covalent crosslinks into reversible supramolecular networks would effectively improve their mechanical strengths, but sacrificed the desired self-healing effect. So, it is a practical significance to explore the influence of irreversible covalent crosslinks on self-healing behavior to prepare self-healing rubbers with enhanced mechanical properties for further application. In this study, the trade-off of covalent crosslinks between the balanced mechanical properties and self-healing effect of a natural rubber/methacrylic acid/zinc oxide (NR/MAA/ZnO) supramolecular network system was studied. Zinc dimethacrylate (ZDMA) is in situ formed from MAA and ZnO during the mastication of NR, which introduce mass of ionic crosslinks to generate a reversible ionic supramolecular network at the initial stage of peroxide-induced vulcanization at 140℃. Then, free radicals continue to initiate covalent crosslinks to strengthen the NR matrix. The tensile strength of NR with slight covalent crosslinks could achieve 1.63 ∼ 3.86 MPa when vulcanization time keeps in 240 ∼ 360 s. At this time, primary continuous covalent crosslink network has little binding effect on rubber chains, and ionic interactions can be smoothly reorganized to ensure excellent self-healing behavior. The considerable self-healing efficiency of 67%∼95% indicates that the vulcanization time at 240 ∼ 360 s is an appropriate choice to achieve a win–win situation for the mechanical properties and self-healing efficiency of NR/MAA/ZnO composites. [ABSTRACT FROM AUTHOR]

Most of the dynamic covalent bonds (DCBs) for self-healing rubber must be activated at relatively high temperatures due to the requirement of high energy during the exchange of dynamic bonds, which may lead to unexpected degradation or excessive crosslinking of rubber. Herein, we designed and fabricated a highly stretchable, self-healable and reprocessable rubber by introducing dynamic disulfide bonds into the crosslink network of epoxidized natural rubber (ENR). Lipoic acid (LA) was firstly uniformly dispersed into ENR via a latex film formation technique, and then underwent a dynamic covalent ring-opening self-polymerization during hot pressing process, during which the carboxyl group of poly(LA) attacked the epoxy group of ENR to form β-hydroxyl ester bond crosslinks. As a result, a revisable covalently crosslinked network without rigid steric hindrance groups was constructed, which exhibited a super self-healing efficiency of 99 % after self-healing at 80 °C for only 3 h. The elongation at break of the elastomer could reach 1115 % and the recovery rate of reprocessing was as high as 91 %. [Display omitted] • Self-healing at a mild temperature (80 °C) to avoid the adverse effect of high temperature on rubbers • The disulfide bonds of LA own smaller steric hindrance which effectively shortens the time of self-healing. • Highly stretchability (the elongation at break was as high as 1115 %) • Fast and efficient self-healing (the healing efficiency ∼99 % after self-healing at 80 °C for 3 h) • Good reprocessing (the recovery rate of the 1st the 2nd reprocessing were 91 % and 88 %, respectively) [ABSTRACT FROM AUTHOR]

As smart materials, piezoelectric ceramics played an important role in actuation, sensing, structural health monitoring and vibration damping systems. This letter reports a novel structure of shear piezoelectric fiber composites (SPFC), which was polarized in the thickness direction, and drived on the transverse direction with interdigitated electrodes. Under a driving condition of 270 V at 0.1 Hz, a fixed SPFC showed a shear strain of 176.5 ppm and a Mylar membrane cantilever beam structure exhibited a tip displacement of 0.343 mm, corresponding to an effective piezoelectric constant d 15 of 400 pm/V. These results provide a novel idea for the SPFC applied in actuation and vibration control areas. [ABSTRACT FROM AUTHOR]

The proposal of S-scheme heterojunction reveals the principle of a new photocatalysis mechanism, which is superior to the effect of traditional heterojunction, and provides a strong guarantee for the development of photocatalysis technology. In this work, BiOIO 3 rich in oxygen vacancies was obtained by a simple calcination method, and then N-CQDs were anchored to the surface of OVs-BiOIO 3 to obtain OVs-BiOIO 3 /N-CQDs composites. The prepared OVs-BiOIO 3 /N-CQDs and the band gap structure matched g-C 3 N 4 were constructed to form a N-CQDs mediated S-scheme heterostructure, and finally the OVs-BiOIO 3 /N-CQDs/g-C 3 N 4 ternary composite was obtained. The structure, morphology and photocatalytic efficiency of the composite were obtained by a series of characterization such as SEM, TEM, XRD, FT-IR, PL, EIS, etc. The results show that, when the reaction conditions is 150 °C and 8 h, the catalyst OVs-BiOIO 3 /N-CQDs/g-C 3 N 4 has the best degradation of 70.5%, which is 1.55 times and 1.24 times OVs-BiOIO 3 (45.6%) and g-C 3 N 4 (56.7%) respectively. The results of reactive species trapping experiment showed that ·O 2 −、·OH play a major role in the photocatalytic process. Conclusively, the mechanism of N-CQDs mediated S-scheme heterojunction is proposed by analyzing all the results. [ABSTRACT FROM AUTHOR]

Abstract Lycium barbarum polysaccharide-doxorubicin (LBP-DOX) nanoparticles were synthesized via a one-step Schiff base reaction between oxidized Lycium barbarum polysaccharide (oxidized LBP) and doxorubicin (DOX). The structure of LBP-DOX nanoparticles was characterized by multi-spectral methods, 1H nuclear magnetic resonance (1H NMR), transmission electron microscopy (TEM), and thermo gravimetric analysis (TGA). The rheological properties of LBP-DOX nanoparticles were studied. With the increase of shear rate, the viscosity of LBP and LBP-DOX nanoparticles gradually decreases at 25 °C. Under the same strain, the storage modulus (G′) and loss modulus (G″) of LBP-DOX nanoparticles were inferior to LBP. The DOX release from LBP-DOX nanoparticles was pH-dependent and was accelerated by decreasing pH. Cytotoxicity study showed that the LBP-DOX nanoparticles have significantly enhanced cytotoxicity in vitro, especially for human Hepatic cancer cell line HepG2. Highlights • LBP-DOX nanoparticles were synthesized by Schiffe base reaction. • Oxidation of LBP aldehyde groups can increase reaction efficiency and reduce side effects. • LBP-DOX nanoparticles have better the pH-responsive. • LBP-DOX nanoparticles are high cytotoxicity to tumor cells. [ABSTRACT FROM AUTHOR]

The perovskite structured lead-free system Na 0.5 Bi 0.5 TiO 3 (NBT) whiskers were synthesized from whiskers of layered tunnel structured Na 2 Ti 6 O 13 (NT), using a topochemical route. Both NT and NBT whiskers show high aspect ratios with an average length of 15 µm and diameter of 1 µm. By prolonging the reaction time from 2 h to 6 h at 900 °C, NT whiskers with monoclinic phase completely transformed to NBT whiskers with pseudocubic phase. Typical strip-like nanodomains are observed in a NBT whisker, which are parallel to each other. The piezoelectric response amplitude for a NBT whisker indicates a large electric field induced strain, corresponding to a S max / E max value of as high as 300 pm/V. This work provides an in-depth instruction to prepare pure NBT whiskers, and gives the detailed piezoelectricity of NBT whiskers to promote their applications in energy harvesting and micro-electromechanical systems. [ABSTRACT FROM AUTHOR]

Abundant geothermal springs occur along the Moxi fault located in western Sichuan Province (the eastern edge of the Qinghai-Tibet plateau), highlighted by geothermal water outflow with an unusually high temperature of 218 °C at 21.5 MPa from a 2010-m borehole in Laoyulin, Kangding. Earthquake activity occurs relatively more frequently in the region and is considered to be related to the strong hydrothermal activity. Geothermal waters hosted by a deep fault may provide evidence regarding the deep underground; their aqueous chemistry and isotopic information can indicate the mechanism of thermal springs. Cyclical variations of geothermal water outflows are thought to work under the effect of solid earth tides and can contribute to understanding conditions and processes in underground geo-environments. This paper studies the origin and variations of the geothermal spring group controlled by the Moxi fault and discusses conditions in the deep ground. Flow variation monitoring of a series of parameters was performed to study the geothermal responses to solid tides. Geothermal reservoir temperatures are evaluated with Na-K-Mg data. The abundant sulfite content, dissolved oxygen (DO) and oxidation-reduction potential (ORP) data are discussed to study the oxidation-reduction states. Strontium isotopes are used to trace the water source. The results demonstrate that geothermal water could flow quickly through the Moxi fault the depth of the geothermal reservoir influences the thermal reservoir temperature, where supercritical hot water is mixed with circulating groundwater and can reach 380 °C. To the southward along the fault, the circulation of geothermal waters becomes shallower, and the waters may have reacted with metamorphic rock to some extent. Our results provide a conceptual deep heat source model for geothermal flow and the reservoir characteristics of the Moxi fault and indicate that the faulting may well connect the deep heat source to shallower depths. The approach of hot spring variation research also has potential benefits for earthquake monitoring and prediction. [ABSTRACT FROM AUTHOR]

Owing to the unfavorable wetting and density difference between graphene and copper, it remains challenging to achieve homogeneous dispersion of graphene for utilizing the unique nature of graphene in copper matrix composites. Here, we design an in-situ process to fabricate graphene-like carbon (GLC) reinforcing copper matrix composites: GLC can be directly fabricated on commercial copper particles using modified PECVD method followed by vacuum hot pressing, which is high-efficiency and can be massively produced for graphene reinforced metal matrix composites in industrial level. After hot pressing, the GLC with ultralow content (170 to 350 ppm) can be uniformly dispersed and tightly embedded within the copper matrix. A remarkable thermal conductivity enhancement efficiency of 85% and enhanced thermal conductivity (439 W m−1 K−1), accompanied by the higher wear resistance, can be obtained in our GLC reinforced copper matrix composites. In actual arc ablation performance measurement, the breakdown strength and relative arc ablation resistance of GLC/Cu composites can be significantly improved by 106.5% and 33.3% than pure copper, respectively, demonstrating GLC/Cu composites a promising candidate for application as high voltage electrical contacts. [Display omitted] • A facile method for in-situ synthesis of graphene-like carbon reinforced copper matrix composites is developed. • A remarkable thermal conductivity enhancement efficiency and enhanced thermal conductivity can be achieved. • The graphene-like carbon reinforced composites demonstrate a promising candidate for application as electrical contacts. • This work provides an efficient synthesis method for mass production of graphene reinforced metal matrix composites. [ABSTRACT FROM AUTHOR]

The ethylene fused PDI oligomers, especially for the dimer (PDI2), have emerged as alternative building blocks to the parent PDI in constructing NFAs owing to their outstanding optoelectronic properties, twisted configurations as well as concise gram-scale synthesis. In this work, a non-fullerene acceptor (NFA) based on tetraphenylethylene (TPE) core flanked with four PDI2 units, coded as TPE-4PDI2 , was designed and synthesized. The analogue (TriPE-3PDI2) which consists of triphenylethylene (TriPE) and three PDI2 panels was synthesized for comparison. OSCs based on TPE-4PDI2 show a best PCE of 7.10%, which is much higher than that of TriPE-3PDI2 based ones. Moreover, this PCE is also higher than that of TPE-4PDI based devices (5.53%). To the best of our knowledge, the PCE of 7.10% is among the highest values for TPE-cored NFAs based OSCs. These results indicate that PDI2 is a promising building block for constructing high performance NFAs. And this work provides a facile and effective molecule-designing method to promote the PCE of PDI based non-fullerene OSCs. Image 1 • Two PDI2 based non-fullerene acceptors were designed and synthesized. • TPE-4PDI2 based devices obtained a much higher PCE of 7.10% than did TriPE-3PDI2 based OSCs. • PDI2 is a promising building block for constructing high performance NFAs. [ABSTRACT FROM AUTHOR]

In this work, the new polysaccharide-platinum conjugates of 5-aminosalicylic acid modified lycium barbarum polysaccharide linking platinum compounds were designed in order to construct an anticancer metal drug delivery system. The multiple analysis methods were used to describe the chemical structure and physical properties of the polysaccharide-metal conjugates. The results showed that 5-aminosalicylic acid successfully acted as linker which was covalently bound between polysaccharide and platinum compound. The morphology and rheological properties of polysaccharide have been changed by the formation of conjugates, which exhibited certain inhibition specificity to A549 (human lung cancer cell line). The agarose gel electrophoresis and fluorescence microscopy results demonstrated that such conjugates promoted the unwinding of DNA and could significantly damage the nucleus of A549 cells. Cell cycle analyzing the Pt complex of conjugates could cause intracellular DNA damage and induced G2 phase arrest. So, polysaccharide-platinum conjugates might find a range of applications, for example in metal anticancer drug delivery. The new polysaccharide-platinum conjugates of 5-aminosalicylic acid modified lycium barbarum polysaccharide linking platinum compound were designed in order to construct the anticancer metal drug delivery system. Unlabelled Image • Polysaccharide-5-aminosalicylic acid conjugates exhibited better antioxidant ability. • Lycium barbarum polysaccharide as a drug carrier can reduce side effects. • The carboxyl groups of polysaccharide-5-aminosalicylic acid were combined with platinum. • Polysaccharide-platinum conjugates exhibited remarkable anti-tumor activity in vitro. • The rheological properties of modified polysaccharides were changed. [ABSTRACT FROM AUTHOR]