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Several consensus protocols have been proposed in the literature and their convergence properties studied via a variety of methods. In all these methods, the communication topologies play a key role in the convergence of consensus processes. The goal of this paper is two fold. First, we explore communication topologies, as implied by the communication assumptions, that lead to consensus among agents. For this, several important results in the literature are examined and the focus is on different classes of communication assumptions being made, such as synchronism, connectivity, and direction of communication. In the latter part of this paper, we show that the confluent iteration graph unifies various communication assumptions and proves to be fundamental in understanding the convergence of consensus processes. In particular, based on asynchronous iteration methods for nonlinear paracontractions, we establish a new result which shows that consensus is reachable under directional, time-varying and asynchronous topologies with nonlinear protocols. This result extends the existing ones in the literature and have many potential applications.

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The hydrocarbon charge history of the Paleogene in the northern Dongpu Depression was analyzed in detail based on a comprehensive analysis of the generation and expulsion history of the major hydrocarbon source rocks, fluorescence microscopic features and fluid inclusion petrography. There were two main stages of hydrocarbon generation and expulsion of oil from the major hydrocarbon source rocks. The first stage was the main hydrocarbon expulsion stage. The fluorescence microscopic features also indicated two stages of hydrocarbon accumulation. Carbonaceous bitumen, asphaltene bitumen and colloidal bitumen reflected an early hydrocarbon charge, whereas the oil bitumen reflected a second hydrocarbon charge. Hydrocarbon inclusions also indicate two distinct charges according to the diagenetic evolution sequence, inclusion petrography features combined with the homogenization temperature and reservoir burial history analysis. According to these comprehensive analysis results, the hydrocarbon charge history of the Paleogene reservoir in the northern Dongpu Depression was divided into two phases. The first phase was from the late Dongying depositional period of the Oligocene to the early uplift stages of the late Paleogene. The second phase was from the late Minghuazhen period of the Pliocene to the Quaternary. Reservoirs formed during the first period were widely distributed covering the entire area. In contrast, reservoirs formed during the second period were mainly distributed near the hydrocarbon generation sags. Vertically, it was characterized by a single phase in the upper layers and two phases in the lower layers of the Paleogene.

The vapor−liquid equilibrium (VLE) data of different mass fractions of the mixture (ethyl fluoride (HFC-161) + alkylbenzene (AB) lubricant oil) at a temperature range from (278.15 to 348.15) K were measured by single-phase cycle method, and the solubility and miscibility for the mixture (HFC-161 + AB lubricant oil) were analyzed in this paper. The experimental results showed that there was no stratification, no sediment generation, and no color change during the whole experiment for the mixture (HFC-161 + AB lubricant oil). The vapor pressure decreased with the increase of oil concentration. The experimental results were correlated by the nonrandom two-liquid (NRTL) equation. The parameters of the NRTL equation were regressed. From the correlated results, the average relative pressure deviation was 1.4 %, and the maximum relative pressure deviation was 4.2 %. Meanwhile, the results were compared with those of the HFC-161 + polyol ester (POE) lubricant oil mixture in the temperature range of (278.15 to 328.15) K. For a given HFC-161 mass fraction and temperature, HFC-161 is more soluble in POE lubricant oil than in AB lubricant oil. In this work, AB lubricant oil may be a better choice for HFC-161 than POE lubricant oil to some extent.