248 research outputs found

    Design of fl uid pipeline leakage signal acquisition system

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    Fluid, namely liquid and gas, is a necessary resource in national production and life, so fl uid plays a pivotal role in the progress of the whole society and the development of human civilization. If the fl uid leaks, and is not found and treated in time, it will cause huge material losses and waste of resources, what is more, it will cause irreversible environmental damage. This paper takes fl uid pipeline leakage detection as the main research object, the main research is as follows: According to the steady-state pipeline as the main analysis goal, C8051F040 single chip microcomputer as the main processor, DS18B20 temperature sensor, CEMPX221 pressure sensor, LWGY-C model turbine fl owmeter for data acquisition, and the collected data through the CAN interface, RS485 interface to the host computer

    Neutral Models of Microbiome Evolution

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    There has been an explosion of research on host-associated microbial communities (i.e.,microbiomes). Much of this research has focused on surveys of microbial diversities across a variety of host species, including humans, with a view to understanding how these microbiomes are distributed across space and time, and how they correlate with host health, disease, phenotype, physiology and ecology. Fewer studies have focused on how these microbiomes may have evolved. In this paper, we develop an agent-based framework to study the dynamics of microbiome evolution. Our framework incorporates neutral models of how hosts acquire their microbiomes, and how the environmental microbial community that is available to the hosts is assembled. Most importantly, our framework also incorporates a Wright-Fisher genealogical model of hosts, so that the dynamics of microbiome evolution is studied on an evolutionary timescale. Our results indicate that the extent of parental contribution to microbial availability from one generation to the next significantly impacts the diversity of microbiomes: the greater the parental contribution, the less diverse the microbiomes. In contrast, even when there is only a very small contribution from a constant environmental pool, microbial communities can remain highly diverse. Finally, we show that our models may be used to construct hypotheses about the types of processes that operate to assemble microbiomes over evolutionary time

    Models of microbiome evolution incorporating host and microbial selection

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    BACKGROUND: Numerous empirical studies suggest that hosts and microbes exert reciprocal selective effects on their ecological partners. Nonetheless, we still lack an explicit framework to model the dynamics of both hosts and microbes under selection. In a previous study, we developed an agent-based forward-time computational framework to simulate the neutral evolution of host-associated microbial communities in a constant-sized, unstructured population of hosts. These neutral models allowed offspring to sample microbes randomly from parents and/or from the environment. Additionally, the environmental pool of available microbes was constituted by fixed and persistent microbial OTUs and by contributions from host individuals in the preceding generation. METHODS: In this paper, we extend our neutral models to allow selection to operate on both hosts and microbes. We do this by constructing a phenome for each microbial OTU consisting of a sample of traits that influence host and microbial fitnesses independently. Microbial traits can influence the fitness of hosts ("host selection") and the fitness of microbes ("trait-mediated microbial selection"). Additionally, the fitness effects of traits on microbes can be modified by their hosts ("host-mediated microbial selection"). We simulate the effects of these three types of selection, individually or in combination, on microbiome diversities and the fitnesses of hosts and microbes over several thousand generations of hosts. RESULTS: We show that microbiome diversity is strongly influenced by selection acting on microbes. Selection acting on hosts only influences microbiome diversity when there is near-complete direct or indirect parental contribution to the microbiomes of offspring. Unsurprisingly, microbial fitness increases under microbial selection. Interestingly, when host selection operates, host fitness only increases under two conditions: (1) when there is a strong parental contribution to microbial communities or (2) in the absence of a strong parental contribution, when host-mediated selection acts on microbes concomitantly. CONCLUSIONS: We present a computational framework that integrates different selective processes acting on the evolution of microbiomes. Our framework demonstrates that selection acting on microbes can have a strong effect on microbial diversities and fitnesses, whereas selection on hosts can have weaker outcomes.This research was supported by funds to QZ and AR from Duke University

    catena-Poly[[dianilinedichloridocopper(II)]-μ2-2,5-bis­(4-pyrid­yl)-1,3,4-oxadiazole]

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    In the title compound, [CuCl2(C6H7N)2(C12H8N4O)]n, the Cu atom, located on an inversion center, is coordinated by four N atoms from two aniline ligands and two 2,5-bis­(4-pyrid­yl)-1,3,4-oxadiazole ligands. Two Cl atoms lying above and below the plane formed by these four N atoms inter­act weakly with the Cu atom [Cu—Cl = 2.7870 (7) Å]. The trans 2,5-bis­(4-pyrid­yl)-1,3,4-oxadiazole ligands act as bridging ligands, linking adjacent Cu atoms and forming a one-dimensional coordination polymer. Two anilines coordinate with each Cu atom as terminal groups. The structure contains two classical N—H⋯Cl and two non-classical C—H⋯Cl hydrogen bonds

    Poly[(μ2-3,6-di-4-pyridyl-1,2,4,5-tetra­zine)(μ2-thio­cyanato)copper(I)]

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    The title compound, [Cu(NCS)(C12H8N6)]n, is a self-assembled two-dimensional metal–organic network. The Cu atom is linked by two N atoms from two 3,6-di-4-pyridyl-1,2,4,5-tetra­zine ligands and by the N and S atoms from two thio­cyanate ligands in a distorted tetra­hedral environment. The Cu atom and the thio­cyanate ligand occupy a crystallographic mirror plane m, and a crystallographic inversion centre is in the middle of the tetra­zine ring, generating the zigzag fashion of the two-dimensional network. The infinite –Cu—SCN—Cu—SCN– chain is due to translational symmetry along the a axis. These chains are further connected through the 3,6-di-4-pyridyl-1,2,4,5-tetra­zine ligands that bridge the CuI centers, generating a two-dimensional network. There are π—π stacking inter­actions between the pyridine and tetra­zine rings (perpendicular distances of 3.357 and 3.418 Å), with a centroid–centroid distance of 3.6785 (16) Å

    Cooperative Advertising in a Supply Chain with Horizontal Competition

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    Cooperative advertising programs are usually provided by manufacturers to stimulate retailers investing more in local advertising to increase the sales of their products or services. While previous literature on cooperative advertising mainly focuses on a “single-manufacturer single-retailer” framework, the decision-making framework with “multiple-manufacturer single-retailer” becomes more realistic because of the increasing power of retailers as well as the increased competition among the manufacturers. In view of this, in this paper we investigate the cooperative advertising program in a “two-manufacturer single-retailer” supply chain in three different scenarios; that is, (i) each channel member makes decisions independently; (ii) the retailer is vertically integrated with one manufacturer; (iii) two manufacturers are horizontally integrated. Utilizing differential game theory, the open-loop equilibrium-advertising strategies of each channel member are obtained and compared. Also, we investigate the effects of competitive intensity on the firm’s profit in three different scenarios by using the numerical analysis

    Cooperative Advertising in a Supply Chain with Horizontal Competition

    Get PDF
    Cooperative advertising programs are usually provided by manufacturers to stimulate retailers investing more in local advertising to increase the sales of their products or services. While previous literature on cooperative advertising mainly focuses on a "singlemanufacturer single-retailer" framework, the decision-making framework with "multiple-manufacturer single-retailer" becomes more realistic because of the increasing power of retailers as well as the increased competition among the manufacturers. In view of this, in this paper we investigate the cooperative advertising program in a "two-manufacturer single-retailer" supply chain in three different scenarios; that is, (i) each channel member makes decisions independently; (ii) the retailer is vertically integrated with one manufacturer; (iii) two manufacturers are horizontally integrated. Utilizing differential game theory, the open-loop equilibriumadvertising strategies of each channel member are obtained and compared. Also, we investigate the effects of competitive intensity on the firm's profit in three different scenarios by using the numerical analysis
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