An exact diagnostic formalism for finite-amplitude eddy-mean flow interaction is developed for barotropic and quasigeostrophic baroclinic flows on the beta plane. Based on the advection-diffusion-reaction equation for potential vorticity (PV), the formalism quantifies both advective and diffusive contributions to the mean flow modification by eddies, of which the latter is the focus of the present article. The present theory adopts a hybrid Eulerian-Lagrangian-mean description of the flow and defines finite-amplitude wave activity in terms of the areal displacement of PV contours from zonal symmetry. Unlike previous formalisms, wave activity is readily calculable from data and the local Eliassen-Palm relation does not involve cubic or higherorder terms in eddy amplitude. This leads to a natural finite-amplitude extension to the local nonacceleration theorem, as well as the global stability theorems, in the inviscid and unforced limit. The formalism incorporates mixing with effective diffusivity of PV, and the diffusive flux of PV is shown to be a sink of wave activity. The relationship between the advective and diffusive fluxes of PV and its implications for parameterization are discussed in the context of wave activity budget. If all momentum associated with wave activity were returned to the zonal-mean flow, a balanced eddy-free flow would ensue. It is shown that this hypothetical flow u REF is unaffected by the advective PV flux and is driven solely by the diffusive PV flux and forcing. For this reason, u REF , rather than the zonal-mean flow, is proposed as a diagnostic for the diffusive mean-flow modification. The formalism is applied to a freely decaying beta-plane turbulence to evaluate the contribution of the diffusive PV flux to the jet formation.

This work presents a mixed-ligand metal−organic framework (m-MOF) integrated with two ligands, one as a luminophore and the other as a coreactant, on one metal node for self-enhanced electrochemiluminescence (ECL). Both 9,10-di(pcarboxyphenyl)anthracene (DPA) and 1,4-diazabicyclo[2.2.2]octane (D-H 2 ) ligands can be oxidized, generating the cation radicals DPA +• and D-H 2 +• , respectively. The latter can be deprotonated to form the neutral radical (D-H • ) and then react with DPA +• to produce excited DPA* for ECL emission without exogenous coreactants. As a result of the incorporation into the MOF framework and the intrareticular charge transfer between the two ligands, the ECL intensity of the m-MOF was increased 26.5-fold compared with that of the mixture of DPA and D-H 2 in aqueous solution. Moreover, with the process of second oxidation of D-H 2 , stepwise ECL emission was observed as a result of local excitation in the DPA unit, which was identified through density functional theory calculations. Overall, the implementation of the mixed-ligand approach, which combines the luminophore and coreactant as linkers in reticular materials, enriches the fundamentals and applications of ECL systems.

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SUMMARYConventional methods of slices used for slope stability analysis satisfying all equilibrium conditions involves generally solving two highly non-linear equations with respect to two unknowns, i.e. the factor of safety and the associated scaling parameter. To solve these two equations, complicated numerical iterations are required with non-convergence occasionally occurring. This paper presents an alternative procedure to derive the three equilibrium equations (horizontal and vertical forces equations and moment equation) based on an assumption regarding the normal stress distribution along the slip surface. Combination of these equations results in a single cubic equation in terms of the factor of safety, which is explicitly solved. Theoretical testing demonstrates that the proposed method yields a factor of safety in reasonable agreement with a closed-form solution based on the theory of plasticity. Example studies show that the difference in values of factor of safety between the proposed method, the Spencer method and the Morgenstern-Price method is within 5%. Application of the proposed method to practical slope engineering problems is rather straightforward, but its solution is of the same precision as those given by the conventional rigorous methods of slices since it is still within the rigorous context.

An outbreak of suspected iridovirus disease in cultured hybrid grouper (♀Tiger Grouper Epinephelus fuscoguttatus × ♂ Giant Grouper Epinephelus lanceolatus) occurred in the Guangxi Province in July, 2018. In this study, grouper iridovirus Guangxi (SGIV‐Gx) was isolated from diseased hybrid grouper that were collected from Guangxi. Cytopathic effects were observed and identified in grouper spleen cells that were incubated with diseased tissue homogenates after 24 h, and the effects increased at 48 h postinfection. The transmission electron microscopy results showed that viral particles that were about 200 nm in diameter with hexagonal profiles were present in the cell cytoplasm of suspected virus‐infected cells. The presence of SGIV‐Gx (accession number: MK107821) was identified by polymerase chain reaction (PCR) and amplicon sequencing, which showed that this strain was most closely related to Singapore grouper iridovirus (AY521625.1). The detection of SGIV‐Gx infection was further supported by novel aptamer (Q2c)‐based detection technology. The effects of temperature and pH on viral infectivity were analyzed by using reverse transcription quantitative real‐time polymerase chain reaction (RT‐qPCR) and cell culture. The results indicated that SGIV‐Gx was resistant to exposure to pH levels 5, 7, and 7.5 for 1 h, but its infectivity was remarkably lower at pH levels 3 and 10 after 1 h. The analyses showed that SGIV‐Gx was stable for 1 h at 4°C and 25°C but was inactivated after 1 h at 40, 50, and 60°C.

A generalised framework is proposed in this paper incorporating almost all of the existing limit equilibrium methods of slices for slope stability analysis with general slip surfaces. The force and moment equilibrium equations are derived in terms of the factor of safety and the initially assumed normal stress distribution over the slip surface, multiplied by a modification function involving two auxiliary unknowns. These equations are then analytically solved to yield explicit expressions for the factor of safety. Various assumptions regarding the interslice forces can be transformed into a unified form of expression for the normal stress distribution along the slip surface. An iterative procedure is developed to expedite the convergence of the solution for the factor of safety. Experience to date indicates that the process generally converges within a few iterations. Computation schemes are suggested to avoid numerical difficulty, especially in computing the factor of safety associated with the rigorous Janbu method. The present framework can be readily implemented in a computer program, giving solutions of slope stability associated with a number of conventional methods of slices.