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[1] A coupled physical-biological model is used to simulate the ecosystem characteristics in Lake Michigan. The physical model is the unstructured grid, Finite-Volume Coastal Ocean Model (FVCOM). The biological model is a NPZD model, including phosphorus as the nutrient, which is the limiting element in Lake Michigan, phytoplankton, zooplankton and detritus. The models are driven by observed hourly meteorological forcing in 1998 and the model results are calibrated by satellite and in situ data. The main physical and ecological phenomena in the spring of 1998 are captured. During March to May, a circle-like phytoplankton bloom appears in southern Lake Michigan, which looks like a 'doughnut'. The formation mechanisms of the prolonged spring bloom are investigated. It is confirmed that the phytoplankton bloom is forced by rapidly increasing temperature and light intensity in spring. The thermal front that develops in spring inhibits the transport of nutrients and phytoplankton from the nearshore to the deeper water. The wind-driven gyre circulation in southern Lake Michigan induces significant offshore transport, which contributes to the establishment of the circular bloom.

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Irradiation of methyl 3-methoxyl-2-naphthoate (2,3-NA) in methanol solution with light lambda > 280 nm produces anti-head-to-head cubane-like photocyclodimer 1 and [4+4] intermediate 2, which is, to the best of our knowledge, the first incidence of directly obtaining the intermediate in photocyclodimerization of naphthalene analogues. X-ray crystal structural analysis has realized the chirality of 1, and the optically pure enantiomers 1(a) and 1(b) have been achieved by HPLC resolution. To understand the fundamental photocyclodimerization of naphthalene analogues mediated by native gamma-CD, the neutral 2,3-NA was selected as a typical reactant in this work. UV-vis, fluorescence, and (1)H NMR analysis reveal that gamma-CD can encapsulate 2,3-NA to make a stable 2:1 inclusion complex 2,3-NA@gamma-CD both in aqueous solution and in the solid state. Irradiation of 2,3-NA@gamma-CD results in photocyclodimerization with remarkable selectivity and efficiency, whereas no photocyclodimers could be detected in host-free aqueous solution and the neat solids. More importantly, the use of native gamma-CD as a chiral reaction vessel turns out to be an effective and versatile strategy for the enantioselective photocyclodimerization of 2,3-NA. The ee values of 48% in aqueous solution and up to 34% in the solid state for anti-head-to-head photocyclodimer 1 have been achieved upon irradiation of the inclusion complex of 2,3-NA@gamma-CD under ambient temperature and pressure. All of the observations indicate that native gamma-CD with hydrophobic interaction only is capable of regulating the orientation of naphthalene analogue 2,3-NA within the cavity of gamma-CD, and thereby leading to the highest ee value of 48% obtained so far for the photocyclodimerization with native gamma-CD in solution.

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Irradiation of methyl 3-methoxyl-2-naphthoate (2,3-NA) with lambda > 280 nm results in photocyclodimerization to produce cubane-like photocyclodimer 1 and the [4 + 4] intermediate 2. The optically pure enantiomers of the intermediate 2 have been achieved by high-performance liquid chromatography (HPLC) resolution on a chiralcel OJ-RH column. Comparison of the enantiomeric excess (ee) values for photocyclodimer 1 and the intermediate 2 obtained in gamma-CD aqueous solution reveals the stepwise photochemical-chiral delivery for the first time, which is recognized to be a consequence of an in situ increase in the ee value from 39% for the [4 + 4] intermediate 2 to 48% for photocyclodimer 1 upon irradiation of 2,3-NA in the presence of gamma-CD.