The zero‐dimensional polymer [Pb6(μ2OOCCH=CHFc)2(μ3‐OOCCH=CHFc)2(μ2‐η2‐OOCCH=CHFc)2(η2‐OOCCH=CHFc)2(μ4‐O)2] (1), the one‐dimensional chain polymers [Pb(η1‐μ2‐OOCCH=CHFc)2(phen)]n (phen = phenanthroline; (2), {[Cd(μ2‐η2‐OOCCH=CHFc)(η2‐OOCCH=CHFc)(H2O)2](H2O)4}n (3), and the two‐dimensional hybrid polymer {[Cd(η2‐OOCCH=CHFc)(bbbm)1.5Cl]·1.5H2O}n [bbbm = 1,1'‐(1,4‐butanediyl)bis‐1H‐benzimidazole; 4] have been prepared by the reaction of sodium β‐ferrocenylacrylate [FcCH=CHCOONa, Fc = (η5‐C5H5)Fe(η5‐C5H4)] with the appropriate metal salts. Solution‐state differential pulse voltammetry for 1–4 indicated that the half‐wave potentials of the ferrocenyl moieties in these polymers are all shifted to positive potential compared with that of sodium β‐ferrocenylacrylate. The four polymers’ third‐order nonlinear optical (NLO) properties were determined by the Z‐scan technique in DMF solutions. The results show that these polymers possess good nonlinear optical refraction effects. Their hyperpolarizability (γ) values are calculated to be 4.80 × 10–30, 5.19 × 10–30, 1.57 × 10–29, and 2.04 × 10–29 esu for 1–4, respectively. The γ values of the CdII polymers (3 and 4) are slightly larger than those of the PbII polymers (1 and 2), which indicates that the metal ions play an important role in the NLO properties of these polymers. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)

We demonstrate an all-optical strategy for realizing spherical three-dimensional (3D) super-resolution (∼λ3/22) spot arrays of pure longitudinal magnetization by exploiting a 4π optical microscopic setup with two high numerical aperture (NA) objective lenses, which focus and interfere two modulated vectorial beams. Multiple phase filters (MPFs) are designed via an analytical approach derived from the vectorial Debye diffraction theory to modulate the two circularly polarized beams. The system is tailored to constructively interfere the longitudinal magnetization components, while simultaneously destructively interfering the azimuthal ones. As a result, the magnetization field is not only purely longitudinal but also super-resolved in all three dimensions. Furthermore, the MPFs can be designed analytically to control the number and locations of the super-resolved magnetization spots to produce both uniform and nonuniform arrays in a 3D volume. Thus, an all-optical control of all the properties of light-induced magnetization spot arrays has been demonstrated for the first time. These results open up broad applications in magnetic-optical devices such as confocal and multifocal magnetic resonance microscopy, 3D ultrahigh-density magneto-optic memory, and light-induced magneto-lithography.

Nonlinear refraction and absorption in carbon disulfide (CS2) has been investigated using the Z-scan technique with a femtosecond pulse laser at a wavelength of 800 nm in a broad intensity range. It is found that the origin of nonlinearity depends on the laser intensity. At low intensity, the nonlinearity is mainly due to the third-order process. The third- and fifth-order processes are at present simultaneously at high intensity. We also find the critical intensity value which determines whether the fifth-order nonlinear process exists or not by analysis of the divided Z-scan curves at different intensities. The nonlinear absorption is attributed to the three-photon absorption and the nonlinear absorption coefficient is 1.37 × 10−27 m3 W−2.

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Objective: The purpose of this study was to identify trajectories of body mass index (BMI) in toddlers from birth to 2 years old and examine their association with infantile overweight/obesity.Methods: Data were collected from 19,054 children born in any hospital or community healthcare center in Taizhou, China from 2018 to 2019 with at least three BMI measurements after birth. The Latent Class Growth Mixture Model was used to identify distinct BMI trajectories during the first 2 years of infants. Multiple logistic regression models were conducted to explore the associated factors of different BMI trajectories, and log-binomial regression was performed to assess the association between the trajectories and overweight/obesity.Results: Three heterogeneous BMI trajectories were identified and labeled as “lower” (36.21%, n = 6,899), “middle” (53.15%, n = 10,128) and “upper” (10.64%, n = 2,027), respectively. Several characteristics of infants and their corresponding mothers were found to be correlated with infant BMI trajectories, including infant sex, mode of delivery and weight at birth, as well as maternal parity, early pregnancy BMI and status of gestational diabetes mellitus. Furthermore, compared with those in the lower trajectory, infants in the middle [prevalence ratio (PR) = 2.63, 95% confidence interval (95%CI) = 2.17–2.63] or upper (PR = 2.98, 95%CI = 1.51–2.98) trajectory groups were prone to be overweight/obesity at their final observation.Conclusion: Heterogeneous BMI trajectories were observed in our study. Characteristics of both infants and their corresponding mothers could be potential determinants of infant growth. Moreover, infants in the middle and upper trajectory groups were more likely to suffer overweight/obesity.

The optical limiting properties of CuPcTs, NiPcTs and CoPcTs were investigated with nanosecond pulses at the wavelength of 532nm. Among them, CuPcTs exhibits the strongest optical limiting effect. An explanation based on nonlinear absorption and refraction is provided. And also, the relationship between the d-electron configuration and the third-order nonlinear optical properties of CuPcTs, NiPcTs and CoPcTs were discussed.

A nonlinear image technique for characterization of the optical nonlinearities is used to investigate the solid semiconductor ZnSe at 600 nm. The method based on a 4f nonlinear image technique with a phase object is used to obtain the diffraction pattern of the nonlinear filter in solid ZnSe located at the Fourier plane by a CCD camera. The nonlinear absorption coefficient and nonlinear refraction index were both obtained by fitting the nonlinear image. Good agreement between the experiment data and the simulated result are obtained indicating a sensitive and powerful method for nonlinear optical measurements.