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Objective. Breast milk is the best food for newly born infants because it is more digestible and can relieve infants’ gastrointestinal burdens. The purpose of this study was to investigate the application effect of abdominal acupoint massage on feeding intolerance in premature infants. Methods. A total of 50 premature infants with feeding intolerance admitted to our hospital from January 2018 to October 2019 were selected and randomly divided into the control group (n = 25) and the experimental group (n = 25). Among them, the premature infants in the control group received routine therapy, while based on the treatment in the control group, the premature infants in the experimental group were treated with abdominal acupoint massage. After that, the incidence of feeding intolerance, MNA nutritional status score, body mass, development state, length of hospital stay, and response rate were all compared between the two groups to analyze the application effect of abdominal acupoint massage on feeding intolerance in premature infants. Results. The incidence of feeding intolerance of the premature infants in the experimental group was significantly lower than that in the control group, with statistically significant differences ( P < 0.05 ); the MNA nutritional status scores of the premature infants in the experimental group were significantly higher than those in the control group, with statistically significant differences ( P < 0.05 ); the body mass and development state of the premature infants in the experimental group were significantly better than those in the control group, with statistically significant differences ( P < 0.05 ); the length of hospital stay of the premature infants in the experimental group was significantly shorter than that in the control group, with statistically significant differences ( P < 0.05 ); the response rate in the experimental group was significantly higher than that in the control group, with statistically significant differences ( P < 0.05 ). Conclusions. Abdominal acupoint massage therapy can significantly reduce the incidence of feeding intolerance, shorten the length of hospital stay, and improve nutritional status, development state, and response rate in premature infants, with obvious therapeutic effect, which is worthy of application and promotion in clinical practice.

FI is mainly caused by functional disturbance in premature infants, which greatly poses a threat to their growth and development, so a large number of studies on the clinical features of FI should be conducted to provide theoretical support for treatment. The purpose of the study was to investigate the therapeutic effect of acupoint massage on Zusanli on premature infants with feeding intolerance (FI) and their clinical symptoms. A total of 60 premature infants with FI admitted to our hospital over the past two years were selected as the FI group, and another 60 premature infants without FI were selected as the control group. The birthweight and gestational age of the premature infants in the FI group were significantly lower than those in the control group ( P < 0.001 ), whereas there were no significant differences in general information of the premature infants between the two groups ( P > 0.05 ). Vomiting, abdominal distension, and gastric retention are the main clinical symptoms of premature infants with FI, and acupoint massage on Zusanli combined with routine treatment can effectively improve digestive function, relieve clinical symptoms, and shorten treatment time of premature infants with FI, which is worthy of application and promotion in clinical practice.

0.94(Na0.5Bi0.5)TiO3–0.06BaTiO3 (NBT–BT6) ferroelectric thin films have been fabricated on Pt–Ti–SiO2–Si(100) substrate by metal–organic decomposition. The effects of annealing temperature (650–800°C) on the microstructure, and the piezoelectric, ferroelectric, and dielectric properties of the thin films were studied in detail. The residual stress was evaluated by the orientation average method to clarify its dependence on annealing temperature and grain size, and it was correlated with the electric properties to understand the mechanism of piezoelectric enhancement. Among the thin films, NBT–BT6 thin film annealed at 750°C has the largest effective piezoelectric coefficient, 95.1 pm/V, remnant polarization, 49.7 μC/cm2, spontaneous polarization, 105.2 μC/cm2, and dielectric constant, 504, and the lowest dielectric loss, 0.05, and tensile residual stress, 24.5 MPa. For the NBT–BT6 thin film annealed at 750°C, a wide temperature range, 183–210°C, around the phase transition temperature (Tm) was observed in the dielectric temperature plots, and the diffusion coefficients (γ) were quantitatively assessed as 1.6, 1.78, and 1.6. Piezoelectric performance is discussed on the basis of the dispersion phase transition and residual stress.

K0.5Na0.5Nb(1−y)SbyO3 (KNNSy, y = 0.02–0.10) piezoceramics are obtained from the corresponding powder synthesized via a relatively low temperature solvothermal method. Crystalline structures and surface morphologies of these samples are analyzed by X-ray diffraction and scanning electron microscopy. The optimal sintering temperatures of KNNSy ceramics are controlled within 980–1,050 °C. The piezoelectric properties of the KNNSy ceramics are essentially affected by orthorhombic–tetragonal polymorphic phase transition. KNNS0.06 ceramic shows the maximum piezoelectric coefficient (d33) (134 pC/N). In addition, the aging behavior of KNNSy ceramics leads to the instability of their piezoelectric properties, which can be well explained according to defect symmetry conforming principle.

K 0.5 Na 0.5 Nb 1– x Ta x O 3 (KNNT x , x = 0–0.4) powders were synthesized by a novel hydro/solvothermal method at a low reaction temperature (180 °C) and the corresponding ceramics were obtained by normal sintering. Compared with conventional solid-state reaction technique, the optimal sintering temperatures of these ceramics were reduced at least 150 °C. Crystalline structures and surface morphologies were analyzed by X-ray diffraction and scanning electron microscopy. The excellent piezoelectric properties could be obtained by selecting poling temperature near the orthorhombic–tetragonal polymorphic phase transition temperature region. Ta-modified KNN ceramics exhibited better piezoelectric properties than those of pure KNN, and the piezoelectric coefficient d 33 showed the maximum value of 156 pC/N for KNNT0.3 ceramics. In addition, the sintering temperature for maximum d 33 value differed from that for maximum density. The present hydro/solvothermal method provides a new potential route for preparing KNN-based materials at relatively low temperature.

Bi0.5(Na0.85K0.15)0.5TiO3 (BNKT15) thin films were synthesized by metal-organic decomposition (MOD) at annealing temperatures of 650, 680, 710 and 740℃, and the effects of annealing temperature on the microstructure, dielectric properties, remnant polarization (2P(subscript r)) and leakage current density were studied with X-ray diffractometer, atomic force microscope, precision impedance analyzer, ferroelectric analysis station and semiconductor parameter tester. The results show that the thin film annealed at 710℃ exhibits a typical perovskite structure without predominant orientation and a smooth surface with evenly distributed grains. 2P(subscript r) value (67.4 UC/cm^2 under 830 kV/cm) and the leakage current density (1.6×l0^(-6) A/cm^2 at 170 kV/cm) for BNKT15 thin film annealed at 710℃ are better than those for thin films annealed at other temperatures.

New chalcohalide glasses from GeS2–In2S3–CsCl pseudo-ternary system were prepared using the conventional melt-quenching method and its glass-forming region has been determined. The differences ΔT (TP − Tg) of partial glasses are large enough (>100 K) to permit the preparation of performs of considerable size. With the increased content of CsCl, the visible absorption edge (λvis) of these glasses indicates a distinct blue shift while a clear drop of their glass transition temperatures can be seen. The ultrafast non-linearity of partial glasses was measured using the Kerr shutter technique. The non-linear refractive index, n2, was estimated to be in the magnitude of 10−14 cm2/W. Widely transparent range, good glass-forming ability, higher χ(3) and large electronic ultrafast OKE response make these glasses the potential applications in current photonic fields.

In searching for new kind of photoelectric material, chalcogenide glasses in the GeS 2 –Sb 2 S 3 –CdS system have been studied and their glass-forming region was determined. The system has a relatively large glass-forming region that is mainly situated along the GeS 2 –Sb 2 S 3 binary side. Thermal, optical and mechanical properties of the glasses were reported and the effects of compositional change on their properties are discussed. These novel chalcogenide glasses have relatively high glass transition temperatures ( T g ranges from 566 to 583 K), good thermal stabilities (the maximum of deference between the onset crystallization temperature, T c , and T g is 105 K), broad transmission region (0.57–12 μm) and large densities ( d ranges from 2.99 to 3.34 g cm −3 ). These glasses would be expected to be used in the field of rare earth doped fiber amplifiers and nonlinear optical devices.

Utilizing Maker fringe (MF) method, second-harmonic generation (SHG) has been observed within the GeS2–Ga2S3–CdS pseudo-ternary glasses through thermal/electrical poling technique. The SHG phenomenon was considered to be the result of breakage of the glassy macroscopic isotropy originated from the reorientations of dipoles during the thermal/electrical poling process. Under the same poling condition conducted with 5 kV and 280 °C for 30 min, the maximum value of second-order nonlinear susceptibility χ(2) of the poled (100−x)GeS2·x(0.5Ga2S3·0.5CdS) glasses was obtained to be ≈4.36 pm/V when the value of x is equal to 30. Nonlinear dependence of χ(2) on compositions of these glasses can be well explained according to the theory related to the reorientation of dipoles.

By investigating the second-harmonic generation (SHG) of the series (100 − 2x)GeS2·xGa2S3·xPbI2 (x = 5, 10, 15, and 20) chalcohalide glass samples after thermal poling, it was found that there was an optimal poling temperature for each composition and there was also a relation between optimal poling temperature and glass transition temperature. With increasing x, the obtained second-order susceptibility χ(2) shows an increase first and then decrease, and the maximum was seen at x = 15. A dipole reorientation model and structural relaxation causing by Ga2S3 and PbI2 were proposed to explain the dependence of poling temperature on SH intensity for each composition and the presence of the maximum χ(2) in this chalcohalide glass series.

The glass-forming region in the GeS 2 –Ga 2 S 3 –PbI 2 system was determined and the basic parameters of thermal and optical properties (glass transition temperature, density, microhardness and transmission window) for these glasses have been measured. Better thermal stability originated from their larger difference between T x and T g in the range of 107–161 °C, higher glass transition temperatures between 252 and 398 °C and wide optical transmission window from 0.5 to 12.7 μm make these glasses the promising candidate materials for rare earth doped fiber amplifiers and nonlinear optical devices.

To determine the prevalence of and risk factors for myopia in primary school children in Chaoyang District, Beijing.This cross-sectional prevalence survey was conducted in September to October 2011 in 4 schools randomly chosen from among the 126 primary schools in Chaoyang District. Students were assessed with autorefractometry under cycloplegia and checked with retinoscopy for accuracy. Questionnaires were completed by the students' parents.Myopia was present in 36.7 ± 0.7% of 4249 students aged 5-14 years old. The prevalence of myopia in girls (38.6 ± 1.1%) was significantly higher than in boys (35.0 ± 1.0 %) (p = 0.015) and increased with age (p0.001), with the highest prevalence observed in children aged ≥11 years (67.5 ± 1.8%). After adjustment, having a myopic parent (aOR 3.10; 95% CI 2.49-3.86), incorrect reading posture (aOR 2.09; 95% CI 1.75-2.50), reading a book at a distance of20 cm (aOR 1.60; 95% CI 1.16-2.21), studying at home for3 h daily (aOR 1.50; 95% CI 1.12-2.01), studying for1 h continuously (aOR 1.21; 95% CI 1.02-1.45), and reading extracurricular books that utilize a font larger than that used in textbooks (aOR 0.74; 95% CI 0.59-0.94) were all significantly associated with myopia.The prevalence of myopia among primary school children in Beijing increased with age, and was significantly higher in girls ≥10 years old. Myopia was significantly associated with parental myopia, reading posture, distance between the eyes and the book being read, font size used in extracurricular reading material, time spent studying at home, and the duration of continuous study time.

To find new chalcogenide glass possessing larger second-order non-linearity, glasses with compositions Ge-Ga-X-S (X=P, As, Sb) were prepared via melt quenching technique. The amorphous nature of all the compositions of the as-quenched glasses was confirmed by X-ray diffraction(XRD). The glassy thermal properties of the as-quenched glasses were established by differential thermal analyses(DTA). The glass structure was studied by RAMAN spectra and the second order nonlinearity was studied by the Maker Fringe method after the electron beam poling(EBP) and electric/temperature field poling(ETFP) respectively. Additions of various pnicogen atoms into the Ge-Ga-S glasses lead to the difference in the second order nonlinearity of the glass. It's found that glasses with different structures result in different SHG intensities, and even more, a large second order nonlinear susceptibility χ (2) of about 9 pm/V was obtained for all the glasses and the reasons for such a large susceptibility were analyzed.

Third-order optical nonlinearities, chi((3)) of GeS(2)-Ga(2)S(3)-AgCl chalcohalide glasses have been studied systematically utilizing the femtosecond time-resolved optical Kerr effect (OKE) technique at 820nm, showing that the value of chi((3)) enhances with increasing atomic ratio of (S+Cl/2)/(Ge+Ga). From the compositional dependence of glass structure by Raman spectra, a strong dependence of chi;(3) upon glass structure has been found, i.e. compared with [Cl(x)S(3-x)Ge(Ga)-Ge(Ga)S(3-x)Cl(x)] ethane-like s.u. as the structural defectiveness, [Ge(Ga)S(4-x)Cl(x)] mixed tetrahedra make greater contribution to the enhancement of chi((3)). The maximum chisp(3)/spamong the present glasses is as large as 5.26x10(-13)esu (A1 (80GeS(2)-10Ga(2)S(3-) 10AgCl)), and the nonlinear refractive index (n2) of A1 glass is also up to 4.60x10(-15) cm(2)/W. In addition, using Maker fringe technique, SHG was observed in the representative A1 glass poled by electron beam (25 kV, 25 nA, 15 min), and the second-order optical nonlinear susceptibility is estimated to be greater than 6.1 pm/V. There was no evident structural change detected in the as-prepared and after irradiated A1 glass by the Raman spectra, and maybe only electronic transition and distortion of electron cloud occurred in the glasses. The large third/second-order optical nonlinearities have made these GeS(2)-Ga(2)S(3)-AgCl chalcohalide glasses as promising materials applied in photoelectric fields.

Third-order optical nonlinearities, chi((3)) of GeS(2)-Ga(2)S(3)-AgCl chalcohalide glasses have been studied systematically utilizing the femtosecond time-resolved optical Kerr effect (OKE) technique at 820nm, showing that the value of chi((3)) enhances with increasing atomic ratio of (S+Cl/2)/(Ge+Ga). From the compositional dependence of glass structure by Raman spectra, a strong dependence of chi;(3) upon glass structure has been found, i.e. compared with [Cl(x)S(3-x)Ge(Ga)-Ge(Ga)S(3-x)Cl(x)] ethane-like s.u. as the structural defectiveness, [Ge(Ga)S(4-x)Cl(x)] mixed tetrahedra make greater contribution to the enhancement of chi((3)). The maximum chi (3) among the present glasses is as large as 5.26x10(-13)esu (A1 (80GeS(2)-10Ga(2)S(3-) 10AgCl)), and the nonlinear refractive index (n2) of A1 glass is also up to 4.60x10(-15) cm(2)/W. In addition, using Maker fringe technique, SHG was observed in the representative A1 glass poled by electron beam (25 kV, 25 nA, 15 min), and the second-order optical nonlinear susceptibility is estimated to be greater than 6.1 pm/V. There was no evident structural change detected in the as-prepared and after irradiated A1 glass by the Raman spectra, and maybe only electronic transition and distortion of electron cloud occurred in the glasses. The large third/second-order optical nonlinearities have made these GeS(2)-Ga(2)S(3)-AgCl chalcohalide glasses as promising materials applied in photoelectric fields.