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Underground Nuclear Astrophysics in China (JUNA) will take the advantage of the ultra-low background in Jinping underground lab. High current accelerator with an ECR source and detectors were commissioned. JUNA plans to study directly a number of nuclear reactions important to hydrostatic stellar evolution at their relevant stellar energies. At the first period, JUNA aims at the direct measurements of 25Mg(p,γ)26 Al, 19F(p,α) 16 O, 13C(α, n) 16O and 12C(α,γ) 16O near the Gamow window. The current progress of JUNA will be given.
Although many studies worldwide have focused on the relationship between vitamin D and insulin resistance, results remain controversial. Furthermore, concentrations of serum 25-hydroxyvitamin D (25(OH)D) in the Chinese population are unclear. We aimed to investigate vitamin D status and its correlation with insulin resistance among a Chinese adult population.
Serum 25(OH)D, fasting blood glucose, fasting insulin, glycated Hb (HbA1c) and other metabolic parameters were assessed. Neck circumference, waist circumference, hip circumference, weight and height were also measured. Lifestyle factors including smoking and drinking status were obtained. Diabetes mellitus was diagnosed by HbA1c according to the 2010 American Diabetes Association criteria.
Of 7200 residents included, 6597 individuals were ultimately analysed.
We enrolled 2813 males (mean age 52·7 (sd 13·5) years) and 3784 females (52·3 (sd 13·5) years); mean serum 25(OH)D concentration was 43·1 (sd 11·6) and 39·6 (sd 9·8) nmol/l, respectively. Additionally, 83·3 % of participants were 25(OH)D deficient. A significant difference in 25(OH)D was observed between males and females in winter and spring (P<0·001). Furthermore, 25(OH)D concentrations were inversely associated with the homeostasis model assessment of insulin resistance (HOMA-IR) in the overweight and pre-diabetic populations. After adjusting for several variables, 25(OH)D was significantly associated with HOMA-IR in winter. When 25(OH)D values were categorized into quartiles, HOMA-IR was significantly associated with decreasing 25(OH)D.
The majority of the Chinese population was vitamin D deficient and this deficiency was negatively associated with insulin resistance, particularly in the overweight and pre-diabetic populations. Moreover, these associations might be more evident in the winter.
We study the convergence of an Ulm-like Cayley transform method for solving inverse eigenvalue problems which avoids solving approximate Jacobian equations. Under the nonsingularity assumption of the relative generalized Jacobian matrices at the solution, a convergence analysis covering both the distinct and multiple eigenvalues cases is provided and the quadratical convergence is proved. Moreover, numerical experiments are given in the last section to illustrate our results.
In addition to the piezoelectric nanogenerators and triboelectric nanogenerators, recently, the graphene-based nanogenerator has been widely concerned because of its simple assembly, flexibility and high structural stability. There are many interesting effects in graphene applied for nanogenenrators including anion adsorption in electrolyte solution, ion channels in graphene sheets network and the strain (band engineering) effect, etc. In this paper, we focus explicitly on the experimental results, mechanisms and applications of the graphene-based nanogenerator, and introduce our recent research on the graphene-based nanogenerator based on "modulation of the graphene strain-energy band effect". This nanogenerator is expected to have potential applications in active sensors and sustainable power source.
A facile inexpensive route has been developed to prepare ZnO hierarchical materials with microplate/nanohole structures based on the colloidal monolayer template by the precursor thermal decomposition. These hierarchical structured materials demonstrated an excellent superhydrophobicity with self-cleaning effect and an enhanced photocatalytic performance to organic molecules, which are attributed to big roughness and large surface area of such special hierarchical structures. The formation mechanism of such hierarchical structures was investigated in detail by tracing morphology changing at different precursor concentrations. At high precursor concentration, both incompletely restricted ZnO growth of colloidal templates and preferable growth of microplates take place at the same time, and hence, ZnO hierarchical materials with microplate/nanohole structures are formed. With increasing precursor concentration, the number density of ZnO microplates tends to be larger. The large number density of ZnO microplates and holes on the microplates render the sample a large surface area and surface roughness, leading to good superhydrophobicity and photocatalytic activity. Such hierarchical ZnO micro/nanostructured materials have important applications in environmental science, microfluidic devices, etc.
Dielectric capacitors for energy storage are of great importance in modern electronics and electric systems. It is a challenge to realize the high energy density while maintain the low dielectric loss. We investigated an ultra high breakdown electric field of 1.1 GV/m, which is approaching the intrinsic breakdown, in aromatic polythiourea, a new dielectric material that serves a high energy density of 23 J/cm3 as well as high charge-discharge efficiency above 90%. The molecular structure and film surface morphology were also studied, it was proved a polar amorphous phase and glass state material could significantly suppress the high field conduction to several orders smaller compared with regular polymer dielectric materials, which are usually semi-crystalline and in rubber phase.
Our previous epidemiological study indicated that excessive intake of iodine could potentially lead to hypothyroidism. In the present study, we aimed to investigate the time and dose effect of iodine intake on serum thyrotropin (thyroid-stimulating hormone, TSH) levels and to explore the non-autoimmune regulation of serum TSH by pituitary type 2 deiodinase (D2). A total of 360 Wistar rats were randomly divided into five groups depending on administered iodine dosages (folds of physiological dose): normal iodine (NI), 3-fold iodine (3HI), 6-fold iodine (6HI), 10-fold iodine (10HI) and 50-fold iodine (50HI). At 4, 8, 12 and 24 weeks after administration of sodium iodide, blood was collected for serum TSH measurement by chemiluminescent immunoassay. Pituitaries were also excised for measurement of TSHβ subunit expression, D2 expression and activity, monocarboxylate transporter 8 (MCT8) and thyroid hormone receptor β2 isoform (TRβ2) levels. The results showed that iodine intake of 10HI and 50HI significantly increased pituitary and serum TSH levels from 8 to 24 weeks (P < 0·05 v. NI). Excess iodine had no effect on D2 mRNA or protein expression; however, 10HI and 50HI administration significantly inhibited pituitary D2 activities from 8 to 24 weeks (P < 0·05 v. NI). Iodine had no effect on MCT8 or TRβ2 protein levels. We conclude that prolonged high iodine intake inhibits pituitary D2 activity and induces elevation of serum TSH levels. These findings may provide a potential mechanism of iodine excess-induced overt and subclinical hypothyroidism.
A two-step replication strategy to two-dimensional ordered polymer hollow sphere and convex structure arrays is presented based on polystyrene colloidal monolayer and inverse opal made of FeO(OH). We can control formation of a small hole on top of the hollow spheres by the concentration of polymer precursors, which could be of importance in selective permeability, nutrient and drug deliver, biotechnology, and even study of black-body irradiation in micro or nano space. In addition, the fabrication strategy is suitable for the most soluble polymer materials, which can solidify when they are concentrated.
Polyvinylpyrrolidone (PVP) reduction effect on free and complex Ag+ and Au3+ ions was studied from optical measurements by adding a metal precursor (K-30), commonly used as a stabilizer, to PVP. It was found that PVP has a strong reduction effect on free ionic metal, such as Ag+ ion in AgNO3, but much weaker on complex ionic metals, AuCl4− in HAuCl4 and Ag(NH3)2+ in Ag(NH3)2OH. This is explained based on the coordinative field of polar group in PVP molecules.
The on-chip magnetic inductors with patterned permalloy (Ni80Fe20) cores are fabricated on Si-substrates with different resistivities and thicknesses as well as on thin membranes. With the patterned permalloy cores, the on-chip magnetic inductors achieve high self-resonant frequencies over 25GHz in thin membranes. To distinguish the influence from the permalloy core patterns and substrate losses on the inductance and quality factor, multiple solenoids in series and parallel are designed to investigate the resistive, capacitive, and magnetic coupling losses.
We show that there is a well-defined cap-product structure on the Fintushel–Stern
spectral sequence and the induced cap-product structure on the ℤ8-graded instanton
Floer homology. The cap-product structure provides an essentially new property of
the instanton Floer homology, from a topological point of view, which multiplies a
finite-dimensional cohomlogy class by an infinite-dimensional homology class (Floer
cycles) to get another infinite-dimensional homology class.
Transmission electron microscopy (TEM), x-ray diffraction (XRD), photoluminescence (PL) and Raman scattering measurements were applied to study the correlation between the microstructure and physical properties of the GaN films grown by light radiation heating metalorganic chemical vapor deposition (LRH-MOCVD), using GaN buffer layer on sapphire substrates. When the density of the threading dislocation (TD) increases about one order of magnitude, the yellow luminescence (YL) intensity is strengthened from negligible to two orders of magnitude higher than the band edge emission intensity. The full width of half maximum (FWHM) of the GaN (0002) peak of the XRD rocking curve was widened from 11 min to 15 min, and in Raman spectra, the width of E2 mode is broadened from 5 cm−1 to 7 cm−1. A “zippers” structure at the interface of GaN/sapphire was observed by high-resolution electron microscope (HREM). Furthermore the origins of TD and relationship between physical properties and microstructures combining the growth conditions are discussed.
Transmission electron microscopy (TEM), x-ray diffraction (XRD), photoluminescence (PL) and Raman scattering measurements were applied to study the correlation between the microstructure and physical properties of the GaN films grown by light radiation heating metalorganic chemical vapor deposition (LRH-MOCVD), using GaN buffer layer on sapphire substrates. When the density of the threading dislocation (TD) increases about one order of magnitude, the yellow luminescence (YL) intensity is strengthened from negligible to two orders of magnitude higher than the band edge emission intensity. The full width of half maximum (FWHM) of the GaN (0002) peak of the XRD rocking curve was widened from 11 min to 15 min, and in Raman spectra, the width of E2 mode is broadened from 5 cm-1 to 7 cm-1. A “zippers” structure at the interface of GaN/sapphire was observed by high-resolution electron microscope (HREM). Furthermore the origins of TD and relationship between physical properties and microstructures combining the growth conditions are discussed.
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