Choline and betaine are important in the body, from cell membrane components to methyl donors. We aimed to investigate trends in dietary intake and food sources of total choline, individual choline forms and betaine in Chinese adults using data from the China Health and Nutrition Survey (CHNS) 1991–2011, a prospective cohort with a multistage, random cluster design. Dietary intake was estimated using three consecutive 24-h dietary recalls in combination with a household food inventory. Linear mixed-effect models were constructed using R software. A total of 11 188 men and 12 279 women aged 18 years or older were included. Between 1991 and 2011, total choline intake increased from 219·3 (95 % CI 215·1, 223·4) mg/d to 269·0 (95 % CI 265·6, 272·5) mg/d in men and from 195·6 (95 % CI 191·8, 199·4) mg/d to 240·4 (95 % CI 237·4, 243·5) mg/d in women (both P-trends < 0·001). Phosphatidylcholine was the major form of dietary choline, and its contribution to total choline increased from 46·9 % in 1991 to 58·8 % in 2011. Cereals were the primary food source of total choline before 2000, while eggs had ranked at the top since 2004. Dietary betaine intake was relatively steady over time with a range of 134·0–151·5 mg/d in men (P-trend < 0·001) and 111·7–125·3 mg/d in women (P-trend > 0·05). Chinese adults experienced a significant increase in dietary intake of choline, particularly phosphatidylcholine during 1991–2011 and animal-derived foods have replaced plant-based foods as the main food sources of choline. Betaine intake remained relatively stable over time. Future efforts should address the health effects of these changes.

Sepiolite-based composites have great potential for application as flame-retardant and thermal-insulation material but their application and development are limited by poor mechanical properties. The objective of the present study was to combine polyvinyl alcohol (PVA) and 3-aminopropyltriethoxysilane (KH-550) with sepiolite (Sep) to improve its aerogel strength. A universal testing machine, thermogravimetry, and microcalorimetry were used to investigate the mechanical properties, thermal-stability, and flame-retardant properties, respectively, of aerogels. The results indicated that KH-550 can enhance effectively the mechanical properties and flame retardancy of aerogels. The compressive modulus of PVA/Sep vs KH-550/PVA/Sep aerogel was 209.28 vs. 474.43 kPa, the LOI index changed from 26.4 to 30.4%. The porosity of the aerogels was > 96% and the density was < 0.05 g/cm3. The thermal conductivity remained at between 0.0340 and 0.0390 W/(m·K), and the aerogel could recover to > 85% after a 50% compressive deformation. These data indicated that Sep-based aerogel would act as a flame retardant and a thermal insulating material with excellent mechanical properties.

Axisymmetric non-isothermal spreading/dewetting of droplets on a substrate is studied, wherein the surface tension is a function of temperature, resulting in Marangoni stresses. A lubrication theory is first extended to determine the drop shape for spreading/dewetting limited by slip. It is demonstrated that an apparent angle inferred from a fitted spherical cap shape does not relate to the contact-line speed as it would under isothermal conditions. Also, a power law for the thermocapillary spreading rate versus time is derived. Results obtained with direct numerical simulations (DNS), using a slip length down to $O(10^{-4})$ times the drop diameter, confirm predictions from lubrication theory. The DNS results further show that the behaviour predicted by the lubrication theory – that a cold wall promotes spreading, and a hot wall promotes dewetting – is reversed at sufficiently large contact angles and/or viscosity of the surrounding fluid. This behaviour is summarized in a phase diagram, and a simple model that supports this finding is presented. Although the key results are found to be robust when accounting for heat conduction in the substrate, a critical thickness of the substrate is identified above which wall conduction significantly modifies wetting behaviour.

Using a slip-length-based level-set approach with adaptive mesh refinement, we have simulated axisymmetric droplet spreading for a dimensionless slip length down to $O(1{0}^{\ensuremath{-} 4} )$. The main purpose is to validate, and where necessary improve, the asymptotic analysis of Cox (J. Fluid Mech., vol. 357, 1998, pp. 249–278) for rapid droplet spreading/dewetting, in terms of the detailed interface shape in various regions close to the moving contact line and the relation between the apparent angle and the capillary number based on the instantaneous contact-line speed, $\mathit{Ca}$. Before presenting results for inertial spreading, simulation results are compared in detail with the theory of Hocking & Rivers (J. Fluid Mech., vol. 121, 1982, pp. 425–442) for slow spreading, showing that these agree very well (and in detail) for such small slip-length values, although limitations in the theoretically predicted interface shape are identified; a simple extension of the theory to viscous exterior fluids is also proposed and shown to yield similar excellent agreement. For rapid droplet spreading, it is found that, in principle, the theory of Cox can predict accurately the interface shapes in the intermediate viscous sublayer, although the inviscid sublayer can only be well presented when capillary-type waves are outside the contact-line region. However, $O(1)$ parameters taken to be unity by Cox must be specified and terms be corrected to ${\mathit{Ca}}^{+ 1} $ in order to achieve good agreement between the theory and the simulation, both of which are undertaken here. We also find that the apparent angle from numerical simulation, obtained by extrapolating the interface shape from the macro region to the contact line, agrees reasonably well with the modified theory of Cox. A simplified version of the inertial theory is proposed in the limit of negligible viscosity of the external fluid. Building on these results, weinvestigate the flow structure near the contact line, the shear stress and pressure along the wall, and the use of the analysis for droplet impact and rapid dewetting. Finally, we compare the modified theory of Cox with a recent experiment for rapid droplet spreading, the results of which suggest a spreading-velocity-dependent dynamic contact angle in the experiments. The paper is closed with a discussion of the outlook regarding the potential of using the present results in large-scale simulations wherein the contact-line region is not resolved down to the slip length, especially for inertial spreading.

A novel 3-leg 5-DoF parallel manipulator (PM) with a UPU-type composite active constrained leg is proposed and its kinematics and statics are analyzed systematically. First, the formulae are derived for solving the inverse/forward displacements, inverse/forward velocities, and active/constraint forces. Second, the formulae are derived for solving inverse/forward accelerations. Third, a simulation mechanism of this PM is created and its workspace is constructed and analyzed. Finally, the analytic results are verified by its simulation mechanism.

We report in this paper the numerical simulations of the capture into the 3:1 mean-motion resonance between the planets b and c in the 55 Cancri system. The results show that this resonance can be obtained by a differential planetary migration. The moderate initial eccentricities, relatively slower migration and suitable eccentricity damping rate increase significantly the probability of being trapped in this resonance. Otherwise, the system crosses the 3:1 commensurability avoiding resonance capture, to be eventually captured into a 2:1 resonance or some other higher-order resonances. After capture into resonance, the system can jump from one orbital configuration to another one if the migration continues, making a large region of the configuration space accessible for a resonance system. These investigations help us understand the diversity of resonance configurations and put some constraints on the early dynamical evolution of orbits in the extra-solar planetary systems.

A yellow leaf curl disease with chlorotic and yellowish leaves, upward leaf curling and stunting symptoms was observed on tomato in Shantou city of Guangdong province. A virus isolate BS was obtained from a diseased tomato plant. The complete DNA-A sequence of the virus isolate BS was determined to be 2740 nucleotides long, with all the characteristic features of begomovirus genome organization. BS DNA-A encoded six potential open reading frames (ORFs), with two (AV1 and AV2) in virus sense and four (AC1, AC2, AC3 and AC4) in complementary sense, and contained an intergenic region of 269 nucleotides. The results of BLAST searches showed that BS DNA-A had higher sequence identity with reported begomoviruses in Asia than with those in America and Africa. Further sequence comparisons indicated that BS was most closely related to the isolate of Tomato leaf curl Taiwan virus (ToLCTWV-[Taiwan]) with a sequence identity of 97.7%. Nucleotide sequence identities of AV1, AV2, AC1, AC2, AC3, AC4 and intergenic region (IR) between BS and ToLCTWV-[Taiwan] were 98.6, 98.0, 98.0, 97.5, 96.3, 98.6 and 96.6%, respectively, while that of the six ORF-encoded proteins between BS and ToLCTWV-[Taiwan] were 97.7, 99.1, 97.5, 95.6, 91.8 and 99.0%, respectively. Phylogenetic analysis based on the DNA-A sequences has also indicated that BS is most closely related to ToLCTWV-[Taiwan], forming a branch with ToLCTWV-[Taiwan], Tomato leaf curl Guangdong virus and Tomato yellow leaf curl Guangdong virus. The above results demonstrate that BS is an isolate of ToLCTWV.

To date, more than 130 extrasolar planets around main sequence stars are revealed mainly by the Doppler radial velocity measurements. Due to the observational biases, most of the detected planets are moving in orbits close to the host stars, with some in highly eccentric orbits. Dynamical processes during the late stage of planet formation are important to account for the present orbital properties. These processes include: planet migrations and resonance trappings caused by gravitational interactions between protostellar disk and planets, dynamical scattering due to interactions between planets, etc. In this paper, we review the major effects of these dynamical processes on the orbital characteristics of the planet systems.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

Due to the existence of invariant tori, chaotic sea and hyperbolic structures in higher dimensional phase space of a volume-preserving map, the diffusion route of chaotic orbits will be complicated. The velocity of diffusion will be very slow if the orbits are near an invariant torus. In order to realize this complicated diffusion phenomenon, in this paper we study the diffusion characters in the different regions, i.e., chaotic, hyperbolic and invariant tori’s regions. We find that for the three different regions, the diffusion velocities are different. The diffusion velocity in the vicinity of an invariant torus is the slowest one.

We have systematically made the numerical exploration about the perturbation extension of area-preserving mappings to three-dimensional ones, in which the fixed points of area preserving are elliptic, parabolic or hyperbolic respectively. It has been observed that: (i) the invariant manifolds in the vicinity of the fixed point generally don’t exist (ii) when the invariant curve of original two-dimensional mapping exists the invariant tubes do also in the neighbourhood of the invariant curve (iii) for the perturbation extension of area-preserving mapping the invariant manifolds can only be generated in the subset of the invariant manifolds of original two-dimensional mapping, (iv) for the perturbation extension of area preserving mappings with hyperbolic or parabolic fixed point the ordered region near and far from the invariant curve will be destroyed by perturbation more easily than the other one, This is a result different from the case with the elliptic fixed point. In the latter the ordered region near invariant curve is solid. Some of the results have been demonstrated exactly.

Finally we have discussed the Kolmogorov Entropy of the mappings and studied some applications.