The research infrastructure of Chinese foundations, a database for Chinese civil society studies

This paper provides technical details and user guidance on the Research Infrastructure of Chinese Foundations (RICF), a database of Chinese foundations, civil society, and social development in general. The structure of the RICF is deliberately designed and normalized according to the Three Normal Forms. The database schema consists of three major themes: foundations’ basic organizational profile (i.e., basic profile, board member, supervisor, staff, and related party tables), program information (i.e., program information, major program, program relationship, and major recipient tables), and financial information (i.e., financial position, financial activities, cash flow, activity overview, and large donation tables). The RICF’s data quality can be measured by four criteria: data source reputation and credibility, completeness, accuracy, and timeliness. Data records are properly versioned, allowing verification and replication for research purposes

Complementary stabilization by core/sheath carbon nanofibers/spongy carbon on submicron tin oxide particles as anode for lithium-ion batteries

To limit the pulverization of tin-based anode materials during lithiation/delithiation, submicron tin oxide/tin particles are fixed on core/sheath carbon nanofiber/spongy carbon via hydrothermal and carbothermal reduction treatment in this work. During carbothermal reduction, SnO2 nanosheets are converted to spherical Sn submicron particles and simultaneously the hollow spongy carbon is produced and still enwrap on carbon nanofiber. The as-produced flexible film is used for a binder-free anode for lithium ion batteries, without the polymer binder and conductive carbon. At 0.1, 0.5, 1 and 2 A g-1, the composite electrode respectively displays a discharging capacity of 1393.0, 738.2, 583.6 and 382.6 mAh g-1. Moreover, it delivers specific capacity of 726.9 mAh g-1 and coulombic efficiency of 99.45 % after 300 cycles at 0.1 A g-1. The comparison sample of carbon nanofiber/SnOx film without the presence of spongy carbon displays much lower rate performance and worse cyclic performance. The integrated structure of carbon nanofiber/SnOx/spongy carbon results in the remarkable Li-storage performance, in which the carbon nanofiber and spongy carbon synergistically provide conductive channel and buffer zone to hinder the pulverization and peeling of SnOx particles during charging-discharging processes

Shear Modulus of a Carbonate Sand–Silt Mixture with THF Hydrate

The maximum shear modulus (Gmax) is an important factor determining soil deformation, and it is closely related to engineering safety and seafloor stability. In this study, a series of bender element tests was carried out to investigate the Gmax of a hydrate-bearing carbonate sand (CS)–silt mixture. The soil mixture adopted a CS:silt ratio of 1:4 by weight to mimic the fine-grained deposit of the South China Sea (SCS). Tetrahydrofuran (THF) was used to form the hydrate. Special specimen preparation procedures were adopted to form THF hydrate inside the intraparticle voids of the CS. The test results indicate that hydrate contributed to a significant part of the skeletal stiffness of the hydrate-bearing CS–silt mixture, and its Gmax at 5% hydrate saturation (Sh) was 4–6 times that of the host soil mixture. Such stiffness enhancement at a low Sh may be related to the cementation hydrate morphology. However, the Gmax of the hydrate-bearing CS–silt mixture was also sensitive to the effective stress for an Sh ranging between 5% and 31%, implying that the frame-supporting hydrate morphology also plays a key role in the skeletal stiffness of the soil mixture. Neither the existing cementation models nor the theoretical frame-supporting (i.e., Biot–Gassmann theory by Lee (BGTL)), could alone provide a satisfactory prediction of the test results. Thus, further theoretical study involving a combination of cementation and frame-supporting models is essential to understand the effects of complicated hydrate morphologies on the stiffness of soil with a substantial amount of intraparticle voids

Feedback Gating Control for Network Based on Macroscopic Fundamental Diagram

Empirical data from Yokohama, Japan, showed that a macroscopic fundamental diagram (MFD) of urban traffic provides for different network regions a unimodal low-scatter relationship between network vehicle density and network space-mean flow. This provides new tools for network congestion control. Based on MFD, this paper proposed a feedback gating control policy which can be used to mitigate network congestion by adjusting signal timings of gating intersections. The objective of the feedback gating control model is to maximize the outflow and distribute the allowed inflows properly according to external demand and capacity of each gating intersection. An example network is used to test the performance of proposed feedback gating control model. Two types of background signalization types for the intersections within the test network, fixed-time and actuated control, are considered. The results of extensive simulation validate that the proposed feedback gating control model can get a Pareto improvement since the performance of both gating intersections and the whole network can be improved significantly especially under heavy demand situations. The inflows and outflows can be improved to a higher level, and the delay and queue length at all gating intersections are decreased dramatically

Diffractive D_s production in charged current DIS

We present a perturbative QCD calculation of diffractive $D_s$ production in charged current deep inelastic scattering. In the two-gluon exchange model, we analyze the diffractive process \nu N \to \mu^- N \Ds, which may provide useful information for the gluon structure of nucleons and the diffraction mechanism in QCD. The cross section of diffractive $D_s$ production with \xBj=0.005-0.05 and $E_\nu=50$ Gev is found to be $2.7\times10^{-5}$ pb. In spite of this small cross section, the high luminosity available at the $\nu$-Factory in the future would lead to a sizable number of diffraction events.Comment: 6 pages, 5 eps figures, final version to appear in PL

On Two-Body Decays of A Scalar Glueball

We study two body decays of a scalar glueball. We show that in QCD a spin-0 pure glueball (a state only with gluons) cannot decay into a pair of light quarks if chiral symmetry holds exactly, i.e., the decay amplitude is chirally suppressed. However, this chiral suppression does not materialize itself at the hadron level such as in decays into $\pi^+\pi^-$ and $K^+K^-$, because in perturbative QCD the glueball couples to two (but not one) light quark pairs that hadronize to two mesons. Using QCD factorization based on an effective Lagrangian, we show that the difference of hadronization into $\pi\pi$ and $KK$ already leads to a large difference between ${\rm Br} (\pi^+\pi^-)$ and ${\rm Br}(K^+K^-)$, even the decay amplitude is not chirally suppressed. Moreover, the small ratio of $R={\rm Br}(\pi\pi)/{\rm Br}(K\bar K)$ of $f_0(1710)$ measured in experiment does not imply $f_0(1710)$ to be a pure glueball. With our results it is helpful to understand the partonic contents if ${\rm Br}(\pi\pi)$ or ${\rm Br}(K\bar K)$ is measured reliably.Comment: revised versio

Optimization with a Genetic Algorithm for Multilayer Electromagnetic Wave Absorption Cement Mortar Filled with Expended Perlite

Abstract: Due to the complexity of the design of multilayer electromagnetic (EM) wave absorbing materials, it is difficult to establish the relationship between material parameters (type and filling ratios) and EM properties using traditional trial and error methods. Based on the measured EM parameters within a few materials and Boltzmann mixing theory, a database of EM parameters was thereafter built up. In this study, the genetic algorithm (GA) was used to design the multilayer wave-absorbing cement mortar. In order to verify this method, a multilayer mortar was fabricated and measured. The simulated and measured results are well consistent, which convincingly verifies computer-aided design. In addition, the optimized result expresses that the first layer as a matching layer guides EM waves into the interior of the material, while the other layers as absorption layers attenuate EM waves. The multilayer material may not meet the impedance gradient principle but still exhibits better EM wave absorption performance. The reflection loss (RL) of all optimized three layer sample is below –6.89 dB in the full frequency band and the minimum RL is –26.21 dB. This composite absorbing material and the GA method provide more design ideas for the design of future cement-based wave-absorbing materials and save a lot of time and material cost