Quantitative Volume Space Form Rigidity Under Lower Ricci Curvature Bound

Let $M$ be a compact $n$-manifold of $\operatorname{Ric}_M\ge (n-1)H$ ($H$ is a constant). We are concerned with the following space form rigidity: $M$ is isometric to a space form of constant curvature $H$ under either of the following conditions: (i) There is $\rho>0$ such that for any $x\in M$, the open $\rho$-ball at $x^*$ in the (local) Riemannian universal covering space, $(U^*_\rho,x^*)\to (B_\rho(x),x)$, has the maximal volume i.e., the volume of a $\rho$-ball in the simply connected $n$-space form of curvature $H$. (ii) For $H=-1$, the volume entropy of $M$ is maximal i.e. $n-1$ ([LW1]). The main results of this paper are quantitative space form rigidity i.e., statements that $M$ is diffeomorphic and close in the Gromov-Hausdorff topology to a space form of constant curvature $H$, if $M$ almost satisfies, under some additional condition, the above maximal volume condition. For $H=1$, the quantitative spherical space form rigidity improves and generalizes the diffeomorphic sphere theorem in [CC2].Comment: The only change from the early version is an improvement on Theorem A: we replace the non-collapsing condition on $M$ by on $\tilde M$ (the Riemannian universal cover), and the corresponding modification is adding "subsection c" in Section

Controlled Synthesis of Silver Nanoparticles Using Double Reductants and Its Voltammetric Characteristics Study

Constructing robust silver nanoparticles (AgNPs) with good shape and dispersibility is of particular interest in analytical applications. Herein, monodispersibility AgNPs with the average size of 20 nm have been successfully prepared via one-pot method using sodium borohydride and trisodium citrate as co-reductants. The introduction of sodium borohydride greatly accelerated the rate of nucleation, which can effectively solve the problem of broad size distribution. Both shape and dispersibility of AgNPs can be effectively adjusted by simple control of refluxing time or concentrations of the sodium borohydride. We also studied the voltammetric characteristics of the AgNPs using Ag/AgCl solid-state voltammetry. An intense and stable current peak at a low potential could be obtained, which could provide a unique advantage in analytical applications. Copyright © 2016 BCREC GROUP. All rights reserved Received: 5th November 2015; Revised: 21st January 2016; Accepted: 22nd January 2016 How to Cite: Duan, Y., Xu, Z., Jiang, X. (2016). Controlled Synthesis of Silver Nanoparticles Using Double Reductants and Its Voltammetric Characteristics Study. Bulletin of Chemical Reaction Engineering & Catalysis, 11 (1): 115-119. (doi:10.9767/bcrec.11.1.433.115-119) Permalink/DOI: http://dx.doi.org/10.9767/bcrec.11.1.433.115-11

From Common to Special: When Multi-Attribute Learning Meets Personalized Opinions

Visual attributes, which refer to human-labeled semantic annotations, have gained increasing popularity in a wide range of real world applications. Generally, the existing attribute learning methods fall into two categories: one focuses on learning user-specific labels separately for different attributes, while the other one focuses on learning crowd-sourced global labels jointly for multiple attributes. However, both categories ignore the joint effect of the two mentioned factors: the personal diversity with respect to the global consensus; and the intrinsic correlation among multiple attributes. To overcome this challenge, we propose a novel model to learn user-specific predictors across multiple attributes. In our proposed model, the diversity of personalized opinions and the intrinsic relationship among multiple attributes are unified in a common-to-special manner. To this end, we adopt a three-component decomposition. Specifically, our model integrates a common cognition factor, an attribute-specific bias factor and a user-specific bias factor. Meanwhile Lasso and group Lasso penalties are adopted to leverage efficient feature selection. Furthermore, theoretical analysis is conducted to show that our proposed method could reach reasonable performance. Eventually, the empirical study carried out in this paper demonstrates the effectiveness of our proposed method

Transient analysis for fractured gas wells by modified pseudo-functions in stress-sensitive reservoirs

Acknowledgments This article was supported by Excellent Supervisor Fund of Basal Research Fund of China University of Geosciences (Beijing) (Grant No. 53200859546), the National Major Research Programme for Science and Technology of China (Grant No. 2011ZX05009-004). The anonymous reviewers and the editors are greatly appreciated for their careful reviews and detailed comments.Peer reviewedPostprin