BaTiO3系PTCR材料电学性能的复阻抗解析

采用复阻抗解析法研究了ＢａＴｉＯ３系ＰＴＣＲ材料晶粒、晶界的电学性能。结果表明：使用欧姆接触电极的ＰＴＣＲ材料等效电路的复阻抗为：晶粒电阻呈ＮＴＣ特性，而晶界电阻天Ｔ〈Ｔｃ时呈ＮＴＣ特性，Ｔ〉Ｔｃ时呈明显的ＰＴＣ特性；ＰＴＣ效应是一种晶界效应。     

Adaptive variational models for image decomposition

Image decomposition refers to the splitting of an image into two or more components.In this paper,a clean image is separated into two parts:one is the cartoon component,consisting only of geometric structure,and the other is the oscillatory component,consisting of texture.Three parts for noisy image are considered:cartoon,texture,and noise.To better decompose an image,we propose two new variational models.In our models,two adaptive regularization terms are introduced.The two regularization terms are determined by an adaptive function which can discriminate the cartoon and texture of an image automatically.Experimental results illustrate the efectiveness of the proposed models for image decomposition.     

Lattice-based key exchange on small integer solution problem

In this paper, we propose a new hard problem, called bilateral inhomogeneous small integer solution （Bi-ISIS）, which can be seen as an extension of the small integer solution problem on lattices. The main idea is that, instead of choosing a rectangle matrix, we choose a square matrix with small rank to generate Bi-ISIS problem without affecting the hardness of the underlying SIS problem. Based on this new problem, we present two new hardness problems： computational Bi-ISIS and decisional problems. As a direct application of these problems, we construct a new lattice-based key exchange （KE） protocol, which is analogous to the classic Diffie- Hellman KE protocol. We prove the security of this protocol and show that it provides better security in case of worst-case hardness of lattice problems, relatively efficient implementations, and great simplicity.     

Low-complexity optimal spatial channel pairing for AF-based multi-pair two-way relay networks

This paper considers a multi-pair two-way relay system with multi-antenna users and proposes a low-complexity optimal spatial channel pairing （SCP） strategy at the relay station （RS） for such a system. The proposed SCP scheme, following the BD-like beamformer at RS, pairs the uplink spatial subchannels of each user pair with the corresponding downlink spatial subchannels by maximizing sum-rate （Max-SR）. Furthermore, a new mathematical inequality （arrangement inequalities of a product） is developed and applied to obtain sufficient and necessary conditions for achieving Max-SR-SCP. This also yields a simple low-complexity implementation of the proposed SCP in contrast to the NP-hard complexity of the original Max-SR-SCP problem. Simulation results illustrate that the proposed Max-SR-SCP achieves substantial sum-rate gains over other pairing schemes.     

构建我国可信网络空间的思路和建议

随着移动互联网、物联网成长和普及,网络空间不仅成为人与人沟通的工具,也成为物体与物体沟通、人与物体沟通的工具。网络空间已经突破了计算机网络的限制,成为全球性的社交、协作平台,成为人类不可或缺的＂第二生存空间＂。与此同时,网络安全事件层出不穷,严重制约着网络空间的健康发展。一个可信、可靠的网络空间,对于我国经济社会发展具有重要意义。开展构建我国可信网络空间战略研究,有助于针对性地解决我国可信网络空间面临着诸多的问题和挑战,抢占网络空间竞争的制高点。     

借鉴重点国家网络安全建设经验加快完善我国网络安全保障体系

随着新兴信息技术的快速发展和互联网应用的逐步深入,各国对网络空间的重视程度不断加大,而网络安全已经成为制约网络空间健康发展的瓶颈。在此背景下,美国、欧盟等50多个国家和地区已经出台网络安全相关战略,以加强网络安全建设。为此,有必要借鉴国外先进经验,完善我国网络安全保障体系。本文分析了国内外网络安全形势,介绍了美国、欧盟、俄罗斯等重点国家和地区在网络安全建设方面的主要做法,提出来加快我国网络安全保障体系建设的措施建议。     

电子信息产品数据安全隐患探究

随着信息应用水平的提高,以及网络普及程度的加深,电子信息产品也逐渐地走入人们的生活,给人们带来了许多的方便。但是电子信息产品也面临一系列的数据安全隐患,数据和信息一旦泄露,会给国家、机构、个人造成不小的损失。因此,必须对电子信息产品的数据安全隐患进行探究,并且采取强有力的措施来进行预防。笔者根据实际情况,针对电子信息产品数据安全隐患进行了分析,希望能为广大的相关工作者提供一些参考依据。     

富水环境下钢渣骨料体积膨胀行为及抑制方法研究现状综述

钢渣骨料物理力学性能与天然砂石相似,富水环境下钢渣骨料产生体积膨胀是制约其在工程中应用的主要障碍.首先对钢渣骨料的物理力学性能和化学组成进行了综述;分析了富水环境下引发钢渣骨料体积膨胀的主要因素;继而对现有的抑制钢渣骨料体积膨胀技术措施进行了介绍,分析比较了其优缺点;最后提出可借鉴建筑废弃物再生骨料改性技术对钢渣骨料进行表面改性处理,提高钢渣骨料抵抗水分侵入能力,消除钢渣骨料内部膨胀组分遇水发生化学反应,产生膨胀的前提条件,为促进钢渣的资源化利用提供了一条新的思路.     

Photocatalytic behavior of TiO_2 and ZnO prepared with different methods under ultraviolet and visible light irradiation

IntroductionIn recent years photocatalytic oxidation hasreceived considerable attention as an alternativeremediation technology since the method offers anumber of advantages over conventionaltechnologies [1,2] Elimination o…     

柏木油回顾

本文简要回顾中国柏木油之产量、质量和价格。笔者以为中国柏木油价格在国际市场走低多年 ,其主因是香气质量。为改进柏木油香气质量 ,主张以水蒸汽蒸馏技术取代水上蒸馏法 ,不赞成用干馏法或“红锅”法来制取柏木原油。对现有柏木宝贵的天然资源 ,主张由林业部门主导统筹规划和进行科学开发及综合利用。