Deploy Efficiency Driven k-Barrier Construction Scheme Based on Target Circle in Directional Sensor Network

Journal of Computer Science and Technology - With the increasing demand for security, building strong barrier coverage in directional sensor networks is important for effectively detecting...     

Microtopography‐Guided Radial Gradient Circle Array Film with Nanoscale Resolution

Distribution of multimaterials at arbitrary positions with nanoscale resolution and over a large area substrate is essential to future advances in functional graded materials. Such stringent requirements are highly beyond the reach of current techniques, although newly developed 3D printing technologies are addressed. Here, a radial gradient circle array film with the distribution accuracy up to ≈18 nm is fabricated by using microtopographic substrate. A mathematical model is developed to guide the distribution of position, size, shape, and type of materials on an arbitrary section for the given morphology of substrate. The periodic electrical and mechanical properties of the radial gradient circle film are identified, which can be beneficial for further functionalization and applications, such as gradient refractive index lenses, microcoils, and microantennas.     

三峡水库消落区岸线环境综合整治思路初探

三峡水库蓄水运行引起的消落区生态环境问题与岸线安全稳定问题一直受到社会各界的高度重视。实施消落区岸线环境综合整治早已成为业内共识并将陆续进入项目实施阶段。通过对库区沿线部分拟建、在建及已建消落区岸线整治项目工程资料的收集整理,分析了项目全生命周期中可能存在的问题与困难,提出了消落区岸线整治的原则与思路,以期为三峡水库消落区岸线环境综合整治提供借鉴和参考。     

On generic G-prevalent properties and a quantitative K-S theorem for Cr diffeomorphisms of the circle

We will consider a convex subset of a metric linear space and a certain group of actions G on this set, that allow us to define the notion of Haar zero measure on sets that have zero Haar measure for the translation (by adding) invariant HSY prevalence theory. In this way, we will be able to define the meaning of G-prevalent set according to the pioneering work of Christensen. Our setting considers problems which take into account the convex structure and this is quite different from the previous results on prevalence which consider basically the linear additive structure. In this setting, we will show a kind of quantitative Kupka–Smale theorem, and also we generalize a result about rotation numbers which was first considered by J.-C. Yoccoz (and, also by M. Tsujii). Among other things we present an estimation of the amount of hyperbolicity in a setting that we believe was not considered before.     

水泵转子径向圆跳动检测数据修正

针对应用千分表和电涡流传感器进行水泵转子径向圆跳动检测时,检测结果出现正弦变化规律的现象,分析了安装偏心误差对检测结果的影响原理,建立了相应的数学模型.运用最小二乘拟合法计算出变化曲线的幅值及初相位,从而消除偏心误差实现误差分离.结果表明,当将所提方法应用在水泵转子径向圆跳动检测的工程实践中时,可以有效消除安装偏心引起的误差,从而提高检测精确度.拟合平方和误差约为0. 000 9,所提方法可以广泛应用于轴类工件的检测实践.     

A simple and sensitive aptasensor with rolling circle amplification for viable Cronobacter sakazakii detection in powdered infant formula

Cronobacter sakazakii is a foodborne, emerging opportunistic pathogen that causes severe bacteremia, necrotizing enterocolitis, and sepsis with a mortality rate of up to 80%. In this study, we developed a simple and sensitive fluorescent turn-off aptasensor with rolling circle amplification assay for viable C. sakazakii detection in powdered infant formula. The results showed that the proposed aptasensor has good performance and specificity for detecting viable C. sakazakii in pure culture and powdered infant formula samples within 3 h. Under the optimal reaction conditions, there is a linear relationship between fluorescent intensity at 490 nm and logarithmic concentration of C. sakazakii in the range of 2.7 × 10⁵ to 2.7 × 10² cfu/mL, with a limit of detection of 2.7 × 10² cfu/mL in pure culture. The proposed aptasensor achieved a recovery of 104 to 111% in pure culture, and 96 to 107% in spiked powdered infant formula samples. The proposed aptasensor does not require complicated DNA extraction steps or antibodies, and can be performed at 37°C, making it a convenient and sensitive strategy for C. sakazakii detection.     

“流空间”视角下的城市空间网络结构研究——以成渝双城经济圈为例

推动区域协调发展已经成为构建高质量发展国土空间布局的客观需要和解决发展不平衡问题的内在需求，以城市群为核心的经济圈建设成为驱动高质量发展的重要空间层级。为实现成渝双城经济圈的区域一体化及区域多层级协调发展，将流动的生产资源与城市空间结构相结合，基于人流、信息流、技术流、经济流四大流动资源，采用社会网络分析方法，分别从点、线、面3个维度对成渝双城经济圈空间网络结构特征进行分析。研究表明：经济圈内部呈现以成都、重庆为双核心的结构，区域间相互作用，城市中心性整体表现出内部优于外部的空间特征，核心城市对外围城市未充分发挥带动作用；圈内城市链接多表现出高度不对称性，链接对称地区主要集中在成渝中轴地区，城市间的联系有待加强，经济圈外围城市与外界联系较少；区域内部小团体现象明显，团体间联系密度存在差异，整体来看城市集群格局尚未形成，跨省域、跨地区的联系不够，成渝双城经济圈主要是西侧地区围绕成都发展。最后，为构建成渝经济圈一体化及区域多层级协调发展的空间格局，建议突破行政区域限制，构建多领域的跨区域共享协作通道；加强中部地区发展动力，提高外围城市的资源吸收能力；注重经济圈内城市交通建设及信息融合发展，突出核心城市的引领作用和外溢属性，促进城市间技术交流与经济融合。     

资源循环利用对有色金属工业发展的影响

资源循环利用是把全社会已经使用过的物品、边角料、废弃物作为一种资源,经过技术处理重新服务于人类。而循环经济则是一种新的经济模型。资源循环利用对有色金属工业可持续发展意义重大,值得深入研究。本文对有色金属资源循环的必要性及资源循环型社会建立的条件进行了初步分析,以期引起人们的思考。     

钢丝绳锚杆在煤巷支护中的应用

介绍了用钢丝绳锚杆代替木支架支护煤巷的理论根据，施工工艺及二者技术经济效益的分析对比；论述了钢丝绳锚杆的支护参数选择，并提出了该种支护形式的施工建议。