With the acceleration of information network construction, the service applications carried on the network are more and more rich, and the information volume is more and more large, which makes users have higher and higher requirements for network link bandwidth and reliability. People have been trying to find a way to solve the bandwidth bottleneck effectively and provide high network system reliability under the existing conditions. Link aggregation technology solves this network problem well. So the research and implementation of link aggregation technology on network equipment has very important practical significance.

As the requirements of different application scenarios vary, numerous blockchains have been developed. Among them, chains using Byzantine Fault Tolerance consensus (BFT chains for short) occupy a dominant position. Performance modeling is the most common method for guiding chain design and configuration. However, many lack specific models due to the large number of BFT chains. Providing a general framework for them is promising and should demonstrate two important features that BFT chains may differ in: different consensus stages and different packaging rules. This paper is the first to propose a general framework applicable to various BFT chains. We use the bulk-service model in queuing theory to reflect the above two features of various BFT chains and provide calculation methods for them. We give an expression for the confirmation delay of transactions (TXs for short) in the chain and verify it through experiments on various BFT chains. We also use the model for a brief analysis to assist designers in configuring and designing BFT chains.

This study presents a novel approach for handling the intersection of planar parametric curves. By leveraging the inherent properties of parametric curves, our technique simplifies the process by reducing and comparing the ranges of x and y coordinates. The essential advantage of this technique lies in its simplicity, achieved through the reduction and comparison of the x and y coordinates ranges of the two curves. The monotonicity of curves is used during the reduction strategy. We utilize the opposite monotone system within a box to determine the uniqueness and existence of a simple intersection point. Moreover, we comprehensively analyzed singular cases like cusps, self-intersections, and tangents. Examples and comparisons with other methods showcase the algorithm’s robustness and efficiency, particularly for high-degree systems.

分析了加扰技术改善ADC性能的基本原理,通过选择合适的扰动信号注入到理想量化器模型中进行仿真,验证了加扰技术能够随机化量化误差的周期性三角形分布.在加扰技术的实际应用中,首先基于10 bit 25 MS/s Pipelined ADC模型完成加扰仿真,仿真得到ADC的SFDR由74.69 dB提高到了 85 dB.然后对两种ADC芯片进行加扰实验,该加扰技术使两种ADC芯片的SFDR分别提高了 8.29 dB和5.97 dB.理论仿真和实验验证了加扰技术可以明显提高ADC的SFDR,为后期ADC内部集成加扰电路模块做好了准备工作.

大量以信息为中心的应用使得组播再次受到关注.基于共享树的组播方法相较于基于源树的组播方法能够有效地减少组播转发状态,但仍存在一些问题,如RP管理复杂、RP负载过大、传输时延高和流量汇聚等.基于此,文中提出了一种基于名字映射和解析系统(NMRS)的多RP组播方法.针对RP管理复杂和过载问题,所提方法将所有路由器都作为候选RP,并使用NMRS管理候选RP以实现负载均衡.针对时延过高的问题,所提方法使用现场名字映射和解析服务维护局部源信息并为局部的源选择最近的RP,每个组播组建立多个以不同RP为根的共享树.实验结果表明,相较于现有基于共享树的方法,所提的组播方法在仅增加部分组播转发状态的同时能够有效减少RP负载、传输时延和流量汇聚.

芯片级原子钟是一种体积小且功耗低的高精度时钟源,具有广泛的用途.针对这一特点,设计了基于GNSS的芯片级原子钟驾驭算法.以GNSS系统时作为参考,测量芯片级原子钟与GNSS系统时间的钟差,并对芯片级原子钟进行钟差建模,获取其特征参数.通过乒乓法计算出钟驾驭调整量,对芯片级原子钟进行控制,最终将芯片级原子钟驾驭到GNSS系统时间上.经过实验验证,在驾驭时间常数为100s的情况下,芯片级原子钟与GNSS系统时间的时钟同步误差在-7.5～7.5ns之间;1h频率准确度为5.8×10-13;平均时间为10000s时的频率稳定度为3×10-13.

稀土精矿冶炼炉窑是稀土生产工艺的核心装备,会产生大量含氟酸性高温烟气,其中氟化物0.81％、硫酸雾1.06％、二氧化硫0.23％,同时温度达300℃以上,烟气余热丰富,烟气成分的复杂性和特殊性为余热及资源回收利用带来挑战.介绍一种新的稀土精矿冶炼炉窑的高温烟气余热利用技术及其现场中试情况.根据物质流、能量流守恒计算了烟气流量、温度、组分浓度以及余热量,分析了余热回收的可行性和技术难点;提出了新的烟气干法余热回收工艺,依据能源梯级利用原则,通过余热锅炉实现烟气分级降温和余热回收,同时回收高浓度冷凝酸并副产余热蒸汽;该工艺在稀土精矿冶炼炉窑系统进行了现场中试,采集并分析72 h中试数据,取得良好资源目收效果.

目的 为研究热泵在中药材干燥中的性能,并针对批式干燥器干燥不均匀的问题,设计开发一套能够均匀干燥物料的热泵干燥系统.方法 以金丝皇菊为干燥材料,对热泵干燥设备进行实验研究,并对系统的送风温湿度均匀性、系统能效和物料品质进行分析.结果 该系统干燥过程的温湿度、物料含水率的均匀性和温度控制精度都很高,主机室的温度、湿度稳定,且显著高于外界环境,这不仅避免了热泵系统受外界环境因素的影响,且提供了稳定的运行环境.热泵干燥机组的能效约为5.88,系统能效约为1.32,除湿能耗约为0.66 kg/(kW·h).干燥后的金丝皇菊花瓣未出现明显的色差、卷曲和破损现象,干花的完整度高.结论 新型热泵干燥系统能够满足金丝皇菊的工艺要求,最终得到的金丝皇菊的干燥品质较高.该研究为热泵技术在中药材干燥领域的应用提供实际案例和技术参考.

In this paper, we study graphical conditions for structural controllability and accessibility of drifted bilinear systems over Lie groups. We consider a bilinear control system with drift and controlled terms that evolves over the special orthogonal group and the special unitary group. Zero patterns are prescribed for the drift and controlled dynamics with respect to a set of base elements in the corresponding Lie algebra. The drift dynamics must respect a rigid zero- pattern in the sense that the drift takes values as a linear combination of base elements with strictly non-zero coefficients; the controlled dynamics are allowed to follow a free zero pattern with potentially zero coefficients in the configuration of the controlled term by linear combination of the controlled base elements. First of all, for such bilinear systems over the special orthogonal group, the zero patterns are shown to be associated with two undirected graphs whose connectivity and connected components ensure structural controllability. Next, for bilinear systems over the special unitary group, we introduce two edge- colored graphs associated with the drift and controlled zero patterns, and prove structural controllability conditions related to connectivity and the number of edges of a particular color.

中国科学院国家授时中心已启动建设国家高精度地基授时系统.光纤时间传递分系统作为高精度授时系统的重要组成部分,需要不断针对关键技术问题提出解决方案,从而提升光纤时间同步的准确度与稳定度,以达到构建与国家标准时间偏差优于100 ps的高精度光纤时间同步网络的目标.本文报告了中国科学院国家授时中心在长链路光纤时间传递的研究进展.利用研制的光纤时间同步设备在871.6 km的实地光纤链路上得到了29.8 ps的时间同步标准差,3.85 ps@1 ks的时间稳定度,25.4 ps的不确定度;在此基础上针对后向反射光噪声的关键问题进行技术改进,在总长度为1085 km的实地光纤链路上实现了色散误差修正功能的双波长光纤时间同步,得到了18 ps的时间同步标准差,5.4 ps@4×104 s的稳定度,63.5 ps的不确定度.

Many bandwidth-intensive applications (such as online live, online games, etc.) are more suitable for using multicast to transmit information. Due to the advantages in scalability, Shared Tree (ST) is more suitable for large-scale deployment than Source-Based Tree (SBT). However, in ST-based multicast, all multicast sources need to send multicast data to a center node called a core, which will lead to core overload and traffic concentration. Besides, most existing multicast protocols use the shortest path between the source or the core and each receiver to construct the multicast tree, which will result in traffic overload on some links. In this paper, we propose an Identifier and Locator Decoupled Multicast approach (ILDM) based on Information-Centric Networking (ICN). ILDM uses globally unique names to identify multicast services. For each multicast service, the mapping between the multicast service name and the addresses of multicast tree nodes is stored in the Name Resolution System (NRS). To avoid core overload and traffic aggregation, we presented a dynamic core management and selection mechanism, which can dynamically select a low-load core for each multicast service. Furthermore, we designed a path state-aware multicast tree node selection mechanism to achieve traffic load balancing by using low-load links more effectively. Experimental results showed that our proposed multicast approach outperformed some other multicast methods in terms of core load, number of join requests, link load, traffic concentration, and routing state.

Many information-centric services have emerged, such as IPTV and video conferencing. These services put a lot of demands on scalable multicast communication. However, traditional IP multicast has low adoption because of its poor scalability. Therefore, some stateless multicast methods were proposed, which encapsulate the destination’s information into the packet header without requiring routers to maintain the multicast forwarding state. However, stateless multicast also faces some problems, such as ingress router overload, high forwarding overhead, packet redundancy, etc. In addition, most multicast methods cannot optimize the multicast tree because the multicast flow is simply forwarded along the shortest path tree from the source to receivers. This paper proposes an Adaptive Hierarchical Hybrid Multicast (AHHM) based on Information-Centric Networking. To balance the forwarding states and forwarding overhead, AHHM is designed as a two-layer structure, in which the upper layer establishes a stateful main tree and the lower layer establishes several stateless sub trees. The router on the main tree is defined as the multicast join node (MJN), and AHHM uses the Name Resolution System to maintain the mapping between each multicast group name and corresponding MJNs. To optimize the multicast transmission path, we designed the minimum cost selection strategy for users to select the appropriate MJN to join. Simulation results show that compared with Source-Specific Multicast (SSM) and Bit Index Explicit Replication (BIER), AHHM can not only reduce the multicast forwarding states but also reduce the control overhead and link load.

汽车变速箱装配过程中部分零部件分装涉及到选择调整垫片的过程,垫片尺寸是否合适将直接影响变速箱整体的装配质量,为了满足新型号变速箱的数字化生产需求以及提高生产系统的工作准确性,需要将人工经验为主导的传统制造模式向轻量化、智能化的新型制造模式转化.本文结合某企业MQ250变速箱装配线的具体需求,为了提高生产现场的数字化程度以及对测量任务的管理能力,设计并实现了一套新型的变速箱零部件装配的测量系统.首先根据相对测量的原理,设计了测量模块,并分析了测量模块最优化的问题,最终通过最小二乘法实现了测量模块的优化.经过实际生产情况表明,本测量系统适应了MQ250变速箱零部件的装配需求,保证装配效率的情况下提升了整体装配质量,提高了装配生产线的数字化水平.

工业炉窑是我国的能耗大户,每年耗能约占全国总能耗的1/4.在能源日益紧缺、环境污染严重的今天,工业炉窑节能减排工作十分紧迫.工业炉窑的生产是不同设备、不同工序协同生产的一个过程,包含物质与能量在各个系统之间的转换与转移,因此工业炉窑的物质流和能量流分析是炉窑实现高能效和低排放的基础.一般的方法主要从炉窑的产品用能或余热利用角度来分析,未将工业炉窑作为一个系统,整体来考察物质流和能量流状况.基于节点计算法,从工业炉窑整体系统出发,建立一种工业炉窑物质流与能量流匹配的数学模型,获得了典型工业炉窑不同部位的能量收支情况;同时采用热力学第二定律的炯分析方法研究炉窑系统的(火用)损失,明确了炉窑节能的重点部位.采用该方法开展了3 200 t/d典型水泥炉窑的物质流和能量流分析计算,结果表明,水泥炉窑的热量损失主要包含高温损失与低温损失,其中高温损失主要是炉窑壁面散热损失与煤粉未燃尽的碳热损失,分别占6.84％与1.95％,炯损失分别为4.17％与2.59％,有较大的节能潜力;低温热损失包含烟道尾部烟气的排烟热损失、出冷却机熟料带出的显热等,AQC炉和SP炉的热量损失各占3.06％和6.19％,(火用)损失分别为1.26％和1.45％,仍有利用价值.针对高温和低温热量损失的不同原因,对于炉窑的节能潜力进行了评估,提出采用先进保温、富氧煅烧、低温余热再利用等新技术,可进一步降低炉窑的煤耗;此外,也推荐了减少设备电耗的新技术,如采用高效风机以及永磁电机等,结合富余蒸汽拖动风机以及节能管控等技术,有望实现熟料烧成系统零电耗的目标.

In this paper, we propose distributed algorithms that solve a system of Boolean equations over a network, where each node in the network possesses only one Boolean equation from the system. The Boolean equation assigned at any particular node is a {\em private} equation known to this node only, and the nodes aim to compute the exact set of solutions to the system without exchanging their local equations. We show that each private Boolean equation can be locally lifted to a linear algebraic equation under a basis of Boolean vectors, leading to a network linear equation that is distributedly solvable using existing distributed linear equation algorithms as a subroutine. A number of exact or approximate solutions to the induced linear equation are then computed at each node from different initial values. The solutions to the original Boolean equations are eventually computed locally via a Boolean vector search algorithm. We prove that given solvable Boolean equations, when the initial values of the nodes for the distributed linear equation solving step are i.i.d selected according to a uniform distribution in a high-dimensional cube, our algorithms return the exact solution set of the Boolean equations at each node with high probability. Furthermore, we present an algorithm for distributed verification of the satisfiability of Boolean equations, and prove its correctness. Finally, we show that by utilizing linear equation solvers with differential privacy to replace the in-network computing routines, the overall distributed Boolean equation algorithms can be made differentially private. Under the standard Laplace mechanism, we prove an explicit level of noises that can be injected in the linear equation steps for ensuring a prescribed level of differential privacy.

高温固体比热容是工业流程设计中常用的热物性数据,但通过实测获取温度达数千度的固体比热容比较困难,因此许多含有复杂晶格的固体经常只存在有限温度范围内的比热容测量数据.爱因斯坦模型和德拜模型可以适用于简单的单原子晶体或某些双原子晶体比热容预测,但多原子复杂晶格固体的德拜温度或爱因斯坦温度难以准确获得,使得这些模型难以准确预测这些固体比热容.因此,利用统计热力学方法,针对含多原子复杂晶格固体比热容的测试困难问题,提出一种高温固体比热容的双参数预测方法;该方法将多原子固体的晶格振型分为声学支与光学支,假设这些固体的单个晶格原胞具有唯一的德拜特征温度ΘD和爱因斯坦温度ΘE;通过晶体学的基本参数获得德拜特征温度ΘD,通过固体比热容的有限试验数据或简单物质的热物性,反算出复杂晶格固体的爱因斯坦温度ΘE;然后利用这2个主要影响参数预测高温固体的理论比热容.采用该双参数预测方法对典型单原子、双原子与多原子晶体的比热容进行了预测计算,计算结果与试验数据对比验证表明,该方法误差主要在温度拐点和高温区附近,在宽范围变化的温度区间内比热容的预测误差小于5％,有望为流程工业的固体热物性数据提供一种简单可靠的确定方法.

针对于循环式干燥塔的高温差、变负荷的特性,本文研发了一种新型循环式稻谷热泵干燥系统,并对其进行稻谷干燥的实验研究.实验结果表明:该系统可以在16～23℃的环温条件下,实现送风温度范围为63～70℃,且其制热性能系数达到了4.04～4.65,整个干燥过程的除湿能耗比为3.31 kg/(kW·h).系统平均每降1％水分的稻谷烘干成本为2.42元/t(干稻谷),相对于燃油型和生物质型稻谷干燥系统,该系统的干燥成本分别降低了64.41％和42.38％.本文研究为热泵系统在循环式谷类塔式干燥系统应用提供了技术支持和理论依据.

传统制药行业是废气排放的大户,干燥生产过程会产生大量含挥发性有机物(VOCs)的废气.传统处理方法是先通过水喷淋降温吸收,再通过生物法、等离子体或(和)光催化进行VOCs降解处理后直接对空排放,对某些含特殊异味的废气处理效果不理想,很难实现达标排放,增加企业生产成本且造成不良社会影响,与我国节能减排和近零排放的号召相矛盾.目前一种新型的闭式循环处理技术为含VOCs废气处理提供了全新解决方案,带动废气处理过程的技术创新,推进化工行业废气处理技术进步.

针对转炉放散煤气传统的直燃排放造成严重的能源浪费和环境污染问题,采用溶胶凝胶法制备CuCe0.75Zr0.25Oy新型催化剂,研究了反应气体积分数对CO自持催化燃烧的影响规律.结果 表明,CO自持燃烧发生的临界条件为3％ CO+3％O2/N2;CO与O2体积分数的增大均促进了CO完全转化温度的提前,有利于CO自持燃烧反应的进行;随CO2体积分数增大,导致CO完全转化所需炉温越来越高,不利于CO)自持燃烧反应的进行.同时进行了CuCe0.75Zr0.25Oy催化剂的热稳定性实验研究,结果表明,10％CO+90％合成空气条件下,CuCe0.75Zr0.25Oy催化剂在100 h内具有高热稳定性,催化剂活性基本保持不变,催化剂表面反应温度保持在310.0±3.0℃.

This paper aims to provide a systemic analysis to social opinion dynamics subject to individual biases. As a generalization of the classical DeGroot social interactions, defined by linearly coupled dynamics of peer opinions that evolve over time, biases add to state-dependent edge weights and therefore lead to highly nonlinear network dynamics. Previous studies have dealt with convergence and stability analysis of such systems for a few specific initial node opinions and network structures, and here we focus on how individual biases affect social equilibria and their stabilities. Two categories of equilibria, namely the boundary and interior equilibria, are defined. For a few fundamental network structures, some important interior network equilibria are presented explicitly for a wide range of system parameters, which are shown to be locally unstable in general. Particularly, the interval centroid is proven to be unstable regardless of the bias level and the network topologies. Next, we prove that when the initial network opinions are polarized towards one side of the state space, node biases will drive the opinion evolution to the corresponding interval boundaries. Such polarization attraction effect continues to hold under even directed and switching network structures. Finally, a number of numerical examples are provided to validate our study and advance the understanding of the nonlinearity inherited within the biased opinion evolution.