Novel method for transferring access control list rules to synchronize security protection in a locator/identifier separation protocol environment with cross‐segment host mobility

Extended access control lists (ACLs) are used to filter packets for network security. However, in current network frameworks, ACL rules are not transferred simultaneously with devices that move across network segments. The Internet Engineering Task Force proposed the Locator/Identifier Separation Protocol (LISP), which enables routers (xTRs) to configure ACL rules for blocking immobile endpoint identifiers (EIDs). However, when an EID moves from the original xTR to a new xTR, the ACL rules at the original xTR cannot be transferred with the EID. Thus, the new xTR lacks the corresponding ACL rules to effectively block the EID, resulting in security risks. The highlights of this study are as follows. First, a method is proposed for dynamically transferring ACL rules in LISP environments and frameworks. Second, the map‐register and map‐notify protocols were combined to encapsulate and transfer the ACL rules and thus obviate an additional process required to transfer these rules. Third, the experimental results verified that the proposed method can be used to achieve synchronized security protection in an LISP environment involving cross‐segment EID movements.     

Searching General Sufficient‐and‐Necessary Conditions for Ultrafast Hydrogen‐Evolving Electrocatalysis

The development of cost‐effective and high‐performance electrocatalysts for the hydrogen evolution reaction (HER) is one critical step toward successful transition into a sustainable green energy era. Different from previous design strategies based on single parameter, here the necessary and sufficient conditions are proposed to develop bulk non‐noble metal oxides which are generally considered inactive toward HER in alkaline solutions: i) multiple active sites for different reaction intermediates and ii) a short reaction path created by ordered distribution and appropriate numbers of these active sites. Computational studies predict that a synergistic interplay between the ordered oxygen vacancies (at pyramidal high‐spin Co³⁺ sites) and the O 2p ligand holes (OLH; at metallic octahedral intermediate‐spin Co⁴⁺ sites) in RBaCo₂O_5.5+δ (δ = 1/4; R = lanthanides) can produce a near‐ideal HER reaction path to adsorb H₂O and release H₂, respectively. Experimentally, the as‐synthesized (Gd_0.5La_0.5)BaCo₂O_5.75 outperforms the state‐of‐the‐art Pt/C catalyst in many aspects. The proof‐of‐concept results reveal that the simultaneous possession of ordered oxygen vacancies and an appropriate number of OLH can realize a near‐optimal synergistic catalytic effect, which is pivotal for rational design of oxygen‐containing materials.     

Street-Level Landmarks Acquisition Based on SVM Classifiers

High-density street-level reliable landmarks are one of the important foundations for street-level geolocation. However, the existing methods cannot obtain enough street-level landmarks in a short period of time. In this paper, a street-level landmarks acquisition method based on SVM (Support Vector Machine) classifiers is proposed. Firstly, the port detection results of IPs with known services are vectorized, and the vectorization results are used as an input of the SVM training. Then, the kernel function and penalty factor are adjusted for SVM classifiers training, and the optimal SVM classifiers are obtained. After that, the classifier sequence is constructed, and the IPs with unknown service are classified using the sequence. Finally, according to the domain name corresponding to the IP, the relationship between the classified server IP and organization name is established. The experimental results in Guangzhou and Wuhan city in China show that the proposed method can be as a supplement to existing typical methods since the number of obtained street-level landmarks is increased substantially, and the median geolocation error using evaluated landmarks is reduced by about 2 km.     

肢腿履带足机构抬腿工况动力学分析与实验研究

为验证肢腿履带足机构肢腿系统的结构强度,以单肢腿系统为研究对象,基于拉格朗日法建立其抬起工况的动力学模型,推导了其上、下肢腿关节驱动力矩的表达式并予以验证。同时,通过对肢腿履带足机构单腿抬起工况进行动力学仿真,揭示了其支撑腿、抬起腿各铰接点所受力的时域变化规律,并对受力最大的抬起腿的强度进行了有限元模拟与实验验证。结果表明：在肢腿履带足机构单腿抬起工况下,其抬起腿上肢腿的最大应力为165.9 MPa,安全系数为3.04,下肢腿的最大应力为122.9 MPa,安全系数为2.81,均满足单腿抬起过程中的强度要求;抬起腿各铰接点处最大应力的模拟值与测试值的相对误差均在18%以内。研究结果验证了肢腿履带足机构抬腿工况动力学分析方法的正确性以及其结构的安全性和合理性,可为其他肢腿型机构的设计及应用提供参考。     

Decomposition of 1,2‐dichloroethane in an RF plasma environment

A radio frequency (RF) plasma system has been used to decompose 1,2‐dichloroethane (DCE). Final products were identified by a Fourier transform infrared (FTIR) spectrometer. The main products of DCE decomposition in O₂/Ar plasma were CO₂, CO, and HCl. Other minor chlorinated products were CCl₄, C₂HCl₃, C₂H₃Cl, C₂Cl₄, CHCl₃, C₂HCl₅, and COCl₂. Nonchlorinated products were C₂H₂, C₂H₄, C₂H₆, and HCOOH. The plasma reactor with a brass electrode had a higher decomposition fraction of DCE [η, (C_in ? C_out)/C_in × 100%] than that obtained with other materials (Au, Ni, and Cr). Different electrode configurations (inner and outer) were also evaluated for the decomposition of DCE. Argon plus oxygen was found to be the most suitable carrier/auxiliary gas for DCE decomposition. In addition, operational parameters for DCE decomposition in RF plasma including concentration, operational pressure, and total gas flow rate were evaluated. Copyright © 2003 Society of Chemical Industry     

Alkaline earth metal-based catalyst and process for selective hydrocarbon conversion to acetylene and carbon monoxide

A multi-step process that employs a Ni-modified mixed alkaline earth metal oxides (AEMO) has been developed for the selective conversion of hydrocarbons to C₂H₂ and CO. The initial process step is the catalytic decomposition of a gaseous hydrocarbon mixture at an elevated temperature (ca. 800 °C) over Ni/AEMO, generating H₂, trace CO, carbon (C), and trace alkaline earth metal carbide (MC₂). The Ni/AEMO/C/MC₂ material is then heated to consume the remaining carbon, generate more MC₂, and evolve CO. Then, Ni/AEMO/MC₂ is cooled and reacted with excess H₂O at a low temperature (20 < T (°C) < 80) to selectively generate C₂H₂ and Ni/AEM(OH)₂·zH₂O. In the final process step, Ni/AEM(OH)₂·zH₂O is decomposed to yield H₂O and Ni/AEMO, which is recycled within the process. The most advanced Ni/AEMO materials developed thus far exhibit intrinsic production capacities exceeding 2000 μmoles of C₂H₂ per gram of Ni/AEMO per process cycle.     

500kV线路瓷绝缘子雷击断串故障分析

在机电负荷、污秽及环境温湿度等多重环境影响下,盘型悬式瓷绝缘子瓷件内微孔可能会逐渐扩展,直至开裂受潮,导致其机械强度和绝缘性能减弱,在遭受雷击或污闪时极有可能导致绝缘子炸裂、断串等恶性事故发生。针对一起500 k V线路瓷绝缘子雷击断串故障,结合雷电定位系统、线路分布式故障定位系统进行了线路耐雷水平分析。通过绝缘子试验,可判定故障原因为故障前已存在多片低零值绝缘子,当雷电绕击C相造成绝缘子串闪络后,大部分工频续流能量从低零值绝缘子头部瓷件内部放电通道泄放,产生的热量导致绝缘子炸裂脱开并引发断串。建议对线路低零值绝缘子进行排查,并合理采用疏导型防雷措施,对多雷区塔位优先安装线路避雷器。