ID-Based Public Auditing Protocol for Cloud Storage Data Integrity Checking with Strengthened Authentication and Security

Cloud storage service reduces the burden of data users by storing users’ data files in the cloud. But, the files might be modified in the cloud. So, data users hope to check data files integrity periodically. In a public auditing protocol, there is a trusted auditor who has certain ability to help users to check the integrity of data files. With the advantages of no public key management and verification, researchers focus on public auditing protocol in ID-based cryptography recently. However, some existing protocols are vulnerable to forgery attack. In this paper, based on ID-based signature technology, by strengthening information authentication and the computing power of the auditor, we propose an ID-based public auditing protocol for cloud data integrity checking. We also prove that the proposed protocol is secure in the random oracle model under the assumption that the Diffie-Hellman problem is hard. Furthermore, we compare the proposed protocol with other two ID-based auditing protocols in security features, communication efficiency and computation cost. The comparisons show that the proposed protocol satisfies more security features with lower computation cost.     

超长波天文观测微卫星宽带有源天线设计

月球轨道超长波天文观测微卫星(path finder of discovering the sky at the longest wavelengths,DSL-P)是国际首次开展绕月轨道超长波干涉技术验证实验。DSL-P工作频率1~30 MHz,其关键技术之一为宽带有源天线。介绍了DSL-P宽带有源天线的方案,重点分析其噪声特性,通过仿真和测试获取有源天线的噪声性能,分析宽带有源天线对系统设计指标的满足度。研究表明,用于超长波观测的宽带有源天线并不是传统意义上的被动天线和前置放大器的组合,其主要作用是阻抗匹配,并可兼顾噪声要求。     

基于时空频特征融合的距离-速度复合欺骗干扰识别技术研究

针对距离-速度复合欺骗干扰信号形式复杂及识别难度大的特点,提出了一种基于时空频特征融合的距离-速度复合欺骗干扰识别算法。首先,分析真实目标和虚假目标在空域、频域和时域的特征差异;然后,针对真假目标在不同域的特征区别,分别提取回波点迹的空域特征和频域特征;最后,将提取的空域及频域特征在时域进行融合,采用先积累后判别和基于二进制检测两种特征融合方法,利用时空频融合特征对距离-速度复合欺骗干扰进行判决。仿真结果表明,该算法能够对距离-速度复合欺骗干扰进行有效的识别。     

Structure and function of Zika virus NS5 protein: perspectives for drug design

Zika virus (ZIKV) belongs to the positive-sense single-stranded RNA-containing Flaviviridae family. Its recent outbreak and association with human diseases (e.g. neurological disorders) have raised global health concerns, and an urgency to develop a therapeutic strategy against ZIKV infection. However, there is no currently approved antiviral against ZIKV. Here we present a comprehensive overview on recent progress in structure–function investigation of ZIKV NS5 protein, the largest non-structural protein of ZIKV, which is responsible for replication of the viral genome, RNA capping and suppression of host interferon responses. Structural comparison of the N-terminal methyltransferase domain and C-terminal RNA-dependent RNA polymerase domain of ZIKV NS5 with their counterparts from related viruses provides mechanistic insights into ZIKV NS5-mediated RNA replication, and identifies residues critical for its enzymatic activities. Finally, a collection of recently identified small molecule inhibitors against ZIKV NS5 or its closely related flavivirus homologues are also discussed.     

A method for recovery of iron,titanium, and vanadium from vanadium-bearing titanomagnetite

An innovative method for recovering valuable elements from vanadium-bearing titanomagnetite is proposed. This method involves two procedures: low-temperature roasting of vanadium-bearing titanomagnetite and water leaching of roasting slag. During the roasting process, the reduction of iron oxides to metallic iron, the sodium oxidation of vanadium oxides to water-soluble sodium vanadate, and the smelting separation of metallic iron and slag were accomplished simultaneously. Optimal roasting conditions for iron/slag separation were achieved with a mixture thickness of 42.5 mm, a roasting temperature of 1200°C, a residence time of 2 h, a molar ratio of C/O of 1.7, and a sodium carbonate addition of 70 wt%, as well as with the use of anthracite as a reductant. Under the optimal conditions, 93.67% iron from the raw ore was recovered in the form of iron nugget with 95.44% iron grade. After a water leaching process, 85.61% of the vanadium from the roasting slag was leached, confirming the sodium oxidation of most of the vanadium oxides to water-soluble sodium vanadate during the roasting process. The total recoveries of iron, vanadium, and titanium were 93.67%, 72.68%, and 99.72%, respectively.