An efficient certificateless aggregate signature scheme

Aggregate signature can aggregate n signatures on n messages from n signers into a single signature that convinces any verifier that n signers sign the n messages, respectively. In this paper, by combining certificateless public key cryptography and aggregate signatures, we propose an efficient certificateless aggregate signature scheme and prove its security. The new scheme is proved secure against the two representative types adversaries in certificateless aggregate signature under the assumption that computational Diffie-Hellman problem is hard. Furthermore, from the comparison of the computation cost of the new scheme with some existing certificateless aggregate signature schemes in group sum computation, scalar multiplication computation, Hash computation and abilinear pairings computation, it concludes that the new scheme reduces the computation cost in scalar multiplication computation in half and maintains the same in the other computation costs.     

Identity-based blind signature from lattices

Blind signature allows a user to get a signature of a signer on an arbitrary message,and the verifier can convince that the signature is indeed signed by the signer without leaking any information about the message.This property is necessary when the user’s privacy needs protection,such as a bank bill,a trade secret,etc.As an alternative of public key infrastructure,the identity-based system can simplify the key management procedures in certificate-based public key systems.Inspired by the requirement of identity-based blind signature in the post quantum world,we research on identity-based blind signature based on hard lattice problems under the random Oracle model.We propose a construction built upon the blind signature by Rückert,and it is proved to be one-more unforgeable against selective identity and chosen message attacks(s ID-CMA)and unconditionally blind.The proposed scheme has 2 moves,and its security can be reduced to the small integer solution(SIS)problem.     

Estimation of DOA and polarization with COLD sensors based on quaternion model

The quaternion multiple signal classification (Q-MUSIC) algorithm generally requires four-dimensional spectral peak search to estimate the direction of arrival (DOA) and polarization parameters, which would result in the huge computation burden. A dimension reduction Q-MUSIC algorithm (DRQ-MUSIC) based on L-shaped array is presented to reduce the computational complexity in this paper. The proposed algorithm divides the steering vector into three parts, and estimates each part separately, thus DOA and polarization parameters can be estimated only by N times one-dimensional spectral peak search, where N denotes the sources number. Besides, pair match is not required. Finally, simulation examples demonstrate the effectiveness and feasibility of the proposed algorithm.     

Effect of plasticizer poly(ethylene glycol) on the crystallization properties of stereocomplex-type poly (lactide acid)

The effects of the plasticizer poly(ethylene glycol)(PEG) on crystallization properties of equimolar poly(L-lactide)(PLLA)/poly(D-lactide)(PDLA) blends were investigated. Formation of the stereocomplex-type poly(lactide acid)(sc-PLA) crystallites was confirmed by Wide-angle X-ray diffraction(WAXD) and differential scanning calorimetry(DSC) analyses. Sc-PLA crystallites without any homochiral poly(lactide acid)(hc-PLA) formed, as the result of the incorporation of the plasticizer PEG(more than or equal to 10%(wt)) at a processing temperature(240 ℃). Moreover, when the MW of PEG reached 1 000 g × mol–1, the crystallizability of stereocomplex crystallites was the best. Isothermal crystallization kinetics further revealed that PEG could accelerate the crystallization rate of sc-PLA, with the optimum crystallization kinetic parameters being obtained at 10%(wt) PEG. Several crystallization kinetics equations were applied to describe the effect of PEG on the crystallization behavior of sc-PLA. The influence of PEG on the spherocrystal morphologies of sc-PLA was also investigated using polarized optical microscopy.     

Cloning and characterization of <Emphasis Type="Italic">UL</Emphasis>34 gene of pseudorabies virus HB isolate

In this study, China isolate HB of pseudorabies virus (PRV) was confirmed and genotypically characterized by amplifying and sequencing of partial UL34, a conservative gene involved in the egress of nucleocapsids from the nucleus, for phylogenetic analysis. The open reading frame (orf) of UL34 of PRV HB isolate is composed of 786 nucleotides, which encoded 262 amino acids. In addition, a potential transmembrane domain (241-260 aa) and 11 potential phosphorylation sites were also found in the UL34 of PRV HB isolate. Multiple amino acids alignment indicated that UL34 proteins of PRV strains derived from different geographic origins were highly conservative, but some mutations were also found. Phylogenetic analysis based on UL34 protein indicated that PRV HB strain was evolutionarily distinct from other recent China strains sequenced so far, forming a single clade within the phylogeny. Moreover, PRV HB isolate had close evolutionary relationship with BoHV-1 and BoHV-5 within the Alphaherpesvirinae. Taken together, these results indicated that PRV strains were in the progress of evolution. This study has expanded the knowledge of genetic profiles of PRV strains.     

Existence of global attractor for the one-dimensional bipolar quantum drift-diffusion model

In this paper, we investigate a one-dimensional bipolar quantum drift-diffusion model from semiconductor devices. We mainly show the long-time behavior of solutions to the one-dimensional bipolar quantum drift-diffusion model in a bounded domain. That is, we prove the existence of the global attractor for the solution.     

Redox-responsive molecular gels based on camptothecin prodrug with disulfide linkage for controlled and sustained drug release

A novel camptothecin (CPT) prodrug was successfully synthesized by conjugating CPT to adamantanecarboxylic acid (AD) via a cleavable disulfide linkage. The resulting CPT-ss-AD prodrug could act as a low molecular weight gelator to form molecular gels in water/water-miscible organic solvent mixture. Meanwhile, biodegradable amphiphilic block copolymer mPEG-b-P (MAC-co-DTC) (PPMD) was also employed as an organic framework together with CPT-ss-AD to form gel structure. CPT-ss-AD/PPMD gel exhibited less compact molecular arrangement but much more stability than CPT-ss-AD gel. The two kinds of gels could effectively release the original CPT under reductive condition at a near-constant rate without any initial burst. As compared to CPT-ss-AD single-component gel, the two-component gel, CPT-ss-AD/PPMD, had a significantly higher release rate of CPT, while 3-[4,5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide (MTT) assays also indicated highly potent cytotoxic activity against HeLa cells.     

Relationship between the specific surface area of rust and the electrochemical behavior of rusted steel in a wet-dry acid corrosion environment

The relationship between the specific surface area (SSA) of rust and the electrochemical behavior of rusted steel under wet-dry acid corrosion conditions was investigated. The results showed that the corrosion current density first increased and then decreased with increasing SSA of the rust during the corrosion process. The structure of the rust changed from single-layer to double-layer, and the γ-FeOOH content decreased in the inner layer of the rust with increasing corrosion time; by contrast, the γ-FeOOH content in the outer layer was constant. When the SSA of the rust was lower than the critical SSA corresponding to the relative humidity during the drying period, condensed water in the micropores of the rust could evaporate, which prompted the diffusion of O₂ into the rust and the following formation process of γ-FeOOH, leading to an increase of corrosion current density with increasing corrosion time. However, when the SSA of the rust reached or exceeded the critical SSA, condensate water in the micro-pores of the inner layer of the rust could not evaporate which inhibited the diffusion of O₂ and decreased the γ-FeOOH content in the inner rust, leading to a decrease of corrosion current density with increasing corrosion time.     

Reduction behavior and kinetics of vanadium-titanium sinters under high potential oxygen enriched pulverized coal injection

In this work, the reduction behavior of vanadium-titanium sinters was studied under five different sets of conditions of pulverized coal injection with oxygen enrichment. The modified random pore model was established to analyze the reduction kinetics. The results show that the reduction rate of sinters was accelerated by an increase of CO and H₂ contents. Meanwhile, with the increase in CO and H₂ contents, the increasing range of the medium reduction index (MRE) of sinters decreased. The increasing oxygen enrichment ratio played a diminishing role in improving the reduction behavior of the sinters. The reducing process kinetic parameters were solved using the modified random role model. The results indicated that, with increasing oxygen enrichment, the contents of CO and H₂ in the reducing gas increased. The reduction activation energy of the sinters decreased to between 20.4 and 23.2 kJ/mol.     

A novel process for the recovery of iron,titanium, and vanadium from vanadium-bearing titanomagnetite:sodium modification-direct reduction coupled process

A sodium modification-direct reduction coupled process was proposed for the simultaneous extraction of V and Fe from vanadium-bearing titanomagnetite. The sodium oxidation of vanadium oxides to water-soluble sodium vanadate and the transformation of iron oxides to metallic iron were accomplished in a single-step high-temperature process. The increase in roasting temperature favors the reduction of iron oxides but disfavors the oxidation of vanadium oxides. The recoveries of vanadium, iron, and titanium reached 84.52%, 89.37%, and 95.59%, respectively. Moreover, the acid decomposition efficiency of titanium slag reached 96.45%. Compared with traditional processes, the novel process provides several advantages, including a shorter flow, a lower energy consumption, and a higher utilization efficiency of vanadium-bearing titanomagnetite resources.