#### Table of Content

20 January 2019
Volume 54 Issue 1
High-end forum
Ionic liquid gels
Juan GAO,Xiao-lin WANG,Heinz HOFFMANN,Jing-cheng HAO
JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE). 2019, 54(1):  1-18.  doi:10.6040/j.issn.1671-9352.9.2018
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Ionic liquid gels (Ionogels) are the kind of gels formed by using ionic liquids as dispersing media. As new mixed materials, ionogels not only keep the original properties of ionic liquids, but also solve the problems of ionic liquid spillover. The high plasticity in shape meets the needs of special materials and expands the application of ionic liquids. There are many kinds of ionogels, which can be divided into physical and chemical types. Recent years, the structures, properties and applications of ionogels have become one of the hot topics in colloid and interface sciences, as well as the main contents of soft matters. The progress in the construction, structures, properties and applications of ionogels in recent years is reviewed and summarized, which can provide an important theoretical guidance for the construction and applications of ionogels in the future.

Ball-milled CaCO3 nanoparticles for removal of Pb2+ in solution
Zhen-yu FENG,He-chun JIANG
JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE). 2019, 54(1):  19-25, 35.  doi:10.6040/j.issn.1671-9352.0.2018.361
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Nano-sized CaCO3 granules were prepared by ball milling to remove Pb2+ in solution. The results of X-ray diffraction (XRD) clearly indicated that the products after the sorption experiments were composed of CaCO3 and PbCO3. The analysis of selected area electron diffraction (SEAD), transmission electron microscopy (TEM) mapping and scanning electron microscopy (SEM) images demonstrated the generation of PbCO3 nanocrystals and the surface-adsorption of Pb2+ on the CaCO3 adsorbents. The sorption isotherms and kinetics were also considered. All of the results indicated that the main type of interaction between Pb2+ and the as-prepared CaCO3 is dissolution-precipitation accompanied by surface-adsorption.

Influence of stand structure of Acer truncatum forest on rainfall redistribution based on modified Gash model
Yi-ran LI,Rong-hua ZHANG,Ze-dong LI,Yong NIU,Yong-tao ZHANG
JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE). 2019, 54(1):  26-35.  doi:10.6040/j.issn.1671-9352.0.2018.387
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Canopy interception is the starting point of rainfall distribution in forest ecosystem, and accurate simulation of canopy interception is the basis of exploring forest hydrological process. In order to study the influence of stand density on canopy interception and the adaptability of Gash modified model in stand structure, the Acer truncatum forests with two kinds of forest density in Badaling Forest Park of Beijing were taken as the research object. The simulation analysis of the canopy interception process was carried out, and the adaptability of the Gash correction model was discussed for the stand structural characteristics of the A. truncatum forest. The results showed that: (1) In the growing season of 2013, the measured values of the throughfall, stem flow and canopy interception of A. truncatum forest with the density of 3 665 strain/km2 were 365.5 mm, 38.19 mm and 69.82 mm, and the simulated values by the modified Gash model were 386.45 mm, 33.86 mm and 53.21 mm. Compared with the measured values, the relative errors were 5.73%, 4.33% and 23.80% respectively. The throughfall, stem flow and canopy interception of A. truncatum forest with the density of 1 090 strain/km2 were 380.2 mm, 19.04 mm and 74.25 mm, and the simulated values by the modified Gash model were 368.37 mm, 13.71 mm and 91.43 mm. And the relative errors were 3.12%, 27.99% and 23.13% compared with the measured values. Under the sparse forest conditions, more rainfall penetrated the canopy and entered the next hydrological effect layer of the forest ecosystem. The simulation results of the Gash modified model also showed basically consistent characteristics. The simulation accuracy of the model to the A. truncatum forest can basically meet the needs. (2) Sensitivity analysis of six key parameters in the Gash modified model was carried out, such as the average rainfall intensity (${\bar R}$), the drainage partitioning coefficient (Pt), the canopy storage capacity (S), the canopy cover fraction per unit area (c), the trunks storage capacity (St), the average saturated canopy evaporation rate(${\bar E}$). The influence of the six parameters on the A. truncatum forest with high density was R > S > E > St > c > Pt. And it was S > R > E > C > St > Pt on the A. truncatum forest with low density. It can be concluded from the analysis that it is the key to improve the simulation accuracy of the modified Gash model by selecting the appropriate time scale to calculate the average rainfall intensity and the canopy storage capacity. Proper thinning can provide better water conditions for stand growth.

Effects of successive-planting poplar plantation on soil microbial community
Ying ZHANG,Xue-song MA,Ru-yan JING,Feng-yun MA,Jian-yao GUO,Yan-ping WANG,Hua-tian WANG
JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE). 2019, 54(1):  36-46.  doi:10.6040/j.issn.1671-9352.3.2018.385
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The metagenome sequencing was used to analyze the changes of microbial community between the first and the second continuous cropping of poplar plantations for understanding the effect of successive-planting on soil microbial community, meanwhile the content of phenolic acid in soil was analyzed. The results showed that there were no significant differences in soil microbial community diversity and uniformity while significant differences (P < 0.05) were found in the composition and abundance of microbial community after successive-planting of poplar plantation. Microorganisms from eight categories and sixty-three genera were found with Bacillus being the dominant. The continuous cropping had significant effects on soil microbial community composition and abundance in poplar plantations. The relative abundance of nine genera microbes was significantly increased(P < 0.05) and the relative abundance of seven genera was significantly decreased (P < 0.05) in the soil of second generation forest. The relative abundance of genes related to metabolism such as DNA repair and protein recombination, secondary metabolites biosynthesis, transport and catabolism was decreased. The total content of phenolic acids in soil was significantly increased (P < 0.05), and there was a general correlation between the variation of microbial diversity and phenolic acid content.

Evaluation method of information system grade protection based on DIT
Yao-yao DU,Ping PAN,Jin-hua LINGHU
JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE). 2019, 54(1):  47-52.  doi:10.6040/j.issn.1671-9352.3.2018.002
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The configuration of information system security policy was an important measure and component of the level protection of information system. The purpose was to ensure the optimal minimum security configuration under the corresponding security level. Based on the theory of information distance this paper, establishes a distribution function by random investigation of the allocation of information system assets security strategy, and measures the confidence interval of the assets qualitatively, thus constructs the evaluation method of the level protection level of the information system. The method is simple, intuitive and high reliability; It provides a new theoretical basis and method for grading protection evaluation.

A user behavior trust evaluation combined with sliding window and recommended trust
Ze-nan WU,Li-qin TIAN,Zhi-gang WANG
JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE). 2019, 54(1):  53-59.  doi:10.6040/j.issn.1671-9352.3.2018.007
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A new evaluation method of user behavior trust by adopting social characteristics of trust and computer requirements for assessment is proposed. This method improves the sliding window, and makes reasonable calculation of user behavior evidence through the initial setting of the sliding window, the size of the window, the interval of the sliding and the update of the window content, so as to improve the scalability of the user behavior evaluation. Meanwhile, combined with the recommended trust mechanism to further enhance the credibility of user behavior assessment. Finally, the trust value of the user behavior obtained is compared with the default trust evaluation standard of the system to obtain the user trust level. Finally, through the experimental data analysis, the evaluation method has the characteristics of finer granularity, the evaluation object is the user rather than the service provider, and the evaluation result is more in line with the actual situation.

Comparative study on neural network structures in power analysis
LIU Biao, LU Zhe, HUANG Yu-wei, JIAO Meng, LI Quan-qi, XUE Rui
JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE). 2019, 54(1):  60-66.  doi:10.6040/j.issn.1671-9352.3.2018.004
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In order to explore the difference of different neural networks used in power analysis, we use DPA_Contest_V4 dataset to complete our experiment. After the mask is cracked, the deep neural network and the traditional machine learning like SVM are firstly used. Then, the impact of the changes in the structure of the neural network model on the experimental results is analyzed. Finally, a comprehensive comparison of different network models is made by combining the cyclic neural network. The experimental results show that the neural network model is superior to the traditional machine learning model and the recurrent neural network model is superior to the deep neural network model when experimental conditions are the same. Among them, the activation functions of neural networks with different layers are different, which will lead to great changes in the experimental results.
Searchable encryption with data integrity verification in cloud storage
YAO Ke, YANG Hai-ning, QIN Jing
JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE). 2019, 54(1):  67-78.  doi:10.6040/j.issn.1671-9352.0.2018.133
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In order to improve the practicability of the searchable encryption, a searchable encryption(SE)system which can verify the integrity of the searched data in the cloud is constructed. And a secure protocol uses multi-file proofs of retrievability as the building block to achieve the verifiable integrity of searchable encryption on multi-type files. Compared with the existing work, the proposed protocol improves the security and reduces the computational overhead.
A certificate-based short signature scheme
ZUO Li-ming, CHEN Lan-lan, ZHOU Qing
JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE). 2019, 54(1):  79-87.  doi:10.6040/j.issn.1671-9352.2.2018.056
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Combining the merits of certificate-based public key cryptography and short signatures, a certificate-based short signature scheme was proposed. Firstly, based on the k-CAA problem and Inv-CDH problem, the security of the scheme was proved in the random oracle model. Then, the signature scheme was compared with several schemes in the efficiency, theoretically. Finally, the signature scheme was implemented by the PBC library and was compared with several typical schemes in the actual operating efficiency. The result shows that the average time consumption is reduced by about 24.7% and 17.5% compared with the certificate-based Lius scheme with bilinear pairings and the certificate-based Lis short signature scheme respectively, which is close to the certificate-based Lis and Zhous schemes without bilinear pairings and Bonehs short signature scheme.
Blockchain-based anonymous cryptocurrency payment system
ZHANG Jian-hong, BAI Wen-le, OU Pei-rong
JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE). 2019, 54(1):  88-95.  doi:10.6040/j.issn.1671-9352.2.2018.028
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To achieve the users privacy protection and prevent double-spending as well as quick transaction confirmation, a blockchain-based anonymous cryptocurrency payment system is proposed by utilizing blockchain technique, Mixcoin model and proxy pre-resignature. In the payment phase, the transaction users signature is transformed into the signature of the authorized organization by using the proxy pre-signature, which reduces transaction confirmation time and improves transaction efficiency. Based on Diffie-Hellman key agreement, the common public key which is produced between the user and the merchant is act as the payees account, which realizes the anonymity of payees account well, and implements the transaction privacy protection. Compared with the other two schemes, the proposed scheme has the advantages over the others in terms of general preformation.
Ternary Montgomery algorithm on Hessian curve over GF(3m)
JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE). 2019, 54(1):  96-102.  doi:10.6040/j.issn.1671-9352.2.2018.017
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To raise the efficiency of scalar multiplication on Hessian elliptic curves, a scalar multiplication algorithm on Hessian curve over GF(3m)is proposed by expressing the scalar k in ternary form and combining with the original Montgomery algorithm, and the formulas for fast point addition, point doubling and point tripling are used on the bottom layer. The analysis results show that compared with the original Montgomery ladder algorithm in different coordinate systems, the new algorithm is improved by 20.5% on average. Compared with the scalar multiplication algorithm based on Co-Z operation, the improvement is 34.8%. Compared with signed width-4 sliding windows on the same curve, the improved efficiencies in JacIntersect coordinates and standard projective coordinates are 2.03% and 13.8%, respectively. In different projective coordinates, the new algorithm on the Hessian curve is 33.3% ~ 48% faster than on the Weierstrass curve.
Dynamic level scheduling algorithm for cloud computing based on failure regularity-aware
QI Ping, WANG Fu-cheng, WANG Bi-qing, LIANG Chang-yong
JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE). 2019, 54(1):  103-115.  doi:10.6040/j.issn.1671-9352.3.2018.143
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Due to the characteristics of dynamic, heterogeneity and distributed, parallel tasks in cloud computing environment cannot be accomplished because they are vulnerable to resource node failure and communication link failure. Aiming at the problem that the reliability of dynamically providing cloud resources is low and the parameters of resource failure law are dynamically changing under the failure recovery mechanism. Firstly, the local characteristics of failure nodes and communication links in different periods are described by using Weibull distribution. Then, according to the analysis of various kinds of interaction between parallel tasks, a resource reliability evaluation model based on variable parameter failure rules is proposed. Finally, the model is incorporated into the DLS algorithm to obtain the reliable dynamic level scheduling algorithm CFR-DLS, so that the reliability of alternative resources is fully considered when calculating the scheduling level. Simulation results show that the proposed CFR-DLS algorithm can greatly improve the reliability of cloud services while only increasing a small amount of additional failure recovery overhead.
Hopf bifurcation of a SIRC epidemic model with delay
LI Le-le, JIA Jian-wen
JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE). 2019, 54(1):  116-126.  doi:10.6040/j.issn.1671-9352.0.2018.366
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This article concerns a SIRC model for Influenza A with time delay. The basic reproduction number R0 is calculated. For the model without delay, we demonstrate the conditions for global stability of equilibria. And we show that the delay can only change the stability of the endemic equilibrium and lead to the existence of Hopf bifurcation. By applying the center manifold theorem, normal form theory, we also derive some explicit formulae determining the bifurcation direction and the stability of the bifurcated periodic solutions. Finally, numerical simulation is given to support our results.