无线网络环境的安全可复原密钥管理与重验机制

在无线移动网络环境中,服务器端对其所属客户端的用户进行密钥管理与身份重新确认等处理程序,同时藉由时间点分群验证的方式来减轻服务器端在计算上的负荷量。此外,当进行资料交换的端点发生严重错误而被迫中断联机或需重新激活时,系统将会通过本身的稽核资料对先前已验证的密钥与用户资料进行复原动作,因此可在资源有限的系统当中,避免重复运算的情况发生,同时考虑在不过度增加既有传输成本等前提下,提出安全的密钥管理与回复验证等机制,进而确保复原程序后的密钥与用户资料本身的正确性与完整性。

论查尔斯·赖特“重彼岸、善超验”的诗歌艺术

美国桂冠诗人查尔斯·赖特的诗歌存在大量以基督教教义为主题、以基督元素为铺垫的作品,其诗歌的灵性与神性受到评论家的广泛关注。但赖特一方面承认“神性及神性之冥思”是其诗歌重要的主题,另一方面又否认自己是虔诚的基督徒,并撇清其诗歌创作具有传教目的。本文围绕赖特在诗歌创作中展现的对基督教教义的核心问题“受难复活”“罪与原罪”“死亡意义”的探寻,从“徘徊的信仰”“怀疑的忏悔”“死亡的超验”三个维度来勾勒他“重彼岸、善超验”的诗歌图景,从而印证他将诗歌艺术化身为与上帝沟通的桥梁、灵魂建构的工具的诗学理念。

重急症治验举隅

例1:结核性脑膜炎患者;金××,女,42岁。会诊日期:1987年10月14日。患者于今年9月初突然患剧烈头痛,伴呕吐、高热、体温达39～40℃。至下旬渐致神志艨胧。入院检查:颈项强直。

图书馆定量分析中的专家权重问题研究

本文针对近年来图书馆定量研究中的专家权重确定问题,将专家权重划分为先验权重和后验权重,并通过实证研究获得较客观专家综合权重,使图书馆定量化决策分析更加科学合理。

群决策中专家权重确定方法研究综述

在群决策过程中,专家权重起着非常重要的作用,它直接影响着群决策的结果。本文介绍了早期群决策的研究情况,并对1987年至2007年间的国内群决策文献进行了分类。文章将专家权重分为先验权重和后验权重,并对现有专家权重的确定方法进行了分析总结。

Evaluation Test Research of DR Inspection System for Circumferential Welds in Long Distance Pipeline

Digital radiographic(DR)testing equipment has been widely promoted and applied in the inspection of circumferential welds in oil and gas pipelines.In order to establish a comprehensive quality control system for digital radiographic testing and fully evaluate the integrated system inspection ability of equipment,personnel,and processes,a scientific and standardized evaluation method to the system is very necessary.Here investigates the precedents of relevant non-destructive testing evaluation methods at home and abroad,considers the testing characteristics of DR equipment,develops a complete set of DR testing system evaluation procedures.It deeply studies the adaptability methods of program processes from defect production to slicing processing and data statistical calculation for digital radiographic testing evaluation.To check the repeatability and reliability of the detectable system,five process welds with 200 real metallographic defects were fabricated in the laboratory.From the detected results,the DR system has good repeatability in image quality,and the detectable defect size reaches 0.85 mm under achieving 90%detection probability at a confidence level of 95%,the error of detected defect length is±2 mm,and the error of detected defect localization is±5 mm.The qualitative and quantitative detection of defects are accurate and reliable.The test further confirmed the reliable detection ability of the DR detection system,and fully validated the scientific and practical evaluation method designed.The research on the evaluation test method can serve as an important link in the quality control system for the on-site application of digital ray equipment in long-distance pipelines.The designed program,test,and evaluation content can serve as an important basis for the formulation of relevant specifications or standards.

可食性膜在食品保鲜中的应用现状及研究进展

在食品保鲜领域,可食用天然抗菌保鲜膜是一种重要的可生物降解膜,具有易降解、成本低、来源广等特点。介绍了多糖膜、蛋白膜和脂质膜3种可食性涂膜在食品保鲜中的应用现状,综述了复合成膜技术、纳米颗粒制备技术及添加植物精油在制备可食性涂膜中的研究进展,以期为可食性包装材料在保鲜领域中的进一步研究提供参考借鉴。

基于改进语言评估标度的专家后验权重确定方法研究

针对大型复杂项目的高度不确定性,专家评价的模糊性和差异性等特点,本文给出了一种实用的语言评估新标度,并提出了不确定扩展语言信息的概念。利用改进的语言评估标度分别探讨确定语言信息、不确定语言信息及不确定扩展语言信息下的专家后验权重的确定方法,认为前两者均为后者的特殊表现形式。最后用型号项目风险评价实例证明了方法的科学有效性以及评价结果的合理性。

Modeling Heavy Metal Movement in Soil

[Objective] The migration process and feature of CdCl2 in the vertical and horizontal profiles of soil were studied by the stimulating experiment to present the theory for the treatment of significant pollution accident.[Method]The column leaching device was taken to simulate the vertical and horizontal migration of CdCl2 in the soil profile under two-phase rainfall during 16 days.The portable manual control negative pressure pump was taken to extract soil solution sample and the Cd concentration was determined by the atomic absorption spectrophotometer.[Result]During the whole experiment,the obvious horizontal and vertical migration features of CdCl2 appeared.The CdCl2 covered the whole horizontal profile in 0.5 h and the whole vertical profile in 146 hours.The relative variation rate of Cd in the different depth of bulk showed that the rapid passing time differed in the different depths.In the depth of 15,35 and 55 cm,the rapid passing time were about 48,117 and 266 h,respectively.[Conclusion]The simulating device used in this paper could well investigate the vertical and horizontal distribution and migration of contaminant.Under the condition of greater rainfall,the CdCl2 gave priority to the horizontal runoff in the surface soil,followed by the vertical migration.

基于加权的多无量纲指标信息融合故障诊断方法

针对传统D-S证据理论的组合规则存在高冲突问题,提出了一种改进加权的D-S证据理论,结合时域中的5种常用无量纲指标,对旋转机械进行了故障诊断。首先,由于不同的无量纲指标对故障的敏感程度不同,可将各无量纲指标自身固有的诊断可靠度作为证据的先验权重;其次,计算各证据间的证据距离,构建证据距离矩阵以及相似矩阵,获得各证据的后验权重。通过分析多级离心风机故障诊断实验平台的实验结果,发现采用复合权重的多无量纲指标信息融合方法的诊断结果可信度明显提高,并且高冲突证据的融合问题也能得到有效解决,证明了该方法的可行性和有效性。

Reconstruction of the linac photon spectrum based on prior knowledge and the genetic algorithm

In order to derive the linac photon spectrum accurately both the prior constrained model and the genetic algorithm GA are employed using the measured percentage depth dose PDD data and the Monte Carlo simulated monoenergetic PDDs where two steps are involved.First the spectrum is modeled as a prior analytical function with two parameters αand Ep optimized with the GA.Secondly the linac photon spectrum is modeled as a discretization constrained model optimized with the GA. The solved analytical function in the first step is used to generate initial solutions for the GA’s first run in this step.The method is applied to the Varian iX linear accelerator to derive the energy spectra of its 6 and 15 MV photon beams.The experimental results show that both the reconstructed spectrums and the derived PDDs with the proposed method are in good agreement with those calculated using the Monte Carlo simulation.

Establishment of a Multiplex PCR System for Detecting Transgenic Ingredients from Citrus

[Objective] This study aimed to establish a multiplex PCR system for de- tecting transgenic ingredients from Citrus. [Method] Based on the pBI121 plasmid sequences published in GenBank and actin gene sequence of Citrus, the primers specific to CaMV35S promoter, NOS promoter, NOS terminator and actin gene were designed, to establish a multiple PCR system which could detect four types of sequences. In addition, orthogonal tests were performed to determine the optimal concentrations of all the components in PCR reaction system, as well as the optimal PCR cycle parameters. [Result] The optimal PCR reaction system should contain 2.5μl of 10xPCR buffer, 2.0μl of MgCI2 （25 mmol/L）, 2.0 μl of dNTP mixture （2.5 mmol/L of each dNTP）, 1.0 μl of actin gene primers （10μmol/L）, 1.0μl of 35S promoter primers （10 μmol/L）, 1.5 μl of NOS promoter primers （10 μmol/L） and 0.5 μl of NOS terminator primers （10μmol/L）, 0.1 μg of template DNA, 1.25 U of Taq DNA polymerase; ddH20 was added to the total reaction system of 25μl. The PCR reaction program consisted of pre-denaturing at 94℃ for 5 min; 31 cycles of denaturing at 94℃ for 30 s, annealing at 64.1℃ for 45 s and extension at 72℃ for 50 s; final extension at 72℃ for 10 min. The reaction system optimized with the orthogonal tests could detect as less as 0.1% transgenic component in the tested samples. [Conclusion] The MPCR detection system established in this study can meet the requirements in theory for detecting the genetically modified ingredients in Citrus or the deep-processed products.

Security Risk Analysis on the Nutrients and Heavy Metals of Biogas Slurry in Agricultural Application

[Objective] This study was to provide scientific basis for the security application of biogas slurry in agriculture through the analysis on the security risk of nu- trients and heavy metals of biogas slurry in agricultural application. [Method] The components of the slurry produced by the anaerobic digestion of straws and manures were systematically analyzed. Different types of biogas slurry with different concentrations were used to conduct the germination test. [Result] The types and proportions of raw materials, and alkali pretreatment affected the compositions and nature of the biogas slurry. Alkali pretreatment could reduce the contents of heavy metals and improved the contents of nitrogen, phosphorous, organic matter and available components. The contents of heavy metals in the biogas slurry were as follows： Cd of 8.76 μg/kg, Cr of 52μg/kg, Pb of 210 μg/kg, Hg of 0.512 μg/kg, As of 140μg/kg, and the contents of Cu and Zn were the highest among the heavy metals, respectively, 279 and 680 μg/kg. All the contents were under the limit standards of the urban wastes for agricultural use. The germination tests of the seeds verified that the slurry with the concentration of lower than 5% could accelerate the germination, while the salt stress could inhibit the growth of seedlings in the slurry. [Conclusion] When the dung are uses as the raw materials for fermentation, appropriate control should be conducted on the feeding proportion or the heavy metals should be pre-removed; when the slurry is used as the liquid fertilizer to apply in the farmland, the dilution or desalting treatment should be conducted at first.

Optimal Conditions for the Purification of Sesamin by Recrystallization

[Objective] Sesamin has been widely used in healthy food and medicines in recent years due to its prominent biological functions. This study was aimed to determine the optimal parameters for sesamin recrystallization, to obtain high-quality and high-purity sesamin. [Method] The effects of solid-liquid ratio, heating tempera- ture and cooling temperature on sesamin recrystallization were investigated by sin- gle-factor experiments and orthogonal array testing （ORT）. The purity of resulting sesamJn was investigated by HPLC, [Result] The optimal conditions for the purifica- tion of sesamin were solid-liquid ratio of 1：10, heating temperature of 45 ℃ and cooling temperature of 25 ℃. Under these conditions, the purity of sesamin reached 95.26%. [Conclusion] Recrystallization is an effective technique to purify sesamin from sesame meal. Moreover, HPLC is also an ideal method for analyzing the purity of sesamin.

Relationship between repeated triaxial test and Hamburg wheel tracking test on asphalt mixtures

Both the repeated triaxial test （RTT） and the Hamburg wheel tracking test （HWTT） are adopted to evaluate the high temperature performance of the stone mastic asphalt （SMA） and the mastic asphalt （MA）. The correlation of the permanent deformations of the MA and the correlation of the deformation developments of the SMA between the two tests are analyzed, respectively. Results show that both the two tests can effectively identify the high temperature performance of mixtures, and the correlation between the final results of the two tests as well as that between the deformation developments of the two tests are excellent with R20.9. In order to further prove the correlation, viscoelastic parameters estimated from the RTT results is used to simulate the rutting development in the HWTT slabs by the finite element method （FEM）. Results indicate that the correlation between the two tests is significant with errors less than 10%. It is suitable to predict the rutting development with the viscoelastic parameters obtained from the RTT.

Study on the Acute Toxicity and Genetics Toxicity of Bensulfuronk-methyl on Danio rerio

[Objective] The aim was to study the effect of bensulfuron-methyl herbicide on acute toxicity and genetics toxicity of Danio redo. [ Method] Median lethal concentration was calculated by acute toxicity test, and analyzing the herbicide whether existing in potential toxicity to aquatic organisms or not. Based on the study of acute toxicity, genetics toxicity was carried out, by calculating the micronucleus rate to judge bensulfuron-methyl herbicide whether existing in potential toxicity or not. [ Result ] The LD5o （24 h and 48 h） of bensulfuron-methyl herbicide are 0.698 ml/L and 0.637 ml/L respectively, the safe concentration was 0.159 ml/L. The results on the effects of micronucleus （MN） in erythrocytes of Danio redo induced by bensulfuron-methyl at different times and different concentrations showed that the MN rate of control group was 0.010 3%, the highest MN rate of experimental group reached to 0. 372%, it also indicated that bensulfuron-methyl herbicide had genetics toxicity to Danio redo. At the same detection time, there was dose-effect relationship of MN rate in erythrocytes between treatment and control groups with different concentrations. In the same treatment group, the MN rate in erythrocytes reached to peak value at 24 h, and decreased at 48 h and 72 h with the infection time was prolonged. [ Conclusion ] The study provides some basis for scientifically selecting and reasonably using herbicide.

丙烯酸-2,4,6-三硝基苯乙酯的合成及热分解

以TNT、甲醛为原料,在弱碱性条件下反应合成得到2,4,6-三硝基苯乙醇(PicCH2CH2OH);PicCH2CH2OH在浓硫酸催化下和丙烯酸在甲苯中回流反应24h,合成得到丙烯酸-2,4,6-三硝基苯乙酯,产率为62%。采用紫外可见光谱(UV-Vis)、核磁共振氢谱(1HNMR)、红外光谱(FTIR)、质谱(MS)以及元素分析等对产物结构进行了表征。利用热重分析(TG)对产物热稳定性进行了研究,采用Kissinger方法和Ozawa方法计算其热分解活化能Ea分别为99.78,102.96kJ·mol-1。

Improved parallel weighted bit-flipping algorithm

An improved parallel weighted bit-flipping（PWBF） algorithm is presented. To accelerate the information exchanges between check nodes and variable nodes, the bit-flipping step and the check node updating step of the original algorithm are parallelized. The simulation experiments demonstrate that the improved PWBF algorithm provides about 0. 1 to 0. 3 dB coding gain over the original PWBF algorithm. And the improved algorithm achieves a higher convergence rate. The choice of the threshold is also discussed, which is used to determine whether a bit should be flipped during each iteration. The appropriate threshold can ensure that most error bits be flipped, and keep the right ones untouched at the same time. The improvement is particularly effective for decoding quasi-cyclic low-density paritycheck（QC-LDPC） codes.

CRM进入商业性发展

CRM已被视为e-Business平台必不可少的三个要素之一。目前,CRM在北美,欧洲等发达国家市场上方兴未艾,在发展中国家也迅速崛起,年均增长率高达30％以上。国内业界一直在反复论证企业是否确实需要。

Study on the Test Method of Static Earth Pressure Coefficient of Deep Soils

The static earth pressure coefficient of soils is,approximately,considered to be a constant in the view of clas-sical soil mechanics. This is supported by many research results. The high pressure experimental research and analysis of remolding deep soil described herein indicate that the static earth pressure of thick overburden has a notable non lin-ear characteristic. It also appears larger than that of superficial soils. It is necessary for deep coal mine design and con-struction to consider this particularity of soil pressure so as to avoid engineering accidents and heavy loss of life and property.