Risk balance defense approach against intrusions for network server

The paper presents a new defense approach based on risk balance to protect network servers from intrusion activities. We construct and implement a risk balance system, which consists of three modules, including a comprehensive alert processing module, an online risk assessment module, and a risk balance response decision-making module. The alert processing module improves the information quality of intrusion detection system (IDS) raw alerts by reducing false alerts rate, forming alert threads, and computing general parameters from the alert threads. The risk assessment module provides accurate evaluation of risks accordingly to alert threads. Based on the risk assessment, the response decision-making module is able to make right response decisions and perform very well in terms of noise immunization. Having advantages over conventional intrusion response systems, the risk balancer protects network servers not by directly blocking intrusion activities but by redirecting related network traffics and changing service platform. In this way, the system configurations that favor attackers are changed, and attacks are stopped with little impact on services to users. Therefore, the proposed risk balance approach is a good solution to not only the trade-off between the effectiveness and the negative effects of responses but also the false response problems caused by both IDS false-positive alerts and duplicated alerts.     

多孔材料烷烃/烯烃分离技术的研究

以模拟油品为原料,在小型固定床（200 mL）反应器上考察了硅胶、γ-Al₂O₃、13X分子筛、Y分子筛及ZSM-5分子筛等多孔材料对烷烃/烯烃的吸附分离性能;其中硅胶的烷烃/烯烃分离效果最好,在吸附温度为40 ℃、压力为0.5 MPa、解吸剂为正辛烷/甲基环己烷的条件下,烷烃/烯烃分离度最高达到0.81;与其他类型硅胶相比,平均孔径为4~6 nm的B型硅胶传质效果更好,吸附-脱附过程更易趋于平衡。经过焙烧和溶剂再生的吸附剂,与新鲜剂相比,分离效果没有明显的降低。     

Inducing effect of Pb(Zr0.4Ti0.6)O3 thin film derived by different processes in BiFeO3/Pb(Zr0.4Ti0.6)O3 multilayer capacitor at room temperature

BiFeO₃/PZT multilayer capacitor was prepared on Pt(100)/Ti/SiO₂/Si(100) substrate. PZT buffer layer was derived by MOCVD method (label: PZT₁) and sputtering method (label: PZT₂) respectively. XRD analysis indicated that high (110) orientation of BFO in the BFO/PZT₁ structure was achieved. SEM analysis indicated a better microstructure in the BFO/PZT₁ structure compared with BFO/PZT₂. The remnant polarization of the BFO/PZT₁ was 82.5 μ C/cm² at an applied voltage of 8 V, compared with that of 25.2 μC/cm² in the BFO/PZT₂ structure. The BFO/PZT₁ multilayer exhibited little polarization fatigue (<1.5%) upon 1×10¹⁰ switching cycles, at an applied voltage of 4 V. The leakage current density was about 2×10₋₇ A/cm² at an applied voltage 4 V, in the BFO/PZT₁ capacitor. All the results indicated that PZT can act as an inducing layer to the BFO and the MOCVD derived PZT has more inducing effect to the BFO thin film at room temperature. Supported by the National Natural Science Foundation of China (Grant No. 60601003), Ying Tong Education Foundation (Grant No. 101063), and International Cooperation Project from Ministry of Science and Technology of China (Grant No. 2008DFA12000)     

铁基粉末触媒的粒度及其均匀性对合成金刚石的影响

本文利用铁基粉末触媒在国产六面顶压机上进行了金刚石单晶的合成。研究了高温高压条件下（5.7GPa，1370～1650℃），筛分的6种不同粒度（140／170，170／200，200／230，230／270，270／325，325／400）以及未经筛分的混合粒度的铁基粉末触媒生长金刚石的形貌特征。同时研究了粉末触媒粒度均匀性对合成金刚石的影响。结果表明，触媒粒度越均匀，合成金刚石单晶的粒度越集中。触媒粒度以及合成的金刚石晶体分别通过扫描电镜和光学显微镜进行了观测。     

管线钢热模拟压缩试验及应用

管线钢设计成分不同,工艺参数设计也会有所差异。为科学合理地制定管线钢生产工艺,利用Gleeble-3500动态热模拟机对管线钢矩形试样进行了热模拟压缩试验,确定了粗轧再结晶温度,以及精轧温度对组织结构的影响,在最短的时间内,设计出了科学合理、能够指导实际生产的工艺参数。     

Design,Synthesis, and Biological Evaluation of Pyrazoline‐Based Hydroxamic Acid Derivatives as Aminopeptidase N (APN) Inhibitors

Aminopeptidase N (APN) has been recognized as a target for anticancer treatment due to its overexpression on diverse malignant tumor cells and association with cancer invasion, metastasis and angiogenesis. Herein we describe the synthesis, biological evaluation, and structure–activity relationship study of two new series of pyrazoline analogues as APN inhibitors. Among these compounds, 5‐(2‐(2‐(hydroxyamino)‐2‐oxoethoxy)phenyl)‐3‐phenyl‐4,5‐dihydro‐1H‐pyrazole‐1‐carboxamide (compound 13 e ) showed the best APN inhibition with an IC₅₀ value of 0.16±0.02 μm , which is more than one order of magnitude lower than that of bestatin (IC₅₀=9.4±0.5 μm ). Moreover, compound 13 e was found to inhibit the proliferation of diverse carcinoma cells and to show potent anti‐angiogenesis activity. At the same concentration, compound 13 e presents significantly higher anti‐angiogenesis activity than bestatin in human umbilical vein endothelial cells (HUVECs) capillary tube formation assays. The putative binding mode of 13 e in the active site of APN is also discussed.     

Preparation and characterization of styrene-acrylic resin encapsulated C.I. Pigment Yellow 17 and charge control agent multicomponent particles

Styrene-acrylic resin encapsulated C.I. Pigment Yellow 17 (PY17) and charge control agent (CCA) multicomponent composite particles were prepared by mini-emulsion polymerization. The characterization results of transmission electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, and centrifugal sedimentation experiments all verified the encapsulation of PY17 and CCA. The effect of PY17 and CCA dosages on the morphology of multicomponent particles and influence of compound emulsifier dosage on the emulsion stability and the dispersity of latex particles were studied. When the mass fractions of monomers, PY17, CCA, and compound emulsifiers relative to deionized water were 5, 0.4, 0.1, and 0.375%, respectively, the emulsion showed excellent stability; meanwhile, the latex particles had a clear core–shell structure and the best dispersity. The average size of the multicomponent particles changed slightly with the different dosages of PY17, CCA, and compound emulsifiers. Colorimetric analysis of the samples indicated that encapsulation of PY17 may lead to a decrease in yellow value b* but had little effect on its tinctorial strength.     

14机架微张力定(减)径过程壁厚分布的有限元研究

根据钢管微张力定(减)径过程的变形特点,利用MSC.Marc软件进行三维弹塑性有限元分析,模拟钢管通过14机架微张力定(减)径机的变形过程。通过研究钢管断面上的横向壁厚分布,分析其内多边形程度;通过研究整根钢管的轴向壁厚分布,不需进行解析计算,可直接在有限元模型上测得头尾增厚段的切除长度。据此提供分析产品缺陷、指导工艺设计的依据。     

金属热锯机锯齿应力分析

本文提出了锯齿根部应力集中和应力扩散的概念;在一定顶角条件下,锯齿根部应力集中系数和应力扩散系数仅与齿根圆弧的相对半径有关。而与锯齿前角无直接关系。根据这一规律,给出了使锯齿根部处于较佳应力状态的较佳齿形参数配置的原则。     

多孔含硼金刚石多晶体的制备与结构研究

本文介绍了一种多孔含硼金刚石多晶体的制备方法.以含硼金刚石微粉为原料,Co合金为粘结剂,高温高压烧结制备D-D键合的金刚石多晶烧结体.烧结体经强酸处理,蚀出残余的金属,得到多孔含硼金刚石多晶体.实验结果表明:温度在金刚石-钴共熔温度以上,压力在6.0GPa左右,粒度在W20～W28之间,金属含量在14～16vol%范周内,易于获得D-D键合的多孔金刚石烧结体.保温较短时,金刚石烧结不充分,晶粒结合松散,得到的多孔材料孔径较大,但烧结体强度很低.延长保温时间,烧结充分,致密性增加,但孔径减小.