网络大数据安全问题及优化措施

21世纪被称为计算机互联网时代,在“互联网+”的推动下,信息数据日益开放,从因特网中获取数据,已成为人们最重要的数据来源,这为网络大数据的应用和发展创造了良好的环境。但是,随着网络大数据的快速增加,其收集、存储、共享方式发生了翻天覆地的变化,数据的安全性与隐私保护问题也日益突出,成了制约其发展的“拦路虎”,需要对其进行深入研究,并提出有效的对策。文中从大数据和网络安全的概念出发,剖析了网络大数据中的安全问题,并提出了有针对性的优化措施。     

芸豆蛋白抗氧化肽组分对大豆油热氧化稳定性的影响

为了探索英国红芸豆蛋白抗氧化肽组分的抗氧化作用及对油热稳定性的影响,将不同分子量的抗氧化肽组分添加到大豆油中,利用Schaal烘箱法,在63 ℃下加速氧化15 d,研究抗氧化肽对大豆油的过氧化值、酸价、P-茴香胺、羰基价等指标的影响,并对大豆油的氧化稳定性进行评价。结果表明:从0到15 d,SO（不含肽的油）、SO-h₁（含小于1000 Da肽的油）、SO-h₂（含1000～3000 Da肽的油）的过氧化值分别由0.50增加至2.91、1.48及1.57 mmol/kg,酸价分别由0.19增加至0.41、0.37及0.38 mg/kg,P-茴香胺值分别由2.34增加至9.96、8.06及9.75 mg/kg,羰基价分别由5.59增加至14.53、11.87及11.92 meq/kg。SO的增加幅度最大,SO-h₁的增加幅度最小,以上结果均差异显著（P<0.05）。由此可见,氧化指标均随大豆油氧化时间的延长呈增加趋势,从而导致油的热稳定性下降;抗氧化肽组分的抗氧化活性与分子量有关,其中分子量<1000 Da和1000～3000 Da的组分抗氧化效果最佳。此研究为英国红芸豆蛋白抗氧化肽组分的进一步应用提供了理论依据。     

Driving into Intelligent Spaces with Pervasive Communications

Recent advances in digital modulation and transmission, signal processing, wireless access protocols, and IC technology have spawned many intelligent devices and objects. A good example are intelligent transportation spaces (ITSP) which have shown many potential benefits including driving safety, transport efficiency, and comfort that accrue from increased traffic information, reduced driving loads, and improved route management. Although wireline communications might enable some ITSP requirements, the inherent mobility, flexibility and scalability of wireless communications clearly make them critical. Enabling technologies in this area include an array of wireless solutions such as ISM bands, DSRC bands, UWB radio, and MAC protocols     

分光光度法和总有机碳法对超滤膜截留性能测定的比较

分别采用分光光度法和总有机碳(TOC)测定法测定超滤膜对6种标示物(牛血清蛋白,鸡蛋白,α-糜蛋白,PEG20000,PEG10000,PEG6000)的截留率,以比较两种分析方法对膜表征的影响.结果表明:分光光度法和TOC法截留率测定结果较吻合.从数据稳定性来看,两种方法能较一致的测定出超滤膜的切割分子量;但是当截留率较低时,滤出液成分较复杂,两种方法所得结果则存在一定差异.指出分光光度法存在蛋白泡沫、试样液浓度选择、稀释以及PEG显色时间影响问题,并介绍了避免或减轻以上情况的措施.通过比较,发现TOC测定法具有快速、稳定、精确度高、环保等优点.     

冲击荷载作用下岩石破裂损伤的耗能规律

从损伤的实质物理意义出发,提出了损伤参量的抽象分形,把损伤推广应用到岩石的破碎阶段,用损伤插值分形来表示总体损伤,从而构造出损伤与块度的迭代关系式.根据冲击荷载作用下岩石中的能量耗散规律与脆性动态断裂准则,把应力波作用下的疲劳损伤迭代关系式应用到岩石的破坏后阶段,从而得出冲击能量、岩石损伤、块度分布之间的关系.实验研究表明,两种关系计算所得的损伤吻合较好.     

Investigation on the threshold control of safety blasting vibration velocity for the extraction of complicated orebody under railway

The threshold control of safety blasting vibration velocity is a significant process for the underground mining of complicated ore deposit under construction, road, and water. According to the equivalent principle of displacement and velocity of mass point, differential evolution is put forward based on 3DEC dynamic analysis, making the calculation more efficient and accurate. The 3DEC model of the complicated orebody under railway is established according to the topographic maps and geological data of the eastern Pyrite Mine. The stimulus-response distribution of internal stress and displacement fields are demonstrated by analyzing the on-site monitoring vibration displacement and velocity data of the mass point. The reliability of parameter selection, such as blasting simulation waveforms, rock damping, is identified. The safety vibration velocity of railway is set to 4.5 cm/s in line with the requirement of safety blasting rules. Thus, the maximum amount of single-stage explosive in this region is 44.978 kg. The simulation result is in good agreement with the on-site monitoring datum. No displacement and settlement of the 701 railway special line was achieved by choosing the critical amount of the singlestage explosive.     

Properties and mechanism of CFBC fly ash-cement based stabilizers for lake sludge

Circulating fluidized bed combustion(CFBC) fly ash was mixed with cement or lime at a different ratio as a stabilizer to stabilize lake sludge.In order to understand the influences of stabilizers on the lake sludge properties,tests unconfined compressive strength,water stability and SEM observation were performed.The experimental results show that with the increase of the curing time,the strength of all the stabilized specimens increase,especially the samples containing cement.The strength of the specimens is decreased with the increasing of the CFBC fly ash/cement ratio,the optimum ratio between CFBC fly ash and cement is 2:3.The water stability of CFBC fly ash-cement based stabilizers is higher than those of cement and lime.Moreover,the lake sludge stabilization mechanism of CFBC fly ash-cement based stabilizers includes gelation and filling of the hydration products,i e,C-S-H gel and the AFt crystal,which act as benders to solidify those particles together and fill in the packing void of the aggregates.     

一种多指标综合静态电压稳定薄弱母线辨识方法

探讨了一种多指标综合电压稳定性辨识方法。该方法基于节点电压变化、电压有功灵敏度、母线参与因子三个电压指标,以客观赋值与主观赋值组合方法对上述3个指标分别赋予不同权重求得综合指标以辨识系统各节点薄弱程度。最后以湘西南某实际电网为仿真对象进行分析,以单一指标与综合指标分别辨识系统薄弱母线,验证该综合辨识方法的全面性、有效性与科学性。     

含风光柴储的独立微电网容量优化配置研究

针对独立微电网建设中合理配置电源容量、提高供电可靠性和经济性的问题,在设计规划阶段引入能量管理策略,首先建立风光柴储各电源的出力模型,其次通过对系统全年运行综合费用分析,计及发电补贴建立以年度总成本为目标的经济函数,最后以负荷缺电率(LOLP)、可再生能源供电率(RES)、能量丢弃比(DEP)作为评价指标,应用遗传算法(GA)求解独立微网容量优化配置问题。通过分析LOLP的取值对系统容量配置和成本的影响,证明该配置方案具有较高的合理性,选取合理的LOLP值可显著降低系统的成本费用。     

氯化氢用于甘氨酸法草甘膦水解工艺的研究

叙述了在甘氨酸法制备草甘膦工艺中,创新地采用氯化氢代替盐酸进行水解。对比两种工艺,氯化氢水解法具有比盐酸水解法副产氯甲烷的量高出65%、脱溶能耗降低50%、废水量减少27%等优点。氯化氢用于甘氨酸法草甘膦水解过程是一个确实可行的、具有很强竞争性的优良工艺。