可证明安全的需求装载代码协议

主动网络是一种新型的网络,在一些领域已得到初步应用。主动网络中的需求装载代码协议是基于移动代码,装载需求和缓存技术的代码分配协议,可动态配置新的协议和服务。由于已有需求装载代码协议存在被重放的安全缺陷,影响主动节点的性能和效率,为此提出了一个安全有效的改进协议,利用Hash函数的单向性,协议双方无需对报文解密就可判断重放攻击,增强了其抵抗重放攻击的能力,并进行了安全性和计算复杂度分析。     

Effects of Different Gluten Proteins on Starch’s Structural and Physicochemical Properties during Heating and Their Molecular Interactions

Starch–gluten interactions are affected by biopolymer type and processing. However, the differentiation mechanisms for gluten–starch interactions during heating have not been illuminated. The effects of glutens from two different wheat flours (a weak-gluten (Yangmai 22, Y22) and a medium-strong gluten (Yangmai 16, Y16)) on starch’s (S) structural and physicochemical properties during heating and their molecular interactions were investigated in this study. The results showed that gluten hindered the gelatinization and swelling of starch during heating when temperature was below 75 °C, due to competitive hydration and physical barriers of glutens, especially in Y22. Thus, over-heating caused the long-range molecular order and amylopectin branches of starch to be better preserved in the Y22-starch mixture (Y22-S) than in the Y16-starch mixture (Y16-S). Meanwhile, the starch’s degradation pattern during heating in turn influenced the polymerization of both glutens. During heating, residual amylopectin branching points restricted the aggregation and cross-linking of gluten proteins due to steric hindrance. More intense interaction between Y16 and starch during heating mitigated the steric hindrance in starch–gluten networks, which was due to more residual short-range ordered starch and hydrogen bonds involved in the formation of starch–gluten networks in Y16-S during heating.     

Pharmaceutical Cocrystals of Ethenzamide: Molecular Structure Analysis Based on Vibrational Spectra and DFT Calculations

Pharmaceutical cocrystals can offer another advanced strategy for drug preparation and development and can facilitate improvements to the physicochemical properties of active pharmaceutical ingredients (APIs) without altering their chemical structures and corresponding pharmacological activities. Therefore, cocrystals show a great deal of potential in the development and research of drugs. In this work, pharmaceutical cocrystals of ethenzamide (ETZ) with 2,6-dihydroxybenzoic acid (26DHBA), 2,4-dihydroxybenzoic acid (24DHBA) and gallic acid (GA) were synthesized by the solvent evaporation method. In order to gain a deeper understanding of the structural changes after ETZ cocrystallization, terahertz time domain spectroscopy (THz-TDS) and Raman spectroscopy were used to characterize the single starting samples, corresponding physical mixtures and the cocrystals. In addition, the possible molecular structures of ETZ-GA, ETZ-26DHBA and ETZ-24DHBA cocrystals were optimized by density functional theory (DFT). The results of THz and Raman spectra with the DFT simulations for the three cocrystals revealed that the ETZ-GA cocrystal formed an O−H∙∙∙O hydrogen bond between the -OH of GA and oxygen of the amide group of the ETZ molecule, and it was also found that ETZ formed a dimer through a supramolecular amide–amide homosynthon; meanwhile, the ETZ-26DHBA cocrystal was formed by a powerful supramolecular acid–amide heterosynthon, and the ETZ-24DHBA cocrystal formed the O−H∙∙∙O hydrogen bond between the 4-hydroxy group of 24DHBA and oxygen of the amide group of the ETZ molecule. It could be seen that in the molecular structure analysis of the three cocrystals, the position and number of hydroxyl groups in the coformers play an essential role in guiding the formation of specific supramolecular synthons.     

微燃机热电联产系统的天然气供应技术

文章分析了微型燃气轮机需要较高的天然气供应压力与中心城区配气压力不足的矛盾,对日前常用的两种解决方法：直接从管网抽气增压和设置低压储气罐、从罐中抽气增压,进行了分析和比较。此外,列出了现有的抽气压降估算方法和软件模拟方法,供相关研究、设计人员参考。     

一种越野轮胎的结构设计

本文介绍了285/70R17121Q规格越野轮胎的设计.外轮廓方面:轮胎的设计外直径834 mm,充气断面宽292 mm,轮胎的行驶面宽240 mm,设计行驶面弧高度11.8 mm,胎圈着合直径取值430 mm,轮胎的胎圈着合宽度245 mm,轮胎的断面水平轴位置取值0.8423;轮胎的胎面花纹设计分为M型和L型,2种...     

断层垂向封闭性研究现状

在对大量文献调研的基础上,归纳、分析了断层垂向封闭性的形成机理、主要影响因素及当前的主要研究方法。目前,对断层垂向封闭性的研究还不成熟,研究中考虑的因素比较单一,且许多研究方法的应用范围具有局限性,应该发展多角度、多学科综合研究方法,从石油地质学、构造地质学、沉积学、地球化学、计算机图形学等多学科,以及测井、地震、钻井、生产等方面进行综合研究。     

应用水平井技术改善稠油油藏开发效果

高246块莲花油层属于厚层块状砂砾岩底水稠油油藏,已利用直井开发30 a,受油水流度比高、储层非均质性强及出砂、出底水等因素制约,已进入高含水低速采油阶段.综合含水率为71.3%,采油速度为0.18%,且水窜逐年加剧,含水率上升速度高达43%,半数油井因高含水率而关井,区块年产油量指数下滑,达不到标定采收率.针对开发存在的这些问题,以精细油藏描述为基础,以剩余油潜力评价为保障,以水平井技术为依托,进行二次开发研究,部署并实施18口水平井,取得了显著效果,油田采油速度上升到0.35%,综合含水率下降到56%,预计可提高采收率3.4%.     

铁路工程项目评价系统开发

文章分析了现有铁路投资项目经济评价存在的问题,提出了以应用决策支持系统的形式开发铁路投资项目经济评价系统,并给出了系统的功能模型,着重描述了基础数据处理、报表生成和财务指标计算等问题.系统适用于新建、改扩建和项目后评价,实践表明该系统能有效地对投资项目进行经济评价,具有一定的实用价值.     

Comparison of modified injection molding and conventional machining in biodegradable behavior of perforated cannulated magnesium hip stents

In this study,perforated cannulated magnesium(Mg)hip stents were fabricated via modified Mg injection molding and conventional machining,respectively.Additionally,the stent canal was filled with paraffin to simulate injection of biomaterials.The microstructure,mechanical performance,corrosion behavior,and biocompatibility were comparably studied.Scanning electron microscopy(SEM)and energy dispersive spectroscopy(EDS)showed higher affinity of interstitial element such as oxygen and carbon as consequences of routine molding process.After immersion in SBF,machining stents showed reduced degradation rate and increased deposition of calcium phosphate compared to molding stents.Corrosion resistance was improved via paraffin-filling.Consistently,the hemolysis and in vitro osteoblast cell culture models showed favourable biocompatibility in machining stents compared to molding ones,which was improved by paraffin-filling treatment as well.These results implied that the feasibility of the prepared machining stents as the potential in vivo orthopaedic application where slower degradation is required,which could be enhanced by designing canal-filling injection of biomaterials as well.     

模糊综合评价法在城市旱情评价中的应用

在抗旱预案的制定过程中,首先要对旱情进行综合评价。本文对模糊综合评价理论在旱情评价中的应用问题进行了研究与分析,建立了区域旱情模糊综合评价模型,具有较好的客观性、可行性,模型评价结果符合实际情况,在区域旱情的评价中具有一定的应用价值,可为抗旱预案的制定和干旱防治提供科学的依据。