指派问题与最短路径问题的相互关系

尽管指派问题与最短路径问题是运筹学中的经典问题,也为大家所共知;但是,我们却很少知道这两个问题间的相互关系。本文揭示了两问题间的内在联系,进而使我们有可能利用指派问题的匈亚利法来解决最短路径问题。反之,亦可使用最短路径的解决问题方法来处理相应的指派问题。     

液压泵可靠性试验系统控制器的研制

本文介绍了我们最新研制出来的液压泵可靠性试验系统控制器的构成、工作原理及使用效果。     

催裂化装置新型重油雾化器的开发研究

本文提出了一种应用于催裂化装置的新型重油原料雾化器。实验和理论分析的结果表明,这种雾化器具有一系列与催化裂化工艺要求相适应的性能特点,其雾化质量也显著地优越于目前国外比较先进的同类型雾化器的雾化质量。     

双吡唑啉酮类萃取剂BPMOPH的萃取性能

测定了双吡唑啉酮类萃取剂1,6-双(1′-苯基-3′-甲基-5′-氧代吡唑-4′-基)己二酮-[1,6]的酸离解常数及在水和氯仿中的两相分配常数,并研究了它对铀的萃取性能。     

Software watermarking scheme based on multivariate public key cryptosystem

Software watermarking is an efficient tool to verify the copyright of software. Public key cryptosystem-based watermarking is widely researched. However, the popular public key cryptosystem is not secure under quantum algorithm. This paper proposes a novel software watermarking scheme based on multivariate public key cryptosystem. The copyright information generated by copyright holder is transformed into copyright numbers using multivariate quadratic polynomial equations inspired by multivariate public key cryptosystem (MPKC). Every polynomial is embedded into the host program independently. Based on the security performance of MPKC, the robustness and invisibility of the proposed scheme is significantly improved in comparison with the RSA-based watermarking method.     

Evaluation method of software reliability based on SPN model

As a significant measure of software security evaluation, software reliability evaluation is also the basis of software safe operation. Traditional software system security evaluation methods are qualitative evaluation based on the functional and structural measurements, and it often ignores quantitative research based on invalidity and fault. This paper propose a stochastic transition function as a measure parameters of the reliability of stochastic Petri nets (SPN) theory. By calculating the probability of stability of the system, failure and mean time to first failure, it establishes an evaluation and measurement method for software reliability. With example analysis, the method can conduct effective evaluation on the software reliability index quickly and accurately, and meanwhile provides a new method for the software security evaluation.     

肺癌患者放疗前后外周血淋巴细胞亚群变化研究

目的探讨肺癌患者放化疗前后外周血淋巴细胞亚群的变化.方法应用流式细胞仪对30例健康正常人群(对照组)和68例肺癌患者(肺癌组)放化疗前后的外周血T淋巴细胞亚群、B淋巴细胞及NK细胞等进行检测,并比较分析健康人群和肺癌患者的变化情况.结果肺癌组放疗前外周血中CD3~+,CD4~+,CD4~+/CD8~+,CD19~+与对照组相比均有所下降,差异均具有统计学意义(P0.05);CD8~+比例较对照组升高,且差异具有统计学意义(P0.05);而CD56~+比例较对照组升高,但结果无统计学意义(P0.05).肺癌患者放化疗后淋巴细胞亚群CD3~+降低,CD56~+有所升高,差异无统计学意义(P0.05);CD4~+,CD4~+/CD8~+较治疗前降低,CD8~+,CD19~+较治疗前升高,差异均具有统计学意义(P0.05).结论肺癌患者在疾病发生、发展过程中存在淋巴细胞免疫异常和免疫功能紊乱的现象,外周血T,B淋巴细胞及NK细胞的检测对判断患者的免疫功能有一定参考作用.     

Diophantine方程2~m+1=3y~n

证明了方程 2 m+1=3yn 没有适合m >2 ,n >1,y >1的正整数解 (y ,m ,n)     

Na变质对Zn—27Al—Si合金组织性能的影响

通过试验和分析，发现Na对Zn-Al-Si合金中硅晶体的变质机理是Na吸附在硅晶体的生长方式，改变了硅晶产生大量分枝，而不影响硅的形核，试验结果还表明硅相由板块状变为球状后，合金的机械性能有显著提高。