直升机-舰动态配合的舰面流场环境研究综述

研究了制约直升机-舰动态配合性能的首要原因——直升机的载舰在海上风场、舰面特殊结构、舰艇运动等因素作用下形成的非定常舰面紊流场。在总结早期直升机-舰动态配合试验研究特点的基础上,分析了舰面流场海上实测试验的方法及其发展;针对舰面流场模拟普遍采用的CFD技术,分析了舰面流场CFD仿真的发展过程及现状。评价了新型CFD方法——DES在处理大分离涡外流方面的优势,指出了DES在舰面流场仿真领域的光明前景。     

Risk assessment of xenoestrogens in a typical domestic sewage-holding lake in China

Release of domestic sewage leads to accumulation of xenoestrogens in holding waters, especially in closed or semi-enclosed waters such as lakes. In the study, the occurrence, distribution, estrogenic activity and risk of eight xenoestreogens were evaluated in Lake Donghu, China. Nonylphenol (NP), octylphenol (OP), and bisphenol A (BPA) were identified as the main xenoestrogens ranging from tens of ng L⁻¹ (in the surface water) or ng g⁻¹ dw (in the suspended particles and sediment) to tens of μg L⁻¹ or μg g⁻¹ dw. The sum of 17β-estradiol equivalents (∑EEQs) ranged from 0.32 to 45.02 ng L⁻¹ in the surface water, 0.53 to 71.86 ng g⁻¹ dw in the suspended particles, and 0.09 to 24.73 ng g⁻¹ dw in the sediment. Diethylstilbestrol (DES) was determined as the main contributor to ∑EEQs followed by NP. The risk assessment showed a higher risk in the surface water than in the suspended particles and sediment in such domestic sewage-holding lake.     

Opportunities for redistributed manufacturing and digital intelligence as enablers of a circular economy

The linear production of consumer goods is characterised by mass manufacture by multinational enterprises and globally dispersed supply chains. The current centralised model has created a distance between the manufacturer and end user, limiting the opportunity for intelligent circular approaches for production and consumption. Through a mixed method approach, opportunities of circularity are explored for the consumer goods sector. The study presents four lenses to analyse three enterprises through a multi-case study approach to explore the potential of digital intelligence and redistributed manufacturing (RDM) as enablers of circular business models. In addition, the study examines whether Discrete Event Simulation can be used to evaluate the circular scenarios identified through quantifying flows of material that determine traditional economic value (cost/tonne). The mixed method approach demonstrates that, a qualitative systemic analysis can reveal opportunities for circularity, gained through implementing ‘digital intelligence’ and distributed models of production and consumption. Furthermore, simulations can provide a quantified evaluation on the effects of introducing circular activities across a supply chain.     

子密钥数据库安全加密算法研究

探讨数据库的加密特点及其加密方法,并详细介绍一种类似DES(数据加密标准)的分组加密算法———子密钥数据库加密算法;同时分析和讨论如何实现数据库加密、解密以及更新;以微软数据库SQLServer2000为例,介绍数据库加密算法的实现过程,该实例应用广泛,在信息管理系统安全、电子商务等领域有很大的借鉴作用。     

灾害系统模拟技术和方法述评

灾害模拟不仅可以分析各种灾害的动态演变规律,帮助人们识别灾害风险的高低和影响程度,为制定各种防灾减灾措施提供帮助;还可以协助应急预案的制定和相关人员的应急培训.评述了当前灾害系统和灾害应急响应模拟中使用的主要技术和方法,CA方法主要用于模拟各种致灾因子,揭示山崩、火灾等演变规律;MAS主要用于模拟人类系统,反映人们在灾害发生时的认知和反应过程;DES适合各种灾害的突发情景处理,为制定应急预案提供背景和依据;高层次架构和网格平台为大型分布式模拟和利用公共网络提供了可能.未来的灾害模拟将综合各种技术和方法,为综合灾害风险管理提供帮助.     

有关分布式能量系统的原理与应用

从分布式能量系统(DES)的概念及发展意义出发，介绍了系统在实际项目中的具体应用．并进行了性能分析，同时提出了笔者的观点，认为，可以建立适合我国国情的多种形式的分布式能量系统，作为节约能源，保护环境，实现可持续发展的一种有效手段。     

己烯雌酚降解菌株沙雷氏菌的分离鉴定及其降解特性

利用具有降解己烯雌酚(diethylstilbestrol,DES)特性的功能微生物来降解DES、有望实现环境中DES的有效去除,然而迄今关于降解DES的功能菌株及其降解特性的报道很少.本研究通过选择性富集培养,从某污水处理站活性污泥中分离获得1株具有DES降解特性的细菌(菌株S).经形态观察、生理生化试验及16S rDNA序列同源性分析将菌株S鉴定为沙雷氏菌属(Serratia sp.)细菌.菌株S好氧生长,30℃、150 r·min-1摇床培养7 d后,对无机盐培养基中DES(50 mg·L-1)的降解率达68.3%.通过摇瓶实验,优化了菌株S生长和降解DES的最适环境条件:温度30℃,底物浓度40～60 mg·L-1,pH 7.0,接种量5%,盐添加量0 g·L-1,装液量10 mL(100 mL三角瓶).