几株益生乳杆菌耐药性的研究

采用药敏纸片法研究了戊糖乳杆菌、瑞士乳杆茵、干酪乳杆茵等7株益生乳杆茵对11种抗生素的敏感性,结果发现,7株乳杆茵均耐受多种抗生素。对戊糖乳杆茵LP-B耐四环素基因(tetM,tetS和tetW)的初步研究表明,该四环素耐受基因不位于基因组DNA上,是否存在于质粒上及其该基因的转移性等尚有待于进一步研究。     

絮凝浮选技术的研究进展

絮凝浮选具有选择性高、工艺设备简单、环境污染小等优点,在处理含有微细颗粒的悬浮料液方面具有明显的优越性,其分选效果优于常规浮选.就浮选方法、浮选药剂和浮选设备等方面总结了浮选技术的现状,并对其发展趋势进行了展望.     

供应链需求信息共享中信息泄露的机理研究

文章针对供应链成员间共享信息被频繁泄露及其对供应链运作产生的不良后果,构建了单个供应商和两个数量竞争的零售商组成的供应链的信息泄露模型,研究了需求信息不对称条件下需求信息泄露的产生机理,指出供应商为了获得更多收益,会将具有需求信息优势的零售商的私有信息泄露给其他零售商,并在此基础上探讨了需求状况以及零售商销售产品的类型对需求信息泄露行为的影响。     

Landscape fragmentation in Mediterranean Europe: A comparative approach

Maintaining ecosystem continuity has become a central element in spatial planning policies. Several authors acknowledge the environmental, also known as landscape, fragmentation due to human action as one of the main causes which have negative effects on biodiversity. The phenomenon consists of the transformation of larger patches of habitat in smaller ones, or fragments, which tend to be more isolated than in the original condition. It is extremely evident in urban areas, including settlements and various transport and mobility infrastructures, whose main ecological effects include loss of habitat, increased mortality of plants, and isolation of animal and vegetal species. In this paper, we assess landscape fragmentation dynamics of six landscape units belonging to two European regions, i.e. Sardinia in Italy (from 2003 to 2008), and Andalusia in Spain (from 2005 to 2009). We developed on three indices: the Infrastructural Fragmentation Index (IFI), the Urban Fragmentation Index (UFI), and the Connectivity Index (CI). We found that coastal areas generally suffer from an higher pressure due to the demand of longer or faster transport infrastructures and new settlements and less fragmented areas tend to show the most relevant dynamics in a sort of convergent pattern. Even though landscape fragmentation and connectivity are intuitively complementary phenomena, in this paper we did not found any statistical evidence of this associative property.     

Local interests or centralized targets? How China’s local government implements the farmland policy of Requisition–Compensation Balance

The Requisition–Compensation Balance of Farmland (RCBF) is a strict policy in China aimed at controlling farmland conversion and replenishing farmland loss caused by urban expansion through a set of top-down quotas. These conflict with local interests, since land conversion from agriculture to construction is a key tool by which local governments attract investment and raise fiscal revenue. How should local authorities respond to this centralized policy? This paper presents a framework “quantity–quality–productivity–environment” to investigate local governments’ coping strategy and the holistic performance of the RCBF. The empirical study indicated that local jurisdictions placed economic and financial growth first and continued expropriating farmland on a large-scale, including land of high quality, for development. However, impelled by compulsory quotas and supervision from governments at higher levels, local authorities would partly replenish the quantity loss through farmland exploitation, regardless of the quality of the new cropland and the possible environmental impact. Consequently, fast requisition and unqualified compensation undermined the capacity of regional agricultural output. We suggest that the RCBF is not capable of guaranteeing food security, whilst farmland supplementation threatens the local environment.     

Note on a model of Chinese national income determination

A macroeconomic model of Chow (1985) explaining aggregate consumption by the permanent income hypothesis of Robert Hall and aggregate investment by the accelerations principle was found to fit Chinese annual data from 1952 to 1982 well. This note shows that the same model can successfully explain Chinese annual data from 1978 to 2006.     

Stochastic comparisons for the number of working components of a system in random environment

In terms of stochastic orders, the purpose of this paper is to show how the random environment can affect the number of working components of a system with heterogeneous components sharing a common random environment. Applications to a class of semiparametric mixture models, stress-strength model and warm standby system are presented.     

城市交通问题的产权分析

通过对多个城市的观察,发现《中华人民共和国道路交通安全法》的许多条款形同虚设,得不到切实的执行。本文根据产权理论对这一现象进行了分析,解释当前城市交通问题的主要成因即：车辆的增多、无法识别、十字路口和交通意识。产权的主要作用是帮助人们形成与他人交流的信息的预期,有了清晰界定的产权,就可以减少城市交通中人与人之间的不确定性,减小冲突的发生。为此,本文提出了解决城市交通问题的政策建议,即限制行车数量、增强非机动车辆的识别能力和规范十字路口标识,提高公民城市交通意识。通过减少交易成本,清晰的界定产权等手段规范城市交通,从而帮助行人建立稳定的预期,保证道路畅通。     

基于单片机的节能照明控制系统设计

为了减少公共场所尤其是学校教室、写字楼办公室等照明用电的浪费现象,研究并设计了基于单片机控制的智能照明系统,提出采用红外对射管计数器与热释电传感器双重检测、纠错的方法,提高了常规照明系统的工作效率,克服了单一采用热释电传感器时可能出现判断有误的不足,实现室内照明的智能控制,从而达到了人性化的节能控制目标.