数字城市建设现状和发展对策研究——以郑州市为例

随着城市规模不断扩张,城市的运营管理迫切需要信息技术的支撑,数字城市建设成为实现城市信息化的必然方向,是提高城市运营管理水平,解决城市发展建设中各种矛盾问题的着力点和支撑点。     

Bioaccumulation and trophic transfer of polybrominated diphenyl ethers (PBDEs) in a marine food web from Liaodong Bay,North China

The concentrations of 21 polybrominated diphenyl ethers (PBDEs) congeners were analyzed in organisms within a marine food web collected from the Liaodong Bay, North China. The total concentrations of PBDEs in all samples ranged from 0.87 to 91.4 ng g⁻¹ lipid weight (lw). BDE-47 was the predominant congener and had a concentration ranging from 0.30 to 36.1 ng g⁻¹ lw. The trophic magnification factors (TMF) of the PBDEs were calculated using the trophic levels obtained from the stable nitrogen isotope ratios. The TMF value of ∑PBDEs was 3.50 for the entire food web and 2.21 for the food web excluding seabirds. Four concentration ratios, BDE-99/BDE-100, BDE-99/BDE-47, BDE-153/BDE-154 and BDE-183/BDE-154, decreased linearly with the increase of the trophic levels in the invertebrates and the fishes (p < 0.01). The results suggested that the PBDEs were steadily metabolized in the trophic transfer process along the food chain.     

Role of remote sensing in achieving national food self-sufficiency and food security

This paper seeks to explore the role of Remote Sensing in solving the agriculture related problems, which are the basic issues of sustainable development.     

RS和GIS支持下的县域生态安全评价

人类社会的发展迅速影响着自然环境、改变着自然生态系统,致使生态安全形势越来越严峻,局部地区生态的破坏已经威胁到社会经济与农业生产可持续发展的基础。在这种状况下,生态安全研究就显得极为重要。本文采用层次分析法对丹巴县进行RS和GIS支持下的生态安全评价,由生态安全评价结果可知丹巴县生态安全总体堪忧。     

Dynamically authorized role-based access control for grid applications

Grid computing is concerned with the sharing and coordinated use of diverse resources in distributed “virtual organizations”. The heterogeneous, dynamic and multi-domain nature of these environments makes challenging security issues that demand new technical approaches. Despite the recent advances in access control approaches applicable to Grid computing, there remain issues that impede the development of effective access control models for Grid applications. Among them there are the lack of context-based models for access control, and reliance on identity or capability-based access control schemes. An access control scheme that resolve these issues is presented, and a dynamically authorized role-based access control (D-RBAC) model extending the RBAC with context constraints is proposed. The D-RABC mechanisms dynamically grant permissions to users based on a set of contextual information collected from the system and user's environments, while retaining the advantages of RBAC model. The implementation architecture of D-RBAC for the Grid aplication is also described.     

地震行业信息安全体系建设

分析地震行业信息系统的现状和需求,以及在当前环境下如何结合等级保护做好信息安全工作.以山东省地震局为例,通过对安全技术体系、安全管理体系的研究和利用IPsecVPN、UTM等技术构建自防御体系及该体系的整体部署、实施最终建立起一套信息安全体系.通过作者在该方面所做的工作,发现将该安全体系的研究成果应用到整个地震行业信息业务中具有很重要的实际意义.     

“If They Only Knew”: Color Blindness and Universalism in California Alternative Food Institutions

This article takes on the cultural politics of “if they only knew” as it relates to alternative food practice. It draws on surveys and interviews of managers of two kinds of alternative food institutions—farmers' markets and community-supported agriculture—to illustrate the color-blind mentalities and universalizing impulses of alternative food discourse. The ways in which these discourses instantiate whiteness may have a chilling effect on people of color who tend not to participate in these markets proportionate to whites. Minor exclusionary practices may have profound implications for shaping projects of agro-food transformation.     

A Review of “The Future Control of Food: A Guide to International Negotiations and Rules on Intellectual Property,Biodiversity and Food Security”

Abstract

Surface soil texture controls many important ecological, hydrological, and geomorphic processes in arid regions and is therefore important from a land-management perspective. Soil survey efforts have traditionally fulfilled this need, but they are constrained by the size, remoteness, and inaccessibility of many arid regions, which renders simple field measurements prohibitively expensive. This article compares several different predictive soil-mapping techniques with a sparse data set in order to develop surficial soil texture maps. Our results suggest that data collected at the landscape scale can be used as input to predictive soil-mapping techniques to create maps of soil texture at higher fidelity and a fraction of the cost than would be required using traditional methods.     

北京社会治安公共安全空间结构及其影响机制——以城市110警情为例

维护社会安全与稳定是城市公共安全研究的重要课题,随着社会经济转型和城市空间结构变化的影响,北京市的社会治安公共安全呈现出明显的空间规律和特点。本文基于2006-2011年北京市110警情治安数据,结合GIS的空间密度分析方法,刻画北京社会治安公共安全的空间格局,并进一步探讨其空间分异机制。研究发现:①北京社会治安公共安全状况明显改善,犯罪空间形成小集聚多分散的演化特征,形成了多个警情高发的集聚区;②北京公共安全空间变化具有明显的偏向性和差异性,形成西北—东南的极化现象。③不同的犯罪类型其空间分布特征也不同,不同的犯罪类型都存在明显的、各具特色的空间分异特征。④从社会治安公共安全空间分异机制来看,经济功能区、人居环境、交通、流动人口和居民居住环境安全感等要素差异会引发不同的犯罪类型和形成不同的犯罪集聚区。本研究可为首都社会治安防控的空间管理策略和城市公共安全政策制定提供参考。     

中国餐饮业食物浪费的资源环境问题综述

近年来食物浪费以及食物浪费的资源环境问题越来越成为全球关注的焦点,尤其是在发展中国家,食物浪费成为威胁食物安全的另一关键因素。尽管如此,在中国,人们仍然对食物浪费缺乏认识,尤其是餐饮业中消费者的食物浪费。因此,基于国内主流媒体报道的大量餐饮业食物浪费的案例数据资料,本研究针对餐饮业中的食物浪费做了系统的阐述。针对餐饮业食物浪费的初步估计,本研究揭示了我国餐饮业食物浪费的严重性。通过分析国际上大量食物浪费的相关文献资料,本研究具体阐述了食物浪费的资源环境代价。最后,本研究基于生命周期评价方法提出了针对餐饮业食物浪费及其资源环境效应研究的概念框架,以便更有效地减少食物浪费。