南非矿产工业的现状、挑战和前景

南非是世界性矿业大国，对世界矿产品市场有重要影响。本文首先分析了南非矿业的发展现状，然后讨论了所面临的问题和挑战，包括恶化的生态环境、不断升高的矿山生产成本和老化的矿山、不乐观的矿山劳动安全、不断减少的矿业投资等。在此基础上，笔者简要讨论了南非矿产工业的发展前景问题，认为尽管有挑战，但与其它国家相比，南非矿业仍存在一系列比较优势和较大发展潜力。笔者进一步认为，只要化挑战为动力、落实好各项行动计划和创新政策，南非矿业仍会有一个辉煌的未来。     

关于风景园林学会建设的几点思考

改革开放和自主创新是当代中国社会的主旋律之一,也是中国现代化建设可持续进行的重要保证之一。在积累了近30年宝贵经验,参与和见证了中国风景园林事业在现代,特别是在当代的飞速发展历程后,中国风景园林学会正面临着如何顺应国内外形势,特别是如何应对中国城市日新月异的建设进程,加强自身建设,团结和带领中国风景园林行业主动出击、迎接挑战的重大课题。就学会自身体制的改革、工作领域的拓宽等方面提出一点见解,希望能起到抛砖引玉的作用。     

中国地下储气库现状及技术发展方向

中国地下储气库建设经过多年探索,已经进入一个新的发展阶段。已经投产的11座地下储气库群设计工作气量达到180×10~8 m~3,在国内天然气调峰安全保供中发挥了重要作用。但国内地下储气库建设仍面临不少困难:①储气库工作气量增长速度慢,落后于调峰需求量增长的速度;②建设工程技术难度大,投资成本高;③安全运行压力大,风险识别和控制困难;④库址资源少,建库条件复杂;⑤尤其是在现有天然气价格体制下,储气库难以通过自身运营获得经营效益。究其原因,主要是已经形成的运营方式和建库技术尚不足以应对市场和复杂地质条件所带来的挑战。为破解这一系列难题,在开展市场化运作模式探索的同时,更需要加大技术攻关力度,加强研究地质评价与气藏工程、钻井完井工程、储气库注采工程、地面配套工艺及储气库完整性评价等多个方面的核心技术,大幅提高储气库建库效率,以促进我国地下储气库的可持续发展。     

Challenges towards hydrogen economy in China

The increasingly serious energy crisis and environmental pollution caused by the excessive use of fossil fuels have been prompting China to aggressively seek a clean and self-sufficient energy source in the future. In the past decades, hydrogen has emerged as a promising alternative due to its advantages of cleanliness, abundance, high energy density, and high conversion efficiency. However, several challenges have to be overcome for China's successful transition to hydrogen economy. In this paper, the hydrogen supply chain is firstly described to help the readers to clearly understand the hydrogen economy. Subsequently, the feasibility of hydrogen economy is discussed by reviewing viewpoints from the literature. Finally, the challenges of China's transition to hydrogen economy are detailed summarized and discussed, and the strategies for China to develop hydrogen economy were compared with that of Japan and Australia.     

Selecting and assessing challenge problems

Abstract

Organisations conducting research programs often focus the work of their scientists and technologists on challenge problems (CPs). These challenges are designed to ensure that progress is measurable and relevant to the goals of the program sponsor. Generating and selecting pertinent CPs is difficult, as is assessing their value. We describe a method of generating and selecting CPs and its application in a highly collaborative, multi-organisation research program. Thirty-eight biologists, chemists, mathematicians and computer scientists across academic, commercial and government organisations generated and ranked their top choices from among 12 richly described candidate challenge problems. A ranked-choice voting formula was applied. Five CPs were highly scored; the remaining seven were distributed across a lower range of scores. The program sponsor subsequently directed researchers to address six CPs, including the elected five. Analysis of the rationales that participants offered for their CP rankings revealed four domain-independent dimensions of value: capability, speed, impact and synergy. These dimensions of value can help managers of interdisciplinary research programs systematically select a portfolio of CPs that will efficiently apply utilise resources towards program goals and facilitate measurement of scientific progress.     

Growth potential of Listeria monocytogenes in soft,semi-soft and semi-hard artisanal cheeses after post-processing contamination in deli retail establishments

Opportunities for post-processing contamination of cheese may occur in deli retail establishments, either during the further cheese ripening (at maximum 14 °C), during storage and display in the refrigeration cabinet (at maximum 7 °C) or during slicing. A L. monocytogenes post-processing contamination was simulated by inoculation either on the cheese slicing surface or the cheese rind of three soft cheeses (one white-molded raw cow's milk cheese, one pasteurized cow's milk cheese with spicy herbs, one washed rind pasteurized cow and sheep's milk cheese) and two semi-hard cheeses (one smear-ripened raw cow's milk cheese and one natural-ripened raw cow's milk cheese). L. monocytogenes challenge testing was performed on 3 batches of each cheese to assess the growth potential of L. monocytogenes after 14 days storage at either 7 or 14 °C. Substantial growth of L. monocytogenes (>0.5 log CFU/g) was obtained in 79.2% of all individual challenge tests (n = 178) that were performed although huge variation in growth potential was noted among the different cheese types and storage conditions. The growth potential on soft cheeses stored at 7 °C ranged from 1.8 to 4.0 log units and from 3.6 to 5.5 log units upon storage at 14 °C, whilst on semi-hard cheese, this was in general lower, and ranged from 0.1 to 1.4 log units at 7 °C and from 0.0 to 3.0 log units at 14 °C. Overall, increased outgrowth of L. monocytogenes was noted when inoculation was performed on the cheese slicing surface compared to the cheese rind. Thus if occasional post-processing contamination takes place during storage or handling of the cheese, L. monocytogenes has the potential to grow to elevated numbers throughout a reasonably expected storage period of up to 14 days notwithstanding the presence of high numbers of indigenous lactic acid bacteria in these cheeses. Also for a defined cheese type both a considerable inter-batch and intra-batch variability was sometimes noted from the replicate testing, indicating no consistent behavior of L. monocytogenes in these fermented dairy products. As such it is recommended that appropriate hygienic measures are taken to prevent post-processing contamination. Noting the growth potential, absence of L. monocytogenes in 25 g of cheese using a multiple sample subunit approach (n = 5) at the time of production is important to ensure compliance to EU legislation 2073/2005.     

Pornography-seeking behaviors following midterm political elections in the United States: A replication of the challenge hypothesis

The current study examined a prediction derived from the challenge hypothesis; individuals who viciously win a competition of rank order will seek out pornography relatively more often than individuals who viciously lose a competition. By examining Google keyword searches during the 2006 and 2010 midterm elections in the United States, the relative popularity of various pornography keyword searches was computed for each state and the District of Columbia the week after each midterm election. Consistent with previous research examining presidential elections and the challenge hypothesis, individuals located in traditionally Republican states tended to search for pornography keywords relatively more often after the 2010 midterm election (a Republican victory) than after the 2006 midterm election (a Democratic victory). Conversely, individuals located in traditionally Democratic states tended to search for pornography relatively less often following the 2010 midterm election than they did following the 2006 midterm election.     

基于智能卡的电子商务认证

智能卡小巧易于携带，有较强的计算能力及存储用户简要表、加密和非加密数据的大容量空间，并且支持电子商务应用。本文首先讨论了传统电子商务认证面临的问题，然后给出了基于智能卡的安全认证机制。     

Building environmental assessment methods: applications and development trends

The construction and property sector has seen the development of a number of methods for evaluating the 'greenness' of buildings in the 1990s - both for new designs and existing buildings. These range from very detailed life cycle assessment methods, which account for all the embodied and operational environmental impacts of building materials, to higher level environmental impact assessment methods, which evaluate the broader implications of the building's impact on the environment. In between these two are environmental assessment methods such as BREEAM, BEPAC, LEED, and GBA. In this paper, we discuss the potential market applications of these systems and compare and contrast several of the major environmental assessment methods. Le secteur de la construction et de l'immobilier a ete le temoin du developpement d'un certain nombre de methodes permettant d'evaluer les performances ecologiques des batiments dans les annees 1990, tant sur le plan des nouveaux concepts que des batiments existants. Ces methodes vont de l'evaluation tres detailee du cycle de vie, qui tient compte de l'impact specifique et des incidences operationnelles des materiaux de construction sur l'environnement, jusqu'a une evaluation de l'impact environnemental a un niveau plus eleve. Entre ces deux extremes, on trouve des methodes d'evaluation environnementale telles que BREEAM, BEPAC, LEED et GBA. Dans cet article, nous examinons les applications commerciales potentielles des ces systemes; nous comparons, en les opposant, plusieurs methodes majeures d'evaluation environnementale.     

Japanese expectations for green building assessments

The background and feedback on the Green Building Challenge '98 process in Japan is provided by a representative from one of two Japanese teams (representing the Building Constructors' Society). The positive process of validating and adapting the international criteria to particular national circumstances and then customizing these criteria is explained. Three significant benefits to the Japanese building industry are discussed: existing technologies and methodologies were validated, it was discovered that these have potential for world-wide application, the life expectancy of Japanese buildings needs to be lengthened. Future expectations from Japan include: the ongoing refinement of the international framework for the environmental assessment of buildings; the customization of criteria requires further structure and limits, a critical review of the customization process; an expansion embracing both developed and developing nations' new and existing buildings. The prototype green building assessment from GBC '98 has the potential to be refined and adopted as a world-wide methodology and is endorsed as the fastest way to achieve world-wide consensus. Les generalites et le retour d'informations se rapportant au projet Green Building Challenge 98 au Japon sont fournies par un representant de l'une des deux equipes japonaises (association de constructeurs). Cet article s'interesse a la procedure positive de validation et d'adaptation des criteres internationaux a des circonstances nationales specifiques puis leur particularisation. L'auteur examine egalement trois avantages significatifs pour l'industrie japonaise du batiment: le GBC a permis de valider des technologies et des methodologies existantes; on a decouvert qu'elles recelaient un potentieal pour une application mondiale; la duree de vie des batiments japonais doit etre allongee. On attend egalement du Japon des contributions dans les domaines suivants: l'affinage, deja en cours, du cadre international de l'evaluation environnementale des batiments; l'adaptation des criteres exige une autre structure ainsi que des limites; une revue critique du procede d'adaptation; une expansion englobant les batiments nouveaux et existants dans les pays en developpement et dans les pays industrialises. Le prototype d'evaluation des batiments verts a partir du projet GBC 98 peut etre affine et adopte sous forme d'une methodologie mondiale et etre considere comme la methode la plus rapide pour aboutir a un consensus global.