奇特霉菌将植物废料变柴油气

最近,美国科学家在热带雨林中发现了一种粉红色的霉菌.这种霉菌有一种奇特的功能,可以让植物枝叶发酵,转化为燃烧值特别高的柴油气.这项发现为植物能源的利用开辟了新途径,是科学家在寻找可再生能源过程中的一项重大发现.     

能源新方向:细菌产石油

最近,美国科学家在热带雨林中发现了一种粉红色的霉菌。这种霉菌有一种奇特的功能,可以让植物枝叶发酵,转化为燃烧值特别高的柴油气。这个发现为植物能源的利用开辟了新途径,是科学家在寻找可再生能源过程中的一项重大发现。     

重庆地区能源植物的开发利用

植物能源是一种经济环保的可再生能源,发展植物能源是解决能源危机可行措施。对国内外能源植物的开发利用现状及植物能源的优势进行了概括。重庆地区植物资源非常丰富,文章列举了一些适合重庆地区种植的、应用前景广阔的能源植物种类,并就重庆地区能源植物的开发及利用提出建议。     

让植物提供能源

对我们人类来说，植物是一种最古老的能源，它伴随人走过了几十万年。然而，现在人们用石化燃料代替了植物，不少国家的农民还把收割粮食后剩下的秸秆“烧荒”。这是很可惜的，因为这不但会浪费能源，还会增加二氧化碳的排放量，污染环境。因此，不少国家开始开发利用植物能源的新方式。     

能源作物时代尚未到来

从2007年到现在,文冠果种子价格经历了过山车般的行情,很多在高点时入市的企业和农民被套。中国科学院植物研究所能源中心主任助理刘公社博士在接受《农经》记者采访时表示,能源植物和能源作物有着很大区别,在现阶段,农民还不适合参与种植。在产业发展的初期阶段,如何将产业的发展引向深入,走上健康发展之路,真正达到国务院提出的生物质能源发展目标,是摆在每一个从事生物质能源建设者面前的一道难题。     

加快发展我国清洁替代能源

进入新世纪，我国和世界能源面临的主要问题有两点：一是经济增长对能源供给的需求，能源生产和供给要赶上这种需求，尤其是在像我国这样的发展中国家；另一是能源消耗所产生的污染对人类生存环境构成了巨大威胁，特别是矿物燃料燃烧时向大气中排放的ＣＯ２所造成的温室效应。后者，由于我国能源以煤炭为主，２０世纪末，我国已成为仅次于美国的第二大ＣＯ２排放国，占世界总排放量的１４％，倍受世界瞩目。 一、发展清洁能源的必要性 清洁能源，即非矿物能源，也可称为非碳能源，它在消耗时不生成ＣＯ２等有害全球环境的物质。在２１世纪能…     

能源植物的研究现状及发展建议

能源危机是人类即将面临的巨大挑战,生物质能源的开发利用已成为当今国际上的一大热点。本文简要介绍了国内外能源植物的研究现状,并对如何发展我国能源植物提出了几点建议。     

向气泡要能源

面对能源危机,许多国家都在下大力气研究和开发利用“绿色能源”的新技术、新工艺,并且取得了相当可观的成就。最近,两位美国科学家在实验室的一项发现,无疑把能源新技术推到了风口浪尖。     

世界主要发达国家能源政策研究与启示

文章广泛调研了近10年美国、欧盟、英国、法国、德国、日本等国家和地区在能源领域出台的各种官方文件,通过内容分析等研究方法,从战略规划、经费投入、科研布局、组织机制等角度对上述国家和地区的能源政策进行分析。发现各个国家和地区能源政策呈现出一些共同特征,包括:自身资源禀赋是制定能源政策的基础,能源多元化和清洁高效利用是各国能源政策共同目标,科技创新是实现目标的重要抓手。最后,就我国抓住能源变革机遇、打造能源新体系,提出了一些建议。     

小细菌产生大能量

近来美国一些科学家发现除了植物能利用光合作用产生能量外，现在还有一种微小的细菌也具有同样的功能。和植物利用叶绿素进行光合作用提供养分同理，这种喜盐的小细菌会利用一种名为视紫红的蛋白质吸收太阳光，再将之转化为能量。这个发现为最终发明生物太阳能电池提供了可能性。小细菌产生大能量     

A case study of distributed information retrieval architectures to index one terabyte of text

The increasing number of documents to be indexed in many environments (Web, intranets, digital libraries) and the limitations of a single centralised index (lack of scalability, server overloading and failures), lead to the use of distributed information retrieval systems to efficiently search and locate the desired information. This work is a case study of different architectures for a distributed information retrieval system, in order to provide a guide to approximate the optimal architecture with a specific set of resources. We analyse the effectiveness of a distributed, replicated and clustered architecture simulating a variable number of workstations (from 1 up to 4096). A collection of approximately 94 million documents and 1 terabyte (TB) of text is used to test the performance of the different architectures. In a purely distributed information retrieval system, the brokers become the bottleneck due to the high number of local answer sets to be sorted. In a replicated system, the network is the bottleneck due to the high number of query servers and the continuous data interchange with the brokers. Finally, we demonstrate that a clustered system will outperform a replicated system if a high number of query servers is used, essentially due to the reduction of the network load. However a change in the distribution of the users’ queries could reduce the performance of a clustered system.     

Distributed adaptive optimization-based formation tracking with double parameter projections for multi-agent systems

In this paper, a distributed adaptive optimization-based formation tracking strategy with double parameter projections for multi-agent systems is addressed under a centralized task allocation and distributed task execution (CTA-DTE) framework. Since a pre-described formation strategy is unable to adapt to a complex and dynamic environment, an optimization-based approach is proposed to transfer the formation tracking problem into a time-varying optimization one, subject to some constraints with several time-varying parameters which determine the rule of formation configuration change adaptively. These parameters are computed by a centralized unit and allocated to each agent as a global mission. Furthermore, each agent cooperates with others to execute this mission under a distributed optimization-based strategy, which combines a geometric center observer technology and a novel double parameter projections technology. The former ensures accurate tracking of a continuous reference trajectory. The latter guarantees that all agents enter into a time-varying security region and never escape from it, and meanwhile, all agents are attracted towards the best time-varying formation configuration via a gradient descent with a compensation. Finally, some simulation results are illustrated to verify the effectiveness of the strategy.     

中小企业网络营销策略研究

随着网络的普及网络营销也为企业的发展注入了新的血液,但是并非所有的企业开展网络营销的道路都是一帆风顺的,由于受到资金、人才、技术等因素的影响,使得中小企业在发展过程中处处受扰。中小企业在发展如何选择合适的网络营销模式才能与传统营销起到相辅相成的作用、弥补传统营销中的不足,以推动企业的长足发展,因此网络营销的策略选择与研究成为中小企业在发展网络营销时首要考虑的问题。     

测试驱动开发研究

结合目前软件开发过程存在缺陷，充分借鉴极限编程思想，积极倡导应用测试驱动开发方法。分别从测试驱动开发概念、测试驱动开发优点、测试驱动开发实现等方面分别进行了阐述。最后结合实例描述了在软件开发过程中如何应用测试驱动方法和理念。     

创建图书馆员与读者之间的超级链接

读者是图书馆赖以生存的基础和前提条件，为其服务是图书馆永恒的宗旨，而图书馆员是链接图书馆与读者之间的桥梁与纽带。本文在此提倡创建图书馆员与读者之间的超级链接，旨在建立一种良好的人际关系，这对图书馆在新世纪守住阵地，吸引读者，提高馆藏文献信息资源的利用率，具有重要的意义。文章最后还对创建二者之间超级链接对图书馆员素质提出的要求进行了分析探讨。     

A content-location-aware public welfare activity information push system based on microblog

Microblog has become a widely used social media tool, which can help users publish or obtain Public Welfare Activity (PWA) information. Due to the characteristics of large-scale and arbitrary in microblog use, a large amount of messy information is produced, which makes it difficult to discover interesting PWA information. Thus, developing a push system, which can seek a certain number of local potential users for a PWA to be Pushed (PWAP), would be a great help. However, it is challenging to discover users explicitly interested in PWAs and obtain a certain number of local potential users. In this paper, a Content-Location-Aware PWA information Push system based on microblog (CLAP) is proposed, which can seek a certain number of local potential users for a PWAP from massive microblog users, and push the corresponding information to them. Specifically, a topic model and keyword search based method is firstly utilized to discover users who are explicitly interested in the PWAP (i.e., seed users). Secondly, a distance metric learning based method is utilized to obtain a certain number of local potential users by measuring the similarities between seed users and local users. Experimental results demonstrate that the proposed system has a potential to generate superior results.     

Kalman滤波器在单运动目标自动跟踪中的应用

在系列帧图像中对运动目标以直方图为模型的模板方法进行匹配,由于模板匹配计算量非常大,要想在整幅图像中对目标进行搜索匹配,同时又要达到实时是不可能的。我们对目标状态进行可靠的估计,可以在相对较小的区域内完成对模板的搜索,Kalman滤波器就是一个对动态系统的状态序列进行线形最小方差估计的算法。通过以动态的状态方程和观测方程来描述系统,它可以将任意一点作为起点开始观测,采用递归滤波的方法计算。该算法具有计算量小、可实时计算的特点。     

Uncertainty and the inconvenient facts of diagnosis

One common contemporary usage of the term “diagnostic uncertainty” is to refer to cases for which a diagnosis is not, or cannot, be applied to the presenting case. This is a paradoxical usage, as the absence of diagnosis is often as close to a certainty as can be a human judgement. What makes this sociologically interesting is that it represents an “epistemic defence,” or a means of accounting for a failure of medicine’s explanatory system. This system is based on diagnosis, or the classification of individual complaints into recognizable diagnostic categories. Diagnosis is pivotal to medicine’s epistemic setting, for it purports to explain illness via diagnosis, and yet is not always able to do so. This essay reviews this paradoxical use, and juxtaposes it to historical explanations for non-diagnosable illnesses. It demonstrates how representing non-diagnosis as uncertainty protects the epistemic setting by positioning the failure to locate a diagnosis in the individual, rather than in the medical paradigm.     

The “big red button” is too late: an alternative model for the ethical evaluation of AI systems

As a way to address both ominous and ordinary threats of artificial intelligence (AI), researchers have started proposing ways to stop an AI system before it has a chance to escape outside control and cause harm. A so-called “big red button” would enable human operators to interrupt or divert a system while preventing the system from learning that such an intervention is a threat. Though an emergency button for AI seems to make intuitive sense, that approach ultimately concentrates on the point when a system has already “gone rogue” and seeks to obstruct interference. A better approach would be to make ongoing self-evaluation and testing an integral part of a system’s operation, diagnose how the system is in error and to prevent chaos and risk before they start. In this paper, we describe the demands that recent big red button proposals have not addressed, and we offer a preliminary model of an approach that could better meet them. We argue for an ethical core (EC) that consists of a scenario-generation mechanism and a simulation environment that are used to test a system’s decisions in simulated worlds, rather than the real world. This EC would be kept opaque to the system itself: through careful design of memory and the character of the scenario, the system’s algorithms would be prevented from learning about its operation and its function, and ultimately its presence. By monitoring and checking for deviant behavior, we conclude, a continual testing approach will be far more effective, responsive, and vigilant toward a system’s learning and action in the world than an emergency button which one might not get to push in time.     

Projects as communicating systems: Creating a culture of innovation and performance

Although often downplayed and instrumental, there is evidence that communication in projects is essential in achieving value creation. Our main interest in this paper is on temporary continuity, a situation where the temporary becomes a permanent condition in social systems. The question that we have address is: What characterizes project communication in a situation with temporary continuity?We argue for the need to transform communication processes into communication capabilities. In a situation with temporary continuity, there is a need to connect to a large number of value-creating processes, and communicating capabilities need to be a part of a communication system, where the aim is to bind together value-creating processes and communication capabilities. We construct a viable system consisting of five sub-systems. To become a viable system, projects in the form of temporary continuity, must handle the potential conflict between a culture of performance and a culture of innovation. This involves developing social mechanisms for coordination and interaction, with a focus on developing communication capabilities, in parallel with focusing on all of the five value-creation processes.