MATERIALS SCIENCE: Long-Wavelength Lasers Sniff Out New Uses

Just a few weeks after two physicists won the Nobel Prize for figuring out how to make lasers out of semiconductors, researchers announced that they have made those lasers much more useful. A new technique permits the lasers to shine light in regions of the infrared spectrum previously inaccessible to similar devices. The advance may open the door to cheap devices to sniff explosives and other robotic sensors.     

IRANIAN SCIENCE: Iran's Scientists Cautiously Reach Out to the World

Two decades after Iran's Islamic revolution, science in this politically isolated but oil-rich nation may be on the verge of resurgence. The nation's reform-minded president, Mohammad Khatami, and his allies are promising more money for R&D, reorganizing universities to beef up graduate education and research, and cracking open the door to closer cooperation with scientists abroad, including those in the United States. But Iran's government is walking a tightrope between hard-liners on the right who oppose reforms and liberal university students eager for change.     

MATERIALS SCIENCE: Deformations in Extreme Matter

Most materials become narrower in cross section when stretched, but some materials, such as foams, have the counterintuitive property of becoming fatter when stretched (they have a negative Poisson's ratio). In this Perspective, Lakes discusses how his unusual property may arise in isotropic and anisotropic materials. He highlights the study by Baughman et al., who show that anisotropic materials with a negative Poisson's ratio in one direction can be incompressible, i.e., without an overall change in volume upon stretching. This behavior is predicted for materials with very high density, such as neutron star crusts, or very low density, such as ion plasmas, and the validity of the prediction is demonstrated with experimental data for ion plasmas.     

MATERIALS SCIENCE: New Tigers in the Fuel Cell Tank

After decades of incremental advances, a spurt of findings suggests that fuel cells that run on good old fossil fuels are almost ready for prime time. Although conventional ceramic cells, known as solid oxide fuel cells, require expensive heat-resistant materials, a new generation of SOFCs, including one featured on page 2031, converts hydrocarbons directly into electricity at lower temperatures. And a recent demonstration of a system of standard SOFCs large enough to light up more than 200 homes showed that it is the most efficient large-scale electrical generator ever designed.     

SCIENCE FUNDING: Australian Researchers Go for the Gold

Academic scientists are hoping that two new reports calling for increased funding of research and education and an improved climate for commercializing new technology will finally boost an R&D budget that has been stagnant since 1996. One report argues for a variety of measures to reduce the country's reliance on such low-tech commodities as agriculture and precious metals and stimulate innovation. The second report, based on an innovation summit held in February, recommends spending $1.4 billion over 5 years on research, facilities, and education.     

IRANIAN SCIENCE: Iranian Women Hear the Call of Science

Despite institutions such as separate reading rooms for each sex, women are a growing presence at Iran's universities, making up nearly 60% of incoming classes, almost double their share in 1978. But as in many other countries, some female academics in Iran point to a glass ceiling that keeps their representation among university professors low.     

新世纪的信仰教育:困境及出路

文章通过对大学生信仰状况调查，分析了高校信仰教育面临的困境，并对信仰教育的重构与出路作了探讨。     

一种快速提取烟草病毒的方法

为寻找高效快速提取植物总RNA的检测方法,以白肋烟叶片为材料,用Trizol试剂盒提取总RNA。依据黄瓜花叶病毒和马铃薯X病毒的外壳蛋白保守序列设计特异性引物,进行RT-PCR检测,从感病叶片中分别扩增出326bp、392bp的目的片断,而对照叶片中无此扩增带。将PCR产物连接pGEM-T载体上,转化大肠杆菌DH5α,得到了含有目的片断的重组子。序列分析表明,与Gene Bank中报道的这两种病毒核苷酸序列进行比较,同源性均达到96%以上。从而证明Trizol试剂盒可以在1 h内提取到纯度高、含量高、完整性好的总RNA,快速、简便、可靠。     

ESSAYS ON SCIENCE AND SOCIETY: Selling Science to the Public

In this essay, Highfield reflects on his personal experiences as science journalist and editor at the British broadsheet the Daily Telegraph. Highfield believes that scientists can learn from journalists' dialogue approach to science communication. Highfield believes that readers are "ignorant but smart," and are sufficiently sceptical not to believe all the hype that they read. What is most important is that a dialogue is created. For example, large-scale experiments performed by the Daily Telegraph together with the BBC allow the public to get a glimpse of the scientific method that is often ignored.     

PLANETARY SCIENCE: Most-Common Meteorites Find a Home Among the Asteroids

Meteoriticists have long been puzzled by the fact that the most common meteorites, so-called ordinary chondrites, don't appear to have come from the most common asteroids, the S-types. Last week, however, a group of researchers attending the spring meeting of the American Geophysical Union here announced that the 31-kilometer-long S-type asteroid Eros now being orbited by the NEAR Shoemaker spacecraft is made of the same stuff as ordinary chondrites. That conclusion comes from NEAR Shoemaker's first-ever analysis of the elemental composition of an asteroid.     

IRANIAN SCIENCE: Earthquake Researchers Prepare for the Next Big One

When a devastating earthquake rocked the Manjil region in Iran on 20 June 1990, the tremors also shook seismology research in that country. That night, Mohsen Ghafory-Ashtiany rolled out of his bed in Tehran and headed to the danger zone in northwestern Iran, where 13,000 persons perished and 60,000 were injured. He and his then-tiny staff surveyed the damage and mapped out a plan for bolstering earthquake research and preparedness.     

QUANTUM MECHANICS: Enhanced: Schrodinger's Cat Is Out of the Hat

In 1935, Erwin Schr?dinger suggested his famous gedanken experiment of the cat that is simultaneously "dead" and "alive" inside its box until the box is opened. But as Tesche explains in her Perspective, such a macroscopic manifestation of quantum mechanics has remained elusive until recently. The experiments by van der Wal et al. are an important step toward demonstrating that quantum mechanics can describe macroscopic phenomena. The approach may be exploited in quantum computing and quantum cryptography.     

Out of the tropics: evolutionary dynamics of the latitudinal diversity gradient

The evolutionary dynamics underlying the latitudinal gradient in biodiversity have been controversial for over a century. Using a spatially explicit approach that incorporates not only origination and extinction but immigration, a global analysis of genera and subgenera of marine bivalves over the past 11 million years supports an "out of the tropics" model, in which taxa preferentially originate in the tropics and expand toward the poles without losing their tropical presence. The tropics are thus both a cradle and a museum of biodiversity, contrary to the conceptual dichotomy dominant since 1974; a tropical diversity crisis would thus have profound evolutionary effects at all latitudes.     

ESSAYS ON SCIENCE AND SOCIETY: Privatizing the University--the New Tragedy of the Commons

Teaching and research at universities is increasingly funded from private sources. In this essay, Brown highlights the problems associated with this approach and calls for a return to largely public funding. He argues that the public, rather than corporations or individual scientists or even secretive governments, should own the results.     

中国植保机械化:困境与出路

中国植保机械化水平显著滞后于发达国家,并已成为导致农药用量过高、有效利用率偏低、农产品质量安全危机、农残超标严重、对外贸易受阻以及环境污染加剧等系列问题的重要成因,严重阻碍和制约农业现代化的进程和现代农业的可持续发展。文章通过对我国现阶段植保机械化发展状况的浅析,并力图透过发展中存在的诸多问题,进一步提出统一思想,提高认识;因地制宜,科学制定发展策略和路径;强化科研,增强自主创新能力;加强协作攻关,突破核心技术,研制关键设备;加强监督和管理,确保产品质量等促进我国植保机械化水平全面升级的相应对策、措施和建议。     

ESSAYS ON SCIENCE AND SOCIETY: Polygraph Testing and the DOE National Laboratories

A new security policy that mandates polygraph testing as a security measure at U.S. national laboratories has spurred controversy, which is explored in this essay. Congress imposed the requirement last year in response to security failures at the labs. But opponents challenge the scientific validity of the polygraph, and argue that it could tend to undermine the vitality of the labs that it is intended to protect.     

论成文法在农村的困境与出路

农村的成文法数量不断增加,立法质量有所提高,内容上覆盖农村组织法、农村土地法、农村环境保护法、农业科技法等多个种类,形成了以《农业法》为中心,初具规模的农业法律体系。但是由于受到中国传统法律文化、法律移植中存在的弊端,社会转型过程中出现的偏差以及硬件建设和配套制度的滞后与缺失等因素的影响,导致当前农民法律意识落后,对成文法内容的不了解和对其功能的漠视,成为成文法在农村面临的困境。为了摆脱农村成文法的困境,需要对传统法律文化进行扬弃,促进法律与农民的对接,促进工业与农业、城市与农村的协调发展,完善法律硬件建设和配套制度,加快农村法制建设。     

植物病毒的真菌传播及传毒介体油壶菌研究进展

真菌传播植物病毒研究已成为植物病毒学研究的一个重要领域。扼要介绍了40余年来，国内外关于植物病毒的真菌传播及传毒介体油壶菌的研究概况。