Capturing sound, light, and strength with new materials

Physicists, chemists, and other scientists gathered in Boston from 28 November to 2 December for the fall meeting of the Materials Research Society (MRS) to explore everything from the behavior of single atoms to bulk structures. Among the more than 4000 papers and posters presented, attendees learned about novel devices that convert light directly to sound, new techniques for studying minuscule structures called quantum dots, and organic-inorganic hybrid materials.     

节瓜耐热材料的创制及新品种选育

鉴于长期缺乏耐热的节瓜品种,开展了节瓜耐热材料创制及新品种选育等为主要内容的育种研究.结果表明:主侧蔓坐果育种材料可以作为耐热资源进行利用.经组合选配、品比试验、区域试验、生产示范等一系列环节,育成节瓜新品种夏冠一号.生产示范及推广表明,夏冠一号具有耐热兼高产的特性,是目前华南地区夏季高温栽培的适宜品种.2005年通过广东省农作物品种审定.     

Band-gap engineering: from physics and materials to new semiconductor devices

Band-gap engineering is a powerful technique for the design of new semiconductor materials and devices. Heterojunctions and modern growth techniques, such as molecular beam epitaxy, allow band diagrams with nearly arbitrary and continuous band-gap variations to be made. The transport properties of electrons and holes can be independently and continuously tuned for a given application. A new generation of devices with unique capabilities, ranging from solid-state photomultipliers to resonant tunneling transistors, is emerging from this approach.     

造林新材料在岱山海岛造林中的应用

通过3种造林新材料在岱山海岛造林中的应用,观测它们对提高造林成活率的影响.结果表明:3种造林新材料对提高夹竹桃Nerium indicum造林成活率基本没有影响,科瀚98对枫香Liquidambar formosana和银杏Ginkgo biloba造林成活率影响较小.植树宝、科瀚98和GGR可显著提高女贞Ligustrum lucidum,重阳木Bischofia javanica,香樟Cinnamomum camphora和木荷Schima superba的造林成活率.图1表1参6     

Toward an AIDS vaccine

A quarter century of scientific discovery has been applied to developing an AIDS vaccine, yet this goal remains elusive. Specific characteristics of the virus, including the extreme genetic variability in circulating viral isolates worldwide, biological properties of HIV that impede immune attack, and a high mutation rate that allows for rapid escape from adaptive immune responses, render this a huge challenge. However, evidence of protection against AIDS viruses in animal models and control of HIV in humans under certain circumstances, together with scientific advances in understanding disease pathogenesis, provide a strong rationale and objective paths to continue the pursuit of an effective AIDS vaccine to stem the global epidemic.