USB协议栈的设计及其在嵌入式领域的应用

USB已经成为一种非常成功的总线标准。以USB在一个嵌入式系统的实现案例，介绍了USB总线的硬件研发过程及相关USB协议栈的设计与实现，并且探讨了在嵌入式操作系统中基于该协议栈的USB设备驱动的开发以及USB Bios Boot Rom的设计。     

Phytochemical Variation in Quaking Aspen: Effects on Gypsy Moth Susceptibility to Nuclear Polyhedrosis Virus

The performance of gypsy moths (Lymantria dispar) feeding on quaking aspen (Populus tremuloides) is strongly influenced by host foliar chemistry and susceptibility to a nuclear polyhedrosis virus (LdNPV), but the relationship of susceptibility to chemistry is poorly understood. We investigated the effects of genetic and resource-mediated variation in phytochemistry on viral pathogenicity. Trees were grown in pots in a common garden. Disks were punched from aspen leaves, inoculated with LdNPV and fed to third instars. Additional leaves were analyzed for levels of nitrogen, starch, phenolic glycosides, and condensed tannins. Despite marked variation among trees in levels of phenolic glycosides and tannins, we observed minimal variation in larval susceptibility to LdNPV. Viral pathogenicity was only weakly (inversely) correlated with tannin concentrations in one of two experiments. These results suggest that differential defoliation of aspen by gypsy moths in the field is due to the direct effects of host chemistry on larval performance rather than to the indirect effects of host chemistry on efficacy of this natural enemy.     

Effects of Drought Stress and Nutrient Availability on Dry Matter Allocation,Phenolic Glycosides,and Rapid Induced Resistance of Poplar to Two Lymantriid Defoliators

The growth–differentiation balance hypothesis (GDBH) postulates that variation in resource availability can increase or decrease allocation to secondary metabolism, depending on how growth is affected relative to carbon assimilation. Growth and leaf area of black poplar (Populus nigra) increased substantially in response to increased nutrient availability, while net assimilation rate and photosynthesis were less strongly affected. In response, total phenolic glycoside concentrations declined, which is consistent with GDBH. Drought stress decreased net assimilation rate and photosynthesis as well as growth, while increasing total phenolic glycoside concentrations. This pattern does not follow GDBH, which predicts lower secondary metabolism when resource limitation decreases both growth and carbon assimilation. However, there was a strong negative correlation between growth and total phenolic glycoside concentration consistent with a trade-off between primary and secondary metabolism, a key premise of GDBH. Drought decreased the growth of gypsy moth (Lymantria dispar) larvae but had no effect on whitemarked tussock moth (Orgyia leucostigma). Increased nutrient availability had a positive linear effect on growth of whitemarked tussock moth, but no effect on gypsy moth. Treatment effects on gypsy moth corresponded closely with effects on total phenolic glycosides, whereas effects on whitemarked tussock moth more closely tracked changes in nutritional quality. Localized gypsy moth herbivory elicited rapid induced resistance to gypsy moth, with the effect being independent of water and nutrient availability, but did not affect whitemarked tussock moth, indicating that the effects of biotic and abiotic stress on insect resistance of trees can be species-specific.     

基于Centripetal Catmull Rom曲线的经食道超声心动图左心室分割方法

针对2维超声心动图像噪声大且难于分割的特点,提出基于Centripetal Catmull Rom曲线的多尺度活动形状模型的左心室分割方法。该算法在金字塔上层提取2维轮廓法线向量特征并采用马氏距离寻找新的特征点位置;在图像金字塔底层快速提取特征点周围的Log Gabor特征并使用Gentle AdaBoost训练分类器,选择置信度水平最高的点作为新的特征点位置。实验证明,这种方法较之传统活动形状模型分割更为精确且分割结果交互方便,有利于对结果的再编辑。     

Kurt Gottschaldt's ambiguous relationship with national socialism.

Kurt Gottschaldt (1902-1991) was active in psychological research in Germany throughout much of the past century. His best-known contributions relate to three "twin camps" he ran in the late 1930s. These twin camps were designed help assess the relative contributions of heredity and environment in determining the development of psychological attributes and behavior. Gottschaldt's conclusions favored a hereditarian interpretation of his results, and Gottschaldt promoted the relevance of his twin research to "race psychology." Although Gottschaldt is sometimes described as a defender of scientific objectivity who maintained independence from Nazi ideology during the National Socialist era, some of his work suggests that a modest revision of this view may be required. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A discussion of some of the issues facing the regulator in dealing with the newly developing nomadic services including HIPERLAN

HIPERLAN is a new standard for nomadic computer equipment being developed by ETSI. The practicalities of licensing of such computer networks make it unlikely that there will be an individual licensing scheme. Nomadic equipment cannot be restricted to certain regions or countries. There are clear indications that it will play an increasingly large role in communications. The best solution to the issue of nomadic equipment and its future development would appear to be an international effort at spectrum planning and frequency allocation.     

(7R,8S)-cis-7,8-epoxy-2-methyloctadec-17-ene: a novel trace component from the sex pheromone gland of gypsy moth, Lymantria dispar

Considering the vast Eurasian distribution of gypsy moth, Lymantria dispar (Lepidoptera: Lymantriidae), the many subspecies, and their presence in different lymantriid communities, we tested the hypothesis that L. dispar populations in eastern Asia employ one or more pheromone components in addition to the previously known single component pheromone (7R,8S)-cis-7,8-epoxy-2-methyloctadecane [= (+)-disparlure]. Coupled gas chromatographic–electroantennographic detection (GC–EAD) analyses of pheromone gland extracts of female L. dispar sensu lato (including both AGM and NAGM) on four GC columns (DB-5, DB-23, DB-210, and SP-1000) revealed a new trace component that eluted just before (DB-5; DB-210) or after (DB-23, SP-1000) disparlure, and elicited strong antennal responses. Isolation of this compound by high-performance liquid chromatography and hydrogenation produced disparlure, suggesting that the new component had the molecular skeleton of disparlure, with one or more double bonds. Of all possible monounsaturated cis-7,8-epoxy-2-methyloctadecenes, only cis-7,8-epoxy-2-methyloctadec-17-ene co-chro- matographed with the insect-produced compound on all GC columns and elicited comparable antennal responses. In field experiments in Honshu (Japan) with enantioselectively synthesized compounds, (7R,8S)-cis-7,8-epoxy-2- methyloctadec-17-ene (7R8S-epo-2me-17-ene-18Hy) was weakly attractive to male L. dispar, but was less effective as a trap bait than (+)-disparlure, and failed to enhance attractiveness of (+)-disparlure when tested in blends. The antipode, (7S,8R)-cis-7,8-epoxy-2-methyloctadec-17-ene, was not attractive, and when added to (+)-disparlure and/or 7R8S-epo-2me-17-ene-18Hy reduced attractiveness. Thus, the biological role of 7R8S-epo-2me-17-ene-18Hy remains unclear. It may enhance pheromone attractiveness or specificity in other L. dispar populations within their vast Eurasian distribution.     

PCI网卡的BOOT ROM的应用

该文介绍了基于PCI总线规范网卡上的BOOTROM的启动原理,并且给出了一个完整的方案用来开发基于BOOTROM的相关应用。     

“游牧”的回归

此文是一篇非严格意义上的对《不分类的建筑》的书评。与一般的评价式书评不同,它试图通过重构书中阅读的线索,探讨建筑写作的一种立场,即作者所关注的＂游牧＂,在拓展建筑学的知识中所具有的价值,带来的思考和问题。     

标准化在锚链轮设计中的应用

对起锚机和组合起锚绞车中的锚链轮设计问题进行了分析研究,阐述锚链轮在设计中应遵循的一些基本原则及注意事项.