虚拟环境下距离知觉的加工与整合

距离知觉是判断环境中自我与物体之间的距离或者是物体与物体之间的距离,本文简要介绍了虚拟环境下的距离信息线索的加工以及多感官的整合,系统回顾近年来对距离知觉的研究与探索,并对其进行评价.最后,讨论了运用虚拟现实技术研究距离知觉的一些局限性,并对于未来的研究趋势进行了展望.     

虚拟现实技术应用于运动障碍康复的研究

概述了近年来虚拟现实技术在运动障碍康复中的应用。介绍了该技术在运动障碍康复领域的四个重点研究方向：康复机器人、虚拟人、基于触觉反馈和力反馈的虚拟现实康复平台以及游戏机Wii的应用和新进展。最后总结了虚拟现实应用于运动障碍康复的优势及面临的主要挑战。     

储粮环境挥发性化合物与储粮害虫的关系研究进展

每种粮食的储粮环境中都存在有其特征性挥发物,储粮害虫的发生对储粮环境中挥发物具有重要影响。本文简述了顶空式固相微萃取法、浸入式固相微萃取法、电子鼻检测法等储粮挥发物的提取方法及其优缺点,对小麦 Triticum aestivum L.、稻谷 Olyza sativa L.、玉米 Zea mays L.和燕麦 Avena sativa L.等主要储藏粮食种类的挥发性化合物成分、粮食挥发物对昆虫行为反应的影响、主要储粮害虫(赤拟谷盗 Tribolium castaneum、锈赤扁谷盗 Cryptolestes ferrugineus 和象虫 Sitophilus spp.)发生与粮食挥发物的关系等研究进展进行综述,探讨了储粮环境挥发性化合物与储粮害虫关系未来的研究方向,以期对今后储粮害虫生态防治研究与应用提供参考信息。     

浅谈新媒体环境下的产品协作设计

协作设计的研究主要集中在设计过程中协作的互动性与设计高效性,在协作环境中通过计算机与通信技术的支持对自己所见所闻所感的信息进行传递,使协作人员身临其境在一个共同的虚拟工作空间内。随着新媒体技术和通信技术的快速发展,例如网络视频通话、虚拟现实等技术,新媒体技术使设计过程中的信息传播更加高效、准确。     

DNA技术与果树种质资源的保存与研究

本文对已经或将要应用于果树种质资源保存与研究方面的某些DNA技术进行了简要介绍,内容包括DNA技术与果树种质资源保存、DNA技术与果树种质资源研究 。     

DNA技术与果树种质资源的保存与研究

本文对已经或将要应用于果树种质资源保存与研究方面的某些ＤＮＡ技术进行了简要介绍,内容包括ＤＮＡ技术与果树种质资源保存、ＤＮＡ技术与果树种质资源研究。     

柚皮素自微乳不对称膜渗透泵胶囊的制备及体外评价

制备柚皮素自微乳不对称膜渗透泵胶囊并考察其体外释药行为。实验利用球晶技术进行自微乳的固化研究,以醋酸纤维素浓度、栓模浸入聚合物溶液中时间、栓模浸入淬火液中时间为自变量,采用星点设计-效应面优化法,以囊壳厚度和24h药物累积释放度为因变量,确定不对称膜渗透泵胶囊壳的最佳制备工艺。其最佳制备工艺为:醋酸纤维素浓度9.44%,栓模浸入聚合物溶液中时间3.77min,栓模浸入淬火液中时间15.86min,按最佳工艺得到的药物累积释放度为96.27%,囊壳厚度为0.275mm。体外释药行为符合零级释药方程(R=0.9997)。柚皮素自微乳不对称膜渗透泵胶囊可有效控制药物缓慢释放,解决难溶性药物制成渗透泵制剂释药不完全的问题。     

基于近红外光谱实时监测乙醇发酵过程多组分参数

生物量、葡萄糖浓度和乙醇浓度是乙醇发酵过程的重要参数,传统的方法通常对发酵液取样作离线测量,不仅需要采用多种仪器进行测试分析,而且耗时耗力,成为实时过程调控和优化的障碍。文中针对这些重要过程参数提出了一个基于近红外光谱技术的原位实时检测方法。通过采用浸入式近红外光谱仪对发酵溶液进行原位测量,基于多输出最小二乘支持向量机回归(MLS-SVR)方法建立了利用近红外光谱同时分析葡萄糖浓度、生物量和乙醇浓度的多输出预测模型。实验结果表明,该方法能实时准确地检测乙醇发酵过程中的葡萄糖浓度、生物量和乙醇浓度,而且相对于现有的偏最小二乘法(PLS)分别对各组分建模和预测,能明显提高测量准确性和可靠性。     

荧光原位杂交技术及其在环境微生物生态学中的应用研究

荧光原位杂交技术是一种能够同时对微生物进行定性、定量和研究微生物群落空间分布情况的有力工具。简要介绍了荧光原位杂交技术的方法,并对其在人为创制环境和自然环境中特征性微生物种群及群落生态学中的应用研究进行了讨论,指出了该种技术在应用中存在的问题与缺陷,最后对荧光原位杂交技术在堆肥微生物生态中的应用及与其他方法的组合应用进行了展望。     

Internet在化学和生物科学中的应用

简要介绍Internet的基本服务─e－mail、FTP、Telnet在化学和生物科学中的应用；重点介绍基于WWW系统的网络服务，包括基于Web的信息查询、电子杂志、电子会议、虚拟现实。Internet的发展为现代化学和生物科学科技工作者提供了一个崭新的信息交流环境。     

基于Virtools的医院网络虚拟实验室建设

网络虚拟实验室为现代医学提供了新的实验和教学手段,虚拟现实软件Virtools为网络虚拟实验室提供了可行的技术支持。文章在介绍了网络虚拟实验室概念、功能、特性和Virtools的使用特点后,提出利用Virtools开发医院网络虚拟实验室的过程和方法。     

Is my hand connected to my body? The impact of body continuity and arm alignment on the virtual hand illusion

When a rubber hand is placed on a table top in a plausible position as if part of a person’s body, and is stroked synchronously with the person’s corresponding hidden real hand, an illusion of ownership over the rubber hand can occur (Botvinick and Cohen 1998). A similar result has been found with respect to a virtual hand portrayed in a virtual environment, a virtual hand illusion (Slater et al. 2008). The conditions under which these illusions occur have been the subject of considerable study. Here we exploited the flexibility of virtual reality to examine four contributory factors: visuo-tactile synchrony while stroking the virtual and the real arms, body continuity, alignment between the real and virtual arms, and the distance between them. We carried out three experiments on a total of 32 participants where these factors were varied. The results show that the subjective illusion of ownership over the virtual arm and the time to evoke this illusion are highly dependent on synchronous visuo-tactile stimulation and on connectivity of the virtual arm with the rest of the virtual body. The alignment between the real and virtual arms and the distance between these were less important. It was found that proprioceptive drift was not a sensitive measure of the illusion, but was only related to the distance between the real and virtual arms.

Electronic supplementary material

The online version of this article (doi:10.1007/s11571-011-9178-5) contains supplementary material, which is available to authorized users.     

Virtual laboratories in science education: students’ motivation and experiences in two tertiary biology courses

Potential benefits of simulations and virtual laboratory exercises in natural sciences have been both theorised and studied recently. This study reports findings from a pilot study on student attitude, motivation and self-efficacy when using the virtual laboratory programme Labster. The programme allows interactive learning about the workflows and procedures of biological and biochemical experiments, the operation of relevant apparatuses, including the ability to adjust parameters, and the production of results. The programme was used as supplement to mandatory laboratory exercises in two undergraduate courses (i. microbiology and ii. pharmaceutical toxicology) at the University of Southern Denmark. With a theoretical basis in motivational theories, students’ (n = 73) motivation and attitude towards the virtual exercises were evaluated. After completing virtual laboratory cases, the students felt significantly more confident and comfortable operating laboratory equipment, but they did not feel more motivated to engage in virtual laboratories compared to real laboratories. Teachers observed that students were able to participate in discussions at higher levels than in previous years where the programme was not used. The study concludes that virtual laboratories have the potential to improve students’ pre-laboratory preparation.     

Observed Touch on a Non-Human Face Is Not Remapped onto the Human Observer's Own Face

Visual remapping of touch (VRT) is a phenomenon in which seeing a human face being touched enhances detection of tactile stimuli on the observer''s own face, especially when the observed face expresses fear. This study tested whether VRT would occur when seeing touch on monkey faces and whether it would be similarly modulated by facial expressions. Human participants detected near-threshold tactile stimulation on their own cheeks while watching fearful, happy, and neutral human or monkey faces being concurrently touched or merely approached by fingers. We predicted minimal VRT for neutral and happy monkey faces but greater VRT for fearful monkey faces. The results with human faces replicated previous findings, demonstrating stronger VRT for fearful expressions than for happy or neutral expressions. However, there was no VRT (i.e. no difference between accuracy in touch and no-touch trials) for any of the monkey faces, regardless of facial expression, suggesting that touch on a non-human face is not remapped onto the somatosensory system of the human observer.     

Understanding agricultural virtual water flows in the world from an economic perspective: A long term study

The globalization process of the last half century entailed a growing trade in agricultural and food products. As a result, water has been transferred among countries, embodied in these goods. This paper studies the evolution of virtual water flows over the long term, analyzing the main driving factors through Decomposition Analysis. It contributes to the existing literature by offering a dynamic and economic interpretation of the historical changes in virtual water trade flows. In particular, this study points to a gradual increase in virtual water exchange, related to the upsurge of agricultural and food products trade in the world from 1965 to 2010. Although the origins and destinations of virtual water have changed, North America stands out as the primary net exporter of virtual water. Europe and Asia, on the other hand, with a high dependency on foreign water resources, appear as net importers of virtual water. Despite improvements in agricultural yields and the reallocation of production, the virtual water trade continues to increase globally via these significant commercial exchanges.     

三维CT在气管狭窄诊断中的应用

目的：我们检测三维CT在气管狭窄的诊断中的作用和纤维支气管镜相比较,用以帮助临床胸外科医生判断气管结构的解剖学特征。方法：对怀疑气管狭窄的患者64例及20例正常病例检查螺旋CT,其中52例发现腔内新生物造成狭窄,另外12例为外伤后狭窄,应用多平面重建（Mr＇R）、容积重建技术（VRT）、仿真内镜（VE）等技术进行影像的后处理,结果与纤维支气管镜结果相比较。两名放射科医生双盲对照检测并描述了三维CT检查对气管狭窄位置及狭窄程度诊断的精确性。结果：影像形式的检测显示与软性纤维支气管镜结果相同的狭窄,并能够获得关于狭窄的精确的和非侵袭性的形态学上的特征描述,还能够获得疾病腔外范围的额外信息。支气管镜检测结果和多平面重建（MPR）、容积重建技术（VRT）、仿真内镜（VE）的检测结果之间无显著统计学差异（P值分别为0．715,0．413和0．417）。结论：三维CT对于气管来说和传统支气管镜相比能够提供一个高保真度、非侵袭、可再生的评价。他们在高等级气管狭窄的远端开放气道的评价方面具有重要作用,对于无法耐受传统支气管镜的患者是一个可靠的选择。     

A computational model of selection by consequences: log survivor plots

[McDowell, J.J, 2004. A computational model of selection by consequences. J. Exp. Anal. Behav. 81, 297-317] instantiated the principle of selection by consequences in a virtual organism with an evolving repertoire of possible behaviors undergoing selection, reproduction, and mutation over many generations. The process is based on the computational approach, which is non-deterministic and rules-based. The model proposes a causal account for operant behavior. McDowell found that the virtual organism consistently showed a hyperbolic relationship between response and reinforcement rates according to the quantitative law of effect. To continue validation of the computational model, the present study examined its behavior on the molecular level by comparing the virtual organism's IRT distributions in the form of log survivor plots to findings from live organisms. Log survivor plots did not show the "broken-stick" feature indicative of distinct bouts and pauses in responding, although the bend in slope of the plots became more defined at low reinforcement rates. The shape of the virtual organism's log survivor plots was more consistent with the data on reinforced responding in pigeons. These results suggest that log survivor plot patterns of the virtual organism were generally consistent with the findings from live organisms providing further support for the computational model of selection by consequences as a viable account of operant behavior.     

医学信息的虚拟存储及其系统模型的构建

本文引入了医学信息的虚拟存储新理念，用以解决海量医学数据的存储难题，并提出了在上海广电集团所建立的上海远程医学网络平台上的具体设计方案，包括建立虚拟映射，数据访问中数据传输技术的研究以及存储管理的设想。     

Chemoreflex control of breathing during wakefulness in healthy men and women.

This study used a modified CO(2) rebreathing procedure to examine the effect of gender on the chemoreflex control of breathing during wakefulness in healthy men (n = 14) and women (n = 14). Women were tested in the follicular phase of the menstrual cycle. During rebreathing trials, subjects hyperventilated to reduce the partial pressure of end-tidal CO(2) (Pet(CO(2))) below 25 Torr and were then switched to a rebreathing bag containing a normocapnic hypoxic or hyperoxic gas mixture. During the trial, Pet(CO(2)) increased, while O(2) was maintained at a constant level. The point at which ventilation began to rise as Pet(CO(2)) increased was identified as the ventilatory recruitment threshold (VRT). Ventilation below the VRT was measured, and the slope of the ventilatory response above the VRT was determined. Gender had no effect on the hyperoxic or hypoxic VRT for CO(2). Central chemoreflex sensitivity was significantly greater in men than women but not after correction for forced vital capacity. Measures of peripheral chemoreflex sensitivity were similar between genders. However, the slope of the tidal volume (Vt) response to hyperoxic and hypoxic CO(2) rebreathing (corrected and uncorrected) was greater in men than women, respectively. We conclude that central chemoreflex sensitivity is greater in men compared with women as reflected by differences in ventilatory (uncorrected) and Vt (corrected and uncorrected) responses to CO(2). However, gender has no significant effect on the central chemoreflex VRT for CO(2). The peripheral chemoreflex control of breathing during wakefulness is similar between men and women.