摘要：【目的】百合斑驳病毒(lily mottle virus,LMoV)是危害重要食药用百合卷丹的主要病毒之一,每年给百合种植业造成数十亿的损失。通过原位杂交技术明确LMoV在卷丹顶端分生组织中的分布,为百合脱毒培养提供支撑。【方法】采用种植于贵州省清镇市的栽培卷丹作为试验材料,利用RT-PCR并于NCBI网站下载不同地方LMoV分离物构建进化树鉴定卷丹所携带的病毒种类,据检测结果选取LMoV为对象,基于LMoV基因组序列设计并制备RNA荧光探针,开展卷丹茎尖和根尖石蜡切片组织的RNA原位杂交,观察卷丹茎尖和根尖中LMoV的分布。【结果】RT-PCR检测表明卷丹材料侵染了LMoV,构建进化树发现本实验分离物与吉林和辽宁的LMoV分离物关系最近,原位杂交进而表明卷丹茎尖中LMoV杂交信号主要分布在顶端分生组织下方0.15-0.2 mm的组织中,靠近紧挨分生组织叶原基的初生叶基部有较弱的病毒杂交信号,靠近初生叶的成熟叶顶端中病毒荧光信号强烈,感染LMoV的卷丹分生组织中心纵切面无毒区大小为(0.4-0.6)mm×(0.15-0.2)mm;在根尖0.25 mm×0.2 mm分生组织中无杂交信号分布,在皮层细胞中信号最强烈,在根冠和根伸长区信号较弱。【结论】卷丹顶端分生组织及最接近顶端的一个叶原基[大小约(0.4-0.6)mm×0.2 mm]未发现病毒信号,可作为茎尖脱毒的起始材料。根顶端分生组织外侧根冠有较强病毒信号,不适合作为卷丹脱毒培养的外植体。

摘要：Due to the long-term plate tectonic movements in southwestern China,the in-situ stress field in deep formations is *** passing through deep soft-rock mass under non-hydrostatic high in-situ stress field,tunnels will suffer serious asymmetric *** is no available support design method for tunnels under such a situation in existing studies to clarify the support time and support *** study first analyzed the mechanical behavior of tunnels in non-hydrostatic in-situ stress field and derived the theoretical equations of the ground squeezing curve(GSC)and ground loosening curve(GLC).Then,based on the convergence confinement theory,the support design method of deep soft-rock tunnels under non-hydrostatic high in-situ stress field was established considering both squeezing and loosening *** addition,this method can provide the clear support time and support stiffness of the second layer of initial *** proposed design method was applied to the Wanhe tunnel of the China-Laos railway in *** data indicated that the optimal support scheme had a good effect on controlling the tunnel deformation in non-hydrostatic high in-situ stress *** applications showed that the secondary lining could be constructed properly.

摘要：采用GT软件建立电控高压共轨燃油喷射系统模型,并利用构建的仿真模型研究高压油泵的进油阀组件、排油阀组件以及活塞凸轮组件,其三个主要部分的结构参数变化对共轨管中压力波动的影响。通过研究可知高压泵在实际工作时所承受的压力波与活塞的状态有直接关系,且活塞状态包括其质量、长度、直径、容积等。为了更好地研究进排油阀对压力波动之间的关系,选用8组参数进行实验研究并验证进排油阀体直径、质量、弹簧预紧力、弹簧刚度的变化与压力波动之间的相互影响作用,进而通过对比选取最佳阀体。通过仿真分析可知,共轨喷油系统压力波动程度会受到系统结构参数的影响,并可以为系统的优化设计提供参考依据。

摘要：为了规避老年产品操作行为中的姿势风险,快速设计出符合老年人机性能要求的产品,从工业设计出发,提出面向老年俯身作业的人机工程舒适性设计方法.结合视频观察法、出声思考法、问卷法与深度访谈法,获取80名70~89岁中国老年人俯身作业舒适特征数据,提出俯身舒适度计算模型,建立老年俯身作业"红-绿灯"舒适梯度.构建了"面向老年俯身作业的产品人机咨询与评价系统"(PECASE),系统分为基础层、数据层、中间层和表现层4个层面,可以支持面向老年人的创意设计前期、中期与后期的人机适配咨询与评价.以家用滚筒洗衣机设计为例,对系统的可用性进行验证,可以有效地为老年产品创新设计的人机工程分析提供支持.

摘要：The bias drift of a micro-electro-mechanical systems （MEMS） accelerometer suffers from the l/f noise and the tem- perature effect. For massive applications, the bias drift urgently needs to be improved. Conventional methods often cannot ad- dress the l/f noise and temperature effect in one architecture. In this paper, a combined approach on closed-loop architecture modification is proposed to minimize the bias drift. The modulated feedback approach is used to isolate the l/f noise that exists in the conventional direct feedback approach. Then a common mode signal is created and added into the closed loop on the basis of modulated feedback architecture, to compensate for the temperature drift. With the combined approach, the bias instability is improved to less than 13 μg, and the drift of the Allan variance result is reduced to 17 μg at 100 s of the integration time. The temperature coefficient is reduced from 4.68 to 0.1 mg/℃. The combined approach could be useful for many other closed-loop accelerometers.

摘要：针对表贴式高速永磁电机转子护套与永磁体之间过盈配合单一、护套内外表面上作用力跨度较大的问题,提出一种多层护套转子结构,能有效减小护套的总厚度。在满足转子机械性能的前提下,多层护套转子结构通过在每层护套之间施加适当过盈量的方法使护套整体的受力分布更加均匀,提升了护套的使用效率,因此总厚度相比单层护套更薄。为快速分析多层护套转子结构的受力情况,建立了该结构的二维应力场解析计算模型。基于解析模型提出了一种多层护套的设计方法,并用该方法对一台高速永磁电机的转子进行设计,且通过有限元分析验证了该设计方法的准确性。最后,将所设计的多层护套与原单层护套相对比,该结构的护套厚度减小了10%、转子涡流损耗减少了12.6%。

摘要：为研究实际线路环境下的虚拟编组列车编队控制问题,综合考虑系统的实时性和抗扰性,本文提出一种基于扩张状态观测器的触发模型预测控制方法。首先,基于虚拟编组列车动力学方程搭建多车追踪模型,并设计终端函数,确保系统的稳定性;其次,针对模型预测控制中存在计算效率低和资源浪费的问题,引入事件触发机制,在求解优化问题时增加判断条件,以提高系统的实时性;再次,在前馈通路上加入扩张状态观测器,对环境中存在的扰动实时估计并补偿,减少干扰造成模型不准确的现象,提高模型的抗扰动能力;最后,基于MATLAB和Simulink仿真平台设计4列列车追踪的运行场景,并与传统模型预测控制方法进行对比,从控制精度和计算时间两方面验证所提方法的有效性。仿真结果表明:相较于传统模型预测控制方法,本文所提出的事件触发机制中3个阈值τ为0.001,0.010,0.100的计算效率分别提高了47%,64%,73%;在面对外部扰动时,本文所提算法在抗扰性上提高了33%。

摘要：Overseas research has shown that achievement emotions have direct relationships with ＂achievement outcome＂ and＂achievement activities＂. The purpose of the present study aimed to compare the relationships betweenachievement emotions, motivation, and language learning strategies of high, mid and low achievers in Englishlanguage learning at an international university in a southern province in China. Quantitative data were collectedthrough a questionnaire survey of 74 （16 males, 58 females） TESL major students. Results indicated that studentsin general experienced more positive than negative achievement emotions; more intrinsically rather thanextrinsically motivated to learn English; and quite frequently used a variety of learning strategies to overcome theirlearning difficulties. However, Year Four low-achievers experienced more negative achievement emotions. Theyseldom used metacognitive, affective and social learning strategies, and they had lower degrees of intrinsicmotivation. Implications for institutional support for at risk students are discussed.

摘要：Collaborative design is a new style for modern mechanical design to meet the requirement of increasing competition. Designers of different places complete the same work, but the conflict appears in the process of design which may interface the design. Case-based reasoning (CBR) method is applied to the problem of conflict resolution, which is in the artificial intelligence field. However, due to the uncertainties in knowledge representation, attribute description, and similarity measures of CBR, it is very difficult to find the similar cases from case database. A fuzzy CBR method was proposed to solve the problem of conflict resolution in collaborative design. The process of fuzzy CBR was introduced. Based on the feature attributes and their relative weights determined by a fuzzy technique, a fuzzy CBR retrieving mechanism was developed to retrieve conflict resolution cases that tend to enhance the functions of the database. By indexing, calculating the weight and defuzzicating of the cases, the case similarity can be obtained. Then the case consistency was measured to keep the right result. Finally, the fuzzy CBR method for conflict resolution was demonstrated by means of a case study. The prototype system based on web is developed to illustrate the methodology.

摘要：提出一种适用于大规模互联网流量的实时广告流量检测系统,系统以目前最为流行的Adblock规则列表作为基本规则库,将Hash Table快速匹配算法和Aho-Corasick快速匹配算法相结合,对广告流量进行快速实时匹配.此外,为了适应大规模流式数据的需求,将匹配算法部署在并行流式工作框架Spark Streaming之上.模型系统分别在实验室和运营商真实网络环境下的超大规模数据集进行了测试,结果表明,检测系统具有较高的准确率和计算效率.