Small angle X-ray scattering station operational

The Small Angle X-ray Scattering (SAXS) Station with the Beijing Synchrotron Radiation Facility (BSRF) was put into operation at the CAS Institute of High Energy Physics in July, 2007.     

小型航空修理厂维修管理信息系统设计

文章结合某航空修理厂的飞机维修过程,运用UML统一建模语言进行系统分析,系统采用C/S结构,以Powerbuilder作为前台开发工具,以Oracle作为后台数据库管理系统,设计了符合该厂实际的飞机维修管理信息系统,使得飞机维修的信息化管理得以实现,规范了维修生产,提高了管理效率。     

聚丙烯三相结构长周期的小角X射线散射研究

应用小角X射线散射技术研究了聚丙烯的长周期 ,结果表明 ,聚丙烯的相关函数长周期与它的Bragg长周期不相等 ;应用小角散射理论和结晶聚合物的三相结构模型研究了聚丙烯的 2种长周期不同的原因 ,得到结论 ,聚丙烯的Bragg长周期接近于它的相关函数长周期与结晶过渡层的厚度之和 .这个结论与小角散射实验的结果一致 .     

The filament forming reactions of vimentin tetramers studied in a serial-inlet microflow device by small angle x-ray scattering

The structural organization of metazoan cells and their shape are established through the coordinated interaction of a composite network consisting of three individual filament systems, collectively termed the cytoskeleton. Specifically, microtubules and actin filaments, which assemble from monomeric globular proteins, provide polar structures that serve motor proteins as tracks. In contrast, intermediate filaments (IFs) assemble from highly charged, extended coiled coils in a hierarchical assembly mechanism of lateral and longitudinal interaction steps into non-polar structures. IF proteins are expressed in a distinctly tissue-specific way and thereby serve to generate the precise plasticity of the respective cells and tissues. Accordingly, in the cell, numerous parameters such as pH and salt concentration are adjusted such that the generation of functional networks is ensured. Here, we transfer the problem for the mesenchymal IF protein vimentin to an in vitro setting and combine small angle x-ray scattering with microfluidics and finite element method simulations. Our approach is adapted to resolve the early assembly steps, which take place in the sub-second to second range. In particular, we reveal the influence of ion species and concentrations on the assembly. By tuning the flow rates and thus concentration profiles, we find a minimal critical salt concentration for the initiation of the assembly. Furthermore, our analysis of the surface sensitive Porod regime in the x-ray data reveals that the formation of first assembly intermediates, so-called unit length filaments, is not a one-step reaction but consists of distinct consecutive lateral association steps followed by radial compaction as well as smoothening of the surface of the full-width filament.     

A microfluidic cell for studying the formation of regenerated silk by synchrotron radiation small- and wide-angle X-ray scattering

A tube-in-square-pipe microfluidic glass cell has been developed for studying the aggregation and fiber formation from regenerated silk solution by in-situ small-angle X-ray scattering using synchrotron radiation. Acidification-induced aggregation has been observed close to the mixing point of the fibroin and buffer solution. The fibrous, amorphous material is collected in a water bath. Micro-wide-angle X-ray scattering of the dried material confirms its β-sheet nature.     

应用倾角传感器实现对提升机天轮偏摆的检测

本作品拟采用倾角传感器设计提升机天轮偏摆检测装置,旨在利用先进的电工电子技术实现对系统进行改造升级,为矿井生产保障安全。所用的倾角传感器成本低廉、耗能极低,配以电池可以长期工作,将其粘于天轮上,可实时获得偏摆量,并不断地把数据传回地面,在发生危险时再利用报警电路使人员可以及时作出反应,断开电源,排除故障。     

An operational,policy-oriented research categorization scheme

The currently used Basic-Applied research classification schemes and the criteria used to define them: (a) do not really identify different types of research activity but rather motivation of performers and sponsors or the expected generality of results; (b) generate relatively ambiguous statistical data and (c) generate great difficulties among those who have to produce or collect the information. It is suggested that this particular mode of research classification is not optimally responsive to the needs of policy makers, who are primarily interested in the utility of results, and that this utility is related to different operational types of research. A substitute broad research activity taxonomy is proposed based on a single criterion - degree of external intellectual constraints. On this basis, a simplified operational mode of statistical data collection is proposed. It is illustrated how science policy formulation, especially in the areas of resource allocation and organization, would be facilitated by use of these more suitable concepts and the resulting improved quantitative information.     

平山水文站使用水电站过水流量整编方法初探

受下游西枝江水利枢纽蓄水发电影响,平山水文站水流运动场变得复杂,流量测验与整编工作遇到挑战。文章结合实际工作情况,以水电站发电功率及实际水头计算流量,通过编制多个VBA程序进行计算,生成广东省水文系统水文资料整编程序的专用原始运算文件(Z0G文件),运行"水文资料整编程序"即可输出整编成果表。     

案例研究的方法论

我国管理科学与教学研究中案例研究的数量约两年翻一番，但案例研究的质蜈有待提高。案例研究的质量有赖于研究者对案例研究理论基础和操作技术的掌握。本文系统地探讨了案例研究的方法论，并选取国人外有代表性的案例研究论文做了点评。     

JDBC技术的工作原理与实现

本文叙述了Java数据库连接(JDBC)技术的基本原理及数据库访问技术的实现，较完整地介绍了基于B／C模式下网络系统开发中应用JDBC技术访问后台数据库的一般步骤和方法。     

Frequency limitations of active-R filters using operational amplifiers

Active-R filters are designed using internally compensated operational amplifiers (OA) and resistors only. A one-pole or 6 dB roll off model for the PA's is assumed in these designs. This model is adequate for active-RC filters. However, for active-R filters such an assumption leads to serious accuracy as well as stability problems, thereby limiting the highest operating frequency of these filters to well below their potential maximum. It is shown in this article that a two-pole or 12 dB roll off model more accurately reflects the behaviour of the OA's for the above active-R realizations. A quantitative measure of the limitation imposed by this model on such realizations is also presented. Extensive computer simulation and experimental tests have been carried out that verify closely the theoretical predictions.     

A network application model with operational process feature

A network application serves as the response process to the user request. The network application, taking the traffic as operation carrier, is closely related with process features. The existing investigations mainly focus on the traffic generation by capturing request feature, which is insufficient to characterize the application operation with specific processes. Thus, this paper presents a network application model with operational process feature, where the operation process is introduced in network applications in addition to characterizing traffic element from request feature. And the process feature is represented by the random, customized and routine processes, while request feature is described by the heavy-tailed ON/OFF source. Our analysis and simulation show that the traffic of our model admits the ubiquitous statistical laws: the self-similarity and the mean-variance relationship, which further validate our model. Moreover, compared with the traffic generation model without considering complex process features, where traffic distribution is found being positively correlated with node betweenness centrality (BC), the traffic of our model is both positively related with node BC, and much higher on nodes in the specific processes. The proposed model is thus beneficial for traffic control and network enhancement with complex process features.