不同软化曲线形状对裂缝扩展阻力G_R曲线的影响

最近基于裂缝粘聚力提出了描述裂缝扩展全过程阻力变化的GR曲线,所发展的解析解相关于骨料桥联咬合作用造成的非线性断裂过程区的能量耗散,故与该区域材料使用的拉伸软化本构关系即应力-裂缝张开口位移软化曲线有密切联系。鉴于此,该文采用4种不同的软化曲线研究了软化曲线形状对裂缝扩展阻力GR的影响。结果发现,GR曲线对软化曲线敏感,GR曲线的合理性依赖于软化曲线的准确性。在使用准确软化曲线的前提下,GR曲线的特征点与软化曲线的特征点存在相对应关系。     

Rapid Screening of Glucocorticoid Receptor (GR) Effectors Using Cortisol-Detecting Sensor Cells

Cortisol, a stress hormone, plays key roles in mediating stress and anti-inflammatory responses. As abnormal cortisol levels can induce various adverse effects, screening cortisol and cortisol analogues is important for monitoring stress levels and for identifying drug candidates. A novel cell-based sensing system was adopted for rapid screening of cortisol and its functional analogues under complex cellular regulation. We used glucocorticoid receptor (GR) fused to a split intein which reconstituted with the counterpart to trigger conditional protein splicing (CPS) in the presence of targets. CPS generates functional signal peptides which promptly translocate the fluorescent cargo. The sensor cells exhibited exceptional performance in discriminating between the functional and structural analogues of cortisol with improved sensitivity. Essential oil extracts with stress relief activity were screened using the sensor cells to identify GR effectors. The sensor cells responded to peppermint oil, and L-limonene and L-menthol were identified as potential GR effectors from the major components of peppermint oil. Further analysis indicated L-limonene as a selective GR agonist (SEGRA) which is a potential anti-inflammatory agent as it attenuates proinflammatory responses without causing notable adverse effects of GR agonists.     

石墨烯/聚苯胺纳米复合材料的制备及防腐应用研究进展

导电聚苯胺(PANI)具有易合成、易掺杂等特点,石墨烯(GR)及石墨烯衍生材料具有较高的比表面积、良好的导电性、优异的防液体渗漏等物理和化学性质。两者的复合材料表现出优异的机械、电化学、防腐蚀等性能,引起了广泛的关注。介绍了石墨烯/聚苯胺纳米复合材料的制备方法、影响石墨烯/聚苯胺性能的主要因素以及石墨烯/聚苯胺纳米复合材料在防腐中的应用。系统总结了石墨烯/聚苯胺的防腐机理以及在不同基体涂料中的防腐改性,石墨烯的存在增加了腐蚀介质(如H2O和O2)渗透路径的曲折程度,减缓了金属腐蚀速度,从而提高涂料防腐效率。石墨烯/聚苯胺复合材料在防腐方面具有广阔的应用前景,对石墨烯/聚苯胺的复合状态、防腐机理、环境适应性的深入研究是未来该材料的发展方向。     

Probabilistic synthesis against GR(1) winning condition

Reactive synthesis is a technique for automatic generation of a reactive system from a high level specification. The system is reactive in the sense that it reacts to the inputs from the environment. The specification is in general given as a linear temporal logic (LTL) formula. The behaviour of the system interacting with the environment can be represented as a game in which the system plays against the environment. Thus, a problem of reactive synthesis is commonly treated as solving such a game with the specification as the winning condition. Reactive synthesis has been thoroughly investigated for more two decades. A well-known challenge is to deal with the complex uncertainty of the environment. We understand that a major issue is due to the lack of a sufficient treatment of probabilistic properties in the traditional models. For example, a two-player game defined by a standard Kriple structure does not consider probabilistic transitions in reaction to the uncertain physical environment; and a Markov Decision Process (MDP) in general does not explicitly separate the system from its environment and it does not describe the interaction between system and the environment. In this paper, we propose a new and more general model which combines the two-player game and the MDP. Furthermore, we study probabilistic reactive synthesis for the games of General Reactivity of Rank 1 (i.e., GR(1)) defined in this model. More specifically, we present an algorithm, which for given model M, a location s and a GR(1) specification P, determines the strategy for each player how to maximize/minimize the probabilities of the satisfaction of P at location s. We use an example to describe the model of probabilistic games and demonstrate our algorithm.     

基于LP&GR算法的多优先级虚拟机迁移策略研究*

如何对云计算中心的虚拟机(Virtual machine,VM)资源进行合理分配是近年来研究的一个热点问题。针对这一问题,本文提出了一种基于负载预测和灰色关联度(Load Prediction and Gray Relational,LP&GR)的虚拟机资源分配算法,通过预测虚拟机的负载状态防止虚拟机发生过载,并建立了基于虚拟机负载评价函数的决策分配模型。同时为虚拟机的迁移队列设置了多个优先级,结合了抢占式与非抢占式的执行策略,保证了虚拟机的有序迁移,并提高资源利用率。实验结果表明,结合多优先级的LP&GR算法同比其他算法能够有效实现云中心的负载均衡。     

纤维素水凝胶包覆Fe_3O_4类Fenton纳米催化剂的制备及其催化降解性能

采用纤维素水凝胶包覆Fe_3O_4颗粒,制备得到核壳结构的羧甲基纤维素聚丙烯包覆Fe_3O_4类Fenton纳米催化剂(CMC-co-AA/Fe_3O_4),并应用于降解偶氮染料酸性大红GR。考察了体系pH值、催化剂用量、染料初始浓度等参数对降解效果的影响。SEM和FT-IR分析结果表明水凝胶成功地包覆在Fe_3O_4颗粒表面,且壳层厚度为20~30nm。XRD分析显示,包覆层不影响纳米Fe_3O_4的晶型结构,纳米催化剂在使用过程中仍保持Fe_3O_4磁响应性能,能够有效地分离回收。相比传统的Fe_3O_4纳米催化剂,包覆型CMC-co-AA/Fe_3O_4纳米催化剂水溶液显示出了较好的均一分散性。且当pH3直至中性条件下,此时传统未包覆的Fe_3O_4纳米催化剂对酸性大红GR的降解率为0,而CMC-co-AA/Fe_3O_4纳米催化剂的降解率仍能维持36%,说明了水凝胶壳层结构赋予CMC-co-AA/Fe_3O_4纳米催化剂较宽的pH适用范围。重复试验表明,该纳米催化剂在循环使用四次后,对染料的降解率仍能保持98%左右。     

基于ZigBee-GPRS技术的无线传感网络

结合ZigBee和GPRS技术,提出了一种基于二者优势互补的无线传感网络系统实现方案。该方案综合ZigBee技术在短距离、低功耗无线通信和GPRS网络远程数据传输的优势,利用具有ZigBee收发功能的芯片MC13192设计多种类型传感器节点、具有GPRS通信功能的芯片GR47设计ZigBee-GPRS网关,实现了多种参数的实时与远程监控。其技术具有广阔的应用前景。     

Bacterial desulphurization of low-rank coal: A case study of Eocene Lignite of Western Rajasthan,India

High sulfur lignite samples collected from Giral mine was subjected to desulfurization using bacteria Burkholderia sp. GR 8–02 isolated from native lignite. A removal of 50.69% of total Sulfur (S_t) has been observed. The reduction in hydrogen and ash content was found up to 2.92% and 14.78%, respectively. In addition, relative carbon (up to 12.81%) and nitrogen (up to 34.52%) has also been increased. An increase in the relative concentration of volatile matter and fixed carbon (up to 19.47% & 3.29%) has been detected. In addition, the desulfurization of high sulfur lignite with Burkholderia sp. GR 8–02 increased the calorific value from 5.24% to 20.74%.     

AP Collagen Peptides Prevent Cortisol-Induced Decrease of Collagen Type I in Human Dermal Fibroblasts

Cortisol is an endogenous glucocorticoid (GC) and primary stress hormone that regulates a wide range of stress responses in humans. The adverse effects of cortisol on the skin have been extensively documented but the underlying mechanism of cortisol-induced signaling is still unclear. In the present study, we investigate the effect of cortisol on collagen type I expression and the effect of AP collagen peptides, collagen tripeptide-rich hydrolysates containing 3% glycine-proline- hydroxyproline (Gly-Pro-Hyp, GPH) from the fish skin, on the cortisol-mediated inhibition of collagen type I and the cortisol-induced signaling that regulates collagen type I production in human dermal fibroblasts (HDFs). We determine that cortisol downregulates the expression of collagen type I. AP collagen peptides or GC receptor (GR) inhibitors recover the cortisol-mediated inhibition of collagen type I and GR activation. AP collagen peptides or GR inhibitors also prevent the cortisol-dependent inhibition of transforming growth factor (TGF)-β signaling. AP collagen peptides or GR inhibitors are effective in the prevention of collagen type I inhibition mediated by cortisol in senescent HDFs and reconstituted human skin models. Taken together, GR signaling might be responsible for the cortisol-mediated inhibition of TGF-β. AP collagen peptides act as GR-mediated signaling blockers, preventing the cortisol-dependent inhibition of collagen type I. Therefore, AP collagen peptides have the potential to improve skin health.     

基于GPRS的远程电能计量系统设计

通过把移动通信中的GPRS网络应用于传统的工控系统，提出了一种基于GPRS的远程电能计量系统。介绍了系统的硬件组成、工作原理和各组成模块的设计。该系统充分利用移动通信技术，具有高可布性、高数据传愉率等优点。