浅析美国标准环境下电缆选型设计

介绍了美国电气设计标准中的AWG导线规格、电缆材料和截面积的选择以及UL电线电缆标志,结合常规电缆选型设计,整理分析了美国标准与中国标准电缆选型设计的异同,供同行业电气工程师在执行美标工程中参考。     

用锥形量热仪研究阻燃聚丙烯的燃烧行为

采用锥形量热仪比较了溴系阻燃聚丙烯、无卤阻燃聚丙烯的燃烧行为。结果表明:按UL94标准测试V-0阻燃等级的阻燃聚丙烯复合材料,采用无卤阻燃体系比采用溴系阻燃体系具有更低的热释放速率、烟生成速率和总烟释放量。     

浅谈408UL仪器回放因素的设置

本文通过对陆地地震数据记录实例的分析,给出了408UL在时间指数、归一化和自动增益控制三种回放方式下,如何选取合理的回放因素,从而使地震数据的回放能更加突出有效波、提高信噪比。同时,给出了回放因素取舍的理论依据。     

408UL仪器在复杂地表施工时的排列设置方法

408UL仪器先进的设计思想和灵活的应用软件为观测系统的设计带来了很大的方便；它先进的网络传输技术为野外的施工带来了极大的便利。本文讨论了408UL仪器在复杂地表地形施工中的排列设置方法。     

Complete and Prolonged Inhibition of Herpes Simplex Virus Type 1 Infection In Vitro by CRISPR/Cas9 and CRISPR/CasX Systems

Almost all people become infected with herpes viruses, including herpes simplex virus type 1 (HSV-1), during their lifetime. Typically, these viruses persist in a latent form that is resistant to all available antiviral medications. Under certain conditions, such as immunosuppression, the latent forms reactivate and cause disease. Moreover, strains of herpesviruses that are drug-resistant have rapidly emerged. Therefore, it is important to develop alternative methods capable of eradicating herpesvirus infections. One promising direction is the development of CRISPR/Cas systems for the therapy of herpesvirus infections. We aimed to design a CRISPR/Cas system for relatively effective long-term and safe control of HSV-1 infection. Here, we show that plasmids encoding the CRISPR/Cas9 system from Streptococcus pyogenes with a single sgRNA targeting the UL30 gene can completely suppress HSV-1 infection of the Vero cell line within 6 days and provide substantial protection within 9 days. For the first time, we show that CRISPR/CasX from Deltaproteobacteria with a single guide RNA against UL30 almost completely suppresses HSV-1 infection of the Vero cell line for 3 days and provides substantial protection for 6 days. We also found that the Cas9 protein without sgRNAs attenuates HSV-1 infection. Our results show that the developed CRISPR/Cas systems are promising therapeutic approaches to control HSV-1 infections.     

Influences of specimen size and heating mode on the ignitability of polymeric materials in typical small‐scale fire test conditions

Small‐scale fire tests including the Underwriters Laboratories 94 (UL94) vertical burning test and the cone calorimeter test are widely used. In this paper, the ignition times of materials heated by the conical heater of a cone calorimeter and the UL94 flame were measured. It was found that for polymer bars heated by the UL94 flame, the ignition time is relatively short and increases with the specimen thickness. But the contribution of the specimen thickness to the delay of the ignition time is limited. The intrinsic properties of materials play a more important role in the ignition time than the specimen thickness. In addition, respectively corresponding to one‐dimensional, two‐dimensional, and three‐dimensional heat transfer, three heating modes of the UL94 flame were presented and compared with the conical heater. It was found that whether the heat source is the conical heater or the UL94 flame, the ignition time depends on the heat flux and the multidimensional heat transfer. The ignition time decreases with the increasing heat flux, and the magnitude order of the ignition time might drop when the heating mode changes from one‐dimensional to multidimensional heat transfer. Copyright © 2011 John Wiley & Sons, Ltd.     

内置筛网预制式太阳能集热板集热效果试验研究

预制式太阳能集热板是一种新型具有渗透结构的集热板。试验通过有金属筛网和无金属筛网形式制作了2种预制式太阳能集热板,采用对比方法,对2种形式的集热板集热效率、热损失系数UL进行了测试。试验结果表明:2种集热板的热损失系数差异不大,采用有金属筛网渗透结构的集热板比无金属筛网结构的集热板综合集热效果更好。     

国内、外ATSE标准主要内容的对比与分析

本文介绍了国内、外ATSE标准的主要内容，对使用者全面、系统了解该类产品性能有一定的帮助，以利于用户合理选择与使用ATSE。     

异构网络解耦与耦合级联方案覆盖性能比较

针对异构网中上行链路(UL)和下行链路(DL)负载不平衡的问题,提出一种解耦UL/DL级联(DUDA)联合方案。通过双连接简化级联条件推导主、从UL接入距离的概率密度函数,利用随机几何工具推导DUDA UL覆盖概率的一般形式,从而得出整个网络的UL平均覆盖概率。数值仿真结果表明,与传统CUDA方案相比,DUDA联合方案的覆盖性能更优。