某型机载搜救设备总体性能综合调试仪的实现

根据某型机载搜救设备总体性能调试仪的性能要求,按照信号采集与控制、数据分析与处理、测试结果输出及显示的基本结构模型,基于PCI总线和GPIB总线的虚拟仪器技术构建机电一体化测试系统.并具体介绍和分析了有关的设计方案、硬件构成和软件设计.实际运行结果表明,搜救设备总调仪工作稳定可靠,可以简化仪器仪表,缩短测量时间,提高测试效率.     

基于田口正交法的小计量称重配料系统优化设计

针对小计量称重配料过程中人工配料效率低、精度低的问题,对小计量称重配料系统的电磁振动供电电压、落料口高度和出料口大小方面进行了研究,提出了一种自动称重配料系统。通过称重配料实验平台,得出了电磁振动供电电压、落料口高度和出料口大小3个参数的实验数据,利用田口正交实验对称重系统的这三个参数进行了望目特性分析,获得了影响称重精度的因子贡献率以及因子间的交互作用。研究结果表明,田口正交实验法在材料颗粒较均匀的条件下可以优化称重配料系统参数,提高了计量准确度,为小计量称重配料系统的设计提供了参考依据。     

一种扫描机构的结构设计

扫描机构广泛应用在光电探测设备中,是光电探测设备光机分系统中实现对空域搜索和对目标跟踪的重要部件.该部件在光机分系统中的作用主要是在伺服控制器的控制下,根据指令绕方位、俯仰两轴旋转,使瞄准线准确指向球形空域中的指定位置.文中主要介绍了一种扫描机构的结构组成和设计要点.     

溅射气压对直流磁控溅射ZnO:Al薄膜的影响(英文)

采用直流磁控溅射法在玻璃基片上沉积ZnO:Al(AZO)薄膜,溅射气压为0.2～2.2 Pa.通过X射线衍射(XRD)、扫描电子显微镜(SEM)、四探针和紫外–可见分光光度计对AZO薄膜的相结构、微观形貌和电光学性质进行了表征.结果表明:薄膜的沉积速率随着溅射气压的增大而减小,变化曲线符合Keller-Simmons模型;薄膜均为六角纤锌矿结构,但择优取向随着溅射气压发生改变;溅射气压对薄膜的表面形貌有显著影响;当溅射气压为1.4 Pa时,薄膜有最低的电阻率(8.4×104 Ω·cm),高的透过率和最高的品质因子Q.     

Application of Mono‐ and Disaccharides in Drug Targeting and Efficacy

Carbohydrates and their conjugates play important roles in many biological processes including fertilization, differentiation, development, immune response, and infection. Their activities are largely dependent on the properties of terminal mono‐ or disaccharides. Galactose, mannose, fucose, glucose, sialic acid, etc., are commonly used as powerful scaffolds installed on drug molecules for targeting specific tissues including brain, liver, and cancers, and as epitopes for enhancing the targeting of various vaccines. This review focuses on the influence of their structural variations, including changes in sugar type, substituent groups and their positions, as well as length of linker portion, on the targeting of drugs or their efficacy. Particular attention is paid to the targeting properties of mono‐ and disaccharides applied in drug design and discovery.     

A pH and Redox Dual Responsive 4-Arm Poly(ethylene glycol)-block-poly(disulfide histamine) Copolymer for Non-Viral Gene Transfection in Vitro and in Vivo

A novel 4-arm poly(ethylene glycol)-b-poly(disulfide histamine) copolymer was synthesized by Michael addition reaction of poly(ethylene glycol) (PEG) vinyl sulfone and amine-capped poly(disulfide histamine) oligomer, being denoted as 4-arm PEG-SSPHIS. This copolymer was able to condense DNA into nanoscale polyplexes (<200 nm in average diameter) with almost neutral surface charge (+(5–10) mV). Besides, these polyplexes were colloidal stable within 4 h in HEPES buffer saline at pH 7.4 (physiological environment), but rapidly dissociated to liberate DNA in the presence of 10 mM glutathione (intracellular reducing environment). The polyplexes also revealed pH-responsive surface charges which markedly increased with reducing pH values from 7.4–6.3 (tumor microenvironment). In vitro transfection experiments showed that polyplexes of 4-arm PEG-SSPHIS were capable of exerting enhanced transfection efficacy in MCF-7 and HepG2 cancer cells under acidic conditions (pH 6.3–7.0). Moreover, intravenous administration of the polyplexes to nude mice bearing HepG2-tumor yielded high transgene expression largely in tumor rather other normal organs. Importantly, this copolymer and its polyplexes had low cytotoxicity against the cells in vitro and caused no death of the mice. The results of this study indicate that 4-arm PEG-SSPHIS has high potential as a dual responsive gene delivery vector for cancer gene therapy.     

A Time to Kill: Targeting Apoptosis in Cancer

The process of apoptosis is essential for maintaining the physiologic balance between cell death and cell growth. This complex process is executed by two major pathways that participate in activating an executioner mechanism leading to chromatin disintegration and nuclear fragmentation. Dysregulation of these pathways often contributes to cancer development and resistance to cancer therapy. Here, we review the most recent discoveries in apoptosis regulation and possible mechanisms for resensitizing tumor cells to therapy.     

中韩石化武汉乙烯蒸汽管道吹扫分析

介绍我厂蒸汽管网概况,并对蒸汽吹扫原理和参数测算进行分析,制定吹扫方案。介绍我厂蒸汽管线吹扫的流程和吹扫中的问题和原因分析及解决措施。通过总结分析,加深对蒸汽吹扫理论和实际操作方法的认识,对于同类蒸汽管线吹扫具有参考意义。