Depth of focus estimation based on exposure dose distribution

A defocusing exposure dose distribution model is established with the integral effect of light intensity on time taken into account for laser direct writing on a thin photoresist with total reflection substrate. Exposure dose distribution curves are established using the established model for different photoresist depths. A side slope angle is established for each defocusing amount in accordance with the exposure dose distribution curves, and so depth of focus can be estimated by simply checking to see if the maximum side slope angle with the horizontal is in the range of 80-100°. Simulation results indicate that when laser direct writing is done on a thin photoresist with total reflection substrate using a laser with wavelength equal to 442 nm and a lens with numerical aperture equal to 0.5, the depth of focus estimated using the proposed method is 1 μm, which is just 1/3 of the depth of focus estimated using the method based on intensity distribution. It is therefore concluded that it is the integral effect of light intensity on time that causes the depth of focus estimation error, and the proposed method can be used to achieve a more accurate depth of focus estimation compared to the intensity distribution based method.     

1.0 MeV电子辐照致VO_2(B)薄膜结构与光谱改变研究

本文以能量为1.0 MeV的电子束辐照VO2(B)薄膜,对电子辐照在薄膜中产生的缺陷进行了理论计算,同时使用X射线衍射仪、原子力显微镜、分光光度计对薄膜进行测试,分析了电子辐照对薄膜结构、形貌与紫外-可见光谱(280~880nm)的影响。结果显示:电子辐照可以在薄膜中引入点缺陷并产生退火效应,电子辐照使薄膜的表面晶粒细化,辐照后薄膜光谱的吸收峰位发生移动,其移动的最大位移达到21nm,辐照后薄膜的光学禁带宽度也有所增加。     

绝缘体上硅金属氧化物半导体场效应晶体管中辐射导致的寄生效应研究

基于⁶⁰Co γ射线源研究了总剂量辐射对绝缘体上硅（silicon on insulator,SOI）金属氧化物半导体场效应晶体管器件的影响.通过对比不同尺寸器件的辐射响应,分析了导致辐照后器件性能退化的不同机制.实验表明：器件的性能退化来源于辐射增强的寄生效应;浅沟槽隔离（shallow trench isolation,STI）寄生晶体管的开启导致了关态漏电流随总剂量呈指数增加,直到达到饱和;STI氧化层的陷阱电荷共享导致了窄沟道器件的阈值电压漂移,而短沟道器件的阈值电压漂移则来自于背栅阈值耦合;在同一工艺下,尺寸较小的器件对总剂量效应更敏感.探讨了背栅和体区加负偏压对总剂量效应的影响,SOI器件背栅或体区的负偏压可以在一定程度上抑制辐射增强的寄生效应,从而改善辐照后器件的电学特性.     

反熔丝FPGA延时电路γ瞬时辐射效应

 简要叙述了反熔丝FPGA的基本结构,介绍了一种FPGA延时电路的工作原理以及利用该电路在“强光一号”脉冲加速器上进行γ瞬时辐照试验的方法,给出了试验测量结果。分析表明：高剂量率γ瞬时电离辐射会破坏FPGA延时电路一个信号周期的工作状态,因此存在功能失效的可能性。但就整体而论,反熔丝FPGA抗瞬时辐射的性能要优于其它许多大规模CMOS集成电路。     

PZT铁电材料的总剂量辐照效应实验研究

 采用传统固相反应法制备PZT铁电材料,并制作成平行平板无源电容器结构,在ELV-8电子直线加速器上进行了总剂量效应辐照实验。结果表明：样片经过不同强度高能高速直流电子束辐照后的电滞回线随着辐照强度的增加,电滞回线所包围的面积逐渐减小,饱和极化强度、剩余极化强度和矫顽场呈线性减小。其中当辐照剂量为1×10⁸rad（Si）时,饱和极化强度、剩余极化强度和矫顽场的衰减幅度分别为14.1%,15.0%和2.7%,样片抗总剂量辐照能力可达1×10⁸rad（Si）。     

Polyphenolic characterization and evaluation of multimode antioxidant,cytotoxic, biocompatibility and antimicrobial potential of selected ethno-medicinal plant extracts

IntroductionScientific evidence about biological profile of natural products can support their traditional uses. The current work was aimed to assess phytochemical and biological profile of nine medicinal plants collected from Herbalists.MethodsExtracts prepared in different solvents were subjected to phytochemical, antioxidant, enzyme inhibitory, cytotoxic, and antimicrobial activities. Reverse phase-high performance liquid chromatography (RP-HPLC) analysis was performed for the quantification of polyphenols.ResultsResults showed methanol extract (M) being potent as compared to others. Gentian lutea M showed maximum extract recovery (15.00 ± 0.11 % w/w) and TFC (30.82 ± 0.21 μg QE/mg extract). Nigella sativa M displayed highest TPC (44.99 ± 0.43 μg GAE/mg extract) and TAC (334.72 ± 0.35 μg AAE/ mg extract). Results showed noteworthy quantities of vanillic acid, rutin, kaempferol, emodin in ethyl acetate (EA) and methanol (M) extracts of plants assessed by RP-HPLC. Gentisic acid was highest (11.75 µg/mg extract) in T. arjuna M extract. Similarly, maximum %FRSA (82.28 ± 0.03 %) and TRP (160.40 ± 0.38 μg AAE/ mg extract) were depicted by Terminalia chebula and Chamomilla recutita, respectively. Moreover, Mentha longifolia and G. lutea M demonstrated noteworthy (p < 0.05) antibacterial activity against Staphylococcus aureus (14 ± 0.7 mm) and Klebsiella pneumoniae (12 ± 0.3 mm), respectively. Curcuma amada, C. recutita, Murraya koenigii and G. lutea M had significant α-glucosidase activity. Another good solvent for extraction was ethyl acetate (EA), whose extracts were secondary to methanol in producing significant biological profile. For example, EA of N. sativa (TPC: 1.46 ± 0.45 µg GAE/ mg extract), G. lutea (TRP: 160.33 ± 0.52 μg AAE/mg extract: ZOI of 12 ± 0.5 mm in K. pneumoniae) and Mormodica charantia (α-amylase inhibition: 39.5 ± 0.10 %) showed significant bioactivities. All extracts displayed mild antifungal protein kinase inhibition activities and were significantly (greater than80 %: p < 0.05) cytotoxic to brine shrimps with negligible hemolytic activity.ConclusionBriefly, variable polarity solvent extracts of studied plants will be processed for isolation of antioxidant, cytotoxic, carbohydrate enzyme inhibitory and antibacterial compounds.     

Synthesis,pharmacological evaluation,and molecular modeling studies of novel isatin hybrids as potential anticancer agents

A novel series of isatin hybrids 5a-g was designed, synthesized, and characterized spectroscopically. The synthesized compounds were evaluated for their cytotoxic activity against the human breast cancer cell line (MCF-7) by in vitro MTT assay. Amongst the tested compounds, 5e compound bearing benzyl moiety at N₄ piperazine was found to be the most active with the promising IC₅₀ (12.47 µM). Moreover, the active compounds 5e and 5g were subjected to antitumor evaluation (in vivo) against Dalton’s ascitic lymphoma (DAL) cell line and the results suggested that the best active compound 5e can normalize the blood picture in comparison to the standard drug. An in silico molecular docking study using the crystal structure of Hsp90 protein described the role of significant protein–ligand interactions and revealed more insights into the binding mode. The drug-likeliness of the compounds was predicted based on Lipinski's rule of five and pharmacokinetic ADME parameters. Hence, the synthesized isatin hybrids could be novel starting point anticancer lead compounds demonstrating drug-like properties which can be explored further for anticancer drug discovery.