集成压电元件的挠性太阳帆板振动抑制控制系统

针对基频低于1Hz的大挠性太阳帆板,提出了整板主动振动抑制方法。该方法通过在太阳帆板上集成压电元件作为传感器和执行器;针对帆板挠性增大时,同位控制易出现虚假抑制的现象,综合考虑压电传感器的测量数据和板上一点的振动情况,基于正向位置反馈控制律(Positive Position Feedback,PPF),设计了整板振动抑制控制系统。通过Adams和Simulink联合仿真,对控制系统的振动抑制能力进行了考核,结果表明所设计的PPF控制系统避免了虚假抑制,具有良好的整板振动抑制效果。

快堆主容器内液钠晃动抑制方法的研究

在反应堆主容器中的冷却剂属于带有自由液面的不可压缩流体,液面下的冷却剂的流动可能诱发液面的晃动,此外地震力也可能引起液面的晃动,该流动不稳定性可能影响到核反应堆安全运行。通过计算分析预示这些冷却剂不稳定流动的后果,同时将结果反馈到设计中,增加必要的安全设施,将对快堆的安全设计有重要的参考价值。采用粒子法(移动粒子半隐式),对地震引起的晃动和流动引起的晃动,设计了不同尺寸、位置的晃动抑制板,分别模拟了各个环板对晃动的抑制作用,并与无环板的情况进行了比较,通过观察和数据结果分析找到了抑制快堆液钠晃动的较为有效的尺寸和位置,为进一步深入精确的研究提供了参考。

前置超快冷UFCT值在冬季环境下的控制优化

山东某钢厂2150 mm热轧产线在冬季环境下生产时,受室内与轧线冷却水温差大的影响,出口水汽大,异常UFCT值数据频繁出现,影响层冷模型自学习的稳定性。针对该情况,结合现场经验,提出解决方案:采取抑制水汽源水汽扩散和加速逸散水汽吹扫的办法,在超快冷出口高温计位置增设水汽抑制板和风机进行综合优化改善。检验效果表明,在超快冷闭环投入的情况下,实现了冬季中间温度UFCT值的稳定采集。

电务LKJ车载设备功能整合优化的探讨

介绍了CTCS-0级中国铁路列车运行控制系统在使用中出现的电路板烧损、带电拔插插件板、LKJ数据换装、过机功能优化、录音功能优化、远程数据追踪下载等问题,从技术、管理的角度上进行分析、探讨并提出改进建议,给CTCS-0级中国铁路列车运行控制系统的管理和技术进步提供参考和借鉴。

计及环境-电气-机械多参量的配网设备状态评价

针对配网关键设备的状态检修,本文提出一种计及多参量的配电网关键设备状态评价方法。综合考虑设备多时段运行信息以及环境、机械等参量对设备状态的影响,给出了一种计及环境-电气-机械多参量的配电网关键设备状态评价二次修正指标体系,并采用基于"短板效应"抑制的改进型的层次分析法确定各权重,最后基于模糊理论对配电网设备进行状态评价。实例检验结果验证了所提评价方法的合理性和有效性。

Distribution of secretory inhibitor of platelet microbicidal protein among anaerobic bacteria isolated from stool of children with diarrhea

AIM： To study the secretory inhibitor of platelet microbicidal protein （SIPMP） phenotypes of faecal anaerobic isolates from patients with diarrhea.METHODS： Faecal isolates of anaerobic bacteria （B. fragilis, n = 42; B. longum, n = 70; A. israelii, n = 21; E. lentum, n = 12） from children with diarrhea were tested. SIPMP production was tested by inhibition of platelet microbicidal protein （PMP） bioactivity against B. subtilis and was expressed as percentage of inhibition of PMP bactericidal activity.RESULTS： Among anaerobic isolates 80% of B. longum strains, 85.7% of A. israeli/strains, 50% of E. lentum strains and 92.86% of B. fragilis strains were SIPMP-positive. The isolated anaerobic organisms demonstrated SIPMP production at a mean level of 13.8% ± 0.7%, 14.7% ± 1.8%, 3.9% ± 0.9% （P 〈 0.05） and 26.8% ± 7.5% （P 〈 0.05） for bifidobacteria, A. israelii, E. lentum and B. fragilis, respectively.CONCLUSION： Data from the present study may have significant implications in understanding the pathogenesis of microecological disorders in the intestine, as well as for future improvement in the prevention and therapy of anaerobe-associated infections.

Antiviral activities against influenza virus(FM1) of bioactive fractions and representative compounds extracted from Banlangen(Radix Isatidis)

OBJECTIVE: To study the antiviral activities of clemastanin B(CB), epigoitrin, phenylpropanoids portion(PEP) and the mixture of phenylpropanoids, alkaloids and organic acid fractions(PEP+ALK+OA)from Banlangen(Radix Isatidis).METHODS: The experiment consisted of four parts:therapeutic action, prophylaxsis action, inhibition of virus attachment, and direct virucidal action. Cytopathic effect(CPE) and 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium(MTT) were used to assess antiviral activity.RESULTS: CB, epigoitrin, PEP and PEP + ALK + OA fractions from Banlangen(Radix Isatidis) extract significantly increased the viability of MDCK cells pre-infected with the virus compared with the virus control group in all the dilutions(P < 0.01). Pretreated with either pure compounds or chemical frac-tions of Banlangen(Radix Isatidis) extract in all the dilutions significantly improved the viability of MDCK cells(P < 0.01). The inhibition of virus absorption to the host cells by CB, epigoitrin and PEP was in a dose dependent manner.CONCLUSION: CB, epigoitrin, PEP and PEP+ALK+OA exert their anti-influenza activity by inhibiting the virus multiplication, prophylaxsis and blocking the virus attachment. The primary mode of action of PEP and PEP + ALK + OA is the inhibition of virus replication. The inhibitory effects on virus attachment and multiplication are the main modes for epigoitrin.

Receptor-mediated inhibitory mechanisms and the regulation of platelet function

Platelets are derived from megakaryocytes;they circulate in mammalian blood vessels and play essential roles in hemostasis and thrombosis.When platelets encounter injury,they respond by triggering the formation of a blood clot to prevent blood loss(hemostasis).While this is vital for survival,

Slat Noise Suppression Using Upstream Mass Injection

A new approach,mass injection near the slat cusp,is proposed for the suppression of slat noise.The mechanism and efciency of the slat noise suppression using upstream mass injection are numerically studied with hybrid Reynolds-averaged Navier-Stokes simulation/Large eddy simulation(RANS/LES)of a three-component high-lift model.Ffowcs-Williams and Hawking(FW-H)integration is employed to obtain far-field acoustic characteristics.Results show that with injection,aerodynamic capability of the high-lift devices is sustained.In addition,a considerable noise reduction is observed in the downward direction.With detailed analysis of the time-averaged and instantaneous flow fields,two mechanisms are identified as the reason accounting for the noise suppression:upstream mass injection significantly reduces the scale and strength of the vortices stemming from the cusp;the shear layer is lifted up,which relieves the shear layer impingement on the slat lower surface.