基于数字兆欧表自动切换档位的研究与实现

随着电力、电气设备的日益复杂化,对于其安全性能也有了更高的要求,数字兆欧表作为测量绝缘阻值的重要工具,已在工业领域中广泛应用;为了满足测量精度以及兆欧表的可靠性,通过基于S3C2440的嵌入式平台,提出了一种基于数字兆欧表的自动切换档位的实现方案,以达到更加精确的测量;此方案通过判断采集到的电压值选择相应的采样电阻来实现,并结合硬件平台和软件设计,分别介绍了驱动程序和应用程序的编写与测试,并很好地应用到了实际电路中;经测试,能够达到预期的效果,测量精度高,测量误差控制在±2%。     

核电厂隔震结构附加侧向阻尼系统分析模型及减震效果

提出对半埋置/全埋置小堆三维隔震结构附加侧向黏滞阻尼的混合控制系统,达到同时控制水平加速度、水平位移以及摇摆反应且不影响竖向隔震效果的目的。基于隔震层及侧向阻尼系统变形分析,建立考虑隔震层平动及摇摆的耦合效应和侧向阻尼器协调转动变形的刚体动力学模型。基于RG1.60谱选取30条地震输入信号开展参数分析,探究阻尼布置参数、附加阻尼力参数及阻尼滞回形状参数对减震效应的影响。研究发现合理的附加阻尼力与隔震层出力比值区间为10%～20%,最优参数下水平加速度位移可同时分别减小20%,40%,最大摇摆反应减小70%。选取合理阻尼参数对某真实核电厂模型进行案例分析,摇摆角、加速度、隔震层位移等地震响应指标均减小,边支座受拉现象消失,案例数值模拟结果与参数分析规律一致,也与理论分析吻合。     

Peptidyl Virus-Like Nanovesicles as Reconfigurable “Trojan Horse” for Targeted siRNA Delivery and Synergistic Inhibition of Cancer Cells

The self-assembly of peptidyl virus-like nanovesicles (pVLNs) composed of highly ordered peptide bilayer membranes that encapsulate the small interfering RNA (siRNA) is reported. The targeting and enzyme-responsive sequences on the bilayer's surface allow the pVLNs to enter cancer cells with high efficiency and control the release of genetic drugs in response to the subcellular environment. By transforming its structure in response to the highly expressed enzyme matrix metalloproteinase 7 (MMP-7) in cancer cells, it helps the siRNA escape from the lysosomes, resulting in a final silencing efficiency of 92%. Moreover, the pVLNs can serve as reconfigurable “Trojan horse” by transforming into membranes triggered by the MMP-7 and disrupting the cytoplasmic structure, thereby achieving synergistic anticancer effects and 96% cancer cell mortality with little damage to normal cells. The pVLNs benefit from their biocompatibility, targeting, and enzyme responsiveness, making them a promising platform for gene therapy and anticancer therapy.     

Acute vasoconstriction after subarachnoid hemorrhage

OBJECTIVE: Decreased cerebral blood flow (CBF) and cerebral ischemia occurring immediately after subarachnoid hemorrhage (SAH) may be caused by acute microvascular constriction. However, CBF can also be influenced by changes in intracranial pressure (ICP) and cerebral perfusion pressure (CPP). The goal of these experiments was to assess the significance of acute vasoconstriction after SAH and its relationship to changes in CBF, ICP, CPP, and extracellular glutamate concentrations. METHODS: Three experiments were performed using the endovascular filament technique to produce SAH. In the first experiment, CBF, ICP, and CPP were measured for 60 minutes after SAH (n = 21) and were correlated with the 24-hour mortality rate. In the second experiment, rats undergoing SAH (n = 23) or a sham procedure (n = 7) were perfused 60 minutes after SAH for measurement of the circumference and wall thickness of the internal carotid and anterior cerebral arteries and correlation with CBF, ICP, and CPP. In the third experiment (n = 11), extracellular glutamate concentrations determined by hippocampal and cortical microdialysis and high performance liquid chromatography were correlated with physiological changes. RESULTS: CBF reductions to less than 40% of baseline for 60 minutes after SAH predicted 24-hour mortality with 100% accuracy and were used to define "lethal" SAH. In contrast, ICP and CPP 60 minutes after SAH were not correlated with the mortality rate. The vascular circumference was significantly smaller in lethal than in sublethal SAH or sham-operated rats (P < 0.001). Vessel measurements were correlated with both CBF and hemorrhage size (P < 0.01). Extracellular glutamate concentration increased to 600% of baseline after lethal SAH in both hippocampus and cortex and was inversely correlated with CBF (r = 0.9, P < 0.001) but did not increase after sublethal SAH. CONCLUSION: Acute vasoconstriction after SAH occurs independently of changes in ICP and CPP and is associated with decreased CBF, larger hemorrhage size, persistent elevations of extracellular glutamate, and poor outcome. Acute vasoconstriction seems to contribute directly to ischemic brain injury after SAH. Further evaluations of pharmacological agents with the potential to reverse acute vasoconstriction may increase CBF and improve outcome.     

Escherichia coli prlC gene encodes a trypsin-like proteinase regulating the cell cycle

BACKGROUND AND PURPOSE: Mood disorders are common after stroke and may impede physical, functional, and cognitive recovery, making early identification and treatment of potential importance. We aimed to compare the accuracy of the General Health Questionnaire (GHQ-30) and the Hospital Anxiety and Depression (HAD) Scale in detecting psychiatric morbidity after stroke and to determine the most suitable cutoff points for different purposes. METHODS: One hundred five hospital-referred stroke patients completed both the GHQ-30 and HAD Scale 6 months after onset before a blinded psychiatric assessment in which the Schedule for Affective Disorders and Schizophrenia with some supplementary questions was used to determine a DSM-IV (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition) diagnosis. Measures were compared in terms of sensitivity, specificity, and receiver operating characteristic curves. RESULTS: No significant differences were found between the GHQ-30 and the HAD Scale in identifying those patients with any DSM-IV diagnosis (P=0.95), grouped depression (P=0.56), or anxiety (P=0.25) disorders. The previously recommended cutoff points for identifying "cases" for the GHQ (4/5) and for the HAD Scale (8/9 and 11/12) were found to be suboptimal in this population. CONCLUSIONS: The GHQ-30 and HAD scale exhibited similar levels of sensitivity and specificity. Data are presented, taking into account the "cost" of false-positives and negatives, to allow a choice of cutoff points suitable for differing situations.     

带DDE通讯功能的控制仪表

带DDE通讯功能的控制仪表可以在WINDOWS环境下利用商用软件进行各种数据的读取和仪表参数的修改．从而构成具有较高性能价格比的方便易用的集散控制系统．     

多目标群体决策的区间层次分析法研究

基于专家个体判断矩阵,应用数理统计及误差理论,探讨了综合判断矩阵的建立途径,给出了用区间层次分析法求解多目标群体决策问题的算法与步骤,最后以算例说明该方法的实用性及有效性。     

PowerBuilder编程中动态数据交换技术的应用

探讨了Ｗｉｎｄｏｗｓ环境下,在ＰｏｗｅｒＢｕｉｌｄｅｒ实际编程中,动态数据交换（ＤＤＥ）２个方面的具体应用：一是解决了在开发应用程序中,退出某一应用程序时关闭另一应用程序问题;二是在开发ＭＩＳ中,调用Ｅｘｃｅｌ制作复杂报表。实践证明,这些设计是可行的。     

GPS在航天器交会对接中的应用研究

ＧＰＳ动态定位技术应用于交会对接中与目前采用的测量手段相比具有较大优势。文章首先对交会对接各阶段测量精度要求与ＧＰＳ能达到的精度做出比较,在此基础上给邮了ＧＰＳ技术应用于航天器交会对接过程的基本方案,重点讨论各阶段的数学模型,最后论述了其优越性。     

基于模糊神经网络及证据推理的数据融合系统

在研究战术弹道导弹电子对抗条件下作战仿真运用问题时,我们成功地将模糊神经网络与证据推理相结合,弥补了传统多传感器数据融合系统未考虑外界环境因素影响的缺陷,提高了数据融合系统的抗干扰能力,最后简单介绍了仿真系统软件的实现流程。这是作战仿真方法研究及实现的新途径。