保心降压康防治高血压心脏病的实验研究

1．实验动物．健康雄性Wistar大鼠60只，体重180～220g（由黑龙江中医药大学实验动物中心繁育提供）。 2．受试药物及制备（1）保心降压康炙黄芪、枸杞、汉防己、三七、枸杞、丹参、土鳖虫、栝蒌、勾藤（购于黑龙江省药材公司）。（2）阳性对照药：开博通片（卡托普利片），由中美上海施贵宝制药有限公司生产。     

基于高倍物镜的相位显微成像方法

当前基于干涉技术的相位显微成像方法已经被广泛研究,但基于非干涉方法(相位恢复)的相位显微成像研究还很少.本文将相位恢复与显微成像技术相结合,提出并论证了一种基于高倍物镜的相位显微成像方法,适用于微米级相位型物体的显微成像.该方法简单有效,针对高倍物镜显微系统的特性,采用同时移动CCD及显微物镜的拍摄方法,解决了传统拍摄模式下,高倍物镜的采样距离无法满足成像关系的问题.通过CCD采集物面在不同传播的距离衍射放大像,利用测得的强度信息重建物体相位信息.采用直径5μm的聚苯乙烯微球作为待重建样品,使用100×物镜进行显微成像实验.相位分布重建结果反映了样品真实高度的分布变化,证明了该方法的有效性.与基于干涉技术的相位显微方法相比,该方法所使用的实验装置更加简单,易于操作且成本更低.对于生物细胞或组织等相位型样品的厚度或折射率分布测量具有实际应用意义.     

Microstructural evaluation and nanohardness of an AlCoCuCrFeNiTi high-entropy alloy

An AlCoCuCrFeNiTi high-entropy alloy(HEA) was prepared by mechanical alloying and sintering to study the effect of Ti addition to the widely studied AlCoCuCrFeNi system. The structural and microstructural characteristics were investigated by X-ray diffraction(XRD), scanning electron microscopy(SEM), and transmission electron microscopy(TEM). The formation of four micrometric phases was detected: a Cu-rich phase with a face-centered cubic(fcc) structure, a body-centered cubic(bcc) solid solution with Cu-rich plate-like precipitates(fcc), an ordered bcc phase, and a tetragonal structure. The XRD patterns corroborate the presence of a mixture of bcc-, fcc-, and tetragonal-structured phases. The Vickers hardness of the alloy under study was more than twice that of the AlCoCuCrFeNi alloy. Nanoindentation tests were performed to evaluate the mechanical response of the individual phases to elucidate the relationship between chemical composition, crystal structure, and mechanical performance of the multiphase microstructure of the AlCoCuCrFeNiTi HEA.     

Tumour biology: senescence in premalignant tumours

Oncogene-induced senescence is a cellular response that may be crucial for protection against cancer development, but its investigation has so far been restricted to cultured cells that have been manipulated to overexpress an oncogene. Here we analyse tumours initiated by an endogenous oncogene, ras, and show that senescent cells exist in premalignant tumours but not in malignant ones. Senescence is therefore a defining feature of premalignant tumours that could prove valuable in the diagnosis and prognosis of cancer.     

Activation of old carbon by erosion of coastal and subsea permafrost in Arctic Siberia

The future trajectory of greenhouse gas concentrations depends on interactions between climate and the biogeosphere. Thawing of Arctic permafrost could release significant amounts of carbon into the atmosphere in this century. Ancient Ice Complex deposits outcropping along the ~7,000-kilometre-long coastline of the East Siberian Arctic Shelf (ESAS), and associated shallow subsea permafrost, are two large pools of permafrost carbon, yet their vulnerabilities towards thawing and decomposition are largely unknown. Recent Arctic warming is stronger than has been predicted by several degrees, and is particularly pronounced over the coastal ESAS region. There is thus a pressing need to improve our understanding of the links between permafrost carbon and climate in this relatively inaccessible region. Here we show that extensive release of carbon from these Ice Complex deposits dominates (57?±?2 per cent) the sedimentary carbon budget of the ESAS, the world’s largest continental shelf, overwhelming the marine and topsoil terrestrial components. Inverse modelling of the dual-carbon isotope composition of organic carbon accumulating in ESAS surface sediments, using Monte Carlo simulations to account for uncertainties, suggests that 44?±?10 teragrams of old carbon is activated annually from Ice Complex permafrost, an order of magnitude more than has been suggested by previous studies. We estimate that about two-thirds (66?±?16 per cent) of this old carbon escapes to the atmosphere as carbon dioxide, with the remainder being re-buried in shelf sediments. Thermal collapse and erosion of these carbon-rich Pleistocene coastline and seafloor deposits may accelerate with Arctic amplification of climate warming.     

Benjamin-Bona-Mahony方程的平均隐式差分格式

本文对Benjamin-Bona-Mahony(BBM)方程的初边值问题进行了数值研究,提出了一个平均隐式差分格式,讨论了差分解的存在唯一性.然后利用离散泛函分析方法分析了该格式的二阶收敛性与稳定性,然后利用数值实验进行了验证.     

气相色谱—质谱法测定化妆品中5种合成麝香

建立了化妆品中5种合成麝香的气相色谱—质谱联用检测技术.样品采用正己烷于40℃下超声提取20min,采用佛罗里硅土柱净化,其中柱容量为100mg/L,采用气相色谱质谱仪同时检测化妆品中5种合成麝香.5种合成麝香在0～10mg/L范围内线性关系良好,检出限为0.2～100ug/kg,空白样品在10mg/kg加标水平下回收率为94.62％～96.73％,相对偏差为1.19～2.25％.本方法简便,快捷,可同时检测化妆品中5种合成麝香成分.     

谈煤矿企业的电视新闻制作

电视新闻,是借助电视传播的视听符号,对变动的事实的及时报道。电视新闻报道质量好坏,直接影响着电视台的声誉乃至他的兴衰存亡。如何进一步提高电视新闻质量,是摆在电视新闻工作者面前的一项重要任务。煤矿企业自办的有线电视台,有其特殊性：1）传播网络为专用线路,     

发变组差动保护CT的10%误差曲线校核计算

在系统发生故障的情况下,可能发生CT饱和,因此二次电流不能准确的反映实际一次电流,致使保护装置发生误动。因此我们要求在系统发生短路故障时,CT的变比误差不应大于10%。CT的变比误差与一次电流有关外,还与二次负载阻抗有关。在相同的一次电流作用下,二次负担大,CT的误差同样大。10%误差曲线反映了CT变比产生10%的误差前提下,一次电流与允许的负载阻抗之间产生曲线。从这条曲线我们可以看出在现有的二次负担下,承受的最大短路电流;同时也可计算出在系统发生故障产生最大短路电流下,CT所允许的最大二次负载阻抗。