二阶曲面关于中心二次曲面的反配极包络问题

本文将射影空间关于二阶曲面的反配极对应引入三维欧氏空间R~3,用解析的方法,研究了二阶曲面关于中心二次曲面的反配极包络曲面,获得了一系列重要结果。     

用键极性指数加和值确定苯环上取代基的类型

以一元取代苯为模型，提出键极性指数加和值Σδｉｚ及计算方法，用Σδｉｚ判断苯环上取代基的类型及定位能力，结果与文献值相符。     

甜瓜下胚轴极性生根机理的研究 Ⅱ外源吲哚乙酸的效应

甜瓜(Cucumis melon L.)下胚轴在正常情况下因形态学下端的内源IAA含量高于形态学上端的而表现为极性生根.附加外源IAA 2.0mg/L可使倒插于培养基中原来不能生根的形态学上端也能生根.倒插时,生根的下胚轴形态学上端内源IAA含量明显升高.因此甜瓜下胚轴形态学上下端生根与否,决定于两端IAA的含量的相对差异.     

细粒浮选体系中界面极性相互作用理论及应用

本文系统讨论了界面极性相互作用理论及其在细粒浮选研究中的应用。亲水矿粒间水化排斥作用及疏水矿粒间疏水吸引作用主要归因于颗粒间界面极性相互作用。通过测定矿物在已知表面能参数的液体中的接触角,就可确定矿物的表面能参数值。由界面极性相互作用能确定水化或疏水相互作用能量常数,从而计算颗粒间水化或疏水相互作用能曲线,利用EDLVO理论能很好解释矿粒间的凝聚、分散行为。     

Nitric oxide produced by cumulus cells stimulates maturation of mouse oocytes

The effect of sodium nitroprusside (SNP), a donor of nitric oxide, on meiotic maturation of mouse oocytes was studied by injecting N^w-nitro-L-arginine methyl ester (L-NAME) intra-peritoneal (ip), a nitric oxide synthase inhibitor, or culturing oocytes in the medium supplemented with L-NAME or hypoxanthine (HX) to arrest the spontaneous oocyte maturation in vitro. The results showed that the inhibitory effect of L-NAME by injecting 10 mg/kg ip on extrusion of the first polar body only could be reversed by injecting 2.5 mg/kg SNP with L-NAME simultaneously (P < 0.05). Half an hour later ten mice died when given 10 mg/kg SNP ip. The treatment of some concentrations of SNP (10^–7, 10^–6, 10^–5mol/L) significantly stimulated meiotic maturation to metaphase Ⅱ stages in cumulus enclosed oocytes in the presence of HX. However, other concentrations of SNP (10^–8, 10^–4, 10^–3 mol/L) had no effect on HX-arrested oocyte meiotic maturation. The optimal concentration of SNP on CEOs had no effect on DOs. The dose of 10^–3 mol/LL-NAME demonstrated a significant suppression in formation of PB₁, but not in GVBD. This inhibition was reversed by the addition of SNP. These results indicated that the physiological levels of NO produced by cumulus cells could stimulate meiotic maturation of mouse oocytes both in vivo and in vitro.     

ISAR越距离单元走动校正的近似极坐标算法

在ISAR系统中,通常假设不发生越距离单元走动,并应用距离多普勒(RD)算法获得目标的ISAR像。但是当雷达具有较高的分辨率,目标的尺寸较大,或目标在成像相关时间内转过了较大的角度时,散射点的越距离单元走动难以避免。为校正越距离单元走动,提出了一种近似极坐标算法。该算法将相关时间内的雷达回波数据近似为波数域梯形区域上一系列的采样点,并插值得到波数域矩形区域上的采样点,最后通过傅里叶变换得到目标的ISAR像。在目标均匀转动的假设下,该极坐标算法通过近似,不再要求已知目标的转角信息,并且能够较好地校正散射点的越距离单元走动。最后的仿真结果证实了算法的有效性。     

基于多电视台的两种无源雷达成像算法

基于外辐射源的无源雷达成像是当前新体制雷达的研究热点,给出了利用多个电视台作为外辐射源的直接二维快速傅里叶变换成像算法和极坐标成像算法。建立了多基地无源雷达成像模型,通过理论推导得到目标散射函数和雷达接收信号之间的傅里叶变换对的关系。选取15个电视台信号作为外辐射源进行了仿真实验,分析和比较了两种算法的性能,证实了算法的可行性。     

Morphology of polar ionospheric O^＋ ion upflow： FAST observations during quiet time

With energetic ion measurements on FAST satellite, the morphologic features of quiet-time ionospheric O ion upflowing at altitudes of 2000 to 4000 km are drawn out for the first time. The pre-noon cusp/cleft is the predominant region of upflowing occurrence for O with lower energy. Meanwhile the pre-dawn sector near the equatorward edge of the plasma convection dominates the occurrence for the higher energy O ions. No matter whether the energy is lower or higher, the upflows occur often over a wide MLT range of lower latitudes outside the auroral oval. The upflowing within the pre-midnight (21:00― 22:00 MLT) auroral oval carrys larger energy fluxes, with extremely large fluxes for higher energy O appearing near the polar cap boundary. For altitudes of 2000―4200 km under observation, the ion conics occur much more frequently than ion beams. Ion beams are rarely found below 3000 km, while the conics occur uniformly over the observed altitudes.     

lcs空间（X,T）中的几个lcs拓扑

在ｌｃｓ空间（Ｘ，Ｔ）中证明了Ｔａａ（Ｔｋａ）是Ｘ上最大的与Ｔ有相同的绝对凸紧集（紧集）且与Ｔ相容的ｌｃｓ拓扑；（Ｔａ）０（（Ｔｋ）０）是Ｘ上最大的与Ｔ有相同的绝对凸紧集（紧集）且关于偶对（Ｘ，Ｘ′）容许的拓扑（ａｄｍｉｓｓｉｂｌｅｔｏｐｏｌｏｇｙ）．并给出了Ｔａａ（Ｔａ）０的例     

多原子极性晶体系统中杂质态的基态能量

结合多原子极性晶体系统中与声子普适耦合杂质态的性能，采用Huybrechts线性组合算符和么正变换，导出了强，弱耦合下杂质态的基态能量的普适表达式。