基于麦克斯韦电路理论的方环散射体

不同于传统数值计算方法,麦克斯韦电路(MC)理论融合了场的理论和路的理论,使二者高效地结合在一起.运用麦克斯韦电路理论分析方环散射体,研究方环散射体的MC求解方法以及MC的宽带特性,求出其散射电流,数值实验结果与矩量法结果吻合良好.研究还发现,MC可以在一个较宽的频带上得到准确电流解,因此,比其他数值方法更加高效和实用.     

Hormonal control of Sertoli cell metabolism regulates spermatogenesis

Hormonal regulation is essential to spermatogenesis. Sertoli cells (SCs) have functions that reach far beyond the physical support of germ cells, as they are responsible for creating the adequate ionic and metabolic environment for germ cell development. Thus, much attention has been given to the metabolic functioning of SCs. During spermatogenesis, germ cells are provided with suitable metabolic substrates, in a set of events mediated by SCs. Multiple signaling cascades regulate SC function and several of these signaling pathways are hormone-dependent and cell-specific. Within the seminiferous tubules, only SCs possess receptors for some hormones rendering them major targets for the hormonal signaling that regulates spermatogenesis. Although the mechanisms by which SCs fulfill their own and germ cells metabolic needs are mostly studied in vitro, SC metabolism is unquestionably a regulation point for germ cell development and the hormonal control of these processes is required for a normal spermatogenesis.     

年终密考制度初探

年终密考是清乾隆以后实行的一种年度考核地方知府以上官员的制度。这种考核形式具有严密性特点,皇帝通过核对密奏考语达到操掌地方大员的目的。与大计相比,年终密考对地方官员的仕途影响更大。     

钇对ZrCuNiAl系合金非晶形成能力的影响

利用X射线衍射(XRD)和差示扫描量热分析(DSC)研究了添加钇对Zr55 Cu30Ni5Al10Y(=0,1,2,3,4)非晶合金体系玻璃形成能力的影响。用铜模铸造获得的Zr55 Cu30Ni5Al10Y(=0,1,2,3,4)块体非晶合金的临界尺寸从直径6 mm增加到20 mm。分析认为,微量钇的添加可以与合金中的残留氧形成氧化物,降低氧对合金形成非晶态结构的负面效应。因此添加适量的稀土元素钇有利于提高Zr55 Cu30Ni5Al10Y非晶合金体系的玻璃形成能力。     

Numerical Simulation of the Morphology and Moving Velocity for Electrospun Stable Jet

GAMBIT,POLYFLOW and FLUENT POST were used to simulate the morphology and the velocity of electrospun stable jet.Simulation results shows that jet diameter decreases with the increased draw force acted on the stable jet.But too great draw force would lead to thick knots appearing along the jet or stable jet disappearing during electrospinning.There is a linear relationship between the velocity and the moving distance.But the linear relationship does not exist under great draw force.     

图书馆社会教育功能发挥的障碍分析

分析了图书馆社会教育功能发挥的内外部障碍,提出了在学习型社会提倡全民学习、终身学习的背景下,充分发挥图书馆社会教育功能的有效措施。     

对称四甲基六元瓜环、钠离子、对硝基苯酚三元配合物的晶体结构

在有机分子存在条件下,制备得到对称四甲基六元瓜环(TMeQ[6])与Na离子的晶体,并利用单晶X-射线衍射分析方法对其结构进行了测定.结果表明,在对硝基苯酚存在条件下,两个Na离子分别与TMeQ[6]两个端口的两个羰基氧原子直接配位,形成典型的“分子胶囊”结构.“分子胶囊”间通过共用水分子而形成了一维超分子链.而NO2-Ph-OH通过与TMeQ[6]的π-π堆砌和C-H…π相互作用有序地排列在超分子链的周围.     

“工程控制基础”课程改革与建设探索

新技术的发展，对高校培养人才提出了新的需求，为适应这些需求，电子科技大学“工程控制基础课程组”从课程体系建设角度做了大量的探索性工作。文中结合作者的教学改革实践，以培养创新型人才为目标，完善专业培养体系为切入点，对“工程控制基础”课程的目的与要求、课程内容体系、实验教学体系等方面进行的探索性工作进行了归纳与总结。     

典型零件质量检测课程的建设与实践

以典型零件质量检测课程为例,介绍了基于工作过程的理实一体化的教学模式,运用企业实际产品作为教学案例,探讨了理实一体化教学的组织和实施。