蛙峡核的视野区域对应投射和双眼反应

本文用玻璃微电极从黑斑蛙(Rana nigromaculata)左峡核细胞外记录了125个单位的视觉反应,并用钴染色法标记出101个电极尖端位置,以便重建峡核内的视野图。在所记录的单位中,80％对静止光点显示给光(ON)-撤光(OFF)反应,许多单位对通过其感受域的黑、白目标的运动有方向选择性。所有钴标记点都在核内,表明峡核本身是蛙视觉系统的一个局限部分。在峡核内有一个视野投射圈。整个对侧半视野和同侧半视野的鼻侧40°呈区域对应地投射到峡核上。核内的无细胞带是对侧半视野与同侧半视野的分界线,它的背侧是对侧视野代表区。上视野投射到核的嘴半部、尾半部的中央和内腹部分。下视野的代表在尾半部的背部和外侧部。在峡核里观察到15个双眼单位,其中13个主要被对侧眼兴奋,2个几乎同等地被两只单眼兴奋。标记成功的14个双眼单位主要位于峡核嘴半部的髓质内。     

高校图书馆书刊采访决策支持系统

在指出高校图书馆书刊采访科学决策重要性的基础上,分析影响书刊采访决策的基本因素,提出一种科学的书刊采访决策模式.建立了图书供应商选择、采购经费分配、书刊选购决策的数学模型,进而给出书刊采访决策支持系统的设计方案.该系统的应用可提高图书采访质量.     

瞬态光谱测试仪在烟火方面的应用

用３５０～１１００ｎｍ瞬态光谱测试仪对烟火药剂进行谱测试，分析碱金属和碱土金属在烟火药火焰光谱中的辐射波段，计算各红外烟火剂的稳身指数。     

CR环二极磁铁的磁场优化

FAIR项目中的CR环二极磁铁对磁场积分场的误差分布要求很高,通过削斜与加载镜像板的方法是优化磁场的主要方法,文中介绍了对二极磁铁优化方法和对它的处理方法.利用削斜的方法来改变二极磁铁积分场的误差分布,通过复杂的削斜,已将其高场的误差分布优化到±2×10-4.加镜像板的方法主要适合高场,而对低场的调节不明显.另外处理方法的选取对结果的影响也很大,文中对两种方法作了比较.优化模拟计算软件采用的是专门的磁场计算工具OPERA.     

聚合反应动力学的图形方法

本文应用图形方法求解多官能团活性聚合反应的动力学方程组.求解步骤包括:(1)应用Laplace变换,将微分方程组变成代数方程组;(2)用图形规则写出线性代数方程组解的通式;(3)由Fourier-Mellin积分,通过计算残数.完成Laplace变换的反演,得到分子量分布函数的普遍表示式.在此基础上,还计算了各种平均分子量和支化度,并结合可利用的星形聚合物的实验数据,作了初步讨论.     

Optimization of the conditions for extraction of serine protease from kesinai plant (Streblus asper) leaves using response surface methodology

Response surface methodology (RSM) using a central composite design (CCD) was employed to optimize the conditions for extraction of serine protease from kesinai (Streblus asper) leaves. The effect of independent variables, namely temperature (42.5,47.5, X?), mixing time (2-6 min, X?), buffer content (0-80 mL, X?) and buffer pH (4.5-10.5, X?) on specific activity, storage stability, temperature and oxidizing agent stability of serine protease from kesinai leaves was investigated. The study demonstrated that use of the optimum temperature, mixing time, buffer content and buffer pH conditions protected serine protease during extraction, as demonstrated by low activity loss. It was found that the interaction effect of mixing time and buffer content improved the serine protease stability, and the buffer pH had the most significant effect on the specific activity of the enzyme. The most desirable conditions of 2.5 °C temperature, 4 min mixing time, 40 mL buffer at pH 7.5 was established for serine protease extraction from kesinai leaves.     

Normal Families of Zero-free Meromorphic Functions Ⅱ

Let k, m be two positive integers with m ≤ k and let F be a family of zero-free meromorphic functions in a domain D, let h(z) ≡ 0 be a meromorphic function in D with all poles of h has multiplicity at most m. If, for each f ∈ F, f(k)(z) = h(z) has at most k- m distinct roots(ignoring multiplicity) in D, then F is normal in D. This extends the results due to Chang[1], Gu[3], Yang[11]and Deng[1]etc.     

不同基底对TiO2和SiO2薄膜的光学性能的影响

采用溶胶-凝胶法分别在K9玻璃、单晶硅和石英玻璃基底上制备了纳米TiO₂和SiO₂薄膜。利用SEM、UV-Vis及反射式椭圆偏振光谱仪对薄膜的微观结构及光学特性进行了表征和分析。结果表明：3种基底中, 单晶硅基底上TiO₂和SiO₂薄膜折射率最大;在非晶态K9玻璃和石英玻璃基底上TiO₂薄膜折射率和透光率差异较大;SiO₂薄膜在非晶态基底上折射率、透光率相近;3种基底上薄膜的折射率和消光系数都有随波长增大而减小的趋势, 同时Cauchy模型能较好的描述单晶硅基底上两种薄膜在400~800 nm波段的光学性能。     

气相色谱-质谱法同时测定蔗汁中的莠去津与莠灭净残留量

建立了气相色谱-质谱法(GC-MS/SIM)同时测定蔗汁样品中莠去津和莠灭净的方法,并优化了样品前处理和色谱条件.在优化条件下,两种除草剂在0.00-0.60 mg/L范围内线性关系良好,方法的检出限(S/N=3)均为0.001 mg/L.在加标水平为0.050-0.100 mg/L时,两种除草剂的回收率在93%-10...     

ChemInform Abstract: Crystal Structures of New Ternary Rare Earth Silicides Sc3Pr2Si4, Sc1.26Pr3.74Si4 and Sc3.96Nd1.04Si4 with Ordered and Partially Ordered Rare Earth Sites.

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