教育部属高校科研质量管理体系调查研究

为解决质量管理体系在高校中的运行问题, 对教育部属高校质量管理体系建立的基本情况进行了全面调研, 关注体系建立的模式和存在的突出问题, 重点了解体系变更和体系覆盖范围的情况, 为高校科研质量管理体系的研究提供数据支持, 具有重要的实际意义。     

辅助式GPS接收机的快速定位算法研究

提出了一种针对辅助式GPS接收机的快速定位算法。该算法无需比特同步、帧同步和解调电文,仅由伪码相位测量值和误差小于300 km的用户位置估计值即可重构出卫星发射时刻,进而获得伪距观测量并构造包含5个未知数的测量方程组,通过求解该方程组获得用户位置。仿真表明,本文提出的定位解算算法在载噪比低至20 dBHz时仍能实现快速定位,有效减小接收机初次定位时间。     

Towards fast repackaging and dynamic authority management on Android

In order to enhance the security of Android applications, we propose a repackaging and dynamic authority management scheme based on Android application reinforcement methods.Instead of using root privileges and system modification, we introduce a user-level sandbox, which utilizes the native C-level interception mechanism, to further reinforce the risk applications and improve the entire security of Android system. Additionally, by importing and improving the repackaging features, this proposed scheme reduces the potential risks of applications and achieves the goal of the dynamic monitoring of permissions. Finally, a comprehensive evaluation, including efficiency analysis and detection evaluation with 1 000 malwares, whose overall average success rate is about 96%, shows the feasibility and universality of the proposed scheme.     

Two modes of fusion pore opening revealed by cell-attached recordings at a synapse

Fusion of a vesicle with the cell membrane opens a pore that releases transmitter to the extracellular space. The pore can either dilate fully so that the vesicle collapses completely, or close rapidly to generate 'kiss-and-run' fusion. The size of the pore determines the release rate. At synapses, the size of the fusion pore is unclear, 'kiss-and-run' remains controversial, and the ability of 'kiss-and-run' fusion to generate rapid synaptic currents is questionable. Here, by recording fusion pore kinetics during single vesicle fusion, we found both full collapse and 'kiss-and-run' fusion at calyx-type synapses. For full collapse, the initial fusion pore conductance (G(p)) was usually >375 pS and increased rapidly at > or =299 pS ms(-1). 'Kiss-and-run' fusion was seen as a brief capacitance flicker (<2 s) with G(p) >288 pS for most flickers, but within 15-288 pS for the remaining flickers. Large G(p) (>288 pS) might discharge transmitter rapidly and thereby cause rapid synaptic currents, whereas small G(p) might generate slow and small synaptic currents. These results show that 'kiss-and-run' fusion occurs at synapses and that it can generate rapid postsynaptic currents, and suggest that various fusion pore sizes help to control the kinetics and amplitude of synaptic currents.     

On the possible mode of action of neurohormones on cholinesterase activity in the ventral nerve cord of scorpion,Heterometrus fulvipes

Summary It is shown that K_m of ChE is not affected by the neurohormones but V_max is increased and decreased in presence of acceleratory and inhibitory neurohormones respectively. Hence it is suggested that the neurohormones might modulate the enzyme activity by altering the maximal velocities (V_max) rather than affecting the enzyme affinity (K_m) towards the substrate.Acknowledgment. The present study was carried out at S. V. University, Tirupati, A. P. India, and the authors are highly beholden to Prof. K. S. Swami, Head of the Department of Zoology, S. V. University, for his kind help and encouragement. Thanks are also due to the University Grants Commission, New Delhi, India, for placing one of them (N. V.) as a National Research Associate which made the present work possible.     

Comparative effect of silver ion and gibberellic acid on the induction of male flowers on femaleCannabis plants

Summary Silver ion applied as AgNO₃ to the shoot tip of female plants ofCannabis induces male flowers. It is more effective than gibberellic acid (GA₃) in maintaining the induced state.Acknowledgment. G.S. thanks the Council of Scientific and Industrial Research, New Delhi, India, for the award of a Junior Research Fellowship.