试论大汶口文化束发器——兼论与“握牙”习俗的关系

一般认为,大汶口文化束发器是一种装饰品,通过对束发器的形制、来源、作用、相关器物的类比以及流变等一系列问题进行讨论,束发器应为巫觋身份的标识和通天的神器。随着龙山文化的兴起,二元的生业方式逐渐让步于农业,由此带来父权确立和祖先崇拜的兴起,加速了束发器的崩溃。

大汶口文化束发器作用新探

一般认为,大汶口文化的束发器是一种装饰品,集中分布于鲁中南,而其他地区则较为零星。束发器形制的探讨明确了其发展历程。束发器不做平时佩戴、为少数人拥有、性别和年龄区分不显著、作为大汶口文化鲁中南类型的标识之一等特征,表明束发器不应是单纯的装饰品。通过引入文献学和民族学材料作进一步讨论,束发器应是当时猪神祈雨的象征,祈雨的主体便是巫觋。束发器应是巫觋的标识和通天的神器,而其产生的机制则是农业经济的发展与家猪饲养的兴盛。

Influence of positioning errors of optical shaping components for single emitter laser diode on beam shaping effects

Beam shaping is required for semiconductor lasers to achieve high optical fiber coupling efficiency in many applications.But the positioning errors on optics may reduce beam shaping effects,and then lead to low optical fiber coupling efficiency.In this work,the positioning errors models for the single emitter laser diode beam shaping system are established.Moreover,the relationships between the errors and the beam shaping effect of each shapers are analysed.Subsequently,the relationship between the errors and the optical fiber coupling efficiency is analysed.The result shows that position errors in the Z axis direction on the fast axis collimator have the greatest influence on the shaping effect,followed by the position errors in the Z axis direction on the converging lens,which should be strictly suppressed in actual operation.Besides,the position errors have a significant influence on the optical fiber coupling efficiency and need to be avoided.

Energy-Efficient Transceiver Design for Multi-Pair Two-Way Relay Systems

In this paper, we focus on energy-efficient transceiver and relay beamforming design for multi-pair two-way relay system. The multi-antenna users and the multi-antenna relay are considered in this work. Different from the existing works, the proposed algorithm is energy-efficient which is more applicable to the future green network. It considers both the sum-MSE problem and the power consumption problem for the users under the relay power constraint. Based on the optimal condition decomposition(OCD) method, the energy-efficient precoders at the users can be designed separately with limited information exchanged. The proposed relay beamforming algorithm is based on the alternative direction method of multipliers(ADMM) which has simpler iterative solution and enjoys good convergence. Simulation results demonstrate the performance of the proposed algorithms in terms of power consumption and MSE performance.

红山文化玉器

红山文化是新石器时代晚期,分布在我国内蒙古自治区东南部、辽宁西部以及河北北部地区的先民创造的农耕文化,距今大约五、六千年。

Emittance Measurement at BEPCⅡ Linac

Further studies on beam emittance measurement have been made to improve the emittance measurement precision at BEPCⅡ linac.Some problems in the measurement are solved and a code for beam emittance calculation is developed.With these improvements,the emittance measurement precision was upgraded.

Focused ion beam built-up on scanning electron microscopy with increased milling precision

In this work,a focused ion beam(FIB)-scanning electron microscopy(SEM) dual beam system was successfully built by integrating a FIB column and a graphics generator onto a SEM.Real-time observation can be realized by SEM during the process of FIB milling.All kinds of graphics at nanoscale regime,such as lines,characters,and pictures,were achieved under the control of graphics generator.Moreover,the FIB milling line width can be reduced nearly 27% by the introduction of simultaneous electron beam,and a line width as small as 10 nm was achieved.The numerical analysis indicates that the significant improvement on line width is induced by the Coulomb interaction between the electrons and ions.